As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INSPECTION TYPE: C, AFT T/E PANEL REMOVED FOR RECTIFICATION WING UPPER SKIN LWR SURFACE FOUND CORRODED AT WS 390. CORROSION BLEND OUT 0.131 X 1.25 X 2.5 INCHES EXCEED SRM 57-30-01 FIG 1 LIMITS, LEFT WING UPPER SKIN LOWER SURFACE REPAIRED AT WS 390 AREA AS PER HX RS R57-25-35337 & UPS EO B747-5730-22494-A.