What was found
FLT 9831 - ON APPROACH TO PIE, RIGHT MAIN GEAR DOOR WOULD NOT CLOSE ON GEAR EXTENSION. LANDED WITH GEAR DOOR OPEN. INSPECTION OF AREA NOTED DAMAGE TO RIGHT MLG DOOR. DAMAGE DID NOT PREVENT GEAR DOOR FROM LOCKING IN CLOSED POSITION. AIRCRAFT MADE GEAR DOWN MAINTENANCE FERRY FLIGHT TO MIA. FOUND SHEARED RIVET IN L/G SEQUENCE VALVE TORQUE TUBE. REPLACED RIVET, RT MLG DOOR AND HINGE ASSY. RETRACTION TEST NORMAL.