# A Survey of the Effects of Vehicle Configuration on Urban Air Mobility +
## 2 Aerial Urban Vehicle Configurations and Concepts
### Horizontal Take-Off and Landing (HTOL)
#### 2.1.2 Morphing-Wing and Flying Car (Roadable Aircraft)  
Flying cars or roadable aircraft are a category of airplanes that can transform into a car or are suitable to be used on the road and as a car. Curtiss Autoplane, which was invented by [PERSON] in 1917, is probably the first attempt to produce such an aircraft [26]. Convair Model 116 and 118 are also some of the other tries in designing flying cars (Figure 4). Although they had several flight tests, they never experienced commercial success. Looking at the history of flying cars, we may see many other prototypes like Aerocar, Mizar, and  
Figure 3: View of fixed-wing AUVs (**a**) VoltaEro Casio, (**b**) Cirrus SR22, (**c**) Cessna 172, (**d**) King Air 350, (**e**) Citation M2, (**f**) Premier 1, (**g**) Cessna 172, (**h**) DHC-6 Twin Otter, (**i**) PZL-104 Wilga, (**j**) cirrus vision jet, (**k**) Cessna Citation, (**l**) Lancair Evolution. Fulton FA-2 Airphibian. Some concepts use fixed-wing configurations, while others have foldable wings to make them compact enough for on-road transportation. Many concepts in this field are based on morphing or folding wing ideas. This type of wing is usually popular in flying cars. One of the first ideas of such a concept in flying cars dates back to the 1950s when Italian producers of Aerauto PL5C and American Taylor Aerocar used a morphing wing concept to transform from car to plane mode [27]. In such a concept the wing usually folds in car mode to reduce the size of the vehicle. Generally, a morphing wing can increase the system's efficiency, performance, and adaptability [28]. However, the common morphing mechanisms in UAM are different from morphing wings. In these designs, the morphing mechanism usually provides the capability of transformation from aircraft to car. Figure 5 illustrates some flying cars with morphing wing mechanisms. Terrafugia's Transition is an example of a morphing-wing AUV which uses a morphing-wing structure with a twin tail boom to carry two passengers. Its only engine is placed between cabin and tail which provides it with a speed of about 160 km/h. The transition which is a flying car, after numerous prototypes and a primary version, recently obtained an FAA Special Light-Sport Aircraft (LSA) airworthiness certificate. Its morphing wing design provides it with the capability to transform into a car to be used on road [29]. Figure 6 illustrates different views of the Transition. Figure 4: Some of the early roadable aircraft: (**a**) Convair 118, (**b**) Convair 116. Figure 5: (**a**) AeroMobil 3.0, (**b**) Aerauto PL5C, (**c**) Taylor Aerocar III (**d**) AeroMobil 4.0. Another concept is to achieve flight through the utilization of a powered parachute. Designs based on this concept are referred to as a paraplane. The TEC Maverick Flying Car is one such design (Figure 5c). The Maverick was a roadable, multi-purpose powered parachute aircraft designed by ITEC. It was designed to be easy to drive and fly. The vehicle was designed to be mostly driven on the road but had the capability to fly short distances where roads are not available. It used a 190 hp, fuel-injected, 2.5 L Subaru Engine. On the road, it had a top speed of 100 mph with an acceleration of 0 to 60 mph in about 3.9 s and it flew with an airspeed of 40 mph. It had a take-off length of 300 feet and a rate of climb of 600 fpm fully loaded and 1200 fpm unloaded [30]. Table 2 summarizes the advantages and disadvantages of this configuration. The most sensitive part of a flying a car's flight is the takeoff and landing. During the transition phase from ground to sky, the aircraft must open its wings and rotors to change to flight mode. However, due to the complexity of the foldable wing or blade, motor, and transmitter system, there is a possibility of failure in the subsystem. If the aircraft experience any system failure during takeoff or landing, it could result in a dangerous crash, even if the aircraft starts flying it can still be very dangerous for passengers.