Northrop YF - 23 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 agile than the competition . After a four - year development and evaluation process , the YF - 22 was announced the winner in 1991 and entered production as the Lockheed Martin F - 22 Raptor . The U . S . Navy considered using the production version of the ATF as the basis for a replacement to the F - 14 , but these plans were later canceled . As of 2009 , the two YF - 23 prototypes were museum exhibits . Development . American reconnaissance satellites first spotted the advanced Soviet Su - 27 and MiG - 29 fighter prototypes in 1978 , which caused concern in the U . S . Both Soviet models were expected to reduce the maneuverability advantage of contemporary US fighter aircraft . In 1981 , the USAF requested information from several aerospace companies on possible features for an Advanced Tactical Fighter ( ATF ) to replace the F - 15 Eagle . After discussions with aerospace companies , the USAF made air to air combat the primary role for the ATF . The ATF was to take advantage of emerging technologies , including composite materials , lightweight alloys , advanced flight - control systems , more powerful propulsion systems , and stealth technology . In October 1985 , the USAF issued a request for proposal ( RFP ) to several aircraft manufacturers . The RFP was modified in May 1986 to include evaluation of prototypes from the two finalists . At the same time , the U . S . Navy , under the Navalized Advanced Tactical Fighter ( NATF ) program , announced that it would use a derivative of the ATF winner to replace its F - 14 Tomcat . The NATF program called for procurement of 546 aircraft along with the USAF ' s planned procurement of 750 aircraft . In July 1986 , proposals were submitted by Lockheed , Boeing , General Dynamics , McDonnell Douglas , Northrop , Grumman and Rockwell . The latter two dropped out of competition shortly thereafter . Following proposal submissions , Lockheed , Boeing , and General Dynamics formed a team to develop whichever of their proposed designs was selected , if any . Northrop and McDonnell Douglas formed a team with a similar agreement . The Lockheed and Northrop proposals were selected as finalists on 31 October 1986 . Both teams were given 50 months to build and flight - test their prototypes , and they were successful , producing the Lockheed YF - 22 and the Northrop YF - 23 . The YF - 23 was designed to meet USAF requirements for survivability , supercruise , stealth , and ease of maintenance . Supercruise requirements called for prolonged supersonic flight without the use of afterburners . Northrop drew on its experience with the B - 2 Spirit and F / A - 18 Hornet to reduce the model ' s susceptibility to radar and infrared detection . The USAF initially required the aircraft to land and stop within , which meant the use of thrust reversers on their engines . In 1987 , the USAF changed the runway length requirement to , so thrust reversers were no longer needed . This allowed the aircraft to have smaller engine nacelle housings . The nacelles were not downsized on the prototypes . The first YF - 23 ( serial number " 87 - 0800 " ) , Prototype Air Vehicle 1 ( PAV - 1 ) , was rolled out on 22 June 1990 ; PAV - 1 took its 50 - minute maiden flight on 27 August with Alfred " Paul " Metz at the controls . The second YF - 23 ( serial number " 87 - 0801 " , PAV - 2 ) made its first flight on 26 October , piloted by Jim Sandberg . The first YF - 23 was painted charcoal gray and was nicknamed " Spider " and " Black Widow II " , the latter after the Northrop P - 61 Black Widow of World War II . It briefly had a red hourglass marking resembling the marking on the underside of the black widow spider before Northrop management had it removed . The second prototype was painted in two shades of gray and nicknamed " Gray Ghost " . Design . The YF - 23 was an unconventional - looking aircraft , with diamond - shaped wings , a profile with substantial area - ruling to reduce drag at trans - sonic speeds , and an all - moving V - tail . The cockpit was placed high , near the nose of the aircraft for good visibility for the pilot . The aircraft featured a tricycle landing gear configuration with a nose landing gear and two main landing gear . The weapons bay was placed on the underside of the fuselage between the nose and main landing gear . The cockpit has a center stick and side throttle . It was powered by two turbofan engines with each in a separate engine nacelle on either side of the aircraft ' s spine . Of the two aircraft built , the first YF - 23 ( PAV - 1 ) was fitted with Pratt & Whitney YF119 engines , while the second ( PAV - 2 ) was powered by General Electric YF120 engines . The aircraft featured fixed engine nozzles , instead of thrust vectoring nozzles as on the YF - 22 . As on the B - 2 , the exhaust from the YF - 23 ' s engines flowed through troughs lined with heat - ablating tiles to dissipate heat and shield the engines from infrared ( IR ) missile detection from below . The flight control surfaces were controlled by a central management computer system . Raising the wing flaps and ailerons on one side and lowering them on the other provided roll . The V - tail fins were angled 50 degrees from the vertical . Pitch was mainly provided by rotating these V - tail fins in opposite directions so their front edges moved together or apart . Yaw was primarily supplied by rotating the tail fins in the same direction . Deflecting the wing flaps down and ailerons up on both sides simultaneously provided for aerodynamic braking . To keep costs low despite the novel design , a number of " off - the - shelf " components were used , including an F - 15 nose wheel , F / A - 18 main landing gear parts , and the forward cockpit components of the F - 15E Strike Eagle . Operational history . Evaluation . The first YF - 23 , with Pratt & Whitney engines , supercruised at Mach 1 . 43 on 18 September 1990 , while the second , with General Electric engines , reached Mach 1 . 6 on 29 November 1990 . By comparison , the YF - 22 achieved Mach 1 . 58 in supercruise . The YF - 23 was tested to a top speed of Mach 1 . 8 with afterburners . The YF - 23 ' s weapons bay was configured for weapons launch , and used for testing weapons bay acoustics , but no missiles were fired . Lockheed fired AIM - 9 Sidewinder and AIM - 120 AMRAAM missiles successfully from its YF - 22 demonstration aircraft . PAV - 1 performed a fast - paced combat demonstration with six flights over a 10 - hour period on 30 November 1990 . Flight testing continued into December . The two YF - 23s flew 50 times for a total of 65 . 2 hours . The tests demonstrated Northrop ' s predicted performance values for the YF - 23 . The YF - 23 was stealthier and faster , but the YF - 22 was more agile . The two contractor teams submitted evaluation results with their proposals in December 1990 , and on 23 April 1991 , Secretary of the Air Force Donald Rice announced that the YF - 22 was the winner . The Air Force selected the YF119 engine to power the F - 22 production version . The Lockheed and Pratt & Whitney designs were rated higher on technical aspects , were considered lower risks , and were considered to have more effective program management . It has been speculated in the aviation press that the YF - 22 was also seen as more adaptable to the Navy ' s NATF , but by 1992 the U . S . Navy had abandoned NATF . Following the competition , both YF - 23s were transferred to NASA ' s Dryden Flight Research Center at Edwards AFB , California , without their engines . NASA planned to use one of the aircraft to study techniques for the calibration of predicted loads to measured flight results , but this did not take place . Possible revival . In late 2004 , Northrop Grumman proposed a YF - 23 - based bomber to meet a USAF need for an interim bomber , for which the FB - 22 and B - 1R were also competing . Northrop modified aircraft PAV - 2 to serve as a display model for its proposed interim bomber . The possibility of a YF - 23 - based interim bomber ended with the 2006 Quadrennial Defense Review , which favored a long - range bomber with a much greater range . The USAF has since begun the Next - Generation Bomber program . Aircraft on display . Both YF - 23 airframes remained in storage until mid - 1996 , when the aircraft were transferred to museums .