As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FOUND THE RUDDER TORQUE TUBE AND WELDED ON ASSEMBLIES VERY CORRODED. THE WELDED ON PLATE IS ABOVE THE BOTTOM RIB ON THE RUDDER AND CAN ONLY BE SEEN THROUGH A SMALL CUT-OUT IN THE RIB WHERE THE TORQUE TUBE PASSES THROUGH. THE BOTTOM RIB (PN 40039-00) WAS ALSO UNAIRWORTHY DUE TO CORROSION.