What was found
DURING APPROACH FOR LANDING, THE RIGHT LEADING EDGE SLAT DID NOT COME FULLY OUT ON EXTENSION. THE AIRCRAFT DID EXPERIENCE AN UNCOMMANDED ROLL TO THE RIGHT. THE SLAT DISAGREEMENT ANNUNCIATOR LIGHT DID ILLUMINATE AND THE BLUE SLAT EXTEND INDICATOR DID NOT. AS THE AIRCRAFT SLOWED TO 210 KTS BOTH SLATS EXTENDED. ALL INDICATIONS WERE NORMAL AND THE LANDING WAS UNEVENTFUL. MAINTENANCE COULD NOT DUPLICATE THE PROBLEM AND FOUND NO DISCREPANCIES IN THE SYSTEM. AIRCRAFT RETURNED TO SERVICE.