As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING A 300 HR INSPECTION THE MECHANIC FOUND A PLASTIC TYPE PLUG LAYING UNDER THE ELEVATOR BELLCRANK IN THE TAIL SECTION. AFTER RESEARCH AND SPEAKING WITH THE MFG IT WAS DETERMINED THAT THE PLUG/CAP CAME FROM THE TOP OF THE ANTENNA TUBE. THE CAP WAS REMOVED. THERE IS A POSSIBILITY THAT THIS CAP COULD BECOME STUCK IN THE ELEVATOR BELLCRANK OR THE PUSH PULL TUBE COMING FROM THE TAIL.