Air crash investigators have revealed the pilot of a home-made plane reported engine failure before flying under power lines and crashing in a fireball on an oval just metres from a Perth high school.
Aviation enthusiasts Tony White and Ralph Lerch had just taken off from Jandakot airport on December 9 when the air traffic control tower was told of the trouble.
Moments later, after flying low over houses in South Lake, the plane flew beneath a set of power transmission lines before clipping trees that bordered the sports field, and then striking a metal goalpost.
Witnesses heard and saw a fireball near Lakeland Senior High School, and the burning aircraft tumbling along the ground on the sports field before coming to rest.
The two men were hurled free of the wreckage - and both suffered serious burns - but survived.
The amateur-built Glasair III aircraft was destroyed by the impact and what the Australian Transport Safety Bureau (ATSB) described as "an intense post-impact fuel-fed fire".
In an initial summary of their investigation, an examination of the wreckage found the aircraft's left wing was sheared off by the collision with the goalpost, which allowed fuel to pour from the ruptured wing fuel tank.
A nearby CCTV camera also captured the latter part of the impact sequence, showing the fuel ignited almost immediately after the wing collided with the goalpost.
"The aircraft structure, which is constructed primarily of fibreglass/resin and carbon fibre, was almost completely burnt," the ATSB said.
The fully bent-back propeller blades and propeller strike marks on the ground were consistent with a windmilling propeller - which meant it was being driven by the airflow rather than by engine power.
A final ATSB report is expected in May.