The Future of Advanced Air Mobility
Ground Infrastructure

As its name suggests, the concept of urban air mobility (UAM) is focused mainly on providing a new dimension of transportation for cities, with their adjoining suburban sprawls being part of the equation too. And there’s some solid theory and geographical research behind the business model.

In a presentation to the 2019 Web Summit in Lisbon, Portugal, David Wallerstein, chief exploration officer with China-based technology group Tencent Holdings, explained why the company has made a bet on the UAM sector with significant investments in eVTOL startup Lilium Jet. His statistical big picture is that, by 2050, 65 percent of what by then will be a global population of 10 billion people will be living in cities—that’s 6.5 billion people. Today, it is reckoned that about 55 percent of the world’s 7.7 billion population already live in cities. On that basis, almost 2.3 billion people are set to move into cities over the next 30 years—almost 76 million annually, or the equivalent of New York City times nine.

With that, seemingly inevitably, comes congestion and cost. Wallerstein claimed that roads are now the world’s largest infrastructure investment with around $1.5 trillion being spent globally. And it’s not as if that’s buying much joy for gridlocked city dwellers and suburban commuters. This is where Tencent and many other investors see an opportunity for a new wave of aviation to be an agent for capitalist-driven revolutionary change.

Do cities themselves buy into this theory? Yes, said Wallerstein, claiming that Lilium and other pioneers have city leaders from around the world beating down their doors and asking to be part of the solution.

If that’s true, then it has to be said that most of these city leaders appear to have kept their expressions of interest out of the public ear. Cities including Dallas, Los Angeles, and Melbourne (Australia) are known to be collaborating to some extent with Uber in the ride-sharing giant’s plans to establish commercial eVTOL aircraft service from as early as 2023. Uber has been developing plans for so-called Skyports where passengers will embark and disembark from aircraft. It is also investing a lot of effort in computer modeling all aspects of how the aircraft will be operated, including optimized routings through these urban areas—taking account of other air traffic, such as helicopters.

Lilium Air Taxi approaching London landing pad
Lilium Jet is developing its own plans for city center bases from which its eVTOL aircraft can operate.

In October, with much fanfare, Volocopter and its UK-based partner Skyport unveiled a conceptual mock-up of their planned Voloport facilities in Singapore. The German eVTOL aircraft developer views Singapore as a likely early UAM adopter and is eager to demonstrate that aircraft can be safely operated in the city-state.

Perhaps tellingly, Skyports managing director Duncan Walker gave a very candid assessment of the challenges the UAM industry faces in getting city officials to support the development of infrastructure. On September 3, 2019, he told the Global Urban Air Summit at Farnborough in the UK that the support of Singapore’s civil aviation authority, transport ministry, and economic development board has been critical in expediting the approval process for building the vertiport. He explained that his UK-based company is working to develop eVTOL ground infrastructure with several aircraft manufacturers in the U.S., Europe, and Asia.

Volocopter's Voloport passenger facility in Singapore
Volocopter and its partner Skyports recently showcased a design for its planned Voloport passenger facilities in the center of Singapore.

“Generally, the regulatory process for [urban air mobility] ground infrastructure is a complete mess; there is no commonality in regulations, and we need to make better progress with this to achieve scalability worldwide,” said Walker. “The locations we have picked out for development has been driven more by politics, in terms of getting the right support from the authorities, rather than just economics.”

Walker shared the viewpoint of other summit speakers in indicating that social acceptance of eVTOL aircraft operations in urban areas is one of the biggest challenges facing the industry. “Social acceptance does not matter very much to [the authorities] in Singapore, and in China, too, they have a very different view of social acceptance,” he commented. “This business model will launch more quickly in societies that are more accepting of new technology and with a higher tolerance for risk.”

Volocopter's Air Taxi Voloport Interior
Volocopter’s planned Voloport ground facilities are intended to provide air taxi passengers with a place to safely and conveniently board its VoloCity aircraft in downtown locations.

By contrast, according to UK-based aviation consultant Darrell Swanson, city leaders in the UK capital London continue to be overtly hostile to, or at least skeptical about, any expansion of helicopter operations. This does not inspire confidence that they will be especially open-minded about their eVTOL successors, but maybe this is a nettle that the UAM pioneers need to grasp.

In fact, FutureFlight understands from sources close to Singapore authorities that officials there are not thrilled at the perception that they are looking to fast-track UAM implementation. They are reportedly frustrated at having been drawn into the hype surrounding Volocopter’s Voloport unveiling and brief flight demonstration of its prototype for the VoloCity aircraft.

On this basis, democracy could be an obstacle to UAM adoption. Politics apart, there are clearly multiple complex factors relating to ground infrastructure that need to be addressed before cities are in a position to fully embrace the new mode of transportation.

Indeed, leading aerospace group Airbus, which is laying its own plans for a family of eVTOL aircraft, argues that start-ups are trying to get the UAM industry running before it can walk. The European group argues that a completely holistic approach is required to laying the foundations for UAM, with a big emphasis on preparing all aspects of infrastructure and social acceptance.

Apart from the question of where the new generation air taxis will take off and land, there are wider questions about how their operations will be supported. Where will they charge or swap batteries? Can the electric grid support massive new energy demands? How about urban air mobility (UAM) maintenance facilities, emergency landing spots, parking areas? How much will it cost? Who will pay for the infrastructure and how? Will city neighborhoods welcome or reject this new era?

Then there are complex issues relating to how growing volumes of, for the most part, low-altitude air traffic will be managed in congested airspace. Who will control this air traffic? Will federal, state, and local agencies share power over them? Or should air corridors be auctioned to the highest bidders for a term of years? Management of this airspace comes under the heading of UTM, a nestled acronym for unmanned aircraft system/UAM traffic management.

Sticking with vertiport concepts, like Uber’s Skyports and Volocopter’s Voloports, there is very little information about what they will cost and even less clarity about how they may be regulated. There are no regulations for vertiports yet and nobody has an approval process for them, according to Jared Esselman, director of aeronautics for Utah’s Department of Transportation.

Show Me the Money

In his joint Web Summit presentation with David Wasserstein, Lilium Jet founder and CEO Daniel Wiegand showed impressive photos of ground facilities designed to support Lilium operations. One image included a launch pad built on a sun-kissed hillside next to luxury home with its own vineyard. Wiegand estimated the cost of developing a remote vertiport like this at around $500,000 and Wallerstein was quick to add that what he characterized as relatively low set-up costs would make eVTOL aircraft suitable for applications in the developing world.

In a report published in August 2019 by NEXA Advisors (with support from the influential Vertical Flight Society), forecast that over the next 20 years as much as $318 billion could be invested to bring UAM to 74 key cities around the world. The "Urban Air Mobility—Economics and Global Markets" report promises subscribers a detailed analysis of infrastructure needs and opportunities in major metropolitan areas and forecasts a projected growth path for each location in the period 2020 to 2040.

NEXA Report: $32 billion to be spent on urban air mobility infrastructure for 74 cities worldwide by 2040.

According to the study, the potential for developing urban air mobility in each metropolitan area is defined by what NEXA calls its “DNA,” which the company defines as “a complex blend of current transportation issues, congestion, population density, existing transportation infrastructure, regulation, business aviation, gross domestic product, local politics, per capita income, and a host of other issues.” The study uses these factors to determine the likelihood of any given city being either an early or late adopter of eVTOL aircraft.

“The report is also a first attempt to identify the cost of UAM infrastructure: $32 billion for all 74 cities by 2040,” explained NEXA Advisors’ managing partner Michael Dyment. “This is very affordable as potential revenues generated from this infrastructure will be in excess of $244 billion.

The anticipated investment in the UAM market includes infrastructure (vertiports and air traffic management), but also aircraft that Nexa sees being operated in the following five segments: airport shuttle services, on-demand air taxi, emergency services, business aviation, and regional point-to-point charters (of up to 250 miles).

EHang in Jilin, China
With the approval of Chinese authorities, EHang has been able to conduct trial operations with its 216 Autonomous Aerial Vehicle in cities such as Jilin (pictured here) and Guangzhou.

In the first instance, NEXA sees existing helicopter services being best placed to capitalize on rising demand for urban air mobility. The report predicts that Vancouver, Miami, Singapore, and a dozen other cities will accelerate investment in new approaches to urban air mobility from 2020.

NEXA views its estimates of infrastructure costs as conservative while indicating that they are not expected to be as prohibitively high as some fear. In its view, the cost for UAM infrastructure is relatively affordable compared with the ever-spiraling costs of expanding surface transportation.

Another assumption of NEXA’s study is that reliable automated (i.e. pilotless) flight operations will in perhaps 10 to 12 years from now. This, Dyment predicted, will enhance operational safety, enable vehicles to operate in closer proximity to each other and reduce operating costs.

In the U.S. many airports are owned by cities or counties, which could use municipal bonds as well as passenger facility charges to help fund construction of ground infrastructure, Dyment says. But funding sources also could include private capital.

In Europe, Dyment believes that if there’s an accepted public good from UAM, public funding will be made available. “But I think that in the U.S. the capital needed to build out the infrastructure will come almost exclusively from the private sector,” he told FutureFlight. “The feds are broke.”

In NEXA’s view, infrastructure is not going to be built in a city until it’s clear there will be operators to use it and bring in revenues, some of which will help to pay for it. Dyment thinks that in the next five years maybe a dozen cities will begin to have profitable services, but he didn’t specify which he believes these will be.

What’s in a Vertiport?

Vertiports are kind of a blank canvas at the moment, says Rex Alexander, president of consulting firm, Five-Alpha. With more than 18 years of experience in heliport design, he is a VTOL infrastructure advisor to the Vertical Flight Society. Perhaps vertiports could be described as “heliports lite,” he says. At this point he expects vertiports and heliports to be similar in terms of rules and regulations.

Dyment agrees that currently there’s “not terribly much difference” between a vertiport and a helipad. But the prefix “heli” implies the use of a gas-turbine or piston-engine helicopter that burns liquid fuel, produces a lot of noise, and is expensive to operate, he says. Facilities servicing conventional helicopters—and hybrid vehicles—have “heavy-duty” requirements regarding fire suppression, fuel storage, and fuel spills.

There are no vertiport design standards now, agrees Teresa Peterson, vice president of Gannett Fleming, an architectural and design firm and finalist in Uber’s 2018 competition to design UAM infrastructure. “That’s why we’re not rushing to build something.” There are no vertiports in the world yet because there are no standards, building codes, or fire codes, Alexander says.

Basically, air taxis are operating in urban areas today—helicopter operators like Blade, for instance—from conventional heliports. says Mike Hirschberg, executive director of the Vertical Flight Society. “The only difference needed to replace helicopters one-for-one with electric VTOL aircraft is the replacement of all fuel-related services with charging stations—and the associated fire-fighting and all the other support along with it, although that’s not trivial.” Vertical Flight Society executive director Mike Hirschberg told FutureFlight.

Vertiport costs are going to vary widely, based on factors such as the availability of utilities, Peterson adds. She has seen prices from $500,000 to $200 million. “We’re all moving very cautiously,” she acknowledged. Observers cite cost factors ranging from real estate and electrical power at one end to materials and finishes at the other.

The only difference needed to replace helicopters one-for-one with electric VTOL aircraft is the replacement of all fuel-related services with charging stations—and the associated fire-fighting and all the other support along with it, although that’s not trivial.

EVTOL Aircraft on helipad
New eVTOL aircraft should also be able to operate from existing helipads if these can be adapted to include essential features, such as equipment for recharging batteries.

The U.S. Federal Aviation Administration (FAA) says it’s not going to write a standard for vertiports until it has eVTOL aircraft performance data to base the standard on, Alexander says. It sent out a request for information to the manufacturers with a closing date of July 31, 2019. But the aircraft themselves are generally not mature enough yet to be ready for FAA performance testing.

Aircraft design factors are going to affect the full extent of what infrastructure is required, Alexander says. These factors include system redundancies, so that when something goes wrong, you’re not going to just fall out of the sky.

The American Society for Testing and Materials, now known as ASTM International, has a subcommittee under its F38 Committee on Unmanned Aircraft Systems, working on standards for vertiports to support manned and unmanned vehicles. It had hoped to have a consensus-based standard before the end of 2019, but that was unconfirmed as of November.

The subcommittee is looking at the criteria for airspace, for example. It’s possible that instead of an 8-to-1 approach/departure surface ratio—8 units horizontal to 1 unit vertical—the new technology may accommodate a little steeper slope, say 7 to 1, if the new aircraft are proven to be higher in performance capability than a helicopter. That would be significant because it would allow a smaller vertiport footprint on the ground and make it easier to place a facility in an urban environment.

Another group that will impact vertiport design is the International Code Council (ICC) with its International Building Code and International Fire Code. The National Fire Protection Association (NFPA) has NFPA-418, a standard for heliports. It also has started a task group to look at electric aircraft.

Hiding in Plain View

Early ground infrastructure is likely to sprout up from airports, parking garages, and parking lots. In the U.S. many UAM destinations will be airports, Dyment says. Helicopters, today’s urban air taxis, already provide service from Manhattan to New York City airports, so why not eVTOLs?

Pickard Chilton, teamed with the engineering firm Arup, presented a new vertiport concept at the 2019 Uber Elevate conference. This involves retrofit a parking garage intended for Melbourne, Australia, with two touchdown and liftoff pads (TLOFs) at roof corners and seven parking stations.

The design puts much of the hardware that might generate additional loads on the garage along the face of the building, with its own foundation, says Jon Pickard, a principal with the firm. On a sliver of land along the side would be built elements such as the “green light hub” lounge for Uber drivers (or rather pilots), passenger elevators, and TLOF support structures.

The TLOF support structures were necessary because complying with FAA standards allowing simultaneous independent operations would have put the landing pads at the outer limits of the Uber-specified garage dimensions. The structure the design adds to the garage allowed the pads to be “cantilevered out” from the flight deck yet to be fully supported. “We built up our own structure to make sure that it could handle the unique structural loads” of eVTOL landings, Pickard says.

The concept calls for the liberal use of photovoltaic panels to generate power and a “kit of parts” approach to hold down production costs and offer a common passenger experience. As part of a commitment to being environmentally sustainable, Pickard also stresses its use of “mass timber,” which is wood that is “engineered” to be nearly as hard as steel.

Bell Nexus EVTOL vehicles on rooftops
Bell says that it’s AerOS software will manage the safe operation of urban air mobility flights in cities, by ensuring that the new eVTOL aircraft are part of a wider “smart city ecosystem.”

Gannett Fleming has what it calls a PAW concept for vertiports. This consists of a module with one takeoff/landing zone and three parking pads that can be reoriented in various configurations, depending on the space available, Peterson says.

Corgan presented its Connect Evolved design at this year’s Uber Elevate conference. Its greenfield concept for downtown Dallas would place a mixed-use Skyport around an existing section of an elevated highway. The ground level of the facility—below the highway—would incorporate spaces such as a “connection plaza,” where passengers enter and can enjoy parks, fountains, shops, and restaurants, the company says. The site includes two TLOFs plus five parking/charging positions.

The concept aims to engage the community by bringing together divided neighborhoods. The design also would bring into productive use the real estate under the highway, which otherwise would probably be difficult to develop. In a Corgan white paper on vertiports, the company estimates the cost of the Dallas facility, incorporating all of Uber’s requirements, to be just under $50 million, with almost two-thirds of this total being accounted for by the “Skyport structure.”

The Corgan concept also would exploit the FAA’s low-altitude helicopter “skylanes” network for routing eVTOLs above rivers, major roads, and highways, the company says. The additional noise produced by the air taxis would merge with the familiar noise produced by helicopters and cars in this “existing noise corridor.”

Get Real About Real Estate

Air-taxi facilities will come in all shapes and sizes. An unserviced, not heavily used “vertipad” with one or two landing spots, for example, and a no-frills passenger shelter, with no recharging capability, could cost several million dollars, Dyment says, depending on factors such as location. But there will be a large cost range. Depending mainly on the price of real estate, in some cities it could be closer to $800,000 to $900,000, he says.

A multiport, or hub, by contrast, with multiple landing pads and parking spots, if built from scratch, might cost $10- to $11 million, Dyment says, whereas a repurposed garage might cost $2- to $6 million. In a pricey urban area like New York City, however, it could cost two to three times as much. A vertipad in New York City probably would need at least an acre of land, Dyment estimated, because there has to be enough area above the facility for vehicles to be able to maneuver safely.

Lilium FO004 Air Taxi approaching landing pad
INFRASTRUCTUREIn some cities, vertiport facilities could be developed as part of existing buildings, but costs would vary widely.

Land is just one factor. Before a project can be built, there will be spending on site selection studies, environmental studies, airspace studies, concession agreements, the securing of financing, construction permitting, the making of drawings and blueprints, and getting approvals.

If the facility is something more elaborate on top of a parking garage, there will be considerations such as elevators, passenger shelters with furnishings, automobile parking, lighting systems, passenger areas, landing pads and taxiways, electronic landing systems, IT systems, security systems, power grid upgrades, water systems, aeronautical chart preparation, systems for battery recharging and spares, and inspection costs, Dyment adds.

A vertiport would have to have water for bathrooms and fire suppression, with sufficient water pressure to get it up to the roof, Peterson explains. Retrofits may require the installation of new elevators, modifications to stairways, sound proofing, roof modifications, and ventilation systems. She expects that, just as with a transit or subway station, there also would be accommodations for people feeling unwell and interfaces to law enforcement.

Another possibility for siting vertiports, in areas where auto sales are down, could be car dealers’ “vast parking lots,” Dyment suggests. In his view, building a small vertiport in an empty parking lot, along with fire suppression capability, stairs, a waiting room, etc., might be possible in some places for as little as “a few hundred thousand dollars.”

Parking garages are generally overdesigned, Alexander claims. A garage may be designed for 15 stories but only built for 10.  People don’t live in them, so there would be less fire code to meet, he adds. And they are open, so air flows go through them. Fuel systems and electrical grid enhancements would also be easier to put into such places, he says.

If you have to build a vertiport from scratch, what else can you use it for? Perhaps a vertiport in a mini-mall, Alexander muses. In California, for example, people are repurposing malls with apartments and offices to increase their draw—and perhaps in part to compensate for revenue lost to online shopping. If they added a vertiport, the mall could become a destination people want to go to, he says.

Falcon Leonardo Terminal
Leonardo Helicopters has partnered with Abu Dhabi-based Falcon Aviation to develop a purpose-built terminal to support helicopter operations during the Dubai Expo 2020. The concept is intended to pave the way for eVTOL operations in urban areas.
XTI TriFan 600
XTI Aircraft’s TriFan 600 is being designed for longer-range flights of up to around 770 miles, but is still intended to be able to land in city centers for roles such as corporate transportation and emergency medical service.

Grid Issues

Vehicle charging systems are an essential component of the UAM infrastructure but may tax the electrical grid. Many observers put grid enhancement on their to-do lists. The potential costs, however, could be considerable. Charging a 4- to 5-seat eVTOL aircraft will require as much power as is used for a small grocery store, Hirschberg predicts.

The average commercial rate for electricity in the U.S. is $0.1051/kWh, Peterson says. She estimates that Gannett Fleming’s PAW concept—with three parking/charging pads and concurrent charging for three eVTOLs—could cost between $3,000 and $5,000 per day in electrical charges. A larger skyport, with 12 parking/charging pads could range between $15,000 and $17,000 per day. If the location is able to incorporate solar power or other renewable energy options, however, that could decrease their costs by reducing the electricity they draw from the grid.

 “While the power distribution lines…are typically 4160V or 13.8kV to serve residential and light industrial demands, we may need 34.5kV or 69kV lines to meet the power requirements for a PAW or skyport,” Peterson says. The cost to bring in a higher-voltage line can vary from $100,000 to $1 million per mile, depending on where the facility is going to be built and how difficult it will be to install.

Finally, if the required line voltages are not available within a reasonable distance from the proposed vertipad, she says, “we may need to consider a substation,” which would convert higher-voltage transmission lines to the line voltage required for the site. A substation could add an estimated $500,000 to $4 million to a project, depending again on the area and how difficult it will be to build, Peterson explains.

Since eVTOLs and charging stations are still in design, however, it’s difficult to come up with hard numbers for power costs in an urban community, she advises. These cost numbers “are all very rough estimates.” Much will depend on factors such as how quickly the eVTOLs will charge, how much power will be stored on-site, whether renewable power will be available, and how many hours each day the charging will occur.

Dyment predicts that initially vertiports will be located in industrial areas, where the electrical grid is stronger. A larger facility that needs to recharge dozens of batteries efficiently would need to have commercial electric service, he says.

Finding Space

In a previous job with Uber, as head of aviation infrastructure, Alexander looked at vertiports in Los Angeles. For example, how many existing heliports across the vast sprawling metropolis potentially could be used? In most cases the emergency helicopter landing facilities (EHLF) did not meet the standard for a heliport, he says. They didn’t have the right lighting and usually had obstructions.

In a place like downtown LA there’s only so much real estate to play with, Alexander says. You may have only enough room for one vehicle to land and maybe one or two parking places. A lot of older buildings don’t lend themselves very well to the conveyance of people; the elevator may not even go to the roof.

For the locations that might work there were issues such as structural integrity. Then there’s the question of whether you can get the electrical power you need up to the roof, not to mention getting enough water up to the roof. Retrofitting these buildings “gets real expensive real quick,” he says.

Hyundai Uber
South Korean car maker Hyundai Motor Company recently became the latest manufacturing partner for Uber’s planned Uber Air air taxi network. Its S4 aircraft is intended to operate in conjunction with its Purpose Built Vehicle to transport passengers to and from flights.

Regulations can be challenging, Alexander says. His advice to potential investors is to look at what’s on the books. The regulations may well be very restrictive and take a long time to comply with.

There is an opportunity to streamline some of the forthcoming standards, Alexander believes, by putting together a recommended state standard. A group that might be able to do that is the National Association of State Aviation Officials (NASAO). If they came up with a standard for the definition of a vertiport, for example, municipalities could adopt that language.

Early Days

It’s still early days in the UAM revolution. Consider the city of Los Angeles, which Uber has identified as a key U.S. launch site, with initial virtual demonstrations in 2020 and a workable system targeted for 2023.

The Los Angeles Department of Transportation (LADOT)—through a spokesperson—cites a technology action plan that references “urban airspace as part of the public realm of LA and the movement of flying vehicles as part of the larger transportation ecosystem.” The agency is working with the FAA “to identify a clear role for cities to complement the regulatory authority of the FAA.”

The LADOT expects that any possible air taxi facility would be subject to a public engagement process and would need to consider emergency management and existing infrastructure needs. The agency is working with industry to better understand potential quality-of-life issues like aircraft noise before launching a community engagement process. It has not started working on any specific regulations to date, as these will require information about air taxi impacts. LA currently does not have plans to fund any of the physical infrastructure for air taxis although the LADOT will explore the benefits of different funding approaches.

Utah and North Carolina: Local Airspace Management

Other jurisdictions are taking steps to welcome UAM, and not all of them are all that urban in nature. The Utah DOT, for example, is thinking not only about the first few air taxis, but also about the next thousand, Esselman says. He expects that package delivery will come first but that cargo and passenger services will use the same infrastructure and need the same things.

The DOT is looking at infrastructure foundations, such as mini active radar systems that would track not only connected vehicles but also rogue drones. A first step might be installing four or five of these “bricks” on a pole, he suggested. Covering a single county might require 15 to 20 of the miniaturized radar systems.

Real-time kinematic GPS provides far greater accuracy than the standard navigation technology. In addition, dedicated short-range communications (DSRC) or an advanced wireless platform would allow small amounts of data to be transferred very rapidly and seamlessly, Esselman says, allowing vehicles to communicate who and where they are. Weather stations would report on low-altitude conditions, and an aerial traffic operations center would monitor traffic.

Just as the state builds roads, it can build highways in the sky, he says. Utah already has designed a few air corridors. “Essentially we took a road map and elevated it into a 3D corridor,” Esselman explains.

Public funding of a vertiport, as with an airport, would bring benefits and assurances such as protection of the surrounding airspace and public access, says Basil Yap, UAS program manager with the North Carolina DOT’s Division of Aviation. Other considerations are zoning for flight safety and proximity to other modes of transportation.

He doesn’t expect that the federal government will be investing a lot of money in this area. It will be the states and local governments, he predicts, that invest in bringing the first flights to their jurisdictions. While the federal government owns the airspace, if the states are the ones that are investing, they’re going to want to have some say in how local, low-altitude airspace is managed, perhaps through shared jurisdiction.

Esselman contends that assigning companies exclusive rights to use air corridors—the way regulators license wireless spectrum—would be restrictive. Airways, as well as highways, should be “agnostic,” he says. “We don’t care who flies on them.”

Hyundai Purpose Built Vehicle
Hyundai's urban air mobility concept calls for so-called purposebuilt vehicles to transport passengers on the ground to connect with flights in its planned eVTOL aircraft. It recently unveiled a design for the vehicle cabin.

Esselman poses the case of a private company that builds a vertiport on its building’s rooftop. Can that company restrict access to its facility? If the air corridors are publicly managed, do the elevators in the building become part of the public transit system? Can an eVOTL make an emergency landing on a private vertiport?

“Our focus is on air traffic management,” Yap says. First, how to get drones flying beyond line of sight and determine where they fly. Then, how to get larger platforms to fly. And after that, how to add air taxis, he says. Like Esselman, he thinks that cargo deliveries probably will come first but that cargo and passenger aircraft will have very similar infrastructure needs. Both stress the need, with passenger service, to link to other modes of transportation.

In Utah’s traffic management infrastructure concept, the various components are “redundant to each other,” Esselman says. So, if something falls off of the GPS, it will probably still be visible on the radar system and be transmitting its identity and position via wireless communications. Passenger vehicles may also rely more on ADS-B than on GPS, he adds. These vehicles will be large enough to carry ADS-B equipment; that’s one of the things the state is looking into.

Exactly how the local, low-altitude airspace will be managed is something “we’re all going to have to come to grips with,” Esselman says. FAA manages airspace through rules and regulations, but “ultimately I see some sort of shared or delegated authority.”

FAA doesn’t have the budget or the manpower to manage the drone or electric vehicle air traffic flow, Dyment adds. The NEXA partner predicts that the agency will have oversight but will not provide hands-on management or funding. He envisions that cities are likely to grant concessions for UTM networks in their jurisdictions.

The Uber vision of hundreds of flights per hour is not going to happen right away, Alexander says. He envisions a crawl, walk, run evolution where an early iteration might look like a hub-and-spoke system supporting 50 to 60 vehicles. In Dallas, for example, air taxis could start with 6 to 10 vertiports, possibly expanding to 50 over a 10-year period.  

Is Market-controlled Airspace Access the Answer?

Just as regulators auction wireless spectrum licenses, the FAA could auction low-altitude air corridors to efficiently allocate public resources, says Brent Skorup, a senior research fellow at George Mason University’s Mercatus Center. “The FAA should consider demarcating aerial travel corridors and auctioning exclusive use licenses to VTOL operators for use of those corridors,” he wrote in a 2018 working paper. “You need a fair allocation mechanism, and auction is one way to do that,” he told FutureFlight.

The FAA should consider demarcating aerial travel corridors and auctioning exclusive use licenses to VTOL operators for use of those corridors.

Licensing air corridors would enhance safety, deal with the problem of UTM interoperability, help keep UTM technology up to date, and avoid giving first movers undue advantage, he says.

Exclusive use of an air corridor would simplify UTM issues because an operator would know that it would be the only one in its corridor. There would have to be enough corridors to allow competition in the local marketplace, he says. But exclusivity in a particular corridor would give the operator the certainty it needs to finance substantial capital investments.

Right now, Uber anticipates being the predominant UTM operator, Skorup contends. His proposal, however, would allow for multiple UTM providers, as different corridor users could choose their own. Under this plan, flight paths, terminal locations, aircraft size, UTM technologies, and pricing choices would largely be delegated to the licensees.

What about the restrictions to public access that this idea might entail? Airspace is already rationed – on the regulatory side, he says. Every airspace access system excludes people, but a market-based system would be less distorting. We also want to avoid the situation where scarce resources are underpriced, he says.