Overview
The Northrop/McDonnell Douglas YF-23 (informally named "Black Widow II" and "Gray Ghost") was a prototype air superiority fighter developed for the US Air Force's Advanced Tactical Fighter (ATF) programme in the late 1980s. The YF-23 was one of two designs (the other being the Lockheed/Boeing/General Dynamics YF-22) competing to become the Air Force's next-generation air superiority fighter. The YF-23 was arguably the more technologically advanced of the two designs, offering superior stealth, speed, and range, but the YF-22 was selected for production as the F-22 Raptor, partly due to its superior manoeuvrability and lower development risk.
Two YF-23 prototypes were built and flown from 1990 to 1991. The aircraft demonstrated exceptional performance, including supercruise (sustained supersonic flight without afterburner) and low radar cross-section, but lost the ATF competition in April 1991. The YF-23 programme was subsequently cancelled, and no production aircraft were built.
Design and Technology
The YF-23 was a single-seat, twin-engine, supersonic air superiority fighter with an emphasis on stealth and speed. The aircraft's design incorporated several advanced features:
Stealth shaping: The YF-23's planform was optimised for low radar cross-section, with faceted surfaces, canted vertical tails, and shielded engine exhausts. The aircraft's all-aspect stealth was superior to the YF-22's, with a smaller radar cross-section from most angles.
Supercruise: The YF-23 was designed to cruise at supersonic speeds without afterburner, a capability called supercruise. Both prototypes demonstrated supercruise, reaching approximately Mach 1.6 without afterburner. The YF-23's supercruise speed was reportedly higher than the YF-22's.
Engine exhausts: The YF-23's engine exhausts were routed through long troughs on the upper rear fuselage, shielded by the wing trailing edge. This configuration reduced infrared signature and radar cross-section from the rear, but also reduced thrust (due to the longer exhaust path) and complicated cooling.
V-tail configuration: The YF-23 used two canted vertical tails (a V-tail configuration) rather than the conventional two-vertical-tail configuration of the YF-22. The V-tail provided both pitch and yaw control, reducing weight and drag, but was less effective for high-angle-of-attack yaw control.
Manoeuvrability: The YF-23 relied on conventional control surfaces (elevons, ruddervators, and flaperons) for manoeuvring, without thrust vectoring. The YF-22, by contrast, used thrust-vectoring nozzles for enhanced manoeuvrability at high angles of attack. The YF-23's manoeuvrability was adequate but not exceptional, while the YF-22's was clearly superior.
Development History
The ATF programme was initiated in the early 1980s to develop a replacement for the F-15 Eagle, which had been the Air Force's premier air superiority fighter since the 1970s. The ATF requirements called for a fighter with:
- Stealth: Low radar cross-section for survivability against advanced air defences.
- Supercruise: Sustained supersonic cruise without afterburner for rapid response and reduced fuel consumption.
- Manoeuvrability: Superior agility to defeat contemporary and future enemy fighters.
- Advanced avionics: Integrated sensor suite for situational awareness and target engagement.
- Range: Sufficient range for operations in the Pacific theatre without aerial refuelling.
In 1986, the Air Force selected two contractor teams to build prototype aircraft for a fly-off competition:
- Northrop/McDonnell Douglas: Built the YF-23.
- Lockheed/Boeing/General Dynamics: Built the YF-22.
The two YF-23 prototypes were built at Northrop's Hawthorne, California facility. The first prototype (PAV-1, serial 87-800, nicknamed "Black Widow II") was powered by Pratt & Whitney YF119 engines. The second prototype (PAV-2, serial 87-801, nicknamed "Gray Ghost") was powered by General Electric YF120 engines. Both engine types were also tested in the YF-22.
The ATF Competition: YF-23 vs YF-22
The YF-23 first flew on 27 August 1990 at Edwards Air Force Base, California. The YF-22 first flew on 29 September 1990. Both aircraft conducted flight test programmes at Edwards from 1990 to early 1991.
The YF-23's flight test programme demonstrated:
- Supercruise: Both YF-23 prototypes demonstrated supercruise, reaching Mach 1.6+ without afterburner.
- High speed: The YF-23 reached speeds above Mach 2 with afterburner.
- Stealth: The YF-23's radar cross-section was measured and validated, reportedly lower than the YF-22's.
- Range: The YF-23's range was superior to the YF-22's, due to its lower drag and more efficient aerodynamic design.
However, the YF-23 did not demonstrate:
- Thrust vectoring: The YF-23 did not have thrust-vectoring nozzles, while the YF-22 did. The YF-22's thrust vectoring gave it superior high-angle-of-attack manoeuvrability.
- Missile live fire: The YF-23 did not conduct live missile launches during the demonstration, while the YF-22 did (firing an AIM-9 Sidewinder and an AIM-120 AMRAAM).
On 23 April 1991, the Air Force announced that the YF-22 (with the Pratt & Whitney F119 engine) had been selected for production as the F-22 Raptor. The selection was based on several factors:
- Manoeuvrability: The YF-22's thrust vectoring gave it superior manoeuvrability, which the Air Force valued for air-to-air combat.
- Lower risk: The YF-22 was considered a lower-risk design, with more conventional configuration and more mature subsystems.
- Live missile firings: The YF-22's successful live missile firings demonstrated its weapon system integration.
- Cost: The YF-22 was projected to have lower development and production costs.
Legacy
The YF-23 lost the ATF competition but remains a significant aircraft in aviation history. The programme demonstrated several advanced technologies that influenced subsequent aircraft development:
- Stealth design: The YF-23's all-aspect stealth design, with its faceted shaping and shielded exhausts, advanced the state of the art in low-observable technology.
- Supercruise: The YF-23's supercruise capability was validated and subsequently incorporated into the F-22 Raptor.
- V-tail configuration: The YF-23's V-tail design has been studied for subsequent aircraft programmes.
The two YF-23 prototypes are in museum collections:
- PAV-1 (87-800, "Black Widow II"): On display at the National Museum of the United States Air Force, Dayton, Ohio.
- PAV-2 (87-801, "Gray Ghost"): On display at the Western Museum of Flight, Hawthorne, California.
Specifications
| Parameter | Value | |---|---| | Role | Air superiority fighter prototype | | Manufacturer | Northrop / McDonnell Douglas | | First flight | 27 August 1990 | | Competition result | Lost to YF-22 (F-22 Raptor) | | Crew | 1 | | Length | 67.4 ft (20.6 m) | | Wingspan | 43.6 ft (13.3 m) | | Height | 13.3 ft (4.1 m) | | Empty weight | ~29,000 lb (13,150 kg) | | Max takeoff weight | ~55,000 lb (24,950 kg) | | Engines | 2 × Pratt & Whitney YF119 or General Electric YF120 turbofans | | Thrust | ~35,000 lbf (156 kN) each with afterburner | | Max speed | Mach 2.2+ (~1,450 mph / 2,330 km/h) | | Supercruise | Mach 1.6+ without afterburner | | Service ceiling | ~65,000 ft (19,800 m) | | Number built | 2 |
Declassification and Provenance
The YF-23 programme was publicly acknowledged from its inception. The aircraft were displayed publicly, and the ATF competition was extensively reported in the trade press. Both prototypes are on public display in museums.
The gallery image associated with this technology is from a legacy compilation whose CIA-P2 catalog number is a legacy identifier and does not establish CIA authorship, declassification, or provenance. The image appears to show a YF-23 in flight or on the ground, consistent with publicly available photographs.
References
- Northrop Grumman. "YF-23 Advanced Tactical Fighter." Historical product information.
- US Air Force. "Advanced Tactical Fighter Programme." Air Force history.
- National Museum of the United States Air Force. "Northrop YF-23." Museum exhibit.
- Sweetman, Bill. "YF-23 vs YF-22: The ATF Decision." Aviation Week & Space Technology.
- Miller, Jay. The X-Planes: X-1 to X-45. Midland Publishing.