What was found
PREFLIGHT AND OPS CHECK OF TRIM SYSTEM NORMAL. 30 MINUTES INTO FLIGHT, PILOT NOTICED LIMITED RANGE IN ELEVATOR TRIM. PERFORMANCE DEGRADED AND TRIM JAMMED, MANUAL AND ELECTRIC. INSPECTION REVEALED WEAR ON THE JACKSCREW AND DRUM THREADS. PARTS WERE REPLACED AS REQUIRED. TOTAL TIME ON PART UNKNOWN BUT IS SUSPECTED TO BE CONSIDERABLE. RECOMMEND A SPECIAL INSPECTION TO INCLUDE DISASSEMBLY, INSPECTION, AND REPLACEMENT AS REQUIRED OF TRIM DRIVE MECHANISM PARTS AT EACH 1000 HOURS TIME IN SERVICE.