Flying visually in poor visibility continues to be a major aviation concern, following a serious helicopter accident injuring three people in Antarctica on 1 December 2013.
An ATSB investigation into the accident found that an Aérospatiale AS350B2 helicopter, in company with a second helicopter, was on a return flight to Davis Base, Antarctica after supporting a scientific task at a penguin rookery at Cape Darnley. The helicopters refuelled at a fuel cache on the Amery Ice shelf before flying south-east to their next refuelling stop.
Between 1993 and 2013 there were 11 accidents involving inadvertent visual flight into 'instrument meteorological conditions', such as poor weather or cloud.
The ATSB concluded that, as a result of changing weather with a rapid reduction in visual cues, and a breakdown in the pilot's scan of his flight instruments, the pilot probably became spatially disoriented while executing a right turn. The pilot was attempting to return to the previous landing site to wait until the weather improved.
ATSB Chief Commissioner Martin Dolan, said this accident serves as yet another reminder how weather can change very quickly and turn a routine flight into a tragic accident in poor visibility conditions. This is particularly the case in Antarctica.
Mr Dolan said, "Between 1993 and 2013 there were 11 accidents involving inadvertent visual flight into 'instrument meteorological conditions', such as poor weather or cloud".
"In forecast marginal weather, while alternative options such as diverting or turning back are part of the solution, pilot training and the appropriateness of the aircraft's instrumentation must also be considered."
"Pressing on into poor visibility conditions carries a significant risk of severe spatial disorientation due to powerful and misleading orientation sensations," said Mr Dolan.
Following this accident the operator introduced new helicopters with an autopilot to reduce pilot workload. They also introduced simulator training by an experienced Antarctic pilot, a situation awareness course, and training on the limitations of the radar altimeter. The operator also provides decision-making guidance for early avoidance of unexpected white-out conditions.
Read the report: Collision with terrain involving an Aérospatiale Squirrel helicopter, AS350B2, VH-HRQ, 240 km west of Davis Base, Antarctica, on 1 December 2013
SafetyWatch: Flying with reduced visual cues