Chifley Police District commander Superintendent Peter O'Brien said the site remained under police guard overnight with crash investigators and the Australian Transport Safety Bureau (ATSB) to initiate separate investigations into the incident.

Supt O'Brien said the plane took off from Bankstown Airport on Wednesday bound for Orange as part of a training flight. It landed without incident in Orange before taking off again.

Supt O'Brien said that as part of their training the student pilot also had to land and take-off from a remote airport and an airstrip on a Carcoar property was selected for the task.

"It appears they got into difficulty there and crashed," he said.

Supt O'Brien said emergency crews were contacted after the owner of the property heard the crash, went to investigate and came across the scene.

"The plane's transponder had lost contact. The owner of the property heard something and went to have a look," he said.

Supt O'Brien said the crash occurred at around 7.15pm with emergency services arriving on scene about 30 minutes later.

Supt O'Brien said investigations were in their infancy but it appeared a female was flying the plane and a male was the instructor.

"However, that is yet to be confirmed," he said.

Supt O'Brien said crime scene officers guarded the plane overnight, with the victims' bodies expected to be removed this morning.

He said crime scene investigators will be piecing together the final movements of the plane and once that is completed the ATSB would undertake its own inquiries, including looking at the plane itself and taking samples of fuel.

He said a report would be prepared for the coroner.

While investigations are in their infancy, he said the crash appears to have been a tragic accident.

"The weather was pretty good," he said.

"Whether it was pilot error or the plane, that will be determined."

Supt O'Brien asked anyone who may have witnessed the crash or heard something to contact Bathurst Detectives on 6332 8699 or Crime Stoppers on 1800 333 000.