Engine Failure
While in cruise flight, the engine emitted a loud sound and began to run rough. The pilot suspected the loss of a cylinder and diverted toward the nearby Lost Hills, California, airport.
Approach and Obstacle
As the pilot configured for final approach, a truck was observed parked at the end of the runway. The truck remained stationary throughout the approach. When the pilot attempted to add power to execute a go-around, the engine did not respond. The pilot then raised the nose to clear the truck.
Landing and Evacuation
Clearing the truck forced the aircraft to land long. It departed the end of the runway and entered a ditch measuring 15 feet wide and 8 feet deep. Impact with the ditch jammed the doors, requiring the occupants to break the windshield with the fire extinguisher to exit the aircraft.
Post-Incident Inspection
Subsequent examination by the Safety Board's Materials Laboratory determined that the number 4 cylinder articulating rod had experienced a fatigue fracture. The fracture initiated at the corner of the I-beam section and propagated through its cross section.