U.S. Air Force Senior Airman Colby Alexander, 52nd Aircraft Maintenance Squadron avionics technician, powers up an F-16 Fighting Falcon's systems to perform Combat Shield testing at Spangdahlem Air Base, Germany, March 25, 2019. Alexander was preparing for and running the F-16 Fighting Falcon through various system operations checks. (U.S. Air Force photo by Airman 1st Class Kyle Cope)