Accident Sequence
The airplane impacted terrain after an uncontrolled descent. During the descent, while the airplane was in a descending right turn on the downwind side of a mountain, the horizontal stabilator and the left wing separated from the airframe.
Weather Conditions
Prior to departure, the pilot received a full preflight weather briefing and updated that briefing with an abbreviated briefing before takeoff. Both briefings included forecasts for moderate to severe turbulence and icing along the intended route of flight. While en route, the pilot experienced icing conditions and requested a lower altitude. Additionally, the pilot received pilot reports that indicated icing conditions were being encountered in the area of the destination.
The airplane was not equipped with anti-icing or deicing equipment.
A Safety Board weather study identified conditions that were conducive for clouds, turbulence, wind shear, icing, and mountain wave activity.