Supermarine Seafang

The Supermarine Seafang was a British Rolls-Royce Griffon–engined fighter aircraft designed by Supermarine to Air Ministry specification N.5/45 for naval use. It was based on the Spiteful, which was a development of Supermarine's Griffon-engined Spitfire aircraft. By that time the Spitfire was a 10-year-old design in a period of rapid technical development in aviation. The Seafang was outmoded by jet aircraft, and only 18 were built.

Design and development
The Seafang was essentially a Spiteful redesigned for Royal Navy carrier use, with the addition of an arrester hook, a contra-rotating propeller to eliminate engine torque effects, and power folding outer wing panels.

Two prototype Type 396 Seafang Mark 32s were ordered on 12 March 1945 followed by an order for 150 Type 382 Seafang Mark 31s on 7 May 1945. To expedite entry into service the interim Mark 31 was ordered which was a navalised Spiteful, basically a Spiteful with an arrestor hook added. This would allow the Mark 32 to be developed; it would be the definitive naval variant, with the folding outer wings and contra-rotating propeller.

The first Seafang flew in 1946; it was the first interim production Mark 31 VG471. Although 150 of the interim variant were ordered, only nine were completed before the order was cancelled as the urgency of an interim type was removed due to the end of the war.

The first prototype Mark 32 VB895 was first flown in June 1946. It was powered by a Griffon 89 engine rated at 2,350 hp driving two three-bladed contra-rotating propellers. In August 1946, VB895 was demonstrated to the Royal Netherlands Navy at Valkenburg. The same aircraft was flown by test pilot Mike Lithgow in May 1947, during deck landing trials on HMS Illustrious (87). Compared to the Seafire F.47, its performance advantage was not deemed to be enough to disrupt series production of new navalised Gloster Meteor and de Havilland Vampire jet fighters. Also, the Seafang's low-speed handling characteristics were not as good as hoped, and the contemporary Hawker Sea Fury was preferred as a fleet fighter.

Seafang Mark 31 VG474 was used as a development aircraft for the Supermarine Attacker jet, receiving power-operated ailerons and contra-rotating propellers. The Attacker was a jet design which used the Spiteful laminar-flow wing and landing gear.

Variants

 * Type 382 Seafang F Mk.31
 * Interim production variant with a 2,375 hp Griffon 61 engine, five-bladed constant-speed Rotol airscrew. 150 ordered but only 9 built; the rest were cancelled.


 * Type 396 Seafang F Mk.32
 * Two prototypes built powered by a 2,350 hp (1,752 kW) Griffon 89 piston engine, folding wings, increased fuel capacity, dual contra-rotating 3-bladed propellers.

Operators

 * Fleet Air Arm
 * Fleet Air Arm

Type 391
The Type 391 was the last piston-engined fighter to be proposed by Supermarine. In 1943, as the design of the Spiteful and Seafang was proceeding, Supermarine presented a brochure to the Air Ministry describing a "High-Performance Aeroplane for the Royal Navy", designated internally as the Supermarine Type 391. Of greater length and span than the Seafang, the Type 391 was intended to be used as a carrier-borne fighter, with a secondary role as a strike aircraft.

The wing of the Type 391 was similar in outline to that of the Spiteful/Seafang but was larger and, unlike all previous Supermarine fighters, was mid-mounted. The whole section outboard of the undercarriage hinged up, while a wide centre-section incorporated thick roots with tapered leading-edge air intakes. These fed the engine cooling radiators. Because of the higher-mounted wing, the main undercarriage legs were also longer, with the wheels pivoting when raised to fit into wells in the fuselage.

The forward fuselage was lengthened to accommodate the new engine, while the rear had redesigned and enlarged tail surfaces.

The engine was to be a supercharged 24-cylinder sleeve-valve Rolls-Royce 46-H-24 (later known as the "Eagle"), delivering 3,550 hp to an eight-bladed contra-rotating propeller (i.e. four blades in each direction).

Specifications for the Type 391 include a wingspan of 43 ft 6 in (13.3 m), a fuselage length of 39 ft 9 in (12.1 m) and a wing area of 335 ft² (31.2 m²). Maximum weights were 15,750 lb (7,144 kg) as a fighter and 17,250 lb (7,825 kg) when armed with a torpedo. The maximum speed was projected to be 546 mph (879 km/h) at 25,000 ft (7,620 m).