Hi

I have read many articles published by Dick Johnson on performance of various gliders, but I cannot find any information on the methodology he used. The closest I have come to is this from Wikipedia "Flight Test Evaluation series starting in 1976, which measured the performance of sailplanes utilizing the measurement methods taught by Dr Raspet and refined by Johnson". I am guessing that it may have been based on this article "Sailplane Performance Evaluation - Soaring May–June, 1947" by dr Raspet, but I was not able to make any further headway.
If anyone can point me to some source I would appreciate it.

Thanks

Paul