Larry Page is starting a flying car empire, although having even one flying car seems like quite the venture.

It started with Cora, a two-seated flying taxi, which was then followed by a flying boat called Flyer. Now, The Verge has discovered another called the Opener.

Page’s involvement with flying cars, also known as electric vertical takeoff and landing (eVTOLs), started with a small company called Levt Inc, founded by a Stanford aeronautics professor Ilan Kroo. Kroo realized that advances in lightweight airframe materials, computer control and electric batteries could support a small, self-flying electric aircraft.

The idea was that air taxis would be quiet and much safer than traditional helicopters. They could also take off and land in smaller spots like a driveway. Supporters of this idea say that flying taxis could help eliminate congestion on crowded streets.

This concept still has its hurdles. As of today there are not any electric-powered aircrafts or gas-electric hybrids that are commercially in service. Engineers are still working to develop batteries for this project, since flying requires a lot of energy. Currently, eVTOLs are not ready for anything other than short trips from here and there. Experts predict it may be years before technology allows for longer flights.

Page’s interest in flying car projects is at an all-time high despite the risks. At a Google conference in 2013 he said, “We should be focusing on building the things that don’t exist.”

When Page acquired Opener, it was known as SkyKar in 2014. The founder, Markus Leng, said he came up with SkyKar in Ontario, Canada before Kroo. Leng’s first prototype was brought to fruition at his home in 2011.

Opener’s first version of BlackFly was described as “a bit homebrew but really, really cool,” by a source who witnessed it in flight. This same source said that Opener’s engineers did not realize laying up the airframe’s carbon fiber in the correct direction was vital to receive operative strength. Opener denied this account.

Leng recently launched the BlackFly, a single-seater vehicle. It has more style elements than Cora, but has a lower top speed and shorter range. BlackFly has eight rotors and a parachute feature in case of failure.

In order for eVTOL projects to take off, they will need to be more practical than just a billionaire’s toy. The public will need to be convinced that flying cars are safe and affordable.