What was found
MCN - MAJOR REPAIR - DURING C-18 CHECK A .5 INCH CRACK WAS FOUND ON INTERCOSTAL IN THE AFT CARGO COMPARTMENT AT BS 800, RBL 43, WL 164. MAINTENANCE REMOVED DAMAGED INTERCOSTAL AT BS 800, RBL 43, WL 164. FABRICATED A NEW REPLACEMENT INTERCOSTAL, AND INSTALLED REPAIR IAW 737-200 SRM 51-20-1, PG 10-11, 14 & 18A, FIG 3 & 7, SRM 51-30-5, PG 4-5, FIG 2 & 3, AND SRM 51-10-2, PG 32, FIG 32.