Vickers Vanguard

Development

Background

The origins of the Vanguard can be traced back to speculative discussions between Vickers and the airline British European Airways (BEA) conducted as early as 1953, the same year in which the commercially successful Vickers Viscount airliner first entered revenue service. Even at this early stage, the two firms had envisioned the introduction of a successor to the Viscount entering service around 1959. This envisioned successor airliner would possess economics 10 per cent greater than those of the Viscount, while also being considerably faster throughout all operational stages. Out of BEA's internal analysis of various options, which studied both turboprop and pure jet propulsion arrangements, it became clear that a larger aircraft that could accommodate bigger payloads was highly desirable.

On 19 April 1953, BEA's chief executive, Peter Masefield, outlined the company's requirements in a letter to Vickers; these criteria included a cruise speed of 370 knots (430 mph; 690 km/h), a standard range of 1,000 miles (1,600 km), with 305 miles (490 km) in reserve fuel, the ability to accommodate up to 100 passengers, and an explicit preference for a high-wing configuration. Coincidentally, another airline, Trans-Canada Air Lines (TCA), also made contact with the manufacturer with its own list of requirements, calling for a Viscount-like airliner capable of servicing its transcontinental routes while carrying up to 60 passengers. Recognising the potential to fulfil both airlines' requirements in a single airliner, Vickers' design team commenced work on producing such an aircraft.

Vicker's initial proposal, known as the Type 870 or alternatively as the Viscount Major, was incapable of meeting BEA's criteria, and was quickly dismissed. On 14 May 1951, Vickers met with Rolls-Royce representatives to discuss potential engines for their envisioned airliner; the meeting led to the decision to adopt the in-development Rolls-Royce Tyne powerplant for its revised proposal. While considerations towards adopting a turbojets engine were made, a study performed in November 1953 found that such an engine would produce inferior performance over shorter routes to a turboprop counterpart. It was around this time that Vickers' design team also discarded notions of adopting a swept wing, largely due to its providing little benefit at the envisioned airliner's 350-knot (400 mph; 640 km/h) cruise speed, as well as its inferior performance during the approach stage of flight.

Redesign

Despite BEA's initial preference for a high-mounted wing, the company opted for a low-mounted wing following the adoption of a double-bubble fuselage. This type of fuselage was necessary because of the large proportion of freight which BEA needed to carry. It was considered by Vickers to be impractical if carried at the same level as the passengers due to the excessive length that would be required, but carrying the freight in a lengthy hold beneath the main cabin was a practical arrangement. Furthermore, TCA wanted a low-mounted wing, which would make the aircraft easier to refuel, de-ice and service, as well as giving a statistically significant improvement in survival in the event of a water landing.

By 13 April 1955, the range of design studies had been shortlisted down to five, these remaining concepts were jointly evaluated by BEA and Vickers. Of these submissions, it was recognised that the combination of the low-mounted wing and the double-bubble fuselage represented the optimum configuration, having offered the best capacity and versatility amongst other attributes. This conceptual aircraft, referred to as the Type 870 Scheme 16a, could accommodate 88 passengers, a cruising speed of 360 knots (420 mph; 680 km/h) at 25,000 ft (7,600 m), and payload of 20,000 lb (9,100 kg). While BEA were interested in relatively short, sub-1000 mile, routes, its fuel tanks were progressively enlarged over several revisions to give a range of 2,600 miles (4,200 km) so that the airliner would be acceptable to TCA as well.

The Type 900 was a further revision of the design, featuring an expanded payload capacity of 21,000 lb (9,500 kg) and carry up to 93 passengers. Following some relatively minor revisions, which largely bolstered the gross weight upwards, that were made to better suit the design to the needs of global customers, the definitive Type 950 proposal emerged. On 20 July 1960, BEA placed an initial order for 20 Type 950s, the type becoming subsequently known as the Vanguard; the airline publicly announced the order and its intended plan for the new airliner to succeed the Viscount in its fleet.

At the time, TCA was, while intensely interested in the airliner, not yet willing to commit itself, partially due to the basic model not entirely fulfilling its requirements, such as the level of capacity for air mail. Vickers recognised that a high-density seating configuration, accommodating up to 139 passengers to be carried, would likely be attractive to more operators, and designed the Type 952 model for this market.