What was found
WHEN REMOVING LT RUDDER PEDAL AND ARM ASSYS TO ACCESS FIREWALL INSIDE OF RUDDER ARM, TUBE WAS FOUND BADLY CORRODED. THERE WAS NO EVIDENCE OF CORROSION ON OUTSIDE OF TUBE. THE TUBE IS MOUNTED VERTICALLY AND IS OPEN ON TOP AND SEALED ON BOTTOM. ANY WATER THAT ENTERS TUBE IS TRAPPED. WATER PROBABLY CAME FROM PILOT'S BOOTS DURING SEAPLANE OPERATIONS AND MAY HAVE BEEN SALTWATER. SUBMITTER RECOMMENDS SEALING UPPER END OF TUBE TO PREVENT WATER ENTRY.