A BEECH JET 400 CREW LOST 600 FT DURING SEVERE TURB AFTER AN AUTOPLT DISCONNECT.

Narrative

WHILE IN CRUISE FLT AT FL370 WE HAD BEEN ENCOUNTERING CONTINUOUS VERY STRONG MODERATE TURB. AFTER ENDURING THIS FOR SEVERAL MINS; WE REQUESTED A LOWER ALT. WHILE AWAITING CLRNC; THE TURB SUDDENLY TURNED TO SEVERE. THE AUTOPLT DISCONNECTED AND BEFORE I COULD RECOVER; WE HAD DSNDED APPROX 600 FT. THE TURB WAS SO BAD THAT I HAD A HARD TIME MAKING THE ACFT RESPOND TO CTL INPUTS TO CLB. AFTER GETTING THE OK TO CONTINUE OUR DSCNT TO FL330; WHERE WE AGAIN ENCOUNTERED HVY MODERATE TO SEVERE TURB AND ONCE AGAIN THE AUTOPLT DISCONNECTED AND THIS TIME WHILE BEING READY FOR IT TOOK ME 300 FT TO RECOVER. OBVIOUSLY; THERE WAS A FORECAST OF TURB; BUT I HAVE NEVER IN MY FLYING CAREER EVER EXPERIENCED TURB OF THIS MAGNITUDE IN CLR AIR CONDITIONS. I FEEL THAT IF I AND MY FO; WHO IS NEW TO FLYING HIGH PERFORMANCE ACFT; WERE MORE DILIGENT IN MONITORING THE AUTOPLT; WE MAY HAVE POSSIBLY AVOIDED THE EXCESS ALT LOSS CREATED BY THE AUTOPLT DISCONNECT. THIS SHOULD BE A LESSON FOR EVERYONE WHO IS GOING TO OPERATE IN RVSM AIRSPACE.