The origins of the Type 432 lay with a requirements set out in 1939 for twin-engined fighters with 20 or possibly 40 mmcannon. Vickers had set out a proposal for a Griffon-engined aircraft, equipped with a 40 mm cannon in a flexible mounting. This was subsequently encouraged by the Air Ministry. Further development was carried out for a design that could also meet F.6/39 for a fixed gun fighter with 20mm cannon. Specification F.22/39 was drawn up to cover the 40mm project as the Vickers 414 to meet Operational Requirement 76. This was subsequently revised with aircraft redesigns to become specifications F.16/40 and then F.7/41 for OR. 108. In appearance it resembled a larger version of the de Havilland Mosquito and was known as the "Tin Mosquito". The pilot had a pressurised cockpit in the nose, with a bubble dome, similar to an enlarged astrodome. The pressurised cockpit took up the nose section so the cannon would have been fitted in a fairing below the fuselage, to the rear of the aircraft. The aircraft's elliptical wing was built using a unique stressed-skin structure, designed by Barnes Wallis for lightness. The top and bottom were manufactured separately, and then clamped together at the leading and trailing edges, this being named "peapod" or "lobster-claw" structure. This allowed a large internal space unobstructed by ribs, hence capable of housing large fuel tanks.
Operational history
The first prototype Type 432 DZ217 was flown on 24 December 1942. Initial trials revealed serious handling difficulties on the ground, the aircraft snaking while taxiing, necessitating aft movement of the mainwheels to correct the bad tracking. In flight tests, the Type 432 was unable to be landed in a standard "three-point" stance resulting in the replacement of the Irving-type ailerons with new Westland types along with an alteration of tail settings. The estimated maximum speed of 435 mph at 28,000 ft was never attained as the Merlin 61 engines did not run satisfactorily above 23,000 ft. When the competing Westland Welkin was ordered into production, the second prototype of the Vickers fighter, the Type 446, was cancelled, before completion, on 1 May 1943. The first prototype was retained by Vickers for test purposes until the end of 1944, when the aircraft was scrapped after completing only 28 flights.
