A 100-kilogramme aircraft propeller which fell off a Regional Express flight will be recovered after being discovered in a southwest Sydney national park.
Police guarded the propeller overnight at the Georges River National Park in Revesby where a crime scene was established following the discovery.
The propeller, which sheared off Friday's Rex flight from Albury to Sydney, was spotted on Tuesday by a police helicopter.
It was located about 18 kilometres from the airport after the Australian Transport Safety Bureau calculated its likely trajectory using data from the aircraft's flight data recorder.
Investigators have been assessing how best to pick up and then transport the bulky item on Wednesday.