As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INSPECTION TYPE:C, LEFT WING UPPER WING SKIN L/E RABBIT AREA 2 PLACES BULGED UP AT WS 1470-1515 AFT OF NR 1 VC FLAP AREA. CORROSION THROUGH WHOLE THICKNESS AREA 7.3" X 4.3". LEFT WING UPPER WING SKIN REPAIRED AS PER HX RS R57-25-35357 & UPS ENGINEERING FILE 747-57-20080.