Once up, the wings are rotated to provide lift during forward flight, increasing range.

Powered by eight electric motors, each capable of delivering 60kg of thrust, it is said to be able to fly for 25 miles at 60mph and still have reserve power for an emergency landing if required.

The controllers and a pair of batteries for each motor are right behind it in the wing – keeping connections short for reliability, said the company.

Having two batteries per motor increases reliability – and should a battery fail, power can be moved from an adjacent battery from another pair.

The motors weight 1.8kg each, and one, said the company, has been run for 3.5 years, continually simulating take-off, cruse and landing – amounting to simulating 20 circumnavigations, apparently.

Thanks to Steve Kurt for bringing BlackFly to my attention via this YouTube video.