As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT IT WAS NOTED AN ABNORMAL METALLIC NOISE EMANATING FROM THE TAIL BOOM AREA. IT WAS DECIDED TO PERFORM A PRECAUTIONARY LANDING DUE TO THE NOISE HEARD. UPON INSPECTION OF THE AIRCRAFT THE TAIL ROTOR MAST NUT WAS FOUND IN A LOOSE CONDITION. SAFETY WIRE WAS STILL INTACT AND IN THE CORRECT ORIENTATION