What was found
(CAN) DURING CLIMB OUT FLIGHT CREW HAD TO INPUT A CONTROL WHEEL DISPLACEMENT OF 25 DEGREES TO THE RIGHT OF CENTER TO MAINTAIN LEVEL FLIGHT. 1 DEGREE OF SPEED BRAKE LEVER WAS INPUT AND THIS CAUSED A REDUCTION OF CONTROL WHEEL DISPLACEMENT TO 10 - 15 DEGREES. IN CRUISE CONTROL WHEEL DISPLACEMENT WAS 10 DEGREES RIGHT OF CENTER. LIGHT AIRFRAME VIBRATION WAS CONTINUOUS. UPON ARRIVAL, MAINTENANCE PERSONNEL INSPECTED THE WING FLIGHT CONTROLS AND SPOILER SYSTEM AND THE SPOILER DOWN STOP RIB ASSEMBLY AT RIGHT HAND WING STATION 575.2 WAS FOUND CRACKED. THE DOWN STOP RIB ASSEMBLY WAS REPLACED AND THE AIRCRAFT WAS RELEASED FOR SERVICE.