The
Advanced Tactical Fighter (
ATF) was a demonstration and validation program undertaken by the
United States Air Force to develop a next-generation
air superiority fighter to counter emerging worldwide threats, including Soviet
Sukhoi Su-27 and
Mikoyan MiG-29 fighters under development in the 1980s. Lockheed and Northrop were selected in 1986 to develop the
YF-22 and the
YF-23 technology demonstrator aircraft. These aircraft were evaluated in 1991 and the Lockheed YF-22 was selected and later developed into the
F-22 Raptor.