Incident Overview
A solo pilot experienced an engine failure during normal start procedures. After the engine failed to start, the pilot exited the aircraft without setting the parking brake or installing wheel chocks. The pilot then manually rotated the propeller, and the engine started. The aircraft immediately accelerated forward, maintaining a straight ground track, and struck a hangar door, penetrating it.
Sequence of Events
The aircraft was on the ground when the pilot initiated the standard engine start sequence. When the engine did not start, the pilot left the cockpit and moved to the front of the aircraft. By rotating the propeller, the pilot inadvertently caused the engine to start. Without the parking brake engaged or chocks in place, the aircraft moved forward under its own power. It traveled in a straight line until it impacted the hangar door, which was breached by the impact.
Examination Findings
An examination of the ignition switch carried out after the incident revealed a mechanical failure. This failure prevented the magneto from being grounded, even when the ignition key was removed from the switch or the switch was placed in the off position. The condition allowed the engine to start despite the switch being in a position that should have rendered it inoperable.
Summary
The incident occurred during ground operations when the engine started unexpectedly after manual propeller rotation. The aircraft then rolled forward into a hangar, causing damage. The subsequent inspection of the ignition system identified a specific mechanical fault in the ignition switch, which compromised its ability to ground the magneto.