On 5 May 2009, two Robinson Helicopter Company R22 Beta II
helicopters, registered VH-PHT and VH-HCB collided midair about 15
km south-east of Springvale Station, WA. Both helicopters had
departed the station just prior to sunrise that morning to conduct
mustering operations.
The first helicopter was observed departing to the east in order
to make radio contact with an adjoining station prior to heading
for the mustering area. The other helicopter departed about 10
minutes later and was observed heading to the south-east, the
general direction to the area that was to be mustered.
The helicopters were due to refuel at about 0830 at a place to
be arranged, depending on the progress of the mustering operation.
When the pilots failed to respond to radio calls from ground
personnel, a pilot from a nearby station was tasked to conduct a
search by helicopter. The helicopters were subsequently located
about 15km to the south-east of Springvale Station and about 2km
north of the planned mustering area.
The circumstances of the accident were consistent with a midair
collision while the pilots were positioning to commence the muster.
The converging flight paths of the helicopters, pilot fatigue and
sun glare from the rising sun are identified as contributing safety
factors.