A BEECH 200 ON TKOF CLB AT 1500 FT WHEN THE AUTOPLT WAS ENGAGED; GOT A TRIM FAIL LIGHT AND UNCOMMANDED FULL NOSE UP TRIM. TURNING OFF AUTOPLT AND ELECTRIC TRIM; NO HELP. CALLED PAX FORWARD TO HELP IN PITCH CTL.

Narrative

AFTER TKOF FROM ZZZ ARPT AT APPROX 1500 FT MSL; I ENGAGED THE AUTOPLT AND OBSERVED A TRIM FAIL ANNUNCIATOR LIGHT FOLLOWED BY AN UNCOMMANDED TRIM MOVEMENT TO FULL TRIM NOSE UP POSITION. AFTER TURNING OFF THE AUTOPLT AND ELECTRIC TRIM BY USE OF THE AUTOPLT INTERRUPT SWITCH ON THE PLT'S CTL WHEEL; I WAS STILL UNABLE TO REGAIN CTL OF THE PITCH TRIM. I THEN PULLED THE PITCH TRIM CIRCUIT BREAKER AND WAS STILL UNABLE TO DEACTIVATE THE TRIM MOTOR; I HAD TO CALL A PAX FORWARD INTO THE COCKPIT TO ASSIST IN MAINTAINING CTL OF PITCH ATTITUDE OF THE ACFT. ONLY BY LOWERING THE LNDG GEAR; REDUCING POWER; AND PLACING THE FLAPS IN THE APCH POSITION AND ACCEPTING SLOWER THAN USUAL AIRSPD WAS I ABLE TO CTL THE ACFT AND MAINTAIN AN ACCEPTABLE DSCNT AND APCH PROFILE. I BELIEVE THAT THE PRIMARY CAUSE OF THE INABILITY TO REGAIN CTL OF THE PITCH TRIM WAS THE FAILURE OF THE INITIAL INSTALLER OR SUBSEQUENT MAINT INSPECTORS TO IDENTIFY THE IMPROPER ELECTRICAL RIGGING OF THE AUTOPLT AND TRIM SYSTEM. FURTHER MY FAILURE TO IDENTIFY AND RPT AN UNACCEPTABLE CONDITION OF THE PITCH TRIM AND AUTOPLT OPERATION DURING PREVIOUS OPERATION OF THE ACFT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE MAINT ACTION TO CORRECT THE UNCTLED NOSE UP PITCH IS UNKNOWN AS THE AIRPLANE IS STILL IN A MAINT FACILITY FOR REPAIR. THE RPTR STATED USING MANUAL CTL; THE PITCH CTL WAS CONTROLLABLE. HOWEVER; WHEN RELEASED; THE AIRPLANE WOULD THEN PITCH NOSE UP.