Pilotless Spy Planes and Automatic Airliners

The 20-hour flights of which the latest long-haul airliners are capable might seem very long to you - but imagine an aircraft able to fly nonstop for five years.

That's exactly what the U.S. Defense Advanced Research Project Agency (DARPA) has asked aerospace companies to build, for a new aerial surveillance project that DARPA calls VULTURE.

So serious is DARPA about demonstrating five-year flight duration that it scheduled an industry-day event on June 7 so it could discuss the project in detail with likely bidders.

DARPA wants VULTURE, which will almost certainly be solar-powered, to be able to carry a 1,000-pound payload. This would include onboard sensors and communications equipment and would generate 5 kilowatts of electricity to power the aircraft's systems.

VULTURE stands for Very-high altitude, Ultra-endurance, Loitering Theater Unmanned Reconnaissance Element. The word "Unmanned" is key: It'll be a long time before any people-carrying aircraft will be able to stay aloft for five years.

But the proposition is much more realistic if you use an unmanned aerial vehicle (UAV).

UAVs have been around for a long time: the first, the Kettering "Bug", was developed during World War One.

When Capt. Ronald Reagan sent a photographer along to Radioplane in 1945 to take pictures of women assembling the company's OQ-3 remote-control target aircraft, the photographer snapped some shots of a young woman called Norma Jean Daugherty. The pictures brought her fame - as Marilyn Monroe.

For aviation, UAVs represent the wave of the future, particularly for military uses.

Aircraft that don't have to take into account the limitations imposed by human physiology can be much more maneuverable than piloted aircraft. And they can perform dull, long or dangerous missions unsuitable - or physically impossible - for people.

Because they are unmanned, UAVs can be designed to suit specific tasks and to offer performance characteristics piloted aircraft can't match.

They can be very small or very large. Some proposed UAV projects involve airships, while many existing programs use aircraft very like the remote-control models sold in hobby shops. Some UAVs are helicopters - and one test-flown successfully in the United Kingdom is a tiny flying saucer.

UAVs now represent very big money. Armed forces throughout the world - including all four arms of the U.S. military, as well as the Coast Guard - already operate a huge variety of UAVs. The U.S. Air Force's Predator and Global Hawk UAVs are famous because of the roles they have played in the Iraq and Afghanistan conflicts.

At least 90 percent of all UAV use today is military. That doesn't mean UAVs can't be used widely for civilian applications too. In Japan, nearly 2,000 tiny Yamaha RMAX helicopters, powered by two-stroke motorcycle engines, are used to spray small rice paddies with pesticide.

UAVs would be ideal for aerial jobs such as police surveillance, pollution-control monitoring, fighting forest fires and inspecting pipelines, said Andre Clot, vice-chairman of United Kingdom-based Unmanned Aerial Vehicle Systems Association (UAVSA), established to promote civil use of UAVs.

"If it's dangerous, dull or dirty, UAVs are not a bad idea," said Clot.

But a major problem must be solved for UAVs to see wide application in civil aviation. The world's civil aviation regulators must become satisfied that UAVs can operate safely and seamlessly within the complex air traffic control and civil airspace systems established for human-piloted aircraft.

To do so, UAVs must be able to sense and avoid other aircraft flying nearby and operators must have reliable communications links with their UAVs to maintain control over them at all times - and to make sure they know exactly where their UAVs are.

Safety and control standards must be completely equivalent to those involving piloted aircraft. Also, UAVs will need to provide to air traffic controllers and pilots of other aircraft the same information about their flight plans that manned aircraft provide.

The key is for companies to design their UAVs to the same structural standards and with the same control and communications capabilities as piloted aircraft, said Clot.

In the UK, aerospace manufacturers now classify their unmanned products as "aircraft" rather than "UAVs" to engender this thinking.

The increasing degree to which control of piloted aircraft and their communications is becoming automated works in favor of the UAV. So does the growing automation of air traffic management.

Digital automation techniques for aircraft control and communication are the same for piloted aircraft as for UAVs. Once all communications and control is digitized, with each aircraft sending back data to the ground all the time, anything that goes wrong with one can be fixed very quickly throughout the entire fleet.

"We will lose a few times, but we will get much better very quickly," said Clot. "Reliability will jump."

Airliners already operate largely automatically, particularly when landing in poor weather. As the automation of aviation accelerates, the idea of flying on a pilotless airliner may become fact sooner rather than later.

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