U.S. Air Force Staff Sgt. Jeffrey Villa, 86th Operations Support Squadron Air Field Operations Flight Air Traffic Control Tower watch supervisor, tests the operability of a light gun on Ramstein Air Base, Germany, Aug. 1, 2017. Air traffic controllers use light guns to communicate with aircrew when radios are down because air traffic controllers guide aircraft to safe landing. (U.S. Air Force photo by Senior Airman Elizabeth Baker)