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kanban
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F-22 Now Grounded For Fourth Month

Tue Aug 09, 2011 2:15 am

The F-22 has been grounded now since May and I don't read of any solution to the problem...
http://www.minyanville.com/dailyfeed...dication&medium=portals&from=yahoo

"There is a lot of nasty stuff getting pumped into the pilots’ bloodstream through what they’re breathing from that OBOGS [On-Board Oxygen Generation System]. That’s fact,” one former F-22 pilot told Dave Majumdar of the Air Force Times a few weeks ago. “How bad it is, what type it is, exactly how much of it, how long -- all these things have not been answered.”

Whatever it is the pilots are breathing has been causing hypoxia -- a lack of oxygen that can lead to reduced brain function, memory loss, and cognitive problems. On top of that, anti-freeze, propane, and synthetic motor oil have recently been found in F-22 pilots' bloodstreams."

question where is this nasty stuff coming from.?.. I will hazard a quess that this oxygen system is is chemically different than the canisters on commercial a/c.

Awhile ago there were people saying scrap the F-35 .. make more F-22s... it now appears that both have problems.
 
rwessel
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RE: F-22 Now Grounded For Fourth Month

Tue Aug 09, 2011 4:31 am

Quoting kanban (Thread starter):
question where is this nasty stuff coming from.?.. I will hazard a quess that this oxygen system is is chemically different than the canisters on commercial a/c.

It extracts O2 from the atmosphere. The idea is to do away with the need for O2 as a consumable. No chemical O2 generators involved. Although it's obviously not working very well. One would assume that leakage from some pumps, compressors, hydraulics, the fuel system, the engine exhaust, or something, is getting into things. While I have no idea how it bears on the F-22's OBOGS, compressors leaking lubricant into breathing gas have injured and killed lots of people.

Quoting kanban (Thread starter):
Awhile ago there were people saying scrap the F-35 .. make more F-22s... it now appears that both have problems.

Whatever issues the F-22 might have, this is ultimately a pretty small one. You're talking about a single isolated system. No matter what the resolution, it's not going to have a big impact on the overall aircraft.
 
Cadet985
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RE: F-22 Now Grounded For Fourth Month

Tue Aug 09, 2011 5:29 am

Quoting kanban (Thread starter):
Awhile ago there were people saying scrap the F-35 .. make more F-22s... it now appears that both have problems.

Time to consider upgrading the F-15 and F-16 fleets. I'm sure Boeing and Lockheed Martin would not complain.

Marc
 
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kanban
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RE: F-22 Now Grounded For Fourth Month

Tue Aug 09, 2011 3:25 pm

Quoting rwessel (Reply 1):
compressors leaking lubricant into breathing gas have injured and killed lots of people.

not to mention lubricant and O2 equals fire...

How does lack of this system affect the usage envelop?... or are pilots hooked in 100% of the time?
 
HaveBlue
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RE: F-22 Now Grounded For Fourth Month

Tue Aug 09, 2011 4:32 pm

The F-22 that crashed in Alaska in November of 2010 and killed Capt. Jeffrey Haney was directly linked to a problem with the oxygen system, and they have been restricted to flying at 25,000' max since then and because of that.

And is it possible it also played a role in the 2009 crash of an F-22 out of Edwards? The USAF claimed it was GLOC related, but I'm thinking this may have been a contributing factor? Pulling 9 G's with a substandard oxygen system might be problematic. About that crash:

"It is possible such a system could have spared the most recent f-22 crash, when Lockheed test pilot David Cooley briefly lost situational awareness during a 9g manoeuvre. As he regained awareness, the f-22 was already diving through 14,000ft at M1.6. Cooley ejected a moment before the f-22 crashed, but the aerodynamic forces at M1.4 killed him."

http://www.flightglobal.com/articles...-wreckage-pilot-still-missing.html

Quoting kanban (Reply 3):
How does lack of this system affect the usage envelop?... or are pilots hooked in 100% of the time

I'm fairly certain that the US armed services require the pilot to wear an oxygen mask from takeoff to touchdown, though I don't know how strictly that rule is followed. At 50,000' humans have a useful consciousness of 10 seconds or less without breathing apparatus, the 25,000' imposed ceiling on the Raptor gives the pilot time to dive down below 18,000' quickly where the air is breathable without the need for any systems.
Here Here for Severe Clear!
 
HaveBlue
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RE: F-22 Now Grounded For Fourth Month

Tue Aug 09, 2011 5:42 pm

Okay I just read the United States Air Force Aircraft Accident Investigation Board Report on David Cooley's F-22 crash at Edwards in 09 and I am less inclined to believe it was oxygen related. It was absolutely A-LOC related, perhaps excaserbated by his having a cold and the TC not calling 'point complete', but he definitely was fighting off GLOC and not doing so very well.
Here Here for Severe Clear!
 
wvsuperhornet
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RE: F-22 Now Grounded For Fourth Month

Thu Aug 11, 2011 10:11 pm

Quoting Cadet985 (Reply 2):
Time to consider upgrading the F-15 and F-16 fleets. I'm sure Boeing and Lockheed Martin would not complain.

Marc

Boeing might not but lockmart would whine like a little girl (no offense intended to little girls if any are here)...  

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