What happened
The helicopter was conducting a pipeline patrol at low altitude when it experienced a partial loss of power. Following the mechanical failure, the pilot initiated an autorotation. The aircraft ultimately impacted trees and marsh land during this emergency descent.
The investigation
Post-acc examination of the engine revealed that the fuel control governor spring, part number 2529242, had fractured. This breakage drove the fuel control system to idle, resulting in the loss of power that necessitated the autorotation.
Findings
The accident was caused by fuel exhaustion due to a mechanical failure of the fuel control governor spring. The helicopter was on a pipeline patrol at low altitude at the time of the power loss. Examination of the engine after the accident revealed that the fuel control governor spring, part number 2529242, had broken driving the fuel control to idle.