Accident Sequence
The pilot did not deice the wings prior to departure. At the time of takeoff, moderate snow was falling. The takeoff roll was observed to be longer than normal. After becoming airborne, a witness reported seeing the wings rocking from side to side. The aircraft then struck trees located approximately one mile from the end of the runway, resulting in a crash and subsequent fire.
Investigation Findings
Post-accident examination revealed snow contamination on the top surface of one wing that had not been consumed by fire, as well as on the top of the horizontal stabilizers and elevators. No mechanical discrepancies were found with the engine or the airframe. The aircraft was determined to have been overloaded: it exceeded the maximum structural takeoff weight by 360 pounds and the reduced takeoff weight allowed for flight in icing conditions by 1,100 pounds.
Probable Cause
The probable cause of the accident was the pilot's failure to de-ice the airplane before departure and his decision to conduct the takeoff at a weight exceeding both the maximum structural takeoff weight and the limit imposed for icing conditions, which resulted in an inadvertent stall.