Report on Tiltrotor Osprey in Iraq

Michael Smith

Thu Jul 31 19:45:15 -0700 2008

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And now there is a new player in the field of short take off and landing (STOL) load carriers. WhiteKnightTwo can fly high enough to get above a lot of low tech anti aircraft fire, and at low altitude it should be almost as manoevurable as an Osprey.

Report on Tiltrotor Osprey in Iraq

AB3A

Fri Aug 01 04:43:26 -0700 2008

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My impression of the Osprey is that it is a critter that could only have been designed by a committee of people with orthogonal concerns that they were unwilling to compromise on.  Occasionally, such committees really do come up with very useful results.  However, they need to compromise a bit. 

For example, what if instead of landing and taking off vertically, we said we wanted this thing to land and take off on very short, unimproved runways.  Given 100' of runway you could build some very useful troop transports that might be able to fly pretty fast. 

Those aircraft exist.  Add a set of JATOs to them, and you could get in and out of some very tight places.  Ever seen "Fat Albert" do a JATO takeoff in a Blue Angels demo? 

The problem is that the folks who insisted upon being able to do vertical takeoffs and landings wouldn't consider the alternative of very slow flight. 

If anyone has ever seen the Itty Bitty Runway act at an air show, it proves that with reasonable forward motion, you can put an airplane down on a helicopter pad without a whole lot of fuss. 

Until the materials and engines improve (and there is hope that they will), I think the Osprey will remain a dangerous aircraft to fly.

Report on Tiltrotor Osprey in Iraq

peacefinder

Fri Aug 01 11:29:19 -0700 2008

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As I understand it, it was specified to meet a tactical requirement of the Marines. It had to be able to lift a $payload from something similar to an LHD, fly far and fast to an unimproved drop zone, deliver its cargo on the ground, and take off to return. Furthermore it should be able to cycle out to deliver a new load with nothing more than a reload of cargo and fuel. Much of that requirement that could be done with helicopters, but the problem with them I think is both range (how far can they drop inland?) and speed (how many drops can be made in an hour?). The ability to use completely unimproved landing zones rules out anything but a VTOL craft, while the quick sortie interval probably rules out any kind of JATO-dependent craft.

It's a brutally difficult requirement from an engineering perspective, but the Marines evidently are so firm in that requirement that they've stuck with the Osprey for, what, twenty years?

Report on Tiltrotor Osprey in Iraq

MegaZone

Fri Aug 01 15:35:12 -0700 2008

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The V-22 Osprey is primarily a replacement for the CH-46 Sea Knight, so STOL would be useless, VTOL is a hard requirement.  The Osprey can actually do STOL, and when it does it can carry more payload, but VTOL is required for shipboard operations, for dropping off and picking up troops in remote locations - anywhere there is no airstrip, handling sling loads, etc.

Using a tilt-rotor instead of a conventional helicopter provides benefits in range and speed.  The Marines want to be able to get in and out of hot areas faster, helicopters are often lost in transit as they fly low and relatively slow.  The Osprey is also slated for use in special operations and SAR, when being able to transit fast is important, and you need to be able to hover and land vertically when you get to the destination.

There do seem to be issues with the engines, and there is an effort underway to address that.  It may come down to needing to replace the Allison AE-1107 engines with something else if they can't correct the issues.  But odds are they'll get it worked out.

As for the issue of losing altitude with a busted engine, there are important facts missing.  What was the pressure altitude?  If they were flying in hot conditions and/or at high altitude, both of which are likely in the region, then any aircraft can be impacted by a loss of power.  Was it in wing borne or rotor borne flight when it happened?  Rotor borne is much more dependent on power.  The Osprey can certainly maintain altitude on one engine, that's been demonstrated, but there are real world limitations - the higher the pressure altitude the more power is required and the greater the impact of any loss.

The V-22 is the first production tilt rotor, it should be expected that it will experience issues as it breaks new ground.  The same things happened with the first jets, the first helicopters, etc.  There will be unexpected engineering issues that come up, even with modern design tools.

Report on Tiltrotor Osprey in Iraq

justin

Sat Aug 02 10:53:18 -0700 2008

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You are using techno-babble to obfuscate the issue.

The Osprey was developed to solve problems with speed and carrying capacity that the Air Cavalry (and similar groups) encountered in VIETNAM.

In Veitnam, advances in helicopter technology allowed the military to use a new type of engagement. They could use helicopters to bring a large ammount of troops into an inaccessable area in a short ammount of time, and theoretically bring out the injured faster.

The PROBLEM was that there never seemed to be enough room on the helicopters to take away all the wounded fast enough. Soldiers had to watch their friends die in their hands because the choppers were too slow or filled to capacity.

Those are the problems the Osprey was originally intended to resolve. Straight line speed and capacity (with helicopter-level VTOL ability).

Now, the boondoggle begins...

The problem is, and always has been that the two rotors can't auto-rotate.

If one rotor fails, the damn thing flips over. At low altitudes (where you're most likely to take fire from small arms that could take out one of the rotors), the thing can't transform to a plane fast enough to glide down. In one incedent, the thing was doing a demonstration (that was supposed to show that it was past it's problems and ready for deployment) in front of Congressmen. An engine failed and it flipped, killing everyone inside, including all the ace test pilots who had worked on developing it for over a decade...all this *in front of congressmen*

Just like any Military boondoggle, it's become a big session of CYA (cover your ass). No one wants to admit that the thing doesn't work AS INTENDED and doesn't solve the problems it was supposed to solve.

Sure it can VTOL. Sure it's fast in straight line flight. But it's never going to do what it was intended to do in it's current incarnation. It's not approved for use in the heavy combat situations it was originally intended for.

Boondoggle...50 Billion-plus down the drain so high up military can save face.

Report on Tiltrotor Osprey in Iraq

MegaZone

Sat Aug 02 13:21:55 -0700 2008

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It isn't technobabble, it is the accepted terminology.  And you're also incorrect.  The crash 'in front of congressmen' was due to a *fire* in a nacelle.  It had nothing to do with the ability to auto-rotate.  If the rotor hub in ANY helicopter burns, you're going to have a hard time staying in the air.  The Osprey can auto-rotate under normal conditions - normal being the loss of an engine, not a nacelle on fire.  There is a shaft that connects the two nacelles that allows one engine to power both rotors and keeps them in sync even with loss of all power.  I'll also note that the crash in question was in 1992, very early in the life of the Osprey, and it didn't involve 'flipping'.

Perhaps you're confused with the next incident listed, in which the Osprey suffered a rotor stall during a steep simulated combat approach and that resulted in a flip.  But that was due to vortex ring state, something which can happen to *all* helicopters, not just the Osprey.  And it only happened because the crew exceeded the then permitted limits.  They broke the flight rules which were in place deliberately to help prevent just that kind of accident.  The Osprey's flight control system was subsequently modified to help alert crews to keep them out of the flight states where they may encounter a vortex ring condition, but that's all you can do - it is still possible to induce the problem, as it is in all helicopters.

And you seem to ignore that the helicopter being replaced is the CH-46 Sea Knight which is what?  A tandom rotor helicopter.  And the US Army and USAF both use which helicopter as their primary heavy lift helicopter?  The CH-47 Chinook, the Sea Knight's bigger brother - also tandem rotor.  The Osprey isn't so different from these helicopters in practice.  They both have their dual engines in the tail, and use a long drive shaft to power the front rotor.  So there is experience with such power distribution and gearing systems.

You lose one rotor on ANY tandem rotor helicopter and you're in trouble.  It happens to Chinooks and Sea Knights - loose one and you flip.  Period.  It is like losing a wing on a conventional aircraft.  The Osprey at least has the option of gliding if it happens with enough altitude, the -46/47 are doomed any any altitude.  On the -46/47 the rotors also inter-mesh, and if they loose sync the rotors will destroy each other, and that has happened - in fact it happened at an airshow in front of major brass and the public, back in the 80s I think.  I can't be arsed to look up the date.

Conventional single-rotor helicopters also suffer fires, transmission failures, tail rotor failures, etc.  Does that make them all boondoggles too?

And you refer to the conditions in Vietnam as if that makes your point, but quite the contrary.  The conditions in Iraq and Afghanistan are, if anything, even more demanding than Vietnam, with regard to air supply and medevac.  The development of MANPADS has increased the threat environment.  And the distances and terrain involved put a greater demand on rapid ingress and egress, plus provide pretty much constant 'hot and high' flight conditions which really tax aircraft, especially helicopters.  Being able to get in and out quickly while still being able to VTOL is not something unique to Vietnam which magically became unnecessary once that conflict was over.

The V-22 is getting a lot of attention because it is new and different.  But if you look at the development of other military aircraft you'll see that it is fairly common for them to have development issues including the loss of airframes during development and into their early service lives as they go through their teething cycle.  And this, unfortunately, has often included the loss of life.

The tilt-rotor shows a lot of promise, and it is started to deliver on those promises.  The Osprey itself has gone through several improvement cycles with modifications based on experience in testing and deployment, and it will continue to do so.  The BA609 commercial tilt-rotor, which is based on the experience developing the V-22 Osprey, is also now flying and progressing nicely.

The Osprey is really the first of its kind.  Its predecessors were only research aircraft, such as the XV-15 (one of the two of which also crashed when a bolt came loose in flight, BTW), it is the first attempt at a production model of a new type of aircraft.  To not expect it to have some teething issues would be unreasonable.  And, unfortunately, a number of the issues it has had are not at all endemic to the design but rather are human error or carelessness such as mis-wiring engine controls.  That kind of mistake can, and has, doomed any aircraft.  They get more attention when it happens on a special aircraft such as the Osprey.

As for not being approved for specific types of operation, that's normal operating procedure for the first deployment of any new system.  You crawl before you walk before you run, to build up confidence.  Other current examples include the initital combat deployments of the Dassault Rafale by the French, and the initial deployments of the Eurofighter Typhoon.  When the C-130J first entered service it was kept to more of the 'milk run' missions until confidence and experience were gained, and that was a derivative of a 50-year old design with a proven record.  So that argument is a red herring.  This is the first combat deployment of the Osprey, it would not be a prudent risk to toss it in the deep end and hope everything works as expected.  Of course you would hope so, but many plans and expectations wither when exposed to combat for the first time.  So you do it in phases and ramp up over time.

Report on Tiltrotor Osprey in Iraq

justin

Sat Aug 02 14:09:18 -0700 2008

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Well, obviously you know more about it than I do, tech-wise. I appreciate your knowledge of the specifics, but I remain unconvinced. I still see its existence as a 'boondoggle' and here's why:

"Being able to get in and out quickly while still being able to VTOL is not something unique to Vietnam"

That was never my point. I brought up 'nam to emphasize the original intent of the aircraft and compare it to what has been birthed...decades and billions of dollars later.

Specifically, you state that the V-22 is slated to replace the twin-rotor CH-46 Sea Knight. That's its mission NOW. It was originally intended for the Vietnam-inspired uses that I described (and you tacitly acknowledge).

One of the main characteristics of a gov't boondoggle is all the revisionist history necessary to turn the project into something people can label as a 'success' and that's what I see going on here. This is the crux of my argument.

Also,

"As for not being approved for specific types of operation, that's normal operating procedure for the first deployment of any new system. You crawl before you walk before you run, to build up confidence"

Cop out...'crawling before you can walk' is one thing (ex. mercury>gemini>apollo missions), but this beast languished for decades, mired in the stench of government mismanagement and CYA politicking.

Let's continue to use the apollo space missions as a comparison. They allowed us walk on the moon and develop ICBM capabilities for the cost of approx. $135 billion (in 2005 dollars, from wikipedia) *within 10 years* of the project's inception.

The V-22 took over 20 years at the cost of $50 billion, and it *still* isn't capable of fulfilling its original mission. Now, I understand the time needed to develop new aircraft and the sacrifices (fatal accidents included, unfourtunately). I respect the people who develop new aircraft. But your argument that this is 'typical development problems' is BS and a total cop out.

Well, the bitch is here (v-22) and even Obama is tooling around in it. For the record, I think it's cool. My point is that 'cool' does not cover the immense boondoggle of it's development, and I disapprove of any revisionist history or whitewashing to overlook that fact. We need to know what was done wrong so we can avoid it in the future.

Just think: if military brass had been focused on delivering an aircraft that completed the mission (as originally envisioned...fast+VTOL+large capacity+heavy combat) instead of myopically ramming the tilt-rotor design through the pipeline, everything would have worked out better.

Anyway, thanks for the lively discussion. Again I appreciate your deep tech. knowledge of the project.

Report on Tiltrotor Osprey in Iraq

MegaZone

Sat Aug 02 15:12:02 -0700 2008

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I'm an aviation geek - I subscribe to Aviation Week for enjoyment. :-)  I studied Aerospace Engineering for the first few years of college (in the early 90s) before I got sucked into computing, which became my career.  I've been interested in the Osprey for a long time just because it is interesting and different, and we don't see a lot of radical change with new designs most of the time.

I agree that it has had an overly long development period, but a lot of that has been due to hot and cold budgets.  The Osprey was nearly cancelled a few times and had its budget slashed, and that really prolonged the development and raised the costs dramatically.  Perhaps we've ended up with a better aircraft because of it, since there was more time to revise the design and learn from mistakes, but perhaps we'd already be on the V-22C model by now if it had gone into service earlier.  It is something we'll never know.

Specifically, you state that the V-22 is slated to replace the twin-rotor CH-46 Sea Knight. That's its mission NOW. It was originally intended for the Vietnam-inspired uses that I described (and you tacitly acknowledge).

We're not really saying very different things - one of the helicopters widely used by the Marines for that mission in Vietnam? The CH-46 Sea Knight. So performing that mission has always meant, in part, replacing the Sea Knight.  Even today, the Sea Knight is the helicopter the Marines still primarily use for those missions.  That's not really a new goal for the Osprey. The Marines had hoped to have replaced the Sea Knight years ago at this point, the airframes are very old. And they stopped buying new models in anticipation of the Osprey having been in service earlier.  Performing those Vietnam-inspired uses and replacing the Sea Knight are really the same goal, since the Sea Knight is what they use for those Vietnam-inspired uses today.

Other models the Marines used in Vietnam have largely been retired already as the fleet has been simplified. The CH-53 is still in service, but in the form of the new model CH-53E Super Stallion. (And that's in the process of being evolved into an even larger, heavier lift CH-53K model.) The CH-53E is almost an all-new aircraft compared to the CH-53A-D models.  Similarly the Marines still fly the AH-1 Cobra, but today's AH-1W SuperCobra and AH-1Z Viper are a far cry from the early models used in Vietnam.  I'd be surprised if they have any components in common with the early models.  Same goes for the UH-1Y Venom which is only superficially similar to the Huey's of Vietnam.  The CH-46 is really the only aircraft from the Vietnam era the Marines are still flying that hasn't changed all that much.  Not to say it is identical or anything, but the last US airframes were built in 1971 - the war was still on in Vietnam when those airframes rolled off the line.  The US Navy retired all of their units by 2004.  The newest CH-46 airframes are 37 years old.  Sure, they've been upgraded in service a few times, most recently in the 90s, but they're really wearing out.

I don't know what other design could really do what the tilt-rotor does, and not be more complex.  The 'X-wing' concept for stopped rotor flight would provide the same basic features, but proved to be hugely complex and expensive, far more than tilt-rotors, and was dropped.  Sikorsky is just now resuming work on the coaxial ABC (Advancing Blade Concept) design, as they now feel the technology has reached the point where it is feasible to make it work.  They tried it in the past, but ran into problems with the materials and design tools of the day.  Today's composites and computing power give them a better shot.  But it is still a research effort, probably a decade away from production possibilities.

Some argue that the tilt-wing is simpler than the tilt-rotor, but it has issues in the transition from rotor-borne to wing-borne flight (and vice-versa) as the wing is still at a very high angle of attack while the rotors are losing vertical light in transition.  There are tilt-rotor concepts where the engines remain horizontal while the rotors pivot through a gearbox.  It makes for a more complex gearbox, but simpler engine design and mounting.  But it is still a tilt-rotor in the end.

The problem with high speed flight in helicopters has always been rotor stability.  The advancing blade bites into the air with the speed of the rotor *plus* the forward speed of the aircraft, so it runs into compression shock before the airframe.  Meanwhile the retreating blade only bites with the rotational speed *minus* the forward speed of the aircraft, so it encounters aerodynamic stall earlier.  And you get an imbalance in lift well before that, of course.  Modern rigid, hingeless rotors and advanced blade designs (like the British BERP rotor blades) have allowed helicopters to reach speeds older models couldn't dream of, but they still can't match fixed wing flight.  Concepts like ABC show promise, but much work remains to be done.

If we'd skipped the tilt-rotor and poured the same funding into advanced helicopter designs, would we be closer?  Probably, sure.  But from what I've seen in the fundamentals, companies like Sikorsky, AugstaWestland, Bell, etc, have never stopped doing R&D because there is commercial demand and competition.  And there have been fundamental issues to overcome with materials, simulation, etc.  So, personally, I don't believe we'd have a deployable helicopter with performance to match the Osprey by this point, and probably not until next decade. 

And given the even greater hurdles and costs than the Osprey, such a program would have been more likely to be canceled - like the RAH-66 Comanche.  That program started out as the LHX with broad goals of replacing the UH-1, OH-6, OH-58, and AH-1 with radical new technologies.  And it was slashed repeatedly until it was a much reduced partial replacement for the OH-58 and AH-1, and then cancelled completely.

Instead the ARH-70 is replacing the OH-58D, and it is an 'off-the-shelf' commercial design, the Bell 407.   Which is kind of ironic, because the Bell 407 is a modern commercial version of the Bell 206 - the model the OH-58 was based on!  And some of the UH-1 and OH-58A-C missions will be taken over by the UH-72, which is the commercial Eurocopter EC145.  But the Army is still looking for a replacement for the remainder of the UH-1 missions, and the OH/MH-6 soldiers on with no replacement in sight, except maybe the Fire Scout UAV, at least for some missions.

I don't think the issue is with the V-22 so much as with Pentagon procurement policies in general.  Almost every major program in recent years has suffered cost overruns and schedule delays.  Even after suffering a major black eye on aerial tanker acquisition, and knowing Congress and everyone else was watching them closely, the USAF *still* royally screwed up on the new tanker competition and had the GAO uphold Boeing's protest and force a new competition.  And this is also after the GAO previously upheld protests over the SAR helicopter competition, forcing a recompete there as well.  You'd think they'd learn from the repeated black eyes, but they just can't seen to get it right these days.  It seems to be systemic.

Report on Tiltrotor Osprey in Iraq

phred14

Fri Aug 01 06:33:12 -0700 2008

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As a teenager, I remember reading an editorial cartoon that seems relevant.  It showed a general and a ridiculous hodge-podge weapons system.  The first line, "At last we've got a weapons system that is immune to attack."  The last line, "It's got parts built in all 435 Congressional districts."

Sideline on air shows...  In New York there's a place called the "Rhinebeck Aerodrome".  They still fly aircraft from WWI and prior.  Last time I was there they flew a plane from 1910 (Berlioz?) with controls that worked by wing-warping.  They had a Fokker triplane (Red Baron) on static display, and flew a Sopwith Camel.  (Snoopy)

The airshow opens with a biplane in the air.  The pilot throws out a roll of toilet paper, then sees how many times he can cut it with his wing as it unrolls toward the ground.

Report on Tiltrotor Osprey in Iraq

Nathan Smith

Fri Aug 01 09:05:35 -0700 2008

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What surprises me is that they have various congress critters flying around in them.  Obama and McCain flew in them in Iraq.