Fatal Problems Continue To Plague F-22 Raptor 379
Hugh Pickens writes "The LA Times reports that even though the Air Force has used its F-22 Raptor planes only in test missions, pilots have experienced seven major crashes with two deaths, a grim reminder that the U.S. military's most expensive fighter jet, never called into combat despite conflicts in Iraq, Afghanistan and Libya, continues to experience equipment problems — notably with its oxygen systems. New details from an Air Force report last week drew attention to a crash in November 2010 that left Capt. Jeff Haney dead and raised debate over whether the Air Force turned Haney into a scapegoat to escape more criticism of the F-22. Haney 'most likely experienced a sense similar to suffocation,' the report said. 'This was likely [Haney's] first experience under such physiological duress.' According to the Air Force Accident Report, Haney should have leaned over and with a gloved hand pulled a silver-dollar-size green ring that was under his seat by his left thigh to engage the emergency system (PDF). It takes 40 pounds of pull to engage the emergency system. That's a tall order for a man who has gone nearly a minute without a breath of air, speeding faster than sound, while wearing bulky weather gear, says Michael Barr, a former Air Force fighter pilot and former accident investigation officer. 'It would've taken superhuman efforts on the pilot's behalf to save that aircraft,' says Barr. 'The initial cause of this accident was a malfunction with the aircraft — not the pilot.'"
Re:Use the old O2 system? (Score:5, Informative)
The new systems are smaller and lighter. Also, at least from the original crash report, the oxygen system wasn't at fault. It shut down like it was supposed to (it was operated by bleed air from the engine, the ECS detected a hot bleed air leak and shut off the bleed air valves. If you don't check a hot bleed air leak, you can set the plane on fire or melt parts of it), but the pilot struggled to activate the emergency oxygen system and had significant difficulty with this due to the bulky gear he was wearing.
While struggling with activation of the EOS, he lost track of time and became disoriented, failed to notice that his aircraft attitude had changed, and attempted a dive recovery far too late to save himself.
Re:Bleeding Edge Aviation (Score:5, Informative)
Yes, but the existing planes are constantly updated. Military planes are not like commodity cars, which get build once and only receive new wipers every now end then. The airforce plans to use them for decades. Also, the insight gained will influence the next generation of fighters.
My grandfather the B-17 and B-24 pilot had some saying about the first couple hundred B-17 (or was it B-24?) engines pretty much being no good, lots of return to base after engine failure, a couple times for him personally, he even had a wing fire (obviously, survived, somehow). No big deal if the first couple hundred fail, because they made thousands.
Sounds like they're doing that with the F-22, the first couple hundred are kind of learning experiments. Whoops, they only made a couple hundred and then shut down the line. Well, thats not gonna work so well.
Re:Use the old O2 system? (Score:4, Informative)
Actually its almost exactly like taking the water pump out of a 1960 ford falcon and being surprised you can't use it on a 2011 ford F-150.
Re:Things that make you go "Huh?" (Score:2, Informative)
First thing:
None of what you said matters. Accidents are situational. Pilots are trained in a lot of things to reduce the number of accidents, but accidents will still happen. His attention became channelized, or in other words, he fixated on a couple of tasks and that doomed him. He lost situational awareness. That's how things happen in the pilot world.
Second thing:
Hypoxia was not factor. Had it not been, you're essentially dead after about half a minute. No, you're not actually dead, but your brain is no longer able of doing anything useful. Your period of useful consciousness is over. This is not like working out: Someone who's working out still has oxygen being delivered to their brain. Someone suffering from hypoxia is running on very borrowed time. This is similar, but not the same, to G-LOC. When you exceed a certain number of G's abruptly, or do not do the G-straining maneuver properly, the brain runs on its 5-second oxygen reserve, and you will literally go out like a light once that's gone. No grey-outs, no warnings, nothing. Just sleeping.
Re:Bleeding Edge Aviation (Score:5, Informative)
No, that is not what this means.
"Air bleed" is the method by which the OBOGS generates breathable air. It's called "bleed" because it "bleeds" off a small amount of air from the engine's compressor system. (This air can also be used for deicing flight surfaces, generating power, and other purposes).
An "air bleed failure" means that either no air is getting into the system, or a sensor failed and it thinks no air is getting into the system.
To summarize, this wasn't a failure where air was bleeding, this was a failure of the system that bleeds air from the engine for the pilot to breathe. That's important to understand.
Re:We don't want your crappy jets (Score:2, Informative)
Why are you [Americans] pushing us Canadians sooooo hard to buy your latest super-jet blah blah blah blah blah
As an American, I assure you Canadians I couldn't fucking care less whether you buy the F-22 to defend yourselves, or even whether you deign to defend yourselves at all. Actually, I think you have the F-22 confused with the F-35. It might interest you to know that export sale of the F-22 is barred by American federal law.
Seriously. It's just not on my radar. Not on the radar of anybody I know.
Re:Bleeding Edge Aviation (Score:5, Informative)
No. Read the report:
http://usaf.aib.law.af.mil/ExecSum2011/F-22A_AK_16%20Nov%2010.pdf [af.mil]
This wasn't a case of extraordinary circumstances. This was calm, high altitude flight where a critical (but understood) subsystem failed.
The pilot then became distracted by the system failure possible because of oxygen deprivation, or because the emergency air control was in an ergonomically challenging location. While distracted, he became inverted (240 degree roll during descent) and didn't attempt to correct until 3 seconds prior to impact.
The ergonomic issue may be a contributing cause. but a pilot *must* be able to continue instrument scan while dealing with an emergency. Just because you're air doesn't work doesn't mean you can't still crash while dealing with that.
It's sad, but more or less understood what happened.
Re:Bleeding Edge Aviation (Score:5, Informative)
Sure any programmer with his salt knows how to fix it and should have though about it before hand... However things slip threw the cracks, as you are focusing on proof of concepts, then by the time you got the proof of concept working you were behind schedule and never really went back and looked at your data inputs (for that one routine).
Then it goes out and you end up looking like an idiot.
Mistakes happen, most mistakes that cause the biggest problems are the ones that are easiest to solve, and are often just overlooked mistakes.
Because Oxygen system wasn't cutting edge, I am willing to bet no one stressed out too much over it, as it was a piece of cake issue. Well it got overlooked and it cost peoples lives (which is much worse then looking like an idiot). But where was the mistake.... Lets go back to the code example.
Sure you are to blame because you coded it, but QA should have tested common names with special characters, management should have adjusted their project plan because you were having issues getting some proof of concepts working... Mistakes even big ones really isn't any ones problem but usually due to a full breakdown in the organization.
Re:Use the old O2 system? (Score:4, Informative)
Easy. With bottled air, you've got to cart around what you can breathe. You're limited by that, and it takes up space and weight.
The early F-16s didn't have OBOGS. When they got an engine upgrade (block 50, I think) they recieved OBOGS. From the company that builds the OBOGS, here's the advantages:
http://www.cobham.com/media/75388/SYSTEM%20F-16%20OBOGS%20ADV10556.pdf [cobham.com]
The problem is that if something goes wrong, you have to shut the system down. In this case a sensor detected hot air entering the system, which is a sign of a fire, or a potential cause of one. So the system shuts down, and the pilot needs to go to his emergency O2 supply. But this guy struggled trying to activate it. Possibly an ergonomic problem that needs to be addressed.
Generally speaking though, OBOGS is a sound, logical way to go.
Re:Bleeding Edge Aviation (Score:5, Informative)
You've mixed things up, it makes no sense. I've read the report. Here's what happened:
1. The fire control system (FCS) detected a bleed air duct leak and has closed the isolation valves, cutting off engine bleed air from reaching the bleed air manifold (or duct). Bleed air is hot air from the compressor, used to power other systems. This triggers the "C BLEED HOT" caution.
2. Loss of bleed air made the following systems inoperational: environmental control system (ECS), forced air cooling for avionics et al (ACS), oxygen generator (OBOGS), inert gas generator (OBIGGS), cabin pressurization.
3. About 5 seconds after the bleed air was cut off, a new caution appeared: "OBOGS FAIL". This means the oxygen generator is out and you have to activate emergency oxygen generator on your seat - soon. That one is on your seat because it has to supply you with oxygen when you eject.
4. About 14 seconds later, a sensor picks up loss of oxygen pressure to the mask (from failed OBOGS).
That's all there's to it. Apparently the pilot never managed to activate emergency oxygen, and while fumbling with that he also bumped the control stick and rudder, causing the aircraft to fly a "random" trajectory. The cabin is cramped, and with extra cold weather gear it's nigh impossible to activate that emergency oxygen without bumping into things. That is a design issue, as well as the awkward way of activating that emergency oxygen system (you have to pull a ring from a hip level about 2 in. forward (away from you) with 40lb or more of force.
The report is here [airforce-magazine.com].
Re:Bleeding Edge Aviation (Score:5, Informative)
For example, recently the USAF asked for $8 billion to upgrade the F-22 fleet to be able to use the much vaunted datalink capability. That's more than 10% of the current program cost.
Sort of.
The Air Force asked for the support contract limit to be raised from the existing $6 billion to $7.4 billion
That extra $1.4 billion represents several upgrades, including data link.
Re:Bleeding Edge Aviation (Score:5, Informative)
Sigh. Mistake upon mistake in those comments. The computer didn't detect any oxygen leaks. It detected a leak of hot air (bleed air) that is used to power various things, including oxygen generator (OBOGS). Since an uncontained leak of bleed air is likely to start a fire, the bleed air was automatically cut off by closing isolation valves at the engines. Thus it was no more powering the oxygen generator. The pilot fumbled for about 30s trying to activate emergency oxygen, eventually failing to do so, but while he was fumbling he bumped the control stick and rudder pedals, sending the aircraft on an uncontrolled inverted dive.
The bleed air is really hot -- between 1200F to 2000F (650C to 1000C). PHX (primary heat exchanger) then cools it down to 400F (200C).
There was some maintenance done in the previous months that required disconnecting the bleed air ducts, the accident investigators didn't think that anything went wrong there.
The bleed air leak was survivable, but somehow the pilot couldn't get emergency oxygen going, and lost situational awareness. When he tried to recover from the dive, it was too late.
Re:Bleeding Edge Aviation (Score:1, Informative)
My grandfather the B-17 and B-24 pilot had some saying about the first couple hundred B-17 (or was it B-24?) engines pretty much being no good
Hell, the P51-Mustang was widely considered a strategic misstep until the British put their awesome engines in it. Its only because of those engines the Mustang is legend today. Hell, the Osprey is much loved by troops now but I'm sure we've all heard about those accidents.
As others have said, new military might ALWAYS requires sacrifice at the alter. Anyone who says otherwise is either ignorant, and therefore not worth listening to, or a politician with an angle. It really is that cut and dry. That's not to say everyone should turn a blind eye to effort without reward, but death, even in peace time, is a COMMON fact of life in the military.
Re:Bleeding Edge Aviation (Score:3, Informative)
Computers shouldn't be running oxygen supplies anyway.
Re:Bleeding Edge Aviation (Score:4, Informative)
The report mentions that in tests they managed to activate the system while installed backwards, but I wonder if that's only because it was under controlled conditions. Is there the slightest chance in hell that anyone could do this in an emergency (which is literally the only time you would ever have to do this)?
And then the fact that it's hard to locate if dropped due to the cable jamming, a failure to exert the necessary force, etc. Short of removing the system entirely, I don't think it's possible to design anything worse. This design is a textbook example of how not to design an emergency system.
Re:Bleeding Edge Aviation (Score:5, Informative)
The standard term is "bleed air", not "air bleed". (I was an F-16 engine mech and crew chief (and Comm/Nav on Phantoms and Broncos).
We don't yet know what caused the bleed air leak. but bleed air ducting isn't something new and leaks tend to be either because of improper connection or duct failure (bleed air is bled from the engine compressor, but it's HOT and at very high volume).
http://defensetech.org/2011/12/15/af-alaska-f-22-crash-due-to-pilot-error/ [defensetech.org]
"While the oxygen generating system on Haneyâ(TM)s jet didnâ(TM)t fail, it did shut down because oxygen from the bleed air system, which feeds the OBOGS, was leaking into the engine spaces"
Cooling and running it through a molecular sieve to save doing LOX servicing is theoretically a good idea, but the MAIN reason to have OBOGs is to get rid of the base LOX plant, support equipment, and servicing personnel.
Some "ancient" history:
http://www.f20a.com/f20obogs.htm [f20a.com]
Re:Bleeding Edge Aviation (Score:5, Informative)
Laminar flow gave it range via low drag and therefore reduced fuel consumption. It was unsatisfactory for its mission until the British got a hold of it and in fact, initially failed to perform up to anticipation. With the US made engine, it could only perform down low and high altitude performance was a requirement for long distance bomber escort. Without the British's contribution to the P51, it would have been little more than a footnote in history. Period.