As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT CRUISE ALTITUDE THE AIRCRAFT EXPERIENCED FULL LEFT RUDDER DEFLECTION. EMERGENCY PROCEDURES WHERE INITIATED. DURING RECOVERY PROCEDURES ALTITUDE LOSS OF 15,000 FEET. YAW DAMPENER WAS DISABLED AND AIRCRAFT CONTROLS RETURNED TO NORMAL. AIRCRAFT RETURNED TO DESTINATION WITHOUT FURTHER INCIDENT.