As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RT WING LOWER SKIN PANEL NR 7 AT BUTT LINE 65 INTERNAL INTERGRANULAR CORROSION. THE DEFECTIVE PANEL WAS FIRST DETECTED BY A FUEL LEAK AT BUTT LINE 65. FURTHER INVESTIGATION REVEALED EXFOLIATION FROM INTERGRANULAR CORROSION. THE CORROSION WAS CONCEALED BY LAYERS OF FUEL TANK BARRIER SEALANT.