The Northrop/McDonnell Douglas YF-23 was an American single-seat, twin-engine stealth 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, nicknamed “Black Widow II” and “Gray Ghost”
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Both the Raptor and a fully operational F-23 would have carried eight air-to-air missiles internally that was the Air Force requirement.
Moreover, the operational jets were essentially identically in terms of avionics—both competitors had proposed similar avionics suites.
In fact, the Raptor ended up with the radar that was initially proposed for the YF-23.