Perhaps the biggest hurdle related to the vehicles themselves centers around cost. “Building these vehicles needs to be much more cost effective than light aircraft are today,” says Goodrich. The UAM market will demand thousands of aircraft produced annually. But there’s a commercial risk, suggests Burak Uzman, general manager of Coriolis Composites USA, a provider of robotic cells and software for automated composite additive manufacturing. “Is there a business case for people to buy, lease or operate them?” asks Uzman. “That is highly dependent on the price tag of the air vehicle, and a lot of that will be driven by the composite airframe.”

The second primary area of consideration is infrastructure – everything needed to make the journey seamless from the take-off location to the landing location. This includes heliports, streets, elevators, buildings and more. “We are talking about an unprecedented level of integration of all these systems, both fixed and mobile infrastructure, in a way that is completely opaque to the users, but guarantees safety, reliability and availability,” says Hartman.

Another key component related to infrastructure is air traffic management – particularly if the vehicles transition from piloted to unmanned aircraft. “You can’t just take the unmanned piece and add it as a separate component of the manned traffic system,” says Shestopalov. “The manned traffic system is a different beast, where everything is manual and done via radios and monitors. Unmanned traffic systems have digital traffic management tools that will have to be integrated in.”

The final challenge – gaining public acceptance – is equally important to the hurdles associated with the vehicles and infrastructure. The introduction of a new modality of transportation into cities presents a host of societal barriers related to safety, privacy, noise and more. “UAM is an inevitable wave,” says Shestopalov. “The question is how do we get people on board more quickly? A lot of that has to do with proving out the technology and showing things can work – having use cases that are low risk.”

Vehicles and Enabling Technologies

Many groups are focused on “showing things can work,” developing aircraft and technologies that will enable UAM. These include three highlighted here – a UAM startup, a traditional aerospace manufacturer and a large government agency.

Lilium’s four founders all attended the Technical University of Munich. When they launched the company with the mission to create a revolutionary urban air mobility solution, the co-founders evaluated more than 20 existing aircraft concepts, from multicopters to tilt rotor aircraft. None were quite what they were looking for, so the engineers designed an eVOTL with 36 engines mounted on its flaps.