While flying Self_motion at 33,000 ft , the aircraft 's speed gradually decreased Cause_change_of_position_on_a_scale until it entered an aerodynamic stall .

The cause Causation of the accident was determined Deciding to be a loss of control of the plane in turbulence , resulting in an involuntary steep descent Motion_directional which created Creating aerodynamic loads in excess of those for which the craft had been designed Create_artwork .