percent of the passengers travelling on that route. Adopting the Mach 2 limit also meant it was relatively easy to compare emerging design concepts and the real life experience garnered from operating Concorde, which had attained 15,000 flight hours fleetwide at this point. A maximum range of 10,000 km was also found to cover 75% of all non-stop long range routes being operated worldwide as of the 1990. Passenger capacity was roughly double that of Concorde, seating 200 passengers; it was speculated that up to 250 could be accommodated on a shorter range ATSF variant. The basic configuration of the ATSF was broadly similar to Concorde, even to the point of intentionally mimicking design features such as its nose and cockpit. However, reused elements were typically refined for greater aerodynamic efficiency, improved usability, and to address some shortcomings. While an ogee delta wing was also used on the ATSF, substantial effort was placed onto redesigning the wing and fuselage to attain better performance, such as a cruise lift/drag radio of 10. Much attention was paid to the wing and landing gear as to reduce drag; boundary layer control to achieve and maintain laminar flow was also investigated. Engine installation and selection was also examined; it was quickly found that powerplants that were either substantially larger or heavier would have an undue impact on performance. Even in 1990, the Rolls-Royce/Snecma Olympus 593 turbojet engine, as used on Concorde, still provided the best supersonic performance available amongst existing powerplants. However, if required to perform extended flights at subsonic speeds, it was found that a low-bypass turbofan was optimal. Four engine manufacturers, SNECMA, Rolls-Royce, Pratt and Whitney, and General Electric, had submitted proposals with which to power the ATSF. By 1994, a trilateral partnership between British Aerospace, Aérospatiale, and the German aircraft manufacturer DaimlerChrysler Aerospace had been formed to develop a supersonic successor to Concorde, which was referred to as the European Supersonic Commercial Transport (ESCT). Amongst other criteria, this project had a similar passenger capacity, top speed, and range to the earlier ATSF. While likely to have been so, it is unclear if this project was a rebranding or restructuring of the earlier ATSF. Irrespectively, the ESCT appears to have taken the role, and place, of the early ATSF project. See also High Speed Civil Transport Supersonic transport References External links http://www.sae.org/technical/papers/901890 Delta-wing aircraft Abandoned civil aircraft projects Supersonic transports