An investigation into a crash which killed six people north of Sydney has revealed the pilot may have suffered carbon monoxide poisoning.
British businessman Richard Cousins, four members of his family and Canadian pilot Gareth Morgan died after the plane made a 270-degree turn, entered a narrow bay and then suddenly nosedived into the water.
The lightweight plane bound for Sydney’s Rose Bay wasn’t required to carry a cockpit voice or flight data recorder, leaving investigators to determine the plane’s fatal flight path from the passenger’s photographs and witness accounts.
The Australian Transport Safety Bureau’s chief commissioner Greg Hood said on Friday the aviation medical specialist engaged by the ATSB had advised checking the blood samples of those on board for carbon monoxide.
The results of the toxicology report, handed to the ATSB in March, found Mr Morgan and two passengers had elevated levels of carbon monoxide.
“From that consultation with medical experts, and research into the effects of carbon monoxide on aircraft operations, the ATSB considers the levels of carbon monoxide were likely to have adversely affected the pilot’s ability to control the aircraft,” Mr Hood said.
“The ATSB found pre‑existing cracking of the engine exhaust collector-ring, which could lead to exhaust leakage into the engine bay. Further, the ATSB found a breach in the firewall from missing bolts used to secure magneto access panels in the firewall under the instrument panel in the cabin.”
Mr Hood added “any breach in the firewall” can allow gases into the cabin from the engine bay, in this case the carbon monoxide, which poisoned Mr Morgan.
The ATSB is yet to issue its final report.
But Mr Hood added it’s a reminder for people flying aircrafts to carry out routine inspections.
“The ATSB is reminding aircraft maintainers that the primary mechanism for the prevention of carbon monoxide exposure to aircraft occupants is to carry out regular inspections of aircraft exhaust systems to identify and repair holes and cracks, and to detect breaches in the firewall,” he said.
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