What happened
The pilot reported that during the pre-flight inspection, he operated the fuel boost pump as part of the standard procedure. After completing this step, he exited the aircraft to manually rotate the propeller. During a subsequent telephone interview, the pilot stated that he could not recall removing the ignition key from the switch before leaving the cockpit.
After pulling the propeller through approximately one-quarter of a turn, the engine started unexpectedly. Because the ignition remained active and no one was in the controls, the aircraft began to taxi on its own power. The uncontrolled aircraft moved forward and collided with a parked aircraft and two other vehicles.
The investigation
A post-accident inspection of the aircraft's ignition system was conducted to determine if any mechanical failures contributed to the event. The examination revealed no discrepancies or malfunctions within the ignition components.
Findings
The primary factor in this incident was the pilot's failure to ensure the ignition switch was turned off before exiting the aircraft. This oversight allowed the engine to start when the propeller was manually rotated, leading to the uncontrolled movement of the aircraft. The lack of a pilot in the cockpit prevented any attempt to stop the taxiing plane.
Safety message
Pilots must always verify that the ignition switch is turned off and removed before leaving the aircraft. This simple step prevents accidental engine starts and ensures the safety of surrounding property and personnel.