No Root Cause In Hand

Despite an extensive investigation, the Air Force has yet to pinpoint the cause of a series of “physiological incidents” with F-22 pilots that led to the grounding of the Raptor fleet last year, stated service officials Thursday. “We do not have a root cause in hand,” said Gregory Martin, retired Air Force general, in presenting the findings of the Air Force Scientific Advisory Board’s seven-month study into the F-22’s oxygen-generation system during a Pentagon briefing. Martin led this effort, which tried to determine why Raptor pilots have experienced symptoms akin to insufficient oxygen supply in flight. Among its findings, the study concluded that contaminants identified in the pilots’ air supply have not risen to levels known to cause health risks or impaired performance. Further, it highlighted that the F-22’s on-board oxygen-generation system, backup system, and emergency oxygen system are not classified as “safety-critical items.” The study recommended installing a backup oxygen supply for the aircraft’s life-support system and adding a ground collision-avoidance system to the aircraft. The study panel also recommended continued data collection and pilot monitoring, an activity that Air Combat Command is now leading. (F-22 briefing transcript)