Even as Spitfires and Hurricanes flown by the “Few” were engaged in mortal combat with Bf 109s and He 111Fs during the Battle of Britain, the RAF was already looking forward to a time when it might have to defend England against new German aircraft capable of operating at altitudes of 35,000 feet or greater. No existing fighter was capable of fulfilling this need, so the service called upon the British aviation industry to submit proposals for a new type able to meet high altitude threats.
Among the designs put forward was the Vickers 432, the final fighter to be built by the company, and another creation of Barnes Wallis. The 432 was reminiscent of the Mosquito, but had an all-metal fuselage and a pressure cabin with a small bubble canopy for the single crewman. A pair of Merlin 61s would provide the new interceptor a top speed of 400 mph at better than 40,000 feet. The destruction of enemy aircraft would be achieved by a pack of six 20mm Hispanos under the nose.
The first of two projected 432 prototypes flew from Farnborough in late December -1942, However, although German penetrations of UK airspace would continue almost to the end of the war, by this time the threat of a renewed all-out offensive by the Luftwaffe was receding. The 432 was passed over, although the competing Westland Welkin was to be bought in small numbers. The prototype Vickers fighter was never fitted with armament or an operational pressure cabin, and construction of the second aircraft was abandoned in the fall of 1943.