The focus of the Australian Transport Safety Bureau (ATSB) investigation was a crash involving a Cessna 182 aircraft on July 5, 2015 that injured the three occupants.

On that day the pilot had taken off from a private airstrip about 100km south-west of Bourke and after a flight of about 15 to 20 minutes, prepared to land on the same airstrip.

During the approach, "about 5 feet" above the ground, the aircraft sank rapidly and landed heavily.

The nose wheel detached from the aircraft and the aircraft bounced into the air, touched down a second time and dug into soft ground, before flipping over and coming to rest upside down.

The crash resulted in "substantial damage", according to the report, and the pilot and two passengers suffered minor injuries.

The pilot reported the property received about 100mm of rain over a two-week period that stopped about a week before the incident, the report said, and cold weather in the interim had prevented the soil from drying.

Before take-off the pilot had driven over the runway surface and assessed it suitable for landing, but below the runway surface there was a soft layer of earth extending about half a metre down that had not been evident during the runway inspection.

The report said the pilot was unsure what had caused the aircraft to "sink" faster than usual.

The wind had been light and variable, and the extra sink and speed of descent combined with the soft surface led to the aircraft landing gear digging in and flipping the aircraft over, the report said.

The report said the incident highlighted the importance of identifying and managing risks associated with unsealed airfields.

"Potential hazards such as changes in the runway surface following rain can be hard to detect," the report read.

"Changes in the runway surface can adversely affect the outcome of a hard landing."