As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING HEAVY MAINTENANCE, CORROSION WAS DISCOVERED ON EXTERNAL SKIN LOCATED UPPER SURFACE AT LEVEL RIB 7 ON LH WING; PERFORMED PERMANENT REPAIR LOC EXTERNAL SKIN BETWEEN RIB 7 UPPER SURFACE ON LH WING IAW EA 57-0384-18 REV.0 PART 1 & 2 / EC A18-990-01. REF. AEROMAN NR 2018-395091 FOR DETAILS.