First announced back in 2013, with an upgraded prototype unveiled earlier this year, Terrafugia's TF-X flying car is about as close as the world’s gotten to our collective dream of someday commuting via cloud alleys.

And now the Massachusetts-based aircraft company has hit its next big milestone - the US Federal Aviation Administration (FAA) has given it special permission to run in-air tests with an autonomous drone version of its flying car.

Now, before you get too excited, the model they’ll be testing in US airspace is not only unmanned - it's a mere tenth of the size of their actual flying car prototype. But that's not so bad, because having the flexibility to actually test a miniature version of the TF-X 'in the field' is expected to fast-track the R&D phase of their actual, real-life flying car.

Their scale model will be permitted to reach altitudes of 121 metres and speeds of 160km/h. It can use US air space throughout the country, but the team behind it must be in communication with the relevant authorities at all times.

"Extensive sub-scale flight testing of sUAS [small Unmanned Aircraft Systems], along with wind tunnel testing and aerodynamic simulation, are key to refining the vehicle’s design," Terrafugia said in a press statement.

According to Aero News Network, these tests will be crucial to the development of the actual TF-X flying car, due to the aircraft’s unique engineering. "Because of the unconventional configuration of the TF-X, it is vital to achieve sustained, stabilised hovering with smaller models before developing a full-size TF-X prototype," they report.

If the TF-X ever makes it to market, it will have a cruising speed of 322 km/h (200 mph) with an 805-km (500-mile) flight range, and will require no runway space whatsoever to take off and land.

The four-passenger hybrid vehicle will include rechargeable batteries that can be changed either by its engine or by electric car charging stations. It will be small enough to drive on regular roads and fit in regular garages, and the flying part will be computer operated, so you won't have to be a pilot to drive one.

As we reported earlier in the year:

"When you want to go into flying mode, the wings will fold out, and twin electric motor pods on the ends will power up and lift the car off the ground using 1 megawatt of power. Two small helicopter-style propellers will provide thrust when needed, and are then folded back in when the car is cruising."

Terrafugia says it's looking at eight to 12 years of development for their flying car, but winning approval to get their scale model airborne is keeping them on track nicely. We'll just have to wait and see what the next phase will be. Watch this space.