The Air Force Still Doesn’t Know What’s Choking Its Stealth Fighter Pilots

America’s newest stealth fighters have a major problem: their pilots can’t breathe, due to some sort of malfunction in the planes’ oxygen-generation systems. For months, the Air Force has been studying the problem, which temporarily grounded the entire fleet of F-22 Raptors and may have contributed to a pilot’s death. Today, the Air Force admitted they still don’t know exactly what’s causing the issue.

See the full article at Wired