What was found
PILOT REPORTED THAT IN CRUISE WHILE PERFORMING A TURN, THE ELEVATOR TRIM STARTED TO RUNAWAY. PILOT WASN`T ABLE TO MANUALLY TRIM THE ELEVATOR BACK. HAD TO DISENGAGE AUTOPILOT SYS AND MANUALLY FLY THE ACFT, AND PERFORMED A LANDING BACK TO DEPARTURE AIRPORT. ON GROUND, I DOWNLOADED THE FAULT HISTORY DATA BASE AND E-MAILED THE FHDB TO MFG REPS AND THEY CAME UP WITH THE SOLUTION. THEY ADVISED WE REPLACED THE TRIM ADAPTER. REPLACED TRIM ADAPTER AS REQUESTED BY MFG REP. PERFORMED OPS TEST AFTER REPLACEMENT OF PART AND NO DEFECTS WERE NO NOTED.