Concern over the on-board oxygen generation system on the F-22 jet has spread to other Air Force fighter and trainer aircraft including the F-15E managed at Robins Air Force Base.
Air Combat Command decided to stand down its fleet of F-22 Raptors on May 3. The issue stems from a November crash of the Air Force’s newest air superiority fighter in Alaska, although no specific cause of that accident has been released.
ACC told Air Force Times that nine suspected cases of hypoxia – possibly related to a malfunctioning OBOGS – have been recorded since the mid-2008. Additional incidents were recorded, with a significant uptick in frequency, immediately prior to the stand down decision, ACC confirmed. On-board oxygen generation is critical for fighter pilots at altitudes above 18,000 feet.
“No other airframes have been stood down due to this investigation,” Capt Jennifer Ferrau, an ACC spokeswoman, told The Times. “However, a parallel investigation is taking place on the A-10, F-16, F-35 and T-6 aircraft.”
Russell Alford, the Aerospace Sustainment Directorate’s lead engineer at Robins, said the F-15E is the only Robins-managed aircraft that uses an OBOGS. Several different designs are used in the process of converting engine bleed air to breathable oxygen.
Alford said the device onboard the F-15E has been in use since the early 1990s and has safely accumulated over 675,000 flight hours. The same system is also used on F-15s flown by Saudi Arabia, Korea and Singapore, the lead engineer noted, “where it has a stellar track record.”
“The F-15 system program office is supporting the Air Force investigation,” Alford said, “although the F-15Es do not use the same design as the F-22 fleet.”