What was found
MCN - MAJOR REPAIR - DURING C-04 CHECK EXFOLIATION CORROSION WAS FOUND ON UPPER SURFACE OF FLOORBEAM Y-1292, FORWARD SIDE OF FR 68. MAINTENANCE REMOVED CORROSION AND FOUND MATERIAL LOSS TO BE OUT OF LIMITS. REMOVED FLOORBEAM Y-1292, FORWARD SIDE OF FR 68 TO FR 70; FABRICATED A NEW REPLACEMENT FLOORBEAM; INSTALLED REPAIR PART IAW A320 SRM 51-42-11 PG 39-41, FIG 18, SRM 51-42-11 PG 6-7 AND SRM 51-49-00 PG 24.