Air Force knows what failed on U.S. Osprey in Japan crash, but still doesn't know why

It doesn't matter the "why" what matters the fact it's crash, that's can not be deny. Another fact, crash in 2023 is not the first one.

Some Marines just crashed a CH-53E in the mountains east of San Diego and you do not hear cries wanting to ground the fleet, oh the helicopter is too dangerous, even though its mishap rate per 100,000 flight hours is greater than that for the MV-22. Five good Marines died because they made a really bad decision to fly over tall mountains during a major storm. No word on the cause yet.

Old saying: it's better to be sitting on the ground wishing you were flying than to be flying and wishing you were on the ground. Been there, done that. Still have sage green seat upholstery somewhere in my lower GI tract from the rhythmic puckering o_O

Afraid military will close 'ranks' around this matter, keep the truth out of the media, due to ongoing operational and security concerns. But my speculation is probably correct....so sorry, no juicy inside info!

While it might be possible to bury the results of a mishap investigation if the mishap occurred in a way that it was not widely known by the public or it happened in a combat theater where it could be written off to enemy action, this mishap is too public to bury the resulting investigation.

I was a detachment safety officer for a time, which required me to attend mishap investigation training, and being a military pilot was intimately familiar with mishaps and their investigations. Nobody on the safety side of the house wants anything buried. They want to know the truth so they can come up with ways to prevent future repeats of the mishap.

The way the military works is very different than how the civilian world works. There are dual investigations, one is a legal investigation by the JAG and the other is a mishap investigation by the relevant service safety agency. Anything you tell the mishap investigation is considered to be privileged information that legally cannot be used by the JAG investigation. The idea is that the military wants their aircrew to tell the mishap investigation the truth so they can use that information to prevent future mishaps. You can clam up and take the 5th all day long with the JAG investigation and still tell the mishap board you messed up with no fear what you tell the mishap board can come back and bite you in a Courts Martial or lawsuit.

Pilot error most likely. Ospreys are safe. Safer than helicopters and fixed wing aircraft the pro-us military commenters will tell you.

Statistically over 90% of aircraft mishaps in both military and civil aviation are due to pilot error, but this particular mishap seems to fit the remaining under 10% that are not due to pilot error.

Greed conquers all. It started with a few southern senators who insisted on building the Osprey in their home state.

The V-22 fuselage is made in Pennsylvania. Last time I checked, not a southern state. The final assembly happens in Amarillo, Texas. Also, not a southern state. Texas is a "western" state, with some southern attributes ... er ... east of Houston.

Aircraft designers weren't opposed to designing it. It was a challenge. We studied the V-22 design in my aircraft design class, along with many other aircraft. The gearbox was known to be a big challenge by everyone. When you build something that nobody has ever built previously, there are challenges and risks. We aren't making a Presidential vehicle created to survive anything. The X-plane the V-22 was based on didn't carry anywhere near the same weights or have the same range.

Until you do it, everyone says it can't be done. These are military aircraft, not commercial airliners. The rules are different.

Do half of the posters on here even bother to read before commenting?

“At this time, the material failure that occurred is known but the cause of the failure has not been determined. Engineering testing and analysis is ongoing to understand the cause of the material failure, a critical part of the investigation.

Material failure is not pilot error.

Why is this news? Asking why in Japan to beat the story to death? Reverse it and ask why so many things here are done the way they are would clearly drive you mad. Time to move on. It’s an accident.

Kumagaijin...

Pilot error most likely.

No, they know a part failed but don't know why the part failed. Or probably closer to the truth, they don't want to say why the part failed.

To say they know how why but don't know why is not real encouraging.

There is a difference between "knowing" and "suspecting". Knowing means you can reproduce the issue in test setups that mirror actual flight conditions without extreme measures. Guessing prematurely AND publishing the guess is detrimental to actually finding the truth. It puts the investigators on a path that becomes harder and harder to step back from if the suspicion for the root cause isn't actually the root cause. Better to not say anything about the likely cause until it is 100% known.

Some engineering problems don't allow for 20 yr lifespans of the component. This is why aircraft and rotorcraft have maintenance schedules, so parts that wear out can be replaced BEFORE a critical failure.

People would be surprised about the maintenance overhaul schedules for helicopters. Some critical parts must be replaced every 450 hours. The V-22 gearbox replacement schedule isn't public. Materials Science isn't exactly a science under extreme situations. Materials have very different properties and failures in extreme conditions. Gear teeth operate at extremes.

Knowing that a part broke is different from knowing why it broke.

Killing passengers is bad for every vehicle - cars, bikes, trucks, trains, airplanes and rotorcraft.

People would be surprised about the maintenance overhaul schedules for helicopters. Some critical parts must be replaced every 450 hours. The V-22 gearbox replacement schedule isn't public. Materials Science isn't exactly a science under extreme situations. Materials have very different properties and failures in extreme conditions. Gear teeth operate at extremes.

When I was flying Chinooks there was a requirement for a transmission ring gear inspection every 50 flight hours. This requirement emerged out of a tragic fatal crash of a civil Chinook in the North Sea that was traced to a main gearbox failure. That fact didn't stop me from loving just about every second I spent in a Chinook, but it did make me hawk the torque gauge and be very very careful to never over torque it lifting a load, and a Chinook at sea level has more than enough power to break the gearboxes. That is deliberate because as altitude, humidity and temperature increase, engine power decreases. Having that much power gives you the margin to lift heavy loads under extremes of temperature and altitude (think places like Afghanistan or Papua New Guinea). It's up to the pilots to stay within the published performance limits.

Don't see anyone suggesting it was foul play. Why ground the fleet for one action of foul play?

I'm sure the military industry complex doesn't want you to know 'why' either.

That's a ridiculous statement. The cause, once understood, will be widely published and the remedial actions likewise widely published. This is done so aircrews and the Marines who ride in them as well as their families have confidence in their aircraft. In all my time in the US Navy I never once saw a mishap investigation or the cause of a mishap buried to protect anybody. Not once.

@ Desert Tortoise Spot on I am familiar with JAG couldn't have written that post better!

Afraid military will close 'ranks' around this matter, keep the truth out of the media, due to ongoing operational and security concerns. But my speculation is probably correct....so sorry, no juicy inside info!

While it might be possible to bury the results of a mishap investigation if the mishap occurred in a way that it was not widely known by the public or it happened in a combat theater where it could be written off to enemy action, this mishap is too public to bury the resulting investigation.

I was a detachment safety officer for a time, which required me to attend mishap investigation training, and being a military pilot was intimately familiar with mishaps and their investigations. Nobody on the safety side of the house wants anything buried. They want to know the truth so they can come up with ways to prevent future repeats of the mishap.

*The way the military works is very different than how the civilian world works. There are dual investigations, one is a legal investigation by the JAG and the other is a mishap investigation by the relevant service safety agency. *Anything you tell the mishap investigation is considered to be privileged information that legally cannot be used by the JAG investigation. The idea is that the military wants their aircrew to tell the mishap investigation the truth so they can use that information to prevent future mishaps. You can clam up and take the 5th all day long with the JAG investigation and still tell the mishap board you messed up with no fear what you tell the mishap board can come back and bite you in a Courts Martial or lawsuit.

theFu Not all of the posters here are engineers so don't expect them to have analytical problem solving skills. Good post. It seems most posters here expect things to be built to last with no problems at all. If they ever went to a CDR well Critical Design Review where these complex system are discussed perhaps they might get an idea or maybe not understand how these sophisticated machines work. They are not just rolled off a manufacturing line and put in the field. The majority of things today are being controlled by software. Now ask yourself have you ever heard a Software engineer say that their programming is 100% error free? How many times have you purchased something that is controlled by software and you have to continuously get updates. Parts have a shelf life and reliability engineers and stress engineers test these part to understand the MTBF mean times between failures, so their is expectations and that is why they have maintenance records. Investigations take time and this is why nothing has come out concrete.

To say they know how why but don't know why is not real encouraging.

There is a difference between "knowing" and "suspecting". Knowing means you can reproduce the issue in test setups that mirror actual flight conditions without extreme measures. Guessing prematurely AND publishing the guess is detrimental to actually finding the truth. It puts the investigators on a path that becomes harder and harder to step back from if the suspicion for the root cause isn't actually the root cause. Better to not say anything about the likely cause until it is 100% known.

Some engineering problems don't allow for 20 yr lifespans of the component. This is why aircraft and rotorcraft have maintenance schedules, so parts that wear out can be replaced BEFORE a critical failure.

People would be surprised about the maintenance overhaul schedules for helicopters. Some critical parts must be replaced every 450 hours. The V-22 gearbox replacement schedule isn't public. Materials Science isn't exactly a science under extreme situations. Materials have very different properties and failures in extreme conditions. Gear teeth operate at extremes.

Knowing that a part broke is different from knowing why it broke.

Killing passengers is bad for every vehicle - cars, bikes, trucks, trains, airplanes and rotorcraft.

@HopeSpringsEternal Please, sir. If you know it's those nasty ChiComs just spill the beans!

ask yourself have you ever heard a Software engineer say that their programming is 100% error free? 

In my company, never. I’d be evaluating the engineer’s competence if they made such a claim, as no respectable engineer would make such a claim. We report to our clients that “there are no known outstanding issues” - and even that is rare, as in complex systems there are almost always known issues.

I worked in an environment writing avionics software for a long running program (govt program, not executable program). That team was tasked to create error free code and there were processes to help achieve that outcome. In the 5 yrs I worked in that job, the team error rate dropped to 1 bug found every 2 yrs for 20 programmers. It was very expensive to get that level of quality. We used CPI - Continuous Process Improvement - methods to track hundreds of things around every code change. In my 5 yrs there, I introduced 1 critical bug that made it through all the formal design, code and testing reviews of our team. Further, it made it passed 5 levels of external testing. Only in the last testing level, was the flaw found. So, that bug was assigned to me. I'd actually specifically asked, in writing, the customer's person responsible for overseeing the code development and acceptance about that exact line of code. She responded in writing too - with "don't touch it". While it was a critical bug, the craft would have still worked correctly due to redundancy. 1 of 4 control outputs wouldn't be correct. The other 3 were fine.

When I left the job there, it was widely believed that all critical errors in the software had been found. Jump forward to the end of the program in 2011 and someone had the bright idea to review all the critical bugs found from that date to the end and when the bugs were introduced. 104 critical bugs (total loss of vehicle possible) were in the software when we all (over 100 experts) believed it to be bug-free.

14 people did die in that craft over the years, but I can say that it was never due to software errors. Those failures were always hardware and management decisions to fly after been told about risks involved. Management (the customer) accepted the risks. Each of those failures was used to improve decisions in the future. After one of the failures, $B were spent on hardware and software to give the people on-board a chance at survival. While I didn't know the people on the craft well, I'd most of them. We knew that failing in creating the safest software that we could was important. Lives were at risk. Those lives rippled throughout the community. Kids knew each other, so if their father or mother was killed, everyone knew it. How could I look at the son or daughter of someone who died due to a mistake I'd made? I couldn't. I'd like to think that nearly all the people building aircraft have the same level of conscious and professionalism. We know upper managers don't always and it appears some line assembly workers may not. Those people are the exception and need to be fired.

I seriously doubt any foreign state had anything to do with this crash.

We know that it altered course to try and land earlier, so reading between the lines, we can speculate that the chip warning light did indeed come on and the pilot was on-course to land ASAP. Sadly, the engine let go as we also know, and they didn't make it.

If they are not blaming Chinese aftermarket parts, which had to be an early possibility, then the problem must be in the metal quality of a regular part, or gearing interface, which could still lie throughout the fleet. Naturally they will not want to be talking about it right now.

I'm sure the military industry complex doesn't want you to know 'why' either.

Rest In Peace to the fallen warriors.

@HopeSpringsEternal Please, sir, tell us more!

Pilot error most likely. Ospreys are safe. Safer than helicopters and fixed wing aircraft the pro-us military commenters will tell you.

Need to ensure aircraft part(s) and/equipment in question are being properly produced and maintained.

For example, an automotive brake can look fine, but if it's intentionally incorrectly assembled, say missing a key part, the braking system will fail. That gets dangerous.

If there's foul play then it's no accident and since there's no human/pilot error, foul play's a distinct possibility, making it newsworthy. Seems media coverage a strategy to help to fish for investigative info/leads?

Greed conquers all. It started with a few southern senators who insisted on building the Osprey in their home state. Aviators and aircraft designers opposed the building of the Osprey due to foreseeable deficiencies and design flaws. So aircrews who lost their lives in Osprey crashes are paying the price for political greed.

As pilot error is both common and easy to assess, one should assume the problems lies elsewhere. Besides mechanics, equipment vendors also possible.

Afraid military will close 'ranks' around this matter, keep the truth out of the media, due to ongoing operational and security concerns. But my speculation is probably correct....so sorry, no juicy inside info!

It doesn't matter the "why" what matters the fact it's crash, that's can not be deny. Another fact, crash in 2023 is not the first one.

Seems they may have rogue mechanic(s). Always risk with heavy equipment and someone who's loyalty lies elsewhere...