Arizona-based start-up Krossblade seems to think the same way with its SkyCruiser concept – an electric hybrid aircraft that not only switches between being an airplane and a quadcopter, but can be driven on the road as well.

Ever since the Wright brothers took off from Kitty Hawk in 1903, aviation has been a question of trade offs. Airplanes are fast, fuel efficient, can cover long ranges, and carry heavy cargoes, but they can't hover and they need runways to takeoff and land. Helicopters can hover and land on a dime, but they're relatively slow, gulp fuel, aren't exactly long distance champs, and aren't in the same cargo league as airplanes. And to make either machine into something that can drive on the road usually ends up as something that's both a poor aircraft and a poor car.

The tricky bit of squaring the circle of the airplane and the helicopter has been a dream of aeronautical engineers for decades, resulting in everything from a flying truck to the V-20 Osprey. The Krossblade SkyCruiser's takes the convertiplane approach. In normal flight, the SkyCruiser is pushed along by two 150 bhp electric motors in the tail, but when switching from horizontal to vertical flight, a set of four "switchblade" rotor arms fold out from the fuselage to take the load.