What was found
DURING M-CHECK, FOUND AFT CABIN FLOORBEAM BS 1640 BBL "0" TO RBL 54" CORRODED AT UPPER SKIN & LOWER SKIN SURFACE AROUND FASTENER HOLE. BLENDED OUT AREAS BEAM 1640 BBL 0 TO RBL 54 AND FOUND TO BE OUT OF LIMITS IAW SRM 53-40-51, FIG 101, SHEET 1 AND SHEET 3, DETAIL III. REMOVED ANGLE BRACKET FOR ACCESS AT STA 1640, LBL 2 IAW SRM 51-40-02. REMOVED T-CHORD AND SPLICE PLATES AT STA 1640, LBL 15 TO RBL 56 IAW SRM 51-40-02, LOCATED & DRILLED AND FINISHED FAB OF NEW T-CHORD IAW SRM 53-00-51 REPAIR I, FIG 201. TREATED AND PRIMED PARTS OF REPAIR IAW SRM 51-20-01AND PAINTED PARTS IAW AMM 51-21-00. INSTALLED NEW T-CHORD AND ANGLE BRACKETS IAW SRM 53-40-51 AND SRM 51-40-02.