Aircraft of the Royal Air Force
Boulton Paul Defiant
There is, without a doubt, that the Supermarine Spitfire was one of the most famous of all World War Two aircraft. It was glamorized by the media, and children young and old would look up towards the skies watching a dogfight or see a squadron of RAF fighters come swarming in towards a formation of German bombers. They would hardly know one aircraft from another, but they would all include a Spitfire in their exclamations. "It's a Spitfire" or "D'yer see that Spitfire shoot that bomber down, weeeeeooooooow".
But the Spitfire that we knew at the end of the war was far different from the version that flew in the Battle of Britain and even to that of pre 1939 Spitfires. At wars end, the Supermarine Spitfire was a streamlined fighting machine, it was the mainstay of Fighter Command, but let us not take anything away from the Hurricane which in itself was a superb aircraft.
Supermarine gained their experience in fast and manoeuvrable aircraft with experience gained in winning the Schneider Trophy Air Races. But the concept of the Spitfire really began way back in 1930 when Supermarine submitted their design (Westland and Blackburn Aircraft Companies also submitted designs) in relation for the construction of an all metal type fighter aircraft that would have a fabric covered wing area as well as tailplane sections. This was to comply with specification F.7/30.
The wings were of gull wing design, the fixed undercarriage had streamlined fairings over the wheels, and it was powered by a single Rolls Royce Goshawk engine which provided just 600 horsepower giving the Type 224 a top speed of only 228 miles per hour (367 kph). Armament was two .303 guns in the fuselage and one in each of the wheel fairings. The 224 first took to the air on 19th February 1934, and because of its poor performance it failed to be accepted as a potential fighter aircraft. Supermarine had great plans for the Type 224, but because of its failure in every department, the company had to do something quick to be able to prove to the authorities that they were capable of producing a good hard working fighter aircraft.
THE TYPE 300 - SPITFIRE MK I - SPITFIRE
MK II - SPITFIRE MK III
Supermarine had for some time enjoyed success in aircraft design and with many aircraft bearing similarities to the Schneider successes including the 224, something different had to be designed. Sydney Camm was now in the process of designing the Hurricane at Hawker's works at Weybridge. Naturally Supermarine knew of this and it soon became apparent as to the design and the potential of the Hurricane.
Reginald Mitchell set about in designing a completely new type of aircraft. They stayed with the required specifications as called by F.7/30 in producing a metal bodied cantilever type fighter aircraft. Mitchell decided that the wings should be metal as well as the fuselage believing that fabric covered wings on an aircraft with a metal body at high speed would provide the aircraft with weak spots. The cockpit of the aircraft was enclosed and formed part of the design lines of the body, while the narrow undercarriage was retractable with the wheel being lifted into wheel wells under the wings.
The design was a streamlined, yet strong, an aircraft that had all areas that would cause any form of resistance to wind removed. It was claimed, as the aircraft made its early test flights that not only did this Type 300 look exciting it was yet the most attractive aircraft ever designed.
By the end of 1934 the Type 300 was eventually ordered as a prototype, and further testing was done and it was put through a series of strenuous tests. By 1935, the aircraft with its Rolls Royce PV12 now glycol cooled engine (this engine was later to be known as the Merlin), and four .303 Browning machine guns in each wing gave a performance good, or maybe even better than expected.
The aircraft flew on official tests in March 1936, and by June of the same year, and by now the name Type 300 had been dropped and the name Spitfire had been officially adopted, the aircraft went into production as Spitfire Mk I. Already Rolls Royce had reworked the Merlin power unit and the Merlin II and III had the power output increased to 1,000 hp. The basic design was a 12 cylinder unit in V formation. The first Spitfire I's began flying on May 14th 1938 with the first of them going into service use by the RAF in August.
Spitfire Mk I's remained until June 1940, but until then, thirty of them had been equipped with twin 20mm cannons at the expense of the .303 Brownings. To distinguish the two, the Spitfire Mk I's equipped with machine guns were designated IA's, while those that had the cannons fitted were designated IB's. In all, 1,537 Spitfire Mk IA's were built and 30 Spitfire Mk IB's. The Spitfire IB's were not favoured with pilots, the cannons were often jamming leaving them a defenceless aircraft and pilots requested to be returned to the Spitfire IA's.
At the outbreak of the Second World War, the Mk I's were the mainstay of Fighter Command along with the Hurricane. When air support was needed in Norway and in France, Fighter Command sent only one squadron to Norway and ten to France. By this time Britain had lost some 500 fighters in this early part of the war. The Mk I Spitfire was to continue service throughout the Battle of Britain, and was a worthy opponent of its German equivalent, the Messerschmitt Me 109. But in August 1940, at the height of the battle, the Spitfire Mk I gave way to a faster and more powerful Mk II with its Merlin Mk XII power plant. Most of these MK II's were to arrive after the Battle of Britain, although some squadrons had been allocated them in late August and during September 1940. The first recorded Mk II being shot down was with 611 Squadron on September 11th 1940.
By now, the Supermarine Spitfire, with not only the specifications, but as further testing of the aircraft proved, was a fighter aircraft that was superior in every department to anything that was flying at the time. Sleek and swift, manoeuvrable, strong and well constructed.
The Merlin engine had received a power increase to 1,175 horsepower and was designated the Merlin XII. The differentiating versions of A's and B's continued and production of these totalled 751 Mk IIA's and 170 Mk IIB's.
The Spitfire Mk III, also introduced in 1940, but not allocated to operational service until 1941, while still cosmetically looking like a Spitfire, it had a greater improvement in airframe construction and also had a reduced wing span. Again, improvements had been made to the Merlin XII engine and was redesignated the Merlin XX, and the tail wheel was also made to retract into the fuselage. When it seemed that the Mk III was almost at its best, and in July 1940 it was intended to build 1,000 of them, but a slightly redesigned version, a prototype Mk V was under way and testing was being done on a four cannon arrangement. Because of this, the target of 1,000 Mk III's was never reached.
SPITFIRE MK V - SPITFIRE MK VI
Supermarine went back to the Mk I airframe for the prototype Mk V and installed a more potent Merlin 45 engine that although rated at 1,185 horsepower, its combat rating at 9,250 ft was actually 1,470 hp. The Merlin 45 engine was also installed into the Mk II airframe and in total 150 of these were made and became known as Mk V conversions. The designated Spitfire Mk V as well as boasting the 1,185hp Merlin 45 engine, had either eight .303 machine guns, four in each wing, these were Mk VA's and only 94 were built. The MK VB was equipped with four .303 machine guns, two in each wing and two 20mm cannons, and 3,911 of these were built. The Mk V also saw the introduction of the series "C", and the Spitfire MK VC had four cannons with four machine guns and these totalled 2,467 aircraft.
The first prototype MK V flew in December 1940 and MK VA's were placed in service almost immediately. The MK VB saw service in March 1941, (I have no record as to when the MK VC entered service).
Many versions of the MK V followed, depending as to which field of conflict the aircraft were assigned to. Some were assigned to low altitude flying and for this many of the MK VB's had their wing span reduced to 32 feet 2 inches and the Merlin 45 engine was replaced by the Merlin 45M, the Merlin 50M and the Merlin 55M, all of which performed better at low altitudes. These low altitude versions were designated LF MK VB's. Other versions included the medium altitude Mk's. These aircraft were designated F MK VA, F MK VB and F MK VC. The Merlin power plant was configured in a number of configurations and all these F series MK V's has either a Merlin 45, 46, 50, 50A or 56 engine installed. All these MK V's became successful fighter aircraft.
First deliveries of Spitfires with major changes took place in February 1942 when the Spitfire MK VI was introduced. The MK VI received the all new Merlin 47 engine that was rated at 1, 415 hp providing the aircraft with a top speed of 374 mph and the pilot cockpit was now pressurised. This MK VI also had an increase in wing span being increased to 40 feet 2 inches.
THE SPITFIRE AT SEA
The admiralty saw the potential of the Spitfire, and requested that a version be designed that could operate from its aircraft carriers. The request was granted and designs were made for a Sea Spitfire. As early as 1940, designs were being submitted based on the Spitfire MK I which would have an arrestor hook and folding wings so that it could be stored in aircraft carrier hangers below deck. But in 1940 there was a shortage of fighter aircraft during both the Battle of France and the Battle of Britain that supply of Spitfire Mk I's to the RAF took precedence over the Admiralty's request hence supply of Spitfires to the Navy did not commence until early 1942. The first Spitfire to fly with arrestor hook and folding wings did not take place until January 1942 when a modified MK VB made tests with the Navy. A further conversion took place that provided the aircraft with catapult spools and the undercarriage was given additional strengthening, and an A frame type of arrestor hook was incorporated.
It was not until about March 1942 that this naval version of the Spitfire was given the name of Seafire. The first conversion was known as the Seafire MK I and the second conversion was known as the Seafire MK II. The Royal Navy was supplied with 165 Seafire's during the early part of 1942 which were based on the Spitfire VB.
In June 1942, 375 Seafire MK IIC's were supplied to the Royal Navy. these where basically Spitfire MK VC's and given the same conversions as the MK II with the exception that the Merlin 32 engine drove a four bladed propeller which improved low altitude flying. In the November of 1942 a Seafire MK IIC was altered so that the wings could be folded for storage on aircraft carriers, this was to be a prototype for the proposed MK III. Manufacture of the Seafire MK III was given to both the Westland Aircraft Company and Cunliffe-Own Ltd, which now also boasted a powerful 1,470 hp Merlin 55. 1,263 of these MK III were made all being used by Britain's Navy by June 1943. Many of these MK III's also had the Merlin 55M engines that had increased horsepower to 1,585. Other than these aircraft, there were many more Spitfires and Seafires produced. Each one being produced for its own individual reason to that it would perform well to the task that it was designed for. These Models included:
Supermarine further developed the Seafire with types 45, 46 and 47. Fitted with the Rolls Royce Griffon 61 which produced 2,035hp giving the Seafire a top speed of 455 mph. The type 46 was fitted with an all round vision bubble canopy. Like the Spitfire, the Seafire had reached its peak and was the ultimate Seafire. It continued service with the Royal Navy finally curtailing its long career during the Korean War. One of the few aircraft that still bearing its original design saw service in two wars.
But the story of Spitfire does not end there. In 1942, under specification request F.1/43, another aircraft was designed based on similar lines to the Spitfire. The experience gained in the Spitfire's production was used in the new design of the Type 371. But because of Spitfire production, it was two years before 371 saw its first flight. At the commencement of production the aircraft was designated the Supermarine Spiteful. It used the same fuselage as the Spitfire, a longer nose to enclose the Griffon 61 engine with two stage supercharger, completely redesigned wings that were very unSpitfire, a bubble canopy and larger tail fin.
In January 1945, a second prototype included a five bladed propeller, slimmer fuselage and the Griffon 61 engine was replaced with the 2,375hp Griffon 69. Top speed of the Spiteful was a staggering 486 mph, and it would climb to 20,000 feet in just 4.9 minutes. Only about 20 were built with just 16 of them taking to the air. This was due to the fact that at the end of the war, the jet engine was making an impact in aircraft manufacture, and even Supermarine was busy designing its first jet aircraft the Attacker in 1944.
But in 1945, Supermarine was to have one last attempt at producing a piston engined propeller driven aircraft. This was the Seafang, a naval version of the Spiteful. Specifications were similar to the Spiteful with the exception that fittings that would make it destined for naval operations were included. After this, Supermarine was to enter the jet age and, Reginald Mitchells Spitfire will go down in the annals of modern history as one of the exciting and successful fighter aircraft of the Second World War.
Picture at top:
Spitfire IIA with the markings from 41 Squadron Hornchurch.
Christopher Sommerville Our War Weidenfeld & Nicolson 1998 p47