What happened
During the final approach phase, the aircraft experienced a gradual reduction in airspeed, eventually reaching a speed near its stall threshold. Approximately 600 feet past the final recorded flight data, the aircraft struck the ground in a nose-down orientation. The impact characteristics were consistent with an aerodynamic stall.
While witnesses near the crash site reported visibility issues and heavy sleet, observations made two miles prior to the accident site indicated the aircraft was flying under an overcast layer without precipitation. It is believed the aircraft transitioned into a lake effect band of heavy sleet during the concluding portion of the approach. The aircraft, which featured modified 5-bladed propellers, was noted by other operators to be prone to rapid deceleration, particularly when the propeller levers were moved to the high RPM position.
Findings
Post-accident inspections confirmed there were no mechanical malfunctions or failures present prior to the crash. Investigators determined that the pilot's difficulty maintaining airspeed was likely influenced by a lack of recent flight experience in this specific turboprop model, as the pilot typically operated larger corporate jets and had not flown this aircraft in eight months.
Additional contributing factors included the increased workload associated with performing in-flight deicing procedures. Furthermore, the aerodynamic impact of the heavy sleet encountered just before the crash likely played a role in the loss of airspeed and the subsequent stall.