The final attempt by Vickers to develop a fighter for the RAF began in 1939 with a design for a twin-engined heavy fighter featuring an armament of a 40mm Vickers cannon in a dorsal turret. As the Type 414, this corresponded with the requirements of Specification F.22/39 for a 400 mph (644 km/h) two-seat fighter. The aircraft was to carry four 20-mm cannons, with the possibility of later mounting two 40-mm cannons.

 

Under a design team led by Rex Pierson, Vickers-Armstrongs Ltd. (Vickers) had been working on a fighter with a single flexibly-mounted 40-mm cannon installed in the aircraft’s nose. The twin-engine aircraft was powered by Rolls-Royce Griffon engines and met the requirements of F.6/39, aside from its armament. Vickers met with the Air Ministry in April 1939 to discuss the aircraft’s potential. The Air Ministry was sufficiently impressed and issued Specification F.22/39 that covered the Vickers fighter, which carried the internal designation Type 414. Specification F.6/39 was subsequently cancelled in November 1939.

 

Turret development began in a Wellington test-bed but, in the course of 1940, the requirement was changed via Specification F.16/40, to emphasise high-altitude performance, as there were growing fears that the Luftwaffe would be able to launch operations over Britain at altitudes beyond the capabilities of existing RAF fighters. A more conventional armament of 20mm cannon was adopted in the revised Vickers 420 design to the new specification, but further changes were called for in Specification F.7/41, including a pressure cabin.

 

Two Type 414 prototypes were ordered on 30 August 1939, and they were assigned serial numbers R2436 and R2437. After inspection of the Type 414 mockup in early February, the Air Ministry inquired about the possibility of installing several 20-mm cannons in place of the single 40-mm cannon. Vickers responded with aircraft proposals incorporating eight 20-mm cannons or two 40-mm cannons.

 

Vickers designated the fighter with 20-mm cannons as the Type 420. Two cannons were positioned in the aircraft’s nose, and three were on each side of the cockpit. Vickers and the Air Ministry discussed the Type 420 in June 1940, and Specification F.16/40 was issued for the aircraft’s development. The Type 420 was given a high priority, and an order for two prototypes was expected. The order for two Type 414 prototypes was still in place. However, the Type 420 took precedence, and work on the Type 414 slowed substantially.

 

In early January 1941, the Air Ministry requested a design change to reduce the number of 20-mm cannons to six. At the same time, Vickers had designed a high-altitude fighter that used many components from the Type 420. The high-altitude aircraft was armed with four 20-mm cannons and powered by two Rolls-Royce Merlin engines. The Air Ministry was interested in Vickers’ proposal, as they felt there was an urgent need for a heavily armed, high-altitude fighter aircraft to intercept high-altitude German bombers that were expected in the skies over Britain. However, high-altitude German bombing raids were never undertaken en masse and did not present a significant threat to Britain during World War II.

 

In March 1941, work on the Type 414 was stopped completely, and discussions with Rolls Royce commenced regarding the acquisition of Merlin engines. In May 1941, Vickers detailed the specifics of the high-altitude aircraft, which it had designated as Type 432. The Vickers response to this final requirement was Type 432, completely re-stressed and with an armament of six 20mm cannon in a ventral blister. The original contract for the Type 414/420s was cancelled in 1941 and a new one substituted for two Type 432s. Design work on the Type 432 continued, resulting in the switch to a single-seat cockpit placed in the nose of the aircraft and six 20-mm cannons installed in a ventral fairing. Each cannon had 120 rounds of ammunition. The Air Ministry ordered two Type 432 prototypes on 9 September 1941, and the aircraft would be built to the new Specification F.7/41. The two Type 432 prototypes were issued serial numbers DZ217 and DZ223.

 

 

As finally built, the Type 432 was the first Vickers aircraft of wholly stressed-skin construction of stressed-skin aluminum panels that were flush-riveted to the closely-spaced circular structures that made up the airframe, and it made use of a so-called "lobster-claw" design for the wing torsion box, in which heavy-gauge skin had a thickened section to house the span wise spar booms, giving a profile shaped like a lobster claw so that conventional wing spars and ribs were omitted. Fabric covered the aft section of the wings and the aircraft’s control surfaces. The fuselage was a streamlined tube and the coolant radiators for the engines were buried within the wing. The pilot was accommodated in a relatively small, self-contained pressure cabin, his head being enclosed by a small, double-glazed dome, or "bubble", which hinged to one side for access and egress.

 

The Type 432 mockup was inspected in late December 1941, and the first prototype, DZ217, was built throughout 1942. The aircraft was built at Foxwarren, a special Vickers dispersal site for experimental work near Brooklands in Surrey, England. The site did not have an airfield, so the Type 432 was disassembled and transported to Royal Aircraft Establishment Farnborough for its first flight.

 

The Vickers Type 432 prototype DZ217 appears shortly after its completion at Foxwarren.

 

Powered by two Rolls-Royce Merlin 61 12-cylinder Vee-type engines rated at 1520hp (1,178 kW) at 23,500 ft (7,163 m), the first prototype Type 432 was flown on 24 December 1942, piloted by Tommy Lucke, initial trials revealing serious handling difficulties on the ground, the aircraft snaking while taxying and necessitating 3 in (76 mm) aft movement of the mainwheels to correct the bad tracking. The impossibility of making a three-point landing was only rectified by replacement of the Irving-type ailerons with surfaces of Westland type and alteration of tail settings. The competitive Westland Welkin was ordered into production and the second prototype of the Vickers fighter, the Type 446, was cancelled on 1 May 1943 before completion. This decision was not made official until 1 May 1943.

 

The first prototype was retained by Vickers for test purposes until the end of 1944. The estimated maximum speed of 700km/h at 8535m was never attained as the Merlin 61 engines did not run satisfactorily above 7010m.

 

The sole Type 432 aircraft continued to fly occasionally until November 1944. Some efforts were made throughout the aircraft’s existence to improve its handling and flight qualities, as the Type 432 was noted as having heavy controls. Only 28 flights were made, and the aircraft was never submitted for official trials or tested to its maximum performance. Additionally, the 20-mm armament and the pressurized cabin were never installed. Although the Type 432 exceeded 400 mph (644 km/h) in a slight dive, the highest speed obtained in level flight was 380 mph (612 km/h), recorded on 14 May 1943. One of the factors that limited flight testing was that the Merlin engines installed in the Type 432 did not run well above 23,000 ft (7,010 m). Since the Type 432 had no future as a production aircraft, the performance issues of its Merlins were never fully investigated.

 

The entire Type 432 program was cancelled at the end of 1943.

 

Aircraft observers were a regular fixture during World War II, keeping an eye out for any enemy action in the skies over Britain. The rarely-seen and oddly-shaped Type 432 was only listed as “AP1480” in the recognition handbooks. This non-descript designation led the spotters to dub the Type 432 as the “Tin Mossie” on account of the aircraft’s resemblance to the wooden de Haviland Mosquito.

 

 

Engines: Rolls-Royce Merlin 61, 1520hp

Fuel capacity: 506 USG / 421 Imp gal / 1,914 lt

Top speed est: 320 mph (515 km/h) at sea level

Top speed est: 435 mph (700 km/h) at 28,000 ft (8,534 m)

Top speed est: 400 mph (644 km/h) at 40,000 ft (12,192 m)

Cruise speed est: 400 mph (644 km/h) at 29,500 mph (8,992 m)

Service ceiling: 43,500 ft (13,259 m)

Initial climb rate: 2,750 fpm (14.0 m/s

Vickers 432