As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING HEAVY CHECK INSPECTIONS ON CFII, CORROSION FOUND ON WTBF STRUCTURE LOWER FLANGE AT RIB45 BETWEEN LBL30 AND RBL30. CORROSION AT RIB 45 REMOVED BY BLEND-OUT IAW SRM 51-10-03 AND FOUND TO BE WITHIN LIMITS IAW SRM 53-04-02 AD01 REV 46 DEC 03/21.