The pilot of a Cessna 150 light aircraft which collided with terrain near Ogilvie, in mid-west WA, likely experienced an incapacitating medical event prior to the aircraft entering a spiral dive, an ATSB investigation has determined.
On 21 March 2025, the single-engine Cessna 150M collided with terrain next to Ogilvie Road, about 84 km north-west of Geraldton. The pilot, the aircraft's sole occupant, was fatally injured.
The aircraft had earlier taken off from Geraldton Airport for a planned ferry flight to Shark Bay.
There was no available radar or ADS-B recording of the flight, but the ATSB was able to recover data from a damaged Garmin 296 GPS which was fitted to the aircraft.
That data indicated that about 30 minutes into the flight the aircraft had briefly deviated right of its track, then entered a shallow left turn which transitioned into a spiral dive, before the collision with terrain about three minutes after the initial deviation.
"Wreckage examination found no evidence of any in-flight failure of the airframe or flight controls, and the engine was producing power throughout the descent," ATSB Chief Commissioner Angus Mitchell said.
The ATSB's final report notes the pilot was acutely unwell in the days preceding the accident, and was very likely still symptomatic during the flight.
"Based on the pilot's significant aviation experience and medical history, and the established sequence of events, it was determined the pilot likely experienced an incapacitating medical event resulting in a deviation off track and the uncorrected spiral dive," Mr Mitchell said.
The ATSB consulted with an independent medical professional and the Civil Aviation Safety Authority, as well as the pilot's general practitioner, next of kin, and designated aviation medical practitioner (DAME), to consider possible medical events which could have incapacitated the pilot, including cardiovascular conditions and acute gastroenteritis.
"While it is very likely the pilot experienced an incapacitation event, the evidence available did not allow the exact nature of the incapacitation to be determined," Mr Mitchell said.
The investigation's final report advises pilots to ensure they conduct the 'IMSAFE' checklist prior to every flight.
The checklist, created by the US Federal Aviation Administration, prompts pilots to consider whether factors such as illness, medication, stress, alcohol, fatigue or emotion could affect their performance and compromise flight safety.
"Pilots are encouraged to integrate this checklist into their pre-flight routine, no matter how routine the flight," Mr Mitchell said.
"Prioritising personal fitness for flight duty helps reduce risk, not only for the pilot, but for passengers, crew and the public."
You can find here the final report: Collision with terrain involving Cessna 150M, VH-WWU, 40 km north‑west of Northampton, Western Australia, on 21 March 2025
