Like a drone that you sit in – but would you feel safe?

"Absolutely, that has been an important inspiration for me," says Mr Ternstrom, who co-founded Swedish firm Jetson with Tomasz Patan. Recently, his company released a video of its prototype personal flying machine, the Jetson ONE, in action. The clip quickly clocked more than 12m views on YouTube in about four weeks. The filming location, a desert-like area, was deliberately chosen for its sci-fi feel. It is actually a military training ground in Poland. A helmeted pilot sits in the centre of what looks like a large drone, with its multiple spinning rotors. The craft zooms across the landscape, blowing up dust. This is an electric vertical take-off and landing vehicle, or eVTOL. Personal eVTOLs are among the smallest rideable aircraft around and generally have capacity to transport just one passenger - the pilot. The vehicle's diminutive size helps to keep down their price tag but there is another advantage for firms seeking to sell them. In the US, the Federal Aviation Administration (FAA) says that ultra-light vehicles - which weigh less than 254lbs (115kg) and have a maximum speed of 55kts (63mph; 101km/h) - can be flown without a pilot's certificate.