AFSOC grounds CV-22 fleet

The AIr Force Special Operations Command has stood down all 52 CV-22 Osprey aircraft under their umbrella. Two aircraft in the last six weeks have had clutch engagement problems, with an additional two since 2017. The problem is described as a "hard clutch engagement", where the clutch in one of the two engines slips when it engages. This causes the aircraft to instantly transfer power to the other engine, to allow the aircraft to continue flying. The clutch quickly reengages, causing the power to instantly transfer back to the first engine. The rapid transfer back and forth causes the aircraft to lurch, and requires the crew to immediately land. In a worst case scenario the crew could lose control of the aircraft. So far that hasn't happened in any of the incidents. AFSOC is working with the JPO, but currently haven't been able to gather enough data to determine a root cause.

WASHINGTON — Air Force Special Operations Command has grounded all 52 of its CV-22 Osprey tiltrotor aircraft indefinitely as the result of a “increased number of safety incidents” involving an unknown and potentially dangerous issue with the clutch, Breaking Defense has learned.

AFSOC Commander Lt. Gen. Jim Slife ordered the safety standdown on Tuesday in the wake of two safety incidents that had occurred over the past six weeks, with a total of four such events occurring since 2017, AFSOC spokeswoman Lt. Col. Becky Heyse said in a statement.

AFSOC describes the problem as a “hard clutch engagement.” Basically, the clutch inside a gearbox that connects one of the CV-22’s two Rolls-Royce Liberty AE1107C engines to the propeller rotor is slipping for an unknown reason, Heyse said. When that happens, the power load transfers nearly instantaneously to the other engine — a design feature that would allow the Osprey to keep flying even if one engine fails. Then, in most cases, the initial clutch re-engages, and the power load rapidly shifts back to the original propeller rotor and engine.

breakingdefense.com...

a reply to: Zaphod58

Is it just me or does it seem like the Osprey has been plagued with issues over the years? I don't know much about this stuff, but I seem to recall hearing about issues more with this aircraft than others.

I'm amazed by the Osprey and have no doubt the engineering hurdles to develop it must have been orders of magnitude harder than with more conventional craft.

Well derp! I should have read the whole article.

The V-22 has generated controversy over its 30 years of operations due to a history of a range of safety issues, which have sometimes led to crashes and fatalities.

Cool aircraft though. I hope they iron out the bugs and it stays around.

a reply to: Blaine91555

The early development of the Osprey was plagued with serious problems. They had four crashes that were very high visibility accidents. One was a full up test that included a full load of Marines. The aircraft was coming in to land, flipped over from a Ring Vortex State, and came down in a river killing all 19 on board. There were 30 people killed in development and testing from those accidents. Since 2010, there have been something like 8 crashes, with 20 people killed all told. Due to the accidents in development, Bell sat down and did a major redesign they called Osprey 2.0, and basically changed a lot of the control systems. People still say how unsafe it is, despite having a significantly better record than most of the rotorwing systems that are flying.

a reply to: Zaphod58
I saw that flight of four take off, I was supposed to be on one of the four, but ended having to work that night. They needed bodies, for weight.

The thing with those is the fact that they don’t glide, nor can do an auto rotation.

a reply to: 38181

They don’t, but their safety record isn’t as bad as people keep saying. They’re not the greatest aircraft, but I’d rather be in one of them over a -53.

Didnt they recently move some to Japan.

a reply to: Zaphod58

At least in some video games and movies in theory they look interesting.

I just saw these do their demonstration at EAA Airventure in Oshkosh. They demoed just about every other day. I always get uneasy being on the flight line when they're showing off so close to the crowd.

originally posted by: Zaphod58
a reply to: 38181

They don’t, but their safety record isn’t as bad as people keep saying. They’re not the greatest aircraft, but I’d rather be in one of them over a -53.

a reply to: musicismagic

Japan bought them.

Wonder if the clutch system is mechanical or Hydraulic?

a reply to: Zaphod58

Any Euporean Countries? i thought this would exclusive to "US/UK" only.

Well that explains why i haven't seen any of them flying lately. Usually they rip 2-3 deep over my house pretty low.

a reply to: Zaphod58

What is likely to replace the Osprey's capability in the field?

The osprey seemed to be highly practical for many types of operations.

a reply to: Blackfinger

They're looking at software, mechanical, and hydraulic systems, so all three are involved.

a reply to: vNex92

There are currently no European operators, but USAF aircraft in Europe are involved. Indonesia has been approved for sales, and India is very interested, but with their track record, it'll be awhile before they get them if it goes forward.

a reply to: Axios

Right now, nothing is planned. The Navy just went operational with the CMV-22B for COD work, and both the CV and MV just started a nacelle upgrade that will both protect the engine from FOD in brownout conditions, and make working on the engines easier.

a reply to: Zaphod58

That is a pretty serious body count. There are certainly a lot of accidents and deaths listed in this Wiki article.

Sounds like rotor-wing systems are a risky business. Seems like a fundamental concept flaw.

a reply to: Blaine91555

A number of those are relatively minor though. Things that could happen to any plane, regardless of if it was a tiltrotor or not. If you look at the crashes, and fatalities, they're spread out pretty far. If you look at just about any fixed wing aircraft, you'll find a lot of accidents. The F-16 is one of the most popular fighters in the inventory, but its service entry was a total disaster. In 1975, the Class A mishap rate was 621.12, per 100,000 flight hours. In 1976, it was 442.48 per 100,000. From 1979-1982, they had one year where the mishap rate was under 10/100,000, when it hit 8.86. There have been 383 Class A mishaps from FY75-FY21 with 11,616,876 flight hours. The V-22 has a shorter life so far, with 7 operational aircraft being destroyed between FY00 and FY21. The average annual Class A mishaps for the F-16 comes in at 8.15 lifetime, and 3.30 annual average. The V-22 stands at 0.32 and 6.00.

AFSOC has lifted the grounding. Crews are being instructed to wait at least 2 seconds after takeoff before going to full power.

www.defensenews.com...

An undisclosed number of V-22s have been grounded pending a change to the input quill assembly. The Pentagon hasn't disclosed what the time limit is that will require the assembly to be changed, but aircraft under that time limit can continue flying regular missions, and training flights.

www.defensenews.com...