Supermarine Spitfire Prototype (K5054) - replica  [@ RAF Tangmere]

The legendary Supermarine Spitfire was designed by a team under the direction of the brilliant designer Reginald Mitchell and traced its ancestry to Supermarine’s racing floatplanes developed for the Schneider Trophy contest.

After the success of the “S” series, Mitchell’s team thought that designing a fighter to the Air Ministry specification F.7/30 would be a relatively simple affair.  The first attempt, the Type 224 design, was first flown in 1934 and its gull winged design was not a success, however, it should be considered a valuable stepping stone to the Type 300 that followed.  The design was also hampered by the evaporative cooling design of the 660 hp Rolls Royce Goshawk engine.  The F.7/30 fighter contract was eventually awarded to the Gloster Gladiator biplane because of its climb rate advantage over the monoplane designs.

Even before the type 224 was rejected for the F7/30 specification Mitchell had begun work on a new project, the type 300, which would become the Spitfire.  It was intended to use the Goshawk engine so again the design included a strong metal leading edge in front of the wing spar to act as the condensation tank for the steam cooling.  When the new Rolls Royce PV12 engine (later to become the Merlin) was substituted, the strong metal leading edge was retained because the Merlin was originally envisaged as having steam cooling like the Goshawk (albeit with a small back-up radiator).  After the first few Mk A and B Merlins used this composite cooling system the Mk C and all subsequent Merlins switched to an all-liquid system.  This used Ethelene Glycol, which transferred heat energy better than water, and hence meant the radiators could be made smaller.

The strong leading edge structure of the Spitfire's wing was no longer needed as a condenser tank, but it was retained.  Out of such fluke design evolutions was the classic Spitfire wing developed, the key to the aircraft's success.  The wing was extremely strong, having a central spar made up of hollow sections that slotted into each other.  The result was not unlike a leaf-spring, providing great resilience.  The metal leading edge "box" in front of the spar adding to this strength.  The wheels retracted outwards into the wing, meaning the undercarriage mechanism could be put in the thickest part of the wing, this kept the wing thin.  The undercarriage retracted into bays to the rear of the wing spar meaning the structural integrity of the spars leading edge "box" was not impaired.  As if this not enough the wings incorporated "wash-out" meaning the angle to the air flow was slightly greater near the fuselage than at the tip.  It meant the pilot got plenty of warning of a stall as the aircraft would start to "talk" to the pilot through feedback to the controls.  This is particularly important in combat as in a tight turn the aircraft needs to be kept just on the "edge" of stalling to get the minimum turning circle.  The Spitfire's wing turned out to be capable of withstanding very high "mach" numbers.  In fact the wing's performance at high speed was better than the wings designed for the early jet fighters ten years later!

Mitchell gave the type 300 a monocoque fuselage, which meant that the interior was unobstructed by bracing struts or wires.  This was in contrast to the Hawker Hurricane, which had a fuselage constructed like a fabric covered biplane.  The space inside the Spitfire was put to good use in photo reconnaissance Spitfires where large cameras were mounted behind the pilot pointing downwards and to the side.

The Spitfire prototype, with the serial number K5054, first flew from what is now Southampton airport at 4:35 pm on the 5^th March 1936 for an 8 minutes flight with Mutt Summers, Vickers chief test pilot, at the controls.  Upon landing he spoke the legendary Spitfire words "I don't want anything touched" - meaning it handled beautifully - no adjustments were needed.  In subsequent test flights and after slight modifications K5054 reached 348 mph in level flight and 380 mph in a dive, with Jeffery Quill at the controls.  On the strength of the first RAF test flight by the commander of RAF Martlesham’s A Flight, Humphrey Edwards-Jones, a contract for 310 planes was placed with Supermarine by the Air Ministry.  The total price of the contract was £1,395,000 or £4,500 per aircraft, excluding the engine, radio and guns.  The contract was for the planes were officially issued on the 3^rd June, just eight days after the RAF’s first flight.  In its summary of the flying qualities, the final report stated: - "The aeroplane is simple and easy to fly and has no vices.  All controls are entirely satisfactory for this type and no modification to them is required .  .  .  .  The controls are well harmonized and appear to give an excellent compromise between manoeuvrability and steadiness for shooting.  Take-off and landing are straight-forward and easy .  .  .  In general the handling of this aeroplane is such that it can be flown without risk by the average fully trained service fighter pilot."  The final cost of K5054 was about £20,765, with the Air Ministry and Rolls Royce paying £12,478 and £7,500 respectively, leaving Supermarine's final cost for building the Type 300 prototype Spitfire at around £787.  K5054 was further refined and modified to become the pattern for the successive II and III Spitfires.  Ironically K5054 was destroyed in an accident on the 4^th September 1939; a day after the declaration of was on Germany, at the Royal Aircraft Establishment at Farnborough.  The pilot, F/Lt White, died of his injuries.

There was no doubting that Mitchell had delivered a thoroughbred! It had required a superhuman effort, working not only the long hours and dealing with a multitude of technological problems but also fighting the pains and anxieties of cancer.  He lived long enough to see the prototype fly for he died on the 11^th June 1937, just 42 yrs old.

In 1983 Jeffrey Quill, the famous Spitfire test pilot, decided that the contribution to military aviation by Reginald Mitchell had never truly been recognised.  Accordingly, a group comprising Quill, Dr Gordon Mitchell (Mitchell's son) and members of the original design team joined forces with the Spitfire Society and decided to sponsor a full size replica of Spitfire prototype K5054 (the original having been destroyed in the late 1930s).  Fund-raising began and a partnership was forged with Aerofab Restorations of Andover who would construct the aircraft.  The result of these endeavours was unveiled at the RAF Tangmere museum in May 1993 when Quill was able to report that the replica is "99% the original prototype".  K5054 is on long-term loan from the Spitfire Society.

Supermarine Spitfire Mk Ia (K9942)  [@ RAF Cosford]

On the 4^th August 1938 Jeffery Quill,  delivered K9789 the first production Spitfire to 19 Squadron at RAF Duxford, a unit then equipped with the Gloster Gauntlet biplane, the predecessor of the Gloster Gladiator.  The first Gauntlet had been delivered to the RAF in February 1935, just three and a half years earlier.

Of the 1566 Spitfire Is that were built, K9942 is the oldest surviving example of its type, the 155^th aircraft off the production line and was delivered to 72 squadron on 24^th April 1939.  Flying Officer James Nicholson often flew the aircraft during its operational career with 72 Squadron; he was later awarded the only Fighter Command Victoria Cross.  The aircraft went on to serve with various OTU`s during the war years before being allocated for museum use on 28^th August 1944.  K9942 is now restored to its 1939 appearance when it was allotted to 72 Squadron.  72 Squadron was formed on the 2^nd of July 1917 at Upavon and was disbanded on the 22^nd of September 1919.  The Squadron was re-formed from a flight of 1 Squadron at RAF Tangmere on the 22^nd of February 1937 in Gloster Gladiators.  It was in the April of 1939 when they received their first Spitfire's.

Supermarine Spitfire Mk Ia (X4590)  [@ RAF Hendon]

Ordered from Supermarine on the 9^th June 1940 (an inspection in 1995 revealed that the port wing dated from the 11^th March 1938) and fitted with a Merlin III (photograph - right) engine, X4590 was delivered to 609 Squadron on the 8^th October 1940 and first flew on the 10^th October 1940.  X4590 claimed its first (half share) kill on the 21^st October 1940 when it downed a Ju 88 A5 (w/nr 8116, code 9K+BH of 1/KG51) that had been on a mission against the Gloster Aircraft Works at Brockworth, then busy producing Hurricanes.  During this period X4950 flew alongside Spitfire R6915 (see below).  Transferred to 66 Squadron on 24^th February, to 57 OTU on 7^th April 1941, to 303 (Polish) on 18^th July 1941, to 43 Groups' Disposal Account as surplus to requirements and then to 37 MU for storage on the 31^st October 1941.  On the 14^th February 1942 X4590 was allocated to 53 OUT and remained with the unit until 20^th March 1944.  During this period X4590 was involved in a number of flying related accidents and flew alongside Spitfre K9942 (see below).  Both aircraft were sent to 52 MU on the 28^th August 1944 to be packed for Museum purposes.  In September 1954 X4590 went on public display for the first time at Horseguards Parade, London, during Battle of Britain Week.  During the 1960s and the early 1970s X4590 and K994 were used for mobile display work but, unlike K9942, X4590 was not used in the making of the “Battle of Britain” film.  Formally transferred to the RAF museum collection on the 15^th November 1972, X4590 arrived at Hendon in 1978. 

Supermarine Spitfire Mk Ia (P9444)  [@ Science Museum]

P9444 was delivered to the RAF on 5^th April 1940 and assigned to 72 Squadron with whom it flew in the Battle of Britain.  Unfortunately, it crashed on 3^rd July 1940 and was moved to 1 Civilian repair unit.  Although 9444 never flew operationally again it was used for training and display duties before being transferred to the Science Museum in 1954.  P9444 is currently displayed in 72 Squadron markings.

A Supermarine S.6B [below right], which flew at a maximum speed of 407 mph, won the International Schneider Trophy [below left] outright in 1931. 

Mitchell's design was so superior to the original Air Ministry Specification F.36/34 to which it had been submitted that a new one was drafted to cover the production of a prototype.  This aircraft, K5054, made its first flight on 5^th March 1936 and, like the Hawker Hurricane, with which it was to share so much fame, was powered by a Rolls-Royce Merlin C engine.  The Air Ministry issued a contract for the production of 310 Spitfires in June 1936, at the same time as the Hurricane contract, and the first examples were delivered to 19 Squadron at Duxford in August 1938.  Eight other squadrons had equipped with Spitfires by September 1939, and two Auxiliary Air Force units, 603 and 609, were undergoing operational training.  The total production of the Spitfire was 20,351 and  2334 examples of the naval version, the Seafire.  The last aircraft in the Spitfire/Seafire lineage, VR971 - a Seafire 47, left the production line at Supermarine on the 28^th January 1949.

The photograph on the right shows a stainless steel model of a Mk I which was used in 1941 for wind tunnel investigations into high speed dive characteristics.

Supermarine Spitfire Mk Ia (R6915)  [@ Imperial War Museum]

R6915 flew 57 operational sorties during the Battle of Britain, accounting for 2 kills, another 2 shared kills, and 4 damaged while serving with 609 Squadron.  It is displayed in its original wartime colours and has been at the Imperial War Museum since 1946. 

The Spitfire Mk I was powered by a Merlin [photographs below] II or III engine and 1,583 were built.  It was this variant that saw the most combat in the Battle of Britain.

The Mk II with the Merlin XII, being issued to the squadrons of Fighter Command in September 1940.  The Mk II production, including the Mk IIb, which mounted two 20mm (0.79in) cannon and four 7.7mm (0.303in) machine guns in place of the standard eight 7.7mm (0.303in), totalled 920 aircraft.  During the battle, from 1^st July to 31^st October 1940, 361 of the 747 Spitfires delivered to Fighter Command were destroyed, not all in combat.

Supermarine Spitfire Mk IIa (P7350)  [@ RAF Coningsby]

The Spitfire Mk III was an experimental ‘one-off’ Merlin XX powered aircraft (2 built), while the Mk IV (229 built) was a photo-reconnaissance (PR) Merlin 45 powered variant.   It was actually produced after the next variant, the Mk V, which began to reach the squadrons in March 1941.  

Supermarine Spitfire Mk Vb (BM597)  [@ RAF Duxford]

Converted from Mk I or II airframes and strengthened to take the Merlin 45, the Mk V was to be the major Spitfire production version, with 6479 new examples, together with Mk I and Mk II conversions, completed.   The type came in three wing configurations, the Va with eight machine-gun armament, the Vb with four .303 machine guns and two 20mm cannon and the Vc (the universal wing) which would take two or four cannon and four machine guns and the provision for the carriage of 500 lb of bombs.   Each type was also produced with wings clipped from 36' 10" to 32' 2" for low altitude work.   The Spitfire V, however, failed to provide the overall superiority Fighter Command needed so badly.  At high altitude, where many combats took place, it was found to be inferior to the BF 109F, and several squadrons equipped with the Mk V took a severe mauling. 

To counter the activities of high-flying German reconnaissance aircraft the Spitfire Mk VI (100 built) was produced, with a long, tapered wing and a pressurized cockpit.  Basically an high altitude version of the Mark V with the wing-span extended to 40'2" and powered by the Merlin 47.  The Merlin drove a four-bladed propeller which remained the standard airscrew until the introduction of five-blade propeller on the Griffon engined Mk XIV.

The Mk VII (140 built), also with a pressurized cockpit, was powered by a Merlin 61 engine (photograph - right), a two-stage, two-speed, inter-cooled power-plant which was to take development of the Merlin to its ultimate.

The Mk VIII preceded the Mark IX on the drawing board but entered service later.  Without pressurisation the Mark VIII was the medium to low altitude version of the Mk VII.  Powered by a Merlin 63 or 66 it a retractable tail-wheel, later versions had a wider chord rudder, and had a top speed of 408 mph (compared to 357 mph for the Mark V) and provision for one 500 lb and two 250 lb bombs.  By 1946 it equipped only RAF units in the Middle and Far East.  A total of 1,658 were built.

By the end of 1945 the Mk Is, IIs, IVs and VIIs were out of RAF service completely and the last Mk VIII left 253 Squadron in December 1947.

Supermarine Spitfire LF Mk IXc (MH434)  [@ RAF Duxford]

The answer to the problems experienced with the Spitfire V [see Fw 190] was to marry an Mk V airframe with a Merlin 61 engine.  The resulting combination was the Spitfire Mk IX, which for a stopgap aircraft turned out to be a resounding success! Deliveries to the RAF began in June 1942 and 5665 were built, more than any other mark except the Mk V.  Many Mk IXs were production-line or retrospective conversions of the Mk V to the IX standard.  With the Merlin 61 it had a similar performance to the Mk VIII, although the tail-wheel was fixed.  It came in three types according to altitude, the LF (Low Flying) with clipped wings, the standard span medium altitude fighter and the HF (High Flying) with a standard wingspan but with a the Merlin 70 engine.  The types were fitted with either the "b", "c" or "e" wing, the latter accommodating two 20mm cannon and two 0.5 calibre machine guns.  Some later models had the broad-chord rudder, a cut-down rear fuselage and tear-drop canopy.  The type was finally withdrawn from RAF operational service in May 1948.

Spitfires Mk X and XI were unarmed PR variants.  The armament was replaced by cameras which came in three fits, the X fit was two F.8 cameras with a 20in lens, the Y fit one F.24 camera with a 14in lens and the Z fit one F.52 camera with a 36in lens.  Like the Mk VIII the Mk X (16 built) was produced out of sequence.  It was a pressurised XI but fitted with the Merlin 64 while the Mk XI (471 built with some IX conversions) was the PR version of the Mk IX.

The Mk XII (1943) fighter, powered by a Griffon III engine, was developed specifically to counter the low-level attacks by Focke-Wulf 190s.  Only 100 were built and they were out of RAF service by 1946.  Similarly, the PR Mk XIII was out of RAF service by 1946.  Powered by the Merlin 32, only 18 were built.

Supermarine Spitfire FR Mk XIVe (MV293)  [@ RAF Duxford]

The Mk XIV was based on the Mk VIII with an airframe strengthened to take a Griffon [photograph - below] 65 or 67 engine.  It was the first Griffon engined Spitfire variant to go into large-scale production (957 built) and the first examples were issued to No 322 (Netherlands) and No 610 Squadrons in March and April 1944.  The prototype, built to specification F.4/40, first flew in 1941.  In order to keep the overall length broadly the same as in the Merlin engined variants the camshaft and supercharger gear was moved forward, however, this still made it 1½ ft longer than the Mk IX.  The increase in length together with the inclusion of a five-blade propeller was compensated for by a larger fin and rudder.  The fuselage contours also changed on the nose, with fairings on either side to accommodate the cylinder blocks.  As with the later models of the Mark IX the rear fuselage was cut down and a tear-drop canopy fitted.  The mark also included a clipped wing version for low altitude work and a FR (Fighter Reconnaissance) version which was equipped with an obliquely mounted F.24 camera.  Apart from the four 20mm Hispano cannon there was provision for one 500lb bomb or Mark IX rocket projectiles.

Built by Vickers-Armstrong, at Keevil, then to 33 MU on 27^th February 1945 for storage.  Delivered to 213 MU for packing in August and shipment to the Indian Air Force.  Arriving in Karachi in October, MV293 joined the IAF as No 48 in December 1947.  Later with the IAF Technical College, Jalahalli, MV293 was recovered from Bangalore and crated to the UK.  The first flight after restoration at Duxford was on 14^th August  1992.

Supermarine Spitfire FR Mk XIVe (MT847)  [@ Manchester Museum of Science & Technology]

MT847 entered RAF service with 6 MU on 28^th February 1945 and remained in service with 226 OCU as UU-A until 14^th November 1950.  Stored until 1952, MT847 under went Gate Guardian duties until 1986 when it was moved to the Aerospace Museum at RAF Cosford.  Since 22^nd March 1995 it as been on loan to the Manchester Museum of Science and Technology.

Since the Mk XV was a Seafire variant the next Spitfire to be built was the Mk XVI.  It entered service in 1944 and was a ground-attack variant, very similar to the Mk IX, but powered by a Packard built Merlin 266 engine.  Some later models had the cut-down rear fuselage and rear-view canopy.  This variant (1054 built) was the last Merlin engined Spitfire in RAF front-line service and was withdrawn when released from 63 Squadron in May 1948, however, the type continued in service with 612 Squadron of the RAuxAF until June 1951 and well into the mid 1950s with second-line or training units.

Supermarine Spitfire LF Mk XVIe (TD248)  [@ RAF Duxford]

Built at Castle Bromwich in early 1945 TD248 was delivered to 6 MU at Brize Norton on 11^th May 1945 and then to 695 Squadron until May 1951.  Placed in storage, it latter became an instructional airframe with the ATC, a gate guardian and was used in 'The Battle of Britain' film.  Following intensive restoration from 1990 to 1992 it was painted in 41 Squadron Spitfire F21 red/silver racing colours that participated in the Blackpool Air Races of 1947 but it is now back in war time colours.

Supermarine Spitfire LF Mk XVIe (RW393)  [@ RAF Cosford]

RW393 entered RAF service with 6 MU on the 20^th July 1945 and was transferred in November 1947 to 203 Advanced Flying School.  In 1950, RW393 was made personal a/c of AOC Fighter Command and retired on 6^th July 1954 to become an instructional airframe with 602 Squadron.  From August 1956 to 1989 RW393 performed gate guarding duties at RAF Turnhouse as XT-A and was used in the 1968 “Battle of Britain” film.  In 1989, RW393 was sent to RAF St Athan for storage pending disposal and arrived at RAF Cosford in May 1995.

Supermarine Spitfire LF Mk XVIe (TE462)  [@ RAF East Fortune]

Built in 1945, TE462 never saw RAF squadron service and spent most of its active life with various MU units.  For a while it was also the gate guardian at RAF Ouston, Northumberland, before becoming the first aeroplane to be acquired by the Royal Scottish Museum in 1971.

With the Mk XVII designation being allocated to the Supermarine Seafire, the Mk XVIII was just beginning to enter RAF service at the end of WW2.  Essentially an Mk XIV airframe, but with a new wing and increased fuel capacity, all 300 that were built had clear-view canopies.  200 of them were fighter-reconnaissance variants which were fitted with one oblique and two vertical F.24 cameras.  The Mk XVIII Spitfires of 60 Squadron flew the last RAF Spitfire fighter sortie on 1^st January 1951 with an attack on a terrorist jungle hideout in Johore, Malaysia.

Like the Mk XVIII the PR Mk XIX was just beginning to enter service at the end of WW2.  It was built around an Mk XIV fuselage with an Mk VC wing and a Griffon 66 engine.  541 Squadron received the first of 225 that were built in June 1944.  This variant was the last Spitfire to fly in British military markings when the remaining three aircraft of the Temperature and Humidity Flight at RAF Woodvale were withdrawn in June 1957.  (All three are now operated by the RAF Battle of Britain Memorial Flight)

Supermarine Spitfire F.24 (PK724)  [@ RAF Hendon]

Powered by a Griffon 61 and driving a five-blade airscrew the F.24 was the final production Spitfire.  It carried extra fuel tanks in the fuselage and had the enlarged elliptical fin and rudder of the Spiteful.  Only 54 F.24s were completed (plus some F.22 conversions) with four Hispano Mk V 20mm cannon and zero-length underwing rocket launchers.  Most went into store although 80 Squadron was fully equipped with the type until they were replaced by the Hornet in December 1951.

PK724 was first flown in February 1946 and was delivered to 33 MU at Lynham in the October.  Following modifications by Westland Aircraft Ltd it arrived at 9 MU at RAF Cosford in February 1950.  Late in 1954 it became a non-effective airframe and moved to RAF Norton, Sheffield, later the next year for instructional purposes.  It served as a Gate Guard at RAF Gaydon before arriving at the Museum in May 1971.  In total, this aircraft amassed only 7 hours flight time.

The more powerful Griffon engine had provided a 100 mph greater top speed than the early Spitfires and almost twice the rate of climb.  The weight of firepower from its four 20 mm cannon had tripled over the types' original fit of eight machineguns.

The Spitfire on the right at RAF Elvington (York Air Museum) is a replica of R6690, a Mk Ia, and it commemorates 609 (West Riding) Squadron, Royal Auxiliary Air Force.  The original R6690 was flown in the Battle of Britain by the Commanding Officer, Sqn Ldr H S 'George' Darley and was shot down over South London on 15^th September 1940 by a Messerschmitt Bf 110 killing P/O Daunt, the pilot.  The Squadron shot down 85 enemy aircraft during the Battle and went on to become the first Spitfire Squadron to be credited with 100 victories.