Return of the blimp

摘要

If you thought all unmanned air vehicles (UAVs) were variations on the familiar fixed-wing autonomous aircraft, then think again. Working with $0.5bn (￡0.33bn) of US defence funding, a team of US and British engineers is developing a 250ft-long reconnaissance drone based on a class of vehicle that many regard as little more than an intriguing footnote in aviation history; the airship.