What was found
AFTER REMOVAL OF THE LEFT NACELLE COVER AND FUEL CELL, SEVERE CORROSION WAS FOUND. ALSO, AFT SIDE OF LT FIREWALL DISCOLORED FROM HEAT AND THE FUEL CELL HEAT SHIELD IS BURNED THROUGH. THE HEAT DAMAGE IS BELIEVED TO BE CAUSED BY A PREVIOUS EXHAUST FAILURE. THIS AIRCRAFT IS WELL MAINTAINED, HANGARED MOST OF THE YEAR, AND NOT HIGH TIME. SUBMITTER BELIEVES THIS IS A SERIOUS PROBLEM THAT MAY GO UNDETECTED ON MANY SIMILAR AIRCRAFT.