Lights on a panel indicate power is connected during a gun hydraulic bleed and leak test on a mock F-16CM Fighting Falcon body during training at the 372nd Training Squadron, Detachment 202 F-16 Field Training Detachment at Shaw Air Force Base, S.C., April 25, 2017. The operational check ensures the gun functions properly after its removal and reinstallation. (U.S. Air Force photo by Senior Airman Kelsey Tucker)