The original Aerosonde, an Australian-made UAV which undertook the first successful crossing of the Atlantic, covering some 3270km in 27 hours on just six litres of fuel!

You can forget any idea that UAVs are just tiny radio-controlled model aircraft with perhaps a video link for remote monitoring.

Global Hawk (pictured above) is big, a full-sized aircraft; it weighs more than 11 tonnes and has a payload of over 900kg. And it has a wing-span of 35.42 metres and is 13.53 metres long.

Not only that, Global Hawk has a range of more than 25,000km, an endurance of 36 hours and a maximum altitude of more than 65,000 feet.

By comparison, a Cessna Citation business jet weighs about 16 tonnes, has a payload of about 620kg, a wing-span of 19.4 metres and is 22 metres long. Its range is about 5,500km and ceiling (maximum altitude) is 50,000 feet.

Yes, Big Brother in the form of a UAV could be watching you right now!

Global Hawk is one of many in a long line of UAVs which really came into their own during the Gulf War in 1991. SILICON CHIP had a series of four articles on UAVs during 1993 and a review of the models described then shows just how far we have come in the intervening eight years. UAVs are now very complex devices.

Here is a machine that requires the most advanced computer technology, electronic control and surveillance equipment, aeronautical engineering, and finally a unique approach to mission planning by the UAV control team. They might be unmanned but they require a skilled team to control them.