Supersonic Transport Aircraft: Brief Summaries of the Papers Presented at the Royal Aeronautical Society All‐Day Discussion on December 8, 1960

Arguments in favour of selecting a cruising speed of about M=2.0 for a long‐range supersonic transport aircraft have been given by Morgan, and Kuchemann has shown that the slender wing shapes provide the basis for the layout of the aircraft, and has given the general properties which would lead to the achievement of optimum cruising lift‐drag ratios. The four components of supersonic drag were considered and with reference to a datum wing it was shown that the layout selected for best cruising efficiency alone would not give the lightest aircraft for the required duty if the influence of off‐design performance and component weights were taken into account. The parameter s/l was shown to be the effective variable and it was suggested that layouts having reduced wing area and increased span to length ratios (s/l) were likely to be the most successful. Bearing in mind the extra power required, calculations indicated that a reduction in plan area from the datum could give lower approach speed, reduced take‐off distance and a reduction in noise intensity. Further trends in this direction indicate aircraft shapes having a high percentage of their total volume contained within the fuselage, and it might then be possible to produce a favourable interference force between the wing and fuselage flow fields and so to improve the lift‐drag ratios which had been assumed in the derivation of these shapes. In the discussion that followed it was considered that forward view promised to be as good as for current subsonic aircraft, and the author stated that mock‐ups to investigate this item were being prepared. It was considered that the expense and complication of variable geometry were not acceptable in a first generation supersonic transport.