Westland Whirlwind


1st Flight 1938

Crew: 1

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 sq ft (23 m2)

Airfoil: root: NACA 23017; tip: NACA 23008

Empty weight: 8,310 lb (3,769 kg)

Gross weight: 10,356 lb (4,697 kg)

Max takeoff weight: 11,445 lb (5,191 kg)

Powerplant: 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

Propellers: 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

Range: 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


Guns: 4 × Hispano 20 mm cannon with 60 rounds per gun

Bombs: optionally 2 × 250 lb (115 kg) or 500 lb (230 kg) bombs


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 under wing 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.

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