NORTHROP
F-89 SCORPION


The Northrop F-89 Scorpion was one of the primary defenders of North American airspace during the Cold War. A total of 1052 Scorpions were built. During its career, the F-89 equipped 36 active Air Force Units and 17 Air National Guard squadrons. One of the most heavily armed fighter aircraft, the F-89 was the backbone of the North American Air Defense Command for more than 17 years. The F-89 was the first multi-seat, all-weather jet interceptor. It was the first aircraft designed to carry an all-rocket armament and the first to carry the Hughes Falcon air-to-air guided missile, and notably the first combat aircraft armed with air-to-air nuclear weapons (the unguided Genie rocket). The Museums F-89 is currently located at Cable Airport.

The Scorpion stemmed from a 1945 United States Army Air Forces Army Air Technical Service Command specification ("Military Characteristics for All-Weather Fighting Aircraft") for a jet-powered night fighter to replace the P-61 Black Widow. Bell Aircraft, Consolidated-Vultee, Douglas Aircraft, Goodyear, Northrop and Curtiss-Wright all submitted proposals.

Northrop submitted four different designs, prepared by Jack Northrop's team, including a radical flying wing but settled on the N-24, a slim-bodied aircraft with a cantilevered mid-mounted wing and two Allison J35 turbojet engines with afterburners. It was to have radar and a crew of two, with an armament of four 20 mm (.79 in) cannon in a unique trainable nose turret. One of the unusual aspects of the design was the use of Northrop's "Deceleron", a combination aileron/dive brake/flap that could be accommodated in the slim wing design. The unique feature added to the prototype during development was to become a Northrop trademark, still used today on the B-2 Spirit. Contracts for two prototypes were issued in December 1946, while Douglas with their XF3D-1 Skynight and Curtiss for their XF-87 Blackhawk prototypes also were awarded development contracts.

The initial XP-89 prototype made its first flight on 16 August 1948, with test pilot Fred C. Bretcher at the controls. For much of the testing period, Curtiss's entry had been the front-runner for the contract, but in a competition fly-off with its main competitors, the Northrop design proved superior. Other USAF interceptors such as the F-94 Starfire and F-86 Sabre had been adapted from day fighter designs.

Production was authorized in January 1949, with the first production F-89A being accepted September 28, 1950. It had AN/APG-33 radar and an armament of six 20 mm (.79 in) T-31 cannons with 200 rpg. The swiveling nose turret was abandoned, and 300 US gal. fuel tanks were permanently fitted to the wingtips. Underwing racks could carry 16 5 in (127 mm) aerial rockets or up to 3,200 lb (1,455 kg) of bombs.

Only eighteen F-89As were completed, which were mainly used for tests and trials, before the type was upgraded to F-89B standard, with new avionics. The type entered service with the 84th Fighter-Interceptor Squadron in June 1951. These had considerable problems with engines and other systems, and soon gave way to the F-89C. Despite repeated engine changes, problems persisted, compounded by the discovery of structural problems with the wings that led to the grounding of the F-89 and forced a refit of 194 -A, -B, and -C models.

The major production model was the F-89D, which first flew 23 October 1951 and entered service in 1954. It removed the cannon in favor of a new Hughes E-6 fire control system with AN/APG-40 radar and an AN/APA-84 computer. Armament was two pods of 52 2.75 in (70 mm) "Mighty Mouse" FFAR rockets, for a total of 104. A total of 682 were built.

Proposed re-engined F-89s, designated F-89E and F-89F, were not built, nor was a proposed F-89G that would have used Hughes MA-1 fire control and GAR-1/GAR-2 Falcon air-to-air missiles like the F-102 Delta Dagger.

The subsequent F-89H, which entered service in 1956, had an E-9 fire control system like that of the early F-102 and massive new wingtip pods each holding three Falcons (usually three semi-active radar homing GAR-1s and three infrared GAR-2s) and 21 FFARs, for a total of six missiles and 42 rockets. Problems with the fire control system delayed the F89-H's entry into service, by which time its performance was notably inferior to newer supersonic interceptors, so it was phased out of USAF service by 1959.

The final variant was the F-89J. This was based on the F-89D, but replaced the standard wingtip missile pod/tanks with 600 gal. fuel tanks and fitted a pylon under each wing for a single MB-1 Genie nuclear rocket (sometimes supplemented by up to four conventional Falcon air-to-air missiles). The F-89J became the only aircraft to fire a live Genie as the John Shot of Operation Plumbbob on 19 July 1957. There were no new-build F-89Js, but 350 -Ds were modified to this standard. They served with the Air Defense Command, later renamed the Aerospace Defense Command (ADC), through 1959 and with ADC-gained units of the Air National Guard through 1969. This version of the aircraft was extensively used within the Semi Automatic Ground Environment (SAGE) air defense system.


XF-89 First prototype, powered by two 4,000 lb. Allison J-35-A-9 engines. XF-89A Second prototype. Fitted with more powerful (5,100 lb. thrust, 6,800 lb. with afterburner) J-35-A-21A engines and revised, pointed nose with cannon armament. F-89A First production version, eight built. Fitted with revised tailplane and six cannon armament. DF-89A F-89As converted into drone control aircraft. F-89B Second production version with upgraded avionics. 40 built. DF-89B F-89Bs converted into drone control aircraft. F-89C Third production version with more powerful engines (5,600 lb. thrust, 7,400 lb. with afterburner J-35-A-21 or -33). 164 built. YF-89D Conversion of one F-89B to test new avionics and armament of F-89D. F-89D Main production version which saw deletion of the six 20 mm (.79 in) cannons in favor of 104 rockets in wing pods, installation of new Hughes E-6 fire control system, AN/APG-40 radar and the AN/APA-84 computer. This new system allowed the use of a lead-collision attack in place of the previous lead-pursuit-curve technique. A total of 682 built. YF-89E One off prototype to test the Allison YJ71-A-3 engine (7,000 lb. thrust, 9,500 lb. with afterburner), converted from F-89C. F-89F Proposed version with new fuselage and wings and J71 engines, never built. F-89G Proposed version equipped with Hughes MA-1 fire control and GAR-1/GAR-2 Falcon air-to-air missiles, never built. YF-89H Modified F-89D to test features of F-89H. Three converted. F-89H Version with E-9 fire control system, six GAR-1/GAR-2 Falcon missiles and 42 Folding Fin Aircraft Rockets (FFAR). 156 built.

Northrop F-89J in 1972 F-89J Conversion of F-89D with underwing hardpoints for two MB-1 Genie nuclear armed rocket and four Falcon missiles, and either carrying the standard F-89D rocket/fuel pod or pure fuel tanks. A total of 350 were converted from F-89Ds.

Operators:
United States United States Air Force
Air National Guard

Data from Scorpion with a Nuclear Sting:

Crew: 2
Length: 53 ft 9½ in (16.40 m)
Wingspan: 59 ft 8½ in (18.20 m)
Height: 17 ft 6 in (5.33 m)
Wing area: 606 ft² (56.30 m²)
Empty weight: 25,194 lb (11,428 kg)
Loaded weight: 37,190 lb (16,869 kg)
Max takeoff weight: 42,241 lb (19,161 kg)
Powerplant: 2 × Allison J35-A-35 afterburning turbojets. 5,440 lb. thrust (24.26 kN) each
Thrust with afterburner: 7,200 lb. (32.11 kN) each

Performance
Maximum speed: 635 mph (552 knots, 1,022 km/h) at 10,600 ft (3,200 m)
Ferry range: 1,366 mi (1,188 nm, 2,200 km)
Service ceiling: 49,200 ft (15,000 m)
Rate of climb: 7,440 ft/min (37.8 m/s)

Armament

Rockets:
104× 2.75 in (70 mm) "Mighty Mouse" folding-fin aerial rockets
16× 5 in (127 mm) aerial rockets on underwing racks or

Bombs: 3,200 lb (1,500 kg)

 

 

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