During the 1950s the British lead in aircraft design was continually eroded by a series of technical and commercial disasters. The technically daunting Bristol Brabazon met all of its demanding performance requirements, but proved to be a commercial failure when customers felt the transatlantic market wasn't big enough to justify such a large and expensive aircraft. Meanwhile the De Havilland Comet suffered a series of mysterious and deadly accidents which cast a pall over the market for jetliners, another area where the British technological lead might have proved decisive. In fact the fatigue failures exposed in the Comet led to prolonged testing of other promising designs like the Bristol Britannia, which were so delayed that their production was eclipsed by US designs when they finally reached service. The leading US contender, the Boeing 707 series, gained much from the KC-135 Stratotanker project.
Throughout this period the industry had been producing a series of advanced test aircraft however, and had extensively studied the problems of sustained high-speed flight. By the mid 1950s two designs had been shown to have a lift-to-drag ratio suitable for supersonic cruise, a sharply swept "M-wing" pioneered at Armstrong-Whitworth, and very slender delta wings. By 1956 there was enough official interest in this research for the Supersonic Transport Aircraft Committee, or STAC, to be formed under Sir Morien Morgan to investigate the creation of a supersonic transport.
By the early 1960s it was clear that despite their best efforts, the United Kingdom had lost supremacy in the airliner market to the United States. In March 1959 STAC recommended that the UK should build two supersonic designs, a long range 150 seat aircraft to cruise at Mach 2 for the London to New York route, and a shorter range aircraft to cruise at Mach 1.2 for use in Europe. Higher speeds up to Mach 3 had been considered and found to be possible, but it appeared that a practical upper limit was Mach 2.2, above this speed the duralumin used for most aircraft construction would start to go soft due to the heat of friction, and some new material would have to be used instead.
| Type 198 |
| One of the high-wing versions |
At the same time Russell started a parallel study on a similar sized plane built of steel was conducted as Type 213. However this proved uneconomical when their own Bristol 188 design started into production that year. Although much of the problem can likely be traced to the novelty of the 188's steel construction, it cost many times more than conventional designs. From then on Russell was interested only in designs of Mach 2.2 or less, the upper limit for aluminum.
| Type 223 |
In 1961, Sud Aviation revealed their plans for the Super Caravelle at the Paris Air Show. By this point STAC was looking at producing the Type 223, but the cost was going to be enormous. Throughout 1962 the two companies and their respective governments talked about forming a consortium to share development and production costs on similar parts. On November 29, 1962 an agreement was signed, and the Concorde project started. Originally two versions of the same basic design were going to be offered, a larger transatlantic version with a size about that of the Type 223, and a smaller short/medium range version similar to the Super Caravelle. However as the group started talking to prospective customers, it soon became clear that the smaller version was not commercially interesting, and it was eventually dropped.