An attempt to fly after last light in Arnhem Land resulted in the crash of a Robinson R22 and the death of the pilot, according to an ATSB report released today.
VH-LOS was on mustering duties in a swamp near Ramingining in November 2022, when the aircraft failed to return to the mustering camp as scheduled. A search by team members failed to find the aircraft, which wasn't located until the following day.
The aircraft was found destroyed and the pilot, who had managed to escape from the wreckage, dead beside the helicopter.
ATSB investigators determined that the pilot attempted to fly back to the camp after the end of civil twilight, resulting in a collision with the ground. The pilot sustained injuries that were survivable, but a broken femur restricted mobility such that the pilot was unable to re-enter the aircraft to trigger the locator beacon.
A pathologist's report concluded that the pilot died of exposure, having had to spend the night beside the aircraft.
“The ATSB investigation found that the accident flight occurred after nautical twilight and in dark night conditions. The pilot likely became spatially disoriented, leading to a collision with terrain,” said ATSB Director Transport Safety Dr Stuart Godley.
“Dark night conditions provide no useable external visual cues and in these environments all VFR pilots, including those with endorsement to operate under the night VFR, will experience an increased risk of spatial disorientation.
“The ATSB encourages all VFR pilots to take note of the tragic consequences associated with dark night flight in this accident.
“Landing 10 minutes before last night provides reliable method for VFR pilots to ensure they have the necessary visual cues.”
ATSB investigators also said that authorities not being informed when the aircraft went missing resulted in delays in locating the pilots, compounded by the pilot's inability to trigger the locator beacon.
Dr Godley noted that the investigation highlights how remote locations can present an increased risk of fatal consequences from otherwise survivable accidents.
“Pilots operating in remote locations should carefully consider the use and location of equipment such as a personal locator beacon, to maximise the likelihood it will be accessible to them in the event of an accident,” he said.
The full investigation report is on the ATSB website.