The Westland Whirlwind was the first twin engined fighter to enter RAF service. When it first appeared it was faster at low altitude than any single seater fighter, and its four 20mm cannon gave it the heaviest firepower of any fighter in the world. With these attributes one might expect the Whirlwind to have been a highly successful aircraft, but in fact only two squadrons were ever equipped with the type, one of them after production had been cancelled.
The Whirlwind was developed in response to the Air Ministry specification F.37/35, which called for a four-cannon armed fighter. Five aircraft were submitted in response to the specification, of which three were for twin-engined aircraft. The first prototype Whirlwind flew on 11 October 1938, and Westland were awarded a production contract for 200 aircraft in January 1939.
The Whirlwind was a low-wing monoplane, with a small frontal area. The twin engined design allowed the guns to be grouped in the nose. The cockpit was placed above the wing, and given a bubble canopy. As a result the pilot had a good all-round view. It was powered by the Rolls-Royce Peregrine engine, a 12-cylinder liquid-cooled engine based on the earlier Kestrel.
The choice of engine was the aircraft's downfall. Although the Peregrine was a good engine at low level, power fell off at higher altitudes. It was also unreliable, slow to produce and had limited development potential. As the Battle of Britain demonstrated, altitude and speed were the deciding factors in fighter combat. The Whirlwind’s excellent performance at low level was becoming increasingly irrelevant for a modern fighter aircraft.
Whatever positive features the Whirlwind possessed, they were not enough to save it from the fate of every new Rolls-Royce powered aircraft not powered by the crucial Merlin. In December 1940 the Air Ministry cancelled all but the first 112 production aircraft.
By the time the Whirlwind was cancelled it was only in use with one squadron. No. 263 squadron had suffered heavily in the Norwegian campaign, culminating with the disastrous loss of its aircraft on HMS Glorious. In July 1940 the reformed squadron received its first Whirlwinds, flying them in parallel with a number of Hurricanes until November 1940.
The squadron became operation with the Whirlwind in December 1940, performing convoy patrols from Exeter. The Whirlwind’s first confirmed kill came on 8 February 1941, when the squadron shot down an Arado Ar 196 floatplane. In the summer of 1941 the squadron began to carry out offensive sweeps across occupied France, and in 1943 it began to use the “Whirlibomber”, a modified Whirlwind that could carry two 500lb bombs. The squadron retained its Whirlwinds until December 1943, when they were replaced with Typhoons.
No. 137 squadron became the second unit to receive the Whirlwind, getting its aircraft in September 1941. It began offensive operations across the channel on 24 October 1941 and kept its Whirlwinds until June 1943, when they were replaced by rocket armed Hurricanes.
Engine: Two Rolls-Royce Peregrine inline piston engines
Horsepower: 885hp each
Span: 45ft 0in
Length: 32ft 9in
Max speed: 360mph at 15,000ft
Armament: Four 20mm cannon in nose
Bomb load: 1,000lb