Westland P.9 Whirlwind

[Hobilar]

The Westland P.9 Whirlwind was designed in 1936 by W.E.W. Petters (see note 1) to the requirements of Air Ministry specification F.37/35 for a high-performance fighter, armed with four cannon. It would become the Royal Air Force's first twin-engined single-seat fighter and the first such aircraft to be used in numbers by any of the belligerent powers. Of orthodox all metal stressed-skin construction, the Whirlwind introduced several design innovations later to be widely adopted. It had an extremely slim fuselage (the cross section of which was less than that of the engine nacelles), and the four Hispano cannon were closely grouped in the fuselage nose to give a dense concentration of fire. The all-round vision cockpit was an advanced feature, and the coolant radiators were ducted within the centre section of the wing, In addition the Whirlwind incorporated Fowler-type flaps which extended from aileron to aileron.

A contract for two prototypes (L6844 and L6845) was placed in February 1937, with the first of these flying on the 11th October 1938. An initial production order for 200 machines was placed in January 1939 (followed by a second order for a similar number), with deliveries to fighter squadrons being scheduled to commence during the following September. Unfortunately deliveries the first Peregrine engines (in essence a modernised version of the classic Kestrel) did not reach Westland until January 1940, and, in consequence, the first Whirlwinds did not enter service until June, 1940.

Teething and delivery problems with the Peregrine engines (See Note 2) coupled with a number of flying accidents and a high landing-speed which restricted the number of airfields from which it could operate, resulted in production being terminated in January 1942 after the completion of just 112 production aircraft. These aircraft equipped just two squadrons of the RAF (No.263 Squadron from June 1940, and No.137 Squadron from November 1941. Both would re-equip with Typhoons in November 1943.

Notes:

1. W.E.W. Petters would later be the chief designer of the post-war English Electric Canberra.
2. Rolls-Royce being, at that time, more concerned with improving and maximising production of the important Merlin engine.

Bibliography:

• Aircraft of World War II (Chris Chant, Dempsey-Parr, 1999)
• The Complete Book of Fighters (William Green and Gordan Swansborough, Salamandar, 1997).
• Warplanes of the Second World War-Fighters Volume 2 (William Green,MacDonald,1961).
• World Aircraft Information Files (Aerospace Publishing Periodical).

[Hobilar]

No.263 Squadron R.A.F. undertook a number of light day bomber escort duties with their Whirlwind fighters. The best known of the operations undertaken being the escort of six Blenheim squadrons as far as Antwerp on August 12, 1941. In the summer of 1942, the Whirlwinds of both squadrons were fitted with racks for two 250-lb or 500-lb bombs (redesignated Whirlwind IA), These subsequently undertook low-level cross-channel attacks on locomotives, bridges, shipping, harbour installatons, and other targets until 1943 when both Squadrons re-equipped with Typhoons.

[Hobilar]

One Whirlwind(P6972) underwent night fighting trials in 1940 with No.25 Squadron and at one period the first prototype (L6844) was fitted with twelve 0.303-in Browning guns. Another Whirlwind was fitted experimentally with a single 37-mm cannon.

[Hobilar]

For a twin-engined aircraft the Whirlwind was highly manouvrable and its handling characteristics were frequently referred to as delightful. Also its performance at low altitude was superior to that of many contemporary single engined fighters. Unfortunately, rather poor maintenance characteristics and continuous teething troubles suffered by its Peregrine geared and supercharged engines (which powered no other service type), coupled with serious delays in engine deliveries conspired to restrict the Whirlwinds career to only two R.A.F. squadrons.

[Aggie08]

Good post, you could have probably combined all those into your first post though. I never really heard much about this bird but I liked its look. And 12 .303's? Good god! How many bullets/second does that work out to?

[Hobilar]

[Graeme]

Petter's original design layout.

[Graeme]

Originally Posted by Hobilar

and at one period the first prototype (L6844) was fitted with twelve 0.303-in Browning guns.

Another source says that the 12 Browning gun arrangement was produced in mock up form only, by Martin-Baker, but never fitted. It was an 'insurance policy' in case the 4 cannon arrangement proved too difficult. It wasn't.

Another Whirlwind was fitted experimentally with a single 37-mm cannon.

37mm cannon experimentally fitted to L6844.



The four cannon arrangement finally adopted.

[Airborne]

For 1940 it sure was futuristic.
The Whirlwind was the only product from Westland Aviation to reach front line status in WW2.

Hi Hobilar, Good to see you again. PM me if you'd like to.

[Trautloft]

great post,thanks The Whirlwind is one of my fav.ww2 a/c at all.

im interested in the total losses/claims.
i found on luftwaffe.cz a german ace who claimed 2 whirlwinds, how many of the 112 been lost finally? how was its sortie/loss ratio, and how many crashes been caused by the teething Peregrine engine?

[Hobilar]

Westland P.9 Whirlwind

Country of Origin: United Kingdom

Type: Single-seat Escort fighter and fighter-bomber

Powerplant: Two 885 hp Rolls-Royce Peregrine 1 liquid cooled V-12 engines

Span: 45 ft (13.72 m)
Length: 32 ft 3 in (9.83 m)
Height: 10 ft 6n (3.20 m)
Wing Area: 250 sq ft (23.22 m²)

Weight: Empty 8,310 lb (3,969 kg)
Maximum takeoff (with bombs) 11,388 lb (5,166 kg)

Speed: 360 mph (579 km/h)
Service Ceiling : 30,000 ft (9,145 m)
Range: 800 miles (1,287 km)

Crew: 1

Armament: Four 20mm Hispano Mk.I cannon plus two 250-lb (115 kg) or 500-lb (230 kg) bombs

[SteveH]

I've always wondered how much more successful it would have been with Merlins. Can you imagine?

Steve

[merlin]

Originally Posted by SteveH

I've always wondered how much more successful it would have been with Merlins. Can you imagine?

Steve

Not very successful at all, probably the wings would fall off,or else the props would slice through the fuselage.
The aircraft was designed for the small Peregrine engine. Anything larger just would not fit!!

[johnbr]

That is why I would have gone with the RR exe.

[freebird]

Originally Posted by merlin

Not very successful at all, probably the wings would fall off,or else the props would slice through the fuselage.
The aircraft was designed for the small Peregrine engine. Anything larger just would not fit!!

Westland DID make designs for a Merlin powered Whirlwind, but the Air ministry did not proceed. It sure would have been fast! But they decided to concentrate on the Beaufighter instead