The charts above display measured airspeed-over-ground in WWIIOnline 1.34. Dots are actual data-points, curves are interpolated. Airspeeds were calculated by flying parallel to grid-lines and timing the time it takes to cross the 16km grid once the airspeed has stabilized. The accuracy of the data is high: Repeated measurements by different people yielded numbers within the difference of 0.3km/h. Nevertheless, it may contain errors and feel free to speak up (for instance in this forum) if you suspect something to be amiss.