Lockheed Martin Boeing F-22 Raptor

In 1981 the United States Air Force (USAF) developed a requirement for a new air superiority fighter, the Advanced Tactical Fighter (ATF), to replace the capability of the F-15 Eagle, primarily the F-15A, B, C and D variants. ATF was a demonstration and validation program undertaken by the USAF to develop a next-generation air superiority fighter to counter emerging worldwide threats, including development and proliferation of Soviet-era Su-27 "Flanker"-class fighter aircraft. It was envisioned that the ATF would incorporate emerging technologies including advanced alloys and composite materials, advanced fly-by-wire flight control systems, higher power propulsion systems, and low-observable/stealth technology. See More.