As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CORROSION WAS FOUND ON RIGHT WEB AND STRINGERS. REPLACED THESE PARTS LAST YEAR FOR SAME REASON. THE REPLACED PARTS HAD BEEN PAINTED WITH EPOXY PRIMER PRIOR TO INSTALLATION. IT HAS BEEN NOTED THAT ALL PLACES THAT CORRODED BOTH TIMES HAD BEEN IN DIRECT CONTACT WITH UPHOLSTERY THAT WAS INSTALLED 2.5 YEARS AGO. SUSPECTS FABRIC WAS SPRAYED WITH SOME FORM OF FIRE RETARDENT THAT IS CORROSIVE.