SOCATA TBM 700 — Ludington, MI

What happened

The airplane was removed from an unheated hangar during a period of moderate snowfall. About 15 minutes later, the instrument-rated pilot taxied the airplane to the runway for departure, with visible snow accumulation on the ground and on the airplane wings, and horizontal stabilizer. The airplane was equipped with wing surface deice boots; however, deice boots are used to dislodge ice that may accumulate while in flight.

According to the airplane’s pilot operating handbook, all snow, frost, and ice must be removed from all wing and control surfaces during the preflight inspection. On icy or snow-covered runways, anti-icing fluid must be sprayed on the wings, control surfaces and in landing gear wells, shortly before take-off. The risks of snow and ice accumulation on control surfaces were further outlined in a 2018 service letter (SL) from the airplane manufacturer, which stated that takeoffs with snow or ice adhering to the wings should not be attempted because this could drastically affect performance due to the reduced aerodynamic lift and increased drag resulting from disturbed airflow. The SL further provided the appropriate recommendations to assist the operator in checking proper implementation of on ground de-icing or anti-icing procedures. The departure airport did not offer de-icing or anti-icing services.

The airport manager, who watched the airplane take off, said the departure appeared to be normal until the left wing dropped shortly after rotation. Another witness said that the airplane was loud and low. She said the airplane was in a left-wing-low attitude before it cleared a line of trees and then impacted the ground. The airplane was destroyed by impact forces and a postimpact fire.

The impact and fire damage precluded functional testing of the flight controls, and related systems. Signatures on the engine and propeller were consistent with power and rotation at the time of the accident. Examination of the wreckage did not reveal preimpact anomalies that would have precluded normal operations.

The left wing dropping during the climb was likely the result of snow accumulation on the airplane surfaces; the reduced aerodynamic lift and increased drag resulted in an aerodynamic stall and loss of control during the attempted climb after takeoff.

An editorial "what led to it / how to avoid it" analysis for this accident is generated separately and will appear here.