As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GEG - FLIGHT 2356 IN CRUISE PHASE OF FLIGHT, RUD TRIM WENT FULL RIGHT UNCOMMANDED. CREW NEUTRALIZED SITUATION AND RAN CHECK LIST, AND PULLED CIRCUIT BREAKERS. REPLACED AILERON/RUDDER TRIM PANEL. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.