Are drone deliveries a realistic prospect?

That's what the likes of Amazon hope. Drones have the potential to carry small items quickly from one place to another without having to worry about traffic, personnel costs or labour strikes. But it's a bit more complicated than that: drones as we know them today are either giant, expensive killing machines or small, hovering things that can carry little more than a camera. Most can already ferry a small box of items weighing a couple of kilograms, but Amazon and others are looking to build drones capable of carrying up to 25kg for around 10 miles, likely meaning packages weighing under 3kg each. Good enough for onions and a pint of milk – but forget getting your next washer-drier flown into your back yard.