As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT PILOT AUTOPILOT HAD A PROBLEM AND AFTER THE AUTOPILOT WAS SHUT OFF THE RUDDER WENT FULL RIGHT. USING THE RUDDER CONTROLS THE PILOT WAS ABLE TO FLY THE AIRCRAFT TO THEIR PLANNED DESTINATION OF IAD. MX DISCOVERED THE YAW SERVO WAS DEFECTIVE. MX REPLACED GSA-80 WITH PN: 011-00877-20 SN: 19Z018546 OVERHAULED UNIT. MX RELOADED SW0767.25 AND APPLICABLE YAW FILES. OPS CHECK GOOD.