Incident Overview
During an agricultural spray dispersal flight, a helicopter was fueled with the last 25 gallons of fuel from a fuel truck. Shortly after departure, while conducting a swath run at an altitude of approximately 8 feet above ground level and a speed of 60-70 mph, the engine abruptly stopped. The pilot attempted to execute a 'quick stop' maneuver, but the helicopter subsequently collided with terrain.
Post-Crash Examination
Following the accident, a fuel sample was taken from the low point drain of the fuel truck, which revealed only a small amount of water. However, a fuel sample taken from the pressure side of the helicopter's airframe fuel filter system indicated approximately 20 percent water content. When the helicopter's fuel tank was defueled, the owner retrieved approximately 2.5 gallons of water out of a total 40-gallon fuel quantity.
Conclusion
The investigation identified significant water contamination in the helicopter's fuel system, with the water likely introduced during the fueling process. The presence of water in the fuel led to engine stoppage and subsequent collision with terrain.