Accident Sequence
During the final approach, the airplane gradually decelerated to near its stall speed. The last recorded data showed the aircraft about 600 feet before impact. The airplane then struck the ground in a nose-down attitude consistent with an aerodynamic stall.
Aircraft Information
The airplane was equipped with 5-bladed propellers. Other pilots reported that this modification caused the aircraft to decelerate rapidly, particularly when the speed and propeller levers were moved to the high rpm (forward) position. Postaccident examination revealed no preaccident mechanical failures or malfunctions.
Weather Conditions
Witnesses near the accident site reported very heavy sleet with low visibility conditions. However, a witness located near the final approach flightpath, approximately 2 miles before the accident site, observed the airplane flying below an overcast cloud layer with no precipitation present. Based on witness accounts and weather data, the airplane likely entered a lake-effect band of heavy sleet during the final portion of the flight.
Pilot and Passenger Information
The pilot typically flew a larger corporate jet and had not operated the accident airplane for eight months. The passenger was a student pilot with an interest in becoming a professional pilot.
Investigation Findings
The investigation determined that the pilot's poor airspeed control on final approach was likely influenced by a lack of recency in the turboprop airplane. The workload associated with inflight deicing tasks may have also contributed to the poor airspeed control. Additionally, the aerodynamic effects of the heavy sleet encountered near the accident site likely contributed to the stall to some degree.