Staff Sgt. James Winn, 113th Maintenance Squadron aerospace propulsion technician, performs phase maintenance on the fan frame of an F-16 Fighting Falcon engine at Joint Base Andrews, Md., March 27, 2017. The F-16 must go through different inspections to ensure the quality and safety of the aircraft for mission readiness. In this case, the aerospace propulsion technicians are responsible for the tear down, inspection and build-up of F-16 engines after 4,000 flight hours. (U.S. Air Force photo by Airman 1st Class Gabrielle Spalding)