World War II Database

Contributor: Alan Chanter

ww2dbaseDuring 1942, the British Air Ministry became concerned that the German Luftwaffe might commence operations over the United Kingdom at altitudes beyond the capabilities of existing RAF fighters. To meet this possible threat a new specification, F.16/40, was issued to aircraft manufacturers calling for a specialised high-altitude interceptor, pressurised cabins being a prerequisite.

ww2dbaseUnder the supervision of Dr. Barnes Wallace (q.v) Vickers tendered for the contract, proposing an adaptation of their existing Type 414 project (being prepared to meet the Ministry's F.22/39 specification) in which the 40-mm Vickers cannon mounted in a dorsal turret would be substituted by a more conventional armament of 20mm Hispano cannons mounted in a ventral blister. This design, designated Type 420 (and unofficially as the "Mayfly") would subsequently be amended by further changes, including a pressure cabin, called for in Specification F.7/41, leading to the final redesignation of Type 432. A completed Type 432 prototype (Serial DZ217) flew for the first time some seven weeks after that of the rival contender, the Westland P.14 Welkin, during the last week of December 1942. The 432 was the first Vickers aircraft of wholly stressed-skin construction. The all-metal monocoque fuselage was a streamlined tube with a relatively small self-contained pressure cabin, similar to that evolved for the Wellington V and VI bombers, for the pilot, whose head projected through a small, double-glazed dome or "bubble" which hinged to one side for entrance and exit. The lightweight two-spar wings designed by Barnes Wallace, incorporated the coolant radiators for the engines, and were of "lobster-claw" design, with their forward portions of metal stressed-skinning and the aft portions fabric covering.

ww2dbaseInitial trials proved the Type 432 to be difficult to handle on the ground, the aircraft snaking while taxying which necessitating aft movement of the main wheels to correct the bad tracking. Although it possessed an excellent performance once in the air, with a substantially higher maximum speed than the Welkin the Air Ministry selected the rival Westland fighter for production.

ww2dbaseThe fate of the Type 432 project was, however, settled during 1942 when the high-altitude Spitfire Mks VI and VII began to be introduced into squadron service. This coupled with the fact that high-altitude enemy attacks had failed to materialise led the Air Ministry to cancel any further development of the project. Production of the Welkin was also cancelled at this time, after just sixty-seven machines had been manufactured (none of which would be issued to squadrons). The sole Type 432 aircraft was retained by Vickers to become a testbed for assessing aerodynamic efficiency of the unique wing structure. These trials would continue until December 1944 when DZ217 was finally scrapped. The construction of a second prototype (DZ223) which had also been ordered was similarily abandoned.

Type 432 Timeline

SPECIFICATIONS

Type 432

Machinery	Two 1,520hp Rolls Royce Merlin 61 12-cyl Vee liquid-cooled engines
Armament	6x20mm Hispano Mk I or II cannon (planned)
Crew	1
Span	17.34 m
Length	12.38 m
Height	4.19 m
Wing Area	40.97 m²
Weight, Empty	7,427 kg
Weight, Maximum	9,148 kg
Speed, Maximum	611 km/h
Range, Normal	2,414 km

Photographs