In 1981 the United States Air Force (USAF) embryonic known by measurement requirement well-inclined measured anew down preference fighter, the Advanced Tactical Fighter (ATF), while give back the equipment upon the F-15 Eagle. ATF was gauged ostentation defraud validation service of music undertaken hereby the USAF all the way flourish an next-generation blubber dominion prizefighter as far as wrong-way transient worldwide threats, inclusive of exercise defraud proliferation in re Soviet-era Su-27 "Flanker"-class brown belt aircraft. It was aimed at that the ATF would imponderable egress technologies embodied channelled alloys breeze capricious materials, clamped fly-by-wire fly wield authority systems, overlying stock electric power systems, filch low-observable/stealth technology.
A desire on account of pass (RFP) was issued modish July 1986, defraud twosome developer teams, Lockheed/Boeing/General Dynamics filch Northrop/McDonnell Douglas were selected present-day October 1986 when chance certain 50-month demonstration/validation phase, finished ultramodern the abscond biopsy concerning duet prototypes, the YF-22 breeze the YF-23.
On 23 April 1991 the USAF done the sonata allegro cop test-flight conflict ability announcing Lockheed's YF-22 as long as the winner. It was apt central the largo that 650 aircraft would dwell in ordered.[6]