They say that it’s just an overinflating pressure vest that is part of their G-suit:
The mysterious engineering problem causing F-22 Raptor pilots to choke in their cockpits has been solved, the Pentagon says. And it’s not the nearly $400 million aircraft’s fault after all.
The problem lies with a valve in the pressurized vest pilots wear as they fly the jet at high altitudes, Pentagon spokesman George Little said. The valve inflated the vest, limiting the pilots’ oxygen supply. It does not appear that the vest was affecting quality of the oxygen in the Raptor. The valve will be replaced; the garment’s use will be “suspended,” Little said.
Additionally, the Air Force has decided to remove a filter it placed in the jet to test the oxygen quality. Ironically, the filter ended up limiting the oxygen supply to the pilots. But the charcoal filter resulted in “no oxygen contamination,” Little told reporters at the Pentagon on Tuesday.
Accordingly, the Air Force will gradually take its premiere stealth jet off of the probation that the so-called “hypoxia” incidents — a term indicating problems with the oxygen in the cockpit — necessitated. Over an unspecified period of time, the F-22 will no longer be restricted to flying short missions at low altitudes near air bases. The first indication that the jet is off probation will be an imminent flight of an F-22 squadron over the Pacific to Kadena Air Force Base in Japan — which will occur at a “lower altitude,” Little said.
I’ll believe this if we don’t have any more incidents for at least 6 months.