Northrop YF-23(competitor of F-22)

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".
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 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 2,000 feet (610 m), which meant the use of thrust reversers on their engines. In 1987, the USAF changed the runway length requirement to 3,000 feet (914 m), 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 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.

General characteristics

• Crew: 1 (pilot)
• Length: 67 ft 5 in (20.60 m)
• Wingspan: 43 ft 7 in (13.30 m)
• Height: 13 ft 11 in (4.30 m)
• Wing area: 900 ft² (88 m²)
• Empty weight: 29,000 lb (13,100 kg)
• Loaded weight: 51,320 lb (23,327 kg)
• Max. takeoff weight: 62,000 lb (29,000 kg)
• Powerplant: 2 × General Electric YF120 or Pratt & Whitney YF119 turbofan, 35,000 lbf (156 kN) each

Performance

• Maximum speed: Mach 2.2+ (1,650+ mph, 2,655+ km/h) at altitude
• Cruise speed: Mach 1.6 (1,060 mph, 1,706 km/h) supercruise at altitude
• Range: over 2,790 mi (over 4,500 km)
• Combat radius: 750–800 nmi (865–920 mi, 1,380–1480 km)
• Service ceiling: 65,000 ft (19,800 m)
• Wing loading: 54 lb/ft² (265 kg/m²)
• Thrust/weight: 1.36