The Westland Whirlwind was a British twin-engined heavy fighter developed by Westland Aircraft. It was the Royal Air Force's first single-seat, twin-engined, cannon-armed fighter, and a contemporary of the Supermarine Spitfire and Hawker Hurricane. It was one of the fastest aircraft in service when it flew in the late 1930s, and was much more heavily armed than any other. However, protracted development problems with its Rolls-Royce Peregrine engines delayed the entire project and only a relatively small number were ever built. During the Second World War only two RAF squadrons were equipped with the Whirlwind, and despite successful use as a fighter-bomber it was withdrawn from service in 1943.
The Whirlwind was quite small, only slightly larger than the Hurricane in overall size, but smaller in terms of frontal area. The landing gear was fully retractable and the entire aircraft was very "clean" with few openings or protuberances. Radiators were in the leading edge on the inner wings rather than below the engines. This careful attention to streamlining and two 885 hp Peregrine engines powered it to over 360 mph (580 km/h), the same speed as the latest single-engine fighters.
General characteristics
Crew: One pilot
Length: 32 ft 3 in (9.83 m)
Wingspan: 45 ft 0 in (13.72 m)
Height: 11 ft 0 in (3.35 m)
Wing area: 250 ft² (23.2 m²)
Airfoil: NACA 23017-08
Empty weight: 8,310 lb (3,777 kg)
Loaded weight: 10,356 lb (4,707 kg)
Max. takeoff weight: 11,445 lb (5,202 kg)
Powerplant: 2 × Rolls-Royce Peregrine I liquid-cooled V12 engine, 885 hp (660 kW) at 10,000 ft (3,050 m) with 100 octane fuel each
Propellers: de Havilland constant speed propeller
Propeller diameter: 10 ft (3.28 m)
Performance
Maximum speed: 360 mph (313 knots, 580 km/h) at 15,000 ft (4,570 m)
Stall speed: 95 mph (83 knots, 153 km/h) (flaps down)
Range: 800 mi[40] (696 nmi, 1,288 km)
Combat radius: 150 mi (130 nmi, 240 km) as low altitude fighter, with normal reserves[21]
Service ceiling: 30,300 ft (9,240 m)
Armament
Guns: 4x Hispano 20 mm cannons with 60 rounds per gun
Bombs: 2x 250 lb (115 kg) or 500 lb (230 kg) bombs