As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE REPAIRING A FUEL LEAK, CORROSION WAS DISCOVERED IN TWO PLACES INSIDE THE FUEL TANK, ON THE FORWARD RADIUS OF THE RT AFT OUTBOARD SPAR CAP. THE FIRST AREA OF CORROSION WAS DISCOVERED AT WS 208.1 AND WAS 1 INCH IN LENGTH. THE SECOND AREA WAS LOCATED AT WS 190.21 AND MEASURED 6.5 INCHES IN LENGTH. BOTH AREAS OF CORROSION WERE DEEPER THAN THE ALLOWABLE REMOVAL LIMITS. THE SPAR CAP WAS CHANGED WITH NEW.