Patent applications filed by Volocopter in the U.S. last year show the German air taxi developer is working on a winged eVTOL design that would deliver greater range than its two-seat VoloCity multicopter, which the company intends to certify with the European Union Aviation Safety Agency by late next year.
According to the patent filing, Volocopter’s longer-range eVTOL design includes front and aft wings attached to the fuselage, with beams structurally connecting the wings on either side and three propellers attached to each beam in “an essentially vertical orientation.” Two additional propellers, oriented horizontally for forward flight, are located at the rear of the aircraft.
“Generally, contemporary eVTOL aircraft designs suffer from poor aerodynamic efficiency . . . since they incorporate several systems in order to vertically lift the aircraft as well as to move it horizontally,” the patent filing states, making the case for differentiation from existing patents. “In particular, none of the known designs can be regarded as naturally stable aircraft.”
Volocopter’s patent filing also cites a lack of “comfortable passenger entry in to the fuselage” as a concern with existing designs, mainly due to “the low vertical position of the propulsion and lifting system.”
“It is the object of the invention to propose a novel VTOL aircraft design which overcomes most if not all of the above disadvantages, thus achieving a VTOL aircraft with increased natural stability, increased aerodynamic efficiency, reduced weight, noise level and power consumption as well as better scalability,” the patent application states.
Volocopter’s emphasis to date on its VoloCity multicopter, a concept almost 10 years in development, is markedly different from the aircraft design approach taken by most other leading eVTOL developers, opting for lift-plus-cruise, tilt-rotor or tilt-wing concepts that deliver greater performance at the cost of complexity. Volocopter is betting not only that the simplicity of a multicopter will beat other designs to certification and to market, but that larger aircraft with four or five seats will be poorly suited to inner-city flying and produce too much noise for communities and regulators to accept.
Since 2018, however, a small team within Volocopter has focused on a winged, lift-plus-cruise design — depicted in the above patent application that was published in December — that would deliver greater range to address other potential markets. The vast majority of the company’s resources and talent remain focused on the VoloCity, which Volocopter believes will address 60 percent of the urban air mobility market, and that is not expected to change for the next five years.
Volocopter recently closed a €200 million Series D, though rumors continue to circulate that the company is considering going public via merger with a special purpose acquisition company (SPAC) later this year.