Once upon a time, flying cars were a staple of science fiction.

The long-expected travel convergence between automobile and aircraft may finally be about to unfold.

This is a pivotal time for the auto industry, with new automation and electrification technologies threatening to disrupt a century-old business model.

It's not surprising, then, that some of the major names in the automobile industry have set their eyes on the nascent field of personal air mobility.

Firms such as Porsche, Daimler and Toyota are behind some of the most daring startups in the nascent eVTOL (electric vertical takeoff and landing aircraft) industry that aims to revolutionize urban transportation by taking to the air.

According to this vision, we will move around cities in fleets of electrically powered, lightweight air vehicles capable of vertical takeoff and landing that can be summoned at the click of an app.

These vehicles will be as ubiquitous in the urban landscape of tomorrow as their ground-based equivalents are today.

Sounds far-fetched? Some cities, such as Dubai, have already been testing the concept in a limited way. The Emirate is drawing up plans for an eVTOL rollout.

For automakers, the emergence of new mobility technologies is, at the same time, a threat -- diverting journeys from their core ground transportation business -- and an opportunity to redefine themselves as mobility providers in a broader sense.

Daimler, best known for its Mercedes luxury car brand, is an undisputed pioneer when it comes to car-making, thanks to its historical link to Karl Benz, who in 1885 built the Benz Patent-Motorwagen, regarded as the world's first production automobile. 

The German firm may be on the cusp of repeating this feat through its investment in Volocopter, an all-electric vertical lift aircraft with capacity for two passengers and specially designed to be flown in urban environments. 

Daimler's innovation arm, called Lab1886, is one of the investors behind this startup that has already completed its first flight in a European city and is in the pole position for a Dubai roll-out in the near future.

Volocopter has also caught the eye of Chinese automaker Geely (owner of Sweden's Volvo as well as a major Daimler shareholder), which recently led to the successful closure of a €50 million investment round.

But this isn't Geely's only investment in the field of air mobility. The Chinese automaker is hedging its bets by also investing in California-based Terrafugia.

Remarkably, Terrafugia's concept resembles a proper "flying car," such as those imagined by science-fiction writers of yesteryear. 

The aptly named Terrafugia Transition is able to drive on roads and fit in a garage, just like any normal car, but can also, at the user's command, deploy a set of wings and take off and fly like an airplane.

In November 2018, Terrafugia declared that its first vehicle would go into production in 2019 but, one year later, it's yet to materialize.

Not to be outdone, Japanese automaker Toyota is also getting into air mobility through its venture capital arm. 

Toyota AI Ventures is an investor in California-based Joby Aviation, which proposes a manned eVTOL electric aircraft able to carry five passengers 150 miles (240 kilometers) on one charge. In its product pitch, Joby highlights the speed and quietness of its vehicle compared to other alternatives. 

The startup is still in stealth mode, but has already received some $130 million in venture funding. Its backers include some prominent Silicon Valley investors and JetBlue Technology Ventures, the venture capital arm of the airline of the same name.

Jim Adler, Toyota AI Ventures' founding managing director, told CNN Travel, "One of the areas we've been exploring is technologies that fundamentally change the way people move around -- on land, at sea or in the air.

Joby Aviation's vision of delivering safe, affordable, and accessible air-transportation-as-a-service fits squarely in Toyota AI Ventures' view of the future of transportation: one that is highly networked, increasingly automated, multi-modal and widely available."

Bonny Simi, president at JetBlue Technology Ventures, tells CNN Travel that the nascent eVTOL industry combines expertise from both the automaking and aerospace worlds. 

On the one hand there is the potentially high-volume production of relatively small vehicles, and on the other there is all the avionics technology involved. 

Then there's a key element that's also very relevant to the future of the auto industry: batteries. 

"Why are we seeing all these movements in the eVTOL market just now? Mainly because of advances in battery technology," says Simi. "The current electrically powered designs can deliver on all three main advantages of the eVTOL concept: safety, noise and cost."