Before flying Ubers can zip people over crowded city streets, regulators and planemakers such as Boeing Co. and Airbus SE will first need to figure out a series of safety conundrums and technical dilemmas.

Among the questions: What’s a reasonable amount of backup energy to require for winged electric vehicles, especially when current battery technology will only support about 20- to 30-minute journeys? U.S. regulators require commercial jetliners to carry extra reserve fuel in case flights are forced off schedule by foul weather, congested airports or other causes, or if the plane has to divert to another airport.

“A 30-minute reserve isn’t going to work on a 20-minute flight time,” said John Langford, founder of Aurora Flight Sciences, purchased last year by Boeing for its pioneering work in autonomous flight.

It’s the type of multifaceted challenge, encompassing new technologies and regulatory complexities, that the Chicago-based manufacturer plans to tackle with a newly formed unit, Boeing Next. The company is creating the operation as a companion to HorizonX, its venture-capital arm, which is focused on fostering futuristic technologies. Steve Nordlund will head both initiatives.

Fleets of strange new electric flying machines are apt to be buzzing over congested city streets within years -- not decades, given the rapidly evolving technology for batteries and artificial intelligence, Greg Hyslop, Boeing’s chief technology officer, told reporters at the Farnborough air show.

The new unit will serve as an incubator of sorts, he said. If it proves successful, Boeing Next eventually could "stand up on its own" as a business.

‘Inflection Point’

“We’re at an inflection point where things will change, and change rapidly,” Hyslop said.

E-commerce and creaky “terrestrial infrastructure” that’s struggling to keep pace with increasingly mobile populations are among the forces driving this new trend. But formidable obstacles remain, starting with the complex traffic system needed to keep flying taxis from colliding with buildings, cars, drones, conventional aircraft and of course people on the ground.

Aerospace analyst Richard Aboulafia is among the skeptics that the new technology, and regulations to manage it, will be developed in the next decade.

“2040 is very aggressive to me, but not inconceivable,” he wrote earlier this year. To take root, the industry will need “an alchemical mix of autonomy, hyper-efficient manufacturing, battery improvements/air vehicle electrification, and the discovery of unobtanium,” he quipped.

Flying Uber

Boeing bolstered its portfolio of unconventional pilotless aircraft last year by buying Aurora, which is among the companies vying to develop a flying taxi with Uber Technologies Inc. Aurora has been inventing autonomous vehicles since the late 1980s, and its portfolio of novel flying machines includes a two-seat robotic copter known as an eVTOL (an abbreviation for electric vertical take-off and landing).

Aurora decided to merge with Boeing after realizing it would need far deeper resources to win regulatory support for its revolutionary new vehicles and the artificial intelligence that will operate them, Langford said Tuesday. Its first project following the acquisition: developing a new eVTOL for Boeing.

As to the fuel-reserve conundrum, “that’s a case where the regulators are being very, very reasonable,” Langford said. Manufacturers will need to craft a plan that addresses what can go wrong, along with the flexibility of vehicles that don’t need 5,000-foot-long runways. Another Aurora invention involves helicopters that can rapidly and safely select their own landing sight.

“The real question: is there a market for a plane that flies 20 to 30 minutes?” Langford said. “We’ll see. We’re going to do the experiments and we’re going to find out.”