The Battle of Britain (11 page)

Like Hawker, Supemarine failed by some six months to meet the Plan F target of delivery completion by March 1939. The problem was that the Spitfire, which was of all-metal stressed-skin construction, was not a simple aeroplane to build, the wing leading-edge being especially diffficult. As time went by, and in particular after the Supermarine works in Southampton had been heavily bombed in September 1940, Spitfire production would be dispersed widely over southern England and would bring 65 different manufacturing units into play.

That development was still well in the future in August 1938, however, when No. 19 Squadron at RAF Duxford received two early production Spitfires and began a 400-hour intensive flying trial. Two more squadrons received Spitfires in 1938 and, by September 1939, another four Regular units were flying the Supermarine fighter, and four AAF squadrons were equipped or equipping.

Like the early Hurricanes, the first Spitfires off the assembly line had the Merlin II engine driving a two-bladed fixed-pitch wooden airscrew. They attained 352mph (566km/h) at 19,000ft (5,790m) a maximum
climb rate of 2,420ft/min (737m/min), and an altitude of 20,000ft (6,100m) in 9.4 minutes. With the 78th production aircraft, the wooden two-blader gave place to a de Havilland Hamilton two-pitch three-bladed metal propeller which, although incurring a weight penalty and having only a marginal effect on level speed, bestowed a significant improvement in the climb. No bullet-proof windscreen or armour was initially fitted, and although standard armament was envisaged as eight wing-mounted 0.303in Browning guns each with 300 rounds of ammunition, a shortage of these weapons led to the installation of only four guns each in early machines. Later, the introduction of a bullet-proof external windscreen was to be followed by provision of a 6mm armour plate behind the pilot's head. After pilots on the first squadron had complained that they banged their heads on the flat roof of the cockpit canopy, a ‘humped' canopy was introduced, giving the Spitfire its characteristic profile.

With the DH two-position propeller, the Spitfire I had a tare weight of 4,517lb (2,049kg) and operated at a normal loaded weight of 5,844lb (2,651kg). It had a maximum speed of 346mph (557km/h) and cruised at 304mph (489km/h) at 15,000ft (4,570m). The time to that altitude was 6.85 min and service ceiling was 30,500ft (9,300m). From a standing start, it reached 50ft (15m) above the ground in a distance of 1,605ft (489m), but required almost 300ft (91m) more than this distance to come to a stop, from the same altitude. The normal range of 415 miles (668km) included a 15-min allowance for take-off and climb, and could be extended to more than 600 miles (965km) by reducing the cruising speed to 175mph (282km/h).

Like the Hurricane, the Spitfire I benefited considerably from the installation of a variable-pitch constant speed propeller, to permit which a switch was made to the Merlin III with effect from the 175th aircraft. A massive effort between June and August 1940 ensured that all the Spitfire Is then in service were fitted with the DH constant speed unit and this became standard on the later production Spitfire Is.

Evaluation of a Bf 109E-3 captured in France had already revealed that the German fighter was superior in a number of respects to the Spitfire I when originally fitted with the two-position propeller. The Messerschmitt fighter was marginally faster than its British contemporary at most altitudes, and it could out-climb the Spitfire up to 20,000ft (6,070m), above which height the British fighter enjoyed an edge, Both fighters suffered some aileron heaviness at the upper end of their speed scale. While the
Spitfire possessed superior manoeuvrability at all altitudes as a result of its lower wing loading, its turning circle being appreciably smaller, the Bf 109E could always elude the Spitfire in a dive, the float carburettor of the British fighter's Merlin engine placing it at a distinct disadvantage in this situation.

During 1939, single examples of the Spitfire I and the Hurricane I had each been fitted with a pair of 20mm cannon, with 60 rounds per gun. The Hurricane, with Oerlikon guns, was credited with destruction of a Dornier 17 on August 13, 1940, while undergoing evaluation with No. 151 Squadron, but the large-scale application of cannon armament to the Hawker fighter had to await the production of the Mk IIC, with four of the 20mm weapons apiece. The Hispano guns fitted in the Spitfire proved prone to stoppages but, after trials with the prototype installation, a batch of 30 Mk Is was similarly fitted and – with four 0.303in Brownings later added to the wing armament – were delivered from June 1940 for use by No. 19 Squadron. They were the only cannon-armed fighters operated by the RAF during the Battle of Britain. These Spitfires were designated Mk IBs, and those with the original eight-gun armament then became, retrospectively, Mk IA.

Also paralleling Hurricane development, a Mk II version of the Spitfire emerged during the course of the Battle, but reached the squadrons too late to have a decisive effect. The Spitfire IIA retained the eight-gun armament of its predecessor but introduced a l,175hp Merlin XII engine which drove a Rotol constant-speed airscrew. Whereas the Spitfire IA had its armour added in service, the IIA left the factory with armour installed. The Spitfire IIA attained a maximum speed of 357mph (574km/h) at 17,000ft (5,180m), could reach an altitude of 20,000ft (6,070m) within seven minutes of unstick and had a maximum climb rate of 2,620ft/min (798m/min). The first two squadrons converted to fly Spitfire IIs in September 1940.

Once RAF Fighter Command had discarded its outdated tactics, of which the Luftwaffe's Bf 109E fighters took full advantage during the opening phases of the Battle, the Spitfire and its German opposite number proved remarkably evenly matched. Each possessed some characteristics superior to those of its opponent and, all things being equal, the outcome of a combat depended largely on the prowess of the pilots involved.

The production difficulties with early Spitfires were shown by comparative figures for mid-1940, when the rate was still averaging only 80 a
month compared with 236 a month for the Hurricane. It would be early 1942 before the monthly output of Spitfires exceeded that of Hurricanes, and the slow build-up of production in 1938/39, combined with losses suffered by Fighter Command during the fighting over France (despite Dowding's insistence that the precious Spitfires should not be deployed with either the AASF or the Air Component of the BEF) meant that the line was drawn exceedingly thin in August 1940.

Although outnumbered by Hurricanes in the ratio of three to two throughout the summer of 1940, the Spitfires of Fighter Command inflicted more than half the total losses suffered by the Luftwaffe in the assault on Britain – a statistic that underlines the Supermarine fighter's particular merit in air-to-air fighting. By the very nature of the conflict, the Luftwaffe's losses in single-seat fighters were appreciably lower than those of the RAF, however, and the Spitfire squadrons alone lost 118 fighters in combat during August, a further 55 being damaged. Adding to those lost or damaged in accidents or by enemy bombing, 237 Spitfires were deleted from the inventory during that month alone and total output of the factories engaged in Spitfire production amounted to only 163 machines. Attrition in September was even more serious, 156 being manufactured and 281 being lost to strength, of which 130 were destroyed and 80 damaged in combat. In the week ending September 13, the reserves reached their lowest ebb, with only 47 Spitfires ready for delivery in storage units.

What the outcome of the Battle of Britain would have been had the Spitfire not been available is now purely of academic interest, but what is certain is the fact that no combat aircraft ever gave better service to the country of its birth. Sadly, the same cannot be said of the Boulton Paul Defiant, the operational record of which as a day fighter can only be described as disastrous.

The concept of a two-seat single-engined fighter with all of its armament concentrated in a massive power-operated turret was based in the belief that a gunner with no responsibility for flying the aircraft and able to traverse his battery of guns through 360 degrees had more chance of hitting the enemy than a pilot who had to point his aircraft in the direction in which he wished to fire. Not properly appreciated by those who fostered this concept was the way that it divided responsibility between
pilot and gunner, and required the pilot not only to fly the aircraft, but also to think in abstract terms of his gunner's line of sight. All too easily, it would transpire, enemy fighters could creep in under cover of the blind spot beneath the tail and deliver a
coup de grace
.

Designed to an Air Ministry Specification under the direction of J. D. North, the P.82, as the Defiant was at first designated, was an aircraft generally similar in overall size to the Hurricane. Its all-metal structure was conventional in most respects, its only unusual feature being the method of attaching the light alloy skinning to the stringers and ribs and then attaching these to the fuselage frames and wing spars. This obviated the need to preform the skins and, by riveting them while flat and countersinking the rivets, an exceptional surface finish was obtained, helping to obviate the adverse effect on performance of the drag of the bulky dorsal turret.

The first prototype made its inaugural flight at Wolverhampton on August 11, 1937, and attained 302mph (486km/h) on the power of its Merlin I engine. Its flying characteristics were pronounced excellent. It displayed very few vices, stability was highly satisfactory, and there was practically no change of trim when the undercarriage and flaps were lowered.

An initial contract for 87 Defiant Is was placed in March 1937, and 363 more were ordered in 1938. Production was delayed, as for the Hurricane also, by the decision to use the Merlin II rather than the Merlin I, and by the time the first production Defiant flew on July 30, 1939, it was powered, in fact, by a Merlin III, the version with a standardised shaft for DH or Rotol constant-speed propellers.

In its production form, the Defiant I had an empty weight of 6,078lb (2,757kg) and a normal loaded weight of 8,318lb (3,773kg). At that weight, the maximum speed was 250mph (402km/h) at sea level and 304mph (489km/h) at 17,000ft (5,180m), the cruising speed being 259mph (417km/h) at 15,000ft (4,572m). Initial rate of climb was l,900ft/min (579m/min), the time to 15,750ft (4,800m) was 8.5 min and the service ceiling was 30,350ft (9,250m). A range of 465 miles (748km) was achieved at the quoted cruising speed.

Installed in the Defiant I as a removable, self-contained unit, the Boulton Paul A Mk IID turret mounted four 0.303in belt-fed Brownings each with 600 rounds, and its hydraulic system formed an integral part of the turret itself. The bare turret weighed 361lb (164kg), to which was
added the 88lb (40kg) of the four guns, 106lb (48kg) for ammunition, and some 35lb (16kg) for the gunner's oxygen equipment, sights, etc. Normal loaded weight at 8,318lb (3,773kg) was some 1,700lb (771kg) more than that of the similarly powered Hurricane, yet the gross wing area of the two-seater was less than that of the single-seater. It was hardly to be expected, therefore, that the Defiant would be able to compete on the score of level speed, climb rate or manoeuvrability.

This was soon borne out by comparative trials between a Defiant and a Hurricane conducted by No. 111 Squadron in October 1939, but the RAF now had a desperate need for fighters, the Defiant was just coming ‘on stream' and there could be no going back. That same month, No. 264 Squadron formed at Sutton Bridge to be the first to fly the Defiant, with which it became operational at Martlesham Heath in 1940. Early operational results were, at best, mixed, although there were claims of remarkable successes in the last weeks of May 1940 during patrols over Dunkirk, when the Defiants were probably mistaken for Hurricanes by Luftwaffe fighter pilots who tried to attack from above and behind – a fatal error.

Even so, the operations over France took a heavy toll of No. 264 Squadron and it was back to strength only just in time for the Battle of Britain, alongside No. 141, which had formed in June as the second squadron to fly Defiants. The latter had a disastrous first engagement with Bf 109Es south of Folkestone on July 19, losing two aircraft in the first firing pass by the Luftwaffe fighters and four more when the enemy made a second attack from below and dead astern – revealing that the Defiant's fatal weakness had been taken to heart. Thrown into battle at the end of August, No. 264 Squadron suffered a similar fate, being left with only three serviceable Defiants within a week. Both squadrons were then withdrawn from further action in the Battle, leaving the Defiant to find its forte in nocturnal operations, which it would soon be called upon to fulfil.

Night operations were also to prove to be the most suitable for the Bristol Blenheim IFs that equipped six squadrons of Fighter Command in mid-1940. The Blenheim had been designed, under the direction of Frank Barnwell, to provide the RAF with a high-speed light bomber, and a version had then been produced to provide the RAF with a replacement for the Hawker Demon turret fighter. The concept of a twin-engined
multi-seat long-range fighter was to prove as flawed as that which produced the Defiant.

The first all-metal cantilever monoplane of stressed-skin construction to enter production for the RAF, the Blenheim marked the beginning of a new era in the equipment of the service after several years of acute uneasiness concerning the obsolescence of the RAF's operational aircraft inventory. It was a cornerstone of the expansion programme, and its conversion from three-seat light bomber to heavy fighter in 1938 was prompted by what was considered, by the standards of the day, a fully adequate performance coupled with sturdiness and excellent handling characteristics.

Credited, at the time of its service introduction, with a performance that would allow it to outpace most contemporary service aircraft in all categories, the Blenheim was to be revealed wanting early in the conflict. As a bomber it proved woefully vulnerable to fighter attack, being deficient in both defensive armament and armour, and it lacked the performance necessary for a fully effective strategic fighter.