What was found
MCN - MAJOR REPAIR - DURING 8-DAY CHECK CORROSION WAS FOUND ON RT KEEL BEAM AT BS 540, STR 27 RT. MAINTENANCE CUTOUT DAMAGED AREA OF KEEL BEAM LOWER CHORD FROM BS 500A TO BS 540; FABRICATED A NEW REPLACEMENT SECTION OF KEEL BEAM CHORD, 3 EACH FILLERS, AND 2 EACH ANGLES; INSTALLED REPAIR PARTS IAW B737-300 SRM 53-60-12, FIG 203.