What happened
The accident occurred shortly after the helicopter began its climb following takeoff. During this phase of flight, the low rotor RPM warning light illuminated and the associated horn sounded, indicating a critical drop in engine power or rotor speed. In response to these warnings, the pilot took immediate corrective action by lowering the collective pitch control. This maneuver was intended to reduce drag on the rotor system and maintain rotor rotation using stored kinetic energy, effectively placing the aircraft into an autorotation descent.
The pilot managed the descent and attempted a landing. However, upon touchdown, the left skid of the helicopter collapsed under the impact or weight distribution. Following the collapse of the landing gear component, the main rotor blades made contact with the ground surface, resulting in significant structural damage to the rotor system and airframe.
The investigation
A post-accident examination of the aircraft was conducted to determine the mechanical cause of the power loss. Investigators focused on the fuel delivery system, specifically inspecting the fuel control unit responsible for regulating engine performance. The inspection revealed that the fuel control unit had not been properly adjusted prior to the flight. This mechanical discrepancy prevented the engine from receiving the correct fuel flow required to maintain adequate rotor RPM during the climb phase.
Findings
The primary factor contributing to the accident was the improper adjustment of the fuel control unit. This maintenance error led to a loss of power shortly after takeoff, forcing the pilot to execute an emergency autorotation landing. While the pilot's response to the warning indicators was technically appropriate for the situation, the underlying mechanical failure made the incident unavoidable.