Supermarine Spitfire

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Spitfire
Supermarine Spitfire Mk I from No. 19 RAF Squadron
Type	Fighter
Manufacturer	Supermarine
Designed by	R.J. Mitchell
Maiden flight	5 March 1936
Introduced	1938
Retired	1952, RAF
Primary user	Royal Air Force
Produced	1938 - 1948
Number built	20,351 plus 2,334 Seafires
Unit cost	£15,000
Variants	Seafire Spiteful

The Supermarine Spitfire was an iconic British single-seat fighter used by the RAF and many Allied countries in the Second World War.

Produced by Supermarine, the Spitfire was designed by R.J. Mitchell, who continued to refine the design until his death from cancer in 1937. Its elliptical wing had a thin cross-section, allowing a higher top speed than the Hawker Hurricane and other contemporary designs; it also resulted in a distinctive appearance, enhancing its overall streamlined features. Much loved by its pilots, the Spitfire saw service during the whole of the Second World War, in all theatres of war, and in many different variants.

More than 20,300 examples of all variants were built, including two-seat trainers, with some Spitfires remaining in service well into the 1950s. Although its great wartime foe, the Messerschmitt Bf 109, in its many variants, rivalled the Spitfire's production statistics, the Spitfire was one of the few fighter aircraft to be in continual production before, during and after the Second World War.

Vickers (the parent company of Supermarine) first came up with the name Shrew for the new aircraft and, on hearing this, Mitchell is reported to have said, "...sort of bloody silly name they would give it." The name Spitfire was suggested by Sir Robert MacLean, director of Vickers at the time, who called his daughter Ann "A little spitfire". The word dates from Elizabethan times and refers to a particularly fiery, ferocious type of person, usually a woman. The name had previously been used unofficially for Mitchell's earlier F.7/30 Type 224 design.

Design and development

Supermarine's Chief Designer, R.J. Mitchell, had won four Schneider Trophy seaplane races with his designs: (Sea Lion II in 1922, S 5 in 1927, S 6 in 1929 and S 6b in 1931), combining powerful Napier Lion and Rolls-Royce "R" engines with minute attention to streamlining. These same qualities are equally useful for a fighter design, and, in 1931, Mitchell produced such a plane in response to an Air Ministry specification (F7/30) for a new and modern monoplane fighter.

This first attempt at a fighter resulted in an open-cockpit monoplane with gull-wings and a large fixed, spatted undercarriage. The Supermarine Type 224 did not live up to expectations; nor did any of the competing designs, which were also deemed failures.

Mitchell immediately turned his attention to an improved design as a private venture, with the backing of Supermarine's owner, Vickers. The new design added gear retraction, an enclosed cockpit, oxygen gear and the much more powerful newly developed Rolls-Royce PV-12 engine, later named the Merlin.

By 1935, the Air Ministry had seen enough advances in the industry to try the monoplane design again. They eventually rejected the new Supermarine design on the grounds that it did not carry the required eight-gun armament, and did not appear to have room to do so.

Once again, Mitchell was able to solve the problem. It has been suggested that by looking at various Heinkel planes, he settled on the use of an elliptical planform, which had much more chord to allow for the required eight guns, while still having the low drag of the earlier, simpler wing design. Mitchell's aerodynamicist, Beverley Shenstone, however, has pointed out that Mitchell's wing was not directly copied from the Heinkel He 70, as some have claimed; the Spitfire wing was much thinner and had a completely different section. In any event, the elliptical wing was enough to sell the Air Ministry on this new Type 300, which they funded by a new specification, F.10/35, drawn up around the Spitfire.

The elliptical wing was chosen for superior aerodynamic attributes but it was a complex wing to construct and the Messerschmitt Bf 109's angular and easy-to-construct wing offered similar performance (model per model) to the Spitfire. It has been reported that the Bf 109 took one-third the man hours to construct compared to the Spitfire.

One flaw in the thin-wing design of the Spitfire manifested itself when the plane was brought up to very high speeds. When the pilot attempted to roll the plane at these speeds, the aerodynamic forces subjected upon the ailerons were enough to twist the entire wingtip in the direction opposite of the aileron deflection (much like how an aileron trim tab will deflect the aileron itself). This so-called aileron reversal resulted in the Spitfire rolling in the opposite direction of the pilot's intention.

The prototype (K5054) first flew on 5 March 1936, from Eastleigh Aerodrome (later Southampton Airport). Testing continued until 26 May 1936, when Mutt Summers, (Chief Test Pilot for Vickers (Aviation) Ltd.) flew K5054 to Martlesham and handed the aircraft over to Squadron Leader Anderson of the Aeroplane & Armament Experimental Establishment (A&AEE).

The Air Ministry placed an order for 310 of the aircraft on 3rd June 1936, before any formal report had been issued by the A&AEE, interim reports being issued on a piecemeal basis.

A feature of the final Spitfire design that has often been singled out by pilots is its washout feature, which was unusual at the time. The incidence of the wing is +2° at its root and −½° at its tip. This twist means that the wing roots will stall before the tips, reducing the potentially dangerous rolling moment in the stall known as a spin. Many pilots have benefited from this feature in combat when doing tight turns close to the aircraft's limits, because when the wing root stalled it made the control column shake, giving the pilot a warning that he was about to reach the limit of the aircraft's performance.

The early versions were fitted with the P8 Air Ministry magnetic compass, of a nautical design which was of over-engineered brass construction and mounted on 4 anti-vibration dampers. Internally it also had a pressure diaphram to compensate for altitude changes. The unit was modified later in the war with the rare P8 M, and later the P11. After the war this type of compass was replaced with the new American "Eyeball" type seen in most aircraft today.

Production

To build the Spitfires in the numbers needed, a whole new factory was built at Castle Bromwich, near Birmingham as a "shadow" to Supermarine's Southampton factory. Although the project was ultimately led by Lord Nuffield who was an expert in mass construction, the Spitfire was a bit too complex and Supermarine and Vickers engineers were needed. The site was set up quickly from July 1938 - machinery being installed two months after work started on the site.

Variants

There were 24 marks of Spitfire and many sub-variants. These covered the Spitfire in development from the Merlin to Griffon engines, the high speed photo-reconnaissance variants and the different wing configurations.

Naval versions

A naval version of the Spitfire, called the Seafire, was specially adapted for operation from aircraft carriers. Modifications included an arrester hook, folding wings and other specialized equipment. However, like the Spitfire, the Seafire had a narrow undercarriage track, which meant that it was not well suited to deck operations. Due to the addition of heavy carrier equipment, it suffered from an aft centre-of-gravity position that made low-speed control difficult, and its gradual stall characteristics meant that it was difficult to land accurately on the carrier. These characteristics resulted in a very high accident rate for the Seafire.

The Seafire II was able to outperform the A6M5 ( Zero) at low altitudes when the two types were tested against each other during wartime mock combats. Contemporary Allied carrier fighters such as the F6F Hellcat and F4U Corsair, however, were considerably more powerful. A performance advantage was regained when late-war Seafire marks equipped with the Griffon engines supplanted their Merlin-engined predecessors.

The name Seafire was arrived at by collapsing the longer name Sea Spitfire.

RAF service

The first Spitfires claimed their first victims in early September 1939. Unfortunately, the downed aircraft were RAF Hawker Hurricanes, attacked by accident.

R.J. Mitchell and his Spitfire are often credited with winning the Battle of Britain. This is a view often propagated within popular culture, such as in the film The First of the Few (which was not historically accurate).

The Spitfire was one of the finest fighters of the war; aviation historians and laymen alike often claim it to be the most aesthetically appealing. It is, however, frequently compared to the Hawker Hurricane, which was used in greater numbers during the critical stages of 1940. Although early Spitfires and Hurricanes carried identical armament (eight .303 inch / 7.696 mm machine guns), the placement of the Hurricane's guns was better, yielding a closer pattern of fire. A slower top speed, however, made the Hurricane more vulnerable against the German fighter escorts. Wherever possible, the RAF tactic during the Battle of Britain was to use the Hurricane squadrons to attack the bombers, holding the Spitfires back to counter the German escort fighters. In total numbers, the Hurricane shot down more Luftwaffe aircraft, both fighters and bombers, than the Spitfire, mainly due to the higher proportion of Hurricanes in the air. Seven of every 10 German planes destroyed during the Battle of Britain were shot down by Hurricane pilots. Losses were also higher among the more numerous Hurricanes.

The Mark I and Mark II models saw service during the battle and beyond, into 1941. Both of these used eight .303 machine guns and although having this number of guns sounds impressive, the fact is that this relatively small calibre armament was more suited to shooting down the wood/canvas machines of the First World War. It was relatively common during the Battle of Britain for the (metal) German planes to safely return to base with surprisingly high numbers of .303 bullet holes. The use of a smaller number of larger calibre guns would have been far more effective; this was rectified in later versions of the Spitfire. The Mark V entered service in early 1941, and was the first to feature cannon armament (although a few Mark Is had two 20 mm Hispano-Suiza cannon fitted in 1940). The configuration of two 20 mm cannon and four .303 machine guns was standard during the mid-war years.

Another contemporary, the Luftwaffe's Messerschmitt Bf 109, was similar in attributes and performance to the Spitfire. Some advantages helped the Spitfires win many dogfights, most notably, maneuverability - the Spitfire had higher rates of turn than the Messerschmitt. Good cockpit visibility was probably a factor, as well, as the early Bf-109s had narrow, panelled, heavily-framed cockpit windows. At this time, the Merlin engine's lack of direct fuel injection meant that both Spitfires and Hurricanes, unlike the Bf 109E, were unable to simply nose down into a deep dive. This meant the Luftwaffe fighters could simply "bunt" into a high-power dive to escape attack, leaving the Spitfire spluttering behind as its fuel was forced by negative "g" out of the carburettor. RAF fighter pilots soon learnt to "half-roll" their aircraft before diving to pursue their opponents. The use of uninjected carburettors was calculated to give a higher specific power output, due to the lower temperature, and hence the greater density, of the fuel/air mixture fed into the motor, compared to injected systems. In March 1941, a metal diaphragm, with a hole in it, was fitted across the float chambers. It partly cured the problem of fuel starvation in a dive, and became known as " Miss Shilling's orifice" as it was invented by a female engineer named Shilling. Further improvements were introduced throughout the Merlin series, with injection introduced in 1943. Production of the Griffon-engined Spitfire Mk XII had begun the year before.

The introduction of the Focke-Wulf Fw 190 in late 1941 along the Channel front proved a shock to RAF Fighter Command, the new German fighter proving superior to the current Mark Vb in all aspects except turning radius. Losses inflicted on RAF Fighter Command and its Spitfires were heavy as air superiority thus switched to the Luftwaffe units through most of 1942, until the Merlin 61-engined Mark IX version started to see service in sufficient numbers later in the year. In an attempt to achieve some degree of parity with the Fw 190, some squadrons still operating the Mark V received specially modified versions that had four feet of wing-tip removed (to improve their rate of roll) and reduced supercharger blades on the Merlin for optimum performance at lower altitudes. These aircraft were designated LF Mark V officially but were also known by their pilots as "Clipped, Clapped and Cropped Spits," also referring to the fact that many of these Spitfires, thus modified, had seen better days.

The first Spitfires to see overseas service were Mark Vs flown from the deck of the aircraft carrier HMS Eagle to Malta in March 1942. In the months that followed, some 275 Spitfires were delivered to the beleaguered island. To counter the prevalent dusty conditions, the Spitfires were fitted with a large Vokes air filter under the nose, which lowered the performance of the aircraft through induced drag. The Spitfire V and, later, much-improved, longer-ranged Mark VIIIs also soon became available in the North African theatre and, henceforth, featured heavily with the RAF, SAAF and USAAF during the campaigns in Sicily and Italy.

The first Griffon-engined Mk XII flew on August 1942, but only five had reached service status by the end of the year. This mark could exceed 450 mph (724 km/h) in level flight and climb to an altitude of 30,000 feet (10,000 m) in under eight minutes. Although the Spitfire continued to improve in speed and armament, it remained short-legged throughout its life except in the dedicated photo-reconnaissance role, when its guns were replaced by fuel.

As the American strategic bombing campaign gathered momentum in mid-1943, the need for fighter escort meant much of Fighter Command's Spitfire force was utilised in this role while the US fighter groups worked up to operational status. The inadequate range of the Spitfire however, meant the RAF support operations were limited to northwest France and the Channel. As the battle intensified over occupied Europe, USAAF fighters like the P-47, P-38 and P-51 bore the brunt of bomber protection. The Spitfire IX squadrons had to bide their time until the invasion of Europe before engaging the Luftwaffe fighter force.

By then, the newer Griffon-engined Spitfires were being introduced as interceptors, where limited range was not an impediment. These faster Spitfires were used to defend against incursions by high-speed "tip-and-run" German fighter-bombers and V-1 flying bombs over Great Britain.

As American fighters took over the long-range escorting of USAAF daylight bombing raids, the Griffon-engined Spitfires progressively took up the tactical air superiority role as interceptors, while the Merlin-engined variants (mainly the IX and the Packard-engined XVI) were adapted to the fighter-bomber role.

After the Normandy landings, Spitfire squadrons were moved across the Channel, operating from tactical airfields close to enemy lines. As the Allied air forces achieved air supremacy, Spitfire pilots had fewer opportunities to combat German aircraft, concentrating their efforts on roaming over German territory, attacking targets of opportunity and providing tactical ground support to the army units. The newer, faster marks of Spitfire were retained in Britain to counter the V-1 flying bomb offensive in mid-1944, although these aircraft, too, were deployed across the Channel before the war in Europe ended.

Although the Griffon-engined marks lost some of the favourable handling characteristics of their Merlin-powered predecessors, they maintained their manoeuvring advantage over German (and American) designs in Europe throughout their production.

The first Spitfires in the Far East were two PR IV photo-reconnaissance marks in October 1942. The threat of Japanese attacks on Northern Australia prompted the dispatch of Spitfire Vbs in late 1942. No 1 Wing RAAF (No 54 Squadron RAF, 452 and 457 squadrons RAAF) was formed in Darwin, the first kill being achieved in February 1943, and saw constant action until September 1943. Spitfire VIIIs were received in April 1944. In the Burma/India theatre, the first Spitfire Vs were not received until September 1943.

Spitfire pilots, used to European combat conditions, were shocked to find that they could not follow the Japanese Mitsubishi Zero through a turn. They were forced to adopt tactics similar to those used by the American pilots, akin to manoeuvers that German pilots had been forced to adopt when facing Spitfires and Hurricanes. British pilots in the Far East relied on their far higher speed, especially in a dive, and greater firepower to prevent Japanese pilots from using the Zero's turning advantage. Zeros could not tolerate dive speeds much higher than their maximum level flight speeds due to increasing aileron stiffness and wing structural limits.

Service in other air forces

Apart from the RAF, Spitfires served with most of the Allied air forces in the Second World War, especially the Royal Canadian Air Force (RCAF), Royal Australian Air Force (RAAF), South African Air Force (SAAF) and Royal New Zealand Air Force (RNZAF). It was one of only a few foreign aircraft to see service with the United States Army Air Forces. Several European countries also operated Spitfires based in the UK, including French, Norwegian, Polish, Dutch and Czechoslovakian squadrons in the RAF.

The RAAF, the Royal Indian Air Force and the RAF also used Spitfires against Japanese forces in the Pacific theatre.

There is evidence that the Luftwaffe also used captured Spitfires to attack Allied targets: one such episode was the strafing of civilians from the village of Grendon, Northamptonshire in 1940.

Following the Second World War, the Spitfire remained in use with many air forces around the world, including the Royal Australian Navy, Belgian Air Force, Union of Burma Air Force, Royal Canadian Navy as the Seafire, Czech Air Force, Danish Air Force, Egyptian Air Force, Armee de l'Air and the French Navy Aeronavale, Royal Hong Kong Auxiliary Air Force, Irish Air Corps, Israeli Air Force, Italian Air Force, Royal Netherlands Air Force, Royal Norwegian Air Force, Royal Thai Air Force, Portuguese Air Force, Swedish Air Force, Syrian Air Force, Turkish Air Force, Rhodesian Air Force, and the SFR Yugoslav Air Force.

Spitfires played a major role in the Greek Civil War, flown by the RAF and SAAF during October-December 1944, and by the Hellenic Air Force from 1946 to the end of the war in August 1949.

Spitfires last saw major action during the 1948 Arab-Israeli War, when — in a strange twist — Israeli Air Force Spitfires flown by formerly RAF pilots in World War II like Ezer Weizman were engaged by Egyptian Spitfires and Royal Air Force Spitfires. However, some air forces retained Spitfires in service until well into the 1960s.

Speed and altitude records

During the spring of 1944, high-speed diving trials were being performed at Farnborough to investigate the handling of aircraft near the sound barrier. Because it had the highest limiting Mach number of any aircraft at that time, a Spitfire XI was chosen to take part in these trials. Due to the high altitudes necessary for these dives, a fully feathering Rotol propeller was fitted to prevent overspeeding. It was during these trials that EN409, flown by John Martindale, reached 606 mph (975 km/h) in a 45-degree dive. Unfortunately the engine/propeller combination could not cope with this speed and the propeller and reduction gear broke off. Martindale successfully glided the 20 miles (30 km) back to the airfield and landed safely.

"That any operational aircraft off the production line, cannons sprouting from its wings and warts and all, could readily be controlled at this speed when the early jet aircraft such as Meteors, Vampires, P-80s, etc could not, was certainly extraordinary" — Jeffrey Quill

On 5 February 1952, a Spitfire Mk. 19 of No. 81 Squadron RAF based in Hong Kong achieved probably the highest altitude ever achieved by a Spitfire. The pilot, Flight Lieutenant Ted Powles, was on a routine flight to survey outside air temperature and report on other meteorological conditions at various altitudes in preparation for a proposed new air service through the area. He climbed to 50,000 feet (15 240 m) indicated altitude, with a true altitude of 51,550 feet (15 712 m), which was the highest height ever recorded for a Spitfire. However, the cabin pressure fell below a safe level, and in trying to reduce altitude, he entered an uncontrollable dive which shook the aircraft violently. He eventually regained control somewhere below 3,000 feet (900 m). He landed safely with no discernible damage to his aircraft. Evaluation of the recorded flight data suggested that, in the dive, he achieved a speed of 690 mph (1110 km/h) or Mach 0.94, which would have been the highest speed ever reached by a propeller-driven aircraft. Today, it is generally believed that this speed figure is the result of inherent instrument errors and has to be considered unrealistic.

Planes remaining in use

About 50 Spitfires and a few Seafires remain airworthy, although many air museums have static examples. The RAF maintains some for flying display and ceremonial purposes in the Battle of Britain Memorial Flight at RAF Coningsby in Lincolnshire.

The Temora Aviation Museum in Temora, New South Wales, Australia, have two airworthy Spitfires: a Mk VIII and a Mk XVI, which are flown regularly during the museum's flying weekends.

Area51Aviation, a British company specializing in ex-military aircraft (particularly jets) have both a Spitfire and Seafire at their Home Airfield at North Weald Airfield.

The Black Spitfire is a black-painted Spitfire which belonged to Israeli pilot and former president Ezer Weizmann. It is on exhibit in the Israeli Air Force Museum in Hatserim and is used for ceremonial flying displays.

Kermit Weeks flys a restored Mk XVI from his Fantasy of Flight museum in Florida.

Spitfire in film and television

Spitfires are featured in several motion pictures

• Battle of Britain (1969) starring Sir Laurence Olivier, Michael Caine, Christopher Plummer and many others. Set in 1940, this film features several flying sequences involving Spitfires, as well as a surprising number of other flying examples of Second World War-era British and German aircraft. The film's production company was "Spitfire Productions, Steven S.A."
• Piece of Cake (television) (1987) starring Tom Burlinson. When it aired on the BBC in 1987, this was the most watched BBC miniseries in history. Based on the novel by Derek Robinson, the six part miniseries covered the prewar era from early 1939 to "Battle of Britain Day," 15 September 1940. The series had time to develop its large cast, and depicted the air combat over the skies of France and Britain during the early stages of the Second World War, though using several flying examples of late model Spitfires in place of the novel's Hawker Hurricanes. There were shots of several Spitfires taking off and landing together from grass airstrips.
• The movie Cruel Blue World was about a Free Czech pilot flying a Spitfire during WWII.

Memorials

• Sentinel, a sculpture by Tim Tolkien in Castle Bromwich, England, commemorating the main Spitfire factory.

Operators

• Australia ( RAAF, RAN), Belgium, Burma, Canada, Czechoslovakia, Denmark, Egypt, France, Greece, Hong Kong, India, Ireland, Israel, Italy, Netherlands, New Zealand, Norway, Poland, Portugal, Rhodesia, South Africa, Soviet Union, Sweden, Syria, Thailand, Turkey, United Kingdom, United States, Yugoslavia.

Specifications

Spitfire Mk Vb

Data from The Great Book of Fighters and Jane’s Fighting Aircraft of World War II

General characteristics

• Crew: one pilot
• Length: 29 ft 11 in (9.12 m)
• Wingspan: 36 ft 10 in (11.23 m)
• Height: 11 ft 5 in (3.86 m)
• Wing area: 242.1 ft² (22.48 m²)
• Empty weight: 5090 lb (2309 kg)
• Loaded weight: 6622 lb (3000 kg)
• Max takeoff weight: 6770 lb (3071 kg)
• Powerplant: 1× Rolls-Royce Merlin 45 supercharged V12 engine, 1470 hp at 9250 ft (1096 kW at 2820 m)

Performance

• Maximum speed: 330 knots (378 mph, 605 km/h)
• Combat radius: 410 nm (470 mi, 760 km)
• Ferry range: 991 nm (1140 mi, 1840 km)
• Service ceiling: 35,000 ft (11 300 m)
• Rate of climb: 2665 ft/min (13.5 m/s)
• Wing loading: 28 lb/ft² (137 kg/m²)
• Power/mass: 0.22 hp/lb (360 W/kg)

Armament

• Guns:
  
  • 2 × 20 mm (0.787 in) Hispano-Suiza HS.404 cannon, 60 (later 120) rounds/gun
  • 4 × .303 in (7.70 mm) Browning machine guns, 350 rounds/gun
• Bombs:
  
  • 250 lb (110 kg) assorted ordnance or
  • 1 × 500 lb (230 kg) bomb