NTSB

Probable Cause: The pilot’s delay in performing a go-around after a likely encounter with low-level wind shear, resulting in a hard landing. Contributing to the accident were the pilot’s failure to recognize the severity of the actual and forecasted weather near the airport and his continued approach to the airport with a thunderstorm and associated convective activity.

Probable Cause: The pilot’s exceedance of the airplane’s critical angle of attack during initial climb, which resulted in an aerodynamic stall/spin and loss of control that the pilot did not recover from.

Probable Cause: The pilot’s failure to maintain clearance from a power line during a low-level aerial application
flight. Contributing to the accident was the pilot’s fatigue.

Probable Cause: The pilot’s improper landing flare, which resulted in an aerodynamic stall. Contributing to the accident was his delayed decision to initiate a go-around.

Probable Cause: The mechanic’s failure to properly secure the oil suction screen plug during recent maintenance, which resulted in an oil leak and subsequent loss of engine power due to oil starvation.

Probable Cause: The pilot’s improper landing flare and hard landing, which resulted in the left axle fracturing from bending overstress.

Probable Cause: The pilot’s failure to maintain adequate airspeed while maneuvering at low altitude, which resulted in an exceedance of the airplane’s critical angle of attack and a subsequent aerodynamic stall.