What was found
MCN - MAJOR REPAIR - "C" - DURING C-17 CHECK CORROSION WAS FOUND ON FLOOR BEAM UPPER FLANGE AT BS 947, LBL 10 TO RBL 10. MAINTENANCE REMOVED 6 EACH FLOOR SUPPORT, 1 EACH INTERCOASTAL BRACKET ASSEMBLY, AND TEE CHORD FROM LBL 32 TO RBL 33. FABRICATED AND INSTALLED NEW TEE CHORD BS 947, LBL 32 TO RBL 33, REINSTALLED INTERCOASTAL BRACKET AND 6 EACH FLOOR SUPPORTS BS 947 TO BS 967, REPAIRS C/W IAW B737-300 SRM 53-00-51 PG 207-211, SRM 51-40-02 PG 6-7, 16-19, & 45.