determined from the offset release point
ing the vertical lines of the pilot balloon
as it is the point of origin.
scale with those on the plotting board.
(9) Continue to move the pilot balloon scale
The wind direction is read and recorded
from plot to plot until the wind direction
to the nearest 10 mils. This procedure is
for all points has been determined and
used for each succeeding plot.
entered in column 7 of DA Form 4469.
(8) Scale ML-577/UM is constructed so that
(10) Windspeed is determined by measuring
the black azimuth can be read directly.
the horizontal travel in each zone, in
When an offset release point is used, the
meters, with Rule MP126-A. This is
wind direction for zone No. 1 must be
Figure 3-3. Zone wind plotting board.
and (9) above, and entered in column 5
done between plotted points, as deter-
on DA Form 4469.
mined in procedures given in (7), (8),