Fatal helicopter crash likely due to pilot being disoriented, out of practice in instrument skills - report

Friday, 17 November 2023

A fatal helicopter crash in Otago in September 2021 was likely due to the pilot becoming disoriented in darkness and cloud, combined with being out of practice in instrument skills, the Transport Accident Investigation Commission says.

On Friday, TAIC issued its final report into the AS350 ‘Squirrel’ helicopter crash, which occurred on September 16, 2021 and resulted in the death of its sole-occupant pilot.

TAIC chief investigator of accidents Naveen Kozhuppakalam said the commission was now calling on the Civil Aviation Authority (CAA) to resolve issues around the ambiguity of night visual flight rules (night VFR) and guidance.

“The rules are meant to keep pilots to within 25 nautical miles of the point of departure; but the commission found that aviators, operators and instructors are able to interpret the words to allow pilots to fly at night from one 25-mile zone to the next and so on across country.

“This is much further than intended; it puts pilots at risk of encountering night flying conditions outside their capabilities. That’s very likely what happened in this accident.”

Another anomaly was that while complex skills like flying with only instruments require regular practice, the CAA’s current rules and guidance did not require night VFR pilots to practice regularly, Kozhuppakalam said.

“This is a safety issue because if a pilot loses sight of important visual references – like on a dark night in thickening cloud, without a clearly defined horizon – then there’s more risk they’ll be unable to switch to relying solely on instruments and they’ll be vulnerable to disorientation and losing control of the aircraft. That’s very likely what happened in this accident.”

The pilot, an experienced aviator trained in and qualified for restricted night flying, was flying the helicopter at night from Milton to Alexandra to conduct frost protection over an orchard, the TAIC report said.

Flight data showed that the helicopter was over the Lammerlaw Range when it made a tight descending right-hand turn then a left-hand spiral dive that ended in a near vertical nose-down high-speed impact with the ground. The sole-occupant pilot did not survive.

“The helicopter took off well before sunrise, and with no moon, it was the darkest part of the night. The pilot almost certainly encountered increasing cloud and very likely lost their clearly defined horizon.

“In this situation, ideally, a pilot immediately switches to instrument flight to maintain situational awareness and control of the aircraft. But in this case, although the pilot was current for restricted night flying, it was nine years since they last logged instrument flying practice. So it’s very unlikely the pilot was proficient in flying with sole reference to instruments.

The flight data revealed a high angle of bank turn and rapid descent that was consistent with spatial disorientation and loss of control of the helicopter.

Meanwhile, the company and director of the helicopter firm involved in the fatal crash were charged in July this year.

Alister John Lister, 49, a director Lister Helicopters Ltd, faces multiple charges laid by the Civil Aviation Authority.

Charges include causing or permitting an aircraft “to be operated in a manner which cause unnecessary danger to any other person”.

That danger, according to court documents, was from piloting the helicopter in a night cross-country flight.

That charge carries a maximum penalty of one year imprisonment or a fine not exceeding $10,000.

The company faces the same charge, which has a maximum penalty of $100,000.

Lister, as director, and the company also faced health and safety charges over failing to prohibit night-time cross-country flying for a pilot who did not hold the appropriate licencing or rating, and communicating to clients when it could commence frost-fighting operations.

Lister’s charge carries a maximum penalty of $300,000, while the company faced a maximum possible fine of $1.5 million.

Another charge facing Lister and the company included exposing Harrison to “risk or serious injury’’.

That charge carries a maximum penalty of five years’ jail or a $600,000 fine for the director, and up to $3 million for the company.

The matter is expected to be called again later this year.