The US Air Force (USAF) has stopped flying Lockheed Martin’s F-22 Raptor fighter jets indefinitely due to concerns about faults in the system that supplies oxygen to pilots, the US military announced this week.
The Air Force said it issued an order on Tuesday to stop flying the jets “until further notice” after reports of “oxygen system malfunctions,” although the US AF is looking at all aircraft systems.
The ‘voluntary stand down’ affects all 165 Raptors.
The USAF notes that a voluntary stand down is different from a grounding.
The latter occurs after a catastrophic issue whilst a stand down is a response to a potential issue.
“The stand-down provides Air Force officials the opportunity to investigate the reports and ensure crews are able to safely accomplish their missions,” the USAF said in a statement.
“The stand-down is a prudent measure following recent reports of oxygen system malfunction,” Air Combat Command (ACC) chief General Will Fraser said on May 3.
Air Force officials say the onboard oxygen generating system (OBOGS) may have been a factor in the crash of an F-22 in November last year.
Captain Jeff Haney was killed when his F-22 crashed into the ground on November 16 during a night training flight with another F-22.
Since January, Raptors have been kept at altitudes below 25,000 feet during the ongoing investigation in order to lessen the risk in case the oxygen system did indeed cause the crash.
If the OBOGS failed at 25,000 feet pilots would have time to recover to lower altitudes where there is enough oxygen in the atmosphere.
This is not the case when the aircraft flies at its 50,000 feet ceiling.
As the USAF could not say when the F-22 would be flying again, the entire fleet is standing down indefinitely.