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#1 (permalink) |
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Military Professional
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V-22 in the news again
"A report criticizing the V-22 Osprey from the Washington-based Center for Defense Information has drawn flak from the Marine Corps."
Warning is a pdf. http://www.cdi.org/PDFs/Gailliard%20on%20V-22.pdf |
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#3 (permalink) |
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Military Professional
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I have heard or read of this before, but this is the first time I've seen it all assembled in one place. The USMC has been relying on the V-22 coming up to requirements. The H-46 fleet is geriatric. What a pickle. It is amazing that neither the manufacturer nor the testing authorities have completed ALL the milestone tests. The Osprey is sufficiently different from a helicopter or a conventional fixed wing design and should have undergone the most rigorous testing to find out how it differs from them and how best it can be operated. My personal view (based on no more than the information in the article) is that it was a step too far. It is too big, too heavy, too complicated and too expensive. The downwash problem should have been recognised long ago, but once the Vortex Ring condition reared its ugly head the programme should have been cancelled.
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Semper in excretum. Solum profunda variat. |
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#4 (permalink) |
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Senior Contributor
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Unfortunately yes they did. I had a friend that went down in one on the Patomic years back. Part of the inital "reports" on the V-22 found and blamed a tricky problem considered verticle edge or ring vortexing. This considerable problem led to them being slammed down on the tarmac or surface as they were in verticle transition. I believe they are well beyond this problem now though. A true shame that it cost those lives.
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Fortitude.....The strength to persist...The courage to endure. Last edited by Dreadnought : 12-21-2006 at 10:13 AM. |
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#5 (permalink) |
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Contributor
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The Vortex Ring condition is a pretty standard helicopter phenomenon.
So, what we have is three crashes due to poor parts/QA, for which the blame rests squarely with the manufacturer, and another which is essentially pilot error (the pilot is supposed to be trained to anticipate the VRS and avoid it - it is a KNOWN phenomenon of rotary-wing aircraft) So then, the pilot should have done his transition at speed and altitude - the only two things that let you recover from VRS, or allow you to avoid it completely (especially speed). Helicopter pilot face THE EXACT SAME PROBLEM. If they need to descend quickly they must have a lot of forward speed, -then- slow down and go into hover or near-hover like descent. Last edited by GGTharos : 12-21-2006 at 11:13 AM. |
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#6 (permalink) | |
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Military Professional
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Quote:
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#8 (permalink) |
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Military Professional
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I would like more details on this too. I suspect by 'blade twist' he means the coning angles that rotors are subject to under load, but propellers are not expected to be other than rigid. I would assume there has been a lot of brainpower mobilised in the hope of finding solutions, but has there ever been a project so slow to reach production?
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#10 (permalink) | |
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Military Professional
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Quote:
In the case of helicopter VRS you simply lose lift for a moment then regain control. It apparently happens all the time in Afganistian, the concern I suppose is what happens if the V-22 operates in the thin air in A-stan. Last edited by canoe : 12-21-2006 at 21:14 PM. |
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#11 (permalink) |
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Military Professional
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Not quite. A vortex ring state can lead virtually any helicopter right down to the crash site! It all depends if the airframe driver can encourage the thing into something resembling forward flight in the time and space available to him. Vortex ring develops during descent under power. Some types seem to give a fairly mild ride, others most certainly don't. To add a modicum of complexity to the equation, disc loading and pressure altitude exacerbates the problem. Did somebody mention Afghanistan? Oh dear.
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#12 (permalink) | |
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Military Professional
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Quote:
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#13 (permalink) | |
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Resident Curmudgeon
Military Professional
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Marines Respond to V-22 Study
Seemsd that he dredged up old problems without seeing if they had been addressed.
yes they can go to Afghanistan. The Air Force and MC are flying them every day without this "dangerous" airplane falling out of the sky. Quote:
Last edited by Gun Grape : 12-22-2006 at 23:48 PM. |
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#14 (permalink) |
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Military Professional
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Sounds like someone in uniform is trying a whitewash job, gunnut.
James Darcy states "Never had a request to further explore a single engined take off issue" and some readers may think that reasonable. I don't. What happens when an Osprey loses or has to shut down one engine in flight? It has never been tried, and that is the big worry I have. How is it going to land? It has to be in the rotors up mode as it cannot land like a conventional aircraft. Never been done on one engine. Why not? One day some poor user is going to lose an engine - and then he is supposed to become an instant test pilot under less than ideal conditions? No machine should be released to service until it has been thoroughly tested. Back to square one, the V-22 Osprey has not been matched to the milestone requirements, and all we hear is confusion and procrastination. The answer is simple - test the bloody thing fully, get the best brains behind it and sort the problems out. If they cannot be solved , ditch the program without further delay. |
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#15 (permalink) | |
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Resident Curmudgeon
Military Professional
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Quote:
Ospreys HAVE BEEN TESTED for single engine failure in flight. And have done single engine landings Lee Gaillard slips in "to take off" and then says that it hasn't been tested. This is a false statement. "The V-22 has never been tested to land with one engine shut down. " This is a true statement:"The V-22 has never been tested to take off or land with one engine shut down. " The Osprey has met or exceeded all KPP and milestone requirements. Its been certified not only by the DoD, Don but also by a MIT panel. I do love how he puts forth "defects" that are his own. The V-22 was tested to 14.5mm and he complains that it wasn't tested against "RPG"s. I know a fer APCs that would fail that test. WOuld he like to test his replacement choices against RPGs? Or would that become a nonissue. He also talks about the vunerable descent rate that the V-22 must fly by. 800 FPM. Oh my God, thats so slow that they will be hanging in the air just waiting to be shot down. Oh did he mention the maximum descent rate, in the same environment (low forward speed), of the CH-46 and CH-53? Well no. FYI they are able to swoop down at the blistering speed of 460 FPM. Guess this is the airborne version of the Stryker. Oh wait, that seemed to work pretty good vice being the rolling death trap it was suppose to be. |
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