What happened
During the landing flare, the left engine of the aircraft ceased operation. In response to the engine failure, the dual student initiated a go-around maneuver. During this process, the aircraft entered an uncontrolled roll to the left.
As the instructor attempted to recover control of the aircraft, the dual student froze on the flight controls. The instructor proceeded to place the left propeller into the feathered position. While the instructor continued efforts to regain control from the student, the aircraft struck the ground with the left wing first before spinning around and coming to a stop.
The investigation
Following the accident, the left engine and propeller were removed and placed on an engine test stand. The components were operated at full power, and the testing revealed no evidence of mechanical failure or any malfunction capable of causing the loss of power.