What was found
(AIRCRAFT NOT GROUNDED) (DISCREPANCY DISCOVERED DURING AIRCRAFT HEAVY MX VISIT) NRC 5000-0012: 33284-20 LH WING TRAILING EDGE , RIBLET L BETWEEN RIB 18 AND RIB 19 CORRODED / AT LH WING TRAILING EDGE , RIBLET L BETWEEN RIB 18 AND RIB 19 REPLACED AS PER AIRBUS DOSSIER 81427483 AND REPAIR DRAWING R575-40250 ISSUE C. REPAIR IS CATEGORY A AS PER AIRBUS RDAF/81427483/006/2024#A. REPAIR IS MAJOR DUE TO PSE ITEM. NO FURTHER ACTION REQUIRED. SEE AWS FOR DETAILS AND NDT REPORT MWO 58564-15. RIBLET PN: D5754017020039 AND PO: 2076190.REF AAY ERO R5751-0053 R.00"