|YF-23, nicknamed Gray Ghost (foreground), flying with YF-23
Black Widow II| |Role||Experimental fighter prototype| |National
origin||United States| |First flight||27 August 1990| |Primary
user||United States Air Force| The Northrop YF-23 or
Northrop–McDonnell Douglas YF-23 was an American single-seat,
twin-engine fighter aircraft designed for the United States Air
Force (USAF). The design was a finalist in the USAF's Advanced
Tactical Fighter (ATF) competition, battling the Lockheed YF-22
for a production contract. Two YF-23 prototypes were built with
the nicknames "Black Widow II" and "Gray Ghost". In the 1980s
the USAF began looking for a replacement for its fighter
aircraft, especially to counter the USSR's advanced Su-27 and
MiG-29. Several companies submitted design proposals; the USAF
selected proposals from Northrop and Lockheed. Northrop teamed
with McDonnell Douglas to develop the YF-23, while Lockheed,
Boeing and General Dynamics developed the YF-22. The YF-23 was
stealthier and faster, but less ag