What happened
Shortly after departing from North Sioux City-Graham Field in South Dakota, the aircraft experienced mechanical issues during its initial climb. The crew attempted to manage these difficulties by feathering the left propeller. Following this action, the flight became uncontrollable, leading to a crash into an open field in the vicinity of Sioux City. The impact resulted in a fire that completely destroyed the aircraft type. There were 2 fatalities among the crew members.
Findings
Official investigations concluded that the accident was caused by an uncontrolled descent following an in-flight fire of unknown origin. While the left propeller had been feathered during the flight, investigators determined that there was no malfunction present in the engine itself. The specific cause of the fire that led to the loss of control remains undetermined.