Three people have died as two light planes collided midair before crashing into bushland in Sydney's south-west

ABC reports emergency services rushed to the scene at Belimda Park, near Oakdale at about 2 this afternoon.

Police say three men were found dead at the scene.

Acting Superintendent Calman says the collision happened in uncontrolled airspace, and the crashes, leaving wreckage 1 kilometre apart, were not survivable.