A pilot flying between Bankstown and Cowra had to make an emergency landing in a paddock on Monday afternoon after he became involved in an incident with an 82-year-old passenger.
Police say the pilot was forced to restrain the passenger.
Sources say a brawl broke out between the two men when the passenger tried to take control of the Beech 76 fixed-wing aircraft.
It is believed the 23-year-old pilot was an employee of Basair Aviation College in Bankstown.
The men did not appear to know each other before the flight, a police spokeman said.
The pilot reportedly made a "pan-pan" distress call shortly before making an emergency landing in Oberon, near Bathurst, just before 3pm.
"A pan call means the pilot is in trouble and needs help, but is not in a life-threatening situation," an aviation expert told Fairfax Media.
No one was injured during the landing, however the 82-year-old man was taken to Westmead Hospital with head and facial injuries.
The 23-year-old pilot was also taken to a local hospital suffering from shock.
The aircraft sustained minor damage during the landing.