F-22 Cleared to Fly Again
The U.S. Air Force's top officials approved ending the stand-down of all 170 aircraft after 12 incidents of pilots' experiencing hypoxia. Pilots will use additional protective equipment, according to USAF's announcement.
The U.S. Air Force apparently is satisfied that its F-22 Raptor stealth aircraft are safe to fly, issuing a return-to-fly plan that returned the fleet of 170 aircraft to service Sept. 21. Questions surrounded the F-22's system that provides oxygen to the pilot after 12 incidents where pilots reported hypoxia -– low oxygen -– symptoms, and the USAF announcement did not explain whether the system has been changed.
It said the plan includes these risk mitigation actions: 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," USAF Chief of Staff Gen. Norman Schwartz said. "We're managing the risks with our air crews, and we're continuing to study the F-22's oxygen systems and collect data to improve its performance."
The news release said an Air Force Scientific Advisory Board's report on the oxygen system will be released later this year. The return-to-fly plan "balances safety and the expedient qualification of pilots against the inherent risks of flying advanced combat aircraft," it states, adding that the entire F-22 fleet "will undergo an extensive inspection of the life support systems before returning to flight, with follow-on daily inspections."
The aircraft, which were introduced in 2005, are authorized to fly above 50,000 feet. Their pilots will use additional protective equipment and undergo baseline physiological tests, and the return-to-fly process will begin with instructor pilots and flight leads regaining their necessary proficiency, then follow with other F-22 wingmen.
Forty of the planes are based in Anchorage, Alaska, at Joint Base Elmendorf-Richardson. The Anchorage Daily News has reported in that some veteran pilots believe the F-22 oxygen problem resulted simply from starting the F-22's engines inside buildings rather than outside because of cold outdoor temperatures, with exhaust then entering the planes’ oxygen intakes.