What was found
WHILE AC WAS IN FOR HEAVY CHECK FOUND AFT CABIN FLOORBEAM AT FR 86 THROUGH FR 89 AND RBL 11 IS CORRODED ON UPPER FLANGE. MX REMOVED AND REPLACED FLOORBEAM PN 170-65669-004. (ONE BEAM REPLACEMENT COVERS 3 WORK NR CARDS 6243403, 6243404, 6243416)IAW SRM 51-40-08, 53-23-10, 51-40-02, 51-40-08. AC REMAINS IN IND FOR COMPLETION.