TM 1-1520-240-MTF
2-71
B HOVER (CONT.)
NOTE
Ensure that no aircraft limitations are exceeded
during this maneuver. The goal is to obtain the
maximum torque without endangering the aircraft
or crew (70-100%). Depending on conditions i.e.
aircraft gross weight and DA the check may be
performed on the ground.
a.
712 Torque Differential Check.
(1) While stable on the ground, flat pitch,
100% RRPM move No. 2 ECL to the
Ground detent. Increase RRPM to
100% using beep No. 1 and No. 2
switch. Increase thrust until aircraft is
stabilized at 5 to 20 foot aft wheel height
while maintaining RRPM at 100%.
Record TRQ and N1 values on No. 1
engine when stabilized.
(2) Maintaining a constant thrust position
slowly bring the No. 2 ECL to the FLT
position
while
simultaneously
maintaining the RRPM at 100% with the
No. 1 and No. 2 beep trim switch.
Reduce No. 1 ECL smoothly to the
ground position while maintaining 100%
RRPM with the No. 1 and 2 beep trim
switch. When No. 1 ECL is at the GND
position record TRQ and N1 values on
No. 2 engine.
(3) Smoothly decrease thrust to ground
detent while maintaining 100% RRPM
with No. 1 and No. 2 beep switch.
Decrease RRPM to minimum beep
using 1 and 2 beep switch. Advance No.
1 ECL to flight position. Beep RRPM to
100%.
(4) Difference will be no greater than 6%
between No. 1 and No. 2 ENG TRQ
values.
