Pilot assessment of sea and weather conditions, operator risk controls, and assessment and approval for floatplane operations are among a range of factors the ATSB will consider as it continues its investigation of a fatal floatplane accident off Rottnest Island, Western Australia.
The ATSB's preliminary report from its ongoing investigation details that on the morning of 7 January 2025, the Cessna Caravan with a pilot and 10 passengers on board operated on a passenger flight from South Perth to Rottnest Island, landing on the water at Thomson Bay.
Later that day, the pilot and six of the passengers returned to the aircraft for the return flight to South Perth.
The take-off commenced at about 4pm, on an easterly track towards Phillip Rock, a rocky outcrop at the southern end of Thomson Bay. About 32 seconds later and 600 m from the start of the take-off run, the aircraft became airborne with a high nose attitude, before it rolled rapidly to the left and impacted the water.
Immediately after the collision, the aircraft remained partially afloat, and four surviving passengers moved into a small pocket of air in the rear of the cabin. One passenger opened the top part of the rear right door, through which they and one other passenger escaped.
Another passenger was rescued by a witness, who broke the rear left cabin window and pulled the passenger out of the aircraft, while the fourth passenger also escaped through the window.
The pilot and remaining two passengers were fatally injured.
"This preliminary report has been released to provide timely factual information as to the nature of the accident and updates on where the investigation is likely to focus," ATSB Chief Commissioner Angus Mitchell emphasised.
"As the investigation continues investigators will continue to gather, review and examine evidence, in order to develop our analysis to identify those factors that contributed to the accident, as well as any factors that increased safety risk."
The preliminary report describes events on Rottnest Island prior to the accident flight, including that the pilot exchanged texts with the chief pilot of the operator, Swan River Seaplanes, about sea and wind conditions.
"This included a forecast noting strong and gusting winds, and consideration of an early return to South Perth," Mr Mitchell noted.
"The pilot then boarded a small boat to assess conditions in Thomson Bay, and subsequently elected for a take-off in a different direction to take-offs conducted on prior trips."
The ATSB's subsequent examination of the aircraft wreckage did not identify any damage consistent with the aircraft having struck an underwater landmass or object, while a specialist borescope examination of the engine did not identify evidence of pre-accident damage.
"The engine will be subject to a tear down by the manufacturer Pratt & Whitney Canada, the results of which will be provided to the investigation, and we will also continue our analysis of the aircraft's recorded flight data" Mr Mitchell said.
"The investigation will include analysis of flight data from previous flights, and will seek to understand the handling of the aircraft, particularly in the context of the conditions in Thomson Bay on the afternoon of the accident."
Bureau of Meteorology data, as well as video captured by witnesses and others, showed that conditions on the afternoon were windy with some waves in Thomson Bay.
"The investigation will consider the information the pilot had access to for assessing these conditions, and the procedures and other risk controls used by the operator for assessing and planning take-offs from Thomson Bay," Mr Mitchell said.
"We will also consider the system used by the operator to identify and analyse the risks associated with operating from this location, and the approvals for floatplane operations".
The investigation will also give further consideration to recent maintenance history of the aircraft, which had entered service with the operator on 2 January (having been in storage since March 2024), and to the assessment and approval processes for floatplane operations at Rottnest Island.
"The investigation will seek to uncover and identify systemic safety risk factors. Should any critical risks be identified, we will immediately notify relevant parties so they can take safety action," Mr Mitchell concluded.
You can find here the preliminary report: Collision with water involving Cessna 208 Caravan, VH-WTY, Thomson Bay, Rottnest Island, Western Australia, on 7 January 2025
