The Avion de Transport Supersonique Futur (ATSF) also known as Alliance, was a concept design for supersonic transport that was being worked on by both British Aerospace and Aérospatiale. The aircraft was to be based on the experience learned from the supersonic Concorde, and was to fly at a top speed of roughly Mach 2. Preliminary designs were produced, with some wind-tunnel testing of small-scale models, but development apparently stalled in the early 2000s. History By the mid-1980s, it was recognised that Concorde, the first long-serving supersonic transport, had achieved a niche level of profitability on the busiest Transatlantic routes, but that the airliner had not attracted the widespread use that had been hoped, in part due to political complications and poor economic situation following the 1973 oil crisis. Furthermore, during this era, various organisations were undertaking projects, such as the National Aero-Space Plane in the United States, which were aimed at competing with Concorde as next generation supersonic transports. Some political figures, such as US President Ronald Reagan, were outspokenly optimistic on the topic, and directed funding to such ventures; accordingly, several aerospace companies, not least Concorde's manufacturers, British Aerospace and Aérospatiale, kept a keen eye on these developments and often performed their own studies into future supersonic transports. During the late 1980s, the independent studies performed by British Aerospace and Aérospatiale would coalesce into the Avion de Transport Supersonique Futur (ATSF). A primary objective of this study was to determine not only the technical possibility of such an airliner, but also its commercial viability and compliance with environmental standards, particularly those pertaining to noise and pollution. The study assumed that overland supersonic flight would not be permitted anywhere due to the undesirable sonic booms that people would be otherwise routinely subject to. Operating costs were also examined, as this aspect was particularly valued by airliners, its prospective customer base. The study recognised that both the development and manufacture of the ATSF would have to be economically feasible, avoid undue technical risks, and likely to be built at such a quantity to be profitable. It was decided that the ATSF would retain the same Mach 2 maximum speed as Concorde due to the severe engineering challenges posed by going beyond this point. Market analysis had determined that, so long as a supersonic airliner was at least 1.5 times faster than its subsonic competitors, it would attract at least 20