Emergency services attempted to remove the passenger from the plane who became unresponsive and was unable to be resuscitated.
The 29-year-old male pilot was treated for serious injuries including severe burns.
The pilot was transported to Darwin for further treatment by the Royal Flying Doctors Service yesterday.
Managing director of Aviair, Michael McConachy said it is still unclear as to what caused the plane to crash.
"Aviair has organised trauma counselling and support for staff members and first responders ... and will provide all possible assistance to WA Police and the Australian Transport Safety Bureau to determine the cause of the accident," he said.
"As this is an ongoing investigation, Aviair will continue to work with authorities and no further comment will be provided at this time."
Emergency service were alerted to the crash by a fisherman who saw the plane go down while fishing at Bandicoot Point.
The crash is currently being investigated by WA Police and the Australian Transport Safety Bureau.
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