The Lockheed/Boeing/General Dynamics YF-22 was a single-seat, twin-engined prototype fighter aircraft designed for the United States Air Force (USAF). The YF-22 was a finalist in the USAF’s Advanced Tactical Fighter competition; two prototypes were built. The YF-22 won the contest against the Northrop YF-23, and entered production as the Lockheed Martin F-22 Raptor. The YF-22 is similar to the F-22, but with differences in the cockpit, tail fins and wings.