Accident Overview
During a cross-country flight, the pilot noticed that the aircraft's battery was no longer charging. After landing, the pilot decided to conserve battery power for the return leg by hand propping the engine. The pilot briefed the passenger on the hand start procedure but did not verify the throttle position. The throttle was inadvertently left at the full throttle setting.
Upon starting, the engine immediately surged to full power. The pilot was unable to re-enter the aircraft before it began moving. The airplane proceeded to make two tight left circles on the ramp before colliding with an open hangar and an airplane inside.
Hand Propping Procedure
The Federal Aviation Administration's Pilot's Handbook of Aeronautical Knowledge (FAA-8037-3a) includes a section on hand propping. It advises that a person unfamiliar with the controls should never occupy the pilot's seat during hand propping. Additional precautions include placing chocks in front of the main wheels or, if chocks are not available, securely tying the aircraft's tail.
In this incident, no mention was made of chocks or tie-downs being used. The pilot's failure to notice the full throttle position led to the unintended high-power engine start and subsequent ground collision.