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Aviation History
1955
1955 - 0974.PDF
CO 86 FLIGHT, 15 July 1955 THE STORY OF THE VISCOUNT ... in parallel and it was clear that the firm retained anopen mind on the subject. This specification is interesting because, besidesdealing with the existing VC-2—now called V.630 Viscount—with the three alternative engines andgross weights ranging from 38,170 lb with the Mamba to 39,050 lb with the Naiad, it also describeda longer-range V.640 Viscount Mark II, powered by Naiads, with a gross weight of 43,500 lb. In September 1947, B.E.A. prepared a study ofalternative power units in the VC-2 (P. and D. paper PP/579). In a comparison of versions of the aircraftwith four Merlin 22, four R-2000-3 Twin Wasps, two Centaurus 57 and four Mambas, the study concludedthat the Merlin installation was the most attractive in this size of airframe. The conclusion drawn wasthat the turboprop design should be "stretched" still further. In spite of this, on August 27, 1947, the Ministrywrote to Vickers instructing them to proceed with the Dart which had been fundamentally redesignedand much improved. First one and then both V.609 prototypes were accordingly converted into V.630swith the Rolls-Royce engine. Work proceeded on construction of these aircraft in the experimentalshop at Wisley. Rex Pierson died on January 11th, 1948. By thenconstruction of the first prototype of the design he had inspired was well advanced and it finally flew forthe first time from the grass strip at Wisley aero- drome six months later on July 16th (a photographappears at the head of p.83). The pilot was the late Capt. J. "Mutt" Summers, the veteran Vickers chieftest pilot. G-AHRF, the V.630 was the forty-third prototype he took up on its first flight. As a sidelight on the development of theaeroplane, several of those concerned with the earliest pro- posals for the VC-2 are now dead—including Rex Pierson, "Mutt"Summers, and Sir Hew Kilner. Meanwhile, B.E.A.'s doubts about the economic characteristics of the small-bodied V.630were increasing. The study of the previous September had shown that the turbine was less attractive than equivalent pistonengines in a design with the characteristics of the V.630. Accord- ingly, late in 1947 B.E.A. made proposals for an enlarged Viscountwith a bigger wing and higher weights. These were elaborated in April 1948 when three alternatives were considered: a 32-passenger aeroplane with the V.630 body but an enlarged wing powered with two Bristol Hercules 700 series piston engines;a 40-passenger aeroplane with a correspondingly stretched body, the enlarged wing and four Dart engines of increased power; anda 40-passenger aeroplane with bigger body and wing powered by two Bristol Centaurus piston engines. The Hercules-powered small body/large wing aircraft and theDan-powered large body/wing aircraft seem to have been studied by Vickers as the V.652 and V.653.On August 6th, 1948 B.E.A. proposed to the 19th meeting of the Interdepartmental Civil Aircraft Requirements Committee-|-the Government body at that time responsible for co-ordinating civil aircraft procurement—that it should order an enlargedViscount powered initially with two Centaurus piston engines and that plans should be made to re-engine these aircraft withDart propeller-turbines at a later stage. An alternative B.E.A. proposal was that the Corporation should order an entirely newenlarged Dart-engined Viscount. (These proposals were set out in I.GA.R. Paper No. 35 of November 28th, 1947.) First off the Viscount production line was V.701 G-ALWE, here seen on its maiden flight at Wisley. FKjK of V.700 Prototype 5i4 BEA order for 20 V.70l<~ rKA Orctr for 12 V.tOZs 5 co2 ON5 in C4 in in in \oin in Four phases of Viking and Viscount development: (A) preliminary discussion; (B) design and prototype building; (C) prototype and pre-production flying, and (D) airline service. In the case of the Viking the curve here shown is extended to eight years in B.E.A. service; thereafter this aircraft becomes a secondary type. Neither of these suggestions was accepted by the Government,and B.E.A. agreed instead to confirm the order for 20 Airspeed Ambassadors which had been placed at the end of 1947. Asthese aircraft—later to become known as Elizabethans—were powered with two Centaurus piston engines and were closelysimilar in size to the enlarged Centaurus-powered Viscount pro- posed by B.E;A., this was clearly a logical decision. The firstElizabethan prototype had flown in July of the previous year and the design showed great promise. It therefore seemed likely to bewell ahead of an equivalent Vickers piston-engined design. The confirmation of the Elizabethan order by B.E.A. markedthe lowest point in the fortunes of the Viscount. At this time it seemed that the project was doomed. The early flights of theV.630 prototype that summer started, however, to turn the tide. Turboprops had such obvious attractions that there was soon anew swing of opinion in their favour. This trend was strengthened by proposals from Rolls-Royce for a new, up-rated, Dart engineof 1,400 sJi.p. (1,550 e.h.p.). The scheme, already suggested by B.E.A. to stretch the V.630 so as to improve its economics,immediately became possible with these new engines. Before Vickers finally agreed to do this, however, they produced onefurther set of proposals on the basis of the smaller V.630-type air- frame. In November, 1948 (specification 88840) Vickers proposeda developed V.630 powered by the new 1,400 s.h.p. Dart R.Da.3 engines. This aeroplane had the same small wing and bodyas the V.630 but the gross weight was raised to 45,000 lb. Passenger accommodation for up to 43 passengers was to beprovided, in spite of the small body, by accepting some loss in standards. The cruising speed was 333 m.p.h. These proposals did not appeal to B.E.A. or the Ministry ofSupply, but as a result of further representations from B.E.A. a new Vickers specification (89356) in January 1949 set out for thefirst time proposals for the aeroplane which subsequently became the V.700 series Viscount. On February 24th the Ministry placeda contract with Vickers for one prototype V.700. This was largely an expression of official faith in the prospects of the design onthe part of the then Controller of Supplies (Air) and U.S. (Air) at the Ministry of Supply (Sir Alec Coryton and Mr. Cyril Mus-grave). The second V.609 prototype airframe (G-AHRG) had not been completed in its original form but was diverted for use-as a flying engine test bed for the Rolls-Royce Tay pure jet at the time of the confirmation of the B.E.A. Elizabethan order. Thisaircraft (VX217), known as the V.663, finally flew with two Tays on March 15th, 1950. A third prototype of the original small Viscount had at onetime been contemplated by Vickers as a private venture addition to the two aircraft for the Ministry. Components manufacturedfor this airframe were used for the V.700 and this prototype was thus manufactured in the short time of eighteen months. It (Concluded on page 93)
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