Drones aim high to replace cargo planes

Scientists at odds with authorities in wanting light, less costly, unmanned UAVs to ferry goods around our skies, says Thomas Grose

ON a bright, sunny afternoon in Wiltshire on July 9, a white, unmanned air vehicle (UAV), its two, 2.75-horsepower engines buzzing, taxied smoothly down a finely mowed field of dark-green grass. It lifted off and effortlessly soared to an altitude of 325 feet.

After 10 minutes, the drone, which has a wingspan of 13 feet, gently returned. It was the second of its 20 short test-flights that day. For the first 14, the drone was controlled remotely by a pilot on the ground. The last six were on autopilot, run from a laptop. Small UAVs are a frequent sight in the low altitudes of UK airspace, but this drone was a rare bird because most of its key parts, including the fuselage and fuel tank, were fashioned in lightweight nylon by a 3-D printer.