How to use a graphic flight computer to find ground speed and true heading<br>Align the wind direction under the " true index " mark by rotating the azimuth plate. If the winds are from 330 ° at 20 knots, align 330 under the true index. Align the grid so the center grommet is over one of the heavy lines.
To find ground speeding using a flight computer align the "true index" mark by sliding the azimuth plate.
( z1 align :ARG1 ( z2 mark :mod ( z3 index :ARG1-of ( z4 true ) ) ) :manner ( z5 slide :ARG1 ( z6 plate :mod ( z7 azimuth ) ) ) :purpose ( z8 find :ARG1 ( z9 speed :ARG1 ( z10 ground ) ) :manner ( z11 use :ARG1 ( z12 computer :mod ( z13 fly ) ) ) ) )