A CANADAIR CL-65 IN CLB AT 12000 FT HAD AUTOPLT STAB TRIM WARNING. SWITCHED OFF AUTOPLT AND FOUND MAIN ELECTRIC TRIM ALSO INOPERATIVE. CAUSED BY FAILED MAIN ELECTRIC ACTUATOR.

Narrative

DURING CLB OUT OF ZZZ. THE STAB TRIM WOULD NOT TRIM MORE THAN 4.2 UNITS NOSE DOWN. AUTOPLT WAS UNABLE TO TRIM THE ACFT EITHER. TROUBLE SHOOTING WAS CONDUCTED TO DETERMINE THE CONTROLLABILITY OF THE ACFT. TRIM WAS AVAILABLE AFT BUT NO MORE THAN PREVIOUSLY STATED 4.2 UNITS NOSE DOWN. MAINT CTL WAS CONTACTED BUT OFFER NO NEW IDEAS. FLT CONTINUED TO DESTINATION AT LOWER ALTITUDE AND REDUCED AIRSPEED FOR CONTROLLABILITY AND COMFORT OF PLTS FLYING BY HAND. QRH WAS CONSULTED WITH NO PROCS SO STAB 1 AND 2 INOP WAS USED AS A GRIDLINE AND A ALT LANDING FLAP SETTING WAS USED. ATC WAS ADVISED OF THE SIT AND OUR REDUCED AIRSPEED; BUT NO OTHER ASSISTANCE WAS REQUESTED OR REQUIRED. FLT AND LNDG WAS OTHERWISE NORMAL AND UNEVENTFUL. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE REPLACEMENT OF THE MAIN ELECTRIC ACTUATOR CORRECTED THE PROB. THE RPTR SAID THE AUTOPLT ACTUATOR SHOULD HAVE BEEN REPLACED AS IT ALSO WAS INOPERATIVE. THE RPTR STATED IT WAS HIS BELIEF THAT ONE FAILED ACTUATOR COULD NOT LOCK UP THE OTHER ACTUATOR AS BUILT IN CLUTCHES WOULD DISENGAGE THE FAILED ACTUATOR. THE RPTR SAID RPTS OF STABILIZER TRIM FAILURES ARE NOT OUT OF THE ORDINARY BUT OCCUR MAINLY ON THE GND. THE RPTR STATED THIS AIRPLANE WAS NOT PARKED IN THE RAIN OR SNOW OVERNIGHT AND WX WAS NOT A CAUSE.