This is causing quite a stir here in Japan where the Osprey is, shall we say, a bit unpopular with the public (probably the only US military aircraft most laypersons know by name).

https://www3.nhk.or.jp/nhkworld/en/news ... 2/amp.html

So the CV-22s are standing down for awhile but USMC MV-22s ostensibly are not. USAF believes this safety issue is maintenance related while USMC apparently thinks the solution is enhanced pilot training.

It seems the Osprey just cannot avoid controversy no matter what.

If history is a guide, there will always be something to (understandably) upset the residents of those islands vis-a-vis the American presence. Frankly, I’m glad the Osprey is taking the heat and criticism rather than a few 18-25 year olds making life-shattering mistakes in the time of life where they’re most prone to make them.

P.S. the B-52s and the U-2 laugh at the Osprey’s public recognition.

The difference is that the USMC has experience with the issue dating back to 2010, having about 15 incidents in 12 years. So they include it in their routine crew training, where they handle it as an engine out scenario, to prevent the clutch from reengaging if it slips.

Whereas the USAF experience has been only recent, and they are pausing to be sure it's not a new cause or some effect previously unknown. They do that for any cluster of incidents that are grouped together.

Overall the CV-22 continues to have a safety record about equivalent to the rest of their native fleets. The accident rates are higher across the fleet for the Marines and Navy, than for the Air Force. That's a consequence of the type of service involving ships at sea.

Avatar2go wrote:

The difference is that the USMC has experience with the issue dating back to 2010, having about 15 incidents in 12 years. So they include it in their routine crew training, where they handle it as an engine out scenario, to prevent the clutch from reengaging if it slips.

Whereas the USAF experience has been only recent, and they are pausing to be sure it's not a new cause or some effect previously unknown. They do that for any cluster of incidents that are grouped together.

Overall the CV-22 continues to have a safety record about equivalent to the rest of their native fleets. The accident rates are higher across the fleet for the Marines and Navy, than for the Air Force. That's a consequence of the type of service involving ships at sea.

True enough. The simple fact is the Osprey can handle tough conditions other rotorwing aircraft generally cannot.

LyleLanley wrote:

If history is a guide, there will always be something to (understandably) upset the residents of those islands vis-a-vis the American presence. Frankly, I’m glad the Osprey is taking the heat and criticism rather than a few 18-25 year olds making life-shattering mistakes in the time of life where they’re most prone to make them.

P.S. the B-52s and the U-2 laugh at the Osprey’s public recognition.

Fair point, but Okinawans would have to be pretty old to remember the B-52 accidents at Kadena!

Aaron747 wrote:

Fair point, but Okinawans would have to be pretty old to remember the B-52 accidents at Kadena!

Ah, my apologies! Call it egocentrism or ignorance (hopefully the latter), but I didn’t realize you’d meant Okinawans/Japanese when you said laypersons. Reading it again, I should’ve clued in to your perspective.

Aaron747 wrote:

LyleLanley wrote:

If history is a guide, there will always be something to (understandably) upset the residents of those islands vis-a-vis the American presence. Frankly, I’m glad the Osprey is taking the heat and criticism rather than a few 18-25 year olds making life-shattering mistakes in the time of life where they’re most prone to make them.

P.S. the B-52s and the U-2 laugh at the Osprey’s public recognition.

Fair point, but Okinawans would have to be pretty old to remember the B-52 accidents at Kadena!

I watched a documentary a few months back about the continued US occupation of Okinawa, they make life miserable for the local population.

Kiwirob wrote:

Aaron747 wrote:

LyleLanley wrote:

If history is a guide, there will always be something to (understandably) upset the residents of those islands vis-a-vis the American presence. Frankly, I’m glad the Osprey is taking the heat and criticism rather than a few 18-25 year olds making life-shattering mistakes in the time of life where they’re most prone to make them.

P.S. the B-52s and the U-2 laugh at the Osprey’s public recognition.

Fair point, but Okinawans would have to be pretty old to remember the B-52 accidents at Kadena!

I watched a documentary a few months back about the continued US occupation of Okinawa, they make life miserable for the local population.

It’s a complicated issue...both cultural differences and geopolitical necessity make the situation difficult to change.

Avatar2go wrote:

The difference is that the USMC has experience with the issue dating back to 2010, having about 15 incidents in 12 years. So they include it in their routine crew training, where they handle it as an engine out scenario, to prevent the clutch from reengaging if it slips.

Whereas the USAF experience has been only recent, and they are pausing to be sure it's not a new cause or some effect previously unknown. They do that for any cluster of incidents that are grouped together.

Overall the CV-22 continues to have a safety record about equivalent to the rest of their native fleets. The accident rates are higher across the fleet for the Marines and Navy, than for the Air Force. That's a consequence of the type of service involving ships at sea.

By such a complex and new kind of machine (even though it´s been in service for a long time, I would expect the 3 Services to share experiences, procedures and basic training. Or do they all have to make their own mistakes and learn the hard way indipendently from each other?

steman wrote:

Avatar2go wrote:

The difference is that the USMC has experience with the issue dating back to 2010, having about 15 incidents in 12 years. So they include it in their routine crew training, where they handle it as an engine out scenario, to prevent the clutch from reengaging if it slips.

Whereas the USAF experience has been only recent, and they are pausing to be sure it's not a new cause or some effect previously unknown. They do that for any cluster of incidents that are grouped together.

Overall the CV-22 continues to have a safety record about equivalent to the rest of their native fleets. The accident rates are higher across the fleet for the Marines and Navy, than for the Air Force. That's a consequence of the type of service involving ships at sea.

By such a complex and new kind of machine (even though it´s been in service for a long time, I would expect the 3 Services to share experiences, procedures and basic training. Or do they all have to make their own mistakes and learn the hard way indipendently from each other?

DoD isn’t exactly known for leading the way on safety improvements. People love to blame budget cuts and whatever but the fact is tons of $$$ has been spent since 9/11, but mostly on shiny new hardware - the lion’s share does not go to upkeep or giving pilots more monthly hours.

Aaron747 wrote:

Kiwirob wrote:

Aaron747 wrote:

Fair point, but Okinawans would have to be pretty old to remember the B-52 accidents at Kadena!

I watched a documentary a few months back about the continued US occupation of Okinawa, they make life miserable for the local population.

It’s a complicated issue...both cultural differences and geopolitical necessity make the situation difficult to change.

I don't believe US foreign policy should be more important than the will of the local population.

steman wrote:

By such a complex and new kind of machine (even though it´s been in service for a long time, I would expect the 3 Services to share experiences, procedures and basic training. Or do they all have to make their own mistakes and learn the hard way indipendently from each other?

The Osprey has a joint program office, so one would think all that information is shared between services. However the three models are all slightly different, and have entered service at different times, with varying amounts of experience, so maybe that's a factor.

Then there is also the independence among the services, they may not approach or react to problems in the same way.

The Marines have not offered a root cause, other than to say the clutch may slip in certain rare circumstances, and they train around it. I'm sure the manufacturer must have some explanation for why it happens, that the Marines have accepted. We'll see what the Air Force says.

Kiwirob wrote:

Aaron747 wrote:

Kiwirob wrote:

I watched a documentary a few months back about the continued US occupation of Okinawa, they make life miserable for the local population.

It’s a complicated issue...both cultural differences and geopolitical necessity make the situation difficult to change.

I don't believe US foreign policy should be more important than the will of the local population.

History, far broader than the US alone, would differ.

Kiwirob wrote:

Aaron747 wrote:

Kiwirob wrote:

I watched a documentary a few months back about the continued US occupation of Okinawa, they make life miserable for the local population.

It’s a complicated issue...both cultural differences and geopolitical necessity make the situation difficult to change.

I don't believe US foreign policy should be more important than the will of the local population.

Tokyo’s priorities and the will of Okinawans are also different - complicated history there too. Amongst Okinawans you will find a lot of debate as to whether they are really Japanese or an occupied people. Japan’s foreign policy interest in Taiwanese defense and PRC/DPRK deterrence is in lockstep with that of the US.

Aaron747 wrote:

Kiwirob wrote:

Aaron747 wrote:

It’s a complicated issue...both cultural differences and geopolitical necessity make the situation difficult to change.

I don't believe US foreign policy should be more important than the will of the local population.

Tokyo’s priorities and the will of Okinawans are also different - complicated history there too. Amongst Okinawans you will find a lot of debate as to whether they are really Japanese or an occupied people. Japan’s foreign policy interest in Taiwanese defense and PRC/DPRK deterrence is in lockstep with that of the US.

I would go with the thought that they are an occupied nation. Okinawans are not ethnically Japanese, they have their own language and culture which is different from Japans.

GalaxyFlyer wrote:

Kiwirob wrote:

Aaron747 wrote:

It’s a complicated issue...both cultural differences and geopolitical necessity make the situation difficult to change.

I don't believe US foreign policy should be more important than the will of the local population.

History, far broader than the US alone, would differ.

The US should have no say in this, it should be up to the Japanese and the Okinawan's to decide.

Kiwirob wrote:

GalaxyFlyer wrote:

History, far broader than the US alone, would differ.

The US should have no say in this, it should be up to the Japanese and the Okinawan's to decide.

Easy.

He's simply saying that as an historical trend, when national policy and local's wishes are at odds, the locals usually lose.

Aaron747 wrote:

True enough. The simple fact is the Osprey can handle tough conditions other rotorwing aircraft generally cannot.

Interesting statement. Care to elaborate?

As helicopters go, this is a very high disk loading aircraft, and essentially unable to autorotate. Of course these are prices to pay for a much higher cruise speed than a conventional helicopter.

IADFCO wrote:

Aaron747 wrote:

True enough. The simple fact is the Osprey can handle tough conditions other rotorwing aircraft generally cannot.

Interesting statement. Care to elaborate?

As helicopters go, this is a very high disk loading aircraft, and essentially unable to autorotate. Of course these are prices to pay for a much higher cruise speed than a conventional helicopter.

It's true that the Osprey cannot autorotate in the traditional sense, because the rotors lack sufficient energy storage relative to its weight, to execute the landing flare.

However it does have glide capability in airplane mode, and is designed for horizontal landings with vertical speeds up to 24 feet per second. The aircraft would be sacrificed, but is designed for crew survival.

The reality is that for any accident beginning in hover, neither the Osprey or a traditional helicopter has enough altitude to autorotate, and is going to come down hard. All rotorcraft are vulnerable to power loss in hover. The Osprey has the same advantage as a two-engine helicopter, in that the loss is not total for single engine out.

Just out of general interest, I talked to a person claiming to do ground support for the Osprey, in another forum. He says the issue occurs mainly on the ground, during start & warmup, when the engine speeds are sensed as de-synchronized. In that case, rather than tolerate the resultant clutch slippage & torque imbalance, the Osprey is designed to shift power to one engine.

The unloaded engine then speeds up again, which can lead to the transfer back to that engine, in a hunting action that heavily loads the drivetrain.

He said the crews, if alert, can see it developing and can mitigate by throttling back the unloaded engine, then the loaded engine until they sync at a lower power level. Then with both engines engaged, increase power again.

It can happen in some rare conditions in flight or hover, if the engines have differing operating conditions for some reason. But it's a very noticeable thump when the transfers occur, so an unprepared crew might not immediately realize what's happened.

An USAF CV-22 has apparently been stuck in nature reserve on an island in the northern part of Norway since 12th of August. Full story in Norwegian only (with picture): https://www.nrk.no/tromsogfinnmark/fors ... 1.16087317

The wording wording in article indicates that the helicopter made an immediate landing because of a grounding order. However, the landing was performed on 12th of August and the USAF fleet was grounded on 17th of August (and ungrounded yesterday).

The story says that the helicopter will have to be transported out on land and over sea, which is problematic due the restrictions in the the nature reserve and shallow waters. It continues to say that the helicopter weighs 20 tons.

Wikipedia lists empty weight of the CV-22 as 14.4 tons, which is way less than the lifting capacity of CH-53 (yet alone the Mil-26, which has performed similar operations in Norway earlier). I would assume that siphoning off the fuel and airlifting the helicopter out would be much less a threat to the environment than transportation over land and sea. Anyone want to speculate on this?

Speculation: Even if there is or was a grounding order, a one-off flight should be acceptable. The risk that something happens is low. So it's likely that this CV-22 suffered some kind of malfunction that cannot be fixed there, unrelated to the identified issue that caused the grounding.

USAF has ungrounded the Osprey with some restrictions, that mimic the long-standing Marine procedures and training.

https://www.defensenews.com/air/2022/09 ... h-problem/

So either the core of the Air Force Osprey's were / are different from the Marine version or the Air Force just thought that Marine pilots and their procedures were suspect and not up to scratch. I guess now millions and or billions will be spent getting a mechanical solution to the problem, politics between the services being what they are....

So back in the air no mechanical fix as yet???
https://www.military.com/daily-news/202 ... issue.html

Apparently one Osprey has been stuck in a nature reserve in Northern Norway since August. It made an emergency landing there, and it's impossible to fix the aircraft at the site. The problem is that the whole area is a nature reserve, the beach is very shallow so it's difficult to bring a barge in there.
The Norwegian Defense forces have considered several options in cooperation with the Americans, including laying mats around the whole area to protect the vulnerable flora in the area. Another option is to build a road and a long pier.

The area around the aircraft is protected by armed forces 24/7, and there's a 200 M no-go zone.

In English:
https://www.scramble.nl/military-news/u ... ian-island

In Norwegian:
https://www.nrk.no/tromsogfinnmark/fors ... 1.16087317

The Osprey that has been stuck in a nature reserve in Northern Norway, has been rescued and is on it's way to Bardufoss military air station.

In English
https://www.businessinsider.com/broken- ... &r=US&IR=T

In Norwegian (with video):
https://www.nrk.no/tromsogfinnmark/her- ... 1.16117919
https://www.forsvaret.no/aktuelt-og-pre ... reservatet

The Marines have released the accident report for the June 2022 V-22 Osprey crash that killed all aboard.

The cause was a dual Hard Clutch Engage (HCE) event that destroyed a gearbox in flight. Like all non-coaxial dual-rotor helicopters, the Osprey is not controllable if both rotors are not driven.

https://www.military.com/daily-news/202 ... lying.html

The Osprey has a overrunning sprag clutch on the gearbox input quill/spindle of each engine. The clutches engage when the engines develop enough torque to run the rotors. That allows seamless power transfer from one engine to the other.

However in rare circumstances when both engines are under load, the clutches can begin an unstable "hunt" for a balanced equilibrium between engines. This occurs because the engine RPM will increase as load as removed, and vice-versa. The engines have controllers that communicate and coordinate to prevent this. But it can still happen if the clutches or drivetrain components don't have the same mechanical response.

This was thought to be possibly related to uneven wear in the clutches, so the quills are now replaced every 200 hours of operation. However that did not prevent this accident.