As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(A3NB-53-6186) CORROSION ON AFT CABIN FLOOR BEAM Y254 AR FR66 FW D END. (74-13) () REMOVED CORR. AT FLR BEAM FR66 Y254 IAW SRM 51-74-00. FOUND TO B E OUT OF LIMITS IAW SRM 53-00-14-283-002, REMOVED, REPLACED AND INSTALLED NEW FLR. BEAM ASSY IAW SRM 51-42-11. L=4" W=2" D=0050.