Small electric airplanes, guided by artificial intelligence, that cross over cities to take their passengers from one "vertiport" to another, that's the science-fiction setting that Silicon Valley is promising in just ten years.

"We're going to see the emergence of networks of electric air cabs, both regional and long-distance. The landscape is going to change a lot," says Marc Piette, Belgian founder of Xwing, a startup specializing in autonomous technologies for aviation.

There are several Californian companies actively preparing for this future of mobility, a remedy for traffic jams and pollution.

In a hangar in Concord, in the San Francisco Bay Area, Xwing is focusing on the most confusing factor in the equation: making any plane, aeroplane or vertical takeoff and landing (VTOL) aircraft, fossil-fueled or electric, taxi, take off, fly and land by itself.

And talk to passengers at the same time.

"Autopilot system engaged," a woman's voice declares to Ryan Olson as he sits down at the controls, ready for a trip where he won't touch the instrument panel or the joystick, like an instructor with a well-travelled apprentice.

"The plane is a good student, unlike humans who behave differently every time," says the pilot.

There are cameras, servers, radar, lidar and other sensors, the Cessna Caravan is already autonomous in good weather, and Xwing is working to make it capable of dealing with bad weather on its own.

In early 2022, a Joby eVTOL crashed during a remotely piloted flight when the startup was testing speeds above its limits.

"It's bad for the whole industry when there's an accident (...) But that's what testing is for," recounts Louise Bristow, vice president of Archer, another company.

Archer and Joby's eVTOLs look like helicopters but with one wing and several propellers. They hope to launch their first air cab services by the end of 2024, complete with pilots. Wisk Aero, a startup owned by Boeing and Larry Page - co-founder of Google - is working on an autonomous eVTOL.

Archer has received a pre-order from United Airlines for 200 vehicles and is targeting Los Angeles and Miami to start.

"We're building the Uber of the sky," says Louise Bristow.

She estimates that it will take 10 years "for there to be enough devices in service, for people to get used to travelling this way, and for us to feel the difference" in cities.

According to Scott Drennan, a consultant on new air mobility, these once-dreamy visions are now taking shape thanks to the convergence of three technologies: electric power, computing capabilities and autonomy systems.

But while the technology is well underway, companies face two major challenges: certification and infrastructure. The authorities are not reluctant, but getting their approval "is going to take longer than we think," says the expert.

It will also be necessary to build "vertiports" (vertical airports), and "a digital interface to manage air traffic and the communication of vehicles between them".

Like an elevator

So many reasons why Xwing chose to start with autonomy.

"We took an existing, well-known aircraft. We make the minimum of modifications to convert it into an autonomous aircraft and get it certified, and then we can explore other applications," summarizes Marc Piette.

Doing without pilots should reduce costs and meet demand in underserved regions, which lack neither airports nor planes but rather a manpower.

The startup plans to first equip machines in charge of delivering goods, with a view to commercial operations within two years, before moving on to passengers.

The boss knows he'll face resistance, but he's convinced that these flights will be safer.

"The vast majority of air accidents are caused by human error," he notes, before recalling that thanks to the autopilot, "people already fly by themselves for the most part."

He also explains that autonomy is "simpler" in the air, where the environment is under constant control, unlike roads.

What if hackers took control remotely? "Our technology is designed so that the plane refuses to obey dangerous orders," answers Marc Piette.

When elevators were invented, "people were very afraid to use them without an operator," he says with amusement. "Today, people press the button without question. It will be the same for aviation.