As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING HEAVY MAINTENANCE, CORROSION LOWER SILL FR 68 AT STR 23L IN PASSENGER CABIN; REMOVED CORROSION AT LOWER SILL FR 68 AT STR 23L IAW SRM 51-74-00. EVALUATED REWORK AND FOUND TO EXCEED ALLOWABLE LIMITS. PERFORMED REPAIR IAW SRM 53-41-14-300-001. REF AEROMAN NR 2021-275560