FUTABA FX40 Instruction Manual page 111

Hovering pitch trim
The Hovering Pitch function trims the pitch near
the hovering point. Normally, it is used with the
tuned for changes in rotor speed accompanying
conditions. Adjust the hovering pitch so that
rotor speed is constant. This function can be used
together with the Hovering Throttle Trim function
for more delicate operation.
Setting method
CTRM mode:
N O R M m o d e :
High Pitch/Low Pitch Trim
High Pitch/Low Pitch Trim is the pitch servo
high side and low side trim function.
Setting method
<Model Menu (Helicopter Functions)> 111