The Avenger Air Defense System, designated AN/TWQ-1 under the Joint Electronics Type Designation System, is an American self-propelled surface-to-air missile system which provides mobile, short-range air defense protection for ground units against cruise missiles, unmanned aerial vehicles, low-flying fixed-wing aircraft, and helicopters. The Avenger was originally developed for the United States Armed Forces and is currently used by the U.S. Army. The Avenger system was also used by the U.S.