What was found
DURING HEAVY MAINTENANCE Y765 CABIN FLOORBEAM AT FRAME 66 TO FRAME 70 HAS CORROSION. REMOVED CORROSION ON AFT CABIN FLOORBEAM -Y765 AND FOUND TO BE OUT OF LIMITS. 100 PERCENT MATERIAL LOSS, .079" IAW SRM: 53-10-14. R & R FLOORBEAM IAW SRM 51-42-11, PG 7.