The accuracy of forecast and found winds

In this paper reference is made to Durst’s statistical method of determining the errors in forecasts, and those in winds found by navigators, with some comparative figures for Australian routes. An expression for the error in the found wind is derived also from the separate errors of time, course, airspeed and position finding, and largely confirms the statistical results. It is concluded that, in general, errors in wind finding by the air plot method are of the same order as the errors in 24 hour forecasts, and, for high speed aircraft over ocean routes, are likely to exceed the forecast errors. Results are given of winds found with our aircraft fitted with Distance Measuring Equipment.