Copyright © 2019 Xflight Technologies LLC, Florida, USA
28
J.
TRIM System Servo Orientation (on the ground)
With the AUTOPILOT installed and AHRS/Compass calibration complete for straight and level and the
elevator trim tab and servo installed with the aircraft flying straight and level, you will now be able to
test the TRIM system / servo orientations.
Ensure the correct trim servo movements:
1. With the aircraft on the ground in a straight and level configuration, as it would be in flight and able
to receive satellite signal, switch on the AUTOPILOT. Wait a few seconds for the Flight Controller to
initialize, and the AUTOPILOT to start up and display the AHRS screen.
2. Now switch on the servo circuit to power up the pitch and roll servos. Ensure the elevator trim tab
and roll trim tab or secondary aileron control surfaces are at their correct neutral trim positions.
3. Ensure the AHRS is level, then select the
<AP>
button (first touchscreen button from the left) to
switch the AUTOPILOT into Manual flight mode to enable the TRIM System. You should see
<AP ON>
in
green.
4. Press the pitch up trim switch a few times or press continuously and make sure the elevator trim tab
moves in the correct direction. For a trim tab on a moveable elevator control surface, this would be a
downward movement of the trim tab (allowing the airflow against the trim tab to push the elevator up).
Repeat for pitch down.
Action
Control Surface
Expected Movement
Yoke switch: pitch up
Elevator Trim Tab
Trim Tab Down (Elevator up)
Yoke switch: pitch down
Elevator Trim Tab
Trim Tab Up (Elevator down)
If this is reversed, then you will need to swap over the trim switch wires for pitch up and pitch down.
5. Press the pitch up and pitch down switches simultaneously; the elevator trim tab should move back to
the neutral position.
6. Repeat the process for roll. Press the roll left trim switch a few times or press continuously and make
sure the secondary aileron or trim tab moves in the correct direction as per below.
Action
Control Surface
Expected Movement
Yoke switch: roll left
Port Secondary Aileron
Up
Yoke switch: roll left
Starboard Secondary Aileron
Down
OR
Yoke switch: roll left
Port Aileron Trim Tab
Trim Tab Down (Aileron up)
Yoke switch: roll left
Starboard Aileron Trim Tab
Trim Tab Up (Aileron Down)
Repeat for roll right.
If this is reversed, then you will need to swap over the trim switch wires for roll left and roll right.
