fighter aircraft technology demonstrator 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.
The YF-23 was stealthier and faster, but less agile than its competitor. After a four-year development and evaluation process, the YF-22 was announced the winner in 1991 and the design was developed into the Lockheed Martin F-22 Raptor, which first flew in 1997 and entered service in 2005.
The two YF-23 prototypes are currently museum exhibits.