A BE400A EXPERIENCED FAILURE OF HORIZONTAL TAIL DE-ICE AFTER TAKEOFF. FLT CREW ELECTED TO DIVERT; ENCOUNTERED A TAIL STALL; AND ELECTED TO HAVE CFR STANDING BY. THE APCH AND LNDG WERE EXECUTED AT A HIGHER AIRSPEED THAN NORMAL AND WERE CONCLUDED SUCCESSFULLY.

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WHILE CLIMBING OUT ON THE DEP AND THE SUBSEQUENT VECTORS; I ATTEMPTED TO ENGAGE MY AUTOPILOT AT 3000 FT. I HAD OBSERVED AN 'AUTOPILOT MISTRIM' ANNUNCIATOR APPEAR AND THE AUTOPILOT DISENGAGED. I NOTED THE TRIM POSITIONS AND THEY WERE ALL NORMAL. I ATTEMPTED TO RE-ENGAGE THE AUTOPILOT AND THE ANNUNCIATOR REAPPEARED FOLLOWED BY A HORIZONTAL TAIL DE-ICE FAIL LIGHT. WE COMPLIED WITH THE APPROPRIATE CHECKLISTS AND REQUESTED A RETURN TO ZZZ. AFTER CALCULATING OUR LNDG PERFORMANCE I ELECTED TO DIVERT TO ZZZ1 BECAUSE OF THE LONGER RWYS; WET CONDITIONS AND OUR HIGH LNDG SPEED SINCE OUR SITUATION NECESSITATED A FLAPS 10 LNDG. WHILE LINING UP FOR THE ILS AT ZZZ1 I ENCOUNTERED A TAIL STALL WHICH I WAS ABLE TO RECOVER FROM BUT NEEDED A VERY HIGH APCH SPEED TO MAINTAIN ACFT CTL. AT THAT POINT I HAD MY SIC INFORM ATC TO HAVE CFR STANDING BY AS A PRECAUTION. ONE NOTE OF INTEREST: WE WERE FOLLOWING AN ACR ACFT FOR THE ILS AND WITH OUR HIGH APCH SPEED WE WERE CLOSING IN ON SEPARATION MINIMA. ATC INFORMED US AND WE INFORMED THEM THAT DUE TO OUR SITUATION WE COULD NOT SLOW DOWN OR EXECUTE A GAR MANEUVER. ATC KEPT THE ACR ACFT ON APCH WITH DISREGARD FOR OUR SITUATION WHICH I BELIEVE WAS ALSO A DISTRACTION. THE LNDG WAS EXECUTED WITHOUT INCIDENT. ALL DE-ICE AND ANTI-ICE EQUIPMENT WAS CHECKED AND FUNCTIONING NORMALLY PRIOR TO DEP FROM ZZZ. THIS IS A COMMON PROBLEM WITH THE BE400 AND I BELIEVE THIS WAS A SIMPLE SYSTEM FAILURE THAT CAN HAVE SERIOUS CONSEQUENCES. I ALSO BELIEVE THAT ACTING ON THE SITUATION WITH NO DELAY AND UTILIZING THE TRAINING PROVIDED BY OUR EMPLOYER WAS KEY TO A SAFE OUTCOME.CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT APPARENTLY THE AIR/GROUND STRUT SWITCH FAILED; WHICH CUTS THE POWER TO THE HORIZONTAL TAIL ELECTRIC ANTI-ICE MATS. THEY HAD NO OTHER SYMPTOMS OF THE STRUT SWITCH FAILURE; SO THEY BELIEVE THE SWITCH FAILED AFTER TAKEOFF. THE RPTR FEELS THE TAIL DE-ICE SYSTEM IS OVERLY COMPLICATED AND PRONE TO FAILURE.