The twin-engined Whirlwind showed much potential with its performance and heavy armament. The type would suffer through delays in its production that meant other aircraft entered service
before the Westland Whirlwind and served in the roles it had been intended for the aircraft to do.
Responding to Air Ministry Specification F/37.35 which was issued in 1935 requesting a single-seater fighter with an armament of four cannons for both day and night duties Westland
submitted their Whirlwind design with the prototype flying for the first time on the 11th October 1938. It was announced during January the following year that a contract for 200 aircraft
had been won.
The new aircraft, which would be the first twin-engined fighter of the Royal Air Force, looked promising its firepower at the time was better than any other fighter in the world as was
it's low-altitude performance. Production versions of the aircraft began in July 1940 as No. 263 Squadron based at Drem began the task of eliminating bugs in both the airframe and
Rolls-Royce Peregrine engines. The squadron would claim its first success on the 8th February 1941 when an Arado Ar 196 was shot down despite troubles with its cannon armament.
Due to a shortage of engines deliveries of the Whirlwind were slow with the Royal Air Force receiving only eight of the type by the close of 1940, in fact only two squadrons would be
equipped with the Whirlwind the other being No. 137 Squadron which was formed on the 20th September 1941 at Charmy Down.
Despite the positive performance and armament of the plane its dogfighting abilities at higher altitude was called into question and it could only be used at a limited number of
airfields due to it's high landing speed leading to a second order that had been placed for 200 more aircraft to be cancelled and the initial contract for 200 aircraft cut to just 112.
Another thing against the Whirlwind was that by 1940 the Supermarine Spitfire was being tested with 20mm cannons before they were introduced on the Spitfire Mk II, and so by the end of
1943 the Whirlwind had been replaced by the Hawker Hurricane which re-equipped No. 137 Squadron with Hawker Typhoons re-equipping No. 263 Squadron.
A second prototype, equipped with twelve 0.303-in machine-guns, and a third equipped with a 37-mm cannon were sent to No. 25 Squadron, who at that time were using the Bristol Blenheim,
for night-fighter trials although the Whirlwinds production delays saw the Bristol Beaufighter enter service in this role instead.
January 1942 would see the last of the 112 Westland Whirlwinds leave the production line.