What was found
(CAN) AC WAS ON ROUTE PHF-GSO WHEN THE CREW EXPERIENCED A RT RUDDER DEFLECTION WHICH WAS UNCOMMANDED. THE AP/YD WERE DISCONNECTED AND THE RUDDER WAS REPORTED TO RETURN TO CENTER AT THAT POINT. IT IS NOT KNOWN IF AN EMERGENCY WAS DECLARED TO THIS EVENT. MAINTENANCE TRIP IS IN PREPARATION TO ADDRESS THE PROBLEM INCLUDING THE EXTRACTION OF A FDR DOWNLOAD.