Posted on 03/12/2012 9:11:31 PM PDT by U-238
The U.S. Air Force is still having problems with the pilot's air supply in its F-22 fighters. Recently, there were three more cases of F-22 pilots apparently experiencing problems. The term "apparently" is appropriate because the pilots did not black out and a thorough check of the air supply system and the aircraft found nothing wrong. There have been nearly 30 of these "dizziness or disorientation" incidents in the last four years. That's about one incident per hundred sorties. Only one F-22 has been lost to an accident so far and, while that did involve an air supply issue, it was caused by pilot error, not equipment failure. Meanwhile the air force is spending $7 million to install commercial oxygen status sensors in the air supply systems of its F-22 fighters. This is part of a ten month effort to find out what's causing the air supply on F-22s to get contaminated and cause pilots to become disoriented or pass out. Twice in the past year the entire F-22 fleet was grounded because of the air supply problems. The first grounding lasted 140 days and ended last September. The second grounding lasted a week and ended four months ago. The 180 F-22s comprise the most powerful component of the air force's air combat capability and the brass are eager to find out what is wrong.
(Excerpt) Read more at strategypage.com ...
A few years ago there was a Greek airliner (B-737) climbing out, when a warning horn went off passing about 10,000 feet.
The Captain assumed it was the takeoff warning horn (a malfunction) even though the oxygen masks deployed in the back as they climbed through about 14,000 feet.
The Captain went back to the circuit breaker panel while the first officer flew, and promptly passed out in the floor. The copilot continued the climb and eventually passed out at the controls.
The airplane flew for couple of more hours — eventually a flight attendant got in the cockpit (the intrusion resistant door was locked) who had some training in light aircraft.
The flight attendant couldn’t figure out how to operate the radios but flew it for a while until one engine flamed out due to fuel starvation and the airplane spiraled down into the ground.
Turns out the outflow valve was fully open the whole flight, preventing the airplane from pressurizing, because the Captain missed it on his cockpit setup.
Hypoxia is very serious and as you probably know any airplane with a cabin pressure above 10,000 feet must have supplemental oxygen. Most airliners cruise with a cabin altitude of around 8,000 feet.
But at 50,000 feet and up, where the Raptors like to be, the cabin pressure is likely to be closer to 25,000 feet, which is the altitude limit for unpressurized aircraft with supplemental oxygen. At those cabin altitudes hypoxia is more sudden and supplemental oxygen is a must under normal conditions, not to mention if there were a sudden loss of pressurization.
http://www.nytimes.com/2005/09/06/world/europe/06iht-crash.html
The solution to this continuing problem is obvious.
Convert all the F-22s to drones.
This strategy of converting from people to drones has kept several fighter bases in business, and could keep all our F-22s in business.
[only half] /s
Well, aside from modernized Indian Mig-21...
F-22 Technology On UAV That Crashed In Iran
Could be a small part that fails to the advantage of High-G, but not otherwise like it’s supposed to.
0bama’s all for it if it helps Iran acquire them. China and Russia probably has most of the F-22 technology anyway which could explain how Iran was able to hijack the UAV which uses some of the same technology. Okay, I’m guessing, but no classified information is safe under the umbrella of this regime. Besides, Leon Panetta says the U.N. is the boss anyway. Bottom line?.. ABO in NOV!
The Navy has been working to install an updated solid-state oxygen-monitoring system on all in-service F/A-18s that tracks both oxygen concentration and pressure rather than O2 concentration alone. The Eurofighter Typhoon has such a system and has had no reported Obogs issues.
The problem with OBOGS is that sometimes you don't have any warning. I had a good friend put on his mask in an OBOGS equipped hornet as he took the runway. As the aircraft rotated he could tell something was wrong then he lost his sight. He remembers fumbling for his emergency O2 bottle in his seat that cut off the OBOGS and provides bottled oxygen. He regained his sight passing 3000 ft AGL and 350 knots with the gear still down (slight overspeed there). He almost got killed.
Wow, that is just freaking gorgeous.
Yes the chamber rides are excellent. Civilians don’t get the benefit of them (e.g. the Greek airliner crew).
The AF quit letting everyone experience rapid-decompressions in the altitude chamber to above 30,000 feet after several chamber attendants who were doing multiple sessions were found to be getting the bends. I think after that they were rapid-Ds to about 20k, just enough to demo the noise and condensation.
Not sure what you meant about the friend nearly losing consciousness on takeoff. If he was taking off from a runway, wouldn’t he have been at an altitude not requiring oxygen anyway? Even the runway at La Paz is only at about 13,300 feet.
Thanks...a good update. I’d heard somewhere they used to purge the system with Freon but had to stop for environment reasons and the replacement product could be the problem.
>>One in one hundred sorties is a fantastically high rate for such a critical safety of flight component. They really need to get this figured out soon.
Worth saying again.
Those numbers are merely attrition against a military the size of China. 187 F-22s is not enough.
I was on a hot scramble in an FJ-4 out of Atsugi. Passing about 30M I couldn’t move or feel my right arm. Told the lead I had to abort. Had to pick up my right hand and set it on the side and use my left on the stick. Declared an emergency and got it back on the ground with only my left hand for stick and throttle. Flight surgeon said I had the bends.
In the haste of our scramble, my bailout O2 bottle hose had kinked up and gotten between the sliding canopy and the rail, so I never pressurized the cockpit. I didn’t notice because we were getting vectors and looking for the bogey.
I was lucky the nitrogen bubble blocked the nerves or I would have been in extreme pain. Cheated death again:-))
Right you are. We need many, many more.
“We can still put 150 of them in the air, downing AT LEAST 900 enemy aircraft with each sortie...if we can find them.”
How do you come up with these numbers? What are your kill assumptions based on?
Thanks.
My buddy wasn’t getting classic hypoxia. He was getting histotoxic hypoxia. The OBOGS system was producing poisonous gas to breathe.
There was a (in)famous Tomcat guy that lost feeling in his left hand and declared an emergency because he thought he had the bends. He came back to the boat and after he got out of the cockpit he had a miraculous recovery. The exposure suit (dry suit) he was wearing was one of the ones that had the zipper from arm to arm and it had pinched the nerve in his left arm. He had basically put that arm to sleep.
Okay that explains it — definitely a dangerous setup in a single seat airplane!
Yes it could have easily been much worse — I’m thinking loss of consciousness, or the “staggers”, an inner ear problem.
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