The Lockheed Martin F-22 Raptor is a single-seat, twin-engine, all weather stealth tactical fighter aircraft developed for the United States Air Force (USAF). The result of the USAF's Advanced Tactical Fighter program, the aircraft was designed primarily as an air superiority fighter, but has additional capabilities including ground attack, electronic warfare, and signals intelligence roles. Lockheed Martin is the prime contractor and is responsible for the majority of the airframe, weapon systems, and final assembly of the F-22, while program partner Boeing provides the wings, aft fuselage, avionics integration, and training systems.