Supermarine Type 324

Supermarine

Industry	Aerospace
Founded	1913
Headquarters	United Kingdom

The Supermarine Type 324 and Type 325 were British twin-engine fighter concepts intended to succeed the Supermarine Spitfire and Hawker Hurricane. Neither of these designs, nor the subsequent modified version—the Type 327, which was planned to be armed with cannon—progressed to development or production.

Development

To replace the Hurricane and Spitfire entering service, the Air Ministry issued specification F.18/37, calling for a fighter capable of exceeding 400 mph at 15,000 ft, equipped with twelve .303 inch machine guns. In response, Hawker Aircraft proposed a single-seat, single-engine fighter featuring two engine options: the Hawker Tornado powered by the Rolls-Royce Vulture and the Hawker Typhoon driven by the Napier Sabre engine.

Gloster Aircraft Company submitted two related twin-boom designs armed with twelve Browning machine guns mounted in the nose and powered by a pusher-configured Sabre engine; they also offered a variant derived from their earlier F.9/37 proposal with nose-mounted weaponry. Bristol presented a single airframe design adaptable to three different engines.

In 1938, Supermarine introduced brochures for the Type 324 (company specification No.458) alongside the Type 325. Both featured compact twin-engine layouts with one tractor and one pusher propeller, powered by either Rolls-Royce Merlin or Bristol Taurus engines.

Ultimately, Hawker's designs, which Sydney Camm had been developing since April 1937, were approved and prototype orders were placed for each model.

Overview

The Type 324 was designed as a low-wing monoplane with two engines, incorporating the Spitfire's distinctive elliptical wing design and equipped with a retractable tricycle landing gear system.

Its twin-engine configuration was projected to achieve a top speed of 450 mph. This arrangement also offered benefits such as torque neutralization, enhanced pilot visibility, improved takeoff capabilities, and the ability to utilize the well-established Merlin engine.

Constructed from Alclad aluminum alloy, the aircraft's wing was modularly built to accommodate different engines, like the Taurus, or varied armament setups. Fowler flaps were installed to assist during takeoff and landing phases, while spoiler flaps were added to boost overall aerodynamic performance.

Various weapon configurations were evaluated. The primary armament consisted of twelve Browning machine guns arranged in two groups of six within each outer wing section. These units could be detached along with their ammunition for swift rearming and maintenance.

When the Air Ministry grew concerned about delays in the development of the Westland Whirlwind cannon-armed fighter, they requested revisions to the F.18/37 proposals to incorporate 20mm cannon weaponry. In response, Supermarine abandoned the pusher layout and introduced the Type 327, a fighter armed with six cannons. However, the Ministry concluded that its advantages did not surpass other factors and anticipated that either the Whirlwind or the modified Bristol Beaufort would enter operational service before Supermarine’s design.

Powerplant

Rolls-Royce Merlin Maximum speed: 450 mph Cruising speed at 15,000 ft: 195 mph

Measurements

Span 41 ft x 40 ft Root Chord 9 mm x 9 ft Mean Chord 7.08 mm x 7.08 ft Length 31.5 ft x 33.5 ft Height 10.2 ft x 9.75 ft

References

• Buttler, Tony. Secret Projects: British Fighters and Bombers 1935-1950 (British Secret Projects 3). Leicester, UK: Midland Publishing, 2004.