TruTrak Automatic Pitch Trim - Manual (Page 5)

Auto Trim Installation Manual 2 TruTrak Flight Systems
December 2009 8300-013 Rev C
Automatic Pitch Trim Ground Checkout
Note: If the above technique has been completed and the automatic trim module still does not run the trim, then first
try applying more force to the system when holding the up elevator. If the pitch servo slips easily when holding the
force, ensure that the pitch servo torque is set at the maximum value and hold as much force as possible without
slipping the servo. If the torque is set at the maximum and the system still does not function, check automatic trim
wiring.
The switch in the first slot of the controller is to
switch trim motor direction, see above diagram.
Two small slots are control indication Led’s, see
above.
Potentiometer located on the side of the controller
is used to adjust the speed of trim motor rate of
change, clockwise rotation to increase speed. Too
little of rate will cause trim indicator to show on
auto pilot display. If rate setting is too fast then
aircraft will hunt in pitch.
Power up autopilot.
Red light ON auto trim module at #1
small slot
Engage autopilot
Red light OFF on the auto trim
module at #1 small slot
Apply up elevator pressure.
Is servo holding the
controls
Does Automatic Pitch Trim run the trim servo?
#2 small slot light will flash red or green
Yes
No
Check trim motor control or trim sense wires.
Pins 9 & 10 must go to trim motor.
Pin 4 must go to pitch servo pin 7
Does trim servo run in the
correct direction (up trim
tab) so as to trim up?
Yes No
Check to ensure that trim
servo will run in both
directions by applying
down elevator as well
Flip the switch located in large
slot on the Automatic pitch trim
Module
Check torque wire. Pins 5 or 6
must be >2.5 volts AP engaged.
No
Yes