By Tim Bowler Business reporter, BBC World Service, Farnborough Airshow

The Herti has emerged from secrecy

Almost fifty years ago, Britain's then defence minister, Duncan Sandys, famously predicted the end of the manned fighter aircraft. It did not happen.

At the Farnborough air show this week, pilots are still putting the latest aircraft through their paces for the crowds below.

But down on the ground, alongside the conventional planes, there is a new breed of aircraft here at the show, and they are being designed and built in increasing numbers.

They are pilotless remotely controlled planes - robot planes. Or to give them their correct title UAVs - Unmanned Aerial Vehicles.

Until now they have largely been the preserve of the generals.

The US military routinely uses them over Iraq and Afghanistan.

But now the world's aerospace companies reckon they can make money by selling them to civilians too, for a wide range of tasks such as traffic control, border patrols, or crop and drought monitoring.

Secret revealed

One of this show's main attractions was a small unmanned plane made by the British firm, BAE Systems, with the rather unlikely name of Herti.

Future UAV tasks Oil and gas pipeline observation Coastal protection Border patrols Drug smuggling monitoring Road traffic control Crop and drought monitoring

Herti actually stands for High Endurance Rapid Technology Insertion, and it has been designed to demonstrate just how sophisticated the miniaturised cameras and other onboard sensors and avionics have become.

The reason why people have been coming to the BAE stand in droves, is that until recently Herti was was one of the firm's classified "black" projects.

Even its very existence was unacknowledged, and just to make sure it stayed secret, early models were hidden away in the Australian outback.

Outside BAE's pavilion, standing next to one of the company's more conventional Hawk jet trainers, Herti looks rather strange.

It has a 12-metre wingspan, more than twice the length of its bulbous stubby fuselage.

It is powered by a pusher propeller mounted at the back, can fly for up 25 hours at a stretch, and has a range of more than 1,000 kilometres.

Yet what is truly revolutionary about this plane is its independence.

It is one of the first of a completely new generation of robot drones - what is known as an autonomous UAV.

Put simply, unlike many other existing unmanned planes, it does not need to be controlled by an operator with a joystick in a darkened room.

Herti can think for itself.

Star photographer

Once Herti is programmed correctly, just click your mouse and the plane will do everything else - from takeoff to landing.

Arms and aircraft on display at the show In pictures

Crucially, its sensors are capable of dealing with the unexpected - such as another aircraft crossing its path.

If that happens it can take independent evasive action.

As if to demonstrate its potential, on one of its test flights it surprised even its makers.

The plane's programmers had been expecting it to make a routine flight across the Irish Sea.

Instead Herti's on board sensors spotted something that was not supposed to be there, and automatically took a highly detailed photo of the object.

"To us it looked like miles and miles of empty sea," explains BAE Systems Nigel Whitehead.

"But in this vast expanse it saw something we needed to know more about, so it took a high resolution picture of it."

The object turned out to be a floating lobster pot buoy, but it could equally well have been the head of somebody swept overboard from a boat.

The point is that a human observer would have been unlikely to have seen anything.

This is where unmanned aircraft score over conventional planes, says Mr Whitehead.

"The boring, repetitive tasks that humans find difficult, computers and sensing systems are just designed to do."

Not surprisingly, governments are now scrambling to get to grips with unmanned aircraft, and develop them for civilian uses.

In years to come, intelligent unmanned drones are going to be routinely used for tasks like air sea rescue searches, crop monitoring or drought awareness.

There is no doubt that these planes' computer software will get more sophisticated and their on board sensors, cameras and electronics will get lighter and more compact.