An Australian Transport Safety Bureau (ATSB) investigation report released last week has concluded that the pilot of a Britten-Norman Islander had fewer visual cues than expected when the aircraft collided with terrain in Tasmania three years ago.
VH-OBL was on a flight from Cambridge Airport to Bathurst Harbour in December 2018 when it crashed into the rugged Arthur Range. The pilot, the only person on board, was killed in the impact.
ADS-B data from the aircraft showed that the pilot had tracked from Cambridge Airport direct to Bathurst Harbour, passing over a saddle in the Arthur Range known as "the portals", a route often used in low cloud conditions.
After passing through over the saddle, flight data showed the aircraft made several turns in the valley beyond, which the ATSB says is consistent with the pilot assessing options for a possible route through the range to Bathurst Harbour, before tracking back towards the portals.
While in a turn under power and in pilot control, the aircraft collided with a ridge at an elevation of about 2800 ft.
“The ATSB’s investigation found that the pilot was using a route through the Arthur Range due to low cloud and had continued over a saddle in the range at a lower altitude than previous flights along the same route,” said ATSB Director Transport Safety Dr Stuart Godley.
“During this, the pilot likely encountered reduced visual cues, and while attempting to exit the range, the aircraft collided with a ridge that formed part of the Western Arthur range.
“For pilots, this tragic accident highlights the hazards associated with flying in mountainous terrain and the need to have an escape route. It also shows the challenges of in-flight weather-related decision‑making.”
The investigation also found that the operator, Airlines of Tasmania, gave primary guidance to its pilots for operations to Bathurst Harbour verbally and was not well documented, which resulted in pilots having varied understandings of the expectations regarding weather-related decision-making at the portals.
The ATSB’s investigation also found that, while not a contributing factor to the accident, the operator’s safety management processes had "limited opportunities to proactively identify risks in all operational activities and to assess the effectiveness of risk controls."
In January 2020, Airlines of Tasmania introduced specific guidance for its south‑west Tasmanian operations, introducing visibility requirements for pilots using the direct route through the Arthur Range saddle.
In addition, the operator added further information and guidance to its training syllabus, and introduced changes to its safety management system.
Another aspect of the ATSB’s investigation was an analysis of CASA’s oversight of Airlines of Tasmania, including surveillance activities.
The investigation found that, whist it was not a contributing factor to the accident, CASA’s process for acquitting repeat safety findings was not effective.
While there were ongoing communications with the operator, CASA did not conduct any formal surveillance activities specifically related to the operator's safety management system.
The full report is on the ATSB website.