TM 1-1520-240-10
7A-6-1
SECTION VI. TAKEOFF
7A-6-1. Description.
The takeoff chart, figure 7A-6-1, defines distances re-
quired to clear obstacles of 50 feet, 100 feet, 150 feet,
and 200 feet based upon maximum hover height capabil-
ity and true airspeed. The procedure for takeoff is the
level flight acceleration technique. The maximum hover
heights shown are indicative of helicopter performance
capability and do not imply that this hover height must be
maintained through takeoff.
NOTE
The maximum hover heights shown are indic-
ative of helicopter performance capability and
do not imply that this hover height must be
maintained through takeoff.
7A-6-2. Use of Chart.
The primary use of the chart is illustrated by the exam-
ples.
a.
To determine the distance required to clear an
obstacle, it is necessary to know maximum hover height
(hover capability), obstacle height, and climbout true air-
speed. Calculation of maximum hover height is de-
scribed in Section V, Hover. Enter the chart for the re-
quired obstacle height, move right to desired true
climbout airspeed, then down and read distance required
to clear obstacle.
b.
A hover check should be made prior to takeoff to
verify hover capability. If winds are present, hover capa-
bility will be greater than predicted since the hover chart
is based on calm wind conditions.
7A-6-3. Conditions.
a.
The takeoff chart is based on calm wind condi-
tions. Since the surface wind velocity and direction can-
not be accurately predicted, all takeoff planning should
be based on calm air conditions. Takeoff into the wind will
improve takeoff performance.
CAUTION
A tailwind during takeoff and climb - out
will increase the distance for obstacle
clearance and may prevent a successful
takeoff.
b.
Takeoff performance data are based on the use
of maximum torque available at 100% RRPM
