It is possible the pilot of the Swan River Seaplanes Cessna Caravan that crashed on take-off at Rottnest Island off the Western Australian coast on January 7 killing three was hit by a freak wind shear event.
Pilot James Wong, 34, and two passengers, a 65-year-old woman from Switzerland and a 60-year-old man from Denmark, were killed when the seaplane plummeted into the water shortly after takeoff near Thomson Bay on the afternoon of January 7.
The Australian Transport Safety Bureau has issued its preliminary report into the Swan River Seaplanes tragedy but aside from a temporary loss of power did not draw any conclusions. That will come later.
However an investigation by this website and its advisors has found that the winds on the day were SSW at 25kts according to the AWIS (Aerodrome Weather Information Service) but the pilot took off in an Easterly direction.
Graphic shows previous departure flightpaths in amber and the fatal plane crash aircraft in light blue. ATSB
That direction is not typical for this Swan River Seaplanes operation with most take-offs to the south but it appears the pilot chose that route to remain in calmer waters as it was quite choppy.
On lift off the plane appears to stall and turns left wing down and impacts the water.
Where the aircraft lifted off it was at the point where it comes out of the wind shadow of Thomson Bay and is hit by the full force of the SSW winds from the right which could have created a freak windshear event.
The winds around Rottnest are notorious for being gusty with sudden directional change.
Compounding that event is the exhaust thrust from the PT6 turboprop engine that pushes the aircraft left and the rotation of the propeller that also turns the aircraft left.
The ATSB report shows a temporary reduction in power but that doesn’t indicate an engine failure as the power was reinstalled almost immediately. It is possible this was no more than a movement in the throttle lever.
Swan River Seaplanes has been operating for 8 years with an unblemished safety record prior to this accident
In a statement Kristy Bailey, Director Swan River Seaplanes said:
“Swan River Seaplanes acknowledges the release of the preliminary report from the Australian
Transport Safety Bureau (ATSB) and continues to fully cooperate with the ongoing investigation.
“Our deepest sympathies remain with the families and loved ones affected by this tragic accident.
We greatly appreciate the thorough work of the ATSB and other authorities in examining the incident.
“As this is a preliminary report, it does not draw conclusions but presents the factual information
gathered so far. In addition to supporting the official investigation, we have conducted our own
independent technical and operational review and support the information outlined in the report.
“Swan River Seaplanes has operated for eight years with an unblemished safety record prior to this
accident. Safety remains our highest priority, and we continue to work closely with investigators while
reviewing any further findings that contribute to aviation safety.
We want to assure our passengers, crew, and the public that we have taken all necessary steps to uphold the highest safety standards.”
The ATSB report said that:
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.
