On November 16, 1996, a Hughes 369D (registration N5225C) was involved in an aviation accident near Forks, WA. Investigators recorded the probable cause as: Fuel contamination disrupted the flow of fuel from the engine fuel nozzle(s). This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A helicopter lost engine power during an external load/logging operation and collided with trees during an emergency landing, sustaining substantial damage. Investigation found fuel contamination in the storage tank and helicopter fuel filter.
Incident
A helicopter experienced a loss of engine power while conducting an external load/logging operation. The pilot performed an emergency landing, during which the helicopter collided with trees, resulting in substantial damage.
Investigation
An investigation was conducted to determine the cause of the engine power loss. The operator provided fuel samples from the fuel supplier, the storage tank, and the helicopter's fuel filter to an independent laboratory for testing.
Findings
Laboratory analysis revealed that the fuel sample from the supplier was free of contamination. However, contamination was detected in the samples taken from the storage tank and the helicopter's fuel filter. The investigation concluded that fuel contamination disrupted the flow of fuel from the engine fuel nozzle(s), leading to the loss of engine power.
Probable cause
Fuel contamination disrupted the flow of fuel from the engine fuel nozzle(s).