Emergency services were called to a Lake Canobolas Road property at around 10pm after a quad bike had rolled, trapping the man underneath. The man, who was returning to his residence from a nearby function centre, was unconscious when he was found under the bike with witnesses lifting the bike off him.

Police and four ambulance crews responded with paramedics working to stabilise the man before he was air-lifted to Westmead Hospital in the Toll ambulance rescue helicopter. Police confirmed surgery was performed on a fractured skull, possible broken arm and bruising on the brain.

A Westmead spokesman confirmed the man was critical