A CESSNA 560XL IN CLB AT 8000 FT HAD STABILIZER MISCOMPARE LIGHT ON; RAN CHKLIST AND CLBED TO FL310. DIVERTED DUE TO PITCH DEVS. CAUSE UNKNOWN.

Narrative

AFTER TKOF AND FLAPS UP; HYD PRESSURE LIGHT WAS NOTED OUT. APPROX 15 SECONDS AFTER LIGHT NOTED OUT; STABILIZER MISCOMPARE LIGHT ILLUMINATED. ACFT WAS SLOWED IN CLB AND CHKLISTS WERE COMPLETED; TO INCLUDE R2 FOR MISCOMPARE LIGHT. LIMITATIONS WERE 200 KTS/MACH .62 ON AIRSPD AND FL410. WE CALLED MAINT AND DECIDED TO DIVERT TO ZZZ TO A SVC CTR. AFTER DEV COORD AND COMPLETION OF NORMAL CHKLISTS; WE CLBED TO FL310. CHKLIST H2 WAS RUN FOR THE ACCOMPANYING HYD PRESSURE LIGHT ON. WHEN PULLING THE HYD CTL CIRCUIT BREAKER; A LOUD THUMP WAS FELT AND HEARD; ONCE PUSHING IN THE CIRCUIT BREAKER; SAME THUMP WAS FELT AND HEARD. APPROX 10 SECONDS LATER; THE STABILIZER MOVED DOWN; CAUSING PITCH DEVS AND STABILIZER MISCOMPARE LIGHT EXTINGUISHED. DUE TO THE SHUDDER FELT WHILE THE MALFUNCTION WAS IN PROGRESS; AND UNCERTAINTY OF THE STABILIZER CONTINUING TO WORK AND EFFECT ON PITCH CTL; THE DECISION WAS MADE TO DIVERT TO APA. (STABILIZER MISCOMPARE LIGHT WAS ON FOR APPROX 30 MINS.) CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE MISCOMPARE LIGHT IS A FUNCTION OF THE COMPARISON OF STABILIZER POS AND FLAP POS. THE RPTR SAID IN THIS CASE; THE FLAPS WERE FULLY RETRACTED AND THE MISCOMPARE LIGHT WAS ON CONTINUOUSLY UNTIL THE CIRCUIT BREAKER WAS PULLED (WITH A LOUD THUMP) AND RESET (AGAIN WITH A LOUD THUMP); ACCOMPANIED WITH THE STABILIZER MOVING DOWN. THE RPTR STATED WITH THE STABILIZER MOVING; THE MISCOMPARE LIGHT WENT OUT; BUT THE PITCH DEVS STARTED AND THE DECISION WAS THEN MADE TO DIVERT. THE RPTR SAID THE MAINT ACTION IS UNKNOWN BUT THE AIRPLANE IS NOW FLYING.