V-22 can't autorotate. Say what?
The V-22 is an attempt to create a helicopter/aeroplane hybrid, just like the Rotodyne, compound helicopters and a myriad of what used to be called "convertiplanes".
The glass-half-full approach is to regard it as both an inefficient helicopter and an inefficient aeroplane. The CH-53E has about the same power and empty weight, and can lift a buttload more stuff. The C-27J is a military cargo aeroplane with the same basic engines as the V-22, has a much greater payload and is faster and has a longer range. And neither needs a 5000 psi hydraulic system.
But if you need vertical capability, the V-22 actually exceeds the performance of the helicopter (range and productivity) once you get past a certain range. In particular, that's why the Spec Ops community loves it and why it works for NEOs. But as a utility trash-hauler, it's really not that much of an improvement over a modern helo. You can try to develop a CONOPS that makes sense, but it's tough (particularly when your heavy-lift and escort aircraft are still helicopters).
And Special Ops is exactly why it exists. If anyone else here remembers, the Marines were happily going about replacing the Phrog (in the early 80s) with a helicopter called HXM. But that was just after the Tehran rescue failure, and people in DC were dreaming of a magic solution that would work next time.
Consequently, people who were, to varying degrees, naive, opportunistic and optimistic invented JVX, which was based on a successful demonstrator and combined SO, Navy (including ASW), Air Force, Army and Marine requirements in a giant program that would (through economies of scale) deliver a tilt-rotor to the Marines for the price of a helo AND lay the basis for a commercial aircraft.
The optimism lay in timing and performance - the real aircraft is much heavier and needs more power/fuel than was predicted at the start, and the initial design was horribly expensive and unreliable. And as time went by and the costs got higher, everyone except SO (who loved it still) and the Marines (who had nailed their colors to the mast) bailed out. And the commercial idea was a load of dingo's kidneys from the get-go.
The glass-half-full approach is to regard it as both an inefficient helicopter and an inefficient aeroplane. The CH-53E has about the same power and empty weight, and can lift a buttload more stuff. The C-27J is a military cargo aeroplane with the same basic engines as the V-22, has a much greater payload and is faster and has a longer range. And neither needs a 5000 psi hydraulic system.
But if you need vertical capability, the V-22 actually exceeds the performance of the helicopter (range and productivity) once you get past a certain range. In particular, that's why the Spec Ops community loves it and why it works for NEOs. But as a utility trash-hauler, it's really not that much of an improvement over a modern helo. You can try to develop a CONOPS that makes sense, but it's tough (particularly when your heavy-lift and escort aircraft are still helicopters).
And Special Ops is exactly why it exists. If anyone else here remembers, the Marines were happily going about replacing the Phrog (in the early 80s) with a helicopter called HXM. But that was just after the Tehran rescue failure, and people in DC were dreaming of a magic solution that would work next time.
Consequently, people who were, to varying degrees, naive, opportunistic and optimistic invented JVX, which was based on a successful demonstrator and combined SO, Navy (including ASW), Air Force, Army and Marine requirements in a giant program that would (through economies of scale) deliver a tilt-rotor to the Marines for the price of a helo AND lay the basis for a commercial aircraft.
The optimism lay in timing and performance - the real aircraft is much heavier and needs more power/fuel than was predicted at the start, and the initial design was horribly expensive and unreliable. And as time went by and the costs got higher, everyone except SO (who loved it still) and the Marines (who had nailed their colors to the mast) bailed out. And the commercial idea was a load of dingo's kidneys from the get-go.
And the commercial idea was a load of dingo's kidneys from the get-go.
In fact - is that a problem for Special Ops?
airsound
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Originally Posted by Revolutionary
What happens next?
AEI in VTOL mode results in a 17° AOA and 4800-5,000 fpm ROD. The aircraft will be written off, but the scenario is considered survivable for the crew & pax.
For AEI in CTOL mode, the V-22 exhibits a 3800-4000 fpm ROD and 160-170 kt descent speed. As previously mentioned, landing at 0° chews-up the V-22’s proprotors (and probably doesn't do the donks & xmsn much good either), but is seen as a preferable to the VTOL scenario.
The V-22's 4.5:1 wing loading is about the same as that of an MD80.
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Avoid imitations
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I maintain if they wanted be there more quickly they would have been better off buying a new large helicopter and setting off a bit earlier 
The reason that VTOLs like the V-22 have not appealed to the civil market is one of those interesting interplays of engineering and economics...
The idea of a one-pad heliport (like the top of the PanAm building in NY) is an economic non-starter. The traffic is so limited that the service will never be more than Concorde-plus in the narrowness of the market.
So let's make a vertiport with (say) five to ten gates. First off, it's too big for the roof of the PanAm building - it will need some parking as well - and it will have a big noise impact, so it will be off to the edge of town on a brownfield site.
So far, so good...
BUT
This site is now fairly large, several hundred yards from end to end. Adding a short runway does not make it that bigger or more expensive. And even an ultra-short-runway aircraft - with a balanced field length of 2500 feet or so - is a hell of a lot less complicated, more effiicient and quieter than a VTOL. You can get 2500 feet out of a pretty conventional airplane (no cross-shafts or other monkey business).
And it's all so logical that it was thought through this way 35 years ago, in a big US DoT/FAA/industry study, and they actually came up with a spec for a 50-seat quiet STOL airliner, and the Canadians...
... actually built one.
And it was not a great success, but it was the McGuffin that started the idea of London City Airport, and it probably cost less to develop than was spent on the incredibly mendacious campaign for the commercial tilt-rotor.
The idea of a one-pad heliport (like the top of the PanAm building in NY) is an economic non-starter. The traffic is so limited that the service will never be more than Concorde-plus in the narrowness of the market.
So let's make a vertiport with (say) five to ten gates. First off, it's too big for the roof of the PanAm building - it will need some parking as well - and it will have a big noise impact, so it will be off to the edge of town on a brownfield site.
So far, so good...
BUT
This site is now fairly large, several hundred yards from end to end. Adding a short runway does not make it that bigger or more expensive. And even an ultra-short-runway aircraft - with a balanced field length of 2500 feet or so - is a hell of a lot less complicated, more effiicient and quieter than a VTOL. You can get 2500 feet out of a pretty conventional airplane (no cross-shafts or other monkey business).
And it's all so logical that it was thought through this way 35 years ago, in a big US DoT/FAA/industry study, and they actually came up with a spec for a 50-seat quiet STOL airliner, and the Canadians...
... actually built one.
And it was not a great success, but it was the McGuffin that started the idea of London City Airport, and it probably cost less to develop than was spent on the incredibly mendacious campaign for the commercial tilt-rotor.
Avoid imitations
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The Mil Mi-12 was a good example of how aircraft concepts can look good on paper, but flawed in practice. Much larger than anything before or since, with fantastic lift capability, this helicopter was so large that it needed an airport to work from. And the practical advantage therefore, in practice, was - nothing. A fixed wing was more practical. They built two prototypes; it never went into production.
If the tilt rotor can't get into helipads, it needs an airport and then......
I just hope they can get some use for the huge amount of money poured into the project.
If the tilt rotor can't get into helipads, it needs an airport and then......
I just hope they can get some use for the huge amount of money poured into the project.
I just hope they can get some use for the huge amount of money poured into the project.
What are you saying? Engineeers' kids put through college... retired Marines getting well-paid gigs in business development... Fat contributions to Rep. Curt Weldon's campaign...
What are you saying? Engineeers' kids put through college... retired Marines getting well-paid gigs in business development... Fat contributions to Rep. Curt Weldon's campaign...
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There seems to be incessant bitching about every new project, "it doesn't do this, it doesn't do that etc". Osprey, as per every other project is recieving it's criticism. Look at our own (UK) projects, Typhoon, MRA4, Merlin, all over budget, under performing new aircraft. I take my hat off to the designers, engineers and military personnel who've had the balls to design, build and introduce into service something radical and new that opens up new opportunities for commanders in theatre.
As for the points about vortex ring, the ROD figures quoted seem a lot higher than <500 fpm below 40kts that I stick to. Put any troop carrying helicopter into vortex ring and you risk killing all on board.
As for lack of redundancy, all helicopters have the tail rotor drive/control issue, 1 main gear box, as well as the inevitable other little bits that could have been designed better.
As for engine failure, it has 2, it will fly on 1, the chance of a double failure is very remote. Think how often military helo's are in the avoid curve (or 'death curve' as it realistically can be) if they lose 1 of 2 (or 3 engines). Merlin with 3 engines isn't necessarily safe twin, and you may have to ditch or 'cushion the touchdown'. Of course Osprey has it's faults and weaknesses, but so does nearly everything else (especially rotary) that flys. I'd like a go in one!
As for the points about vortex ring, the ROD figures quoted seem a lot higher than <500 fpm below 40kts that I stick to. Put any troop carrying helicopter into vortex ring and you risk killing all on board.
As for lack of redundancy, all helicopters have the tail rotor drive/control issue, 1 main gear box, as well as the inevitable other little bits that could have been designed better.
As for engine failure, it has 2, it will fly on 1, the chance of a double failure is very remote. Think how often military helo's are in the avoid curve (or 'death curve' as it realistically can be) if they lose 1 of 2 (or 3 engines). Merlin with 3 engines isn't necessarily safe twin, and you may have to ditch or 'cushion the touchdown'. Of course Osprey has it's faults and weaknesses, but so does nearly everything else (especially rotary) that flys. I'd like a go in one!
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I recall the early '90s when C17 was called Buddha. We called it that because it was big & fat, sat around & did nothing, yet eveyrone worshipped it. I was there when they created missions for it so it would have something to do. I recall hearing all of the issues of airdrop (can't drop personnel), short field work (wasn't meeting design spec), etc.
It has proven to be a more capable aircraft than anyone ever dreamed & still isn't being flown to its potential (at least by USAF). It also still has some problems.
The DT&E and OT&E phase of any new aircraft is designed to find flaws so they can be fixed prior to production or deployment. With public access to information, the Internet, mass media, etc. - every flaw is public knowledge and typically latched onto by the nay-sayers & scare-mongerers very quickly these days. Most of these people have an agenda, or at least a bias.
That doesn't mean we produce perfect planes, rather, we have a deliberate process to discover flaws so we might fix them earlier rather than later.
The Osprey is one of the few radical departures from traditional aviation design - as such, it's taken longer to develop. It still has flaws.
Most of the "limitations" on the Osprey or "things it can't do" are history at this point as they stem from early DT&E programs. One of my favorites is that you can't fastrope out of an Osprey. Pure & utter BS - the Osprey has always been able to fastrope troops from the tail - during DT&E they attempted to see if it was feasible out the side door - it's not. This gets twisted by people with an agenda to - "you can't fastrope out of it"
In many respects, you have to un-learn aspects of both rotary & fixed wing employment to appreciate the Osprey. It really is a new category/class of aircraft.
I'm still waiting on the C-model though!
It has proven to be a more capable aircraft than anyone ever dreamed & still isn't being flown to its potential (at least by USAF). It also still has some problems.
The DT&E and OT&E phase of any new aircraft is designed to find flaws so they can be fixed prior to production or deployment. With public access to information, the Internet, mass media, etc. - every flaw is public knowledge and typically latched onto by the nay-sayers & scare-mongerers very quickly these days. Most of these people have an agenda, or at least a bias.
That doesn't mean we produce perfect planes, rather, we have a deliberate process to discover flaws so we might fix them earlier rather than later.
The Osprey is one of the few radical departures from traditional aviation design - as such, it's taken longer to develop. It still has flaws.
Most of the "limitations" on the Osprey or "things it can't do" are history at this point as they stem from early DT&E programs. One of my favorites is that you can't fastrope out of an Osprey. Pure & utter BS - the Osprey has always been able to fastrope troops from the tail - during DT&E they attempted to see if it was feasible out the side door - it's not. This gets twisted by people with an agenda to - "you can't fastrope out of it"
In many respects, you have to un-learn aspects of both rotary & fixed wing employment to appreciate the Osprey. It really is a new category/class of aircraft.
I'm still waiting on the C-model though!
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It has long been a fundamental requirement designed into flying machines of all types that, should things, for whatever unlikely reason, suddenly go quiet, there is an additional option open to the crew and passengers to dying. It would seem that the Osprey does not offer an additional option. You wouldn't find me getting into one, however radical and innovative it may be considered.
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Clockwork Mouse - Ever flown in a modern airliner?? You know, with a nice new fly by wire control system?? Ever worried about a total electrical failure in that airliner?? Maybe you've flown to the USA in a twin engine airliner, did you worry away about a twin engine failure?? I'd much rather be in an Osprey with a double engine failure than in a 777 mid Atlantic.
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I heard the Osprey is a replacement for the aircraft (Herks and H-53) that attempted the Tehran hostage rescue. The one where they all piled up at 'Desert One'.
The idea is an a/c like the V-22 (had they had it at the time) could have:
1. Launched off the carrier- like the H-53s did.
2. Do a long transit with the troops/ 'hostages' in the back without having to refuel (so no herks needed)
3. Do the vertical landing at the hot end and pick up the hostages.
4. Missed out the 'Desert One' scenario altogether.
Who says the military doesn't equip for the last war they fought?
The idea is an a/c like the V-22 (had they had it at the time) could have:
1. Launched off the carrier- like the H-53s did.
2. Do a long transit with the troops/ 'hostages' in the back without having to refuel (so no herks needed)
3. Do the vertical landing at the hot end and pick up the hostages.
4. Missed out the 'Desert One' scenario altogether.
Who says the military doesn't equip for the last war they fought?
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No - the Osprey is not a replacment for the Herk/H-53. The Iran Hostage Rescue mission, Operation Eagle Claw, is merely the standard they are using to measure performance.
Most proponents of the McRaven philosophy of Relative Superiority and the key element of Surprise suppose that the single biggest risk for Eagle Claw was it required two days to execute. The quest for conducting this type of long-range mission in a "single period of darkness" has been used as the standard to measure the Osprey against.
I suppose it's been applied retro-actively - in other words, we decided we liked the Osprey & tried to figure out how we would have used it in the past.
That's why it's linked to Eagle Claw - not as a replacement for Herks & -53s.
FWIW - It would have required refueling had it done the Iran Rescue Mission. It also would have had to go in much larger numbers than the RH-53s. Part of the problems I alluded to very early in this thread about letting the Marines dictate the dimensions before AFSOC got involved...
Maybe the C-model will be bigger!
Most proponents of the McRaven philosophy of Relative Superiority and the key element of Surprise suppose that the single biggest risk for Eagle Claw was it required two days to execute. The quest for conducting this type of long-range mission in a "single period of darkness" has been used as the standard to measure the Osprey against.
I suppose it's been applied retro-actively - in other words, we decided we liked the Osprey & tried to figure out how we would have used it in the past.
That's why it's linked to Eagle Claw - not as a replacement for Herks & -53s.
FWIW - It would have required refueling had it done the Iran Rescue Mission. It also would have had to go in much larger numbers than the RH-53s. Part of the problems I alluded to very early in this thread about letting the Marines dictate the dimensions before AFSOC got involved...
Maybe the C-model will be bigger!
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"Part of the problems I alluded to very early in this thread about letting the Marines dictate the dimensions before AFSOC got involved..."
Yes, heaven forbid we let the Marines insist that it fit where they need it to fit, and in the numbers they need.
Everyone knows it is much better to stick with a "let it grow as big as it needs to, then build new (larger) ships to operate it" plan, right?
Yes, heaven forbid we let the Marines insist that it fit where they need it to fit, and in the numbers they need.
Everyone knows it is much better to stick with a "let it grow as big as it needs to, then build new (larger) ships to operate it" plan, right?
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Originally Posted by GreenKnight121
Yes, heaven forbid we let the Marines insist that it fit where they need it to fit, and in the numbers they need.
Everyone knows it is much better to stick with a "let it grow as big as it needs to, then build new (larger) ships to operate it" plan, right?
Everyone knows it is much better to stick with a "let it grow as big as it needs to, then build new (larger) ships to operate it" plan, right?
What I said previously, & I'll say again, is Bell approached AFSOC first, but AFSOC could not afford the R&D for the small quantity they would buy & since no one else in the USAF was going to buy them (although I think they'd be a perfect CSAR-X candidate), they had to pass. Besides which, AFSOC gets no money for aircraft themselves - they get MFP-11 money ONLY to modify existing aircraft for the SOF mission.
By the time AFSOC gained approval to pursue V-22, several key design parameters had been fixed in place by USMC. Most painfully for AFSOC (and SOCOM by extension), the dimensions of the cargo compartment - no existing SOF vehicles fit. This is not the USMC fault, nor is it an indictment of that aspect of the program.
This is a common problem for AFSOC (and other SOF units) - not enough buying power due to small quantities & no (or few) separate lines of funding.
For example, the same thing happened with Panoramic NVGs. I tested prototypes in '97, but AFSOC couldn't afford to fund the remaining R&D, so we had to pass. AFRL approached ACC, specifically the A-10 community, who jumped on it. Only after ACC bought enough of them to bring per-unit costs down did AFSOC say they'd get in. They get in at the end though & have to wait for ACC to take delivery of all of theirs first. Oh by the way, ACC keeps adding more & more requirements to them (and rightfully so for their mission) - this is delaying deployment, adding to weight, complexity, & cost and there's no telling when we'll see them...I'd have been happy with the prototypes!! Last I heard, cost was almost four times prototype costs!
One of the reasons I believe SOCOM should be a separate command - funding. But that's another can of worms!
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I saw 3 at Kirtland in August, so I guess the USAF has them too. These will be MV-22 then?
Have to say, they don't 'look right' to me. And you know what they say abput aircraft that 'look right' don't you?
Have to say, they don't 'look right' to me. And you know what they say abput aircraft that 'look right' don't you?
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Originally Posted by brain fade
I saw 3 at Kirtland in August, so I guess the USAF has them too. These will be MV-22 then?
Being career AFSOC, seems backwards to me.
I think they have four here at Kirtland.
Thank you, US Herk, for your knowledgeable and helpful posts.
I wonder if you have a view on something I suggested a few posts ago (#42), that V-22 is so noisy, especially in the hover and transition, that its use as an AFSOC vehicle could be compromised. After all - special operations surely need as much visual and aural stealth as you can manage?
airsound
I wonder if you have a view on something I suggested a few posts ago (#42), that V-22 is so noisy, especially in the hover and transition, that its use as an AFSOC vehicle could be compromised. After all - special operations surely need as much visual and aural stealth as you can manage?
airsound
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Have to say, they don't 'look right' to me. And you know what they say abput aircraft that 'look right' don't you?
“I’m quite sure those V-22 grapes are sour,” said the disappointed fox. “No need for me to try to jump high enough to taste them.”
I wonder if you have a view on something I suggested a few posts ago (#42), that V-22 is so noisy, especially in the hover and transition, that its use as an AFSOC vehicle could be compromised.
.How much quieter is a helo of equivalent size? Answer: not much.
In regard to to the size of the V-22, apparently the USMC specified that it have the same cabin size and folded deck parking footprint as an H-46. In hindsight, the V-22 should have been larger, at least as big as the proposed CH-53K.
“I’m quite sure those V-22 grapes are sour,” said the disappointed fox. “No need for me to try to jump high enough to taste them.”
I wonder if you have a view on something I suggested a few posts ago (#42), that V-22 is so noisy, especially in the hover and transition, that its use as an AFSOC vehicle could be compromised.
.How much quieter is a helo of equivalent size? Answer: not much.
In regard to to the size of the V-22, apparently the USMC specified that it have the same cabin size and folded deck parking footprint as an H-46. In hindsight, the V-22 should have been larger, at least as big as the proposed CH-53K.
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For what it's worth, I have flown the Sim :-)
I had the privelege of a couple of sessions in a V-22 fixed base sim sateside earlier this year, and it was impressive. The PFD goves you LOTS of cues that you may be about to enter a high sink-rate situation and an audible warning if the descent rate gets too high. Also, the nacelles can be tilted quite far forward of the vertical while maintaining adequate ground clearance, which allows short takeoffs and landings to be performed. My background is fixed wing and I found it quite easy to hover. Transition was also a non-event in handling terms, the FCS seemed well sorted.
It seems a lot of people on this thread have criticised the V-22 without actually having had anything to do with it. My advice would be keep your badly informed (or utterly ignorant) comments to yourself. Yes it is expensive, yes it has some unique vulnerabilities due to its unique design, but if a mission needs a VTOL aircraft with long range and high speed transit, it will outperform conventional helos by a big margin. I await with interest reports on how it does in Iraq, and hope it does well.
As for people who think you can get out of VR using collective - I NEVER EVER want to be in a helicopter with you
It seems a lot of people on this thread have criticised the V-22 without actually having had anything to do with it. My advice would be keep your badly informed (or utterly ignorant) comments to yourself. Yes it is expensive, yes it has some unique vulnerabilities due to its unique design, but if a mission needs a VTOL aircraft with long range and high speed transit, it will outperform conventional helos by a big margin. I await with interest reports on how it does in Iraq, and hope it does well.
As for people who think you can get out of VR using collective - I NEVER EVER want to be in a helicopter with you