What's the latest on tilt rotors?
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Pinochy-Unc:
I think I can help you on this easy one.
A. The 90/95 point is extremely relevant because it completely destroyed your silly asymmetrical VRS theory, but it is even more relavant that it proves you blatantly make up stories. Then you try to lie your way out with a new one and get caught in it again(do you know how to spell c-r-e-d-i-b-i-l-i-t-y?)! We could count this attempted slither-out as a third attempt but it’s too comical to worry about.
B. See A. above. Once again it proves your character (or lack of). Even though you can’t understand how settling can happen, three people who fly tandem types say it does- and even with the DREADED asymmetrical VRS!!! Must be deadly.
You completely missed JF’s point. He did NOT side step issues on serviceability-he included it in his overall assesment of the program(guess you were sleeping)-
“Reliability
History suggests that mechanical/electrical problems and even software issues can be hacked in time whatever aircraft we are talking about. My crystal ball suggests the potential benefits that the tiltrotor has to offer civvy and military alike are so big that the engineering aspects WILL be solved in time. It’s called progress and on a scale of Wright flyer to today’s best military and civil aircraft in less than 100 years the current tiltrotor issues look pretty small beer.”
There’s another perfect example of your missing the truth when it is right in front of your eyes. No matter how many times John Farley and PTIUAE put the facts in front of your eyes…you keep saying THEY are not addressing the issues!!! No wonder neither JF or PTIUAE want to lower themselves to respond directly to you anymore...if you listened to what they say like they listened to you they might think its worth it.
Time to wake up and smell the roses Pinochy-Unc, and see what people are saying to you!!! Try listening to the EXPERTS for a change!
You are very good at falsifying things and after these threads you have a lot of solid experience. Sounds like there is an opening for a guy with your qualifications in the Marine training squadron. If the Marines are looking for a Few Good Falsifyers…you’re their man.
I think I can help you on this easy one.
A. The 90/95 point is extremely relevant because it completely destroyed your silly asymmetrical VRS theory, but it is even more relavant that it proves you blatantly make up stories. Then you try to lie your way out with a new one and get caught in it again(do you know how to spell c-r-e-d-i-b-i-l-i-t-y?)! We could count this attempted slither-out as a third attempt but it’s too comical to worry about.
B. See A. above. Once again it proves your character (or lack of). Even though you can’t understand how settling can happen, three people who fly tandem types say it does- and even with the DREADED asymmetrical VRS!!! Must be deadly.
You completely missed JF’s point. He did NOT side step issues on serviceability-he included it in his overall assesment of the program(guess you were sleeping)-
“Reliability
History suggests that mechanical/electrical problems and even software issues can be hacked in time whatever aircraft we are talking about. My crystal ball suggests the potential benefits that the tiltrotor has to offer civvy and military alike are so big that the engineering aspects WILL be solved in time. It’s called progress and on a scale of Wright flyer to today’s best military and civil aircraft in less than 100 years the current tiltrotor issues look pretty small beer.”
There’s another perfect example of your missing the truth when it is right in front of your eyes. No matter how many times John Farley and PTIUAE put the facts in front of your eyes…you keep saying THEY are not addressing the issues!!! No wonder neither JF or PTIUAE want to lower themselves to respond directly to you anymore...if you listened to what they say like they listened to you they might think its worth it.
Time to wake up and smell the roses Pinochy-Unc, and see what people are saying to you!!! Try listening to the EXPERTS for a change!
You are very good at falsifying things and after these threads you have a lot of solid experience. Sounds like there is an opening for a guy with your qualifications in the Marine training squadron. If the Marines are looking for a Few Good Falsifyers…you’re their man.
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I was blessed tonight to have dinner with one of the chief design engineers of the V-22 Osprey. I just meet him tonight and he apparently spent nearly all of his career at Bell Helicopter (from the 60s onward) working on tilt-rotor technology until his retirement. He was deeply involved with the XV-15 project as well as the V-22 project. His area of responsiblity seemed to center on the design of the rotors and the cyclic controls. He was a very nice gentleman and I enjoyed the conversation I had with him greatly, and I hope I have the opportunity to talk with him again sometime in the future.
We were able to discuss both of the recent V-22 crashes, the troubled hydraulic system, some of the rotor system design characteristics, and the Vortex Ring problem. One of the first things I learned from him was how the V-22 yawed in a hover (I actually didn't know how it worked before this conversation). It yaws with differential cyclic (most of you probably knew that ).
We agreed that the cause of the crash last April was most likely "Settling with Power" or "Vortex Ring State". In discussing the rotor design, he told me that the disk loading in hover on the tilt-rotor is quite a bit higher that it would normally be in a conventional helicopter. He said this is because the rotor also has to work as a propeller in airplane mode, and this places certain restrictions on the design of the rotor for use in hovering. The rotor disk has to be smaller than it would normally be for a conventional helicopter (for propeller mode efficiency), therefore to generate the correct mass airflow through the rotor in hover mode, the air has to go through the rotor at a much higher velocity. This creates a higher velocity downwash in the hover, which can exacerbate brownout or whiteout conditions, search and rescue operations, and shipboard disembarkations as discussed in the articles posted above.
This design feature may also play a role in creating "Vortex Ring State" under conditions that are somewhat different from that of a conventional helicopter. I don't know exactly how different the conditions might be, but it does seem that the descent rates required to create the condition may be higher than that of a conventional helicopter, with air columns above the rotors that are also descending at a higher rate. This would produce a corresponding reduction in the allowable response time for the pilot to escape the condition (by approaching the ground faster), with a longer time period needed to arrest the higher descent rate (recover to 0+ fps) once forward cyclic was applied. We agreed that specific pilot training to avoid this problem would be necessary for all tilt-rotor pilots.
We discussed the December crash, and he believes as I do, that the cause was a hydraulic system failure exacerbated by a computer software failure to switch to a backup hydraulic system. We both scratched our heads as to why a 5000 psi hydraulic system was chosen for this new aircraft, although he generally supported the idea of using the lighter newer technology of this system. He thought pioneering all of these new technologies on a single aircraft was generally good, however I thought that the aircraft should be certified with a 3000 psi hydraulic system, at least until the problems with the 5000 psi system can be worked out.
He told me that the hydraulic lines on the aircraft are titanium and are smaller in diameter than a typical 3000 psi system. This is because the transferred fluid volumes used in flight at these pressures are lower. The actuators are also smaller (thus using lower fluid volumes) which also contributes to the system's overall lighter weight. The current problems with this system are twofold in that the pressure seals in the actuators are failing at these high pressures, and the lines are flexing too much (as pressurized lines always do, with more pressure producing more flexing) causing chaffing and line failures. The hydraulic system's incomplete ability to deal with these higher pressure levels are the main source of the hydraulic system maintenance problems. The civil 609 by contrast is being developed with a more conventional 3000 psi system (as also stated in one of the articles above).
It also seems to me that with this high pressure hydraulic system, the failover method to a backup system has to be near bullet proof. Computer swith over alone may not be adequate.
In the end, we both felt that the problems with the V-22 could be solved as long as some funding continues and everyone is patient in allowing the outstanding issues to be worked out.
We discussed other issues, which I might post later when they become relevant.
------------------
Safe flying to you...
[This message has been edited by Flight Safety (edited 18 February 2001).]
We were able to discuss both of the recent V-22 crashes, the troubled hydraulic system, some of the rotor system design characteristics, and the Vortex Ring problem. One of the first things I learned from him was how the V-22 yawed in a hover (I actually didn't know how it worked before this conversation). It yaws with differential cyclic (most of you probably knew that
).We agreed that the cause of the crash last April was most likely "Settling with Power" or "Vortex Ring State". In discussing the rotor design, he told me that the disk loading in hover on the tilt-rotor is quite a bit higher that it would normally be in a conventional helicopter. He said this is because the rotor also has to work as a propeller in airplane mode, and this places certain restrictions on the design of the rotor for use in hovering. The rotor disk has to be smaller than it would normally be for a conventional helicopter (for propeller mode efficiency), therefore to generate the correct mass airflow through the rotor in hover mode, the air has to go through the rotor at a much higher velocity. This creates a higher velocity downwash in the hover, which can exacerbate brownout or whiteout conditions, search and rescue operations, and shipboard disembarkations as discussed in the articles posted above.
This design feature may also play a role in creating "Vortex Ring State" under conditions that are somewhat different from that of a conventional helicopter. I don't know exactly how different the conditions might be, but it does seem that the descent rates required to create the condition may be higher than that of a conventional helicopter, with air columns above the rotors that are also descending at a higher rate. This would produce a corresponding reduction in the allowable response time for the pilot to escape the condition (by approaching the ground faster), with a longer time period needed to arrest the higher descent rate (recover to 0+ fps) once forward cyclic was applied. We agreed that specific pilot training to avoid this problem would be necessary for all tilt-rotor pilots.
We discussed the December crash, and he believes as I do, that the cause was a hydraulic system failure exacerbated by a computer software failure to switch to a backup hydraulic system. We both scratched our heads as to why a 5000 psi hydraulic system was chosen for this new aircraft, although he generally supported the idea of using the lighter newer technology of this system. He thought pioneering all of these new technologies on a single aircraft was generally good, however I thought that the aircraft should be certified with a 3000 psi hydraulic system, at least until the problems with the 5000 psi system can be worked out.
He told me that the hydraulic lines on the aircraft are titanium and are smaller in diameter than a typical 3000 psi system. This is because the transferred fluid volumes used in flight at these pressures are lower. The actuators are also smaller (thus using lower fluid volumes) which also contributes to the system's overall lighter weight. The current problems with this system are twofold in that the pressure seals in the actuators are failing at these high pressures, and the lines are flexing too much (as pressurized lines always do, with more pressure producing more flexing) causing chaffing and line failures. The hydraulic system's incomplete ability to deal with these higher pressure levels are the main source of the hydraulic system maintenance problems. The civil 609 by contrast is being developed with a more conventional 3000 psi system (as also stated in one of the articles above).
It also seems to me that with this high pressure hydraulic system, the failover method to a backup system has to be near bullet proof. Computer swith over alone may not be adequate.
In the end, we both felt that the problems with the V-22 could be solved as long as some funding continues and everyone is patient in allowing the outstanding issues to be worked out.
We discussed other issues, which I might post later when they become relevant.
------------------
Safe flying to you...
[This message has been edited by Flight Safety (edited 18 February 2001).]
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Flight Safety:
Sounds like an interesting conversation. PTIUAE had mentioned the higher disk loading as something that would allow VRS to form earlier than a helicopter that had lower disk load. As you mentioned, he said the answer is defining the limits and avoiding them. After all, with an aircraft that can do what none other in creation can do you would of course expect some limitations somewhere. He mentioned too that because of shipboard size limitation they had no choice but to shorten the blade length to less then what is best, lowering drag in the airplane mode but adding to the increased disk loading in HC mode - the old give and take.
You mentioned it takes a HIGHER descent rate to get into VRS for a tilt rotor. That sounds like a good thing rather than bad- giving a larger flight envelope before getting into it. But I know what you mean-once your get into it- you would then be at a higher descent rate- so less time before hitting the ground if you let it happen close to the ground. If you put a helicopter in at that same higher descent rate close to the ground you would be in at least an equeal mess because you’’d be HEAVILY into VRS by that point (if you stormed into it too low to the ground- then no altitude for recovery)
I was told on the V-22 hydr has not only a problem because of the 5000PSI pressure- also less redundancy then a 609. 609s supposedly have complete separation with no switching to backups required while V-22s share fluid with shuttling valves. Really seems like the 609 is a next generation T/R and the V-22 should modify to catch up! Definitely needs some work.
I agree with your summation- it will all work out in the end.
Thanks for the valuable input. Look forward to more.
[This message has been edited by HeliFlight (edited 18 February 2001).]
Sounds like an interesting conversation. PTIUAE had mentioned the higher disk loading as something that would allow VRS to form earlier than a helicopter that had lower disk load. As you mentioned, he said the answer is defining the limits and avoiding them. After all, with an aircraft that can do what none other in creation can do you would of course expect some limitations somewhere. He mentioned too that because of shipboard size limitation they had no choice but to shorten the blade length to less then what is best, lowering drag in the airplane mode but adding to the increased disk loading in HC mode - the old give and take.
You mentioned it takes a HIGHER descent rate to get into VRS for a tilt rotor. That sounds like a good thing rather than bad- giving a larger flight envelope before getting into it. But I know what you mean-once your get into it- you would then be at a higher descent rate- so less time before hitting the ground if you let it happen close to the ground. If you put a helicopter in at that same higher descent rate close to the ground you would be in at least an equeal mess because you’’d be HEAVILY into VRS by that point (if you stormed into it too low to the ground- then no altitude for recovery)
I was told on the V-22 hydr has not only a problem because of the 5000PSI pressure- also less redundancy then a 609. 609s supposedly have complete separation with no switching to backups required while V-22s share fluid with shuttling valves. Really seems like the 609 is a next generation T/R and the V-22 should modify to catch up! Definitely needs some work.
I agree with your summation- it will all work out in the end.
Thanks for the valuable input. Look forward to more.
[This message has been edited by HeliFlight (edited 18 February 2001).]
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To heliflight, I just wanted to point out the information on the higher disk loading came from the gentlemen that I spoke with. The speculation on the differences in the nature of VRS on the V-22 from conventional helicopters was my speculation, not his. I just wanted to be clear on that.
My speculation on the nature of VRS on the V-22 was based on the higher velocity of the downwash and air mass moving through the rotors in a hover (compared to a conventional helicopter). It also came from the fact that the crash last April occurred when the pilot made a high rate descent (2200 fpm ??) when approaching to land.
Again that my speculation, not the gentlemen's whom I had to pleasure to have dinner with. We discussed the disk loading issue and the pilot training issues that would help to avoid the problem.
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Safe flying to you...
[This message has been edited by Flight Safety (edited 19 February 2001).]
My speculation on the nature of VRS on the V-22 was based on the higher velocity of the downwash and air mass moving through the rotors in a hover (compared to a conventional helicopter). It also came from the fact that the crash last April occurred when the pilot made a high rate descent (2200 fpm ??) when approaching to land.
Again that my speculation, not the gentlemen's whom I had to pleasure to have dinner with. We discussed the disk loading issue and the pilot training issues that would help to avoid the problem.
------------------
Safe flying to you...
[This message has been edited by Flight Safety (edited 19 February 2001).]
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I just read that the current V-22 flight manual restricts descent rates in hover mode to 800 fpm or less.
I also don't understand why you would design the hydraulic systems to "share" fluids with each other. I mean, wouldn't a low fluid level in a single system generally indicate a leak in that system? So why would you transfer fluid from a known good system into a "leaky" system. That makes no sense to me.
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Safe flying to you...
[This message has been edited by Flight Safety (edited 19 February 2001).]
I also don't understand why you would design the hydraulic systems to "share" fluids with each other. I mean, wouldn't a low fluid level in a single system generally indicate a leak in that system? So why would you transfer fluid from a known good system into a "leaky" system. That makes no sense to me.
------------------
Safe flying to you...
[This message has been edited by Flight Safety (edited 19 February 2001).]
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From the Experts: 33 / 103
Reuters, Monday, Feb. 19, 2001
U.S. Marines Skipped Key Tests of Osprey - Report
WASHINGTON (Reuters) - The Marine Corps omitted tests of the MV-22 tilt-rotor aircraft that would have provided more data on a descent problem later implicated in a crash that killed 19 Marines last April, the Washington Post said Monday, citing a report by the General Accounting Office.
The GAO report, which has not been publicly released, also said the Marine Corps had warnings about troubles in the aircraft's hydraulics system, according to the Post.
Military investigators now believe that a frayed hydraulics line was a key factor in a second crash of the aircraft, also known as the Osprey. In that accident, last December, four more Marines died.
The Department of Defense inspector general is investigating allegations of falsified maintenance records in the $40 billion Osprey program after receiving an anonymous letter and tape recording alleging that the commander of the corps' only MV-22 squadron told subordinates to falsify maintenance records on the eight remaining aircraft.
The report by the GAO, the investigative arm of Congress, cast serious doubt on both the safety and reliability of the troubled Osprey and on the rigor of Marine Corps testing of the aircraft, which takes off and lands like a helicopter but can tilt its rotors forward to fly like an airplane.
The GAO said that not enough was known about the Osprey's design and performance before production started and that the limiting of tests reduced the chance to gain a realistic view of the Osprey's mettle for combat, rescue missions or aid flights, according to the Post.
DOUBTS ABOUT CAPACITY
The GAO report also found that the Osprey's cabin might be too small to carry 24 Marines equipped for combat, saying that "15-18 combat Marines may be the limit." If that proves true, it could undercut one of the reasons cited by the Marines for favoring the Osprey over helicopters such as the UH-60 Black Hawk, which is designed to carry 11 combat-loaded troops.
The hybrid helicopter is built jointly by Boeing Co. and Textron Inc.
The GAO prepared its review for a panel convened by the Pentagon to assess the Osprey after the two recent crashes.
The GAO report referred to maintenance troubles, particularly with the Osprey's hydraulic systems, which required servicing so frequently that it "is concerning," according to Marine investigator reports filed after the April Osprey crash and cited by the GAO, the Post said.
In a similar vein, the GAO said tests that could have uncovered added information about a phenomenon known as "vortex ring state" -- which occurred during the April crash, when an Osprey coming in for a rapid landing lost lift, rolled and flipped over -- were deleted or deferred to meet "program cost and schedule pressures," the Post said.
Instead of the 103 tests first scheduled on the phenomenon, 49 were slated, and of those, only 33 were actually flown during testing phases, the GAO briefing said.
Reuters, Monday, Feb. 19, 2001
U.S. Marines Skipped Key Tests of Osprey - Report
WASHINGTON (Reuters) - The Marine Corps omitted tests of the MV-22 tilt-rotor aircraft that would have provided more data on a descent problem later implicated in a crash that killed 19 Marines last April, the Washington Post said Monday, citing a report by the General Accounting Office.
The GAO report, which has not been publicly released, also said the Marine Corps had warnings about troubles in the aircraft's hydraulics system, according to the Post.
Military investigators now believe that a frayed hydraulics line was a key factor in a second crash of the aircraft, also known as the Osprey. In that accident, last December, four more Marines died.
The Department of Defense inspector general is investigating allegations of falsified maintenance records in the $40 billion Osprey program after receiving an anonymous letter and tape recording alleging that the commander of the corps' only MV-22 squadron told subordinates to falsify maintenance records on the eight remaining aircraft.
The report by the GAO, the investigative arm of Congress, cast serious doubt on both the safety and reliability of the troubled Osprey and on the rigor of Marine Corps testing of the aircraft, which takes off and lands like a helicopter but can tilt its rotors forward to fly like an airplane.
The GAO said that not enough was known about the Osprey's design and performance before production started and that the limiting of tests reduced the chance to gain a realistic view of the Osprey's mettle for combat, rescue missions or aid flights, according to the Post.
DOUBTS ABOUT CAPACITY
The GAO report also found that the Osprey's cabin might be too small to carry 24 Marines equipped for combat, saying that "15-18 combat Marines may be the limit." If that proves true, it could undercut one of the reasons cited by the Marines for favoring the Osprey over helicopters such as the UH-60 Black Hawk, which is designed to carry 11 combat-loaded troops.
The hybrid helicopter is built jointly by Boeing Co. and Textron Inc.
The GAO prepared its review for a panel convened by the Pentagon to assess the Osprey after the two recent crashes.
The GAO report referred to maintenance troubles, particularly with the Osprey's hydraulic systems, which required servicing so frequently that it "is concerning," according to Marine investigator reports filed after the April Osprey crash and cited by the GAO, the Post said.
In a similar vein, the GAO said tests that could have uncovered added information about a phenomenon known as "vortex ring state" -- which occurred during the April crash, when an Osprey coming in for a rapid landing lost lift, rolled and flipped over -- were deleted or deferred to meet "program cost and schedule pressures," the Post said.
Instead of the 103 tests first scheduled on the phenomenon, 49 were slated, and of those, only 33 were actually flown during testing phases, the GAO briefing said.
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Key Tests Omitted on The Osprey
GAO Assails Program
By Mary Pat Flaherty and Thomas E. Ricks
Washington Post Staff Writers
Monday, February 19, 2001
To save time and money, the Marine Corps omitted tests of the V-22 Osprey that would have provided additional data on rapid descents that contributed to a crash that killed 19 Marines in April, according to a new report by the General Accounting Office.
The GAO report, which has not been publicly released, also says the Marines had warnings about troubles in the aircraft's hydraulics system. Military investigators now believe that a frayed hydraulics line was a key factor in a second Osprey crash in December in which four more Marines died.
Overall, the GAO review casts serious doubt on both the safety and reliability of the troubled Osprey and on the rigor of Marine Corps testing of the aircraft. The Marine Corps touts the Osprey, which takes off and lands like a helicopter but can tilt its rotors forward to fly like an airplane, as the best replacement for its Vietnam-era helicopters, contending they will fly much faster and farther and carry more troops and equipment than the aging fleet.
But the 31-page GAO review challenges many of the assertions. Not enough was known about the Osprey's design and performance before production started, the review contends, and test restrictions and waivers reduced the chance to gain a realistic view of the Osprey's mettle for combat, rescue missions or aid flights.
The report said the Osprey's cabin may be too small to carry 24 Marines equipped for combat, stating that "15-18 combat Marines may be the limit." If that criticism proves accurate, it would partially undercut one of the reasons the Marines cite for favoring the Osprey over helicopters such as the UH-60 Black Hawk, which is designed to carry 11 combat-loaded troops.
The GAO review also echoes worries raised by other evaluators about reliability and maintenance challenges and cautions that any major design changes and upkeep expose the government to significant costs. The GAO drew on its own work and details from reports by investigators of the two crashes, as well as other federal studies, for its briefing.
When asked generally about assertions that the Osprey falls short of its operational concept -- that is, how it would work in real-world missions -- Marine Commandant Gen. James Jones said last week: "I think it's there, and I think it works. I know it's better than helicopters, by a long shot." In the same interview, Jones said he does not "have blinders on" about the Osprey, which has been promoted by the Marines for 18 years. If more tests are needed, Jones said, "we'll do that."
The GAO prepared its review for a panel convened by the Pentagon to assess the Osprey program after the two most recent crashes: one in April in Marana, Ariz., that killed 19 Marines and a December crash near New River, N.C., that killed four more and grounded all Ospreys. In addition to the panel's continuing inquiry, the Osprey is the object of a nearly complete investigation into the causes of the December crash.
A separate investigation is ongoing into allegations a senior officer in a North Carolina squadron ordered crews to falsify maintenance records to improve the aircraft's performance rating.
The GAO was one of several organizations that briefed the Pentagon panel. Until the panel delivers its findings based on all that it has heard, the Marines are withholding comment, said Marine Brig. Gen. John F. Sattler. "We don't want to get into a point-counterpoint on every presentation," he said yesterday.
The GAO report cites maintenance troubles, particularly with the Osprey's hydraulic systems, which control the aircraft's movements. They required servicing so frequently that it "is concerning," according to Marine investigator reports filed after the April Osprey crash and cited by the GAO. Problems with hydraulics and software appear to have caused the December crash, the Marines said last week, although the final accident report is pending.
In a similar vein, the GAO notes that tests that could have uncovered added information about an aerodynamic phenomenon known as "vortex ring state" -- which the Marines said occurred during the April crash when an Osprey coming in for a rapid landing lost lift, rolled and flipped over -- were deleted or deferred in earlier testing to meet "program cost and schedule pressures." Instead of the 103 tests first scheduled on the phenomenon during testing, 49 were slated, and of those, only 33 were actually flown during test phases, the GAO briefing states.
The Marine Corps blamed pilot error for exposing the Osprey to vortex ring state in April, and has since stepped up testing on the problem. All helicopters are vulnerable to the problem, but the Osprey, with its two side-by-side rotors, "appears to be less forgiving than conventional helicopters," according to briefing materials. The consequence of exceeding guidelines for descents in the Osprey "appears to be excessively grave," it continues.
The Marines have bought 10 production-level V-22s, manufactured as the Corps and its industry partners -- Bell Helicopter Textron of Fort Worth and Boeing Helicopters of Ridley Township, Pa., near Philadelphia -- sought approval from the Pentagon for a full acquisition. The Marines hope to buy 360 Ospreys at an estimated cost of $57 million apiece. A decision on whether to move to full-scale production was set for December but was delayed after the North Carolina crash and now awaits results of the Pentagon panel's review.
The GAO report is striking for the doubts it casts on the operational concept of the Osprey.
The report found that the "downwash" of air from the Osprey's two huge 38-foot-wide rotors is so severe it sometimes "creates brownout and whiteout conditions," which would impede troops trying to move into combat positions. The downward flow also makes it "hazardous" for troops to get out of the aircraft by sliding down a rope, a technique sometimes used to insert forces in areas where there is no open space available for landing. The downwash also can force sand and snow into the Osprey's interior and its components, the report said.
The report also notes that at various times, tests were limited during other conditions the Osprey likely would encounter, including not testing in cold weather where icing conditions could arise, in areas where storm clouds were close by and in situations that required several Ospreys to fly in formation.
© 2001 The Washington Post Company
GAO Assails Program
By Mary Pat Flaherty and Thomas E. Ricks
Washington Post Staff Writers
Monday, February 19, 2001
To save time and money, the Marine Corps omitted tests of the V-22 Osprey that would have provided additional data on rapid descents that contributed to a crash that killed 19 Marines in April, according to a new report by the General Accounting Office.
The GAO report, which has not been publicly released, also says the Marines had warnings about troubles in the aircraft's hydraulics system. Military investigators now believe that a frayed hydraulics line was a key factor in a second Osprey crash in December in which four more Marines died.
Overall, the GAO review casts serious doubt on both the safety and reliability of the troubled Osprey and on the rigor of Marine Corps testing of the aircraft. The Marine Corps touts the Osprey, which takes off and lands like a helicopter but can tilt its rotors forward to fly like an airplane, as the best replacement for its Vietnam-era helicopters, contending they will fly much faster and farther and carry more troops and equipment than the aging fleet.
But the 31-page GAO review challenges many of the assertions. Not enough was known about the Osprey's design and performance before production started, the review contends, and test restrictions and waivers reduced the chance to gain a realistic view of the Osprey's mettle for combat, rescue missions or aid flights.
The report said the Osprey's cabin may be too small to carry 24 Marines equipped for combat, stating that "15-18 combat Marines may be the limit." If that criticism proves accurate, it would partially undercut one of the reasons the Marines cite for favoring the Osprey over helicopters such as the UH-60 Black Hawk, which is designed to carry 11 combat-loaded troops.
The GAO review also echoes worries raised by other evaluators about reliability and maintenance challenges and cautions that any major design changes and upkeep expose the government to significant costs. The GAO drew on its own work and details from reports by investigators of the two crashes, as well as other federal studies, for its briefing.
When asked generally about assertions that the Osprey falls short of its operational concept -- that is, how it would work in real-world missions -- Marine Commandant Gen. James Jones said last week: "I think it's there, and I think it works. I know it's better than helicopters, by a long shot." In the same interview, Jones said he does not "have blinders on" about the Osprey, which has been promoted by the Marines for 18 years. If more tests are needed, Jones said, "we'll do that."
The GAO prepared its review for a panel convened by the Pentagon to assess the Osprey program after the two most recent crashes: one in April in Marana, Ariz., that killed 19 Marines and a December crash near New River, N.C., that killed four more and grounded all Ospreys. In addition to the panel's continuing inquiry, the Osprey is the object of a nearly complete investigation into the causes of the December crash.
A separate investigation is ongoing into allegations a senior officer in a North Carolina squadron ordered crews to falsify maintenance records to improve the aircraft's performance rating.
The GAO was one of several organizations that briefed the Pentagon panel. Until the panel delivers its findings based on all that it has heard, the Marines are withholding comment, said Marine Brig. Gen. John F. Sattler. "We don't want to get into a point-counterpoint on every presentation," he said yesterday.
The GAO report cites maintenance troubles, particularly with the Osprey's hydraulic systems, which control the aircraft's movements. They required servicing so frequently that it "is concerning," according to Marine investigator reports filed after the April Osprey crash and cited by the GAO. Problems with hydraulics and software appear to have caused the December crash, the Marines said last week, although the final accident report is pending.
In a similar vein, the GAO notes that tests that could have uncovered added information about an aerodynamic phenomenon known as "vortex ring state" -- which the Marines said occurred during the April crash when an Osprey coming in for a rapid landing lost lift, rolled and flipped over -- were deleted or deferred in earlier testing to meet "program cost and schedule pressures." Instead of the 103 tests first scheduled on the phenomenon during testing, 49 were slated, and of those, only 33 were actually flown during test phases, the GAO briefing states.
The Marine Corps blamed pilot error for exposing the Osprey to vortex ring state in April, and has since stepped up testing on the problem. All helicopters are vulnerable to the problem, but the Osprey, with its two side-by-side rotors, "appears to be less forgiving than conventional helicopters," according to briefing materials. The consequence of exceeding guidelines for descents in the Osprey "appears to be excessively grave," it continues.
The Marines have bought 10 production-level V-22s, manufactured as the Corps and its industry partners -- Bell Helicopter Textron of Fort Worth and Boeing Helicopters of Ridley Township, Pa., near Philadelphia -- sought approval from the Pentagon for a full acquisition. The Marines hope to buy 360 Ospreys at an estimated cost of $57 million apiece. A decision on whether to move to full-scale production was set for December but was delayed after the North Carolina crash and now awaits results of the Pentagon panel's review.
The GAO report is striking for the doubts it casts on the operational concept of the Osprey.
The report found that the "downwash" of air from the Osprey's two huge 38-foot-wide rotors is so severe it sometimes "creates brownout and whiteout conditions," which would impede troops trying to move into combat positions. The downward flow also makes it "hazardous" for troops to get out of the aircraft by sliding down a rope, a technique sometimes used to insert forces in areas where there is no open space available for landing. The downwash also can force sand and snow into the Osprey's interior and its components, the report said.
The report also notes that at various times, tests were limited during other conditions the Osprey likely would encounter, including not testing in cold weather where icing conditions could arise, in areas where storm clouds were close by and in situations that required several Ospreys to fly in formation.
© 2001 The Washington Post Company
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Thanks F.S. :
I understand your situation of the VRS speculation. Seems logical, but there are no doubt other variables that have to be looked at before we say it takes a HIGHER rate of descent to get into VRS in a tiltrotor. I would imagine overall it must be easier to get into than in a helicopter - but definitely avoidable as long as you don't go out of the envelope. I heard that 800 fpm limitation in the flight manual was there since before the Arizona VRS accident. I've heard two stories on it, one that the 800fpm limit applied whenever you are under 40kt airspeed, the other that it applied when the nacelles were beyond 80 degrees aft- either way they were definitely way outside the specific flight manual limits at 2200fpm in Arizona.
Don't quote me on the sharing fluids- that came from one newpaper article that made a brief mention of sharing fluid between systems with a shuttle valve (maybe like the BO 105?). Doesn't make much sense to me either. The person I keep in touch with by e-mail has great knowlege on the 609 but is not involved with the V-22 so no official news here. Lu Zuckerman used to work on the hyd system with Boeing but unfortunately it was many years ago and a lot has apparently been modified since then. Maybe you can find out from the V-22 engineer you met recently- could be time for another dinner!!!
Please let us know if you find out more details- Thanks.
I understand your situation of the VRS speculation. Seems logical, but there are no doubt other variables that have to be looked at before we say it takes a HIGHER rate of descent to get into VRS in a tiltrotor. I would imagine overall it must be easier to get into than in a helicopter - but definitely avoidable as long as you don't go out of the envelope. I heard that 800 fpm limitation in the flight manual was there since before the Arizona VRS accident. I've heard two stories on it, one that the 800fpm limit applied whenever you are under 40kt airspeed, the other that it applied when the nacelles were beyond 80 degrees aft- either way they were definitely way outside the specific flight manual limits at 2200fpm in Arizona.
Don't quote me on the sharing fluids- that came from one newpaper article that made a brief mention of sharing fluid between systems with a shuttle valve (maybe like the BO 105?). Doesn't make much sense to me either. The person I keep in touch with by e-mail has great knowlege on the 609 but is not involved with the V-22 so no official news here. Lu Zuckerman used to work on the hyd system with Boeing but unfortunately it was many years ago and a lot has apparently been modified since then. Maybe you can find out from the V-22 engineer you met recently- could be time for another dinner!!!
Please let us know if you find out more details- Thanks.
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Pinochy-Unc:
Uh ohh... Over 6 pages now!!! And this last post is just another rewrite by a different paper of the GAO report that has already been covered many times here (same report, just different reporters writing about it). Could this be another “a filibustering attempt to deflect the reader's attention from the very real problems facing your flaws and foibles in a desperate bid to recapture your credibility” to use your own words!!!
Well at least you are not adding any new False theories to the end so I guess we can give you credit for improvement.
By the way... how is your application coming along for the Marine training squadron position(A Few Good Falsifyers needed!) If you need a reference- have them contact me... I'll verify your great qualifications for the job!!!
Uh ohh... Over 6 pages now!!! And this last post is just another rewrite by a different paper of the GAO report that has already been covered many times here (same report, just different reporters writing about it). Could this be another “a filibustering attempt to deflect the reader's attention from the very real problems facing your flaws and foibles in a desperate bid to recapture your credibility” to use your own words!!!
Well at least you are not adding any new False theories to the end so I guess we can give you credit for improvement.
By the way... how is your application coming along for the Marine training squadron position(A Few Good Falsifyers needed!) If you need a reference- have them contact me... I'll verify your great qualifications for the job!!!
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Pinochy-Unc:
Wow... you REALLY are getting desparate. Posting ANOTHER reprint of the same report on the GAO by a differnt writer. Well, if you want to hide the fact that all of your theories had been disproven, I guess burying those posts with repetition is one way.
A bit SAD though.
Perhaps counseling will help. You have become the PPRune SPAM KING. At least you are top of the class at something now.
I have an idea for you. Why don't you post the same article on EVERY thread on the forum. And then create a hundred or so new topics and put it there too. If you don't have quality- go for Quantity!!!
The More the Better. Keep up the good work
I hate to be repetitive (like some people we know), but to use your own words it looks like:
“a filibustering attempt to deflect the reader's attention from the very real problems facing your flaws and foibles in a desperate bid to recapture your credibility”
Wow... you REALLY are getting desparate. Posting ANOTHER reprint of the same report on the GAO by a differnt writer. Well, if you want to hide the fact that all of your theories had been disproven, I guess burying those posts with repetition is one way.
A bit SAD though.
Perhaps counseling will help. You have become the PPRune SPAM KING. At least you are top of the class at something now. I have an idea for you. Why don't you post the same article on EVERY thread on the forum. And then create a hundred or so new topics and put it there too. If you don't have quality- go for Quantity!!!
The More the Better. Keep up the good work
I hate to be repetitive (like some people we know), but to use your own words it looks like:
“a filibustering attempt to deflect the reader's attention from the very real problems facing your flaws and foibles in a desperate bid to recapture your credibility”
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LU Zuckerman
Reference your post on page one of this thread:
"the hydraulic system can operate ten to a hundred times more than predicted in the reliability analysis."
I came across this (from an ex-Lockheed designer):
"And I'm betting that the hydraulic problems that they've been having in such low-time aircraft are simply due to the self-reinforcing vibrational feedback of such a high-pressure system (5000 psi versus normal 2500 - 3000psi). They just didn't anticipate that the fine diameter titanium piping would be subject to much more than the internal hydraulic pressures and normal actuation shocks. In a higher pressure system, high-rate cycling hyd pressures can set up a high frequency, high amplitude destructively resonating "echo" that would normally require at least one set of properly placed QUINCKE valves per system for absorption of the vibration. These are like coils that simply flex at the correct harmonic and relieve the hammer-blow shocks in the lines (of chattering actuators) . A system poorly provisioned with them would be leak and failure-prone due to the harmonically reinforced pressure spikes."
I'd thought the accumulator was the shock-absorber. But maybe the higher pressures need interim shock-absorption - particularly in something that's a lot more than a utility hydraulic system - as you've indicated in your post.
Reference your post on page one of this thread:
"the hydraulic system can operate ten to a hundred times more than predicted in the reliability analysis."
I came across this (from an ex-Lockheed designer):
"And I'm betting that the hydraulic problems that they've been having in such low-time aircraft are simply due to the self-reinforcing vibrational feedback of such a high-pressure system (5000 psi versus normal 2500 - 3000psi). They just didn't anticipate that the fine diameter titanium piping would be subject to much more than the internal hydraulic pressures and normal actuation shocks. In a higher pressure system, high-rate cycling hyd pressures can set up a high frequency, high amplitude destructively resonating "echo" that would normally require at least one set of properly placed QUINCKE valves per system for absorption of the vibration. These are like coils that simply flex at the correct harmonic and relieve the hammer-blow shocks in the lines (of chattering actuators) . A system poorly provisioned with them would be leak and failure-prone due to the harmonically reinforced pressure spikes."
I'd thought the accumulator was the shock-absorber. But maybe the higher pressures need interim shock-absorption - particularly in something that's a lot more than a utility hydraulic system - as you've indicated in your post.
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Pinochy-Unc:
Excellent 'theory' P-U(no pun intended)
I hate it when those DUMB engineers forget to put in enough'QUINCKE valves' !!!
Nothing more annoying.
I am sure your idea will fix it right up.
Keep up the good work...
It's very believeable.
Excellent 'theory' P-U(no pun intended)
I hate it when those DUMB engineers forget to put in enough
'QUINCKE valves' !!!Nothing more annoying.
I am sure your idea will fix it right up.
Keep up the good work...
It's very believeable.
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From Air Safety Week:
Light look at serious business. It is that time of year again when members of the Ostriches Anonymous Association (OAA) vote for the winner of their Oliver Ostrich "Head in the Sand" award. The award is presented annually and anonymously to the individual or organization uttering the most outrageous statement ignoring, denying or discounting a significant aviation risk. The idea is to use humor as a means of improving safety awareness. The winner, upon whom the coveted "Oliver" is bestowed, will be announced at the association's February 23d Ostrich Watchers Ball held at the Cavanaugh Air Museum in Addison, Texas.
This year, the seven finalists are:
FAA airspace and rules division: which determined that a 497-foot-MSL-tall tower did NOT meet the criteria to be a hazard despite being sited along the path of a special VFR corridor in Anchorage, Alaska, which requires pilot to fly below 600 feet MSL. Oliver's Astute Analysis: Of course the bureaucrats in the FAA's Airspace and Rules Division (ATA-400) don't actually FLY airplanes, so let's have them ride along as passengers on a couple of one-mile-visibility days and see if they can spot the tower and its guy-
wires.
Government auditors. "The manufacturer performed slipshod work, used out-of-date blueprints and improperly inspected parts - but flight safety was not threatened." Oliver's Astute Analysis: Obviously true so long as the airplanes remain on the assembly line.
NASA and military aerodynamic experts have known for years that a tiltrotor aircraft could enter vortex ring state on one rotor, said the managing director of Petroleum Tiltrotors International in Dubai (PTI-UAE). But testing was not done before the Arizona crash because engineers believed that the V-22 would never encounter it if the pilots stayed within prescribed speed and descent parameters, he said. . ArticleLINK1
"We really didn't do the research on this because we didn't envision pilots getting into this condition," said Zuk, chief of NASA's advanced tilt-rotor technology office. "It's not something [where] you say, stop the V-22 program. Absolutely not. The key is pilot awareness." ArticleLINK2
Aircraft manufacturer: During a planned engine replacement cracks were discovered in some nuts holding bolts to the aft mount of the engine:
"Failure of one nut in no way affected the engine's safe attachment to the pylon. The mounting had four bolts. Consequently safety was in no way and at no time compromised. Spares were readily available worldwide." Oliver's Astute Analysis: If the missing nut in no way affects the engine's safe attachment to the pylon, why is it there?
FAA engineers: "The pilots could continue flying if a cable broke, so it was not considered a crucial part. We did not think the situation was urgent." (In response to charges that the FAA waited 17 months before advising carriers about the failure of a control cable manufacturer to test cables the military found were failing at 50% of the rated load.) Oliver's Astute Analysis: Obviously, we needn't worry about other 'non-crucial' parts, like wheel, tires, avionics, and an occasional B747 outboard engine, all of which have occasionally been lost and the airplane continued to fly.
Manufacturer's president: "There is absolutely no connection" between our efforts to reduce manufacturing inspections and the 8-inch hairline cracks found in at least 40 airplanes. Oliver's Astute Analysis: If fuel tank stringers are added to the pilots' walk-around inspections, the pilots' cursory preflight can be blamed for any fuel leaks that develop. >> OAA, e-mail [email protected] <<
CBS article
Light look at serious business. It is that time of year again when members of the Ostriches Anonymous Association (OAA) vote for the winner of their Oliver Ostrich "Head in the Sand" award. The award is presented annually and anonymously to the individual or organization uttering the most outrageous statement ignoring, denying or discounting a significant aviation risk. The idea is to use humor as a means of improving safety awareness. The winner, upon whom the coveted "Oliver" is bestowed, will be announced at the association's February 23d Ostrich Watchers Ball held at the Cavanaugh Air Museum in Addison, Texas.
This year, the seven finalists are:
FAA airspace and rules division: which determined that a 497-foot-MSL-tall tower did NOT meet the criteria to be a hazard despite being sited along the path of a special VFR corridor in Anchorage, Alaska, which requires pilot to fly below 600 feet MSL. Oliver's Astute Analysis: Of course the bureaucrats in the FAA's Airspace and Rules Division (ATA-400) don't actually FLY airplanes, so let's have them ride along as passengers on a couple of one-mile-visibility days and see if they can spot the tower and its guy-
wires.
Government auditors. "The manufacturer performed slipshod work, used out-of-date blueprints and improperly inspected parts - but flight safety was not threatened." Oliver's Astute Analysis: Obviously true so long as the airplanes remain on the assembly line.
NASA and military aerodynamic experts have known for years that a tiltrotor aircraft could enter vortex ring state on one rotor, said the managing director of Petroleum Tiltrotors International in Dubai (PTI-UAE). But testing was not done before the Arizona crash because engineers believed that the V-22 would never encounter it if the pilots stayed within prescribed speed and descent parameters, he said. . ArticleLINK1
"We really didn't do the research on this because we didn't envision pilots getting into this condition," said Zuk, chief of NASA's advanced tilt-rotor technology office. "It's not something [where] you say, stop the V-22 program. Absolutely not. The key is pilot awareness." ArticleLINK2
Aircraft manufacturer: During a planned engine replacement cracks were discovered in some nuts holding bolts to the aft mount of the engine:
"Failure of one nut in no way affected the engine's safe attachment to the pylon. The mounting had four bolts. Consequently safety was in no way and at no time compromised. Spares were readily available worldwide." Oliver's Astute Analysis: If the missing nut in no way affects the engine's safe attachment to the pylon, why is it there?
FAA engineers: "The pilots could continue flying if a cable broke, so it was not considered a crucial part. We did not think the situation was urgent." (In response to charges that the FAA waited 17 months before advising carriers about the failure of a control cable manufacturer to test cables the military found were failing at 50% of the rated load.) Oliver's Astute Analysis: Obviously, we needn't worry about other 'non-crucial' parts, like wheel, tires, avionics, and an occasional B747 outboard engine, all of which have occasionally been lost and the airplane continued to fly.
Manufacturer's president: "There is absolutely no connection" between our efforts to reduce manufacturing inspections and the 8-inch hairline cracks found in at least 40 airplanes. Oliver's Astute Analysis: If fuel tank stringers are added to the pilots' walk-around inspections, the pilots' cursory preflight can be blamed for any fuel leaks that develop. >> OAA, e-mail [email protected] <<
CBS article
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Updated: Wednesday, Feb. 21, 2001 at 01:24 CST
Report says V-22 pilots weren't well-prepared
The flight manual and training program failed in warning crews of the dangers they faced, the GAO report notes.
By Bob Cox and Jennifer Autrey
Star-Telegram staff writers
Pilots at the controls of a V-22 Osprey that crashed in Arizona last year had received little warning or preparation for the hazardous conditions that caused the accident, according to a government report.
The report released Tuesday by the General Accounting Office cited Navy and Marine officials who concluded that the V-22 flight manual and training program did little to warn pilots of the dangers they faced.
Separately, a Pentagon advisory board also criticized the Navy for cutting corners during testing of the Osprey to save money and make up for schedule delays, Bloomberg News reported Tuesday.
According to the GAO report, the Marines' accident investigator wrote that the "manual and V-22 ground school syllabus provides insufficient guidance/warning as to high rate of descent/slow airspeed conditions and the potential consequences."
The two reports are the latest in a series critical of the Marines for rushing to buy the V- 22 despite myriad problems with the revolutionary tilt-rotor aircraft.
Officially, the Marines have blamed the April 8 crash that killed 19 servicemen on errors by the aircraft's crew. The pilots, according to the accident report, descended too fast with too little airspeed and got caught in a turbulent condition, known as vortex ring state, that caused the V-22 to lose lift, roll over and crash.
The GAO report was prepared for Defense Secretary Donald Rumsfeld and a blue ribbon panel reviewing the V- 22 program. The report draws heavily on previously undisclosed portions of the Marines' crash report and the Navy report evaluating the V-22, and also cites reviews by other Defense Department agencies.
Navy officials also found shortcomings in the V-22 training regimen. The flight operations manual for the V-22 "lacked adequate content, accuracy and clarity," according to the report.
Specifically, although the flight manual warned pilots that "settling with power" -- another term for the turbulent phenomenon that caused the Arizona crash -- could occur if the V-22 descends at a rate greater than 800 feet per minute and less than 46 miles per hour, it didn't warn pilots that they might not be able to control the aircraft if they violated those parameters. The manual is called the NATOPS, short for Naval Air Training and Operating Procedures Standardization.
In addition to the lack of clear warnings in the flight manual, the conditions that could lead to a crash were not replicated in the V-22 flight simulator.
The GAO found that "the V- 22 appears to be less forgiving than conventional aircraft" when it enters vortex ring state. And it noted that many flight tests, including some that would have provided greater insight into the V-22's susceptibility to the turbulent air condition, were cut to save money and time.
The V-22 is built jointly by Fort Worth-based Bell Helicopter Textron and Boeing's helicopter unit in Ridley Park, Pa.
Jim Furman, an Austin lawyer representing the widow of the co-pilot in the Arizona crash and himself a former Army helicopter pilot, said the GAO comments are important.
"The NATOPS manual is the bible," Furman said. "It tells the pilot how the aircraft is going to fly and react to certain situations."
Furman said information gained by test pilots during flights is communicated to pilots undergoing training through the manual. Flying without the manual, or with an incomplete one, "is like trying to put together a kid's bike without the instructions," he said.
But a source close to the Marines said that the pilots of the doomed V-22 knew the dangers posed by too fast a descent.
"The nature of the warning is clear, that it is dangerous," said the source, who requested anonymity. "That point is unambiguous in the NATOPS."
The source also said that "the Marine Corps believes sufficient testing was done to establish a very conservative, safe flight envelope" for the V- 22 that, if it had been followed by the pilots in Arizona, would have prevented the fatal crash.
Bloomberg News reported Tuesday that the Defense Science Board, which advises the Pentagon on technical issues, singled out the V-22's testing as symptomatic of how the military evaluates major weapons programs before committing billions of dollars for production.
"The V-22 severely reduced early development testing in order to save money and recover schedule," the board said.
The two reports will fuel a growing debate in Congress over whether to scrap the V-22 program, analysts said. The Senate Armed Services Committee, which commissioned the science board report, plans hearings on the Osprey. Russell Feingold, D-Wis., has introduced a bill to freeze the program pending results of the ongoing investigations.
"It's really the Marine Corps vs. the rest of the world on the safety of the program's future," said Richard Aboulafia, a military aviation analyst with the Teal Group, a defense market analysis group based in Washington, D.C.
The Marine Corps, which wants the aircraft for both military and nonmilitary missions, has put all its political energy into pushing the program, both inside and outside the Pentagon, Aboulafia said.
Bob Cox, (817) 548-5534
Send comments to [email protected]
Jennifer Autrey (817) 390-7126
Send comments to [email protected]
linktoArticle
Report says V-22 pilots weren't well-prepared
The flight manual and training program failed in warning crews of the dangers they faced, the GAO report notes.
By Bob Cox and Jennifer Autrey
Star-Telegram staff writers
Pilots at the controls of a V-22 Osprey that crashed in Arizona last year had received little warning or preparation for the hazardous conditions that caused the accident, according to a government report.
The report released Tuesday by the General Accounting Office cited Navy and Marine officials who concluded that the V-22 flight manual and training program did little to warn pilots of the dangers they faced.
Separately, a Pentagon advisory board also criticized the Navy for cutting corners during testing of the Osprey to save money and make up for schedule delays, Bloomberg News reported Tuesday.
According to the GAO report, the Marines' accident investigator wrote that the "manual and V-22 ground school syllabus provides insufficient guidance/warning as to high rate of descent/slow airspeed conditions and the potential consequences."
The two reports are the latest in a series critical of the Marines for rushing to buy the V- 22 despite myriad problems with the revolutionary tilt-rotor aircraft.
Officially, the Marines have blamed the April 8 crash that killed 19 servicemen on errors by the aircraft's crew. The pilots, according to the accident report, descended too fast with too little airspeed and got caught in a turbulent condition, known as vortex ring state, that caused the V-22 to lose lift, roll over and crash.
The GAO report was prepared for Defense Secretary Donald Rumsfeld and a blue ribbon panel reviewing the V- 22 program. The report draws heavily on previously undisclosed portions of the Marines' crash report and the Navy report evaluating the V-22, and also cites reviews by other Defense Department agencies.
Navy officials also found shortcomings in the V-22 training regimen. The flight operations manual for the V-22 "lacked adequate content, accuracy and clarity," according to the report.
Specifically, although the flight manual warned pilots that "settling with power" -- another term for the turbulent phenomenon that caused the Arizona crash -- could occur if the V-22 descends at a rate greater than 800 feet per minute and less than 46 miles per hour, it didn't warn pilots that they might not be able to control the aircraft if they violated those parameters. The manual is called the NATOPS, short for Naval Air Training and Operating Procedures Standardization.
In addition to the lack of clear warnings in the flight manual, the conditions that could lead to a crash were not replicated in the V-22 flight simulator.
The GAO found that "the V- 22 appears to be less forgiving than conventional aircraft" when it enters vortex ring state. And it noted that many flight tests, including some that would have provided greater insight into the V-22's susceptibility to the turbulent air condition, were cut to save money and time.
The V-22 is built jointly by Fort Worth-based Bell Helicopter Textron and Boeing's helicopter unit in Ridley Park, Pa.
Jim Furman, an Austin lawyer representing the widow of the co-pilot in the Arizona crash and himself a former Army helicopter pilot, said the GAO comments are important.
"The NATOPS manual is the bible," Furman said. "It tells the pilot how the aircraft is going to fly and react to certain situations."
Furman said information gained by test pilots during flights is communicated to pilots undergoing training through the manual. Flying without the manual, or with an incomplete one, "is like trying to put together a kid's bike without the instructions," he said.
But a source close to the Marines said that the pilots of the doomed V-22 knew the dangers posed by too fast a descent.
"The nature of the warning is clear, that it is dangerous," said the source, who requested anonymity. "That point is unambiguous in the NATOPS."
The source also said that "the Marine Corps believes sufficient testing was done to establish a very conservative, safe flight envelope" for the V- 22 that, if it had been followed by the pilots in Arizona, would have prevented the fatal crash.
Bloomberg News reported Tuesday that the Defense Science Board, which advises the Pentagon on technical issues, singled out the V-22's testing as symptomatic of how the military evaluates major weapons programs before committing billions of dollars for production.
"The V-22 severely reduced early development testing in order to save money and recover schedule," the board said.
The two reports will fuel a growing debate in Congress over whether to scrap the V-22 program, analysts said. The Senate Armed Services Committee, which commissioned the science board report, plans hearings on the Osprey. Russell Feingold, D-Wis., has introduced a bill to freeze the program pending results of the ongoing investigations.
"It's really the Marine Corps vs. the rest of the world on the safety of the program's future," said Richard Aboulafia, a military aviation analyst with the Teal Group, a defense market analysis group based in Washington, D.C.
The Marine Corps, which wants the aircraft for both military and nonmilitary missions, has put all its political energy into pushing the program, both inside and outside the Pentagon, Aboulafia said.
Bob Cox, (817) 548-5534
Send comments to [email protected]
Jennifer Autrey (817) 390-7126
Send comments to [email protected]
linktoArticle
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Pinochy-Unc
Looks like PTIUAE is in with some good company...
Dr. John Zuk is the head of Advanced Vertical Flight Research at NASA where he has worked as a research scientist on vertical flight SAFETY an Development for over 25 years!!!
I guess that Orville and Wilbur would have been the undeniable winners of the Award a few years back for their silly Wright Flyer!!!
Where can we sign up!!?? Seems like winning makes you part of "who is who" in Aviation!!!
And by the way... Congrats to YOU!!!
In case you didn't hear>>>
PPRune forum readers have voted you the new "H.U.B." Award recipient!!!
This is the first Annual "Head Up the Backside" Award for the incredibly Astute"QUINCKE valve" discovery!!!
You continue to make us PROUD P-U!!!
Only you could have done it...
**************************************************
UPDATE!!!:
Sorry Pinochy-Unc... Another one of your inept attempts to change the FACTS has been Debunked!!!
Your attempt to ADD Dr. John Zuk (NASA Scientist) and PTIUAE to the "Award List" has been exposed!!!
Of the seven on YOUR list,, Five recieved Awards- the ONLY two that are NOT ON THE LIST are the two YOU ADDED!!! (both pro-tilt rotor comments)
You have once again publicly humiliated yourself (What else is new)
OSTRICHES ANONYMOUS ASSOCIATION
Results For Year 2000 "HEAD-IN-THE-SAND-AWARD"
The purpose of the Ostriches Anonymous Association is to promote aviation safety and risk awareness through the use of humor by sponsoring Oliver Ostrich "Head-In-The-Sand Award."
The "OLIVER" is presented annually to: the anonymous individual or organization who contributes most by conscious action, decision, or purposeful neglect to either the denial, the discounting or the ignoring of significant aviation risks or opportunities.
PRESS RELEASE
Grand Prize
FAA Airspace & Rules Division: which determined that a 497-foot-MSL-tall tower did NOT meet the criteria to be a hazard despite being sited along the path of a Special VFR Corridor in Anchorage, Alaska, which requires pilots to fly below 600 feet MSL. Oliver's Astute Analysis: Of course the bureaucrats in the FAA's Airspace and Rules Division (ATA-400) don't actually FLY airplanes, so let's have them ride along as passengers on a couple of one-mile-visibility days and see if they can spot the tower, or its guy-wires.
Sighting made by Ira Rimson, Albuquerque, NM
who is awarded the 2000 ARTF (Award of the Ruffled Tail Feathers)
The ARTF includes a Life Membership in OAA sponsored this year by Southwest Airlines, a prestigious wall plaque, and a $300 cash prize from Vedax Sciences
1st Runner Up
FAA Engineers: "The pilots could continue flying the plane if a cable broke, so it was not considered a crucial part. We did not think the situation was urgent." (In response to charges that the FAA waited 17 months before advising carriers about a control cable manufacturer which was not testing cables that military tests had found to fail at 50% of rated load.) Oliver's Astute Analysis: Obviously we needn't worry about other "non-crucial" parts, like wheels, tires, avionics, and an occasional B-747 outboard engine, all of which have occasionally been lost and the airplane continued to fly.
Sighting was made independently and simultaneously by Captain Tom Brown, Danbury, CT;
Danna Henderson, Albuquerque, NM; Annette Ruddy, Amarillo, TX; and Dr. Gerry Snyder, Tucson, AZ.
2nd Runner Up
Aircraft Manufacturer: "Failure of one nut in no way affected the engine's safe attachment to the pylon. The mounting had four bolts. Consequently safety was in no way and at no time compromised. Spares were readily available worldwide." During a planned engine replacement cracks were discovered in some nuts holding bolts to the aft mount of the engine. Oliver's Astute Analysis: If the missing nut "in no way affects the engine's safe attachment to the pylon", why is it there at all?
Sighting made by "Botswana Bill" Scott, Gaborone, Botswana
3rd Runner Up
Government Auditors: "The manufacturer performed slipshod work, used out-of-date blueprints and improperly inspected parts - but flight safety was not threatened." Oliver's Astute Analysis: Obviously true so long as the airplanes remain on the assembly line. Too bad they let them out of the door. Since the FAA believes that quality standards are only for paper work, the subsequent fatal accident must have been caused by bad luck. Sighting made independently and simultaneously by
Dr. Rudi Mortimer, Champaign, IL and Ira Rimson, Albuquerque, NM
4th Runner Up
Manufacturer's President: "There is absolutely no connection between our efforts to reduce manufacturing inspections and the 8-inch hairline cracks found in at least 40 of our airplanes. Oliver's Astute Analysis: If they add the fuel tank stringers to the pilots' walk-around inspections. The pilots' cursory preflight can be blamed for any fuel leaks that develop.
Sighting made by Ira Rimson, Albuquerque, NM
[This message has been edited by HeliFlight (edited 09 March 2001).]
Looks like PTIUAE is in with some good company...
Dr. John Zuk is the head of Advanced Vertical Flight Research at NASA where he has worked as a research scientist on vertical flight SAFETY an Development for over 25 years!!!
I guess that Orville and Wilbur would have been the undeniable winners of the Award a few years back for their silly Wright Flyer!!!
Where can we sign up!!?? Seems like winning makes you part of "who is who" in Aviation!!!
And by the way... Congrats to YOU!!!
In case you didn't hear>>>
PPRune forum readers have voted you the new "H.U.B." Award recipient!!!
This is the first Annual "Head Up the Backside" Award for the incredibly Astute
"QUINCKE valve" discovery!!! You continue to make us PROUD P-U!!!
Only you could have done it...
**************************************************
UPDATE!!!:
Sorry Pinochy-Unc... Another one of your inept attempts to change the FACTS has been Debunked!!!
Your attempt to ADD Dr. John Zuk (NASA Scientist) and PTIUAE to the "Award List" has been exposed!!!
Of the seven on YOUR list,, Five recieved Awards- the ONLY two that are NOT ON THE LIST are the two YOU ADDED!!! (both pro-tilt rotor comments)You have once again publicly humiliated yourself (What else is new)
OSTRICHES ANONYMOUS ASSOCIATION
Results For Year 2000 "HEAD-IN-THE-SAND-AWARD"
The purpose of the Ostriches Anonymous Association is to promote aviation safety and risk awareness through the use of humor by sponsoring Oliver Ostrich "Head-In-The-Sand Award."
The "OLIVER" is presented annually to: the anonymous individual or organization who contributes most by conscious action, decision, or purposeful neglect to either the denial, the discounting or the ignoring of significant aviation risks or opportunities.
PRESS RELEASE
Grand Prize
FAA Airspace & Rules Division: which determined that a 497-foot-MSL-tall tower did NOT meet the criteria to be a hazard despite being sited along the path of a Special VFR Corridor in Anchorage, Alaska, which requires pilots to fly below 600 feet MSL. Oliver's Astute Analysis: Of course the bureaucrats in the FAA's Airspace and Rules Division (ATA-400) don't actually FLY airplanes, so let's have them ride along as passengers on a couple of one-mile-visibility days and see if they can spot the tower, or its guy-wires.
Sighting made by Ira Rimson, Albuquerque, NM
who is awarded the 2000 ARTF (Award of the Ruffled Tail Feathers)
The ARTF includes a Life Membership in OAA sponsored this year by Southwest Airlines, a prestigious wall plaque, and a $300 cash prize from Vedax Sciences
1st Runner Up
FAA Engineers: "The pilots could continue flying the plane if a cable broke, so it was not considered a crucial part. We did not think the situation was urgent." (In response to charges that the FAA waited 17 months before advising carriers about a control cable manufacturer which was not testing cables that military tests had found to fail at 50% of rated load.) Oliver's Astute Analysis: Obviously we needn't worry about other "non-crucial" parts, like wheels, tires, avionics, and an occasional B-747 outboard engine, all of which have occasionally been lost and the airplane continued to fly.
Sighting was made independently and simultaneously by Captain Tom Brown, Danbury, CT;
Danna Henderson, Albuquerque, NM; Annette Ruddy, Amarillo, TX; and Dr. Gerry Snyder, Tucson, AZ.
2nd Runner Up
Aircraft Manufacturer: "Failure of one nut in no way affected the engine's safe attachment to the pylon. The mounting had four bolts. Consequently safety was in no way and at no time compromised. Spares were readily available worldwide." During a planned engine replacement cracks were discovered in some nuts holding bolts to the aft mount of the engine. Oliver's Astute Analysis: If the missing nut "in no way affects the engine's safe attachment to the pylon", why is it there at all?
Sighting made by "Botswana Bill" Scott, Gaborone, Botswana
3rd Runner Up
Government Auditors: "The manufacturer performed slipshod work, used out-of-date blueprints and improperly inspected parts - but flight safety was not threatened." Oliver's Astute Analysis: Obviously true so long as the airplanes remain on the assembly line. Too bad they let them out of the door. Since the FAA believes that quality standards are only for paper work, the subsequent fatal accident must have been caused by bad luck. Sighting made independently and simultaneously by
Dr. Rudi Mortimer, Champaign, IL and Ira Rimson, Albuquerque, NM
4th Runner Up
Manufacturer's President: "There is absolutely no connection between our efforts to reduce manufacturing inspections and the 8-inch hairline cracks found in at least 40 of our airplanes. Oliver's Astute Analysis: If they add the fuel tank stringers to the pilots' walk-around inspections. The pilots' cursory preflight can be blamed for any fuel leaks that develop.
Sighting made by Ira Rimson, Albuquerque, NM
[This message has been edited by HeliFlight (edited 09 March 2001).]
Guest
Posts: n/a
Inside the Pentagon:
February 22, 2001
DOD TEST DIRECTOR CITED 'FUNDAMENTAL' DESIGN ISSUE IN V-22 CRASH RISK
More restrictions may be needed to avoid 'vortex ring state
Before leaving the Pentagon late last month, the top defense equipment tester, Philip Coyle, told a panel reviewing the Marine Corps' troubled V-22 tiltrotor aircraft program that a dangerous flight condition -- one that can lead to a crash -- stems from a "fundamental" characteristic of the Osprey that "cannot be remedied by minor design changes," according to a briefing obtained by Inside the Pentagon.
The flight condition, called "vortex ring state" or VRS, is believed responsible for a V-22 crash last April in Arizona that killed 19 Marines. The phenomenon is triggered by the combination of a rapid descent with a slow airspeed. But Coyle and others worry that the conditions under which an Osprey can enter a VRS are not well understood, and that a pilot can very rapidly find himself in a state of what is sometimes termed "power settling," which is hard to reverse.
In a Jan. 12 briefing to the Pentagon's "Blue Ribbon Commission," Coyle quoted the joint Navy-Air Force test team commander as reporting last October that the VRS phenomenon "occurs very rapidly with little or no warning to the pilots." Then-Defense Secretary William Cohen created the blue ribbon panel in December to review the Osprey program and recommend how to proceed following the second of two fatal crashes last year alone. The commission is expected to report its findings after several months of inquiry.
In a briefing to the panel on the same day that Coyle appeared, the General Accounting Office said the Pentagon's chief tester had found that the onset of vortex ring state in the V-22 "can occur in the proprotor on one side without the other side losing lift. In such a case, the aircraft tends to roll sharply into the side that first loses lift, resulting in large, unexpected bank angles, followed immediately by rapid dropping of the nose of the aircraft and a steep dive. At low altitudes, there may be no opportunity for recovery" (ITP, Feb. 1, p1). In his own presentation to the Blue Ribbon Commission, Coyle said the V-22's unique tiltrotor design, which allows the aircraft to take off and land like a helicopter but fly like a turboprop plane, appears to increase the risk of the Osprey experiencing a dangerous form of VRS. The chief tester based his findings on an eight-month operational evaluation period that ended last July for the hybrid rotorcraft, which the Corps views as critical for ferrying large numbers of Marines quickly in and out of a battle area. "The side-by-side rotor configuration of V-22 is susceptible to asymmetric onset of VRS with one-rotor-in/one-rotor-out conditions resulting in large rolling moments and departure from controlled flight," Coyle told the panel, according to the briefing. "Such a characteristic is fundamental and cannot be remedied by minor design changes. [The] only near-term solution is to restrict operations to avoid proximity to [the] VRS region." In fact, the Marine Corps has been exploring the parameters under which VRS can occur in the Osprey. In follow-on developmental test flights begun last summer, service pilots attempted to duplicate the conditions of the April crash -- but only at a high enough altitude to allow sufficient time and space for the aircraft to recover (ITP, Aug. 24, 2000, p1).
Although the Marine Corps acknowledged at the time that it needed to better understand the conditions in which VRS might occur in the Osprey, service officials said pilots in the April crash violated flight restrictions that, if followed, would have prevented the phenomenon from affecting the plane and bringing it down.
The V-22 program manager, Marine Corps Col. Nolan Schmidt, told ITP last August that the Naval Air Training and Operating Procedures Standardization manual, known as NATOPS, issued clear parameters that pilots in the April crash had ignored.
But the Marine Corps' own Judge Advocate General found that NATOPS -- as well as the V-22 ground school syllabus -- provide "insufficient guidance/warning as to high rate of descent/slow airspeed conditions and the potential consequences," according to the GAO briefing.
In his January presentation to the blue ribbon panel, Coyle warned that "restriction on [rate of descent] alone may not suffice" to prevent VRS. It "may be necessary to impose quick-stop and related restrictions, restrictions on yaw rates under some conditions and restrictions on proximity" to other aircraft, according to the briefing. Coyle said a proximity warning could be installed in the V-22 cockpit as "a significant operational aid, but will be of little value in situations where VRS is entered by rapid control inputs." Restrictions may also be necessary for "approach and departure operations in rugged terrain or at-sea with strong winds," the briefing states.
The tester advised that "more basic research, supplemented by flight testing, is required to map the VRS envelope of V-22 and understand the consequences of operations near the boundary of this phenomenon." The ability of a pilot to determine if the aircraft is at or near the boundary of VRS while in flight may be further degraded by a cockpit gauge that poorly displays small differences in ascent or descent, according to the briefing and other defense sources. Coyle told the commission that the Osprey's "vertical velocity indicator" is "difficult to read." Questions yet to be answered, Coyle said, include:
* "If operational restrictions on the flight envelope turn out to be sufficient to resolve the issue, can the USMC do its primary mission with such restrictions?"
* "If the mission can be done without the imposed restrictions, how common will be the situation where a crew exceeds the limitations?" Coyle raises the possibility that a crew will lose situational awareness under stress, face unusual wind conditions, or experience an emergency that requires a descent through "autorotation," a capability helicopters commonly have -- but the Osprey lacks -- for a semi-controlled landing with the engines cut off.
Although the April accident is widely attributed to VRS, the Marine Corps JAG report appeared to be unwilling to close the book on that, allowing for the possibility that other factors beyond vortex ring state played a role.
Referring to two recorded incidents of uncontrolled formation flight incidents during operational evaluation, the JAG said the lack of understanding as to the causes, "coupled with limited development formation testing . . . make it difficult to completely exclude turbulence [in the wake of a nearby aircraft] or downwash [dirt or sand kicked up by the rotors] as potential contributors to the [April] mishap." In Coyle's view as well, the Osprey faces a variety of safety risks. Last year he identified 177 failures of "flight-critical subsystems" in the Marine Corps V-22 Osprey tiltrotor aircraft that potentially endangered safety, InsideDefense.com reported Feb. 8. -- Elaine M. Grossman
Osprey Accident link
February 22, 2001
DOD TEST DIRECTOR CITED 'FUNDAMENTAL' DESIGN ISSUE IN V-22 CRASH RISK
More restrictions may be needed to avoid 'vortex ring state
Before leaving the Pentagon late last month, the top defense equipment tester, Philip Coyle, told a panel reviewing the Marine Corps' troubled V-22 tiltrotor aircraft program that a dangerous flight condition -- one that can lead to a crash -- stems from a "fundamental" characteristic of the Osprey that "cannot be remedied by minor design changes," according to a briefing obtained by Inside the Pentagon.
The flight condition, called "vortex ring state" or VRS, is believed responsible for a V-22 crash last April in Arizona that killed 19 Marines. The phenomenon is triggered by the combination of a rapid descent with a slow airspeed. But Coyle and others worry that the conditions under which an Osprey can enter a VRS are not well understood, and that a pilot can very rapidly find himself in a state of what is sometimes termed "power settling," which is hard to reverse.
In a Jan. 12 briefing to the Pentagon's "Blue Ribbon Commission," Coyle quoted the joint Navy-Air Force test team commander as reporting last October that the VRS phenomenon "occurs very rapidly with little or no warning to the pilots." Then-Defense Secretary William Cohen created the blue ribbon panel in December to review the Osprey program and recommend how to proceed following the second of two fatal crashes last year alone. The commission is expected to report its findings after several months of inquiry.
In a briefing to the panel on the same day that Coyle appeared, the General Accounting Office said the Pentagon's chief tester had found that the onset of vortex ring state in the V-22 "can occur in the proprotor on one side without the other side losing lift. In such a case, the aircraft tends to roll sharply into the side that first loses lift, resulting in large, unexpected bank angles, followed immediately by rapid dropping of the nose of the aircraft and a steep dive. At low altitudes, there may be no opportunity for recovery" (ITP, Feb. 1, p1). In his own presentation to the Blue Ribbon Commission, Coyle said the V-22's unique tiltrotor design, which allows the aircraft to take off and land like a helicopter but fly like a turboprop plane, appears to increase the risk of the Osprey experiencing a dangerous form of VRS. The chief tester based his findings on an eight-month operational evaluation period that ended last July for the hybrid rotorcraft, which the Corps views as critical for ferrying large numbers of Marines quickly in and out of a battle area. "The side-by-side rotor configuration of V-22 is susceptible to asymmetric onset of VRS with one-rotor-in/one-rotor-out conditions resulting in large rolling moments and departure from controlled flight," Coyle told the panel, according to the briefing. "Such a characteristic is fundamental and cannot be remedied by minor design changes. [The] only near-term solution is to restrict operations to avoid proximity to [the] VRS region." In fact, the Marine Corps has been exploring the parameters under which VRS can occur in the Osprey. In follow-on developmental test flights begun last summer, service pilots attempted to duplicate the conditions of the April crash -- but only at a high enough altitude to allow sufficient time and space for the aircraft to recover (ITP, Aug. 24, 2000, p1).
Although the Marine Corps acknowledged at the time that it needed to better understand the conditions in which VRS might occur in the Osprey, service officials said pilots in the April crash violated flight restrictions that, if followed, would have prevented the phenomenon from affecting the plane and bringing it down.
The V-22 program manager, Marine Corps Col. Nolan Schmidt, told ITP last August that the Naval Air Training and Operating Procedures Standardization manual, known as NATOPS, issued clear parameters that pilots in the April crash had ignored.
But the Marine Corps' own Judge Advocate General found that NATOPS -- as well as the V-22 ground school syllabus -- provide "insufficient guidance/warning as to high rate of descent/slow airspeed conditions and the potential consequences," according to the GAO briefing.
In his January presentation to the blue ribbon panel, Coyle warned that "restriction on [rate of descent] alone may not suffice" to prevent VRS. It "may be necessary to impose quick-stop and related restrictions, restrictions on yaw rates under some conditions and restrictions on proximity" to other aircraft, according to the briefing. Coyle said a proximity warning could be installed in the V-22 cockpit as "a significant operational aid, but will be of little value in situations where VRS is entered by rapid control inputs." Restrictions may also be necessary for "approach and departure operations in rugged terrain or at-sea with strong winds," the briefing states.
The tester advised that "more basic research, supplemented by flight testing, is required to map the VRS envelope of V-22 and understand the consequences of operations near the boundary of this phenomenon." The ability of a pilot to determine if the aircraft is at or near the boundary of VRS while in flight may be further degraded by a cockpit gauge that poorly displays small differences in ascent or descent, according to the briefing and other defense sources. Coyle told the commission that the Osprey's "vertical velocity indicator" is "difficult to read." Questions yet to be answered, Coyle said, include:
* "If operational restrictions on the flight envelope turn out to be sufficient to resolve the issue, can the USMC do its primary mission with such restrictions?"
* "If the mission can be done without the imposed restrictions, how common will be the situation where a crew exceeds the limitations?" Coyle raises the possibility that a crew will lose situational awareness under stress, face unusual wind conditions, or experience an emergency that requires a descent through "autorotation," a capability helicopters commonly have -- but the Osprey lacks -- for a semi-controlled landing with the engines cut off.
Although the April accident is widely attributed to VRS, the Marine Corps JAG report appeared to be unwilling to close the book on that, allowing for the possibility that other factors beyond vortex ring state played a role.
Referring to two recorded incidents of uncontrolled formation flight incidents during operational evaluation, the JAG said the lack of understanding as to the causes, "coupled with limited development formation testing . . . make it difficult to completely exclude turbulence [in the wake of a nearby aircraft] or downwash [dirt or sand kicked up by the rotors] as potential contributors to the [April] mishap." In Coyle's view as well, the Osprey faces a variety of safety risks. Last year he identified 177 failures of "flight-critical subsystems" in the Marine Corps V-22 Osprey tiltrotor aircraft that potentially endangered safety, InsideDefense.com reported Feb. 8. -- Elaine M. Grossman
Osprey Accident link
Guest
Posts: n/a
Pinochy-Unc:
That was very interesting. We were hoping you would show us exactly the same thing you have been posting over and over (using different writers saying the same thing- all from the same original report)
Show us one thing that was said here that has not been said over and over in your other posts. Notice the date of the briefing is January 12, so for a month and a half you have been repeating the words of one person- Philip Coyle. The pilots that fly the V-22 completely disagree with him.
You can keep stating the same words of one man over and over- but saying it a thousand times does not make it true. My bet is that the technology will be proven good and the V-22 will be an outstanding success.
You will be proven wrong in the same way that every "theory" you tried to come up with on this forum has been proven to be full of BALONEY (you must work for Oscar Meyer to have such an endless source )
When the technology is completely developed and tiltorotors are flying all over the world- you and Philip can move to a place where you won't be humiliated everytime you see one fly over (antartica maybe???)
So keep on giving us repeats of the same comment by one report and one person- the rest of us know what the majority of the EXPERTS say. (notice John Farley and PTIUAE don't bother talking to you any more- seems like you are all alone in your Baloney Shooting contest)
Don't worry though P-U- I am here to keep you company
That was very interesting. We were hoping you would show us exactly the same thing you have been posting over and over (using different writers saying the same thing- all from the same original report)
Show us one thing that was said here that has not been said over and over in your other posts. Notice the date of the briefing is January 12, so for a month and a half you have been repeating the words of one person- Philip Coyle. The pilots that fly the V-22 completely disagree with him.
You can keep stating the same words of one man over and over- but saying it a thousand times does not make it true. My bet is that the technology will be proven good and the V-22 will be an outstanding success.
You will be proven wrong in the same way that every "theory" you tried to come up with on this forum has been proven to be full of BALONEY
(you must work for Oscar Meyer to have such an endless source )When the technology is completely developed and tiltorotors are flying all over the world- you and Philip can move to a place where you won't be humiliated everytime you see one fly over (antartica maybe???)
So keep on giving us repeats of the same comment by one report and one person- the rest of us know what the majority of the EXPERTS say. (notice John Farley and PTIUAE don't bother talking to you any more- seems like you are all alone in your Baloney Shooting contest)
Don't worry though P-U- I am here to keep you company
Guest
Posts: n/a
Pinochy-Unc:
Hey... now that was a tricky one! It's the same old GAO report- But it was released in its entirety on Tuesday (of course the only quotes in the article are all the same we have heard over and over since BEFORE the official release) But thanks for that P-U, we really appreciate seeing it again.
And by the way... just heard the GOOD news...CONGRATULATIONS to you... you were interviewed by the Star-Telegram about the discussions on PPRune!! That's great...
Uh oh... wait a minute... they only included quotes in the series of articles from PTIUAE and not a SINGLE ONE from YOU!!!
WHY do you suppose that is P-U??? Tell you what:
1. Look in the mirror
2. Turn sideways so you can see your profile
3. See that big, long Pinochio Nose...
Ah Ha!!
Didn't PaPa Jeppeto warn you what would happen...????
I'm afraid it is your old Nemesis again...
C-R-E-D-I-B-I-L-I-T-Y
THink about it...
Hey... now that was a tricky one! It's the same old GAO report- But it was released in its entirety on Tuesday (of course the only quotes in the article are all the same we have heard over and over since BEFORE the official release) But thanks for that P-U, we really appreciate seeing it again.
And by the way... just heard the GOOD news...CONGRATULATIONS to you... you were interviewed by the Star-Telegram about the discussions on PPRune!! That's great...
Uh oh... wait a minute... they only included quotes in the series of articles from PTIUAE and not a SINGLE ONE from YOU!!!
WHY do you suppose that is P-U??? Tell you what:
1. Look in the mirror
2. Turn sideways so you can see your profile
3. See that big, long Pinochio Nose...
Ah Ha!!
Didn't PaPa Jeppeto warn you what would happen...????
I'm afraid it is your old Nemesis again...
C-R-E-D-I-B-I-L-I-T-Y THink about it...
Guest
Posts: n/a
Here's a safety issue with the V-22 that some may not have thought about.
The rotor blades, being made of composite material, are designed to "broom straw" if the engine nacelles get stuck in the forward flight position and the aircraft has to make a run on landing.
I have one problem with this, the V-22 is a combat rotorcraft.
As you know the rotor blades on helicopters such as the AH-64s and the UH-60s are designed to withstand a direct 23mm anti-aircraft hit and still remain intact so the aircraft can continue flying. We all know what happens when a conventional helicopter loses a rotor blade.
In hover mode the loss of a rotor blade from ground fire would have disasterous consequences for the V-22, just as it would for any helicopter. In forward flight mode, the loss of a rotor blade would still be bad, as I can't imagine the asymmetric flight characteristics of the V-22 are anything short of terrible. With the two rotors being linked by a cross shaft, the loss of a rotor blade even in forward flight would still be bad, as shutting one rotor down to prevent the aircraft from shaking itself apart, would mean loss of both rotors.
Come to think of it, there's no way a V-22 could fly in forward flight with a failed rotor blade. If it survived the shaking, it'd be a glider.
I personally think that rotor blades designed to "broom straw" on impact are a bad choice for a combat rotorcraft. I'd be hard pressed to fly a rotorcraft into combat with rotor blades that could turn into horse tails on impact from ground fire. Does anyone else see a problem with this?
------------------
Safe flying to you...
[This message has been edited by Flight Safety (edited 23 February 2001).]
The rotor blades, being made of composite material, are designed to "broom straw" if the engine nacelles get stuck in the forward flight position and the aircraft has to make a run on landing.
I have one problem with this, the V-22 is a combat rotorcraft.
As you know the rotor blades on helicopters such as the AH-64s and the UH-60s are designed to withstand a direct 23mm anti-aircraft hit and still remain intact so the aircraft can continue flying. We all know what happens when a conventional helicopter loses a rotor blade.
In hover mode the loss of a rotor blade from ground fire would have disasterous consequences for the V-22, just as it would for any helicopter. In forward flight mode, the loss of a rotor blade would still be bad, as I can't imagine the asymmetric flight characteristics of the V-22 are anything short of terrible. With the two rotors being linked by a cross shaft, the loss of a rotor blade even in forward flight would still be bad, as shutting one rotor down to prevent the aircraft from shaking itself apart, would mean loss of both rotors.
Come to think of it, there's no way a V-22 could fly in forward flight with a failed rotor blade. If it survived the shaking, it'd be a glider.
I personally think that rotor blades designed to "broom straw" on impact are a bad choice for a combat rotorcraft. I'd be hard pressed to fly a rotorcraft into combat with rotor blades that could turn into horse tails on impact from ground fire. Does anyone else see a problem with this?
------------------
Safe flying to you...
[This message has been edited by Flight Safety (edited 23 February 2001).]
Guest
Posts: n/a
Flight Safety:
I'm afraid I haven't heard anything on the ballistics tests that were done (but I'm sure Pinochy-Unc would be tickled to make something up for you- perhaps a couple of"QUINCKE valves" will make the blades "bullet proof") . I am sure though that that type of testing would be a high priority as it is for any rotorcraft going into a combat situation.
Is that really true about 60s and 64s being able to take a 23mm through the blade? I could just imagine what a 20mm direct hit would do and I know I wouldn't like to be flying that bird.
This sounds like another good one for the Chief engineer friend of yours (two dinners now?!)
Let us know. Thanks.
[This message has been edited by HeliFlight (edited 24 February 2001).]
I'm afraid I haven't heard anything on the ballistics tests that were done (but I'm sure Pinochy-Unc would be tickled to make something up for you- perhaps a couple of
"QUINCKE valves" will make the blades "bullet proof") . I am sure though that that type of testing would be a high priority as it is for any rotorcraft going into a combat situation.Is that really true about 60s and 64s being able to take a 23mm through the blade? I could just imagine what a 20mm direct hit would do and I know I wouldn't like to be flying that bird.
This sounds like another good one for the Chief engineer friend of yours (two dinners now?!)
Let us know. Thanks.
[This message has been edited by HeliFlight (edited 24 February 2001).]