Over the last years, innovative concepts of civil high-speed transportation aircraft were proposed. These vehicles have a strong potential to increase the cruise range efficiency at high Mach numbers, due to efficient propulsion units combined with high-lifting vehicle concepts. In this context, the necessity to have a simple and reliable tool for the estimation of the aerodynamic performance of such vehicles is of primary importance in the first phases of the design, when a quick response is needed for each design modification/improvement that is made. The objective of this thesis is to improve the prediction of the aerodynamic performance of a new high-speed vehicle since the conceptual design phase.