The YF-23 Black Widow II was Northrop Grumman's (teamed with McDonnell Douglas Corporation) answer to the American ATF (Advanced Tactical Fighter) challenge proposed by the United States Air Force (USAF). The YF-23 competed unsuccessfully with the Lockheed / Boeing / General Dynamics offering - the YF-22 "Lightning II" - later adopted into service as the F-22 "Raptor. The YF-23 ended its days as a museum showpiece and only two flyable prototypes were completed during the project run.
The curvy, low profile YF-23 was a stark contrast from the sharp edges of the YF-22 and featured a wide, almost pancake-like airframe structure with blended wing elements. The pilot sat within the forward section of the fuselage and given access to a completely digital, then-ultra-modern cockpit offering relatively excellent vision. Intakes, to aspirate the twin engine arrangement, were positioned along the underside of the fuselage. The twin tail fins were outward-canted and straddled the thrust-vectoring engine outlets. No horizontal tailplanes were featured.
One element of the development phase of the competition was to evaluate two experimental turbofan engines - the Pratt & Whitney YF119 and the General Electric YF120. As such, each YF-23 prototype was fitted with one set of the available engines. The first prototype was designated "PAV-1" and carried YF119 engines and the second prototype - "PAV-2" - fitted YF120 engines. The YF119 eventually won out over the YF120 and went on to power the F-22 Raptor fighter in service.
The name of "Black Widow II" - following the original Northrop P-61 "Black Widow" twin-engine night-fighter aircraft of World War 2 - was not an official designation used by the USAF nor by Northrop Grumman but is believed to have gained steam from an internal contest held by the YF-23 team. To further enhance this "unofficial" name, future test flights of the YF-23 were seen with a red hourglass insignia on the belly of the craft, this symbol synonymous with the North American spider the "Black Widow".
A first-flight was had on August 27th, 1990.
The YF-23, with its thrust vectoring engines and Fly-by-Wire control scheme, proved itself a sound aircraft. It showcased the then-popular "supercruise" function which was a new concept of achieving sustained supersonic flight without the use of fuel-thirsty afterburner or any other form of specialized engine augmentation. This allowed the YF-23 to achieve impressive straight-line speeds while still retaining a stealth-like capability. Stealth was further enhanced by the YF-23's low profile as well as a classified make-up of the airframe concerning its skin material. It is said that this next-generation aircraft could avoid nearly 100% detection from most any radar system of the period.
Standard armament was to become a fixed 20mm M61 Vulcan cannon for close-in work. Internal bays were to house 4 x AIM-7 Sparrow or AIM-120 AMRAAM medium-ranged air-to-air missiles as well as 2 x AIM-9 short-ranged missiles. These were ever fitted to the two prototypes.
As built, the YF-23 exhibited a running length of 67.4 feet, a wingspan of 43.6 feet and a height of 13.10 feet. Empty weight was 29,000lb and a MTOW of 62,000lb was reported. Performance included a maximum speed of Mach 2.2 (Mach 1.6 on supercruise) with a range of nearly 3,000 miles and a service ceiling of 65,000 feet. Combat radius equaled 800 miles.
Despite proving faster and more stealthy than the competing Lockheed submission, the YF-22 outshone the Black Widow in ability. It won out the ATF completion and quickly ended the hopes of the YF-23 design team. For a short time, the United States Navy (USN) was interested in a navalized version of the YF-23 to succeed its aging line of Grumman F-14 "Tomcat" fleet defense fighters but nothing came of this. A dedicated fighter-bomber version of the YF-23 was also briefly on in the works (for the USAF) in 2004 but this initiative ultimately fell to naught by 2006. After the fly-off, the YF-23 prototypes were handed over to the Dryden Flight Research Center (Edwards AFB) to undergo additional testing under the NASA banner but, again, nothing came of this.
The YF-23 prototypes ended their days as separate museum displays, one residing at the Western Museum of Flight (Torrance, California) and the other at the National Museum of the United States Air Force (Dayton, Ohio).