Urban Aeronautics has redesigned its CityHawk VTOL aircraft while also confirming plans for the five-seat vehicle’s ducted fans to be powered by a combination of electric motors and hydrogen fuel cells. The Israel-based company is also introducing new flight controls and navigation systems and has started work on a new technology that incorporates changes from the version it has been testing for three years.
The new fuselage still features two of Urban Aeronautics’ patented Fancraft counter-rotating ducted fans to the front and the rear. Unlike most VTOL aircraft, the CityHawk has no wing or rotors, with most of the lift coming from the fans and a very limited contribution from the fuselage as a lifting surface.
According to CEO Nimrod Golan-Yanay, the design benefits from a reliability and safety perspective by having no external moving parts, reducing safety risk from factors such as ice accumulation and collision with powerlines. It also means the CityHawk has a smaller footprint, which the company says will allow it to operate to and from city streets and rooftops, subject to regulatory approval under existing Part 27 rules covering rotorcraft.
“Wherever you can park your car, I can land this aircraft,” Golan-Yanay told FutureFlight. “Wherever our competitors can land one [of their eVTOL aircraft], we can land four. This means four times the passengers and five times the revenues for the same infrastructure.”
The company has just completed a round of flight testing with the original technology demonstrator powered by a Safran Arriel 2N turboshaft helicopter engine. The aircraft, which weighs around a ton, has been operating fully autonomously at low altitudes of around 15 meters (49 feet) over rural terrain.
Urban Aeronautics is still evaluating the possible case for bringing a turbine-powered version of the aircraft to market early for specific applications such as emergency medical flights. Apart from passenger services, the company also sees CityHawk being valuable for cargo operations, with its 194 cubic feet of space for carrying freight and a maximum takeoff weight of 1,930 kg (4,246 pounds).
The redesigned CityHawk is expected to deliver a similar performance to the first technology demonstrator, with a range for a pilot plus four passengers of around 100 miles and speeds of up to 150 mph. Projected noise levels at around 700 feet would be around 78 dB that Urban Aeronautics says would be acceptable in city environments.
It is the desire to gain social acceptance for this mode of transportation that has prompted the company to make the switch from a gasoline-burning propulsion system to hydrogen-electric power. The plan is to integrate a pair of electric motors with new hydrogen-fuel cells being developed by California-based start-up HyPoint, with which Urban Aeronautics has been in a partnership since June 2020. The hydrogen will be stored in carbon fiber cylinders installed between the aft duct and the cabin.
Golan-Yanay, who joined the company in early 2020 and became CEO around eight months ago, said that it has rejected the idea of a battery-based electric propulsion system because it considers the available energy density from these to be insufficient to support the vehicle’s performance. He claimed that the CityHawk's hydrogen-based propulsion system will deliver 20 times the energy density of comparable battery-based eVTOL designs.
Urban Aeronautics hopes to be ready to fully launch the new version of the CityHawk in early 2022, starting with a technology demonstrator. It has not published a timeline for achieving type certification and bringing the aircraft to market for roles including intra-city passenger transportation and emergency medical support.
Other partners for the CityHawk include Kearfott, which is providing the navigation systems to support stable hovering at low altitudes in urban environments. The aircraft’s avionics suite is expected to be built around an as-yet-unspecified “simplified control system” and 360-degree sensors.
The existing technology demonstrator is fitted with Elbit Systems' EVS 4000 enhanced vision system. Urban Aeronautics says it is also working with the Israeli avionics group on a head-up primary flight display for the aircraft. The company also has partnerships in place with flight booking platform Ascent and vertiport developer Skyports.
Over the last six months, Urban Aeronautics has raised an unspecified amount of bridge funding that Golan-Yanay said is sufficient for it to keep advancing the CityHawk program. He is now seeking to raise between $50 million and $100 million. “This would take us to the next phase but would not be enough to complete the whole journey,” he explained.
That next phase would involve producing three production-conforming prototypes to initiate the certification phase, with further funding needs anticipated within a year or so to complete the approval process. Reflecting on reports earlier this year that the Israeli company might seek partnerships in the United Arab Emirates, Golan-Yanay indicated that this prospect remains a distinct possibility following the recent Abraham Accords diplomatic agreement. In addition to Israel, he identified Dubai as a potential early adopter location for eVTOL air taxi services.
Urban Aeronautics has made an agreement with Israel's Bazan Group to supply hydrogen for a planned demonstration project.