Osprey crash in Japan

Velocity173 said:
Well it’s OR rates have never been it’s strong suit. Keep hearing it hasn’t matured yet but jeez, it’s been in service for 16 years. Some of the maint stuff should’ve been worked out long ago. The aerodynamic quirks are understandable but they still have clutch and sand ingestion issues???
Click to expand...
My knowledge is limited to watching V-22s fly. Then seeing some parked on the ground. That’s about it. But I was around the rotorcraft community for a while, and there’s always some oddball thing coming up. For example, you may remember short shafts in the Black Hawks blowing up and catching fire —that one was tricky. My former boss was on a red team to investigate it. As we saw on the video you posted, parts and their respective suppliers can turn out to be an issue. If you’ve got stuff running around in a gearbox or in a clutch and somebody changed suppliers or the metallurgy changed— well, then you got a problem.
 
Having been at the beginning of the AH-64 fielding process there were similar issues with it. 9 out of the first 10 battalions (21-24 aircraft per battalion) suffered a fatal class A accident (all fatals are class A) during the Battalion certification process. The 10th Battalion was the first to complete the certification without an accident. The V-22 has been around for almost 25 years so a little longer in the tooth than the AH-64 at the time…
 
Warlock said:
The V-22 has been around for almost 25 years so a little longer in the tooth than the AH-64 at the time…
Click to expand...
Agreed, so why the clutches or whatever going bad all of a sudden?
 
Piperonca said:
Agreed, so why the clutches or whatever going bad all of a sudden?
Click to expand...
The "clutches" are equal to a freewheel unit you are familar with and are located in the input quill from each engine. And the problem has been around for years.

While the root cause is not known, they have put a life limit on the clutches as there was a trend in high time failure rates.

Technically one clutch actually slips first then reengages which causes the drivetrain damage. And its usually the interconnect system that suffers the damage and not the clutch directly.

Other rotor type aircraft have suffered similar issues with these clutches/freewheel units over the years. So its not exclusively a V22 issue. For example, during a ground run on a BO105 had a clutch slip and twisted an input shaft.

Regardless, on the V22 accident side the causes are basically split between mechanical snd pilot error. And when compared to other military aircraft its reliability % is in the middle as well.
 
Bell206 said:
Regardless, on the V22 accident side the causes are basically split between mechanical snd pilot error.
Click to expand...
I've always thought that the pilot error percentage was further partitioned with design-induced mishaps, including controls/displays or flying qualities being sub-optimal.
 
6 per 100,000 hrs for the Air Force and that was back in 2021. USMC seems to be getting better results but I know they have OR rate issues as well. Guy I worked with got 8 hrs in a year with the Reserves. Said they broke a lot.

thediplomat.com

Is the Osprey Safe?

The latest fatal crash off Japan has resurrected worries regarding the aircraft’s track record.
thediplomat.com
 
Piperonca said:
I've always thought that the pilot error percentage was further partitioned with design-induced mishaps, including controls/displays or flying qualities being sub-optimal.
Click to expand...
Given the high profile of V22 accidents the reports I've seen keep the mechanical/systems issues separate from the pilot induced issues. On that side you'll see flying aircraft outside its design parameters as a common error cause.

And its not so much that the aircraft has matured as the basic design has not matured yet. The V280 will be the next design level and will probably suffer its own design issues as the tiltrotor design continues to mature.

Keep in mind the V22 was the 1st production model after 40 years of prototypes.
 
Last edited:
No details given from NAVAIR.
 
Bell / Boeing product but I think it’s mostly Bell.

Sitting on the ramp for three months didn’t do those airframes any good. Hopefully they were doing weekly run ups and cycling the systems.
 
Velocity173 said:
Bell / Boeing product but I think it’s mostly Bell.
Click to expand...
Last I read, Boeing handles the fuselage and its sub-systems to include the cockpit and flight controls. Rolls Royce provides the engines. Bell provides the prop-rotors, tail, wing, and handles the final assembly and flight checks.
 
Wonder what happened with those troublesome V-22 clutches, how they work on the V-280, and whether any advances will eventually propagate back to the Marines. It's a bad thing when you're flying along doing everything right, even preflighted correctly, then your machine kills you and everyone on board.
 
Piperonca said:
Wonder what happened with those troublesome V-22 clutches, how they work on the V-280, and whether any advances will eventually propagate back to the Marines. It's a bad thing when you're flying along doing everything right, even preflighted correctly, then your machine kills you and everyone on board.
Click to expand...
I *think* that the V-280 system has significant differences. If you note, they changed how the movement happens on the pod vs the whole thing rotating. They may have kept mishaps hush hush but the V-280 test program seems to have been notably crash-free. And I’ve personally seen the thing flying over populated areas near Arlington, TX.

www.flightglobal.com

Bell pulls apart V-280 tiltrotor in post-demonstration autopsy

After flying its V-280 Valor tiltrotor for 214h, Bell is picking apart the decommissioned aircraft to see if it can find signs of wear and tear.
www.flightglobal.com www.flightglobal.com
 
Piperonca said:
Wonder what happened with those troublesome V-22 clutches, how they work on the V-280, and whether any advances will eventually propagate back to the Marines.
Click to expand...
The V280 uses clutches also but I'm sure they are of a different design. But doubtful will make it back to the V22 unless they make a redesigned clutch for the V22 drivetrain which I believe they are.

Basically the V280 and V22 are only similar in category type as the V280 is a radically different design aircraft-wise.
 
Bell206 said:
The V280 uses clutches also but I'm sure they are of a different design. But doubtful will make it back to the V22 unless they make a redesigned clutch for the V22 drivetrain…
Click to expand...
Reminds me somewhat of the C-5 wing spar that had to be redesigned. The fatigue life was different from predicted, long story short. That was expensive but in a war fighting machine it had to be done.
 
Piperonca said:
Reminds me somewhat of the C-5 wing spar that had to be redesigned. The fatigue life was different from predicted, long story short. That was expensive but in a war fighting machine it had to be done.
Click to expand...
Or like the F-111. They started getting cracks in the wing box that required a complete redesign. Not sure if the A-6 wing fatigue issues were premature but they were just starting to replace their metal wings with composite when that program was cancelled. Had at least three wing failures that I know of.

 
Piperonca said:
Reminds me somewhat of the C-5 wing spar that had to be redesigned.
Click to expand...
But one thing to keep in mind is sprag clutch issues are not exclusive to the V22. A number of other helicopters have had similar issues. The main issue with the V22 is how the drivetrains interconnect to power the rotors in the event of an engine failure. With both engines on line feeding the interconnect gearbox if one clutch slips then has a hard engage there's a lot of torque being "turned off-turned on" in a very short time. In a conventional drivetrain if a clutch slipped then re-engaged the most you would get is a twisted input shaft.

Its my understanding the V280 interconnect system doesn't have an interconnect gearbox and the power sharing is more "conventional" at the prop rotor gearbox. But who knows if that new system won't develop its own issue as well.
 
Last edited:
You must log in or register to reply here.
Back
Top