Rise of the sky robots?

One hundred years after French aviation pioneers Bleriot, Breguet and Esnault-Pelterie organised the first international 'Airborne Locomotion Exhibition', visitors to the 48th Paris Air Show witnessed a somewhat under-stated 'first flight' event: the first airborne demonstration of an unmanned aerial vehicle (UAV). Air shows are historically the aircraft-makers' shop window for the latest developments in speed, performance, manoeuvrability and the like, but in recent years a green theme has emerged alongside the engineering parameters, especially in commercial aviation. At Le Bourget this year, it made itself known in the form of green logos, surface decoration on stands and even a 'turf'-covered engine cowling.