I recently read "The Dream Machine" by Richard Whittle on the V-22 after checking it out from my library.
It covers the XV-15 program in some detail -- the XV-15 from it's description in the book was a pretty sweet machine, it was pretty docile enough to be used for all sorts of PR stunts, like sending it overseas to Paris in 1981, and then landing on the steps of the Capitol in 1990ish as part of a V-22 program demo. And of course, everyone from Barry Goldwater to SECNAV John Lehman wanted a demo ride in it.
There was also a proposed movie star role for the XV-15 in about 1995. A movie company was looking to use the XV-15 to land a woman on a ship off of Newfoundland to help some treasure hunter.
Bell declined it due to possible worries about the icy weather and the fact that the XV-15 was still set up for flight test instrumentation.
The movie turned out to be TITANIC, where Cameron instead used a Sea King instead. Oh well.
Bell's engineers had a conceptual design for a sort of slightly scaled up XV-15, a V-15B if you will carrying 12 troops; but marketing led by Dick Spivey overruled them, saying that the USMC wanted a 24-man craft.
Additionally, Spivey put forth the argument that if they pushed a 12 man aircraft, there would be pressure to just buy the UH-60 Blackhawk series instead, especially since the Navy was about to buy a whole bunch of marinized SH-60s.
Spivey is one of the central characters of the book; and he comes off as a kind of sad figure. He basically ruined his first marriage and spent his entire professional life at Bell endlessly chasing the White Whale of a operational tilt-rotor by endlessly flacking the concept to whoever would listen at the Pentagon, and then once the JVX (V-22) program got started, he spent a lot of time either selling it or trying to save it from cancelation.
What really got the JVX program off the ground in the early 1980s was SECNAV Lehman. At the time, the idea was that the USMC would fund development of the Boeing-Vertol Model 360 "Plastic Phrog" for about $2 billion. The Model 360 would use composites, carry 18-24 troops and cruise at 180 knots, replacing the earlier CH-46.
Lehman was adamantly against "paying $2 billion for another helicopter!" and he all but ordered that the Marines' CH-46 replacement be a tilt-rotor.
The Marines didn't help matters much with the JVX specifications that launched the program:
JVX was to carry Marines to a distance of 50 to 110 nautical miles while flying no higher than 3,500 ft. All dandy?
Except Tilt-rotors are actually at their most efficient flying high and fast -- at around 30,000 to 45,000 feet.
Then the whole thing had to operate from a LHA. The JVX specs said that the JVX would have to be capable of taxiing past the ship's island with it's rotors turning.
The closest rotor had to clear the island by 12'8" and the landing gear tires would have to stay 5' from the outboard deck edge.
This means each proptor could only be 38' or less in diameter.
Bigger rotors mean smaller disc loading and more thrust generated per horsepower.
The higher the disc loading, the bigger your engines are, and you need a heavier structure to support them, more fuel to run the engines, etc etc in a weight spiral.
The USMC envisioned a JVX of about 20-25,000 lbs empty; about 4,000 lbs more than the CH-46.
The USN was far more realistic -- NAVAIR put a maximum empty weight of 31,886 lbs.
The only people who bid were the consortium of Bell-Boeing Vertol; who had earlier agreed by handshake of their corporate execs to pursue a 50/50 split. This decision caused many of the problems that would plague the program; since there was no clear person/company in charge to make the tough decisions, like there would have if it was a 60/40 split.
As they tried to make a tilt-rotor that would meet the performance goals in JVX, the plan was to use an uncommonly large amount of composites in the aircraft; and composites were very much an unknown area in the 1980s. This led to many problems as they were doing things nobody had ever done before, like make a very large aircraft fuselage out of composites.
For the engines, GE and Pratt were developing engines under a Army development program for helicopters called Modern Technology Demonstrator Engines (MTDE).
GE's offering was the GE27; it weighed 850 lbs and had great SFC, and was heavily favored by the Bell-Boeing engineers. Pratt was offering their PW3005. Allison was offering the T406, a variant of their T56 that powered the C-130 and P-3.
NAVAIR went to SECNAV Lehman and told him that we want the GE engine. Lehman turned them down and told them to go with Allison's proposal.
Why?
Because to Lehman, the T406 was the cheapest of them all, and because it operated at lower Turbine Inlet Temperatures, it could be "tuned up" to give more power easily than the other engines.
Of course, the T406s weighed 1,050 lbs each, and forced Bell-Boeing to completely redesign the Osprey's engine mounts, fuel lines and structure -- that added 600 lbs to the V-22.
The V-22A prototypes that emerged in 1989 tipped the scales at 39,450 lbs empty.
The plane then went through a long gestation from 1988-1992, because of Dick Cheney.
Dick Cheney tried repeatedly to kill the program, but kept getting overruled by Congress during that period due to a very aggressive campaign by the USMC and Bell-Boeing partisans.
For example, did you know that the UAW designated the V-22 as a "priority"; meaning that if a Democrat wanted a 100% rating from the UAW, he had to vote for the V-22, even if he was normally anti defense?
What Cheney finally settled on was to prevent the V-22 from going into EMD. He basically kept it in FSD, with money going towards building prototypes, rather than for a full scale production line for LRIP aircraft for four years.
This....was probably a very good idea; as those four years gave the V-22 team time to tackle many of the problems in the V-22A by essentially totally redesigning the aircraft into the V-22B.
Of course, the 20 July 1992 crash that caused a V-22A to crash into the Potomac river in full view of Congressmen at Quantico...showed many problems with the V-22's original design.
What happened was that somehow some combustible fluid had begun to leak into the right nacelle during the V-22A's 3~ hour flight from Eglin to Quantico.
It was probably due to a oil seal being installed backwards in the proptor gearbox. Because the plane flew in horizontal flight mode for the three hour flight, the oil collected in the bottom of the engine cowling and sat there.
But when the nacelles tilted for vertical landing, the oil then rushed into the engine where it caught fire. It then caused an engine surge.
This surge triggered a governor which was designed to prevent engine overspeed. The pilots reset the flight control system, as it was SOP for with the V-22A to make sure it was real and not a glitch in the wiring.
This caused both engines to rapidly increase in power, overspeeding both. This caused the right engine to fail.
Now, you're saying, what about that famed cross-link driveshaft that lets one engine drive the other in an event like this?
Because the crosslink driveshaft has to turn 90 degrees to get to the proptor; there's a second driveshaft in each nacelle called the Pylon driveshaft.
This driveshaft in order to save weight was made out of composites. The specific composites that shaft were made of melt at 240F. The fire in the right nacelle was about 900~F.
The driveshaft melted and deformed enough to cause the right proptor to stop. But that wasn't all. Due to it's deformation and because it was still getting power through the crosslink; it then tore through various electrical and hydraulic lines in the nacelle; causing the flight control computer to die and freeze the nacelles in their 58 degree angle that they were found at the bottom of the Potomac River.
Of course, a wild card then got thrown into the game. The Clinton/Gore candidacy, seeking a way to make themselves tough on defense; endorsed the Osprey both during visits to Bell and in a debate with Bush I.
The V-22 was one of those odd military programs that the Republicans were lukewarm on, while the Democrats had an above average interest.
Clinton's election ensured that the V-22 would proceed to EMD and that Bell-Boeing would get a second try with the V-22B.
80% of all the engineering drawings for the V-22B were new; and instead of the fuselage being nearly all composite, it was only 43%.
Newer developments in high strength milled aluminum construction enabled each aluminum fuselage frame made to weigh six pounds *less* than the composite frames. The switch to more traditional materials also eliminated 18,500 metal fasteners previously needed to hold the composites together.
They saved 800 pounds by replacing the older-style CRT MFDs and avonics in the A model with newer lighter LCD MFDs and avonics.
They also saved 300 pounds and $300,000 by replacing the 'bed frame' stationary ring made out of composites on the V-22A with a flex ring system made out of stainless steel on the V-22B. The ring was at the heart of the wing folding system. This was only possible because an older engineer who had promoted the bed frame ring had retired, allowing the competiting system to be used.
By 1999, the V-22B looked to be all past it's growing pains.
And then two V-22s crashed in 2000.
The two central causes were essentially:
1.) Bell-Boeing basically designed the V-22 to be very maintenance unfriendly. The classic case of engineers designing the perfect widget and forgetting how to make sure someone can mantain it in the real world.
This was also not helped by the "no clear responsibility or leader" brought about by the 50/50 split in responsibility between Bell/Boeing.
2.) The MARINES were pushing very very hard to get the V-22 into service as fast as possible to relieve their CH-46 crisis. This led to maintenance gundecking; reporting availability rates far far higher than actually were the case; skipping key parts of flight testing, compressing the data points gathered during flight test, etc.
The end result of the two crashes was that sanity returned to the V-22 program office.
DoD set up a joint office with Bell/Boeing with the authority to order things changed -- one of their first tasks was to essentially redesign a large part of the engine nacelles to be more easily maintainable with input from senior aircraft maintenance men in the Marine Corps during the redesign program.
The Marines also stepped back in their desire to get the V-22 as fast as possible in order to do a proper flight test program.
They did a lot of testing the true edge of the Osprey's envelope in the restructured flight test program post 2000. It turned out that vortex ring state issue was not as bad as feared and also that the V-22 was much more manouverable at low altitudes and speeds than initally thought.
In the end though; you're left with the impression that while the V-22 is probably very technically impressive; it was a bridge too far for the Marine Corps.
It tied up a quarter century of procurement efforts and Marine Prestige on Capitol Hill as they kept trying to save the program; and resulted in a plane that costs $74 million (MV-22B buy of 30 planes in FY2011 USN Budget).
This is only about $10 million less than a Super Hornet in the USN's FY2011 request, and twice the cost of what the US Army is paying for new-build CH-47Fs ($35.6m) in the FY2011 request.
It's essentially the perfect replacement for a MH-53 if you want to do all sorts of spooky things that require you to fly hundreds of nautical miles behind enemy lines, land in a small space, and then fly back to safety without refueling. However, as a notational replacement for the CH-46 in the 50-110 nm OTH Amphibious assault role; it doesn't have a clear advantage at such short distances that justifies it's cost versus a more conventional rotorcraft.
It covers the XV-15 program in some detail -- the XV-15 from it's description in the book was a pretty sweet machine, it was pretty docile enough to be used for all sorts of PR stunts, like sending it overseas to Paris in 1981, and then landing on the steps of the Capitol in 1990ish as part of a V-22 program demo. And of course, everyone from Barry Goldwater to SECNAV John Lehman wanted a demo ride in it.
There was also a proposed movie star role for the XV-15 in about 1995. A movie company was looking to use the XV-15 to land a woman on a ship off of Newfoundland to help some treasure hunter.
Bell declined it due to possible worries about the icy weather and the fact that the XV-15 was still set up for flight test instrumentation.
The movie turned out to be TITANIC, where Cameron instead used a Sea King instead. Oh well.
Bell's engineers had a conceptual design for a sort of slightly scaled up XV-15, a V-15B if you will carrying 12 troops; but marketing led by Dick Spivey overruled them, saying that the USMC wanted a 24-man craft.
Additionally, Spivey put forth the argument that if they pushed a 12 man aircraft, there would be pressure to just buy the UH-60 Blackhawk series instead, especially since the Navy was about to buy a whole bunch of marinized SH-60s.
Spivey is one of the central characters of the book; and he comes off as a kind of sad figure. He basically ruined his first marriage and spent his entire professional life at Bell endlessly chasing the White Whale of a operational tilt-rotor by endlessly flacking the concept to whoever would listen at the Pentagon, and then once the JVX (V-22) program got started, he spent a lot of time either selling it or trying to save it from cancelation.
What really got the JVX program off the ground in the early 1980s was SECNAV Lehman. At the time, the idea was that the USMC would fund development of the Boeing-Vertol Model 360 "Plastic Phrog" for about $2 billion. The Model 360 would use composites, carry 18-24 troops and cruise at 180 knots, replacing the earlier CH-46.
Lehman was adamantly against "paying $2 billion for another helicopter!" and he all but ordered that the Marines' CH-46 replacement be a tilt-rotor.
The Marines didn't help matters much with the JVX specifications that launched the program:
JVX was to carry Marines to a distance of 50 to 110 nautical miles while flying no higher than 3,500 ft. All dandy?
Except Tilt-rotors are actually at their most efficient flying high and fast -- at around 30,000 to 45,000 feet.
Then the whole thing had to operate from a LHA. The JVX specs said that the JVX would have to be capable of taxiing past the ship's island with it's rotors turning.
The closest rotor had to clear the island by 12'8" and the landing gear tires would have to stay 5' from the outboard deck edge.
This means each proptor could only be 38' or less in diameter.
Bigger rotors mean smaller disc loading and more thrust generated per horsepower.
The higher the disc loading, the bigger your engines are, and you need a heavier structure to support them, more fuel to run the engines, etc etc in a weight spiral.
The USMC envisioned a JVX of about 20-25,000 lbs empty; about 4,000 lbs more than the CH-46.
The USN was far more realistic -- NAVAIR put a maximum empty weight of 31,886 lbs.
The only people who bid were the consortium of Bell-Boeing Vertol; who had earlier agreed by handshake of their corporate execs to pursue a 50/50 split. This decision caused many of the problems that would plague the program; since there was no clear person/company in charge to make the tough decisions, like there would have if it was a 60/40 split.
As they tried to make a tilt-rotor that would meet the performance goals in JVX, the plan was to use an uncommonly large amount of composites in the aircraft; and composites were very much an unknown area in the 1980s. This led to many problems as they were doing things nobody had ever done before, like make a very large aircraft fuselage out of composites.
For the engines, GE and Pratt were developing engines under a Army development program for helicopters called Modern Technology Demonstrator Engines (MTDE).
GE's offering was the GE27; it weighed 850 lbs and had great SFC, and was heavily favored by the Bell-Boeing engineers. Pratt was offering their PW3005. Allison was offering the T406, a variant of their T56 that powered the C-130 and P-3.
NAVAIR went to SECNAV Lehman and told him that we want the GE engine. Lehman turned them down and told them to go with Allison's proposal.
Why?
Because to Lehman, the T406 was the cheapest of them all, and because it operated at lower Turbine Inlet Temperatures, it could be "tuned up" to give more power easily than the other engines.
Of course, the T406s weighed 1,050 lbs each, and forced Bell-Boeing to completely redesign the Osprey's engine mounts, fuel lines and structure -- that added 600 lbs to the V-22.
The V-22A prototypes that emerged in 1989 tipped the scales at 39,450 lbs empty.
The plane then went through a long gestation from 1988-1992, because of Dick Cheney.
Dick Cheney tried repeatedly to kill the program, but kept getting overruled by Congress during that period due to a very aggressive campaign by the USMC and Bell-Boeing partisans.
For example, did you know that the UAW designated the V-22 as a "priority"; meaning that if a Democrat wanted a 100% rating from the UAW, he had to vote for the V-22, even if he was normally anti defense?
What Cheney finally settled on was to prevent the V-22 from going into EMD. He basically kept it in FSD, with money going towards building prototypes, rather than for a full scale production line for LRIP aircraft for four years.
This....was probably a very good idea; as those four years gave the V-22 team time to tackle many of the problems in the V-22A by essentially totally redesigning the aircraft into the V-22B.
Of course, the 20 July 1992 crash that caused a V-22A to crash into the Potomac river in full view of Congressmen at Quantico...showed many problems with the V-22's original design.
What happened was that somehow some combustible fluid had begun to leak into the right nacelle during the V-22A's 3~ hour flight from Eglin to Quantico.
It was probably due to a oil seal being installed backwards in the proptor gearbox. Because the plane flew in horizontal flight mode for the three hour flight, the oil collected in the bottom of the engine cowling and sat there.
But when the nacelles tilted for vertical landing, the oil then rushed into the engine where it caught fire. It then caused an engine surge.
This surge triggered a governor which was designed to prevent engine overspeed. The pilots reset the flight control system, as it was SOP for with the V-22A to make sure it was real and not a glitch in the wiring.
This caused both engines to rapidly increase in power, overspeeding both. This caused the right engine to fail.
Now, you're saying, what about that famed cross-link driveshaft that lets one engine drive the other in an event like this?
Because the crosslink driveshaft has to turn 90 degrees to get to the proptor; there's a second driveshaft in each nacelle called the Pylon driveshaft.
This driveshaft in order to save weight was made out of composites. The specific composites that shaft were made of melt at 240F. The fire in the right nacelle was about 900~F.
The driveshaft melted and deformed enough to cause the right proptor to stop. But that wasn't all. Due to it's deformation and because it was still getting power through the crosslink; it then tore through various electrical and hydraulic lines in the nacelle; causing the flight control computer to die and freeze the nacelles in their 58 degree angle that they were found at the bottom of the Potomac River.
Of course, a wild card then got thrown into the game. The Clinton/Gore candidacy, seeking a way to make themselves tough on defense; endorsed the Osprey both during visits to Bell and in a debate with Bush I.
The V-22 was one of those odd military programs that the Republicans were lukewarm on, while the Democrats had an above average interest.
Clinton's election ensured that the V-22 would proceed to EMD and that Bell-Boeing would get a second try with the V-22B.
80% of all the engineering drawings for the V-22B were new; and instead of the fuselage being nearly all composite, it was only 43%.
Newer developments in high strength milled aluminum construction enabled each aluminum fuselage frame made to weigh six pounds *less* than the composite frames. The switch to more traditional materials also eliminated 18,500 metal fasteners previously needed to hold the composites together.
They saved 800 pounds by replacing the older-style CRT MFDs and avonics in the A model with newer lighter LCD MFDs and avonics.
They also saved 300 pounds and $300,000 by replacing the 'bed frame' stationary ring made out of composites on the V-22A with a flex ring system made out of stainless steel on the V-22B. The ring was at the heart of the wing folding system. This was only possible because an older engineer who had promoted the bed frame ring had retired, allowing the competiting system to be used.
By 1999, the V-22B looked to be all past it's growing pains.
And then two V-22s crashed in 2000.
The two central causes were essentially:
1.) Bell-Boeing basically designed the V-22 to be very maintenance unfriendly. The classic case of engineers designing the perfect widget and forgetting how to make sure someone can mantain it in the real world.
This was also not helped by the "no clear responsibility or leader" brought about by the 50/50 split in responsibility between Bell/Boeing.
2.) The MARINES were pushing very very hard to get the V-22 into service as fast as possible to relieve their CH-46 crisis. This led to maintenance gundecking; reporting availability rates far far higher than actually were the case; skipping key parts of flight testing, compressing the data points gathered during flight test, etc.
The end result of the two crashes was that sanity returned to the V-22 program office.
DoD set up a joint office with Bell/Boeing with the authority to order things changed -- one of their first tasks was to essentially redesign a large part of the engine nacelles to be more easily maintainable with input from senior aircraft maintenance men in the Marine Corps during the redesign program.
The Marines also stepped back in their desire to get the V-22 as fast as possible in order to do a proper flight test program.
They did a lot of testing the true edge of the Osprey's envelope in the restructured flight test program post 2000. It turned out that vortex ring state issue was not as bad as feared and also that the V-22 was much more manouverable at low altitudes and speeds than initally thought.
In the end though; you're left with the impression that while the V-22 is probably very technically impressive; it was a bridge too far for the Marine Corps.
It tied up a quarter century of procurement efforts and Marine Prestige on Capitol Hill as they kept trying to save the program; and resulted in a plane that costs $74 million (MV-22B buy of 30 planes in FY2011 USN Budget).
This is only about $10 million less than a Super Hornet in the USN's FY2011 request, and twice the cost of what the US Army is paying for new-build CH-47Fs ($35.6m) in the FY2011 request.
It's essentially the perfect replacement for a MH-53 if you want to do all sorts of spooky things that require you to fly hundreds of nautical miles behind enemy lines, land in a small space, and then fly back to safety without refueling. However, as a notational replacement for the CH-46 in the 50-110 nm OTH Amphibious assault role; it doesn't have a clear advantage at such short distances that justifies it's cost versus a more conventional rotorcraft.
