AN ACR SMT CREW RPTS THAT THEY HAD A FAILED STICK PUSHER ON THE GND; FORTUNATELY.

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ON TAXI OUT FROM FREEPORT RAMP; WE PERFORMED 'BEFORE TKOF' CHKLIST. WHEN FO ATTEMPTED TO CYCLE CTLS TO CHK FREEDOM OF MOVEMENT; WE DISCOVERED THAT THE STICK PUSHER HAD ACTIVATED AND WAS HOLDING THE YOKE FULL FORWARD. WE CHKED ALL SWITCH POS AND INDICATORS; AND FOUND NOTHING ABNORMAL. WE HAD NO INDICATION OF STALL; VISUAL OR AURAL. WE RETURNED TO THE GATE AND THE FLT WAS CANCELED. AFTER A MECH WAS FLOWN IN TO DISCONNECT THE STALL AVOIDANCE SYS; WE FERRIED HOME UNEVENTFULLY (WITH NO STALL WARNING OR STICK PUSHER FUNCTIONING). THE SMT HAS A HISTORY OF STICK PUSHER ACTIVATION DURING NORMAL FLT. I AM FAMILIAR WITH ONE SUCH CASE AT OUR AIRLINE WHERE; IF NOT FOR THE HEROIC EFFORTS OF THE CREW; THE ACFT WOULD HAVE BEEN DESTROYED. SUPPOSEDLY; THE MANUFACTURER AND THE USERS HAD DEVELOPED PROCS TO DEAL WITH; AND A MECH FIX TO PREVENT INADVERTENT STICK PUSHER ACTIVATION. OUR SIT WOULD HAVE BEEN VERY GRAVE HAD THIS HAPPENED WHILE AIRBORNE. NEITHER THE FO NOR I WERE ABLE TO OVERPWR THE PUSHER FORCE. SUPPOSEDLY; A CLUTCH IS BUILT INTO THE SYS TO LIMIT PUSHER FORCE. OBVIOUSLY IT WAS NOT FUNCTIONING PROPERLY. THE FACT THAT THE SMT IS ALLOWED TO CONTINUE TO OPERATE WITH SEVERE DESIGN DEFICIENCIES IN ITS STALL WARNING; ELECTRICAL; NOSE STEERING AND OTHER SYS IS A TRAVESTY! WE ALL KNOW WHAT THE ULTIMATE OUTCOME WILL BE IF THIS ACFT IS ALLOWED TO CONTINUE TO OPERATE WITHOUT A COMPREHENSIVE DESIGN REVIEW; AND MANDATED MODIFICATION PROGRAM. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTING CAPT STATES THAT THIS POPULAR TYPE OF COMMUTER ACFT HAS HAD A PROB WITH ITS STALL AVOIDANCE SYS (SAS) STICK PUSHER FOR QUITE SOME TIME. HE REFED AN ARTICLE IN THE CURRENT ISSUE OF A PLT'S UNION MAGAZINE WHERE THIS PROB IS ADDRESSED AND WHERE THE NTSB 'PROBABLE CAUSE' WAS CHANGED SEVERAL YRS AFTER A FATAL ACCIDENT. THE RPTR HAS TALKED AT LENGTH WITH HIS CHIEF PLT AND WILL CALL THE FAA SAFETY HOT LINE. HIS ACR'S MAINT SECTION FOUND THAT THE SAS COMPUTER WAS WORKING PROPERLY; BUT THE CLUTCH HAD DISINTEGRATED AND THE PARTS JAMMED THE CLUTCH IN THE ACTUATE POS FORCING THE NOSE DOWN.