Spare F-16 Fighting Falcon engines sit on engine trailers inside the 56th Component Maintenance Squadron Propulsion Flight facility at Luke Air Force Base, Ariz., Oct. 2, 2018. The propulsion team is in the midst of relocating to Holloman AFB, which will be the future location for F-16 pilot training under the 19th Air Force. (U.S. Air Force photo by Staff Sgt. Franklin R. Ramos)