Supermarine Spiteful

Supermarine

Industry	Aircraft manufacturing
Founded	1913
Founder	Hubert Scott-Paine
Headquarters	Southampton , United Kingdom
Products	Aircraft, including the Spitfire, Spiteful, Seafang, Attacker

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The Supermarine Spiteful was a British fighter aircraft created by Supermarine during World War II to succeed the Spitfire. Equipped with a Rolls-Royce Griffon engine, it featured an innovative wing design aimed at enabling safer flight at elevated speeds, along with inward-retracting landing gear for improved aerodynamics. Additional modifications included an enlarged fin to enhance the limited stability seen in Griffon-powered Spitfires. The wing's development was formalised under Air Ministry specification F.1/43, with intentions not only for a new aircraft but also to potentially replace the elliptical wing used in ongoing Spitfire production.

Although the Spiteful was prepared for mass production as the war drew to a close, testing revealed only slight performance gains over existing fighters, and its progress was soon eclipsed by emerging Jet engine technology. From an initial order of 150 units, just 19 were constructed. The Royal Navy pursued a carrier-capable variant known as the Supermarine Seafang, but this model saw limited production as well. The innovative wing developed for the Spiteful later served as the basis for the jet-powered Supermarine Attacker.

Background

In 1942, the British Air Ministry requested that Supermarine develop a new wing for the Supermarine Spitfire to enhance its rolling performance. The design was to incorporate a laminar flow wing section. By November of that year, Supermarine’s chief designer, Joseph Smith, had begun work on this innovative wing. The design team discovered that the Spitfire’s capabilities at speeds exceeding 480 miles per hour (770 km/h) were hindered by the aeroelasticity effects on its elliptical wing. Although R.J. Mitchell’s original elliptical wing design had been progressively reinforced and adapted throughout the war to accommodate increased engine power, achieving even greater speed and altitude necessitated a fundamentally new wing concept. The development proceeded in partnership with the National Physical Laboratory located in Teddington.

In September 1942, Supermarine introduced Specification No 469, marking the initial phase of designing what would become the Type 371, later designated as the Spiteful. By 30 November, Specification No 470 was issued, which stated:

Specification 470 detailed that thicker wing skins were preferred to increase rotational stiffness, essential for maintaining effective aileron responsiveness at elevated speeds. While the prototype featured a dihedral of 3°, plans were made to raise this angle in future models. To enhance ground handling characteristics, the Spitfire’s outward-retracting undercarriage was replaced with an inward-retracting system that positioned the wheels farther apart, addressing a known vulnerability in the original design that complicated landings.

The Air Ministry responded positively to these advancements and in February 1943 released Specification F.1/43 for a single-seat fighter equipped with a laminar flow wing. This specification also required excellent pilot visibility, foldable wings to accommodate potential Fleet Air Arm operations, armament consisting of 4 × 20 mm (0.787 in) cannon, and contra-rotating propellers. The new fighter was to utilize a fuselage based on the Spitfire Mk VIII. Under this specification, three aircraft featuring contra-rotating propellers were commissioned primarily as experimental platforms to evaluate both the new wing and propeller system. Initially, Supermarine had discretion over whether to fit Merlin or Griffon engines; this decision evolved so that two prototypes would be powered by Griffons and one by a Merlin, all equipped with contra-rotating propellers. The specification also envisaged applying this wing design to Mark VIII or Mark 21 Spitfire airframes (powered by Merlin and Griffon engines respectively), anticipating production use from late 1944 onward. However, alterations in wing spar spacing meant this wing could not serve as a direct replacement. Internally at Supermarine, this wing was identified as Type 371—a designation extended to refer to the entire aircraft design.

Prototype evaluations

The newly designed wing was installed on a modified Spitfire XIV (serial NN660), following a revision by the Air Ministry which altered the initial requirement of using a Mk VIII fuselage. The Mk XIV was selected to enable direct performance comparisons between the new wing and the previous elliptical design. Although the maiden flight was scheduled for 15 March 1944, delays in manufacturing the wing postponed delivery and subsequently the first flight.

On 30 June 1944, Supermarine's lead test pilot Jeffrey Quill conducted the inaugural flight of NN660 at Vickers' flight development center located at RAF High Post, Wiltshire. While the aircraft demonstrated significantly higher speed compared to an unaltered Spitfire XIV, the wing exhibited stall characteristics that, though acceptable, did not meet the superior standards set by the earlier elliptical wing. Tragically, NN660 was lost on 13 September 1944 during an improvised low-altitude simulated dogfight against a standard Spitfire XIV, resulting in the death of test pilot Frank Furlong. No definitive cause for the crash was determined; however, the accident report suggested a possible temporary seizure or disconnection of the aileron control rods during flight. Quill himself experienced a similar aileron jam during a high-g turn in NN664, though he managed to recover due to sufficient altitude. Following this incident, control mechanisms were redesigned, which delayed the initial flight of the second prototype (NN664). By December, Supermarine faced criticism from the Ministry for slow progress. Flight tests confirmed that while performance surpassed that of equivalent Spitfires, it fell short of expectations; moreover, even minor contamination such as mud or insect splatter disrupted laminar flow and diminished speed.

To enhance pilot visibility during deflection shooting and address directional instability, the Spitfire's fuselage was redesigned to incorporate a larger fin and rudder. This instability emerged after fitting more powerful Griffon engines and was further aggravated by introducing four- and five-bladed Rotol propellers. Concurrently, Supermarine engineered the airframe to accommodate either Griffon or Merlin powerplants. The revised design incorporated the new fuselage but initially did not include the larger fin and rudder. The second prototype, NN664, took to the air unpainted on 8 January 1945. Further modifications aimed at resolving issues identified during testing involved changes to the wing profile and enlargements of the fin, rudder, tailplane, and elevators. Although these tail enlargements enhanced handling characteristics, they also resulted in a slight reduction in maximum speed.

While faster than its predecessor, the Spiteful’s speed improvement over the Spitfire was less pronounced than anticipated. It also experienced greater adverse effects from compressibility and demonstrated inferior stall behavior compared to earlier models.

Name

Discussions regarding the official service designation for any new aircraft derived from the Spitfire began as early as 1943. Among the options considered by the Air Council, the RAF's governing authority, was the name "Victor." However, this choice was ultimately dismissed as it conveyed an unwarranted sense of arrogance and failed to evoke qualities of speed or aggression. The development of a novel wing design to replace the Spitfire's original elliptical wing—dating back to the 1930s—rekindled debates about naming. Some opposed retaining the Spitfire name for a model that significantly diverged from Mitchell’s initial design, although many stakeholders, including pilots and the AOC Fighter Command, resisted any renaming. The Air Member for Supply and Organisation expressed that there was no justification for applying the Spitfire name to an aircraft that was fundamentally different and not a true successor. He noted that few components were interchangeable with the original Spitfire, and continuing to use that name would complicate supply logistics.

In October 1943, the Air Council was informed that Prime Minister Winston Churchill had taken an interest in selecting the name and wished to discuss it with the Secretary of State. Sir Charles Portal, then Chief of the Air Staff, preferred "Valiant" over "Victor." By November, aiming to resolve the issue, the Council decided to designate the Spitfire XXI as "Valiant," contingent on Admiralty approval. However, Supermarine opposed this choice, advocating instead for a name beginning with "S." Portal proposed "Spiteful," which was accepted without objection during a meeting held in March 1944.

Production

The Spiteful entered production under the designation Spiteful F.XIV, inheriting its numerical suffix from the original Spitfire Mk XIV. This numbering system was intended to accommodate Merlin-powered variants, although none were eventually produced. Supermarine initially received orders for 650 units. Subsequently, this figure was curtailed in stages: first by 260 aircraft, then by another reduction leaving only 80 to be completed, and finally a third cancellation brought the total down to just 22 machines. The maiden production example, RB515, undertook its first flight lasting 15 minutes on 2 April 1945. A week later, it suffered damage following a forced landing at RAF Boscombe Down but was repaired and returned to service.

With jet propulsion technology emerging rapidly, the order was terminated in May 1945, mere days before hostilities ended in Europe; only a limited number of Spitefuls had been manufactured by then. Supermarine then received a replacement contract for 150 Seafang fighters. Although several Spiteful aircraft were formally accepted by the RAF for evaluation purposes, none were deployed operationally at squadron level. For instance, NN664 was delivered for official testing at Boscombe Down in June 1945, followed by NN667 between February and June of the subsequent year. The overall assessment rated performance as "below average," citing dissatisfaction with cockpit ergonomics and lengthy turnaround times for refueling and rearming. By March 1946, Supermarine had been informed that RAF requirements limited the Spiteful’s role to that of a "low altitude attack aircraft." During that year, RB516 was dispatched to the Aeroplane & Armament Experimental Establishment to evaluate its potential as a fighter-bomber. When Supermarine raised objections to this change in status, development of the Spiteful project was ultimately discontinued. In July 1948, thirteen Spiteful airframes were sold off for scrap metal.

Variants

Three distinct variants of this model were identified. Aircraft equipped with the Griffon 69 engine paired with a five-blade Rotol propeller received the designation F. Mk 14. The remaining two versions, F Mk 15 and F Mk 16, primarily differed in the type of engine installed or the number of propeller blades used.

Variant	Engine	Weight	Maximum speed	Remarks
F Mk 14	Griffon 69 engine featuring a five-blade Rotol propeller and short intake 2,375 hp (1,771 kW)	9,950 lb (4,510 kg)	483 mph (777 km/h) at an altitude of 21,000 feet (6,400 m)	A total of 19 units produced, including two prototypes and 17 production aircraft: RB515–RB525, RB527–RB531, and RB535.
F Mk 15	Griffon 85 engine with a six-blade contra-rotating propeller 2,350 hp (1,750 kW)	10,200 lb (4,600 kg)	476 mph (766 km/h)	Only one unit constructed: RB520, which served as an interim Seafang prototype in early 1945 and was fitted with a Tailhook.
F Mk 16	Griffon 101 engine 2,420 hp (1,800 kW)	9,950 lb (4,510 kg) at takeoff	494 mph (795 km/h) at 28,500 feet (8,700 m), 408 miles per hour (657 km/h) at sea level	Converted from RB518, this aircraft was utilized for propeller development in 1948, equipped with a Griffon 101 engine and a two-stage three-speed supercharger. It later received the F. Mk 16 designation. Its top speed of 494 mph (at 27,500 ft) set a record for British piston-engined aircraft.

"Jet Spiteful"

Main article: Supermarine Attacker

Around late 1943 or early 1944, Smith suggested that the company create a straightforward jet fighter design based on the Spiteful's wing. This concept aligned with Rolls-Royce’s ongoing development of a new jet engine, initially known as the B.41 and later named the Rolls-Royce Nene. The Air Ministry approved Smith's Type 392 project, recognizing that the wing design was suitable for jet propulsion, and issued specification E.10/44 for an experimental aircraft initially called the "Jet Spiteful" (with the naval variant termed "Jet Seafang"). A contract was awarded for three prototypes, followed by an order in July for six E.10/44 units and eighteen E.1/45 naval versions. The prototype Type 392 (TS409) completed its maiden flight on 27 July 1946. However, the RAF did not place orders for the E.10/44 due to its performance offering only marginal improvements over existing jets such as the Gloster Meteor and de Havilland Vampire.

The Admiralty showed interest in adopting this design as a naval fighter and issued specification E.1/45 accordingly. The aircraft, named the Supermarine Attacker, became the Royal Navy's inaugural jet fighter. It had a brief operational tenure during the 1950s and continued service with the Pakistan Air Force until 1964.

Supermarine Seafang

Main article: Supermarine Seafang

In the mid-1940s, doubts existed regarding the capability of jet-powered aircraft to operate effectively from Royal Navy aircraft carriers. Consequently, a naval adaptation of the Spiteful was commissioned under specification N.5/45, which was later designated as the Seafang. The first prototype involved modifying a Spiteful XV (RB520) by adding an arrestor hook. The initial complete Seafang prototype was identified as VB895. Following this, ten Seafang F.Mk 31 units were produced, with two—VG471 and VG474—serving as additional prototypes. The ultimate fully navalized F Mk 32 model featured folding wingtips, a "sting"-style arrestor hook, and twin three-blade contra-rotating propellers. Nevertheless, only two prototypes (VB893 and VB895) reached completion. The emergence of the Supermarine Attacker in August 1951 rendered the Seafang obsolete. Additionally, Smith's laminar flow wing design was incorporated into the Supermarine Type 391, a derivative of this aircraft.

Specifications (Spiteful XIV)

File:Supermarine Spiteful.svg

Illustrations of the Spiteful Mk.XIV displaying both the elliptical tailplane inherited from the Spitfire and its updated wing configuration

External links

• Spiteful & E.10/44 hosted on Jets45 (self-published)
• Spiteful image and specifications available at 1000aircraftphotos.com (self-published)