As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE IN HEAVY MAINTENANCE IS WAS NOTED THAT THE WING CENTER SECTION UPPER SKIN LBL 24 BS 760 HAS CORROSION. REMOVED CORROSION PERFORMED NDT TESTING, SHOT PEENED AREA, OVER SIZED FASTENER HOLES AND INSTALLED NEW FASTENERS. NO OTHER DEFECTS WERE NOTED. AIRCRAFT WAS RETURNED TO SERVICE.