A CANADAIR CL65 IN CLB BTWN 10000 AND 15000 FT EXPERIENCED ELEVATOR FLUTTER OR VIBRATION IN CTL COLUMN TWICE IN 2 SECOND INTERVALS CAUSED BY A FAILED RIGHT ELEVATOR CTL PWR UNIT.

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HAD NOTICED A BRIEF (APPROX 2 SECONDS) VIBRATION IN CTL YOKE 2 TIMES DURING THE 3 PREVIOUS LEGS. DIDN'T KNOW WHAT IT WAS; BUT DUE TO AIRSPACE WE WERE FLYING IN (LGA AND YUL) CONSIDERED POSSIBILITY OF WAKE TURBULENCE. ON LAST OF 4 LEGS (MYR TO ZZZ) NOTICED THIS OCCURENCE AGAIN ON CLIMB OUT -- NO POSSIBILITY OF WAKE TURBULENCE ENCOUNTER. NOTED THIS OCCURRED AT ABOUT 300 KIAS BTWN 10000 AND 15000 FT ON THE 3 TIMES THAT IT OCCURRED. BROUGHT UP FLIGHT CTL SYNOPTIC PAGE DURING CRUISE AND NOTICED RIGHT ELEVATOR ICON 'JIGGLING' -- LEFT ELEVATOR ICON STEADY. CONTACTED MAINT CTL VIA COMMERCIAL RADIO AND DESCRIBED PROB. MAINT CTL SAID LITTLE EXCEPT TO CONTINUE AND BRING IT TO ZZZ AND THEY WOULD LOOK AT IT. CONTINUED FLIGHT WITH SOME APPREHENSION AND DECIDED; WITH FO INPUT; THAT WE WOULD DIVERT IMMEDIATELY IF ANY CTL CHANGES WERE NOTED. DISCUSSED POSSIBLE RELATIONSHIP BTWN POSSIBLE ELEVATOR PROB AND AUTOPLT DISCONNECT AT FLAP EXTENSION ON PREVIOUS APPROACHES. ALSO DISCUSSED PLANS FOR APCH -- CAREFUL MONITORING OF FLT CTL PAGE; AUTOPLT BEHAVIOR; YOKE 'FLUTTER.' NATURALLY; NONE OF THE OBSERVED OCCURENCES WERE SEEN DURING LAST APCH. LANDED UNEVENTFULLY AND WROTE UP ACFT AND ALL OBSERVED ITEMS. LINE MAINT 'TESTED' ELEVATOR MOVEMENT AND FOUND IT TO BE 'WITHIN LIMITS.' I EXPLAINED OBSERVED ITEMS AND SAID I WOULD NOT FLY ACFT UNTIL IT WAS INSPECTED. BRIEFED CAPT WHO WAS TO TAKE ACFT NEXT AND ADVISED HER NOT TO ACCEPT ACFT. CONTACTED CHIEF PLT TO ADVISE OF POSSIBLE FLT CTL PROB. HE SENT TO HANGAR WHERE INSPECTION FOUND A 'HARD FAILURE' OF AN ELEVATOR SERVO. ALSO REPLACED ELEVATOR POSITION SENDER. IF I HAD KNOWN THIS IN FLT; I WOULD HAVE DIVERTED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE CAUSE OF THE VIBRATION WAS THE RIGHT ELEVATOR PWR UNIT WHICH WAS DISCOVERED TO BE FAULTY. A RIGHT ELEVATOR POSITION SENSOR WAS ALSO REPLACED. THE AIRPLANE WAS ONLY REMOVED FROM SERVICE WHEN HE INSISTED IT NOT TO BE FLOWN AND AFTER A CALL TO THE CHIEF PLT. THIS WAS ONE OF THE OLDER AIRPLANES IN THE FLEET WITH 15000 HOURS.