Civil tilt rotors

[Jackonicko]

Ok call me a fat, unadventurous, unimaginative snob....

But I think that if I was the kind of high net worth individual they're aiming the 609 at, I'd really rather fly from heliport to airfield on a nice, spacious S76, AW139 or Bell 222 and then be decanted to my waiting Gulfstream than to duck and wriggle into the cramped confines of the 609, unless I was going to be sitting behind the stick.

And if the whole Vortex Ring issue has come quite so close to scuppering military tilt rotor ops, can we really believe that a civil tilt rotor will be accepted (even if it somehow gets certificated) by enough people to make it a goer?

Feel free to point out where I'm going wrong, please!

[MSP Aviation]

Maybe it'll be like the Starship. A fantastic, underappreciated machine. I'll buy up the entire production run of 22 or so for cheap, and have an unlimited supply of parts for when I need. :8

[SASless]

Does the 609 have the same autorotative capability as the Osprey......as in "none"?


1. LACK OF AUTOROTATION CAPABILITY

Although it was initially believed that V-22 would have a full autorotation capability, it is now generally agreed that the V-22 cannot autorotate in any practical sense. Although the V-22 has performed an autorotation in a technical sense, the test procedure was carefully structured to allow for a safe entry (the engine power was slowly removed to allow the aircraft to establish a stable autorotation.) In a practical autorotation, the aircraft must be able to enter a stable autorotative state following an abrupt power interruption. Although an abrupt removal of engine power in V-22 has never been done, such an event would probably result in loss of control because of the inability to maintain rotor RPM. This is especially true if the failure occurs in transition mode (60 deg nacelles)[1], the common configuration used for “slinging” external loads.

The single autorotation test in V-22 also demonstrated that the attempt to recover from autorotation to a safe landing by using stored rotor energy to arrest the rate of descent failed markedly. The test data indicate that the aircraft would have impacted the ground at a rate of descent of about 3700 ft/min (61.7 ft/sec) ¾ a fatal rate-of-descent. Authoritative proponents, e.g., the NASA Review Team, have argued that autorotation is not a needed capability for the V-22 due to the low probability of a two-engine failure. My analysis of Navy safety data shows that the Navy/USMC experiences a dual engine failure in a helicopter about once every 3 to 4 years due to fuel contamination onboard a ship. Historically, such accidents have usually been survivable because the helicopter autorotates into the water and the crew and passengers quickly scramble out. If such an event were to occur in V-22, it will probably be fatal to crew and passengers because the aircraft will not smoothly enter autorotation, but most probably depart from controlled flight, and because the cabin is too cramped for a rapid egress.

We know from the combat record in Vietnam[2] that many ground fire hits on a helicopter result in a need for an immediate autorotation. Of the 3,000 or so helicopters lost during the Vietnamese conflict, fully 80 to 90 percent were lost on approach to landing (i.e., where V-22 would be operating in helicopter mode), approximately half safely autorotated to the ground, thereby saving the crews. Even though the V-22 rotors are interconnected, some combat fire hits can be expected to result in loss of both an engine and the rotor interconnection. Such combat events in V-22 would be fatal.

Autorotation is to a helicopter pilot (and his passengers) what an ejection seat is to a fighter pilot. When everything goes wrong, as it often does in a combat environment, autorotation is all a helicopter pilot has to save his and his passenger’s lives. As good as the V-22’s survivability features may be (and they are very good), there will still be times when everything does go wrong; at those times autorotation could be the difference between a chance for survival and a fatal outcome. The lack of autorotation capability in V-22 is inherent in this tilt-rotor design given current technology options. The mission advantages provided by the tilt-rotor design, such as long range and high speed, afford survivability advantages during the ingress portion of a mission, but for landings into a hot zone, the lack of autorotation capability is an important factor whose consequences should be clearly understood.

In my view, V-22 fails to meet the ORD threshold requirement to be able conduct a “survivable emergency landing with all engines inoperative” over a large portion of its operational envelope – helicopter mode flight below about 2000 above ground level. From higher altitudes, or when operating in airplane it is generally believed that V-22 is capable of conducting a survivable, all engines-inoperative emergency landing, although considerable risk is incurred in such a maneuver because of the very high sink rate of V-22 and the high airspeed needed for the maneuver.

[ShyTorque]

I've followed this project since the concept was first publicised, about thirty years ago. It seemed a great idea back then but the practical disadvantages (low payload, tricky handling at low speed, huge cost) unfortunately seem to outweigh the benefits of the higher cruise speed. It was meant to be a thoroughbred but somehow it now seems to have turned out to be more of a mongrel.

I forsee that it will be unable to use many UK helipads, often confining it to airfields - in which case a simple turbo-prop could be used.

Will it ever gain certification in UK? I now have grave doubts about this.
To be quite honest, as the holder of both rotary and fixed wing professional licences, I'm not sure I'd want to operate it.

I'd far rather put my stake money on the long overdue re-emergence of the Autogyro, utilising tip jet drive for low speed work, which is inherently safer, has a far better payload and can be made far cheaper yet still use small helipads (bring back the Fairey Rotodyne http://www.helis.com/50s/h_rotdyn.php ).

[SASless]

This link will take you to the article from which I quoted previously.

http://www.g2mil.com/V-22safety.htm

Within the article are links to additional articles that pertain to the discussion of tilt rotors.....each reader is left to their own to determine the validity of the arguments set forth.

I have been hanging around MCAS Cherry Point lately and have talked to a few Marine aviators who, shall we say, sing not of the prowess of the Osprey.

[Dave_Jackson]

http://www.unicopter.com/1505.gif
Tilt-rotor (http://www.unicopter.com/1505.html) http://www.unicopter.com/Boxing.gif Interleaving (http://www.unicopter.com/1505.html)


Now who has half a billion dollars available for the development of the Interleaving? :O

[FH1100 Pilot]

Dave, the problem is that the money has already been spent on the tilt-rotor and there's no changing horses now. Remember, funding for Bell's tiltrotor goes all the way back to their first military development contract in 1953 (see XV-3). So waaaay too much money has been spent on this concept to abandon it now. By God, we're GOING to make it work!

In the 1950's, helicopters were maybe 100 knot machines. Someone, somewhere once upon a time got convinced that vectored-thrust was the "wave of the future...it just has to be!" And the funding fun began!

And since vectored-jet-thrust (e.g. Harrier) is impractical for civilian use, it leaves us with the only alternative: vectored helicopter thrust. Okay, but what to do about those big o'l dang proprotors hanging down below the fuselage? Well they started off big (like real helicopter rotors) but that didn't work that well, so they got smaller and smaller. And finally they got so small that autorotation capability went out the window. And they still stick down below the fuselage! Oh well...

Yeah, but. Proponents will say, "Yeah...but...is the ability to autorotate really a big deal? How many dual engine-failures do we hear about in King Airs?" Okay, so autorotative capability may or may not be an issue depending on how successfully the marketing guys can overcome the slight perception that the 609 is a helicopter. "Hey, it's a King Air that only spends 0.00000001% of its time hovering! Whaddya worried about?"

Along with the small-diameter proprotors comes high downwash velocities (and not insignificantly, high noise from all the horsepower needed to lift the thing to a hover). So let's cut the crap - you won't be seeing too many 609's operating out of smallish "heliports," even the existing ones in industrial parks if they are surrounded by residential areas. The tiltrotor, when not operating form an airport is going to need room...LOTS of room. No steep, slow approaches for this baby! Why not?

A-VRS. A-VRS? Yeah, "asymmetric" vortex ring: one in/one out. Well, that's either an issue or not depending on who you want to believe. The manufacturer and the military say that it's not an issue when the tiltrotor is operated within certain parameters. The infamous A-VRS crash in Marana, Arizona was a "fluke" they'll say. Never happen again! Well, they won't come out and actually say that, but they'll imply it. The trouble is, one bad A-VRS accident has already happened on what should have been a relatively routine formation landing that somehow got screwed up. Heh- we know that such "screw-ups" never happen in aviation, right? Never happen again! Umm yeah, maybe.

Let's be honest - getting into A-VRS at low altitude is pretty much unrecoverable. It'll hit the ground inverted or nearly so. It's fatal. Problem for you? The comparably-sized S-76 has gotten itself into some pretty strange accidents in its history while operating off-airport. Okay, so operating off-airport involves a certain amount of risk. And maybe, as that U.S. Marine guy recently alluded to, accidents are inevitable. ("Alluded to???" He came right out and flat said it!)

So "buying in" to a tiltrotor requires overcoming some strong helicopter philosophies and assumptions. Can this happen? It will be interesting to see.

I do know one thing: The first A-VRS accident of a civil Fortune 500 tiltrotor will kill it. If there is an accident in which A-VRS is even hinted at being a causal factor, it's dead. Especially if the accident occurs early in the operational history.

On the other hand! The lure of the tiltrotor concept may be strong enough to make it succeed where the aforementioned Beech Starship did not. The question is: Will it be enough for Bell to offset the development cost? On this, my personal jury is still out. I'm no fan of the tiltrotor concept - never have been. It's a bastard design that does nothing really well. It's just different.

People like to draw comparisons between the tiltrotor and the first helicopters and the skepticism that they are/were viewed. But I think that's not correct. The peculiar and unique capabilities of the helicopter were obvious and attractive from the start - if you consider the "start" Leonardo da Vinci's first designs.

The uses for and applications of the tiltrotor are not so readily apparent. Unless I'm missing something (and I'll admit that I'm no visionary). Not only that, it has some huge obstacles to overcome. Try as Bell might, I'm not sure the tiltrotor will ever be "ready for prime time" as they used to say. I mean, over 50 years of development hasn't even given us anything but a couple of prototype "proof-of-concept" models that - at least the ones that haven't crashed - are relegated to museums.

Maybe we should give 'em another fifty years?

[SASless]

The Marana crash was a situation where number two in the formation got into a "fast and steep" situation after over-arc'ing on a night formation approach.
Now how many of us have experienced that really rare situation?:rolleyes:


Throw in the lack of cabin space and the huge cost difference between Chinooks/Sikorsky's and the Osprey and one can only shake their heads in disgurst.


Last time we had a Texan in the office during a war, Bell helicopters flourished....funny how that happens!:ugh:

Perhaps we should ask Nick about politics in aircraft procurement programs.:E

[JohnDixson]

For FH1100 and SASless,

Sometime ago Nick Lappos offered some thoughts about whether the Marana crash was VRS or in reality quite a different aerodynamic situation. Maybe he will respond with that discussion here. In any case, postulating a vortex ring state boundary at 40 KIAS and -800 FPM and stating that boundary exists essentially for all helicopters flies in the face of all of the undersigned's experience in attempting to force helicopters into this state.

[212man]

I'm sure Tom McDonald would beg to differ...
http://www.boeing.com/rotorcraft/military/v22/tilttimes/nov03.pdf

[IFMU]

I'd far rather put my stake money on the long overdue re-emergence of the Autogyro, utilising tip jet drive for low speed work, which is inherently safer, has a far better payload and can be made far cheaper yet still use small helipads (bring back the Fairey Rotodyne http://www.helis.com/50s/h_rotdyn.php ).


The Groen brothers are attempting a resurgance of this concept:

http://www.groenbros.com/gyrodyne_tech.php

They seem to be actively recruiting people to join their effort.

-- IFMU

[mckpave]

I have sat back and read the attacks on the V-22 and tiltrotor technology in general for many years now but the time has come to place my position here. I will qualify my comments by saying that I'm very intimate with the V-22 and whether or not it can perform the mission. Is it the greatest thing since sliced bread...NO but it is indeed a very impressive aircraft. I'll address SASless' comments first. Frankly, you don't have a clue with your comments and constant quoting of critics. Have you ever flown the aircraft or even the simulator? Have you ever actually spent time around the aircraft, the crews that fly it, or the people who maintain it? The critics will never accept the words of those involved with the program because they are dead set against it, regardless of how the answers are presented.

I'll state this plain and simple, VRS is no greater an issue in the V-22 than any helicopter!! You can argue the assymetrical issue all you want but the fact remains that the descent rates required to encounter VRS are quite large and you're already in a very bad situation if this occurs. Marana was a tragedy, a good friend of mine was killed there, but they simply put themselves into an extremely bad situation. The mandated tests after this mishap actually expanded the envelope.

Time and time again the critics argue the same issues over and over despite rejections from those more familiar with the machine. I'd be happy to back these critics if they would bring up some of the true drawbacks but they won't because they'll find that they are quite trivial compared to the "showstoppers" they like to harp about.

Another argument continues to revolve around comparable helicopters. Again, look at the facts. This aircraft was designed to replace one helicopter, the H-46. Cabin dimensions and number of troops is nearly identical. And despite what you want to say, the V-22 can take the H-46 load twice as far in the same amount of flight time, no doubt, it's been proven. Here's an example, the V-22 has been flown nearly the width of the US in less than 6 hours with one fuel stop and landed to a helipad. Name a helicopter that can equal those flight times. The critics will immediately think this was some rigged test but it wasn't, it was an actual training mission.

My last comments concern the men and women involved in the program. We are not liars or idiots. We do not have death wishes. We believe in the aircraft and are working are collective butts off to make it as capable as possible. Unfortunately we've been handcuffed by constant criticism and oversight and frankly have to walk on eggshells all the time. The critics will continue to whine and moan but the important thing to remember is this, very few of them have actually ever flown in or even seen a V-22 in person, you can justify their comments by that.

[JohnDixson]

For 212 Man,

Actually I don't recollect that Tom made the statement that the 40 KIAS/-800FPM boundary existed for all helicopters as well. I believe it was the program folks. Tom MacDonald was a USN pilot attached to the NAVPRO at Sikorsky and is well remembered by the undersigned as a very fine aviator and an upstanding gentleman. He has a lot of experience in the 53E as I recall, and I'd bet that if you asked him if he could enter VRS at 40kt/-800 fpm in the E........

And if the 40kt/-800 fpm boundary existed for all the rest of the helicopter fleets, you'd think that all of those flight manuals would be in revision.

Not an anti tilt rotor person, as I believe that the market place will see the reality of its advantages and costs ( not $ ) soon enough, as Nick's notes imply.

[Dan Reno]

Yes, the AF sees the V-22 as just another Cessna Citation that will OCCASIONALY need to hover, but that's not what the MC needs or wanted but was sold on. The AF does a lot of flying from one protected place to a far-off hostile place, hover then head back. The MC needs the V-22 to act like a pogo stick and that is where the V-22 fails. I read elsewhere the AF V-22 could live with one set of tires a year whereas the MC would need to change them out monthly. Yes, it has accumulated a lot of straight and level flights and impressed all with it's great acceleration but it was supposed to be a replacement for perhaps the MC's best combat proven A/C ever, the H-46. The frog jumps from the boat to shore and back 3 or 4 times an hour ALL day and night. It lands in the dirt and mud and always comes back aboard filthy but flyable. It does hop after hop, sometimes taking off and landing a dozen times an hour. Medivacs in hot LZs, gunners pouring out lead in defense from both sides, wounded on the cable and internals wider than a pallet. Pogo stick versus a flying broom stick. Yep, the AF has something they can get by with but the MC is screwed!. BTW, I'm a H-53 guy.

[FH1100 Pilot]

mckpave says: "I'll state this plain and simple, VRS is no greater an issue in the V-22 than any helicopter!!"

Nice sound bite, but wrong. Plainly and simply, wrong.

When we think of VRS in helicopters, it is an event triggered by the vertical movement of the fuselage and rotor system together. The reason that tiltrotors are more susceptible to VRS (and its killer relative, A-VRS) is that you can tilt the nacelles rearward while the fuselage is still in forward flight. Thus, the inflow that the proprotors are seeing can be more "vertical" that might be apparent to the pilot. This is why the tiltrotor can get into VRS with forward airspeed while a helicopter needs to be below ETL.

While practicing VRS entries in a helicopter, it is impossible to know when the rotor will "break." It will do it when conditions are exactly right for itself, and it may not happen at exactly the same parameters every time. That is the chaotic nature of a rotor system. We pilots understand this.

If a tiltrotor aircraft enters VRS, there is no guarantee that both proprotors will go into it at the same time...or even that both of them will. The prospect of only one proprotor entering VRS at low altitude is horrifying. If the pilot does not immediately recognize that one proprotor is on the edge of VRS (as happened to Majors Brow and Gruber that night in Marana), his instinctive, natural reaction will be to counter any roll excursions with opposite stick, increasing the pitch of the down-going proprotor - just the exact wrong it needs.

Now maybe I'm totally wrong and it wasn't A-VRS at all. Whatever was the true cause of the Marana crash, it is clear that the V-22's roll rate exceeded the ability of the pilots to control it that fateful night. They were decellerating and decending...had the nose up and the nacelles tilted aft. Suddenly it rolled over and dove for the ground. Inexplicable, "one in a million" type of accident? Maybe. Let us hope so. But the fact that it happened once should tell us that it will happen again. Pilots sometimes do dumb things, no matter how many rules, guidelines, limitations and/or procedures are put in place to guard against them. Or maybe they're just inexperienced, or have low make/model time. Whatever. Don't believe me? Check out YouTube. Type in "Aircraft Crashes" to the search field.

I'm sure that all of the people working on the V-22 program have a lot of themselves invested in it. I'm sure they feel very emotionally involved, and take criticism of the aircraft personally. I'm also sure it's an exciting, fun aircraft to fly. Its capabilities are awesome.

But critics need not be expert V-22 pilots to comment on the design. And the critics have to ask, "As fantastic a flying machine as it is, do we really need this thing as a combat aircraft?"

Now me, I won't comment on the fact that after all this time the V-22 still doesn't have a gun. Maybe the Marines will be clairvoyant enough to know that every LZ they send the aircraft to will be enemy-free with no possibility of hostile fire. Let's hope so!

And me, I won't comment on the NAVAIR website figure that the HOGE altitude limit is a mere 5,000 feet. I guess the Marines and Air Force only plan to use the V-22 in relatively low altitude, desert-type scenarios. Let's hope all future wars are held at sea level.

And come to think of it, what altitude is considered "HOGE" for the V-22? How high can it hover and still be IGE? I would imagine/guess that every landing will involve at least some OGE time. Or maybe not, who knows what techniques they'll use when push comes to shove?

I really hadn't planned on commenting on the V-22. But some of its performance characteristics are relevant to the 609. Plus, I just don't think that people should be barred from saying anything about it simply because they haven't flown it. It's not a magic machine. It's an aircraft, plain and simple. Sure, it's an aircraft with some unique capabilities. How it will be used, and how well it will do in those uses are still in question, if not in doubt.

[Ian Corrigible]

It's beginning to look like the next-generation JHL will also be a tilt. The 'One-JHL' reference design selected by the JIPT to represent the platform in wargames bears a strong resemblance to Abe Karem's OSTR offering, and listening to the staffers it's clear that the DoD is heavily focused on speed, which may well favor the OSTR and QTR over the ATRH and X2.

I/C

[212man]

John,
it was this quote I was referring to: "Sometime ago Nick Lappos offered some thoughts about whether the Marana crash was VRS or in reality quite a different aerodynamic situation".

I entirely agree with you that the parameters you refer to are not going to cause VRS in a modern machine, and in general I think it is used to 'blame' all manner of mishandling.

[SASless]

Macrave,

Back in post six of this thread where I listed the link to the articles....I said this.....

Within the article are links to additional articles that pertain to the discussion of tilt rotors.....each reader is left to their own to determine the validity of the arguments set forth.


Are you so sensitive to any criticism of the V-22 that you can not take the time to read and consider "all" that was said?

Being a tax payer...I certainly have the right to question how my Tax dollars get spent.

The fact I consider the V-22 to be a complete waste of our hard earned dollars due to the cost alone.....just as the waste of money on the Harrier year after year....is my opinon and as such is just as valid as any other opinion.

I would suggest the lives of our Marines hold way too much value to be lost in training missions that could wait until the machine is fully tested and cleared for operational testing. It is no mean feat for the Mudders to run off and run onto an aircraft in the dark.....sandbags would be much cheaper than Marines if one was merely trying to achieve a certain weight for those tests.

It sounds to me that someone way up the food chain has bought into this concept and by God it is gonna fly....no matter what we have to do and no matter how we have to ignore the obivious.

Simple question....how does a Huey Cobra provide escort to a flight of V-22's?

Does the Marine Corps think that mission will now justify the Harrier?

I would suggest the Marines would be much better served to buy more 53's and even Blackhawks than waste all this money on V-22's that cost way more than the helicopters that would replace it.

Prove to me wrong and I will eat my Go Army-Beat Navy ball cap in front of an Evening Parade at Eighth and I.

[Jackonicko]

Far be it for me to try to drag us back to the thread, but the V-22 is one thing - a civil tilt rotor is another.

Is a civil tilt rotor's role like Dan Reno's characterisation of the USAF mission - and therefore likely to succeed, or are the potential handling/safety issues so intractable that it will fail?

[Tango and Cash]

I think the civil tiltrotor's success/failure will ultimately come down to $$$$--purchase price and operating/mx costs. There will be issues, and probably some bent metal, but the basic tiltrotor design has been flying since the 1950s. Any word on what Bell-Agusta is currently asking for the BA609?

[Ian Corrigible]

Any word on what Bell-Agusta is currently asking for the BA609?
About as much as an A109E. And an EC135. And a B430. (Plus change.)

:E

I/C

[slgrossman]

I really hadn’t intended to jump into this discussion, but what the heck. I’ve had an interest in tilt-rotor technology since the XV-15 first caught my fancy way back in the early 1980s. However, I have no intimate knowledge of the aircraft and only a passing familiarity with the aerodynamics.

One thing is rather telling, though. The fact that it’s taken so long to bring the aircraft to operational status says an awful lot about the technical challenges that had to be overcome, challenges which may not be completely solved. The V-22 is one amazingly complicated machine considering the propulsion and drive train, the flight control hydraulics, the wing and blade fold (not a consideration in the BA 609), etc. Additionally, I imagine the software, which controls every aspect of the aircraft, is revised almost constantly as new glitches crop up. I think it’s going to continue to be a challenge to operate and maintain for a long time to come, but with so much invested in it to date, as friend once told me, “it’s an aircraft that’s doomed to success.”

The tilt-rotor has been described as the combination of a poor helicopter with a poor airplane. How poor a helicopter and how poor an airplane? In which regime does it give up more? Perhaps, considering the amount of time it will spend in each regime, the inefficiencies may be less of a factor than some might think.

As far as the tilt-rotor’s inability to safely autorotate, I guess it goes against the nature of helicopter pilots, but in this case we must think of it more as an airplane, and accept the likelihood (inevitability?) of structural damage.

Personally, I don’t see any way the civil tilt-rotor will be viable in the commercial market. It will be a perfect fit for only a handful of operators who require vertical takeoff and landing capability at the end of long transit legs. The cost of owning and operating one will be prohibitive, excluding most of those who might consider it. My prediction: when all is said and done, for the same price as a 609 you could purchase and operate a nice mid-size twin helicopter and a nice 8-passenger turboprop.

Nick,

You’ve made this argument before and I have to agree with you. A CH-53, which has a similar footprint aboard ship, can carry a significantly larger load than the V-22, albeit more slowly. If time and combat power are factors, it will generally put more troops on the beach in a given time by virtue of its greater payload. However, at some range there is a crossover. I don’t have the figures to allow me to calculate it, but I suspect it’s something like 100-200 miles. That’s probably not a very practical distance for an amphibious assault. The V-22 will make its money on the long hauls, which seems to be the way the Air Force plans to use it. It remains to be seen how well it will support Marine Corps doctrine.

SASless,

I’m not up on modern tactics, but twenty years ago Marine Cobras used to escort faster CH-53s by simply leaving earlier, arriving in position to cover the LZ just prior to the transports’ arrival. If the transports needed escort en route to the objective we used fixed wing which flew racetracks or parallel routes, depending on the threat.

FH1100 Pilot,

From what I've read, I have to say I believe that A-VRS is a red herring. It does not seem to me to be a phenomenon likely to be encountered during normal operations. In fact, I’ll stick my neck out and say it’s probably less likely to be encountered than LTE in a Bell 206. It’s quite apparent that the maneuver leading up to the Marana, AZ crash was poorly flown. That’s not to say those guys weren’t good pilots, only that they made an error on that particular occasion. Similarly, the approach-turn stall while turning final in an airplane is a proven killer. Can you name an aircraft that doesn’t have some inherent characteristic which can bite you if mishandled? I love the old quote, “The Piper Cub is the safest aircraft in the world. It can just barely kill you.”

Door guns are pretty typical armament for military transport helicopters (eg. H-60, H-46, H-47, H-53). I doubt fitting a .50 cal would present much of a challenge on the V-22 (if it hasn’t already been done).

All aircraft give up HOGE performance as altitude increases. In the case of the V-22 it occurs above 5000’. Many missions can still be performed at reduced gross weight. If it’s a deal breaker for a particular mission you use something else or make more trips. I seriously doubt the aircraft it’s replacing could do better.

-Stan-

[Graviman]

From Boeing site:
http://www.boeing.com/rotorcraft/military/v22/v22spec.htm
http://www.boeing.com/rotorcraft/military/ch47d/ch47dspec.htm

[HELOFAN]

Two things I learnt from being in the sim of the BA-609 Tilt Rotor, that relate to what had just been mentioned earlier.
They Do auto rotate , but more like a brick ( instructors words not mine ) !
Actually it will autorotate in helicopter mode though the rate of decent is huge & the airspeed is huge & you WILL walk away from the scene but the A/C is bent lots.
Also the A/C can land with the nacelles forward in Air Plane mode and the rotors /props bust off cleanly the point they contact the ground......they know this as during test flying they got stuck in A/P mode and thats how they brought it in & thats what happened.
I am told it was really slick & easy.
It was neat , clean , fairly damage free & no one was harmed !
Personally......
It was neat to fly, and though I agree its tight in the back ( I dont mind ...its not me sitting there LOL ) , especially in the Corporate layout , I think they would definatly be bought as I think more PPL want the speed in shorter routes, with great places to land as does the Heli.

[ShyTorque]

"Quote:
Originally Posted by ShyTorque
I'd far rather put my stake money on the long overdue re-emergence of the Autogyro, utilising tip jet drive for low speed work, which is inherently safer, has a far better payload and can be made far cheaper yet still use small helipads (bring back the Fairey Rotodyne http://www.helis.com/50s/h_rotdyn.php ).

The Groen brothers are attempting a resurgance of this concept:
http://www.groenbros.com/gyrodyne_tech.php
They seem to be actively recruiting people to join their effort.
-- IFMU"

Yes, good stuff; We discussed the Groen project some time ago here:
http://www.pprune.org/forums/showthread.php?t=199334&highlight=groen+brothers

[mckpave]

I knew one post would lead to another. SASless, "mckrave",thanks for the name calling, very professional, I'm sure you'll think of another cute remark after this post.

There seems to be a lot of worry over the V-22 not meeting the Marine Corps mission. I think a better statement would be that the MC mission doesn't meet the V-22's performance. Don't blame the airplane because of the lack of evolution in the mission. Now I'm not an MC history expert but I do know that in the early stages of the JVX proposal, the vision for the MC mission was over-the-horizon, deeper water operations, hence the need for a faster, longer-range platform. Has that happened? I don't think so but once again, it's not the V-22's fault that the doctrine hasn't changed. So I guess what I'm saying is that I agree with you in some way but the Marines can only blame themselves if they don't exploit the capabilities.

As far as the AF mission, first and foremost if you think they're not going to operate it in a hostile environment, from takeoff to landing, then you are dead wrong. If you think it's not going to rely on the V-22's hover ability then once again you're wrong. Fast Ropes and hoists are the bread and butter of the AF mission. I can attest to the fact that right now as I type this, the AF is operating the CV-22 exactly like they will in combat: dirty, dusty, ugly, high altitude landing zones, at night and guess what? It performs as advertised. It can and does have HOGE capability at 5000ft, with full fuel and cargo, sometimes yes and sometimes no, but it's pretty darn common to trade one for the other to get the mission done, nearly all combat helicopters do the same thing. Lastly, I'd consider launching from a ship afloat offshore pretty "protected".

My argument all along hasn't been about correct choices for missions rather the attacks on the airplane's performance and safety. The airplane performs quite well actually, especially if you come from a helo background. Sad thing is that it could be even better if it weren't designed to fit a certain box size for a ship. If you read my earlier post, I never said A-VRS wasn't an issue. The real issue however, is what conditions brought about the VRS in the first place. And once again I'll state, it's no different than a helicopter, same airflow, same descent rates. The Marana crash was indeed a combination of cross controlling and VRS, at least from what people believe, but the fact remains that they got themselves into a very dangerous regime of flight and the result may very well have been the same if they were in an H-46 or H-53. I don't have the actual figures to quote but the descent rate was huge. No, aft nacelle will not induce VRS any moreso than a helicopter. I do it all the time, probably thousands over the years and have yet to enter VRS. And there are many others like me yet no VRS entry with aft nacelle and level deck. Maybe and aerodynamicist can explain it to me but all I have are actual practical events. My last comment on the V-22 is that it's not the best helo nor the best turboprop but it does combine some important characteristics of the two quite well. If you read my comments closely you'll see that I use the term, "airplane" because that's a closer representation of what it is instead of constanting comparing it to a helicopter. It does indeed enter autorotational flight and IMHO, the descent rates and airspeeds aren't all that excessive, the problem lies in the flare due to a very low inertia rotor system. I dare say it could be a survivable manuever but the conditions must be just right. Do we consider this a big issue? No, because we spend over 90% of our flight time in airplane mode. Sure, things could very well happen in helicopter or conversion mode but it's easy to find critical phases of flight for every aircraft.

Back to the civil tiltrotor topic and you'll probably be surprised to learn that I actually agree with the folks here who think it won't amount to much. It will fit a niche market for companies currently owning say a King Air and helo because they can replace both with one airplane but will it be as efficient? I'm not so sure of that, the King Air can land on about 3000 feet of runway, that accounts for nearly 90% of all US runways at least. The King Air is faster, lower DOCs, and flies higher, in reality it totally outperforms the 609. The 609 can only compete with a helo once the ranges get long, say over 150 miles. But again there are those nagging little things called initial and operating costs. I believe the 609 will have DOCs comparable to a helo, especially an S-76-type helo, but the purchase cost is way too high. Again, niche market, large companies with money to burn, or the few that can replace two with one. Not a lot of options.

I'm not intending get into a Pi$$ing contest with the critics just trying to counter the armchair V-22 "experts" from quoting sources and reports from folks who have very little if any experience with the airplane. My viewpoint is from being very closely related to the operations of this machine for several years now, I've seen the good and bad. It's also to defend the very professional, intelligent, and dedicated individuals working in all areas of the program who deserve some credit for their continued hard work. Once again, we're not idiots nor brainwashed, we believe in the airplane and more importantly, tiltrotor technology. I guess I could sit back and throw darts at all types of helicopters and missions out there too but I don't because I don't live it and don't feel I have the right to do so (whether I'm a taxpayer or not), unless I truly understand the situation. That's my biggest complaint; the critics who consider themselves experts but don't have a dog in the fight or are blatantly biased in their opinions due to associations with other groups.

[Dan Reno]

To refresh alls memory from way back TWO DECADES ago, the V-22 was touted as the H-46's replacement which means first and foremost it has to do everything the H-46 did, and it has not. It may find a home with the AF and newly formed MC special ops since there's very little hovering overall needed to perform their mission. But otherwise, it is a flop and justily deserves the title of: Flying Pork Rind!

[rjsquirrel]

mckpave's memory is as short as the V22's hover capability.

He says, "it's not the V-22's fault that the doctrine hasn't changed"

Yes, it is. The V22's fault is that it is missing almost 7 tons of promised performance. It was originally proposed and bought by the USMC as the JVX with a useful load of 28,000 lbs. The Bell proposal had 22,000 lbs empty weight, and 50,000 lbs hover weight. In its awful development, the V22 LOST 12,000 lbs of hover payload when its empty weight grew to 34,000 lbs. That lost 12,000 lbs is what makes it a dog, and meant that the USMC cannot do what they thought they could with the aircraft.

He said "It performs as advertised." Only when you read the brand new revised ads. The early ads of the V22 showed it maneuvering like a helicopter, and even showed armed versions, because its awful maneuver characteristics were not known (or at least hidden). Now we find it is forbidden to maneuver, and must be flown like a stable transport or the crew will die. Not exactly as advertised...

He also said, "That's my biggest complaint; the critics who consider themselves experts but don't have a dog in the fight or are blatantly biased in their opinions due to associations with other groups." Yep, anyone who thinks the V22 is a dog, too expensive, too little payload, no great advantage over a helicopter except that it can kill you faster - is biased.... or they read its pitiful flight manual.

[mckpave]

Forbidden to manuever?? Kill me faster? Very little hovering overall needed to perform their (the AF) mission?? Sorry but once again another believer of wrong information. Where do you get this stuff from?? Have you flown the V-22, or even the simulator? How do you get such inside information? Sarcasm is meant completely here because it's the prime example of completely crap information. I'm not going to argue with you about cost or "given up" capability. All I can do is offer you insight from someone who flies and operates the airplane and I don't see ONE thing backing up your claims. Guess you'd rather believe others who have no true knowledge of the program instead of someone who deals with it everyday. It maneuvers exactly like a helo, at least the cargo class helos I've been associated with, no restrictions, not sure where you get this load of crap from but it's proven wrong everyday. Okay, you got me, I'm not a textbook of JVX knowledge, but let's see, over 50,000 lbs. gross weight, full fuel and still had OGE power, fact not fiction. Not perfect and probably doesn't meet your spec but still pretty darn capable. Maybe somewhere in there we're arguing apples and oranges.

Again, I'll state for the record, you want to argue true issues with the airplane then I'll get behind you but I'm afraid you'll not find them as "sexy" as you want them to be. As far as cost goes, yep, you're right, it's darn expensive. But in case you haven't guessed it so is every single other defense program out there compared to the equipment replaced. Sure, I'd love for it to cost less but that's out of my hands all I know is that I can do pretty much the same things I did in my previous aircraft but a whole lot faster. In my world, that's a HUGE benefit, especially when I'm getting shot at. Believe me if you want, that's your choice, like I said I'm just some guy who flies it and doesn't sit in an armchair thinking about it.

[rjsquirrel]

mckpave,
The way you brag about having REAL experience only proves that the selection method used to pick V22 pilots matches the V22's capability.

That you think "gross weight hover" is a measure of success is another failing that you have. The lost 12,000 lbs means nothing to you, of course, as does the fact that a helicopter would hover with MORE range, MORE vertical climb rate and MORE weapons to defend itself. The fact that the machine carries what it carries is somehow an argument that you use as if it means something! If the V22 carried less, and your mission was cut the same amount (which it was, pavemck, at least three times as the V22 fell shorter and shorter) than you would still be right in your twisted logic, since you and the services sold your souls to be sure nobody reported the truth, instead they reported that the "V22 does the (watered down) mission".

Three facts to back up how poor the V22 is - prove them wrong with something besides macho bragging about your flight experience, pavemck:

1) the Black Hawk can go farther than a V22 when they both take off from 10,000 feet, the Chinook can go three times farther than either.

2) from any LZ at any altitude, the V22 carries 40% of the payload, and carries it less distance than the CH-53E,although they both have the same power and the same empty weight. Payload means combat power, armor protection, extra fuel and maneuver capability.

3) The V22 has to be babied into and out of the LZ because it has so little maneuver capability.

[Jackonicko]

Mck Pave,

You obviously think that the V-22 is a useful military tool.

Do you think that the concept is sufficiently mature to form the basis of a viable CIVIL aeroplane?

Is the difference between a tilt wing V-22 and a tilt rotor BA609 significant?

[Dan Reno]

MCKPAVE's identity is known in the unit where he's assigned therefore he's actually commenting to them and telling them that he's a team player regardless of all the facts, PR and BS. Over the past two decades a lot of military and gov types connected to the V-22 did the same so as to curry favor with the mfg and have landed good jobs. Kissing up to superiors is a favorite amongst the AF types and some in the MC who usually just keep quiet about this flying pork rind or do their time quietly in fear of the UCMJ and get out. Your comments are damaged goods and DOA here because everyone knows you are simply singing to your superiors Sir. Sullied data is of little use when lives are at stake and lets hope you're not whistling in the dark over your personal doubts about this beast without gonads..

[SASless]

Having been a Chinook pilot in a former life....I feel qualified to discuss Air Assault issues with some basis for my statements.

I assume CH-46's, the aircraft the V-22 is to replace, also receives similar tasking as does the Chinook.

One very important issue that most seem to ignore is the effects underslung loads will impose on the "speed" of the aircraft.

Hi-density, Low Drag, underslung loads ride very well at high speeds. That is understood, and I suppose the V-22 can reach the speeds of the CH-46 thus the comparison would revolve about weight carried, and perhaps cost per mile or cost per hour.

The killer of the "speed advantage" argument lies in hi-drag aerodynamic underslung loads. There....all aircraft are required to fly very slowly in order to prevent the load from oscillating to the point it has to be jettisoned for safety sakes.:ugh:

I will make a bet....dog droppings to doughnuts....MacPave can hold the stakes in his mouth.....the Marines will revert to CH-53's hauling the external loads and the V-22's will clutter the carrier deck while the work of supplying the ground forces is done by helicopters.:E

When that happens, the Marine Corps will have a very stark moment of clarity....and it will not be very pretty for them. The realization they have diverted their funding all these years into a project that just will not perform the mission.

Then what???:uhoh:

[slgrossman]

SASless,

The primary driving force behind the V-22 has always been the Marine Corps' need to replace its medium lift aircraft, the CH-46. While the Navy uses (or used) the CH-46 extensively for vertrep (ship-to-ship cargo transport), for the Marines it was always primarily a troop mover. The heavy lifting was normally done by the CH-53s. So, while the V-22 does have the capability to lift external loads, that was probably never intended to be its primary job.

mckpave,

I for one would be very interested in hearing more about the actual capabilities of the V-22. There's obviously a lot of bias against the aircraft on this forum, so a strong proponent is quite welcome, especially one with real-world experience flying the aircraft.

An aircraft which replaces a 40+ year-old design should be expected to outperform it in nearly every respect. Can you give us some insight here?

To All,

The V-22 is here and it will be with us for quite some time. I think the real question is whether the Marine Corps will have to adapt its tactics to accommodate the shortcomings of the aircraft, or will the aircraft expand the Marine Corps' capabilities.

-Stan-

[Dan Reno]

SLGROSSMAN

http://www.cdi.org/PDFs/Gailliard%20on%20V-22.pdf (http://www.cdi.org/PDFs/Gailliard%20on%20V-22.pdf)
http://www.cdi.org/staff/index.cfm?LocationID=1&OfficeID=1 (http://www.cdi.org/staff/index.cfm?LocationID=1&OfficeID=1)
http://www.boeing.com/rotorcraft/military/v22/ (http://www.boeing.com/rotorcraft/military/v22/)
http://www.bellhelicopter.textron.com/en/aircraft/military/bellV-22.cfm (http://www.bellhelicopter.textron.com/en/aircraft/military/bellV-22.cfm)
http://v22forum.com/v22forum/forum/ (http://v22forum.com/v22forum/forum/)

[SASless]

It is odd how things happen.....just last night the Commandant of the Marine Corps was interviewed by the media on a C-Span program. During that interview he was asked about the V-22 Osprey and whether the Mission set had changed over the course of the program.

He very clearly stated the Osprey is to replace both the CH-46 and CH-53D aircraft in the USMC Inventory.

He also said it was heading to a combat theater in August of this year.

We shall soon see how this works out I guess.

[slgrossman]

SASless,

I have to admit that I've been out of the loop for awhile, but it's my understanding that the "D" model CH-53s were kept around (and some were recalled from long-term storage) in order to restore the Marines' medium lift capability lost due to attrition and operational restrictions placed on the CH-46s. Since the CH-53D comes with a significant external cargo capability I'm sure it's still used in that capacity, but I'm pretty certain the Marines' primary heavy lift aircraft, the aircraft that's assigned that mission by doctrine, has been and will continue to be the CH-53E and its follow-on, the CH-53K.

Dan Reno,

Forgive me for being obtuse, but could you elaborate on the links you posted.

-Stan-

[Dan Reno]

Sure Stan,

You asked Pave for more insight and he's done that already by parroting Bell and customer gibberish so I thought you should go directly to the source rather than what we've already heard from him. Kinda like leaving out the middle man. Get it? Enjoy.

[skiddriver]

Stan is correct. The CH-53D is considered a medium lift asset. The V-22 is not intended as a primary external lift operator, though it needs to be qualified to conduct these operations. All the CH-53Ds are homeported in Hawaii, but of course are subject to the same high ops tempo all of the armed services enjoy right now.

It's been a long time since I worked (peripherally) on the V-22 test program (test plan review and chase flight) but I try and keep up with it through some of the USNTPS chums who are still active participants. There is a lot of baseless imagining being thrown around as fact in this discussion.

I'm not a huge proponent of the V-22 because I think it's R&M (reliability and maintainability) performance is going to be an achille's heel. However, the "only a helicopter can do this mission" crowd need to find another hobby. The V-22 holds down a different if partially overlapping spot with helicopters on the mission spectrum. It outperforms helicopters in some areas and is outperformed in others. It's the Marine Corps' decision at the end of the day if the mission capabilities embodied in the V-22 are sufficient, with oversight from the procurement crowd and all of the other congressional hoopla. If you want to better understand why the Marine Corps wants the V-22, spend some time understanding the Marine Corps' mission and how they plan to meet it.

[SASless]

Skiddr,
The essence of the USMC beach assault strategy can be set forth by the following concept......"Over the Horizon Assault" can it not?

That accounts for the new hover craft, the high speed amphib tractor, and the V-22 supported by the Harrier, all carried to the area of operations by the Gator Navy.

When was the last time the Marines did a contested amphibious assault? Inchon was it?

How does one prep the beach prior to arrival of the first wave? Land lightly armed troops behind the beach defenses by V-22....and then hit the beach with the hi-speed amtracs...followed by hovercraft and helicopters bring the "heavy" guns and support equipment?

What Naval Gunfire support can be used from over the horizon?

A link to a good article about the USMC mission in the 21st Century.....

http://www.globalsecurity.org/military/ops/exwar.htm

[skiddriver]

SASless,

Pretty good article, though OMFTS and STOM are being expanded by the JICs on Seabasing and Forcible Entry that you can peruse at the DTIC site http://www.dtic.mil/futurejointwarfare/jic.htm.

The traditional forced beach entry was significantly limited to a very few bits of shoreline that could support conventional landing craft. The goal is to avoid set piece beach assaults and use maneuver and the uncertainty caused by maneuver to force the enemy to defend more land than they can cover. Additionally, it is a concept that moves away from the massed fleets required for traditional beach assault.

The history on the value of extending assault fronts isn't definitive, but the use of narrow entry points has been universally recognized as less than effective.

The concept is to move from a wholly land-based version of maneuver warfare to one that encompasses the near shore to over-the-horizon area. As we found when we were denied passage from Turkey into Iraq during the start of OIF, our options for land maneuver start drying up pretty quickly. I think the answer in that case was to drop a few thousand paratroopers into Northern Iraq, an option whose lack of supportability has been proven time and time again. How do you provide supporting fires for a paradrop behind enemy lines? Can we really only fight against countries adjacent to places where we have land bases?

Seabasing is one arrow in the quiver, and (duh) is only intended for use against coastal and near coastal adversaries. The Marine Corps and Navy spearheaded the use of MPS fleets to speed the delivery of war fighting assets into theater, a concept subsequently copied by the Army in their APS fleet. I think you'll see the seabasing and joint forced entry concept will work for both the Marine Corps and Army as well.

[SASless]

As evidenced by the establishment of forward bases in Afghanistan by USMC CH-53's from Gator's 400nm from the target landing areas.:D