On 23 February 2007, the owner-pilot of a Van's Aircraft Inc RV-4 aircraft, registered VH-ZGH, was observed conducting aerobatic manoeuvres in the designated Moorabbin aerobatic area over Clyde North. At approximately 1740 Eastern Daylight-saving Time, witnesses observed the aircraft descending in a spin after completing a stall turn. The aircraft then appeared to enter an unstable spiral dive and, at approximately 500 m above the ground, pieces were observed separating from the aircraft. The aircraft was seen to impact the ground almost vertically and was destroyed by impact forces and a post-impact fire. Both occupants were fatally injured.
The investigation found that the pilot probably lost control of the aircraft performing an aerobatic manoeuvre and entered a spin from which he was unable to recover. The investigation also found that the pilot performed manoeuvres in an aircraft that was loaded above the maximum weight limit for aerobatic flight, and with the centre of gravity outside the rear limit.