What was found
AIRCRAFT DEPARTED RJCC WITH A DESTINATION OF PANC. WHILE EN ROUTE, THE AIRCRAFT EXPERIENCED A PITCH TRIM FAILURE AFFECTING CHANNEL 1 & CHANNEL 2, INCLUDING A FAILURE OF MACH TRIM. THE AUTOPILOT REMAINED ENGAGED THROUGHOUT THE EVENT. THE FLIGHTCREW UTILIZED THE APPLICABLE PROCEDURES MANUAL TO TROUBLESHOOT THE SYSTEM ANOMALY AND COMPLIED WITH ALL PUBLISHED LIMITATIONS. BASED ON SYSTEM STATUS AND AIRCRAFT CONTROLLABILITY, THE CREW CONTINUED THE FLIGHT TO THE INTENDED DESTINATION WITHOUT DECLARING AN EMERGENCY. THE AIRCRAFT LANDED NORMALLY AT PANC. FOLLOWING LANDING, THE AIRCRAFT WAS REMOVED FROM SERVICE FOR MAINTENANCE EVALUATION AND CORRECTIVE ACTION. MAINTENANCE TROUBLESHOOTING IDENTIFIED A FAULTY STAB TRIM DISCONNECT SWITCH. THE SWITCH WAS REPLACED, APPROPRIATE MAINTENANCE ACTIONS WERE COMPLETED, AND THE AIRCRAFT WAS RETURNED TO SERVICE FOLLOWING VERIFICATION OF PROPER SYSTEM OPERATION.