TM 1-1520-240-10
7-9-1
SECTION IX. CLIMB DESCENT
7-9-1. Description.
a. Climb and descent performances may be seen in
figure 7-9-1, which presents change in torque to climb or
descend at selected GWs.
b. The climb performance charts, figure 7-9-2, shows
relationships between GW, initial and final altitude and
temperatures, time to climb, and distance covered and
fuel used while climbing. The chart is presented for
climbing at hotter and colder temperatures, intermediate
torque (30 minute operation).
7-9-2. Use of Charts.
a.
To determine torque change for a specified rate
of climb or rate of descent (fig. 7-9-1), enter rate of climb
or descent and move right to gross weight, move down
and read torque change. This torque change must be
added to the torque required for level flight for climb, or
subtracted for descent, to obtain total climb or descent
torque.
b. Rate of climb or descent may also be obtained by
entering with a known torque change, moving upward to
gross weight, moving left and reading rate of climb or
descent.
c.
To use the climb performance charts (fig. 7-9-2),
enter at the top left at the known gross weight, (for heli-
copters with EAPS installed, enter chart at actual GW
plus 1000 pounds), move right to the initial press alt
(pressure altitude), move down to the FAT at that altitude,
and move left and record time, distance and fuel. Enter
again at the GW, move right to the final altitude, and
move down to the FAT at that altitude, and move left and
record time, distance, and fuel. Subtract the time, dis-
tance, and fuel values of the initial altitude-temperature
condition from those of the final altitude-temperature
condition to find the time to climb, distance covered, and
fuel used while climbing.
7-9-3. Conditions.
The climb and descent charts are based on 100%
RRPM. The climb speed schedule shown in figure 7-9-2
(see insert) is for optimum climb, that is, minimum power
required and maximum power available (30 minutes). It
is an average schedule for the GW range and atmo-
spheric conditions for the CH-47D.
