Slovakia’s Flying-Car Pioneer Tests Latest Prototype
Designers of urban air taxis are quick to correct anyone who calls their vehicles “flying cars,” as most are intended to fly over cities and not drive on the streets.
But developers of true fly/drive vehicles continue to tout their progress toward the long-sought dream of a flying car in every garage. The latest is Slovakia’s KleinVision, which conducted the first airfield pattern flights with a prototype of its AirCar (V5) at the end of October.
Like another Slovakian company, AeroMobil–and there is a connection between the two–KleinVision is developing a fly/drive vehicle styled after a supercar. Designs being developed by the Netherlands’ PAL-V and U.S. startup Samson Sky, meanwhile, are more akin to motorcycles.
Another U.S. startup, Terrafugia, was developing the Transition roadable aircraft for certification under FAA light sport rules, but has gone quiet since its acquisition by Chinese carmaker Geely in 2017.
PAL-V’s three-wheel Liberty, however, recently received approval for road usage in Europe and will be undergoing endurance testing while the company works toward European Union Aviation Safety Agency (EASA) certification. Deliveries are planned to begin in 2022.
Samson has begun runway testing its three-wheel Switchblade, but so far just as a road-going vehicle. Where the Switchblade has wings that swing out of bays under the body, and an extending tail, the Liberty is an autogiro with a rotor that folds and tail that retracts for road use.
AeroMobil flew an earlier prototype of its vehicle in 2014 and unveiled a fourth-generation design, the AeroMobil 4.0, in 2017. There has been no news on an expected 2020 first flight, but according to the company’s website a commercial launch is planned for 2022.
The AirCar (V5) is the fifth generation of flying car designed by Stephan Klein, who was co-founder and chief designer at AeroMobil from 2011 until he left in 2017 to form KleinVision. According to Klein, where the AirMobil is a roadable aircraft, the AirCar is closer to the concept of a flying car.
“This new model aircraft has features of a sports car,” said Klein, who worked on projects with Audi, BMW and Volkswagen at Slovakia’s Academy of Fine Arts and Design. “I would like to transfer this knowledge about design and product to this world of aircraft.”
Key features are the wing-fold mechanism, extending tail and lifting body. “The major difference is in the way AirCar transforms into aircraft mode compared to AeroMobil,” Klein told Aerospace DAILY. “As a consequence, the AirCar is shorter than the AeroMobil and can park in a standard parking lot.”
The AeroMobil has high-set wings that swing back over the body for road use. The rear wheels are mounted well aft in the dual vertical tails and overall the front-wheel-drive vehicle is almost 6 m (19.7 ft.) long–about 1 ft. longer than a Chevrolet Suburban SUV.
The AirCar has mid-set wings that first fold along their span, then swing inboard to stow between the twin booms of the tail, which extends for flight and retracts for road use, reducing the two-seat vehicle’s overall length to 5.2 m.
Unlike in the AeroMobil, the AirCar’s body generates lift. “The central part of the fuselage has been designed in such way that the resulting aerodynamic force generates 27% of the lifting force,” Klein said.
On the road, the front-wheel-drive AirCar sits nose down to generate downforce. Additionally, a spoiler deploys under the nose and the high-set horizontal tail generates an adjustable downforce to improve stability and handling.
There is also a big difference in the takeoff maneuver, Klein said. Where the AeroMobil lifts off with a horizontal body attitude, the AirCar rotates like a conventional aircraft to take off.
The latest flights of the AirCar (V5) prototype follow earlier tests with a full-scale unmanned model powered by a 20-kW electric motor. The manned prototype then completed 8 hr. of short takeoffs and landings in 2019.
The late October flights took place at Piestany Airport in Slovakia. The vehicle took off from the grass and reached 1,000 ft. altitude, then completed two full circuits of the airfield. KleinVision’s goal is to complete 50 hr. of testing with this prototype.
This first prototype is powered by a 1.6-liter, 140-hp BMW car engine for test purposes only. The second prototype will be powered by a 300-hp aircraft engine under development by South Africa’s Adept Airmotive and planned for FAA certification.
The Adept engine is liquid cooled and digitally controlled and can easily be built into the center fuselage, Klein said, driving the front wheels in road mode via a conventional gearbox and differential or the pusher propeller in flight mode via a belt drive.
The Adept engine will meet the latest European emission standards for road vehicles, he said, while allowing the AirCar to take off in 300 m and carry a 300-kg (660-lb.) useful load at cruise speeds in flight of up to 300 kph (185 mph).
KleinVision plans to initially offer the AirCar as an experimental-category kitplane while it works toward EASA CS-23 certification of the vehicle. The company hopes to have the kit on the market within six months, says theoretical physicist Anton Zajak, investor and co-founder of KleinVision.
In another difference from the AeroMobil, Klein said, the AirCar’s design can easily be modified to a four-seat version, and a variant with twin engines for commercial air-taxi flights over populated areas. An amphibious version is also possible, he said.