Das letzte Projekt 2014 - geboren aus der Idee, was aus der schnittigen Westland Whirlwind hätte werden können, wenn man ihr ordentliche Triebwerke (Merlins) verpasst hätte... Und dies ist dann daraus geworden:
Some background:The Westland Whirlwind was a British twin-engined heavy fighter developed by Westland Aircraft. It was the Royal Air Force's first single-seat, twin-engined, cannon-armed fighter, and a contemporary of the Supermarine Spitfire and Hawker Hurricane.
A problem for designers in the 1930s was that most agile combat aircraft were generally small. These aircraft had limited fuel storage and only enough flying range for defensive operations. A multi-engined fighter appeared to be the best solution to the problem of range, but a fighter large enough to carry an increased fuel load might be too unwieldy to successfully engage in combat. Germany and the United States pressed ahead with their design programs, resulting in the Messerschmitt Bf 110 and the Lockheed P-38 Lightning.
The first Whirlwind prototype (L6844) flew on 11 October 1938. Construction had been delayed chiefly due some new features and also the late delivery of the original Peregrine engines. Further Service Trials were carried out at Martlesham Heath, where the new type exhibited excellent handling and was very easy to fly at all speeds. It was one of the fastest aircraft in service when it flew in the late 1930s, and was much more heavily armed than any other.
However, protracted development problems with its Rolls-Royce Peregrine engines delayed the entire project. The combat radius also turned out to be rather short (only 300 miles), and the landing speed high, which hampered the type's utility. The major role for the Whirlwinds, however, became low-level attack, flying cross-channel "Rhubarb" sweeps against ground targets and "Roadstead" attacks against shipping.
Time went by and worked against the Whirlwind: By 1940, the Supermarine Spitfire was mounting 20 mm cannons, so the "cannon-armed" requirement was also being met, and by this time the role of escort fighter was becoming less important as RAF Bomber Command turned to night bomber missions. The main qualities the RAF were looking for in a twin-engine fighter were range and carrying capacity (to allow the large radar apparatus of the time to be carried), in which requirements the Bristol Beaufighter could perform just as well as or even better than the Whirlwind.
In order to catch up in performance, Westland 's team around Teddy Petter attempted in summer 1942 to mate the Whirlwind's compact fuselage with the much more potent Rolls-Royce Merlin engine. Most apparent external change were the longer engine nacelles and an added fin fillet in order to improve directional stability. In order to counter the CG shift associated with the longer engines, the rear fuselage was stretched by 2'with a plug, similar to the Focke Wulf Fw190 D-9.
More changes had to be done under the Whirlwind's skin: the wings' main spar had to be reinforced, as well as the outer wings' hull (now all-metal, including the rudders, and now able to carry unguided RP-3 rockets) and the landing gear. The extended fuselage was used to add a fuel tank behind the cockpit, which would compensate range losses due to the higher overall weight and power output. Furthermore, the original Hispano cannons with drum magazines were replaced by belt-fed Mk. II cannons, which more than doubled the four guns' magazine capacity (from 240 shells to 560).
The net power improvement by +34% resulted in a significant higher top speed and better acceleration and rate of climb at medium altitude. But the overall performance benefit of the Merlin engines was less convincing than expected. More modern/potent Merlin versions were considered, but their shortage (being reserved for Spitfires and Mosquitos) eventually led to a stop of that idea. Furthermore, the Whirlwind simply offered not much further development potential, e. g. as a night fighter.
In the end, only 22 Whirlwinds were converted from FB.1 airframes to the updated FB.2 status in the course of March to June 1943. These machines also received exhaust flame dampers, a special night-flying cockpit and other modifications for night intruder missions, including an appropriate black underside and red codes.
During the Second World War only two RAF squadrons were equipped with the Whirlwind FB.1, and only one with the FB.2. By July 1943, after moving to RAF Hunsdon, the 157th Squadron began intruder attacks on German fighter bases with its revamped Whirlwind FB.2s and new Mosquito Mk VIs.
In November 1943 it moved to RAF Predannack in Cornwall, closer to the German bases. However, in March 1944 it moved to RAF Valley and flew defensive patrols over the Irish Sea, while the Whirlwinds kept up “Rhubard” attacks on the continent, including various ground attack missions on V-1 and V-2 launch sites located in Holland. In May 1944 the 157th Squadron moved again, to East Anglia, and received Mosquito Mk XIXs.
The Squadron’s new task was to support bomber streams as part of No. 100 Group RAF, and in the wake of these long range duties the Whirlwind FB.2s were finally retired. The last flight took place on 6th of September 1944.
General characteristics:Crew: One pilot
Length: 35 ft 4 1/2 in (10.80 m)
Wingspan: 45 ft 0 in (13.72 m)
Height: 11 ft 0 in (3.35 m)
Wing area: 250 ft² (23.2 m²)
Airfoil: NACA 23017-08
Empty weight: 8.800 lb (3.,995 kg)
Loaded weight: 11.467 lb (5.206 kg)
Max. take-off weight: 12.665 lb (5,750 kg)
Powerplant:2× Rolls-Royce Merlin XX liquid-cooled V-12, 1,185 hp (883 kW) at 21,000 ft (6,400 m),
driving de Havilland constant speed propellers with a diameter of 9 ft 10 in (3.00 m)
Performance:Maximum speed: 435 mph (701 km/h) at 15.000 ft (4.570 m)
Stall speed: 95 mph (83 knots, 153 km/h) (flaps down)
Range: 800 mi (696 nmi, 1.288 km)
Service ceiling: 35.200 ft (10.729 m)
Armament:4x belt-fed 20 mm (.79 in) Hispano Mk II cannons, 140 RPG each
2x 250 lbs (115 kg) or 500 lbs (230 kg) bombs, or two racks with 8× RP-3 unguided air-to-ground rockets.
Zum Bausatz:Obwohl ich seit rund 35 Jahren bastel' habe ich noch keine Whirlwind gebaut! Zeit das nachzuholen, direkt mit Umbau. Der wurde möglich, weil ich vor einiger Zeit die Triebwerkszellen einer Airfix-Mosquito, die ich auf Sternmotoren umgerüstet hatte, für solch ein Projekt beiseite gelegt hatte. Und ich hatte endlich Glück, einen bezahlbaren Whirlwind-Bausatz zu finden, in diesem Falle das Bilek-Remake des antiken Airfix-Kits.
Zuerst wollte ich nur die Triebwerke austauschen, letztlich entschied ich mich für eine Komplettimplantation der Mossie-Zellen - was die Kiste zwar etwas nasenlastig macht, aber einfacher war, da quasi alle Mosquito-Teile inkl. Propeller ein Nummer größer sind. So mussten die Propellerblätter jeweils auch um 3mm gekürzt werden, damit es halbwegs passt.
Das Fahrwerk wiederum stammt OOB vom Bilek-Bausatz, weitere Ergänzung ist die Finne vorm Seitenruder und die Raketen-Roste, die auch von der Airfix-Mosquito stammen. Im Cocpit wurde ein Armaturenbrett ergänzt und die Haube zersägt, um sie geöffnet darstellen zu können. Das war's aber auch schon.
Bemalung und Markierung sind klassisch (Dunkelgrün/Ozeangrau oben, unten Schwarz für Nachtangriffe aufs kontinentale Festland) und einem realen Vorbild nachempfunden, die Markierungen zusammengepuzzelt. Die Invasionsstreifen sind alles Decals, in weiten Teilen von der Airfix-Mosquito; nur die weißen Streifen auf der Tragflächenunterseite sind aus einzelnen, weißen Streifen (TL Modellbau) improvisiert. Zuletzt wurde das Modell leicht verwittert, und mit Graphit Auspuff- und Schmauchspuren ergänzt.
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Kurz hatte ich überlegt, daraus einen Rennflieger zu machen, denn die "aufgemotzte" Whirlwind hat durchaus etwas Popeye-artiges. Aber letztlich blieb ich der Ursprungsidee treu - einem subtilen Umbau.
Thema: What if? Westland Whirlwind FB.2, RAF No. 157 Fighter Sq.; Predannack, Frühjahr 1944 (Gelesen 3039 mal)