Westland Whirlwind

Whirlwind

Picture - Westland Whirlwind in a rare Second World War colour photograph

Role: Heavy fighter
National origin: United Kingdom
Manufacturer: Westland Aircraft Limited
First flight: 11 October 1938
Introduction: June 1940
Retired: October 1943
Primary user: Royal Air Force
Produced: 1940 - January 1942
Number built: 116

The Westland Whirlwind was a British twin-engined heavy fighter developed by Westland Aircraft. It was the Royal Air Force's first single-seat, twin-engined, cannon-armed fighter, and a contemporary of the Supermarine Spitfire and Hawker Hurricane. It was one of the fastest aircraft when it flew in the late 1930s, and was much more heavily armed than any other. However, protracted development problems with its Rolls-Royce Peregrine engines delayed the entire project and only a relatively small number were ever built. During the Second World War only two RAF squadrons were equipped with the Whirlwind, and despite successful use as a fighter-bomber it was withdrawn from service in 1943.

Background

The Whirlwind's origin lay in the new aircraft being developed for the RAF in the mid 1930s, following the last biplane fighters. With higher attack speeds giving shorter opportunities for firing on targets, it was decided to increase the minimum level of armament fitted to aircraft. Instead of two rifle-caliber machine guns, eight were specified. At the same time it was recognized that cannons such as the 20mm Hispano-Suiza HS.404 which could fire exploding ammunition offered another route to heavy firepower and requests were made for aircraft designs which could carry four of these cannons.

A serious problem for air planners of the 1930s was that one could only build a nimble combat aircraft if it was small. Such an aircraft would have limited space for fuel, and would only have enough range to fight in defensive operations. A multi-engined fighter appeared to be the best solution to the problem of range, but it seemed that any fighter large enough to incorporate a substantial fuel load would be too unwieldy to successfully engage its single-engine counterparts in combat. Germany and the United States pressed ahead with such programs anyway, which resulted in the Messerschmitt Bf 110 and the Lockheed P-38.

Design and development

Picture - Westland Whirlwind prototype L6845 c.1940

The claims made about the Bf 110 piqued the interest of the British Air Ministry, who issued specification F.37/35 in 1935, which called for a single-seat day and night fighter armed with four cannon. Six aircraft were submitted in response to the specification, of which three were twin-engined types: the Boulton Paul P.88, the Bristol Type 153A, the Hawker F.37/35 (which was a Hurricane variant), the Supermarine 312 (a Spitfire variant), the Supermarine 313 and the Westland P.9 which was successful. A contract was placed in February 1937 for two prototypes of Westland's design.

Westland's design team, under the new leadership of Teddy Petter (who was later to design the English Electric Canberra, Lightning and Folland Gnat) designed an aircraft that employed state-of-the-art technology. The monocoque fuselage was a small tube with a T-tail at the end, although as originally conceived, the design featured a twin tail which was discarded when large Fowler flaps were added that caused large areas of turbulence over the tail unit. The horizontal stabilizer (tailplane) was moved up out of the way of the disturbed air flow caused when the flaps were down. The airframe was built completely of stressed-skin duraluminium, with the pilot sitting high under one of the world's first full bubble canopies, while the low and forward location of the wing made for superb visibility (except for directly over the nose). Four 20 mm cannon were mounted in the nose, making it the most heavily armed fighter aircraft of its era; the clustering of the weapons also meant that there were no convergence problems as with wing-mounted guns. Hopes were so high for the design that it remained "top secret" for much of its development, although it had already been mentioned in the French press.

The first prototype (L6844) flew on 11 October 1938 with further Service Trials carried out at Martlesham Heath. It exhibited excellent handling and was very easy to fly at all speeds. The only exception was the inadequate directional control during takeoff which necessitated an increased rudder area above the tailplane. Production orders were contingent on the success of the test program; delays caused by over 250 modifications to the two prototypes led to an initial production order for 200 aircraft being held up until January 1939 followed by a second order for a similar number, deliveries to fighter squadrons being scheduled to begin in September 1940.

The Whirlwind was quite small, only slightly larger than the Hurricane in overall size, but smaller in terms of frontal area. The landing gear was fully retractable and the entire aircraft was very "clean" with few openings or protuberances. Radiators were in the leading edge on the inner wings rather than below the engines. This careful attention to streamlining and two 885 hp Peregrine engines powered it to over 360 mph (580 km/h), the same speed as the latest single-engine fighters. The speed quickly garnered it the nickname Crikey, (a minced oath meaning "my god!" or more accurately "Christ's keys!").

But there were problems as well. The aircraft had limited range, under 300 miles combat radius, which made it marginal as an escort. More troublesome were the continued failures of the Peregrine engine. It was originally intended to be one of Rolls' main designs, but the Merlin had become much more important to the war effort and the Peregrine was relegated to a secondary status; the first deliveries of Peregrine engines did not reach Westland until January 1940.

By 1940, the Supermarine Spitfire was mounting 20 mm cannons, so the "cannon-armed" requirement was also being met, and by this time the role of escort fighter was becoming less important as RAF Bomber Command turned to night bomber missions. The main qualities the RAF were looking for in a twin-engine fighter were range and carrying capacity (to allow the large radar apparatus of the time to be carried), in which requirements the Bristol Beaufighter could perform just as well as or even better than the Whirlwind.

Development and delivery problems with the Peregrine engines, along with a number of flying accidents and the aircraft’s high landing speed (which restricted the number of airfields from which it could operate), resulted in Whirlwind production being ended in January 1942, after the completion of just 112 production aircraft. Westland campaigned for the creation of a Mk II model, initially designed around a more powerful 1,010 hp Peregrine which was aborted owing to Rolls-Royce's cancellation of further development of the engine. Additional proposals by Petter similarly remained as "paper projects" and included re-engining with Bristol Hercules, American radials and even using two 1,400 hp Merlin XX engines, each concept being rejected by the Air Ministry.

Operational history

The first squadron to receive the Whirlwind was No. 25, then based at North Weald. The squadron was fully equipped with Bristol Blenheim IF night fighters when Squadron Leader K. A. K. MacEwen flew prototype Whirlwind L6845 from Boscombe Down to North Weald on 30 May 1940. The following day it was flown and inspected by three of the squadron's pilots, and the next day was inspected by the Secretary of State for Air, Sir Archibald Sinclair, and Lord Trenchard. Two days later the second Whirlwind, a production model, was again flown in from Boscombe Down by Squadron Leader MacEwen, and later that day a pilot of the squadron solo'ed in it. On 17 June the AOC-in-C Fighter Command recommended that No. 25 Squadron be re-equipped with Bristol Beaufighter night fighters, as it was already an operational night fighter squadron, and Whirlwinds were not being produced fast enough. The three Whirlwinds supplied to No. 25 Squadron were transferred to No. 263 Squadron.

The first production Whirlwind delivered to No. 263 Squadron was P6966, which was collected by Squadron Leader H. Eeles on 24 June and flown to Grangemouth, where 263 Squadron was reforming after disastrous losses in the Norwegian Campaign, in which only four pilots survived. After the decision had been made that No. 263, not No. 25, would be the first operational Whirlwind squadron, No. 263 had to make do with the three initial aircraft, and was supplied with additional Hurricanes until more Whirlwinds became available. Slow deliveries and the delays involved in converting from Hawker Hurricanes to the new fighter, resulted in the squadron not becoming operational with Whirlwinds until December 1940.

The first Whirlwind was written off on 7 August when Pilot Officer McDermott had a tyre blow out while taking off in P6966. In spite of this he managed to get the aircraft airborne. Flying Control advised him of the dangerous condition of his undercarriage, and to land the aircraft in such condition was extremely hazardous. PO McDermott bailed out of the aircraft between Grangemouth and Stirling. The aircraft dived in and buried itself 30 feet into the ground (see Survivors).

No. 263 squadron became operational with the Whirlwind in December 1940, carrying out convoy patrols from Exeter. The Whirlwind’s first confirmed kill occurred on 8 February, when Pilot Officer Graham (P6969) shot down an Arado Ar 196 floatplane. Unfortunately PO Graham was never seen again, and was believed to have died in the attack. From then on the Squadron was to have considerable success with the Whirlwind while flying against enemy Ju 88s, Do 217s, Bf 109s and Fw 190s. The squadron went on to carry out day bomber escort missions with the Whirlwinds, including the escort of six Blenheim squadrons to Antwerp on 12 August 1941. A second Whirlwind squadron, No. 137, flew the type from September 1941 until June 1943. In the summer of 1942, both squadrons' Whirlwinds were fitted with racks to carry two 250 lb or 500 lb bombs and redesignated Whirlwind IA, and nicknamed Whirlibombers. These undertook low-level cross-channel "Rhubarb" sweeps, attacking locomotives, bridges, shipping and other targets.

Channel Dash

No. 137 Squadron's worst losses were to be on 12 February 1942 during the Channel Dash, when they were sent to escort five British Destroyers, unaware of the escaping German warships Scharnhorst and Gneisenau. Four Whirlwinds took off at 13:10 hours, and soon sighted warships through the clouds about 20 miles from the Belgian coast. They descended to investigate and were immediately jumped by about 20 Bf 109s of Jagdgeschwader 2. The Whirlwinds shot at anything they got in their sights, but the battle was against odds. While this was going on, at 13:40 two additional Whirlwinds were sent up to relieve the first four, still unaware of the danger. All six Whirlwinds failed to return.

Mx�nsterland

From 24 October until 26 November 1943, Whirlwinds of 263 Squadron made several large attacks against the German blockade runner Mx�nsterland, in dry dock at Cherbourg. As many as 12 Whirlwinds participated at a time in dive bombing attacks carried out from 12,000 to 5,000 ft using 250 lb bombs. The attacks were met by very heavy anti-aircraft fire, but virtually all bombs fell within 500 yards of the target. Only one Whirlwind was lost during the attacks.

Modifications

One Whirlwind (P6972) was tested as a night fighter in 1940 with No. 25 Squadron while the first prototype was tested with an armament configuration of 12 0.303 machine guns. Another Whirlwind had a single 37 mm cannon fitted.

Deactivation

The last Whirlwind mission to be flown by 137 Squadron occurred on 21 June 1943 when five Whirlwinds took off on a "rhubarb" attack against the German airfield at Poix. Pilot Officer Barclay (P6993) was unable to locate the target and instead bombed a supply train north of Rue. While returning, the starboard throttle jammed in the fully open position and the engine eventually lost power. PO Barclay made a forced landing in a field next to Manston, but the aircraft was a complete write-off - a sad farewell to the Whirlwind, though like in so many other crash landing in the type, the pilot walked away unhurt.

In December 1943, No. 263 Squadron, the first and last squadron to operate the Whirlwind, turned in their planes and converted to the Hawker Typhoon. On 1 January 1944, the type was officially declared obsolete. The remaining serviceable aircraft were transferred to No. 18 Maintenance Unit, while those undergoing repairs or overhaul were only allowed to be repaired if they were in near-flyable condition, an official letter forbidding aircraft needing repair to be worked on.

Evaluation

At low level, the aircraft was a devastating fighter-bomber, armed with both cannons and bombs, and it could hold its own with the Bf 109 at low level. The performance of the Peregrine engine fell off at altitude, so the Whirlwind was used almost exclusively at low level. Though the Peregrine is a much-maligned powerplant, in actuality it would prove more reliable than the troublesome Napier Sabre engine used in the Hawker Typhoon, the Whirlwind's successor.

In the ground-attack role the Whirlwind excelled, proving to be both an excellent bombing platform, and highly durable. The presence of a second engine meant that many seriously damaged aircraft were able to return from dangerous bombing missions over occupied France and Belgium with one engine knocked out, something that the Whirlwind's successor, the Hawker Typhoon, could not do.

The Whirlwind's four 20mm cannon were to prove extremely effective. From 1941 until 1943 the aircraft would become a frequent unwelcome sight over German airfields, marshaling yards, and locomotives. The Whirlwind was used to particularly good effect as a gun platform for destroying German supply trains. Pilots were often credited with several trains damaged or destroyed in a single mission. The aircraft was also very successful in hunting and destroying German E-boats which operated in the Channel.

The Whirlwind became distinguished for its survivability during crash landings and ground accidents. The placement of the wings and engines ahead of the cockpit allowed the aircraft to absorb a great deal of damage while the cockpit area remained largely intact. As a result, many pilots were able to walk away unhurt from aircraft that were totally written off, a rare occurrence in 1930s era aircraft.

All pilots who flew this aircraft enthused about it in the air. If the Whirlwind had a fault, it was its high approach and landing speed. Because of the low production level, based on the number of Peregrines available, no redesign of the wing was contemplated, although Westland did test the effectiveness of leading-edge slats to reduce speeds. When the slats were activated with such force that they were ripped off the wings, the slats were wired shut.

Philip J.R. Moyes notes in Aircraft in Profile 191: The Westland Whirlwind:

The basic feature of the Whirlwind was its concentration of firepower: its four closely-grouped heavy cannon in the nose had a rate of fire of 600 lb./minute - which, until the introduction of the Beaufighter, placed it ahead of any fighter in the world. Hand in hand with this dense firepower went a first-rate speed and climb performance, excellent manoeuvrability and a fighting view hitherto unsurpassed. The Whirlwind was, in its day, faster than the Spitfire down low and, with lighter lateral control, was considered to be one of the nicest "twins" ever built… From the flying viewpoint, the Whirlwind was considered magnificent.

The basic feature of the Whirlwind was its concentration of firepower: its four closely-grouped heavy cannon in the nose had a rate of fire of 600 lb./minute - which, until the introduction of the Beaufighter, placed it ahead of any fighter in the world. Hand in hand with this dense firepower went a first-rate speed and climb performance, excellent manoeuvrability and a fighting view hitherto unsurpassed. The Whirlwind was, in its day, faster than the Spitfire down low and, with lighter lateral control, was considered to be one of the nicest "twins" ever built… From the flying viewpoint, the Whirlwind was considered magnificent.

Bruce Robertson, in The Westland Whirlwind Described quotes a 263 Squadron pilot as saying, "It was regarded with absolute confidence and affection.”

The aircraft is well summed up by Francis K. Mason’s comments in Royal Air Force Fighters of World War Two, Vol. One:

Bearing in mind the relatively small number of Whirlwinds that reached the RAF, the type remained in combat service, virtually unmodified, for a remarkably long time…The Whirlwind, once mastered, certainly shouldered extensive responsibilities and the two squadrons were called upon to attack enemy targets from one end of the Channel to the other, by day and night, moving from airfield to airfield within southern England.

Bearing in mind the relatively small number of Whirlwinds that reached the RAF, the type remained in combat service, virtually unmodified, for a remarkably long time…The Whirlwind, once mastered, certainly shouldered extensive responsibilities and the two squadrons were called upon to attack enemy targets from one end of the Channel to the other, by day and night, moving from airfield to airfield within southern England.

The last words on the subject were perhaps best stated by Dr. G. Buckwell who, as a young Sergeant Pilot with 263 Squadron, was shot down in a Whirlwind over Cherbourg. "The Whirlwind was great to fly - we were a privileged few":

In retrospect the lesson of the Whirlwind is clear… A radical aircraft requires either prolonged development or widespread service to exploit its concept and eliminate its weaknesses, Too often in World War II such aircraft suffered accelerated development or limited service, with the result that teething difficulties came to be regarded as permanent limitations.

In retrospect the lesson of the Whirlwind is clear… A radical aircraft requires either prolonged development or widespread service to exploit its concept and eliminate its weaknesses, Too often in World War II such aircraft suffered accelerated development or limited service, with the result that teething difficulties came to be regarded as permanent limitations.

Variants

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. Whirlwind I Single-seat twin-engine fighter aircraft, 400 ordered, 114 built Whirlwind IA Single-seat twin-engine fighter-bomber aircraft, fitted with underwing bomb racks. At least 67 conversions made from the original Mk I fighter.

Operators

United Kingdom

Royal Air Force
No. 25 Squadron RAF tested three aircraft between May and July 1940. Squadron's "ZK" code letters; it has not been confirmed if code letters were painted on the aircraft, or not. Three aircraft were passed on to No. 263 Squadron which was just being equipped with them.
No. 263 Squadron RAF operated Whirlwinds between July 1940 and December 1943. Aircraft had applied Squadron's "HE" code letters.
No. 137 Squadron RAF operated Whirlwinds between September 1941 and June 1943. Aircraft had applied Squadron's "SF" code letters.

US Navy, one aircraft was sent to the USA for trials in June 1942 and survived there until at least late 1944.

Survivors

With the end of production in January 1942, the Whirlwind became another "also-ran." Today none exist, as surviving airframes were scrapped at 5MU - RAF Kemble.
The last surviving Whirlwind was P7048, which had been damaged in May 1943 and returned to the Westland works at Yeovil for repair. After it was repaired it remained the only serviceable Whirlwind, and the only one to survive the Second World War. The aircraft was eventually civil registered postwar as G-AGOI and used as a company hack for a short time before being scrapped in 1947.
In October 1979, the remains of Whirlwind P6966, the first Whirlwind to be lost, were recovered near Grangemouth by enthusiasts in a dig group. The two Peregrine engines were recovered, as well as many pieces of the airframe.
Plans for a 2/3 scale replica were marketed for home building in the late 1970s and early 1980s as the Butterworth Westland Whirlwind.
In 2003, UK aircraft restorer Tony King announced that he would lead a group to build a Westland Whirlwind replica from scratch. Built in aluminium throughout, the full-scale replica was intended to taxi under its own power. Since the project announcement, further work appears to be stymied.

Specifications (Whirlwind)

Data from

General characteristics

Crew: One pilot
Length: 32 ft 3 in (9.83 m)
Wingspan: 45 ft 0 in (13.72 m)
Height: 11 ft 7 in (3.53 m)
Wing area: 250 ft� (23 m�)
Empty weight: 8,310 lb (3,770 kg)
Loaded weight: 10,356 lb (4,697 kg)
Max takeoff weight: 11,410 lb (5,175 kg)
Powerplant: 2x� Rolls-Royce Peregrine I Liquid-cooled V-12, 885 hp (660 kW) each

Performance

Maximum speed: 360 mph (560 km/h)
Range: 808 miles (1,300 km)
Service ceiling: 30,315 ft (9,240 m)
Rate of climb: 1.550 ft/min (474 m/min)
Wing loading: 41 lb/ft� (204 kg/m�)
Power/mass: 0.17 hp/lb (0.28 kW/kg)

Armament

Guns: 4x Hispano 20 mm cannons with 60 rounds per gun
Bombs: 2x 250 lb (115 kg) or 500 lb (230 kg) bombs

Related development

Westland Welkin

Comparable aircraft

de Havilland Mosquito
de Havilland Hornet
Focke-Wulf Fw 187
Focke-Wulf Ta 154
Gloster F.9/37
Fokker G.1
XF5F Skyrocket

Related lists

List of aircraft of the RAF

Bibliography

Bingham, Victor. Whirlwind, The Westland Whirlwind Fighter. Shrewsbury, UK: Airlife Publishing Ltd., 1987. ISBN 1-85310-004-8.
Crawford, Alex and Phil H. Listemann. "Westland Whirlwind Mk.I." (Allied Wings No.4). London: Casemate Pub & Book Dist Llc, 2008. ISBN 2-9526381-8-7.
Green, William, ed. "Foremost with Four Cannon." Flying Review International', Volume 19, No. 7, April 1964.
Green, William. Warplanes of the Second World War, Fighters, Vol. 2. London: Macdonald, 1961.
Green, William and Gordon Swanborough. WW2 Aircraft Fact Files - RAF Fighters, Part 3. London: Jane's, 1981. ISBN 0-7106-0119-0.
Hall, Alan W. Westland Whirlwind F.Mk.I (Warpaint Series no.54). Luton, Berfordshire, UK: Warpaint Books, 2006. No ISBN.
James, Derek N. "From High Hopes to Low Level" (Database). Aeroplane, May 2006.
James, Derek N. Westland (Images of England). Gloucestershire, UK: Tempus Publishing Ltd., 1997. ISBN 0-7524-0799-6.
James, Derek N. Westland: A History. Gloucestershire, UK: Tempus Publishing Ltd., 2002. ISBN 0-7524-2772-5.
James, Derek N. Westland Aircraft since 1915. Annapolis, Maryland: Naval Institute Press, 1991. ISBN 1-55750-921-2.
James, Derek N. "Westland's Double Trouble" (Database). Aeroplane, May 2006.
Mason, Francis K. Royal Air Force Fighters of World War Two, Volume One. Windsor, Berkshire, UK: Hylton Lacy Publishers Ltd., 1969.
Mondey, David. Westland (Planemakers 2). London: Jane's Publishing Company, 1982. ISBN 0-7106-0134-4.
Morgan, Eric B. "Westland P.9 Whirlwind." Twentyfirst Profile, Vol.2, No.14. New Milton, Hertfordshire, UK: 21st Profile Ltd., ISBN 0-961-8120-11.
Moyes, Philip J.R. Westland Whirlwind (Profile No. 191). London: Profile Publications, 1967.
Ovcx�cx�k, Michal and Karel Susa. Westland Whirlwind: Mk.I Fighter, Mk.I fighter-bomber. Prague, Czech Republic: Mark 1 Ltd., 2002. ISBN 80-902559-6-5.
Robertson, Bruce. Westland Whirlwind Described. Dandenong, Victoria, Australia: Kookaburra Technical Publications, 1970. ISBN 085-88000-4-7.
Taylor, John W.R. "Westland Whirlwind" Combat Aircraft of the World from 1909 to the present. New York: G.P. Putnam's Sons, 1969. ISBN 0-425-03633-2.

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