What was found
DURING HEAVY MAINTENANCE: LEFT WING T/E STRUCTURAL RIB IS CORRODED ON THE UPPER ATTACH FLANGE BETWEEN APPROX RIB 20 AND 21 ON THE AFT SIDE OF THE AFT SPAR; (RESOLVED ON W/O: 1355989 TASKCARD: NR-00004) REF HAECO WO 169006 NR 32271 FOR WORK PERFORMED; REMOVED AND REPLACED RIBLET SUPPORT IAW AIRBUS DWGD57541714 CAPSEALED FASTENERS ON RIBLET SUPPORT IAW A320 SRM 51-24-00 (LEAK CHECK ON NR 32152) AND DWG D57541714. SDR APPLIED TO LOG PAGE 4156214, AND MX220 CREATED.