The Battle of Britain (10 page)

Both Spitfire and Hurricane had been conceived at a time when ‘fighter' meant, to the RAF, a single-seat, fixed undercarriage biplane with an armament of four 0.303in machine guns and no greater concession to fighting efficiency than an enclosed cockpit for the pilot. Advances in aerodynamics, aero engineering and power plant development in the mid-'thirties, however, opened up the possibility of major improvements in performance and combat ability – improvements that were quickly seized
upon by Reginald Mitchell and Sydney Camm in their positions as chief designers, respectively, of Supermarine and Hawker Aircraft.

Often going beyond the Air Ministry's ‘official' requirements as set out in a succession of Specification documents in the early 'thirties, Mitchell and Camm both produced low-wing monoplanes with enclosed cockpits, retractable undercarriages and eight-gun armament, powered by the then new Rolls-Royce Merlin liquid-cooled in-line engine, In design terms, the Hurricane was a little older than the Spitfire, and later in the war it would prove less amenable to development. What mattered in 1940, though, was the fact that it was available in useful numbers, was easy to fly, rugged and able to sustain considerable damage and still return to base. Slower in the climb and in level speed than the nimble Spitfire, the Hurricane was well suited to the task of intercepting the relatively slow bomber formations, leaving the Spitfires to deal with the escorting fighters. This division of roles also helped to account for the greater success of the Hurricane in kill-to-loss ratio during the Battle.

Design of the Hurricane had begun in 1934, and its first flight had been made, from Hawker's establishment within the confines of the historic Brooklands motor racing circuit at Weybridge in Surrey, on November 6, 1935. Sydney Camm's design team at nearby Kingston upon Thames already had long experience of fighter design for the RAF, and drew heavily upon this experience to produce what was at first seen as a ‘Monoplane Fury' – the Fury being the elegant biplane that still epitomised the equipment of Fighter Command upon its formation within the RAF in July 1936. Such advanced features as an enclosed cockpit and retractable undercarriage were combined with traditional methods of construction using a tubular metal structure and fabric covering, that meant that the Hurricane could be easily and rapidly produced in existing facilities – an advantage not enjoyed by the Spitfire with its advanceds stressed-skin construction and complex shapes.

In February 1936, the prototype Hurricane (as yet unnamed), powered by an early Merlin C producing 990hp and driving a Watts fixed-pitch two-bladed wooden propeller, was tested at the Aircraft and Armament Experimental Establishment (A & AEE) at Martlesham Heath, giving Service pilots their first opportunity to experience the improvements in performance and handling that were to become available. At a weight of
5,672lb (2,572kg), the prototype demonstrated a speed of 315mph (506km/h) at the Merlin's rated altitude of 16,200ft (4,937m) with 6lb/sq in boost. After taking off into a 5mph (8km/h) wind with a run of 795ft (242m) to reach the 81mph (130km/h) lift-off speed, the Hurricane climbed to 15,000ft (4,570m) in 57 minutes and to 20,000ft (6,100m) in 8.4 min. Service ceiling was 34,500ft (10,515m) and the estimated absolute ceiling was 35,400ft (10,800m).

Convinced that the RAF would buy the new fighter in the prevailing mood of rearmament, the Hawker company decided, in March 1936, to proceed with the production drawings and to make plans for large scale production. Three months later, that action was vindicated when the Air Ministry confirmed Hurricanes were to be included in its expansion Plan F (which also provided for 300 Spitfires). By the time the Battle of Britain began, every single fighter in the hands of the RAF counted, and the early launch of Hurricane production had helped to ensure that just enough machines were in fact available to Fighter Command.

Even so, meeting the RAF's rapidly expanding needs proved to be no simple matter and the Plan F target of 600 Hurricanes to be delivered by March 1939 was missed by some six months. There had been a succession of relatively minor but time-consuming problems with prototype development, especially related to the Merlin and the early intention to fit the Merlin F (Mk I) in the production Hurricane was changed to make use of the improved Merlin G (Mk II) – which required a redesign of the installation and the front fuselage profile before production could begin. The cockpit canopy also produced its share of problems, with five failures recorded on the prototype before a satisfactory design was evolved.

The first production Hurricane I flew at Brooklands on October 12, 1937, fitted with an early example of the Merlin II and at a weight of 5,459lb (2,476kg). The second aircraft was in the air six days later, and production deliveries then built up rapidly. Meanwhile, during 1936, the prototype had been fitted with the planned armament of eight Browning machine guns and first firing trials had been made. Design of a metal-covered wing was in hand, but to avoid production delays the Hurricane I retained the fabric-covered wing, in which the guns were grouped in two quartets, positioned to fire just outside the propeller disc and therefore requiring no complicated synchronisation gear. Each gun was provided with 300 rounds, and the two batteries of guns were harmonised to
converge at 650 yards (594m) – although with experience this distance was to be reduced eventually to 200 yards (183m).

Service use of the Hurricane began with No. 111 Squadron at Northolt, which was fully equipped by February 1938. By July 1939, 12 regular squadrons were flying the Hurricane I, to be followed by six Auxiliary Air Force squadrons, converting to the fighter role from bomber or army cooperation in which the AAF had previously operated. Powered by the Merlin II and still using the two-bladed fixed-pitch wooden propeller, the standard Hurricane I in 1938 had a tare weight of 4,732lb (2,146kg) and a normal loaded weight of 6,056lb (2,747kg) when carrying full ammunition and 77.5 Imp gal (352 1) of fuel. This gave a range of 340 miles (547km) at 275mph (442km/h) at 15,000ft (4,575m), but with full tankage of 97 Imp gal (441 1), the max take-off weight was 6,202lb (2,813kg) and the range increased to 680 miles (1,094km), with an endurance of 4.2 hrs, at the economical cruising speed of 162mph (261km/h). Max speed was 312mph (502km/h), the time to 15,000ft (4,575m) was 7 min and service ceiling was 33,000ft (10,058m). The take-off distance to clear 50ft (15.2m) was 1,800ft (549m) at normal weight and 1,890ft (576m) at max weight.

A second major version of the Hurricane would make its first flight on June 11, 1940 and, as the Hurricane IIA, would begin to reach the squadrons on September 4, 1940, just too late to figure effectively in the Battle of Britain itself. Thus, those squadrons engaged throughout August and most of September were still mounted on the Hurricane I, albeit somewhat improved by comparison with the 1938 delivery standard. An armoured bulkhead had been introduced forward of the cockpit and, when Hawker Aircraft's second production batch began leaving the assembly line in September 1939, a bullet-proof windscreen had been standardised. This batch also adopted the Merlin III engine which featured a shaft capable of taking either a Rotol or de Havilland three-bladed constant-speed propeller. While some Hurricanes were produced during 1939 with the DH two-position propeller, a major conversion programme was started on June 24, 1940 to fit the Rotol constant-speed unit which allowed the pilot to select optimum engine power for the various stages of flight. Significantly improving the Hurricane I's climb performance, Rotol propellers had been fitted to all Hurricanes by mid-August 1940. With the 81st Hurricane of the second batch, the fabric-covered wing finally gave place to an all-metal stressed-skin wing and, on
February 2, 1940 the first Hurricane with rear armour protection for the pilot was flown.

Before battle was joined, the fact that the Hurricane was inferior in most performance respects to its principal German opponent, the Messerschmitt Bf 109E, had been accepted. The Bf 109E was faster at all altitudes, and could out-climb and out-dive the Hurricane with ease. Thus, if the German pilot elected to break off the engagement, the pilot of the Hurricane was powerless to pursue his erstwhile opponent. But in low-altitude manoeuvrability and turning circle at all altitudes the Hurricane had the upper hand and, provided the Bf 109E did not join combat with an altitude advantage, the Hurricane was its match. Apart from its performance inferiority, the Hawker fighter was not found wanting, and its sturdier structure enabled it to withstand battle damage that would have rendered its antagonist
hors de combat
.

The Hurricane's admitted shortcomings in performance compared with that of the Bf 109E led to it being allocated the primary task of dealing with the Luftwaffe bomber formations – which seldom operated much above 16,000 - 17,000ft (4,877 - 5,181m) – leaving the faster-climbing Spitfires to keep the escorting Bf 109Es occupied. In the heat of battle it rarely proved possible to co-ordinate the attacks of both Hurricane and Spitfire formations in such an optimum fashion, however, and all too frequently Hurricanes intercepting a bomber formation were attacked from above by escorting Bf 109Es.

By the end of 1939, the RAF had received more than 600 Hurricane Is and production was at the rate of 100 a month – a figure that had been more than doubled by the middle of 1940. Losses had been suffered in France, totalling almost 300 machines and many of the RAF's most experienced pilots, but the massive production effort – in which Gloster joined with Hawker, flying its first Hurricane I at Hucclecote on October 20, 1939 – and the herculean task of repairing those aircraft damaged during the Battle of Britain itself ensured that ‘the Few' did not run out of fighters in 1940. By the end of the Battle, some 1,700 Hurricanes had served with Fighter Command, and 696 had been lost to the Service, either permanently or temporarily, in the two months of fighting.

Had the Battle continued longer, the Hurricane IIA would have been able to reduce substantially the margin of performance superiority enjoyed by the Bf 109E. With a l,260hp Merlin XX engine, this mark could reach 20,000ft (6,095m) in 8.2 minutes and had a maximum speed of 342mph
(550km/h) at 22,000ft (6.705m). Soon to have the benefit of heavier firepower – either 12 machine guns or four cannon – the Hurricane IIs would continue to do battle with the Luftwaffe, by night as well as day, in the months that followed the Battle of Britain itself.

Like the Hawker team, the design staff of the Supermarine Aviation subsidiary of Vickers (Aviation) Ltd had become interested in the early 'thirties in the RAF's need for a new fighter, and by 1934 was actively engaged in the design of an ‘experimental high-speed single-seat fighter'. Known as Design 300, this was conceived by the team led by R. J. Mitchell and based more on experience of high-speed flight obtained through the design of the Schneider Trophy-winning seaplanes than upon familiarity with fighter design. Ordered by the Air Ministry as a single prototype in December 1934, the Supermarine 300 – forerunner of the Spitfire – owed more to the instinctive creativity of a brilliant designer than to the intelligent application of experience, as exemplified by the Hurricane.

Be that as it may, the result was an aircraft that was of similar configuration to the Hurricane, similarly powered and armed and first flown some six months after the Hawker prototype, on March 5, 1936, at East-leigh near Southampton. If the Hurricane was a reliable workhorse – albeit a thoroughbred – the Spitfire was a ballerina, an impression fostered by the powder-blue finish adopted for the prototype and enhanced by the frail, narrow-track undercarriage. Outnumbered by the Hawker fighter in the Battle of Britain, the Spitfire was destined to outproduce, outfly and outlast the Hurricane. But it was in 1940 that (in the words of test pilot Jeffrey Quill) ‘the little Spitfire somehow captured the imagination of the British people at a time of near despair, becoming a symbol of defiance and of victory in what seemed a desperate and almost hopeless situation'.

The Spitfire prototype went to the A & AEE in July 1936, at which time it had a Merlin C driving a de Havilland fixed-pitch two-bladed wooden propeller. It was tested at a weight of 5,322lb (2,418kg), and was found to have a speed of 349mph (561km/h) at 16,800ft (5,120m) and 324mph (521km/h) at 30,000ft (9,145m). It took 17 minutes to reach the latter altitude and 5 min 42 sec to get to 18,000ft (5,485m), and had a service ceiling of 35,000ft (10,670m). The performance edge over the Hurricane was thus already evident, and handling was good, too, the
Service pilots at the A & AEE reporting that the prototype was ‘simple and easy to fly and had no vices'. It had well harmonised controls, which appeared to give an excellent compromise between manoeuvrability and steadiness for shooting. The report concluded that the Spitfire (as the Supermarine 300 was to be named before it entered service) could be ‘flown without risk by the average fully trained service fighter pilot'.

One of its most endearing qualities, evident from the prototype onwards, was its extremely docile behaviour at the stall, particularly under conditions of high
g
. On the debit side, longitudinal stability was a matter of some concern from the start, and called for a constant development effort as later marks were introduced. Of more concern during the period of the Battle of Britain were the high lateral stick forces encountered at the upper end of the speed range, and not overcome until modified ailerons were introduced in 1941.

In accordance with the provision of Expansion Plan F, the Air Ministry ordered 310 Spitfire Is on June 3, 1936 defining a standard of aircraft that was generally similar to the prototype. Powered, like the contemporary version of the Hurricane, by a l,030hp Merlin II, the first production aircraft flew on May 14, 1938, at Eastleigh, where the final assembly line was fed by the manufacturing centres at Woolston and Itchen, near Southampton.