A futuristic robot plane which can take off, land and even avoid bad weather without any human intervention is currently circling British skies.

The unmanned passenger plane is being flown in a series of trials to test robotic pilots' abilities to avoid colliding with other small aircraft.

The engineers behind the new technology say the hi-tech flying machine is the future of air travel.

Until now, unmanned aircraft have been limited to military use in war zones such as Afghanistan.

British police have also used small remote controlled models fitted with surveillance cameras.

Both of these examples usually need pilots on the ground to fly the aircraft remotely.

But this latest advance in air travel -- the first unmanned civilian aircraft -- can fly completely without a human pilot.

It uses on-board cameras to scan the sky for potential hazards and the robotic pilot is able to spot other aircraft, hot air balloons and even parachutists, and take action to avoid them.

The cameras also detect clouds, allowing the robotic planes to navigate out of the way of dangerous weather conditions.

"It is doing all the things a human pilot would be doing," said Lambert Dopping-Hepenstal, engineering director of systems and strategy at BAE Systems, which has developed the technology.

"The level of autonomy can be gradually increased. The system flies by itself on a pre-programmed course until it detects something is wrong.

"Then it suggests manoeuvres that an operator using a laptop on the ground can confirm or reject.

"If the communication link goes down or the operator is not paying attention, the on-board system will take action to keep the aircraft safe."

The system is being tested in the UK in a converted Jetstream passenger aeroplane being flown in an 80-mile wide area of airspace over the Irish Sea, off the coast of Preston.

A spokesman for the Civil Aviation Authority, which is part of the consortium carrying out the pilot-less tests, said unmanned aircraft were currently restricted to "segregated airspace" where they were being tested.