Westland Whirlwind

The Westland Whirlwind was a British twin-engined heavy fighter.

A contemporary of the Supermarine Spitfire and Hawker Hurricane, it was the first single-seat, twin-engined, cannon-armed fighter of the Royal Air Force.

When it first flew in 1938, the Whirlwind was one of the fastest combat aircraft in the world and with four 20 mm Hispano-Suiza HS.404 autocannon in its nose, the most heavily armed. 

Protracted development problems with its Rolls-Royce Peregrine engines delayed the project and only 114 Whirlwinds were built.

During the Second World War, only three RAF squadrons were equipped with the aircraft and, despite its success as a fighter and ground attack aircraft, it was withdrawn from service in 1943.


P.9 prototype

Single-seat twin-engine fighter aircraft prototype

Two built (L6844 and L6845), can be distinguished from later production samples by the mudguards above the wheels (Though the first production sample (P6966) had them as well), the exhaust system and the so-called ‘acorn’ on the joint between fin and rudder.

L6844 had a distinctive downward kink to the front of its pitot tube, atop the tail not seen again in following models.

L6844’s colour was dark grey. L6844 had opposite-rotation engines, L6845 had the same rotation engines as per production machines.

Whirlwind I

Single-seat twin-engine fighter aircraft, 400 ordered, 2 prototype & 114 production aircraft, total aircraft built 116

Whirlwind II

Single-seat twin-engine fighter-bomber aircraft, fitted with underwing bomb racks, were nicknamed “Whirlibombers”.

At least 67 conversions made from the original Mk I fighter.

Experimental variants A Mk I Whirlwind was tested as a night fighter in 1940 with No. 25 Squadron.

The first prototype was armed with an experimental twelve 0.303 machine guns and another one 37 mm cannon.

Merlin variant Westland proposed fitting Merlin engines in a letter to Air Marshal Sholto Douglas.

The proposal was rejected but Westland used the design work already performed in developing the Welkin high-altitude fighter.





32 ft 3 in (9.83 m)


45 ft 0 in (13.72 m)


11 ft 0 in (3.35 m)

Wing area

250 sq ft (23 m2)



NACA 23017


NACA 23008

Empty weight

8,310 lb (3,769 kg)

Gross weight

10,356 lb (4,697 kg)

Max take-off weight

11,445 lb (5,191 kg)


2 × Rolls-Royce Peregrine I V-12 liquid-cooled piston engines, 885 hp (660 kW) each at 10,000 ft (3,000 m) with 100 octane fuel


3-bladed de Havilland-Hydromatic, 10 ft (3.0 m) diameter variable-pitch propellers


Maximum speed

360 mph (580 km/h, 310 kn) at 15,000 ft (4,600 m)

Stall speed

95 mph (153 km/h, 83 kn) flaps down


800 mi (1,300 km, 700 nmi)

Combat range

150 mi (240 km, 130 nmi) as low altitude fighter, with normal reserves

Service ceiling

30,300 ft (9,200 m)

Time to altitude

15,000 ft (4,600 m) in 5 minutes 54 seconds, 30,000 ft (9,100 m) in 20 minutes 30 seconds



4 × Hispano 20 mm cannon with 60 rounds per gun


Options of 2 × 250 lb (115 kg) or 500 lb (230 kg) bombs.



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