What was found
THE AIRCRAFT HAD A 12 DEGREE UNCOMMANDED ROLL TO THE LEFT WITH AUTOPILOT-B ENGAGED WHILE ON APPROACH. THE FIRST OFFICER DISCONNECTED B-AUTOPILOT AND THERE WERE NO FURTHER PROBLEMS. THE FLIGHT CONTROL COMPUTER WAS REPLACED AS A PRECAUTIONARY MEASURE. A LAND VERIFY TEST WAS PERFORMED IAW MM 22-03-00. *S/D* SHOP FINDINGS REVEALED NO TROUBLE FOUND WITH THE FLIGHT CONTROL COMPUTER. IN ADDITION, A 90 DAY REVIEW OF ATA 22 AND 27 SINCE THIS EVENT, REVEALED NO ADDITIONAL REPORTS OF AIRCRAFT UNCOMMANDED ROLL.