Witnesses have described seeing a light plane lose control and nosedive before crashing near Canberra in April, killing two men on board.
Investigations are continuing into what caused the Cessna 172 fixed-wing aircraft to crash into a farming paddock in Sutton, near the ACT border.
The plane had taken off from Canberra Airport with a 31-year-old pilot from rural Victoria and an 18-year-old passenger from Albury on board. They had been contracted to perform aerial inspections of an electrical network.
The Australian Transport Safety Bureau on Friday released a preliminary report into the crash.
It said witnesses had described seeing the plane flying low above the trees before making a sharp descent shortly before it hit the ground.
"Witness reports indicated that a loss of control and entry into a spin preceded the ground impact," ATSB transport safety director Stuart Macleod said.
An examination of the wreckage showed the plane hit the ground in a "near-vertical, nose-down" fashion.
ATSB investigators have mapped the accident site with a drone, retrieved aircraft components for further analysis and downloaded flight-related electronic data.
"As the investigation progresses, the ATSB will continue to analyse the aircraft's flight path and recorded data, and review pilot qualifications, maintenance records and the operator's procedures for conducting flight survey aerial work," Mr Macleod said.
Oberon Aviation Services in April said it was devastated by the crash and would support the families of its crew members how ever possible.
"We can't speculate on what might have caused this tragic accident while formal investigations are underway," the company said in a statement.
"However, our families and staff can be assured that we will leave 'no stone unturned' in finding the cause of this accident."