Boeing testing green UAV

ST. LOUIS, March 9 (UPI) -- The hydrogen-powered Phantom Eye unmanned aircraft can fly for more than four days because of its advanced propulsion system, defense giant Boeing Co. said.

Boeing Co. announced it started work on the Phantom Eye, which it said is its first unmanned, liquid-hydrogen powered, high-altitude, long-endurance demonstrator aircraft.

The twin-engine Phantom Eye has a 150-foot wingspan. It can carry a 450-pound payload for more than four days at an altitude of 12 miles, the company said.

Darryl Davis, the president of Boeing Phantom Works, said the key to the endurance of the Phantom Eye was its propulsion system.

"After five years of technology development, we are now deploying rapid prototyping to bring together an unmanned aerial vehicle with a breakthrough liquid-hydrogen propulsion system that will be ready to fly early next year," he said.

The Phantom Eye is designed for "persistent presence" over target areas for intelligence, reconnaissance, surveillance and communication missions.

The long-endurance Phantom Eye grew out of the piston-powered Condor that broke altitude and endurance records in the 1980s. The propulsion system for the Phantom Eye completed an 80-hour test March 1 and is set for its first flight in December.