The pilot of a helicopter that crashed in the NSW Snowy Mountains region on Friday has been flown to hospital.
NSW Ambulance was called to the Kosciuszko National Park just before noon on Friday after reports a helicopter had crashed near the Guthega power station.
Five men, including the pilot, were on board the Bell 206L helicopter conducting aerial surveying work when hit the ground east of Guthega dam.
NSW Police said the pilot has been flown to hospital in a serious but stable condition.
Ambulance road crews and rescue helicopters have been sent to the scene and are assessing how to transport the remaining patients to hospital.
The four men are not believed to be seriously injured but will be taken for further assessment.
A critical care doctor and paramedic have been sent to the remote scene, where paramedics are working to winch the remaining passengers to safety.
Australian Transport Safety Bureau chief commissioner Angus Mitchell said an investigation has commenced and safety investigators will be on the scene from Saturday morning.
"Investigators will examine the wreckage and site surrounds, and will retrieve any relevant components for further examination," Mr Mitchell said.
Those on board the helicopter will also be interviewed as the ATSB continues its investigation into the cause of the crash.