What was found
(AIRCRAFT NOT GROUNDED), DISCREPANCY NOTED DURING AIRCRAFT HEAVY MX VISIT, MAJOR REPAIR LT WING BOTTOM SKIN HAS CORROSION AT FUEL PUMP FSTR HOLE NR 121, BTW RIBS 1 & 2, LT WING BOTTOM SKIN PANEL NR 2 LOWER SURFACE BTW RIBS 1-2 AT FUEL PUMP FASTENER HOLE NR 121 IAW DWG R57258270, ISSUE C. PERMANENTLY REPAIRED IAW DOSSIER 80967127, SRM 57-21-11-283-059, REV 154. REPAIR CATEGORY B.