What's the latest on tilt rotors? [Archive]

UNCTUOUS

11th May 2000, 00:11

The articles I keep seeing (see box below) and the direct transcripts of Marine Aviation Chief Lt General Fred McCorkle's press brief - lead me to believe that they are at risk of believing their own (and Boeing/Bell) hype about "there being nothing wrong with the design". So I have sent via two different routings, the following "heads up" to Col Dennis Bartels who is leading the investigating team. I've no doubt that he has all sorts of AMES people to hand and a wealth of technical advisors. However Bartels' own background is totally in the CH46 and as I've said, tandem overlapping rotored birds don't catch the vortex ring "flu".

http://www.usmc.mil/marinelink/announce.nsf decision to resume flights
http://www.usmc.mil/marinelink/announce.nsf MV22 mishap info
http://www.defenselink.mil/news/Apr2000/t04112000_t411dasd.html LtGen Fred McCorkle's briefing

So in the interests of not seeing any more Marines "hit the dirt", I deemed it cheekily appropriate for them to have an outside opinion. Even when military crashes are involved I doubt very much that, under the "party system" of manufacturer participation in the investigation, you can expect all the potential bad news to surface. And now that you also are privy to this disclosure having been made, just stow it away so that you can ask them the hard questions when this accident is replicated at some time in the future.

To: Col Dennis Bartels (of Dept of Avn, HQMC Aviation Mishap Board (AMB) OPNAVINST 3750)

Subject: There is an INBUILT DESIGN Problem with the V-22 Osprey

I understand that V22's are shortly to be restored to flight status and that the accident profile is to be re-flown. All that I have read, by way of official releases and media reporting, leads me to believe that the phenomenon of vortex ring, as it applies to the V22, is not thoughly understood. Perhaps it would just make me feel less complicit in future accidents if you would read the following dissertation on the hazard.

The best way to visualize vortex ring (VR) is to imagine forcing a plunger slowly down a loose-fitting water-filled pipe. You get a spill-over inflow around the periphery of the disc's upper surface (about the top quarter/third outer annulus). This is analogous to what happens below translational speed in a helo. That spill-over air is the rotor-disc version of that self-same lift-dependent vortex that spills off the end of a FW's wingtips. In a FW it is greater at low alt, low IAS, high AUW, high AoA. It is greater in the Rotary Wing (RW) because of centrifugal flow. In fact if you've heard of "behind the drag curve", that is what happens in a FW, below min drag IAS, when it starts taking more power to fly more slowly. In a FW the vortices get "left behind" and above translational speed in a helo the vortices are simply shed and left behind (as in the FW). But unfortunately, in a RW, below translational speed on a steep approach, the spill-over can become entrained air (i.e. your downwards flight-path approximates your rotor downwash) . So the drop to below translational speed on a steep approach is the entry to the VR high-threat area - so to speak. The instinctive reaction to a higher Rate of Descent is to increase collective (more blade angle and more fuel to generate more power to maintain N2 RPM). The result is greater spill-over, greater entrainment and the effect sneaks further in along the rotor disc. That area of the disc is in effectively now what, in a FW, would be a negative angle of attack - i.e. power increases only drive you downwards faster. And the outer area of the disc, because of the blade's higher rotational velocity, is where most of your lift (and lift dependent drag) comes from. It is really ALL bad news - nil good. In a straight "chopper", because of ingrained pilot instincts, the situation can rapidly deteriorate - but it is not irretrievable if you act quickly enough.

The lack of rotor interaction (as in the CH46 and Chinook's contra-rotating and overlapping discs) may well be why the V22 is more prone to vortex ring than those conventional dual-rotor helo's. I've never heard of a Chinook or Sea Knight falling foul of it, probably because vortex figures-of-eight are a physically impossible non-entity. So with side-by-side non-overlapping tilt-rotors you've got a big problem; what happens when, due to environmentals or piloting factors, the vortex ring effect hits asymmetrically? (high-rate steep descent, relative wind, gust-blanking of one nacelle, tight-cored thermal, or simply localized wind effects causing you to suddenly drop below translational speed as you descend). In the Osprey, the inducement of such a condition may be due to simply picking up a gust-dropped wing with lateral stick movement. The power and blade-angle on that dropped wing's nacelle is increased - and maybe just enough to trigger the condition (i.e. enter VRing). Entry into a VR condition means that the wing will drop further/faster, requiring a larger correction (and remember we said that that was bad news). The effect, as in the MV-22, would be a quick roll past 90 deg and a nose-drop to the downward vertical. I doubt that recognition + reaction time + nacelle swivel-rate (12 secs) could possibly resolve that asymmetric case - for a life-saving "burst-out" of the recirc bubble. It’s illustrative if the MV-22’s response to an attempted “wing-levelling”, in an assy VR condition, could be likened to a FW's auto-rotative entry into a spin. Every incident of asymmetric vortex ring will be a killer because of the control system and instinctive pilot response. e.g. Right wing drops and pilot applies left stick to pick it up. This feeds in greater blade angle and power on the side locked into the Vortex Ring condition (which increases the adverse roll-rate). If you wish, liken it to trying to pick up a dropping [auto-rotating] wing with aileron in a conventional FW aircraft.

Once a recirculation bubble forms and you are IN that vortex ring condition in a conventional helo, the recognition feature is that a higher collective setting will undesirably beget a higher rate-of-descent. The only way out is to utilize available altitude as your escape path and jam that cyclic forward, breaking out of that recirc bubble by accelerating through translational speed (i.e. by doing this, the vortex ring is "shed"). Unfortunately I can think of no similar solution for the V-22 with its rotor configuration. I doubt that nacelle-tilt rates (i.e. a 12 second transition), once you take into account recognition and reaction time, would be anywhere sufficient for escape (according to the loadmaster witness, the MV22 "hit the ground two to three seconds after flipping"). The asymmetric nature of the Osprey's vulnerability would seem to make it a very conclusive condition.

Terrain can be a factor in that it can cause localised wind effects that hit you unexpectedly in the descent and create the conditions for vortex ring (i.e. you can suddenly lose "translational" lift due to tree-line or terrain shielding of the relative wind). Translational lift is where the blades aren't in true air-chopping hover mode any more, i.e. you experience a lift gain and drag loss because the rotor-disc entity is now generating the lift. As you pass through about 15-18 knots airspeed, you notice a distinct change in rotor-slap noise and an apparent surge in power (both during accel and decel to the hover). But unexpectedly drop below translational speed during a steep approach, and it can be "Hello Mr Vortex Ring". That is the problem they will face in envisaged V-22 ops - conversion to rotor-borne flight may be a direct transition straight into the VR hazard area. Relative wind could be the big bugbear for the Osprey's gust response. To explain, just think about the exposure of the RH nacelle as against the LH nacelle in a wind-gust from (say) 2:30 to 3:00 o'clock. One's part-blanked, one's not.

In a true "chopper", late realization is the big hazard because you are intentionally descending anyway - yet as ground-rush sets in, you belatedly become aware that your rate is high so you pull in a little power (to decrease the ROD). You become momentarily confused because the rate increases (rather than decreases) so you pull in a little more power etc etc. Got the idea? Very quickly you are in a world of hurt. Of course it would now appear that the MV22 accident crew wore it just on one side. That's insoluble.

The Osprey rotors are contra-rotating and that could be a complicating factor also. This (contra-rotating props) brings up another consideration. As all glider pilots know, Coriolis has its influence upon which direction thermals rotate (clockwise or counter-clockwise, dependent upon hemisphere). Might be drawing a long bow, but if you were to be unfortunate enough to fly, below translational speed on approach, through a thermal (rapidly rotating and fast rising air), would the effect upon each contra-rotating rotor be the same? Given that:

a. You may already be in the ball-park for vortex ring formation and,
b. the effect upon each V-22 rotor might be quite dissimilar, and that
c. You could fairly expect that a lateral stick input will be required (as in any gust upset)....the inference being that he lateral stick input will be altering blade angle and power on both sides - perhaps enough to trigger the condition asymmetrically.
d. Military operations (formations) may lead to VR as a function of wake turbulence from a preceding Osprey in the same flight.

I am wondering if it would do any good to mount the Osprey's engines so that, as the rotor shafts rotate upward from the forward flight mode to the vertical/hover mode, they would also tilt inward so that the rotor wash would be directed outward to some degree. The hovering tilt-inward solution? It would require the nacelle gear-boxes to be re-splined but it may be possible to go for about ten degrees at great technical cost. It would also effectively rob the aircraft of 1-2% power in the hover - where it needs it. I'm not sure that it would make a great difference, sort of similar to wing-taper, winglet end-plates or greater aspect ratio in a FW to reduce losses due to wake vortices. Moreover, you might end up with a part-disc effect and out-of-balance air-loads on the rotor (and cyclical stresses on the transmission gear-boxes).

I myself think that sucking some power out of the disc for a powerful bleed-air fed wing-tip reaction jet nozzle may be the answer. Perhaps such a jet could also be used for induced-flow empowering of the ailerons at slow speed. Short of that, perhaps an emergency JATO to achieve a rapid exit from a recirc bubble.

It will be interesting to see how they resolve this and whether they will try to optimistically avoid any redesign. I remain unconvinced that the asymmetric VR condition will not repeatedly revisit the Osprey Fleet. The fact that they haven't hit the condition before may simply be due to the fact that a specific VR investigation was never designed into any Osprey Flight Test Schedule. Now that it's in "operational development" as an operational Marine a/c, you have to expect that uninvestigated foibles may well emerge.

[This message has been edited by UNCTUOUS (edited 11 May 2000).]

ShyTorque

11th May 2000, 03:00

UNCTUOUS, all very good stuff, mate! I always thought they would have a long way to go before they discovered all the aerodynamic "funnies" of such a beast. Vortex ring of one or both discs was something I have wondered about in the past, especially during the transitional phases of flight. Another possible difficult malfunction is nacelles stuck forwards / down for landing...

Does anyone know if they are utilising mainly rotary experienced pilots on "uppers" to cope with the higher cruise IAS, or mainly fixed wing jocks with extra training to cope with the slow speed stuff?

------------------
The best insurance is to Fly safe!

UNCTUOUS

11th May 2000, 21:09

http://199.97.97.163/IMDS%AEROWORLD%read%/home/content/u sers/imds/feeds/comtex/2000/05/09/up/0000-4039-us-marine-crash (http://199.97.97.163/IMDS%AEROWORLD%read%/home/content/users/imds/feeds/comtex/2000/05/09/up/0000-4039-us-marine-crash)

Wishful and wistful GUNG HO

I am not an opponent of tilt-rotor technology however I do firmly believe that LtGen McCorkle is erring in that he has already:
a. attributed the cause to pilot error
b. averred that there is absolutely nothing wrong with the Osprey design
c. Spoken of having his pilots re-fly the accident profile tomorrow (a mite hazardous at this stage in my opinion)
d. Reassured all and sundry that there can be nothing wrong with the V22 if he and Gen Mick Ryan are going to be on the first one airborne now that the suspension (not a grounding) has been lifted.

Now I see all the above as a bit dunder-headed, if not Colonel Blimpish. It's got nothing to do with aviation safety nor sensible, prudent investigation. It is all crazily designed to protect the Osprey program from falling back into the clutches of a precocious Congress. Just look at some extracts from McCorkle's Press Briefing:

"The commandant is confident the MV-22 is fully airworthy, with no design flaws," said Lt. Gen. Fred McCorkle.
"When he hit 15 degrees angle of bank he was in big trouble," he said.

"By the time he realized he was in trouble, it was already too late," McCorkle said. Nevertheless, "it's beyond me why they didn't" pull out of it, he said.

COMMENTARY: Those HIGH angles of bank will get you every time.

OK Marines, listen up. The Commandant has said it was PILOT ERROR and there'll be no more of these accidents. Semper Fi!

Military Pilot Error: Henceforth to be known as a "McCorklism".

The Problem with Press Reporting

If it wasn't so serious, such hierarchy pronouncements would be laughable. They're worthy of a three stooges script.
Therefore my cynical COMMENTARY: Those HIGH angles of bank will get you every time. ( 15 degrees? )

I'll now repeat myself a bit here:
"And no doubt all the pilots will be careful not to get in that VR groove again. Sooner or later however, because it's there as a lethal trap, someone else will overcook it a bit and fall (OS)prey to it. They are calling it pilot error simply because at some stage of the approach he did wind it up to 1700fpm. However I'm willing to bet that the point of actual onset (of the VR condition) hasn't been picked and that it was shortly before the loadmaster saw him "flip at about 285ft, impacting 2 to 3 seconds later" (which exact figure obviously came from the CSMU) (aka crash survivable memory unit). If you think about it, he was unlikely to be descending at anywhere near 1700fpm at <300ft and the "flip" at 300ft or thereabouts was likely to have been the exact onset point of the asymmetric VR condition. You don't have to be Mandrake to work that one out - it falls straight out of the onset scenario. It just bears out my point that you can hit VR during a steep approach simply as a function of many different factors. Pick up a bit of a tail-wind due to local wind shear or terrain shielding and you end up arcing over (parabolically) in order to keep your LZ sight picture. That's enough to put you in the VR frame."

This breakdown simply contradicts the impression given by the Marines Press Briefing which intentionally conveyed the illusion that the accident crew brought it upon themselves by allowing their descent rate to wind up to as high as 1700fpm (but at what stage?). Elsewhere it's said that the (average?) rate of descent was 1000fpm (which isn't horrendously in excess of the allegedly recommended max of 800fpm). In other words, if the V22 is so handling sensitive that an extra piddling 200fpm is going to be disastrous, it's an accident going everywhere to happen. A combat aircraft has to be fairly forgiving as well as robust in its handling qualities - or it's a sitting duck.

"Analyses of the data retrieved from the data recorder, called a Crash Survivable Memory Unit (CSMU), along with extensive engineering investigations have confirmed that all aircraft systems and software were operating properly at the time of the accident."
OPERATING PROPERLY? Does this clearly say to you that the aircraft was not at fault? It does to the Marine Commanders. Think about the possible incongruities here.

http://www.usmc.mil/news/news99.nsf/78474d8d567cc4648525657d0064a54a/3de1ff7ac09b4808852568da0069e57b?OpenDocument

But, just possibly, there is a design flaw built into the tilt-rotor concept. This should be the concern. Have you asked Bell-Textron and Boeing FSR's to put their hands on their hearts and swear that the V-22's susceptibility to asymmetric (or symmetrical) vortex ring was tested as part of the Developmental Flight Test Schedule (now completed)? Have you seen it in writing? Why would there be some or any reticence about showing you such a document, the test-profiles flown and the data-points - if they indeed exist? Why are they only now talking about carrying out some wind-tunnel testing? Surely that data exists already? GOT THE IDEA?

If you had simply mentioned "vortex ring" in the issue (immediately after I brought it up) you'd have had the scoop of the year - well before it hit the news. You decided not to - your decision. After all, it is a $36Billion contract and people tend to think thrice before stirring Bell (let alone Boeing). So I quite understand. I also understand that, not being a pilot, it is hard for you to grapple with some of these concepts. I am not a XXXXX employee nor a US citizen so I can understand your further reservations that I might be putting you in harm's way. It might be better to stick with straight reporting of Press briefings. Perhaps you can pick up on this thread after the next V-22 accident.

<As I understand your analysis, the "lack of rotor interaction may well be why the V-22 is more prone to vortex ring" than conventional (CH-46 and Chinook) helicopters. I understand what you are saying here, but am unclear as to why this is the case. >
To me, the tandem overlapping rotor case (CH46, CH47) is quite clear and calls up a mind's eye view of two circularly incomplete (because of the overlap) interlocking vortices, helically rotating in opposite directions (because of the contra-rotating rotors) - and because of that, essentially cancelling each other out (because of the overlap and contrary rotation). For a vortex ring to form and strengthen, it must retain its circular integrity (you can't have a recirculation bubble shaped like a figure-of-eight or distended ellipsoid). Just as Nature abhors a vacuum so does aerodynamics detest a discontinuity. Any tendency toward a strengthening recirculation would be dissipated by the mutually beneficial turbulent interaction of the contra-rotating and overlapping tandem rotor configuration.

You don't have to state anything as being fact. You can simply postulate a theory and ask the embarassing questions (espec about flight-test schedules and wind-tunnel testing) and see if they are able to rise to the occasion. I'm sure Woodrow and Bernstein would approve of that tactic, - and, as a bonus, it keeps you clear of the arcane aerodynamics.

Declaring a new design concept to be unflawed after it's just killed a whole bunch of people in very benign circumstances is both wishful thinking and very cavalier.

[This message has been edited by UNCTUOUS (edited 12 May 2000).]

UNCTUOUS

14th May 2000, 20:30

Amazingly enough, if you go to the web-site for the American Helicopter Society, you'll find 50 odd academic papers on Osprey aerodynamics - but there were obviously no studies done on the V-22's susceptibility to "vortex ring" (let alone asymmetric vortex ring). If you go to NASA AMES and NASA Langley sites and search similarly, you'll find zip. There are plenty of learned treatises on literally every other aspect of the Osprey's aerodynamics - but the one "biggy" slipped through the cracks.
They did run a quarter-scale model through the AMES wind-tunnel at NAS Moffett. http://quest.arc.nasa.gov/aero/team/fjournals/young/ly12-29.html
But it appears that vortex ring wasn't on the test schedule.
http://www.bellhelicopter.textron.com/content/download/clipart/images/v22-1.gif
http://www.bellhelicopter.textron.com/content/download/clipart/images/v22-2.gif
http://www.bellhelicopter.textron.com/content/download/clipart/images/v22-3.gif

[This message has been edited by UNCTUOUS (edited 14 May 2000).]

Pinger

15th May 2000, 02:31

Good job no-one thought of these arguments before Mesrs Wright did their stuff at Kittyhawk a century ago...Imagine the headlines...

Hmm. Inherently unsafe...too slow you'll fall into the ground...Spinning, omigod!!!!fall out; the altitude'l kill you...landing, ground cushion makes it impossible. Travel over 30 MPH and you'll all suffocate.

Send for my horse! (careful, might fall off it!)

Where will we all be if we give up innovating in the name of progress?

"Folks, welcome aboard this Bloody Uncomfortable Mk 29 horse and cart, our fright time from London to Manchester is eleven days....."

Good on Boeing, the Marines Corps, Uncle Sam and all others involved in this project. I hope it works, despite the doom-sayers.

Remember the Harrier?

Capt Tercrue

16th May 2000, 01:30

UNCTUOUS
A very well argued treatise on a little understood subject.
However you are incorrect in one area. Vortex Ring does occur in contra-rotating tandem helos. During a trial some five years ago by RWOETU(Rotary Wing Operational Evaluation and Training Unit) a pilot known to me experienced what was subsequently, positively confirmed as VR. It occurred during a very high (5000'+) hover. and was in all respects identical to a conventional Helo VR state. High ROD, Low IAS,Power applied. Since then the recommended recovery is as you stated, except that a bias towards the left side is helpful(clean, air to the advancing blades). I thought you might be interested.

Pants

16th May 2000, 01:57

Not knowing much on the subject I have a quick question, should the V-22 have an engine failure in the hover how does it recover? I was just wondering, is it my impression or is it well and truly screwed?

UNCTUOUS

16th May 2000, 14:46

Capt Tercrue
Thanks. I spoke to some buddies with a lot of time on the Chook (CH47) and they'd not run into it in many hours on type. I can remember talking to some CH54 (Skycrane) types in SVN after they'd hooked out my busted bird and they said they were very fearful of VR because of their normal profiles. My interest dates from a personal encounter. But I can't see how an overlapping tandem-rotored helo could generate a consistent vortex, yet I admit that I'd not found anything academic that said yea or nay. But more importantly, it would seem that it has been overlooked as a potential pitfall for the tilt-rotor breed. The TP's at Pax River will probably have some exciting rides whilst coming to terms with it. I wish them luck.

Pants
If you look at the following URL's I think the answer will jump off the page.
Unfortunately they thought about engine failure but disregarded pitch-lock, VR (espec asymm) and transmission failure. Nacelle-tilt gear-box failure can be accommodated because the blades are composites and will simply break off (harmlessly and hopefully symmetrically) during any enforced "run-on" landing.
http://www.navair.navy.mil/V22/fltcntls.htm
http://www.navair.navy.mil/V22/propul.htm
http://www.navair.navy.mil/V22/convert.htm

http://www.helis.com/h/v22an.gif

Pants

16th May 2000, 21:29

thanx UNCTUOUS

UNCTUOUS

18th May 2000, 23:06

http://www.angelfire.com/me/swissair111memorial/modded/ThatVexingVortexRing.html

PTI UAE

22nd May 2000, 21:34

The information being released by the Marine Corps continues to give increasing indications that 'asymmetrical settling with power' was the cause of the April V-22 accident in Arizona. As pointed out above, when the vortex ring state develops on one side, the result would be a dropping of the wing on that side. The instinctive reaction of the pilot would be to use lateral cyclic stick in the opposite direction of the falling wing. This causes an increase of collective pitch on the rotor system that is in the vortex ring state. As we know, that is exactly the worst thing to do when a settling with power condition exists as it further worsens the resultant reduction in lift provided.

The existence of this phenomenon is certainly not a death blow for tiltrotor technology. It is a limitation that contributes to the defining of the normal operations flight envelope. Compare the above situation to what happens to an airplane when a poorly trained or inexperienced pilot allows the aircraft to stall while on approach for landing. If the airspeed is allowed to reduce to the point of aerodynamic stall (critical angle of attack is reached) the airplane will begin to lose altitude, and it is very likely a wing will drop. If the pilot then does what is instinctive -- pulls back on the yoke to stop the loss of altitude, and applies opposite aileron -- the aircraft will enter a stall/spin and at that point, lacking the altitude necessary for recovery, the pilot will be powerless to prevent the aircraft from impacting the ground. Unfortunately low time pilots repeat this scenario many times every year resulting in numerous unnecessary deaths. This does not prove that all airplanes are dangerous, or indicate that they should all be permanently grounded.

In the same way that a fixed-wing a/c should not go below 1.3 times the stall speed when on final approach, a single rotor helicopter should not descend at a rate of 300 fpm or more at slow speeds. Violating these limitations at low altitude has time and again resulted in the same devastating consequence experienced by the V-22 in Arizona when it was operated outside of its normal flight envelope. Does this mean that the use of all helicopters should be stopped? The characteristic of 'asymmetrical settling with power' in tiltrotors is by no means a fatal flaw necessitating the cancellation of an aircraft that more than doubles the range and speed capabilities of the helicopters they are replacing. When you develop an aircraft with dramatically increased capabilities at the high speed end, it is quite typical that there will be low speed limitation penalties that accompany the advances. However, it goes without saying that accidents with loss of life are not an acceptable price to pay for an increased capability to deploy troops further and faster than ever before.

The undeniable answer to preventing accidents in the future is training and experience. Pilots must learn to recognize the conditions that will put them outside the normal flight envelope, and apply correct recovery techniques when appropriate. All aircraft flying today have 'dangerous' characteristics in certain flight regimes that must be avoided, regardless of whether you are in an airplane, helicopter, or tiltrotor. When pilots are not properly trained to understand and recognize the conditions to be avoided, disastrous consequences are inevitable.

The Marine crew that perished in the April crash had a number of contributing factors working against them. The most obvious is a lack of experience in tiltrotors, having only 80 or 90 hours each in the V-22. Combine that with the extremely high workload environment of flying at night, flying with night-vision goggles, and flying in formation in a simulation of a high pressure rescue/extraction of civilian hostages in the final phase of an operations evaluation. Operating under these circumstances would be difficult for highly experienced tiltrotor pilots. Like many military operations, this type of flying will always be categorized as high risk, particularly when you throw in a real life high-threat location. But in time missions such as this will be able to be carried out successfully by those pilots who are now gaining experience in the military. It is terrible that 19 people lost their lives in an accident that should not have happened, but hopefully the lessons learned will save lives in the future.

Before any judgment is made on exactly what happened, why it happened, and how do we prevent it from happening again, we need to wait for ALL of the facts to be in. Fortunately there was a FDR, CVR, an eye witness on the ground, and the entire event was being filmed in infrared by an F/A-18 flying overhead at altitude. So it is likely that all the facts needed for complete analysis will be available, and that appropriate evaluation and recommendations will be forthcoming. The Marines more than anyone are interested in ensuring that this event never occurs again. The V-22's return to service shows their confidence in tiltrotor technology. That confidence comes from 45 years of tiltrotor research, including 11 years of flying the V-22.
R. Denehy, ATP - ASMEL, ASES, RH; CFI - ASM, RH; CFII - A&H

UNCTUOUS

24th May 2000, 23:53

PTI UAE
I find your contribution wholly unconvincing and a continuance of the denial process. Your comparison with the fixed wing stall/spin evolution is taking simile a bit too far IMHO (see later). There is always lacking any viable suggestion as to how Osprey crews are to avoid the AsymmVR condition - or recover. It will always be there - just a flick of the wrist away, and much much more insidious than an inept "stall/spin on finals" scenario. Anyway, specifically:

1. "a single rotor helicopter should not descend at a rate of 300 fpm or more at slow speeds.(???)" Unfortunately, I assure you that this sort of sedate operation will not work in an operational environment. I've got 13 months in SVN backing me up on this.

2. Pilots must learn to recognize the conditions that will put them outside the normal flight envelope (in a dynamic situation, as in Marana, just how do you do that? it's a momentary entry), and apply correct recovery techniques when appropriate (which are??). Don't be coy, just what are they?

3. All aircraft flying today have 'dangerous' characteristics in certain flight regimes that must be avoided, regardless of whether you are in an airplane, helicopter, or tiltrotor (quite trite. Not sure that this is a valid argument in support of asymmVR being an acceptably benign characteristic - rather sweeping assertion). In a FW, an ASI and an accelerometer will keep you out of trouble (except for coffin corner). What does the Osprey crew have? "Keep scanning that VSI Bloggs, watch out for any lag. It'll kill you"

4. When pilots are not properly trained to understand and recognize the conditions to be avoided, disastrous consequences are inevitable. AsymmVR will always be there - just a flick of the wrist away, and much much more insidious than an inept "stall/spin on finals" scenario. They'll have no aural/visual/instrument warning of its onset or imminence.

5. The Marine crew that perished in the 8 April crash had a number of contributing factors working against them. The most obvious is a lack of experience in tilt-rotors, having only 80 or 90 hours each in the V-22. If you're inferring here that AsymmVR had been identified as a possible outcome of exceeding the rather lose envelope laid down, you had better check your facts. My conclusion therefore is that, because it was a wholly unanticipated flight condition, it would not have mattered if they'd had ten times that MV-22 experience. And it would have happened in daylight just as easily. The formation station overshoot that precipitated the AsymmVR was no more likely at night than day.

6. But in time, missions such as this will be able to be carried out successfully by those pilots who are now gaining experience in the military. I guess we could discuss here the largish detachment of Apaches that went to Kosovo but weren't used because of the crew's inexperience and high accident rate.

7. and the entire event was being filmed in infrared by an F/A-18 flying overhead at altitude. Incorrect (retracted later by Gen McCorkle). But the eye-witness evidence is quite determinative.

8. The Marines more than anyone are interested in ensuring that this event never occurs again. That is the problem. It most assuredly will - because the susceptibility is built into the design concept and the propensity is in the style of operation. The solution is likely to be quite elusive. Warning systems of 2% chord L.E. pressure transducers will record the condition (delta t of spanwise lift distribution), but as found in RAE trials, cannot forecast it. There are too many variables close to the normal operation. What sort of buffer will there be in the new envelope and how can it be infallibly observed? (AsymmVR being automatically fatal and all). It is supposedly a combat area aircraft and is meant to be able to manoeuvre aggressively. Therein lies the conundrum.

9. The V-22's return to service shows their confidence in tilt-rotor technology. That confidence comes from 45 years of tilt-rotor research, including 11 years of flying the V-22. So why has the condition only now come to light (and detailed attention in flight trials, wind-tunnelling and modeling that's now underway)?

There is a light at the end of the tunnel in that you've brought yourself to address the problem as AsymmVR and not talked about settling, lead a/c wake, turbulence etc., as per most USDoD and Marine PR. But questions remain.

How do you differentiate between a "picking up the dropped wing" (with differential collective) instinctive response from either:
(1) a straight entry into asymmVR (because you're verging on the condition)
(2) or an entry that is a compound of picking up a gust-dropped wing (or even simply banking) whilst at the edge of the envelope (in the VR ball-park)?

"Late in the piece" (rolling) realization of asymmVR is around about the point where you would pull the crutch-handle, but what are they to do by way of recovery? Roll the long way round?

So in my opinion it's the dynamics of the condition's onset that needs to be understood -as well as the proximity of the condition to the required normal operation's parameters. I don't see asymmetric (engine fail) scenarios leading to asymmVR. Most of the ardent defences head off on that red herring - but it's irrelevant. Of course, for both the USN and USMC, the air-flow dynamics of what's happening at the carrier's fan-tail will also be food for thought.

My critics may hold that I'm a doomsayer but you have to review any such denial in the light of the well-witnessed and recorded circumstances of the Marana accident. If that accident hasn't got repeatability written all over it, then I'm a Monkey's Uncle. If I was a Pax River Osprey TP I'd be taking my pneumonia pills and doing some non-stop malingering. I kid you not. Finally, to compare:

Conventional helo:
Attempting to enter a high OGE (out of ground effect) hover whilst heavy could lead to VR, but it is more normally entered as an unhappy coincidence of your downwash with a steep approach path (i.e. at low IAS) when accompanied by a high Rate of Descent. Once the vortex forms and you don't move positively in relation to it, it will only be "stoked" by a higher collective power selection. It is quite recognizable when it happens (for some-one who's seen it and knows what's occurring). It takes quite a height sacrifice (http://www.angelfire.com/me/swissair111memorial/modded/UH1HA.jpg) to escape that downward helix. If you're maintaining a pretty well level disc, a Vortex Ring will stay with you at quite surprisingly high speeds (20 to 30 kts of sideways, forwards, rearwards). You do need to shove the cyclic forward and tilt that rotor disc at a reasonable incline in order to "shed" it (i.e. it's "sticky"). Of course the whole new ball-game is that with the Osprey's asymmVR you don't get that chance. Your input is instinctive (as for a wing-drop) - but quite terminal.

Osprey:
The Marana MV-22 slightly overshot his starboard abeam position after a station change (tactically lose in trail and he swapped sides to the stbd echelon for the final approach). His required movement back to behind the leader's three o'clock (relative) position was sufficient to put him in the VR ball-park. Once you're there (in that ball-park) I guess it takes as little as a lateral stick movement to enter asymmVR (which they'd done to pick up their line to their own hover termination point .... and that's when they hit it). His earlier high ROD was probably not a factor. He hit it after that station change re-position. The Marines admit that wake turbulence from the leader had nought to do with it. On the promising side, now that they know about it, they'll be trying to avoid it. The problem is that a FW operating envelope is relatively easy to stay inside of - only asymmetric rolling g will give you un-instrumented and un-forecast grief. In the Osprey the forbidden and lethal edge of the asymmVR envelope will always be only a mishandle away.

Whatsoever their hopes and wishes, the actual entry into that asymmVR ball-park is so easy that sooner or later it must happen again. It just takes a whimsy of the wind and a bit of unaggressive manoeuvre to set it up. Marana proved that. Not doing the wind-tunnel and flight-tests for the possible condition just shows what compulsory optimism and gung-ho can do for a program. That oversight has led them into a total conundrum simply because the fatal flaw is designed into the basic concept.

So for your first post here on this forum PTIUAE, I don't think you've achieved what you were asked to. Feel free to provide any facts that will counter that opinion. You've been writing PR releases for too long methinks. Say hello to Tom.
[email protected]

[This message has been edited by UNCTUOUS (edited 24 May 2000).]

John Farley

25th May 2000, 15:57

Perhaps enough water has flowed under the bridge since the USMC MV-22 tragedy for us to be able to see the simple issues at the core of the accident.

Regardless of which organisation’s hat one is wearing I believe there is no arguing with the premise that IF asymmetric vortex ring (VR) is allowed to develop on an MV-22 when flying at low level in the helicopter mode, a high rate of roll will develop with catastrophic results.

From the purely pilot’s perspective, a similar situation can happen to a Harrier fitted with the original metal wing during a transition to or from the hover. Because the Harrier is directionally unstable at these speeds the pilot is responsible for keeping it pointing the way it is going by use of his feet. If he does not do this, or worse still actually tries to use his feet to control heading or track over the ground (instead of banking) then the aircraft’s dihedral effect will have it on its back in a trice.

The way the manufacturer tackled this lethal threat (sadly, as is the way of the world, only after the first fatal) was to develop warning systems that announced the ONSET of the problem while any lateral out of trim was still small and still being contained instinctively by the pilot using his lateral controls.

Now forget Harrier and think Osprey.

The prevention of roll induced by asymmetric VR needs two things:

1 An early warning that the flow on either proprotor is TENDING towards VR

2 A rapid AUTOMATIC configuration change to the aircraft to take it away from the detected incipient VR conditions.

Some years ago the Aerodynamic Research Flight at RAE Bedford carried out trials with a helicopter fitted with instrumented rotor blades so they could measure aerodynamic pressures at 2% chord. I rang the (now retired) scientist in charge of that research and he explained how they could detect the spread of VR as it developed along the blade. From this I
conjecture that perhaps a couple of such sensors (optimally positioned) on each Osprey blade might just produce the necessary error signal of DIFFERENT aerodynamic circumstances on parts of the SAME blade, to satisfy a solution to the warning system requirement. Given that each rotor has three blades the triple redundancy of such a system also appeals to me.

If early warning IS shown to be possible by whatever technique (but please leave the pilot out of this as he is more than busy enough doing a demanding military task) then I think the battle is won because I don’t see para 2 above as being difficult to sort out.

VR is by all accounts not a very stable state of affairs (as the RAE found when trying to stay in it for the trials I mentioned earlier) so I have a gut feel that a quick AUTO nudge forward
(5 deg?) of the engine nacelle tilt angle might be sufficient to kill the build-up of VR before it spreads to the whole blade.

If all this is allied with a unique and unmistakable warning to the pilot to initiate a go-around then perhaps the job of avoiding the accident might be completed.

Checkboard

26th May 2000, 21:57

How about, instead of re-engineering a 10° inboard tilt of the rotors when transitioning to hover, you just tack on a couple of JATO rockets, with an "Oh my God! Help Me!" trigger switch on the cyclic to accelerate out of a VR situation. Gotta be cheaper - and could be used in a few other tactical situations...

UNCTUOUS

29th May 2000, 23:29

That JATO solution would give an instantaneous clearance out of the vortex ring condition and (I guess) could be triggered by an FCS control follow-up circuit.
Scenario: Aircraft inadvertently enters AsymmVR during approach
i.e. 1. roll starts (within set FCS inputted parameters of airspeed, nacelle-tilt, Rate-of-descent and RadAlt height)
2. pilot makes normal instinctive differential-collective input to correct (as if for a gust-dropped wing)
3. FCS detects no roll-restorative response to side-stick applied in the correct sense (i.e. a decrease of some order of magnitude in the rolling moment, but in fact identifies an increase - which confirms that it's AsymmVR)
4. FCS decision is "Uh Oh, this is bad Kharma" and auto-fires "set 1" of emerg JATO (fuselage mounted and deployed together with gear extension ).
5. Aircraft accelerates out of vortex as roll-rate approaches bank of 60° (or thereabouts), regains differential collective controllability and aborts or does further circuit and approach (with "set 2" armed).
FCS = PFCS (primary flight control system) AFCS=Auto (both FBW aka fly-by-wire).
Flight control laws are all set by software and easily changed.

In fact, in order to gather useful empiric evidence of the AsymmVR condition, they would need to have something similar (to JATO) in order to ensure safety. i.e. it would probably be a sine qua non of any realistic trials and testing. When you think about the problems of replicating the condition in a full or quarter-scale tunnel, they are considerable. No tunnel is large enough that you can guarantee that the amount of air entrainment within a "stoked" vortex is representative of the free-flight unencapsulated open-air circulation.

The size of any such JATO kit need be no greater than 2000lbs of thrust for 15 seconds (= about 25kgs weight penalty per rocket, or about 100kgs overall). Perhaps simply having that four-simultaneous capability may also enable them to lower the safety margins in some other areas - to make up for it. It could also be used for emergency overweight STOVL departures (embassy bug-outs). Alternatively an underfuselage (over-fuselage) centre-line thrusting pair may do the job (and avoid the possibility of asymmetric firings). C130 had six JATO bottles per side but two per side would probably do the trick for the Osprey, two attached to each fuel sponson and firing a set at a time in the AsymmVR scenario.

Minus factor include the presence of explosive ordnance (particularly on a carrier), as well as the weight. A properly programmed FCS should preclude any nuisance firings.

There may be another vital VR factor at work here. The original XV-15 (upon which they did all the early proof-of-concept work) only had a 90 degree nacelle tilt capability. In the V-22 (all variants AFAIK) they increased this to 95 degrees in order to be able to back it up on the ground or reverse whilst hover-taxiing (an important capability on a crowded flight-deck as well as on a crowded tarmac). It makes sense to me that they may have had the use of that rearwards thrusting capability in order to slow more quickly on the approach in helicopter mode (i.e. it's unlikely to have been "gated out" because they had no way of knowing that it could severely exacerbate any AsymmVR problem). To explain this last point, think of it as being very similar to VIFFing in the Harrier (Vectoring In Forward Flight that the Harrier uses in Air Combat Tactics in order to turn inside an adversary - or for braking on the ground). The only airborne use for it in the V-22 would be to make the plane-to-helo conversion a much later and swifter, more dynamic process (i.e. good for tactical surprise).

However, here's the rub. The use of it would make the Osprey much more likely to encounter VR, simply because it (VR) would not require a terribly steep approach angle or high rate of descent if 95 degrees of rotor-disc tilt was being utilised to kill energy (potential i.e. excess height or kinetic as in speed). Five degrees may not seem much but when you're talking about a standard 3 to 8 degree approach angle, it's a lot. It would be enough, particularly with a tailwind, to ensure that you were descending in your own "bad air" even at much higher speeds than you would expect to encounter VR. Normally they just would not need to use it unless, say, they had a need to quickly kill excess energy - for instance if, as in the Marana case, the wingman had overshot his leader and had very little time to get back in position. The more I think about it, the more that makes sense. So on four counts it would explain why they'd not encountered VR earlier in the test & eval program (at all):

a. Firstly, as we know, no-one had expected that the Osprey was susceptible to it and so no-one had suggested testing for it.

b. Any testing that may have been done earlier (on the XV-15) would have been reassuring, but being limited to 90 degrees of nacelle-rotor tilt, quite invalid regarding the Osprey.

c. It may be that the Osprey is vulnerable to AsymmVR only when 90 degrees tilt is exceeded) - such as when a very rapid correction is needed (as in the Marana aircraft's overshoot of the leader's abeam position).

d. Any testing done on the V-22 may have preceded the decision to go to 95 degrees (which was done for ground-handling reasons)

At the very least, I'd be asking whether there was any prohibition (or even caution) for use of >90 degrees of nacelle rotor-tilt airborne. Was there any idea as to what implications it could have? I'd guess the answer (through the "smoke and mirrors" reply that you'd get) would be quite revealing. I may be wrong but I suspect that it is neither "locked out" nor "detented" when airborne. I'd guess that neither the PFCS or AFCS software has any inhibitors programmed in either. Whether or not they'd tell you that is debatable. It may all of a sudden be not FOI'able and even a matter of National Security. But it's worth asking these questions.

What I'm saying here is that it could simply be yet another case of "unintended consequences". Life and aviation is choc-a-bloc with those hind-sightable instances of human fallibility.

PTI UAE

3rd Jun 2000, 13:46

UNCTUOUS
Please don’t misinterpret my comments as an attack on you personally. The best way to carry on a discussion in a forum is to concentrate on the issues at hand (as Mr. Farley has done quite effectively in his posting). My intent is not to embarrass you, but only bring to your attention the obvious flaws in your analysis that come from a lack of understanding of tiltrotor technology. I was in your position a number of years back, and could very well have come to the same conclusions that you have. However, my approach to reaching a final opinion differs from yours in that rather than theorize based on my limited knowledge, I prefer to go to the experts who work with the technology on a daily basis. It is incredible how much research on tiltrotor technology has been done by NASA and Bell over the years (courtesy of hundreds of millions of taxpayer dollars), and no, you will not find more than a fraction of the reports on the AHS or NASA web sites. The work is ongoing, a few months back I stood in one of the remarkable wind tunnels at NASA Ames where a fully functioning scaled replica of the V-22 was being assembled. This is only the latest in a number of long-term wind tunnel testing programs that included not only scaled models, but actual full-size aircraft with the XV-3 and XV-15 (and for the future there is talk of full size V-22 testing). There was a long list of very complex issues that were being closely examined during this research. It is not simply a matter of ‘running it through the wind tunnel’ as you stated in an earlier post. An incredible amount of data is accumulated by the numerous high tech monitoring systems that measure to a degree of accuracy most of us would not have thought possible. The dedication of the many people working on tiltrotor research at NASA is truly admirable, and their goal is no less than to contribute to the development of revolutionary a/c that combines dramatic technological advances that have been achieved on a number of fronts in aviation.

In my limited experience I have had the opportunity to fly the XV-15, the V-22 simulator at Pax River, and the incredible VMS simulator at NASA Ames Research Center (capable of pulling positive and negative Gs). This is of course nothing compared to the NASA, Bell and military test pilots that have spent years flying the XV-15 and V-22. I keep in regular contact with some of these individuals, and have great respect for the level of knowledge and expertise they have accumulated. I have included below some responses to my queries from a senior engineer/test pilot at NASA who has almost twenty years experience in tiltrotors. He knows far better than you and I what is known or not known on the subject of tiltrotor flight characteristics.

Some good news for you is that the V-22 crash is not being investigated only by Bell/Boeing and the Marines. The NASA rep that I have been in communication with just returned from the Naval Safety Center where he was leading a team which is “doing a NASA independent review of data from the V-22 accident.” NASA does not have to answer to, or coordinate with, the military investigators other than to present their final analysis. During his investigation, his people reviewed the available recorded data from the Crash Survivable Memory Unit (CSMU) of the a/c that went down in Arizona. He is not at liberty to release the details to the public at this point, but on initial review it was clearly evident to him that the pilots were “way outside of normal or reasonable boundaries or limits.” From numerous meetings and discussions with this individual, I can tell you that although he is an ex-military pilot himself, he does NOT fall in line with the opinions expressed by the military. During the past couple of decades that he has been working for NASA flying almost everything imaginable, he spent five years (1990 – 1995) as the NASA representative to the V-22 Integrated Test Team at Pax River. From that experience, he does not hesitate to point out where he disagrees with how the military have conducted their research and development program.

In the opinion of the NASA investigator, initial indications are in fact that the aircraft was in a situation that should have never have been allowed to develop. As a highly experienced tiltrotor pilots, he and his colleagues all agree they would never have allowed themselves to go so far outside normal operating parameters, or to use the control inputs in the way they were used in any circumstance. The outcome of having done so was inevitable. When these details are released (the sooner the better) it will be evident to all that asymm VR state is not a condition that is by any means entered ‘at the flick of a wrist,’ and it is not a condition caused by external environmental factors.

Asymmetric settling with power in tiltrotors has been known and understood by those at NASA and in the military for many years. The reason there was no in depth test and evaluation program by the Marines with the V-22 was because it was felt that the phenomenon was so far outside of the normal flight envelope that it would not be encountered. This was wrong – dead wrong. Combat conditions (or simulated combat conditions) all too often create situations that cause the pilots to enter regimes that the a/c was not designed for. In hind sight I would imagine it is painfully obvious to them that more wind tunnel and simulator testing was warranted, as well as actual flight testing when deemed safe based on the wind tunnel and simulator results. The lessons learned from this data need to be thoroughly understood by all pilots transitioning into tiltrotors so that it is completely clear what conditions/actions will produce fatal consequences.

The NASA pilot mentioned above has done extensive flight testing to explore the outer limits of the flight envelope and beyond in both fixed-wing and rotorcraft. Based on his experience he believes that at the very least the impending conditions of the phenomenon will be able to be safely tested in actual flight in a controlled manner that will provide answers without loss of life. Obviously with any flight testing there is an inherent element of risk, but the trials will be conducted at altitude where recovery can be accomplished safely. Regardless of the results of this testing program, the RECOVERY techniques practiced will have no direct application to the low altitude scenario that took place at Marana. The purpose is to more clearly define where and how the state develops, and how it can be RECOGNIZED before it progresses to the point of no return. This information can then be used to determine the solution to preventing a reoccurrence of this type accident in the future, whether that solution is to modify the aircraft, add warning or control devices, restructure pilot training with much greater detail and emphasis on understanding, avoidance, recognition and recovery, or restrict certain operations (or a combination thereof).

As to your questions/comments:
1. Nobody will be issued a private pilot license in the US without being able to recite verbatim the three basic requirements for getting into settling with power. From the FAA publication AC 61-13B (as well as other education and training publications that concur): “the following combination of conditions are likely to cause settling with power: 1) A vertical or nearly vertical descent of at least 300 fpm. Actual critical rate depends on gross weight, RPM, density altitude, and other pertinent factors……” I can’t speak to what the CAA/JAA etc. like to use as guidelines, but we all have to start somewhere to keep pilots safe. In demonstrating settling with power to students I have never been able to induce the condition with less than 500 fpm, however this does not mean it is not possible. Ray Prouty gives an excellent description of settling with power if you need further clarification.

2. Just as your initial assertion that tandem overlapping rotor systems (CH-46, CH-47) do not experience settling with power was shown to be false by those who fly the a/c, your claim that getting into asymm VR is a ‘momentary entry’ has been disproved by those who actually fly tiltrotors. According to the experience obtained by the NASA test pilot commenting below, your statement is in complete contradiction with the facts. In response to my question, he described his experience with the onset of the condition, as well as the basic recovery technique, “In the XV-15, on at least one occasion, I have come to a hover or near hover at altitude, 4 or 5 thousand feet, and picked up a pretty high sink rate with lots of power applied. Now, as a tiltrotor pilot, it was second nature to move the nacelles forward 10 degrees or more and apply appropriate power to fly right out of the condition. I have never encountered any asymmetrical conditions and you would have to work REAL hard to create them – way outside of normal or reasonable boundaries or limits.” Again the NASA pilot has seen the CSMU data, and as a former combat pilot himself, has made the assessment based on his experience that the Marana accident did not take place while performing a maneuver anything near ‘normal.’ No one would deny that the Marana V-22 crew had no recovery options available to them when they entered the asymm VR state at 285 ft above the surface. At altitude, in other than extreme conditions, forward movement of the nacelles has an immediate effect on changing relative wind/AOA conditions that cause settling with power, just as we in the helicopter world can escape the VR state by using forward cyclic and reduced power -- as long as circumstances permit it (not possible at extreme rates of descent and critically low altitude – sound familiar?). And note that so far, we are only discussing recovering at a stage when indications show an ‘impending or incipient’ asymm VR state. The forthcoming wind tunnel, simulator and flight tests will determine accurately what if any techniques can be used to recover from asymm settling. It may be that only avoidance of entering the extreme rate of descent and application of violent control inputs that the NASA investigator saw evidence of on the CSMU could have saved the V-22 crew. Perhaps Mr. Farley is correct in his suggestion that a warning device or automatic configuration change might be the answer.

3. Your comment here does not make sense. Nobody is saying that asymmetrical VR is anything less than deadly. Further, to deny that dangerous flight regimes exist in airplanes or helicopters is foolish, and I’m sure you do not subscribe to that belief. We cannot look at the tiltrotor with tunnel vision. Comparative relationships with other categories of aircraft should be drawn in order to correctly assess the capabilities and vulnerabilities as they relate to defining whether or not an aircraft is within our definition of ‘safe.’ For instance, when you say the design of a tiltrotor is deficient in that transmission failure or pitch lock have not been considered. The first thing I think of is what will happen to me if one these catastrophic events happens tomorrow when I’m flying along in a Bell 212 (or any other helicopter in existence) – it certainly has been considered by the design engineers, and there is no ‘back up.’ The answer is to minimize risk to the greatest degree possible by using the highest possible standards in the construction of the rotor and transmission components. And in the case of the transmission, add warning devices such as temperature gauges, pressure gauges, warning lights (temp & press), and chip detectors so that an impending failure will be recognized in order to provide the pilot with enough time to get the a/c on the ground before complete failure occurs. We can’t wear blinders when it comes to admitting that the only way to guarantee 100% safety in aviation is not to fly. That said, every effort must be made to ensure that we come as close to absolute safety as we possibly can. Regarding warning instrumentation, perhaps more can be done. But don’t be so hard on A/S and VSI indicators – sure, they’ve got limitations – but they’ve kept me and a lot of other helicopter pilots from getting into unanticipated settling with power for a lot of decades. Give us something better, and we’ll use it. But if you use the instruments we have knowing their limitations, they can provide you with good information.

4. As already shown above, those who have a great deal of experience in tiltrotors (which both you and I lack) attest to the fact that the asymm VR condition is far from insidious to say the least. Why do you think in all the thousands of hours of XV-3, XV-15, and V-22 flight testing, including pushing the envelope boundaries to what was believed to be their safest limits, the phenomenon had never been encountered in flight (an awful lot of ‘wrist flicking’ going on there)?
On the other hand, the all too frequent occurrence of the fixed-wing stall/spin scenario that I described in my previous post continues to be repeated again and again. For those of us with experience and a thorough understanding of the conditions that lead to a fixed-wing aerodynamic stall, we would not consider it an insidious event. However, for those with insufficient experience and inadequate training in airplane category aircraft (ex. 80 or 90 hrs) it can be very much more insidious than what it takes to get into assym VR in a tiltrotor, but just as fatal.

5. Again your statements are in complete contradiction with the opinions of those who do posses the facts. Those who possess actual experience say you are most definitely wrong in your assessment that experience would not aid pilots in strengthening their ability to better recognize and stay out of a position that would allow asymm VR to develop. A thorough knowledge of asymm VR should be possessed by all tiltrotor pilots (no doubt from April on that will be the case in the Marine Corp). It certainly appears something was lacking in the education and training process. Again, according to those with experience with tiltrotors, the vital element that was missing in this case it was the ability to recognize the extreme rates of descent combined with low airspeed that created the condition. Although the CVR did not record anything during the event itself, shortly before the accident the wing pilot transmitted. “Lead you’re too hot, lead you’re too hot!” As the lead a/c continued on at a higher airspeed, the wing a/c apparently did a dramatic full aft stick rapid deceleration that put the a/c into the deadly low speed/low altitude/ extremely high rate of descent combination that will kill you whether it is caused by settling with power or asymmetrical settling with power. Add to that a 28 degrees Celsius temperature, a 2100 ft msl altitude, quartering tailwind, massive right pedal and heavy left lateral stick inputs and things begin to pile up.

6. I don’t have enough knowledge of the facts to pass judgment on what took place in Kosovo.

7. Regarding the infrared video taken of the accident by an F/A-18 from above – I’m not saying this is the case, but when the military has a picture or video of one of their a/c crashing, and the press is clamoring to get at it, these things have had a habit of disappearing. (Mention of the existence of the tape came from a non-DOD source investigating the accident.) How many photos of the early F-117 crashes have you seen? Do you think none were taken? Think about it.

8. Again, your basic assertion that ‘the SUSCEPTIBILITY is built into the design concept’ has already been shown to be a false premise as attested to by those who have actual experience with the aircraft (have you even seen a tiltrotor?). Rather than being susceptible to the condition, it actually takes extreme rates of descent with radical control inputs to enter it. Mr. Farley seems to disagree with your theory that a warning device is not possible. Personally I don’t have the expertise to judge, but if it is deemed feasible and beneficial as a result of the upcoming wind tunnel testing at NASA, I should hope we will see one fitted as standard equipment.

9. I won’t beat a dead horse to death. By this point you should be aware that although the phenomenon was known of, it was not looked into because it was considered too far out of the normal flight envelope to investigate further. It was believed that the conditions required to encounter it were too extreme to consider. They were wrong. The fact that the accident did occur shows greater understanding is required and it will now be studied further. No matter how extreme the conditions must be to get you into it, the point is it can happen. All the options for making this the last accident of its kind that were discussed earlier must be completely researched and action taken (see above).

‘PR releases’?? ‘Say hello to Tom’?? I think you missed the mark again on this one UNCTUOUS. I am working with an offshore helicopter operator in the Persian Gulf, and will hold the position of managing director of Petroleum Tiltrotors International which currently has five 609s on order. This is why we are more interested than many that the correct lessons are learned from the tragic crash of the V-22 in Arizona, and that there is no ‘hidden fault’ in the technology. We are in a position to cancel our 50 million dollar order at anytime prior to delivery, and I can assure you that if we feel the a/c is not safe, we would do so. We are not going to risk our lives or the lives of our customers if all our questions are not answered fully.

I appreciate your interest in the subject, and especially appreciate your “asking the hard questions.” If tiltrotor technology is to be completely understood, we must all do this. And we need to demand complete answers without any room for doubt. Settling for anything less is unacceptable. If there is a requirement for additional warning devices that need to be added, we must insist on it. I am fortunate to be in the position to serve as Chairman of the 609 Industry Steering Committee (ISC) which is tasked with determining the scheduled maintenance requirements for the 609. The committee is comprised of operators that bring to the table some of the most experienced personnel in the rotorcraft industry (including Bristow, PHI, Canadian Helicopters, Scotia (CHC owned Brintel/Rotortech), and Shell Oil among others). We sit side by side with the FAA and Transport Canada in analyzing every relevant system and component on the aircraft. We are able to use whatever data we need from the V-22 development program to fully evaluate potential failures of systems, or potentially dangerous design characteristics, and we can demand a resolution to the problem. Bell cannot say ‘no’ to the regulatory members of or committee, as to do so would mean denial of certification. Thus far, to say that Bell has been totally cooperative is an understatement. We have complete access to their design engineers, test pilots etc., as well as independent expertise with our NASA contacts. Bell clearly recognizes that producing a safe aircraft is not just to their benefit, it means the survival of their program.

I am expecting additional information from NASA and Bell and will try to keep you updated as more information becomes available. Theories are great, but they work even better when we have the facts to support them. By the way, if you are really interested in some of the history of what has been learned during the development of tiltrotor technology, the NASA test pilot quoted above has co-authored a publication that is for sale by the Government Printing Office. It is part of the NASA Monograph Series (#17) entitled “The History of the XV-15 Tilt Rotor Research Aircraft” (NASA SP-2000-4517).

[This message has been edited by PTI UAE (edited 12 July 2000).]

PTI UAE

3rd Jun 2000, 14:00

UNCTUOUS
PS: Your most recent posting was incorrect with reference to the XV-15 nacelle tilt angle range. The XV-15 does extend back to 95 degrees tilt. Both in the simulator and the XV-15 we used this 5 degree aft tilt to act as a giant 'air brake' for rapid deceleration. In addition, it's used as a brake while ground taxiing (you don't need to touch the wheel brakes), and it's also kind of fun ground taxiing backwards (make sure you have lots of open ramp space!!)

Jeep

3rd Jun 2000, 17:00

PTI nice post. what type of pilots are you going to recruit, rotors/fixed/both? is there any data to which take to the tilt system better? is there no difference? would appreciate your thoughts.

Robbo Jock

5th Jun 2000, 15:41

PTI, just out of interest, is there any difference between tilting the nacelles back to achieve rapid deceleration and hauling back on the stick to achieve the same ?

By the way, I've got both a fixed-wing licence and a rotary CPL. Very low hours, but hey, I'm cheap and I don't mind supplying my own sun cream !

John Farley

6th Jun 2000, 00:31

Robbo Jock

Its not really my business to reply to this -but pulling the stick back will change the wing angle of attack and also your view, as well as tilting the rotor thrust line.

Tilting the rotors back will not change the view and the wing aerodynamics will be less affected (some change inevitable due to them being in the downwash)

Being able to violently control forward speed without changing view can be a real godsend at times. Some times ones view is only just including the nearby osstacles and yanking the nose up then (in a chopper, tiltrotor or Harrier) can really add to the problem...

I hope you get the job

Robbo Jock

6th Jun 2000, 15:24

Thanks for that, I hadn't considered the forward view. I was just thinking in terms of the rotor aerodynamics wrt vortex ring entry conditions. Tilting the rotors and tilting the whole plane would appear to achieve the same object - changing what could be considered a nice, flat, forward moving disc into one that is 'sinking' into its own downwash.

Obviously, you can haul the nose up a lot further than 5 degrees, but if you're on the edge of VR anyway (asymmetric or otherwise) tilting the nacelles or the nose is going to drop you right in it (literally and figuratively) isn't it ?

By the way, thanks for the wishes, but I think I'll be at the back of a very long queue for that one.

[This message has been edited by Robbo Jock (edited 06 June 2000).]

PTI UAE

6th Jun 2000, 19:43

Jeep
Those who will adapt most readily to tiltrotors are dual rated pilots, followed very closely by helicopter-only pilots. Airplane-only pilots on the other hand, would be a distant third, as they would have to learn rotorcraft basics (hovering skills etc.) while helicopter-only pilots will have no difficulty performing enroute fixed-wing tasks.

The main advantage of having rotorcraft pilots with at least some f-w experience is stall recognition and recovery ability when nacelles are in the horizontal position. There may be times during slow speed maneuvering in the airplane mode that not being able to recognize an imminent stall could spell disaster. There are a few negative-transfer habits that come from helicopter flying (stall recognition being the only one of a potentially critical nature), but nothing that good training and experience will not overcome.

The FAA in Part 61 (Certification of Pilots and Flt Instructors) has already issued powered-lift requirements, and I believe Part 141 is complete now also. Requirements for Part 142 still need to be determined. The Bell training facility will be operating under Part 142, and for entry into the program they are requiring pilots to be in possession of three ratings: helicopter, airplane, and an instrument rating in either helicopters or airplanes. I don’t know if they have determined whether or not a multi-engine rating will be req’d, and I’m not sure whether the category ratings (airplane & rotorcraft) will both have to be commensurate with the rating sought (i.e., is it OK to have a commercial helicopter license with only a private airplane rating when seeking a commercial tiltrotor rating).

As far as flying the aircraft itself: when you are in the helicopter mode, it flies just like a helicopter; when you’re in the airplane mode, it feels just like a twin-engine airplane. And although I can’t claim to be an expert, the transition phase feels suprisingly natural, and something that can be adapted to without much difficulty. I must say that in a hover the XV-15 felt much more stable than any helicopter I’ve ever flown. There is virtually no weather vaning tendency at all, perhaps a characteristic of all tandem rotor systems in general. You can hardly tell which way the wind is coming from – you set the cyclic and the a/c just sits there like a rock. As far as the airplane characteristics, the stall is very benign with no radical tendencies. Standard recovery procedures of lowering the nose and adding power apply, although if you are in an intermediate mode (i.e. 60 degrees as we practiced it) the more efficient recovery technique is to simply push the nacelle switch forward and fly out of it.

HCN

8th Jun 2000, 01:20

PTI UAE, John Farley and any other thoughtful, informed observer:
I am a reporter with Helicopter News and Rotor & Wing. We cover the helicopter industry and have been tracking the MV-22 incident closely. These exchanges are highly illuminating. If it is OK with you, I would like to followup by phone/e-mail. We are totally cooperative trade press with no desire to play "gotcha." In fact, I am happy to run quotes by you or, if your prefer, not quote you at all. My main goal/motive is understanding and accuracy about the MV-22 and tiltrotor technology. Is there an e-mail address or phone number by which I can reach you? My e-mail is: "[email protected]." Many thanks.
HCN

PTI UAE

8th Jun 2000, 14:47

Robbo Jock
Sorry for the delayed response. I’m on holiday doing some island hopping, and only get into the business center periodically. John Farley gave you a good description of how tilting the nacelles has advantages other than just some of the ‘fun stuff’ you can do with the capability. Being able to control the angle of the fuselage is like having a new added dimension. For instance, standard practice on descent into a confined area is to use a 95 degree nacelle angle setting (5 degrees aft) which provides greatly enhanced visibility at a time when it is most needed. Doing this essentially brings the windshield down lower into your sight picture, and effectively increases the area you can see on approach. Those of us in the offshore industry will be especially appreciative of this ability. Approaching drilling rigs or platforms in a helicopter when the wind is such that the approach path puts the main structures and obstacles out of your sight picture can be very uncomfortable, and leaves little for visually judging your speed and rate of descent (especially at night). Being able to drop the nose 5 degrees while maintaining a normal descent profile makes a tremendous difference when visual references would otherwise be minimal. Another advantage of being able to tilt the nacelles beyond the normal swashplate range is that it allows a much steeper slope landing capability than conventional helicopters can offer. These are just a couple of added-value things helicopter pilots will appreciate when transitioning to powered lift a/c. It takes a little getting used to, but for an experienced tiltrotor pilot, taking advantage of these new capabilities will become second nature.

While sitting in the NASA VMS control room I watched a UH-60 pilot on loan from the Army perform a normal tiltrotor take-off and conversion (the Army still has lots of interest in the V-22, but not enough money for procurement). The room erupted with laughter as we watched the external visual display which shows the aircraft as it would be seen flying in real life (you can see the gear, flaps, nacelles, and flight controls move as well as see the attitude change as it flies over a runway, past the control tower, trees, bridges etc.) During the laughter the comment was made, “there’s another helicopter pilot take-off.” I had no idea what he had done wrong, as it looked perfectly natural to me. It was then explained to the Army Major that he had lowered the nose as he added power for departure. Standard procedure in the tiltrotor is to let the nacelles do the work for you. As the nacelles move forward, the ‘cyclic’ stick is used to simply hold the fuselage level, producing a smoother and more comfortable take-off for passengers than can be accomplished in a helicopter (or by an airliner for that matter!).

As for your concern over the additional 5 degrees contributing to an early entry into settling with power/asymmetrical settling, I would imagine that there would be at least some effect on the earlier development of the vortex ring state. By changing the disk angle by 5 degrees you are changing the disk plane relative-wind by that amount, and the blade resultant relative-wind by a lesser amount. I couldn’t quantify the effect (I’ll leave that to the aerodynamicists), but according to the pilots who have been flying tiltrotors for many years, getting into the phenomenon takes extreme conditions. I was taken through what I considered some pretty ‘wild’ maneuvers that are routinely done by test pilots, and we did not begin to encounter any problems. Those of us in the civilian world are going to be operating in a much more docile environment and a more restrictive envelope than our counterparts in the military. However, we are all very interested and will all benefit from the information that will be forthcoming from the wind tunnel, simulator and flight tests to further explore and define the conditions that allow an a/c to enter the state.

Regarding employment, we are not in the hiring mode yet, but we are collecting applications for pilot and engineer (mechanic) candidates now. If you would like to you can send your resume/CV to the address below, and I would recommend periodic updates if your experience level is low. BAAC has recently announced a program delay of 8 months (first flight is now scheduled for August next year) as the result of changing the manufacturer of the 609’s composite fuselage. Initial deliveries will probably be around the 1st quarter of 2003, so you have time to build your flight time!! Good luck to you, it’s definitely a worthwhile pursuit.

Send to:
Aerogulf Services Co. (LLC)
Attn: R.M. Denehy
Dubai International Airport
PO Box 10566, Dubai
United Arab Emirates

[This message has been edited by PTI UAE (edited 15 June 2000).]

PTI UAE

8th Jun 2000, 14:56

HCN
The office can be contacted at [email protected], although it may be best to use [email protected] as I check this address periodically while travelling.

Robbo Jock

9th Jun 2000, 15:47

PTI UAE,

Thank you. My CV (such as it is !) is in the post. (As are, I've no doubt, many others !)

HeliFlight

14th Jun 2000, 21:56

INCREDIBLE! As a first timer at PPRuNe, I must say I have seen a lot of discussion on the accident, but nothing anywhere like this!

Somebody should definitely set up a TILTROTOR category here to exploit the expertise and give those of us with questions the opportunity to ask the experts that are obviously present here!

The beginning postings were a bit sad and uninformed, but the latter told me more about tiltrotors than I have seen anywhere, AND I HAVE BEEN LOOKING.

THANKS

tiltrotor

15th Jun 2000, 05:01

OK, well, here are some of my thoughts for people that are interested. It was really quite interesting to read the 2 page article posted recently about settling with power (or the Vortex ring state, as others may call it) that may have contributed to the Crash of the V22 operated by the US MArine Corps earlier this year. Well, to keep a long discussion short, I do not agree that it should be blamed on a design fault or the basic concept. Considering the effort that has been made by both, the U.S. military and Bell/ Boeing I would say that it is an excellent concept. The tiltrotor as in the V22 or the B609 will not replace the helicopter, nor will it replace the airplane. But it will fill a new market which may not be possible to be satisfied by any conventional aircraft. And there are allready many positive aspects before the aircraft is even out with the operators.
To come back to the original article, I believe that there have been some controversial results and maybe there will never be a definite conclusion to the accident. It does look however that there is nothing wrong with the aircraft. That is not up to me do discuss. I would like to mention though that it probably would be much more appropriate to target the training and qualification programs for the aircrew on the V22. Due to it's high cost and tremendous pressure on the operational status of the aircraft, I personally believe that the training requirements are not satisfactory enough for the operations conducted. After all it is a brandnew design and aspect of aviation. Just imagine yourself as a 100 hr. wonder trying to do an operational insertion of troops using night vision googles in an aircraft you may not feel quite comfortable with yet. I would say, well, you are asking for trouble. But what it comes down to is that it really couldn't be blamed on the aircraft or a design fault on it. I do agree that there are some sysytems which I personally think could be implemented to improve the safety of the aircraft. But I guess that the designers would sure have thoguth about it. Anyway, any airplane, if you misshandle it, can be stalled. Any helicopter, if you misshandle it, can enter the Vortex ring state. What it comes down to is pilot tarinig, recognition and avoidance of these flight conditions. I also do not necessarily agree with the fact that flying out of it is the only way to recover from the above condition. Yes, it is so according to the text book, but anybody who has done some slinging or other operations involving a lot of OGE hovering will know that there is other ways around it.
Anyway, I think to put a moral to the story,
the Tiltrotor concept is very new and the media and people have always tried to find fault with new things. Just remember the millennium bug- the world was gonna break down- did it? Well, it wasn't that bad after all.
Modern aircraft design is very, very advanced and especially on the B609 there is tremendous effort being made to counteract and correct problems before the aircraft will come out. The B609 industry steering committee is doing a fantastic job and the input from the members involved does help to make the cost cheaper and the aircraft safer and easier to maintain for the future operators. What will happen, well, just like with the millennium bug we will not know until the aircraft is flying. The test flying so far is really going great from what I understand. The effort made by the manufacturer and industry members certainly helps a lot to predict most of the aspects.
And think back, it took more than 25 years for the Bell 212 to proof it's reliablity. So give the concept some time.

What I would like the concerned people to consider though is to maybe revise the standards of training and the requirements for the aircrew. As for the B609 I do believe this issue may not be of such importance since the operational flying will maybe not be as challenging. However, the military may well be better of to, and I am sure this is done, considering the training syllabus and minimum training before going "hot".

I would appreciate any feedback on my thought and welcome anybody to challenge my view-points.

PTI UAE

21st Jun 2000, 05:49

Tiltrotor
Yes, you are right, the tiltrotor is definitely a niche aircraft that will not replace airplanes or helicopters (although there may be some instances where companies currently using a both a turboprop and a helicopter may be able to use the tiltrotor in place of the two a/c). The two basic requirements that exist for the tiltrotor to be effective in a particular civilian operation are:
1) There must be an absolute need for vertical take off and landing capability at one or both ends of the flight. – If not, a turboprop airplane would be able to perform the operation more economically flying airport to airport.
2) The distances to be flown must be greater than a minimum of about 100nm. -- If not, a helicopter will be able to perform the operations more economically due to its lower initial acquisition cost (DOCs for the 609 are expected to be slightly higher than a 412).

The key to the potential success of the first civilian tiltrotor also rests with its ability to operate using the existing helicopter ground infrastructure. When the Civil Tilt Rotor Development Advisory Committee (CTRDAC) prepared their feasibility report for Congress in the mid 90s, they referred mainly to a 40 or 75 passenger a/c. The projected saturation of major metropolitan airports by the year 2010, and the lack of available real estate for new airports meant some alternative method of mass transport must be developed. Although the report came back with a resounding affirmative response for the projected success of the tiltrotor in a future transport role, the CTRDAC pointed to the critical need for publicly funded infrastructure development.

In order to be successful, vertiports that will be needed to support transport tiltrotor operations will have to be built either in, or very close to city centers (preferably with over water approaches that do not overfly congested areas). This can only be accomplished with public support. Public support can only be gained with understanding and confidence in the technology, and so Bell/Boeing (now Bell/Agusta) decided that a small civil tiltrotor should be introduced that can operate using the existing helicopter infrastructure. This way the general public will have time to learn about and become familiar with the capabilities of tiltrotors before the introduction of a large-scale transport version.

The 609 will be 44 feet long and 60 feet across (proprotor tip to tip). These dimensions are not far off from those of a Bell 212 which are 48 feet across (blade diameter) and 58 feet long (main rotor tip to tailrotor tip). I’m sure there will be some offshore platforms that 609s will not be able to land on safely, but by far the majority of platforms, drilling rigs and helipads currently being used by helicopters should present no problems. And it sure is nice being able to visually see the furthest extremity of your aircraft when you’re maneuvering on the ground rather than trying to estimate how much distance exists between the nearest obstacle and your tailrotor!!

Scattercat

9th Aug 2000, 16:51

Has anyone out there got any hard facts on what sort of licence / qualifications will be required for tiltrotors?? I've heard suggested that F/W & Helo' will both be req'd ? I'd be interested in various coutries positions. (I'm in Aussie)
Cheers

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sprocket

12th Aug 2000, 09:34

Scattercat,check out this thread on this forum (pprune)
http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000289.html
or go to the "MV22 Osprey Accident Theory" on pg 2 of this forum....A bloke who goes by the user name "PTI UAE" has put some addresses on a couple of his posts. Or try emailing him at his "Profile address"

Good Luck

------------------
Its a big thing..when you look into it!!

flyerh

14th Aug 2000, 00:38

The FAA are the only ones that have given this serious consideration,the CAA will probably wake up to the fact when one buzzes them at Gatwick. so far the FAA have said that if you want to be a captain after the factory coarse you will need a helicopter ATP and a multi engined fix wing CPL.
If you only have a ATP(H)you will need 500 hrs on type before you can be a captain.
This may all change though as the project progresses,I know I will be getting mine!

PTI UAE

24th Aug 2000, 18:17

Scattercat,

As far as I have heard, the only regulatory agency working with the FAA on certification and regulatory issues for tiltrotors is Transport Canada, although I would imagine that the Italian aviation authorities must be involved to some degree because of the Agusta participation. It appears that others are taking a ‘wait and see’ attitude, and are not participating directly in the process. I’m sure they will have access to all of the certification data etc. to use in developing their own regulations, and they will have the FAA and Transport Canada established regulations and procedures to use as a baseline. If the other agencies delay too long, it could create difficulties for a number of operators that plan on flying 609s in Europe, Australia etc. The following will provide you with an update on the current plans by Bell for certifying tiltrotor pilots and engineers.

In order to be admitted into the Bell training program, they require that you have three ratings: helicopter, airplane and an instrument rating in EITHER one. This is a BHTI requirement to enter the BA609 Pilot Qualification Course, not an FAA requirement. The program is scheduled to be four to six weeks in duration, and will include a minimum of 24 hours of simulator time and initially 15 hours in the aircraft. The time in the a/c may be reduced later based on observed performance by early participants in the program. It is a proficiency-based course, so additional time may be provided on an individual basis as needed, and obviously nobody will pass unless they meet the performance guidelines. The purchase of the simulator has been fully funded (initially Level ‘C,’ then later to be certified as Level ‘D’), and will be set up in the combined Pilot and Engineer Training Center being built at Alliance field in Texas.

I received some clarification from Bell on the specific type of license and ratings needed to qualify for a commercial/instrument powered lift (Part 142):

When seeking a Commercial/Instrument Powered-Lift rating, you DO NOT need to have a commercial license for BOTH categories. You must have a commercial (CPL) issued for one or the other, EITHER airplane OR helicopter (as is the case with the instrument rating). So having a commercial-helicopter, and private-aeroplane (or vice versa) is sufficient.

A multi-engine rating is NOT a mandatory requirement, although it is strongly recommended. A single-engine land rating is acceptable. It was also stated that although experience with pressurized aircraft is preferred, it is NOT mandatory.

Requiring the powered-lift candidates to have airplane, helicopter, and instrument ratings have helped BHTI gain approval for the reduced training hours under Part 142. Part 61 requires 72 hours, and Part 141 would likely require 40 to 50 hours. In order to qualify for a Powered-Lift ATP you would need to complete the Bell course for Commercial/Instrument, then accumulate 250 hours as PIC in tiltrotors along with the other requirements detailed in FAR Part 61 which would then make you eligible to take the check ride.

At this point Bell says it appears likely that the training slots allotted for each aircraft sold by BAAC will be 2 pilots and 3 technicians although we would like to see higher numbers.

The engineer/mechanic course is expected to be 3 weeks long. Each technician may attend 3 maintenance slots, or 3 may attend one of the following:

Field Maintenance Course - (4 Wks)
Line Maintenance Course - (2 Wks)
Electrical Maint Course (2 Wks)
Flight Control Maint Course (2 Wks)
Integrated Avionics Maint Course (1 Wk)

The above info. Is not yet set in stone, but it is what Bell is using as their basic guidelines at this time. Below is a statement issued by Joel Brown, the Supervisor of Tiltrotor Training at Bell.

************************************************************ *********

BA609 Pilot and Maintenance Courses

We are in the process of developing the BA609 Pilot Qualification Course
curriculum. The course will be validated via internal training for our company test pilots, instructor pilots, and pilots from the FAA Certification Office & FAA Flight Standards Service.

After first flight and during flight test, we will update the curriculum for customers who will be operating the BA609. The BA609 Pilot Qualification Course will be offered to support issuance of FAA Powered Lift Private, Commercial, and Airline Transport (ATP) ratings, in conjunction with BA609 Type Certification. This course will include academic, Full Flight Simulator (FFS), and flight training. The course length is not yet set, but may range from 4 to 6 weeks and include approximately 30 to 40 hours combined FFS and aircraft flight time.

Customers must meet the prerequisites of Airplane/Helicopter dual rating and a commercial certificate with an instrument rating in either category prior to attending the BA609 Pilot Qualification Course. Additional training will be available for applicants who do not meet course prerequisites. The Bell Agusta Aerospace Company (BAAC) or BHTI will provide this training for a fee, or assist the customer in obtaining it from another source.

We expect to begin training customer pilots shortly after aircraft type certification. Initially, training slots will be limited and the priority will go to:
1st: BA609 customers to be trained in conjunction with a new aircraft delivery.
2nd: BA609 Operator Customers requesting training at own expense.
3rd: Other Customers requesting training at own expense.

Additional courses will be offered to support issuance of FAA Powered Lift Instrument, Certified Flight Instructor (CFI), and Certified Flight Instrument Instructor (CFII) ratings in the BA609. Refresher Courses will also be offered in each of these categories.

The following maintenance courses will be developed and offered to customers to support maintenance of the BA609: Field Maintenance, Line Maintenance, Component Repair and Overhaul, Electrical Maintenance, Flight Control Systems Maintenance, and Integrated Avionics Systems Maintenance. In addition, Bell will update the existing BHTI Composite Repair Course to include unique BA609 structural repairs.

At this time, the prices for BA609 courses have not been established.
************************************************************ *********

[This message has been edited by PTI UAE (edited 25 August 2000).]

HeliFlight

30th Aug 2000, 11:27

PTI UAE:

EXCELLENT post (as usual). This is exactly what those of us interested in the Tilt Rotor are looking for! I'll definitely circulate this around. Please keep us updated. Thanks

Scattercat

4th Sep 2000, 03:18

Thanks for the exellent info' PTI UAE. Sorry it's taken so long to get back. (I've been out of the loop for a couple of weeks).

Cyclic Hotline

12th Dec 2000, 19:31

Tuesday December 12 10:03 AM ET
Marine Corps Osprey Suffers Another Fatal Crash

By Charles Aldinger

WASHINGTON (Reuters) - The Marine Corps faced new questions Tuesday about its tilt-rotor MV-22 "Osprey'' aircraft after one crashed in North Carolina Monday night, killing three marines and leaving a fourth missing and presumed dead.

No cause was immediately determined for the accident in a wooded area north of the Marine Corps New River Air Station in southeastern North Carolina. It was the second fatal training crash this year of the revolutionary MV-22, which uses rotating wingtip engines to take off and land like a helicopter.

The Navy recently postponed for several weeks a decision on whether to go into full-scale production of the first of 360 MV-22s, built by Boeing Co. and the Bell Helicopter division of Textron Inc., after a Pentagon (news - web sites) report criticized maintenance problems in the aircraft.

That initial production contract to be signed next spring would be worth up to $1 billion for 20 aircraft. But the long-range value of production could be $30 billion including sales to the Marine Corps, Navy and Air Force Special Operations.

The Marine Corps itself plans to buy 360 of them at a cost of more than $44 million each, although a recent report by Philip Coyle, the Pentagon's director of test and evaluation, worried that the cost could escalate sharply.

Another of the hybrid helicopter airplanes crashed on a training mission in Arizona last April, killing all 19 marines on board. That crash was blamed on pilot error.

Defense Of The New Aircraft

The MV-22 is designed to replace the Marine Corps CH-46 medium-lift helicopter first bought in 1964, and both the Pentagon and Marine Corp recently defended the new aircraft despite Coyle's report.

Monday night's crash occurred during a training mission, the Marine Corps said.

Rescuers reached the crash site in a heavily wooded area about 10 miles (16 km) north of the Marine Corps New River Air Station in the southeastern part of the North Carolina.

Marine spokesman Capt. James Rich said rescuers located the remains of three crewmembers but were unable to immediately identify them, and were searching for the fourth.

The crewmembers were Lt. Col. Keith M. Sweaney, 42, from Richmond, Va.; Maj. Michael L. Murphy, 38, from Blauvelt, N.Y.; Staff Sgt. Avely W. Runnels, 25, from Morven, Ga.; and Sgt. Jason A. Buyck, 24, from Sodus, N.Y.

The aircraft belonged to the Marine Medium Tiltrotor Training Squadron 204 based at New River.

Coyle said in his recent report that the MV-22 was effective for its intended mission of delivering Marine troops ashore. But he said there were troublesome and potentially costly maintenance problems.

"I don't agree that the V-22 is a troubled program ... it is a maturing program,'' Marine Brig. James Amos told reporters on Nov. 30 in response to questions about the Coyle report.

Both Pentagon spokesman Ken Bacon and Amos, deputy director of aviation for the Marine Corps, stressed at the time that while there are always maintenance problems with new aircraft, those are ironed out and fixed over time.

Amos said problems with attaching cables and wires to the carbon airframe of the V-22 had been fixed along with some initial difficulty in folding the propellers and wings to make the aircraft better fit aboard navy launch ships.

"In terms of the costs of making the plane operate, the costs of keeping the plan operating, it (the Coyle report) does conclude that they could be lower,'' Bacon said.

"And the Marines are confident that the costs will be lower, and that they will get lower as they begin to get this into the force and they begin working on the plane.''

212man

12th Dec 2000, 21:14

Sad news. To put it in perspective though, what is the 'normal' accident rate that the US Army/USMC experience in night training? I gather it is quite high (in absolute numbers, not necessarily relative to the high hours flown).

Things don't auger too well for the '609 though, I guess it must raise questions of confidence in the basic viability of the thing.

------------------
Another day in paradise

HeloTeacher

12th Dec 2000, 21:19

It hasn't shaken my confidence, but unfortunately the common man on the street who isn't aware of the operating environment, newness of the design, or of the nuances of VTOL flight will carry the fear of tiltrotors long after this incident is put to rest.

We will have that much more work cut out for us later on...

widgeon

13th Dec 2000, 02:22

If you want to check out a particularly nasty thread on this see rec.aviation.rotorcraft , there is an almighty pissing match going on between the Bell Boeing and Sikorsky supporters.
Condolences to all close to the victims.

HeliFlight

13th Dec 2000, 15:54

You are right 212 man, we must keep it in perspective. The F117 crashed twice in one year, and it went on to have the most lethal accuracy rate of any aircraft in the Gulf war.

Fortunately I don't think it will have much impact on the 609 program because they are so far from first delivery. The newly announced schedule shows that customers won't be seeing them for over three years (1st quarter of 2004). But for the V-22 program it's real bad news. The pentagon was just about to decide on whether to go into an accelerated acquisition rate. The Marines are completely confident in tiltrotor technology after over 10 years of test flying it, but they won't be getting them as fast as they would like to.

Lu Zuckerman

13th Dec 2000, 18:35

Assuming that the mechanical and electronic systems are 100% reliable the major problem with the V22 is reparability. When I worked on the program, I had to assess the maintenance actions that would result from the failure of every composite structural element in the aircraft. In all of my years in the business of Product Integrity this was the first time I had to deal with structure. It seems that the US Navy is the only military service in the States that has elected to use this option of the specification governing the preparation of Failure Modes and Effects Analyses (FMEA).

Since the structural elements were made from composite materials they had no natural or generic failure modes. This meant that the only means of failure of function was to consider external mechanical forces that would cause structural failure. The way the V22 is constructed the entire back end was made of one-piece construction and all of the internal structure was attached to the tail section by clips.

If in fact the external force caused structural deformation or failure of the part under analysis the force necessary to cause the damage had to pass through the outer shell which is one piece. Although the predicted rate of occurrence was minimal it could be shown that the overall availability would be seriously effected. The very nature of the construction of the back end was that the repair had to be made under the same conditions as those used in the manufacture of the back end. This meant that they had to have a very large number of spares at the second level of maintenance or the entire back end had to be shipped back to the factory or overhaul facility.

Another problem (at least at that time) was the Navy had only one approved method of repairing structural composites. After completion of the repair the entire damaged area had to be X-rayed.
The problem was that the repair material was opaque to X-rays and the efficacy of the repair could not be determined.

The analytical approach to the damage process only considered external force trauma. Battle damage or, hard landings or being hit by a Stinger type missile were not considered. So when this composite monster gets down and dirty with the grunts it will be wide open to ground fire of all types and landings on unprepared strips will also take its’ toll. When it has returned to the Assault Ship it will most likely not be able to be repaired and as the assault goes on the attrition rate could be 100%.

I personally don’t think this part of the operational process ever got much thought.

------------------
The Cat

Tricky Woo

14th Dec 2000, 00:44

As always, Lu Zuckerman, you continue to surprise me as your deep involvement in some amazing projects...

However, while you raise some valid points as to the long-term viability of the airframe under harsh conditions, I think that the US Marines are going to be more concerned as to why two Tilt-rotors have fallen out of the sky in only a few months.

More development required?

offshoreigor

14th Dec 2000, 02:04

My condolences to the families.

I don't think we should be making such comparisons between the V-22 (Military, doing a military job) and the Bell/Boing 609 (Civilian offshore/Ambulance flying).

I think you could look at any type in the world that is both military and civilian and you would find similar accident rates weighted against the military. The nature of the job has certain built in risks that would be totally unacceptable to a customer in the civil aviation world.

I don't think the V-22 loss rate will affect the 609 program unless it too experiences similar losses.

Cheers, OffshoreIgor http://www.pprune.org/ubb/NonCGI/eek.gif

212man

14th Dec 2000, 02:12

I tend to agree, and to add to my earlier point: look at the Apache losses in Kosovo (well, they didn't actually get to Kososvo, but let's not rub that in!). Night training at low level is inherently risky and the accident rate bears that out. What I was trying to say was that it's 'perceived' viabilty by the buying client may be damaged. If they see hidden software or mechanical problems lurking and waiting to give them a headline grabbing bite, they may back off slightly from buying it.

------------------
Another day in paradise

Lu Zuckerman

14th Dec 2000, 02:15

To: Tricky Woo

I agree that the solution to the two crashes is paramount. However, the main reason that the V22 exists was that the Marines convinced the US Congress that the V22 was extremely reliable. If for a moment you could look at the V22 as a tandem rotor helicopter that can fly like an airplane they took comparitive reliability histories and proved the reliability of the V22 because they said it was made mainly of composite material which under all applications had proven to be more reliable than aluminum structure.

They said it was resistant to corrosion, it was resistant to exfoliation and it had a longer life than metal structure. When you manipulate the numbers in this way it is easy to prove your point.

This aircraft is far more sophisticated than a CH-47 and as such is subject to a lot of failures that would cause loss of the aircraft. In the design they tried to design out all single point failures but obviously they didnt.

One V22 was lost because they didn't take into consideration that flammable fluids could leak into the engine nacel and catch fire. A second V22 was lost because the flight control system and associated computer systems were miswired. Now, they have to determine what caused the last two crashes.

In my post above I eliminated mechanical failure and only addressed structural damage which could seriously effect the availability of the V22 Fleet. The mechanical and electronic problems will also add to the unavailability.

Regarding the Arizona crash which was blamed on too rapid a desent you may have read my previous posts on Just helicopters and possibly here on PPRuNe where I said that the V22 and the 609 were being certificated as a powered lift aircraft and there may be no requirement to demonstrate autorotation.

In those posts I indicated that a Boeing Engineer told me that the autoration decent speed was 4-6000 feet per minute. He may not have been autorotating when he crashed but it was said that the pilot was decending at to high a rate. Just imagine what will happen if the V22 has to autorotate and he does not have time to make a run on landing as an aircraft. They will have to install airbags in the seats for pilots and passengers.

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The Cat

Cyclic Hotline

14th Dec 2000, 10:08

The accompanying article details a couple of pertinent aspects of the seriousness of this accident, not only in it's timing, but also politically.
The aircraft was returning from a night landing training mission when the accident occurred. The crew issued a Mayday prior to the crash. The aircraft commander was the chief of the test programme and was to command the first operational squadron. The final build decision was to be made next week, and is being postponed until a full review is complete. All of this is occurring during a change in Presidential administration.
Dick Cheney (under the previous Bush administration} cancelled the programme, only to see it reinstated by the current administration!

Regarding the potential effects upon the AB609 (or other tilt-rotors), they must be considered significant. The manufacturers had envisioned generating considerable operational experience with the military programme. This allows a significant number of aircraft to be proven in the field and the identification and rectification of potentially hazardous conditions prior to an adverse condition occurring on a flying machine.

If the V-22 programme should be curtailed or cancelled, it might prove to be difficult for the operators to convince the customerthat the aircraft can be operated safely. This is certainly one of the highest priorities of anyone operating utilising,or insuring helicopters. Just look at the history of commercial helicopter operations, and the traumatic times that virtually every type has experienced, principally, but not limited to, the inception of service.

In the early operational stage of a new type, every flight is an exploration ito unknown territory. Every component and system is being exposed to the realities of operational, environmental and practical maintenance experience. This trend continues until the overhaul and life-limit cycle is completed and the knowledge from experience can be quantified. (The complexity of the Marine version of this machine must be seen to be believed - it is amazing.)

The secondary stage is the replacement of parts due to overhauls, life limits, maintenance related removal, or failure. In this stage the growth from experience continues during component overhaul. It also continues with the replacement of original parts with new, improved, or modified parts. There always remains the possibility that modifications or alterations may compromise the integrity of the original design, for a variety of reasons, including environmental conditions, corrosion, manufacturing defects, etc.

The tertiary stage is the mature aircraft, where the predictabilty and reliabilty of parts can be accurately forecast. The performance and envelope is known and understood. The maintainability of the aircraft is proven, and identifiable defects have been remedied. At this stage the longer term effects on airframes and non-removed systems become apparent. Skin and airframe fitting corrosion, flight controls and electrical wiring become primary areas for maintenance activity and inspection. There continues to be the risk of manufacturing production, material, or process defect in replacement parts during this phase, which may create previously unknown problems to occur. On condition items may ultimately display failure rates that determine appropriate action be taken to intercept failures.

The problem for any product is to successfully transition from each of these stages to the next. If you consider the commercial helicopters curently in the marketplace and the path to success from certification, the process is anything but predictable, and there is a real possibility of failure at each and any stage. At one point you couldn't give an S76 away, likewise the failure and removal of the BV234 Chinook from offshore support, is related directly to customer decisions not to utilize these aircraft (applies to other products also). The Wessex was withdrawn from service overnight, by the sole commercial operator of the model. When reliability and safety are not to acceptable and predictable standards for commercial operation, the customer walks away from the product and the operator is left holding the bag!

These are not theories, but proven experience in the helicopter (and aviation) world.
A couple of examples:
Sikorsky S61. Main Rotor Spindles,(Process, Design, Corrosion). CT58 Engine Turbine wheels (design and manufacture). Sikorsky S76. Main Rotor Spindles, (design, process). Main rotor mast (current). Allison C30 Engine (Engine lube system) Boeing Vertol BV234. Forward Gearbox (design, corrosion) Eurocopter AS332. Main transmission (design, materials). Main Rotor Spindles, (design, materials).

This could be a long list, Bell models, A-stars, Lycoming 101 engines, Allison 250 series engines, the Westland W30, but I'm sure you have the picture.

For the MV-22 and the tilt-rotor concept as a whole, the near future will hold some tremendous challenges. I am not suggesting the programme will not succeed, simply that the path ahead, is anything but clear, and the scrutiny the programme is attracting may affect it's marketability in the initial stages.

Marines Ground Osprey Fleet

By ROBERT BURNS, AP Military Writer

WASHINGTON (AP) - The Marine Corps' chief of aviation says the crash of an MV-22 Osprey in North Carolina should not be a "show stopper'' for the troubled $40 billion program. It appears increasingly likely, however, that it will be up to the next administration to decide whether to build a full fleet.

The Marines now plan to buy 360 over the next 14 years to replace aging helicopters. Three of the first 15 delivered - including prototypes and experimental models - have been involved in fatal crashes, including two this year that reduced the fleet of operational models from 10 to eight.

Four Marines were killed in the crash Monday several miles from Marine Corps Air Station New River, near Jacksonville, N.C. The four bodies remained at the scene Wednesday morning. The $43 million aircraft burst into flames upon crashing in a heavily wooded area.

The Pentagon (news - web sites) grounded the aircraft, and Defense Secretary William Cohen planned to appoint a panel of outside experts to review Osprey performance, cost and safety issues.

The tilt-rotor Osprey takes off and lands like a helicopter but flies like an airplane. Built by Boeing Co. and Bell Helicopter Textron, it is a linchpin of the Marine Corps' aviation future. The Air Force also plans to buy 50 of the aircraft, which have the potential to be adapted for a wide variety of missions.

Lt. Gen. Fred McCorkle, head of Marine Corps aviation, told a Pentagon news conference that the Osprey had been conducting night landing practices and was returning to New River when the pilot issued a distress call at 7:27 p.m. That was the last word from the Osprey before it crashed about seven miles from the base.

"Whatever is wrong with it - or if there was something wrong with it that caused this accident - we plan on finding out what it was and fixing it,'' the three-star general said. He said a flight data recorder had been recovered intact, but there was no immediate indication of what caused the accident.

McCorkle said he remained confident in the Osprey, despite the second fatal crash this year.

"I don't think this will be a show-stopper,'' he said, referring to the possibility of the program being canceled.

The Marine Corps already has spent $10 billion on the program.

If George W. Bush (news - web sites) is the next president, he will bring to Washington the man who tried unsuccessfully to cancel the Osprey program billions of dollars ago - Dick Cheney (news - web sites), who scratched the Osprey from the Pentagon budget shortly after he became secretary of defense in 1989. Congress put it back.

The Navy Department, which has responsibility for naval as well as Marine Corps programs, had been expected to make a final decision this month whether to approve moving the Osprey into full-rate production. On Tuesday, the day after the Osprey crash, the Marines asked that a decision be put off indefinitely.

The Marines had hoped to get the go-ahead for full-rate production this year and to field the first operational squadron next year.

Defense Secretary William Cohen, a supporter of the Osprey, is going to appoint a panel of technical experts to review the entire Osprey program, spokesman Kenneth Bacon said Tuesday. The review will focus on safety, performance and cost issues in light of Monday's crash and other issues.

Lt. Col. Keith M. Sweaney, 42, of Richmond, Va., the pilot of the Osprey that crashed Monday, was to become commander of the first Osprey squadron. He was chief of the Osprey testing program and had recently briefed top Marine Corps and Navy leaders on the aircraft's performance and suitability.

The three other victims were identified as Maj. Michael L. Murphy, 38, originally of Blauvelt, N.Y. and most recently of Wilmington, N.C.; Staff Sgt. Avely W. Runnels, 25, of Morven, Ga.; and Sgt. Jason A. Buyck, 24, of Sodus, N.Y.

Before becoming a test pilot for the Osprey, Murphy spent three years as one of the pilots flying President Clinton on the Marine One helicopter.

In April, an Osprey crashed in Arizona, killing all 19 Marines aboard. That stirred questions among the victims' families and in Congress about the Osprey's safety. The aircraft were grounded until June, and this fall, after more testing and evaluation, the Marines declared the aircraft to be "operationally suitable.''

At a news conference Tuesday, McCorkle, the Marine Corps aviation chief, expressed sympathy for the families of the latest victims.

He said the accident investigation board will be headed by a general officer - a more senior official than normal - indicating the seriousness of the problem.

"We want to make sure everyone knows that this is not `business as usual,''' McCorkle told reporters. "This program is very, very important to the Marine Corps, to me and I think to the nation, and we're going to work very hard to find out what happened.''

[This message has been edited by Cyclic Hotline (edited 14 December 2000).]

HeliFlight

14th Dec 2000, 15:30

Tricky Woo & Lu (that rhymes!),

There is no mystery about the Arizona crash that occurred in April. That accident was investigated and closed by the Marines, the manufacturers, and an independent investigation by NASA. They all came up with the same conclusion: pilot error. The pilot in the lead a/c lost his wings after the investigation. The V-22 developed settling with power due to a rate of descent in excess of 2000 fpm at 285 ft AGL! There was a quartering tailwind, 2100ft elevation, and 28 deg C. The pilot violently pulled full aft on the stick, rapidly decreasing a/s and developed the inevitable vortex ring state. Because of the unique side by side rotor configuration, it developed 'asymmetrical’ settling with power. If the wind was directly on the nose or tail, it would have been 'normal' settling with power, but it doesn't matter, they would have all been killed regardless. If you put a CH-46 in the identical scenario, the result would have been the same.

Look at the thread at <A HREF="http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000289.html" TARGET="_blank">http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000289.html</A>
This was the incredible discussion that started off slamming tiltrotor technology, and by the end, when the true facts were presented, it turned around into a positive discussion.

Lu is right about the other accidents. In the 11 ½ years it has been flying, there have been four V-22 accidents, three of them fatal. None of them though showed tiltrotor technology to be flawed. It seems that all of them could have been anticipated and prevented though.

Accident 1 (Jun 91): Miswiring of two of the three lateral cyclic inputs, crashed on first flight in a hover (no fatalities). Should have been caught by quality control at many levels.

Accident 2 (July 92): Ingestion of transmission fluid during transition to H-C mode. A simple drain hole could have prevented it.

Accident 3 (Apr 00): Pilot Error (see above).

As far as accident 4 (Dec 00), – the black boxes will tell. In the mean time, the press will have a field day slinging mud at the military as they always do (see Cyclic Hotline's post).

The bottom line is it’s not the technology that’s flawed, and 4 accidents of a military a/c over 11 ½ years is not out of line with what has been experienced with other a/c. As 212man said, we need to keep it in perspective..

[This message has been edited by HeliFlight (edited 14 December 2000).]

[This message has been edited by HeliFlight (edited 16 December 2000).]

UNCTUOUS

16th Dec 2000, 00:06

Subject: V-22 Settling Problem Disclosed, Navy Claims It's Unrelated ToMishap

Inside The Navy
August 21, 2000

V-22 Settling Problem Disclosed, Navy Claims It's Unrelated To Mishap

An audit of the V-22 Osprey program by the Pentagon's inspector general reveals officials knew a year ago the tiltrotor had a problem with "settling due to loss of interim power" but decided the deficiency was not important enough to immediately spend money correcting it.

The report discloses for the first time that military testers identified a specific settling deficiency associated with the V-22 last September, and Osprey program officials labeled the problem "nonmajor" and not worth fixing before the start of operational testing and evaluation, the phase in which Marines were participating at the time of an April 8 crash that killed 19 Marines. Such deficiencies are valid but do not restrict the V-22 from meeting its mission, the audit report says.

V-22 program officials told Inside the Navy last week the problem is minor and not related to the phenomenon called power settling that is believed to have contributed to the fatal April 8 Osprey crash.

The Marine Corps and the Defense Department have a lot riding on the V-22, which operates like a helicopter for takeoffs and landings and, once airborne, converts to a turboprop plane. The Marine Corps is buying 360 of the aircraft and the Air Force is buying 50. Defense Secretary William Cohen has predicted all of the military services will one day rely on tiltrotor technology. A team of Bell Helicopter and Boeing builds the high-profile V-22.

At press time, the V-22 program office told ITN in brief comments the settling deficiency is not related to vortex ring state, nor related in any way to the mishap, even though the words used in the DOD IG report to describe the problem echo terms used to explain the fatal April 8 crash.

"Interim power is selectable by the pilot and provides for additional rotor thrust and power margin up to mast torque values of 109 percent at a rotor speed of 103.8 percent Nr," the program office said in a written statement to ITN. "By design, interim power is deactivated at nacelle angles less than 80 degrees or airspeeds greater than 50 knots."

ITN has learned that V-22 pilots who fail to observe certain airspeed and rotor-angle rules can lose interim power, causing the aircraft to settle without warning. While this concern was noted by military testers, Rear Adm. John Nathman, then the Navy's top aviation requirements official, said last September the program could proceed to operational evaluation without immediately fixing the problem. Officials maintain this issue is not a serious safety concern. The Navy's response to the DOD IG report,
published with the audit on Aug. 15, claims the deficiencies described are "in no way safety related."

For months, the Marine Corps has publicly dismissed the possibility that the V-22 might be especially susceptible to the vortex ring state.

"No, absolutely not," Lt. Gen. Fred McCorkle told reporters on May 9 when asked if there was is any evidence to suggest the V-22 is more susceptible than other rotorcraft to power settling or settling with power. McCorkle, the assistant commandant for aviation, said he believes the V-22 is less susceptible to such conditions when compared to other helicopters. "In fact, I would say [the V-22 is] less [susceptible] because of the amount of power that it's got." That day, McCorkle also said the mishap investigation was "concentrating on flight characteristics which are not peculiar or unique to the V-22 but can be experienced in all our helicopters . . . or any others in the world."

The Marine Corps concluded the mishap aircraft was piloted into a descent that was too rapid and steep. That flight induced the "vortex ring state" or rotor blade stall, which caused an asymmetric loss of lift of the rotors, the service announced. The pilots of the two aircraft involved were deemed responsible for the mishap and those from the surviving aircraft were disciplined.

When the Marine Corps Judge Advocate General investigated the recent Osprey tragedy, it concluded the mishap did not appear to be a result of any design, material, or maintenance factors specific to tiltrotors, but the JAG noted it is relatively unusual for the contributing factors in this mishap to cause the loss of a helicopter.

"It's primary cause, that of a MV-22 entering a Vortex Ring State and/or blade stall condition is not peculiar to tiltrotors," the JAG report states. The contributing factors to the mishap -- a steep approach with a high rate of descent and slow airspeed, poor aircrew coordination, and diminished situational awareness -- are also not peculiar to tiltrotors, the report continues. "However, the end result, departure form controlled flight, is more extreme than results experienced in most rotorcraft to date," the JAG report concludes.

When the service released copies of the JAG report, the opinions and recommendations sections were deliberately omitted, leaving unresolved key questions about their contents.

It is well documented that the vortex ring state is powerful and dangerous enough that pilots of rotorcraft caught in the unstable flight condition can lose control of aircraft if they fail to take proper action. Rotorcraft caught in the state require an unusual amount of power to maintain rotor thrust. The term "power settling" comes from pilots' observations that in some cases a helicopter keeps coming down even though full engine power is applied, according to "Practical Helicopter Aerodynamics" by R. W. Prouty.

The V-22's settling problem is one of the "nonmajor" deficiencies referenced in the Naval Air Warfare Center's integrated operational assessment, which was completed on Sept. 20, 1999. The NAWC report, which said major tests planned for the V-22 were not completed, identified limitations in major operational effectiveness. Additional testing would be needed to resolve certain critical operational issues, the NAWC concluded. However, fixes would not be in place to support operational evaluation testing. NAWC recommended various flight envelope and mission limitations, and prohibited maneuvers and operations for operational evaluation testing. However, despite the limitations, that report recommended the V-22 proceed to operational evaluation testing.

Some key Osprey problems -- such as those concerning the cargo handling system and protection from nuclear, chemical and biological agents -- were given high priority and the program office made plans to correct them during operational testing, the report indicates. Other deficiencies, including the settling problem, were dismissed by the program office as lesser issues, according to the DOD IG report.

The V-22 program office believed it "did not need to delay operational test and evaluation or to commit scarce program resources" to correct the settling deficiency before operational test and evaluation, the report states.

Pentagon spokesman Rear Adm. Craig Quigley spoke generally about the V-22 audit on Aug. 17.

"Let me just say everybody wants this system to work properly," Quigley said. "It is in everybody's interest that a good, tough review of the program at all levels be conducted. But as with any other new aircraft development program, there are going to be bugs in it."

Quigley said the Pentagon looks forward to rigorous testing and reviews of the V-22 program to find bugs, "so that those responsible for the program can work out a plan to correct them and come to an aircraft that will serve our military well for many years to come."

The admiral said reviewing and fixing problems with the V-22 is not something officials are shying away from. "We welcome the closest possible scrutiny of the program at all levels, so that we can all work towards a good aircraft that's safe and reliable and affordable and meets all of our criteria by the time it's put into the field," he said.

-- Christopher J. Castelli

UNCTUOUS

16th Dec 2000, 00:23

Lunch this week with Tom McDonald after the RAEs Lecture that Tom gave (as part of Farnborough). They are very apprehensive about the "settling with power" situation for a number of reasons (which I'll address shortly). So no-one should expect the Farnborough display by the V-22 to include much of a "wringing out". The draft GAO Report, of which I have a copy thanks to an insider, indicates a distinct reluctance to refer to more than a "power settling problem". It does not mention Marana nor AsymmVR (per se) and hides the sole reference amongst many other quite innocuous house-keeping style engineering underway fixes. It's this report that will decide the October go-ahead on production. So it would seem that they are still in denial and I can understand that after all the time, effort and expense.
McDonald offers no excuse for the exclusion of VR or AsymmVR from the FlightTest Program. As I have pointed out before, much of what should have been done in wind-tunnels was achieved parametrically via high-speed computation and the VMS (vertical motion simulator). I'd have thought Blind Freddy could have picked the flaw in this approach - however no-one did.
There were other reasons for it. Just like simulator time, actual blowing wind-tunnel time was at a premium so they had to go over and use a Dutch Tunnel for essentials. It was also a fact that commercial pressures related to noise certification for the FAA of the 609 changed all their priorities for testing somewhat. Whatever, it all fell through the cracks.
McDonald showed slides of a V-22 in a frightening momentary >40 deg AOB towards the island during its flight-deck trials. It was the only one of 330 deck approaches that came unstuck. Theory now is that it wasn't really the PIO that it was then ascribed to, it was a transient settling condition (i.e. AsymmVR) caused by transitting the bad air abaft the ramp. It's quite possible depending on carrier speed and relative wind to get quite bad transitory turbulence effects (from the island) just behind the ship.
Normally an F14 or such-like is quickly through such turbulence but an Osprey is at a low IAS and quite vulnerable at that stage. Perhaps it's why all the Harrier approaches terminate abeam their spots and they then cross the deck sideways to alight. Of course a transient condition caused by bad air is much different to the ingrained condition caused by self-induced flight parameters entering the VR envelope.

I assume you are not PTI-UAE. I was becoming quite bored with the exchange with him simply because he wasn't addressing the issues directly. I found his come-backs very trite. He obviously has a vested interest. However I have had quite a number of emails asking for a response/further input so I may do that soonish - time permitting. I imagine that (from your address)
your company can see itself getting necessarily involved in the 609 and has become a "stake-holder" so to speak. I myself am quite supportive of the project but the admissions by McDonald plus some other project insights that I've had (Pentagon level and USMC) make me very wary that suppression of genuine concerns about the basic concept has become the order of the day.
Only time and a concerted effort to define the safe flight envelope will prove me wrong. Defining a safe flight envelope and providing an acceptable buffer zone without unduly limiting the V-22 will be a huge challenge. In other words, Marana is eminently repeatable - notwithstanding any errors that may have been made by the lead ship or the accident crew.

If you were to ask me for a solution I would offer up increasing the number of blades and going for greater disk solidity. That tends to cut down the vortex size, intensity and delay the VR threshold. McDonald agreed that they do need a fix of some sort that will take care of the incipient condition. But I'm betting that that will not become any sort of priority until after the next accident. Some correspondents have asked me why it's of any greater concern than the wing drop that you get at the FW stall. My easy answer to that is that anyone with any situational awareness can tell that he's near that stall and can take normal stall recovery (including some rudder to halt the further wing drop). As he adds power and unloads, a FW pilot will fly it out and the asymmetry will have been of no great concern (except in an accelerated "g stall" involving a "flick" roll -
but that should never be the case near the ground). The Marana accident did involve something akin to a "flick" roll, it always will. The instinctive corrective action (differential collective applied laterally through the cyclic to pick up the dropping wing) is the one thing that is always going to greatly exacerbate the condition into a rapidly terminal roll. So if we simplistically take the MV-22B at Marana (as a function of total V-22 flight hours to that date) or the 1/330 deck approaches and extrapolate this across a 400 aircraft military fleet, I calculate a loss at about every 12,700 hours of Mil V22 flight hours (in a fully mature fleet circa 2007)- about four times a year to AsymmVR. Whether this will be acceptable or not as an attrition rate remains to be seen. Because it's a people carrier it's not really the same as losing an F16 every so many flight hours. After a few accidents, Marines will have to be boarded at gun-point.

This is just a quick note and I have other thoughts on the subject so if you
have any response, criticisms or inputs I'd be glad to receive them. Perhaps
you'd like to address them on that same thread on Pprune.

regards

>From: [email protected]
>To: [email protected]
>Subject: Vortex Ring
>Date: Mon, 10 Jul 2000 14:10:04 EDT
>
>Jim -
>
>Back on May 16, you provided us with an interesting perspective on "That
>Vexing Vortex Ring." Is there any more recent information that would cause
>you to expand upon or change the theories expressed in that communication?
>
>Many thanks.
>
>Rhett Flater
>AHS Executive Director

UNCTUOUS

16th Dec 2000, 00:31

It's not likely that this latest MV22 accident was Asymmetric Vortex Ring
(asymmVR). They have been having troubles with the cross-ship drive-shaft
couplings that link the two rotors (and that were designed to resolve the
problem of engine failures i.e. the power-plant itself).

However transmission failure, drive-shaft, couplings etc are not the V22's
biggest potential failing. These are hardware problems and not "designed
in". The asymmVR problem is such that, once encountered, it is a fatal
conclusion. As far as I know, nothing that has been done or trialled during
the months of recent proving flights at Patuxent River have circumvented
this fact of life. Recovery is possible, recognition and height permitting,
in a normal helo but the unsubtle asymmetric nature of it in the Osprey
simply means that recovery (as for a "dropped" wing) simply exacerbates the
condition and increases the terminal roll-rate. Marine and Eval Team
attention has been concentrating on avoiding the condition. Unfortunately
the type of dynamic flight profiles that a combat aircraft will fly simply
means that the condition will always be lurking at the edge of that flight
envelope - and very definitely EASILY encountered.

It's indeed a pity that the designers didn't do more design proving and
tunnel-testing because it became slowly obvious (after the Marana crash)
that the problem is married to the tri-bladed prop-rotor decision. A four-bladed prop-rotor design
would be much less likely to encounter VR and a five-bladed rig supposedly
would not. This trend away from VR susceptibility is a function of
rotor-disc "solidity". The tri-bladed prop-rotor was decided upon as a compromise
between span and blade technology management (weight and complexity of the
pitch-control at the rotor-head and tilt mechanisms).

At this late stage of development (of both the Osprey and 609) asymmVR is a
disastrous failing. I honestly don't see how they could certify a civil
variant of the V-22 or the 609.

It would now appear that the Osprey has more than one basic design problem. If asymmVR wasn't bad enough, there is now evidently also the problem wrought by the failure of the cross-ship drive-shaft and its intricate coupling. As you can appreciate, without it a donk failure on one side would be uncontrollable - so it was a facility logically and necessarily provided in order to accommodate an engine failure. However, if that facility itself fails, the only solution in airplane mode is to uniformly and simultaneously flatten the blade-pitch on each side, and enter autorotation by "tilting" the nacelles toward helicopter mode (wherein the airflow - and not the engine- is driving the blades ). My spies tell me that the Marine Corps does not permit full-blown entry into auto-rotation for practise. My guess is that whilst it may have been a real engine failure, it was more likely brought about by a simulated (training) failure. Recent failures associated with the cross-ship drive have been "warning lights". I assume they'd be eccentricity, overtorque or chip detector lights for gear-box oil.

In the engine failure case, the cross-ship drive should enable full controllability. However if the cross-ship drive failed, they would have to very quickly reduce the good engine to flight idle. The differential thrust of flight idle on one side (and a truly dead donk on the other) would soak up much of the differential collective control available - i.e. they would thereafter simply run out of lateral controllability as they reduced airspeed near the ground (simply because the aileron's aerodynamic control effectiveness diminishes as forward speed is lost). What they needed to do (but which would have required the mental agility of the Shadow and the reflexes of J.C. Van Damme) was to flame-out (fuel-chop) the other engine also. However this then diminishes the hydraulic and electrical generating capability somewhat - so firstly they'd have to start the APU. Not likely in the time available I hear you saying. So, in these circumstances, slowing down for the classic helicopter-style autorotative zero-groundspeed arrival was not an option. Perhaps it needs an auto-deploying RAT (ram air turbine).

But I would guess that this highly experienced MV-22 crew found the fatal flaw in the design whilst simulating engine failure (i.e. by winding back one engine to flight idle). If the cross-ship drive-shaft or coupling failed under the torque-stress of wind-up or -down, the drag on the simulated inoperative engine's reduction gear-box would likely lead to a loss of RPM/decreased pitch on one side and a resulting rolling moment. You then have a similar (to engine-failure case) differential residual thrust situation - both engines at flight idle but one carrying the drag of the cross-ship drive. I'd guess that no weak-link was able to be built into the cross-ship system - or even a manual disconnect - it having to be capable of carrying the power in either direction.

I've nursed a sneaking suspicion about the cross-ship drive being unequal to some situations. A gracefully degrading engine or even a sudden flame-out would probably not transfer excessive torque to the drive. But an uncontained failure, engine seizure, transmission gear-box failure? Any of these would be hard on a drive that passes large amounts of raw power through angled-drive gear-boxes - and so I'd guess those gear-boxes and couplings are probably the Achille's Heel in the system.

So stand by to be fascinated as the tester-boys at Patuxent River try to find a way around this major glitch - assuming that I'm right in my analysis of what's been disclosed. As I've been saying all along, the lack of real tunnel-testing and an over-reliance on computational modelling has led them into one bind after another. Garbage in, garbage out is not necessarily the same processed problem as "nil entry always equates to nil result". IMHO that's why test-flying and tunnelling was first utilised. It always disclosed problems that you never dreamed existed. And if you never suspected them, how could you ever model them for computational number-crunching. If number-crunching is now your primary proof-testing method, you must be prepared to learn further in the hard school of knocks. The USMC is rediscovering that truism.

But it's good to see Gen McCorkle on CNN supporting the Osprey to the hilt. What else is a Marine General to say?

[This message has been edited by UNCTUOUS (edited 05 February 2001).]

HeliFlight

16th Dec 2000, 01:29

Hello Unctuous,

It’s so nice to see you are back. You got the biggest public spanking since Saddam Hussein in the Gulf war, one that will go down in history. Your cheeks are still obviously glowing RED!! Please tell us why you hid yourself for six months in shame and took six months to return (your last post was 29 May). A little bit morbid of you to return when you see an opportunity to try and twist the facts again. PTIUAE may have been trite to you, if that’s how you describe the guy holding the paddle (along with John Farley, the development test pilot for the Harrier). All of us on PPRune have been waiting for you to reappear. It’s great to have you back. Please tell us what other user names you have been using in the mean time (over the last six months) to hide your identify (those glowing cheeks will always give you away though!) From the length of your posts, you obviously haven’t lost your long windedness. The facts though, still seem to be overridden by your “theories.” Distortion sometimes takes a little extra effort.

Regarding recent accidents, here is some FACTUAL input that has been recently posted:

There is no mystery about the Arizona crash that occurred in April of this year. That accident was investigated and closed by the Marines, the manufacturers, and an independent investigation by NASA. They all came up with the same conclusion: pilot error. The pilot in the lead a/c lost his wings after the investigation. The V-22 developed settling with power due to a rate of descent in excess of 2000 fpm at 285 ft AGL (this is a 57,000lb gross wgt a/c!! – a lot of momentum to stop)! There was a quartering tailwind, 2100ft elevation, and 28 deg C. The pilot violently pulled in MAX power, and pulled FULL aft on the stick, rapidly decreasing a/s and developed the inevitable vortex ring state. Because of the unique side by side rotor configuration, it developed 'asymmetrical’ settling with power. If the wind was directly on the nose or tail, it would have been 'normal' settling with power, but it doesn't matter, they would have all been killed regardless. If you put a CH-46 in the identical scenario, the result would have been the same.

In the 11 ½ years that the V-22 has been flying, there have been four accidents, three of them fatal. The most important fact is that none of them showed tiltrotor technology to be flawed. However, it appears that all of them could have been anticipated and prevented.

Accident 1 (Jun 91): Miswiring of two of the three lateral cyclic inputs, crashed on first flight in a hover (no fatalities). Should have been caught by quality control at many levels.

Accident 2 (July 92): Ingestion of transmission fluid during transition to H-C mode. A simple drain hole could have prevented it.

Accident 3 (Apr 00): Pilot Error (see above).

Accident 4 (Dec 00): – the black boxes will tell. In the mean time, the press will have a field day slinging mud at the military as they all too often do (and Unctuous will join right in).

The bottom line is that the technology is sound and proven -- 4 accidents of a military a/c over 11 ½ years is not out of line with what has been experienced with other a/c, and in fact, it is much better than most. As other professionals in the aviation community keep emphasizing, “we need to keep it all in perspective…”(the Wright Brothers had it much worse than this, but thankfully they didn’t give up!!)

By the way Jim, I am sure you will be posting heavily in an attempt to exonerate yourself, and I must warn you in advance – there will be testimony from your own worst enemy against you – YOURSELF (your earlier posts in this thread, so please try to keep it consistent - thanks)

[This message has been edited by HeliFlight (edited 16 December 2000).]

HeliFlight

16th Dec 2000, 02:51

Also Jim,

I noticed that the e-mail you "acted" like you were responding to above was sent to you in mid-July. Can you explain why you waited 5 months to respond, and "acted" as though you were responding directly to his inquiry!?

I'm sure this will be a good one if you do decide to answer it!

Happy Holidays, Jim

>From: [email protected]
>To: [email protected]
>Subject: Vortex Ring
>Date: Mon, 10 Jul 2000 14:10:04 EDT
>
>Jim -
>
>Back on May 16, you provided us with an interesting perspective on "That
>Vexing Vortex Ring." Is there any more recent information that would cause
>you to expand upon or change the theories expressed in that communication?
>
>Many thanks.
>
>Rhett Flater
>AHS Executive Director

[This message has been edited by HeliFlight (edited 15 December 2000).]

UNCTUOUS

16th Dec 2000, 11:37

Marines' Osprey is just an albatross
J. Stryker Meyer
Commentary
The Marine Corps calls its controversial MV-22 tilt-rotor hybrid aircraft the Osprey. A better name would be the albatross. Or perhaps, the killer albatross. If Dwight Eisenhower were alive, he'd point to the MV-22 as the epitome of how the military-industrial complex can foist an inadequate aircraft upon the military at great expense to taxpayers.

On Dec. 5, a decision will be made whether the MV-22 should go into the first round of full production by Bell Helicopter-Boeing. The production schedule calls for 360 of the aircraft with 38-foot prop-rotors to be built at $40 million to $70 million each.

It is billed as the future of Marine Corps aviation. It can fly like a turboprop airplane and while in flight, the wings rotate upward, with the nacelles locking into place above the aircraft, giving it the flight characteristics of a helicopter. It's supposed to replace the aging, Vietnam-era helicopters, the CH-46 and CH-53. If the green light is given, American taxpayers will spend billions on an aircraft that many specialists say has a fatal design flaw and has failed to live up to its performance criteria. The aircraft that has moved through the military and congressional approval process with serious flaws hidden from Congress and the public by obfuscation and deception blanketed under an iron veil of military secrecy.

As a military affairs reporter for the North County Times, I covered some aspects of what the military calls its operational evaluation, in which it tests the aircraft on a day-to-day basis. I've flown in it, talked to mechanics who have worked on it and to brave, dedicated recon Marines who have flown in it. I've also talked to knowledgeable skeptics who say this albatross should be buried before it kills more young Marines during training missions.
Here are some of the reasons it should be terminated from military use. The aircraft has a fatal flaw. It's called power settling, or asymmetrical vortex ring state. Power setting occurs when one prop-rotor loses its lift capability while in flight. When that happens, the other prop-rotor continues to grip the air, pulling the aircraft upward and into a roll before turning toward the earth and plowing into the ground with deadly force, as the MV-22 did in an April 8 crash in Marana, Ariz. It crashed during a test flight, carrying 19 Marines, killing everyone aboard.

The Marine Corps laid blame for the crash on the pilots, saying they exceeded the flight parameters of the aircraft. The military says the pilots exceeded the recommended rate of descent of 800 feet per minute. But some critics have asked when that rate of descent was placed in the training manual for the MV-22. Was it before or after April 8? One source said it was placed in the manual in June.

Neither power settling nor asymmetrical vortex ring state were programmed into computer-controlled flight simulator programs that the pilots used while learning how to fly the MV-22. They had to log a minimum of 65 hours on the flight simulators, yet there was no training in place for power settling. In May, Helicopter News editor John R.
Guardino stated, "There is a serious knowledge gap concerning the Osprey and (power settling).
While the phenomenon affects all helicopters, it may pose a special (asymmetric) challenge to the MV-22."

Many of the early pilots for the MV-22 were drawn from fixed-wing aircraft. Helicopter pilots learn about power settling and train for it. But with this new bird, little if any training was conducted on power settling. Now the Navy and Marines are looking into having power settling programmed into their flight simulators.

During the operational evaluation and early tests of the MV-22, to save time and money, the more dangerous flight profiles such as power settling were not tested. The fact that test pilots cut corners by flying only the less dangerous profiles is documented in an accident report, one insider said. However, neither the public nor the families of Marines killed on April 8 will ever see the critical comments in the accident report. And the pilots' flight logs, which document problems and concerns with the MV-22, are not available for public scrutiny.

It wasn't until 21 Aug that test pilots attempted to duplicate some of the crash conditions at Naval Aircraft Test Center in Patuxent River, Md., Marine Corps Col. Nolan Schmidt, the V-22 program manager, told "Inside The Pentagon" magazine. The military boasts about the MV-22's ability to fly farther than any helicopter, with midair refuel capabilities, and to carry huge amounts of weight...and the MV-22 may be good for routine ferrying of troops and cargo. Yet even in that area, there is a concern. Buried deep in one report is the fact that it takes 20 minutes for military personnel wearing goggles to unload a vehicle from the MV-22. The vehicle fits so tightly into the aircraft that air crew members have to be careful not to tear the inside of the aircraft when removing it.

Also, special aluminum planks have to be placed inside the MV-22 before a vehicle is driven inside it, because without those planks the aircraft floor can't support the weight of the vehicle.

I have an opinion about this, stemming from my days in Vietnam, when I ran top-secret reconnaissance missions into Laos and Cambodia during two tours of duty with Special Forces. A key to recon team success on a mission was quick insertion into a target area. I've been inserted into targets by Air Force, Army and South Vietnamese pilots. The key was a quick approach into the landing zone, and our six-man recon team exiting the helicopter quickly, running to the wood line as the aircraft hastily exited the area.

The MV-22 can't approach a landing zone as quickly or as hard as a helicopter. The MV-22 has to spend more time on the landing zone than a helicopter because the men inside have to exit down a rear ramp. With the old UH-1H, or Hueys, and today's modern UH-60, there are two doors, where the men can watch the ground as the ship approaches the landing zone, while others can watch the wood line for enemy forces.

In the MV-22, there is no observation option. There are no defensive weapons. On the helicopters, there are door gunners on each side. With the MV-22, the men inside are blind to the target until the tailgate goes down.

I hope I'm wrong about more Marines dying in training in the MV-22.
The Marine Corps' rotor aviation wing finds itself between a rock and hard place. The helicopters they're flying are old and require extensive maintenance. Marine leaders have banked their future on the MV-22, instead of the modern CH-60 helicopter. Yet mechanics on MV-22s say intensive labor is needed to keep these new aircraft in the air. What will happen after they've been around for a decade or two?

There should be a full congressional hearings on the MV-22 before any funding is approved for full production. The hearings should feature the men who actually fly the aircraft, the critics who have seen the problems and have been stifled from speaking publicly. The hearings should present testimony from flight crews, not the likes of Col. Schmidt or any of the generals who want the MV-22. A GAO investigation of the MV-22 has turned up damning information. However, the GAO moves slowly and no time has been set for the release of that critical report.

J. Stryker Meyer is a North County Times staff writer.

11/26/00

HeliFlight

16th Dec 2000, 13:14

Osprey seen rising despite deadly crashes

By Chris Stetkiewicz

SEATTLE, Dec 12 (Reuters) - Despite two crashes killing 23 Marines in the last eight months, the versatile MV-22 Osprey tilt-rotor aircraft will probably survive an intense Pentagon probe and move to full-scale production, defense analysts said on Tuesday.

The U.S. Marine Corps has no other option for replacing its aging fleet of CH-46 troop-transport helicopters and will push hard for the Osprey designed to take their place.

"Unless they find a problem that is unfixable at any cost, the Marines have to go forward. They have mortgaged the future of their rotary wing fleet on the Osprey," said Joseph Collins, a senior fellow at the Center for Strategic and International Studies.

"There is no walking away from it," added Collins, a retired U.S. Army colonel.

Taking off and landing like a helicopter but flying like an airplane, the MV-22 can ferry troops twice as fast and twice as far as the Vietnam War era CH-46, vastly improving responsiveness and rescue capacity, analysts said.

"This thing is pivotal for the Marine Corps. If it doesn't happen its whole concept of operation comes unraveled," said Loren Thompson, defense analyst at the Lexington Institute, a Virginia-based think tank.

PRODUCTION ON HOLD

The Pentagon postponed a decision on MV-22 production that had been expected next week and the Marine Corps grounded its eight remaining MV-22s after four Marines were killed on a training flight crash in North Carolina on Monday night.

Last April 19 Marines died in an Osprey crash in Arizona that was blamed on pilot error.

For the Osprey's builders, led by Boeing Co. <BA.N> and Textron Inc. <TXT.N>, the program represents up to $30 billion in U.S. and overseas military sales, though experts said the delays could add to the cost of building the hybrid aircraft.

"Obviously they have to find out what the problem is. If it is pilot error again, it would seem like this is a pretty difficult thing to fly," said Paul Nisbet, aerospace analyst at JSA Research in Newport, Rhode Island.

"If it crashes with that kind of frequency they have to fix it to make it easier to fly," Nisbet added. "Obviously when you are ferrying passengers it can't be too frequent."

Seattle-based Boeing called the decision to delay the production "prudent," adding that it shared the Pentagon's safety concerns but noting the Marines' enthusiasm for the Osprey.

"We continue to feel as enthusiastic as our customer that this is the only replacement... for the CH-46," said Doug Kinneard, a spokesman for Boeing's Philadelphia-based rotor craft unit.

On the New York Stock Exchange Boeing shares rose 3/4 to close at 69-1/8 on Tuesday, while Textron shares fell 13/16 to finish at 46.

Previous mixed-use aircraft, such as the hovering Harrier "jump jet" flown by the Marines, have suffered higher crash rates than fixed-wing aircraft, but have survived because they serve particular needs, analysts said.

"They are difficult, but I think this problem will be worked around," Nisbet said.

MIXED POLITICAL SUPPORT

Politically, the MV-22 has strong support in Pennsylvania and Texas, where it supports jobs at plants run by Boeing and Textron's Bell Helicopter unit.

But ironically a win by Texas Gov. George W. Bush over Vice President Al Gore in their battle for the White House might not bode well for the Osprey.

Bush's running mate Dick Cheney fiercely opposed the Osprey when he ran the Defense Department under Bush's father, former President George Bush.

"Bush has already promised a comprehensive assessment of all defense aviation programs," said Jay Behuncik, defense specialist at Washington Analysis Group. "What happened today is hardly helpful. It throws up a huge question mark."

Still, Behuncik joined others in predicting the Osprey will survive, driven as much by necessity as anything else.

"This is one of the Marines' top priorities. They are certainly not going to disavow that need," he said.

18:53 12-12-00

HeloTeacher

16th Dec 2000, 17:12

I have a solution, put fewer airplane pilots into a helicopter. VRS is not a great revelation to us.

HeliFlight

16th Dec 2000, 17:55

Exactly right HeloTeacher. Too bad Unctuous isn't able to make the obvious connection. He's too busy trying to make the accident fit his fantasy theories that have been proven wrong by the test pilots and investigators. The ability to recognize what is obvious to a helicopter pilot is what is needed, not a new design.

As I mentioned in another post regarding the Arizona accident, the PIC's experience was nearly 3800hrs total time but not much in a helicopter (35.7 in TH-56, 20hrs in CH-46 and CH-53, and only 97.2 in tiltrotors). The copilot had more helicopter experience (although even less tiltrotor time than the PIC) but he was apparently retrieving something from the floor that had distracted him (accidents are almost always a chain of events). Indications are that neither pilot recognized the symptoms of settling with power. It appears that their applying full power was an attempt to arrest the rate of descent. Using experienced helicopter pilots with a tiltrotor is the only thing that would make sense from a safety standpoint (the MV-22 is replacing the Marine CH-46s and CH-53s).

But not only is that not always the case, the problem gets worse when you add to that the fact that General Blot added the 'Blottle!' For those that are not familiar with it, that is the nickname given to the ‘power lever’ in a V-22. Originally it worked just like a helicopter collective – you pull it up and you increase the power and collective pitch, push it down and you reduce power and collective pitch. General Blot took a flight in the V-22 when he was in charge of the initial Osprey program. Having come from a Harrier background, he said, “get rid of that, I want a Throttle type configuration” similar to the Harrier. The result was that the guys that would be most qualified to fly tiltrotors (helicopter pilots coming into the program from CH-46s and Ch-53s) had to contend with required responses opposite to what had been ingrained through their experience.

This can be directly attributable to the first crash of a V-22 in 1991. The a/c had 2 of 3 fly-by-wire systems miswired in the lateral cyclic so that moving the stick left rolled the a/c right and vice-versa. On the very first test hover of the aircraft, the pilot, Grady Wilson, entered an unstable condition after entering the hover and didn’t know what the problem was. He got the a/c down onto the ground before serious problems occurred, but when he experienced a hard bounce and started to go airborne again, he reverted to old helicopter habits (as many of us would) and ‘pushed down on the collective.’ This of course meant pushing forward on the “Blottle” and resulted in an increase in power that launched the a/c into the air. That’s where the lateral cyclic control reversal took effect, the a/c rolled over and was destroyed. Incredibly nobody was seriously hurt. Thank goodness common sense prevailed with the 609 and they went with a more sensible collective style movement.

SPS

16th Dec 2000, 18:31

This might be overly simplistic but I'll
throw it in anyway.

VR - Well understood to be made worse if an
unwary Pilot increases pitch (and therefore
angle of attack) and adds power (therefore increasing induced flow) by raising collective, misguidedly thinking this action will arrest ROD.

The problem is related to the volume and speed of induced flow as more recirculation is encouraged by more induced flow.

So, much more likely that VR would be encountered at large angles of attack and high volumes of induced flow.

The blades of the V22 seem to have a lot of pitch applied in design. Their relatively small disc area suggests a high induced flow. Are they close to the line already?

If close to critical, the discs (or just one of them) would not need much of;
(A) an updraft to further oppose induced flow, thereby increasing recirculation (doesn't matter if the upward relative airflow is due to ROD or updraft)
or
(B) a downdraft increasing induced flow and pushing down the wing at the same time, encouraging the pilot to lift that wing by pulling more pitch...increasing induced flow...

At least in a Heli we can fly forwards and out,(if we have the height) no 12 seconds to wait.

I hope a lot of work now gets done on investigating this, whatever the General says.

SPS

UNCTUOUS

16th Dec 2000, 21:10

SPS - well said (and beat me by moments)
HeliFlight
It would be more productive if you addressed specifics instead of waffling on boorishly. It doesn't help your credibility and just makes it apparent that you are either being tasked to respond contrarily on this forum or are a "vested interest" (or both). So please try to keep it professional and in keeping with the high standards of most of this thread. It's probably being read by people who have a personal (and not just a vested) interest. If you disagree, do it point by point - and validate your opinions.

It would seem that there is a REAL problem in getting across to the USMC and some on this forum that Osprey asymmVR and simple settling with power (aka VR) are two different birds (although of the same feather).

VR: Helicopter
Recirculation leading to high rate of descent during steeper approaches to an LZ or OGE hover. Condition exacerbated (i.e. rate of descent increased) by the instinctive addition of power. Recognition sometimes delayed due to diminished depth perception (night) / ground-rush appreciation (at higher levels). Recovery is normally accomplished by forward cyclic and "flying out" of the vortex (an overshoot). Environmental factors include high density altitude, high AUW, steeper approaches and calm (or tail-) wind components on approach. In some types (eg UH-1, Kiowa) it can also be aurally detected as a distinctive background blade-sound level change. Onset is normally rapid and initial instinctive pilot response of increased collective is normally required to accentuate the condition and stimulate recognition. Night and NVG onset is frequently unrecognised due to poorer visual cues. Condition is best avoided by consciously arcing under rather than committing to a constant angle steep approach (or worse, an arcing-over approach - one that becomes latterly steeper due to tailwind). Rarity? Rare enough to almost always make it a nasty surprise.

asymmVR TiltRotor
Induced recirculation on one side only (i.e. always asymmetric due to differential collective inputs). Likelihood of symmetrical encounters remain extremely low. Initiating factors are same as for helo except insofar as the condition can be induced by low IAS roll inputs / wing-drop corrections during high RoD. Recognition/recovery is not a consideration as condition (once encountered) is rapid-rolling and terminal. Attempted (instinctive) recovery inputs simply accelerates the roll-rate. Avoidance is solely by pilot consciousness of the possibility and observation of flight-envelope limits. Avoidance can be enhanced by avoiding tailwind components - however low-level factors such as formation landing positioning, late overshoot, manoeuvre, high RoD, wake turbulence, thermal activity and topographically induced shear can cause onset. Rarity? Will be frequent enough to become an attrition-rate entry argument. Further problems? Acute awareness of the conclusive nature of the condition will become THE inhibiting factor in operational environments (aka "sitting duck").

I'm not against the Osprey or 609, nor am I a doomsayer. However it is apparent why quintessential problems are emerging latterly. Much of the "testing" was via computational number-crunching (resolving the designer's problem that wind-tunnel time was hard to come by at the time). AsymmVR was simply not considered. If you don't concede this then simply email me the relevant paper (or a URL). So the program, being desperately full of yea-sayers, needs a Devil's Advocate. The GAO does its best, but the brokers and lobbyists have gotten to them as well. Would the USMC ever turn it off? The USMC have been waxing doctrinaire about the Osprey's Force Multiplier effect (and its other goodies) since I was at Staff College. So it was really built-to-order and had its gestation as a logical alternative to the problems with the tilt-wing. Not to have it come to fruition would mean generations of (now) senior Military Officers with egg all over their faces. They all left their mark on its promise in their War College essays and staff-paper studies over a decade ago. Possible technological failure of the project was an unacceptable rider for any USMC essayist aspiring to general officer rank. The US Army has always been reticent about it because they see a genuine need to spread resources around, not put all eggs in fragile baskets - and they usually have to apply the KISS Principle anyway. The USMC's future force development is now so irretrievably tied into the MV22 that its cancellation would cause major morale and directional problems. But that's now the direction that it's possibly headed, more's the pity.

tiltrotor

16th Dec 2000, 23:46

Unctuous,

Come on man, read the posts. Everything has been laid out as clear as day
for you. The rest of us get it! Those of us in the helicopter world
recognize that there was no living through the 2000fpm & 285ft scenario
whether it was assymm settling or normal. If it was a helicopter in that
situation (especially a 57000lb one!) we'd be dead too. If you really fly
helicopters you wouldn't have the slightest problem recognizing this! Time to move on mate.

rotorque

18th Dec 2000, 12:58

We Helicopter guys should probably be a little less critical of Fixed wing drivers not recognising Vortex Ring. In most cases we get a hint of the approaching VR by a 'twitching' of the tail rotor. This is due to the recirculating air at the back end playing silly buggers with the T/R. I am assuming that the same tell tale would be non-existent in the V22. I understand that this is just one type of tell tale but from personal experience, it is one of the best hints that you are close to the edge.

I have a question for you guys. How is the V22 controled in the yawing axis? Is it by a differential vectoring of the pods? If NOT - could a boot full of opposite rudder help to correct a wing low situation. I am assuming of course that there is still at least some airflow over the wing.

One last point, another way to get out of Vortex Ring is to just lower the collective. This is great if you have altitude up your sleeve, but even so, I have found through experience that you can 'milk' the collective to disrupt the formation of a vortex.

The moral of my little story is that I don't think it is a design 'fault' either, and as in Helicopters there are ways to deal with the inherent problems that are associated with coming back to earth.

Cheers.

UNCTUOUS

18th Dec 2000, 22:33

OSPREY FLIGHT CONTROLS

How Do They Work?

<A HREF="http://www.geocities.com/Heartland/Oaks/8553/Osp/OspreyFltControl.htm" TARGET="_blank">http://www.geocities.com/Heartland/Oaks/8553/Osp/OspreyFltControl.htm</A>

FlyAny

18th Dec 2000, 23:07

I haven't read all the posts on this thread as yet but, I have seen a point expressed here as fact that I feel compelled to debunk as finitely as I can. It has been said tandem rotor helicopters will not enter settling with power as a vortex ring state. With eighteen years in tandem rotor helicopters and nine of those based at 6000'msl and flying to just under 15000'msl, I want you to understand that the tandem rotor helicopter will very certainly suffer this condition if there is only the necessary lack of diligence to allow it to happen. I was twice responsible for not being smart enough for both of us and earned the necessity of recovering the aircraft as my penance. Another rodeo trick you can expect to hear about in the future of tilt rotor aircaft is the prop rotor on the outside of the turn going through ETL when a too fast pedal turn into the wind is made around the opposite prop rotor.

rotorque

19th Dec 2000, 15:53

Thanks UNCTUOUS,

It seems like that link was just waiting for me all come along and ask the obvious !!

No doubt the powers that be have tested the idea, but I can't help but think that a boot full of opposite pedal could help the situation. Your diagrams say that its unlikely, it probably is, but could the tilting forward of the disk and the subsequent travel help to remove the disk from the Vortex Ring State. I guess similar to the flying out (forward) of the VR in a conventional helicopter. Even in the extreme case of the aircraft rotating 90 degrees (or more), it will effectively remove the condition.

It's nice to have all this time to think about it - I don't suppose that 2 seconds is enough for a reaction to take place after recognition etc anyway.

Further testing maybe ?

HeliFlight

19th Dec 2000, 19:03

RotorTorque,

In an earlier post by PTIUAE he relayed the comments of a NASA test pilot who spent years flying the XV-15 and the V-22. He said the he did experience settling with power (not at 285 feet of course!) and got out of it "instinctively" as an EXPERIENCED Tiltrotor pilot by simply moving the nacelles forward with a push of the switch. The moment the nacelles started moving the vortex ring was disrupted and he flew right out of it. The problem is the pilots in the Marana crash never had the opportunity to develop this "instinct" (80 and 90 hours of tiltrotor experience for pilot and copilot)and obviously the training they had was not deep enough to to prepare them for what they had gotten into. Worse than that, in this case it doesn't matter because they were in so far and at such a low altitude that nothing they could have done would have gotten them out at that point. It doesn't matter if the settling was assymmetrical or normal (if the wind was on the nose or tail it would have been normal settling) they were finished at that point regardless. The same way that if we were in a 57000lb helicopter we would not have been able to lower the collective and push forward on the cyclic to fly out of it.
Your moral of the story should be the title of this thread, you are right, there is no fault in the design.

Unctuous,

You have demonstrated in this thread that you are the KING of WAFFLERS. But it is nice to hear you talk about professionalism though. Obviously the posting by PTI UAE on June 3, 2000 where he lectured you on your lack of professionalism on forums has made a lasting impact on you (that’s the post when you never showed up again for 6 months). However your consistency of never letting the facts get in the way of your theories hasn’t changed since your first post. You keep showing us the facts that we already know (and all agree with) in an endless manner, but completely miss the point of what they mean. You sprinkle your silly theories in between the facts, and expect we will believe those theories which have been indisputably ruled out earlier in the thread by testimony from people who have ACTUALLY BEEN FLYING the aircraft for thousand of hours! Your arguments hold as much water as a sieve. The press will draw their conclusions regardless of the facts, but those of us in the business should know better. We look at the facts and are supposed to have a better idea of what they mean than a journalist trying to make headlines.

If you are wondering why nobody is lining up behind you on this forum, it’s because you have destroyed you credibility over and over again in your previous posts. IE XV-15 theory, Chinooks don’t experience settling with power, your choosing to ignore the opinions of those who fly tiltrotors when you have never even seen one, etc. etc. When you are proven wrong you make up a new theory and swear by that one too. You have already been proven wrong with hard evidence POINT BY POINT, again and again throughout the thread and given indisputable evidence by the guys that have experience with them! Your response to the extraordinary point by point dismantling of your theory was to disappear for 6 months (and wait for a tragic crash that killed 4 Marines to try and boost your ego – sorry, it doesn’t work that way).

Speaking of point by point, it seems that you are the one not willing to answer the questions. Let’s try again: 1. Where were you for 6 months 2. How do you respond to the dismantling of your theory on the XV-15 that supposedly did not go to 95 degrees (5 degrees aft). 3. Do you think a 57,000 lb helicopter would have survived the scenario of over 2000 fpm ROD at 285 ft pulling in full aft stick to reduce airspeed and full power (IE there is no difference between asymmetrical + normal settling, you are dead either way, and that’s the important thing (avoiding it that is). There are some points for you, give it a try (many more to come).
There are a lot of questions readers are curious about. You failed to answer before, what was your user name for the 6 months that you stopped posting under the Unctuous name. (can’t imagine you went hot and furious on this thread, got blasted out of the water, and then came back to try again to apply your theory to the latest crash)

The writer of an article you posted said the MV-22 cannot do everything a small helicopter can do. That could be true. SO WHAT!!.. There are a lot of things a tiltrotor can do that a helicopter cannot (that’s why the Marines want them!) Aviation is all about give and take. Even if there is a more restrictive envelope for settling with power avoidance, you can’t describe it as technologically flawed and throw it out. The obvious answer is DEFINE THE ENVELOPE thoroughly and TRAIN for avoidance. We're not going to throw away all airplanes because they can’t hover or autorotate, and we won’t throw out all helicopters because they get into settling with power, or retreating blade stall, or dynamic rollover and can’t go over 200kts. PERSPECTIVE!

No I have not been “tasked” by anybody with showing the obvious flaws in what you call a theory. I do it for personal satisfaction being a part of this memorable thread. The only disappointing part is that I have joined after th "knock-out punch” has been thrown. Like Bruce Willis in the Sixth Sense (excellent movie) you just have not come to realize what has happened to you yet. I thought it was funny when you said I must have a “vested interest in the tiltrotor.” Wrong again (you must be used to that by now!). You can add this to your list of mis-fire claims being proven wrong on this thread. You don’t seem to have a good handle on theories OR people. Why Is it when anyone disagrees with you, you say they must have a vested interest. You accused PTIUAE of working for a manufacturer writing public relations notices (and called him “Tom”!?), and he gave you extensive details on his background and proved that he was more interested in finding out if there is a design flaw in tiltrotors then you are. Rhett Flater, the guy you responded to and assumed he was a “stake-holder” in the 609, is the Director of the American Helicopter Society, and a former US Marine helicopter pilot. So tell us, how much is Sikorsky paying you to make your posts? (maybe you are the one with the vested interest)

Have you noticed that you have a following of one on this forum (yourself). I’m sure you will come up with a good theory to explain it away (you are good at that and it won’t bother you when it is proven wrong). Do you think there might be a good reason for that? Think about it and you will be able to avoid further humiliating yourself. We are supposed to be the experts capable of interpreting the facts. Don’t be mislead by media stories that make claims that are definitely not backed up by the facts (and don’t be foolish enough to parade those baseless claims around as facts). It might be fun to make up theories, but it’s more rewarding to make a useful contribution by attacking the things that are really bad about the aircraft (like the blottle that REALLY serves no purpose and has REALLY caused an accident already!)

[This message has been edited by HeliFlight (edited 19 December 2000).]

[This message has been edited by HeliFlight (edited 19 December 2000).]

Cyclic Hotline

22nd Dec 2000, 01:51

MV-22 Suffered Hydraulic Problem Before Crash

WASHINGTON (Reuters) - A Marine Corps MV-22 tilt-rotor helicopter suffered a "hydraulic malfunction'' before it crashed in North Carolina on Dec. 11, killing all four crewmembers, the corps said on Thursday.

The corps added in a statement from the Pentagon (news - web sites) that it was not yet known whether the problem had anything to do with the crash. Hydraulic pressure is used by pilots to keep control of aircraft.

It was the second fatal crash this year of one of the revolutionary aircraft and prompted Defense Secretary William Cohen to order an investigation into the troubled $40 billion program.

The Marine Corps postponed a decision on whether to begin initial full-scale production of the MV-22, built jointly by Boeing Co. and Textron Inc., after the crash.

Thursday's Marine Corps statement said initial review of data from the MV-22's "black box'' flight recorder "shows the aircraft did experience a hydraulic malfunction -- however the magnitude of the hydraulic malfunction or whether it relates to the mishap is not yet known.''

Lu Zuckerman

22nd Dec 2000, 05:16

To: Cyclic Hotline

The Hydraulic system may have downed the V22 it also got me fired from a consulting job at Boeing Helicopters in Philadelphia.

I continually brought the subject up of reduced reliability of the hydraulic system due to higher than anticipated cyclic operation. I did this several times and each time I did my boss told me it was a Bell problem. I would disagree and that ended the conversation. Each time I raised the subject he would get progressively more angry. Finally he had my contract cancelled.

Here is the problem. The hydraulic servos had two phases of operation. One phase was when the V22 was in the helicopter mode and the servos would be commanded to change the swashplate position just like on a helicopter. Flying in the helicopter mode represents only a minor fraction of the total duty cycle for the hydraulic system. When in the airplane mode the hydraulic servos are maintained in a rigid position holding the swashplate in the position necessary to place pitch in the proprotor for forward flight. Unless the pilot changes the collective pitch to change thrust levels on the prop the servos never move. The entire life cycle was predicated on this kind of scenario and this in turn established the reliability requirements for the system.

Now I’m going to say something and I don’t want British trained pilots to jump on me and tell me I’m wrong. When in the airplane mode the proprotor responds to the gyroscopic turning moments induced when the aircraft deviates from straightforward flight. The same thing is true for an aircraft propeller. In the case of the propeller the shaft is held rigid in the engine nose case or in smaller engines the crankcase. The propeller wants to precess but it can’t. The proprotor on the other hand is mounted in elastomeric elements that will permit the proprotor to precess.

Built into the proprotor are flapping sensors. If flapping (read precession) is detected the hydraulic servos would be commanded to restore the proprotor to the normal or flat or, originally commanded position. This precession also causes thrust divergence. Because the proprotors are counter rotating the thrust line will be different for the two proprotors making it difficult to control the aircraft. This divergence will be different for every maneuver. Because the V22 spends a lot of time maneuvering while on a mission and, especially when getting ready to discharge troops in a landing zone the hydraulic system can operate ten to a hundred times more than predicted in the reliability analysis.

Please don’t think that I am saying this was the cause for the failure. It is just something to consider.

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The Cat

widgeon

22nd Dec 2000, 06:36

Lu , maybe on your CV you should just list the places you haven't worked !!.
Although it would seem the list would be very short.

HeliFlight

22nd Dec 2000, 15:41

Lu,

Now that is interesting. It is a pleasure to see someone look at potential problems in the V-22 with a degree of knowledge not shared by some on other threads. Bringing to light what could be a REAL problem can only be beneficial to the program. It is nice to read details on what could be an actual problem in the aircraft described by somebody with EXPERIENCE.

Thanks. Keep up the good work!

Lu Zuckerman

22nd Dec 2000, 19:59

On another thread about the V22 accident one of the participants on the thread made a comment about vortex ring state and the possibility of generating asymmetrical lift causing a roll over. Well, here is another problem that the V22 might incur when it goes into operation. But first, I have to set the scene for my comments later.

Many years ago a group of Marine HRSs (Sikorsky S-55) were placed on the flight deck of a carrier. The main landing gear were backed up to the very edge of the flight deck placing part of the disc over the deck and part about eighty feet over the water. When they started the rotors spinning and pulled collective one half of the disc was in ground effect and the other was not. As they began to rise off of the deck one-by-one they tipped backwards and fell into the ocean.

The V22 may have a similar situation in that when it comes in to land on its’ assigned spot it must parallel the path of the ship and move sideways while moving at the same forward speed of the ship. At some point, one proprotor will be over the flight deck in ground effect while the other proprotor is eighty feet over the water. Whether this will induce a rolling moment is yet to be determined.

In a similar situation, I almost had a pilot buy the farm for both of us. We were in an HTL-1 (early model 47) mounted in floats. This was in Greenland and we were spotting cracks in the ice and, providing this information to the ships Skipper to help simplify his passage through the ice fields.

Normally when the ship was underway, the pilots would lift off and keep climbing while at the same time moving sideways and letting the ship move away from us and then, push forward cyclic. In this particular case the pilot wanted to try something different. He just lifted off of the flight deck and left the ship move away from us. We were in ground effect relative to the ship but when it moved forward we were about fifty feet above the water and not generating enough lift. Even though we were on floats if we hit the water the turbulence generated by the ships screws would have turned us over. With presence of mind the pilot pulled more collective and pushed lateral cyclic to get us out of the turbulent airflow coming off the ship.

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The Cat

Dalebert

26th Dec 2000, 12:13

It sounds like the V22 has aerodynamics problems, but I think the V22 has even bigger mechanical problems. (I am a mechanical engineer, but I don't claim to be an aero expert. I know a thing or two about mechanical systems, however.)

Simply put, the V22 is a flying Rube Golberg Contraption. I wouldn't trust a surface vehicle with that many moving parts.

Let's see: moving engines, structural pivot points for the entire engine / transmission assembly, power shaft passing through the pivot points and across the entire width of the aircraft through flexing wings, full collective pitch mechanism for two rotors, hydraulics to move the pivots, wing flaps...

It has no backup recovery methods. (glide, autorotate, eject) When one of the parts fails, you just drop like a rock.

Also note critical parts in close proximity to help the domino effect. For example, see the first fatal V22 crash where an engine fire took out the transmission shaft.

Some have said the aircraft is "not mature." That concept has been in development for over three decades! Okay, quiz time: what does it tell you when a huge budget and three decades of R&D doesn't produce a reliable product?

Answer: Brute-force engineering won't make a good idea out of a bad one.

I won't fly on a tiltrotor. Neither should you.

Dalebert, Mechanical Engineer

UNCTUOUS

26th Dec 2000, 13:20

The Blottle
The Bell/Boeing Osprey will be flown by both helicopter pilots (who are used to a collective control) and FW pilots but USMC Brig Gen Harold W. Blot Jr early on decided to replace the collective with a throttle "in an effort to reduce pilot workload in combat".
Some experienced helo pilots are still concerned that transferring between the two types of controls will cause accidents. Pilots used to pulling up on a collective to cushion an autorotation might inadvertently (under stress) pull back on a V-22 throttle in the same situation.
Samuel Porter, V-22 Project Manager at the Naval Air Test Centre at NAS Patuxent River characterised the debate as more of a training issue. Porter's experience with experimental V/STOL aircraft goes back to the 1960's and includes work on the CL-84, XC-142 and the XV-5. Some of these had throttles and some had collectives.
The V-22's power-lever grip (aka throttle) currently has six individual control switches, including a nacelle position switch and a chaff/flare dispenser switch. "A throttle is easier to operate in heavy turblence and under high g loadings", Porter said. He is concerned about pilots trying to hold a constant power setting whilst pulling 4g's and having to fight against a collective trying to drop to the floor. "We feel that for the fixed wing flight a throttle would be better". Blot, one of the first US pilots to fly the Harrier, said that what they'd learnt in thrust-vectoring is that you have to keep the pilot workload down to two things at a time. The Harrier experience had been to set full power on take-off and be left with attitude control with the right hand and thrust-vectoring with the left. On landing the nozzles went forward and the left hand just had to ease the power. With the V-22 now, the computer handles the power and all the pilot has to do is vector thrust and control attitude.
As envisioned by Blot, a V-22 take-off would proceed thusly: the pilot adds full power, advancing the PCL with his left hand whilst using his right hand on the cyclic to maintain the aircraft in a level attitude. As the aircraft lifts, the pilot will begin vectoring thrust by rotating the engine nacelles forward, using his left hand to roll the thumb-switch on the PCL. The object is to stay on a mentally pictured climb-out vector. If the nacelles are tilted and the rotor lift is dumped before the wing has picked it up, the aircraft will drop below the chosen flight-path. If the nacelles are vectored too slowly the aircraft will climb above the chosen flight-path - so the thumb-vectoring rate is a vital skill.
The whole question of the ultimate design of what has become known as the "blottle" remains contentious - with advocates both for and against. However on June 11th 1991 the Blottle claimed its first victim. The pilot attempting to fight what appeared to be chaotic roll instability at a height of only 15 ft tried to land but the left engine nacelle (tipped by an IR suppressor) hit the ground. A mis-blottle caused a fast lift-off followed by a rotor-first arrival. The nose dropped and the aircraft rolled inverted. The anti-Blottle brigade had tasted first blood. Even though the aircraft was being flown in PFCS (primary versus AFCS automatic flight control system), an assertion that the accident would not have happened in its FBW mode failed to dissuade the critics. Some insisted that it was a hardware accident and some questioned the role that software may have played. Notwithstanding the basic roll problem, the in extremis use of the blottle, in an attempt to recover, seemed to prove that old instincts die hard. Coupled with the aircraft's intricate complexity and its vulnerability to asymmetric vortex ring states, the Blottle constitutes a challenging addition to a combat area aircraft.

http://www.geocities.com/Heartland/Oaks/8553/blottle1.jpg

http://www.geocities.com/Heartland/Oaks/8553/blottle2.jpg

PTI UAE

26th Dec 2000, 19:36

Unctuous,

Welcome back. It has been a long time. Very good job on the description of the “blottle” in that last posting – well, until you got to the last line anyway. You described the history very accurately, and identified the problem of the thrust control lever configuration followed by good commentary on the consequences, both actual and potential. You added opinions of your, own most of which were in line with the facts that you presented. Congratulations.

I read your other recent postings, however, and unfortunately there were many inaccuracies that I believe need to be addressed. To start with, I was quite surprised to see the comment in your post on 15 December that I “was not addressing the issues directly.” As we both know, this is not an accurate statement. Perhaps you have forgotten that I replied to every one of your points (one through nine) in my post of 3 June. You never provided a response to the post, but rather decided to disappear for six months. It has been a long time, so perhaps it will help to refresh your memory if I reprint those points here. It may be a little clearer for you if I pair your original comments with my responses. If you remember, the bold print were excerpts you had taken from a previous post of mine, and you added your comments immediately after (not bold). I added my responses to your comments in bold after your comments. It winds up being lengthy, but it may make it easier for you so that you won’t have to go back and forth to your previous post.

I very much dislike being repetitive, but as others have told you in this discussion, your new entries have been nothing more than a rehash of your original posts. You provided no response six months ago these points, so perhaps you missed them. Here they are again in an easier to read format:
____________________________________________________________ _____
UNCTUOUS
Please don’t misinterpret my comments as an attack on you personally. The best way to carry on a discussion in a forum is to concentrate on the issues at hand (as Mr. Farley has done quite effectively in his posting). My intent is not to embarrass you, but only bring to your attention the obvious flaws in your analysis that come from a lack of understanding of tiltrotor technology. I was in your position a number of years back, and could very well have come to the same conclusions that you have. However, my approach to reaching a final opinion differs from yours in that rather than theorize based on my limited knowledge, I prefer to go to the experts who work with the technology on a daily basis. It is incredible how much research on tiltrotor technology has been done by NASA and Bell over the years (courtesy of hundreds of millions of taxpayer dollars), and no, you will not find more than a fraction of the reports on the AHS or NASA web sites. The work is ongoing, a few months back I stood in one of the remarkable wind tunnels at NASA Ames where a fully functioning scaled replica of the V-22 was being assembled. This is only the latest in a number of long-term wind tunnel testing programs that included not only scaled models, but actual full-size aircraft with the XV-3 and XV-15 (and for the future there is talk of full size V-22 testing). There was a long list of very complex issues that were being closely examined during this research. It is not simply a matter of ‘running it through the wind tunnel’ as you stated in an earlier post. An incredible amount of data is accumulated by the numerous high tech monitoring systems that measure to a degree of accuracy most of us would not have thought possible. The dedication of the many people working on tiltrotor research at NASA is truly admirable, and their goal is no less than to contribute to the development of revolutionary a/c that combines dramatic technological advances that have been achieved on a number of fronts in aviation.
In my limited experience I have had the opportunity to fly the XV-15, the V-22 simulator at Pax River, and the incredible VMS simulator at NASA Ames Research Center (capable of pulling positive and negative Gs). This is of course nothing compared to the NASA, Bell and military test pilots that have spent years flying the XV-15 and V-22. I keep in regular contact with some of these individuals, and have great respect for the level of knowledge and expertise they have accumulated. I have included below some responses to my queries from a senior engineer/test pilot at NASA who has almost twenty years experience in tiltrotors. He knows far better than you and I what is known or not known on the subject of tiltrotor flight characteristics.
Some good news for you is that the V-22 crash is not being investigated only by Bell/Boeing and the Marines. The NASA rep that I have been in communication with just returned from the Naval Safety Center where he was leading a team which is “doing a NASA independent review of data from the V-22 accident.” NASA does not have to answer to, or coordinate with, the military investigators other than to present their final analysis. During his investigation, his people reviewed the available recorded data from the Crash Survivable Memory Unit (CSMU) of the a/c that went down in Arizona. He is not at liberty to release the details to the public at this point, but on initial review it was clearly evident to him that the pilots were “way outside of normal or reasonable boundaries or limits.” From numerous meetings and discussions with this individual, I can tell you that although he is an ex-military pilot himself, he does NOT fall in line with the opinions expressed by the military. During the past couple of decades that he has been working for NASA flying almost everything imaginable, he spent five years (1990 – 1995) as the NASA representative to the V-22 Integrated Test Team at Pax River. From that experience, he does not hesitate to point out where he disagrees with how the military have conducted their research and development program.
In the opinion of the NASA investigator, initial indications are in fact that the aircraft was in a situation that should have never have been allowed to develop. As a highly experienced tiltrotor pilots, he and his colleagues all agree they would never have allowed themselves to go so far outside normal operating parameters, or to use the control inputs in the way they were used in any circumstance. The outcome of having done so was inevitable. When these details are released (the sooner the better) it will be evident to all that asymm VR state is not a condition that is by any means entered ‘at the flick of a wrist,’ and it is not a condition caused by external environmental factors.
Asymmetric settling with power in tiltrotors has been known and understood by those at NASA and in the military for many years. The reason there was no in depth test and evaluation program by the Marines with the V-22 was because it was felt that the phenomenon was so far outside of the normal flight envelope that it would not be encountered. This was wrong – dead wrong. Combat conditions (or simulated combat conditions) all too often create situations that cause the pilots to enter regimes that the a/c was not designed for. In hind sight I would imagine it is painfully obvious to them that more wind tunnel and simulator testing was warranted, as well as actual flight testing when deemed safe based on the wind tunnel and simulator results. The lessons learned from this data need to be thoroughly understood by all pilots transitioning into tiltrotors so that it is completely clear what conditions/actions will produce fatal consequences.
The NASA pilot mentioned above has done extensive flight testing to explore the outer limits of the flight envelope and beyond in both fixed-wing and rotorcraft. Based on his experience he believes that at the very least the impending conditions of the phenomenon will be able to be safely tested in actual flight in a controlled manner that will provide answers without loss of life. Obviously with any flight testing there is an inherent element of risk, but the trials will be conducted at altitude where recovery can be accomplished safely. Regardless of the results of this testing program, the RECOVERY techniques practiced will have no direct application to the low altitude scenario that took place at Marana. The purpose is to more clearly define where and how the state develops, and how it can be RECOGNIZED before it progresses to the point of no return. This information can then be used to determine the solution to preventing a reoccurrence of this type accident in the future, whether that solution is to modify the aircraft, add warning or control devices, restructure pilot training with much greater detail and emphasis on understanding, avoidance, recognition and recovery, or restrict certain operations (or a combination thereof).

As to your questions/comments:
1. "a single rotor helicopter should not descend at a rate of 300 fpm or more at slow speeds.(???)" Unfortunately, I assure you that this sort of sedate operation will not work in an operational environment. I've got 13 months in SVN backing me up on this.

Response: Nobody will be issued a private pilot license in the US without being able to recite verbatim the three basic requirements for getting into settling with power. From the FAA publication AC 61-13B (as well as other education and training publications that concur): “the following combination of conditions are likely to cause settling with power: 1) A vertical or nearly vertical descent of at least 300 fpm. Actual critical rate depends on gross weight, RPM, density altitude, and other pertinent factors……” I can’t speak to what the CAA/JAA etc. like to use as guidelines, but we all have to start somewhere to keep pilots safe. In demonstrating settling with power to students I have never been able to induce the condition with less than 500 fpm, however this does not mean it is not possible. Ray Prouty gives an excellent description of settling with power if you need further clarification.

2. Pilots must learn to recognize the conditions that will put them outside the normal flight envelope (in a dynamic situation, as in Marana, just how do you do that? it's a momentary entry), and apply correct recovery techniques when appropriate (which are??). Don't be coy, just what are they?

Response: Just as your initial assertion that tandem overlapping rotor systems (CH-46, CH-47) do not experience settling with power was shown to be false by those who fly the a/c, your claim that getting into asymm VR is a ‘momentary entry’ has been disproved by those who actually fly tiltrotors. According to the experience obtained by the NASA test pilot commenting below, your statement is in complete contradiction with the facts. In response to my question, he described his experience with the onset of the condition, as well as the basic recovery technique, “In the XV-15, on at least one occasion, I have come to a hover or near hover at altitude, 4 or 5 thousand feet, and picked up a pretty high sink rate with lots of power applied. Now, as a tiltrotor pilot, it was second nature to move the nacelles forward 10 degrees or more and apply appropriate power to fly right out of the condition. I have never encountered any asymmetrical conditions and you would have to work REAL hard to create them – way outside of normal or reasonable boundaries or limits.” Again the NASA pilot has seen the CSMU data, and as a former combat pilot himself, has made the assessment based on his experience that the Marana accident did not take place while performing a maneuver anything near ‘normal.’ No one would deny that the Marana V-22 crew had no recovery options available to them when they entered the asymm VR state at 285 ft above the surface. At altitude, in other than extreme conditions, forward movement of the nacelles has an immediate effect on changing relative wind/AOA conditions that cause settling with power, just as we in the helicopter world can escape the VR state by using forward cyclic and reduced power -- as long as circumstances permit it (not possible at extreme rates of descent and critically low altitude – sound familiar?). And note that so far, we are only discussing recovering at a stage when indications show an ‘impending or incipient’ asymm VR state. The forthcoming wind tunnel, simulator and flight tests will determine accurately what if any techniques can be used to recover from asymm settling. It may be that only avoidance of entering the extreme rate of descent and application of violent control inputs that the NASA investigator saw evidence of on the CSMU could have saved the V-22 crew. Perhaps Mr. Farley is correct in his suggestion that a warning device or automatic configuration change might be the answer.

3. All aircraft flying today have 'dangerous' characteristics in certain flight regimes that must be avoided, regardless of whether you are in an airplane, helicopter, or tiltrotor (quite trite. Not sure that this is a valid argument in support of asymmVR being an acceptably benign characteristic - rather sweeping assertion). In a FW, an ASI and an accelerometer will keep you out of trouble (except for coffin corner). What does the Osprey crew have? "Keep scanning that VSI Bloggs, watch out for any lag. It'll kill you"

Response: Your comment here does not make sense. Nobody is saying that asymmetrical VR is anything less than deadly. Further, to deny that dangerous flight regimes exist in airplanes or helicopters is foolish, and I’m sure you do not subscribe to that belief. We cannot look at the tiltrotor with tunnel vision. Comparative relationships with other categories of aircraft should be drawn in order to correctly assess the capabilities and vulnerabilities as they relate to defining whether or not an aircraft is within our definition of ‘safe.’ For instance, when you say the design of a tiltrotor is deficient in that transmission failure or pitch lock have not been considered. The first thing I think of is what will happen to me if one these catastrophic events happens tomorrow when I’m flying along in a Bell 212 (or any other helicopter in existence) – it certainly has been considered by the design engineers, and there is no ‘back up.’ The answer is to minimize risk to the greatest degree possible by using the highest possible standards in the construction of the rotor and transmission components. And in the case of the transmission, add warning devices such as temperature gauges, pressure gauges, warning lights (temp & press), and chip detectors so that an impending failure will be recognized in order to provide the pilot with enough time to get the a/c on the ground before complete failure occurs. We can’t wear blinders when it comes to admitting that the only way to guarantee 100% safety in aviation is not to fly. That said, every effort must be made to ensure that we come as close to absolute safety as we possibly can. Regarding warning instrumentation, perhaps more can be done. But don’t be so hard on A/S and VSI indicators – sure, they’ve got limitations – but they’ve kept me and a lot of other helicopter pilots from getting into unanticipated settling with power for a lot of decades. Give us something better, and we’ll use it. But if you use the instruments we have knowing their limitations, they can provide you with good information.

4. When pilots are not properly trained to understand and recognize the conditions to be avoided, disastrous consequences are inevitable. AsymmVR will always be there - just a flick of the wrist away, and much much more insidious than an inept "stall/spin on finals" scenario. They'll have no aural/visual/instrument warning of its onset or imminence.

Response: As already shown above, those who have a great deal of experience in tiltrotors (which both you and I lack) attest to the fact that the asymm VR condition is far from insidious to say the least. Why do you think in all the thousands of hours of XV-3, XV-15, and V-22 flight testing, including pushing the envelope boundaries to what was believed to be their safest limits, the phenomenon had never been encountered in flight (an awful lot of ‘wrist flicking’ going on there)?
On the other hand, the all too frequent occurrence of the fixed-wing stall/spin scenario that I described in my previous post continues to be repeated again and again. For those of us with experience and a thorough understanding of the conditions that lead to a fixed-wing aerodynamic stall, we would not consider it an insidious event. However, for those with insufficient experience and inadequate training in airplane category aircraft (ex. 80 or 90 hrs) it can be very much more insidious than what it takes to get into assym VR in a tiltrotor, but just as fatal.

5. The Marine crew that perished in the 8 April crash had a number of contributing factors working against them. The most obvious is a lack of experience in tilt-rotors, having only 80 or 90 hours each in the V-22. If you're inferring here that AsymmVR had been identified as a possible outcome of exceeding the rather lose envelope laid down, you had better check your facts. My conclusion therefore is that, because it was a wholly unanticipated flight condition, it would not have mattered if they'd had ten times that MV-22 experience. And it would have happened in daylight just as easily. The formation station overshoot that precipitated the AsymmVR was no more likely at night than day.

Response: Again your statements are in complete contradiction with the opinions of those who do posses the facts. Those who possess actual experience say you are most definitely wrong in your assessment that experience would not aid pilots in strengthening their ability to better recognize and stay out of a position that would allow asymm VR to develop. A thorough knowledge of asymm VR should be possessed by all tiltrotor pilots (no doubt from April on that will be the case in the Marine Corp). It certainly appears something was lacking in the education and training process. Again, according to those with experience with tiltrotors, the vital element that was missing in this case it was the ability to recognize the extreme rates of descent combined with low airspeed that created the condition. Although the CVR did not record anything during the event itself, shortly before the accident the wing pilot transmitted. “Lead you’re too hot, lead you’re too hot!” As the lead a/c continued on at a higher airspeed, the wing a/c apparently did a dramatic full aft stick rapid deceleration that put the a/c into the deadly low speed/low altitude/ extremely high rate of descent combination that will kill you whether it is caused by settling with power or asymmetrical settling with power. Add to that a 28 degrees Celsius temperature, a 2100 ft msl altitude, quartering tailwind, massive right pedal and heavy left lateral stick inputs and things begin to pile up.

6. But in time, missions such as this will be able to be carried out successfully by those pilots who are now gaining experience in the military. I guess we could discuss here the largish detachment of Apaches that went to Kosovo but weren't used because of the crew's inexperience and high accident rate.

Response: I don’t have enough knowledge of the facts to pass judgment on what took place in Kosovo.

7. and the entire event was being filmed in infrared by an F/A-18 flying overhead at altitude. Incorrect (retracted later by Gen McCorkle). But the eye-witness evidence is quite determinative.

Response: Regarding the infrared video taken of the accident by an F/A-18 from above – I’m not saying this is the case, but when the military has a picture or video of one of their a/c crashing, and the press is clamoring to get at it, these things have had a habit of disappearing. (Mention of the existence of the tape came from a non-DOD source investigating the accident.) How many photos of the early F-117 crashes have you seen? Do you think none were taken? Think about it.

8. The Marines more than anyone are interested in ensuring that this event never occurs again. That is the problem. It most assuredly will - because the susceptibility is built into the design concept and the propensity is in the style of operation. The solution is likely to be quite elusive. Warning systems of 2% chord L.E. pressure transducers will record the condition (delta t of spanwise lift distribution), but as found in RAE trials, cannot forecast it. There are too many variables close to the normal operation. What sort of buffer will there be in the new envelope and how can it be infallibly observed? (AsymmVR being automatically fatal and all). It is supposedly a combat area aircraft and is meant to be able to manoeuvre aggressively. Therein lies the conundrum.

Response: Again, your basic assertion that ‘the SUSCEPTIBILITY is built into the design concept’ has already been shown to be a false premise as attested to by those who have actual experience with the aircraft (have you even seen a tiltrotor?). Rather than being susceptible to the condition, it actually takes extreme rates of descent with radical control inputs to enter it. Mr. Farley seems to disagree with your theory that a warning device is not possible. Personally I don’t have the expertise to judge, but if it is deemed feasible and beneficial as a result of the upcoming wind tunnel testing at NASA, I should hope we will see one fitted as standard equipment.

9. The V-22's return to service shows their confidence in tilt-rotor technology. That confidence comes from 45 years of tilt-rotor research, including 11 years of flying the V-22. So why has the condition only now come to light (and detailed attention in flight trials, wind-tunnelling and modeling that's now underway)?
There is a light at the end of the tunnel in that you've brought yourself to address the problem as AsymmVR and not talked about settling, lead a/c wake, turbulence etc., as per most USDoD and Marine PR. But questions remain.
How do you differentiate between a "picking up the dropped wing" (with differential collective) instinctive response from either:
(1) a straight entry into asymmVR (because you're verging on the condition)
(2) or an entry that is a compound of picking up a gust-dropped wing (or even simply banking) whilst at the edge of the envelope (in the VR ball-park)?

Response: I won’t beat a dead horse to death. By this point you should be aware that although the phenomenon was known of, it was not looked into because it was considered too far out of the normal flight envelope to investigate further. It was believed that the conditions required to encounter it were too extreme to consider. They were wrong. The fact that the accident did occur shows greater understanding is required and it will now be studied further. No matter how extreme the conditions must be to get you into it, the point is it can happen. All the options for making this the last accident of its kind that were discussed earlier must be completely researched and action taken (see above).

____________________________________________________________ _________
Now I have beaten a dead horse to death!! Unctuous, I think we should both work on brevity where possible. Let us stop repeating the same thing, and instead try to incorporate new ideas into our thinking. Concentrating on the facts and the objectivity of the analysis is the best way to arrive at a valid conclusion.

4dogs

27th Dec 2000, 10:19

Hi Dilbert,

What I really like is that your statement has been made over many, many years about many, many new technologies - fortunately, it has failed and hopefully will continue to fail to deter those who take us ahead.

A whole lot of very smart people have and will continue to try to develop this technology to become just another commonplace aviation technology. Some will be in it for greed and some will be in it for power - some will lie, some will make stupid decisions and some may not even care. However, the vast majority will be honest, industrious folk just trying to do their best for the benefit of all - I hope they succeed.

People will die - but the deaths will not be wasted even if we cannot make it work - we will have immeasurably added to our knowledge base in a wealth of technical and human disciplines.

By all means be vigilant and, if necessary, blow the whistle on unacceptable human behaviour - but on no account quit!

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Stay Alive,

[email protected]

Lu Zuckerman

27th Dec 2000, 19:13

To: 4dogs

I would like to take on of you points out of context. “Some will be in it for greed and some will be in it for power - some will lie, some will make stupid decisions and some may not even care”. Based on what you have stated it is obvious that you must have worked for either Bell or Boeing on the V22 program.

Here is a little dilly that will help prove the point. When the program started it was agreed that all drawings would be created using a computer based drawing system called CATIA. CATIA was developed by the French for the Airbus program and was widely accepted by the American aircraft industry but not all. Mc Donnell Douglas developed a system called Unigraphics (UG).

In the Bell Boeing relationship the drawings were developed and could be transferred electronically via the Internet. One of the major benefits of CATIA is that it would allow the entire system under design to be viewed on the computer screen as if you were on a tiny aircraft and were flying through the assembled aircraft. You could peel away structure to see what was underneath and look at the smallest piece part of an assembly. It really worked well. As Boeing designed their part of the system ,any Bell designed part of that system, was blank, or at least not in detail. It was assumed that when the Bell designed matured both Bell and Boeing would transfer their part of the design to the other and essentially fill in the blanks.

When they tried this electronic trade of drawings, it was discovered that Bell and Boeing had used different projection angles, and the two drawing systems would not marry. During my last six months on the program they hadn’t solved the problem and if that is still true today then you can’t make a complete fly through on either system.

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The Cat

HeliFlight

27th Dec 2000, 21:11

Uncy,

You obviously read justhelicopters.com. You took everything I said over there a couple of weeks ago on the Blottle and restated it here. But I won’t charge you for plagiarism, after all you did add a pretty picture! By the way, General Blot was only a Colonel when he made his blunderous choice.

Now see if you can get back to answering all those outstanding questions we have been waiting so patiently for. You are still avoiding the issues. Time to stop running from the facts.

Lu Zuckerman

28th Dec 2000, 00:18

To: All

I was specifically and very politely asked not to participate in this thread so as not to add credence to any of the various posts. I did so willingly and then found myself participating on another V22 thread on this same forum.

I don’t know if I got it right but from what I read the pilot was trying to arrest his downward velocity and by pulling aft cyclic he entered the Vortex Ring state and either because of inadequate experience on the V22 or, insufficient altitude he could not tilt his engine pods forward to power out of the situation. Hopefully that is close enough for government work.

His downward velocity was measured a 2000 FPM and he could not slow down. My question is, how does even an experienced pilot autorotate and perform cyclic flares to both slow down and to build up rotor speed if when he enters into a flare, he could enter the vortex ring state causing himself a lot of problems, and since his downward velocity is predicted to be 4-6000 FPM ROD how can he arrest or, at least slow it down in order to at least have a controlled crash.

One other theoretical question, if the aircraft is in an autorotational situation and the proprotors are being propelled by the upward flow of the onrushing relative wind can the vortex ring state be initiated when the flow of air is up and not down. Get out your thinking caps and figure this out.

------------------
The Cat

Dalebert

28th Dec 2000, 01:24

4dogs,

"No matter how far you have gone down the wrong road, turn back." (old proverb)

I do not advocate "quiting" as you suggest. I advocate spending those resources on other more elegant concepts for VTOL. I have some ideas of my own (hire me.) and I am aware of many other concepts for VTOL.

This project is an example of using engineering to (in your own words) "make it work." If anything is that difficult to "make it work," then that is an indicator that it is a bad idea.

Don't give up. Just start over.

Dalebert

Kaitak

28th Dec 2000, 03:40

The best bit of advice my grandfather ever had for me when I joined the Royal Air Force was

'whatever happens, never ever fly a MK1'. Clever man obviously knew I would ever be a Boscombe candidate!

[This message has been edited by Kaitak (edited 27 December 2000).]

UNCTUOUS

19th Jan 2001, 10:09

Subject: MARINE CORPS TO INVESTIGATE OSPREY SQUADRON
>
NEWS RELEASE from the United States Department of Defense No. 026-01
(703)695-0192(media)
IMMEDIATE RELEASE January 18, 2001 (703)697-5737(public/industry)

MARINE CORPS TO INVESTIGATE OSPREY SQUADRON
The Department of Defense today announced that the commandant of the Marine
Corps has directed the inspector general of the Marine Corps to investigate
allegations that the commanding officer of Marine Tilt-Rotor Training
Squadron-204 asked Marines to falsify maintenance records on the squadron's
MV-22 Osprey aircraft.

Marine Corps officials first became aware of these allegations Jan. 12, when
they received a copy of an anonymous letter and audio tape that was mailed
to the Office of the Secretary of the Navy.

The information alleged that the unit commander asked his Marines to falsify
maintenance documents concerning the squadron's MV-22 Osprey aircraft. The
squadron is based at Marine Corps Air Station New River, N.C.

Marine Corps officials said that although the inspector general has yet to
complete his investigation, at this point there appears to be no relation
between these allegations and the causes of either the April 8 mishap in
Marana, Ariz., or the Dec. 11 mishap in North Carolina.

Based upon a preliminary review of the information contained in the package,
the commanding general of the 2nd Marine Aircraft Wing relieved the squadron
commander this morning, pending the inspector general's thorough
investigation of the matter.

For more information, contact Maj. Patrick Gibbons, U.S. Marine Corps
Headquarters, at (703) 614-4309.
-END-

Sent: Friday, January 19, 2001 7:59 AM
Subject: Fw: MARINE CORPS TO INVESTIGATE OSPREY SQUADRON
JAY
> A tid-bit that might be of interest. Looks like it's getting ugly.
> Were they keeping two sets of books to downplay the maintenance burden?
> DEE
> ----- Original Message -----
> From:
> To: <Recipient List Suppressed:>
> Sent: Thursday, January 17, 2001 4:32 PM

I'd guess that it was just a bit of misguided Marine gung-ho (you'd be au fait with that
inhouse Corps concept).
I would also guess that there's been a bit of an hierarchical
sense-of-humour failure following the second fatal Marine V-22 accident -
overlaid on a horrendous overall past couple of accidental years for Marine
aviation (three top operational aircraft grounded at one stage for
mechanical reasons - but each following on from fatalities).

A closer examination might also disclose that it was less the maint burden and more:

a. Marine avn technicians' unfamiliarity with the aircraft coupled with the
pressure to get it "up" as a goer for full-production approval had led to
some contrived tech short-cutting and reporting......maint accidents/incidents that
just had to be kept "off the record" lest it distort the GAO oversight,
Pentagon assessment (Philip Coyle (Dir OT&E)) and Congressional committee's
opinions of the aircraft's viability.

b. A certain understandable degree of mortal fear within the ranks that the
hierarchy would try to get the aircraft a "tick in the box" no matter how many
Marines' blood was to be spilt in the process.

IMHO the aircraft is a lemon simply, as James L put it, because "it's a
piece of delicate Swiss clockwork on a miner's wrist and it's always happier
underground" (but maybe it was me who said that). Those audio tapes can be a
bugger (i.e. leading to a very elucidating "hearing" within a hearing).

I think we've just heard that same sound that I used to get at the corner arcade
machines - just before they refused to play any more - "TILT"

Lu Zuckerman

19th Jan 2001, 17:18

I think some of it may have to do with the operational philosophy of the Marines. Because they are a “fighting force” the aircraft mechanic is a soldier first and a maintenance mechanic third or fourth. The mechanics can be assigned to all sorts of duties not related to their technical assignment. This is borne out in the following: I had an associate that was a Sikorsky techrep assigned to work on CH-53s. On one assignment he had to certify a Marine squadron of CH-53s for duty in Vietnam. What he discovered was that the helicopters were so poorly maintained that he contacted Sikorsky and they contacted the US Navy and the entire squadron was grounded. In some cases major assemblies were so badly deteriorated that they had to be replaced and the bad unit sent to the depot for major overhaul. The helicopters were filthy and there was a lot of corrosion that had to be neutralized and or parts replaced. This does not reflect badly on the capabilities of the mechanics but it does reflect on the Marines, as they do not allow the mechanics sufficient time to perform their maintenance duties.

------------------
The Cat

[This message has been edited by Lu Zuckerman (edited 19 January 2001).]

[This message has been edited by Lu Zuckerman (edited 20 January 2001).]

PTI UAE

19th Jan 2001, 18:20

Unctuous,

I realize that the results of your original posts did not go as you planned. I believe your intent is good, you just need to take a different approach in your analysis. Try to concentrate more on what the facts are actually saying, and when there are questions, do not jump to conclusions in order to come up with a quick theory. Take the time to search out answers to those questions. To do that you must ask those that have the answers directly based on their first hand experience, not those who are speculating in an attempt to grab the biggest headlines. You are correct in that you must watch for individuals who have “hidden agendas.” Try to seek out those who are as impartial as possible, and ask them the questions that will set you on the right path to a valid conclusion. If there are unanswered questions that can be found in the black boxes, then wait for the results of that analysis. Once you have satisfactorily answered all the questions accurately, then it is time to put the facts together to develop your theory.

If you do not follow the correct logic sequence in your analytical approach, you will find yourself trying to make the facts fit your theory. This type of faulty reasoning is putting the cart before the horse, and will inevitably result in false conclusions, and faulty theories.

Your recent posts contain too many flaws and inaccuracies in the analytical process to cover all of them. So for the sake of brevity I will limit the discussion to just two examples contained in the last paragraph of the post you made after your return to the forum on 15 December:
____________________________________________________________ _________
1. Your V-22 Accident Projection
”So if we simplistically take the MV-22B at Marana (as a function of total V-22 flight hours to that date) or the 1/330 deck approaches and extrapolate this across a 400 aircraft military fleet, I calculate a loss at about every 12,700 hours of Mil V22 flight hours (in a fully mature fleet circa 2007)- about four times a year to AsymmVR. Whether this will be acceptable or not as an attrition rate remains to be seen.”

Be cautious of pitfalls that can lead you to a false conclusion. Extrapolation is illegal when it is applied to aircraft performance charts, and it is inaccurate if improperly applied to accident analysis and projections. Caution must be observed in trying to do statistical analysis on a single-occurrence event. Your projection that four V-22 settling accidents will occur annually is based on the number of hours flown to the date of the accident, applied to the number of hours the V-22 fleet will be flying when all squadrons are fully operational. There is no sound basis for assuming a proportionate relation exists out of a single-occurrence event, and the assumption defies commonly accepted guidelines for statistical analysis. Think of it this way -- if the accident occurred during the first hour of flight in the program instead of when it did, your analysis methodology would project an Osprey crash once every flight hour that the aircraft is flown. Based on your numbers, that would be 50,800 V-22 crashes due to settling each year (one crash every 12,700 hrs, four crashes a year, 12,700 x 4 = 50,800hrs annually). I think you would agree that this would probably not be an accurate projection, just as your four per year accident projection has no validity.

2. Your Response to the Fixed–Wing Stall Analogy
”Some correspondents have asked me why it's of any greater concern than the wing drop that you get at the FW stall. My easy answer to that is that anyone with any situational awareness can tell that he's near that stall and can take normal stall recovery (including some rudder to halt the further wing drop). As he adds power and unloads, a FW pilot will fly it out and the asymmetry will have been of no great concern (except in an accelerated "g stall" involving a "flick" roll -but that should never be the case near the ground). The Marana accident did involve something akin to a "flick" roll, it always will. The instinctive corrective action (differential collective applied laterally through the cyclic to pick up the dropping wing) is the one thing that is always going to greatly exacerbate the condition into a rapidly terminal roll.”

The old adage of “a little bit of knowledge is dangerous” seems to apply to some of your “theories.” You must be cautious of applying a limited knowledge base to certain subjects, and offering your comments up as facts. To those readers not familiar with fixed-wing aerodynamics, it appears that you are presenting facts. To those of us that do have some experience in the area, you have demonstrated a disconcerting lack of knowledge of some of the fundamentals, and have described procedures for fixed-wing stall recognition and recovery that if followed, could result in a fatal crash.

First, a fixed-wing stall is created when you exceed the critical angle of attack for that particular wing, and the “wing drop that you get at the FW stall” is not the primary recognition cue of a stall, and in fact, a wing drop may not occur at all. It is very possible for one side to stall before the other, but it is definitely not always the case. There are many variables in fixed wing stall characteristics that will dramatically affect how the a/c behaves when stalled. Do to the length it would take to describe, I will not begin to discuss that here, but would recommend you read some of the many good publications that exist on the subject to acquire a better understanding of the basics.

Second, your generalized comment that ”My easy answer to that is that anyone with any situational awareness can tell that he's near that stall and can take normal stall recovery” is a very dangerous statement that would encourage apathy when vigilance is actually required. Situational awareness is vital (as an example, it could have prevented the Marana accident), but to claim that anyone can recognize they are near a stall is by no means a correct statement in all instances. As I have explained to you previously, the death of literally thousands in stall/spin accidents over the years is undeniable testimony to that. Some a/c posses imminent stall characteristics that are far less obvious than others. For example, high performance laminar flow wings on fighter-type a/c such as the T-38 have been involved in many crashes because of the subtle stall curve. If the condition is allowed to progress at low altitude (as in a base to final turn), it could be too late for corrective action, and no recovery technique will get you out of it (as was the case with low altitude settling in the Marana accident). With this type of wing there is no noticeable stall buffet, significant nose drop, dropping of a wing, or any easily identifiable visual indication whatsoever. Only the AOA indicator or VSI will let you know that the critical condition has developed.

Third, the statement that ”(including some rudder to halt the further wing drop)” is a real invitation to disaster. Using rudder opposite the direction of a rotation is a correct response if you have already entered a spin. But lowering the nose to reduce the angle of attack is the only way to ensure stall avoidance or recovery if altitude is available. Adding power can provide assistance in stall recovery, but use of rudder and/or aileron is absolutely not recommended until the stall is broken as it may aggravate your situation and put the aircraft into a spin. Cross controlling at the moment of a stall will produce a violent reaction in many fixed-wing aircraft. I discovered this the hard way about twenty years ago after demonstrating a robust entry to the maneuver to a student, and suddenly found the two of us hanging from the straps after the a/c rolled inverted (lots of altitude to recover thank goodness!). If this occurs at low altitude, again, no recovery method may be available to prevent a fatal crash.

Fourth, you claim that ”a FW pilot will fly it out and the asymmetry will have been of no great concern (except in an accelerated "g stall" involving a "flick" roll -but that should never be the case near the ground)” is another dangerously false statement. Any time you are in a turn, there is the opportunity to apply positive ‘G’ forces to the a/c. When a force in excess of 1 ‘G’ exists, the airplane will stall at an airspeed higher than the expected 1 ‘G’ stall speed. Back to our famous example, an inexperienced aeroplane pilot who has overshot final approach will have a tendency to over bank and induce higher G forces providing the opportunity to stall at a speed that he may have considered ‘safe.’

Fifth, your statement that ”The instinctive corrective action (differential collective applied laterally through the cyclic to pick up the dropping wing) is the one thing that is always going to greatly exacerbate the condition into a rapidly terminal roll.” demonstrates the true similarity between asymm settling and the fixed-wing stall/spin scenario better than I could have done myself. The key word is ‘instinctive.’ The ‘instinctive’ reaction of trying to raise a dropping wing when experiencing asymm settling is exactly the wrong thing to do in that situation. In the same way that the ‘instinctive’ reaction in trying to raise the nose of a dropping aeroplane when experiencing a fixed-wing stall is exactly the wrong thing to do in that situation. If there is enough altitude to recover, the correct procedure is to move the nacelles forward for asymm settling, and to push forward on the yoke to reduce the angle of attack in a fixed-wing stall. Another good example would be the ‘instinctive’ left cyclic in a negative ‘G’ roll to the right in a helicopter that may result in chopping off your tail boom. All three conditions will get you killed if allowed to develop, particularly at low altitude. The primary preventive method for all three is training for avoidance, recognition, and recovery.
____________________________________________________________ _________

You have a number of other logic-sequence errors and inaccuracies such as the above that are contained throughout your postings. But rather than go over them one by one, I’d recommend that you go back and reapply a new analytical approach to your “theories,” and I think you will be surprised at the results. If you use the approach described above, you will discover that your analysis will result in greater accuracy in developing theories that can be generally accepted as valid.

Good luck to you in the future.

(Oh, well – so much for my attempt at brevity.)

[This message has been edited by PTI UAE (edited 20 January 2001).]

PTI UAE

19th Jan 2001, 18:24

This type of contemptuous conduct needs to be brought to light and investigated thoroughly. If found guilty, nothing short of court martial should be the result for the commanding officer of the training squadron, and for anyone who had knowledge of this breach in safety. Great credit should be given to the “anonymous” individual who provided the evidence. Unfortunately though, it proves that that there are further problems beyond the act itself if this individual had to remain anonymous. There is definitely something wrong with the system overall, and an investigation and restructuring of the general practices and safety reporting system at the base should also be undertaken. There should be nothing in the way of someone with evidence that affects safety, and there are few things worse than tampering with maintenance records.

I have worked with a lot of people in aviation, and maybe I have just been fortunate not to have met anyone who would even remotely consider falsifying maintenance records for any purpose. It has been shocking to see that even maintenance supervisors at Major Airlines in the US have been caught in large scale programs of falsification where countless lives may be placed at risk. There is absolutely no place for this anywhere in aviation. There is no situation that warrants jeopardizing the safety of those who fly whether it be in the military or civilian world.

Unctuous, I understand that keeping emotions out of analysis can sometimes be difficult. But to say that the Marine “hierarchy would try to get the aircraft a “tick in the box” no matter how many Marines’ blood was spilt in the process” and other comments you added have certainly not been proven by the press release you posted. I added a post to your Arizona accident thread that I think could benefit you in the future. I believe you have the right intent, but the accuracy of the conclusions you draw from the facts could be improved if you do not add your emotional ‘beliefs’ without any supporting evidence. (see “MV22 Osprey Accident Theory” thread)

(PS: I have been politely asked via e-mail to help maintain ‘thread integrity’ by posting references to the Arizona Accident only to that thread, and comments on the December North Carolina Accident only to that thread. I will do so.)

[This message has been edited by PTI UAE (edited 20 January 2001).]

PTI UAE

19th Jan 2001, 18:31

Dalebert,

Most of the engineers I have met are fascinated and quite curious as to how the problems you described have been overcome, rather than declare as you have that it’s just not possible to accomplish. I think 4Dogs is right. If people had that attitude when the Wright Brothers were looking for support, we’d still be on the ground today!

The statement you made that tiltrotors have “no backup recovery methods” couldn’t be further from the truth. The amount of redundancy and back ups are like none I have seen on any other aircraft. Triple redundancy is standard in everything from hydraulics to flight control computers (in each case you can lose two of the completely separate systems and carry on the flight). And it can glide, it can autorotate, and in the XV-15 you can even eject!

There are two basic reasons for the very drawn out development period of tiltrotor technology – one is political and the other technological. On the political side, most of us are aware of the Pentagon advisor who for eight years convinced the then Secty of Defense Cheney that it would be better to spend money on nuclear capable projects rather than a new technology a/c for theater operations. He refused to allocate the money to the project even though Congress kept approving the funds and insisting that the development of the technology was in the National interest. As to technology, although the aerodynamic viability of tiltrotor technology was proven in the mid 50’s, it wasn’t until decades later that technology had progressed far enough in developing light weight composites, fly by wire systems, powerful and light turbine engines, sophisticated computer systems etc., all of which are necessary to allow an a/c to be developed with sufficient payload to be useful.

LU,

Things have changed quite a bit on the forum here since the middle of last year. It seems it should no longer be called the “Rotorheads” forum, but rather the “LU Zuckerman” forum (or the “Cat’s Forum” if you prefer). Your knowledge base obviously covers a wide range, and your level of experience is quite impressive.

I have read a couple of your posts on the V-22 and have been very interested in some of the problems you pointed out. I’ve looked into some of them to determine if they might affect the 609. Those of us who are customers are fortunate to have the opportunity to provide our input to the development program. I have had no involvement with the V-22 program as you have, but do have contact with those working on the development of the BA 609 (some of whom have experience with the V-22). Any experience that you have that may relate to the 609 program is of great interest. As I’ve said before, now is the time to look hard at any potential problems, not after the a/c goes into production, and I appreciate any input you may have.

I was told that the CATIA problems between Bell and Boeing you mentioned were resolved over 10 years ago. If you don’t mind me asking, when were you attached to the program? Regarding the hydraulic points you made earlier in the thread, I contacted the lead engineer working on the 609 hydraulic system and asked for his comments on your earlier post. He said that he cannot comment on specifics because of the current investigation, but offered the following:
************************************************************ *********
Electric Hydraulic Valves have been in aircraft for over 50 years. Their evolution has resulted not only in a very reliable device but also in the development of various means on monitoring EHV health to insure performance. Because the electrical portion of the EHV uses wire coils to create a magnetic field, the resistance of these coils can be monitored in-flight to insure the integrity of not only the EHV, but the aircraft electrical interface as well. The final mechanical stage of the EHV uses a hydraulic spool valve to direct fluid flow. Many aircraft monitor the performance of the spool by attaching a LVDT or similar position measuring device to the end of the spool. This allows the EHV spool position to be compared to its electrical commands to identify a failure. All Bell Fly-By Wire aircraft incorporate these EHV monitors on flight control actuators.

Reliability analysis is on aircraft typically used to develop estimates of maintenance requirements and aircraft safety. For maintenance requirements, the typical measure used to evaluate components is Mean Time Between Failures (MTBF). In determining an accurate value for a component MTBF, environmental factors (vibration, temperature, cycling, etc) are often use to raise or lower a value.

For flight safety, the typical measure used is Mean Time Between Flight Critical Failures (MTBFCF). In determining MTBFCF value of a component a very conservative approach is used. Only generally accepted values for component reliability are used. Vendor supplied values are only accepted if real word usage data can be verified. For safety analysis on all Bell aircraft, EHV operating time is the same as flight time.

Finally, at Bell, Flight Safety analysis is performed by a group separate from maintenance reliability and using different data bases.
************************************************************ *********
Lu, if you have a complete list of what you believe are problems on the V-22, I would be truly grateful if you would send it to me at PTI [email protected]. I will try to track down each item individually to find out what if anything has been done to correct the problems on the V-22, and find out if any changes on the 609 might be warranted. The V-22 and 609 are very different aircraft, and in many respects the 609 is seen as the “next generation tiltrotor.” In many areas there are additional redundancies built in that are not included in the V-22. Thank you very much for any assistance you can provide.

[This message has been edited by PTI UAE (edited 19 January 2001).]

PTI UAE

19th Jan 2001, 18:39

North Carolina Accident Update
Some information from the rumor mill is circulating on the possible cause of the December accident. The cause has not yet determined, so take it with a grain of salt at this point. They are saying there was some kind of a "lockup" in one of the V-22 hydraulic systems that prevented the other two systems from working. That certainly sounds strange for at least in the 609 all three systems are completely independent from one another (triple redundancy - only one system req'd to run the a/c). The one place where they "come together" if you want to call it that, is when they power separate actuators that perform the same function, like the flight controls, cyclic and collective movement, powering separate hyd motors on the conversion actuator, etc. An event happened a couple of months ago in the VMSIL (the hydraulic test facility where the 609 systems are being tested) that proved how the system should work in such an event. One of the actuators was purposely failed during testing (I believe it was a collective actuator) and when it stopped functioning, it momentarily failed to go into bypass mode. The power of the other two actuators did what they were supposed to, and physically broke the malfunctioning actuator. Had it happened in real life, there probably would have been a noticeable but momentary jolt felt by the crew and the appropriate CAS warnings would have illuminated. Bell's reaction to this was that the microsecond delay demonstrated a defect in the design that was not acceptable, and it was sent back to the vendor to be redesigned as necessary. It will be interesting to see where the failure occurred in the V-22 if it is hydraulic related. Again, the cause of the crash being hydraulic is only a rumor so far.

rotormatic

21st Jan 2001, 10:08

The CBS show 60 minutes in the States is going to have a story about the V-22 on January 21.

UNCTUOUS

22nd Jan 2001, 00:43

AIR CRASH RESCUE NEWS:

January 21, 2001 -
Crash of Textron-Boeing V-22 Blamed on Bad Hydraulics
WASHINGTON (USA) - The crash of a Textron Inc. and Boeing Co. V-22 plane that killed four Marines last month was caused by a ruptured hydraulic line and software failure, the head of Marines Corps aviation said.

The accident wasn't caused by pilot error, said Lt. Gen. Fred McCorkle.
Nor was the ruptured line caused by shoddy workmanship by the contractors, he said.

"Whatever the problem was with the hydraulics line or with the software, we'll fix,'' McCorkle said. "I don't think that anybody on this one is going to say `pilot error,' because the crew did everything they could do to save the airplane.'' The V-22 Osprey uses a tilt-rotor technology to take off and land like a helicopter and fly like an airplane. The December crash was one of two last year; in April, 19 Marines died in a crash blamed on pilot error.

The Marines' report on the December accident was released along with more evidence that V-22 maintenance records may have been falsified. The $38 billion program to develop the plane will be studied when the Bush administration reviews tactical aircraft programs this year. Ten years ago, then Defense Secretary Richard Cheney -- who'll become vice president tomorrow -- tried unsuccessfully to kill the program because of cost controls.

Letter, Audio Tape The Marine Corps today released the redacted text of an unsigned letter alleging that the commander of the service's only V-22 squadron told mechanics to falsify maintenance records.

Navy Secretary Richard Danzig received the letter -- purportedly sent by a Marine mechanic -- along with an audio tape in which the commander of the Marine Tilt-Rotor Training Squadron- 204 in New River, N.C., is heard ordering that maintenance records be altered.

The Lt. Col. O. Fred Leberman was relieved of duty as commander "because of a loss of confidence,'' McCorkle said.

The letter counters a claim by McCorkle and other service officials that the allegedly falsified records had nothing to do with flight safety.

"This type of deception has been going on for over two years, however, this is the first time it will affect safety,'' said the letter.

"This plane is not ready for the fleet,'' it said. "I have been on the program for 2 years. I have seen very few improvements over this period.

"Everything that is brought up as an issue is just brushed under the rug,'' the letter said. "This might be a great plane one day but not today. It needs to spend at least another 2 years in test, with people who will identify the problems so they can be fixed.'' Analyst's Reaction The Osprey is made by a joint venture of Textron's Fort Worth, Texas-based Bell Helicopter unit and Boeing's Ridley Park, Pennsylvania-based helicopter unit.

An analyst said the latest charges are serious and could have affect the companies' earnings.

"The statement that would be damaging -- if it has any validity -- is that the V-22 needs two more years of testing before it will be ready for production,'' said Paul Nisbet, a defense analyst for JSA Research Inc.

"If that is true, it could jeopardize the program, or at least delay production for another two years. This would delay the ramp-up of big production revenue at Boeing and Textron,'' he said.

`Need to Lie'
"We need to lie,'' Leberman said on the tape. "The reason we need to lie or manipulate the data'' is that until "a full- rate production decision, this program is in jeopardy.'' "Readiness is bad. That came out of (test reports). Everyone is hinging on that particular bit of information. It's something everything is focused on,'' Leberman said.

Leberman was referring to an assessment by the Pentagon's Director of Operational Test & Evaluation, Philip Coyle, who reported in November that the V-22 had a worse reliability record than the 36-year-old CH-46 helicopter it was replacing.

After the Dec. 11 crash, the Navy postponed indefinitely a decision on whether to approve the plane for full-rate production. The first contract for 15 aircraft is worth as much as $1 billion.

"At the end of the day, we believe the V-22 will enter full- rate production,'' said Bob Leder, a spokesman for Textron's Fort Worth, Texas-based Bell Helicopter unit that makes the aircraft with Boeing.

Doctored Records "What we have been doing is reporting aircraft that are down as in `they can't fly' as being `up,' as in `full mission- capable,''' said the letter.
"Full mission-capable'' is the highest readiness status an aircraft can be rated.

The Marine Corps Inspector General is investigating the allegations.

The new allegations come as a four-person board assesses the safety and combat effectiveness of the V-22 before the aircraft is put into full service.

UNCTUOUS

22nd Jan 2001, 00:57

January 20, 2001 -
Officer Admits Osprey Falsifying
WASHINGTON (USA) -
The commander of the Marine Corps' only Osprey aircraft squadron has admitted to superiors that he told subordinates to falsify maintenance records, two senior Marine Corps officials said Friday.
The admission raises the possibility of criminal charges against the officer, Lt. Col. Odin Fred Leberman, although Marine Corps officials said Friday that no decision had been made to start a criminal investigation.
The Marine Corps inspector general began interviewing members of Leberman's squadron Thursday at their Osprey base, the Marine Corps Air Station New River, N.C. He could recommend a criminal probe.

Leberman was fired Thursday, nearly a week after an unsigned letter and an audio tape were delivered anonymously to the office of the secretary of the Navy on Jan. 12 and forwarded to Marine Corps headquarters. The letter accuses Leberman of directing his subordinates to "lie about aircraft reporting.'' "What we have been doing is reporting aircraft that are down, as in they can't fly, as being up, as in full mission capable,'' the letter said, adding that this had been the practice for more than two years.

One day after the letter and tape were received, Leberman was confronted by superiors at New River. "He admitted that he had done essentially what was on the tape,'' one senior official said.

The senior officials discussed the matter on condition they not be identified.

At a Pentagon news conference Friday, Lt. Gen. Fred McCorkle, the head of Marine Corps aviation, told reporters he has no doubt that the alleged falsification of maintenance data played no role in either of two Osprey crashes last year that killed 23 Marines.

"Based on all the information we have at this time, we see no relationship,'' McCorkle said.

McCorkle said an investigation of the cause of the Dec. 11 Osprey crash in North Carolina, which killed four Marines, is ''99 percent complete.'' It concludes that the crash was caused by a failure of the aircraft's hydraulics system, followed by software errors that made the Osprey unflyable.

The last words from the Osprey crew were, "Emergency. We're going down.
We're going down,'' McCorkle said.

The Marine Corps on Friday released copies of the unsigned letter accusing Leberman. It was written by a person - believed to be a member of Leberman's squadron - who described himself as a mechanic with two years of experience with the Osprey.

"Maintainers are being told they have to lie on maintenance records to make the numbers look good,'' the letter said. "This is not what caused the previous two mishaps this year, but if it continues it will cause many more.'' It went on to cite "an attitude that we have to have the plane whether or not it is ready.'' The letter writer also provided an audio tape, allegedly of Leberman telling his subordinates to lie about the maintenance records. An unidentified man's voice - allegedly Leberman's - can be heard saying that Osprey flight readiness records must be falsified because "this program is in jeopardy.'' Leberman made the admission Jan. 13 to his immediate superior, a colonel who in turn passed the word to Maj. Gen. Dennis Krupp, commanding general of the 2nd Marine Aircraft Wing. Krupp relieved Leberman of duty as squadron commander on Thursday, the same day the Marine Corps inspector general arrived at New River to launch an investigation of the squadron.

Leberman, 45, had commanded the training squadron at New River since June 1999.

Calls to New River, where Leberman is based, to seek comment from him were not returned.

Leberman spoke at a memorial Dec. 15 for the four Marines who died in the crash near Jacksonville, N.C., saying each victim contributed to developing the Osprey.

"They were all patriots of their country,'' Leberman said. "They have done the hard job their country has asked them to do.'' The Osprey, which uses tilt-rotor technology to take off and land like a helicopter and fly like an airplane, has come under intense fire from critics, including some members of Congress, since one crashed last April in Arizona, killing all 19 Marines aboard. Investigators blamed it on human error.

The manufacturers are Boeing Co. and Bell Helicopter Textron.

HeliFlight

22nd Jan 2001, 08:44

Unctuous:
MUCH BETTER! Looks like you learned from PTIUAEs' recommendation. By posting articles without adding frivolous comments at the end you can make known a REAL problem without taking away from the serious subject matter with silly comments. Now you have something we can all agree on. Good job. Now could you PLEASE get back to us on all those unresolved points on the MV-22 theory thread that we have all been waiting for. Thank you.

[This message has been edited by HeliFlight (edited 22 January 2001).]

UNCTUOUS

24th Jan 2001, 16:51

From: "Jim Crint" <[email protected]>
To: <[email protected]>
Sent: Wednesday, January 24, 2001 8:08 PM
Subject: Re: V-22 Osprey - December 11 Crash

Dear Rhett
In answer to your query (below), I would expect that it may have gone something like this:

a. Hydraulic System Failure (Pressure) Warning and no automatic backup from / switch to #2 hyd system

b. Attempted resets fail to restore hydraulics from #2 system and pilot attempts "conversion" whilst some accumulator pressure remains (possibly for anticipated autorotation). Conversion stops due to hyd pressure depletion (after a few degrees only - of nacelle tilt) but sufficient to make the AND/OR "gate" for the software to "see" that the a/c is no longer in FW mode (and that a full conversion has been selected).

c. So, nacelle-tilt having failed due to depleted hyd pressures, the Osprey remains in FW mode but .......

d. Control inputs having been made for conversion (and possibly autorotation), as per software-defined parameters, the prop-rotors fine-off significantly over the normal 12 second conversion period - but in FW mode this is ALL massive flat-plate PROP-DRAG and an extreme nose-down attitude would be quickly required for safe FW flying speed. Software-dictated application of differential collective in FW mode would likely also result in both loss of aileron control and weird yawing effects.

e. With prop-rotors at zero-degree tilt (i.e. FW mode), poor (no?) roll-axis control and having lost airspeed to below FW stall values, the Osprey drops a wing and enters a FW spin from 700ft. The evolution (from failure to control loss) has taken 28 seconds.

The software "error" (so called) is likely to have been due to the programmer's failure to anticipate a possible non-resettable hydraulic failure followed by a pilot's solution of conversion (with or without autorotation) - which then fails (due hyd loss) shortly after leaving FW mode. I doubt that a complete loss of hyd pressure (of itself) would cause the prop-rotors to fine-off fully to the flat (fine)-pitch setting (but one never knows for sure). I believe policy has been not to teach or practice MV-22 autorotation as there should be no call for it (with all the back-up systems) so an attempt to enter autorotation is probably unlikely.

The "fining-off" that would occur simply as a result of the software believing that conversion was happening, plus the change to differential collective (lateral) control may have been enough to cause a complete loss of roll-control for an MV-22 stuck in FW mode due to a hyd fail (system or leakage). The solution? Do not attempt conversion -remain in FW mode, lower the gear and the frangible blades should depart their hubs fairly safely on touchdown. This may not be an option on board ship. Software should more closely be gated throughout the conversion mode-change.

As to why the redundant hydraulics couldn't take over, hydraulics are funny like that. It very much depends where the pressure sensors and signalling transducers are with respect to leaks and NRV's, PRV's etc. I suspect that the leak was upstream of a PRV or NRV. Just another Sioux City (UA232) type design glitch I'd suspect - not necessarily software-related. They (design-team) didn't "go with the flow" when thinking through the need for a foolproof rapid transition to secondary hydraulics in any failure scenario. There's a big difference between a hyd-fail in a fixed wing and a tilt-rotor. In the tilt-rotor you cannot sit on your hands or wind the clock. They only had 28 seconds from warning to control loss.

Jim Crint

From: "Rhett Flater, AHS Headquarters"
<[email protected]> Reply-To: "Rhett Flater, AHS Headquarters" <[email protected]>
To: <[email protected]>
Subject: V-22 Osprey - December 11 Crash
Date: Tue, 23 Jan 2001 18:29:40 -0500 Jim -

We exchanged a few emails regarding vortex ring following the April Murana crash of the Marine's V-22. Your comments were very helpful. Currently, I'm following the December 11 investigation and I would be very grateful for any information you may have.

The preliminary indications, as you probably know, are a hydraulic failure (one of two and one-half systems) possibly compounded by a software problem. According to one version, the aircraft was level at 700', when a hydraulic failure warning light appeared. The pilot(s) hit a "reset button" (which one I don't know) 16 times (recorded on the flight data recorder) - after the fourth such effort the proprotors - in full airplane mode (contrary to initial reports) - supposedly went to flat pitch (this is very strange).
The aircraft entered a nose-down attitude 28 seconds later after the initial warning of a malfunction. At this time, the pilot issued his mayday call, "Emergency, emergency. We're going down, we're going down," or something close to that. The aircraft impacted the ground 2 seconds later.

The investigation will, I assume, have to be extended to rule out whether maintenance or operational readiness misrepresentations allegedly encouraged by Col. Leberman were a factor. In the meantime, and until issuance of a definitive report, the industry will be on the receiving end of a great deal of speculation and inuendo, e.g., 60 Minutes, etc.

Do you have any further information?

Best regards.

Rhett M.E.
Rhett Flater
AHS Executive Director
Tel. (703) 684-6777; Fax (703) 739-9279
Email: [email protected]

[This message has been edited by UNCTUOUS (edited 24 January 2001).]

Lu Zuckerman

24th Jan 2001, 18:04

A failure of this type and magnitude should have been highlighted and analyzed during the construction of the respective Failure Mode Effects Analyses (FMEA). It should also have been considered in the construction of a Fault Tree Analysis (FTA).

In my short tenure at Boeing Helicopters I was not aware of the preparation of any safety analyses and the FMEAs were a joke. A former employee of Boeing formed his own company and got a contract to prepare the FMEAs. In order to prepare a detailed analysis the individual must not only be technically knowledgeable but he/she must have direct access to the engineering department. The FMEAs were for the most part prepared in New Jersey and not at the Boeing facilities and the individual analysts would make an appearance at the Boeing facility to do the final preparation of the FMEAs.

Bell on the other hand prepared the FMEAs themselves and were so far behind in the work that Boeing had to provide assistance. It is my asumption that the Bell FMEAs were no better than the Boeing FMEAs.

The completed FMEAs were vetted by an office of the US Navy that was based in the state of Indiana. This office was totally non communicative when pressed for answers relative to the work being done on the FMEAs by two colleagues and myself. My part of the job dealt with structural failures and it in itself was a bigger joke than the basic FMEAs.

------------------
The Cat

PTI UAE

25th Jan 2001, 18:53

January 25, 2001
Defense Dept. Takes Over Marine Inquiry Into Osprey Records
By JAMES DAO

WASHINGTON, Jan. 24 — The Department of Defense inspector general took control today of the investigation into accusations of falsified maintenance records for the Marine Corps' V-22 Osprey aircraft program, raising the possibility that the inquiry would be broadened to include high-ranking Marine officials.

The announcement by Secretary of Defense Donald H. Rumsfeld came less than one week after the Marine Corps began investigating whether the commanding officer of its only V- 22 squadron had ordered subordinates to cover up problems in the program. The innovative aircraft has been plagued by production delays and crashes that have killed 23 marines in the past year.

Rear Adm. Craig Quigley, a Pentagon spokesman, said the Department of Defense inspector general typically assumed control of investigations when there was evidence that wrongdoing might extend above the rank of rear admiral or one-star general.

But Admiral Quigley and Marine officials said they knew of no evidence suggesting that the misconduct extended above the V-22 squadron commander, Lt. Col. Odin F. Leberman. Pentagon officials say Colonel Leberman has acknowledged falsifying records; he has been relieved of his command and transferred to Camp Lejeune, N.C.

The Marine Corps asserted that the Marine Corps commandant, Gen. James L. Jones, independently asked Mr. Rumsfeld this morning to have the Department of Defense inspector general take over the investigation to dispel even the appearance of a conflict of interest.

Still, a senior senator said today that he had heard that Marine officials above Colonel Leberman might have been implicated in the wrongdoing.

"Recently I have heard that it may well have" gone above Colonel Leberman, the senator, Carl Levin of Michigan, the ranking Democrat on the Senate Armed Services Committee, said in an interview.

Mr. Levin and Senator John W. Warner, the Virginia Republican who is chairman of the Armed Services Committee, sent a letter today to Mr. Rumsfeld urging him to appoint an independent panel to investigate the charges of falsified records. Both senators said that they were satisfied to have the Department of Defense inspector general conduct that inquiry.

In their letter, the two senators threatened to block financing of the Osprey program unless "the Defense Department has restored confidence in the integrity of the V-22 program and the people managing it."

A second panel, created late last year by Mr. Rumsfeld's predecessor, William S. Cohen, is reviewing the entire V-22 program.

The Osprey, a tilt-rotor aircraft, takes off and lands like a helicopter, but flies like a propeller plane. The Marine Corps wants to buy a total of 360 of the aircraft, at a total cost of over $30 billion, to replace its fleet of Vietnam-era transport helicopters.

Although the Pentagon has postponed a decision on whether to begin full production of the Osprey, the Marine Corps is still scheduled to receive 20 more V-22's in the coming two years.

The investigation into Colonel Leberman began when the Navy received an anonymous letter two weeks ago from someone claiming to be a Marine mechanic who asserted that efforts to falsify maintenance and performance reports had been "going on for over two years."

Marine officials contend that there is no link between the the two crashes last year and the maintenance records that are said to have been falsified.

Lu Zuckerman

26th Jan 2001, 09:22

Report itemizes risks of Osprey; GAO says full production a threat to Defense budget
By Tony Capaccio
Bloomberg News

WASHINGTON -- The U.S. Defense Department will incur "significant risk" if it approves full production now of the V-22 Osprey, according to the U.S. General Accounting Office.

The $83 million aircraft -- designed to fly like a plane but take off and land like a helicopter -- may prove unsafe and cost more than forecast to maintain, the GAO says in a 31-page assessment obtained by Bloomberg News.

The Osprey, manufactured by Fort Worth-based Bell Helicopter Textron and Boeing's Pennsylvania-based helicopter unit, has a history of safety and reliability problems including two crashes last year that killed 23 Marines. And last week, the Marines said they're reviewing evidence that V-22 maintenance records were falsified.

The Marine Corps on Wednesday turned over to the Defense Department a week- old investigation into allegations that records were falsified.

The decision by the Marine Corps commandant, Gen. James I. Jones, was aimed at preventing the inquiry from being compromised by an "unwarranted" perception that the Marine Corps investigators would try to protect the program, the service said in a statement.

The development came as the top Republican and Democratic members on the Senate Armed Services Committee called on Defense Secretary Donald Rumsfeld to convene an independent review of the allegations.

The panel's chairman, Sen. John Warner, R-Va., and Sen. Carl Levin, D-Mich., warned the new Pentagon chief that the crash-tainted aircraft could be in trouble on Capitol Hill.

"Congress has consistently supported this program," they said in a letter to Rumsfeld. "However, this program will not be able to move forward unless and until the Defense Department has restored confidence in the integrity of the V- 22 program and the people managing it."

An independent investigation is important because there is a possibility that, if maintenance records were fabricated, people other than Marines may have been involved,

Warner said in an interview.

He said he was referring to a letter written by a whistle- blower that said the fabrication of records had begun more than two years ago while the V- 22 was still being tested. He said he was satisfied with Jones' decision to turn over the investigation to the Pentagon.

The Marines say there is no link between the crashes and the maintenance records that are being investigated.

The analysis by the GAO, Congress's independent audit agency, said there is "significant risk with proceeding with full-rate production. Knowledge of V-22 design and performance falls short of what should be known before beginning production."

A decision to authorize production "poses risks for Department of Defense operations and budgets," the GAO said.

The V-22 is susceptible to a steep rate of descent and it " appears to be less forgiving than conventional helicopters" when that happens, the GAO said. A "loss of controlled flight can occur at any time, and consequences are exceedingly grave."

The Jan. 12 assessment was submitted to an independent panel of defense experts convened by former Defense Secretary William Cohen after the Dec. 11 crash.

The GAO report is the latest bad news and will likely fuel opposition in Congress to the Osprey, the Pentagon's sixth- largest weapons program with a price tag of about $38 billion.

"For every one congressman who has been a fervent defender there are three who will look at it as a place to get cash for other programs," said Richard Aboulafia, a military aircraft analyst for the Teal Group in Washington.

"I think there's a good chance the production decision will slip but I still think it will go through," he said. "It's just a matter of time. You don't spend billions developing a totally new way to fly and then abandon it."

The V-22 is to be the Marine Corps' primary aircraft for ferrying troops into combat and for hostage rescues, embassy evacuations and peacekeeping missions. Deployment is scheduled to begin in 2003. Full-scale development of the V-22 started in 1986. About one-third of Bell's 6,400 workers in Fort Worth and Arlington are engaged in V-22 related work. The companies split V-22 revenue.

An earlier deadline for a decision on whether to approve the aircraft for full production was postponed after an accident on Dec. 11 that killed four Marines. A previous crash, on April 8, killed 19 Marines.

The GAO assessment, which melds and interprets the findings of three earlier reports, echoes a Marine Corps legal opinion compiled after the April 8 crash, the GAO said. That opinion hasn't been made public.

Marine Corps spokesman Lt. David Nevers said it would be "inappropriate" for the service to comment on a document submitted to the panel before it has completed its overall evaluation." Spokesmen for Textron's Bell Helicopter unit and Boeing declined to comment.

The GAO assessment will likely be part of the Bush administration's review of tactical aircraft programs, including the Lockheed Martin Corp. F-22 fighter and the experimental joint strike fighter.

Vice President Dick Cheney attempted to cancel the V-22 when he was Defense secretary in the early 1990s because of long-term cost concerns.

Ten years later, those concerns remain. The V-22's poor maintenance record poses long-term risks to Marine and Navy weapons budgets "as cost increases beyond already budgeted funds are likely," the GAO said.

Boeing shares fell 6 cents to $57.43 in trading of 2.9 million shares on the New York Stock Exchange. Boeing shares have risen 29 percent in the past year. Textron shares rose 81 cents to $47.93 in trading of 725,000 shares. Textron shares have dropped 21 percent.

Jonathan S. Landay of Knight Ridder Newspapers contributed to this report.

------------------
The Cat

UNCTUOUS

26th Jan 2001, 21:18

Triple Redundancy in the Osprey

Bell V-22 Osprey - correct sensor outvoted
"John Wodehouse" <[email protected]>
25 Sep 91 09:23:00 EST
Further information about the V-22 crash from Flight International 18-24
September 1991.

"A Bell-Boeing V-22 Osprey tiltrotor is flying again for the first
time since the crash of aircraft number five on its first flight in
June. Aircraft number three has made at least three flights, after
extensive checks by the US Navy (USN).

The USN has also released a brief report on the accident, which
reveals that similar faults have been found in two other aircraft.
It says that TWO roll-rate sensors (my capitals), know as vyros,
which provide signals to the flight control computer, were
reverse-wired. In the triple-redundant system the two faulty units
"outvoted" the correct sensor, leading to divergent roll cycles and
a crash shortly after take-off.

The report says the cockpit interface unit is connected by a
120-wire plug connector in which the vyro unit uses numbers 59 and
60 - which were reversed. Examination of aircraft one and three
revealed that one vyro in each was also reversed.

The number three aircraft flew for 18min on 10 September in a flight
cut short by extremely poor visibility. It flew again the next day,
and was to complete a third flight on 13 September."

What worries me is that aircraft one and three were obviously flying
with one vyro reversed-wired for quite sometime. The triple-redundant
system would have outvoted this vyro, but why was no indication given
that there was a problem at all. What confidence does that provide for
other systems, which depend on voting, if the failure is not reported.

My feeling about triple-redundancy and voting are worried, not so much because
two bad units outvoted the good one in this case, but that the systems design
allowed two aircraft with one bad unit to continue to fly for quite some time without
alerting anyone to the problem.

If the same sort of system allowed an airliner to fly with only two out of
three unit working correctly and a further failure then occurred over
mid-Atlantic, I think passengers might give up flying. From the USN report, we
are lead to believe that this problem existed from aircraft build time and thus
the whole testing of the triple-redundant system must thus be flawed. I just
cannot see how a system can be built that does not allow for the check to see
if all units are working correctly and providing the correct data before
take-off. The facts show that I am not correct here.

Lord John --- the programming peer

[We have reported on similar cases in RISKS before. For example, see
J.E. Brunelle and D.E. Eckhardt, Jr.,
Fault-Tolerant Software: An Experiment with the SIFT Operating System,
Proc. Fifth AIAA Computers in Aerospace Conference, 355-360, 1985,
where two programs written by different people to the spec of a correct
program had a common flaw, and outvoted the correct program. PGN]

UNCTUOUS

26th Jan 2001, 21:23

Re: V-22 Osprey (Wodehouse, RISKS-12.41)
A. Padgett Peterson <padgett%[email protected]>
Thu, 26 Sep 91 08:25:34 -0400
Not having the wiring diagram, second-guessing is dangerous but
consider the case in which the triple sensors are not "reverse-wired" but
cross-wired (e.g. sensor 2 is connected to input 1 & vs). In this case, with
"all good" everything is fine. If 3 fails all is ok. However if 1 or 2 fails,
the other is reported failed, voted out, and an immediate mismatch occurs
between 3 and the failed sensor (still considered good). The flight control
must now rely on some other (and often lesser) means of selection (usually a
calculated value or range checker) of the proper value.

This is an inherent problem in any flight-critical design that relies
on detection of "first-fail". In this case the failed sensor was evidently
a "second-fail" condition but thought "first-fail" & is a very real concern.

Another concern not mentioned (and again merely hypothesised) is that
from the text, it would appear that at least two of the critical triplex sensor
signals are routed through a single connector, not a good idea since connectors
are one of the major failure areas. (there are some other equally dangerous
possibilities that also have to be considered, i.e., if the signals have
redundant routing shouldn't that have caused a mismatch).

On the quadruplex AFTI-F16, one of our concerns that influenced
a number of routing decisions was the number of simultaneous faults that
could be caused by one 20mm cannon shell.

Of course, it is all too easy to second guess a design team after
the fact, on first flight everyone is crossing their fingers, anyone who
isn't shouldn't be there.
Padgett

UNCTUOUS

31st Jan 2001, 23:55

Too many questions remain about the Osprey
J. Stryker Meyer
Commentary
At least one Marine Corps aviator in the troubled MV-22 tilt-rotor hybrid aircraft program has done something to "the proud, the few" that no military enemy accomplished in the Corps¹ 225-year history: He has tarnished its integrity.

Ten days ago, Pentagon investigators raided the Marine Corps MV-22 headquarters in New River, N.C., searching for evidence against the commanding officer of the air squadron who allegedly told his troops to falsify MV-22 maintenance records to ensure that the test aircraft would go into full production. It was a sad day for the Marine Corps.

If the green light were given for full production, it would have allowed the Defense Department to begin spending $30 billion to produce 360 MV-22s despite unanswered questions about whether the high-tech aircraft can perform at the level Marines need to survive in combat.

Many members of Congress want the contracts to flow to the businesses in more than 40 states that will share in the lucrative construction contracts.

But the Dec. 11 crash of an MV-22 that killed four Marine aviators was the second fatal crash in 2000.

The criminal investigation of possible falsification of records has diverted the public's attention from several disturbing flaws in the MV-22, flaws which must be corrected. Because the Corps¹ integrity has been damaged, drastic actions must be taken to restore America's confidence in the Marine Corps' aviation wing.

A presidential panel should be convened, with subpoena power and the ability to offer witnesses immunity from prosecution. Because the Marine Corps¹ integrity is at stake, this panel should have a limited number of Marine or Navy personnel on it. Experts in the Air Force, the General Accounting Office and the Institute for Defense Analysis know the strengths and the flaws of the MV-22. They should be on the panel, whose findings must be made public.

The so-called Blue Ribbon Commission that former Secretary of Defense William Cohen hastily threw together to look into the last MV-22 crash should be terminated. None of its four members are familiar with helicopters, let along a hybrid machine like the Osprey. Evidence from this panel's early hearings indicated it is just another rubber stamp to certify the Corps¹ desire to see this aircraft go into full production.

The Marine Corps¹ top aviation general, Lt. Gen. Fred McCorkle, should be asked to retire, or removed from his position in aviation. The buck stops at his desk. He should step down and insist that the Commandant of the Marine Corps, James Jones, appoint a new director of aviation.

The criminal investigation should be expanded to include the staff of the Defense Department's Officer of Testing and Evaluation. Until Jan 19, Phil Coyle headed that department, which is mandated to study all new weapons systems before they go into full production.

Coyle developed a reputation as a no-nonsense evaluator. However, he was removed from his post Jan19. Government and Pentagon insiders said key staff members under Coyle ignored, misreported and distorted critical comments about the MV-22. Yet no one in the Pentagon appears to be addressing that conduct, conduct which may be criminal.

For example, during a hearing this month, Coyle told the Blue Ribbon Commission that the Navy had a database containing more than 1,000 pages of reports and test results, many of which contained detailed criticisms of the MV-22. However, it is unclear whether Coyle has reviewed that information.

Have officials at the GAO seen it? Have officials from the Institute of Defense Analysis, which studied the MV-22 and handed a critical report to Coyle, been given the database?

In November, Coyle issued a 154-page report on the MV-22 based on the institute's research. However, Coyle must be asked how much more critical his report would have been had he been able to review the Navy data base.

Test officials from Boeing and Bell, who are working on getting the MV-22 approved for full production, should be subpoenaed and forced to testify under oath about these questions:

Why there was no provision for testing and training pilots of the MV-22 on how to cope with the phenomenon called power settling or asymmetrical vortex ring state ---- a condition in which one of the tilt-rotors essentially stalls when the plane is in helicopter mode. When that happens, the other tilt-rotor drives the aircraft upward until it turns toward the earth and plows into the ground. This is what happened in Arizona eight months ago, when 19 Marines died during a test flight.

Why there was no testing for autorotation, again when the aircraft is in its helicopter mode?

The Chief of Naval Operations should be forced to testify why he signed off on so many waivers on the MV-22, making it easier to get the aircraft approved for full production before critical tests were completed. One item waived was a requirement that pilots get a specific number of flight hours documented before they carry passengers.

The Air Force has rigid standards for every new passenger aircraft. Yet for reasons unexplained, that requirement was waived for the MV-22. Navy officials will not release details about that waiver.

The Marine Corps should be ordered to release the complete accident reports on both MV-22 crashes in 2000. The Corps is withholding elements of the April investigation. Why? The report on the December crash has not yet been completed.

The Defense Department's entire weapons purchasing procedure must be reviewed and improved to protect taxpayers' dollars. The system in place today, whether by intent or ineptitude, hides too much from the public and the people who need to know the truth about a new weapons system.

Marine Commandant Jones recently reiterated his confidence in the MV-22. During a June interview, after he and his wife flew in an MV-22 and Jones announced the return to test and evaluation flights, he remained high on the aircraft and the platform which will transport his Marines deep into enemy territory faster than any conventional helicopter in the world.

I've interviewed Jones and remain impressed with his sense of duty and his love and devotion to the Marine Corps. I'm not convinced that Gen. Jones has been given the entire truth about the MV-22, particularly the many critical assessments from Marine aviators who filed complaints in the Navy database that has been hidden from Coyle, the public and investigators.

As a vote of confidence, Jones should be appointed Chairman of the Joint Chiefs of Staff. He has earned that appointment by his outstanding leadership as Commandant.

This reporter is alive today because Marine aviators saved my reconnaissance team several times during missions deep into enemy territory during the Vietnam War. I believe in Marine aviation and wish this series of tragic events had been avoided altogether. Marine aviators have distinguished themselves throughout history.

For Jones, all Marines and the families of the troops killed in MV-22 crashes, a full probe into the aircraft must be conducted publicly. The ongoing criminal cases should resolve the integrity issues.

No more Marines should die in the MV-22 killer albatross until the probe into the MV-22's airworthiness is concluded. Then Jones will be able to make a clear decision based on all of the facts.

North County Times staff writer J. Stryker Meyer served in the U.S. Special Forces in Vietnam from 1968-70.

1/28/01
[email protected]
©1997-2001 North County Times [email protected]

UNCTUOUS

1st Feb 2001, 12:25

Top Marine Generals implicated in Osprey maintenance and safety cover-up:

CBS News:
http://cbsnews.com/now/story/0,1597,268618-412,00.shtml

Dagger Dirk

3rd Feb 2001, 13:22

http://www.geocities.com/dagger_dirk/cheyneyviewa.jpg

UNCTUOUS

3rd Feb 2001, 22:56

http://www.capitolhillblue.com/Article.asp?body=Osprey&Submit=Submit&ID=1197

Conflicts of Interest on Osprey Probe Panel
Friday, February 02, 2001

By JOHN WAGNER
McClatchy Newspapers

A four-member panel appointed to evaluate the future of the Marine's troubled V-22 Osprey program may not be quite as independent as the Pentagon advertised, critics say.

One member of the panel, appointed after a fatal Dec. 11 crash in North Carolina, is Eugene Covert, a retired Massachusetts Institute of Technology professor who held a university position funded by Boeing Co., one of the Pentagon's two primary contractors for the Osprey.

More generally, critics question whether panel members are too tightly connected to the military and the defense industry to render an objective judgment on whether the Marines should move forward with a program that the corps' leaders say is essential to their future.

Besides Covert, the panel includes:

_ Retired Marine Gen. John Dailey, a life-long flight enthusiast who now heads the National Air and Space Museum in Washington.

_ Retired Air Force Gen. James Davis, a lobbyist whose post-military career includes a stint as "safety czar" for discount airline ValuJet.

_ Norman Augustine, the retired chief executive officer of Lockheed Martin Corp., the largest defense contractor in the country.

Former Defense Secretary William Cohen appointed the group, promising "an independent, high-level review" of the performance and safety of the Osprey, a unique aircraft that flies like a plane but takes off and lands like a helicopter.

The $40 billion program was abruptly halted after the Dec. 11 crash in Onslow County, N.C., that killed all four Marines on board. Four of the 15 Ospreys delivered to the Marines thus far have now crashed, killing 30.

The group is scheduled to deliver its findings to new Defense Secretary Donald Rumsfeld within three to four months, and its recommendations could prove pivotal as to whether the program continues.

But not everyone thinks Cohen found the best men for the job.

"Anytime anything in Washington is billed as 'independent,' it rarely is," said Luke Warren, an analyst for the Council for a Livable World, a watchdog group critical of the V-22. "In my mind, an independent panel on something like this should have no connection to the Pentagon whatsoever. The question is whether this thing can fly. There are plenty of civilian engineers who could answer that."

While doubts about the Osprey are growing among key members of Congress, the leadership of the Marines continues to express confidence in the program, even in the wake of recent allegations of doctored maintenance records at Air Station New River, where the V-22 training squadron is based.

Retired Adm. Eugene Carroll, now a weapons analyst with a Washington think tank, said that because of the panel members' military ties, they may feel "institutional pressures" to give the Osprey the benefit of the doubt.

"They're members of the club, and they may not want to jeopardize their membership," Carroll said.

Lt. Col. George Rhynedance, a Pentagon spokesman, said Rumsfeld supports "the process and procedures" of the panel, but he referred all questions about its composition to a Washington consulting firm led by Cohen. A spokesman for the firm did not return phone calls.

Under instructions from the Pentagon, panel members also declined to be interviewed.

Dagger Dirk

4th Feb 2001, 13:38

(From Aviation Week magazine, January 29, 2001)

V-22 Support Fades Amid Accidents, Accusations, Probes

ROBERT WALL/WASHINGTON

The second largest customer for Bell, Boeing's V-22 tiltrotor, the U.S. Air
Force Special Operations Command, is reconsidering its commitment to the
system in the wake of technical problems and revelations about
maintenance irregularities that have thrown the program into turmoil.

Pentagon officials said there is increasing concern
about the V-22 within the Air Force. However, service officials have not
yet decided whether to drop out. Two development CV-22s, the special
operations version of the Osprey, are among the aircraft still grounded
after the Dec. 11 crash of an MV-22 in which four Marines died.

LOSING AFSOC SUPPORT would be an immense blow to the V-22's main proponent,
the Marine Corps, and not only because it could further undermine confidence in
the program. The loss--reducing the tiltrotor procurement by 50
aircraft, the number AFSOC plans to buy--would increase the $66-million
average cost of the aircraft. Some say the cost is actually higher,
although the Marines quote a lower price.

Signs that confidence in the
program is waning also could be detected last week in Congress. Sens.
John Warner (R-Va.) and Carl Levin (D-Mich.), the senior members of the
Senate Armed Services Committee, wrote Defense Secretary Donald H.
Rumsfeld that "this program will not be able to move forward unless and
until the Defense Dept. has restored confidence in the integrity of the
V-22 program and the people managing it."

Additionally, the Senators
asked Rumsfeld to order-up an investigation into charges that the
Marines falsified V-22 maintenance records. The tip came from an
anonymous mechanic at the V-22 training squadron, VMMT-204, who stated
that the squadron commander, Lt. Col. O. Fred Leberman, ordered the
doctoring of information to improve the aircraft's poor reliability
rate. The Marines dispatched a team of eight to Marine Corps Air
Station New River, N.C., home of VMMT-204, to investigate and they
relieved Leberman, who now faces the possibility of a courts-martial. He
was replaced by Marine Col. Richard H. Dunnivan. The senators called on
Rumsfeld to ensure the allegations would be reviewed independent of
other examinations of the program, which include a blue-ribbon panel set
up by former Defense Secretary William Cohen, and two separate accident
investigations. The lawmakers stressed that the latest look should not
involve the Navy Dept., which was investigating the charges. Hearings on
the V-22 are expected later this year, once the findings of several of
these program assessments are completed, said one congressional staffer.

IN AN UNUSUAL MOVE, apparently aimed at defusing the lawmakers' ire, the
Marines announced only hours after the senators' announcement that the
Marine Corps Inspector General (IG) investigation into the fraud charges
was being transferred to the Pentagon IG. "While I have complete
confidence that the (Marine Corps) IG and his staff would conduct a
thorough, complete and unbiased investigation into these allegations, I
am concerned that the nature and gravity of the allegations may invite
unwarranted perceptions of command influence or institutional bias,"
Marine Corps Commandant Gen. James L. Jones said in a statement. He
added that the Air Force also would benefit more from an independent
investigation. Although much of the recent attention has focused on the
falsification of information, perhaps one of the most damning
indictments in the whistle-blower letter was the view that "this plane
is not ready for the fleet." The writer added that "it needs to spend at
least another two years in test, with people who will identify the
problems so they can be fixed." The Marines contend the aircraft has
been tested thoroughly and that further efforts aren't needed. But
serious technical issues remain unresolved. That became clear as the
Marines laid out more information from the nearly complete mishap
investigation into the Dec. 11 crash. The accident was caused by a
confluence of technical problems. Essentially, a combination of
hydraulics and software failure led to the crash, according to Marine
Corps Lt. Gen. Fred McCorkle, who oversees Marine aviation. The flight,
designated Crossbow-8, was on its final approach into New River, about 7
mi. from the airfield. The aircraft was suffering a leak in its No. 1
hydraulic system that drives flight-critical systems, such as actuators
changing the angle of the nacelles and swashplate actuators which are
used to control collective and cyclic blade pitch that allow thrust
control when in airplane mode. At the moment the pilot started
converting the aircraft from its forward-flight, fixed-wing mode into
helicopter mode for landing, the hydraulics failed. The pilot pushed the
rotors from the 90% fixed-wing mode they had reached back to full 100%
fixed-wing settings but the aircraft crashed moments later nonetheless.

The V-22 is equipped with a triple-redundant hydraulic system and a
mechanism that is supposed to be able to compensate for hydraulics
problems in one line within 0.3 sec. Hydraulic levels are monitored by
the flight control computers that monitor system pressure, reservoir
fluid levels and changes in those levels. If an anomaly is detected, a
combination of local switching isolation valve and remote switching
valve are supposed to reroute hydraulics fluid from other systems, in
this case the second and third, to compensate for the loss in the
primary system. But that emergency system failed because of a software
problem, although the Marines wouldn't identify if the faulty logic was
in the flight control computer or another subsystem. Bell has opted for
a less risky hydraulics system in its BA609 civil tiltrotar which will
operate at 3,000 psi. Despite a history of hydraulic problems, McCorkle
contends that the fact that the latest crash was associated with
hydraulics doesn't raise questions about the aircraft. "[T]his
hydraulics failure has zero to do with technology with the tiltrotor or
with the MV-22," he insisted. He said the hydraulics failure was caused
by "a line that was rubbed through." The Marines ruled out that it was
simply a bad hydraulics line, but were unwilling to explain how it could
fail after only 160 flight hours.

THE V-22'S HYDRAULIC system has been
a headache for the Marines for some time ( AW&ST Jan. 1, p. 32). It was
the single largest failure item during the 804.5 hr. of operational
testing. The system was designed to operate at 5,000 psi rather than the
more traditional 2,000-3,000 psi. because it allowed for lighter and
smaller components. But it has also made the hydraulic system
leak-prone, the Pentagon test officials found. Although the Marines
insist the MV-22 is production ready, they are still working on a number
of design changes, particularly in hydraulics. Development testing led
to seven immediate changes, with four more in the works and additional
fixes being considered. The Marines and the informant both said the
falsified maintenance records had nothing to do with the Dec. 11
accident or one last April in which 19 Marines died. "This is not what
caused the previous two mishaps this year, but if it continues it will
cause many more," the anonymous mechanic said. However, it is unclear
whether accurate maintenance records may have led to safety-related
design changes on the aircraft.

Returning V-22s to flying status isn't
expected anytime soon, noted one Marine Corps official. It would have to
wait at the very least until the IG investigation is almost complete.

©January 29, 2001 The McGraw-Hill Companies Inc.

Dagger Dirk

4th Feb 2001, 21:08

FEBRUARY 5, 2001 VOL. 157 NO. 5
NATION
Wounded Osprey
Revelations show that the revolutionary new plane is in deeper trouble than the Marines have said
BY MARK THOMPSON/WASHINGTON

When the Marines stripped Lieut. Colonel Odin Leberman of his command of the corps' lone V-22 Osprey squadron, Leberman admitted that he had told his mechanics to falsify maintenance records to make the troubled aircraft look better. The Osprey, despite 18 years of work and a $12 billion taxpayer investment, needed all the help it could get. Two crashes in the space of eight months had killed 23 Marines, aggravating concerns of the Pentagon about the aircraft's reliability as it weighed going into full-scale production. But now, as the Pentagon begins full-blown probes into both the Osprey and Leberman's conduct, new doubts are being raised about the plane's safety, utility and readiness that go far deeper than the Marines have yet acknowledged.
Some challenges are to be expected when building a revolutionary aircraft that takes off and lands like a helicopter but cruises like an airplane--at twice a chopper's speed. As pilots like to say, military flight manuals are written in blood. The growing question around the Osprey is whether its rotor design has a tendency to push the aircraft into a roll that quickly turns into a fatal plunge. Such dives "can occur at any time and consequences are exceedingly grave," according to an unreleased General Accounting Office report circulating on Capitol Hill. "The V-22 appears to be less forgiving than conventional helicopters."
But even if the plane is safe, there are pressing concerns about the military value of the V-22. While the Marines insist the Osprey is ready for production, it has not been approved for combat maneuvers and lacks its required gun. The winds created by its dual 38-ft. rotors are so strong that landing in a desert kicks up sand "brownouts" that can blind pilots and rescuing someone from the sea is made extremely difficult. Marines climbing down ropes from Ospreys in combat simulations aboard ships or oil platforms have to hit the deck and stay there until the aircraft departs or risk being blown overboard. Communications gear aboard the Osprey is so ineffective that the plane cannot efficiently contact other aircraft, nor can it land at some airports without escort planes outfitted with better electronics to guide it safely through the skies.
But the Osprey's real bugaboo is the amount of maintenance it requires, which is why Leberman ordered his troops to falsify records. "Maintainers are being told they have to lie on maintenance records to make the numbers look good," a V-22 mechanic said in an anonymous letter to the Pentagon. What is amazing is how bad the numbers are--even after the deception. A recent independent review, apparently incorporating the misleading data, said the V-22s were fully prepared for their missions just 20% of the time, well short of the corps' 75% requirement. An Osprey crash last April in Arizona, killing 19 Marines, highlights the plane's maintenance woes. The Osprey had spent only 135 hours in the air during the three months the Marines owned it. Yet it needed 600 repairs--one fix for every 15 minutes of flying time. The Osprey is far less ready for action than the Vietnam-era CH-46 chopper it is supposed to replace.
And then there are the nickel-and-dime problems that many in the Pentagon say shouldn't be cropping up in a planned $38 billion program on the verge of production by Bell Helicopter and the Boeing Co. The doors on each $83 million craft are difficult to open, the interiors lack hand grips so that passengers can safely move about the cabin in flight, and the heating and cooling systems can't maintain comfortable cabin temperatures. In the hot confines of the cabin, Pentagon testers noted, Marines will have to drink a lot of water to be ready to fight, which highlights another shortcoming: the V-22 has no toilet facilities.
Despite these concerns, Marine officers say, the Pentagon was well on its way to approving full-scale production. Then a December Osprey crash killed four Marines and, a month later, disclosures about the fudged records put that decision on hold. For now, the Pentagon's 12 Ospreys remain grounded.
It was more than a decade ago that Dick Cheney, who was then running the Pentagon, tried to kill the program because of its high price tag. But the corps and its allies on Capitol Hill waged war against him and won. Now a new battle over the Osprey looms. If Vice President Cheney decides to wage war again, this time he will come far better armed.
END
http://www.time.com/time/magazine/article/0,9171,97098,00.html

The Sultan

5th Feb 2001, 02:54

Unctuous,

Jesus (not you), these diatribes of yours against the V-22 are wearing thin. Some say you sound like Grady Wilson being coached by Mike Wallace.

The Sultan

UNCTUOUS

5th Feb 2001, 22:56

PTI-UAE
a. I think Lu Zuckerman's first post on this thread says it all regarding your motivation (in addition to his later email to me). I refer to your emailing him (before he'd posted) and asking him not to post on this thread. But as various people kept bringing the thread back onto the page, and thereby accessible, I guess the mystic reason for your last lengthy unfathomable post was to volumetrically (and pastily) consign the thread to readable obscurity. Condescending homilies about basic aerodynamics and glib obfuscations merely constitute a filibustering attempt to deflect the reader's attention from the very real problems facing tilt-rotor design, (flaws and foibles). So that was a bit desperate IMHO and if you'd like to recapture your credibility I suggest you (and inept henchman HeliFlight) try to concentrate on the core issues - as they've latterly emerged. If I appear to be questioning your "impartiality" re the Osprey, perhaps anyone would get the impression from this next thread that your future is very much tied to tilt-rotor success - so your bias and denial is quite understandable. http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000389.html

We'll assume that you're not personally implicated in the great tilt-rotor "tilt".

Reference your 19 Jan post (on the "Another MV-22 Lost"???.thread) and your taking exception to the reference to the "hierarchy having little concern for the troops..":
Well, apart from that being one of the express motivations of the whistle-blower:

a. You must somehow consider that a reported 73.2% (just below min acceptable for full production) versus the real MC rate of 20% does not at all compromise the integrity of the OPEVAL and the fixes that may have otherwise been put in place (and which would have obviously made it a safer operation).

b. Bearing in mind that Generals James Amos and Fred McCorkle are now fully implicated in the maintenance and serviceability data fraud (by their emails), it would seem that the hierarchy was focussing on something other than safety.

c. But don't fret because, looking at the J. Wagner article (on that thread), about the make-up of the "independent" review team (Blue Ribbon Commission), one cannot be at all reassured that the review, as constituted by Cohen, will be impartial at all. i.e. The MV-22B will assuredly go on - as intended by that rubber-stamp exercise.

So perhaps, now having taken in all those points, you might consider your criticism to have been a little unfair. And that is apart from the fact that it was a direct post of an email that accompanied the article - it came from very close aboard. There was nothing emotive about it at all for someone with a little insight into what has been happening on the inside - and the likely outcome of the review.

to mention a few relevant specifics:

a. Cautions about rates of descent at low IAS were added in June (after Marana) to the MV22B's pilot's Manual (NATOPS).

b. The JAG REPORT agrees fully with AsymmVR being a problem:
When the service released copies of the JAG report, the opinions and recommendations sections were deliberately omitted, leaving unresolved key questions about their contents. However as Head of the Civil TiltRotor Consortium you will have seen these (as have I) and know that AsymmVR is assessed as a real problem (as confirmed by the Pax River Flight Trials in August). Abiding concerns about AsymmVR were also reflected in both Director Phil Coyle's OT Report and the recent GAO Report.

Some Telling Quotes:

"Coyle (Dir OT) developed a reputation as a no-nonsense evaluator. However, he was removed from his post Jan19. Government and Pentagon insiders said key staff members under Coyle ignored, misreported and distorted critical comments about the MV-22. Yet no one in the Pentagon appears to be addressing that conduct, conduct which may be criminal." NC Times

"The growing question around the Osprey is whether its rotor design has a tendency to push the aircraft into a roll that quickly turns into a fatal plunge. Such dives "can occur at any time and consequences are exceedingly grave," according to an unreleased General Accounting Office report circulating on Capitol Hill. "The V-22 appears to be less forgiving than conventional helicopters." "The GAO assessment, which melds and interprets the findings of three earlier reports, echoes a Marine Corps legal opinion compiled after the April 8 crash, the GAO said. That opinion hasn't yet been made public in full."

"The contributing factors to the mishap -- a steep approach with a high rate of descent and slow airspeed, poor aircrew coordination, and diminished situational awareness -- are also not peculiar to tiltrotors, the report continues. "However, the end result, rapid departure from controlled flight, is more extreme than results experienced in most rotorcraft to date," the JAG report concludes.

"There's a GAO Report out that says there's a fundamental flaw in the design of the aircraft" Dick Cheney in a PBS interview.

"A recent independent review, apparently incorporating the misleading data, said the V-22s were fully prepared for their missions just 20% of the time, well short of the Corps' 75% requirement. The Osprey had spent only 135 hours in the air during the three months the Marines owned it. Yet it needed 600 repairs--one fix for every 15 minutes of flying time. The Osprey is far less ready for action than the Vietnam-era CH-46 chopper it is supposed to replace." Time Magazine (http://www.time.com/time/magazine/article/0,9171,97098,00.html)

"As the Bush defense mavens settle in, they are expressing an early predilection to press on with the F-22 (fighter) program. More vulnerable than the F-22 is the V-22 tiltrotor. Said one (military) briefer of the new senior civilian leaders: 'It's still not ready for production after 10 years of development, and the Bush Administration doesn't want to be tainted by supporting it.' They think the Marines could buy UH-60 variants, CH-53's, and the improved CH-47 for vertical lift assignments". Jan 01 Aviation Week magazine in the WASHINGTON OUTLOOK column on page 25:

Now remember that these aren't UNCTUOUS opinions, but quotes from reports based on the JAG report, GAO assessments and the PAX River Trials' Findings.

by contrast:
some PTI-UAE Quotes:
"?.add warning devices such as temperature gauges, pressure gauges, warning lights (temp & press), and chip detectors so that an impending failure will be recognized in order to provide the pilot with enough time to get the a/c on the ground before complete failure occurs." - suggest you check timings on Dec 11th crash.

"?your theory that a warning device is not possible." -waiting anxiously (but not expectantly). The dynamic nature of the asymmVR onset (two secs to unrecoverable) would likely be such that any software-based warnings would be coincident with the terminal roll.

"It was believed that the conditions required to encounter it were too extreme to consider. They were wrong. The fact that the accident did occur shows greater understanding is required and it will now be studied further. No matter how extreme the conditions must be to get you into it, the point is it can happen." << consider that 95 degree tilt plus interim power may be a deadly combination for AsymmVR entry.>>

I concede that 95 degree rotor-tilt was a later add-on to the XV-15

Problems (a continuing lack of understanding) exemplified by:
"No, absolutely not," Lt. Gen. Fred McCorkle told reporters on May 9 (and again at a later date) when asked if there was is any evidence to suggest the V-22 is more susceptible than other rotorcraft to power settling or settling with power. McCorkle, the assistant commandant for aviation, said he believes the V-22 is less susceptible to such conditions when compared to other helicopters. "In fact, I would say [the V-22 is] less [susceptible] because of the amount of power that it's got."

Solutions
The only way to stave off the lethal potentiality of asymmVR as a rapid onset terminal handling problem is to go for greater disk solidity (more blades means a progressively less intense vortex-sheet and delayed ring formation). Three is not enough, five would be good - but of course there is a great weight penalty for that, as well as prohibitive complexity in a five-bladed hub.

There are some politicial obstacles to cancelling the V-22. Assembly to be in Texas (Bush's home state) and in Pennsylvania (in district of Rep. Kurt Weldon, conservative Republican). Is Sikorsky an option? The plant is in Connecticut, home of Sen. Joe Lieberman, Gore's ex-running mate. Politics may triumph over performance.

I'd guess that only about 50% of soft orders for 609's will fold. But being "soft" orders, the funds are quite productively sitting in escrow - so maybe none at all in the long interim.

BTW John Farley and I don't have any disagreements at all. We're long-time friends - and from the same service. His first post to the thread was at my instigation. You can have copies of our emails at the time if you'd like. JF knows exactly who I am and my background. He's always been a gentleman and me a pragmatist. At least, if he's disagreed with what I've had to say, he's not brought it to my attention. Not trying to put him on the spot here at all. It's just that you (PTI UAE) brought it up (although the point was lost on me).

http://www.g2mil.com/V-22.htm The V-22 Fiasco

http://cbsnews.com/now/story/0,1597,268618-412,00.shtml Top Marines in Osprey Cover-up
http://www.angelfire.com/me/swissair111memorial/modded/ThatVexingVortexRing.html
(six pages)

[This message has been edited by UNCTUOUS (edited 05 February 2001).]

Lu Zuckerman

6th Feb 2001, 20:43

To: All

The individual that requested that I not add credence to the various posts by posting a reply has asked me to clarify one point. It was not PTI that made the request alluded to in the post by Unctuous. So, I guess an apology is in order

------------------
The Cat

VLift

6th Feb 2001, 22:22

Lu

You were asked not to add creedence to an argument? From your post above.

"One other theoretical question, if the aircraft is in an autorotational situation and the proprotors are being propelled by the upward flow of the onrushing relative wind can the vortex ring state be initiated when the flow of air is up and not down. Get out your thinking caps and figure this out."

First understand that the vortex ring we worry about in the context of this discussion as opeators of rotory wing aircraft is not normally the one at the blade tip but the one created near the center of the rotor system at the line of demarcation between the normally downflowing air and the upflow of air caused by the aircraft descending at a rate faster than the air from the rotor system in this area is descending. No bonus for sentence structure is claimed.
Helicopter pilots are taught this as a basic part of operational theory. No thinking caps required.

If the aircraft is in an autorotational situation and has no appreciable forward speed component the rotor RPM will slow, as the resultant realitive wind is at too great an angle to provide for the forward rotation of the blades.

As the rotor slows the air being pushed down in the center of the system is even less and more of the center area is occupied by air going up through the rotor system. So, more of the rotor system is not contributing lift, aircraft descends faster.

Now increase pitch and further increase the resultant angle and make all above worse.

With sufficient forward speed in autorotation, the resultant wind is at a sufficient angle to not exceed stall angle of the blade section. Also remember that a forward speed autorotation and a too steep descent at a too slow airspeed are different maneuvers, hopefully.

So, vortex ring state is not a problem associated with what a helicopter pilot considers an autorotation, a maneuver designed to help deal with a problem, not cause it. (Hovering auto not considerd)

[This message has been edited by VLift (edited 06 February 2001).]

Lu Zuckerman

6th Feb 2001, 23:09

To: V Lift

I guess I didn’t have my thinking cap on when I formulated the question.

The problem as I see it is covered in the second and second last paragraphs in my post. It was my understanding that the pilot tried to arrest his descent rate by pulling aft cyclic and at that time he entered into the Vortex Ring State and the aircraft fell out from underbneath him and he crashed. At that time he was falling at 2000 FPM. My question was if a V22 pilot has to enter into an autorotation (with no other conversion available) and his rate of descent is 4-6000 FPM and he enters into a cyclic flare (which is what the pilot in Arizona did) to arrest his rate of descent will he or, will he not enter into Vortex Ring State. The two situations appear to be the same. Even if he doesn’t enter into Vortex Ring State he is still unable to arrest his rate of descent in order to keep from crashing the aircraft.

IMHO

------------------
The Cat

PTI UAE

8th Feb 2001, 13:35

UNCTUOUS,

Here we go again…some kids just never learn. Once again you have driven off the cliff of absurdity, but this time you forgot to fasten your safety belt.
____________________________________________________________ _________
a. (the first ‘a’ ;) ) Starting at the top, you have completely missed the mark again (or pulled an “Unctuous” as we like to say). I made no request of Lu Zuckerman to refrain from posting on this thread. The individual who e-mailed him also contacted me to request that I not make any posts on a thread that Mr. Zuckerman was posting to at that time. The reason given was to “maintain thread integrity” by keeping posts related to the Marana accident only on that thread, and posts pertaining to the North Carolina accident only on that thread. If you read the P.S. on the bottom of my post on 19 January on the ‘Marine V-22 Maint Falsification’ thread, you will see where I described that request which was made to both myself and Mr. Zuckerman. Once again you have failed to get the facts straight before posting. I will give you credit for one thing though – consistency.
____________________________________________________________ ________
As far as your comments on the length of my previous post – ‘those who live in glass houses should not throw rocks.’ If you do a side by side comparison, I would imagine you have taken up at least five times as much space with your posts than I have with mine. Take a look at the length of the post you made above compared to my previous post that you were complaining about – were you making “a filibustering attempt to deflect the reader's attention from the very real problems facing your flaws and foibles in a desperate bid to recapture your credibility”? Furthermore, my two posts were in response to seven unanswered posts of yours, some of which were more “voluminous” than mine (but if you want to say mine is bigger than yours, that’s fine with me). The bottom line is: if you stop posting so much BS, I can reduce the amount of anti-BS postings.
____________________________________________________________ ________
Regarding my involvement as a future operator of the 609, I have always been forthcoming on this forum. A better forum link than the one you chose to show my exact involvement would be: http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000289.html
I have provided my name, contact numbers, and other background details so that all are free to evaluate my comments knowing my perspective. I have no connection with the V-22 program, and although we are an operator of Bell Helicopters, I have no direct affiliation with any manufacturer including Bell or Boeing. As a participant on the 609 Steering Committee, we are bringing our views as rotorcraft operators to the process at Bell’s request to ensure the end-users point of view is not overlooked.

You on the other hand make continuous but vague claims to having “inside information” (which invariably turns out to be false). I take great care to ‘footnote’ sources of information to prove reliability, while you make great efforts not to. Perhaps it’s time for you to come out of the closet.
____________________________________________________________ _________
It appears you lost the plot again after your in-depth and highly illuminating discussion on ‘length of posts.’ I could not locate a sequential “b.” to respond to, so I will go on to your subsequent a. through c. I have made my position on the Marine falsification of records known on previous posts, but as you apparently missed those comments, I will reiterate:

Those with knowledge of records falsification appear to be at the highest levels in Marine Corp. aviation. The inexcusable cover-up they participated in is having an effect opposite of what they had planned, and is doing far more harm to the program than the maintainability problems they were trying to hide. The exceedingly low mission capable rates that were being experienced should have been dealt with openly and head-on.

If the MV-22 is showing a 26% mission capable rate, the only reasonable response is to determine why the rate is so low, and then decide how it can be brought up to acceptable levels. If it is not possible to bring the rate up to where it needs to be, then the program should be cut without question. If the rate can be improved to where it needs to be (as the Marines involved obviously believe it can be), then additional acquisitions should be put on hold until the required fixes are in place. Attempting to push the aircraft into a high acquisition rate before it is ready makes no sense. The result would be the large-scale acquisition of an aircraft not up to the job, and might create unnecessary potential risk to those who fly in it. Resolving problems before accelerating acquisition was the only logical path, and it is incredible that there are those in positions of control who were not able to recognize that. Obviously “percentages” can be misleading when you are dealing with a “fleet” of only ten aircraft (ex., simply pouring the wrong hydraulic fluid into five a/c could ground them and knock your mission-capable rate down by 50% for an extended period). But it is clear that some with hands-on experience believe real problems exist that need to be addressed. This can be seen in the statement made by the mechanic that blew the whistle on the Marine falsification when he wrote to the Secretary of the Navy, “This might be a great plane one day, but not today..”

The exposing of this attempted cover-up should serve as a warning to anyone that may consider maintenance falsification in the future, and the system as a whole should be thoroughly investigated and restructured as necessary to restore credibility. The loss of credibility by those in command of Marine aviation makes the Pentagon decision to take charge of the investigation the correct one. As I’ve said before, those involved must be made accountable for their actions.

As far as my criticism of your comment, Marine “hierarchy would try to get the aircraft a “tick in the box” no matter how many Marines’ blood was spilt in the process” – the criticism stands without question. When looking at the actions of individuals like the Marines that had knowledge of the records falsification, only someone with great arrogance and ignorance would dare say that they thought it would be a OK if their fellow Marines died as a result of raising mission-capable numbers. When the facts are in, what they did may warrant court martial and dismissal from the service, but their actions were not a malicious intent to allow Marines to die.
____________________________________________________________ _________
As to your miscellaneous quotes and disconnected ramblings about the Pentagon report by Philip Coyle, you provided the summation of what you were getting at in your own words. You made a post to the ‘Marine Falsification’ thread on 5 February that you subsequently deleted when a concerned reader had reached the limit of his tolerance with your claims. That post actually contained the final clue needed to confirm your intense motivation for tearing down tiltrotor technology regardless of the facts – you showed us it is pure, unadulterated EGO. Prior to this it was a bit baffling as to why you demonstrated such enthusiastic glee in both instances when Marines lost their lives in V-22 crashes, but it is now clear. Here is your last paragraph (verbatim) in the post that you deleted:

“It's also been quite gratifying to see Unctuous being quoted directly (although without attribution) in Phillip Coyle's (Director OT&E) Report as well as the GAO Report (I'm sure you've also got copies as head of the Civil Tilt-Rotor Consortium).”

You have hung your vanity out the bedroom window for all to see with this and the other comments in that post. You need to understand that you have looked with ‘tunnel vision’ and taken a few comments in Mr. Coyle’s report that are similar to yours, and declared yourself ‘famous.’ It is time to come back down to earth and listen to some of us lowly humans. If you read the report with a subjective outlook (your great self-proclaimed omniscience should give you that ability) you will find that there are a much larger number of positive comments for the technology than negative. Many of these are identical to the points myself and others have been trying to get across to you in this forum. I do not even remotely believe that Mr. Coyle made his comments because he reads PTI UAE on PPRuNe, and you would be better off to ‘reel’ in the EGO, and get a ‘real’ life. As ‘The Sultan’ tried to explain to you on another thread, ‘you are not Jesus, contrary to your personal beliefs.’ (Or perhaps you should just call your ‘insider’ friends at the Pentagon and demand that Mr. Coyle give you credit for your outstanding contributions)
____________________________________________________________ _________
Responses to “some PTI Quotes:”
1) Your childish attempt at distortion by taking a quote of mine regarding the methods of detection for impending transmission failure currently used on all helicopters being operated around the globe, and applying it to a probable catastrophic hydraulic failure on an accident currently under investigation deserves no response (other than: there you go again… ;).

2) As to your statement regarding warning devices for AssymVR, see the ‘John Farley’ response below.

3) The fact that you finally conceded that you posted false information devoid of the facts regarding the XV-15 tilt-angle was very promising. And knowing this admission would discredit the lengthy dissertation on your theory of how the V-22 developed AssymVR on this thread, it was a big step for you. But the fact that you blatantly lied and tried to pretend that it was an ‘add-on’ is disappointing and a sign the old UNCTUOUS is still with us. According to the NASA engineers that worked on the project, the XV-15 was built with 95 degree capability from the original design.

Having succeeded in conceding ‘half a point’ above, go back to the beginning of this thread and read through the posts with a new and more honest outlook. You will find that you have literally dozens of points you made (or tried to make) that have been clearly been proven false to an objective reader. You’ve started something good, see if you can carry on.
____________________________________________________________ _______
Your comment on the 609 options contains one falsehood (you speculate without a basis of knowledge) and one complete lie (you make a claim of knowledge when the truth is completely opposite – a very common thread throughout your posts).

The falsehood, “only about 50% of the soft order for 609’s will fold.” You couldn’t be much further from reality here (what else is new). The cost of development of the technological advances incorporated into the 609 have caused the value of locked-in orders to rise sharply. Options are now worth a tremendous amount more, and are being treated like gold.

The lie: “the funds are quite productively sitting in escrow…” There is no interest accrued that would be returned to an option holder in the event they claim back their deposit. Hence, ‘productive escrow’ is not a motivation for customers not to cancel orders. There is no penalty or gain relating to the initial deposit if a customer decides not to purchase an aircraft
____________________________________________________________ ________
As to your last comments, you may know Mr. Farley, but as you have proven time and again on this forum, You are no John Farley! Trying to put yourself even remotely in the same category with him is like comparing a Great White Shark to a neutered minnow.

Your comment, “if he’s disagreed with what I have to say, he’s not brought it to my attention” really hits at the heart of your problem – you don’t understand what people are saying to you. Look at the two quotes I took from posts in this thread:

UNCTUOUS: “The dynamic nature of the asymmVR onset (two secs to unrecoverable) would likely be such that any software-based warnings would be coincident with terminal roll.”

John Farley: ”…From this I conjecture that perhaps a couple of such sensors (optimally positioned) on each Osprey blade might just produce the necessary error signal of DIFFERENT aerodynamic circumstances on parts of the SAME blade, to satisfy a solution to the warning system requirement.”

When you read the following quote posted earlier by Mr. Farley, do you think that he is not ‘disagreeing’ with your repeated claim that AssymVR is a fatal flaw in tiltrotor technology:
John Farley: VR is by all accounts not a very stable state of affairs (as the RAE found when trying to stay in it for the trials I mentioned earlier) so I have a gut feel that a quick AUTO nudge forward (5 deg?) of the engine nacelle tilt angle might be sufficient to kill the build-up of VR before it spreads to the whole blade.

Mr. Farley also mentions in detail that the Harrier had a similar characteristic which was resolved. Try going back and read his posts again. At least I see one good thing from your comments: you have proven that you are not selective as to who you choose to ignore – it’s everyone that doesn’t agree with you.
____________________________________________________________ _________

Now do you see how I responded to your points one by one above? It is really quite easy when we stick to the facts. The reason you repeatedly come out on the short end of the stick is your inability to focus on what is true. When you start inventing facts, you lose credibility. Despite requests from forum readers, you have repeatedly avoided answering all of the challenges that were posed to you with regard to falsehoods contained in your “theories.” Your avoidance is a natural reaction to having been so badly discredited on this forum, as is engaging in irrational and false attacks as you have done above. You can run, but you cannot hide from the facts.

Now that I have indulged you in your ‘tit for tat’ exchange, I think it is time to return to professionalism. Personal attacks, and false accusations do not benefit anyone, and worse, it takes away from the point of the forum – to engage in constructive discussions of aviation issues.

[This message has been edited by PTI UAE (edited 09 February 2001).]

HeliFlight

8th Feb 2001, 18:16

Uncy doodle doo:

After this typical blunder of yours charging ahead without knowing what you are talking about, you have really made yourself the laughing stock. If you can get a hold of a big red nose and long floppy shoes, there’s a good job opening for you in the CIRCUS.

I take it back…THAT was this biggest public spanking since Saddam in the Persian Gulf War! Uncy you dropped your pants and bent over for him with that post, so you did it to yourself. Talk about asking for it!

I was the one who sent e-mails to both LU Zuckerman and PTIUAE. I asked them to keep the different accident threads separate so people can see the difference between the ridiculous fiction you were trying to push about the Arizona accident “theory””, and the serious discussion going on about hydraulics on the other thread.

And tell your “HENCHMAN” he can stop posting different articles ad nauseam that all say the same thing using different words. We heard it all…and nobody is disagreeing!

Anyway…Don’t worry about your credibility…. You don’t have any on this Forum.(yes...Lu Zuckerman e-mailed me your message to find out who said you had no credibility)

And by the way….How does that foot taste??? The facts speak louder than fiction-but I am sure you learned nothing, I’ll bet anything you’ll be back for more of the same. It would be hilarious if it wasn’t so sad. You actually believe yourself, but luckily you are the only who does(except for your biggest fan Philip Coyle of course)

For PTIUAE:
I really like that “pull an Unctuous one…that is going to be REALLY popular over here.

[This message has been edited by HeliFlight (edited 08 February 2001).]

helidrvr

8th Feb 2001, 18:31

:rolleyes: What is it about the number 22 that gets some people's blood boiling to the point where they lose all sense of perspective? Lu, have you checked the out-of-trim characteristics of the Osprey yet? :)

QED http://www.pprune.org/ubb/NonCGI/cool.gif

------------------
You are welcome to visit HELIDRVR here (http://helidrvr.cjb.net)

HeliFlight

8th Feb 2001, 18:44

Sorry about that helidrvr. I think your right, I'm afraid I got a bit carried away.

I'm feeling a little out of trim myself.

I guess you could say I "Pulled an UNCTUOUS" :) :) :) :) :) :)

HeliFlight

[This message has been edited by HeliFlight (edited 08 February 2001).]

John Farley

8th Feb 2001, 19:04

PTI UAE and Unctuous now hear this…………..

Cor chaps! Heavy posts!

May I be allowed some comments on the bit of a duel that has developed?

From my perspective it seems that PTI UAE is pro a civvy tiltrotor application and Unctuous is anti the USMC using the MV-22 as a device with which to force their way in to a defended area day and night.

I don’t see any conflict between those views. Or if you prefer it I think you are both right
on the big issues (if not all the little ones)

Why?

Asymmetric VR

Asymmetric VR requires such a high rate of descent before it can threaten safety that it should be perfectly straightforward to stay well clear of it while landing a civvy tiltrotor. I do not see it lurking in the background of every civvy tiltrotor approach any more than the stall or spin lurks in the background of every airliner landing. So I back PTI UAE’s efforts to press ahead with attempts to obtain high speed cruise as well as VTO/VL

So far as the military combat application is concerned I fear the jury is still out on the asymmetric VR thing. Exactly where is the boundary on the MV-22? If it is established that the boundary is clear and can be reliably stated in suitable terms (a big if) the next issue is how close can it be cuddled up to – given whatever aids or warning devices may be developed? Clearly a combat landing needs EVERY bit of manoeuvrability the device can provide. If this turns out to be too restricted (less than current choppers for example) the job starts to look dodgy. I am certain a lot of good minds are currently wrapped round those issues and the likes of us can only wait and see what transpires.

Reliability

History suggests that mechanical/electrical problems and even software issues can be hacked in time whatever aircraft we are talking about. My crystal ball suggests the potential benefits that the tiltrotor has to offer civvy and military alike are so big that the engineering aspects WILL be solved in time. It’s called progress and on a scale of Wright flyer to today’s best military and civil aircraft in less than 100 years the current tiltrotor issues look pretty small beer.

You have a good day, both of you. JF

PTI UAE

8th Feb 2001, 19:57

Thank you John,

As usual your words of wisdom are right on the money. I’m afraid that both Unctuous and myself allowed our discussion to degenerate to the level we have seen on other threads in recent times. I was quite pleased that we had been able to conduct good discussions of the issues until lately. I must share the blame, as I too allowed the comments to become personal rather than an impartial discussion of what are important matters in both the development of civil aviation technology and defense acquisition concerns.

Jim,

I apologize for getting a little too personal in my comments to you. You are certainly entitled to your opinion, and in spite of the fact that I strongly disagree with your methodology of analysis and theories, I respect your right to voice your opinion.

I will not spend time and use space on the forum in responding to what has become a discussion with too great an emphasis on individuals rather than the issues. It is more important that discussions are conducted in a courteous and professional manner if they are to achieve anything at all.

I will not engage you in personal exchanges again. If anyone has questions as to the validity of your statements, they should feel free to e-mail me at PTI [email protected] and I will research their questions and respond.

Good luck in your future.

[This message has been edited by PTI UAE (edited 08 February 2001).]

John Farley

8th Feb 2001, 20:25

PTI UAE and Unctuous

OK, moving on to details

You may view the following as off the wall or as common sense. Only time will tell…

When I was fortunate to fly the first prototype P1127 in 1964, I found it a real handful. taking off and landing in whatever mode. It seemed to me to require more skill than I could guarantee and each time I got out I was grateful that I had not bent it. I was clearly leaning pretty heavily on my luck. During the next five years the P1127 produced the Kestrel and that produced the Harrier. By 1971 I was at Pax River helping Lt Harry Blot decide how the USMC should go about their business in it.

This AV-8A needed the pilot to operate two controls with his left hand - a conventional throttle and a nozzle selection lever. Thirty years later as the AV-8B it is still the same and needs special training in techniques as a result. However, it is no longer a difficult aircraft to control and needs no special piloting skills (whatever the mates may try and tell you in the bar)

BUT, if you accidentally move the wrong lever you will likely crash. For example raising
the nozzles in the hover or closing the throttle in the hover. There are plenty more in the same category (all tried and tested) such as raising the nozzles on a VTO and charging across the ground on a demo fully armed into the nearest bunker, closing the throttle off the bow of a ship during an STO instead of putting the nozzles down, This sort of simple mistake (not an error of handling skill) can of course be made by anyone. Just like the Blottle case that Unctuous explained so well.

OK, so how do we prevent such mistakes and thus save the cost of specialist conversion training let alone the accidents? An obvious start is to use the possibilities offered by automation to require only one left hand control. In this case the blottle or a collective. Perhaps a bit better, but still (as we know) far from perfect depending on the pilot’s background.

So my preferred solution is to only use one hand, the right one, to fly the aircraft. I will rephrase that, use only one hand, the right one to steer the aircraft. I don’t think pilots (any more) should fly (ie use skill to control) aircraft. Rather they should only tell the aircraft the manoeuvre they want it to perform.

From 1971 to the current date a research Harrier has been flying looking at simplifying the piloting task for a powered lift aircraft. This VAAC Harrier can be flown in many different modes. The one I far and away prefer (and all the current Harrier mates hate) is to use the right hand only. It is just two years since I last had an opportunity to look at the latest software standard but in the way of things I am sure it will be even better now than then.

Both of you could both go out to that aeroplane and with no more brief than I am going to give you below do a VTO go out to Vmax, decelerate and come back and do a VL.

How so? Strap in, take the pins out (after all there are such things as bird strikes) and when you are ready pull the stick back. (that means you want to go up by the way) The computer will say OK we have no airspeed so it puts the nozzles down, opens the throttle fully and up you go. At 50 feet (say) you let the stick go to centre. The computer says OK not up and not down so it hovers. Being real test pilots you then say Ha! - and wedge the stick fully forward. Oh dear says the computer, we have a right one here, doesn’t he realise we are at only 50 feet I am going to creep down from here.

Pull back again to go up, and when clear of obstacles ahead hold the trim type switch on the top of the stick fully forward. That is the go faster signal. If you hold it there the aircraft will take you through transition and when the nozzles are aft reduce the flap appropriate to the speed.

Do what you want to in the - go left - go right - go up - go down - business and enjoy your trip. Adjust your speed as you wish on the - go faster - go slower - switch.

When you want to land you know what to do, hold the switch back until it stops where you want it to and push the stick forward to go down.

Now that is what I call progress from the P1127

Of course the mates HATE it, because it makes them all the same as each other.

So gentlemen, what’s wrong with “flying” your tiltrotor like that?

The Nr Fairy

8th Feb 2001, 20:52

John :

I'm only adding my two penn'orth because if I don't mention it now I'll forget.

The brief you mention is so simple even I could have a go at it. However, it relies on lots of clever electronics doing the right thing at the same time. If they decide they're the master, rather than a willing slave, then some sort of manual reversion is needed, rather than throw an expensive aircraft away just because Bill Gates expanded into mission-critical systems. Where does that leave our one-handed pilot ?

PTI UAE

8th Feb 2001, 21:20

John,

Interesting point you make as it parallels some of the discussions that have gone on over 609 flight control. The flight control computers in today’s aircraft have become so sophisticated that you can program almost anything you want into them. Triple redundancy is of course required to counter the fact that the weak link in the chain (us humans) are doing the programming.

During the transition from helicopter to aeroplane mode (and vice versa), the flight control computers can be made to automatically compensate for a combination of the changing thrust vector produced by the proprotors as the nacelles are tilted, and the gradual increase/decrease in lift being developed as the airflow changes over the wings caused by the variance in forward airspeed. The question comes up as to what the pilot would prefer to be feeling on the flight controls during the conversion (again anything desired can be programmed into the computers). Some pilots prefer to have a requirement to put in physical inputs to counter the change in the direction of the thrust vector so that they “feel” they have control over the varying forces during transition (i.e. when the proprotors tilt up, they want to be pushing forward on the stick to counter the change). Others prefer to let the computer do all the work so that they never have to know what the thrust vector and increasing/decreasing wing lift status is at any given moment in time. I tend to agree with the latter, as there will occasionally be those situations when the weather is down to minimums with driving rain, turbulence, a difficult approach, at night, etc., and the pilot workload will already be difficult enough without adding “normal” control variances into the mixture.

I don’t consider myself particularly lazy, but I like to have everything as easy as possible when the chips start piling up on the other side (although, like your mates, I must confess that I prefer to have two sticks in my hands rather than one -- no Blottle though thank you!).

Nr Fairy,

Perhaps not my place to respond to your question, but I think that technology has already put us at the point where there is too much going on for us simple human-beings to be able to handle. Most modern fighters and airliners have already made the transition to fly-by-wire systems (mandating computer control) for weight, rapid response and other concerns. The pilot will always be the final authority, but just as with the space shuttle, modern aircraft with greater capabilities than we have ever seen before are going to need the power of computers to control them.

[This message has been edited by PTI UAE (edited 08 February 2001).]

VLift

8th Feb 2001, 22:26

I am of the school mentioned above that doesn’t like the potential effects of electronic failure. I believe in the simplistic view that if the level of automatic function in the flight control arena is not supported by redundancy and reliability well beyond my wildest fear, I don't want to find that out while trying to build a vertical learning curve re-learning how the fly an aircraft that hasn’t had much need of me up to the "ah s***" point.
And maybe a different perspective is valid; how much automation is really necessary. I bought a television so I'm not completely against progress. But, I don't think symbiotic shuld mean the pilot should be outvoted by the machine with finality, or that the pilot can’t function without the machine. Modern commercial aircraft obviously don’t subscribe to my view. Don't know about their pilots.
I do however believe the pilots of military aircraft need help keeping things organized and executed when their decision per second ratio is at combat speed.

Mr. Farley, why is it you say that asymmetrical VR requires such a high rate of descent. The inference I read was a higher rate than single rotor VR. I’m curious.

John Farley

9th Feb 2001, 03:07

PTI UAE and Nr Fairy

I’m not keen on the term fly-by-wire because it is does not actually tell you much. Control through computer is literally more accurate, but for me the term that best describes what we are talking about lately in this thread is Manoeuvre Demand. Sadly, although much in use in the RAE during the 1950s, this apposite phrase never came into general use.

Back to aeroplanes. Once I had my first personal experience of an automatic system that FLEW the aircraft better than I could (actually an autoland trials Comet IV back in the 60s in a howling crosswind that was beyond my capabilities) I became a sucker for augmented and automatic systems.

Of course they can fail, and this is Nr Fairy’s valid point. Personally I do not think the answer to failures lies in manual reversion. Even without the complexity, weight and cost of installing both the automatic and the manual systems, there are the issues of training and currency in the reverted state, to say nothing of the fact that the job may well have moved on to one where it is beyond the pilot (like fog landings). No, the answer to failures is redundancy. It has to be.

So, in my simple world the question regarding synthetic handling and using computers is not “can it do the job?” (we know it can do that) but “will it be reliable enough?”

How reliable is that? Well ten times less likely to crash the aeroplane than a human pilot was what was chosen in the 60’s for certification of early autolanders. As one in every million civil landings (in those days) was a fatal accident due to pilot error (of whatever sort) the failure rate for autolands was set at one in ten to the 7th. Seemed to work. Come to think of it I don’t ever recall an autoland crash in line ops.

I promise to let it drop now!

John Farley

9th Feb 2001, 03:29

VLift

Sorry I did not mean to give that impression

I talked of Asymm VR just 'cos I think that it is quite likely that one side will get VR just before the other. No reason for thinking that, just guessing that control activity will happen to cause one side to go first. Could be quite wrong.

JF

Hoist

9th Feb 2001, 19:28

Having flown in both the 107 and the 234 in logging/fire fighting operations I would like to let all know that a tandem rotor can indeed get into settling with power. It is normally in the aft rotor, perhaps due to extreme decel angles but it does happen. The best method of recovery is to kick in pedal (sorry, forget if left or right is best) to get the head into clean air. I have experienced it so this is not a story. I suspect that the C130 driver/pilot did the natural thing when a wing started to drop and applied opposite lateral cyclic. This would have aggrivated the situation. Had he applied a pedal input to advance the rotor, he may have been able to recover. Since the Marines apparently do not train in Settling with Power recovery and since they seem convinced that a helicopter driver cant handle going more than 150kts in cruise, I expect they will continue to have problems. I still havent heard any feed back on the latest accident, if it was mechanical or pilot induced. Any info?

Hoist

9th Feb 2001, 19:58

Sorry, my last post was a bit behind considering where the Vert Lift conversation is at this point.
John brings up some very good points about using computers to eliminate some of the pilot "ooops" input. I started flying in the TH55 and I am now in a Bell 430, complete with a Rogerson Krados IIDS/EFIS display. Autopilot and Weather Radar as well. I have to admit that it makes life a lot easier when you turn on cruise control, coupled to the GPS and able to display your course/weather/4 closest airports etc. Even with this capability, we still practice manual IFR approaches in case of "black box" failure. I guess my point is that all the electronics are very nice but you still need some type of "two hands" backup in case electrons dont want to play.
Another problem is the FAA. When I was at Bell, I asked the test pilots why there wasnt a max power button on the collective that would use the FADEC to give you max engine power without exceeding any limitations. You currently have to bring the aircraft to a hover, then look inside to beep up the engines, a bit of a task when at max gross/gusty winds near a building. The response was that the FAA was concerned about the pilot having an overide in case of emergency. Which is more apt to cause a problem, the once in a blue moon engine malfunction or contact with an obstruction while hovering the aircraft? Bell said they came up with an overide but there were other issues that made it prohibitive. From what I'm reading, I think it is a major concern for Bell that if they use this available technology, the FAA is not going to be able to cope (accept) its cababilities.

HeliFlight

9th Feb 2001, 21:47

Attention UNCTUOUS:
Uh oh....did you read the above post- there goes another one of your theories-tandem helicopters do experience settling with power unlike your earlier claim. And not only that-they have ASSYMETRICAL settling with power!!!

Sounds like another fatal flaw in the technology as you describe it. Guess this must happen at the flick of the wrist so we better permanently ground and cancel all production of Chinooks and Ch-46s before they start experiencing a crash every few flight hours. (too dangerous for military missions especially) :) :) :)

This could be a mission for UNCTUOUS II - the sequel!! Better Rev up your posting motor!!! (and find lots of good articles about it that all say the same thing in different words so you can post them one after another to really keep people interested)

Cyclic Hotline

10th Feb 2001, 20:45

This link was posted on another site. Contains some interesting information.

http://www.insidedefense.com/public/special.asp

HeliFlight

10th Feb 2001, 23:51

Unctuous:
You have been posting e-mail from Rhett Flater the Director of the American Helicopter Society as though he was one of your biggest supporters. All of the items showed him asking questions that would make us believe you and him were in total agreement on the V-22. The letter from him below to the NY Times should set the record straight.
************************************************************ ******

Editor
The New York Times
229 West 43rd Street
New York, NY 10036

Sir:

Your editorial, “Dangerous Deceptions on the Osprey,” omits several facts essential to understanding the importance of the Marine’s V-22 Osprey program. The unique tiltrotor technology embodied in the V-22 provides capabilities unmatched by any other aircraft anywhere in the world. For the US Marine Corps, the V-22 Osprey proffers speed and range unsurpassed by existing helicopter designs, coupled with the ability to take off or land anywhere; this performance is vital to meet the Marine’s mission of rapid deployment anywhere in the world. It may be a “20-year old idea,” as your editorial states, but there is nothing – whether existing today or on the drawing boards – which offers comparable performance, capability, and operational flexibility.

Tiltrotor technology has been demonstrated by more than 4,000 hours of flight tests under the most rigorous standards. There have been four crashes during the life of the program, three of which involved tragic loss of life. The history of military aircraft development, however, suggests that risk is regrettably inherent in all programs featuring advanced design. None of the V-22 accident reports issued thus far suggests a fundamental flaw in tiltrotor technology.

The three investigations currently underway – the accident investigation, the Inspector General’s inquiry into Colonel Leberman’s conduct, and the oversight study ordered by the Secretary of Defense led by a panel of independent experts - are wholly appropriate. All Marine V-22 aircraft have been grounded pending evaluation of these reports. In the meantime, the media and the public should avoid a rush to judgment to terminate the program as recommended in your editorial, until – at the least – the reports become public and the facts are on the table for all to see.

Very truly yours,

M.E. Rhett Flater
Executive Director
AHS International

(The American Helicopter Society International)

UNCTUOUS

11th Feb 2001, 01:44

Feingold Floor Statement on Proposed V-22 Legislation

V-22 Special Report Main Page (http://www.insidedefense.com/public/special.asp)

Click here to view Bill Text (http://www.insidedefense.com/public/Feingold.htm)

S. 272. A bill to rescind fiscal year 2001 procurement funds for the V-22 Osprey aircraft program other than as necessary to maintain the production base and to require certain reports to Congress concerning that program; to the Committee on Appropriations and the Committee on the Budget, concurrently, pursuant to the order of January 30, 1975, as modified by the order of April 11, 1986, with instructions that the Budget Committee be authorized to report its views to the Appropriations Committee, and that the latter alone be authorized to report the bill.

Mr. Feingold: Mr. President, today I am introducing the Osprey Safety, Performance, and Reliability Evaluation Act of 2001. This legislation would delay the procurement of the V-22 Osprey tilt-rotor aircraft for one year, and would require reports from the Secretary of the Navy and the Department of Defense's Inspector General regarding the program.

The Osprey is an experimental tilt-rotor aircraft that takes off and lands like a helicopter, but flies like an airplane by tilting its wing-mounted rotors forward to serve as propellers. The premise for the aircraft is to combine the operational flexibility of a helicopter with the speed, range, and efficiency of a fixed-wing aircraft.

The Marines, Air Force, and Navy all want to purchase versions of this aircraft. The MV-22 would be used by the Marines for missions such as troop and cargo transport and amphibious assault; the CV-22 would be used by the Air Force for special operations; and the HV-22 would be used by the Navy for search and rescue missions.

I want to be very clear. This bill does not terminate the V-22 program. It does not affect the Marine Corps' ability to continue the research, development, testing, and evaluation of this aircraft.

This bill delays the start of full-rate procurement of the MV-22 Osprey, the Marines' version of this aircraft, for one year. It also delays the procurement of four CV-22s, the Air Force's version of this aircraft, for one year.

There are serious allegations and serious questions surrounding the V-22 program. Thirty Marines have died in Osprey crashes since 1991. Many questions regarding the validity of maintenance records and the safety and viability of this aircraft remain unanswered.

We cannot, in good conscience, move forward with the full-scale procurement of the MV-22 until these allegations have been investigated fully and until these questions have been answered.

We should not move forward with the procurement of this aircraft until further testing has been done to address potentially serious design flaws that could continue to endanger the lives of our military personnel.

We owe it to our men and women in uniform to put their safety first. They are willing to go into harm's way while serving their country. That service should not include being put into harm's way by a potentially unsafe aircraft. We should not move forward with the procurement of an aircraft that crashed as recently as December. We should not procure this aircraft until the Department of Defense is absolutely certain that all major design flaws have been corrected.

The legislation that I am introducing today will delay full-rate production of the MV-22 for one year. This delay is prudent given the ongoing controversy that has loomed over this program during the last weeks and months.

I want to reiterate that this legislation does not require the Department of Defense to terminate the Osprey program. I appreciate the importance of this program to the Marine Corps. I agree that they need to replace the aging CH-46 Sea Knight helicopters that they currently have. However, I am not sure that the Osprey is the safest and most cost-effective alternative to the Sea Knight.

I know that the leaders of the Marines and the Air Force have the greatest concern for the safety of their personnel who are and who will be assigned to the Osprey program. I share that concern. My bill would require the Marine Corps to wait one year to move to full-rate production of the MV-22. Because the airframes for the MV-22 and the CV-22 are 90 percent similar, it follows that the four CV-22s the Air Force plans to buy this year may be subject to many of the same design flaws that have been found in the MV-22. For that reason, my bill would also require the Air Force to wait one year to procure the four CV-22s, which would be used to train their pilots.

I realize that an effort is being made to address the design flaws found during testing of this aircraft resulting in some changes in the new planes that are scheduled to go into production in fiscal year 2001. However, I remain concerned about the many unanswered questions, and the potentially costly retrofits that these aircraft would require as more information about the safety and reliability of the Osprey continues to come to light. In my view, it would be more prudent and more cost effective to wait to move to full-rate production until these questions have been answered.

For those reasons, my bill rescinds most of the fiscal year 2001 procurement funds for the MV-22 and the CV-22, but leaves enough funding in place to maintain the integrity of the production line. These rescissions would return to the taxpayers more than $1.2 billion dollars. This kind of investment should not go forward until we are sure that the Osprey is safe.

The bill does not affect the $148 million in research and development funding for this program. During the next year, vigorous research and testing on the problems that remain should continue once the decision has been made to resume test flights.

This program has a troubled history. Thirty Marines have been killed in Osprey crashes since 1991, twenty-three of them in the past eleven months alone. The Osprey program has been grounded since the December crash that killed four Marines. Following that crash, former Secretary of Defense William Cohen appointed a blue ribbon panel to study the Osprey program. That panel's report is due to be presented to Secretary of Defense Rumsfeld in March or April of this year. In addition, two investigations on the December crash are ongoing.

The safety of our men and women in uniform should be the top priority every time the Department of Defense develops and procures new technology, whether it be weapons, ships, or aircraft.

During his tenure as Secretary of Defense, Vice President Cheney tried to cancel the V-22 program in each of his budget requests from fiscal year 1990 through 1993 because he believed the program was too costly. Congress disagreed, and the program continued to receive funds.

When asked about the Osprey program last month, the Vice President said, ?Given the track record and the loss of life so far, it would appear to me that there are very serious questions that can and should be--and I hope will be--raised about the Osprey.?

I agree with Vice President Cheney's statement, and I hope that this legislation will help to get answers to these serious concerns.

One additional concern about this program is its cost. The Marines, the Air Force, and the Navy each want to buy a version of this aircraft, for a total of 458 aircraft at a cost of $38.1 billion, or about $83 million per Osprey. Some defense observers have argued that the mission of the Osprey could be performed by less costly helicopters.

Another concern is the safety of the aircraft. One of the newspapers in my home state of Wisconsin, the Milwaukee Journal Sentinel, has called the Osprey a ?lemon with wings.? Is that a fair description? There is reason to pause and take a good look at the program and find out. In addition to the four crashes that have occurred since 1991, there are also a number of unanswered questions regarding the design and performance of the aircraft.

The MV-22 underwent operational evaluation, OPEVAL, between October 1999 and August 2000. During OPEVAL, in June 2000, a draft DOD Inspector General's report cited 23 major operational effectiveness and suitability requirements that would not be met prior to the scheduled December 2000 Milestone III decision on whether to enter into full-rate production of the MV-22 in June 2001. The Marine Corps conceded that these problems exist, and said they had been aware of these deficiencies prior to the beginning of the OPEVAL.

In October 2000, the Navy announced that the MV-22 had been judged operationally effective and suitable for land-based operations. In November 2000, the MV-22 was also judged operationally effective and suitable for sea-based operations.

Following the completion of OPEVAL, the Department of Defense's Director of Operational Testing and Evaluation, Philip Coyle, released his report on the MV-22. This report, which was issued on November 17, 2000, makes a number of recommendations regarding further testing that should be conducted on this aircraft, including testing on a number of requirements for the aircraft that were waived during OPEVAL.

Particularly troubling are the MV-22's Mission Capable, MC, and Full Mission Capable, FMC, rates at the end of OPEVAL. These ratings demonstrate the availability of the aircraft--the amount of time that each MV-22 is able to fly versus the amount of time that each MV-22 is unavailable due to maintenance needs.

The Mission Capable rating represents the percentage of time that the test aircraft were able to perform at least one of their assigned missions. The Marine Corps' objective for the MC rate is between 82 and 87 percent. At the end of OPEVAL, the MC rate for the MV-22 was 49 percent. That means, Mr. President, that the MV-22 test fleet was capable of performing at least one of its missions only 49 percent of the time during OPEVAL. From 1995-1999, the entire CH-46 fleet Sea Knight fleet, which the Osprey is supposed to replace, was rated Mission Capable 79 percent of the time.

The Full Mission Capable rate, FMC, is defined as the percentage of time that the aircraft could perform all of its assigned missions. The Marine Corps' objective for FMC is 75 percent. At the end of OPEVAL, the MV-22 had a FMC rate of only 20 percent. From 1995-1999, the CH-46 fleet had a FMC rate of 74 percent.

I want to say this again--at the end of OPEVAL, the MV-22 test fleet was capable of performing all of its assigned missions only 20 percent of the time. The Coyle report says that part of this low rating can be attributed to problems with the blade fold wing stow, BFWS, system, and that measures to address this problem will be incorporated into all new MV-22s.

While both the MC and the FMC both improved over the course of OPEVAL, both rates are still well below the Marines' own requirements. By delaying the full rate production of the MV-22 for one year, the Marines will have the opportunity to further improve these crucial rates, including testing the modifications to the BFWS system, and potentially save countless maintenance hours and costs over the life of this program.

In addition to the problems outlined in the Coyle report, a General Accounting Office report released last month titled ?Major Management Challenges and Program Risks: Department of Defense? also expresses concern about the Osprey program. The report states that ?the DOD . . . begins production on many major and nonmajor weapons without first ensuring that the systems will meet critical performance requirements.? The report cites a number of examples, including the Osprey. GAO reports that ?the Navy was moving toward a full-rate production decision on the MV-22 Osprey aircraft without having an appropriate level of confidence that the program would meet design parameters as well as cost and schedule objectives.?

This finding is just another of the many reasons why the full-rate procurement of the MV-22 and the procurement of four CV-22s should be delayed. I share GAO's concern about the frequency with which DOD moves into full-rate production of systems that may not have been adequately tested. This rush to production often raises safety concerns and costs the taxpayers large sums for costly retrofits to address problems that were often evident -- but not fixed -- before full-rate production began. And even if the Osprey is proven to be safe, questions still remain about its cost.

I am also deeply troubled by the allegations that the Commander of the Marine Tilt-Rotor Training Squadron 204 may have ordered his team to falsify maintenance records for the MV-22. An anonymous DOD whistle blower released a letter and documentation, including an audio tape on which it is reported that the Commander is heard telling his squadron to ?lie? about maintenance reports on the MV-22 until the Milestone III decision to move into full-rate production of the aircraft had been made. This decision was scheduled to be made in December 2000, but has been postponed indefinitely. The Commander has been relieved of his command pending a full investigation by the DOD Inspector General's office.

There have been reports that high-ranking Marine Corps officers may have known about the low MC and FMC rates for the MV-22 in November 2000, and that one of them may have released inaccurate information to the press regarding the Mission Capable rates of the MV-22.

An electronic mail message from one of these officers to a superior officer dated November 11, 2000, states that the information regarding the MV-22 MC and FMC rates for November contained in the message should be ?close held? and that the MC and FMC rates for Squadron 204 were 26.7 percent and 7.9 percent, respectively. The message also said that the sender ?had hoped to be able to use some recent numbers next month when [his superior] meet[s] with Dr. Buchanan for his Milestone III/FRP decision in December . . . this isn't going to help.?

Later that month, on November 30, 2000, the officer who reportedly sent that electronic mail message participated in a DOD press briefing at which the Osprey was discussed in some detail. During this press briefing, the officer said the following regarding the Mission

Capable rates of the MV-22s being tested by Squadron 204: ? . . . as I was walking down here [to the briefing], I pulled the first 13 days of November, mission-capable rate on those airplanes, and the average is 73.2 percent for the first 13 days in November of those nine airplanes. So when we start talking about the airplane, even since OPEVAL, improving and getting better, the answer is it is absolutely a resounding yes.?

This information is contrary to the electronic mail message that the officer in question reportedly sent to a superior officer only nine days before, which stated that the MC rate for the MV-22s being tested by Squadron 204 for November 2000 was only 26.7 percent. That is a difference of 46.5 percent. News reports last week said that the officer admitted sending the message and attributes the discrepancy in the MC rate figures to a new software system.

I understand that these very serious allegations are still being investigated, and I agree that all of those involved deserve a fair and impartial investigation. We should not rush to judgment about the alleged conduct of any of these personnel, all of whom who have dedicated their lives to serving and protecting this country. However, we must remain cognizant of the fact that the outcome of this investigation could have an enormous impact on the Osprey program.

This still unfolding situation is another reason why the full rate procurement of the MV-22 should be delayed. Until these disturbing allegations have been fully investigated to determine whether records were falsified in order to make the Osprey appear safe and reliable, the Department of Defense should not move ahead with this program.

Because of the safety concerns outlined above, Mr. President, my bill requires the Secretary of the Navy to submit a report to the Congress on the V-22 program that includes: a description of the planned uses for the fiscal year 2001 research and development funding for the Osprey program; a description of the actions taken as a result of the Coyle report; and a description of the manner in which the Navy and the Marine Corps have responded to the allegations of the falsification of maintenance records at Squadron 204. The bill also requires the DOD Inspector General to report to

the Congress on the results of its investigation into the alleged falsification of maintenance records at Squadron 204. It would require that these reports be submitted three months after the enactment of this legislation or on the date of the Milestone III decision regarding full-rate production of the MV-22 Osprey, whichever is earlier.

The safety of our men and women in uniform should be the principle that guides this important decision. We should not begin to procure the MV-22 in mass quantities until we know for certain that this aircraft is safe, that its maintenance records are accurate, and that the design flaws described in the Coyle report have been adequately addressed.

S. 272

Be it enacted by the Senate and House of Representatives of the United States of America in Congress assembled,

SECTION 1. SHORT TITLE.

This Act may be cited as the ?Osprey Safety, Performance, and Reliability Evaluation Act of 2001?.

SEC. 2. RESCISSIONS.

(a) IN GENERAL.--Of the funds made available in the Department of Defense Appropriations Act, 2001 (Public Law 106-259), the following amounts are rescinded from the following accounts:

(1) ?Aircraft Procurement, Navy?, $856,618,000, of which $776,760,000 shall be derived from ?V-22 (Medium Lift)? and $79,858,000 shall be derived from ?V-22 (Medium Lift) (AP-CY)?.

(2) ?Aircraft Procurement, Air Force?, $358,440,000, of which $335,766,000 shall be derived from ?V-22 Osprey? and $22,674,000 shall be derived from ?V-22 Osprey (AP-CY)?.

(b) LIMITATION ON USE OF REMAINING FUNDS.--Following the rescission made by subsection (a)(1), the balance of the funds remaining available for obligation in the account involved for ?V-22 (Medium Lift)? may be used only to carry out activities necessary to maintain the production base for such aircraft program.

SEC. 3. REPORTS TO CONGRESS.

(a) SECRETARY OF THE NAVY REPORT.--The Secretary of the Navy shall submit to Congress a report on the V-22 Osprey aircraft program. The report shall include the following:

(1) A description of the activities carried out, and programmed to be carried out, using funds appropriated for that program for research, development, test, and evaluation for fiscal year 2001.

(2) A description of the actions taken by the Secretary as a result of the report on that program issued by the Director of Operational Test and Evaluation of the Department of Defense dated November 17, 2000.

(3) A description of the manner in which the Marine Corps and the Department of the Navy have responded to the reports of data falsification concerning the Osprey aircraft by Marine Corps personnel assigned to Marine Medium Tilt-Rotor Training Squadron 204.

(b) INSPECTOR GENERAL REPORT.--The Inspector General of the Department of Defense shall submit to Congress a report on the results, as of the submission of the report, of the investigation of the Inspector General into the V-22 Osprey aircraft program.

(c) TIME FOR SUBMISSION OF REPORTS.--The reports under subsections (a) and (b) shall each be submitted not later than the earlier of the following:

(1) The date that is three months after the date of the enactment of this Act.

(2) The date of the Milestone III decision for the V-22 Osprey aircraft program approving the entry of that program into full-rate production.

MAIN ARTICLE (http://www.insidedefense.com/public/special.asp)

HeliFlight

11th Feb 2001, 22:00

UNCTUOUS:
The articles in the post above have some very good points. And we all appreciated it when Cyclic Hotline posted the above links on the MV-22 Osprey Accident thread yesterday. It is very good that you did not add any silly artificial stories at the end for a change. But posting the entire text of a legal proposal that does not give us any new facts except that this proposal was made (not even voted on yet,-even if it passes only delays purchases) can only mean you are making “a filibustering attempt to deflect the reader's attention from the very real problems facing your flaws and foibles in a desperate bid to recapture your credibility” to use your own words. :)
Maybe if you open two or three more threads and post it there too it might be even more interesting for everybody. You probably knew we all like reading the same thing several times as long as you like it. But it’s a little incredible that right after you accuse PTIUAE of using a too much space (even though you use 10 x as much). Maybe you should change the name from UNCTUOUS to MEGABYTE-MONGER. But if it makes you feel good then go ahead and post it 4 or 5 more times.I guess if you don’t have quality in your arguments you might as well go for quantity. Good thing you don’t have to pay by the KB.

Maybe time to listen to The Sultan in the post above. Looks like the silent (but getting fed up) majority are beginning to get vocal. New and relevant facts are great and interesting no matter what side it supports, but don’t repeat other people’s posts when you can’t find your own- just print it out a couple of times on your printer so we don’t all have to keep reading with you.

Looks like you pulled another UNCTUOUS. :) :) :) :)

And by the way…you don’t need the big red nose to go with the long floppy shoes any more. After your posts on the MV-22 Osprey Accident thread-, that long Pinocchio nose will be plenty to get you that Circus job! :) :) :)

HeliFlight

12th Feb 2001, 19:50

UNCTUOUS:

Uh Oh......
http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000751.html

Looks like we're both pulling an UNCTUOUS :) :) :) :) :)

UNCTUOUS

13th Feb 2001, 22:11

Top Marine Clears Osprey's Design in Crash
By JAMES DAO

WASHINGTON, Feb. 12 — The Marine Corps has conclusively determined that the Dec. 11 crash of a V-22 Osprey that killed four marines was a result of hydraulic and computer failures, not the aircraft's hybrid tilt-rotor design, the commandant of the corps said today.

The Marines are hoping that the finding, part of a crash report they expect to send to Secretary of Defense Donald H. Rumsfeld as early as this week, will be the first step toward rehabilitating the costly and troubled V-22 program, which has been plagued by two fatal accidents and accusations of falsified maintenance reports in the last year alone.

"The thing I would say now is it doesn't appear to be anything that has to do with tilt-rotor physics," the commandant, Gen. James L. Jones, said of the December crash in an interview today. More generally, the commandant said that "there is sometimes out there an idea that an aircraft that takes off like a helicopter and flies like a plane can't do either very well," but that "so far the physics of the tilt rotor doesn't lend itself to that type of criticism."

Some aircraft experts have questioned the inherent safety of the Osprey, on whose wings are rotors that can tilt up like a helicopter's or forward like a plane's. Those questions, dealing with the craft's aerodynamic stability, are being reviewed by an expert panel appointed late last year by William S. Cohen, then the secretary of defense.

General Jones said he was optimistic that the Marines' final crash report would include assurances from the Defense Department's inspector general that the December crash, as well as a fatal crash last April, were not a result of falsified maintenance records at the Osprey squadron's headquarters at the New River Marine Corps Air Station in North Carolina. That case is a subject of a separate inquiry.

"You want to be sure that you can de-link any insinuation that there might have been a maintenance problem or anything that could have been, and should have been, caught with either crash," General Jones said. "I'm reasonably optimistic that we're going to be able to do that."

The Osprey, built by the Boeing Company's helicopter division and Textron Inc.'s Bell Helicopter unit, has been one of the Pentagon's most controversial programs for over a decade. The aircraft, still experimental, will have a price tag of well over $30 billion should full production proceed, and already had a record of crashes before the one last April.

In 1989, Dick Cheney, then the defense secretary, tried to cancel the Osprey to save money. But Congress kept it alive. Then, last April, safety questions that had already emerged grew all the more serious when an Osprey crashed in the Arizona desert, killing all 19 marines on board. Those questions multiplied with the December crash, near the New River station.

And in January, the Marines opened in investigation of the Osprey squadron at New River after receiving an anonymous letter accusing the squadron commander of ordering subordinates to cover up maintenance problems. In addition to the letter was a tape recording that appeared to implicate the commander, Lt. Col. Odin F. Leberman. Colonel Leberman has been relieved of command, and the inquiry has been taken over by the Pentagon's inspector general, who is investigating whether high-ranking Marine officers might have pressured the colonel to falsify the records.

General Jones declined today to provide details about the causes of the hydraulic and computer malfunctions that he said led to the December crash. But he said investigators had found amid the debris a broken hydraulic line that, he said, proved their hypothesis that a hydraulic failure had caused the pilot, considered the best in the V-22 squadron, to lose control.

The hydraulic system enables the pilot to control the speed and direction of the aircraft by adjusting its wings, rotors and rotor engine casings. Pentagon officials in charge of testing the craft had warned of worn hydraulic lines in existing Ospreys in the weeks before the crash.

Investigators have also concluded that because of a computer software malfunction, an emergency backup for the hydraulic system did not work. One person familiar with elements of the investigation said the software appeared to have been incorrectly written, creating even greater problems for the pilot as he struggled to regain control in the seconds before the crash.

General Jones said today that the Osprey was extremely important to the Marine Corps, because it can fly much farther and faster than the Vietnam-era helicopters it is supposed to replace. But he said he would be the first to support canceling the program if it were proved to be inherently unsafe. "We should never have preconceived notions that you can't receive bad news," he said. "And if it's bad news, I'll be the first to stand up as a moral issue and say, `We ought not to do this.' "

UNCTUOUS

13th Feb 2001, 23:07

LU the answer to your last post (differences between autorotation and VR) is at: http://www.helicoptersonly.com/Training/Settling_with_Power/settling_with_power.html

Hoist: Dec 11th Crash Theory: see http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000658.html and below

Totally irrelevant non-issues:
a. The XV-15 did (or did not) originally have a 90 degree (only) tilt?
b. I still cannot see how contra-rotating and overlapping tandem rotors could suffer from VR. Nature abhors a discontinuity (i.e. a helical vortex consisting of a figure-of-eight with two intersecting annulus of opposite rotation??). However I accept that someone posted earlier that he had, despite my information from an experienced CH47 pilot that he'd never - and precisely why this was an impossibility. So it's all weakly anecdotal and it's also mightily irrelevant. It was originally introduced by me simply to illustrate one of the aspects of VR - but then became a giant red-herring. I'm always suspicious of those who seize upon inconsequentialities - because it clearly indicates that they'd rather obfuscate than get into the narrower basic issue.

JF adroitly addressed the probable irrelevance of AsymmVR to the T/R in its sedate civil guise and I think he may be right - but a four-bladed prop-rotor would be a better idea on the 609 for the reasons given below. Four-bladed would also resolve some of the Blade Vortex Interaction noise that dictates the approach area acoustic foot-print. JF nailed the concerns regarding the MV-22 in the tactical combat arena. That remains the big question. It will be a long while before grunts are happy down back, the same guys who'd jump into a CH-53, UH-1 or UH-60 without a thought. But I think JF neatly side-stepped the quintessential issues on serviceability (reliability and availability) and maintainability/supportability. At this juncture, some short time after that first big MEU lift over the beach, a high percentage of MV-22's will be found to be unflyable (scattered between the LZ, beach and flattop). As LU has pointed out, it's too intricate and vulnerable - too many potentially downing discrepancies. That's why the US Army pulled out 15 years ago, it's why the CV-22 might yet be assessed as not suitable for USAF Special Ops.

The basic question remains unanswered. Susceptibility to AsymmVR has been demonstrated at Marana and in the transient incident (rapid wing-drop) as it crossed the Saipan's fan-tail wake on deck-trials. The USMC position is that the aircraft has to be flown way outside the approved envelope to encounter it. But it may also be that the condition can be encountered because of environmentals (a mild downwind component at height that leads to an arcing-over steepening approach …. or……dynamic control inputs in challenging gusty conditions) or avoidance action (pylon wires).

"the biggest tailwind that I could ever personally find in looking at the CSMU data, the Crash Survivable Memory Unit, was eight knots". LtGen McCorkle dissent from JAG Report

One hope is that tilt-rotors can be instrumented and fitted with a warning and/or reaction control system. The reality is that a number of aircraft (V-22 and XV-15) have been fitted with blade pressure transducers for ten years as part of the TRAM trials for acoustic mapping - and all that needs to be known about prop-rotor airfoil behaviour (vortices) is documented. Blade Vortex Interaction (BVI) is the main component of T/R noise. It's also a fact that the only way in which the T/R can be made more neighbourhood noise-friendly would be to now opt for a four-bladed prop-rotor or the Boeing five-blade config (active control of blade pitch having only a limited effect). Both noise signature (for more covert approach) and AsymmVR problems would be thereby alleviated, as well as rotor downwash for hoisting, roping, rapelling and external load slinging. Undoubtedly SHCT, QTR (and possibly the follow-on 609 models) will go that way. At present all the pro T/R Vertiport blurbs are talking about "community acceptance" and steering clear of any mention of "noise" - and for good reason.

this email received today probably adds to the knowledge-base:
"Hi, I've been following the Pprune discussion on the Osprey and thought I'd pass on a few observations. My background was a long-term association with the CL-84 tilt-wing. It was a bygone era and a different technology but the basic problems remain the same and I've kept in touch. Something you seem to have overlooked is the basic difference between the prop-rotor and the rotor in evaluating vortex ring effect. The onset characteristics for T/R VR are yet to be quantified but they are demonstrably different to helo VR because the prop-rotors are a semi-rigid, underslung and teetering compromise. The smaller rotor diameters, high blade-loadings, stiff graphite-epoxy, high aspect ratio, high-twist tapered format blades, elastomeric mount, wing interaction and diff collective lateral flight-control, IMO create an aerodynamic phenomena similar to helo VR but unique to tilt-rotors.
In the T/W the wing tended to dampen any vortex ring formation but in the T/R the flat wing would tend to laminate and reinforce the condition. The CL-84 had two four-bladed 28ft prop-rotors and with a low blade-loading and higher disc solidity showed no signs of VR.. To go on, the XC142 had four three-bladed 14ft propellers (propellers not being vulnerable to VR, it wasn't). The V-22 has 38ft diam three-bladed high-twist rotors with low solidity and obviously is. But we always had ejection seats and that saved our pilots on each of the CL-84 crashes.

Certainly the one big factor for the Osprey is that any wing-drop correction will always be toward or further into the incipient VR condition - lateral control being by differential collective. But there's another factor also. It is also a well-known fact that the rate of descent plays a large role in how well the initial instability of the vortex-ring condition establishes itself (stabilises) and how long the condition will then last. Introducing collective pitch shortly after the onset of a helo vortex-ring condition can demonstrate how easily the vortex-ring condition and inflow through the disk can diverge, making it an extremely difficult condition from which to then recover. Because of the Osprey's lateral control automatically (via the AFCS) increasing collective pitch at the outset of VR formation, the condition becomes similarly "locked in". i.e. you achieve something similar to a helicopter pilot failing to recognise VR and attempting to resolve the increased descent rate by adding power. Flt ctrl Load Limiting won't ever protect against that. There's one other error in your post. The engines, transmission and proprotors actually tilt through 97º 30' between forward flight and steepest approach gradient or tail-down hover, not 95º. So it's actually a 7.5º steeper forward projection of the tilt-rotor downwash in helicopter approach mode. The Osprey would get an earlier VR onset because of both it and the simultaneous use of the interim/contingency power feature that cuts in for use at over 80 degree nacelle-tilt. I think you will also find that the XV-15 has always had 95º nacelle-tilt. You can confirm that by talking to Brent Wellman of the Army/NASA Rotorcraft Division at Moffett. He was the XV-15 TRRA Test Director.

With regard to your analysis of the possible cause of the 11 Dec crash, you blamed the
automatic control of configuration change during conversion (i.e. its auto-transfer of control from aerodynamic surfaces to rotor-blade pitch changing). But the flaperons and ailerons also automatically go to droop during hover to reduce downloads on the wing and failure of one nacelle actuator automatically results in both nacelles reverting to helicopter mode for a vertical or run-on emergency landing. Following hyd failure either of these last two software-automated aspects could also have caused a rapid loss of control.
regards"

UNCTUOUS

13th Feb 2001, 23:33

from the Washington Post:
Perhaps most importantly, the GAO briefing details previously unreleased conclusions by the Marine Corps' own Judge Advocate General Manual investigation of the V-22 accident last April. GAO quotes the JAG report as saying the V-22 "appears to be less forgiving than conventional helicopters," and it was a cause for concern "to see how 'easy' it was for the recipe of uncontrolled flight to be concocted."

Before the JAG's conclusions surfaced publicly in this GAO briefing, Marine Corps officials pointed to "a combination of human factors" as the cause of the April crash, which occurred in Arizona and killed 19. The service said the pilots put the Osprey into too rapid a descent given its relatively slow airspeed, a dangerous combination Marine officials say was proscribed in the official flying manual. These conditions, officials said, could potentially leading to "power settling" or "vortex ring state."

GAO quotes Philip Coyle, then-director of operational test and evaluation for the Pentagon, as saying the onset of vortex ring state in the V-22 "can occur in the proprotor on one side without the other side losing lift. In such a case, the aircraft tends to roll sharply into the side that first loses lift, resulting in large, unexpected bank angles, followed immediately by rapid dropping of the nose of the aircraft and a steep dive. At low altitudes, there may be no opportunity for recovery."

"There may be little or no warning for a V-22 pilot that the aircraft is about to enter this phenomenon," Coyle said.
The Marine Corps JAG Manual report agreed. "The fact that this aircraft found itself in a vortex ring state condition with no apparent warning to the aircrew, but also departed controlled flight, is particularly concerning," the JAG report stated. Moreover, the manual cited by the Marine Corps as offering restrictions that could have prevented such a crash is unclear on this point, the JAG Manual investigation found.

The Naval Air Training and Operating Procedures Standardization manual, known as NATOPS, as well as the V-22 ground school syllabus, provide "insufficient guidance/warning as to high rate of descent/slow airspeed conditions and the potential consequences," the JAG found.

HeloTeacher

14th Feb 2001, 19:23

Seems like in typical military fashion you beleive that plank pilots have the answers, helo pilots should shut up and go sleep in a tent, and a gadget will solve all your problems :-(

VRS at low altitude is a killer for all helicopters, but we manage not to die in droves. We use our ROTARY wing EXPERIENCE to AVOID the problem, RECOGNIZE the onset if it happens, and apply APPROPRIATE recovery action.

This was for you UNCTUOUS.

HeliFlight

16th Feb 2001, 23:49

Nice try HeloTeacher, but old Pinochy-Unc has his head so far up an unnamed location he can’t see or hear what anybody says if its not in line with his fantasy world. He’s been disproven with the FACTS and testimony from the people that actually fly the aircraft over and over but he will not listen to the truth. He has been so badly humiliated on a public forum that he is not capable of backing away from it. His only chance is to tell a thousand lies and hope somebody will eventually believe it is the truth.

He’s obviously punch drunk after haven been beaten up so badly by earlier posts. He actually posted an e mail message on another thread that completely contradicts his theory –and he didn’t even realize it! We shouldn’t feel too bad for ourselves having to see his endless dribble that’s been repeatedly disproven… imagine how his poor mother feels!!! :) :) :)

HeliFlight

17th Feb 2001, 00:03

Pinochy-Unc:
I think I can help you on this easy one.
A. The 90/95 point is extremely relevant because it completely destroyed your silly asymmetrical VRS theory, but it is even more relavant that it proves you blatantly make up stories. Then you try to lie your way out with a new one and get caught in it again(do you know how to spell c-r-e-d-i-b-i-l-i-t-y?)! We could count this attempted slither-out as a third attempt but it’s too comical to worry about.
B. See A. above. Once again it proves your character (or lack of). Even though you can’t understand how settling can happen, three people who fly tandem types say it does- and even with the DREADED asymmetrical VRS!!! Must be deadly.

You completely missed JF’s point. He did NOT side step issues on serviceability-he included it in his overall assesment of the program(guess you were sleeping)-
“Reliability
History suggests that mechanical/electrical problems and even software issues can be hacked in time whatever aircraft we are talking about. My crystal ball suggests the potential benefits that the tiltrotor has to offer civvy and military alike are so big that the engineering aspects WILL be solved in time. It’s called progress and on a scale of Wright flyer to today’s best military and civil aircraft in less than 100 years the current tiltrotor issues look pretty small beer.”

There’s another perfect example of your missing the truth when it is right in front of your eyes. No matter how many times John Farley and PTIUAE put the facts in front of your eyes…you keep saying THEY are not addressing the issues!!! No wonder neither JF or PTIUAE want to lower themselves to respond directly to you anymore...if you listened to what they say like they listened to you they might think its worth it.
Time to wake up and smell the roses Pinochy-Unc, and see what people are saying to you!!! Try listening to the EXPERTS for a change!

You are very good at falsifying things and after these threads you have a lot of solid experience. Sounds like there is an opening for a guy with your qualifications in the Marine training squadron. If the Marines are looking for a Few Good Falsifyers…you’re their man. :) :) :)

Flight Safety

18th Feb 2001, 13:08

I was blessed tonight to have dinner with one of the chief design engineers of the V-22 Osprey. I just meet him tonight and he apparently spent nearly all of his career at Bell Helicopter (from the 60s onward) working on tilt-rotor technology until his retirement. He was deeply involved with the XV-15 project as well as the V-22 project. His area of responsiblity seemed to center on the design of the rotors and the cyclic controls. He was a very nice gentleman and I enjoyed the conversation I had with him greatly, and I hope I have the opportunity to talk with him again sometime in the future.

We were able to discuss both of the recent V-22 crashes, the troubled hydraulic system, some of the rotor system design characteristics, and the Vortex Ring problem. One of the first things I learned from him was how the V-22 yawed in a hover (I actually didn't know how it worked before this conversation). It yaws with differential cyclic (most of you probably knew that :) ).

We agreed that the cause of the crash last April was most likely "Settling with Power" or "Vortex Ring State". In discussing the rotor design, he told me that the disk loading in hover on the tilt-rotor is quite a bit higher that it would normally be in a conventional helicopter. He said this is because the rotor also has to work as a propeller in airplane mode, and this places certain restrictions on the design of the rotor for use in hovering. The rotor disk has to be smaller than it would normally be for a conventional helicopter (for propeller mode efficiency), therefore to generate the correct mass airflow through the rotor in hover mode, the air has to go through the rotor at a much higher velocity. This creates a higher velocity downwash in the hover, which can exacerbate brownout or whiteout conditions, search and rescue operations, and shipboard disembarkations as discussed in the articles posted above.

This design feature may also play a role in creating "Vortex Ring State" under conditions that are somewhat different from that of a conventional helicopter. I don't know exactly how different the conditions might be, but it does seem that the descent rates required to create the condition may be higher than that of a conventional helicopter, with air columns above the rotors that are also descending at a higher rate. This would produce a corresponding reduction in the allowable response time for the pilot to escape the condition (by approaching the ground faster), with a longer time period needed to arrest the higher descent rate (recover to 0+ fps) once forward cyclic was applied. We agreed that specific pilot training to avoid this problem would be necessary for all tilt-rotor pilots.

We discussed the December crash, and he believes as I do, that the cause was a hydraulic system failure exacerbated by a computer software failure to switch to a backup hydraulic system. We both scratched our heads as to why a 5000 psi hydraulic system was chosen for this new aircraft, although he generally supported the idea of using the lighter newer technology of this system. He thought pioneering all of these new technologies on a single aircraft was generally good, however I thought that the aircraft should be certified with a 3000 psi hydraulic system, at least until the problems with the 5000 psi system can be worked out.

He told me that the hydraulic lines on the aircraft are titanium and are smaller in diameter than a typical 3000 psi system. This is because the transferred fluid volumes used in flight at these pressures are lower. The actuators are also smaller (thus using lower fluid volumes) which also contributes to the system's overall lighter weight. The current problems with this system are twofold in that the pressure seals in the actuators are failing at these high pressures, and the lines are flexing too much (as pressurized lines always do, with more pressure producing more flexing) causing chaffing and line failures. The hydraulic system's incomplete ability to deal with these higher pressure levels are the main source of the hydraulic system maintenance problems. The civil 609 by contrast is being developed with a more conventional 3000 psi system (as also stated in one of the articles above).

It also seems to me that with this high pressure hydraulic system, the failover method to a backup system has to be near bullet proof. Computer swith over alone may not be adequate.

In the end, we both felt that the problems with the V-22 could be solved as long as some funding continues and everyone is patient in allowing the outstanding issues to be worked out.

We discussed other issues, which I might post later when they become relevant.

------------------
Safe flying to you...

[This message has been edited by Flight Safety (edited 18 February 2001).]

HeliFlight

18th Feb 2001, 16:12

Flight Safety:
Sounds like an interesting conversation. PTIUAE had mentioned the higher disk loading as something that would allow VRS to form earlier than a helicopter that had lower disk load. As you mentioned, he said the answer is defining the limits and avoiding them. After all, with an aircraft that can do what none other in creation can do you would of course expect some limitations somewhere. He mentioned too that because of shipboard size limitation they had no choice but to shorten the blade length to less then what is best, lowering drag in the airplane mode but adding to the increased disk loading in HC mode - the old give and take.

You mentioned it takes a HIGHER descent rate to get into VRS for a tilt rotor. That sounds like a good thing rather than bad- giving a larger flight envelope before getting into it. But I know what you mean-once your get into it- you would then be at a higher descent rate- so less time before hitting the ground if you let it happen close to the ground. If you put a helicopter in at that same higher descent rate close to the ground you would be in at least an equeal mess because you’’d be HEAVILY into VRS by that point (if you stormed into it too low to the ground- then no altitude for recovery)

I was told on the V-22 hydr has not only a problem because of the 5000PSI pressure- also less redundancy then a 609. 609s supposedly have complete separation with no switching to backups required while V-22s share fluid with shuttling valves. Really seems like the 609 is a next generation T/R and the V-22 should modify to catch up! Definitely needs some work.

I agree with your summation- it will all work out in the end.

Thanks for the valuable input. Look forward to more.

[This message has been edited by HeliFlight (edited 18 February 2001).]

Flight Safety

19th Feb 2001, 06:19

To heliflight, I just wanted to point out the information on the higher disk loading came from the gentlemen that I spoke with. The speculation on the differences in the nature of VRS on the V-22 from conventional helicopters was my speculation, not his. I just wanted to be clear on that.

My speculation on the nature of VRS on the V-22 was based on the higher velocity of the downwash and air mass moving through the rotors in a hover (compared to a conventional helicopter). It also came from the fact that the crash last April occurred when the pilot made a high rate descent (2200 fpm ??) when approaching to land.

Again that my speculation, not the gentlemen's whom I had to pleasure to have dinner with. We discussed the disk loading issue and the pilot training issues that would help to avoid the problem.

------------------
Safe flying to you...

[This message has been edited by Flight Safety (edited 19 February 2001).]

Flight Safety

19th Feb 2001, 09:17

I just read that the current V-22 flight manual restricts descent rates in hover mode to 800 fpm or less.

I also don't understand why you would design the hydraulic systems to "share" fluids with each other. I mean, wouldn't a low fluid level in a single system generally indicate a leak in that system? So why would you transfer fluid from a known good system into a "leaky" system. That makes no sense to me.

------------------
Safe flying to you...

[This message has been edited by Flight Safety (edited 19 February 2001).]

UNCTUOUS

19th Feb 2001, 16:47

From the Experts: 33 / 103
Reuters, Monday, Feb. 19, 2001

U.S. Marines Skipped Key Tests of Osprey - Report
WASHINGTON (Reuters) - The Marine Corps omitted tests of the MV-22 tilt-rotor aircraft that would have provided more data on a descent problem later implicated in a crash that killed 19 Marines last April, the Washington Post said Monday, citing a report by the General Accounting Office.

The GAO report, which has not been publicly released, also said the Marine Corps had warnings about troubles in the aircraft's hydraulics system, according to the Post.

Military investigators now believe that a frayed hydraulics line was a key factor in a second crash of the aircraft, also known as the Osprey. In that accident, last December, four more Marines died.

The Department of Defense inspector general is investigating allegations of falsified maintenance records in the $40 billion Osprey program after receiving an anonymous letter and tape recording alleging that the commander of the corps' only MV-22 squadron told subordinates to falsify maintenance records on the eight remaining aircraft.

The report by the GAO, the investigative arm of Congress, cast serious doubt on both the safety and reliability of the troubled Osprey and on the rigor of Marine Corps testing of the aircraft, which takes off and lands like a helicopter but can tilt its rotors forward to fly like an airplane.

The GAO said that not enough was known about the Osprey's design and performance before production started and that the limiting of tests reduced the chance to gain a realistic view of the Osprey's mettle for combat, rescue missions or aid flights, according to the Post.

DOUBTS ABOUT CAPACITY

The GAO report also found that the Osprey's cabin might be too small to carry 24 Marines equipped for combat, saying that "15-18 combat Marines may be the limit." If that proves true, it could undercut one of the reasons cited by the Marines for favoring the Osprey over helicopters such as the UH-60 Black Hawk, which is designed to carry 11 combat-loaded troops.

The hybrid helicopter is built jointly by Boeing Co. and Textron Inc.

The GAO prepared its review for a panel convened by the Pentagon to assess the Osprey after the two recent crashes.

The GAO report referred to maintenance troubles, particularly with the Osprey's hydraulic systems, which required servicing so frequently that it "is concerning," according to Marine investigator reports filed after the April Osprey crash and cited by the GAO, the Post said.

In a similar vein, the GAO said tests that could have uncovered added information about a phenomenon known as "vortex ring state" -- which occurred during the April crash, when an Osprey coming in for a rapid landing lost lift, rolled and flipped over -- were deleted or deferred to meet "program cost and schedule pressures," the Post said.

Instead of the 103 tests first scheduled on the phenomenon, 49 were slated, and of those, only 33 were actually flown during testing phases, the GAO briefing said.

UNCTUOUS

19th Feb 2001, 16:56

Key Tests Omitted on The Osprey
GAO Assails Program

By Mary Pat Flaherty and Thomas E. Ricks
Washington Post Staff Writers
Monday, February 19, 2001

To save time and money, the Marine Corps omitted tests of the V-22 Osprey that would have provided additional data on rapid descents that contributed to a crash that killed 19 Marines in April, according to a new report by the General Accounting Office.

The GAO report, which has not been publicly released, also says the Marines had warnings about troubles in the aircraft's hydraulics system. Military investigators now believe that a frayed hydraulics line was a key factor in a second Osprey crash in December in which four more Marines died.

Overall, the GAO review casts serious doubt on both the safety and reliability of the troubled Osprey and on the rigor of Marine Corps testing of the aircraft. The Marine Corps touts the Osprey, which takes off and lands like a helicopter but can tilt its rotors forward to fly like an airplane, as the best replacement for its Vietnam-era helicopters, contending they will fly much faster and farther and carry more troops and equipment than the aging fleet.

But the 31-page GAO review challenges many of the assertions. Not enough was known about the Osprey's design and performance before production started, the review contends, and test restrictions and waivers reduced the chance to gain a realistic view of the Osprey's mettle for combat, rescue missions or aid flights.

The report said the Osprey's cabin may be too small to carry 24 Marines equipped for combat, stating that "15-18 combat Marines may be the limit." If that criticism proves accurate, it would partially undercut one of the reasons the Marines cite for favoring the Osprey over helicopters such as the UH-60 Black Hawk, which is designed to carry 11 combat-loaded troops.

The GAO review also echoes worries raised by other evaluators about reliability and maintenance challenges and cautions that any major design changes and upkeep expose the government to significant costs. The GAO drew on its own work and details from reports by investigators of the two crashes, as well as other federal studies, for its briefing.

When asked generally about assertions that the Osprey falls short of its operational concept -- that is, how it would work in real-world missions -- Marine Commandant Gen. James Jones said last week: "I think it's there, and I think it works. I know it's better than helicopters, by a long shot." In the same interview, Jones said he does not "have blinders on" about the Osprey, which has been promoted by the Marines for 18 years. If more tests are needed, Jones said, "we'll do that."

The GAO prepared its review for a panel convened by the Pentagon to assess the Osprey program after the two most recent crashes: one in April in Marana, Ariz., that killed 19 Marines and a December crash near New River, N.C., that killed four more and grounded all Ospreys. In addition to the panel's continuing inquiry, the Osprey is the object of a nearly complete investigation into the causes of the December crash.

A separate investigation is ongoing into allegations a senior officer in a North Carolina squadron ordered crews to falsify maintenance records to improve the aircraft's performance rating.

The GAO was one of several organizations that briefed the Pentagon panel. Until the panel delivers its findings based on all that it has heard, the Marines are withholding comment, said Marine Brig. Gen. John F. Sattler. "We don't want to get into a point-counterpoint on every presentation," he said yesterday.

The GAO report cites maintenance troubles, particularly with the Osprey's hydraulic systems, which control the aircraft's movements. They required servicing so frequently that it "is concerning," according to Marine investigator reports filed after the April Osprey crash and cited by the GAO. Problems with hydraulics and software appear to have caused the December crash, the Marines said last week, although the final accident report is pending.

In a similar vein, the GAO notes that tests that could have uncovered added information about an aerodynamic phenomenon known as "vortex ring state" -- which the Marines said occurred during the April crash when an Osprey coming in for a rapid landing lost lift, rolled and flipped over -- were deleted or deferred in earlier testing to meet "program cost and schedule pressures." Instead of the 103 tests first scheduled on the phenomenon during testing, 49 were slated, and of those, only 33 were actually flown during test phases, the GAO briefing states.

The Marine Corps blamed pilot error for exposing the Osprey to vortex ring state in April, and has since stepped up testing on the problem. All helicopters are vulnerable to the problem, but the Osprey, with its two side-by-side rotors, "appears to be less forgiving than conventional helicopters," according to briefing materials. The consequence of exceeding guidelines for descents in the Osprey "appears to be excessively grave," it continues.

The Marines have bought 10 production-level V-22s, manufactured as the Corps and its industry partners -- Bell Helicopter Textron of Fort Worth and Boeing Helicopters of Ridley Township, Pa., near Philadelphia -- sought approval from the Pentagon for a full acquisition. The Marines hope to buy 360 Ospreys at an estimated cost of $57 million apiece. A decision on whether to move to full-scale production was set for December but was delayed after the North Carolina crash and now awaits results of the Pentagon panel's review.

The GAO report is striking for the doubts it casts on the operational concept of the Osprey.

The report found that the "downwash" of air from the Osprey's two huge 38-foot-wide rotors is so severe it sometimes "creates brownout and whiteout conditions," which would impede troops trying to move into combat positions. The downward flow also makes it "hazardous" for troops to get out of the aircraft by sliding down a rope, a technique sometimes used to insert forces in areas where there is no open space available for landing. The downwash also can force sand and snow into the Osprey's interior and its components, the report said.

The report also notes that at various times, tests were limited during other conditions the Osprey likely would encounter, including not testing in cold weather where icing conditions could arise, in areas where storm clouds were close by and in situations that required several Ospreys to fly in formation.

© 2001 The Washington Post Company

HeliFlight

19th Feb 2001, 16:57

Thanks F.S. :
I understand your situation of the VRS speculation. Seems logical, but there are no doubt other variables that have to be looked at before we say it takes a HIGHER rate of descent to get into VRS in a tiltrotor. I would imagine overall it must be easier to get into than in a helicopter - but definitely avoidable as long as you don't go out of the envelope. I heard that 800 fpm limitation in the flight manual was there since before the Arizona VRS accident. I've heard two stories on it, one that the 800fpm limit applied whenever you are under 40kt airspeed, the other that it applied when the nacelles were beyond 80 degrees aft- either way they were definitely way outside the specific flight manual limits at 2200fpm in Arizona.

Don't quote me on the sharing fluids- that came from one newpaper article that made a brief mention of sharing fluid between systems with a shuttle valve (maybe like the BO 105?). Doesn't make much sense to me either. The person I keep in touch with by e-mail has great knowlege on the 609 but is not involved with the V-22 so no official news here. Lu Zuckerman used to work on the hyd system with Boeing but unfortunately it was many years ago and a lot has apparently been modified since then. Maybe you can find out from the V-22 engineer you met recently- could be time for another dinner!!!

Please let us know if you find out more details- Thanks.

HeliFlight

19th Feb 2001, 17:17

Pinochy-Unc:

Uh ohh... Over 6 pages now!!! And this last post is just another rewrite by a different paper of the GAO report that has already been covered many times here (same report, just different reporters writing about it). Could this be another “a filibustering attempt to deflect the reader's attention from the very real problems facing your flaws and foibles in a desperate bid to recapture your credibility” to use your own words!!! :) :) :)

Well at least you are not adding any new False theories to the end so I guess we can give you credit for improvement.

By the way... how is your application coming along for the Marine training squadron position(A Few Good Falsifyers needed!) If you need a reference- have them contact me... I'll verify your great qualifications for the job!!! :) :) :)

HeliFlight

19th Feb 2001, 18:29

Pinochy-Unc:

Wow... you REALLY are getting desparate. Posting ANOTHER reprint of the same report on the GAO by a differnt writer. Well, if you want to hide the fact that all of your theories had been disproven, I guess burying those posts with repetition is one way.

A bit SAD though. http://www.pprune.org/ubb/NonCGI/frown.gif http://www.pprune.org/ubb/NonCGI/frown.gif http://www.pprune.org/ubb/NonCGI/frown.gif Perhaps counseling will help. You have become the PPRune SPAM KING. At least you are top of the class at something now. :)

I have an idea for you. Why don't you post the same article on EVERY thread on the forum. And then create a hundred or so new topics and put it there too. If you don't have quality- go for Quantity!!!

The More the Better. Keep up the good work :) :) :)

I hate to be repetitive (like some people we know), but to use your own words it looks like:
“a filibustering attempt to deflect the reader's attention from the very real problems facing your flaws and foibles in a desperate bid to recapture your credibility”

UNCTUOUS

19th Feb 2001, 19:37

LU Zuckerman
Reference your post on page one of this thread:

"the hydraulic system can operate ten to a hundred times more than predicted in the reliability analysis."

I came across this (from an ex-Lockheed designer):

"And I'm betting that the hydraulic problems that they've been having in such low-time aircraft are simply due to the self-reinforcing vibrational feedback of such a high-pressure system (5000 psi versus normal 2500 - 3000psi). They just didn't anticipate that the fine diameter titanium piping would be subject to much more than the internal hydraulic pressures and normal actuation shocks. In a higher pressure system, high-rate cycling hyd pressures can set up a high frequency, high amplitude destructively resonating "echo" that would normally require at least one set of properly placed QUINCKE valves per system for absorption of the vibration. These are like coils that simply flex at the correct harmonic and relieve the hammer-blow shocks in the lines (of chattering actuators) . A system poorly provisioned with them would be leak and failure-prone due to the harmonically reinforced pressure spikes."

I'd thought the accumulator was the shock-absorber. But maybe the higher pressures need interim shock-absorption - particularly in something that's a lot more than a utility hydraulic system - as you've indicated in your post.

HeliFlight

21st Feb 2001, 21:05

Pinochy-Unc:

Excellent 'theory' P-U(no pun intended)

I hate it when those DUMB engineers forget to put in enough :)'QUINCKE valves' :) !!!
Nothing more annoying.

I am sure your idea will fix it right up.

Keep up the good work... :) :) :)
It's very believeable.

UNCTUOUS

21st Feb 2001, 23:32

From Air Safety Week:

Light look at serious business. It is that time of year again when members of the Ostriches Anonymous Association (OAA) vote for the winner of their Oliver Ostrich "Head in the Sand" award. The award is presented annually and anonymously to the individual or organization uttering the most outrageous statement ignoring, denying or discounting a significant aviation risk. The idea is to use humor as a means of improving safety awareness. The winner, upon whom the coveted "Oliver" is bestowed, will be announced at the association's February 23d Ostrich Watchers Ball held at the Cavanaugh Air Museum in Addison, Texas.
This year, the seven finalists are:

FAA airspace and rules division: which determined that a 497-foot-MSL-tall tower did NOT meet the criteria to be a hazard despite being sited along the path of a special VFR corridor in Anchorage, Alaska, which requires pilot to fly below 600 feet MSL. Oliver's Astute Analysis: Of course the bureaucrats in the FAA's Airspace and Rules Division (ATA-400) don't actually FLY airplanes, so let's have them ride along as passengers on a couple of one-mile-visibility days and see if they can spot the tower and its guy-
wires.

Government auditors. "The manufacturer performed slipshod work, used out-of-date blueprints and improperly inspected parts - but flight safety was not threatened." Oliver's Astute Analysis: Obviously true so long as the airplanes remain on the assembly line.

NASA and military aerodynamic experts have known for years that a tiltrotor aircraft could enter vortex ring state on one rotor, said the managing director of Petroleum Tiltrotors International in Dubai (PTI-UAE). But testing was not done before the Arizona crash because engineers believed that the V-22 would never encounter it if the pilots stayed within prescribed speed and descent parameters, he said. . ArticleLINK1 (http://www.star-telegram.com/news/doc/1047/1:TOPHOME3/1:TOPHOME30219101.html)

"We really didn't do the research on this because we didn't envision pilots getting into this condition," said Zuk, chief of NASA's advanced tilt-rotor technology office. "It's not something [where] you say, stop the V-22 program. Absolutely not. The key is pilot awareness." ArticleLINK2 (http://www.star-telegram.com/news/doc/1047/1:TOPSTORY/1:TOPSTORY0218101.html)

Aircraft manufacturer: During a planned engine replacement cracks were discovered in some nuts holding bolts to the aft mount of the engine:
"Failure of one nut in no way affected the engine's safe attachment to the pylon. The mounting had four bolts. Consequently safety was in no way and at no time compromised. Spares were readily available worldwide." Oliver's Astute Analysis: If the missing nut in no way affects the engine's safe attachment to the pylon, why is it there?

FAA engineers: "The pilots could continue flying if a cable broke, so it was not considered a crucial part. We did not think the situation was urgent." (In response to charges that the FAA waited 17 months before advising carriers about the failure of a control cable manufacturer to test cables the military found were failing at 50% of the rated load.) Oliver's Astute Analysis: Obviously, we needn't worry about other 'non-crucial' parts, like wheel, tires, avionics, and an occasional B747 outboard engine, all of which have occasionally been lost and the airplane continued to fly.

Manufacturer's president: "There is absolutely no connection" between our efforts to reduce manufacturing inspections and the 8-inch hairline cracks found in at least 40 airplanes. Oliver's Astute Analysis: If fuel tank stringers are added to the pilots' walk-around inspections, the pilots' cursory preflight can be blamed for any fuel leaks that develop. >> OAA, e-mail [email protected] <<

CBS article (http://cbsnews.com/now/story/0,1597,272978-412,00.shtml)

UNCTUOUS

21st Feb 2001, 23:51

Updated: Wednesday, Feb. 21, 2001 at 01:24 CST

Report says V-22 pilots weren't well-prepared
The flight manual and training program failed in warning crews of the dangers they faced, the GAO report notes.
By Bob Cox and Jennifer Autrey
Star-Telegram staff writers

Pilots at the controls of a V-22 Osprey that crashed in Arizona last year had received little warning or preparation for the hazardous conditions that caused the accident, according to a government report.

The report released Tuesday by the General Accounting Office cited Navy and Marine officials who concluded that the V-22 flight manual and training program did little to warn pilots of the dangers they faced.

Separately, a Pentagon advisory board also criticized the Navy for cutting corners during testing of the Osprey to save money and make up for schedule delays, Bloomberg News reported Tuesday.

According to the GAO report, the Marines' accident investigator wrote that the "manual and V-22 ground school syllabus provides insufficient guidance/warning as to high rate of descent/slow airspeed conditions and the potential consequences."

The two reports are the latest in a series critical of the Marines for rushing to buy the V- 22 despite myriad problems with the revolutionary tilt-rotor aircraft.

Officially, the Marines have blamed the April 8 crash that killed 19 servicemen on errors by the aircraft's crew. The pilots, according to the accident report, descended too fast with too little airspeed and got caught in a turbulent condition, known as vortex ring state, that caused the V-22 to lose lift, roll over and crash.

The GAO report was prepared for Defense Secretary Donald Rumsfeld and a blue ribbon panel reviewing the V- 22 program. The report draws heavily on previously undisclosed portions of the Marines' crash report and the Navy report evaluating the V-22, and also cites reviews by other Defense Department agencies.

Navy officials also found shortcomings in the V-22 training regimen. The flight operations manual for the V-22 "lacked adequate content, accuracy and clarity," according to the report.

Specifically, although the flight manual warned pilots that "settling with power" -- another term for the turbulent phenomenon that caused the Arizona crash -- could occur if the V-22 descends at a rate greater than 800 feet per minute and less than 46 miles per hour, it didn't warn pilots that they might not be able to control the aircraft if they violated those parameters. The manual is called the NATOPS, short for Naval Air Training and Operating Procedures Standardization.

In addition to the lack of clear warnings in the flight manual, the conditions that could lead to a crash were not replicated in the V-22 flight simulator.

The GAO found that "the V- 22 appears to be less forgiving than conventional aircraft" when it enters vortex ring state. And it noted that many flight tests, including some that would have provided greater insight into the V-22's susceptibility to the turbulent air condition, were cut to save money and time.

The V-22 is built jointly by Fort Worth-based Bell Helicopter Textron and Boeing's helicopter unit in Ridley Park, Pa.

Jim Furman, an Austin lawyer representing the widow of the co-pilot in the Arizona crash and himself a former Army helicopter pilot, said the GAO comments are important.

"The NATOPS manual is the bible," Furman said. "It tells the pilot how the aircraft is going to fly and react to certain situations."

Furman said information gained by test pilots during flights is communicated to pilots undergoing training through the manual. Flying without the manual, or with an incomplete one, "is like trying to put together a kid's bike without the instructions," he said.

But a source close to the Marines said that the pilots of the doomed V-22 knew the dangers posed by too fast a descent.

"The nature of the warning is clear, that it is dangerous," said the source, who requested anonymity. "That point is unambiguous in the NATOPS."

The source also said that "the Marine Corps believes sufficient testing was done to establish a very conservative, safe flight envelope" for the V- 22 that, if it had been followed by the pilots in Arizona, would have prevented the fatal crash.

Bloomberg News reported Tuesday that the Defense Science Board, which advises the Pentagon on technical issues, singled out the V-22's testing as symptomatic of how the military evaluates major weapons programs before committing billions of dollars for production.

"The V-22 severely reduced early development testing in order to save money and recover schedule," the board said.

The two reports will fuel a growing debate in Congress over whether to scrap the V-22 program, analysts said. The Senate Armed Services Committee, which commissioned the science board report, plans hearings on the Osprey. Russell Feingold, D-Wis., has introduced a bill to freeze the program pending results of the ongoing investigations.

"It's really the Marine Corps vs. the rest of the world on the safety of the program's future," said Richard Aboulafia, a military aviation analyst with the Teal Group, a defense market analysis group based in Washington, D.C.

The Marine Corps, which wants the aircraft for both military and nonmilitary missions, has put all its political energy into pushing the program, both inside and outside the Pentagon, Aboulafia said.

Bob Cox, (817) 548-5534

Send comments to [email protected]

Jennifer Autrey (817) 390-7126

Send comments to [email protected]
linktoArticle (http://www.star-telegram.com/news/doc/1047/1:HOMEPAGE7/1:HOMEPAGE70221101.html)

HeliFlight

22nd Feb 2001, 00:20

Pinochy-Unc

Looks like PTIUAE is in with some good company...
Dr. John Zuk is the head of Advanced Vertical Flight Research at NASA where he has worked as a research scientist on vertical flight SAFETY an Development for over 25 years!!!

I guess that Orville and Wilbur would have been the undeniable winners of the Award a few years back for their silly Wright Flyer!!! :)

Where can we sign up!!?? Seems like winning makes you part of "who is who" in Aviation!!!

And by the way... Congrats to YOU!!!
In case you didn't hear>>>
PPRune forum readers have voted you the new "H.U.B." Award recipient!!! :)
This is the first Annual "Head Up the Backside" Award for the incredibly Astute :)"QUINCKE valve" :) discovery!!! :)

You continue to make us PROUD P-U!!! :)
Only you could have done it...
**************************************************
UPDATE!!!:
Sorry Pinochy-Unc... Another one of your inept attempts to change the FACTS has been Debunked!!! http://www.pprune.org/ubb/NonCGI/frown.gif
Your attempt to ADD Dr. John Zuk (NASA Scientist) and PTIUAE to the "Award List" has been exposed!!! http://www.pprune.org/ubb/NonCGI/redface.gif Of the seven on YOUR list,, Five recieved Awards- the ONLY two that are NOT ON THE LIST are the two YOU ADDED!!! (both pro-tilt rotor comments)
You have once again publicly humiliated yourself (What else is new)

OSTRICHES ANONYMOUS ASSOCIATION
Results For Year 2000 "HEAD-IN-THE-SAND-AWARD"

The purpose of the Ostriches Anonymous Association is to promote aviation safety and risk awareness through the use of humor by sponsoring Oliver Ostrich "Head-In-The-Sand Award."

The "OLIVER" is presented annually to: the anonymous individual or organization who contributes most by conscious action, decision, or purposeful neglect to either the denial, the discounting or the ignoring of significant aviation risks or opportunities.

PRESS RELEASE

Grand Prize
FAA Airspace & Rules Division: which determined that a 497-foot-MSL-tall tower did NOT meet the criteria to be a hazard despite being sited along the path of a Special VFR Corridor in Anchorage, Alaska, which requires pilots to fly below 600 feet MSL. Oliver's Astute Analysis: Of course the bureaucrats in the FAA's Airspace and Rules Division (ATA-400) don't actually FLY airplanes, so let's have them ride along as passengers on a couple of one-mile-visibility days and see if they can spot the tower, or its guy-wires.
Sighting made by Ira Rimson, Albuquerque, NM
who is awarded the 2000 ARTF (Award of the Ruffled Tail Feathers)
The ARTF includes a Life Membership in OAA sponsored this year by Southwest Airlines, a prestigious wall plaque, and a $300 cash prize from Vedax Sciences

1st Runner Up
FAA Engineers: "The pilots could continue flying the plane if a cable broke, so it was not considered a crucial part. We did not think the situation was urgent." (In response to charges that the FAA waited 17 months before advising carriers about a control cable manufacturer which was not testing cables that military tests had found to fail at 50% of rated load.) Oliver's Astute Analysis: Obviously we needn't worry about other "non-crucial" parts, like wheels, tires, avionics, and an occasional B-747 outboard engine, all of which have occasionally been lost and the airplane continued to fly.
Sighting was made independently and simultaneously by Captain Tom Brown, Danbury, CT;
Danna Henderson, Albuquerque, NM; Annette Ruddy, Amarillo, TX; and Dr. Gerry Snyder, Tucson, AZ.

2nd Runner Up
Aircraft Manufacturer: "Failure of one nut in no way affected the engine's safe attachment to the pylon. The mounting had four bolts. Consequently safety was in no way and at no time compromised. Spares were readily available worldwide." During a planned engine replacement cracks were discovered in some nuts holding bolts to the aft mount of the engine. Oliver's Astute Analysis: If the missing nut "in no way affects the engine's safe attachment to the pylon", why is it there at all?
Sighting made by "Botswana Bill" Scott, Gaborone, Botswana

3rd Runner Up
Government Auditors: "The manufacturer performed slipshod work, used out-of-date blueprints and improperly inspected parts - but flight safety was not threatened." Oliver's Astute Analysis: Obviously true so long as the airplanes remain on the assembly line. Too bad they let them out of the door. Since the FAA believes that quality standards are only for paper work, the subsequent fatal accident must have been caused by bad luck. Sighting made independently and simultaneously by
Dr. Rudi Mortimer, Champaign, IL and Ira Rimson, Albuquerque, NM

4th Runner Up
Manufacturer's President: "There is absolutely no connection between our efforts to reduce manufacturing inspections and the 8-inch hairline cracks found in at least 40 of our airplanes. Oliver's Astute Analysis: If they add the fuel tank stringers to the pilots' walk-around inspections. The pilots' cursory preflight can be blamed for any fuel leaks that develop.
Sighting made by Ira Rimson, Albuquerque, NM

[This message has been edited by HeliFlight (edited 09 March 2001).]

UNCTUOUS

23rd Feb 2001, 18:15

Inside the Pentagon:
February 22, 2001

DOD TEST DIRECTOR CITED 'FUNDAMENTAL' DESIGN ISSUE IN V-22 CRASH RISK

More restrictions may be needed to avoid 'vortex ring state

Before leaving the Pentagon late last month, the top defense equipment tester, Philip Coyle, told a panel reviewing the Marine Corps' troubled V-22 tiltrotor aircraft program that a dangerous flight condition -- one that can lead to a crash -- stems from a "fundamental" characteristic of the Osprey that "cannot be remedied by minor design changes," according to a briefing obtained by Inside the Pentagon.

The flight condition, called "vortex ring state" or VRS, is believed responsible for a V-22 crash last April in Arizona that killed 19 Marines. The phenomenon is triggered by the combination of a rapid descent with a slow airspeed. But Coyle and others worry that the conditions under which an Osprey can enter a VRS are not well understood, and that a pilot can very rapidly find himself in a state of what is sometimes termed "power settling," which is hard to reverse.

In a Jan. 12 briefing to the Pentagon's "Blue Ribbon Commission," Coyle quoted the joint Navy-Air Force test team commander as reporting last October that the VRS phenomenon "occurs very rapidly with little or no warning to the pilots." Then-Defense Secretary William Cohen created the blue ribbon panel in December to review the Osprey program and recommend how to proceed following the second of two fatal crashes last year alone. The commission is expected to report its findings after several months of inquiry.

In a briefing to the panel on the same day that Coyle appeared, the General Accounting Office said the Pentagon's chief tester had found that the onset of vortex ring state in the V-22 "can occur in the proprotor on one side without the other side losing lift. In such a case, the aircraft tends to roll sharply into the side that first loses lift, resulting in large, unexpected bank angles, followed immediately by rapid dropping of the nose of the aircraft and a steep dive. At low altitudes, there may be no opportunity for recovery" (ITP, Feb. 1, p1). In his own presentation to the Blue Ribbon Commission, Coyle said the V-22's unique tiltrotor design, which allows the aircraft to take off and land like a helicopter but fly like a turboprop plane, appears to increase the risk of the Osprey experiencing a dangerous form of VRS. The chief tester based his findings on an eight-month operational evaluation period that ended last July for the hybrid rotorcraft, which the Corps views as critical for ferrying large numbers of Marines quickly in and out of a battle area. "The side-by-side rotor configuration of V-22 is susceptible to asymmetric onset of VRS with one-rotor-in/one-rotor-out conditions resulting in large rolling moments and departure from controlled flight," Coyle told the panel, according to the briefing. "Such a characteristic is fundamental and cannot be remedied by minor design changes. [The] only near-term solution is to restrict operations to avoid proximity to [the] VRS region." In fact, the Marine Corps has been exploring the parameters under which VRS can occur in the Osprey. In follow-on developmental test flights begun last summer, service pilots attempted to duplicate the conditions of the April crash -- but only at a high enough altitude to allow sufficient time and space for the aircraft to recover (ITP, Aug. 24, 2000, p1).

Although the Marine Corps acknowledged at the time that it needed to better understand the conditions in which VRS might occur in the Osprey, service officials said pilots in the April crash violated flight restrictions that, if followed, would have prevented the phenomenon from affecting the plane and bringing it down.

The V-22 program manager, Marine Corps Col. Nolan Schmidt, told ITP last August that the Naval Air Training and Operating Procedures Standardization manual, known as NATOPS, issued clear parameters that pilots in the April crash had ignored.

But the Marine Corps' own Judge Advocate General found that NATOPS -- as well as the V-22 ground school syllabus -- provide "insufficient guidance/warning as to high rate of descent/slow airspeed conditions and the potential consequences," according to the GAO briefing.

In his January presentation to the blue ribbon panel, Coyle warned that "restriction on [rate of descent] alone may not suffice" to prevent VRS. It "may be necessary to impose quick-stop and related restrictions, restrictions on yaw rates under some conditions and restrictions on proximity" to other aircraft, according to the briefing. Coyle said a proximity warning could be installed in the V-22 cockpit as "a significant operational aid, but will be of little value in situations where VRS is entered by rapid control inputs." Restrictions may also be necessary for "approach and departure operations in rugged terrain or at-sea with strong winds," the briefing states.

The tester advised that "more basic research, supplemented by flight testing, is required to map the VRS envelope of V-22 and understand the consequences of operations near the boundary of this phenomenon." The ability of a pilot to determine if the aircraft is at or near the boundary of VRS while in flight may be further degraded by a cockpit gauge that poorly displays small differences in ascent or descent, according to the briefing and other defense sources. Coyle told the commission that the Osprey's "vertical velocity indicator" is "difficult to read." Questions yet to be answered, Coyle said, include:

* "If operational restrictions on the flight envelope turn out to be sufficient to resolve the issue, can the USMC do its primary mission with such restrictions?"

* "If the mission can be done without the imposed restrictions, how common will be the situation where a crew exceeds the limitations?" Coyle raises the possibility that a crew will lose situational awareness under stress, face unusual wind conditions, or experience an emergency that requires a descent through "autorotation," a capability helicopters commonly have -- but the Osprey lacks -- for a semi-controlled landing with the engines cut off.

Although the April accident is widely attributed to VRS, the Marine Corps JAG report appeared to be unwilling to close the book on that, allowing for the possibility that other factors beyond vortex ring state played a role.

Referring to two recorded incidents of uncontrolled formation flight incidents during operational evaluation, the JAG said the lack of understanding as to the causes, "coupled with limited development formation testing . . . make it difficult to completely exclude turbulence [in the wake of a nearby aircraft] or downwash [dirt or sand kicked up by the rotors] as potential contributors to the [April] mishap." In Coyle's view as well, the Osprey faces a variety of safety risks. Last year he identified 177 failures of "flight-critical subsystems" in the Marine Corps V-22 Osprey tiltrotor aircraft that potentially endangered safety, InsideDefense.com reported Feb. 8. -- Elaine M. Grossman

Osprey Accident link (http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000289.html)

HeliFlight

23rd Feb 2001, 19:37

Pinochy-Unc:
That was very interesting. We were hoping you would show us exactly the same thing you have been posting over and over (using different writers saying the same thing- all from the same original report)
Show us one thing that was said here that has not been said over and over in your other posts. Notice the date of the briefing is January 12, so for a month and a half you have been repeating the words of one person- Philip Coyle. The pilots that fly the V-22 completely disagree with him.

You can keep stating the same words of one man over and over- but saying it a thousand times does not make it true. My bet is that the technology will be proven good and the V-22 will be an outstanding success.

You will be proven wrong in the same way that every "theory" you tried to come up with on this forum has been proven to be full of BALONEY http://www.pprune.org/ubb/NonCGI/frown.gif (you must work for Oscar Meyer to have such an endless source :))

When the technology is completely developed and tiltorotors are flying all over the world- you and Philip can move to a place where you won't be humiliated everytime you see one fly over (antartica maybe???)

So keep on giving us repeats of the same comment by one report and one person- the rest of us know what the majority of the EXPERTS say. (notice John Farley and PTIUAE don't bother talking to you any more- seems like you are all alone in your Baloney Shooting contest)

Don't worry though P-U- I am here to keep you company :) :) :)

HeliFlight

23rd Feb 2001, 20:18

Pinochy-Unc:
Hey... now that was a tricky one! It's the same old GAO report- But it was released in its entirety on Tuesday (of course the only quotes in the article are all the same we have heard over and over since BEFORE the official release) But thanks for that P-U, we really appreciate seeing it again. :)

And by the way... just heard the GOOD news...CONGRATULATIONS to you... you were interviewed by the Star-Telegram about the discussions on PPRune!! That's great...
Uh oh... wait a minute... they only included quotes in the series of articles from PTIUAE and not a SINGLE ONE from YOU!!! http://www.pprune.org/ubb/NonCGI/redface.gif http://www.pprune.org/ubb/NonCGI/redface.gif http://www.pprune.org/ubb/NonCGI/redface.gif

WHY do you suppose that is P-U??? Tell you what:
1. Look in the mirror
2. Turn sideways so you can see your profile
3. See that big, long Pinochio Nose...
Ah Ha!!

Didn't PaPa Jeppeto warn you what would happen...????

I'm afraid it is your old Nemesis again...
http://www.pprune.org/ubb/NonCGI/redface.gif C-R-E-D-I-B-I-L-I-T-Y http://www.pprune.org/ubb/NonCGI/redface.gif

THink about it...

Flight Safety

23rd Feb 2001, 20:33

Here's a safety issue with the V-22 that some may not have thought about.

The rotor blades, being made of composite material, are designed to "broom straw" if the engine nacelles get stuck in the forward flight position and the aircraft has to make a run on landing.

I have one problem with this, the V-22 is a combat rotorcraft.

As you know the rotor blades on helicopters such as the AH-64s and the UH-60s are designed to withstand a direct 23mm anti-aircraft hit and still remain intact so the aircraft can continue flying. We all know what happens when a conventional helicopter loses a rotor blade.

In hover mode the loss of a rotor blade from ground fire would have disasterous consequences for the V-22, just as it would for any helicopter. In forward flight mode, the loss of a rotor blade would still be bad, as I can't imagine the asymmetric flight characteristics of the V-22 are anything short of terrible. With the two rotors being linked by a cross shaft, the loss of a rotor blade even in forward flight would still be bad, as shutting one rotor down to prevent the aircraft from shaking itself apart, would mean loss of both rotors.

Come to think of it, there's no way a V-22 could fly in forward flight with a failed rotor blade. If it survived the shaking, it'd be a glider.

I personally think that rotor blades designed to "broom straw" on impact are a bad choice for a combat rotorcraft. I'd be hard pressed to fly a rotorcraft into combat with rotor blades that could turn into horse tails on impact from ground fire. Does anyone else see a problem with this?

------------------
Safe flying to you...

[This message has been edited by Flight Safety (edited 23 February 2001).]

HeliFlight

23rd Feb 2001, 22:22

Flight Safety:
I'm afraid I haven't heard anything on the ballistics tests that were done (but I'm sure Pinochy-Unc would be tickled to make something up for you- perhaps a couple of :)"QUINCKE valves" :) will make the blades "bullet proof") :). I am sure though that that type of testing would be a high priority as it is for any rotorcraft going into a combat situation.

Is that really true about 60s and 64s being able to take a 23mm through the blade? I could just imagine what a 20mm direct hit would do and I know I wouldn't like to be flying that bird.

This sounds like another good one for the Chief engineer friend of yours (two dinners now?!)

Let us know. Thanks.

[This message has been edited by HeliFlight (edited 24 February 2001).]

Lu Zuckerman

24th Feb 2001, 08:25

To: HeliFlight and Flight Safety

It is true that the UH-60 and the AH-64 were designed to be ballistic tolerant to being hit by a single 23mm High explosive round. The operative word is single.

The Army also lied to the pilots of the Apache relative to its’ invulnerability to the ZSU 23-4 weapons system. This was the primary weapon that would be used against the Apache if it were to attack a group of Warsaw Pact tanks.

This weapon was also being supplied to all of the governments that were in league with the Warsaw Pact. The U S Army commissioned a study by a so-called ”Think Tank” to study the effectiveness of the ZSU 23-4 against the Apache. It was their considered opinion that the ZSU 23-4 was inaccurate, It had a low degree of reliability and that if the ZSU 23-4 did hit the Apache with one round, the pilot would have sufficient time to evade any further hits by dropping below the tree line. Then again, there are not very many trees in the Middle Eastern wastelands.

The uninitiated reader should understand that the ZSU 23-4 has a rate of fire of 1200 rounds per minute and that if one round hit its’ mark, there would be forty or fifty rounds right behind the first round. When I was on contract with Agusta helicopters I took a two-week holiday in Yugoslavia.

While there, I watched a T V program, which was describing the weaponry of the Warsaw Pact. One of the weapons demonstrated was the ZSU 23-4. In the demonstration the weapon was pointed on a line parallel to a stand of trees. A helicopter popped up from behind the trees and in an instant the weapon acquired the helicopter and was pointed directly at it. The helicopter then dropped below the treetops and at that time the gun was turned off. The helicopter was allowed to fly away and the gun was turned on. It immediately started to fire and it swept an arc approximately 30 to 45 degrees on either side of center. The trees started to explode. It looked like there were hundreds of chain saw wielding loggers in the tree stand felling trees as fast as they could. It appeared to the writer that if a hail of 23mm bullets didn’t hit the helicopter, a falling tree would destroy it.

Regarding the V-22, it is not as much a case of invulnerability to taking a round it is more a case of reparability and availability after taking a round or suffering other major battle damage. The methodology of repair has to be the same as the procedure for construction. If the structure was cured in an autoclave the repair must be cured in an autoclave. The entire back section of the V-22 fuselage is made of one piece of continuous composite lay-up. If it suffers major damage it must be removed and sent back to the factory or depot for repair. In smaller damage areas the Navy specified the use of a common repair procedure for composite material. However, on the V-22 they specified that the repair had to be X-rayed to determine that there were no voids in the repair that would compromise the integrity of the repair. It turned out that the repair material was opaque to X rays and voids, if present, could not be detected. That was six years ago. Hopefully by now they have developed new repair procedures. However, based on what is going on now, I would not think that they have made any changes.

It is also my personal opinion that the Comanche has the same problem due to its' method of construction.

------------------
The Cat

[This message has been edited by Lu Zuckerman (edited 24 February 2001).]

[This message has been edited by Lu Zuckerman (edited 24 February 2001).]

[This message has been edited by Lu Zuckerman (edited 24 February 2001).]

HeliFlight

24th Feb 2001, 16:39

Thanks LU:
Good stuff on the UH-60 and AH-64. I'd hate to be on the HOT END of a ZSU 23-4 no matter what I was flying!!!

Some of your stuff on the V-22 may be outdated, but at least it comes from a basis in fact. You don't make up "theories" that have no basis in reality that wind up being disproven a post or two later (like someone we know). http://www.pprune.org/ubb/NonCGI/redface.gif

[This message has been edited by HeliFlight (edited 24 February 2001).]

muhdzailan

26th Feb 2001, 16:26

The V-22 Osprey is a multifunction aircraft that is useful for search and rescue operations and transport flight.Sadly,due to two crashes involving the aircraft,it should be examined and checked toroughly before it is certified "Fit to Fly".

UNCTUOUS

26th Feb 2001, 16:28

US GAO savages V-22 test programme

21 February 2001The US Government Audit Office (GAO) has issued a report on the state of the V-22 test programme that may well be the final nail in the coffin of an ill-fated tilt-rotor aircraft procurement for the US Marine Corps.
In a letter to the US Secretary of Defence, Donald Rumsfeld, the GAO says, "Our review of the V-22 program, which is already in low-rate initial production, revealed that the Department planned to proceed with a full-rate production decision without knowing whether new technology could meet Marine Corps requirements; whether the design would work as required; or whether the design could be produced within cost, schedule, and quality targets."

In particular the GAO was scathing about the manner in which the initial test programme had been constantly reduced. "Specifically, developmental testing was deleted, deferred, or simulated in order to meet cost and schedule goals. ...To meet cost and schedule targets, the actual testing conducted was less than a third of that originally planned," the letter continued.

Notably the report pointed out that the 113 planned test conditions to investigate Vortex Ring State, a condition where the tilt-rotor settles into its own downwash and loses lift, which may have contributed to the crash in April last year in Arizona, which killed 19 Marines, were reduced to 49. Of these only 33 were actually flown.

The report, Readiness of the Marine Corps' V-22 Aircraft for Full-Rate Production (http://www.gao.gov/new.items/d01369r.pdf) (pdf 270kb download of full GAO Report) concluded that there was significant risk with proceeding with full-rate production because:

**Knowledge of V-22 design and performance parameters fell short of what should have been known before beginning production
**Developmental flight testing was deleted, deferred, or simulated
**Operational test waivers and limitations reduced testing for operational realism
**Assessment was based on reduced system requirements
**Major concerns were raised in OPEVAL, JAG report, OPEVAL database, DOT& E, and other reports
**Risks of moving forward without additional knowledge
**Value of system for Marine Corps operations was not yet established
**Connection between demonstrated problems not known; unknown problems not discovered
**The contract exposed government to responsibility to fund any design modifications -some, perhaps significant, changes were likely
**Longer term risk to modernisation account, as cost increases beyond already budgeted funds were likely
**Marine Corps budget impacted by maintainability shortfalls

The V-22 is the US Marine Corps priority equipment procurement programme, intended to replace the ageing helicopter troop lift capability. The Marine Corps wants the aircraft for its high speed (300Kts) in level flight and for its increased capacity (up to 24 combat equipped troops). However, the GAO even calls the latter into doubt suggesting that approximately 15 combat equipped troops is the real figure.

The V-22 programme has always been controversial. Vice president Dick Cheney tried to kill it in its initial stages when he was Defense Secretary to Ex-President George Bush. Since then the budget has been constantly exceeded, and now runs at some $40 billion for 458 tilt-rotors for the Marines (350), Navy (48) and AirForce (50).

In addition to the accident in Arizona, the V-22 had two crashes (one fatal, 3 USMC and 4 civilians died) during its early developmental stages, and finally a fatal crash in December 2000 when 4 Marines died. The USMC also suspended the commander of the V-22 test squadron in January this year after receiving an anonymous letter alleging falsification of maintenance records. The USMC has denied that poor maintenance was the cause of either of the last two fatal crashes.

The US Department of Defense has halted any decisions on the future of the V-22 programme until a 'Blue Riband' panel of experts, set up in December last year by previous Secretary of Defense William Cohen, and tasked with an " independent, high level review of the programme", has issued its report, expected in the next two months.
Link to Article (http://defence-data.com/current/page9979.htm)

muhdzailan

26th Feb 2001, 16:28

HeliFlight

26th Feb 2001, 17:38

Pinnochy-Unc:
Gee…what a surprise… the same GAO report being written about by a different reporter (different person saying exactly the same thing). You have been posting it all over the other threads- why not here! http://www.pprune.org/ubb/NonCGI/redface.gif

Looks like you are Pulling an Unctuous :) in more ways than one… the only parts of the report being talked about in the General Press is the negative side (which you love)- the rest is never seen. The General Press does this to sell newspapers (you do it for your ego boost- nobody will listen to you anywhere else but here, and even the General Press won’t print your babblings when you try to sell it to them). By the way, I suppose you have been holding back on your most treasured publications (the Tattler and Enquirer) to really prove you are right a little later (your version of a knock out punch). :)

The Industry Press tries to look at the reality of the situation (if it is dangerous- throw it out, if it is safe- make it safer) So now that you have shown us ad nauseum how the people trying to sell papers report the story… let’s see how people who understand what they are talking about say (we already know how you like to ignore the EXPERTS so for sure you won’t like this) But for the rest of us interested in the truth let’s see…

HeliFlight

26th Feb 2001, 17:54

Black Hawk Crash Provides Context for Osprey Woes
Helicopter News, February 22, 2001

The Marine Corps V-22 Osprey continues to suffer from allegations of program mismanagement and the assumption of undue risk. However, other recent events in the rotorcraft world have served to provide some much-needed context for the difficulties that now confront the Osprey.

The most tragic of these events was the crash, earlier this month, of two U.S. Army UH-60 Black Hawks in Honolulu, Hawaii, during a night training exercise involving Night Vision Goggles (NVGs). Six soldiers were killed and 11 personnel were injured when the two Black Hawks “came in contact”

The Army has not yet officially determined what caused the accident, but one of the survivors, Sgt. Leslie Frye Told ABC’s Good Morning America that he saw what appeared to be hanging cargo from one Black Hawk hit the rotor of the second helicopter in which he himself was riding .

“Something did come up on the right-hand side and hit the rotor blades of the helicopter,” he said. “I do not believe it was another helicopter, and the only other thing flying in the air at the time was a Humvee slung under the trail helicopter.”

The tragic incident underscores the fact that rotary flight is inherently dangerous, and that even mature helicopters like the Black Hawk suffer from a disconcerting number of accidents and mishaps. In 1999, for instance, three Black Hawk crashes killed 10 U.S. servicemen. In 1998, five Black Hawk crashes killed three soldiers. And eight Army personnel died I n1997 when two UH-60s crashed.

Significantly, though, this latest Black Hawk incident, like the four V-22 crashes, does not appear to involve any fundamental technological flaw inherent to the aircraft itself. Indeed, all four Osprey accidents are unrelated to tiltrotor technology; none share a common thread; and all have separate causes.

Relative Safety
Thus, when examining the safety and airworthiness of the V-22, the appropriate comparison is not to some utopian standard that does not exist in the real world. Rather, what must be assessed is Osprey’s relative safety vis-à-vis other available rotorcraft.

This point, too, came into stark relief earlier this month when the Navy found cracks in an H-46 Forward Longitudinal Differential Bellcrank, which aids in changing the pitch of the forward rotor head. Failure of the bellcrank results in loss of control of the aircraft.

It was the third time such a crack had been discovered. Consequently, Navy officials have decided to increase the frequency of aircraft inspections from every 25 hours of flight to every 10 hours of flight. The new rule affects all 308 Navy H-46 helicopters, including 229 Marine Corps CH-46Es. A CH-46 crash in December 1998 killed six Marines and one sailor.

“Despite programs to extend the service life of the Sea Knight, maintenance personnel are finding that components that have never before failed are beginning to break due to increased age and fatigue,” said the Marine Corps in a statement. The Marines also note that CH-46 maintenance costs per flight hour rose by 75% between 1993 and 1998 without inflation. Flight hours, meanwhile, declined by 23% during that same period.

GAO Criticism
This is important because the Osprey is earmarked to replace the Corps’s antiquated fleet of CH-46 helicopters. Yet, a number of critics at the General Accounting Office (GAO) most recently argue that, at least for now, the V-22 is an unworthy replacement aircraft. “

Our review of the program… revealed that the [Defense] Department planned to proceed with a full-rate production decision without knowing whether [the] new technology could meet Marine Corps requirements; whether the design would work as required; or whether the design could be produced within cost, schedule, and quality targets. Specifically, developmental testing was deleted, deferred, or simulated in order to meet cost and schedule goals,” the GAO said in a February 20 letter to Defense Secretary Donald H. Rumsfeld.

This may be true, but the GAO’s analysis concerns only the V-22. It does not address the cost involved in the only available immediate alternative, which is to continue to keep the CH-46 airborne. Again, the appropriate comparison is not with an idealized “best practice” procurement envisioned by the GAO. The appropriate comparison lies instead with what alternative options exist in the real world.

The GAO, as befits its watchdog function, has identified a number of areas¾including rapid descent flight envelope testing and air combat maneuvering¾where it believes insufficient testing was done on the V-22. The Marine Corps disagrees, arguing that no aircraft is every perfectly understood and employed when it enters full-rate production.

Indeed, additional testing and refinement, they say, is the norm for all military helicopters and airplanes. In fact, the Osprey has been under development far longer than is warranted; and there is a serious need for this aircraft out in the fleet, where, slowly but surely, it can be mastered and deployed to maximum effect, Corps officials say.

Conclusion
The GAO and the Marines both make strong and convincing cases. Such disagreement is healthy. For its part, the GAO helps to guard against dangerous and rash decision-making by warriors who may be too eager for new aircraft and new technology. Marine Corps zeal and determination, by contrast, helps to guard against a paralyzing obsession with unachievable perfection, which can hinder military and technological progress. The ultimate decision, though, lies with Congress, which will have to make a carefully weighed and deliberate decision.

HeliFlight

26th Feb 2001, 18:12

See Pinnochy-Unc...
this is called being O-B-J-E-C-T-I-V-E http://www.pprune.org/ubb/NonCGI/redface.gif
It means to look at BOTH sides without personal prejudice.
By using this you can come up with an accurate conclusion in the end. It is much better then inventing a false theory then changing the facts whenever you can to make them fit the theory. This means you could avoid all the embarrassment and humiliation you have been through as each one of your fabricated "theories" has come unravelled one by one when they were disproven by ACTUAL facts.

Take a look at the definition of http://www.pprune.org/ubb/NonCGI/redface.gif"unctuous" http://www.pprune.org/ubb/NonCGI/redface.gif in the dictionary and you will be able to better understand why you have such a difficult time with this objectivity stuff that is so alien to you. You have definitely chosen the best name for yourself because it describes your lack of interest in the facts perfectly!!! http://www.pprune.org/ubb/NonCGI/redface.gif http://www.pprune.org/ubb/NonCGI/redface.gif http://www.pprune.org/ubb/NonCGI/redface.gif
(I especially like the excessively smug, greasy, and oily parts :))

[This message has been edited by HeliFlight (edited 26 February 2001).]

UNCTUOUS

26th Feb 2001, 19:12

JAG Report - Opinion Section Quotes
•“After reviewing the evidence collected, it was concerning to see how ‘easy’
it was for the recipe of uncontrolled flight to be concocted.”
•“Aircraft performance envelopes are developed, and procedures and
guidance published (NATOPS) to prevent pilots from putting an aircraft in a
situation that would exceed safe parameters. The MV-22 performance
envelope may be one that fleet pilots can operate within, but given the rigors
of combat, real world operations, and realistic training for both, the
consequences of exceeding this particular envelope appears to be
excessively grave (departure from controlled flight with no warning).”
•“In traditional rotorcraft, Power Settling would cause uncommanded rates of
descent and, depending on altitude, may result in a hard landing or quite
possibly a controlled crash. In all likelihood, however, such an event would
result in the aircraft at least hitting the ground in an upright attitude. In this
respect, with regard to Vortex Ring State and/or Blade Stall, the MV-22
appears to be less forgiving than conventional helicopters. A V-22, because
of the approximately 8’ 8” distance because of its prop-rotors, as evidenced
by this mishap, is capable of having one rotor impacted by the effects of
Vortex Ring State and/or Blade Stall and the other not, resulting in an
asymmetrical condition. We believe that this was the case of the mishap.
The end result was a departure from controlled flight instead of a hard
landing or controlled crash .…”
•“There were, however, two other incidents that occurred during OPEVAL
where pilots reported experiencing an uncommanded roll during section
operations...The fact that the causes of these two incidents are not yet
known, coupled with limited developmental formation testing (4 flights for
11.7 hours), make it difficult to completely exclude wake turbulence or
downwash as potential contributors to the mishap.”

JAG Report - Recommendation Section Quotes
•“All V-22 operators should become acutely familiar with the potential consequences
of high rates-of-descent combined with slow airspeeds that are present with tilt-rotor
design. Though all rotorcraft have the potential to enter into a Vortex Ring
condition, recorded occurrences to date have been rare. The fact that this aircraft
not only found itself in a Vortex Ring State condition with no apparent warning to the
aircrew, but also departed controlled flight is particularly concerning. Until further
testing is conducted on the Vortex Ring State phenomenon, safe flight will require
strict adherence to procedures and limitations.”
•“PMA-275, PMA-205, and the Contractor expedite incorporation of Vortex Ring
State and blade stall warnings and procedures into the MV-22 NATOPS...The
preliminary NATOPS manual and V-22 ground school syllabus provides insufficient
guidance/warning as to high rate of descent/slow airspeed conditions and the
potential consequences.”
•“That NAVAIR continue to explore the aerodynamic effects of formation flight with
the MV-22. The MV-22 will be operationally employed in a similar fashion to
existing fleet aircraft. Multi-ship formations will be the norm as the aircraft executes
its various missions. Questions still remain concerning potential aerodynamic
influences, such as wake turbulence on wingmen during formation flight. Two
‘anomalies in addition to the mishap occurred during OPEVAL where this issue was
at least a concern.”

OPTEVFOR V-22 OPEVAL Report Quotes
• Summary - “The Naval Air Training and Operating Procedures Standardization
(NATOPS) manual lacked adequate applicable content, accuracy, and clarity. Additionally,
because of incomplete developmental testing in the high rate of descent (HROD)
regime, there was insufficient explanatory or emphatic text to warn pilots of the
hazards of operating in this area. The flight simulator did not replicate this loss of
controlled flight regime.”
•“The V-22 has the potential to enter high rates of descent at high nacelle angles
with low airspeed. This condition occurs very rapidly with little to no warning to the
pilots. In simulation at 95 degrees nacelle, 39 KCAS, and 0 feet per minute rate of
descent (ROD), pulling the thrust control lever (TCL) full aft caused an immediate
descent exceeding the 800 feet per minute NATOPS WARNING. If forward TCL is
applied at this point, an uncontrolled flight condition is possible. Within 3 seconds,
the simulator exhibited in excess of 3,000 fpm ROD.”
• Additional Recommendation - “Continue developmental testing to investigate
HROD/loss of controlled flight phenomena and determine safe flight envelope for
these conditions. Consider providing cockpit warning of this condition to the pilots
to preclude entry into unsafe flight regimes.”
• Section 4 Test and Results -”The V-22 technical documentation did not support
the operation and maintenance of the V-22. The NATOPS was plagued with
inaccuracies that degraded flight operations and still contained FSD and EMD
aircraft data not pertinent to production aircraft. Performance charts furnished by
the developer to support OPEVAL were also inaccurate when compared to actual
flight conditions and the CMS. Additionally, because of incomplete developmental
testing in the HROD regime, there was insufficient explanatory or emphatic text to
warn pilots of the hazard of operating in this condition.”

DOT&E Operational Test and Evaluation Report Quotes
• Executive Summary - “Vortex Ring State can occur in all rotary-wing aircraft under
similar conditions of low airspeed and high sink rate. No mechanical or electrical
failures in the aircraft were found to contribute to the mishap…. In the tiltrotor V-22,
the onset of VRS can occur in the proprotor on one side without the other side
losing lift. In such a case, the aircraft tends to roll sharply into the side that first
loses lift, resulting in large, unexpected bank angles, followed immediately by rapid
dropping of the nose of the aircraft and a steep dive. At low altitudes, there may be
no opportunity for recovery.”
•“While the possible existence of VRS in the V-22 was known when flight limits for
OPEVAL were established, the unusual attitude following entry into VRS was not
expected.”
•“In addition, testing to date suggests that should a pilot inadvertently exceed
published limitations, there may be no easily recognizable warning that the aircraft
is nearing the danger zone - and some flight control inputs; e.g., a roll or yaw
command, may trigger an asymmetric thrust condition. Such a situation can easily
be envisioned in flight conditions that place a high workload demand on the pilots;
e.g., night or low visibility, system malfunctions, hostile fire, etc., should a
breakdown of crew coordination or loss of situational awareness occur. Thus, the
first indication the pilot may receive that he has encountered this difficulty is when
the aircraft initiates an uncommanded, uncontrollable roll. High rate-of-descent
(HROD) testing continues to define the VRS phenomenon.”

DOT&E Operational Test and Evaluation Report Quotes
• Executive Summary - “I believe that ongoing developmental testing should
continue to explore the ability to detect proximity to the danger area in the flight
envelope, with the objective of providing meaningful warning to the pilot, or control
limitations, to avoid entry into this danger area and loss of control….This area is
historically left unexamined in other military rotorcraft which put in place restrictions
that rely on information non-specific to their particular airframe.”
•“In addition, follow-on developmental and operational tests should involve multiple
MV-22s, at heavy weights, in close time and space proximity as might be
anticipated in the conduct of a combat assault mission. Such operational test
would increase confidence that appropriate tactics exist to enable the MV-22s to
deliver assault forces to a small area in a short time while avoiding undue exposure
to enemy threats-without subjecting the aircraft to potential loss of control
situations.”
• Operational Effectiveness Areas of Concern - “As noted previously, I fully
endorse ongoing testing activities and recommend research efforts to better
understand the Vortex Ring State phenomenon and the potential danger posed to
the safe operation of the MV-22.”
•“A second, related concern involves the effects of maneuvering limitations imposed
to avoid the vortex ring state danger area...Despite the OPEVAL finding that the
restrictions had no operational impact, I am concerned that this constraint imposed
to avoid loss of control may limit the maneuver capability and hence the
effectiveness of the MV-22 in some operational scenarios. Ongoing developmental
flight testing is intended to more accurately define the danger zone beyond the
NATOPS flight envelope.”

DOT&E Operational Test and Evaluation Report Quotes
•“A second phase of testing is planned by Naval Air Systems Command to fully
explore the potential aerodynamic interactions between MV-22 aircraft in proximity
to each other. Until the final operational constraints upon descent rates and aircraft
separation are established based upon ongoing developmental testing, and the
appropriate tactics are confirmed in operational testing, the potential impact on the
effectiveness of the MV-22 in performing some combat assault missions must be
viewed with some reservations.”
• Assessment of OPEVAL Adequacy - “Examine thoroughly the circumstances in
which the V-22 may depart from controlled flight in low-airspeed, high rates of
descent. Investigate the potential for airflow interactions between nearby V-22s to
initiate or aggravate vortex ring state.”
•“Demonstrate the end-to-end conduct of ‘typical OMFTS scenarios’ involving
multiple MV-22s making repeated back-to-back flights in close proximity in time and
space to each other and other aircraft needed for the operations - as might be
expected during the conduct of combat assault operations.”
•“Confirm the shipboard compatibility of multiple MV-22s operating simultaneously
as would be needed in the conduct of a substantive amphibious assault.”

JAG Report - Opinion Section Quotes
•“The maintenance/removal rate of swashplate actuators, though not causal in this
mishap, is concerning. The MOTT replaced 17 actuators during the OPEVAL
period. Given their critical role in the aircraft’s drive system, reliability of these
actuators is imperative.”
•“The frequency of servicing/maintenance requirements, for aircraft hydraulic
systems, though not causal in this mishap, is concerning. Many maintenance man-hours
have been spent maintaining and servicing the various aircraft hydraulic
systems.”

HeliFlight

26th Feb 2001, 22:03

Sorry Pinnochi-Unc:
The mis-informed OPINIONS of those with no experience in aerodynamics or tiltrotors will not compare to this NEXT Article :) :) :)

Pay close attention to what Ray Prouty has to say. I know that you always disregard what the EXPERTS say, but this is for the rest of us in the REAL world that know Mr. Prouty is the foremost aerodynamicist in the Rotorcraft world.

You just keep humming a tune and look the other way while the rest of us read... http://www.pprune.org/ubb/NonCGI/redface.gif

Bye, Bye P-U :) :) :)

HeliFlight

26th Feb 2001, 22:09

Defense: Catch-22 for the V-22
February 2001-02-26
by John R. Guardiano, Defense Editor

TO MILITARY STRATEGISTS AND rotorcraft enthusiasts, the performance parameters of the V-22 Osprey are inspiring. With twice the speed and range of a helicopter, the tiltrotor can self-deploy over a 500 nautical mile radius and transport 24 combat ready Marines or 15,000 pounds of equipment.

It is not without reason that Lt. Col. Jim Shaffer, operational test director for the Air Force Special Ops CV-22, calls the Osprey the "first revolution in aviation to hit Edwards Air Force Base since the breaking of the sound barrier."

We know, after all, what this aircraft can do and how it will affect America’s ability to project military power. As recently departed defense secretary William Cohen has observed, "The V-22 is the revolution in military affairs."

The cruelest month
V-22 development dates back to 1977, the year of the XV-15 prototype’s first flight. But for all that we know about this technological marvel, these is a great deal that we don’t know.

Such as why, exactly, the Osprey crashed on April 8. The accident board identified a combination of "human factors," the most significant of which were the pilot’s high rate of descent and low forward air speed. This, it was believed, precipitated power settling, or a vortex ring state.

However, subsequent flight tests by the Naval Air Systems Command (NAVAIR) at Patuxent River, Maryland, have shown that the Osprey is a lot more forgiving than had been thought, and that vortex ring may not be all that significant a bugaboo.
The upshot of this testing, ironically, may be an expansion of the V-22 flight envelope to a maximum descent rate of 1,400 fpm at less than 40 knots of forward airspeed. To be sure, the pilots in command on April 8 were descending in excess of 2,000 fpm, and this is believed to have contributed heavily to the crash. NAVAIR, though, is increasingly skeptical that this precipitated a vortex ring state.

"The best thinking right now is that the Osprey suffered some kind of rotor stall that we don’t yet fully understand," says one industry analyst.

"The vortex ring explanation never made any sense to me," adds noted aerodynamicist and R&W columnist Ray Prouty. "By my calculations, the Osprey should have been coming down a lot faster than it was to get into a classic vortex ring state." The doomed MV-22, he concludes, "must have been hit by a meteorite."

Prouty is jesting of course, but he also is making a larger and more salient point—to wit, that rotorcraft development historically has been mired with a great many "unknown unknowns."

Unfortunately, it is what we don’t know that hurts us. Witness last year’s crashes on April 8 and December 11. The V-22, though, is not unique in this regard. Accidents and mishaps seem to be an inevitable byproduct of rotorcraft development, more so than with fixed-wing aircraft.

It’s all part and parcel of the many "unknown unknowns" that afflict helicopters—especially revolutionary new rotorcraft like the Osprey, Prouty says. Or, as military aviators bluntly put it: the flight manuals are written in blood.

None of this is meant to minimize the tragic loss of life that results from these accidents. Rather, it is an attempt to provide some much-needed context.

Media assertions to the contrary, the Osprey is no more "experimental" and "unproven" than the CH-46, CH-53, and HH-60G helicopters that it is replacing.

In fact, the V-22 has been subject to more rigorous testing over a much longer time period than any other rotorcraft. Yet, critics call for the Osprey’s termination. But when a CH-46 crash in December 1998 killed six Marines and one sailor, there were no ringing editorials calling for the aircraft to be grounded before it kills again.

In fairness to the critics, there have been four Osprey accidents in less than a decade and two fatal crashes in eight months. None of these accidents, however, share a common thread, and all have separate causes. They are unrelated, moreover, to tiltrotor technology.

The first (1991) mishap occurred when two of three stabilizing gyros were wired incorrectly and the Osprey’s flight control system malfunctioned. The second (1992) crash involved an engine fire that resulted from oil spillage. The April 8 tragedy, it seems, resulted from a rotor stall. These are risks inherent in any flight test development program. "I would say the V-22 has had some really bad luck," Prouty says.

At presstime, the cause of the December 11 crash remains unknown. Investigators have identified a hydraulic malfunction in the doomed aircraft, but are unsure whether it relates to the mishap.

What distinguishes the V-22 from other rotorcraft isn’t just its novel, hybrid design, but also its high cost ($43 million to $83 million a copy). This has made it an attractive target for budget hawks.

Today, policymakers and the public seem to demand bloodless conflicts. This is a laudable desire, but it ignores history. For example, the Navy and Marine Corps lost 776 aircraft in 1954 versus 24 in the year 2000. This demand also makes it difficult for the military to push the envelope and develop new aircraft like the Osprey.
Hence, the paradox of rotorcraft development: The Osprey promises to save lives by virtue of its superior capabilities, but this promise cannot be realized without the assumption of risk.

HeliFlight

26th Feb 2001, 22:25

Hey Pinnochy-Unc!!!:
The Defense Editor that wrote this is the SAME REPORTER from Rotor & Wing Magazine that asked for an interview earlier on this very same thread!!!
http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000289-2.html

Oh…that’s right, sorry P-U….I forgot…
He only asked to speak to John Farley and PTIUAE http://www.pprune.org/ubb/NonCGI/redface.gif http://www.pprune.org/ubb/NonCGI/redface.gif http://www.pprune.org/ubb/NonCGI/redface.gif
Boy, the Press is really involved with the discussions here (just not with you)
But why on earth would he leave you out when you are the originator of the thread AND the most predominat poster to it??? http://www.pprune.org/ubb/NonCGI/redface.gif

Oh… that’s right:
http://www.pprune.org/ubb/NonCGI/redface.gif C-R-E-D-I-B-I-L-I-T-Y http://www.pprune.org/ubb/NonCGI/redface.gif
(…remember what PaPa Jeppeto told you)

By the Way P-U…. about your “flick of the wrist” fantasy (sorry, I meant “theory” ;):

"The vortex ring explanation never made any sense to me," adds noted aerodynamicist and R&W columnist Ray Prouty. "By my calculations, the Osprey should have been coming down a lot faster than it was to get into a classic vortex ring state."

Another “Uncy-Theory” de-bunked (Gee… what a surprise… guess that makes all of them P-U… Better start manufacturing some more :))

Ed Winchester

27th Feb 2001, 11:28

Hmmmm, is it just me or is there a well-established ritual to this thread?

1. UNCTUOUS (Definition: Unpleasingly flattering/OILY) spends at least half of his life in front of his keyboard regurgitating the same old guff again and again and again.

2. Heliflight rips him to shreds (rather humorously IMHO).

3. BUNKTUOUS types in another ream or 3 of eye torture.

4. See 2.

Heliflight - I'm with you on this one.

BUNKTUOUS - Put down the whip, the horse died months ago.

http://www.stopstart.fsnet.co.uk/smilie/wokka.gif

Ed Winchester

27th Feb 2001, 11:40

Ding Ding, Round 35....

"I've got Heliflight clearly ahead on points, but this OILY chap just won't stay down! He doesn't know when he's been beat. Oh no, Heliflight "DUCK!", the unpleasantly flattering one is attempting another left hook followed by a mind-numbingly boring 'War and Peace'-esque posting containing no original thought whatsoever.

Ah, Heliflight has easily deflected that onslaught with an uppercut and a few slick one-liners to put the Pinochy-Unc back on the canvas. What's this - surely he's not going to get back up? How much telling does this man/keyboard interface need?

Ding, ding. End of Round...........

http://www.stopstart.fsnet.co.uk/smilie/wokka.gif

Cyclic Hotline

7th Mar 2001, 21:29

Sikorsky will be licking their lips, a ready buyer for the military S-92! Of course, maybe Boeing will crank up the Boeing 360 programme again.

By the time the military leaders are announcing this, you know that their political masters are way beyond this point in the decision making process.

I think that this may be a portent for the future of current procurement plans for the MV-22; maybe a scaled back purchase, but with a controlled inception into service. The other benefit, is to ensure that a future problem on the aircraft does not compromise the Marine Corps ability to maintain an aviation capability.

Top Marine Calls for a Backup Plan to Replace Osprey

By JAMES DAO The New York Times
The Marine Corps commandant ordered a search for helicopter alternatives to the V-22 Osprey as concerns grew within the Pentagon that the $40 billion aircraft program would be canceled.

WASHINGTON, March 6 — The Marine Corps commandant, Gen. James Jones, has ordered the Marines to search for helicopter alternatives to the V-22 Osprey, the innovative but problem-plagued aircraft, as within the Pentagon concerns grow that the $40 billion Osprey program will be canceled, Marine officials said.

General Jones's order is the first clear acknowledgment by the Marines that the program is in peril. The Osprey faces a series of potentially debilitating inquiries into its safety, cost and reliability. Two Osprey crashes killed 23 marines last year, and the Pentagon is investigating accusations of falsified maintenance records at the Marines' lone Osprey squadron, in North Carolina.

Marine officials asserted today that General Jones's move did not mean he had lost faith in the safety or capability of the Osprey, which can land and take off like a helicopter and cruise like an airplane. If the Osprey survives the investigations, the Marines still hope to buy 358 of them to replace their Vietnam-era troop transport helicopters.

But there is also a growing sense within the Pentagon that support for the Osprey in the White House and Congress, as well as among many marines, has waned in recent weeks, as newly released reports by Congressional and Pentagon officials have raised questions about the Osprey's effectiveness, affordability and safety — as well as the Marines' management of the program.

"We've got to be pragmatic about this," one senior Marine Corps officer said, noting that General Jones wanted to have a backup plan for replacing aging CH-46 and CH-53 helicopters if the Osprey program was killed.

Senior Marine officials continue to be unenthusiastic about the available helicopter alternatives, none of which can fly as fast or as far as the Osprey.

The main alternative, Marine officials said, would probably be some version of the H-60 Black Hawk, which is made by Sikorsky and is one of the Army's main infantry transport helicopters.

Another option would be to build a new version of the CH-53E Super Stallion, also by Sikorsky, which can carry more troops than the Osprey but is slower and has less range.

In 1991, Dick Cheney, who was then defense secretary and is now vice president, canceled the Osprey program, calling it too expensive. But Mr. Cheney was overruled by Congress, led by delegations from Texas and Pennsylvania where the Osprey is being built by Boeing and Textron's Bell Helicopter unit.

Mr. Cheney has declined to comment on the Osprey since taking office. But Bush administration officials have said the aircraft is high on a list of expensive military programs being reviewed for potential cuts.

A four-member panel conducting a review of the Osprey program is preparing to hold its first public hearing this Friday. Witness are expected to include relatives of marines killed in an Osprey crash last year and their lawyers, who are contemplating suing the manufacturers.

The panel, which is expected to send its final report to Secretary of Defense Donald H. Rumsfeld next month, has already received private briefings from a number of experts who contend that the Osprey may be more aerodynamically unstable, harder to maintain and costlier to operate than the Marines have been willing to acknowledge.

In one briefing, a Navy investigator reported that between 1998 and 2000, two Osprey caught fire after hydraulic lines broke. A frayed hydraulic line, combined with a computer malfunction, is thought to have caused an Osprey crash last December that killed four marines.

In another briefing, the General Accounting Office reported that the Marines canceled important tests on the Osprey in 1997 and 1998 to save time and money. Those tests might have shed light on a potentially dangerous aerodynamic condition known as vortex ring state, which was later ruled the primary cause of an Osprey crash in April 2000 that killed 19 marines, the report said.

"Major concerns about the aircraft's performance and operations remain unresolved," the accounting office said. "These known and potential problems and their associated costs leave open the question of the V-22's real value, as demonstrated, for Marine Corps operations."

Yet another report to the panel, by the Pentagon's chief testing office, raised concerns about the apparent inability of the Osprey to "autorotate," a crash-landing maneuver used when a helicopter loses all power. The Marines contend that the Osprey can glide down to a crash landing like an airplane.

The Department of Defense's inspector general is conducting a separate investigation into accusations that maintenance records were falsified at the Osprey's home base, New River Air Station in North Carolina.

Although the former commander of that squadron, Lt. Col. Odin F. Leberman, is at the center of that inquiry, the investigators are also looking into the possibility that Marine generals who oversaw the Osprey program knew of and perhaps even encouraged improper behavior at New River, military officials say. Colonel Leberman has been reassigned pending the investigation.

The swirl of inquiries and public criticism of the V-22 program have contributed to rising concern within the Marine Corps itself about the safety of the Osprey and the integrity of the program, Marine Corps officials said. It is in part to assuage those fears that General Jones has ordered the search for potential alternatives, those officials said.

In addition, General Jones has made a point in recent weeks of declaring his willingness to cancel the program if the Osprey is proven unsafe, to assure marines and their families that he is not "a zealot" about the aircraft, a senior Marine Corps official said.

"I think what we have to do is essentially not be blinded and not have tunnel vision on this," General Jones said in a recent interview.

He added that he would try to make sure the Marines "never get so far down the road that we have no other options" other than the Osprey.

The option the corps seems to favor most would be to avoid killing the Osprey by putting it back into research and development for possibly a year or longer. The Marines could then spend the money saved on keeping their aging helicopters flying or buying a small number of Black Hawks as an interim measure while the Osprey undergoes new tests or even a redesign.

It is unclear whether efforts by the Bush administration or the Marines to delay or cancel the Osprey program will run into opposition on Capitol Hill. Many members of Congress still view the V-22 program as an important source of jobs for their constituents. And many aerospace industry officials contend that the Osprey's tilt-rotor technology could have commercial applications.

But several Pentagon officials say the driving force behind the Osprey has always been the Marines. If the Marines cool to the program, Congress is likely to follow, one Pentagon official said.

"If the Marines aren't willing to fight for it, people will back away from it," the official said.

RW-1

7th Mar 2001, 22:58

No offense cyclic, wouldn't it be easier to post a link to the article?

Anyways, Yes, I think that we might be looking at its end. With the revelations of other tests that were skipped, etc. Congress certainly will not want to spend more on it, even to bring the issues to a close.

Whether this would hurt the 609? I don't think so, as it was a Bell project all it's own.

------------------
Marc

Cyclic Hotline

8th Mar 2001, 00:44

Or then again, maybe not!

Reason for not posting a link from a news source is the story gets archived and the link changes. Kinda hard to read a dead link? Also some people (like me) aren't very interested in opening the links, and would rather shoot a cursory eye over the story to see if it is of any interest.

US Marines deny Osprey alternatives study report

NEW YORK, March 7 (Reuters) - The U.S. Marine Corps denied on Wednesday a newspaper report that its commandant, General James Jones, has ordered the Marines to search for helicopter alternatives to the innovative but problem-plagued hybrid V-22 Osprey aircraft.

The report in the New York Times online edition on Wednesday was disputed by a Marine Corps spokesman.

"General Jones has not ordered any study of alternatives to the V-22 Osprey to be conducted at the present time,'' the spokesman, Major Patrick Gibbons, told Reuters.

Concerns were growing within the Pentagon that the $40 billion Osprey programme would be cancelled, the newspaper had reported Marine officials as saying.

General Jones's order is the first clear acknowledgment by the Marines that the programme was in peril, the paper said.

The Osprey, which can land and take off like a helicopter and cruise like an airplane, faces a series of potentially debilitating inquiries into its safety, cost and reliability, the paper noted.

Two Osprey crashes killed 23 marines last year, and the Pentagon is investigating accusations of falsified maintenance records at the Marines' lone Osprey squadron, in North Carolina, the paper said.

The Osprey was built and developed by a joint venture of Boeing Co (NYSE:BA - news) and Textron Inc (NYSE:TXT - news) unit Bell Helicopters.

Marine officials asserted on Tuesday that General Jones's move did not mean he had lost faith in the safety or capability of the Osprey, the paper said.

"We've got to be pragmatic about this,'' one senior Marine Corps officer was quoted as saying.

The main alternative, Marine officials were reported as saying, would probably be some version of the H-60 Black Hawk, which is made by Unitied Technologies (NYSE:UTX - news) unit Sikorsky and is one of the Army's main infantry transport helicopters, the paper said.

Another option would be to build a new version of the CH-53E Super Stallion, also by Sikorsky, which can carry more troops than the Osprey but is slower and has less range, it said.

The Sultan

8th Mar 2001, 08:15

Cyclic,

The Marines have stated that your posted article is bull**** (my words not theirs). They just said it was in error.

If this article was true, I wonder what aircraft they would choose:

The CH-53? This type embarrassed the US in Cambodia and at Desert One: against third world opposition in the first case, and self inflicted wounds in the second case. Do not forget the current habit of this type to fall out of the sky on a whim with fatal results due to control system failures (and this after 30 years). Lu, did you work on this one?

The S-92? Hell, I saw a report that this aircraft had to demonstrate a takeoff at 31K lbs to show it might be able to fly 19 civilian passengers 400 miles. If the Marines chose this option you would have to add personal combat gear, FLIR, ECM, RWS, NBC gear, defensive weapons, etc to have a chance in combat. I would bet with this load the S-92 would be lucky to reach 1/4 of the required distance the Osprey can with the same number of passengers before ditching.

The EH-101? Enough said! Lu did work on this one, HUMMMMM!

The UH-60? Just another want-a-be Huey. It would be the safest option as it will not even get off the deck with the required load.

The Sultan

HeliFlight

8th Mar 2001, 17:38

C. Hotline:
If Sikorsky starts licking their lips over a possible V-22 replacement- my bet is the only thing they will get is WET LIPS!!! :)

The Marines have already done in depth studies on the alternatives out there. If the General does ask to have another comparison done it will be for one purpose- to show investigators that no aircraft in existence or on the drawing board comes anywhere near the capabilities of the V-22. The only purpose of the report would be to lay down that information in front of the investigators in the form of a RECENTLY prepared report (the Marines already know what the numbers will show).

Think of it this way- if they say OK let's write off the billions spent on the V-22 right now, so what are the alternatives-
the additional billions to purchase a Sikorsky or other heli replacement (that won't come close to the V-22 speed and range) would be more than spending the ADDITIONAL money to get the bugs out of the V-22 hydraulics and software and carry 0n with Osprey acquisitions. Maybe if everybody knew what the total costs of the program would be when the decision was first made- they might not have went for it (there are limits to what people will pay for an aircraft that goes twice as fast and three times as far as anything else with vertical landing capability). But CONTINUING the program now would be more cost effective than if you dropped the program AND you would wind up with a far superior aircraft.

I would take bets that the MV-22 program WILL eventually move ahead to full production (admittedly they have some maintainability problems to work out first). And that the Air Force WILL approve the special ops version (NOT till the hydr and computer bugs are worked out though).

RW-1:
I think you are right that the V-22 problems will not hurt the 609- it is fully funded through Bell and Agusta and customers are still lining up. But I would take it one step further to say that if the V-22 program were canceled- it would actually be a PLUS for the 609 program. Those military organizations out there that would have loved to have gotten their hands on an aircraft with the V-22s' capabilities would have to settle on the smaller 609. Not a desirable combat aircraft by any means, but for some special ops it would be the ONLY aircraft with anywhere near the capabilities.

The Sultan of smooth made the point well- there just are not comparable options out there that can compete with the tiltrotor for the 21st century. (and none in sight)

[This message has been edited by HeliFlight (edited 08 March 2001).]

mckpave

9th Mar 2001, 09:23

To Sultan: I take considerable offense to your comments about the H-53, and no, I don't work for Sikorsky. Without starting a huge debate that doesn't relate to this topic, your comments are way off the mark and you need to research the true events that occurred at Koh Tang and Desert One. The H-53 has been there when other helos haven't and their exploits have saved this nation's butt many times. I'd happily debate this with you in another forum, but I will not, like others, take a discussion off on a tangent.
Secondly, I will state that I am and have been, a huge proponent of the V-22 but must admit that I'm having my doubts about some issues, not simply because of the accidents, but other things I've learned through the years. I still hope for it's introduction into service, I think this represents the greatest advance in aviation since the introduction of the jet engine. I will also say that there are helo alternatives for many of the proposed V-22 missions that will work, but when speed and range are the critical success factors, the V-22 is the only aircraft currently able to meet the standards. Anyway, I'll step from my soap box.

Lu Zuckerman

9th Mar 2001, 20:26

To: Sultan

In answer to your questions about my involvement with the CH-53 and the EH-101, No and Yes.

To: Everyone else on this thread

The argument used by the US Marines about comparing the V-22 to a helicopter in that the V-22 has a higher speed and a longer range is pure bull s**t. This argument would hold up only if the Marines were discussing redeployment from one edge of the battle zone to another or if it was being re-deployed from one area of the world to another. In all other cases the speed and range are non-starters.

In my statement to Sultan I noted my involvement with the CH-53 and the EH-101. Although he didn’t ask these questions I will supply the answers. I did work on the V-22 and I did work on the LHA. The LHA if you didn’t know is the assault ship that the V-22s fly from and to in the performance of their assigned duties.

In the deployment of the LHA and the Marine battle group as it was originally designed the Navy had a prescribed eleven day scenario that the ship had to comply with. This scenario was broken down into elements that were timed down to the last minute. The typical deployment started with cold Iron or with no steam in the boilers. The orders to move out would be given and the ship had eleven days to get to the battle area. Once at the battle area, the LHA would steam in an elongated oval pattern parallel to the shore and would start discharging landing craft and deployment of the helicopters. There was a mix of 32 helicopters consisting of CH-53s, CH-46s and a few UH1s.

As the battle progressed the ship would then start to recover the landing craft and the helicopters and they would be reloaded and sent off again. This operation would continue until all of the 1800 marines and their support elements had been offloaded and then they would start to bring the wounded and the dead back aboard.

All of this was taking place while the LHA was steaming just a few miles offshore. At the time the LHA was designed, the V-22 had not even been conceived. The battle scenario was overtaken by events in the fact that the V-22 and Air cushion landing craft had been added to the mix. This in itself would allow the LHA to steam further offshore and maybe the V-22s speed might come into play. However the marines were also being offloaded in amphibious tracked vehicles which are not that seaworthy and as such could only travel a minimum distance from ship to shore which required the LHA to stay close to shore.

In light of this, it is my contention that the CH-53 or some other helicopter with the capabilities of the CH-53 is still better and a lot cheaper to procure and maintain than a squadron of V-22s. And, there would be no degradation in the scenario or the efficacy of the equipment involved.

------------------
The Cat

[This message has been edited by Lu Zuckerman (edited 09 March 2001).]

Lu Zuckerman

9th Mar 2001, 23:27

To: HeliFlight

When I was a kid LSD was yet to be invented.

I'm sorry if I hit a nerve.

------------------
The Cat

Lu Zuckerman

10th Mar 2001, 06:10

To: Heli Flight

What is it in my post that you disagree with?

------------------
The Cat

Tricky Woo

10th Mar 2001, 14:27

If Lu is taking LSD then so is the US Navy...

http://www.chinfo.navy.mil/navpalib/factfile/ships/ship-lha.html

I love this bit: "They must be able to sail in harm's way..." Personally, I prefer to go in the opposite direction.

HeliFlight

10th Mar 2001, 15:16

LU:
One statement you made summarizes the problem with the rest of the post:
"At the time the LHA was designed, the V-22 had not even been conceived."
With the V-22 we are talking about FUTURE battles with modified battle plans which change continuously as modern technology is introduced. Battle scenarios for the V-22 will be updated and modifed continuously well into the 21st Century.

You bring up the point that the primary factor which creates the "weak link in the chain" is that the "amphibious tracked vehicles which are not that seaworthy and as such could only travel a minimum distance from ship to shore which required the LHA to stay close to shore."
Lu, we have to remember that at one time the Navy "amphibious vehicles" were horses, and they had to practically drive the ship up on the beach to deploy them. If we decided not to use helicopters or modernize any of our capabilities becasue they are too fast or have too much range compared to the weakest link, we'd still be using horses!! We should not cancel modern technology that IMPROVES our capabilities- we should make that advancement AND IMPROVE those OTHER areas that then become "weak links in the chain" (like the amphibious tracked vehicles).

The battle plans will surely be changing with the addition of the V-22 and its far superior capabilities. The Marines may require new non-amphibious vehicles that can be carried by the V-22. Or after the LZ is secured they could sling load in other vehicles (the V-22 set the world sling load speed record slinging a humvee at well over 200kts!!).

Anyway, these may NOT be the answers, but the point is we need to move forward in our capabilities, not limit ourselves because of the weakest link.

In the area of maintainability and serviceability concerns I think you are right. The problems need to be sorted out before full scale V-22 acquisition starts. Once the bugs are worked out and the reliability is proven- then it is time to move ahead.

Tricky Woo:
Hopefully with the stand-off capability of the V-22, the LHA won't have to "sail in harms way"!!

Lu:
Tricky Woo's link shows that the LHA carries six AV-8Bs along with the helicopters. I've heard people complain there was no available air support to match the V-22's capabilities. Wouldn't the Harrier be the perfect aircraft for that?

[This message has been edited by HeliFlight (edited 12 March 2001).]

OVERTALK

10th Mar 2001, 17:08

"I've heard people complain there was no available air support to match the V-22's capabilities. Wouldn't the Harrier be the perfect aircraft for that?"

Agree. They can pass back the positions of the downed V-22's and, with their built-in cameras, photograph the wrecks. Onboard the LHA, Marine photographers can enhance the wreckage photo's so that damage doesn't look so bad to the decision-makers. Chinooks will then be flown in to retrieve the wrecks and Bell/Textron can make a motza out of wreck rebuilds. Rebuilds are much easier to authorize than budgeting replacements, as it comes out of a different (static) vote. Just have to make sure you at least get the compliance plate. That's how it was done in SVN. A great deal. Everybody wins.

Now if we can just improve their ditching and flotation qualities.

--may I borrow your rose-coloured glasses?

HeliFlight

10th Mar 2001, 19:05

That was very constructive, OverFart...

Hope somebody got a photograph of the wreck you were in>>> :rolleyes:
Sikorsky could have flown in an S-58 to photograph the damage, but rebuilding your nose would probably have broken the national budget!
...and if you were in SVN...I now understand the outcome! http://www.pprune.org/ubb/NonCGI/redface.gif

PS: You won't be needing the glasses...you can't see past the nose on your face anyway http://www.pprune.org/ubb/NonCGI/tongue.gif

[This message has been edited by HeliFlight (edited 10 March 2001).]

Lu Zuckerman

10th Mar 2001, 20:30

To: Heli Flight

I checked the website provided by Tricky Woo and it obviously was created prior to the V-22 being introduced as a participant in the battle plans. I agree with you that the V-22 would allow the LHA/LHD to stay out of harms way however the V-22 is not he only player in the battle scenario. There are LCACs (air cushion) landing craft and this too is quite fast and could allow the ships to stay out of harms way. But you must consider the small landing craft and the amphibious tracked vehicles and the distance they must travel to get to the shore and return for more cargo and troops. To remain 20 miles offshore as opposed to three to five miles offshore you expose the supply and other vehicles to the treachery of the open sea and make them more vulnerable to air attack. The purpose of the AV8s is manifold. They must neutralize the shore defenses; they must defend the landing ships and protect the troop movements towards shore and return. To move the ships further offshore would increase the area that the AV8s had to defend by several orders of magnitude.

The amphibious landing craft have minimal offensive capability but they do have some defensive capability. I don’t know if the V22 can sling load one of these vehicles let alone carry one inside the cargo compartment. What you have suggested is that these vehicles be resized so that they can be carried inside or out side of a V-22. This defeats the entire purpose of the AACs as they are designed to move troops onto a hostile shore in a protected environment. It wouldn’t do much good to carry one onto the shore with no troops inside and then load them aboard under enemy gunfire.

------------------
The Cat

HeliFlight

11th Mar 2001, 15:46

Lu:
I understand what you are saying about the small landing craft and amphibious tracked vehicles. But I still believe that these "weak links in the chain" are the problem (a "solveable" problem)- not the increased capabilities of the V-22. And when you mention exposure to the treachery of the open seas if the LHA remains at a greater stand-off distance, it seems that would be the better option compared to coming in closer to a high threat environment. The increased range of the V-22 would also give them much greater capability to deploy hundreds of miles inland, because the "target" is not always 'on the beach.' I would imagine there would be a number of missions (inland) where the small landing craft and amphibious tracked vehicles would be eliminated from the equation (especially deep-strike/insertion missions).

Don't get me wrong, I think helicopters are more than capable to perform many missions. I'm sure there are scenarios when helicopters would perform at least as well as the V-22, and would be much more cost effective. But the speed and range advantages of the tilt rotor open up a lot of other mission capabilities that are not available with helicopters today. The Marines obviously believe that...

Back to the AV-8Bs- do they have a great enough range to support V-22s on their missions (out and back, plus loiter time while the operation is in progress)?

[This message has been edited by HeliFlight (edited 11 March 2001).]

HeliFlight

12th Mar 2001, 23:03

The following has been relayed from John Farley regarding the AV-8B question:
(Thanks John)
*********************************************
Not an easy question to answer, because I don't know the details of the MV-22 mission in terms of radius, altitude and cruise speed and so on.

In general terms I assume the MV-22s would be at about 300 kts and low level. If I had to escort people low down at that speed my first choice would be to fly faster and higher so as not to be a sitting duck with them. I would plan to leave later than them and pick them up just before indian country and then how I flew top cover from then on would depend on the nature of the threat. An AV-8B with jugs and only air to air weapons would have no trouble with a two hour mission, perhaps longer depending on the average height. I would see nowt wrong with a handover to other AV-8s which could have cruised out high and arrived at the site as the MV-22s started their work, leaving me to go home high if short.

I have little doubt the USMC would have plans for all this stuff from wayback when they conceived the MV-22 programme.

My gut feeling is that there would not be a problem at all, although it might not be the same AV-8s for the complete mission

Regards

John
********************************************

UNCTUOUS

27th Mar 2001, 15:43

Technical Problems Plague Osprey
By JOSEPH NEFF, Staff Writer The News & Observer
March 26, 2001

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OSPREY REPORTS

COYLE REPORT: Philip Coyle was the Pentagon's chief weapons' tester from 1994 to 2000. Here is the presentation he made in January to the V-22 Blue Ribbon Panel, in which he discusses the problems with vortex ring state, false alarm rate, autorotation, maintenance problems and more.
http://newsobserver.com/osprey/coylepanel.pdf
(The file is a 3.19 MB PDF file. You will need Adobe Acrobat to read this report.)

MARINE POSITION PAPER: This is the Marine's position paper on the Osprey's ability to autorotate, a procedure that helicopter pilots use to land if they have lost power.
http://newsobserver.com/osprey/AutorotationsFinal.html

MORE STORIES
http://www.newsobserver.com/osprey/

--------------------------------------------------------------------------------

The Marines have bet $12 billion and 30 lives on the V-22 Osprey, the revolutionary aircraft that takes off like a helicopter and flies like a plane.

But the Osprey is grounded now, as questions fly about whether the Marines and contractors have pushed the Osprey into production too fast, deleting crucial flight tests and waiving core performance requirements along the way.

Three months ago, the V-22's chronic problems with safety and reliability were thrust into the national spotlight by the crash of yet another Osprey, this time into the woods of Eastern North Carolina.

Four Marines died in the Dec. 11 crash near the Camp Lejeune Marine Base. Of 20 Ospreys built, this was fourth to go down and the second in eight months. The body count now stands at 26 Marines and four civilians.

Sometime in the next few weeks, a panel of four defense and technology experts appointed after the December crash to review the V-22 program will deliver a report to Defense Secretary Donald Rumsfeld. The panel's findings will do much to determine the fate of an aircraft that Marine leaders regard as essential to their corps' future.

These are the Osprey's biggest problems, based on a review of crash reports, outside audits, Department of Defense reports, flight manuals, e-mail messages and other documents:

Test pilots have unexpectedly lost control of the Osprey on at least two occasions. One instance of uncontrolled flight, in April 2000, led to a crash in Arizona that killed 19 Marines.

If it loses power, the Osprey cannot land safely in helicopter mode. Conventional helicopters can.

The complex hydraulics system that shifts the engines and rotors from vertical to horizontal is plagued by leaks and requires constant maintenance. A hydraulics failure was the primary cause of the December crash.

Most of the warning signals from the Osprey's diagnostic system -- nearly nine out of 10 -- are false alarms, rendering the warnings all but useless. If a squadron equipped with 12 V-22s had to contend with the current level of false alarms and maintenance problems, five or six craft would be in the repair shop at any one time.

The price per craft has doubled, from $45 million in 1997 to $89.7 million today.

These problems are emerging into public view late in the Osprey's development, but they come as no surprise to those familiar with the craft's history.

For more than a decade, auditors at the Government Accounting Office have warned of the dangers of pushing forward into production before testing was complete.

The Defense Science Board, a Pentagon advisory panel generally supportive of defense contractors, has criticized the Marines and the V-22's chief contractors, Boeing and Bell Helicopter Textron, for cutting corners on tests and waiving performance standards while pushing the craft into production.

"Buy before you fly" is the phrase often used to describe the practice of buying an expensive weapon system before the technology has been fully developed and tested. In military jargon, this is known as concurrency, meaning that development and production proceed at the same time.

Concurrency problems are not new: Half of the B-1 bombers were delivered before crucial tests began. The F-22 fighter is embroiled in a similar buy-before-you-fly wrangle. Many experts predict the same for the National Missile Defense system.

Even so, the Osprey stands out for the extent to which its tests have been waived or canceled. For example, crucial tests on "vortex ring state" -- a loss of lift that occurs when a helicopter descends into its own turbulence, and the cause of the April crash that killed 19 -- were called off in 1998.

The next year, the Chief of Naval Operations issued 22 waivers so the Osprey could move ahead to the critical Operational Test and Evaluation -- the final set of tests before full-scale production of 30 Ospreys a year.

It's not just the Marines who are eager to move to full production. For Bell Helicopter and Boeing, that green light would begin more than a decade of steady revenue, as well as potentially lucrative change orders.

Top Navy and Marine officials had planned to decide in December whether to proceed into full-scale production but postponed the decision after the latest crash.

Some of problems are regarded as fixable with additional engineering and testing; most people associated with the program are confident that the diagnostics and hydraulics systems eventually can be made to work, for example.

The aerodynamic problems, particularly the loss of controlled flight, are more worrisome. Even past Osprey advocates are beginning to question whether the plane can be made safe and reliable.

"I'm starting to get a dark feeling about this aircraft, that maybe we don't understand it," said Bill Lawrence, a former Marine pilot who flew the tiltrotor predecessor to the Osprey and headed the V-22 testing and evaluation program in the early 1990s.

Top-flight technology

A safe and reliable Osprey would be a powerful weapon for the Marines.

The new craft is intended to replace Vietnam-era helicopters, and promises to be better in many ways. It can fly five times as far and carry three times the payload. It can fly twice as fast, so it is less vulnerable to enemy fire. It is also quieter.

It would give the Marines a powerful tool to carry out their bread-and-butter mission: to take off from a ship over the horizon, land assault troops and seize hostile territory.

Advocates have suggested dozens of scenarios in the chaotic post-Cold War world in which the Osprey would be invaluable: thwarting an Iranian invasion of Saudi Arabia; flying Marines from Europe to rescue hostages in East Africa; or ferrying Marines from the United States straight to Central America.

But only if it works.

In 1990, the GAO warned that it was risky for the Marines to begin producing the Osprey while still developing it. Production went forward nonetheless.

The Osprey has now been in the low-rate initial stage of production for four years, but by the Defense Department's schedule, testing will continue until June 2004.

Chuck Spinney, an analyst in the Pentagon's Office of Program Analysis and Evaluation, contends that no company spending its own money would develop a product this way.

Narrow interests, not the national interests, have pushed the Osprey program, Spinney argued. The defense companies seek profit, while the Marines, who have always used hand-me-down aircraft built for other service branches, are hungry for a machine of their own.

"The guy forgotten in this is the taxpayer and the soldier," he said. "We use other people's money and spill other people's blood."

In December 2000, the Defense Science Board sharply criticized the Pentagon for cutting corners when testing weapons systems and cited the Osprey as a prime example.

The board, the pre-eminent advisory board to the Secretary of Defense, accused the Defense Department of viewing the testing process simply "as an impediment" to buying weapons.

Waived or skipped tests, the report argued, raise the likelihood that bugs and glitches will first be found on the battlefield, not the testing ground.

"We should maximize testing to discover any weakness or flaws as early as possible," the board wrote. "Combat is the ultimate test, finding a fault in combat is the ultimate cost of not testing."

The GAO, Congress' watchdog arm, reached a similar conclusion.

"In contrast to best commercial practices, our work has shown that numerous weapon system programs suffer from persistent problems associated with late or incomplete testing," the GAO said in a report on the Osprey last month.

Weapon systems managers actually had incentives to postpone difficult tests or hide negative results, the GAO investigators wrote.

This criticism goes to the heart of a recent Osprey scandal that has damaged the Marines' credibility. In January, the Marines removed the commander of its only Osprey squadron for allegedly ordering mechanics to doctor maintenance records to make the craft look more reliable.

The Navy will not decide whether to go ahead with production of all 458 Ospreys (360 for the Marines and 98 for other branches) until several investigations are complete:

The Defense Inspector General's inquiry into the falsification of maintenance records.

The Naval Safety Center's probe into the December crash.

The examination by the blue-ribbon panel appointed by the Secretary of Defense.

Here is a closer look at the biggest issues:

Uncontrolled flight

For a pilot, there is probably no scarier phrase than "loss of controlled flight."

The most serious instance came last April, when the Osprey crashed in Arizona, killing 19 Marines.

The cause was a phenomenon common to helicopters, known as "vortex ring state" or "power settling."

During rapid descents with low forward speed, a helicopter drops into its own turbulence and loses lift. Applying more power aggravates the problem, increasing the turbulence and causing the helicopter to fall even faster.

To recover, a helicopter escapes the column of disturbed air by dropping its nose and flying forward. A big double-rotor transport helicopter actually self-corrects because the forward rotor loses lift first, causing the nose to drop.

But the Osprey reacts differently in vortex ring state: It tips over sideways. In Arizona, the Osprey turned on its side in less than a second and then smashed nose-first into the ground.

The Marines say the pilot caused the crash by exceeding the Osprey's flight envelope. The flight manual warned the pilot to avoid descending more than 800 feet per minute (FPM) at forward speeds of less than 40 knots. The pilot was operating within the recommended limits until three seconds before he crashed, when his forward speed dropped to 39 knots and the craft abruptly flipped on its side.

"He never had a warning until that second where he departed from flight," said Brian Alexander, a former Army helicopter pilot and lawyer representing several families of the Marines killed in the crash. "The margin is a sheer cliff. It's that razor-thin. He's at 39 knots and whammo, he's ass over teakettle."

Less than a month after the crash, the Marines changed the warning in the flight manual to a blanket prohibition: In helicopter mode, "DESCENT RATE SHALL NOT EXCEED 800 FPM."

This limitation, if it stays, would severely cramp the Osprey's mission capability, pilots said. Descending into combat at 800 FPM would make the Osprey an easy target.

"That makes it a taxicab, not a tactical airplane," said Lawrence, the former V-22 program manager. In Vietnam, Lawrence said he often descended into hot landing zones at 3,000 or 4,000 FPM to avoid enemy fire.

The Osprey fell into uncontrolled flight at least once before.

Marines were testing an Osprey aboard the carrier USS Saipan in 1999. While hovering 10 feet above the deck, one side of the Osprey suddenly banked 37 degrees and narrowly missed crashing into the ship. The pilot applied power, gained altitude and made a safe landing.

Seven other planned incidents occurred last summer as pilots at the Patuxent River Naval Air Station in Maryland attempted to re-create the conditions of the Arizona crash. Flying at 8,000 to 10,000 feet, the pilots pushed the Osprey into vortex ring state and fell more than 1,000 feet before regaining control.

Philip Coyle, until recently the chief weapons tester at the Pentagon, told the blue ribbon panel in January that the side-by-side configuration of the Osprey's rotors makes it susceptible to vortex ring state, especially when the craft is turning.

"Such a characteristic is fundamental and cannot be remedied by minor design changes," he wrote.

As it happens, the Osprey program cut or canceled key tests for vortex ring state. The original plan called for tests of 103 flight conditions -- different configurations of descent, speed, altitude and cargo. In 1998, Osprey program managers reduced this to 49 flight conditions to cut costs and get the program back on schedule. In the end, only 33 were actually flown. Some of the deleted test conditions involved descents at slow forward air speeds with full loads -- the conditions present in Arizona.

"To save dollars and make up for schedule slips, the important ... testing was severely curtailed -- roughly one third of the planned test events were actually flown -- and particularly critical test points were not flown at all," the Defense Science Board Report said.

Autorotation

A helicopter can land without power by "autorotating," a technique that resembles a maple seed spinning to earth. As the helicopter descends, air rushes through the rotors and spins them with enough force to allow the pilot to control the rate and direction of descent. Just before landing, 25 or 50 feet above ground, the pilot pulls up the chopper's nose in a flare. The rotors take a big bite of air, like an umbrella catching in a wind gust. This cuts the helicopter's forward speed and descent, and the helicopter can land.

Early Pentagon specifications called for the Osprey to autorotate. But so far it can't.

The craft's flight manual reads: "WARNING: Practice autorotations, to include entry or glide, are prohibited."

In a position paper published in February for the media and investigators, the Marines danced around this issue.

"It has been asked whether the V-22 can autorotate. Because the answer is yes and no, a detailed discussion is necessary for fully understanding this issue."

The Marines contend that it is unlikely that the Osprey would ever lose power. The plane has two powerful and reliable Rolls-Royce engines. If one fails, the other can power both rotors.

And if it does lose power in both engines, the Marines say the Osprey can successfully glide to a landing in airplane mode.

The Marines have never attempted a glide landing, which would destroy the Osprey's huge rotors. They are 38 feet in diameter and extend below the wheels; they would hit the ground first. The Marines say the rotors are designed to shred into fibrous chunks, not shrapnel-like shards.

When it loses power in airplane mode, the Osprey descends 3,500 feet a minute at a glide ratio of 4.6, meaning it goes forward 4.6 feet for every foot it falls.

"That's a rock," said Tony Mineo, an aviation lawyer in Raleigh who worked eight years as an aeronautical engineer with the Marines. "I'd like to meet the test pilot willing to try this maneuver."

In comparison, a Boeing 707 that loses power has a glide ratio of 15, and falls just 1,200 feet a minute.

The Osprey's rotor design causes yet another problem that would hamper Marine missions. The downwash from its rotors is so powerful -- twice that of the helicopter it replaces -- that the Osprey has not been able to pick people up by rope ladder or at sea. Downwash makes landings difficult in the desert or at night.

Diagnostics

The Osprey's diagnostic systems, its equivalent of the warning lights in a car, have a false alarm rate of 88 percent.

Most times, nothing is wrong when a warning light comes on.

"This is a double killer," said Jim Crouse, a former Army helicopter pilot and aviation lawyer. "The warning light goes on, you kill the mission and land the craft. After awhile you start ignoring the warning light, and then you tape it over or disconnect it. Then it kills the pilot."

The false-alarm rate contributes to the Osprey's unreliability. Records show that the Osprey spends an average of 36 minutes in flight before a mechanical failure or aborted mission. The Marines are shooting for a minimum of 84 minutes on this measure.

"If you talk to the pilots' widows, they'll tell you -- if they weren't flying it, they were fixing it," said Alexander, the former pilot and lawyer representing families in the Arizona crash.

Hydraulics

The complicated hydraulics system accounts for the biggest share of mechanical problems.

Besides deploying landing gear, wing flaps and other parts, the hydraulic system tilts the rotors and engines from airplane to helicopter mode. The system works at high pressure -- 5,000 pounds per square inch, compared with 2,000 to 3,000 pounds in most aircraft.

The higher pressure requires less fluid and smaller parts. This saves weight and allows for a heavier payload. But at 5,000 psi, the system is leak-prone and hard to control. Fluid doesn't ooze at 5,000 psi: It atomizes, like mist from a perfume bottle.

In the December crash near Jacksonville, a software glitch compounded a hydraulic leak.

Twenty-five seconds before the crash, a hydraulic warning light came on.

The pilot followed the flight manual to a T: He pushed the reset button that tells a computer to isolate the leaking system and switch to a backup.

The pilot "did this 15 times, 16 times before he hit the ground," said Coyle, the Pentagon's former chief weapons tester. "Every time he did it, the software did the wrong thing and caused him to lose altitude even faster."

Coyle said making the Osprey safe and reliable will involve more than fixing each troubled piece of it.

The bigger task is to make sure all the pieces and subsystems work together. The whole is greater than the sum of the parts, he said.

"The Marine Corps and contractors have to go over how all this stuff works," Coyle said. "If you have hydraulic failure here, and a fuel failure there, how does the software interact with it? They have a lot of technical work to do."

Staff writer Joseph Neff can be reached at 829-4516 or [email protected]

© Copyright 2001, The News & Observer.

We shall now standby for the usual insulting acerbic irrelevancies from HeliFlight (alias PTI-UAE)

Rotorbike

27th Mar 2001, 17:57

UNCTUOUS
I will tell PTI-UAE you said 'Hello' but I'm afraid he isn't the same guy as HeliFlight.

Another Sunny Day In The Middle East
:)

The Sultan

30th Mar 2001, 07:42

Rotorbike,

When I was deleting emails from Internet lurking pedophiles on my daughter's AOL account, what do I find, but a message from J. Crint (aka Unctuous). While not really being surprised at finding his name amongest the messages I was deleting, I was shocked that the message was conjecturing that I was either PTI-UAE or his mouth piece. He was planning the great outting of HeliFlight as PTI. The length of the rant was truely amazing.

What does this guy have against PTI-UAE, besides IQ envy?

Why does he attack everybody who writes accurately about tilt rotors as if they were an enemy of the profession? From his posts he obviously has never flown one (this is a safe bet, as we do have standards) or has seen one fly in person.

The Sultan

P.S to Unc: From now on post your bull**** here so everyone can get a laugh.

UNCTUOUS

30th Mar 2001, 23:46

Aviation Week & Space Technology
March 26, 2001

V-22 Legal Strategy Targets Bell And Boeing

By Robert Wall, Washington

Regulations that make it virtually impossible for families of soldiers killed in accidents to hold the military accountable mean that Bell Helicopter Textron and Boeing will shoulder the brunt of the legal attacks from last year's V-22 crashes.

The strategy to hold the contractor, rather than the military, accountable became clear when attorneys representing some families of last April's crash of a V-22 laid out their case during a public hearing.

The statements were made as part of a fact-finding session by a blue-ribbon commission investigating the program. It is being headed by Marine Gen. (ret.) John R. Dailey, and includes USAF Gen. (ret.) James B. Davis, Norman R. Augustine and Eugene E. Covert, and is to be completed in late April. The presentations, which the four members sat through silently, also raised new concerns about the tiltrotor.

Despite strong attacks, Bell and Boeing are far from having to pay hefty fines. In fact, according to legal experts the chances of the families prevailing are slim. A 1988 U.S. Supreme Court ruling granted military contractors immunity for liability if the government issued a ''reasonably precise'' specification for the equipment, the gear conformed to it, and the contractor warned the government about any dangers. Furthermore, the close ties between Marines and contractors on this program during development could further complicate legal efforts.

The Supreme Court ruling has provided considerable protection to defense contractors. About 80-90% of cases against military contractors are dismissed in pretrial motions, estimates Phillip K. Kolczynski, a Santa Ana, Calif.-based aviation and product liability attorney. Moreover, he noted, some courts will extend immunity when a continuous dialogue between the contractor and the government is evident, even if it was not concerning the precise problem that may have caused the accident.

''There are circumstances where one can beat [the immunity clause],'' Kolczynski said. However, it would require a sympathetic court and vast knowledge about the equipment problem and how much the government knew about it.

MOST OF THE LEGAL ACTIVITY, so far, has focused on the Apr. 8 crash in which 19 Marines died. Investigators determined the crash was caused by pilot error, with the aircraft descending too fast and encountering vortex ring state, a condition where lift on the rotor is lost. The findings of the Dec. 11 Osprey crash in which four Marines were killed haven't been released. However, service officials have pointed to a hydraulics failure in combination with faulty software as the culprit, raising the specter of more lawsuits.

Given the existing legal challenges, attorneys in the Osprey case have tried to fashion their arguments to exploit the few openings in the law they are afforded. For instance, since government knowledge of problems can lead to immunity for the contractor, Brian J. Alexander, who represents several of the families, lays blame squarely on Bell and Boeing.

''The Marine Corps was unaware of the danger of an asymmetric loss of lift and uncommanded departure from controlled flight due to asymmetric vortex ring state or power settling,'' he maintains. Furthermore, he says that ''contractors are required by law and contract to identify dangers and limitations and propose warnings, cautions and notes for inclusion in the pilot manual. It is clear the contractors have failed to meet these obligations and as a result Marine lives have been lost.''

To support his arguments, Alexander draws mainly on three Pentagon reports: the operational evaluation of the aircraft, the Judge Advocate General's (JAG) findings on the April crash, and a test report from the Pentagon's director of operational test and evaluation issued last year. For instance, he cited the operational evaluation report that says ''the content of the [flight manual] was not suitable for operational use,'' the test community's determination that the V-22's ''unusual attitude following entry into [asymmetric vortex ring state] was not expected,'' and the JAG's assertion that ''the MV-22 appears less forgiving than conventional helicopters.''

Jim Furman, the legal representative for the families of the pilot, Lt. Col. John Brow, and co-pilot, Maj. Brooks Gruber, attacked the assertion that pilot error caused the crash. That determination was made in the JAG report and could curtail any damages Bell and Boeing face even if they are found partially responsible. Furman argued that ''the pilots had no reason to believe that the aircraft would enter this uncontrolled state.'' The reason, he added, was that ''the flight envelope was never thoroughly tested by the contractor or explored during developmental flight tests.''

The first suit was brought on Mar. 9 on behalf of the father of Lcpl. Jason T. Duke. The filing accuses Bell and Boeing of being ''negligent in the design, manufacture, testing, inspection, assembly, certification, regulation, distribution, sale, maintenance, operation and/or repair'' of the V-22 and of failing to warn of problems that ''caused design-induced pilot error and the crash.''

THE BLUE-RIBBON PANEL also heard from a rotorcraft expert. Daniel P. Schrage, director of the Georgia Institute of Technology's rotorcraft center, spoke in support of the tiltrotor saying it was the best technical approach to the operational problem the Marines are trying to solve. However, he also noted that when the Marines finalized a design to take it aboard the ship it ''resulted in substantial constraints on safety.''

Most prominently, the V-22's rotor size had to be reduced to allow shipboard operations. But that adjustment also meant the tiltrotor could no longer autorotate -- a rotorcraft emergency procedure that allows aircraft to be landed despite engine failure. The disk loading went from about 15 lb. per sq. ft. on the XV-15 tiltrotor prototype that could autorotate to about 25 lb. per sq. ft. on the V-22, he said. Although increasing rotor size isn't an option, Schrage said there may be other engineering choices. One would be to add weight to the rotor tips to increase their inertia and give them more energy to offset the downforce caused by the aircraft's weight.

Schrage also speculated that there may be technical solutions to address the V-22 from experiencing asymmetric vortex ring state. He suggested adaptive flight control systems could be devised to sense the flight condition and essentially prevent the pilot from being caught in a flight profile where the aerodynamic instability is experienced.

The safety of the aircraft issue was also raised by U.S. Rep. Robert Filner (D-Calif.), whose district includes Marine Corps Air Station Miramar where MV-22s are supposed to be based. ''My concern is for my community,'' he said, noting that about half the flight paths for the tiltrotor would cut over large parts of heavily populated San Diego county.

Despite the technical questions raised by several of the presentations, none of the critics called for cancellation of the program. Instead, most argued that the Marines, Bell and Boeing should continue working on it to resolve technical problems. Filner, for instance, said the V-22 should undergo ''at least a one-year suspension to thoroughly examine the program.''

V-22 SUPPORTERS ALSO SPOKE out, although neither the contractors nor the Marine Corps provided public testimony. One of the backers was Aerospace Industries Assn. President John Douglass. ''The development of aerospace products can not be done without risk,'' he noted.

Additionally, Douglass maintained that abandoning tiltrotor technology would be a ''huge mistake,'' citing the potential benefits of civil versions of the aircraft. But program critics objected to that statement in particular. Furman argued that it isn't the military's job to ''be testers, evaluators, promoters and sacrificial lambs on the altar of for-profit commercial activities or to enhance a positive balance of trade.''

tiltrotor

31st Mar 2001, 12:19

Hmm, could I be Heli-flight, maybe PTI- UAE or just tiltrotor?

Might I be insane?

Anyway, I am with you guys. I guess it's really time to stop blaming other people of being, well, who really knows?

Actually, who really cares!

The point is that some are trying here to have an objective discussion, so leave the B.S. out of it. And I agree, I keep finding these bogus e-mails by unctious in my personal e-mail, absolutely the last place I want them in.

It appears UNCTUOUS has really flipped a gasket.

I don't know which Institution he is writing from, but they should really
limit his e-mail privileges. He also wrote an incredibly long incoherent
message accusing various different personallities of being PTI-UAE. He has apparently written EVERY person
who has posted to this thread and accused us of being the SAME person! Ouch. Trust me, I know most of these guys and they are definitely not the same.

Time to increase the valium doses!

Get a life and get over it..

And finally a big hello to my friends in the Middle East..another day, another dollar, I'll be back.

HeliFlight

2nd Apr 2001, 08:38

Pinochy-Unc:
We are going to have to rename you :) Paranoia-Unc!!! :)
Speaking of renaming... this thread should be renamed to:
"The UnRaveling of Unctuous!!!"

Pinochy-Unc sent me a ranting endless bunch of non-sensical Uncy-Dribble too that included a threat for me to remove all of my posts by March 15 at 1000 GMT!!! Of course I waited until after the deadline and wrote back for him to post his newest theory on PPRune so we could all see it (he did not respond). P-Unc believes that there is a big Conspiracy against him, and every post disagreeing with him on this thread all comes from the same single person!!! The IP addresses prove we are not the same people- I live in Rockland NY (phone contacts available too!), and PTIUAE is in the middle east, don't know where everybody else is from.

P-Us latest flatulations originated from an e-mail message I sent to PTIUAE asking for information on the Harrier. He cut and pasted my message to John Farley, and P-Unc. took this to mean that he had cracked a Master Conspiracy plot against him!!! From that he assumed that PTIUAE, myself and everybody that does not agree with him is the same person!!! Another great theory based on his in-depth masterful analysis methods. http://www.pprune.org/ubb/NonCGI/redface.gif Equal only to his :)"Quinke Valve" theory :) I have posted before that I ask PTIUAE questions by e-mail, and he has no problem with me posting things I learn from him on this forum. At least I ask people who know- I don't make up theories without trying to find the facts!!! http://www.pprune.org/ubb/NonCGI/redface.gif

Now to disprove your second theory P-U, I will not post ACERBIC responses- but instead the following which shows the MV-22 is not in danger of replacement. It still has hydraulic and electrical problems to be fixed- but it is not likely to be canceled. Notice it does not come from a 'I want to sell newspapers' source like GAO/Coyle regurgitations, and it does not describe claims made by Attorneys involved in a legal suit that will say anything to win their case. (Remember OJ Simpson???) This one comes from a Rotorcraft trade publication that looks into the facts!!!

Osprey Panel Must Explain Fully Its Decision
Helicopter News
Washington, D.C.
Vol. 27, No. 6
March 22, 2001

The independent panel appointed by the Department of Defense to review the embattled V-22 Osprey is expected to opublish its report soon after Easter. No one expects the panel to consign the the aircraft to the dustbin of history. The Osprey's technological promise is too high; its mission capability too great.

In fact, even the aircraft's most severe critics trial lawyers who are now suing Bell Boeing for the wrongful death of the Marines onboard the two Osprey that crashed on April 8 and December 11 of last year say they do not want to kill the program. Instead, they say, they want the manufacturers to "fix" the aircraft, make it safe and airworthy, and only then deploy it out into the fleet.

"Send it back; get it fixed; make it work," said Brian Alexander, an attorney with the New York law firm Kreindler & Kreindler and himself a former Army helicopter pilot. Alexander represents a dozen of the 19 Marines killed in the April 8 crash and he spoke at a public hearing sponsored by the panel on Friday, March 9 in Arlington, Virginia.

For these reasons, the panel is more likely to recommend that the Marine Corps subject the V-22 to further testing to ensure adequate operational performance and safety. But more important than the panel's bottom-line recommendation is its explanation and reasoning.

That is because a dark cloud of suspicion, and indeed paranoia, has descended upon the V-22 program and for a variety of reasons good and bad, warranted and unwarranted. That is why Marine Corps Commandant Gen. James L. Jones pushed for an independent review of the Osprey to clear the air and reassure the public that the program is being administered honestly and judiciously, with due regard for the safety of America's Marines.

The Panel, therefore, has a heavy burden: it must lay out all of the relevant facts and criticisms of the program, and it must weave these facts together into a clear and coherent narrative that forthrightly addresses lingering concerns. This involves making judgments, taking sides, and naming names.

The temptation, of course, is to sidestep this difficult task in the name of personal and institutions comity especially now that lawyers and widows are involved. Who, after all, wants to appear insensitive to a grieving widow? And who wants to (inadvertently) interject himself into a multimillion-dollar class-action lawsuit?

However, it would be a mistake for the panel to ignore or sidestep the serious legal allegations made against the Osprey by Alexander and his fellow lawyers. We live in a litigious society made all the more litigious by the revolution in communications.

Indeed, charges and allegations gain currency and believability simply by their instantaneous and mass propagation. As concerns the V-22, these charges and allegations will go not away simply because the panel ignores them or confronts them only obliquely.

For example, according to William Healy, a Tucson attorney representing the family of Lance Cpl. Jason Duke, Bell Boeing "put a defective product on the market, a product that was dangerously and unreasonably defective."

This either is true or it's not true. The panel has a responsibility to say which is the case and why.

HeliFlight

5th Apr 2001, 20:43

Report: Osprey Flaw Caused Crash

By ESTES THOMPSON
.c The Associated Press

CAMP LEJEUNE, N.C. (AP) - A hydraulics system failure compounded by software problems caused a V-22 Osprey aircraft to crash in December, killing four Marines, a corps investigation being released Thursday concluded. The corps acknowledged it was aware of a problem that could damage the hydraulic line that failed.

The crash was one of two fatal Osprey crashes last year that killed 23 Marines and put the fate of the controversial, multibillion-dollar aircraft program in jeopardy.

A wire bundle had rubbed against a hydraulic line feeding both the primary and backup hydraulic systems to the left engine, chafing it and eventually allowing the line to rupture, said Maj. Gen. Martin Berndt, commander of the 2nd Marine Expeditionary Force.

"The investigation cites a number of reports dating back to June 1999, which describe chafing of hydraulic lines by wire bundles within the (engines) of the V-22,'' he said.

Berndt spoke at a briefing in advance of the release of the full report Thursday afternoon.

The Marines had said in January that they were nearly certain the December crash was caused by a failure of the hydraulics system, which enables the pilot to control the direction of the aircraft.

Berndt said that varying degrees of chafing were found on all eight remaining Ospreys during an inspection after the December crash.

The investigators recommend reviewing the entire computer flight control system and associated software, and the placement of hydraulic lines and wire bundles within the engine, he said.

The Osprey is unique in its ability to take off like a helicopter, rotate its propellers 90 degrees and fly like an airplane.

Another Osprey crash killed 19 servicemen in Marana, Ariz., in April 2000. The fleet has been grounded since the December crash in Onslow County, near Jacksonville.

In the North Carolina crash, Berndt said investigators found the hydraulic system began to malfunction after the plane made a series of left-hand turns.

As the plane's airspeed slowed and the engines began to move automatically from airplane to helicopter mode, the hydraulic line ruptured, Berndt said.

The flight control computer sensed the problem and stopped the rotation of the engines. A reset button lit up and the crew, as instructed, pressed it.

"This action started a chain of unpredicted and uncontrollable events that caused alternating deceleration and acceleration of the aircraft,'' until it stalled and then crashed nose-first, Berndt said.

It took 30 seconds after the hydraulic failure for the plane to hit the ground. During the last 20 seconds, the computer reset program was activated as many as eight to 10 times, Berndt said.

That, along with the hydraulic failure, caused the engines' rotors to change their pitch rapidly and dramatically, sending the airplane out of control.

"The air crew reacted immediately and correctly to the in-flight emergency as they were trained to do,'' Berndt said. "We consider them to be without fault in this tragedy.''

The defense secretary appointed an independent panel to review the program after the latest crash. The accident report's release comes as the panel, headed by retired Marine Gen. John R. Dailey, is preparing its findings and recommendations, which could decide the fate of the Osprey.

The Marine Corps wants to buy 360 Ospreys to replace its fleet of aging CH-46 and CH-53 transport helicopters. They are made by Textron's Bell Helicopters unit and Boeing Co.

Pilots who helped investigate the North Carolina crash said the problems with the hydraulic system and computer were a design flaw that had been known for months but ignored, The Washington Post reported Thursday.

They told the Post the problems could have been detected by more rigorous testing, and slipped by because the Marine Corps wanted to win Pentagon funding for full production of the plane.

AP-NY-04-05-01 1124EDT

hpdunn

10th Apr 2001, 21:43

Unctuous-heliflight-Lu Zuckerman
Have been reading/studying/printing and eschewing you guys for some time. My heart goes out to Unctuous and feel I should join himin his educational pursuits, He appears to be one who is not putting stuff here which comes out of marketing, publishing,or defensive attitude, or otherwise supporting the Iron Triangle. Have been trying to help others understand a few realities - and have a draft paper -- changes/criticisms desired

(now all I need to do is figure out how to attach it!!)

[This message has been edited by hpdunn (edited 10 April 2001).]

Lu Zuckerman

11th Apr 2001, 00:03

To: hpdunn

Copy the text into word. Then copy the text and transfer it into the comment box on the Rotorheads thread.

By the way, how did I get caught up in this? Any comments I made regarding the V22 were based on my having worked on the program for 11 months and that information was based on what existed during my association with the program.

------------------
The Cat

212man

11th Apr 2001, 03:04

Just read the stuff in Flight about the hydraulic pipes chaffing against a wire bundle. Personally I think it's obscene that in this day and age an a/c like that can be brought down by such a ridiculous design flaw (several other a/c were found to have the same problem in earlier stages of wear).

------------------
Another day in paradise

HeliFlight

11th Apr 2001, 20:55

"Obscene" is the right word for it. The worst part is the Marines Knew about it since June of 1999 and did nothing!!! (and it was found in all the other V-22s)Certainly sounds like a no brainer to me. I wonder if this problem is throughout ALL Marine aviation and not just this program.

Hopefully with the spotlight shining on them these days there will be a shake up from top to bottom. Looks like they'll have no choice!

UNCTUOUS

11th Apr 2001, 22:44

hpdunn

Understand from your profile that you are (or were?) Congressional Liaison (aka briefer?).
Thank you for the kind words. If you have taken the time to read all the way through this thread, perhaps you should also look at these URLS - which are also pertinent.

http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000405.html Marine Corps grounds ....

http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000557.html (Another MV-22 lost)

http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000658.html Marine V-22 Maint Fraud

http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000328.html

http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000000.html BA609

http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000389.html Tiltrotor

My interest in the Osprey stems from a visit to the sim at New River some time ago now and contacts with those in the program (past and present), as well as a helo background. If you read through from the beginning, despite all the gay banter to the contrary, it must be obvious to you that I had an inside straight and that pretty much all of what I said has come to pass. I would even lay claim (see much earlier) to email conversation with John Farley (well-known Brit Harrier XTP) well before the Marana accident - that I couldn't figure out how they'd resolved the problem of vortex ring. The "revelation" on the page about the hyd chafing having been known about - that is not news. The derisory comments about the vibration-damping Quincke technology also now looks a bit silly. It takes quite a "rub" in so few flight hours for a titanium hyd line to be penetrated by some soft wiring insulation (i.e. assuming it wasn't eventually arcing).

If you'd like to send your contribution to [email protected] I can refer it to my mentors and give you a useful opinion. You are quite right that this program was hijacked by the vested interests who had so much to lose .... that they've even now got so much more to lose. Those who objected to the way the program was going were never in a position to influence its direction - but they certainly saw it coming and gave me the benefits of their insights.

HeliFlight

11th Apr 2001, 23:31

Pinochy-Unc:
Hey… saw you on the street the other day and I really like that neat head gear. The tin foil hat is excellent- but I really like the antenna fashioned out of a hangar- nice touch. :)

Your right- we all knew you had the "inside straight" http://www.pprune.org/ubb/NonCGI/redface.gif
and boy... now that you mention it you've really done it again- I'm sure there's nothing better for stopping those chaffy wire bundles than a couple of good :)Quinke Valves!!! :)
Really makes a lot of sense :rolleyes:

And now that you have a fan, I notice your resume has done a 180. For your year of postings you never denied your lack of experience with tilt rotors. Now all of a sudden your the ultimate insider with full access to Pax River facilities. You must have re-tuned your antenna direction to beam in some new experience http://www.pprune.org/ubb/NonCGI/eek.gif

That Pinochy-nose is jumping out of our computer screens at us now. :)(remember PaPa Jepetto!!!) :)

[This message has been edited by HeliFlight (edited 13 April 2001).]

hpdunn

20th Apr 2001, 02:00

Scatterchat
Find a new occupation. By time a tiltrotor - other than the old demo that is used to show folks how well it works (about 1/3 size of V-22) you (and I ) will be to old to qualify.

When a member of the Blue Ribbon Panel reaches the conclusion that we will just have to ignore autorotation (because the rotor can't be made large enough-- because it is too large to operate on carrier decks)
acknowledging he was not aware the helicopters have been operating off carrier decks - with helos as large as H-53 --then the whole country of Blue Ribbon Panels is turning into a roll over.Try realestate??

hpdunn

1st May 2001, 20:45

Here is my wrapup after 6 mths of study/reveiew
=============================================
The V-22 Iron Triangle - stll alive.
hpd

The story moves on - and is a classical case of the Iron Triangle revisited.

Whenever the basic procedures are set aside or over-ridden by Congress, Industry and a selected Military element to be the front line Champions --right or wrong -- the system has a way of letting profits obscure realities.

The use of PAC funds - spread widely - creates Congressional pressures within the Administration which can force funding of a quickly thrown together funding program, and ignores the basic requiremnents for a cycle of design, development and testing to be done BEFORE everyone jumps on biard and claims success. \

10-15 years ago there were voices, steeped in history and experience who could not make their voices heard.

Forty to 50 years experience with aerodynamics and design had established basic ground rules for aircraft. For aircraft flying normally -- all propulsion systems were kept on centerline or as close as possible -- to avoid assymetric trust problems. For many years the need for larger rudders was used to off-set problems associated with the need for extra lateral control after an engine failure. It was fundamental, period.

At the same time, helicopter design was growing rapidly, reaching the current multiple applications and uses throughout the world. One of the fundamental design requirements was to design the rotors in such a way as to permit them to provide a capability following engine failures, to generate rotating kinetic energy by having the upward wind forces to drive the rotor as if it were 'gliding' similar to a wing on an aircraft.

This was called "autorotation" and was THE most important item in all training and testing for pilots when learning to operate a helicopter.

The design of helicopter rotors thus resulted in a relatively "low disk loading" design, which both allowed the rotors to operate in autorotation, and to build up lost energy by increasing the rotors speed in descent, which could then provide the required vertical thrust to make a safe landing after engine failure.

In the case of the V-22 design, several of the known design requirements were set aside in an attempt to design an aircraft which could be flown as a normal aircraft and as a helicopter. Past experience suggests that up to a certain size, e.g. the
XV-15, some compromises can be accomplished.

At some point, the increases in size, forces, thrust/propulsion and other design requirements get out of hand. The compromises to force designing (thru the use of multiple redundant computers, hydraulics, fly-by-wire) to reach a certain goal begins to produce results which were either not thought thru or were ignored.

First, in the case of normal flight, we have the V-22 with two 38 foot diameter "propellers" located at the two extreme wingtips. If you had never talked to a pilot or engineer familiar with multi engine aircraft, perhaps it would not have occurred to someone to expect that in windy, turbulent, gusty air -- or when encountering the turbulent airflow wake of another aircraft --- to expect the V-22 to react like any airplane -except much more so (the surface area of the V-22 propellers are perhaps ten times more than that of 'normal' propeller aircraft)-- and to try to roll itself over (without the pilots ability to react properly).

This is not only very scary, it is absolutely dangerous - and far outside normal design parameters for controlling gust loadings.

Next, we look at the propellers -- which in the case of the V-22 have cleverly been renamed 'rotors' -- and their use in the 'helicopter' mode. There are in fact significant differences.

A helicopter rotor blade is essentially a long fairly flexible wing. An aircraft propeller is on the other hand a fairly stiff or hard blade, with little or no flexibility.

For aerodynamic purposes, the rotor blade has a small amount of 'twist' - perhaps several (8-12) degrees.

The V-22 Propeller -as do most all normal aircraft - has a much higher 'twist' (perhaps 45-50 degrees) built into the propeller design, which permit them to operate more efficiently in staight and level flight and is related to the higher speeds of aircraft.

The compromise required for reaching the higher speeds fot the V-22 has come at an unbelievable cost. The propellers themselves are extrememly inefficient when acting like rotors in hovering.

The disk loading (the amount of lifting forces) required to hover the aircraft is on the order of Twice that of any comparable weight helicopter!!

This in turn, significantly REDUCES payload. In fact the V-22 is the only aircraft flying today whose empty weight is about 3/4 of its total gross weight. Most aircraft - including helicopters such as the H-53 - can carry their own weight!! The V-22 only about 1/3-1/4th!

The next result in this compromise of design, is that because of the high disk loading, the aircraft is NOT capable of safe autorotation - and in fact it is 'prohibited' in the USMC flight manual.

If you tell this to a thousand helicopter pilots - some with thousands of hours of experience - they will undoubtedly suggest you are either incorrect - or crazy (and will have little desire to try it out).

The designer response to this is that it is very unlikely to be needed. And -- they will tell you that the multi piece connecting tubes between the two engines will take care of the problem. Perhaps in may cases this may be true.

The reason it is not safe for autorotation is that the propeller design - with a very high twist angle (needed for forward flight) -- is not designed to and does NOT generate sufficient kinetic energy - thru propeller 'spin up' ,when descending in an unpowered condition.

Its basically has very little inertia when it stalls out and very little kinetic energy buildup capability. The patented contractor 'solution' is to start a descent or gliding descent if one engine fails, and to prepare to rotate the engine nacelles rearward when near a landing site (so that the two 38 ft diam propellers do not smash into the ground). Please note that the FAA and military require that an aircraftwith two engines should be allowed to continue safe flight upon single engine failure.

Finally we find that the high twist and high loading of the V-22 propellers, produce a phenomenon similar to - but far far more reaching than that of its sister helicopters.

Whereas helicopters can reach a point where they can "settle with power" if they try to lift to much - or fly too high. In the case of helicopters, the pilot can readily and easily 'fly out' of the settling condition using simple intuitive procedures which he is taught in initial training.

In the case of the V-22 Propellers in hover or approach/conversion modes, the initial airflow changes near the blade tips are essentially the same as for helicopters. As the 'settling' proceeds, the tip vortices on the propeller (twist and high loading) move rapidly inward and form what is now called a Vortex Ring State. At this point -usually on one propeller before the other, the aircraft losooses its controlability very rapidly - and can in a matter of a second or two invert and crash.

If a pilot does recognize and attempt to stop the rollover/tuck down - and tries to offset the uncommanded rollover -- he instinctively - and unfortunately - will do exactly the wrong thing!. It is fatal.

If one studies the costs of the tradeoffs made in force designing a system --(I call it forced designing because it requires the use special software and hardware to force a given goal -- even if the compromizes reduce the efficiencies and increase the risks of life -- at a higher cost) -- there are always several flaws to be found.

We have reached the point in engineering that we can literally do anything we want - even if it makes no sense and costs are out of sight.

Designing a control system which can get out of physical control faster than the computers trying (redundantly) to resolve and initiate changes - is in the end - a folly.

The Combat Military Perspective of the V-22.

Given the foregoing problems and tradeoffs required in the design of the V-22, we
should look at the results of this marvellous - but costly, inefficient and high risk aircraft as it applies to the Defense Department. A review of the DOTE, DOD/IG, GAO and other reports can be used to see the whole picture. The effort here will be to narrow down a few of the dozens of citations.

The V-22 has been touted by the Contractors, Congress and the USMC (in that order) as the most signifcant development in aviation history. Perhaps if more studies and reviews of similar attempts to compromise aerodynamics had been done, an entirely different approach might have been used - instead of the 'forced design' concept. As a military combat aircraft it is simply not, period.

A quick review - after 12+ years of flying and testing:

1. Combat maneuverability has not been tested and is PROHIBITED.
2. Combat Rescue is not possible because the V-22 is not and never was
intended to have a combat rescue hoist installed.
3. Autorotations are Prohibited.
4. The compromize design and resulting aerodynamics have resulted in:
a. higher Downwash
b. no autorotation capability
c. inclination to enter VRS undetected

Conclusions:

The V-22 is an extremely expensive experimental aircraft without any justifiable Combat capabilities for use in actual Combat situations.

The V-22 is NOT a COMBAT capable/suitable AIRCRAFT

Recommendation
If the never satiated desire for Congressional power and PAC monies -- are to be taken care of ---it is Recommended that the V-22 Program, its aircraft, material, and remaining funds be distributed to NASA and the FAA, to determine if their is any potential safe use of the assets
:)

[This message has been edited by hpdunn (edited 04 May 2001).]

Grey Area

1st May 2001, 21:36

To VLift and Lu

VLift you said:
"If the aircraft is in an autorotational situation and has no appreciable forward speed component the rotor RPM will slow, as the resultant realitive wind is at too great an angle to provide for the forward rotation of the blades.
As the rotor slows the air being pushed down in the center of the system is even less and more of the center area is occupied by air going up through the rotor system. So, more of the rotor system is not contributing lift, aircraft descends faster."

Sorry old chap but this is not wholly correct.

You can quite safely carry out a vertical autorotation, with no forward airspeed and no power applied the NR will settle at a higher level than forward auto, but you can remain in this situation as long as you wish. All of the flow through the disk is moving up (lift is produced by the reduction in pressure above the rotor disk, it does not require downward flow - we are talking is Benoulli not Newton).

The problem comes when the pilot decides that a high speed vertical landing may cause an unforseen claim on his life insurance.

Power available: If he applies collective and therefore power he can then induce a VR state quite quickly(!), thus he must transition into forward autorotation before applying power to recover.

Engine Off: To recover kinetic energy from the system to effect a safe landing he needs forward speed, and must therefore transition to forward auto before landing either by collective and flare or collective only.

My most exciting engine off happened in a PFL which began with a vertical auto,followed by a late transition (after my loud "I HAVE CONTROL!) to 35 kt forward auto then a last minute collective check (no flare) to run on as NR decayed rapidly. No sign of VR though.

Conversely my one VR incident occured in a high hover (1000') downwind, recovery by entering auto and stuffing the nose down took 800', close but still 200' in hand!

GA

Lu Zuckerman

2nd May 2001, 01:53

My name is continually referenced in some of the posts on this thread. I will repeat that any comments made by me are dated, as it was almost six years ago that I worked on the V-22 program.

Two of the comments I made regarding the V-22 are:

1) The rate of descent on the V-22 if the pilot elected to perform an autorotation is somewhere between 4-6000 feet per minute and at that rate of descent the pilot can’t arrest his speed to an acceptable level. I brought this to the attention of Boeing and I was ignored.

2) The “Proprotors” as they are officially known are mounted in rubber. When the pilot performs a maneuver while in the aircraft mode the gyroscopic turning moment on the Proprotors will cause them to precess. This misaligns the thrust line of the Proprotor and can cause control problems. Built into the Proprotor is a series of flapping sensors. These sensors “sense” the blade movement and send a signal through the autopilot and the control servos bring the Proprotor back to the neutral thrust line. This causes a very high demand on the hydraulic system and reduces the overall reliability of the hydraulic system. I brought this to the attention of Boeing and they stated that it was a Bell problem. Boeing designed the servo control system. Bell designed the Proprotor. I brought this to the attention of Boeing on four more occasions. The answer was always the same. On the fifth occasion I was fired.

[This message has been edited by Lu Zuckerman (edited 01 May 2001).]

hpdunn

13th May 2001, 06:50

Lu and Unctuous and all takers--
Would it bother any of you if you found the Load Factor (leading edge blade stall)for V-22 in hover, as being below FAA Part 29 at a g-load of about 1.3 to 1.4? Can anyone confirm or recalculate?
Does as C sub t over sigma (aerodynamic blade loading) of 0.18 seem a little high??

[This message has been edited by hpdunn (edited 13 May 2001).]

UNCTUOUS

16th May 2001, 19:55

Obviously the characteristics of a prop-rotor are quite different to those of a helo rotor. The critical area is in the size and strength of the vortices generated and the rate of spread of the vortex sheet.

On the subject of the December crash it has now been admitted that it was not a software flaw, but a control law design flaw:
see Professor Ladkin's lead-in article below and my much earlier comments on this page:
http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000658.html

From Ladkin
My two notes on the December accident to the Osprey, the V-22 tilt-rotor vehicle, subsequent to the JAG briefing and to the appearance of the Blue Ribbon Panel report, appeared in Risks 21.33 and 21.38 respectively, and I also forwarded them to the list.

Readers will recall that I concluded from the JAG briefing material in my note in Risks 21.33 that a failure caused by a software error, which was subsequent to the hydraulic system failure, was indicated by the JAG briefers. The briefers called it a "software anomaly", and indicated that the Primary Flight Control System did something it should not have done, because of software commands. This indicated to me either an implementation failure to meet the design specification, or a failure of the software design to meet PFCS requirements. This is my definition of "software error".

Two circumstances caused me to query that a software error had in fact occurred. First, conversations with New Scientist reporter Duncan Graham-Rowe, and second, the appearance of the Blue Ribbon Panel report with its brief consideration of software reliability (less than one page out of nearly two hundred), along with its recommendations of integrated testing (with pilot-in-the-loop) but no software inspections (which I would have expected, had there been reason to believe that a software error in the PFCS had caused an accident). I produced a ponderous analysis of the JAG briefing and the Blue Ribbon Panel report section on software reliability. The analysis appeared in Risks 21.38.

I concluded that there had been no software error in the strict sense above, that the PFCS indeed had done what it was designed to do, but that the actual physical consequences of that design in that situation had not been sufficiently appreciated at least by the flight crew, and maybe by some or other part of the operations team or engineering teams involved. I enumerated three specific ways in which that might have occurred.

Yesterday I spoke with Professor Gene Covert, one of the Blue Ribbon Panel members, and a colleague of Nancy. I put my conclusions to him. Although a significant amount of his information is privileged, he was able to confirm that there had been no software error in the strict sense above, and that my conclusion (as above) broadly represented likely scenarios for the genesis of the control behavior exhibited in the December accident.

PBL

Cyclic Hotline

21st May 2001, 23:44

Weapons Buyer To Keep Osprey Program
By ROBERT BURNS, AP Military Writer

WASHINGTON (AP) - The Pentagon (news - web sites)'s new chief weapons buyer has decided not to cancel the troubled V-22 Osprey (news - web sites) aircraft program but has taken acquisition authority for the program away from the Navy.

The Osprey, a hybrid aircraft that takes off and lands like a helicopter but flies like an airplane, is designed mainly for use by the Marine Corps, which is part of the Navy Department. After a fatal crash last December - the second for the Osprey in less than a year - the Navy grounded the fleet and put off a decision on whether to begin full-scale production.

The decision to go ahead with the Osprey program was made last week by Pete Aldridge Jr., who was sworn in as undersecretary of defense for acquisition on May 11. The decision, which was not publicly announced, was first reported in Monday's edition of Inside the Navy, a trade publication.

Aldridge told the Navy to go ahead with buying additional Ospreys, but at the lowest possible rate that ensures the manufacturer can continue to work on improvements to the aircraft. He did not specify what that production rate will be.

The decision fits with the recommendation of a Pentagon-appointed panel of experts, which said May 2 that because of serious concerns about the Osprey's safety and design the aircraft should continue in production at a "minimum sustaining level'' until changes can be made.

The Osprey is manufactured by Boeing Co. and Textron's Bell Helicopters unit.

In Philadelphia on Monday, the widow of a Marine pilot killed in a V-22 crash last April urged Congress to ask tough questions before putting the tilt-rotor planes back in operation.

Trisha Brow told a House Armed Services subcommittee hearing that it would be a "horrible disservice'' to the families of 23 Marines killed in the two Osprey accidents last year to fail to solve the aircraft's problems.

"We have paid more of a price for the Osprey than any other taxpayer will ever be asked to pay,'' said Brow, whose husband Lt. Col. John Brow and 18 other Marines were killed in a crash near Tucson, Ariz., on April 8, 2000. A crash last December in North Carolina killed four Marines.

Aldridge took acquisition authority for the V-22 program away from the Navy "because this program is at a critical stage,'' Pentagon spokesman Lt. Col. Dave Lapan said. That means all future production decisions will be made by Aldridge's office rather than the Navy's senior acquisition executive.

It is not clear when the Ospreys will be cleared to resume flying, Lapan said.

He said the Pentagon is forming a new V-22 executive committee to focus in detail on key issues such as testing, technical risk and cost. The committee will have senior representatives from the Navy, Marine Corps, Air Force, Special Operations Command as well as the major V-22 contractors.

Also, Aldridge's office will begin a series of detailed reviews starting in August, Lapan said.

hpdunn

22nd May 2001, 21:47

tHIS MAY JUST BE THE BEGINNING--

The v22 Panel is still working away.
The Air Force and others may start looking at aerodynamic blade loading and stall margins (near lack thereof)

The game ain't over til the fat lady sings --several months from now.

The Sultan

23rd May 2001, 06:06

hpdunn,

The fat lady has sung. The song was the death knell of the transport helicopter. The tiltrotor is here to stay.

The Sultan

HeliFlight

24th May 2001, 18:52

I have to agree with the Sultan. The fat lady has been building to a sonata since last month when the Blue Ribbon Panel appointed by the Secretary of Defense to do an independent investigation came back with the UNANIMOUS recommendation to go ahead with the program. The best part is that they pointed the finger at those responsible for taking shortcuts in the program that led to the problems they’ve had, and they said to put whatever money into the program is needed to fix those problems that the independent panel said can easily be done if corners are not cut. The other investigations that are in progress all look at the same data and no doubt the FACTS will speak louder than the press!!!

The endless discussions over the V-22 program are now pushing around “MUTE” points- the program WILL move ahead.

Anyone who wants to spend their time making up theories, posting nonstop redundant articles, and attacking the V-22 can have at it- but the proof is in the pudding. The V-22 will move ahead and those standing in the corner with the red faces will be the ones who couldn’t quite figure it out.

Roofus

24th May 2001, 18:56

I've no wish to enter into a dispute...but I never could keep me gob shut!
Long live the V-22 & roll on the 609. The future is coming & it looks good.
The speed of a fixed wing coupled with the versatility of a wokka! Superb!

Sorry...how fast does a honda fireblade go?? Is that all! Sheesh....run little man!

hpdunn

24th May 2001, 21:12

Are their any rotor aero engineers out there who understand that the big secret of the Osprey (i.e Albatross)is that it has a PROPELLER blade on it that stalls out at 1.3 to 1.4 g's in GW hover/conversion modes, and does not even marginally meet even FAA certification standards for Aerodynamic Blade Loads?? Would you jump in this machine for Combat Manuevers, or Combat Rescue (no hoist position found beacause of downewash velocities?? OR -- can you imagine the pleaseure a radar directed missle gunner will have when he sees a bird with two 38ft diam propellers heading his way? Initial estimaets are that of 1-2 747's headed his way.

It IS time to go back to realities of engineering and design parameters and get off the gee whiz admiration approach :)

[This message has been edited by hpdunn (edited 24 May 2001).]

HeliFlight

25th May 2001, 18:29

The Proof is in the Pudding............

HeloTeacher

29th May 2001, 20:43

I'm curious, what G-load is a helicopter rotor supposed to stall at?? same conditions: GW hover.

Nick Lappos

31st May 2001, 10:49

The issue is how much thrust the rotor has above that for its basic lift. Most helicopters have about 1.9 to 2.2 G's of thrust available at low speed, mostly due to the excess thrust built into the rotor for use at high speed. This is expressed as the "aerodynamic blade loading" where each square foot of blade is tasked with providing a given amount of lift. Like wing loading, this is a measure of how much extra thrust there is for maneuvering. At the aerodynamic blade loading limit, the rotor stalls, and the aircraft can fall through, or lose control.

Tilt rotors have much more highly loaded rotor blades, mostly because this increases hover payload, and alsobecause when the tilt rotor gets to high speed, the rotor becomes a propeller, and doesn't have to provide lift. The typical tilt rotor has at least 50% more aerodynamic blade loading than the typical helicopter, reducing the rotor thrust in helicopter mode. A typical helicopter has about twice as much low speed maneuver capability as a typical tilt rotor.

Most tilt rotor designs are limited to about 1.4 to 1.5 g's at helicopter mode at mission weight at sea level. For all rotors, this goes down with reduced density at altitude.

(for the techno types, aerodynamic blade loading numbers follow:
Helo about .08, tilt rotor about .125 to .15, typical max blade loading at stall .17 to .21)

mriya225

4th Jun 2001, 09:37

A few good questions from a few good men...

I thought I might share these concerns with you lot--they seem like valid concerns to me:

Best put by a friend in the USMC:

"When are the engineers going to tackle the problem of adding armor? If it's to be internally mounted, the skin of the airframe(along with stringers and other structural support) will have to be modified which will present a number of changes to the flight characteristics of the bird: airfoil will be different which will affect drag-lift-fuel consumption-handling-et al; which in turn will impact range and load, weight and balance, and any attendant maintenance peculiarities which is also going to impact mission capability. If internally mounted, how easily accessible are the mounts going to be - for corrosion treatment/inspection and subsequent hardware or component replacement? And if externally mounted, granted accessibility will not be much of a problem for maintenance - how big a headache is it going to be @ 250 knots? What a drag! This is not a flashback to the 60's . . . or is it? When we put armor on the 46 (pilot, flight control closet, engine) it was not exactly a transition that could be described as smooth as a baby's behind. The impact it had on the airworthiness was significant. I suspect the same will hold true for the Osprey. I wonder if any of the wonder boys in engineering have mentioned any of this to the Commandant. Not yet, at any rate; what are they waiting for? A contract to build 360 of them? Hmmm. What else have they neglected to mention? Hydraulic lines? Oh, no. They have mentioned them. Particularly after the crash on 11Dec. Something about the metallic lines rubbing on wire bundles - what the hell are wire bundles being made out of on that airframe? They ought to use THAT material for the armor that's got to added if the V22 expects to have any longevity in a hot zone offloading or onloading our fellow Marines. Semper fi."

What are your thoughts on these concerns? Mr. Lappos, if you're haunting these rooms, what's the good word?

------------------
"You did WHAT"?!

mriya225

5th Jun 2001, 01:41

Back to the top.

Any help on this would be greatly appreciated.

Nick Lappos

6th Jun 2001, 09:26

mriya225 asked:
When are the engineers going to tackle the problem of adding armor?

The modern way to approach this is to design in "ballistic tolerance" so that the shots that can take the aircraft down are quite improbable. For example, a set views of the airframe are made (long before design is frozen) and analysis of the components that are exposed is made. Several design software tools are available for this. redundant systems, and physical separation of critical components are used to help drop the vulnerability. Critical components designed with multiple load paths to allow strength after impacts. The parts are tested with actual bullet and cannon hits, and the remaining strength is assessed. Often, fatigue tests are run with the damaged parts to judge how much flying time remains after the damage. Multiple electric, flight control and hydraulic systems are used. Armor is used sparingly usually around critical engine and aircraft parts, and around the crew. US Army crews wear ballistic helmets and shields ("chicken plates") across thier chests to round out the ensemble.
The actual "vulnerable area" of a modern combat helicopter might be only a square meter or less for 23mm cannon, and might be zero for typical hand held 7.62 mm weapons. This is typical of Apache, Black Hawk and Osprey.

Considered this way, the V-22 is quite robust, and was judged in the OT&E reports that I read to be very much up to par.

Nick Lappos

------------------

Lu Zuckerman

6th Jun 2001, 20:56

To: Nick Lappos

On the Apache they ran a vulnerability analysis and found that through placement of different equipments and black boxes they could protect the pilots but only from small arms and ground based machine gun fire. The impact energy was dissipated because in the analysis the round was assumed to be tumbling and would make initial impact not pointy end first but hit flat on its' side. All bullets do not tumble with the exception of 7.62 MM. Bigger rounds like 50 Cal. hit pointy end first and in doing so have much deeper penetration than a tumbling round. Also, the Apache had frangible armor that was mounted inside of the skin and each piece of armor was spring mounted to absorb the impact energy. In absorbing this energy the armor plate would jam into the engine and flight controls. 23MM rounds are another story. It is true that tests were performed to demonstrate the resiliency but only one round was used.

This is an excerpt from a letter I sent to John Persinos the editor of Rotor & Wing.

It was directed to the AH-64 but it also applies to the V-22 and Comanche as well.

The Army also lied to the pilots of the Apache relative to its’ invulnerability to the ZSU 23-4 weapons system. This was the primary weapon that would be used against the Apache if it were to attack a group of Warsaw Pact tanks.

This weapon was also being supplied to all of the governments that were in league with the Warsaw Pact. The U S Army commissioned a study by a so-called”Think Tank” to study the effectiveness of the ZSU 23-4 against the Apache. It was their considered opinion that the ZSU 23-4 was inaccurate, It had a low degree of reliability and that if the ZSU 23-4 did hit the Apache with one round, the pilot would have sufficient time to evade any further hits by dropping below the tree line. The uninitiated reader should understand that the ZSU 23-4 has a rate of fire of 1200 rounds per minute and that if one bullet hit its’ mark, there would be forty or fifty rounds right behind the first round. When the writer was on contract with Agusta helicopters he took a two-week holiday in Yugoslavia. While there, the writer watched a T V program, which was describing the weaponry of the Warsaw Pact. One of the weapons demonstrated was the ZSU 23-4. In the demonstration the weapon was pointed on a line parallel to a stand of trees. A helicopter popped up from behind the trees and in an instant the weapon acquired the helicopter and was pointed directly at it. The helicopter then dropped below the treetops and at that time the gun was turned off. The helicopter was allowed to fly away and the gun was turned on. It immediately started to fire and it swept an arc approximately 30 to 45 degrees on either side of center. The trees started to explode. It looked like there were hundreds of chain saw wielding loggers in the tree stand felling trees as fast as they could. It appeared to the writer that if a hail of 23mm bullets didn’t hit the helicopter, a falling tree would destroy it.

------------------
The Cat

[This message has been edited by Lu Zuckerman (edited 06 June 2001).]

HeloTeacher

6th Jun 2001, 22:31

Welcome back Lu, wondered when you'd be around again.

Figured you were still out of town when I didn't get a reply about the R44.

How was the trip?

Nick Lappos

8th Jun 2001, 06:19

to Lu Zuckerman:

Wow! Don't be shy, Lu! Tell us what you feel.

I think you are saying that folks lie about ballistic tolerance, and that lots of trees have been killed by 23mm shells. OK.

I have never seen anyone say that any of the aircraft you mention are invulnerable to large caliber fire. The concept of minimizing the vulnerable area is to specifically allow some items to be vulnerable. By making the exposed area small, the probabilities of being shot down are acceptably low, and mission survivability is at or above required levels.

The way to survive in combat is captured by 4 basic rules: Don't be seen, don't be engaged, don't be hit, and don't be killed. A balance of factors to control each rule allow survivability.

I also believe that when you accuse some other professional person or organization of perpetuating lies, my "Flake Alarm" goes off, and most of the rest you have to say gets drowned out by the ensuing Bull---t alarm.

------------------

Lu Zuckerman

8th Jun 2001, 07:38

To: Nick Lappos

I stand by what I said about the Apache and by extension the V-22. In your post you stated the following:

“The way to survive in combat is captured by 4 basic rules: Don't be seen, don't be engaged, don't be hit, and don't be killed. A balance of factors to control each rule allow survivability”.

If you remember the pictures of the Apaches’ in Desert Storm none of them engaged the troops and armor on the ground as they were intended to. They fired their cannons and Hellfire missiles from a long way from the actual targets because the Army was afraid of loosing too many of them if they engaged excessive ground fire. In the Balkans the Army would not allow the Apaches to engage ground troops because of the possibility of high losses.

In order to apply the four rules stated above the V-22 would have to remain on the hanger deck of the LHA. The V-22 by the nature of its’ mission is required to get down and dirty. There are no trees to hide behind very few hills to hide behind and in order to avoid ground fire they will have to make a big hole approach and shift into helicopter mode and when they do, I pity the crews on those aircraft as IMHO they will be cut to pieces no mater how many vulnerability studies were made.

------------------
The Cat

Nick Lappos

10th Jun 2001, 19:29

Lu,

I guess I mostly object to your assertion that the Army lied, and therefore that the V-22 folks are, too.

The films from Desert Storm prove that the Apache was effective and deadly, and believe me (I have about 1000 hours of Attack Helicopter combat time) standing off is the right way to fight. If you are in a fair fight, you didn't plan it properly!

The vulnerability of aircraft will always be worse than tanks, and armorplating of flying machines will not replace robust systems and good tactics. Nobody I have heard or read lied about Apache or V-22 capabilities from a vulnerability standpoint.

I am in the awkward place of also agreeing with you that speed alone is a poor way to try and survive, and the V-22 will have its hands full in a contested environment.

I also do not like the way it is described as having "twice the speed, twice the payload and four times the range" of the helicopter it replaces, because I think this is often perceived to mean it is that good against any helicopter, which is not true. In reality, the V-22 has "twice the cost, half the payload, the same range and 50% more speed than a modern helicopter."

I also believe that if you start out by saying those you disagree with are liers, you will turn off those you wish to convince, and you lose automatically.

------------------

Lu Zuckerman

10th Jun 2001, 22:50

To: Nick Lappos

Let’s turn the word lied to deceive. To tell the whole truth about the weapons system that the Apache pilots would come up against would not serve the Army very well, as fewer pilots would ask to become Apache pilots. This deception was told to me by one of the senior investigators who wrote a report for the US Congress. The report was made at the request of Les Aspin who at that time was the Chairman, Committee on Armed Services and John Dingle who at that time was Chairman, Subcommittee on Oversight and Investigations. This report (B-238876) was entitled APACHE HELICOPTER; Serious Logistical Support Problems Must Be Solved to Realize Combat Potential. During Desert Storm he spent a great deal of time incountry and monitored the Apache for reliability maintainability and combat deployment. He stated that it was decided to keep the Apaches’ from close in combat because they were afraid that they would be both vulnerable to ground fire and that with their poor reliability they would lose too many aircraft due to parts failure.

You must understand that when the Apache program was initiated NATO was planning on a major land war in 1988 with the Russians and the Warsaw Pact. The battle plan was that the Allied forces would be pushed back to Southern France and into Spain and they would have to fight their way back to Central Europe. The whole concept was that the Apache would be in a ground support roll and would become actively engaged with the tanks and other offensive weapons systems and that the ZSU-23-4 was the major defensive weapon used by the Warsaw Pact and the Russians.

The Apache dynamic systems and the rotor system were tested by being fired at by a single 23MM HE round. The testing proved that the helicopter could successfully fly for at least a half an hour or, it could make a successful autorotation.

The pilots were separated by transparent armor so that if one pilot were hit by a 23MM HEI round his guts would not fly into the adjacent cockpit. My contention is that if one round hit, the second would be right behind it.

In the case of the V-22 they may have performed an extensive vulnerability analysis and as a result, incorporated redundancies and placed less valued equipments in front of more valuable equipments in order to provide ballistic shielding but Plexiglas in the cockpit area offers minimal shielding from even 7.62 MM ground fire.

------------------
The Cat

[This message has been edited by Lu Zuckerman (edited 10 June 2001).]

hpdunn

11th Jun 2001, 18:30

Nick and Lu
Looks like the title of this thread about "Reprieve" needs to be changed to the real situation of Vulnerability,because of lack of Manueverabilty. If the V-22 with about 1/2+ G available in hover/slow airspeed mode cannot manuever - he is a sitting/dead duck situation, which suggests it should'nt be exposed to Comabt Assault or Combat Rescue missions. What is left is a nice but inadequate people carrier -- to where????
There is a new internal group in DOD looking at all of the real life problems. Decisions will probably be made by new DOD and SecNav in about 90 days.

[This message has been edited by hpdunn (edited 11 June 2001).]

mriya225

12th Jun 2001, 00:40

Many interesting issues to solve, gentlemen...

Mr. Lappos,
I appreciate your insight--thanks for your time. For the record, these concerns were passed on to me by a few of the United States Marines who'll be dependant on this technology to keep their 'six' out of the grave.

Lu,
I'd re-nick you "El Gato Magnifico", but the term of admiration is currently being used by my big black cat Madison--the most gorgeous full-on scrapper God ever did create (built like a Maine Coon and definitely not to be trifled with)! Still, you're one of my all-time faves for good reason sugar. Keep on keeping 'em on the straight & narrow.

Thanks again gentlemen, it looks like the Osprey still has a ways to go--but then, we might have known there would be the need for adjustments as the full-scale production progressed.

The Sultan

13th Jun 2001, 07:45

Nick,

You may want to turn on the BS meter for outgoing mail to avoid embarrassing yourself. You sound just like Lu.

The Sultan

Hpdumb: The decision's been made.

hpdunn

15th Jun 2001, 19:06

Jamie - the Flight Yest Engineer
Have been waiting for someone from texas to discuss that little FLAW in engineering design called Ct/Sigma, and its resultant limit load factor. Perhaps you can show all of us who in Texas engineering decided to go for three blades with terrible Ct/sigma - with no manueverability, instead of 4-5 blades which might have made it workable in Combat.
PS It AINT over til the fat lady sings -- and she will NOT sing until about September -Count on it!

[This message has been edited by hpdunn (edited 15 June 2001).]

Nick Lappos

16th Jun 2001, 08:06

to Sultan,

I may sound like a BS'er to you, that's unfortunate, but your call. What I reacted to with Lu was the assertion that the Army or Marines are lying or deceptive.

You don't have to agree with me, and you can think I'm BS'ing, just don't start spouting about how you must be right because others are lying.

------------------

hpdunn

30th Jun 2001, 21:14

Sultan,
I for one --and I think Lu and Nick -- are awatitng your thoughts on Ct/Sigma!! I find it strange that whenever this subject arises, that an unbelievably loud silence follows from V-22 salesman.

Copter Cody

30th Jun 2001, 23:37

Well gentle men, as someone else has said the fat ladie has sung. The death of all chopper pilots as well as choppers as we know it. I fear the worst people, I don't want it to be so. :{ Whats it going to do to medevac or SAR missions?

Cody the distressed chopper pilot

vorticey

1st Jul 2001, 15:11

mriya225..........
the diameter of the rotor in the hover would seem to me to be very small compared to a helicopter of the same weight;- tip voticies would afect a biger % of rotor and would'nt take a lot to induce vortex ring state. is that what you mean by stalling? or is the overpitching of the blade due to weight what you mean??

hpdunn

5th Jul 2001, 06:32

Cody

Fear NOT
The fat lady is a long way away from singing!!She ain't sang!
Helos WILL be around a long time!!

UNCTUOUS

5th Jul 2001, 13:11

V-22 Slowdown Augurs Layoffs

ROBERT WALL/WASHINGTON and PARIS

V-22 woes are about to claim more victims, with layoffs looming as
production of the tiltrotor is slowed to allow prime contractors Bell
Helicopter Textron and Boeing to fix the many design problems that have plagued
the aircraft.
V-22 production for the next fiscal year has been cut back to 12
aircraft from the planned 20. The Air Force is procuring none of the
tiltrotors next year.
The number of layoffs and when they will occur hasn't been resolved yet.
But the goal is to "lose the minimum number of people," says Michael
Tkach, Bell Boeing V-22 program director. Boeing has about 1,500 people
employed on V-22 work, while Bell has about 2,800 employees associated
with the program.
The personnel cuts are necessary even though the production rate is
expected to remain level, with 11 aircraft built this year and 12 more
planned for next year. While design changes are being made, the V-22
program is limited to a minimum sustainment production rate that will
allow the manufacturing line to remain open but not much more. How long
that rate will be sustained depends on progress made, said the new V-22
program manager, Marine Corps Col. Dan Schultz.
However, because of lessons learned in building the first batch of
aircraft, fewer people will be needed to build a similar number in 2002,
Tkach said. Furthermore, before the program was derailed, Bell and
Boeing expected to ramp production to 20 V-22s next year.
IN THE FISCAL 2002 budget, the Air Force has no production funds for
Special Operations CV-22s, although Dov Zakheim, the Pentagon's
comptroller, said that could change in 2003. The Navy budget, under
which the Marine Corps MV-22s are bought, is $542 million for 12
aircraft. "That is our understanding of the optimal number to protect
the industrial base," Zakheim said.
The change in the number of aircraft to be bought also has forced Bell
and Boeing to scramble to alter deals made with suppliers. Purchase
orders were placed with vendors anticipating a 20-aircraft buy. Tkach
said most, if not all, of those deals were adjusted with enough time to
allow suppliers to alter their production lines.
Schultz said he's trying to avoid second-guessing what caused the
current situation and, instead, is focusing on getting the aircraft
fixed and back flying. However, he believes there were weaknesses in the
government-industry partnership. "I don't think the teaming was as solid
as it is now."
A panel convened by the Pentagon to review the program highlighted
several areas of weakness. They include problems with the flight control
system and its testing, reliability deficiencies, design shortcomings in
the hydraulics system, and a need to better understand the aircraft's
flight envelope. One of the findings in the review of the second of two
crashes last year--in which a total of 23 Marines died--was that many
software modes had not been tested. This time "our intent is to test
every failure mode on the aircraft," Schultz said.
Despite the travails, vendors so far have remained supportive of the
program. "None of them are backing away," Schultz said. For instance, he
noted that Moog Inc. used its own funds to redesign a V-22 actuator
valve that now may not require inspection.
In addition to redressing the aircraft's flaws, Schultz also is looking
for opportunities to take out weight and cost. While the V-22 has met
its flight performance requirements, it has been operating with very little
weight margin.
As part of the review process, the Pentagon is reassessing V-22
requirements. However, Marine Corps Commandant Gen. James Jones has
indicated he would like to see as few changes as possible ( AW&ST May 7,
p. 64).
Program officials are shying away from predicting when they'll have the
tiltrotor back flying or production ready. Jerry Daniels, who runs
Boeing's military aircraft and missiles programs, said at the Paris air
show that it would take 60-90 days to "do a good, solid engineering
assessment of the airplane and then lay out a program plan that makes
sense."
The most time-consuming fix is likely to be reengineering the nacelles,
said Jones. The goal is to make them more maintenance-friendly and
mitigate problems with hydraulic lines running through them.
The Marines have laid out a five-step program to salvage the V-22. The
first, trying to get the aircraft ready to resume flight testing, is
underway. The V-22s have been grounded for months while the program's
problems were investigated.
Another major thrust will be to rebuild a base of support for the
tiltrotor. "It's not that the V-22 has that many problems, but people
have certainly lost confidence," Schultz said. He hopes to restore faith in the
program by meticulously resolving the lingering questions.
Late last month, the V-22 got a measure of political support when a key
panel working on Defense Secretary Donald H. Rumsfeld's Pentagon review
endorsed the tiltrotor. "It's a program that's had trouble, obviously,
but that doesn't make it unimportant. In fact, it's extremely important
as a way to move land forces, in particular, amphibious forces," said
Rand's David C. Gompert, speaking for the Conventional Forces Study
panel.
BUT V-22 PROGRAM officials also have to brace for some more bad news.
The Pentagon's Inspector General's office is continuing its
investigation regarding the charge of maintenance data falsification.
The review was to have been completed weeks ago, but has dragged on
because it has proven more complex and more involved than first
expected, Pentagon officials say.
Another unresolved issue is V-22 funding for the current fiscal year.
The Pentagon wants to cut $475 million from production while problems
are fixed, but add $80 million to engineer the fixes. However, the
Senate and House have different opinions. The House would add $40
million to the development budget, but would further cut procurement by
$115 million. The Senate, on the other hand, would only cut the Navy's
V-22 production funds to $150 million from $235 million. The difference
will have to be resolved in a conference between the two bodies.

vorticey

20th Aug 2001, 16:44

in a previous thead somone talked about v22 problems and it seamed to me that because of the small rotors in relation to weight they whould settle with power very easily(vortex ring state), would this be true? :confused:
i would'nt mind gettin an indorcement one day, if they can sort'em out.
what do you's recon?

B Sousa

20th Aug 2001, 20:02

Better stick to the Boomarang, its been around longer and seemingly more reliable. V22s dont yet always come back.

UNCTUOUS

20th Aug 2001, 20:44

>From: "Robert B Cox"
>To: Jim Crint
>Subject: Hello again
>Date: Wed, 08 Aug 2001 20:26:57 -0500
>
>Jim:
>
>Are you still on the V-22 trail? I suspect I know the answer and that
>it's yes.
>
>I've got a guy, retired military and aero engineering degree, who's
>bugging me incessantly about the V-22. He has sent me a diagram chart (http://www.angelfire.com/me/swissair111memorial/modded/images/v.htm) which I
>will attach, claiming it shows -- no proves -- that the V-22 is fatally
>flawed because it simply cannot maneuver. I suspect he's on to
>something, but I don't have the expertise to judge or critique it. So
>I'm passing it around. I'll attach it and the guy's comments. I'd like
>to hear what you think and any suggestions on what to do with it
>(including even throw it away). Please feel free to call if you like.
>
>Thanks.

Robert
Look carefully at a set of helo rotor-blades and note their distinctive features (wash-out, twist, aspect ratio, airfoil section etc). Then observe (statically is sufficient) the available range of cyclic and collective movement in those blades. Note the RPM at which they operate.
Look at a FW's propeller blades and comparatively note the significant physical differences (planform, sectional profile, AR, twist, taper and airfoil section) - and the operating RPM and fine/coarse pitch-change regime.

Look at the problem of physically hybridising rotors and props to become prop-rotors (even without going into the control systems and morphing of control parameters via algorithmic contortions as it changes from FW to helo and back again). It all becomes one huge compromise requiring great sacrifices in robustness of design and utility. Weight and weight distribution, FBW and fail-safe systems redundancy become hyper-critical. The fault mode effects analysis (FMEA) becomes a welter of imponderables (as we've seen). The envelope in which it can operate is similarly constrained. Unmanagageable T/R phenomena such as autorotation and Asymmetric Vortex-Ring are peculiar to the side-by-side prop-rotor configuration, the prop-rotor's lack of inertia, and its hybrid prop-rotor compromise - but both
autos and VR (http://www.angelfire.com/me/swissair111memorial/modded/images/VortexRingDiagrams.htm) are a manageable acceptable fact in helos. The deadly propensity for entering asymmVR (there being no such thing as V22 symmVR) is a function of the prop-rotors - their shape and disk solidity (aka number of blades and operating RPM's), and in particular their behaviour relates to their non-rotorlike characteristics when playing that rotor role. Formation of tip and sheet vortices (and the sudden lethal amalgamation of these) can occur much earlier simply because you have an upward pointing airscrew rather than a pure helo-rotor, and the V-22 prop-rotor loadings are necessarily non-optimal. Factor in the ability to go to 95 degrees aft nacelle-tilt (i.e. project the downwash powerfully ahead into its own downward flight-path) and the high likelihood of a stressed pilot doing that as a means of slowing quickly. Add a simultaneous rolling/directional correction and some gust-factor as in the Marana accident. AsymmVR is always lurking and, once hit because of even the slightest dynamic overshoot of the VR entry parameters, is quite unforgiving and terminal. They'd not done even half of the planned testing so they were fumbling in the dark with the potentialities. They found out the hard way and then went into denial. They're now looking for a warning device to insulate pilots from crossing that deadly point of total control loss. I'm not sure that they'll find it. The dynamics of manoeuvre and low-level turbulence will always mean that a potential overshoot of the VR envelope can happen. Answer? Limit the manoeuvre even if you were able to manoeuvre more because of available airframe strength and power available. But of course power available is not part of any solution for AsymmVR. So the question becomes: "Is an Osprey that is so safety-limited in manoeuvre really a combat proposition?"
The next accident was more than likely a hiatus induced by the hydraulic failure not permitting scheduled nacelle tilt for transition (but the software going ahead anyway and telling the props that they were to become rotors). Not that they've ever been that frank about it of course. So you have the V22 stuck in FW config with the props acting as if they are rotors. If you have an understanding of the subtlety with which the control mode (http://www.angelfire.com/me/swissair111memorial/modded/images/OspreyFltControl.htm) switches over during transition, you'll appreciate that that might have been automatically terminal (as it was).

So apart from this problem of inherent design characteristics, you want to know whether Col Harry Dunn's diagram (http://www.angelfire.com/me/swissair111memorial/modded/images/v.htm) is correct; i.e. is the V22 very restricted in manoeuvre and riding a thin red-line as far as controllability goes.. I've discussed it with him and it certainly would appear so simply because (to keep it brief and non-tech) of the aerody factors outlined above. The early onset of blade stall is simply a function of the prop-rotor design. In the combat arena it will always be a sitting duck - or verging on a lethal loss-of-control if pilots are provoked into excessive manoeuvre by ground-fire. You could say that it has built-in lethality and I predict that if it ever does enter combat service it will vie with the enemy for the dubious honour of who will kill more Marines. Apart from that of course, the Marine carrier-decks will be rapidly awash with broken Ospreys. They are not very supportable and not easily fixed. I fear the USMC got carried away with a Utopian concept and only the US Army got it right. They applied the KISS Principle - overlaid on "more is better".

The man who solves all these problems, and makes it what they want of it, will be semper fi'd into the annals of Marine Corps legend. It will be fascinating to watch it all unfold.