A 100-kilogram propeller that fell off a Regional Express flight bound for Sydney has been found in bushland close to a built-up residential area in the city's south-west.
The 34-seat plane, carrying 16 passengers and three crew, was about 19 kilometres from Sydney Airport when its right-hand propeller flew off last Friday, narrowly avoiding hitting the wing and tail.
The two pilots on board flight ZL-768 from Albury were forced to declare a PAN, which is one step down from a full-scale Mayday, before safely landing at the airport.
On Tuesday, a NSW Police helicopter patrolling Sydney's south-west spotted the propeller in bushland at Revesby.
A crime scene was set up east of The River Road in the Georges River National Park, near the intersection of Prince Street.
The park abuts suburban backyards, and demonstrates how fortunate it was that no one was seriously injured or killed when it fell from the plane.
Ken Stasionis, who lives in nearby Austin Boulevard, said he was shocked to hear that the 100kg propeller had fallen so close to a residential area.
"We're extremely lucky it didn't fall onto a house," he said.
The propeller will be central to the Australian Transport Safety Bureau's investigation into what caused it to break off at the shaft of the Saab 340's right-hand engine.
The ATSB said the location of the propeller in bushland was broadly consistent with its calculations. Investigators had been calculating the likely trajectory of the propeller using data from the plane's flight data recorder.
"The ATSB investigation team will examine the propeller assembly to determine the contributing factors that led to its detachment from the aircraft," it said.
The Saab 340 aircraft's first officer saw the propeller break away, and rotate upwards and to the right before moving in a horizontal direction.
Aviation watchers have said it was "incredibly lucky" the propeller did not hit the wing, fuselage or the tail, which could have been catastrophic for the aircraft and those on board.
A large object falling from 6000 feet also posed a major danger to people below.
In the wake of the incident, Regional Express has temporarily grounded five aircraft to allow engineers to remove propeller gear boxes and shafts similar to those on the Saab 340 forced to make an emergency landing.
With Mick Roberts