Sailplane Performance Flight Testing

Abstract

The traditional partial glide method of measuring glide performances is simple in principler but reguires a high degree of accuracy. Scatter in results arise from two sources, limitations in resolution of instrumentation and from movement of the air. Use of high resolution pressure transducers together with electronic data recording reduces the first source of scatter to a minirnum and provides easy access to statistical analysis, using a computer. In addition, the theoretical shape of the polar curve can be used to obtain a better fit than can be obtained by fitting an arbitrary line through measured points. A value of maximum L/D can be obtained from a statistical analysis of the complete polar curve that will provide a meaningful figure of merit of aerodynamic performance.