Flying The Osprey Is Not Dangerous, Just Different: Veteran Pilots

"ttyymmnn" (ttyymmnn) 07/09/2015 at 13:22 • Filed to: planelopnik

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!!!error: Indecipherable SUB-paragraph formatting!!! is an excellent piece on the flying characteristics of the MV-22 Osprey, with opinions from pilots who have helped develop the aircraft and those who both like and don’t like it. It’s got terrific analysis about how the Osprey is not quite a helicopter, yet not quite an airplane. It requires pilots to develop a new frame of reference on how they fly. Interestingly, those who transition to the Osprey from fixed-wing aircraft have a better experience than those who have all their hours in helicopters.

“One of the biggest problems we’ve had in the [pilot] community is getting past the idea that it’s a helicopter that flies fast,” Leonard said. “It’s not. It’s an airplane that hovers. And if you fly the airplane like a helicopter, yes, it’s very difficult to fly as a helicopter. And if you do that, you have a very good chance of having a problem with controllability because of the way the aircraft operates. If you fly it like an airplane and you are willing to take the time to understand the capabilities of it in helicopter, it’s a very, very easy airplane to fly.”

The numbers don’t lie: the Osprey is a !!!error: Indecipherable SUB-paragraph formatting!!! —in the right hands. The only bone I have to pick with the article is that it compares safety records of the Osprey versus helicopters, without comparing the operational numbers of each type. While there have been few fatal Osprey crashes in recent history, there are only 200+ Ospreys in service, while there are thousands of helicopters of all types in operation. A comparison of percentages would be more enlightening.

I would encourage anybody interested in the MV-22 to give this a careful read. Good stuff.

US Navy photo

McMike > ttyymmnn 07/09/2015 at 13:34

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If you lose power with a airplane, you now have a glider. You hope to find somewhere flat and large to put it down.

If you lose power with a helicopter, you crash. You spend weeks and weeks learning how to hit the ground as slowly as possible.

WTF do you get with an Osprey? Is there enough lift for it to result to powerless flight?

ttyymmnn > McMike 07/09/2015 at 13:37

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That’s a good question. I don’t know.

CKeffer > McMike 07/09/2015 at 13:38

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That is a very good question.

ttyymmnn > McMike 07/09/2015 at 13:42

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Found this on an Airliners.net discussion:

Each rotor is powered independently during normal operations and synchronized via a “synchronization shaft” running through each wing, the top of the fuselage and a couple of universal joints at the wing/fuselage joint. During engine out situations, the shaft and linkages are designed to transfer power from one side of the a/c to the other and the remaining engine is rated to run at a much higher power output for a short period of time. Similar to a Chinook, this makes autorotation possible. That said, the rotor loading on the V-22 is much higher making it a very undesirable thing to attempt. In most cases you’d be much better off handling it like a fixed wing a/c with total loss of power.

So, I guess you’d have to count on only having one engine go out. I would suspect that the odds of losing both engines at the same time are pretty low.

uofime-2 > ttyymmnn 07/09/2015 at 14:54

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doesn’t it have to have it’s nacelles rotated up, not completely horizontal, to land like a fixed wing? I can’t imagine smacking a rotor into the ground would do good things during an emergency landing, guess you better hope hydraulics are still working. Wonder if it has a RAT

The wings are so stubby I can’t imagine the glide ratio is very good either.

Does the prop wash going over the wing substantially increase lift?

once upon a time I saw someone on here or F/A who claimed to have done design work on these, can’t remember who it was unfortunately...

Racescort666 > ttyymmnn 07/09/2015 at 14:55

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As I recall (no source, sorry), this was one of the major design issues. Getting the transfer shaft to operate reliably and predictably. I haven’t really heard of any issues with it so I assume that it’s been worked out.

Racescort666 > ttyymmnn 07/09/2015 at 14:57

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I like how the immediate response from pilots to handling difficulty criticism is “what’s your flight experience?”

You can tell a Finn but you can't tell him much > uofime-2 07/09/2015 at 15:47

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IIRC the propellers are designed to fail in a safe manner if the plane is landed with the nacelles in the horizontal position. From what I remember the blades are designed to “broomstick” when they hit the ground so that the Osprey can be landed in a conventional manner in an emergency situation like an engine failure or a failure of the nacelle rotation system.

uofime-2 > You can tell a Finn but you can't tell him much 07/09/2015 at 16:06

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I figured that was a failure mode the would have thought of. I still wouldn’t want to be on board for that test!

You can tell a Finn but you can't tell him much > ttyymmnn 07/09/2015 at 16:14

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Good read. The passage that really jumped out at me is this one:

“The experience level in the Air Force in the Osprey community is starting to diminish because they picked, initially, many pilots who had the experience to help the program get off the ground, and many of those pilots have been promoted or have retired like myself and are moving on to other jobs,” said Alexander, who flew MH-47 Chinooks for the 160 th SOAR for 15 years before transferring to the Air Force to fly the Osprey. “This is an aircraft that, being rather new still, you don’t have that experience depth or that base to work with.”

Give it another generation of pilots and things will become that much smoother. Then you’ll have enough guys with enough experience that will still be active in the training and development of the new guys coming in. To have a completely new aircraft type that has fundamental differences from literally every other airframe that has ever existed brings a unique set of problems in terms of developing operational experience. Right now there is so little “tribal knowledge” that the current pilots are in the process of writing the book on how to fly this thing.

You can tell a Finn but you can't tell him much > uofime-2 07/09/2015 at 16:21

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I don’t believe they actually did a full profile flight test of that one. The probably just bench tested some propeller (actually proprotor) blades and said “yep, those fail the way we want them too, you’re good to land her on the belly if you need to”.

Rock Bottom > McMike 07/10/2015 at 14:44

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For one thing, losing power in a helicopter isn’t the end of the day. The UH-60 is a little rough to autorotate due to it’s super light and flexy blades (especially the early narrow-chord blade variants), but it can be done. The UH-1 could autorotate very well. I’ve heard stories from old ANG Huey pilots about shutting the engine off in flight to scare the new guy. They say you can land as smooth as if the engine was still on.

Also, the V-22 (like the XV-15 before it) has a central gear box that can send power from one engine to both rotors in the case of an engine failure. That is, if one engine fails, you still have symmetric power and yes, it’s enough to fly and land. And you can land like a plane with the nacelles at about 45 degrees. If you want to talk about what to do when it’s more damaged than that... you’re getting into the realm of “no helicopter can survive that either”.

Rock Bottom > Racescort666 07/10/2015 at 14:48

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Single-engine-out operation was worked out in the XV-15 program in the 1970s. In the wind tunnel.

Racescort666 > Rock Bottom 07/10/2015 at 15:08

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Not just any wind tunnel, the wind tunnel.

Rock Bottom > Racescort666 07/10/2015 at 15:52

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Is there another one?

Racescort666 > Rock Bottom 07/10/2015 at 15:56

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Nothing notable.