The F-4 Phantom II is a twin engine, two-seat, supersonic fighter developed by the U.S. Navy. It was developed as an attack aircraft and later changed into an advanced long-range all-weather interceptor with missile armament. The Phantom was in production from 1958 - 1981 and was used extensively in the Vietnam War. It has been used by 11 other nations and still remains in front line service for seven countries.