F-35A successfully fires GAU-22/A 25mm Gun in flight Published Oct. 22, 2015 By 412th Test Wing Public Affairs EDWARDS AIR FORCE BASE, Calif. -- The F-35A successfully fired the GAU-22/A 25mm Gun system for the first time while in flight Oct. 30, 2015. The aircraft recently completed ground gun firing test at the Edwards Gun Harmonization range with good results enabling progression to first flight. This is one more step in validating the many capabilities of the 5th generation F-35 Lightning II aircraft.