Larry Page’s mystery flying car startup is expanding its fleet of oddball aircraft

Zee Aero registered two new aircraft with the Federal Aviation Administration on January 18, according to filings seen by Business Insider. The aircraft type for both filings is listed as rotorcraft, which means they use rotary wings to fly like a helicopter.

Both of the aircraft use electric engines, according to the registrations which allow Zee Aero to fly the rotocraft for three years.

Kitty Hawk, a smaller subsidiary of Zee Aero that's purportedly working on different flying car designs, also registered in January to fly a four-seater Cessna 172 Skyhawk plane, which is the most-produced aircraft in history.

Larry Page created Zee Aero in 2010 to reinvent personal aircraft transportation, but his involvement was kept secret until a bombshell investigation by Bloomberg Businessweek last year revealed that the billionaire Google cofounder had personally poured over $100 million into the project.

Although flying cars appear to be straight out of science fiction, giant companies including Airbus, Boeing and Uber are all developing flying car prototypes.

Gliders and sailplanes

Collectively, Zee Aero and Kitty Hawk have filed more than a dozen different aircraft registrations with the FAA to date, with the earliest filings dating back to 2014. Different aircraft types that have been registered include electric gliders, rotorcraft, and fixed-wing designs that function more like traditional, commercial planes.

Zee Aero has yet to publicly acknowledge or demonstrate its technology. The company couldn't be reached for comment on its FAA filings.

Since Bloomberg unearthed Page's involvement in June 2016, Zee Aero and Kitty Hawk have registered at least two additional glider and three rotorcraft planes with the FAA. The filings signal that Page, who is the firms' only publicly-known backer, hasn't pulled his financial support, as Bloomberg reported he once threatened to do if his involvement ever became public.

Aside from flying its own designs, the FAA listings indicate that Zee Aero and Kitty Hawk have been testing other outside aircraft, including the fixed-wing Cessna 206 and an ultralight, engine-less sailplane with detachable wings called the SparrowHawk.

Zee Aero's more recent rotorcraft filings suggest that it's indeed working towards a design that Bloomberg earlier said "resembles a giant version of a quadcopter drone." The description also matches paparazzi photos of alleged prototypes and early Zee Aero patents.

It's not clear from the latest FAA filings if the newly registered aircraft are designed to be piloted by a human or to fly autonomously.

Shrouded in secrecy

Zee Aero and Kitty Hawk share the same nondescript headquarters near Google's Mountain View, California headquarters, according to the FAA listings.

Aside from Page's backing, little is known about Zee Aero's management. The startup has around 100 employees, according to LinkedIn, and a handful of open positions listed on its website. The Kitty Hawk division has roughly 30 employees.

Eric Allison lists himself as Zee Aero's CEO since March 2015 on LinkedIn. Prior to that, Allison served as the startup's director of engineering for five years. Zee Aero's president is former Delta executive Fred Reid, according to his LinkedIn profile.

Business Insider recently reported that long-time Twitter engineering exec Alex Roetter had joined the Kitty Hawk team. Bloomberg reported last year that the president of Kitty Hawk was Sebastian Thrun, who helped create Google's self-driving car and "X" moonshot divisions. Thrun is also said it be working on a Blue Apron-like stealth startup revolving around how to make "healthy and tasty" meals at home.

Do you know more about what Zee Aero and Kitty Hawk are up to? Contact this author securely and discreetly at aheath@businessinsider.com or "@alexeheath" on Telegram or Twitter.