What was found
AFT CARGO COMPARTMENT STA 747 TO STA 767 RBL 20 WL 156 INTERCOSTAL HAS AREA OF CORROSION / REMOVED INTERCOSTAL AT AFT CARGO COMPARTMENT STA 727-767 RBL 20 WL 156 REMOVED CORROSION; CORROSION LOSS FOUND OUT OF LIMITS; VERIFIED NEW MATERIALS; FABRICATED NEW INTERCOSTAL TREATED AND PRIMED; PERFORMED CONFORMITY INSPECTION AND INSTALLED NEWLY FABRICATED INTERCOSTAL IAW SRM 51-40-02-0G-0; 53-06-53-1A-2; 53-60-53-01-2; 51-40-05-0G-0; B737 DRAWINGS 146A7505 REV 13; AMM 51-21-41-370-801; 51-21-12-370-804 CIC APPLIED IAW AMM 51-21-91-620-802 PART FABRICATED ON BACKSHOPS W/O 40687-1600-0001 ORIG THICKNESS .032' REMAIN .022' LOSS .010'