As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE UPPER SURFACE OF THE CENTER WING SKIN BETWEEN RBL AND LBL 94.5 AND 104 WAS FOUND WITH EXTENSIVE CORROSION. THE CORROSION WAS MOSTLY ISOLATED TO THE IMMEDIATE AREA AROUND STRINGER-TO-SKIN FASTENERS AND EXTENDED FROM THE FRONT SPAR AT FS 983 TO THE REAR SPAR AT FS 1203.