The pilot of a seaplane that crashed near Sydney, killing five British tourists, suddenly veered off course and made an “inexplicable” steep right-hand turn before the nose dropped and the aircraft plunged vertically into the water.
As investigators detailed accounts of the unusual flight path in a preliminary report into the crash on New Year’s Eve, Sydney Seaplanes, which operated the flight, said it had no explanation and that Gareth Morgan, who died in the crash, was experienced and familiar with the route.
"The key question arising from the report is why the plane crashed, approximately halfway down Jerusalem Bay, which is surrounded by steep terrain and has no exit," said Aaron Shaw, the head of Sydney Seaplanes.
"It is not a route we authorise in our Landing and Take-off Register and the plane simply should not have been where it was.
"Further, the aircraft is then reported to have entered into an 80 to 90 degree bank angle turn. A turn of this nature at low altitude by a pilot with Gareth’s skill, experience and intimate knowledge of the location is totally inexplicable."
The single-engine plane crashed during a routine flight from the exclusive waterside Cottage Point Inn restaurant, about 20 miles north of Sydney, to Rose Bay on Sydney harbour.
Morgan, 44, had more than 10,000 hours of flying experience. He died along with the passengers: Richard Cousins, the 58-year-old head of catering giant Compass, his sons William, 25, and Edward, 23, his fiancee Emma Bowden, 48, and her 11-year-old daughter Heather Bowden-Page.
The Australian Transport Safety Bureau’s initial report noted that the plane had been inspected in November.
It said witnesses reported that the plane’s engine sounded “constant and normal” and that it flew below the height of the surrounding terrain before turning and crashing into the water in a "near vertical position".
Addressing reporters, Nat Nagy, from the bureau, said “one of the key lines of inquiry for us now is to try and work out exactly what was happening throughout that time.”
“So firstly why the pilot turned that way,” he said. “And then whether it was an attempt to turn around or whether it was a planned turn as well.”
Investigators have said Mr Morgan was "very familiar with the area" and would have known he would have been too low to clear the terrain when he entered the bay minutes after taking off at around 3pm.
The seaplane did not have a cockpit voice or flight data recorder, although it was not required to have one by law.
There are hopes that electronic devices including mobiles phones recovered from scene that are being analysed by police may shed light on events on board prior to the crash.
It emerged in the wake of the tragedy that the de Havilland Canada DHC-2 Beaver had been rebuilt after it was involved in a fatal accident in the 1990s, when it was used as a crop duster.
Mr Nagy said investigators were aware of the crash, although the aircraft had been operating "without any issues" since it was recertified in 2000 and the incident was not presently of concern.
The results of post mortem examinations and toxicology tests will be provided to the New South Wales coroner by the state’s police. A final report is expected to be released early next year.