An early prototype of Boeing’s self-driving air taxi completed its first test flight at an airfield in Manassas, Va., on Tuesday, marking what could be an early breakthrough in the company’s vision for autonomous, on-demand flight.

The 30-foot-long, 28-foot-wide aircraft successfully took off, briefly hovered over the ground and landed with a human-size test dummy inside, all of it commanded by the plane’s autonomous navigation and landing systems, according to the Chicago-based aerospace giant.

A YouTube video posted by the company shows the plane loitering on an airfield and then rising off the ground with the help of horizontal rotors at the click of a technician’s computer mouse.

Even though it is a prototype, the “Passenger Air Vehicle” is being touted by Boeing executives as “the future of safe on-demand air travel.”

It is key to the company’s designs for an imagined future where robotic, on-demand air taxis zip passengers around crowded cities.

That Jetsons-like vision has also compelled Audi, Intel, Airbus and others to set up autonomous air taxi efforts of their own.

Boeing executives vowed to be at the forefront of what they called a “revolution” in autonomous flight.

“This is what revolution looks like, and it’s because of autonomy,” John Langford, president and chief executive of Aurora Flight Sciences, said in a statement. “Certifiable autonomy is going to make quiet, clean and safe urban air mobility possible.”

Tuesday’s test flight may have benefited from the involvement of the Silicon Valley ride-hailing start-up Uber, which partnered with Boeing on the project.

The two companies have not disclosed terms of the partnership, making it hard to determine what role, if any, Uber played in the engineering.

The vehicle is part of a Boeing research-and-development division called NeXt, which works with technologists and government regulatory agencies to plan the eventual introduction of self-piloting air vehicles.

The next major milestone for Boeing will be to prove that the Passenger Air Vehicle can safely fly rather than just hover.

The test is also an early success for Boeing’s Manassas-based Aurora Flight Sciences subsidiary, an experimental flight company that Boeing acquired in 2017 for a sum that wasn’t disclosed.

Aurora has made a name for itself in aerospace circles by creating fantastical, loopy aircraft and drone designs that push technical boundaries in areas such as fuel-efficiency, much of the work enabled by U.S. military research and development funding.

In 2015, Aurora Flight Sciences’ Orion drone, designed to be ultra-fuel-efficient so it can fly for days, set the world record for the longest flight of a remote-controlled unmanned aerial vehicle.

Aurora also makes a bizarre-looking, solar-powered drone with three tail fins, called Odysseus, which is designed to operate high in the stratosphere for months in a single flight.

The company plans in 2019 to test-fly an unmanned cargo plane designed to carry up to 500 pounds.

It is all part of a broader effort to relieve traffic in congested cities as the company seeks to “usher in a future of safe, low-stress mobility in cities and regions around the world,” Boeing NeXt General Manager Steve Nordlund said in the company’s announcement.

Whether and when that vision becomes reality could depend on more than just overcoming engineering challenges.

Nordlund said in an email that he thinks passenger air vehicles “could quite possibly be in service in the early 2020s.”

Independent aerospace analysts called that timeline ambitious.

“It’s decades away, if we’re super extra lucky,” said Richard Aboulafia, a Teal Group analyst. “It will be at least 15 or 20 years before the technological problems are solved, and then you have to deal with the economics.”

For such a solution to work, the Federal Aviation Administration would have to think through the safety implications of robotic vehicles zipping past one another in midair while carrying humans.

“Customer acceptance” is also a factor, Nordland said; with so many people already made anxious by today’s commercial airplanes, it seems unlikely that tiny autonomous air taxis would be quickly embraced.

“Its quite possible also that unicorns could achieve air mobility,” Aboulafia said. “You can never rule out anything. But I’d give the unicorns a better shot.”

Safely orchestrating all of it would be no small feat: Preventing flying taxis from crashing into one another as they traverse crowded cities would be much harder than guiding an Uber driver by road to a spot on a map.

Others have raised cybersecurity and privacy concerns.

When people are being flown through the air, “the price of not getting it right is higher,” said Drew Cohen, chief executive of the Maryland-based cybersecurity company Zuul, which focuses on the cybersecurity of transportation infrastructure.