This October 2010 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Aircraft: Beech Baron Injuries: 1 Fatal. Location: Clarion, Iowa. Aircraft damage: Destroyed.
What reportedly happened: According to a witness, the airplane suddenly entered a counterclockwise spinning dive toward the ground, made about four revolutions, and crashed.
During the post-accident examination investigators found significant damage to the cockpit area, including the instrument panel and the area containing the engine controls. The left engine magneto switch was found positioned so that only one magneto of the dual magneto ignition system was active, the left propeller control was in an aft position, and the fuel flow indicator for the left engine showed no fuel flow.
The most recent annual inspection of the airplane was performed more than three years before the accident. Based on the counterclockwise rotation of the airplane, and the position of the engine levers, investigations determined the pilot failed to maintain control of the airplane following an undetermined anomaly with the left engine.
Probable cause: The pilot’s failure to maintain control of the airplane. Contributing to the accident was the loss of left engine power for undetermined reasons.
For more information: NTSB.gov. NTSB Identification: CEN11FA040