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DATABASE SUPERMARINE SPITEFUL & SEAFANG
The new wing design is illustrated well as Spiteful RB515 banks away.
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CROWN COPYRIGHT
The improvements and changes introduced to the Spitfi re enabled new variants to match the equivalent developments in the enemy’s fi ghters, to the point that by the end of the war their destructive power and performance — especially their speed — were far in excess of the marks that in 1940 had taken part in the Battle of Britain. It was hoped that the new tapered, laminar-fl ow wing on the Spiteful would push that performance even higher.
In aviation science, the boundary layer is the layer of air adjacent to the aircraft’s surface which has zero velocity at the surface itself and then increases to free stream velocity — the speed at which the air is moving over the aircraft — at its outer edge. e theory that made the laminar-fl ow wing of interest was that the boundary layer transition point would be moved further aft on the wing surface, and the point where turbulent airfl ow began consequently held back. is would reduce drag because a thin, laminar-fl ow boundary layer would create less skin friction drag than a thicker or turbulent layer. e principal benefi ts were expected to be an improvement in performance, the avoidance of the eff ects caused by compressibility,
and an increase in rolling manoeuvrability as a result of the reduced span and wing area.
Compressibility is the result of shockwaves building up when an aircraft fl ies ever closer to the speed of sound, and during 1943-44 this was becoming more of a concern for fi ghter-type aeroplanes. e pace at which piston engine power had risen in just a short time meant current fi ghters were now much faster than they had been in 1940. e potential was there for still further improvement, but it was also known that drag would increase at these higher speeds and be diffi cult to overcome, leading to the idea of a ‘sound barrier’.
Clearly some research was required, and during 1943 the Royal Aircraft Establishment at Farnborough began testing models in a newly commissioned high-speed wind tunnel. In addition, a full-scale fl ight test programme with Spitfi res commenced under the offi cial title ‘Measurement of Tail Loads’. One of the pilots on the RAE’s Aerodynamics Flight was perhaps closer to the mark when he called this “an attempt to break the world air speed record vertically downwards”, because this work involved full-power dives carried out from around 40,000ft (12,192m), so the ‘Spits’ achieved their peak Mach numbers at altitudes between 25,000ft and 30,000ft (7,620m and 9,144m).
In April 1944 Sqn Ldr Tony Martindale, fl ying Spitfi re IX EN409, exceeded 600mph (965km/h), or Mach 0.90, in a dive from 40,000ft (12,192m) to 27,000ft (8,230m), but in the process the aircraft lost its propeller and the structure was strained quite severely. To get home, Martindale had to glide his mount for 20 miles (32km) with very considerable skill before he was able to make a safe landing at Farnborough. In a later sortie the same pilot recorded more than 600mph in diving from over 36,000ft (10,973m), but this time the engine supercharger
burst. Martindale survived a crash-landing in a wood. Flying at those speeds was a serious and most dangerous business.
Supermarine’s efforts to create a laminar-flow wing appear to have begun officially with discussions at the firm’s Hursley Park facility on 19 November 1942, chief designer Joe Smith and colleagues Clifton, Mansbridge and Taylor being joined by Irving and Thomas from RAE Farnborough. The proposed wing was a straight affair, tapered along both edges, and the provisional dimensions were a span of 35ft (10.67m) and an area of 210 sq ft (19.53 sq m); the thickness/chord ratio was 13 per cent across the innermost 70in (178cm) of the semi-span, tapering to 8 per cent at the tip. The estimated weight was 200lb (91kg) lighter than the wing fitted on the Spitfire F21 and it was hoped that an increase of 55mph (88km/h) in speed would be realised. Taylor had made calculations covering various aileron planforms, which indicated that the larger the ailerons the less the degree of balance required to produce a given maximum rolling moment for a given stick force. It was hoped this wing would give a rate of roll better than any existing fighter.
The meeting brought confirmation that Supermarine should proceed with the full design of the new wing and aileron. On 29 December 1942 it was agreed that four 20mm cannon should be fitted inside the wing. The first two wings were expected to be completed by about August 1943, and Supermarine was instructed to build three prototype fighters using Spitfire VIII fuselages. In due course the new aircraft was to be officially named the Spiteful.
A major contributor in the development work required for this special wing section was the National Physical Laboratory at Teddington which, with the RAE, provided a prolific quantity of tunnel testing. The objective was to maintain laminar flow as far back as possible to a point where there was no interference from the slipstream or from the projecting gun barrels, with the maximum thickness coming at about 42 per cent of the wing chord. This effort embraced a range of variations including different wing settings, increased fin area, five- and six-bladed propellers, alternative radiator ducts and the effects of Mach numbers up to 0.82.
Supermarine chief designer Joseph Smith, one of the masterminds behind these two Spitfire offshoots.
The ill-fated ‘hybrid’ Spiteful prototype NN660, which mated a Spitfire XIV body with the new wing. CROWN COPYRIGHT
The design and construction of the Spiteful was covered by specification F1/43 of May 1943. As noted, this document basically described a single-seat aircraft with the laminar-flow wing and a Spitfire VIII fuselage. Initially Supermarine allocated its Type 371 to just the wing, but later this number covered the full aircraft. At this stage the powerplant was to be either a Rolls-Royce Merlin or Griffon fitted with a contra-rotating propeller, so the wing would also need to be compatible with the Griffonpowered Spitfire 21. In the event, no Merlin-powered aircraft would fly with the laminar-flow surface, but it was not until mid1944 that Supermarine agreed to drop the Merlin Spiteful. The plans for Merlin versions explain why the first Spiteful mark was the Griffon-powered XIV, the direct equivalent to the Griffon Spitfire XIV, because the lower mark numbers had been left vacant for Merlin-powered variants.
A maximum speed of 525mph (845km/h) and a Mach number of 0.83 were used as a basis for the Spiteful’s strength and stiffness calculations. The structure with its straight leading and trailing edges was certainly much easier to build than the Spitfire’s elliptical form, but it did present some new problems. To enable it to bear the loads expected in flight, this thin surface had to be made much heavier for its size than an equivalent thick wing, with the result that there was rather less space available inside for fuel. And from the production standpoint, to ensure laminar flow was achieved, the wing demanded great accuracy of manufacture along with a far better surface finish than was usual. Indeed, for the first time in a production aircraft, this new principle in wing design required contours which had to be accurate to within five thousandths of an inch.
Such was the optimism for this fighter project that by 1 October 1943 proposals had been put forward to switch production at the Castle Bromwich factory to Spitefuls sometime between August and November 1944, though mating the wing to the fuselage would, in the end, necessitate substantial changes to the latter. Production schedules would also be hampered by a lack of available skilled draughtsmen and other labour, a real problem because of the extra care necessary to ensure the wing was made accurately, with its extremely smooth surface.
The three prototype Spitefuls, serials NN660, NN664 and NN667, were covered by a contract dated 4 February 1943. That said, NN660 was in fact a unique hybrid prototype since it had a Spitfire XIV body with its original non-bubble canopy plus the new wing. Supermarine
Spiteful NN664 at Boscombe Down on 29 June 1945. CROWN COPYRIGHT
chief test pilot Jeffrey Quill took NN660 for its maiden flight on 30 June 1944, though taking quite so long to get this machine into the air had brought the manufacturer some criticism. The equivalent Spitfire variant was the MkXIV and NN660 was found to be comfortably faster, but not as quick as had been anticipated or hoped for.
Test pilot Frank Furlong was killed in NN660 on 13 September 1944 during a flight from High Post airfield in Wiltshire, used by Supermarine for flight-testing purposes. During a mock dogfight against a Spitfire XIV, Furlong at one point pulled high g. The Spiteful flicked onto its back and hit the ground near the airfield before the pilot could recover. The reason was never clarified, but it is thought the ailerons may have jammed momentarily, a phenomenon experienced later by Quill himself in NN664, though at a higher and thus safer altitude. During December 1944 Supermarine was again criticised by the ministry over the programme’s slow progress, but Quill finally got the first fullstandard prototype, NN664, into the air on 8 January 1945.
Early Spiteful flight trials had, however, uncovered problems with aileron ‘snatching’ and wing drop ahead of the stall, while under high g there was a pronounced flick at the stall. Covering the wing with wool tufts revealed that, in flight, the area ahead of the ailerons would begin to stall before the rest of the wing. This was the opposite of what happened with the Spitfire, on which the stall began at the root and worked its way along the wing to the tips. The stall on
the laminar-flow wing appeared to begin at the tips and move inwards.
On top of this, when these advanced laminar sections were flight-tested on the Spiteful it became clear that the hopedfor reductions in drag were not being achieved. One factor was that tiny elements of surface roughness — for example, specks of dirt or dead insects stuck to the wing — proved sufficient to create some turbulent flow within the boundary layer, thus destroying the laminar flow and reducing the speed. At higher speeds the laminar sections did delay the onset of shockwaves and the associated increase in transonic drag, but the levels of skin friction drag were found to have changed little when compared to the Spitfire’s wing.
Prototype NN664 began its flying career with a standard Spitfire F21 tailplane and fabric-covered elevators and rudder, but the standard, much larger-area Spiteful tailplane
went on to be fitted. To try and solve some of the Spiteful’s in-flight weaknesses, NN664 later flew with reduced-span ailerons, modified wing sections near the ailerons and beading on the aileron trailing edge. The redesigned and enlarged tail surfaces on this prototype, which were fitted to production machines as well, improved the low-speed handling characteristics, lateral control approaching the stall and lateral stability. But these changes lowered the maximum speed, with the result that the Spiteful’s performance was not now going to be much better than later versions of the Spitfire.
The Spiteful was discussed at a meeting held on 7 February 1945 and attended by J. E. Serby, deputy director of research and development (air) and E. M. Fraser, director-general of aircraft production at the Air Ministry, along with Supermarine’s Joe Smith and general manager Cdr James Bird. Bird stressed how the company was worried about the lack of labour to hold the Spiteful programme on schedule, so perhaps, he suggested, some work should be moved to other factories. He also emphasised that the Spiteful, being the first thin-wing aircraft, should be regarded as a new design on which teething troubles were to be expected. Smith added that flying trials had begun on the second prototype and alterations would be required, chiefly to the tail unit and ailerons (as outlined above), but no serious design difficulties had come to light.
However, in view of the experimental nature of the Spiteful’s design, and the fact that considerably more prototype flying was needed, neither the Supermarine representatives nor Serby felt able to give any estimate of the date on which the fighter would be technically cleared for production. Bird said the production of fuselages and parts was proceeding, but modifications were required and the manufacture of some items had been halted because of the prototype crash. Consequently, it would be necessary to manufacture another 100 to 150 Spitfires to maintain the level of wartime production.
The ministry representatives stated it would be misleading to inflate the aircraft and engine programmes by increasing the quantity of Spitfires without making a compensatory reduction in Spitefuls, particularly as Griffon engines for both were in short supply. For these reasons, and because production tooling was not ready, it was agreed that the Spiteful build-up would have to be slowed and that the resulting gap should be filled by an increase in Spitfire production before the middle of the year.
CROWN COPYRIGHT Development
The Spiteful was a single-seat, low-wing monoplane fi ghter and fi ghter-bomber powered by a Rolls-Royce Griff on 12-cylinder ‘V’-type liquidcooled engine. Its structure and components were all-metal, with stressed skin covering the frames and a surface fi nish taken to very fi ne limits. e laminarfl ow wing shape, formed from Supermarine’s own high-speedsection two-spar mainplane aerofoil, enabled conventional two-spar construction to be employed, unlike the Spitfi re which had a single-spar wing. It was made in two sections with detachable tips and the structure was described by the manufacturer as “very robust”, but the designers still kept the weight very low.
All fl ying controls were conventional, the ailerons being operated by push-pull rods and the elevators and rudder by cables, and metal-covered split fl aps stretched along the trailing edge from the wing roots to the ailerons. e two-spar wing permitted an inwards-retracting undercarriage to be fi tted — it was some 4ft (1.22m) wider than the Spitfi re’s narrow-track gear. e Spiteful’s fuselage was a redesign of the Spitfi re’s. It had more of a humped-back appearance, with the pilot’s seat further reclined than in the Spitfi re, and an improved view over the nose. e type’s large fi n and rudder was also used by latemark Spitfi res and Seafi res, and was thus often referred to as the ‘Spiteful-type’ tail. When in the ‘up’ position the undercarriage was totally enclosed by doors, as was the case with the tailwheel; the mainwheels were fi tted with pneumatic brakes.
e fi xed armament consisted of four 20mm-calibre guns with 624 rounds of ammunition, 167 for each inboard gun and 145 to each outer one, while combinations of rocket projectiles or bombs could go underneath the wings with little loss of performance. A camera gun was provided. Armour protection was added to the cockpit and other vulnerable points, while the fuel tanks (other than those with armour) were self-sealing.
Normal fuel capacity was 178 Imperial gallons (809 litres) and a 90 (409-litre) or 180-Imperial gallon (818-litre) drop tank could be carried without reduction in normal military load. Early Spitefuls could hold only 118 gallons (537 litres) internally, but a 60-gallon (273-litre) tank was introduced in the rear fuselage. e smaller external tank gave
NN664 was the fi rst true Spiteful prototype, fi nished predominantly in natural metal and with the air intake set back. CROWN COPYRIGHT Production Spiteful RB517 with a fi ve-blade propeller.
Spitefuls were built. e FXIV had a Griff on 69 engine, a short air intake and fi ve-blade Rotol propeller, while the FXV was to have Griff on 89s or 90s and a sixblade contra-rotating prop. It is thought that all of the RB serials appeared as MkXIVs since there are no known photos of a MkXV. e Griff on 69 with its two-stage supercharger was little diff erent from the Spitfi re’s Griff on 61; the main change was that the 69 could operate at a maximum of 25lb per square inch boost when using 150-grade fuel, but for 100-octane fuel it had to be restricted to 18lb per square inch using throttle stops.
RB515 made its maiden fl ight on 2 April 1945 with the original Spitfi re F21 tailplane, but after three further fl ights the larger Spiteful tail replaced it. is brought considerable improvements to low-speed lateral control near the stall and better directional stability. However, on production Spitefuls the clean stall at 109mph (175km/h) was preceded by a lateral ‘pecking’ of the wings and then a very sharp port wing drop. With everything down the stall occurred at 101mph (163km/h) and was even more unpleasant with a tendency towards an incipient spin. On 28 September 1945 the fi rst-stage supercharger in RB515’s Griff on disintegrated at 30,000ft (9,144m), but SheaSimonds made a safe wheels-up landing at Farnborough. ere was a possibility of using the Spiteful in the fi ghterbomber role, and with this in mind RB516 was tested as such by the A&AEE from April 1946. RB517 was used to conduct engine cooling and performance testing at Boscombe and RB518 was employed on propeller development; on 28 July 1945 the latter was at Supermarine’s High Post fl ight development airfi eld for diving trials. RB519, RB520 and RB521 were all used for general testing, and RB523 for armament trials.
As the only Spiteful F16, RB518 had its air intake position moved to beneath the nose — in fact, this was the original intake position as used on NN660. It had a fi ve-blade propeller and a Griff on 101 engine. CROWN COPYRIGHT
Jeff rey Quill waits to take off in Spiteful RB522 at the display held at Farnborough between 27 and 30 June 1946. JO WARE e Air Ministry had told Supermarine on 23 August 1945 that the Spiteful was to be dropped from the fi ghter programme, but it could be retained as a fi ghter-bomber. Interest in the type gradually died, however, and it would never enter RAF service. Consideration was given that November to equipping one squadron with Spitefuls for trials, as a replacement for Spitfi re 22s, but this idea was dropped and production came to an end in December 1945. e intention had been to make 88 deliveries in 1945 and another 248 in 1946.
On 9 August 1948 Supermarine reported on a programme of propeller tests using RB518 with a Griff on 101 installed with its two-stage, three-speed supercharger. In this form this one-off airframe was designated as the Spiteful F16, the Roman numerals in UK military designations having now been replaced by Western Arabic ones, and it was fl own at a weight of 8,600lb (3,901kg). RB518 had the original Spiteful air intake and a Seafang-type windscreen and hood. e fl ight test programme compared the level speed performance when an 11ft 0in (3.35m)-diameter, wide-chord, NACA 16-section propeller was fi tted, and then with a double wedge-section propeller of similar diameter. e latter tests came to an end prematurely when RB518 was forced to make a landing with its undercarriage retracted.
It was found that the doublewedge propeller provided a slight gain in level speed — 3-4mph (4.8-6.4km/h) below full throttle height (FTH) — and possibly an increase in full throttle height of up to 1,500ft (457m). e NACA propeller had an FTH of 33,600ft (10,241m) with a speed at that height of 487mph (784km/h); the equivalent double wedge fi gures were 35,100ft (10,698m) and 494mph (795km/h). e fi gure of 494mph logged during a sortie in 1947 was the highest recorded speed by a British pistonengined aircraft in level fl ight.
Between 3 December 1946 and 3 March 1947, no less than 13 Spitefuls arrived at No 6 Maintenance Unit at Brize Norton, most of them in the fi rst few days of December.
Despite the ‘P’ for prototype marking on the fuselage side, VG471 was the first production Seafang. KE Y COLLECTION
These were serials RB516, RB517, RB519, RB520, RB521, RB522, RB524, RB525 and RB527 to RB531 inclusive. All these airframes were sold for scrap in July 1948 to John Dale and Sons at London Colney, presumably in pieces, this company being a specialist in what was termed secondary (recycled) aluminium. The dismantling of prototype NN667 appears to have started on 1 May 1947 and it was transported to Brize Norton for salvage. RB518 was possibly the last Spiteful to survive, being recorded with No 49 MU at Colerne for breakdown on 21 March 1949.
Seafang
From early October 1943, Supermarine looked into the possibility of fitting the laminarflow wing to the Seafire XV, but the concept of a naval Spiteful had no official backing until specification N5/45 of 17 July 1945 was issued to cover such a version, which Supermarine called its Type 396, or the Seafang. The document described a prototype based on the Spiteful, with a maximum folded wingspan of 27ft (8.23m) and a folded height of 13ft (3.96m). A single Griffon 85 or 87 would be fitted; again four 20mm Hispanos would go into the wings, and it could carry bombs or rockets.
Spiteful RB520 was modified with just a sting-type arrestor hook to operate as an interim Seafang prototype, first flying as such in early 1945. Supermarine conducted all the early flight trials with RB520. It was made available for Royal Navy use but never collected, and struck off charge on 13 January 1947. The ‘hooked’ Spiteful made its public debut on 2 October 1945 at a display of new naval aeroplanes
staged by the Admiralty at Heston.
A contract dated 12 March 1945 covered two true Type 396 Seafang FXXXII (Mk32) prototypes, serials VB893 and VB895, fitted with Griffon 89s, contra-rotating propellers and hydraulically operated wingfolding. These airframes were manufactured by Supermarine’s Hursley Park facility and VB895 made its first flight there in early 1946. From 18 June it underwent production testing at Eastleigh, arriving at A&AEE Boscombe Down on 30 June. Information on VB893 is very scarce, but it was delivered to the A&AEE on 20 December 1946. Little more is known, in part because no history card has been found for this aircraft.
Jeffrey Quill displayed VB895 at the event held at Farnborough from 27-30 June 1946 to show off British aerodynamic achievement. Then on 21 August Supermarine test pilot Lt Cdr Mike Lithgow flew the Seafang in front of Dutch, French and
American naval representatives during a four-day visit to Valkenburg in the Netherlands, but this did not generate any export orders. Lithgow had replaced Shea-Simonds in early 1946 and took over from Quill as Supermarine chief test pilot in 1947. Next, in the week from 10 September, Supermarine sent a Seafang 32 and a Seafire 47 to the first post-war Society of British Aircraft Constructors show at Radlett. During its display the Seafang demonstrated exceptional aileron control. Back at High Post in mid-October, VB895 was used to test powerfolding of its wings and a longstroke undercarriage. Further demonstration flying took place at Wisley on 9-10 January 1947.
Deck trials commenced on 1 May 1947, opening with approximately 45 simulated trial landings at Supermarine’s new flight development airfield at Chilbolton. For these Lithgow flew VB895 at an all-up weight of 9,870lb (4,477kg) with flap settings of 30° for take-off and 76° for landing. Engine-off stalling speed was 89kt (164km/h) indicated, at which there was a certain level of elevator and general buffet, the beginnings of general aileron snatching, and a high descent rate. Fortunately, the snatching was much less prevalent during the landing itself and the problem was thought to have been caused by ground effect.
Lithgow considered that both the spring tab elevator and long-stroke oleo legs were vital for deck landings with this aircraft. This was because the former proved most effective in reducing the otherwise large stick forces involved in manipulating the flaps, and the latter would eliminate bounce and absorb the shock of the necessarily heavy landings experienced in carrier operation.
Spiteful RB520 was flown as an interim Seafang prototype after the addition of a sting-type arrestor hook. BAE SYSTEMS
The pitot comb installation fitted to the inboard wing trailing edge of VB475 for measuring the critical Mach number and then establishing the
VB895 flew to RNAS Ford on 20 May 1947 and first went aboard HMS Illustrious for full trials on the following day. Eight landings were completed without incident and the view of the oncoming deck ahead was found to be excellent overall. Indeed, Lithgow realised he could make his final approach, over the last 200 yards (183m), from directly astern. The approach at 95kt (175km/h) was “quite comfortable”, the only criticism being over-light aileron control with no selfcentring tendency, which was a feature of the Spiteful family’s characteristics overall.
Lithgow matched the approach speed of the Seafang against that for the Seafire FR47. Although the position error correction figures were not especially accurate, the Seafire’s approach speed came to 77kt (143km/h) indicated while the Seafang recorded 95kt (175km/h) indicated, so there was little difference. On receiving the ‘cut’ signal, the Seafang sat down on the deck extremely well and without any float. With take-off flap and plus 18lb per square inch of boost, its take-off was straightforward and easy. Lithgow considered the Seafang prototype to be a good deck landing aeroplane, primarily because of the good view and the lack of float when cutting the throttle. Later VB895 was used to trial a 170-gallon (773-litre) drop tank shaped something like a torpedo. Carrying this in flight cut VB895’s speed at 10,000ft (3,048m) from 373mph (600km/h) down to 360mph (579km/h).
On 29 May 1947, VB895 was demonstrated at RAF West Raynham. Then between 27 April 1948 and May 1949 it was on the strength of ‘C’ (Naval) Squadron at A&AEE Boscombe Down for gun clearance trials. To begin with, the ground functioning checks proceeded satisfactorily, but on 10 May 1948 — during ground trials of the Supermarine Attacker jet fighter’s cannon — an explosion in the gun bay seriously damaged VB895’s port mainplane. The wing had to be repaired at Chilbolton and the aircraft rejoined ‘C’ Squadron on 24 June, but there was another explosion in the port wing on 1 October 1948. Chilbolton again made the repairs and VB895 came back to ‘C’ Squadron on 16 December.
As a consequence of these explosions, ventilators were fitted to ensure that for future firings the gun gases would always be cleared out. These had intakes below the wings with the exits above. The development of a gas plug by A&AEE removed any danger of an explosion in the gun bay and enabled air functioning to be checked later with the ventilators removed. After finally being struck off charge, VB895 was used for ‘vulnerability trials’ by the Proof & Experimental Establishment at Shoeburyness, where it may have survived until 1956.
The Spiteful and Spitfire contract also covered 150 production Seafangs with serials VG471-505, VG540-589, VG602-650 and VG664-679. In fact, the Spiteful order was cancelled on 2 May 1945 and the Seafang order placed five days later, so the latter was really a reinstatement. Materials and parts rendered surplus by the Spiteful reduction were to be used in Seafang airframes whenever possible. The Seafangs from VG480 onwards were themselves cancelled, though the first seven were delivered in dismantled form, and the nine actually completed (up to VG479) appeared as F31s with a five-blade Rotol propeller. The last Seafang was completed in 1947.
When compared to the Spiteful the first production Seafang, VG471 — which lacked wing folding — introduced an additional 3° of wing dihedral plus more rounded leading edges, both of which would appear on the Spiteful. VG471 flew in January 1946 and made the journey from High Post to Farnborough on 15 February to begin arrester hook trials. These had to be suspended for a period because the rudder skin became wrinkled during off-centre arrests, to the point where VG471 had to be flown back to High Post on 16 March for modifications including a thickened leading edge. The prototype was back at Farnborough on 27 April. It finally cleared its arrester hook trials on the 30th and A&AEE test pilot Capt Eric Brown undertook the aircraft’s official deck landing assessment on 1 May.
In fact, Brown flew many of the A&AEE’s assessment flights in the Seafang, and the deck trials left him with the impression that the Seafire 47 was the better aeroplane. The contra-rotating propeller and wide undercarriage made taking off in a Seafang easier than in a Seafire 46 with its non-contra-
Seafang VB895 — test-flown from Hursley Park, Eastleigh and Boscombe Down — photographed on 13 December
1946. BAE SYSTEMS HERITAGE, FARNBOROUGH
rotating propellers, because there were no effects from torque roll. In flight the Seafang’s controls were superbly light and effective at normal speeds, but Brown described the Seafang’s stall as “vicious”. Furthermore, lowering the undercarriage and flaps for landing produced a strong nose-up change of trim and the new fighter gave the impression of being unsafe when flying at approach speeds under 110mph (177km/h).
Although the Seafire 47 had slightly inferior performance compared to the Seafang 31, it was clearly the preferable choice as a carrier fighter. The Seafire 47’s performance at high altitude was, in addition, better than expected. In the end the navy rejected the Seafang and went on to order the FR47 in April 1946. Orders were also eventually placed, in quantity, for the Hawker Sea Fury.
This was not the end for the Seafang, though, because the type would find work in several trials programmes. To begin with VG475, a Mk31 fitted with a Mk32 contra-rotating propeller, had a pitot comb unit attached to its inboard wing trailing edge. This permitted the drag coefficient to be compared against the Mach number and necessitated a reduction in aileron span by 15in (38.1cm). VG475’s guns were taken out and the rear fuel tank replaced by cameras, and from 23 June 1947 test pilot John Derry conducted several dives with the aircraft in this form. In one such dive, started at 27,000ft (8,230m), VG475 reached 400mph (644km/h) indicated at 20,000ft (6,096m) and Mach 0.77, but a violent pitching was experienced at Mach 0.75 in the form of a high-frequency phugoid, and it was impossible for the pilot to hold the stick steady. In further dives where the Seafang reached
450mph (724km/h) at 10,000ft (3,048m), and then 480mph (772km/h) at just 1,000ft (305m), there was no problem with pitching, so the phenomenon was related to a specific Mach number. The source proved to be the wake apparatus fitted to the airframe and subsequent modifications permitted VG475 to be taken to Mach 0.83 in a dive without difficulty.
The drag comb tests were ongoing at High Post until, it is thought, 28 August 1947. Previously this aircraft had been there from 15 August 1946 for drag and boundary layer investigations. VG475 was struck off charge on 20 October 1948 as a source of spare parts, and on 16 June 1953 was collected by No 49 MU to go to the Farnborough dump.
Another trial involved the testing of a Servodyne-assisted aileron system on VG474. This aircraft had contra-rotating propellers and had joined ‘C’ Squadron at Boscombe Down on 10 May 1946, where it was
used initially for further takeoff trials and deck landings; in mid-August it moved on to the testing of hydraulic brakes. By 5 September 1947 it was back at High Post where it began handling trials with the Servodyne ailerons, measuring rates of roll. The results were excellent, the Seafang’s rate of roll at medium speeds having been improved considerably. Nevertheless, when flying at 450mph (724km/h) the results were inferior to the follow-on Attacker jet fighter’s spring tabs. The two types had essentially the same wing and the spring tabs were the only change to the Attacker’s ailerons from the Seafang’s standard balance tabs.
In March 1948, Eric Brown flew VG474 with power-operated ailerons which he described as “superb”, except that at speeds in excess of 460mph (740km/h) there was a steep build-up in force. He piloted VG474 again in July 1948 after it had been fitted with Attacker-type ailerons and was able to report nearperfection in lateral control over the entire speed range. VG474 had joined the Royal Navy’s 703 Squadron, a trials and development unit based at Lee-on-Solent, by 10 June 1949, before being struck off charge on 21 August 1950. It became another Seafang to go to the P&EE at Shoeburyness for ‘vulnerability trials’, and most likely it was still there in 1956.
Finally, production Seafangs VG477, VG478 and VG479 were at Vickers-Armstrongs’ facility at Eastleigh in either December 1946 or January 1947, but all three airframes were almost immediately sent to No 6 MU at Brize Norton. There, presumably, they followed the same path to their disposal and scrapping as had the Spitefuls at that same location.
In the July 2001 Aeroplane Lt Patrick Shea-Simonds, a Fleet Air Arm test pilot who was seconded to Supermarine during the period the Spiteful was under test, remembered what the fi ghter was like.
“ ere were obvious similarities with the Spitfi re”, he wrote, “but there were also many diff erences. e cockpit layout of the Spiteful was quite diff erent; it was no longer a ‘Spitfi re cockpit’. e most obvious change was to the seating position, which was more reclined. Sitting in the seat, one’s feet on the rudder pedals felt as if they were ‘up in the air’. Several of the shorter pilots did not like the new seating position. But being 6ft 6in (1.98m) tall, sitting in a Spitfi re even with the seat fully down I always felt rather squashed in. I found the Spiteful cockpit much roomier, and the view over the nose was defi nitely better than in the Spitfi re.”
As Shea-Simonds gained experience in the Spiteful, he found it pleasant to fl y and it performed well at high speed. After the Spitfi re’s superb handling, however, almost any other aircraft was going to be a disappointment.
“ e main snag with the Spiteful was its low-speed handling. e Spitfi re had washout along the wing (the angle of incidence was greatest at the wing root, and decreased progressively toward the tip). If you held a Spitfi re straight and level, throttled back and
eased back on the stick, the stall started at the wing root and worked its way out toward the tips. If you continued to hold the aircraft straight, it could be made to sink in a stalled glide with a measure of lateral control.
“ e approach to the stall in the Spiteful was quite diff erent. With the laminar-fl ow wing there was no wash-out, and the stall seemed to begin at the tips and work its way in. You did not get a violent wing-drop, but you did get a wing-drop and there was pronounced ‘kicking’ of the ailerons. As a warning of a stall that was reasonable enough, but it felt nothing like as pleasant as the Spitfi re’s. When it approached the stall, the Spiteful felt as if it was about to do something nasty. On the fl are-out before
landing, for example, it felt as if it was balanced on a pin and might tilt one way or the other at any moment. In fact the aircraft didn’t do anything unpleasant, but it felt as if it might and that was disconcerting until one got used to it.”
When taxiing, the Spiteful’s handling was again markedly diff erent from that of the Spitfi re: “Many people complained about the Spitfi re’s narrow-track undercarriage, and it certainly wasn’t ideal for deck operations. But it did have a curious sort of ‘bicycle stability’. Once the aircraft was rolling forwards, it tended to go straight in the direction in which it was pointing. e SpitefuI was diff erent. During taxiing and landing runs it tended to wander off course, and one had to rely on diff erential braking to keep it going straight.”
During normal operations the Spiteful’s lack of directional stability on the ground was no more than an irritation. But during one fl ight Shea-Simonds suff ered hydraulic failure.
“ e undercarriage, brakes and fl aps were all hydraulically operated in the Spiteful (on the Spitfi re the undercarriage was hydraulically operated, the brakes and fl aps were pneumatically operated). I knew I could get the undercarriage down with the carbon-dioxide emergency system, but I would have no brakes or fl aps. Since I had to make a fl apless landing
The Spiteful’s stall was one area where its fl ying characteristics were defi nitely worse than the ‘Spit’, and its lower-speed handling was less than pleasant. RAF MUSEUM
I decided to go to Boscombe Down, where the runway was much longer than the one at High Post. I got the aircraft down on the ground and was rolling down the runway, but as the speed fell away the rudder became less and less effective. The aircraft started to wander to one side. With no brakes, all I could do was to give a quick burst of engine to put slipstream over the rudder and get the aircraft going straight again. I ran on down the runway with a series of ever-decreasing ‘blips’ of the engine, gradually getting slower and slower. The Spiteful ran off the end of the runway at a walking pace and came to rest on the grass without damage.”
Supermarine’s design team worked hard to improve the Spiteful’s low-speed handling characteristics. Redesigned and enlarged tail surfaces gave better lateral control and stability at low speed. These were fitted to the first production aircraft, RB515, soon after its first flight in April 1945. The new tail was also fitted to NN664, and was standard on all subsequent Spitefuls. Shea-Simonds wrote, “The aircraft were all fitted with new wings having slightly blunted leading edges, and enlarged tails. We also tested it with root spoilers and modified ailerons. The changes improved the aircraft’s lowspeed handling, which became noticeably more pleasant. But these improvements were all made at the expense of all-out level speed. As a result, the performance of the Spiteful was little better than that of the Spitfire 22.”
RB515 was designated as a Spiteful FXIV. During a test flight in RB515 on 28 September 1945, Shea-Simonds experienced a near-catastrophic engine failure. He had taken off from High Post to examine handling and longitudinal stability at 30,000ft (9,144m). Up to 28,000ft (8,534m) the climb was normal, and he reduced power to bring the aircraft to maximum cruising speed in level flight at 30,000ft (9,144m). Slowly the indicated air speed increased to 240mph (386km/h), but, “Suddenly there was a loud explosion and I saw something (a piece of the engine) fly past the cockpit on the starboard side. The engine began to vibrate very violently, and oil streamed back over the windscreen and cockpit hood. The engine rpm counter was hard against the upper stop, reading 4,000rpm. Obviously the propeller had ‘run away’.”
A Spiteful, probably RB515, demonstrates its agility, the rate of roll having been a particular improvement over the Spitfire. JO WARE
The prop’s constant-speed unit had failed, putting the blades into fully fine pitch, and the engine went into overspeed, literally shaking itself to pieces. Shea-Simonds continued, “l took what action I could to deal with the situation. I brought the constant-speed control lever back to positive coarse pitch, closed the throttle, pulled the engine cut-out, turned off the fuel and switched off the ignition. At the same time I pulled the nose up, reducing speed to 140mph (225km/h) indicated. I then opened the cockpit hood, released my safety harness and prepared to abandon the aircraft. I expected the engine either to disintegrate completely or to be torn from its mounting. The vibration and high rpm persisted, while oil and glycol streamed around and into the cockpit.”
A test pilot’s duty was to get his aircraft back on the ground
in one piece, if possible. The damaged aeroplane was a valuable piece of evidence, and unless the fault was corrected others would encounter it. Shea-Simonds prepared to bail out, but resolved to stay with the aeroplane and save it if he could.
“After about 15 seconds,” he recalled, “the rpm fell rapidly, the propeller came to a stop and the vibration ceased. I called Boscombe Down on the radio and informed them that my engine had blown up and I was preparing for a forced landing. By this time I was over the Swindon area, which like Boscombe and High Post was covered in cloud. To the east the skies were clear, and as I did not feel like letting down through cloud with the engine out, and could see Farnborough clear and within gliding distance, I decided to land there. I had plenty of height, and once the vibration ceased the Spiteful handled quite well as a glider.”
Shea-Simonds refastened his harness and began his approach to Farnborough from the southwest. Although this would bring him in for a downwind landing, the surface wind was light and he preferred to approach the airfield over open country rather than over the town.
“It was obvious that the hydraulic systems were no longer working fully, and I had no idea what damage had been done to them. Rather than risk finding that only one undercarriage leg would extend, I decided to land the aircraft with the wheels up. I selected flaps down and worked the hand pump until resistance ceased, at which point I had about quarter-flap. I made my final approach and landed wheels-up on the grass alongside the main runway. Surprisingly, the touchdown was the least dramatic part of the whole business. The Spiteful had a large wide-span radiator under each wing, and it slid along the grass on these; it felt just like putting down a flying-boat on water. As I touched down I saw the fire tenders and ambulance driving down the runway, practically in formation with me.”
Later examination revealed the Griffon’s first-stage supercharger had disintegrated completely. There had been considerable damage to the hydraulic, glycol and oil pipes at the rear of the engine, as well as to the cowling and fillets in the vicinity of the supercharger. On the starboard side, part of the crankcase had shattered and at least one connecting rod had broken. For saving the aircraft, Shea-Simonds received a King’s
Commendation for valuable service in the air. RB515 suffered surprisingly little damage and, repaired and with a new engine, it resumed flying.
In October 1945 the Spiteful took part in a display of the latest British military and captured German aircraft at Farnborough. It made little impression, though, as Shea-Simonds recalled, “Jeffrey [Quill] flew the Spiteful on the first day and I flew it on the second. The occasion was embarrassing for us, however, because Geoffrey de Havilland stole the show with his very
impressive demonstration of the Vampire. It was clear that the end was in sight for the pistonengined fighter.”
Some accounts have declared that developing the Spiteful and Seafang was a big mistake — a
Armament trials made use of Spiteful RB523, which carried 20mm guns in the wings.
BAE SYSTEMS HERITAGE, FARNBOROUGH ‘Spitfire too far’. In part, perhaps this is true, but much was gained from these programmes. The creation of the tapered laminarflow wing was of benefit to and used by the Supermarine Attacker jet fighter that followed, while the testing conducted with the Spiteful and Seafang, both in the air and in the wind tunnel, made a serious contribution to the knowledge of aerodynamics at transonic speeds, so they can hardly be considered a waste of effort. In addition, regardless of how promising these aircraft might have been, or not, they were always going to be defeated by the arrival of the jet fighter. And it should not be forgotten that the Spiteful remains one of the fastest piston aircraft ever to have flown.
Thanks to Phil Butler and the National Archives.
