Editing Concorde (section)

===Partnership with Sud Aviation===
France<!-- do not link major countries--> had its own SST plans. In the late 1950s, the government requested designs from the government-owned Sud Aviation and [[Nord Aviation]], as well as [[Dassault]]. All three returned designs based on Küchemann and Weber's slender delta; Nord suggested a [[ramjet]]-powered design flying at Mach 3, and the other two were jet-powered Mach 2 designs that were similar to each other. Of the three, the [[Sud Aviation Super-Caravelle]] won the design contest with a medium-range design deliberately sized to avoid competition with transatlantic US designs they assumed were already on the drawing board.{{sfn|Conway|2005|p=70}}

As soon as the design was complete, in April 1960, [[Pierre Satre]], the company's technical director, was sent to Bristol to discuss a partnership. Bristol was surprised to find that the Sud team had designed a similar aircraft after considering the SST problem and coming to the same conclusions as the Bristol and STAC teams in terms of economics. It was later revealed that the original STAC report, marked "For UK Eyes Only", had secretly been passed to France to win political favour. Sud made minor changes to the paper and presented it as their own work.{{sfn|Owen|2001|p=49}}

France had no modern large jet engines and had already decided to buy a British design (as they had on the earlier subsonic [[Sud Aviation Caravelle|Caravelle]]).{{sfn|Owen|2001|p=47}} As neither company had experience in the use of heat-resistant metals for airframes, a maximum speed of around Mach 2 was selected so aluminium could be used&nbsp;– above this speed, the friction with the air heats the metal so much that it begins to soften. This lower speed would also speed development and allow their design to fly before the Americans. Everyone involved agreed that Küchemann's ogee-shaped wing was the right one.{{sfn|Conway|2005|p=70}}

The British team was still focused on a 150-passenger design serving transatlantic routes, while France was deliberately avoiding these. Common components could be used in both designs, with the shorter-range version using a clipped fuselage and four engines, and the longer one a stretched fuselage and six engines, leaving only the wing to be extensively redesigned.{{sfn|Owen|2001|p=41}} The teams continued to meet in 1961, and by this time it was clear that the two aircraft would be very similar in spite of different ranges and seating arrangements. A single design emerged that differed mainly in fuel load. More-powerful [[Rolls-Royce Olympus|Bristol Siddeley Olympus]] engines, being developed for the [[TSR-2]], allowed either design to be powered by only four engines.{{sfn|Owen|2001|p=50}}