[header] How to use a graphic flight computer to find ground speed and true heading [title] Align the wind direction under the " true index " mark by rotating the azimuth plate. [step] If the winds are from 330 ° at 20 knots, align 330 under the true index. [title] Align the grid so the center grommet is over one of the heavy lines. 
[step] It doesn't matter which line is used at this point. [title] Mark the wind speed by counting up from the center grommet.