The flight departed Richmond at 1038 and proceeded normally to RAAF Base East Sale, where the pilots performed a touch-and-go landing[6] with a simulated failed engine[4] before continuing south towards the ocean at an altitude of 5000 ft.[7] Lewin briefed the next exercise, which would involve flying the aircraft at the minimum controllable airspeed (VMCA) with both engines on the left wing at idle thrust and without hydraulic assistance available to operate the flight controls.

In preparing for the manoeuvre, Ellis, the pilot under instruction, first turned off the rudder boost, configured the aircraft with flaps 25 and began reducing speed to VMCA.

[4] The flight engineer and instructor both expressed surprise at the reduced effectiveness of the rudder with the hydraulic boost disabled, but there was no discussion of discontinuing the exercise.

At this point, the cockpit voice recorder (CVR) indicated Ellis was struggling with the physical workload required to maintain control, followed by Lewin telling him to "wrestle with the beastie!".

[4] Shortly after, the pilots began to discuss how to "get out of" the situation; at around this time, the sound of the stick shaker could be heard on the recording as the aircraft stalled and entered a spin.

Initial rescue and recovery efforts were led by Victoria Police dive teams, who located the wreckage in 50 ft (15 m) of water and recovered one body.

[1] A contributing factor may have been Lewin's considerable experience as a pilot and instructor in the Lockheed P-3 Orion, in which he had successfully performed similar asymmetric flight exercises many times without issue.

There were also broader organisational issues that factored into the accident, including a loss of operational knowledge as pilots left the air force faster than they could be trained.