They should talk to Aramaki
His always work.
The troubled, revolutionary V-22 "Osprey" tiltrotor aircraft - which takes off and lands like a helicopter, but flies from place to place like a fixed-wing plane - appears to have finally left most of its development snags behind it. The first operational Osprey squadron has been operating in Iraq for three months, initially …
When I think back to the history of flight and radical flight technology, it often takes many years to get it all sorted out, e.g., jet engines, helicopters, computer-driven flight controls, trans-supersonic flight, et cetera. It took years and many lives were lost along the way because pilots were willing to take the risk. Even the now reliable Harrier had its problems and it took years to sort out techniques to avoid hot-gas ingestion scenarios (one reason Lockheed beat out Boeing on the JSF).
While we are successfully using the Osprey as a truck, let's not forget that helicopters were used only in this way until the Vietnam War, 20 years after the first whirlybirds flew at the end of WWII.
The Marines want and need this technology because they need something that gets them deeper and faster into enemy territory. Having the speed and range of the Osprey lets them fly less obvious routes making it harder to defend any particular high value asset, or allows the Marines to insert troops at a place and time that the opponent has not prepared for.
The difference between then and now is the immediacy of media as every little flaw and major accident becomes fodder for media outlets to air the dirty laundry. Just look at your own headlines and your slogan, El Reg. We love to hear and read through all the hype and PR, but sometimes we need to step back and realize that there are real serious people out there letting it all hang out.
> What happens if an engine fails?
Then the other engine supplies power to both rotors through a cross-shaft. What? You don't think they thought of this? Oh wait, this IS the Americans, here.
One of the development problems was resonance and vibration problems in this cross-shaft, as well as designing a robust mechanism to make sure power gets routed as necessary, no matter what the failure mode of the engine.
> VMM-263 has a lot of extra technical support above that which a normal squadron could expect
Ha! In other words they've got a bunch of sharp guys keeping things running, instead of your usual 18yo with a wrench and some chewing gum. These extra techs have probably been told if one crashes and it ends up on the news, it's their ass.
Actually there is a traverse drive shaft that can drive the opposing propeller. As you observe the asymmetrical thrust would be uncontrollable.
Unfortunately one can generalize that when a jet engine ceases to function on a aircraft like this, it is because of being shot, not from lack of maintenance. See the problem yet?
Well.... if you manage to hit it enough times to knock out the engine you are quite likely to have damaged other components thereby rendering the traverse drive shaft and associated gear boxes etc, so much scrap metal as well.
So, someone thought of this and at least tried to address it. How successful that turns out to be depends on what sort of damage any particular aircraft receives.
I wondered too about what happens if an engine fails, but then you could ask the same question about the Chinook. Maybe the Osprey is in fact safer, because it could do an aeroplane emergency landing, as opposed to the Chinook, which can only go down.
This looks fun - roll on the civilian version :-D
When a turboprop aircraft loses one engine does the aircraft start spinning around the one remaining propellor? I dont think so. They have a thing called a gearbox, maybe you've heard of it??? :P
Oh and for the record, the props are so huge so that if one engine fails the other is large enough to carry the weight of the entire aircraft. It would be a very uncomfortable ride, and you would be looking to land very quickly but you should not fall out of the sky!
Actually it can operate on a single engine, there IS a facility to divert some of the output from a single engine to the opposing rotor - I may be wrong, but I believe that the power-transmission system is (at least in part) hydraulic in nature and this is (at a very simple level) just a question of opening the valves to crosslink the transmission systems. Obviously performance would be severely effected by single engine operation, but it IS possible. What I don't know is whether it can autorotate with those smaller rotors(compared to a conventional helicopter) and I don't know how effectively it can glide on those (comparatively) stubby wings.
I suspect that, once it's proven in military use, it may find specialist civilian use. But it seems to me that most helipads will be too small for it, and it won't be the most efficient machine for performing jobs currently done by fixed-wing aircraft. And the operating costs might be prohibitive.
The V-22 design includes enough engine power to fly the aircraft on one engine. The design also includes a transmission connection between engines (think long.cross-wing drive shaft). As a result, the loss of one engine is not a catastrophic failure. The aircraft is designed to fly normally on one engine, just as are all other twin engine aircraft. The same kinds of limitations apply as might apply with a conventional twin engine aircraft. Specifically, the loss of an engine will entail some loss of performance and reduction in range. However, the aircraft is designed to land safely at an unprepared field if necessary. Most conventional twin-engine aircraft cannot do that.
Argh! Now you're making me remember all sorts of cool 1950s and 1960s Brit stuff like the GT3 gas turbine locomotive (http://www.enuii.org/vulcan_foundry/oddities/gt3.htm) and the TSR2 (http://www.thunder-and-lightnings.co.uk/tsr2/history.php) aircraft.
No wonder Gerry Anderson was able to make Thunderbirds in those days, he just had to look around to see the best of British boffinry inventing the future. If he were to start again today he'd be forced to produce a puppet series set in a futuristic celebrity estate agents.
I want my future back!
Quote: 'What happens if an engine fails? It doesn't look as if it could fly on a single engine without spinning around. I assume they have to land as quickly as possible.'
The two props are linked by a drive shaft running through the wing and so can run on a single engine. You only need the power of the two engines for take off and flying at high speed.
So if an engine did fail, you could probably just carry on flying as normal, although landing would probably be a bit on the bumpy side with the reduction in power.
Anyone seen 28 Weeks Later?
If that pilot could dismember zombies with a fairly regular helicopter, think what he could do in an Osprey, with those big blades pointed forwards. Crowds of insurgents in open fields -- beware!
P.S. Regarding the "Aramaki" comment at top... I seem to recall their tiltrotor didn't handle a suicide bomber jumping in the back too well.
Forget this as death-tek, it's the logistic uses where it will really shine.
Most battles aren't won by the side with the flashiest guns but the side that gets the most bullets to the front.
Heavier loads over longer distances to helipad sized landing fields is a very, very important improvement.
... my Daddy (may he RIP) was doing systems engineering on this bird. He laid (partial?) claim to the name "Osprey", too, but I can't ask him anymore. But he did bring home some tilt-rotor goodies - like little snap-together models and posters.
The project was tough, and the props were an ongoing source of consternation. And like any airframe, every ounce counted. I wish I had quizzed him more on the avionics. Ah well.
The V22 would have a multitude of uses in civil life. It would have greater range and speed then a helicopter (so beats a helicopter when these things are a requirement) and doesn't need a landing strip like an aircraft.
Imagine emergency rescue for one use - the V22 (or civilian offspring) could take off from a hospital landing pad in a city, rotate to plane mode, fly at high speed to crash/emergency site, rotate to helicopter mode, land. Do whatever needs to happen (pick up hurt people, etc.) take off helicopter style, fly back high speed plane style, and land back at the hospital landing pad!
Another use is aerial surveying, the ability to hover is not something that your average surveying plane can do, and the ability to get to the survey site at high speed means you save money on fuel compared to a conventional helicopter!
Only problem with a system like this is the really high maintenance cost from the mechanical rotation. That and it does look a bit larger then a standard helicopter but i imagine a civilian version would be a bit smaller...
To be honest, I've never really been a fan of the V-22. To my mind, the emphasis placed on the amazing complex tilt-rotor technology has diverted attention and funding from other equally (if not more so) viable approaches like autogyros with ultra-high inertia rotors (see Cartercopter), or the Carnard Rotor Wing (see the X-50 Dragonfly or the Whispercraft from "The Sixth Day").
I can't help thinking that if they'd just updated the Rotodyne with modern technology, the programme would have gone a lot faster and been a lot cheaper.
aaaaahhh! 5 people asking what happens if an engine fails and 5 more replying!
reload before posting, people. It's only F5, or ctrl+R, or that button near the address bar. Or even for the more enlightened browsers: <mouse_gesture>up+down
Hi Brutus. I do mod duty. It takes up quite a bit of my day since you lot are highly productive when it comes to comments - haven't worked it out, but it's in the several hundreds every day and suspect it hits 1000 now and then. They go through pretty much continuously, albeit in a bit of a batchy way, and we read every one, just like Blue Peter or something. (Actually it'd be lovely if you could send in some of your own drawings sometimes, for variety.)
So, y'know, I'm pretty busy. How about you?
Engine failure is one thing but a jammed non-rotating engine pod is another. The rotors are too big for a conventional landing- even with the gear down its a fairly major prop strike.
It's a nice trip back to my childhood- I remember seeing articles about it in Look and Learn or Speed and Power back in the early 70s. IIRC it was touted in the anti-tank role
Check this out. If you're looking for video of the Osprey other than the five and ten year old crash video, there's only two new videos of the Osprey in Iraq - a Fox report and a Marine video.
It's a Hajj story but the Osprey's land out int he middle of nowhere. OOHRAA
...and that's why we have the V-22. It isn't the best way to do the job; it wasn't even the best proposal! We had autogyro designs (AH-56) in the 1960s that beat the V-22's performance, didn't require extensive (and expensive) technology development, and didn't have weird flight-dynamics problems. But some general saw those rotor pods go "zoop-zoop", and that just tickled him all over, so it was the V-22 from there on out.
Although one of the things that did for the AH-56 was a minor malfunction in the weapons system that accidentally shot an anti-tank missile at a reviewing stand full of VIP's. Whoops.
> We had autogyro designs (AH-56) in the 1960s that beat the V-22's performance
An autogyro uses an unpowered main rotor spun by the slipstream to generate lift. This means autogyros are fundamentally incapable of hover or vertical take-off or landing. How is an autogyro, then, supposed to be able to exceed the performance of a tilt-rotor when it can't match it for flight regimes.
Further, the YAH-56 wasn't an autogyro; it was a compound helicopter, with a driven main rotor, and lift and thrust augmentation in forward flight from a set of stub fixed wings and a tail-mounted pusher propeller, respectively.
Finally, the YAH-56 was a two-seat attack helicopter, the V-22 is a heavy assault transport. Would you also argue that a Boeing 747 is a shit design because it can't outperform fighter jets? Even then, though...
Maximum Speed: YAH-56 = 244mph, V-22 = 316mph
Cruising Speed: YAH-56 = 225mph, V-22 = 246mph
Ceiling: YAH-56 = 20,000ft, V-22 = 26,000ft
Rate of climb: YAH-56 = 3,000ft/min, V-22 = 2320ft/min
> Although one of the things that did for the AH-56 was a minor malfunction in the
> weapons system that accidentally shot an anti-tank missile at a reviewing stand
> full of VIP's. Whoops.
Did you make that one up yourself, are are you merely repeating a whopper you picked up elsewhere?
The prime manufacturer Boeing has a website at
The http://www.flightlevel350.com/ website has sublinks to a 4:26 video of the V-22 in flight which was apparently taken in the first quarter of 2006 at Euless, TX, USA. Euless is the home of Bell Helicopter where a lot of development of the concept has been done. Bell is a partner with Boeing, building the major airframe systems. Bell Helicopter has a website on the V-22 at http://www.bellhelicopter.com/en/aircraft/military/bellV-22.cfm.
During 1995-96, I worked on some of the cockpit avionics for the V-22 at sub-contractor Honeywell Defense Avionics in Albuquerque, one of many subcontracts on the project. Neat stuff. LCDs that do not fade in direct sunlight get rid of most of the steam-gages of older aircraft. Keyboards, computers, and displays are all special.
As for the problems mentioned in the posts before this one, there have been a lot of people doing worst case analysis on this bird for close to 25 years and you can be sure anything you can think of, they have foreseen and addressed if not eliminated. Particularly the pilots - they are always the first at the scene of the accident. There are still risks but then driving on the public streets is risky.
Now all we need is a few more wars for it to operate in successfully to offset the absurd financial/human cost of over 30 years of development.
Don't get me wrong, innovation is fine. I admit I am something of a Luddite, however. To that end, I approach technological "marvels" with apprehension and as much empericism as I can muster. I figure, though, that if you take the money spent on this tilt-rotor hotrod's teething pains, you coulda bought a full air task force of existing aircraft to do the same job. And spare parts. And fuel. Or the Iraqis could be organized into an effective fighting force and we could furnish them with an entire functional air arm (a longshot, I know).
I have been having this very same discussion with a couple friends of mine over the intervening years. The lastest line of reasoning has been that this aircraft has brought about so much advancement in various technologies that it has paid for itself. 'Course they said that about the B-1 (the B-what?). Splatted 3 of 'em (fortunately without full crew complement). Pretty plane, though. Finally gave up on further purchase, although there are a few airwings of them hither and yon.
A few years ago, it was found that the wing roots of F-16s were cracking out at a number of cycles far under what the manufacturer claimed for designed loads.
Then there was the Blackhawk fiasco. And on...yadda yadda yadda....
Or maybe I am just being too skeptical.
HARK! Ospreys in the distance!
Biting the hand that feeds IT © 1998–2020