The afterburner of an F-16 Fighting Falcon is run during a hush house engine test at Kunsan Air Base, Republic of Korea, Dec. 9, 2015. The hush house is an engine test facility that is similar to a sound booth in a musical production studio. It keeps all of the sound inside of the facility to prevent any noise from being heard outside. (U.S. Air Force photo by Staff Sgt. Nick Wilson/Released)