As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 851 - SEA-FWA - DURING CRUISE, THE FILGHT CREW NOTICED THAT THE AUTOPILOT IN A MODE WITH THE HEADING SELECTOR ON OR OFF INTERMITTENTLY LOCKS UP. REMOVED AND REPLACED THE AUTOPILOT CONTROL PANEL. OPERATIONAL CHECKS ON THE GROUND FOUND NORMAL. THE AIRCRAFT WAS RETURNED TO SERVICE. (M)