Vickers Viscount

The Vickers Viscount was a British medium-range turboprop airliner first flown in 1948 by Vickers-Armstrongs, making it the first such aircraft to enter service in the world. A product of the Brabazon Committee, it was a ground-breaking aircraft making use of a brand-new form of propulsion, the turboprop engine, replacing the conventional piston engine. The Viscount was well received by the public for its favourable cabin conditions, which included pressurisation, significant reductions in vibration and noise, and large panoramic windows. Due to these unique advantages, it went on to be one of the most successful and profitable of the first generation post-war transport aircraft types;[1] a total of 445 Viscounts were built for a wide range of international customers, including the North American market. Origins The Viscount was developed in response to the Brabazon Committee's Type II design for post-war use, calling for a small sized, medium range pressurised aircraft to fly its less-travelled routes, carrying 24 passengers up to 1,750 mi (2,816 km) at 200 mph (320 km/h).[2] During discussions between the committee and Vickers' Chief Designer Rex Pierson, Vickers advocated the use of turboprop power, believing piston engines to be a dead end in aviation. The Brabazon committee was not so convinced, but agreed to split the specification into two types, the Type IIA using piston power, which led to the Airspeed Ambassador, and the turboprop-powered Type IIB which Vickers was selected to develop in April 1945.[3] British European Airways (BEA) was involved in the design and asked that the aircraft carry 32 passengers instead, but remained otherwise similar. The first design in June 1945 was based on the Viking with four turbo-prop engines and 24-seat and designated the VC-2 or Type 453.[4] Later a double-bubble fuselage was proposed to give extra underfloor cargo space.[4][5] Both these early designs were not pressurised and it was soon realised that for economic operations at 20,000 ft (6,100 m) it needed pressurisation, the two early designs were abandoned and a circular cross-section varian was offered at the beginning of 1946.[4] The resulting 28-seat VC-2 was financed by the Ministry of Supply with an order for two prototypes but before the contract for the prototypes was signed the government asked for the capacity to be increased to 32-seats, this resulted in a fuselage increase from 65 ft 5 in (19.94 m) to 74 ft 6 in (22.71 m) and an increased wingspan of 89 ft (27 m).[N 1][4] The contract for the aircraft to Air Ministry specification C.16/46 was signed on 9 March 1946 and Vickers allocated the designation Type 609 and the name Viceroy to the aircraft.[4] Although George Edwards had always favoured using the Dart other engines were still being considered including the Mamba which the government specified for the two prototypes, the choice of the Mamba engine increased the gross weight of the aircraft but Vickers made sure that the engine nacelle would fit either the Mamba or Dart.[4][6] While the Dart was making better progress in development than the Mamba the government asked in August 1947 for the second prototype to be Dart-powered.[4] The second prototype was designated as the Type 630 and was later named as the Viscount.[4] The first prototype already under construction was converted to the Dart engine as a Type 630 as well.[4] The resulting Vickers Type 630 design was completed at Brooklands by Chief Designer Rex Pierson and his staff in 1945, a 32-seat airliner powered by four Rolls-Royce Dart engines providing a cruising speed of 275 mph (443 km/h). An order for two prototypes was placed in March 1946, and construction started almost immediately in the company's Foxwarren Experimental Department. Originally to be named Viceroy after the viceroy of India, Lord Louis Mountbatten; the aircraft was renamed as Viscount following India's independence in 1947.[7] There was some work on replacing the Darts with the Armstrong Siddeley Mamba, but this was dropped by the time the prototypes were reaching completion. After Pierson's death in 1948, George Edwards (later Sir George Edwards) took over as chief designer and assumed all technical control over the Viscount project.[