Aircraft: Alon A2. Injuries: None. Location: Forks, Wash. Aircraft damage: Substantial.
What reportedly happened: The pilot planned on starting his airplane by hand-propping, because the battery was dead. After loading his passenger, he set the throttle and the parking brake, but he did not tie down the airplane or place chocks in front of its wheels.
When he pulled the propeller through, the engine started immediately.
However, he had placed the throttle in a position that resulted in a higher RPM than he expected. Due to the high RPM, the parking brake was unable to hold the airplane in position, and it started rolling forward with only the passenger inside.
The pilot’s attempt to get into the cockpit were unsuccessful. Although the passenger was able to steer the airplane along the taxiway, she did not know how to stop the airplane, and the Alon went through a fence and over an embankment.
According to the pilot, there were no malfunctions or anomalies with the parking brake system or the throttle mechanism.
Probable cause: The pilot’s incorrect placement of the throttle prior to starting the airplane by hand. Contributing to the accident was that the pilot did not ensure that the airplane was restrained in a manner that would keep it from moving forward.
NTSB Identification: WPR12CA095
This February 2012 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.