CONSUMER COMPLAINED ABOUT THE TRANSMISSION DESIGN. THE VEHICLE SLIPPED INTO NEUTRAL EVEN IF GEAR WAS SUPPOSE TO BE IN DRIVE. *MR THE CONSUMER WAS CONCERNED ABOUT A FATAL BUS ACCIDENT NHTSA REPORTED ON THE SIERRA TRAILWAYS. THE TRANSMISSION WOULD EASILY GO INTO NEUTRAL EVEN IF SUPPOSED TO BE IN DRIVE DUE TO THE LOCATION DESIGN. AN ACCIDENT OCCURRED WHERE THE MOTORCAOCH HAD BEGUN TO FISH TAIL WHILE ON A CURVE. THE DRIVER RECOVERED THE VEHICLE FROM THE FISH TAIL AND GAINED SPEED. APPROXIMATELY 36 SECONDS LATER THE DRIVER LOSS CONTROL OF THE VEHICLE ON ANOTHER CURVE, WHICH DRIFTED OFF THE RIGHT SIDE OF THE ROAD, STRUCK A MILE POST AND A DELINEATOR, RETURNED TO THE ROAD, ROTATED CLOCKWISE 180 DEGREES TOWARD THE CENTER LINE, AND DEPARTED THE NORTH SIDE OF THE ROADWAY BACKWARD. THE VEHICLE ROLLED AT LEAST 1.5 TIMES DOWN A 40 FOOT DEEP EMBANKMENT AND HAD COME TO REST ON ITS ROOF. PRIOR TO THE ACCIDENT, THE DRIVER HAD CALLED A TOW TRUCK TO JUMP START THE BATTERY, WHICH HAD REMAINED PARKED DURING A THREE DAY STAY. A COUPLE DAYS AFTER THE ACCIDENT, THE STATE BOARD AND COLORADO STATE PATROL INVESTIGATORS CONDUCTED A PRELIMINARY BRAKE INSPECTION AND FOUND A SMALL LEAK IN A FITTING FOR THE SERVICE INTAKE TO THE RIGHT DRIVE AXLE AIR CHAMBER. THE INVESTIGATORS COULD NOT DETERMINE WHETHER THE FAULTS OCCURRED AT THE TIME OF THE ACCIDENT, SEVERAL MONTHS BEFORE THE ACCIDENT, OR AFTER. WHEN THE MOTORCOACH FISH TAILED AT MILE POST 272.3, THE TRANSMISSION RETARDER WAS ENGAGED