Vickers Vanguard Vickers Type 950

The Type 950 is the designation with which Vickers-Armstrongs closed the long series of studies that followed the success of the Viscount. Discussions with British European Airways about a successor began in early 1953, and Trans-Canada Air Lines soon became interested in a broadly similar aircraft. Around sixty layouts were evaluated during development, including high-wing versions that were dropped because of the more complicated undercarriage retraction arrangements. By 13 April 1955 the field had been narrowed to five proposals, jointly evaluated by BEA and Vickers; the winner, the Type 870 Scheme 16a, combined a low wing with a double-bubble fuselage, giving a long hold beneath the cabin for the large volume of freight BEA carried. TCA wanted the low wing because it made refuelling, de-icing and servicing easier and improved survival in a water landing. After the Type 900, which raised the payload, relatively minor revisions that mainly increased the gross weight produced the definitive proposal: the Type 950. The programme was developed entirely as a Vickers private venture.

The Rolls-Royce Dart of the Viscount was the first powerplant considered, but Rolls-Royce indicated that a new engine, the RB.109, was well under way; it became the Tyne. It was first run in April 1955 and was developed primarily for the Vanguard. The production aircraft for BEA were fitted with four Tyne Mk.506 engines of 4985 equivalent shaft horsepower each; the sources do not state which Tyne version the prototype itself carried.

The prototype, designated Type 950/1 and registered G-AOYW, was rolled out at Brooklands (Weybridge, Surrey) on 4 December 1958 and began a series of ground runs on its Tyne engines. The first flight had been planned for December, but the engines were returned to Rolls-Royce for minor work. On 20 January 1959 G-AOYW finally took off from Brooklands, flown by Vickers chief test pilot G. R. 'Jock' Bryce with Brian Trubshaw as co-pilot. It was an 18-minute flight: a simple transfer of about five kilometres from the Weybridge factory to the company's test airfield at Wisley, from where the proper flight-test programme was then flown.

According to the English Wikipedia, development went relatively smoothly with one notable exception: more than 2000 flights were needed to resolve stalling characteristics judged unacceptable. A Russian aviation magazine notes that the prototype's trials proved the aircraft's economy, especially on sectors of up to 800 km, despite the arrival of jets. On 22 April 1959 it was joined by the first production aircraft for BEA, G-APEA (Type 951). In the last weeks of trials with BEA in early 1960, engine-related difficulties appeared that required the compressor rotor to be modified; according to the German Wikipedia, these defects were uncovered by the engine trials flown with the fourth production aircraft, G-APED, and they delayed the certificate of airworthiness until December 1960. With the problem solved, the Vanguard entered scheduled service with TCA on 1 February 1961 and with BEA on 1 March 1961.

Only one flying Type 950 was built; two further fuselages were used as static test airframes. Given the brief life of the programme — only 44 Vanguards were built in all — G-AOYW, known as 'Yankee Whisky', was scrapped at Wisley in late 1964. It does not survive.