As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING APPROACH FOR LANDING WHEN CREW SELECTED SLAT DEPLOYMENT, THE AIRCRAFT HAD AN UNCOMMANDED ROLL TO THE LEFT ACCOMPANIED BY SLAT DISAGREEMENT LIGHT. COMPLIED WITH COM PROCEDURES, THE SLATS WERE RETRACTED AND THE AIRCRAFT LANDED WITHOUT INCIDENT. THE RIGHT T-DUCT MOUNTING BOLT HOLES WERE IMPROPERLY DRILLED CAUSING THE T-DUCT TO BIND DURING SLAT OPERATION. RIGGED BOTH T-DUCTS AND REPLACED THE LOWER LEFT SLAT ACTUATOR DUE TO LEAKING. AIRCRAFT RETURNED TO SERVICE.