WEATHER will be a key focus in the ongoing investigation into the Anna Bay helicopter crash that claimed five lives in September, a preliminary report into the inquiry has revealed.
The Australian Transport Safety Bureau (ATSB) on Thursday released its preliminary report into how the tragedy unfolded on September 6 this year.
Queensland men Jamie Ogden and Grant Kuhnemann, married Sydney couple Jocelyn Villanueva and Gregory Miller, and the chopper's pilot and owner David Kerr - also a Queensland man - died in the crash.
Coinciding with the release of a report into a separate incident near Coffs Harbour the same month, the authority urged pilots to consider their actions to avoid accidents linked to weather or low visibility.
"It is important to stress that both investigations are still in their early stages, and the ATSB will not publish its findings until the final investigation reports are released," ATSB executive director transport safety Nay Nagy said.
"But the ATSB notes that weather and environmental conditions are a focus for both investigations, and weather-related general aviation accidents remain one of the ATSB's most significant causes for concern in aviation safety.
"Weather and low visibility-related accidents often have fatal outcomes, which is all the more tragic because they are almost always avoidable."
The bureau noted 101 cases of pilots qualified to fly under visual flight rules entering instrument meteorological conditions were reported in Australia airspace in the decade to June 30.
Nine were accidents that included 21 deaths.
"Pilots without a current instrument rating should always be prepared to amend and delay plans to fly due to poor or deteriorating weather and environmental conditions, and not to push on," Mr Nagy said.
"If you're faced with deteriorating weather or if something just doesn't feel right, don't push it, make a precautionary landing. If you do decide to push on, it could be the beginning of an accident sequence."
It notes the ongoing investigation will examine the pilot's qualifications, experience and medical history as well as weather conditions and pre-flight preparation.
Maintenance of the helicopter, provision of air traffic services and flight data will also be examined.
The report notes that the helicopter left Coffs Harbour about 4.50pm before contacting the Williamtown tower about 5.55pm into forecast conditions that "included moderate to severe turbulence and wnd gusts up to 38 knots".
"From [6pm], severe turbulence was forecast with wind gusts up to 45 knots occurring," the report notes.
The pilot sought permission to fly higher "to take advantage of favourable winds" about 5.55pm, indicating he wanted to fly at between 3000 and 3500 feet.
After discussions with the tower about his route, the pilot at 6.05pm dropped to 2700 feet due to "a sudden wind gust affecting the helicopter's altitude".
Gaining clearance to fly at the lower altitude, the pilot "commented on the turbulent conditions that were being experienced."
About 2.3 kilometres from Anna Bay at 6.11pm, the aircraft began to turn offshore "for about one minute 20 seconds ... before commencing a rapidly descending, left turn."
Several attempts to contact the pilot two minutes later went unanswered.
The bureau report also notes the pilot, who held both private and commercial licences, had conducted a single-engine helicopter flight review in October last year that was valid until late 2020.
"His logbook indicated he had a total of 1440.5 flying hours experience," it states.