| U.S. Air Force Staff Sgt. Tony Simper prepares to spur gear the drum exit unit of an F-16 Fighting Falcon aircraft gun system at Aviano Air Base, Italy, Feb. 6, 2007. Simper is an aircraft armament system journeyman with the 31st Maintenance Squadron. U.S. Air Force photo by Airman 1st Class Liliana Moreno |