Sky highways

Arthur wakes up suddenly. He had arrived home late from the party last night. All he could remember was that parking was a nightmare! But where on earth did he leave his car? He opens his curtains and there it is - sitting on top of his neighbour's roof. Uh-oh!

Inventors have been working on the idea of a flying car for over 100 years. In 1917 a version called the Curtis Autoplane, which had a removable fuselageThe main body of an aircraft. and wings, was unveiled in New York - but it was never fully developed.

In 1946 four prototypes of the Fulton Airphibian were built. With a detachable propellor and fabric wings, it was officially certified as safe to fly, but there was not enough investment to make it commercially viableCapable of working successfully.. The 1949 Taylor Aerocar, which had an air speed of 110mph and a range of up to 500 miles, suffered the same fate.

According to one expert, Andrew Glass,¹ the biggest challenge is to "create a machine that is robust, rugged and probably heavy enough to withstand the rigours of the road - the bumps and the occasional fender-benders - and at the same time a machine that is light enough and aerodynamic enough to be safe in the air."

With this in mind, the main focus today is on a type of vehicle called EVTOL - short for "electric vertical take-off and landing". Dozens of companies around the world are working on the idea, including Toyota, Boeing, Airbus and Uber.

EVTOLs come in many forms. Some are like four-propeller drones, but on a very large scale.

The German company Lilium has developed a six-seater with 30 electric jets which lift it off the ground and then tilt to propel it forwards.² Boeing's Wisk has wings and propellers.

VoloCopter has come up with the two-seater VoloCity. With helicopter-style rotors, it has a range of 22 miles. The company hoped that it would carry VIPs across Paris during this summer's Olympics, but the city council has now rejected the idea.

EVTOL enthusiasts argue that they are a cheaper, quieter and less polluting alternative to helicopters. The Californian company Joby Aviation plans to use them to ferry passengers to airports in New York and Los Angeles next year. Its founder JoeBen Bevirt hopes it will eventually become cheaper than taking a taxi or Uber.³

The main technical challenge lies with batteries, which are heavy and expensive. Relying on them limits an EVTOL's range and the conditions it can operate in: it would not be able to fly around a storm as a helicopter can. And for a taxi service to work, the battery would have to be charged very quickly, which would shorten its life.

Then there is the issue of how EVTOLs should operate. Hugh Martin, who advises cities on transport policy, says there are several questions:

"Where will these vehicles be allowed to fly? Where will they take off? Where will they land? Who decides what is possible? That's going to take a long time to get figured out."

Are they a good idea?

Yes: A drastic solution is needed to the traffic jams that plague cities. EVTOLs would make it possible to get from A to B much faster and reduce the pollution caused by traditional cars and helicopters.  

No: The traffic on the ground is bad enough - to have it in the sky as well would be awful. And the safety issues are enormous: a car crash on land might not kill you, but one in the air certainly would.

Or... EVTOLs are much closer to helicopters than to cars. The fact that so many companies are working on them is an admission that the idea of a car with wings is basically impractical.