ASA Electronics E6-B - Manual (Page 32)

32
Determining Winds in Flight
Winds aloft forecasts are frequently in error. If you
have an autopilot and some free time, you can
calculate the actual winds at your location and
altitude. It helps if you have GPS, too.
To solve an inflight wind problem you need your
ground speed, true heading, true course, and true
airspeed. Let’s assume your true course is 180°,
your true heading is 160°, your last ground speed
Figure 23