As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING HEAVY MAINTENANCE, CORROSION WAS DISCOVERED ON AFT CABIN Y464 FLOORBEAM FRAME 64+11 STR 23L; REMOVED AND REPLACED AFT CABIN Y464 FLOORBEAM IAW SRM 51-42-11/51-72-11 AT FR64+11 THRU 68+6 STR23L. ALL WORK ACCOMPLISHED ON NR 444484/26664/902984