All new Air New Zealand planes are being fitted with security cameras so pilots can keep an eye on the cabin.

The systems are meant to prevent potential terrorist hijacking threats and also act as evidence in cases of air rage.

At present, pilots are protected by a door chime and a spy-hole in the flight-deck door through which they can identify a person attempting to gain access.

Airline Pilots' Association president Mark Rammell said the cameras were "the way of the future" because the protocol on leaving the flight deck had changed in the past few years.

"Pilots used to go back there (into the cabin) and see what was going on.

"Since 9/11 we are up there and that's it. They keep us segregated. It's a little bit taboo to go down the back of the airplane."

Pilots' Association aviation security co-ordinator Paul Lyons said he understood Air New Zealand's Boeing 777 fleet already had the technology and most new planes were now coming with it as standard issue, despite the United States' Federal Aviation Administration not making it compulsory.

A recent select committee on the Aviation Security Legislation Bill also decided not to legislate for the cameras, as the 1990 Civil Aviation Act already had jurisdiction to require them.

Air New Zealand submitted to the committee that all its planes on order would have the cameras and it was considering the business case for retrofitting its Boeing 747-200 and 767-300 aircraft.

Lyons said there were a variety of camera systems that ranged from a single camera monitoring the flight-deck door to a number of cameras that covered and recorded the entire cabin.

The cameras would meet two main objectives: surveillance and evidence, although they would be fixed to give only an overall impression of the cabin, he said.

Pilots would not be distracted by the cameras as they would be switched on only when necessary, he said.