Airplanes Were Grounded May 3 Due To An Oxygen System Issue

The Secretary of the Air Force Michael Donley and Chief of Staff Gen. Norton Schwartz have recently approved an implementation plan developed by Air Combat Command officials that will allow the F-22 Raptor to resume flight operations after a four-month stand down.

The commander of Air Combat Command directed a stand-down of the fleet May 3 as a safety precaution, following 12 separate reported incidents where pilots experienced hypoxia-like symptoms. The incidents occurred over a three-year period beginning in April 2008. Officials remain focused on the priorities of aircrew safety and combat readiness. The return-to-fly plan implements several risk mitigation actions, to include rigorous inspections, training on life support systems, and continued data collection.

"We now have enough insight from recent studies and investigations that a return to flight is prudent and appropriate," Schwartz said. "We're managing the risks with our aircrews, and we're continuing to study the F-22's oxygen systems and collect data to improve its performance."

In a task force approach to implementation, Air Combat Command officials developed a comprehensive incremental return-to-fly plan that balances safety and the expedient qualification of pilots against the inherent risks of flying advanced combat aircraft, officials said.

The entire fleet will undergo an extensive inspection of the life support systems before returning to flight, with follow-on daily inspections, officials said. The aircraft is capable and authorized to fly above 50,000 feet. Pilots will use additional protective equipment and undergo baseline physiological tests. The return-to-fly process will begin with instructor pilots and flight leads regaining their necessary proficiency, then follow with other F-22 wingmen.

Prior to the stand down, ACC officials convened a Class E Safety Investigation Board in January 2011 to look into hypoxia-related reports. At the same time, a Hypoxia Deep-Dive Integrated Product Team began an in-depth study on safety issues involving aircraft oxygen generation systems.

In June 2011, the Secretary of the Air Force directed the Air Force Scientific Advisory Board to continue the oxygen generation study concurrent with the ongoing SIB. A releasable report will be made available later this year.

FMI: www.af.mil