| Spiteful | |
|---|---|
| Supermarine Spiteful FXIV, RB517 | |
| Role | Fighter |
| Manufacturer | Supermarine |
| Designer | Joe Smith |
| First flight | 30 June 1944 |
| Status | Out of service |
| Primary user | Royal Air Force |
| Number built | 19 (2 prototypes and 17 production) |
| Developed from | Supermarine Spitfire |
| Variants | Supermarine Seafang Supermarine Attacker |
The Supermarine Spiteful was a British Rolls-Royce Griffon-engined fighter aircraft designed by Supermarine to Air Ministry specification F.1/43 during the Second World War as a successor to the Spitfire.
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By 1942, Supermarine designers had realised that the aerodynamics of the Spitfire's wing at high Mach numbers might become a limiting factor in increasing the aircraft's high-speed performance. The main problem was the aeroelasticity 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) IAS[nb 1]. If the Spitfire was to be able to fly higher and faster a radically new wing would be needed.[1]
Joseph Smith and the design team were aware of a paper on compressibility, published by A D Young of the R.A.E, 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[nb 2]. On November 1942 Supermarine issued Specification No 470 which (in part) stated;
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 (20 m2) 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.[1]
Specification 470 described how the wing had been designed with a simple straight-tapered planform 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 dihedral of 3° it was intended that this would be increased in subsequent aircraft.[1] Another change, to improve the ground-handling, was replacing the Spitfire's narrow-track, outward-retracting undercarriage 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 FAA requirements. The new fighter was to use a fuselage based on a Spitfire VIII.[2]
The new wing was fitted to a modified Spitfire XIV NN660, in order to make a direct comparison with the earlier elliptical wing, and was first flown on 30 June 1944 by Jeffrey Quill. 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 Mitchell's earlier elliptical wing. NN660 crashed 13 September 1944, killing pilot Frank Furlong. No reason for the loss was officially established.[3]
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 propeller blade area due to the introduction of the four-bladed and subsequent five-bladed Rotol 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).
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 jet 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 aircraft carriers so it was decided to develop a naval version of the Spiteful, to specification N.5/45,[4] subsequently named Seafang.
The Seafang featured folding wingtips, a "sting"-type arrester hook and a Griffon 89 or 90 engine, fed from an extended carburettor air intake driving a new Rotol six-bladed contra-rotating propeller. The first one produced was a converted Spiteful XV (RB520) but with the successful operation of the de Havilland Sea Vampire from the carrier HMS Ocean in 1945, the need for the Seafang disappeared.
With the end of the Second World War, Supermarine entered into discussions with Société Nationale de Constructions Aéronautiques du Nord (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.
In late 1943 or early 1944, Supermarine's chief designer Joe Smith suggested Supermarine develop a simple jet fighter based around the Spiteful's wing, and use a new jet engine being proposed by Rolls-Royce (later the Nene). This proposal was accepted and a new specification, E.10/44, was issued by the Air Ministry for an experimental aircraft which was initially referred to as the Jet Spiteful; the prototype TS409 first flew on 27 July 1946. The E.10/44 was not ordered by the RAF, as its performance was not substantially better than the Gloster Meteor and de Havilland Vampire, but the Admiralty expressed an interest in the aircraft for use as a naval fighter and issued specification E.1/45 around it. The aircraft was subsequently named Attacker and had a successful (if short) career with the Fleet Air Arm and the Pakistan Air Force.
The enlarged fin/rudder of the Spiteful was also used on the Spitfire Mark 22 and 24s and Seafire Mark 46 and 47s and was usually referred to as the "Spiteful type" tail.
Data from Supermarine Aircraft since 1914 [5]
General characteristics
Performance
Armament
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