Well, it may have been 56 years since “The Jetsons” was first on TV, but flying cars are finally about to become real.

The last few months have been filled with news of companies that unveiled, demonstrated, or released videos of their “air taxis,” as they’re often called. They’re basically giant-sized versions of drones — giant enough to carry a person, or two, or five.

Why now? Because all the necessary ingredients have aligned: Batteries with high enough energy density to carry these copters into the air; composite materials like carbon fiber light enough to work; avionics (aircraft software and electronics, developed for regular drones) cheap and reliable enough to adapt; and collision-avoidance systems advanced enough to keep these things from crashing.

The beauty of these personal copters is that since they’re all electric, they’re really quiet. They could fly at low altitude without becoming a nuisance to people on the ground. And, of course, they’re pollution-free: zero emissions.

All of these models can be autonomous. You plug in your destination, and the thing flies you there. Some have a joystick so that you can seize control of it if you want, and most can also be remote controlled.

These air taxis are built with redundancies of the major elements, so even if something goes wrong, you won’t drop out of the air. Many have low-altitude parachutes, too.

Now, don’t get all excited. You can’t buy a passenger drone yet — that moment will probably come in 2020 at the earliest, and they’ll cost hundreds of thousands apiece. Even then, nothing will happen in the U.S. until the Federal Aviation Administration comes up with rules to govern how these things use the airspace.

Oh, and by the way: Even with all the advances in batteries and materials, these things are still super limited in flight time. You’re lucky to get 20 minutes in the air.

But the trend is unmistakable: A lot of companies have working prototypes that are taking real people on real flights.

Who’s taking off first?

Here are some of the flying machines that have surfaced recently:

eHang 184

This Chinese drone maker has been working on the eHang air taxi for four years, and it’s fairly far along. Since the capsule holds only one person, it’s small — about the size of a car. The prototype has made over 1,000 tests in China, sometimes in high winds and at even at night.

Here are the specs:

• 10-mile range

• 80 mph top speed

• Partnered with the Dubai government, who wants to develop air taxis to service its cities

• Lands automatically in case of a malfunction

A two-passenger model is on the drawing board.

Volocopter

One of the highlights of CES 2018 was watching this gigantic, 18-rotor craft land on the stage during Intel’s keynote presentation. (Also at CES: The Volocopter’s first passenger was Intel’s CEO, Brian Krzanich.)

The details:

• Designed and built in Germany, where it has approval to fly

• Autonomous, joystick-operated, or remote controlled

• Carries two passengers

• 18 rotors, parachute

• 70mph cruising, 17-mile range

• Conducting test flights in Dubai

• Estimated price $300,000

Passenger Drone

Weirdly enough, this California passenger-drone company is called Passenger Drone, and so is its product — the Passenger Drone. It carried its first passenger in November.

• 16 rotors on 8 spindles

• Autonomous, joystick-operated, or remote controlled

• Carries two passengers

• Top speed: 45 mph

• 25 minutes per charge

• 20-minute flight time

Joby

This copter is the brainchild of JoeBen Bevirt, who made his fortune from selling — I kid you not —flexible-arm GorillaPod camera tripods. Now, with the help of $100 million in investments from Toyota, JetBlue Technology Ventures, and Intel, it’s preparing a sleek VTOL (vertical takeoff and landing) copter that can carry four passengers and a pilot for 150 miles. (Full disclosure: My wife does PR work for JetBlue Tech Ventures.)

A couple of weeks ago, Joby invited a pair of Bloomberg reporters to witness an unmanned flight. They weren’t allowed to take pictures or even describe the thing, which is a bummer. But they watched it fly, remote controlled, for a 15-minute flight. “Bevirt says thousands of these sky cabs will one day shuttle people around cities, soaring above the conventional traffic below,” goes the article.

Vahana

This prototype, developed by European plane maker AirBus, has propellers that point upward for takeoff, like a helicopter’s, and then rotate forward, like a plane’s. The company flew it, unmanned, for the first time last month.

Details are sketchy — they don’t even have a website (only a blog) — but here’s what we know:

• Single-passenger

• “Productzable prototype” in 2020

• Parachute

Illium

Unlike most air taxis, which are propeller planes, this one is an electric jet with a 180-mile range.

Here’s the video of its maiden (unmanned) flight:

The bullet points:

• Holds two people

• 180-mile range

• 275 mph

• Vertical take-off and landing

• First manned flight planned for 2019; on-demand flights by 2025

• Based in Germany

And the rest

Just about any deep-pocketed company who’s anyone is diving in. For example:

• Uber Elevate, its self-driving air taxis, are nothing more than a white paper and a killer CGI video at this point. But clearly, they’re all in on the concept; they expect to launch the air-taxi service within a decade.

• Boeing bought Aurora Flight Services, maker of VTOL planes, in hopes of exploring the air-taxi concept.

• Larry Page, CEO of Alphabet, has spent $100 million to fund two electric-craft companies. There’s Zee.Aero, which has prototypes for two VTOL electric passenger planes, and Kitty Hawk, which is making a no-license-required personal hovercraft for use over water.

• Zunum Aero is working on electric versions of traditional passenger jets (700-mile range).

We know this much about technology and disruptive change: Everything takes longer than we think, everything has unintended consequences, and everything’s subject to government regulation.

But with this much money and so many companies all chasing this dream, it seems likely that air taxis really will take off — at some point.

David Pogue, tech columnist for Yahoo Finance, welcomes non-toxic comments in the Comments below. On the Web, he’s davidpogue.com. On Twitter, he’s @pogue. On email, he’s [email protected]. You can sign up to get his stuff by email, here.