Advanced Tactical Fighter 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 demonstrator aircraft . These aircraft were evaluated in 1991 and the Lockheed YF - 22 was selected and later developed into the F - 22 Raptor . History . Background . In 1981 , USAF began forming requirements for a new air superiority fighter intended to replace the capability of the F - 15 Eagle . In June 1981 a request for information ( RFI ) for the Advanced Tactical Fighter ( ATF ) was published by the Air Force . Design concepts were provided by defense contractor s . The common areas among the concepts were Stealth , STOL and supercruise . It was envisioned that the ATF would incorporate emerging technologies including advanced alloys and composite material , advanced fly - by - wire flight control systems , higher power propulsion systems , and low - observable , or stealth technology . In September 1983 , study contracts were awarded to seven airframe manufacturers for further definition of their designs . By late 1984 , ATF requirements had settled on a fighter with a maximum takeoff weight of , a mission radius of , supercruise speed of Mach 1 . 4 - 1 . 5 and the ability to use a runway . A request for proposals ( RFP ) for the fighter ' s engine , called the Joint Advanced Fighter Engine ( JAFE ) , was released in May 1983 . Pratt & Whitney and General Electric received contracts for the development and production of prototype engines in September 1983 . Request for proposals . A request for proposals ( RFP ) for the fighter was issued in September 1985 . In May 1986 , the Air Force changed the RFP so that final selection would involve flying prototypes . In July 1986 , proposals were provided by Boeing , General Dynamics , Lockheed , Northrop , and McDonnell Douglas . Two contractors , Lockheed and Northrop were selected in October 1986 to undertake a 50 month demonstration / validation phase , culminating in the flight test of two prototypes , the YF - 22 and the YF - 23 . Under terms of agreements between Lockheed , General Dynamics , and Boeing , the companies agreed to participate in the development jointly if only one company ' s design was selected . Northrop and McDonnell Douglas had a similar agreement . Because of the added weight for thrust vectoring / reversing nozzles and related systems on the F - 15 S / MTD research aircraft , the Air Force changed the runway length requirement to and removed the thrust reversers on the ATF in late 1987 . Two examples of each prototype were built for the Demonstration - Validation phase : one with General Electric YF120 engines , the other with Pratt & Whitney YF119 engines . The first YF - 23 made its maiden flight on 27 August 1990 and the first YF - 22 first flew on 29 September 1990 . Flight testing began afterwards and added the second aircraft for each competitor in late October 1990 . The first YF - 23 with P & W engines supercruised at Mach 1 . 43 on 18 September 1990 and the second YF - 23 with GE engines reached Mach 1 . 6 on 29 November 1990 . The YF - 22 with GE engines achieved Mach 1 . 58 in supercruise . Flight testing continued until December 1990 . Following flight testing , the contractor teams submitted proposals for ATF production . Selection . Following a review of the flight test results and proposals , the Air Force announced the Lockheed YF - 22 with Pratt & Whitney engines as the competition winner on 23 April 1991 . The YF - 23 design was more stealthy and faster , but the YF - 22 was more agile . The US Navy had begun considering a version of the ATF called Navy Advanced Tactical Fighter ( NATF ) in 1986 . It has been speculated in the aviation press that the YF - 22 was also seen as more adaptable to the NATF . The Navy abandoned NATF by 1992 . The Lockheed team was awarded the contract to develop and build the Advanced Tactical Fighter in August 1991 . The YF - 22 was modified into the production F - 22 Raptor version . The Northrop YF - 23 design was later considered by the company for modification as a bomber , but the proposals have not come to fruition .