What was found
DURING 5,000 HOUR INSPECTION, THE RUDDER WAS REMOVED FOR S/B (REPAIR OF RUDDER TORQUE TUBE ASSY BONDING JUMPERS) FOUND CORROSION ON TORQUE TUBE INTERNAL AND EXTERNAL. ON FURTHER INVESTIGATION (EDDY CURRENT INSP) A CRACK INDICATION WAS NOTED .020 INCH DEEP BY 1 INCH LONG. TORQUE TUBE WAS REMOVED AND REPLACED. PROBABLE CAUSE: MOISTURE INGRESSION THROUGH WIRE BUNDLE HOLE. ENGINEERING EVALUATE FOR POSSIBLE INTERNAL INSPECTION CRITERIA OF TORQUE TUBE AND ENVIRONMENTAL SEALING AS REQUIRED. (K)