Two people killed when a small plane built from a kit crashed south of Sydney are believed to be men, NSW police say.
The pair have not been formally identified but investigators say the men are aged 67 and 68 years.
The plane hit the ground in Appin, sparking a grass fire about 3pm on Monday.
It is understood to have taken off from Temora in NSW's Riverina region and was also reported near Goulburn before the incident.
Investigators from the Australian Transport Safety Bureau arrived at the Appin crash site on Tuesday afternoon.
They are expected to pore over the wreckage of the of the Subaru-powered Glasair Super II over coming days.
"We do know that it was a small two-seater, single-engine, kit-built experimental aircraft initially coming out of the United States," Chief Commissioner Angus Mitchell said.
Mr Mitchell said his team was trying to determine whether the amateur-built aircraft was under power when it crashed and whether it was undergoing any sort of practice run, including a landing and take-off manoeuvre called a touch-and-go.
Whether the men planned to land the plane at a small airstrip in Appin is also yet to be determined.
Small aircraft often don't have many recording devices, but the plane would be searched for mobile phones in case usable data could be retrieved.
Eyewitness accounts could also provide valuable information.
"There were a number of planes in the area, there are a number of people who have seen the plane in its final phases of flight and then lost sight of it as it's gone behind the trees," Mr Mitchell said.
"Exactly what it was doing at the time, how low it was - we have to piece together."
He said it was too early to speculate based on witness accounts until they have been verified with other sources.
The bureau's initial safety investigation will include an assessment of aircraft and pilot records, the aircraft's maintenance history and weather information.
A preliminary report is expected to be delivered within eight weeks.
Police will prepare a report for the coroner.
The safety bureau is also at the scene of a fatal light plane crash in the Northern Territory after a Cessna 210 crashed during a flight from Nhulunbuy to Katherine.
Mr Mitchell said 2022 had been one of the worst years on record for light plane fatalities, with 23 deadly crashes across Australia.
"We're certainly hoping ... we can start next year with much safer skies than we've had in these past 12 months," he said.
