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More hypoxia incidents have occurred since the F-22 returned to the skies

The USAF's premiere air superiority fighter, the F-22 Raptor, had a rough year in 2011. There were several incidences of pilots exhibiting hypoxia-like symptoms that led to the aircraft being placed on stand-down for months while an investigation took place into the possible causes of the issue.
Fingers were pointed at the onboard oxygen generation systems and the OBOGS failure was thought to have contributed to the fatal crash of a Raptor pilot in 2010. That fatal crash was instead ruled pilot error.
On January 13, a report from the Pentagon's top tester was published on the grounding of the F-22 Raptors last year. According to the report, the Raptor stand-down last year was due to "suspected contamination problems with the aircraft environmental control system and associated onboard oxygen generation system from later April through late September 2011."
The report was penned by chief operational tester J. Michael Gilmore and confirms that toxins entering the cockpit of the F-22 had cause over twelve incidents that were similar to hypoxia. The USAF lifted the grounding before a hard answer to the cause of the problems was found. Since the grounding was lifted, the Raptors in the fleet have flown over 6,000 times. Defense News reports that more incidents of the hypoxia-like symptoms have occurred despite the precautions put into effect to install charcoal filters and have pilots wear pulse oximeters.
[Source: Lockheed Martin] 

Air Force spokeswoman Jennifer Ferrau said, "There have been approximately 90 events of interest and 15 are being investigated for potential physiological incidents -- 8 involving pilots and 7 involving aircraft maintenance personnel. This translates to a 1.8 percent event rate since the return to flight in September."
In USAF parlance an "event of interest" is an indication of a malfunction in a system or a data point that has not caused hypoxia-like symptoms. A "physiological event" is one that has produced hypoxia symptoms.
Ferrau said, "Any event involving hypoxia-like symptoms may be categorized by Air Force Instructions as a physiological incident following an investigation."

Source: DefenseNews

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The smoking gun that wasn't loaded
By drycrust3 on 1/16/2012 6:28:56 PM , Rating: 5
...and the OBOGS failure was thought to have contributed to the fatal crash of a Raptor pilot in 2010. That fatal crash was instead ruled pilot error.

"There have been approximately 90 events of interest and 15 are being investigated for potential physiological incidents -- 8 involving pilots and 7 involving aircraft maintenance personnel. This translates to a 1.8 percent event rate since the return to flight in September. "

From the 16th December Daily Tech article:
"I find the cause of the mishap was the MP's [mishap pilot] failure to recognize and initiate a timely dive recovery due to channelized attention, breakdown of visual scan and unrecognized spatial disorientation." ... The report read, "The MP most likely experienced a sense similar to suffocation." ...

This sort of report makes my blood boil. Everyone agrees there was a problem with the aircraft before the crash, and everyone agrees that there was a problem after the crash, but, low and behold, on the exact day of the crash, on just that one flight, when something akin to a cork in the oxygen feed is prevelant, it didn't have anything to do with the crash?
As I see it, if the oxygen had failed and the pilot had "dived the aircraft" and brought it home safely, then no one would have done a thing about the oxygen problem.

By Ringold on 1/16/2012 9:25:15 PM , Rating: 2
Glad I wasn't the only one that read all this and got the feeling they were using brave pilots, with millions of dollars of irreplaceable training, as test rats.

RE: The smoking gun that wasn't loaded
By bug77 on 1/17/2012 5:15:25 AM , Rating: 2
The way I read that, is test-pilots are most likely trained for such incidents. In this case, the pilot failed to initiate an emergency dive that would have saved both the pilot and the plane.

These are planes in their test phase after all. You can't just sit behind a desk designing a plane until it's 100% and then test it. It's just not possible.

By BZDTemp on 1/17/2012 5:43:57 AM , Rating: 2
Since the pilot is sitting inside the plane and not out in open air it's not sure an emergency dive for breathable air would have worked. Remember this is not about lack of oxygen in the breathing system but about all sort of gasses that should not be in the air feed to the pilot.

By cjc1103 on 1/17/2012 7:33:13 AM , Rating: 4
Then F-22 has in fact passed the test phase and is operational. The last F-22 production fighter has been rolled out, and no more will be made. Having said that, there are obviously still problems that need to be worked out. The onboard OGS using engine bleed air was state of the art, and supposed to reduce the need for support and maintenance. Instead, it has turned into the achilles heel of the aircraft. How embarassing for the Air Force, their front line fighter can't fly because of this. I doubt it would be easy, or even possible, to retrofit an old-style liquid oxygen system to the F-22. I hope the F-35 has a better oxygen system.

RE: The smoking gun that wasn't loaded
By Amicus Curiae on 1/17/2012 8:28:11 AM , Rating: 2
What toxins? Name them. What is the source? In what quantity? Who measured them and with what method? There are complaints. There are suspicions. There are accusations. There is no smoking gun.

RE: The smoking gun that wasn't loaded
By TSS on 1/17/2012 9:26:44 AM , Rating: 1

Symptoms of mild acute poisoning include lightheadedness, confusion, headaches, vertigo, and flu-like effects

This would be my first bet. But then again if the air your breathing carries too much Co2, No2 and not enough O2, you're going to black out. If it carries too much O2 it'll burn up your lungs from the inside. Really, it can be any number of causes.

In any case, what i wouldn't bet on is the pilots not breathing. If there ever where trained air men, they are in the USAF. If 1 messes up, sure. 2, can happen. 3, something's not right here. I believe we are past that point for some time now.

RE: The smoking gun that wasn't loaded
By Deaks2 on 1/17/2012 9:36:41 AM , Rating: 2
As per:


Toxins found in pilots’ blood include oil fumes, residue from burned polyalphaolefin (PAO) anti-freeze, and, in one case, propane. Carbon monoxide, which leaves the blood quickly, is also suspected.

“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 said. “How bad it is, what type it is, exactly how much of it, how long — all these things have not been answered.”

The blood tests were performed after each of the 14 incidents in which pilots reported various cognitive dysfunctions and other symptoms of hypoxia. One couldn’t remember how to change radio frequencies. Another scraped trees on his final approach to the runway — and later could not recall the incident.

RE: The smoking gun that wasn't loaded
By Amicus Curiae on 1/17/2012 12:16:22 PM , Rating: 2
"That’s fact, one former F-22 pilot said..."
Who is this guy? Why does he know more than the people who are looking at all the measured data? He speaks with certainty and authority. Why can't we know who he is?

By geddarkstorm on 1/18/2012 2:54:41 AM , Rating: 2
Explain how seven maintenance personnel also experienced the hypoxia like events when they -aren't flying the planes-, just working on them. This suggests that something nasty is being produced by the plane, not simply a lack of oxygen, which is abundant when on the ground.

RE: The smoking gun that wasn't loaded
By FaaR on 1/18/2012 8:34:59 AM , Rating: 2
What's up with all the irrelevant questions? And your blatant trolling?

Maintenance crew?
By geddarkstorm on 1/16/2012 4:51:18 PM , Rating: 2
How did seven of those guys experience hypoxia like events? This is sounding more like some sort of toxin is being made that's behind it all.

RE: Maintenance crew?
By MGSsancho on 1/16/2012 5:40:35 PM , Rating: 2
Pure Oxygen can be considered a toxin. Personally I am glad it was decided to do more investigation into problems that have arisen.

By DougF on 1/16/2012 2:38:21 PM , Rating: 1
Testing possible weak points? Hmmm?

Parts made in China?
By Lord 666 on 1/17/2012 12:09:15 AM , Rating: 1
Toxic milk, baby formula, toys... F-22 parts?

It could be CO?
By ct760ster on 1/17/2012 1:55:15 AM , Rating: 1
Not to be a brain-dead explanation but could some of the engines exhaust being leaking inside the cockpit and poisoning inadvertently it's occupant.

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