Now that electric cars have become mainstream, Uber and some other prominent tech firms are focusing their attention on the next evolution in personal transportation: flying cars. Uber recently hired Mark Moore, an aircraft engineer at NASA, to head up its Uber Elevate program, which wants to fill the urban skies with electric-powered vehicles capable of taking off vertically like helicopters. Moore is famous for a 2010 whitepaper (PDF) in which he described the feasibility of the concept. “Uber continues to see its role as an accelerant-catalyst to the entire ecosystem, and we are excited to have Mark joining us to work with manufacturers and stakeholders as we continue to explore the use case described in our whitepaper,” Nikhil Goel, a product manager at Uber, wrote in a statement to Bloomberg, which broke the story of Moore’s hiring. Uber has tinkered with the concept of flying cars since at least 2016, when it published a whitepaper (PDF) detailing how such vehicles could remake how people commute. But it isn’t the only tech firm experimenting in this arena: Google co-founder Larry Page is reportedly funding a flying-car startup called Zee.Aero, which also aims to produce a vehicle that can take off and land without a runway. According to its Website, Zee.Aero is currently hiring aircraft wiring technicians, aerodynamics engineers, flight-test engineers, and machinist/programmers. Despite the optimistic predictions by some pundits that flying cars are but a few years away, several regulatory hurdles stand in the way of Uber, Zee.Aero, and their ilk. As Uber points out in its own whitepaper, any vehicle that expects to cruise the skies must comply with stringent FAA regulations in the U.S., a process that currently takes years. Pilot training is another issue. The Uber whitepaper assumes that an onboard computer will have the ability to handle any onboard emergencies that might arise, such as an engine shutdown, which in turn would limit the amount of training needed by human pilots. However, pilot training and certification remains a rigorous process, and it remains to be seen whether government regulators would allow people to fly aircraft at low altitude over densely populated areas with only a few hours of instruction. Last but certainly not least, city infrastructure would need to adjust to accommodate this new type of vehicle. In addition to establishing takeoff and landing points, cities (and perhaps even the federal government) would need to establish “travel lanes” at certain altitudes for flying cars. The rise of flying cars would also demand the creation of emergency protocols: what happens, for example, if two vehicles collide over a busy intersection? Can a city forbid flying cars from taking off if the weather turns rough? While the whole concept might seem far-fetched—and more than a little reminiscent of classic sci-fi films such as “Blade Runner” or “The Fifth Element”—the tech industry has a way of pouring money and resources into a vision until it comes to life. After all, who could have predicted, in the years before Tesla, that electric cars would have become so lusted-after? Meanwhile, if you’re an aerodynamics engineer, or know how to wire an aircraft, you could see more job opportunities open up if more tech firms decide to pursue flying cars as the Next Big Thing.