ATSB Chief Commissioner has cited Plan Continuation Bias as a factor in the fatal crash of an R182 RG Skylane in August last year, according to an investigation report published last week.
VH-EHM was on a charter flight from Dalby, QLD, to Archerfield in August 2022 when the aircraft crashed in the D'Aguilar Range in bad weather, 19 nm short of its destination.
The pilot had departed into forecast IMC weather without an instrument rating, with the track showing several deviations and turns. Flight data showed the aircraft crossed the Great Dividing range with minimal clearance as the pilot proceeded to the Lake Manchester VFR route.
ATSB Chief Commissioner Angus Mitchell believes the pilot then flew into non-VMC.
“The aircraft very likely entered cloud while manoeuvring in this area," Mitchell said, "resulting in the pilot losing visual reference with the ground, eventually leading to controlled flight into terrain.
“The pilot was probably influenced by plan continuation bias – an internal pressure or desire to get to the destination – to continue the flight, which probably became stronger as they got closer to Archerfield."
ATSB investigators could find no reason for the pilot to have continued the flight into IMC, and noted it was unlikely that the pilot was not under any organisational pressures to continue the flight.
However, the ATSB report also notes the operator of the aircraft's hazard and risk register, which formed part of
the organisation's safety management system, did not identify inadvertent entry into IMC as a hazard, which reduced the ability of the organisation to effectively manage the related risk.
The operator has since removed aeroplane operations from their AOC and updated their hazard and risk register for helicopter operations to include inadvertent entry into IMC.
Mitchell said VFR pilots needed to make good decisions when faced with IMC.
"Be prepared to amend and delay plans to fly due to poor or deteriorating weather and environmental conditions, and not to push on,” he said.
“Have alternate plans in case of unexpected changes in weather, and make timely decisions to turn back, divert or hold in an area of good weather.”
The full report is on the ATSB website.