GA PLT HAD POSSIBLE ENTRY TO CLASS B AIRSPACE WITHOUT CLRNC DUE TO MALFUNCTIONING AUTOPLT AND PARTIAL LOSS OF ACFT CTL.

Narrative

I TOOK OFF FROM FFZ AT MESA; AZ; FOR A FLT TO A DESERT STRIP NEAR KINGMAN; AZ. AFTER LEAVING TWR FREQ; I CALLED PHX APCH AND APPRISED THEM OF MY PLAN AND ASKED FOR FLT FOLLOWING. AS I WAS CLBING OUT ON AUTOPLT; I WAS GIVEN A SQUAWK CODE. AFTER DIALING IN THE CODE; I BEGAN TO SET UP MY GPS TO FLY DIRECTLY TO MY DEST. PRIOR TO BEING CLRED INTO CLASS B AIRSPACE; MY ELECTRIC TRIM MECHANISM BEGAN TO ADVANCE IN THE UP DIRECTION FOR NO KNOWN REASON. AS I WAS TRYING TO CORRECT THIS SIT BY DEPRESSING THE DOWN TRIM SWITCH; PHX APCH CALLED TO SAY THAT I WAS APCHING THE ALT OF CLASS B AIRSPACE AND TO DSND IMMEDIATELY. BEING UNABLE TO REVERSE THE ADVANCING UP TRIM WITH DOWN TRIM; I SHUT OFF THE AUTOPLT TO DSND MANUALLY. UNFORTUNATELY; BY THAT TIME; I HAD ADDED IN SO MUCH DOWN TRIM THAT THE ACFT WENT INTO A NEARLY VERT DIVE. PHX APCH CALLED AGAIN REQUESTING IMMEDIATE ACKNOWLEDGEMENT OF THE DSCNT REQUEST AND I RESPONDED THAT I WAS IN A DIVE. PHX APCH THEN GAVE ME A TELEPHONE NUMBER TO CALL FOR A POSSIBLE CLASS B AIRSPACE VIOLATION. I COULD NOT CALL FROM THE DESERT STRIP DUE TO LACK OF PHONE BUT DID CALL ON MONDAY AND TUESDAY. I WAS TOLD TO CALL BACK BOTH TIMES DUE TO THE FACT THAT THE SHIFT SUPVR ON DUTY SATURDAY MORNING WAS NOT ON DUTY WHEN I CALLED. DUE TO MY FIRST PRIORITY; WHICH WAS TO FLY THE AIRPLANE; I DID NOT MAKE NOTE OF THE PEAK ALT ATTAINED. I HAVE NOT YET TALKED TO PHX TRACON AND DO NOT KNOW IF I DID IN FACT VIOLATE THE CLASS B AIRSPACE. I DO KNOW THAT I WAS SLIGHTLY E OF A DIRECT LINE BTWN FFZ AND SDL.