Westland · Twin-Engine Heavy Fighter / Long-Range Escort Fighter / Fighter-Bomber · UK · WWII (1939–1945)
Open in interactive gallery →The Westland Whirlwind was a British twin-engine single-seat heavy fighter that promised much, delivered briefly, and was cancelled prematurely. Westland built 116 Whirlwinds between 1940 and January 1942. The aircraft used two small Rolls-Royce Peregrine I 12-cylinder V-engines (885 hp each) — the only production aircraft ever to use the Peregrine, an engine Rolls-Royce abandoned development of after the Whirlwind contract ended. The Whirlwind was withdrawn from RAF service in November 1943 after just 2 years of front-line operations, despite being one of the heaviest-armed and fastest fighters of its era at low altitude.
The Whirlwind's armament was extraordinary for 1940: four 20 mm Hispano cannons concentrated in the nose — the heaviest fixed forward armament of any RAF fighter of WWII (more than the typical 8 .303-cal Browning of contemporary Spitfires and Hurricanes). Maximum speed 360 mph at 15,000 ft (faster than the contemporary Hurricane's 340 mph and roughly equal to the Spitfire's 367 mph at the same altitude). Range 800 miles. Service ceiling 30,000 ft. The Peregrine engines gave good performance at low and medium altitudes but had no two-stage supercharger, limiting the Whirlwind to medium altitudes only.
Combat service was concentrated in 1941-1943 with 137 and 263 Squadrons RAF, attacking German shipping in the English Channel and German airfields in occupied France. Whirlwinds escorted Bristol Blenheim bombers on cross-Channel sweeps and conducted low-level intruder strikes on Luftwaffe airfields. The aircraft's heavy 20 mm cannon armament made it devastatingly effective in low-level strafing — pilots reported turning German fighters into "pieces of metal in mid-air". But the Peregrine engine's reliability problems, combined with Rolls-Royce's decision to drop the engine in favour of expanded Merlin production, doomed the type.
The Whirlwind was withdrawn from RAF service in November 1943. Westland's proposed redesign with Rolls-Royce Merlin engines (the Welkin) was cancelled in favour of the Mosquito. About 4 Whirlwind airframes survive in 2026 in static-display condition; one airworthy Welkin replica is being constructed in the U.K. The Whirlwind is one of the most-loved "what if" aircraft of WWII; pilots who flew it generally praised the aircraft, while RAF leadership concluded the Peregrine engine was not worth the maintenance burden.
The Westland Whirlwind was a British twin-engine fighter from early World War II. Only 116 Whirlwinds were built between 1940 and 1942. The plane was small, fast, and had heavier guns than any other British fighter of its time. But it was retired after just two years of front-line service.
The Whirlwind had four big 20 mm cannons packed into the nose. That was much heavier firepower than the eight rifle-caliber machine guns on a Spitfire or Hurricane. The cannons all fired together, so a short burst could badly damage enemy bombers.
The plane used two small Rolls-Royce Peregrine V-12 engines, each with 885 horsepower. Its top speed was 360 mph at low altitudes — faster than most enemy fighters at low altitudes. The Whirlwind is about as long as a city bus.
The Whirlwind's big problem was its engines. Rolls-Royce stopped improving the Peregrine to focus on the Merlin engine used in the Spitfire and Hurricane. With no engine upgrades available, the Whirlwind could not be improved. The Royal Air Force retired the type in November 1943.
The Whirlwind's engines were never improved. Rolls-Royce decided to focus on the Merlin engine used in the Spitfire, Hurricane, and Lancaster — these were the most important British planes. Without engine upgrades, the Whirlwind could not be made faster or stronger. So the Royal Air Force retired the plane early.
A 20 mm cannon is a big aircraft gun that shoots explosive shells about the size of a small banana. Machine guns shoot small rifle bullets, but cannons shoot bigger shells that can punch through enemy armor. Four 20 mm cannons together gave the Whirlwind enough firepower to wreck enemy bombers in seconds.
Rolls-Royce decided to abandon Peregrine engine development in favour of expanded Merlin production for the urgent Spitfire and Hurricane requirements. The Whirlwind was the only production aircraft using the Peregrine; without engine production it had no future. RAF Air Ministry chose not to order Westland's proposed Merlin-engine redesign (the Welkin) in favour of producing more Mosquitoes.
Four 20 mm Hispano cannons concentrated in the nose. This was the heaviest fixed forward armament of any RAF fighter of WWII — much heavier than the typical 8× .303-cal Browning of contemporary Spitfires and Hurricanes. The 20 mm shells could destroy small ships, locomotives, and aircraft in single bursts that .303 rounds would barely scratch.
At low and medium altitudes, yes — barely. Whirlwind: 360 mph at 15,000 ft. Contemporary Spitfire Mk II: 367 mph at the same altitude. Above 25,000 ft the Whirlwind's lack of two-stage supercharging dropped its speed below the Spitfire's; Whirlwind crews flew at lower altitudes where the Peregrine engines performed best.
116 airframes between 1940 and January 1942 at Westland's Yeovil plant. Production ended when Rolls-Royce stopped Peregrine production. Some uncompleted airframes were converted to Welkin development articles or scrapped.
About 4 airframes survive in 2026 in static-display condition. The Whirlwind Project (UK) is constructing an airworthy Whirlwind reproduction; first flight was projected for 2024-2025 but has been delayed by engine-availability problems (no Peregrine engines exist).