After the Second World War, the Viking was an important airliner with British airlines, pending the development of turboprop aircraft like the Viscount. An experimental airframe was fitted with Rolls-Royce Nene turbojets and first flown in 1948 as the world's first pure jet transport aircraft. Military developments were the Vickers Valetta and the Vickers Varsity. The first prototype (designated the Type 491 and registered G-AGOK) was built by the Vickers Experimental Department at its wartime Foxwarren dispersal site and was first flown by 'Mutt' Summers at Wisley Airfield on 22 June 1945.[5] This aircraft crashed on 23 April 1946 due to a double engine failure; no fatalities occurred as a result of the crash. Following successful trials of the three prototypes the British Overseas Airways Corporation (BOAC) ordered 19 aircraft. The first BOAC aircraft flew on 23 March 1946. The prototypes were then used for trials with the Royal Air Force which led to orders for military versions (the Viking C2 (12 ordered as freighter/transports) and the modified Valetta C1). The initial 19 production aircraft (later designated the Viking 1A) carried 21 passengers, they had metal fuselages and - except for the wing inboard of the nacelles - fabric-clad geodetic wings and tail units. Following feedback from customers, the next 14 examples, known as the Viking 1, featured stressed-metal wings and tail units. The next variant, the Viking 1B, was 28 in (71 cm) longer, carrying 24 passengers with up-rated Bristol Hercules piston engines, achieved a production run of 115. One of this batch was changed during production to so that it could be fitted with two Rolls-Royce Nene turbojet engines, with its first flight on 6 April 1948. Production finished in 1948, including 16 for the RAF of which 4 were for the King's Flight, but in 1952 BEA adapted some to a 38-passenger layout, taking the maximum payload up from 5,500–7,200 lb (2,500–3,300 kg). All Vikings featured a tailwheel undercarriage. The 58th Viking (c/n 158) became the prototype of the military Valetta, of which 262 were produced for the RAF. When production of this strengthened but externally similar type ended in 1952, a flying classroom version with tricycle undercarriage was already being delivered to the Royal Air Force (RAF), called the Varsity. The production of 161 Varsities kept the Hurn works busy until January 1954, and they enjoyed a long service life. Examples are preserved at Brooklands Museum, the Imperial War Museum Duxford and the Newark Air Museum. Royal Australian Air Force - One Viking C2 in service from 1947 to 1951. No. 2 Squadron RAAF No. 34 Squadron RAAF Vickers Viking with RR Nene jet engines. Vickers Valetta with strengthened floor and cargo door. Vickers Varsity with tricycle undercarriage.
