The pilot's failure to maintain adequate airspeed during an initial climb, which resulted in the exceedance of the critical angle of attack, subsequent aerodynamic stall, and impact with terrain. Contributing was the pilot’s decision to operate the airplane above its maximum gross weight.

The pilot’s failure to maintain adequate airspeed while on approach for landing, which resulted in a loss of airplane control and a hard landing.

the pilot's failure to maintain aircraft control during a landing attempt. A contributing factor was his failure to check the snow conditions in the field before the flight.