The investigation into what caused a fatal plane crash on Australia Day in Perth has analysed other disasters including the 2015 Shoreham Airshow crash in the UK that killed 11 people.

Perth pilot Peter Lynch and his passenger and partner Endah Cakrawati died when the Grumman G-73 amphibious aircraft crashed into the Swan River during the City of Perth's annual Skyworks event on Australia Day.

The Grumman sea plane crashed into the Swan River on Australia Day, killing its two occupants. Credit:Mike Graham

The seaplane nose-dived into the water about 5pm in a plunge the Australian Transport Safety Bureau said was "consistent with an aerodynamic stall".

The plane broke on impact in front of hundreds of horrified witnesses gathered along the Swan River foreshore to watch an air display Mr Lynch was part of in the lead up to the fireworks show.