1:72 Supermarine Spitfire L.F. Mk.Xb (early); aircraft VF-Q/EP120 of the USAAF 5th FS (52nd FG, 12th AF); during Operation Torch, Northern Africa, November 1942 (Whif/modified Revell kit)
+++ DISCLAIMER +++
Nothing you see here is real, even though the conversion or the presented background story might be based on historical facts. BEWARE!
The Supermarine Spitfire was a British single-seat fighter aircraft used by the Royal Air Force and other Allied countries before, during and after World War II. Many variants of the Spitfire were built, using several wing configurations, and it was produced in greater numbers than any other British aircraft. It was also the only British fighter produced continuously throughout the war.
The Spitfire was designed as a short-range, high-performance interceptor aircraft by R. J. Mitchell, chief designer at Supermarine Aviation Works, which operated as a subsidiary of Vickers-Armstrong from 1928. Mitchell pushed the Spitfire's distinctive elliptical wing designed by Beverley Shenstone to have the thinnest possible cross-section, helping give the aircraft a higher top speed than several contemporary fighters, including the Hawker Hurricane. Mitchell continued to refine the design until his death in 1937, whereupon his colleague Joseph Smith took over as chief designer, overseeing the Spitfire's development through its multitude of variants and many sub-variants. These covered the Spitfire in development from the Merlin to Griffon water-cooled inline engines, the high-speed photo-reconnaissance variants and the different wing configurations.
One exception was the Spitfire Mk. X: it was the only variant powered by a radial engine, and it looked quite different from its sleek Merlin-powered brethren. Early in its development, the Merlin engine's lack of fuel injection meant that Spitfires and Hurricanes, unlike the Bf 109E, were unable to simply nose down into a steep dive. This meant a Luftwaffe fighter could simply "bunt" into a high-power dive to escape an attack, leaving the Spitfire behind, as its fuel was forced out of the carburetor by negative "g". An alternative engine was to solve this issue. Another factor that suggested an air-cooled engine were theatres of operations in the Far East, primarily India: the hot and humid climate was expected to be a severe operational problem for the liquid-cooled Merlin. As a further side effect a radial engine was expected to be easier to maintain under these conditions than the Merlin.
The project of a radial-powered Spitfire variant was eventually launched in late 1940. The choice for the power unit fell on a Bristol Taurus II 14-Cylinder engine, which had an appreciable small diameter, was available in ample numbers and had about the same power output as the early Merlin variants used in the Spitfire Mk. I and II (1.030 hp/740kW). In order to save time and keep the radial engine variant as close as possible to the Spitfire V design, the production type of that era. The new type’s structure and fuselage were only adapted to a minimum to allow the bulkier power unit and its periphery to be taken. The fuselage was widened in front of the cockpit section, a new engine mount was integrated and the Merlin’s radiator bath and respective piping were removed. The oil cooler under the port wing was retained, though, and the Taurus engine was from the start outfitted with dust filters, so that all resulting Spitfire Mk. Xs left the factory tropicalized. Like the Spitfire Mk. V, different wing armaments were available, e.g. an “A” wing with eight .303 in machine guns and a “B” wing with two 20 mm cannon and four machine guns.
The first Spitfire Mk. Xs, finally outfitted with a more powerful Taurus VI engine, were delivered to homeland RAF units for evaluation from May 1941 onwards. From the start, the radial-powered Spitfire proved to be inferior to the Merlin-powered variants - even to the early Mk. Is – and they were no match to the modern German fighters, especially at high altitude. As a consequence many Mk. Xs received clipped wing tips for better roll characteristics at low altitude (receiving an additional “L.F.” designation), but this did not significantly improve the type’s overall mediocre performance. Only a few Mk. Xs were actually employed by front line units, most were quickly relegated to training units. Later production aircraft were immediately shipped to the Far East or to units in Northern Africa, where they could be used more effectively.
A few machines were also delivered to Egypt (30), the Netherlands (12 for the East Indies NL-KNIL, which eventually ended up in RAAF service) and Turkey (24). In 1942, many machines still based in Great Britain were handed over to the USAAF, being either used for USAAF pilot and conversion training, or they were allocated to the Northern Africa invasion force during Operation Torch.
Since the Taurus-powered Spitfire turned out to be quite ineffective (it was no good either in the fighter or in an alternative ground attack role and 20 mph slower than the comparable Mk. V), production was already stopped in late 1942 after 353 aircraft. At the same time, the Spitfire Mk. IX with a much more powerful Merlin engine entered service, and all resources were immediately allocated to this more potent fighter variant and the idea of the Spitfire with a radial engine was ultimately dropped. Since the Taurus-powered type was quickly phased out of frontline service, the designation was later re-used for a pressurized high-altitude photo reconnaissance variant of the Spitfire, the PR.X, of which only 16 machines were built.
Crew: one pilot
Length: 29 ft 6 in (9.00 m)
Wingspan: 32 ft 2 in (9.80 m)
Height: 11 ft 5 in (3.86 m)
Wing area: 242.1 ft2 (22.48 m²)
Airfoil: NACA 2213 (root)
NACA 2209.4 (tip)
Empty weight: 5,065 lb (2,297 kg)
Loaded weight: 6,622 lb (3,000 kg)
Max. takeoff weight: 6,700 lb (3,039 kg)
1× Bristol Taurus VI 14-Cylinder sleeve valve radial engine, 1.130 hp (830 kW)
Maximum speed: 350 mph (312 kn, 565 km/h)
Combat radius: 410 nmi (470 mi/756 km)
Ferry range: 991 nmi (1,135 mi/1,827 km)
Service ceiling: 36,500 ft (11,125 m)
Rate of climb: 2,535 ft/min (12.9 m/s)
Wing loading: 27.35 lb/ft2 (133.5 kg/m²)
Power/mass: 0.22 hp/lb (0.36 kW/kg)
2× 20 mm Hispano Mk II with 60 RPG
4× .303 in Browning Mk II machine guns with 350 RPG
The kit and its assembly:
My third contribution to the “RAF Centenary” Group Build at whatifmodelers.com, and the next one in chronological order. This one was spawned by the simple thought of “What would a Spitfire with a radial engine look like…?”. I have seen this stunt done in the form of a Fw190/Spitfire kitbash – nice result, but it did IMHO just not look like a “real” Spitfire with a radial engine, rather like an Fw 190 with elliptical wings. And the fact that I had already successfully transplanted a Centaurus engine onto a P-51 airframe made me feel positive that the stunt could be done!
Consequently, the conversion was pretty straightforward. The basis is a Revell 1:72 Spitfire VB (1996 mold), which was – except for the nose section – taken OOB. A simple, nice kit, even though it comes with some flaws, like a depression at the rear of the wing/fuselage intersection and the general need for PSR – not much, but I expected a better fit for such a relatively young mold?
For the engine, I used a personal replacement favorite, the cowling and the engine block from a Mitsubishi A6M2 “Zero” (Hasegawa). The Nakajima Sakae radial engine has a relatively small diameter, so that it serves well as a dummy for the compact Bristol Taurus engine – a replacement I have already used for a radial-powered Westland Whirlwind. The other benefit of the small diameter is that it is relatively easy to blend the round front end into the oval and very slender fuselage of the early Spitfire airframe. This was realized through massive body sculpting from scratch with 2C putty, widening the area in front of the cockpit and expanding its width to match the cowling – I guess that real life engineers would have followed a similar, simple path.
Since the radial engine would not need a radiator, I simple omitted this piece (cut out from the single piece lower wing half) and faired the respective underwing area over with a piece of styrene sheet and PSR. The asymmetrical oil cooler was retained, though. The propeller is a replacement from the scrap box, with a smaller diameter spinner and more slender blades which better suit the open cowling.
Since the Taurus had its best performance at low altitudes, I used the Revell kit’s OOB option of clipped wing tips – a move that makes the aircraft look much faster, esp. with the new, deeper nose section.
Painting and markings:
I did not want classic RAF markings, but still keep the model well within the Centenary GB confines. The original plan had been a classic Dark Green/Ocean Grey livery, which all Spitfire’s in USAAF service and based in the UK received. But I rather wanted to create a frontline aircraft, operated during Operation Torch in late 1942/early 1943 with American roundels – and the grey/green look would not look plausible on a machine taking part in the North African campaign. In fact, any Spitfire with American roundels I found that was used in North Africa carried the RAF Tropical Scheme in Dark Earth/Middle Stone. And, AFAIK, during Operation 'Torch' all British aircraft received American markings in the hope that the Vichy French, who were anti-British due to them bombing their ships in 1940, would switch to the allied cause. They were supposed to think that the Americans would be invading, not British troops as well. So I eventually switched to the classic Tropical Scheme (using Humbrol 29 and Modelmaster 2052 as basic tones), and it does not look bad at all - even though the yellow trim around the roundels does not stand out as much as on a Grey/Green aircraft.
Typically, the RAF codes were retained, as well as – at least during the early phases of Operation Torch – the RAF fin flash. A little personal twist is the pale blue (Humbrol 23, Duck Egg Blue) underside of the aircraft, instead of the typical Azure Blue. The rationale behind is that the Tropical Scheme was originally designed with Sky undersides, and the blue shades were later modifications after initial field experience.
The red spinner is a typical Northern Africa marking, and found on many 5th FS aircraft.
The interior (cockpit, landing gear wells) was painted with RAF Cockpit Green (Modelmaster), while wheels and struts became light grey.
As a standard procedure, the kit received a light black ink wash and a post shading treatment.
The decals were puzzled together from various sheets and sources, the design benchmark was a real USAAF Spitfire Vb from Operation Torch, though. The code letters were taken from an Xtradecal sheet, the roundels come from a Carpena Spitfire sheet, even though I placed American markings in all six positions – the roundels without yellow trim under the wings were taken from a Hobby Boss F6F sheet.
The serial number comes from the Revell kit’s OOB sheet, because it fits perfectly into the kit’s intended time frame. The nose art comes from a P-38 sheet (PrintScale) – not a typical feature for an RAF Spitfire, but a frequent personal decoration among USAAF machines during Operation Torch (e.g. on P-40s).
The Allied yellow ID markings on the wings’ leading edges, which were typically carried by Operation Torch Spitfires, too, were created with generic yellow decal sheet (TL Modellbau), while the maroon machine gun nozzle covers are part of Revell’s OOB sheet.
Finally, the kit received some soot stains around gun and exhaust nozzles, and was finally sealed with matt acrylic varnish.
A bold experiment, and it turned out well. The Zero’s cowling has the perfect diameter for this transplant, and the scratch-sculpted new front fuselage section blends well with the new engine – the whole thing really looks intentional! I am just not certain if the resulting aircraft still deserves the “Spitfire” designation? Even though only the engine was changed, the aircraft looks really different and has a Ki-43ish aura? I guess that a dark green livery and some hinomaru would also look great and pretty plausible?