Tech Sgt. John Heaton, 363rd Training Squadron armament apprentice course instructor, shows his class how to mount an M61A1 gatling-gun into an F-16 Falcon simulator at Sheppard Air Force Base, Texas, Feb. 15, 2018. Heaton’s class is in block 11 of 12 and scheduled to graduate March 7. (U.S. Air Force photo by Alan R. Quevy)