Senior Airman Christopher Lemons, 4th Aircraft Maintenance Squadron avionics technician, attaches an antenna coupler to an F-15E Strike Eagle, Oct. 13, 2015, at Seymour Johnson Air Force Base, North Carolina. The coupler, in conjunction with the Joint Service Electronic Combat Systems Tester, is used to routinely test the effectiveness of the aircraft's threat detection systems. (U.S. Air Force photo/Senior Airman Aaron J. Jenne)