NTSB

The noncertificated pilot’s exceedance of the aircraft’s critical angle of attack, which resulted in an aerodynamic stall.

The pilot’s loss of control due to spatial disorientation.

The pilot’s failure to maintain clearance from power lines while making an evasive maneuver to avoid birds.

The incapacitating effects of an acute myocardial infarction (heart attack), which resulted in the pilot’s loss of airplane control and impact with terrain.

The pilot’s fuel mismanagement and his improper use and placement of the fuel selector, contrary to operating procedures, which resulted in a partial loss of engine power due to fuel starvation.

The student pilot’s failure to maintain directional control during a rejected takeoff, which resulted in a runway excursion and impact with a ditch.

The airframe and powerplant mechanic’s lack of experience in the overhaul of the engine model and the improper torque of the crankshaft gear bolt, which resulted in fatigue failure of the bolt and a total loss of engine power during an approach for landing.

The pilot’s failure to maintain yaw control and his exceedance of the airplane’s critical angle of attack during an aborted landing, which resulted in an aerodynamic stall.

The pilot’s distraction and subsequent loss of situational awareness and visual horizon in overcast sky conditions, which led to an unrecognized descent during a low-level maneuver and subsequent impact with snow-covered terrain.