As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FOUND AIRFRAME SIDE OF FLAP HINGE UNAIRWORTHY DUE TO SEVERE INTERGRANULAR EXFOLIATION. DEFECT WAS FOUND DURING AN ANNUAL INSPECTION. AIRCRAFT WAS EQUIPPED WITH A 'SPEED KIT' STC NR SA4023WE, WHICH INCLUDED FLAP HINGE FAIRINGS WITH THE FLAP HINGE FAIRINGS INSTALLED. INSPECTION OF THE HINGES IS LIMITED. THE FAIRINGS ON THIS AIRCRAFT WERE ATTACHED WITH BLIND RIVETS. RECOMMEND REMOVING FAIRINGS AT EACH INSPECTION.