Final report into 2022 Norseman plane crash unable to conclude exact reason for tragedy

The cause of a fatal surveying plane crash west of Norseman three years ago will remain a mystery after an investigation ended with not enough evidence to make a conclusive finding.

The report by the Australian Transport Safety Bureau handed down on Friday looked into the March 2022 crash 124km west of Norseman which killed pilot Hugh Sterle.

It found the plane lost control for unknown reasons while making a manoeuvre during a low-level geophysical survey operation.

It also found likely that control of the aircraft was lost as it was operating at an altitude where recovery was not possible.

The surveying included flying at low levels and turning with high-angled banking. The plane had previously conducted 24 successful turns of this nature during the operation.

ATSB chief commissioner Angus Mitchell said the plane may have stalled, but there was not enough evidence to know for sure.

“While an aerodynamic stall situation is a plausible explanation for the loss of control, this could not be conclusively established due to a lack of available evidence, including no recorded data beyond the last known position of the aircraft, and no witness observations,” he said.

According to investigators, the style of turns are necessary for the surveying but also carried higher risk due to lower altitude.

Mr Mitchell said the investigation made several findings which should be noted by the industry.

“Air work such as mustering, spraying and geophysical survey are conducted at low levels out of operational necessity, which creates an inherently high‑risk operating environment,” he said.

“Operators are responsible for effectively managing this heightened risk with adequate and effective processes and controls.”

While the plane recorded its final location at around 1.45pm the wreckage was not found until nearly 7pm as a result of the procedures in place.

Despite the time taken to find the wreckage, investigators noted a quicker response time was unlikely to have prevented the fatality.

Mr Mitchell said in future, cutting down the response time was important.

“The emergency response was not initiated until 30 minutes after the aircraft’s estimated time of arrival, which was 3 hours after satellite tracking had stopped and attempts to contact the pilot had been unsuccessful,” he said.

“Although an earlier response was very unlikely to have altered the outcome in this tragic case, minimising the time for search and rescue and enabling emergency services to respond as quickly as possible is essential.”

While the exact cause could not be found, the report still laid down recommendations to improve pilot safety.

These including improving documentation of policies which would help stop the deviation from an operator’s expectations and the erosion of safety margins.

It also stressed the importance of a pre-operations risk assessment to better mitigate safety concerns.

Since the crash, aviation consultant business MAGSPEC Aviation which was operating the flight has implemented an updated job safety analysis, more procedures for satellite tracking and including a requirement for fixed emergency locator transmitters on all aircraft.

Tributes flowed for Mr Sterle after death notices placed in The West Australian by family members spoke of a “gorgeous” and “beautiful boy taken so suddenly”.

“A life so tragically cut short but so richly lived. May you fly high Hughie,” his uncle and Labor senator Glenn Sterle and wife Fiona wrote.