NTSB

The pilot’s continued flight into adverse weather, and his failure to maintain altitude during the instrument approach. The severe icing, moderate turbulence, and low-level wind shear were factors.

The flight instructor’s inadequate compensation for the gusty crosswind conditions.

The passenger’s inadvertent application of the left brake during landing roll, which resulted in a swerve to the left and impact with trees.

The pilot’s failure to maintain an adequate airspeed that resulted in a stall. A contributing factor was the group of trees located near the departure end of the runway.

The pilot’s failure to maintain aircraft control during the missed approach, which resulted in an inadvertent stall and impact with terrain. The ice was a factor.

The pilot’s inadequate compensation for a crosswind during the landing flare, which resulted in a loss of control.

The failure of the propeller to crankshaft attachment bolts due to fatigue. A contributing factor was the improper installation of the propeller assembly by maintenance personnel.

The fracture and failure of the right landing gear actuator, which resulted in a gear collapse during the landing roll.

The pilot’s failure to maintain terrain clearance during a cruise descent. The darkness and mountainous terrain were factors.