What happened
On 28 October 2013, two AS350 Squirrel helicopters operated by The Helicopter Line were conducting a scenic flight and snow landing near Mount Tyndall in the Otago province. The first aircraft had already landed on a snowfield. As the second helicopter, ZK-IMJ, attempted its approach, the pilot initiated a go-around due to being too high on the approach.
During this maneuver, the aircraft drifted toward the stationary helicopter, ZK-HAE. The tail rotor assembly and lower vertical stabilizer of ZK-IMJ struck the main rotor blades of the parked aircraft. This impact caused the tail rotor and stabilizer to detach immediately. Deprived of its tail rotor, ZK-SDJ became uncontrollable, spinning rapidly before crashing approximately 70 meters from the parked helicopter. The pilot sustained a severe brain injury, while all passengers on board sustained injuries, including three passengers who required hospital treatment.
The investigation
The Transport Accident Investigation Commission (TAIC) examined the wreckage in Wanaka and Wellington, reviewing maintenance records, pilot training history, and operator policies. Investigators also analyzed passenger video footage, which captured the initial approach and the presence of blowing snow near the parked aircraft. The inquiry reviewed the pilot's flying experience, noting his extensive background in ski-plane operations but relatively recent transition to helicopter flight.
Findings
While the Commission could not definitively determine the exact cause of the collision, it identified several contributing factors. Blowing snow likely played a role by reducing visibility and obscuring ground references during the approach. The investigation also noted that the pilot's approach involved a significant drift toward the stationary aircraft. The Commission ruled out technical failures, aircraft performance issues, or environmental factors other than the blowing snow, though it could not entirely exclude the possibility of a pilot misjudgment or an underlying medical condition.
Safety action
Following the inquiry, the Commission identified a significant safety risk regarding the practice of allowing passengers to disembark or embark while helicopter rotors are still turning on snow surfaces. To address this, a recommendation was made to the Director of Civil Aviation to ensure that operators' safety management systems specifically address the hazards of passenger movement during active rotor operations in snow environments.