TM 1-1520-238-10
7A-66
Change 3
Section VI. DRAG
7A.22. DESCRIPTION.
The drag chart (fig 7A-18) shows the change in frontal
area for each wing-stores combination that can be
installed on the helicopter. The baseline configuration in-
cludes the Wire Strike Protection System (WSPS).
7A.23. USE OF CHART.
To determine the change in frontal area ( F) and the as-
sociated multiplying factor, it is necessary to know what
combination of stores is installed. Enter the chart at the
top, move down to the illustration that matches the desired
combination, and then move right and read F and the
multiplying factor. Use the multiplying factor and data in
Section VI, Cruise to determine the resulting change in
torque.
7A.24. CONDITIONS.
The drag chart is based on the mission configuration hav-
ing zero change in frontal area. If the WSPS is installed,
increase the frontal area for all configurations in the drag
table by 1.9 sq ft and increase the multiplying factor by
0.19.
