Incident Overview
A helicopter contracted by the Maui Police Department was conducting low-altitude surveillance operations in mountainous terrain when it struck a powerline, causing the tail rotor to separate. The pilot reported descending slowly through a gulch while police officers onboard performed their surveillance duties.
Sequence of Events
According to the pilot, the helicopter was proceeding at a slow speed down a gulch. A powerline was strung across the gulch, and the tail rotor made contact with the wire. The impact caused the tail rotor to detach from the helicopter. Immediately after separation, the helicopter began to spin. The pilot stated that he responded by reducing engine power to idle and lowering the collective control.
Descent and Landing
Following the loss of tail rotor authority and the onset of uncontrolled rotation, the helicopter descended into trees. The pilot noted that he observed the wires approximately two seconds before the collision but was unable to avoid them due to strong winds and the momentum of the helicopter.
Pilot Actions and Conditions
The pilot's decision to reduce power and drop the collective was described as an immediate response to the spin. The encounter with the powerline occurred while the aircraft was at low altitude and slow speed, conditions typical for surveillance operations. The pilot attributed the inability to evade the wires to the combination of wind conditions and the helicopter's forward momentum.