Accident Sequence
The aircraft departed from runway 34L and maneuvered into a left downwind leg for the same runway. Witnesses reported that the engines were set to high power during the downwind, but the aircraft's speed remained slow. As the aircraft approached abeam midfield, it turned left, then entered a descent and crashed west of the airport. Impact occurred on an east-southeast heading at a descent angle of 15 to 17 degrees.
Post-Impact Findings
Examination of the wreckage revealed that the left fuel selector was in the "off" position, but the actuating cable had pulled through its housing, presumably during impact. The right fuel selector was on. Both propeller blades had separated from the crankshaft, showing evidence of torsional failure.
Elevator Trim System Issues
A history of elevator trim problems had been noted prior to the flight. Maintenance on the elevator trim system had been performed just before the accident flight. The elevator trim actuators were found reversed, which reversed the direction of trim movement. Both elevator trim tabs were positioned beyond the full nose-down trim stop. The force required to override the trim at the full nose-down position was calculated as follows: 121 to 136 pounds at 100 knots, 197 to 203 pounds at 150 knots, and 200 to 305 pounds at 200 knots. Additionally, the elevator trim chain was found off its sprocket and jammed between the bearing plate and a bracket. One of two bolts securing the bearing plate was missing, and the other bolt was only finger tight.