Saving pilots' lives is cool and all. So is holding on to some cash. But one of the biggest reasons why militaries have become so infatuated with robot planes might be the drones' ability to hang around in the air.
Flying a plane is tiring. A pilot can only last so long before he needs a break. That's why long range bombers, like the B-52, usually take a pair of 'em into the air.
Drones, on the other hand, don't tucker out. They can keep flying as long as there's fuel to be had. The Global Hawk unmanned aerial vehicle (UAV), for example, can stay in the air for 31 hours straight.
That's a hell of a non-stop flight. But it's only a fraction of the endurance that drone-makers believe will eventually be possible. Take away a drone's need for gas, by loading it up with solar panels or fuel cells, and you might have a UAV that can stay airborne just about indefinitely.
Electric vehicle maker AC Propulsion took a big step toward that goal earlier this month, setting a new unmanned endurance record by keeping its SoLong UAV in the skies for 48 hours in a row, Aviation Week reports.
"The flight probably could have lasted a third night, and perhaps a fourth and a fifth," the magazine adds. AC founder "Alan Cocconi landed after 48 hr. 16 min. because the pilots [operating the plane from the ground] were exhausted, not because the battery was low on juice."
[SoLong is] a powered sailplane of Cocconi's own design with solar cells built into the wing. It weighs 28.2 lb., has a 15.6-ft. span, and takes off with its own 1-hp. motor from a wheeled dolly. The control system includes a sophisticated autopilot with inertial, barometric and GPS references; a television camera gives an over-the-nose pilot's-eye view. It's easy to dismiss the project due to the small size of the aircraft and the 5 X 8-ft. ground station, but the flight system is equal to those many times larger.
There could be major bucks for Cocconi & Co., if they can build their system out to industrial strength -- and not just in defense contracts. As I noted in the Times back in 2002...The big commercial opportunity is likely to be in missions at 50,000 feet and higher that last for months. There, drones can serve as "long-endurance, orbiting relays -- airborne cell towers," Mr. Newcome of Adroit Systems wrote in the trade journal Unmanned Vehicles.
Traditional cell towers are expensive -- up to $1 million each -- and cover three square miles or less. Given their mobility, drones could offer a cheaper alternative.
Several companies are already looking to outlast Cocconi's vrew. AeroVironment, the previous long-range champ, is designing a hydrogen-powered drone (right) that can stay in the sky for a week or more.
