As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ELEVATOR TRIM TAB BECAME TIGHT AND HARD TO USE, AND FINALLY IT BECAME INOPERATIVE. IT IS VERY DIFFICULT TO GET TO THIS PROBLEM, SINCE THE PART CONTAINING THE MOVABLE TRIM TAB IS ENCASED IN A TIGHT TUBE AND IT IS ABOVE THE OVERHEAD AND BELOW THE OUTER FABRIC SKIN OF THE AIRPLANE IN THE COCKPIT AREA.