Supermarine Spitfire

The airflow through the main radiator was controlled by [Vous devez être inscrit et connecté pour voir ce lien] exit flaps. In early marks of Spitfire (Mk I to Mk VI) the single flap was operated manually using a lever to the left of the pilot's seat.

When the two-stage Merlin was introduced in the [Vous devez être inscrit et connecté pour voir ce lien] the radiators were split to make room for an intercooler radiator; the radiator under the starboard wing was halved in size and the intercooler radiator housed alongside.

Under the port wing a new radiator fairing housed a square oil cooler alongside of the other half-radiator unit.

The two radiator flaps were now operated automatically via a [Vous devez être inscrit et connecté pour voir ce lien].

Un MK XI australien

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The light alloy [Vous devez être inscrit et connecté pour voir ce lien] at the trailing edge of the wing were also pneumatically operated via a finger lever on the instrument panel.

Only two positions were available; fully up or fully down (85°). The flaps were normally lowered only during the final approach and for landing, and the pilot was to retract them before taxiing.^{[Vous devez être inscrit et connecté pour voir ce lien]}

The ellipse also served as the design basis for the Spitfire’s fin and tailplane assembly, once again exploiting the shape’s favourable aerodynamic characteristics.

Both the elevators and rudder were shaped so that their centre of mass was shifted forward, thus reducing control-surface flutter.

The longer noses and greater propeller-wash resulting from larger engines in later models necessitated increasingly larger vertical and, later, horizontal tail surfaces to compensate for the altered aerodynamics, culminating in those of the Mk 22/24 series which were 25% larger in area than those of the Mk I.^{[Vous devez être inscrit et connecté pour voir ce lien]}

Spitfire F 22. Photo MoD UK

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Improved late wing designs


As the Spitfire gained more power and was able to manoeuvre at higher speeds, the possibility that pilots would encounter [Vous devez être inscrit et connecté pour voir ce lien] increased, and the Supermarine design team set about redesigning the wings to counter this.

The original wing design had a theoretical aileron reversal speed of 580 mph (930 km/h), which was somewhat lower than that of some contemporary fighters.

The [Vous devez être inscrit et connecté pour voir ce lien] noted that, at 400 mph (640 km/h) [Vous devez être inscrit et connecté pour voir ce lien], roughly 65% of aileron effectiveness was lost, due to wing twist.

The new wing of the [Vous devez être inscrit et connecté pour voir ce lien] and its successors was designed to help alleviate this problem; the wing's stiffness was increased by 47%, and a new design of aileron using [Vous devez être inscrit et connecté pour voir ce lien] and geared [Vous devez être inscrit et connecté pour voir ce lien] meant that the theoretical aileron reversal speed was increased to 825 mph (1,328 km/h).

Alongside of the redesigned wing Supermarine also experimented with the original wing, raising the leading edge by one inch (2.54 cm), with the hope of improving pilot view and reducing drag.

This wing was tested on a modified F Mk 21, also called the F Mk 23, (sometimes referred to as "Valiant" rather than
"Spitfire").

The increase in performance was minimal and this experiment was abandoned.

Supermarine developed a new[Vous devez être inscrit et connecté pour voir ce lien] wing based on new aerofoil profiles developed by NACA in the United States, with the objective of reducing drag and improving performance.

Supermarine estimated that the new wing could give an increase in speed of 55 mph (89 km/h) over the Spitfire Mk 21.

The new wing was initially fitted to a Spitfire Mk XIV; later a new fuselage was designed, with the new fighter
becoming the [Vous devez être inscrit et connecté pour voir ce lien].

Le lien sur le " Spiteful "

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By 1942, Supermarine designers had realised that the aerodynamics of the Spitfire's wing at high [Vous devez être inscrit et connecté pour voir ce lien] numbers might become a limiting factor in increasing the aircraft's high-speed performance.

The main problem was the [Vous devez être inscrit et connecté pour voir ce lien] of the Spitfire's wing; at high speeds the relatively light structure behind the strong leading edge torsion box would flex, changing the airflow and limiting the maximum safe diving speed to
480 mph (772 km/h) [Vous devez être inscrit et connecté pour voir ce lien].

If the Spitfire was to be able to fly higher and faster a radically new wing would be needed.

Spitful

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Joseph Smith and the design team were aware of a paper on [Vous devez être inscrit et connecté pour voir ce lien], published by A D Young of the [Vous devez être inscrit et connecté pour voir ce lien], in which he described a new type of wing section; the maximum thickness and camber would be much nearer to the mid-chord than conventional airfoils and the nose section of this airfoil would be close to an ellipse.

"A new wing has been designed for the Spitfire with the following objects[sic];

1)To raise as much as possible the critical speed at which drag increases, due to compressibility, become serious.

2) To obtain a rate of roll faster than any existing fighter.

3) To reduce wing profile drag and thereby improve performance."

"The wing area has been reduced to 210 sq ft and a thickness chord ratio of 13% has been used over the inner wing where the equipment is stored.

Outboard the wing tapers to 8% thickness/chord at the tip.

Spitful :

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Specification 470 described how the wing had been designed with a simple straight-tapered [Vous devez être inscrit et connecté pour voir ce lien] to simplify production and to achieve a smooth and accurate contour.

The wing skins were to be relatively thick, aiding torsional rigidity which was needed for good aileron control at
high speeds.

Although the prototype was to have a [Vous devez être inscrit et connecté pour voir ce lien] of 3° it was intended that this would be increased in subsequent
aircraft.

Another change, to improve the ground-handling, was replacing the Spitfire's narrow-track, outward-retracting [Vous devez être inscrit et connecté pour voir ce lien] with a wider-track, inward-retracting system.

The Air Ministry were impressed by the proposal and, in February 1943, issued Specification F.1/43 for a single seat fighter with a laminar flow wing; there was also to be provision made for a wing folding scheme to meet possible [Vous devez être inscrit et connecté pour voir ce lien]
requirements.

The new fighter was to use a fuselage based on a Spitfire VIII.

Spitful

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The new wing was fitted to a modified [Vous devez être inscrit et connecté pour voir ce lien][Vous devez être inscrit et connecté pour voir ce lien], in order to make a direct comparison with the earlier elliptical wing, and was first flown on 30 June 1944 by [Vous devez être inscrit et connecté pour voir ce lien].

Although the new Spitfire's speed performance was comfortably in excess of an unmodified Spitfire XIV, the new wing
displayed some undesirable behaviour at the stall which, although acceptable, did not come up to the high standards of [Vous devez être inscrit et connecté pour voir ce lien] earlier elliptical wing.

Dessin d'airwar.ru du Spitful :

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In the meantime, the opportunity had been taken to redesign the Spitfire's fuselage, to improve the pilot's view over the nose and to eliminate a slight directional instability by using a larger fin and rudder.

This instability had been apparent since the introduction of the more powerful Griffon engine.

The instability was exacerbated by the increase in [Vous devez être inscrit et connecté pour voir ce lien] blade area due to the introduction of the four-bladed and subsequent five-bladed [Vous devez être inscrit et connecté pour voir ce lien] airscrews for the next aircraft, NN664 (for which Specification F.1/43 had been issued).

The updated design incorporated the new fuselage (although lacking the enlarged fin/rudder) and, as it was now substantially different from a Spitfire, the aircraft was named "Spiteful" (although "Victor" had been originally proposed).

Spitful :

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Production and service use

The Spiteful was ordered into production as the Spiteful XIV (having no preceding marks of its own, the numerals were carried over from the original Spitfire XIV conversion), and 150 of the aircraft were ordered.

With the advent of [Vous devez être inscrit et connecté pour voir ce lien] propulsion, however, the future of high-performance fighters was clearly with the jet fighter, and so the order was later cancelled with only a handful of Spitefuls built.

At the time however, there was some uncertainty over whether jet aircraft would be able to operate from the Royal
Navy's [Vous devez être inscrit et connecté pour voir ce lien] so it was decided to develop a naval version of the Spiteful, to specification N.5/45, subsequently named [Vous devez être inscrit et connecté pour voir ce lien].

Supermarine Seafang :

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The Seafang featured folding wingtips, a "sting"-type arrester hook and a Griffon 89 or 90 engine, fed from an extended [Vous devez être inscrit et connecté pour voir ce lien] air intake driving a new Rotol six-bladed [Vous devez être inscrit et connecté pour voir ce lien] propeller.

The first one produced was a converted Spiteful XV (RB520) but with the successful operation of the [Vous devez être inscrit et connecté pour voir ce lien] from the carrier [Vous devez être inscrit et connecté pour voir ce lien] in 1945, the need for the Seafang disappeared.

With the end of the Second World War, Supermarine entered into discussions with [Vous devez être inscrit et connecté pour voir ce lien] (SNCAN) about licence production of the Spiteful in France, but again the introduction of jet fighters overshadowed the piston-engined fighter and the talks came to nothing.

Seafang deux hélices


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