As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) WHILE COMPLYING WITH AD CF-81-25R, FLUORESCENT PENETRANT INSPECTION SHOWED NUT ON THE RT UPPER AFT WING BOLT WAS CRACKED. THE NUT WAS ALSO FOUND TO BE THREAD BOUND WHEN TORQUED TO SPECIFICATIONS. A NEW WING BOLT KIT WAS INSTALLED WHICH CORRECTED THE PROBLEM.