As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING HEAVY MAINTENANCE, CORROSION UPPER SURFACE OF UPPER SKIN OF THE CENTER WING BOX BTW +Y1292 AND +Y1732 IN PASSENGER CABIN; ACCOMPLISHED REPAIR ON ON CENTER WING BOX IAW EC A21-1360-21. WORK ACCOMPLISHED ON AEROMAN NR 2021-491731 (CLASSIFIED A MAJOR REPAIR)