Save Steering Trim

If the vehicle does not track straight in MANUAL mode with steering at neutral, you can either adjust the steering mechanics to correct, or use the RCx_OPTION = 5 (Save Trim) to correct. Using the steering channel’s trim tab or sub-trim in the transmitter is not recommended (after RC calibration is completed), since it will appear as a constant pilot steering request in non-MANUAL modes.

Save Trim

Activating Save Trim on the channel with RCx_OPTION = 5, will instantly capture the current output of the Steering Channel servo (normally SERVO1) and store it as its SERVOx_TRIM value. This can be repeated by de-activating and re-activating the rc channel function. The output is saved only at the moment of activation. It can be used in any mode except LOITER or HOLD.


This is best used in ACRO mode when the autopilot is maintaining heading. Autonomous modes like AUTO or RTL, may capture the output during a maneuver to turn to a waypoint, crosstrack correct, or be loitering at the end, and store incorrect results. But it can be used if careful as to when its applied. It can also be used during MANUAL mode by trimming at the transmitter for straight track, activating, and then returning the trim to center.