As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CORROSION WAS DISCOVERED ON THE WING CENTER SECTION UPPER SKIN, TOP SURFACE, BETWEEN STR U-15 TO THE AFT SPAR AND RBL 75 TO 95. THE CORROSION CONCENTRATED AROUND THE STRINGER TO SKIN FASTENER HOLES ABOVE THE AFT SPAR AND STR 3 TO 8, 11, 12 AND 15. THE FASTENER HOLES WERE SPOTFACED WITH A MAX DEPTH OF 0.072 AND COUNTERSINK WASHERS WERE INSTALLED.