The Republic XF-103 Thunderwarrior was an American project to develop a Mach 3 interceptor to knock down Soviet bombers. Despite a prolonged development, it never flew.

Development

In 1949 the USAF issued a request for an advanced supersonic interceptor, known as the "1954 Interceptor " project, or Weapon System WS-201A. It was to be a supersonic aircraft with all-weather capability, radar, and air-to-air missile armament.

Republic was one of six companies to submit proposals. The Republic proposal, AP-57, was selected for further development on 2 July 1951, along with the Convair design that eventually became the F-102 Delta Dagger.

AP-57 was an extremely advanced design intended to be built almost entirely of titanium, capable of speeds up to Mach 4 (2,600 mph/4,160 km/h) at 80,000 ft (24,390 m). To provide such performance it was intended to have a Wright J67 turbojet (a license-built version of the Bristol Olympus engine) supplemented by an RJ55-W-1 ramjet for high-speed use. Both engines were fed by a large ventral intake.

The fuselage was completely smooth, with the cockpit submerged to reduce drag. There was no canopy for the pilot, only two small side windows. The airframe was a tailed delta wing configuration, with a delta planform and additional horizontal tailplane. The vertical fin was supplemented by a folding ventral fin for high-speed stability. Weapons were to be carried in fuselage weapons bays. Guidance was to be provided by the same Hughes MA-1 radar fire control system (originally MX-1179) as the later F-106 Delta Dart.

Although the design was authorized for further development under the designation XF-103 in September 1951, and a full-sized mockup was built in 1953, the Republic design was considered far too risky in its advanced technology to have a realistic chance of production. The Convair F-102 Delta Dagger was adopted instead. Continued development and manufacturing problems finally brought about an end to the XF-103 project on 21 August 1957. No flying prototypes were ever completed.

The "Thunderwarrior" name was apparently a company designation, not an official USAF popular name.

Specifications (XF-103, as designed)

General Characteristics

• Crew: one pilot
• Length: 77 ft (23.5 m)
• Wingspan: 34 ft 5 in (10.5 m)
• Height: 16 ft 7 in (5.1 m)
• Wing area: 401 ft² (37.2 m²)
• Empty: 24,949 lb (11,340 kg)
• Loaded: 38,505 lb (17,502 kg)
• Maximum takeoff: 42,864 lb (19,484 kg)
• Powerplant: Wright XJ67 -W-3 turbojet with 15,000 lb (66.9 kN) thrust, augmented by one Wright XRJ55 -W-1 ramjet with 18,800 lb (83.8 kN) thrust

Performance

• Maximum speed: 1,985 mph (3,176 km/h) at altitude, 2,600 mph (4,160 km/h) with ramjet
• Combat radius: 245 mi (392 km)
• Ferry range: 1,545 mi (2,472 km)
• Service ceiling: 69,000 ft (21,036 m)
• Rate of climb: 19,000 ft/min (5,793 m/min)
• Wing loading: 96 lb/ft² (470 kg/m²)
• Thrust-to-Weight: 0.57:1 (afterburner, no ramjet); 0.95:1 (afterburner and ramjet)

Armament

• internal weapons bays in fuselage sides for six GAR-3 Falcon air-to-air missiles and 36x 2.75-in (70 mm) FFAR rockets.

External link

• USAF Museum: XF-103

Related content

Related development:

Comparable aircraft:

Designation sequence: F-100 - F-101 - F-102 - XF-103 - F-104 - F-105 - F-106