On June 28, 2003, a Bell 47G-5A (registration N8413D) was involved in an aviation accident near Sandusky, MI. Investigators recorded the probable cause as: The ignition switch had an internal fault causing it to ground out the ignition system. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A helicopter sustained substantial damage after a hard landing during an autorotation. The engine failed at 400 feet, and the pilot flared early to avoid a drainage ditch. Investigation found a faulty ignition switch.
Accident Summary
A helicopter experienced an in-flight loss of engine power while cruising at approximately 400 feet above ground level. The pilot initiated an autorotation but flared early to avoid a drainage ditch, resulting in a hard landing in a field. The helicopter sustained substantial damage.
Investigation Findings
Post-accident inspection revealed continuity of the engine and flight controls. The spark plugs and exhaust tubes were clean, and the fuel tanks contained fuel. The magnetos functioned when tested independently of the ignition system. However, the inspection identified an internal fault in the ignition switch that caused it to ground out the ignition system.
Probable cause
The ignition switch had an internal fault causing it to ground out the ignition system.
