The rise of urban air mobility (UAM) and electrically powered vertical takeoff and landing (eVTOL) aircraft is arguably the most exciting technology to emerge recently in business aviation, offering the promise of transporting passengers and cargo over large metropolitan areas quickly and efficiently.
While development of such vehicles is proceeding at a rapid pace, it remains to be seen when we’ll see large numbers of eVTOL aircraft flying over major cities, as regulators and industry stakeholders work to develop the dedicated air traffic management (ATM) system necessary to ensure those aircraft operate safely.
“This is an entirely new direction for our industry,” said Paul McDuffee, business development executive for Boeing’s NeXt division on future mobility and vice chair of NBAA’s recently launched Emerging Technologies Committee. “I can assure you a lot of smart people are peeling away the onion layers and coming up with concrete suggestions.”
In addition to the FAA and joint industry/regulatory working groups, entities such as ASTM International, the global standards organization, are developing voluntary standards for UAM operators that could help shape future regulations. NASA also is working with these entities to define what a workable and safe UAM ATM will eventually look like.
“We fundamentally recognize there will be a lot more drones than manned aircraft operations in the skies, and we want to be able to accommodate them without overloading air traffic control or compromising manned aviation.”
Dr. Parimal Kopardekar Director, NASA’s Aeronautics Research Institute
“We fundamentally recognize there will be a lot more drones than manned aircraft operations in the skies, and we want to be able to accommodate them without overloading air traffic control or compromising manned aviation,” said Dr. Parimal Kopardekar, director of NASA’s Aeronautics Research Institute and a member of NBAA’s Emerging Technologies Committee.
That will require a new air traffic management system that operates quite differently than today’s ATC system, in which controllers are the only ones with information about all aircraft operating in their airspace.
“Instead, we need a ‘managed by exception’ environment,” Kopardekar said, “which is possible only with a digital network model in which all the aircraft are connected and sharing information about current operations and constraints, and the FAA is able provide restrictions to airspace operations and maintain situational awareness of all operations.”
Developing the ATM Environment
While ensuring the safety of UAM operations and proper separation from manned aircraft are critical steps in the process, developing a functional and manageable ATM system for eVTOL involves more than just airspace considerations – a city’s entire infrastructure will be affected.
“For example, consider the addition of a vertiport at an existing train station,” said Yolanka Wulff, co-executive director of the Community Air Mobility Initiative (CAMI), an organization that is supporting the widespread acceptance of UAM operations. “What happens if a light rail connection goes down, and you must divert the aircraft coming in to accommodate the multimodal connection? What do you do with a weather situation when commuters using UAM perhaps cannot fly? Those commuters must find a different mode that day. Those aren’t FAA issues per se, but it’s all interrelated.”
McDuffee also noted these potential transportation ripple effects.
“If we undergo a quantum shift in UAM propulsion to all-electric power, now we’re talking about additional demands on the power grid, on top of increased use by electrically powered automobiles and other ground vehicles,” he said.
“There is also significant concern about noise,” continued McDuffee, “with a lot of work underway not only to reduce its intensity, but also its frequency and nature. Studies need to be done on what the tolerance level will be over densely populated areas.”
Kopardekar noted another consideration that he believes has been overlooked by some people: the supply chain environment needed to support large eVTOL fleets.
“We’re not just speaking of the challenge of accommodating UAM vehicles,” explained Kopardekar, “but the need to design, manufacture, maintain and repair them. That will require a totally different manufacturing and supply chain network that scales closer to the automotive sector than what we presently have in the aerospace industry.”
As stakeholders grapple with these and other challenges, it’s clear that UAM operations will be phased-in gradually, with vehicles defined under what NASA terms “UAM Maturity Levels” (UML) ranging from 1-6, with higher numbers representing greater autonomy.
“Industry is fairly optimistic that we can accommodate the 2023 time frame for limited operations of vehicles below UML-4,” Kopardekar said. “As the scale picks up, however, we’ll obviously need a more sophisticated system.”
For the moment, discussions about the ATM environment for UAM are just that: talking over the challenges with teams of stakeholders working to identify possible solutions. The next step will be modeling and simulations to test out those concepts with all stakeholders – UAM developers, regulators and local communities – taking part.
“CAMI is involved through participation in several working groups tackling these issues,” Wulff said. “We’re also working with NASA to understand the requirements that metropolitan planners may use to overlay an ATM schematic onto their current planning software to model and simulate how to integrate UAM into their environment.”
From there, the process will evolve to actual flight testing.
“It’s hard to predict when that will happen,” McDuffee said. “People initially thought it would be a much easier task just 1-2 years ago, but we’re now hearing estimates of 10 years out, or more, before we see routine, scalable business operations with UAM.
“We see this as a market with tremendous opportunity,” he concluded, “but we’re speaking of adapting a new mode of transportation into a system never intended to accommodate these kind of operations.”
Review NBAA’s unmanned aircraft and urban air mobility resources at nbaa.org/uas.