What happened
During a VFR flight from Boise to Salmon, Idaho, the pilot experienced significant engine irregularities shortly after takeoff. While performing the initial climb, the engine underwent a surge before appearing to stabilize. In an attempt to manage the situation, the pilot adjusted the power to 3-3 inches of manifold pressure and set the propeller to 2,550 rpm.
Following this adjustment, the engine suffered another loss of power accompanied by a second surge, after which the propeller ceased rotation entirely. Faced with total engine failure, the pilot initiated an emergency landing in an open field located across a road. While attempting to maneuver under a power line at the edge of the field, the pilot failed to detect a telephone pole on the far side of the roadway. The left wing of the aircraft type struck the pole, causing the plane to cartwheel and crash.
The accident resulted in three fatalities and minor injuries for others, though some reports indicate all seven occupants survived with varying degrees of injury, including four who remained uninjured.
Findings
An investigation into the mechanical failure determined that the crankshaft had failed due to fatigue. Additionally, the presence of high obstructions and the collision with a utility pole were identified as contributing factors during the final approach and landing phase.