The US Air Force resumed normal flight operations with the F-22 Raptor in early April after modifications were completed across the fleet to aircrew life support equipment, including the upper pressure garment and related hoses, valves and connectors. Completion of these modifications eliminates the need to restrict flight operations to remain within a thirty-minute flying distance from an airfield suitable for landing. F-22 pilots have also resumed their alert mission in Alaska after the Automatic Back-up Oxygen System, or ABOS, was installed in Raptors based at Elmendorf AFB. Altitude restrictions have also been incrementally removed for F-22s that have received the ABOS modification. ABOS provides additional protection to F-22 pilots. Officials expect completion of the ABOS modifications by July 2014.
