SECTION V. HOVER
The hover chart, figure 7-5-1, presents torque required
to hover at 100% RRPM at various combinations of PA,
FAT, GW, and wheel height for single and dual engine
7-5-2. Use of Chart.
a. The primary use of the charts is illustrated by the
example. To determine the torque required to hover, it is
necessary to know PA, FAT, GW, and desired wheel
height. Enter the upper right grid at the known pressure
altitude, move right to the temperature, move down to
gross weight. Move left to desired wheel height, deflect
down and read torque required for dual engine or single
n addition to the primary use, the hover ceiling
charts (fig. 7-5-2) may be used to predict maximum hover
height. This information is necessary for use of the
takeoff chart found in figure 7-6-1. To determine
maximum hover height, it is necessary to know PA, FAT,
GW, and maximum torque available. Enter at the known
pressure altitude, move right to FAT, move down to gross
weight, move left to intersection with maximum torque
available and read wheel height. This wheel height is the
maximum hover height.
c. The hover charts may also be used to determine
maximum GW for hover at a given wheel height, PA, and
temperature. Enter at known pressure altitude, move
right to the FAT, then move down to the bottom of the
lower grid, and read density altitude. Now enter lower left
grid at maximum torque available. Move up to wheel
height, then move right to density altitude and read GW.
This is the maximum gross weight at which the helicopter
a. The hover chart is based on calm wind, level
surface, and 100% RRPM.
b. Hover in ground effect (HIGE) data is based on
hovering over a level surface. For normal transition from
hover to forward flight, the minimum hover wheel height
should be 10 feet to prevent ground contact. If helicopter
is to hover over a surface known to be steep, covered
with vegetation, or if type of terrain is unknown, the flight
should be planned for hover out of ground effect (HOGE)
c. EAPS installation has negligible effect on hover
torque figure 7-5-1.
d. Hover ceiling charts, figure 7-5-2, with EAPS
installed, reduce gross weight by 700 pounds.