There's good news and there's bad news for the latest round of oxygen system incidents for the Air Force's F-22 Raptor. The bad news is they are still popping up, the good news is the Air Force says they know why the two most recent ones occurred.
The two incidents occurred on July 6 and June 26 when the pilots for the two F-22s reported oxygen system failures. Opposed to the previous problems the F-22 has seen over the past two years with pilots suffering from hypoxia symptoms in flight, the Air Force claims they know why these problems occurred
Lt. Col. Tadd Sholtis, a spokesman for Air Combat Command, told CNN the Air Force has investigated one and is investigating the July 6th incident with both incidents listed as "cause known." Previous problems with the F-22's oxygen system have been listed as "cause unknown" during the investigations.
"The recent incidents that have resulted in new expressions of concern are of a different kind than the ones we have been focused on in recent months," Sholtis told CNN's Security Clearance blog.
A pilot from the 1st Fighter Wing reported a restriction of air reaching his face mask on his final approach before landing on June 26. After he landed he engaged the emergency oxygen system on the runway. The investigation found the restriction was caused by a "stuck valve" and the pilot has returned to flying, according to the CNN report.
The most recent incident on July 6 is still under investigation. A Hawaii National Guard pilot's warning indication popped for the Onboard Oxygen Generating System and declared an in-flight emergency. Because the pilot received the OBOGS warning, the Air Force is confident that was the cause of the problem, Sholtis told CNN.
The fact the Air Force knows what caused the problem is a step in the right direction, but the program is under such intense scrutiny that any oxygen problem is receiving Congressional attention. U.S. Sen. Mark Warner, D-Virginia, and Rep. Adam Kinzinger, R-Illinois, sent letters to the Air Force asking for more information about both incidents.