What's the latest on tilt rotors?
Guest
Posts: n/a
Hello Unctuous,
It’s so nice to see you are back. You got the biggest public spanking since Saddam Hussein in the Gulf war, one that will go down in history. Your cheeks are still obviously glowing RED!! Please tell us why you hid yourself for six months in shame and took six months to return (your last post was 29 May). A little bit morbid of you to return when you see an opportunity to try and twist the facts again. PTIUAE may have been trite to you, if that’s how you describe the guy holding the paddle (along with John Farley, the development test pilot for the Harrier). All of us on PPRune have been waiting for you to reappear. It’s great to have you back. Please tell us what other user names you have been using in the mean time (over the last six months) to hide your identify (those glowing cheeks will always give you away though!) From the length of your posts, you obviously haven’t lost your long windedness. The facts though, still seem to be overridden by your “theories.” Distortion sometimes takes a little extra effort.
Regarding recent accidents, here is some FACTUAL input that has been recently posted:
There is no mystery about the Arizona crash that occurred in April of this year. That accident was investigated and closed by the Marines, the manufacturers, and an independent investigation by NASA. They all came up with the same conclusion: pilot error. The pilot in the lead a/c lost his wings after the investigation. The V-22 developed settling with power due to a rate of descent in excess of 2000 fpm at 285 ft AGL (this is a 57,000lb gross wgt a/c!! – a lot of momentum to stop)! There was a quartering tailwind, 2100ft elevation, and 28 deg C. The pilot violently pulled in MAX power, and pulled FULL aft on the stick, rapidly decreasing a/s and developed the inevitable vortex ring state. Because of the unique side by side rotor configuration, it developed 'asymmetrical’ settling with power. If the wind was directly on the nose or tail, it would have been 'normal' settling with power, but it doesn't matter, they would have all been killed regardless. If you put a CH-46 in the identical scenario, the result would have been the same.
In the 11 ½ years that the V-22 has been flying, there have been four accidents, three of them fatal. The most important fact is that none of them showed tiltrotor technology to be flawed. However, it appears that all of them could have been anticipated and prevented.
Accident 1 (Jun 91): Miswiring of two of the three lateral cyclic inputs, crashed on first flight in a hover (no fatalities). Should have been caught by quality control at many levels.
Accident 2 (July 92): Ingestion of transmission fluid during transition to H-C mode. A simple drain hole could have prevented it.
Accident 3 (Apr 00): Pilot Error (see above).
Accident 4 (Dec 00): – the black boxes will tell. In the mean time, the press will have a field day slinging mud at the military as they all too often do (and Unctuous will join right in).
The bottom line is that the technology is sound and proven -- 4 accidents of a military a/c over 11 ½ years is not out of line with what has been experienced with other a/c, and in fact, it is much better than most. As other professionals in the aviation community keep emphasizing, “we need to keep it all in perspective…”(the Wright Brothers had it much worse than this, but thankfully they didn’t give up!!)
By the way Jim, I am sure you will be posting heavily in an attempt to exonerate yourself, and I must warn you in advance – there will be testimony from your own worst enemy against you – YOURSELF (your earlier posts in this thread, so please try to keep it consistent - thanks)
[This message has been edited by HeliFlight (edited 16 December 2000).]
It’s so nice to see you are back. You got the biggest public spanking since Saddam Hussein in the Gulf war, one that will go down in history. Your cheeks are still obviously glowing RED!! Please tell us why you hid yourself for six months in shame and took six months to return (your last post was 29 May). A little bit morbid of you to return when you see an opportunity to try and twist the facts again. PTIUAE may have been trite to you, if that’s how you describe the guy holding the paddle (along with John Farley, the development test pilot for the Harrier). All of us on PPRune have been waiting for you to reappear. It’s great to have you back. Please tell us what other user names you have been using in the mean time (over the last six months) to hide your identify (those glowing cheeks will always give you away though!) From the length of your posts, you obviously haven’t lost your long windedness. The facts though, still seem to be overridden by your “theories.” Distortion sometimes takes a little extra effort.
Regarding recent accidents, here is some FACTUAL input that has been recently posted:
There is no mystery about the Arizona crash that occurred in April of this year. That accident was investigated and closed by the Marines, the manufacturers, and an independent investigation by NASA. They all came up with the same conclusion: pilot error. The pilot in the lead a/c lost his wings after the investigation. The V-22 developed settling with power due to a rate of descent in excess of 2000 fpm at 285 ft AGL (this is a 57,000lb gross wgt a/c!! – a lot of momentum to stop)! There was a quartering tailwind, 2100ft elevation, and 28 deg C. The pilot violently pulled in MAX power, and pulled FULL aft on the stick, rapidly decreasing a/s and developed the inevitable vortex ring state. Because of the unique side by side rotor configuration, it developed 'asymmetrical’ settling with power. If the wind was directly on the nose or tail, it would have been 'normal' settling with power, but it doesn't matter, they would have all been killed regardless. If you put a CH-46 in the identical scenario, the result would have been the same.
In the 11 ½ years that the V-22 has been flying, there have been four accidents, three of them fatal. The most important fact is that none of them showed tiltrotor technology to be flawed. However, it appears that all of them could have been anticipated and prevented.
Accident 1 (Jun 91): Miswiring of two of the three lateral cyclic inputs, crashed on first flight in a hover (no fatalities). Should have been caught by quality control at many levels.
Accident 2 (July 92): Ingestion of transmission fluid during transition to H-C mode. A simple drain hole could have prevented it.
Accident 3 (Apr 00): Pilot Error (see above).
Accident 4 (Dec 00): – the black boxes will tell. In the mean time, the press will have a field day slinging mud at the military as they all too often do (and Unctuous will join right in).
The bottom line is that the technology is sound and proven -- 4 accidents of a military a/c over 11 ½ years is not out of line with what has been experienced with other a/c, and in fact, it is much better than most. As other professionals in the aviation community keep emphasizing, “we need to keep it all in perspective…”(the Wright Brothers had it much worse than this, but thankfully they didn’t give up!!)
By the way Jim, I am sure you will be posting heavily in an attempt to exonerate yourself, and I must warn you in advance – there will be testimony from your own worst enemy against you – YOURSELF (your earlier posts in this thread, so please try to keep it consistent - thanks)
[This message has been edited by HeliFlight (edited 16 December 2000).]
Guest
Posts: n/a
Also Jim,
I noticed that the e-mail you "acted" like you were responding to above was sent to you in mid-July. Can you explain why you waited 5 months to respond, and "acted" as though you were responding directly to his inquiry!?
I'm sure this will be a good one if you do decide to answer it!
Happy Holidays, Jim
>From: [email protected]
>To: [email protected]
>Subject: Vortex Ring
>Date: Mon, 10 Jul 2000 14:10:04 EDT
>
>Jim -
>
>Back on May 16, you provided us with an interesting perspective on "That
>Vexing Vortex Ring." Is there any more recent information that would cause
>you to expand upon or change the theories expressed in that communication?
>
>Many thanks.
>
>Rhett Flater
>AHS Executive Director
[This message has been edited by HeliFlight (edited 15 December 2000).]
I noticed that the e-mail you "acted" like you were responding to above was sent to you in mid-July. Can you explain why you waited 5 months to respond, and "acted" as though you were responding directly to his inquiry!?
I'm sure this will be a good one if you do decide to answer it!
Happy Holidays, Jim
>From: [email protected]
>To: [email protected]
>Subject: Vortex Ring
>Date: Mon, 10 Jul 2000 14:10:04 EDT
>
>Jim -
>
>Back on May 16, you provided us with an interesting perspective on "That
>Vexing Vortex Ring." Is there any more recent information that would cause
>you to expand upon or change the theories expressed in that communication?
>
>Many thanks.
>
>Rhett Flater
>AHS Executive Director
[This message has been edited by HeliFlight (edited 15 December 2000).]
Guest
Posts: n/a
Marines' Osprey is just an albatross
J. Stryker Meyer
Commentary
The Marine Corps calls its controversial MV-22 tilt-rotor hybrid aircraft the Osprey. A better name would be the albatross. Or perhaps, the killer albatross. If Dwight Eisenhower were alive, he'd point to the MV-22 as the epitome of how the military-industrial complex can foist an inadequate aircraft upon the military at great expense to taxpayers.
On Dec. 5, a decision will be made whether the MV-22 should go into the first round of full production by Bell Helicopter-Boeing. The production schedule calls for 360 of the aircraft with 38-foot prop-rotors to be built at $40 million to $70 million each.
It is billed as the future of Marine Corps aviation. It can fly like a turboprop airplane and while in flight, the wings rotate upward, with the nacelles locking into place above the aircraft, giving it the flight characteristics of a helicopter. It's supposed to replace the aging, Vietnam-era helicopters, the CH-46 and CH-53. If the green light is given, American taxpayers will spend billions on an aircraft that many specialists say has a fatal design flaw and has failed to live up to its performance criteria. The aircraft that has moved through the military and congressional approval process with serious flaws hidden from Congress and the public by obfuscation and deception blanketed under an iron veil of military secrecy.
As a military affairs reporter for the North County Times, I covered some aspects of what the military calls its operational evaluation, in which it tests the aircraft on a day-to-day basis. I've flown in it, talked to mechanics who have worked on it and to brave, dedicated recon Marines who have flown in it. I've also talked to knowledgeable skeptics who say this albatross should be buried before it kills more young Marines during training missions.
Here are some of the reasons it should be terminated from military use. The aircraft has a fatal flaw. It's called power settling, or asymmetrical vortex ring state. Power setting occurs when one prop-rotor loses its lift capability while in flight. When that happens, the other prop-rotor continues to grip the air, pulling the aircraft upward and into a roll before turning toward the earth and plowing into the ground with deadly force, as the MV-22 did in an April 8 crash in Marana, Ariz. It crashed during a test flight, carrying 19 Marines, killing everyone aboard.
The Marine Corps laid blame for the crash on the pilots, saying they exceeded the flight parameters of the aircraft. The military says the pilots exceeded the recommended rate of descent of 800 feet per minute. But some critics have asked when that rate of descent was placed in the training manual for the MV-22. Was it before or after April 8? One source said it was placed in the manual in June.
Neither power settling nor asymmetrical vortex ring state were programmed into computer-controlled flight simulator programs that the pilots used while learning how to fly the MV-22. They had to log a minimum of 65 hours on the flight simulators, yet there was no training in place for power settling. In May, Helicopter News editor John R.
Guardino stated, "There is a serious knowledge gap concerning the Osprey and (power settling).
While the phenomenon affects all helicopters, it may pose a special (asymmetric) challenge to the MV-22."
Many of the early pilots for the MV-22 were drawn from fixed-wing aircraft. Helicopter pilots learn about power settling and train for it. But with this new bird, little if any training was conducted on power settling. Now the Navy and Marines are looking into having power settling programmed into their flight simulators.
During the operational evaluation and early tests of the MV-22, to save time and money, the more dangerous flight profiles such as power settling were not tested. The fact that test pilots cut corners by flying only the less dangerous profiles is documented in an accident report, one insider said. However, neither the public nor the families of Marines killed on April 8 will ever see the critical comments in the accident report. And the pilots' flight logs, which document problems and concerns with the MV-22, are not available for public scrutiny.
It wasn't until 21 Aug that test pilots attempted to duplicate some of the crash conditions at Naval Aircraft Test Center in Patuxent River, Md., Marine Corps Col. Nolan Schmidt, the V-22 program manager, told "Inside The Pentagon" magazine. The military boasts about the MV-22's ability to fly farther than any helicopter, with midair refuel capabilities, and to carry huge amounts of weight...and the MV-22 may be good for routine ferrying of troops and cargo. Yet even in that area, there is a concern. Buried deep in one report is the fact that it takes 20 minutes for military personnel wearing goggles to unload a vehicle from the MV-22. The vehicle fits so tightly into the aircraft that air crew members have to be careful not to tear the inside of the aircraft when removing it.
Also, special aluminum planks have to be placed inside the MV-22 before a vehicle is driven inside it, because without those planks the aircraft floor can't support the weight of the vehicle.
I have an opinion about this, stemming from my days in Vietnam, when I ran top-secret reconnaissance missions into Laos and Cambodia during two tours of duty with Special Forces. A key to recon team success on a mission was quick insertion into a target area. I've been inserted into targets by Air Force, Army and South Vietnamese pilots. The key was a quick approach into the landing zone, and our six-man recon team exiting the helicopter quickly, running to the wood line as the aircraft hastily exited the area.
The MV-22 can't approach a landing zone as quickly or as hard as a helicopter. The MV-22 has to spend more time on the landing zone than a helicopter because the men inside have to exit down a rear ramp. With the old UH-1H, or Hueys, and today's modern UH-60, there are two doors, where the men can watch the ground as the ship approaches the landing zone, while others can watch the wood line for enemy forces.
In the MV-22, there is no observation option. There are no defensive weapons. On the helicopters, there are door gunners on each side. With the MV-22, the men inside are blind to the target until the tailgate goes down.
I hope I'm wrong about more Marines dying in training in the MV-22.
The Marine Corps' rotor aviation wing finds itself between a rock and hard place. The helicopters they're flying are old and require extensive maintenance. Marine leaders have banked their future on the MV-22, instead of the modern CH-60 helicopter. Yet mechanics on MV-22s say intensive labor is needed to keep these new aircraft in the air. What will happen after they've been around for a decade or two?
There should be a full congressional hearings on the MV-22 before any funding is approved for full production. The hearings should feature the men who actually fly the aircraft, the critics who have seen the problems and have been stifled from speaking publicly. The hearings should present testimony from flight crews, not the likes of Col. Schmidt or any of the generals who want the MV-22. A GAO investigation of the MV-22 has turned up damning information. However, the GAO moves slowly and no time has been set for the release of that critical report.
J. Stryker Meyer is a North County Times staff writer.
11/26/00
J. Stryker Meyer
Commentary
The Marine Corps calls its controversial MV-22 tilt-rotor hybrid aircraft the Osprey. A better name would be the albatross. Or perhaps, the killer albatross. If Dwight Eisenhower were alive, he'd point to the MV-22 as the epitome of how the military-industrial complex can foist an inadequate aircraft upon the military at great expense to taxpayers.
On Dec. 5, a decision will be made whether the MV-22 should go into the first round of full production by Bell Helicopter-Boeing. The production schedule calls for 360 of the aircraft with 38-foot prop-rotors to be built at $40 million to $70 million each.
It is billed as the future of Marine Corps aviation. It can fly like a turboprop airplane and while in flight, the wings rotate upward, with the nacelles locking into place above the aircraft, giving it the flight characteristics of a helicopter. It's supposed to replace the aging, Vietnam-era helicopters, the CH-46 and CH-53. If the green light is given, American taxpayers will spend billions on an aircraft that many specialists say has a fatal design flaw and has failed to live up to its performance criteria. The aircraft that has moved through the military and congressional approval process with serious flaws hidden from Congress and the public by obfuscation and deception blanketed under an iron veil of military secrecy.
As a military affairs reporter for the North County Times, I covered some aspects of what the military calls its operational evaluation, in which it tests the aircraft on a day-to-day basis. I've flown in it, talked to mechanics who have worked on it and to brave, dedicated recon Marines who have flown in it. I've also talked to knowledgeable skeptics who say this albatross should be buried before it kills more young Marines during training missions.
Here are some of the reasons it should be terminated from military use. The aircraft has a fatal flaw. It's called power settling, or asymmetrical vortex ring state. Power setting occurs when one prop-rotor loses its lift capability while in flight. When that happens, the other prop-rotor continues to grip the air, pulling the aircraft upward and into a roll before turning toward the earth and plowing into the ground with deadly force, as the MV-22 did in an April 8 crash in Marana, Ariz. It crashed during a test flight, carrying 19 Marines, killing everyone aboard.
The Marine Corps laid blame for the crash on the pilots, saying they exceeded the flight parameters of the aircraft. The military says the pilots exceeded the recommended rate of descent of 800 feet per minute. But some critics have asked when that rate of descent was placed in the training manual for the MV-22. Was it before or after April 8? One source said it was placed in the manual in June.
Neither power settling nor asymmetrical vortex ring state were programmed into computer-controlled flight simulator programs that the pilots used while learning how to fly the MV-22. They had to log a minimum of 65 hours on the flight simulators, yet there was no training in place for power settling. In May, Helicopter News editor John R.
Guardino stated, "There is a serious knowledge gap concerning the Osprey and (power settling).
While the phenomenon affects all helicopters, it may pose a special (asymmetric) challenge to the MV-22."
Many of the early pilots for the MV-22 were drawn from fixed-wing aircraft. Helicopter pilots learn about power settling and train for it. But with this new bird, little if any training was conducted on power settling. Now the Navy and Marines are looking into having power settling programmed into their flight simulators.
During the operational evaluation and early tests of the MV-22, to save time and money, the more dangerous flight profiles such as power settling were not tested. The fact that test pilots cut corners by flying only the less dangerous profiles is documented in an accident report, one insider said. However, neither the public nor the families of Marines killed on April 8 will ever see the critical comments in the accident report. And the pilots' flight logs, which document problems and concerns with the MV-22, are not available for public scrutiny.
It wasn't until 21 Aug that test pilots attempted to duplicate some of the crash conditions at Naval Aircraft Test Center in Patuxent River, Md., Marine Corps Col. Nolan Schmidt, the V-22 program manager, told "Inside The Pentagon" magazine. The military boasts about the MV-22's ability to fly farther than any helicopter, with midair refuel capabilities, and to carry huge amounts of weight...and the MV-22 may be good for routine ferrying of troops and cargo. Yet even in that area, there is a concern. Buried deep in one report is the fact that it takes 20 minutes for military personnel wearing goggles to unload a vehicle from the MV-22. The vehicle fits so tightly into the aircraft that air crew members have to be careful not to tear the inside of the aircraft when removing it.
Also, special aluminum planks have to be placed inside the MV-22 before a vehicle is driven inside it, because without those planks the aircraft floor can't support the weight of the vehicle.
I have an opinion about this, stemming from my days in Vietnam, when I ran top-secret reconnaissance missions into Laos and Cambodia during two tours of duty with Special Forces. A key to recon team success on a mission was quick insertion into a target area. I've been inserted into targets by Air Force, Army and South Vietnamese pilots. The key was a quick approach into the landing zone, and our six-man recon team exiting the helicopter quickly, running to the wood line as the aircraft hastily exited the area.
The MV-22 can't approach a landing zone as quickly or as hard as a helicopter. The MV-22 has to spend more time on the landing zone than a helicopter because the men inside have to exit down a rear ramp. With the old UH-1H, or Hueys, and today's modern UH-60, there are two doors, where the men can watch the ground as the ship approaches the landing zone, while others can watch the wood line for enemy forces.
In the MV-22, there is no observation option. There are no defensive weapons. On the helicopters, there are door gunners on each side. With the MV-22, the men inside are blind to the target until the tailgate goes down.
I hope I'm wrong about more Marines dying in training in the MV-22.
The Marine Corps' rotor aviation wing finds itself between a rock and hard place. The helicopters they're flying are old and require extensive maintenance. Marine leaders have banked their future on the MV-22, instead of the modern CH-60 helicopter. Yet mechanics on MV-22s say intensive labor is needed to keep these new aircraft in the air. What will happen after they've been around for a decade or two?
There should be a full congressional hearings on the MV-22 before any funding is approved for full production. The hearings should feature the men who actually fly the aircraft, the critics who have seen the problems and have been stifled from speaking publicly. The hearings should present testimony from flight crews, not the likes of Col. Schmidt or any of the generals who want the MV-22. A GAO investigation of the MV-22 has turned up damning information. However, the GAO moves slowly and no time has been set for the release of that critical report.
J. Stryker Meyer is a North County Times staff writer.
11/26/00
Guest
Posts: n/a
Osprey seen rising despite deadly crashes
By Chris Stetkiewicz
SEATTLE, Dec 12 (Reuters) - Despite two crashes killing 23 Marines in the last eight months, the versatile MV-22 Osprey tilt-rotor aircraft will probably survive an intense Pentagon probe and move to full-scale production, defense analysts said on Tuesday.
The U.S. Marine Corps has no other option for replacing its aging fleet of CH-46 troop-transport helicopters and will push hard for the Osprey designed to take their place.
"Unless they find a problem that is unfixable at any cost, the Marines have to go forward. They have mortgaged the future of their rotary wing fleet on the Osprey," said Joseph Collins, a senior fellow at the Center for Strategic and International Studies.
"There is no walking away from it," added Collins, a retired U.S. Army colonel.
Taking off and landing like a helicopter but flying like an airplane, the MV-22 can ferry troops twice as fast and twice as far as the Vietnam War era CH-46, vastly improving responsiveness and rescue capacity, analysts said.
"This thing is pivotal for the Marine Corps. If it doesn't happen its whole concept of operation comes unraveled," said Loren Thompson, defense analyst at the Lexington Institute, a Virginia-based think tank.
PRODUCTION ON HOLD
The Pentagon postponed a decision on MV-22 production that had been expected next week and the Marine Corps grounded its eight remaining MV-22s after four Marines were killed on a training flight crash in North Carolina on Monday night.
Last April 19 Marines died in an Osprey crash in Arizona that was blamed on pilot error.
For the Osprey's builders, led by Boeing Co. <BA.N> and Textron Inc. <TXT.N>, the program represents up to $30 billion in U.S. and overseas military sales, though experts said the delays could add to the cost of building the hybrid aircraft.
"Obviously they have to find out what the problem is. If it is pilot error again, it would seem like this is a pretty difficult thing to fly," said Paul Nisbet, aerospace analyst at JSA Research in Newport, Rhode Island.
"If it crashes with that kind of frequency they have to fix it to make it easier to fly," Nisbet added. "Obviously when you are ferrying passengers it can't be too frequent."
Seattle-based Boeing called the decision to delay the production "prudent," adding that it shared the Pentagon's safety concerns but noting the Marines' enthusiasm for the Osprey.
"We continue to feel as enthusiastic as our customer that this is the only replacement... for the CH-46," said Doug Kinneard, a spokesman for Boeing's Philadelphia-based rotor craft unit.
On the New York Stock Exchange Boeing shares rose 3/4 to close at 69-1/8 on Tuesday, while Textron shares fell 13/16 to finish at 46.
Previous mixed-use aircraft, such as the hovering Harrier "jump jet" flown by the Marines, have suffered higher crash rates than fixed-wing aircraft, but have survived because they serve particular needs, analysts said.
"They are difficult, but I think this problem will be worked around," Nisbet said.
MIXED POLITICAL SUPPORT
Politically, the MV-22 has strong support in Pennsylvania and Texas, where it supports jobs at plants run by Boeing and Textron's Bell Helicopter unit.
But ironically a win by Texas Gov. George W. Bush over Vice President Al Gore in their battle for the White House might not bode well for the Osprey.
Bush's running mate Dick Cheney fiercely opposed the Osprey when he ran the Defense Department under Bush's father, former President George Bush.
"Bush has already promised a comprehensive assessment of all defense aviation programs," said Jay Behuncik, defense specialist at Washington Analysis Group. "What happened today is hardly helpful. It throws up a huge question mark."
Still, Behuncik joined others in predicting the Osprey will survive, driven as much by necessity as anything else.
"This is one of the Marines' top priorities. They are certainly not going to disavow that need," he said.
18:53 12-12-00
By Chris Stetkiewicz
SEATTLE, Dec 12 (Reuters) - Despite two crashes killing 23 Marines in the last eight months, the versatile MV-22 Osprey tilt-rotor aircraft will probably survive an intense Pentagon probe and move to full-scale production, defense analysts said on Tuesday.
The U.S. Marine Corps has no other option for replacing its aging fleet of CH-46 troop-transport helicopters and will push hard for the Osprey designed to take their place.
"Unless they find a problem that is unfixable at any cost, the Marines have to go forward. They have mortgaged the future of their rotary wing fleet on the Osprey," said Joseph Collins, a senior fellow at the Center for Strategic and International Studies.
"There is no walking away from it," added Collins, a retired U.S. Army colonel.
Taking off and landing like a helicopter but flying like an airplane, the MV-22 can ferry troops twice as fast and twice as far as the Vietnam War era CH-46, vastly improving responsiveness and rescue capacity, analysts said.
"This thing is pivotal for the Marine Corps. If it doesn't happen its whole concept of operation comes unraveled," said Loren Thompson, defense analyst at the Lexington Institute, a Virginia-based think tank.
PRODUCTION ON HOLD
The Pentagon postponed a decision on MV-22 production that had been expected next week and the Marine Corps grounded its eight remaining MV-22s after four Marines were killed on a training flight crash in North Carolina on Monday night.
Last April 19 Marines died in an Osprey crash in Arizona that was blamed on pilot error.
For the Osprey's builders, led by Boeing Co. <BA.N> and Textron Inc. <TXT.N>, the program represents up to $30 billion in U.S. and overseas military sales, though experts said the delays could add to the cost of building the hybrid aircraft.
"Obviously they have to find out what the problem is. If it is pilot error again, it would seem like this is a pretty difficult thing to fly," said Paul Nisbet, aerospace analyst at JSA Research in Newport, Rhode Island.
"If it crashes with that kind of frequency they have to fix it to make it easier to fly," Nisbet added. "Obviously when you are ferrying passengers it can't be too frequent."
Seattle-based Boeing called the decision to delay the production "prudent," adding that it shared the Pentagon's safety concerns but noting the Marines' enthusiasm for the Osprey.
"We continue to feel as enthusiastic as our customer that this is the only replacement... for the CH-46," said Doug Kinneard, a spokesman for Boeing's Philadelphia-based rotor craft unit.
On the New York Stock Exchange Boeing shares rose 3/4 to close at 69-1/8 on Tuesday, while Textron shares fell 13/16 to finish at 46.
Previous mixed-use aircraft, such as the hovering Harrier "jump jet" flown by the Marines, have suffered higher crash rates than fixed-wing aircraft, but have survived because they serve particular needs, analysts said.
"They are difficult, but I think this problem will be worked around," Nisbet said.
MIXED POLITICAL SUPPORT
Politically, the MV-22 has strong support in Pennsylvania and Texas, where it supports jobs at plants run by Boeing and Textron's Bell Helicopter unit.
But ironically a win by Texas Gov. George W. Bush over Vice President Al Gore in their battle for the White House might not bode well for the Osprey.
Bush's running mate Dick Cheney fiercely opposed the Osprey when he ran the Defense Department under Bush's father, former President George Bush.
"Bush has already promised a comprehensive assessment of all defense aviation programs," said Jay Behuncik, defense specialist at Washington Analysis Group. "What happened today is hardly helpful. It throws up a huge question mark."
Still, Behuncik joined others in predicting the Osprey will survive, driven as much by necessity as anything else.
"This is one of the Marines' top priorities. They are certainly not going to disavow that need," he said.
18:53 12-12-00
Guest
Posts: n/a
Exactly right HeloTeacher. Too bad Unctuous isn't able to make the obvious connection. He's too busy trying to make the accident fit his fantasy theories that have been proven wrong by the test pilots and investigators. The ability to recognize what is obvious to a helicopter pilot is what is needed, not a new design.
As I mentioned in another post regarding the Arizona accident, the PIC's experience was nearly 3800hrs total time but not much in a helicopter (35.7 in TH-56, 20hrs in CH-46 and CH-53, and only 97.2 in tiltrotors). The copilot had more helicopter experience (although even less tiltrotor time than the PIC) but he was apparently retrieving something from the floor that had distracted him (accidents are almost always a chain of events). Indications are that neither pilot recognized the symptoms of settling with power. It appears that their applying full power was an attempt to arrest the rate of descent. Using experienced helicopter pilots with a tiltrotor is the only thing that would make sense from a safety standpoint (the MV-22 is replacing the Marine CH-46s and CH-53s).
But not only is that not always the case, the problem gets worse when you add to that the fact that General Blot added the 'Blottle!' For those that are not familiar with it, that is the nickname given to the ‘power lever’ in a V-22. Originally it worked just like a helicopter collective – you pull it up and you increase the power and collective pitch, push it down and you reduce power and collective pitch. General Blot took a flight in the V-22 when he was in charge of the initial Osprey program. Having come from a Harrier background, he said, “get rid of that, I want a Throttle type configuration” similar to the Harrier. The result was that the guys that would be most qualified to fly tiltrotors (helicopter pilots coming into the program from CH-46s and Ch-53s) had to contend with required responses opposite to what had been ingrained through their experience.
This can be directly attributable to the first crash of a V-22 in 1991. The a/c had 2 of 3 fly-by-wire systems miswired in the lateral cyclic so that moving the stick left rolled the a/c right and vice-versa. On the very first test hover of the aircraft, the pilot, Grady Wilson, entered an unstable condition after entering the hover and didn’t know what the problem was. He got the a/c down onto the ground before serious problems occurred, but when he experienced a hard bounce and started to go airborne again, he reverted to old helicopter habits (as many of us would) and ‘pushed down on the collective.’ This of course meant pushing forward on the “Blottle” and resulted in an increase in power that launched the a/c into the air. That’s where the lateral cyclic control reversal took effect, the a/c rolled over and was destroyed. Incredibly nobody was seriously hurt. Thank goodness common sense prevailed with the 609 and they went with a more sensible collective style movement.
As I mentioned in another post regarding the Arizona accident, the PIC's experience was nearly 3800hrs total time but not much in a helicopter (35.7 in TH-56, 20hrs in CH-46 and CH-53, and only 97.2 in tiltrotors). The copilot had more helicopter experience (although even less tiltrotor time than the PIC) but he was apparently retrieving something from the floor that had distracted him (accidents are almost always a chain of events). Indications are that neither pilot recognized the symptoms of settling with power. It appears that their applying full power was an attempt to arrest the rate of descent. Using experienced helicopter pilots with a tiltrotor is the only thing that would make sense from a safety standpoint (the MV-22 is replacing the Marine CH-46s and CH-53s).
But not only is that not always the case, the problem gets worse when you add to that the fact that General Blot added the 'Blottle!' For those that are not familiar with it, that is the nickname given to the ‘power lever’ in a V-22. Originally it worked just like a helicopter collective – you pull it up and you increase the power and collective pitch, push it down and you reduce power and collective pitch. General Blot took a flight in the V-22 when he was in charge of the initial Osprey program. Having come from a Harrier background, he said, “get rid of that, I want a Throttle type configuration” similar to the Harrier. The result was that the guys that would be most qualified to fly tiltrotors (helicopter pilots coming into the program from CH-46s and Ch-53s) had to contend with required responses opposite to what had been ingrained through their experience.
This can be directly attributable to the first crash of a V-22 in 1991. The a/c had 2 of 3 fly-by-wire systems miswired in the lateral cyclic so that moving the stick left rolled the a/c right and vice-versa. On the very first test hover of the aircraft, the pilot, Grady Wilson, entered an unstable condition after entering the hover and didn’t know what the problem was. He got the a/c down onto the ground before serious problems occurred, but when he experienced a hard bounce and started to go airborne again, he reverted to old helicopter habits (as many of us would) and ‘pushed down on the collective.’ This of course meant pushing forward on the “Blottle” and resulted in an increase in power that launched the a/c into the air. That’s where the lateral cyclic control reversal took effect, the a/c rolled over and was destroyed. Incredibly nobody was seriously hurt. Thank goodness common sense prevailed with the 609 and they went with a more sensible collective style movement.
Guest
Posts: n/a
This might be overly simplistic but I'll
throw it in anyway.
VR - Well understood to be made worse if an
unwary Pilot increases pitch (and therefore
angle of attack) and adds power (therefore increasing induced flow) by raising collective, misguidedly thinking this action will arrest ROD.
The problem is related to the volume and speed of induced flow as more recirculation is encouraged by more induced flow.
So, much more likely that VR would be encountered at large angles of attack and high volumes of induced flow.
The blades of the V22 seem to have a lot of pitch applied in design. Their relatively small disc area suggests a high induced flow. Are they close to the line already?
If close to critical, the discs (or just one of them) would not need much of;
(A) an updraft to further oppose induced flow, thereby increasing recirculation (doesn't matter if the upward relative airflow is due to ROD or updraft)
or
(B) a downdraft increasing induced flow and pushing down the wing at the same time, encouraging the pilot to lift that wing by pulling more pitch...increasing induced flow...
At least in a Heli we can fly forwards and out,(if we have the height) no 12 seconds to wait.
I hope a lot of work now gets done on investigating this, whatever the General says.
SPS
throw it in anyway.
VR - Well understood to be made worse if an
unwary Pilot increases pitch (and therefore
angle of attack) and adds power (therefore increasing induced flow) by raising collective, misguidedly thinking this action will arrest ROD.
The problem is related to the volume and speed of induced flow as more recirculation is encouraged by more induced flow.
So, much more likely that VR would be encountered at large angles of attack and high volumes of induced flow.
The blades of the V22 seem to have a lot of pitch applied in design. Their relatively small disc area suggests a high induced flow. Are they close to the line already?
If close to critical, the discs (or just one of them) would not need much of;
(A) an updraft to further oppose induced flow, thereby increasing recirculation (doesn't matter if the upward relative airflow is due to ROD or updraft)
or
(B) a downdraft increasing induced flow and pushing down the wing at the same time, encouraging the pilot to lift that wing by pulling more pitch...increasing induced flow...
At least in a Heli we can fly forwards and out,(if we have the height) no 12 seconds to wait.
I hope a lot of work now gets done on investigating this, whatever the General says.
SPS
Guest
Posts: n/a
SPS - well said (and beat me by moments)
HeliFlight
It would be more productive if you addressed specifics instead of waffling on boorishly. It doesn't help your credibility and just makes it apparent that you are either being tasked to respond contrarily on this forum or are a "vested interest" (or both). So please try to keep it professional and in keeping with the high standards of most of this thread. It's probably being read by people who have a personal (and not just a vested) interest. If you disagree, do it point by point - and validate your opinions.
It would seem that there is a REAL problem in getting across to the USMC and some on this forum that Osprey asymmVR and simple settling with power (aka VR) are two different birds (although of the same feather).
VR: Helicopter
Recirculation leading to high rate of descent during steeper approaches to an LZ or OGE hover. Condition exacerbated (i.e. rate of descent increased) by the instinctive addition of power. Recognition sometimes delayed due to diminished depth perception (night) / ground-rush appreciation (at higher levels). Recovery is normally accomplished by forward cyclic and "flying out" of the vortex (an overshoot). Environmental factors include high density altitude, high AUW, steeper approaches and calm (or tail-) wind components on approach. In some types (eg UH-1, Kiowa) it can also be aurally detected as a distinctive background blade-sound level change. Onset is normally rapid and initial instinctive pilot response of increased collective is normally required to accentuate the condition and stimulate recognition. Night and NVG onset is frequently unrecognised due to poorer visual cues. Condition is best avoided by consciously arcing under rather than committing to a constant angle steep approach (or worse, an arcing-over approach - one that becomes latterly steeper due to tailwind). Rarity? Rare enough to almost always make it a nasty surprise.
asymmVR TiltRotor
Induced recirculation on one side only (i.e. always asymmetric due to differential collective inputs). Likelihood of symmetrical encounters remain extremely low. Initiating factors are same as for helo except insofar as the condition can be induced by low IAS roll inputs / wing-drop corrections during high RoD. Recognition/recovery is not a consideration as condition (once encountered) is rapid-rolling and terminal. Attempted (instinctive) recovery inputs simply accelerates the roll-rate. Avoidance is solely by pilot consciousness of the possibility and observation of flight-envelope limits. Avoidance can be enhanced by avoiding tailwind components - however low-level factors such as formation landing positioning, late overshoot, manoeuvre, high RoD, wake turbulence, thermal activity and topographically induced shear can cause onset. Rarity? Will be frequent enough to become an attrition-rate entry argument. Further problems? Acute awareness of the conclusive nature of the condition will become THE inhibiting factor in operational environments (aka "sitting duck").
I'm not against the Osprey or 609, nor am I a doomsayer. However it is apparent why quintessential problems are emerging latterly. Much of the "testing" was via computational number-crunching (resolving the designer's problem that wind-tunnel time was hard to come by at the time). AsymmVR was simply not considered. If you don't concede this then simply email me the relevant paper (or a URL). So the program, being desperately full of yea-sayers, needs a Devil's Advocate. The GAO does its best, but the brokers and lobbyists have gotten to them as well. Would the USMC ever turn it off? The USMC have been waxing doctrinaire about the Osprey's Force Multiplier effect (and its other goodies) since I was at Staff College. So it was really built-to-order and had its gestation as a logical alternative to the problems with the tilt-wing. Not to have it come to fruition would mean generations of (now) senior Military Officers with egg all over their faces. They all left their mark on its promise in their War College essays and staff-paper studies over a decade ago. Possible technological failure of the project was an unacceptable rider for any USMC essayist aspiring to general officer rank. The US Army has always been reticent about it because they see a genuine need to spread resources around, not put all eggs in fragile baskets - and they usually have to apply the KISS Principle anyway. The USMC's future force development is now so irretrievably tied into the MV22 that its cancellation would cause major morale and directional problems. But that's now the direction that it's possibly headed, more's the pity.
HeliFlight
It would be more productive if you addressed specifics instead of waffling on boorishly. It doesn't help your credibility and just makes it apparent that you are either being tasked to respond contrarily on this forum or are a "vested interest" (or both). So please try to keep it professional and in keeping with the high standards of most of this thread. It's probably being read by people who have a personal (and not just a vested) interest. If you disagree, do it point by point - and validate your opinions.
It would seem that there is a REAL problem in getting across to the USMC and some on this forum that Osprey asymmVR and simple settling with power (aka VR) are two different birds (although of the same feather).
VR: Helicopter
Recirculation leading to high rate of descent during steeper approaches to an LZ or OGE hover. Condition exacerbated (i.e. rate of descent increased) by the instinctive addition of power. Recognition sometimes delayed due to diminished depth perception (night) / ground-rush appreciation (at higher levels). Recovery is normally accomplished by forward cyclic and "flying out" of the vortex (an overshoot). Environmental factors include high density altitude, high AUW, steeper approaches and calm (or tail-) wind components on approach. In some types (eg UH-1, Kiowa) it can also be aurally detected as a distinctive background blade-sound level change. Onset is normally rapid and initial instinctive pilot response of increased collective is normally required to accentuate the condition and stimulate recognition. Night and NVG onset is frequently unrecognised due to poorer visual cues. Condition is best avoided by consciously arcing under rather than committing to a constant angle steep approach (or worse, an arcing-over approach - one that becomes latterly steeper due to tailwind). Rarity? Rare enough to almost always make it a nasty surprise.
asymmVR TiltRotor
Induced recirculation on one side only (i.e. always asymmetric due to differential collective inputs). Likelihood of symmetrical encounters remain extremely low. Initiating factors are same as for helo except insofar as the condition can be induced by low IAS roll inputs / wing-drop corrections during high RoD. Recognition/recovery is not a consideration as condition (once encountered) is rapid-rolling and terminal. Attempted (instinctive) recovery inputs simply accelerates the roll-rate. Avoidance is solely by pilot consciousness of the possibility and observation of flight-envelope limits. Avoidance can be enhanced by avoiding tailwind components - however low-level factors such as formation landing positioning, late overshoot, manoeuvre, high RoD, wake turbulence, thermal activity and topographically induced shear can cause onset. Rarity? Will be frequent enough to become an attrition-rate entry argument. Further problems? Acute awareness of the conclusive nature of the condition will become THE inhibiting factor in operational environments (aka "sitting duck").
I'm not against the Osprey or 609, nor am I a doomsayer. However it is apparent why quintessential problems are emerging latterly. Much of the "testing" was via computational number-crunching (resolving the designer's problem that wind-tunnel time was hard to come by at the time). AsymmVR was simply not considered. If you don't concede this then simply email me the relevant paper (or a URL). So the program, being desperately full of yea-sayers, needs a Devil's Advocate. The GAO does its best, but the brokers and lobbyists have gotten to them as well. Would the USMC ever turn it off? The USMC have been waxing doctrinaire about the Osprey's Force Multiplier effect (and its other goodies) since I was at Staff College. So it was really built-to-order and had its gestation as a logical alternative to the problems with the tilt-wing. Not to have it come to fruition would mean generations of (now) senior Military Officers with egg all over their faces. They all left their mark on its promise in their War College essays and staff-paper studies over a decade ago. Possible technological failure of the project was an unacceptable rider for any USMC essayist aspiring to general officer rank. The US Army has always been reticent about it because they see a genuine need to spread resources around, not put all eggs in fragile baskets - and they usually have to apply the KISS Principle anyway. The USMC's future force development is now so irretrievably tied into the MV22 that its cancellation would cause major morale and directional problems. But that's now the direction that it's possibly headed, more's the pity.
Guest
Posts: n/a
Unctuous,
Come on man, read the posts. Everything has been laid out as clear as day
for you. The rest of us get it! Those of us in the helicopter world
recognize that there was no living through the 2000fpm & 285ft scenario
whether it was assymm settling or normal. If it was a helicopter in that
situation (especially a 57000lb one!) we'd be dead too. If you really fly
helicopters you wouldn't have the slightest problem recognizing this! Time to move on mate.
Come on man, read the posts. Everything has been laid out as clear as day
for you. The rest of us get it! Those of us in the helicopter world
recognize that there was no living through the 2000fpm & 285ft scenario
whether it was assymm settling or normal. If it was a helicopter in that
situation (especially a 57000lb one!) we'd be dead too. If you really fly
helicopters you wouldn't have the slightest problem recognizing this! Time to move on mate.
Guest
Posts: n/a
We Helicopter guys should probably be a little less critical of Fixed wing drivers not recognising Vortex Ring. In most cases we get a hint of the approaching VR by a 'twitching' of the tail rotor. This is due to the recirculating air at the back end playing silly buggers with the T/R. I am assuming that the same tell tale would be non-existent in the V22. I understand that this is just one type of tell tale but from personal experience, it is one of the best hints that you are close to the edge.
I have a question for you guys. How is the V22 controled in the yawing axis? Is it by a differential vectoring of the pods? If NOT - could a boot full of opposite rudder help to correct a wing low situation. I am assuming of course that there is still at least some airflow over the wing.
One last point, another way to get out of Vortex Ring is to just lower the collective. This is great if you have altitude up your sleeve, but even so, I have found through experience that you can 'milk' the collective to disrupt the formation of a vortex.
The moral of my little story is that I don't think it is a design 'fault' either, and as in Helicopters there are ways to deal with the inherent problems that are associated with coming back to earth.
Cheers.
I have a question for you guys. How is the V22 controled in the yawing axis? Is it by a differential vectoring of the pods? If NOT - could a boot full of opposite rudder help to correct a wing low situation. I am assuming of course that there is still at least some airflow over the wing.
One last point, another way to get out of Vortex Ring is to just lower the collective. This is great if you have altitude up your sleeve, but even so, I have found through experience that you can 'milk' the collective to disrupt the formation of a vortex.
The moral of my little story is that I don't think it is a design 'fault' either, and as in Helicopters there are ways to deal with the inherent problems that are associated with coming back to earth.
Cheers.
Guest
Posts: n/a
I haven't read all the posts on this thread as yet but, I have seen a point expressed here as fact that I feel compelled to debunk as finitely as I can. It has been said tandem rotor helicopters will not enter settling with power as a vortex ring state. With eighteen years in tandem rotor helicopters and nine of those based at 6000'msl and flying to just under 15000'msl, I want you to understand that the tandem rotor helicopter will very certainly suffer this condition if there is only the necessary lack of diligence to allow it to happen. I was twice responsible for not being smart enough for both of us and earned the necessity of recovering the aircraft as my penance. Another rodeo trick you can expect to hear about in the future of tilt rotor aircaft is the prop rotor on the outside of the turn going through ETL when a too fast pedal turn into the wind is made around the opposite prop rotor.
Guest
Posts: n/a
Thanks UNCTUOUS,
It seems like that link was just waiting for me all come along and ask the obvious !!
No doubt the powers that be have tested the idea, but I can't help but think that a boot full of opposite pedal could help the situation. Your diagrams say that its unlikely, it probably is, but could the tilting forward of the disk and the subsequent travel help to remove the disk from the Vortex Ring State. I guess similar to the flying out (forward) of the VR in a conventional helicopter. Even in the extreme case of the aircraft rotating 90 degrees (or more), it will effectively remove the condition.
It's nice to have all this time to think about it - I don't suppose that 2 seconds is enough for a reaction to take place after recognition etc anyway.
Further testing maybe ?
It seems like that link was just waiting for me all come along and ask the obvious !!
No doubt the powers that be have tested the idea, but I can't help but think that a boot full of opposite pedal could help the situation. Your diagrams say that its unlikely, it probably is, but could the tilting forward of the disk and the subsequent travel help to remove the disk from the Vortex Ring State. I guess similar to the flying out (forward) of the VR in a conventional helicopter. Even in the extreme case of the aircraft rotating 90 degrees (or more), it will effectively remove the condition.
It's nice to have all this time to think about it - I don't suppose that 2 seconds is enough for a reaction to take place after recognition etc anyway.
Further testing maybe ?
Guest
Posts: n/a
RotorTorque,
In an earlier post by PTIUAE he relayed the comments of a NASA test pilot who spent years flying the XV-15 and the V-22. He said the he did experience settling with power (not at 285 feet of course!) and got out of it "instinctively" as an EXPERIENCED Tiltrotor pilot by simply moving the nacelles forward with a push of the switch. The moment the nacelles started moving the vortex ring was disrupted and he flew right out of it. The problem is the pilots in the Marana crash never had the opportunity to develop this "instinct" (80 and 90 hours of tiltrotor experience for pilot and copilot)and obviously the training they had was not deep enough to to prepare them for what they had gotten into. Worse than that, in this case it doesn't matter because they were in so far and at such a low altitude that nothing they could have done would have gotten them out at that point. It doesn't matter if the settling was assymmetrical or normal (if the wind was on the nose or tail it would have been normal settling) they were finished at that point regardless. The same way that if we were in a 57000lb helicopter we would not have been able to lower the collective and push forward on the cyclic to fly out of it.
Your moral of the story should be the title of this thread, you are right, there is no fault in the design.
Unctuous,
You have demonstrated in this thread that you are the KING of WAFFLERS. But it is nice to hear you talk about professionalism though. Obviously the posting by PTI UAE on June 3, 2000 where he lectured you on your lack of professionalism on forums has made a lasting impact on you (that’s the post when you never showed up again for 6 months). However your consistency of never letting the facts get in the way of your theories hasn’t changed since your first post. You keep showing us the facts that we already know (and all agree with) in an endless manner, but completely miss the point of what they mean. You sprinkle your silly theories in between the facts, and expect we will believe those theories which have been indisputably ruled out earlier in the thread by testimony from people who have ACTUALLY BEEN FLYING the aircraft for thousand of hours! Your arguments hold as much water as a sieve. The press will draw their conclusions regardless of the facts, but those of us in the business should know better. We look at the facts and are supposed to have a better idea of what they mean than a journalist trying to make headlines.
If you are wondering why nobody is lining up behind you on this forum, it’s because you have destroyed you credibility over and over again in your previous posts. IE XV-15 theory, Chinooks don’t experience settling with power, your choosing to ignore the opinions of those who fly tiltrotors when you have never even seen one, etc. etc. When you are proven wrong you make up a new theory and swear by that one too. You have already been proven wrong with hard evidence POINT BY POINT, again and again throughout the thread and given indisputable evidence by the guys that have experience with them! Your response to the extraordinary point by point dismantling of your theory was to disappear for 6 months (and wait for a tragic crash that killed 4 Marines to try and boost your ego – sorry, it doesn’t work that way).
Speaking of point by point, it seems that you are the one not willing to answer the questions. Let’s try again: 1. Where were you for 6 months 2. How do you respond to the dismantling of your theory on the XV-15 that supposedly did not go to 95 degrees (5 degrees aft). 3. Do you think a 57,000 lb helicopter would have survived the scenario of over 2000 fpm ROD at 285 ft pulling in full aft stick to reduce airspeed and full power (IE there is no difference between asymmetrical + normal settling, you are dead either way, and that’s the important thing (avoiding it that is). There are some points for you, give it a try (many more to come).
There are a lot of questions readers are curious about. You failed to answer before, what was your user name for the 6 months that you stopped posting under the Unctuous name. (can’t imagine you went hot and furious on this thread, got blasted out of the water, and then came back to try again to apply your theory to the latest crash)
The writer of an article you posted said the MV-22 cannot do everything a small helicopter can do. That could be true. SO WHAT!!.. There are a lot of things a tiltrotor can do that a helicopter cannot (that’s why the Marines want them!) Aviation is all about give and take. Even if there is a more restrictive envelope for settling with power avoidance, you can’t describe it as technologically flawed and throw it out. The obvious answer is DEFINE THE ENVELOPE thoroughly and TRAIN for avoidance. We're not going to throw away all airplanes because they can’t hover or autorotate, and we won’t throw out all helicopters because they get into settling with power, or retreating blade stall, or dynamic rollover and can’t go over 200kts. PERSPECTIVE!
No I have not been “tasked” by anybody with showing the obvious flaws in what you call a theory. I do it for personal satisfaction being a part of this memorable thread. The only disappointing part is that I have joined after th "knock-out punch” has been thrown. Like Bruce Willis in the Sixth Sense (excellent movie) you just have not come to realize what has happened to you yet. I thought it was funny when you said I must have a “vested interest in the tiltrotor.” Wrong again (you must be used to that by now!). You can add this to your list of mis-fire claims being proven wrong on this thread. You don’t seem to have a good handle on theories OR people. Why Is it when anyone disagrees with you, you say they must have a vested interest. You accused PTIUAE of working for a manufacturer writing public relations notices (and called him “Tom”!?), and he gave you extensive details on his background and proved that he was more interested in finding out if there is a design flaw in tiltrotors then you are. Rhett Flater, the guy you responded to and assumed he was a “stake-holder” in the 609, is the Director of the American Helicopter Society, and a former US Marine helicopter pilot. So tell us, how much is Sikorsky paying you to make your posts? (maybe you are the one with the vested interest)
Have you noticed that you have a following of one on this forum (yourself). I’m sure you will come up with a good theory to explain it away (you are good at that and it won’t bother you when it is proven wrong). Do you think there might be a good reason for that? Think about it and you will be able to avoid further humiliating yourself. We are supposed to be the experts capable of interpreting the facts. Don’t be mislead by media stories that make claims that are definitely not backed up by the facts (and don’t be foolish enough to parade those baseless claims around as facts). It might be fun to make up theories, but it’s more rewarding to make a useful contribution by attacking the things that are really bad about the aircraft (like the blottle that REALLY serves no purpose and has REALLY caused an accident already!)
[This message has been edited by HeliFlight (edited 19 December 2000).]
[This message has been edited by HeliFlight (edited 19 December 2000).]
In an earlier post by PTIUAE he relayed the comments of a NASA test pilot who spent years flying the XV-15 and the V-22. He said the he did experience settling with power (not at 285 feet of course!) and got out of it "instinctively" as an EXPERIENCED Tiltrotor pilot by simply moving the nacelles forward with a push of the switch. The moment the nacelles started moving the vortex ring was disrupted and he flew right out of it. The problem is the pilots in the Marana crash never had the opportunity to develop this "instinct" (80 and 90 hours of tiltrotor experience for pilot and copilot)and obviously the training they had was not deep enough to to prepare them for what they had gotten into. Worse than that, in this case it doesn't matter because they were in so far and at such a low altitude that nothing they could have done would have gotten them out at that point. It doesn't matter if the settling was assymmetrical or normal (if the wind was on the nose or tail it would have been normal settling) they were finished at that point regardless. The same way that if we were in a 57000lb helicopter we would not have been able to lower the collective and push forward on the cyclic to fly out of it.
Your moral of the story should be the title of this thread, you are right, there is no fault in the design.
Unctuous,
You have demonstrated in this thread that you are the KING of WAFFLERS. But it is nice to hear you talk about professionalism though. Obviously the posting by PTI UAE on June 3, 2000 where he lectured you on your lack of professionalism on forums has made a lasting impact on you (that’s the post when you never showed up again for 6 months). However your consistency of never letting the facts get in the way of your theories hasn’t changed since your first post. You keep showing us the facts that we already know (and all agree with) in an endless manner, but completely miss the point of what they mean. You sprinkle your silly theories in between the facts, and expect we will believe those theories which have been indisputably ruled out earlier in the thread by testimony from people who have ACTUALLY BEEN FLYING the aircraft for thousand of hours! Your arguments hold as much water as a sieve. The press will draw their conclusions regardless of the facts, but those of us in the business should know better. We look at the facts and are supposed to have a better idea of what they mean than a journalist trying to make headlines.
If you are wondering why nobody is lining up behind you on this forum, it’s because you have destroyed you credibility over and over again in your previous posts. IE XV-15 theory, Chinooks don’t experience settling with power, your choosing to ignore the opinions of those who fly tiltrotors when you have never even seen one, etc. etc. When you are proven wrong you make up a new theory and swear by that one too. You have already been proven wrong with hard evidence POINT BY POINT, again and again throughout the thread and given indisputable evidence by the guys that have experience with them! Your response to the extraordinary point by point dismantling of your theory was to disappear for 6 months (and wait for a tragic crash that killed 4 Marines to try and boost your ego – sorry, it doesn’t work that way).
Speaking of point by point, it seems that you are the one not willing to answer the questions. Let’s try again: 1. Where were you for 6 months 2. How do you respond to the dismantling of your theory on the XV-15 that supposedly did not go to 95 degrees (5 degrees aft). 3. Do you think a 57,000 lb helicopter would have survived the scenario of over 2000 fpm ROD at 285 ft pulling in full aft stick to reduce airspeed and full power (IE there is no difference between asymmetrical + normal settling, you are dead either way, and that’s the important thing (avoiding it that is). There are some points for you, give it a try (many more to come).
There are a lot of questions readers are curious about. You failed to answer before, what was your user name for the 6 months that you stopped posting under the Unctuous name. (can’t imagine you went hot and furious on this thread, got blasted out of the water, and then came back to try again to apply your theory to the latest crash)
The writer of an article you posted said the MV-22 cannot do everything a small helicopter can do. That could be true. SO WHAT!!.. There are a lot of things a tiltrotor can do that a helicopter cannot (that’s why the Marines want them!) Aviation is all about give and take. Even if there is a more restrictive envelope for settling with power avoidance, you can’t describe it as technologically flawed and throw it out. The obvious answer is DEFINE THE ENVELOPE thoroughly and TRAIN for avoidance. We're not going to throw away all airplanes because they can’t hover or autorotate, and we won’t throw out all helicopters because they get into settling with power, or retreating blade stall, or dynamic rollover and can’t go over 200kts. PERSPECTIVE!
No I have not been “tasked” by anybody with showing the obvious flaws in what you call a theory. I do it for personal satisfaction being a part of this memorable thread. The only disappointing part is that I have joined after th "knock-out punch” has been thrown. Like Bruce Willis in the Sixth Sense (excellent movie) you just have not come to realize what has happened to you yet. I thought it was funny when you said I must have a “vested interest in the tiltrotor.” Wrong again (you must be used to that by now!). You can add this to your list of mis-fire claims being proven wrong on this thread. You don’t seem to have a good handle on theories OR people. Why Is it when anyone disagrees with you, you say they must have a vested interest. You accused PTIUAE of working for a manufacturer writing public relations notices (and called him “Tom”!?), and he gave you extensive details on his background and proved that he was more interested in finding out if there is a design flaw in tiltrotors then you are. Rhett Flater, the guy you responded to and assumed he was a “stake-holder” in the 609, is the Director of the American Helicopter Society, and a former US Marine helicopter pilot. So tell us, how much is Sikorsky paying you to make your posts? (maybe you are the one with the vested interest)
Have you noticed that you have a following of one on this forum (yourself). I’m sure you will come up with a good theory to explain it away (you are good at that and it won’t bother you when it is proven wrong). Do you think there might be a good reason for that? Think about it and you will be able to avoid further humiliating yourself. We are supposed to be the experts capable of interpreting the facts. Don’t be mislead by media stories that make claims that are definitely not backed up by the facts (and don’t be foolish enough to parade those baseless claims around as facts). It might be fun to make up theories, but it’s more rewarding to make a useful contribution by attacking the things that are really bad about the aircraft (like the blottle that REALLY serves no purpose and has REALLY caused an accident already!)
[This message has been edited by HeliFlight (edited 19 December 2000).]
[This message has been edited by HeliFlight (edited 19 December 2000).]
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MV-22 Suffered Hydraulic Problem Before Crash
WASHINGTON (Reuters) - A Marine Corps MV-22 tilt-rotor helicopter suffered a "hydraulic malfunction'' before it crashed in North Carolina on Dec. 11, killing all four crewmembers, the corps said on Thursday.
The corps added in a statement from the Pentagon (news - web sites) that it was not yet known whether the problem had anything to do with the crash. Hydraulic pressure is used by pilots to keep control of aircraft.
It was the second fatal crash this year of one of the revolutionary aircraft and prompted Defense Secretary William Cohen to order an investigation into the troubled $40 billion program.
The Marine Corps postponed a decision on whether to begin initial full-scale production of the MV-22, built jointly by Boeing Co. and Textron Inc., after the crash.
Thursday's Marine Corps statement said initial review of data from the MV-22's "black box'' flight recorder "shows the aircraft did experience a hydraulic malfunction -- however the magnitude of the hydraulic malfunction or whether it relates to the mishap is not yet known.''
WASHINGTON (Reuters) - A Marine Corps MV-22 tilt-rotor helicopter suffered a "hydraulic malfunction'' before it crashed in North Carolina on Dec. 11, killing all four crewmembers, the corps said on Thursday.
The corps added in a statement from the Pentagon (news - web sites) that it was not yet known whether the problem had anything to do with the crash. Hydraulic pressure is used by pilots to keep control of aircraft.
It was the second fatal crash this year of one of the revolutionary aircraft and prompted Defense Secretary William Cohen to order an investigation into the troubled $40 billion program.
The Marine Corps postponed a decision on whether to begin initial full-scale production of the MV-22, built jointly by Boeing Co. and Textron Inc., after the crash.
Thursday's Marine Corps statement said initial review of data from the MV-22's "black box'' flight recorder "shows the aircraft did experience a hydraulic malfunction -- however the magnitude of the hydraulic malfunction or whether it relates to the mishap is not yet known.''
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To: Cyclic Hotline
The Hydraulic system may have downed the V22 it also got me fired from a consulting job at Boeing Helicopters in Philadelphia.
I continually brought the subject up of reduced reliability of the hydraulic system due to higher than anticipated cyclic operation. I did this several times and each time I did my boss told me it was a Bell problem. I would disagree and that ended the conversation. Each time I raised the subject he would get progressively more angry. Finally he had my contract cancelled.
Here is the problem. The hydraulic servos had two phases of operation. One phase was when the V22 was in the helicopter mode and the servos would be commanded to change the swashplate position just like on a helicopter. Flying in the helicopter mode represents only a minor fraction of the total duty cycle for the hydraulic system. When in the airplane mode the hydraulic servos are maintained in a rigid position holding the swashplate in the position necessary to place pitch in the proprotor for forward flight. Unless the pilot changes the collective pitch to change thrust levels on the prop the servos never move. The entire life cycle was predicated on this kind of scenario and this in turn established the reliability requirements for the system.
Now I’m going to say something and I don’t want British trained pilots to jump on me and tell me I’m wrong. When in the airplane mode the proprotor responds to the gyroscopic turning moments induced when the aircraft deviates from straightforward flight. The same thing is true for an aircraft propeller. In the case of the propeller the shaft is held rigid in the engine nose case or in smaller engines the crankcase. The propeller wants to precess but it can’t. The proprotor on the other hand is mounted in elastomeric elements that will permit the proprotor to precess.
Built into the proprotor are flapping sensors. If flapping (read precession) is detected the hydraulic servos would be commanded to restore the proprotor to the normal or flat or, originally commanded position. This precession also causes thrust divergence. Because the proprotors are counter rotating the thrust line will be different for the two proprotors making it difficult to control the aircraft. This divergence will be different for every maneuver. Because the V22 spends a lot of time maneuvering while on a mission and, especially when getting ready to discharge troops in a landing zone the hydraulic system can operate ten to a hundred times more than predicted in the reliability analysis.
Please don’t think that I am saying this was the cause for the failure. It is just something to consider.
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The Cat
The Hydraulic system may have downed the V22 it also got me fired from a consulting job at Boeing Helicopters in Philadelphia.
I continually brought the subject up of reduced reliability of the hydraulic system due to higher than anticipated cyclic operation. I did this several times and each time I did my boss told me it was a Bell problem. I would disagree and that ended the conversation. Each time I raised the subject he would get progressively more angry. Finally he had my contract cancelled.
Here is the problem. The hydraulic servos had two phases of operation. One phase was when the V22 was in the helicopter mode and the servos would be commanded to change the swashplate position just like on a helicopter. Flying in the helicopter mode represents only a minor fraction of the total duty cycle for the hydraulic system. When in the airplane mode the hydraulic servos are maintained in a rigid position holding the swashplate in the position necessary to place pitch in the proprotor for forward flight. Unless the pilot changes the collective pitch to change thrust levels on the prop the servos never move. The entire life cycle was predicated on this kind of scenario and this in turn established the reliability requirements for the system.
Now I’m going to say something and I don’t want British trained pilots to jump on me and tell me I’m wrong. When in the airplane mode the proprotor responds to the gyroscopic turning moments induced when the aircraft deviates from straightforward flight. The same thing is true for an aircraft propeller. In the case of the propeller the shaft is held rigid in the engine nose case or in smaller engines the crankcase. The propeller wants to precess but it can’t. The proprotor on the other hand is mounted in elastomeric elements that will permit the proprotor to precess.
Built into the proprotor are flapping sensors. If flapping (read precession) is detected the hydraulic servos would be commanded to restore the proprotor to the normal or flat or, originally commanded position. This precession also causes thrust divergence. Because the proprotors are counter rotating the thrust line will be different for the two proprotors making it difficult to control the aircraft. This divergence will be different for every maneuver. Because the V22 spends a lot of time maneuvering while on a mission and, especially when getting ready to discharge troops in a landing zone the hydraulic system can operate ten to a hundred times more than predicted in the reliability analysis.
Please don’t think that I am saying this was the cause for the failure. It is just something to consider.
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The Cat
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Lu,
Now that is interesting. It is a pleasure to see someone look at potential problems in the V-22 with a degree of knowledge not shared by some on other threads. Bringing to light what could be a REAL problem can only be beneficial to the program. It is nice to read details on what could be an actual problem in the aircraft described by somebody with EXPERIENCE.
Thanks. Keep up the good work!
Now that is interesting. It is a pleasure to see someone look at potential problems in the V-22 with a degree of knowledge not shared by some on other threads. Bringing to light what could be a REAL problem can only be beneficial to the program. It is nice to read details on what could be an actual problem in the aircraft described by somebody with EXPERIENCE.
Thanks. Keep up the good work!
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On another thread about the V22 accident one of the participants on the thread made a comment about vortex ring state and the possibility of generating asymmetrical lift causing a roll over. Well, here is another problem that the V22 might incur when it goes into operation. But first, I have to set the scene for my comments later.
Many years ago a group of Marine HRSs (Sikorsky S-55) were placed on the flight deck of a carrier. The main landing gear were backed up to the very edge of the flight deck placing part of the disc over the deck and part about eighty feet over the water. When they started the rotors spinning and pulled collective one half of the disc was in ground effect and the other was not. As they began to rise off of the deck one-by-one they tipped backwards and fell into the ocean.
The V22 may have a similar situation in that when it comes in to land on its’ assigned spot it must parallel the path of the ship and move sideways while moving at the same forward speed of the ship. At some point, one proprotor will be over the flight deck in ground effect while the other proprotor is eighty feet over the water. Whether this will induce a rolling moment is yet to be determined.
In a similar situation, I almost had a pilot buy the farm for both of us. We were in an HTL-1 (early model 47) mounted in floats. This was in Greenland and we were spotting cracks in the ice and, providing this information to the ships Skipper to help simplify his passage through the ice fields.
Normally when the ship was underway, the pilots would lift off and keep climbing while at the same time moving sideways and letting the ship move away from us and then, push forward cyclic. In this particular case the pilot wanted to try something different. He just lifted off of the flight deck and left the ship move away from us. We were in ground effect relative to the ship but when it moved forward we were about fifty feet above the water and not generating enough lift. Even though we were on floats if we hit the water the turbulence generated by the ships screws would have turned us over. With presence of mind the pilot pulled more collective and pushed lateral cyclic to get us out of the turbulent airflow coming off the ship.
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The Cat
Many years ago a group of Marine HRSs (Sikorsky S-55) were placed on the flight deck of a carrier. The main landing gear were backed up to the very edge of the flight deck placing part of the disc over the deck and part about eighty feet over the water. When they started the rotors spinning and pulled collective one half of the disc was in ground effect and the other was not. As they began to rise off of the deck one-by-one they tipped backwards and fell into the ocean.
The V22 may have a similar situation in that when it comes in to land on its’ assigned spot it must parallel the path of the ship and move sideways while moving at the same forward speed of the ship. At some point, one proprotor will be over the flight deck in ground effect while the other proprotor is eighty feet over the water. Whether this will induce a rolling moment is yet to be determined.
In a similar situation, I almost had a pilot buy the farm for both of us. We were in an HTL-1 (early model 47) mounted in floats. This was in Greenland and we were spotting cracks in the ice and, providing this information to the ships Skipper to help simplify his passage through the ice fields.
Normally when the ship was underway, the pilots would lift off and keep climbing while at the same time moving sideways and letting the ship move away from us and then, push forward cyclic. In this particular case the pilot wanted to try something different. He just lifted off of the flight deck and left the ship move away from us. We were in ground effect relative to the ship but when it moved forward we were about fifty feet above the water and not generating enough lift. Even though we were on floats if we hit the water the turbulence generated by the ships screws would have turned us over. With presence of mind the pilot pulled more collective and pushed lateral cyclic to get us out of the turbulent airflow coming off the ship.
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The Cat
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It sounds like the V22 has aerodynamics problems, but I think the V22 has even bigger mechanical problems. (I am a mechanical engineer, but I don't claim to be an aero expert. I know a thing or two about mechanical systems, however.)
Simply put, the V22 is a flying Rube Golberg Contraption. I wouldn't trust a surface vehicle with that many moving parts.
Let's see: moving engines, structural pivot points for the entire engine / transmission assembly, power shaft passing through the pivot points and across the entire width of the aircraft through flexing wings, full collective pitch mechanism for two rotors, hydraulics to move the pivots, wing flaps...
It has no backup recovery methods. (glide, autorotate, eject) When one of the parts fails, you just drop like a rock.
Also note critical parts in close proximity to help the domino effect. For example, see the first fatal V22 crash where an engine fire took out the transmission shaft.
Some have said the aircraft is "not mature." That concept has been in development for over three decades! Okay, quiz time: what does it tell you when a huge budget and three decades of R&D doesn't produce a reliable product?
Answer: Brute-force engineering won't make a good idea out of a bad one.
I won't fly on a tiltrotor. Neither should you.
Dalebert, Mechanical Engineer
Simply put, the V22 is a flying Rube Golberg Contraption. I wouldn't trust a surface vehicle with that many moving parts.
Let's see: moving engines, structural pivot points for the entire engine / transmission assembly, power shaft passing through the pivot points and across the entire width of the aircraft through flexing wings, full collective pitch mechanism for two rotors, hydraulics to move the pivots, wing flaps...
It has no backup recovery methods. (glide, autorotate, eject) When one of the parts fails, you just drop like a rock.
Also note critical parts in close proximity to help the domino effect. For example, see the first fatal V22 crash where an engine fire took out the transmission shaft.
Some have said the aircraft is "not mature." That concept has been in development for over three decades! Okay, quiz time: what does it tell you when a huge budget and three decades of R&D doesn't produce a reliable product?
Answer: Brute-force engineering won't make a good idea out of a bad one.
I won't fly on a tiltrotor. Neither should you.
Dalebert, Mechanical Engineer