Though the idea is not relatively new, and many prototypes have been built over the years, history suggests that an aero-auto hybrid would be a complete failure, since its construction is a compromise between the two functions, and will never fully complete one of these two without partially disabling the other.

In 1918, Felix Longobardi patented a invention at the U.S. Patent Office for a vehicle that could drive on the roads, and fly as well.

A company developed in 2006 named Terrafugia, plans to produce a vehicle called Transition, that would be ready for test flight by the end of the next year. FAA says this vehicle is a lightweight sport aircraft, and would be easier to fly, being more accessible than regular planes are.

The vehicle, as seen in the pictures, has both car-like features, and different aerodynamic surfaces attached to it. Early this summer, the developers of Transition have tested the wing folding at the AirVenture aviation festival. Previous prototypes had manually folding or detachable wings, but Terrafugia wants automated folding wings, so a more rapid and seamless transformation from car to airplane would be available.

The biggest technical difficulty now is to design a power linkage, so that only one motor would be used both while on the ground or in air. The motor must be capable of running on unleaded gasoline, for the simple reason that it can be bought at any petrol station. The gear linkage system between the propeller and the wheels must be light weight, extremely reliable and as simple as possible. The vehicle must pass the same requirements as any normal car, and also respect the FAA rules that impose a maximum weight of 1,320 pounds.

The company would probably start production in 2009 and is planning to build and sell between 50 and 200 vehicles a year. The vehicle would be about the size of a Cadillac Escalade, and will probably cost $148,000 a piece.