As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) CREW REPORTED THAT RUDDER TRIM INPUT (NOSE RIGHT) WAS APPLIED BUT, WHEN TRIM SWITCH WAS RELEASED, THE AIRCRAFT CONTINUED TO YAW PROGRESSIVELY MORE. THE RUDDER TRIM INDICATOR CONFIRMED THAT TRIM WAS STILL BEING APPLIED. THE TRIM SWITCH WAS THEN MOVED TO THE 'NOSE LEFT' DIRECTION AND, AFTER SEVERAL ATTEMPTS, THE YAW WAS ARRESTED. MAINTENANCE REPLACED THE RUDDER TRIM PANEL AND THE PROBLEM HAS NOT BEEN REPORTED SINCE. AIRCRAFT BACK IN SERVICE.