What's the latest on tilt rotors?
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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.
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.
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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:
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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).
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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.
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.
Guest
Posts: n/a
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!
------------------
Stay Alive,
[email protected]
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!
------------------
Stay Alive,
[email protected]
Guest
Posts: n/a
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.
------------------
The Cat
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.
------------------
The Cat
Guest
Posts: n/a
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.
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.
Guest
Posts: n/a
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.
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The Cat
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
Guest
Posts: n/a
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
"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
Guest
Posts: n/a
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).]
'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).]
Guest
Posts: n/a
Marine V-22 Maint Fraud Investigated
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"
>
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"
Guest
Posts: n/a
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.
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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).]
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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).]
Guest
Posts: n/a
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).]
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).]
Guest
Posts: n/a
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).]
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).]
Guest
Posts: n/a
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).]
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).]
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Posts: n/a
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.
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.
Guest
Posts: n/a
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.
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.
Guest
Posts: n/a
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.
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.
Guest
Posts: n/a
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).]
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).]
Guest
Posts: n/a
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).]
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).]
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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.
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The Cat
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.
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The Cat