If it is fitted with a shade that reflects light down on to the ground instead of allowing it to escape wastefully into the sky, so much the better.

ECONOMIST: Going, going, nearly gone

At present the K-MAX has no defensive systems, but Lockheed Martin says the helicopters could easily be fitted with armour, machine-gun pods or flares which could be fired as decoys to divert ground-launched missiles.

ECONOMIST: Autonomous helicopters