Flying car, road able aircraft, dual-mode vehicle and other terms are used to describe the all-purpose vehicle that can fly like an airplane and drive on the highway like an automobile. Make it amphibious and we have the perfect all-purpose vehicle! Nevertheless, this might be taking our ideas a bit too far. It has been the dream of aviation and automobile enthusiasts to have a vehicle that will bring them the best of both worlds. Many drivers stuck in rush hour traffic have fantasies about being able to push a button and watch their car’s wings unfurl as they lift above the stalled cars in front of them. Just as many pilots who have been grounded at an airport far from home by inclement weather have wished for some way to wheel their airplane out onto the highway and drive home. This yearning has resulted in many designs for road able aircraft since as early as 1906.
A designer of a flying car will encounter many obstacles, including conflicting regulations for aircraft and automobiles. As an automobile, such a vehicle must be able to fit within the width of a lane of traffic and pass under highway overpasses. It must be able to keep up with normal highway traffic and meet all safety regulations. It must also satisfy vehicle exhaust emission standards for automobiles. Therefore, the wings must be able to fold (or retract) and the tail or canard surfaces may have to be stow able. The emission standards and crash worthiness requirements will add weight to the design. The need for an engine/transmission system that can operate in the stop and go, accelerate and decelerate environment of the automobile will also add system complications and weight. For flight, the road able aircraft must be lightweight and easy to fly. It must have a speed range at least comparable to existing general aviation airplanes. Conversion from aircraft to car or vice versa must be doable by a single person and the engine must be able to operate using either aviation fuel or auto fuel. Ground propulsion must be through the wheels and not via propeller or jet which would present a danger to nearby people, animals or other vehicles.
While some people use the terms Flying car and road able aircraft interchangeably, or use the latter term to bypass the science fiction connotations of the former, they are explicitly two quite different concepts. One wishing to design such vehicles must first decide which approach is appropriate. The ‘flying car’ is primarily a car in which the driver has the option of taking to the air when desired or necessary. The ‘road able aircraft’ is an airplane that also happens to be capable of operation on the highway.