As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GEG - CLIMBING OUT OF GEG, THE RUDDER TRIM STARTED MOVING TO THE LT WITHOUT PILOT INPUT. MAINTENANCE INSPECTED THE AIRCRAFT AND SYSTEMS AND REPLACED THE PEDESTAL RUDDER TRIM SWITCH. THE OPERATIONAL CHECKS WERE GOOD AND THE AIRCRAFT WAS RETURNED TO SERVICE.