As technology progresses to simplify and ultimately expand access to flight and, more broadly, to vertical space for movement, it leads to adoption of flight into many new applications for which it was not previously suitable. These new applications will touch industries across the economy—some of which are being studied and planned for today, and many of which will be unforeseen and discovered by creative entrepreneurs.
With predictions that more than 65 percent of the world’s population will live in urban areas by 2050,1 demand calls for transportation modalities that can effectively serve the expanding urban and exurban market. This has implications for citizens’ quality of life as well as public services and commerce. Inadequate ground-based infrastructure supporting traditional mobility in and around cities could result in a $1.2 trillion national loss of gross domestic product by 2025,2 with commute times topping 90 minutes or more.
In the longer term, the second-order effects of advanced aerial mobility will impact real estate, land use and city planning, and numerous facets of modern society. This is not a new dynamic but a continuation of a centuries-long relationship wherein transportation shapes spheres of movement, interactions with others, ideas and opportunities and outlooks on society and the world. As such, developing a national vision for advanced aerial mobility, and a plan to execute and achieve it, is squarely in the national interest. The United States stands to benefit both by preparing for its adoption and by moving now to promote U.S. leadership in the technology and systems for this new industry as it builds out worldwide.
The national vision for advanced aerial mobility is based on several key findings and concepts reviewed throughout this study:
- Regulation for safety is inherent in the National Airspace System. It plays a necessary role in design, standardization, and operation of the National Airspace System.
1 U.S. Department of Transportation, “Smart City Challenge” (2016); Texas A&M Transportation Institute, 2015 Urban Mobility Report; Smart Cities Council, “Smart Cities Readiness Guide”; TomTom Traffic Index (2014); World Economic Forum, Strategic Infrastructure report; Deloitte Analysis.
2 U.S. Department of Transportation, “Smart City Challenge.”
- Safety is the highest priority consideration driving the design and planning of advanced aerial mobility system, and of integrating new technologies into the National Airspace System. Safety manifests in technical, regulatory, and societal acceptance issues throughout this space.
- Societal acceptance of advanced aerial mobility is a key factor driving the design and rollout of any advanced aerial mobility system. Acceptance of safety is key, but many other factors beyond the technical attributes of the system will drive how the public perceives, accepts, and adopts advanced aerial mobility. Strategically addressing the health and welfare, including psychoacoustic effects, of vehicle noise up front is a critical element for societal acceptance. Addressing privacy concerns is also key.
- The committee envisions that this will be a very complex system. The nation needs an organized and coordinated plan if it is to develop. A complex system-of-systems of this type will not self-assemble out of uncoordinated efforts.
- Cyber-physical security plays a critical role in the safety and resilience of any advanced aerial mobility system. Achieving cyber-physical security will require new methods, and it will have to be implemented throughout the system in order to support actual security as well as to build public trust in advanced aerial mobility. Public trust in autonomous systems involves security as well as transparency for the public, and this will be a pervasive theme as more autonomous systems (e.g., air, ground, and other) deploy in society.
- There is a reinforcing feedback loop of technology development and real-world flight experience as well as learning from applied operational experiences that is key to the progress of the vision.
- The possibilities of advanced aerial mobility extend beyond just urban air mobility (UAM) and while UAM will be a very large and attractive application and market, there are many useful stepping-stone applications that serve as important precursors to developing the sophisticated capabilities and industry maturation required to implement high-scale UAM.
- Infrastructure plays a key role in advanced aerial mobility deployments. The diverse new applications it will spawn mean new infrastructure—in some cases, infrastructure specific to the application. This infrastructure in many cases will be embedded with technology and connected into networks. This requires standards and partnerships with the private sector, as well as coordination across federal, state, and local bodies to ensure uniformity of regulation. Current standards have gaps and will need to be enhanced.
- Innovation and capital will take the path of least resistance, and industry can act quickly but only in response to clarity from regulators. This path of least resistance means identifying opportunities leading to an acceptable return on investment in the least amount of time. If regulation resists or restricts innovation, investors will not engage. If offshore opportunities motivate investment, it will be valuable to know that and encourage regulators to reassess how they are restricting development and deployment of advanced aerial mobility.
- Regulators and private industry play crucial roles, and these will have to evolve in the face of a new mission versus the orientation of the past 60 years of air mobility, which focused on ensuring safety in a gradually evolving National Airspace System dominated by commercial air travel.
- As new capabilities and flight operations are defined and permitted, private industry will develop technologies and products to fulfill them and will rapidly drive their application into numerous unforeseen areas where they create value. The operational experience gained from the applications and the resulting capabilities built throughout the supply chain and manufacturing base will feed into defining and meeting the demands of the next level of operational complexity, automation, and scale, which, in turn, will be developed and exploited by the private sector as the cycle repeats. However, succeeding in establishing this cycle requires a change in mandate, capabilities, and authority on the public sector side as well as more effective engagement with the private sector.
Recommendation: In order to formulate a U.S. Joint Advanced Aerial Mobility Master Plan, NASA and FAA should form a partnership to manage responsibility and accountability across the various stakeholders to participate in the development of the Master Plan.
There are many challenges that will have to be overcome to achieve the full potential that advanced aerial mobility technology offers. At the highest level, these challenges stem from the fact that the airspace system in its present form was not designed to accommodate the density levels and automated operations needed to make advanced aerial mobility viable.
In Chapter 1, success in achieving the advanced aerial mobility vision was framed as addressing a series of factors, including intrinsic aspects of the system such as safety, regulations, scalability, flexibility, and resilience, as well as aspects that take into account the externalities of environmental responsibility and societal acceptance. These factors are expanded upon in this chapter under a construct that considers the gaps in system characteristics of the airspace system today versus what it will need to evolve into, as well as barriers to achieving the vision and coordinating all stakeholders to define, develop, and deploy a very complex system-of-systems.
Early applications of advanced aerial mobility, such as those operating with less complexity, at lower density, and in more remote areas, will likely face fewer of the challenges outlined below. However, the most demanding applications such as highly automated, high-density UAM operations will emerge as the result of overcoming these challenges.
Gaps in System Characteristics
The success of advanced aerial mobility depends on introducing a new level of capability into the National Airspace System, including the airspace itself, communications methods, air traffic management (ATM) supporting high traffic density, integration of autonomous flight operations, and new types of infrastructure. All of these advancements will have to work alongside and integrate seamlessly with today’s manned commercial and general aviation air operations.
The committee noted a number of technical challenges, which impact safety, scalability, resilience, and other areas. Some of the specific aspects to focus on include the following.
Advanced aerial mobility must demonstrate the high safety levels expected by the public for modern air transportation systems. Safety in today’s National Airspace System is very high for commercial air travel. However, the smaller airplanes and rotorcraft in the general aviation fleet trail commercial aviation in safety, with a fatality rate that exceeds automobile travel (on the basis of passenger miles traveled). Many of the causes of fatalities in general aviation are operational and are due to human factors or inherent vulnerabilities of legacy aircraft such as their age. The ultimate goal for new systems is the best possible safety, and the committee does not believe that advanced air mobility systems that only achieve general aviation safety rates will be viable.
Safety management in the National Airspace System today builds margin around these vulnerabilities. Placing trained humans in the loop to manage safety and building in procedural safeguards such as traffic spacing requirements are both examples. Advanced aerial mobility introduces several underlying changes that correspondingly require new methods to be brought to bear in the approach to safety. Electric propulsion and increasing levels of automation may reduce the instances of certain causal factors but increase instances of other factors or introduce new causes altogether. Similarly, new technology introduced in ATM may experience a similar effect. The system-wide-level complexity of an airspace system supporting advanced aerial mobility can introduce unforeseen interactions that create new hazards to plan for and mitigate. Safely implementing this new capability in the airspace system will first require gaining experience in a low-risk environment and gathering data with which to learn and improve.
Security is already a high priority in today’s airspace system, but the approach and technologies employed will need to change and expand their footprint as advanced aerial mobility systems are scaled. The committee heard
from experts who highlighted the security gap around the need to prevent disruption to operations via attacks on digital communications links, the data that flows over them, or satellite-based positioning systems. Aspects of security today that are based on trust between humans such as voice communications between pilots and air traffic control (ATC) will need to be approached differently as digital links proliferate and potential points of attack from the cyber realm are introduced. Technology gaps also exist with respect to safely managing fallback navigation methods for autonomous systems in the event of global navigation satellite system outages or spoofing.
The committee did not focus on other areas of system-wide security for specific applications such as UAM, including security at vertiports or for air taxi passengers in flight, but acknowledges needed attention in these areas.
Resilience of a system is a measure of the ability to recover quickly from random or intentional disruptions while maintaining an appropriate degree of functionality. Fault Tolerance and Recoverability in today’s National Airspace System is based on a combination of redundant systems in aircraft and throughout the flight environment, as well as processes that rely on trained humans to respond to contingencies. Thus, fault tolerance and recoverability today are handled in some cases through design of systems and in other cases through operational procedures.
Similarly, advanced aerial mobility systems must be able to maintain required minimal functionality when components of the system suffer degradation or outage and have the ability to efficiently recover from contingency events or situations. This applies both at the vehicle level and across the airspace and throughout mobility systems where degradation in one part can have knock-on effects elsewhere.
In the initial implementations, the approach will be similar to today, through design of redundant systems as well as processes with humans in the loop to cover various functions throughout the system. However, as scale and complexity increase, this capability will increasingly need to be handled by systems designed for the task as scale and complexity pass thresholds exceeding the ability for humans to intervene directly. Collection, analysis, and dissemination of sound system reliability data will play an important supporting role here. Additionally, it will be important to consider security and human factor aspects in any potential solutions.
The majority of current communications between aircraft and ATC use voice spoken over VHF radio frequencies. Among the other forms of safety-critical communication in the National Airspace System is information exchanged between aircraft and traffic management systems through radar and transponders, as well as through transponders that communicate directly between aircraft in certain circumstances.
New communication methods are needed to support greater scale and also to support the requirements of unmanned or autonomous aircraft. The committee heard several proposed methods and communications standards that could meet this need. However, consensus around a method or set of methods to focus on has not been reached, nor has agreement been reached on which methods would be considered safety-critical under either nominal or off-nominal conditions. Depending on the application, differing views remain as to the order of communication, such as whether or when vehicles would communicate directly with each other or circumstances when all communication would be with a centralized traffic management system.
Uncertainty also persists with respect to the physical layer for communications links, with options ranging from LTE and 5G networks to satellite links, as well as purpose-built radio frequency links using either licensed or unlicensed portions of the frequency spectrum. Today, there is no globally accepted spectrum for autonomous system command and control. The development of standardized command nonpayload communication capability has been stymied as a result. Overall, a lack of a globally accepted communications architecture is a key gap to solve for and has follow-on impacts for choices and design around ATM solutions for advanced aerial mobility, including autonomous systems.
Integration of Autonomy into the Airspace System
Current airspace configuration, operational rules, and procedures did not anticipate the emergence of an autonomous aviation ecosystem. Introducing autonomous air vehicles carrying freight or passengers alongside manned aviation operations is highly complex. From a design standpoint, vehicles incorporating increasingly automated software capabilities will have to be designed, developed, and certified. Closely interlinked with design aspects, operations will have to be defined and procedures for the airspace system created to work with autonomous flight. These efforts require precise coordination and agreement on the exact overall capabilities the efforts are directed toward.
Current challenges to integrating autonomy into the airspace system include further research and development of core technologies as well as systems engineering to integrate the different components into a system that is field-able and able to support flight testing. Among the many examples of gaps within this field is the lack of detect and avoid capability, or the ability of the autonomous vehicle to remain “well clear” of other users of the airspace so as to not create a collision hazard that impacts safety. The committee heard that the defense community has made substantial progress in these capabilities in recent years and is a potential source of relevant technology transfer.
At present, operation of autonomous vehicles is generally relegated to segregated airspace volumes and over the most rural areas. The expectation is for introduction to continue in line with a trend that introduces new capabilities with respect to the overall risk profile that these operations present, initially favoring lower risk operations—for example, over sparsely populated areas. We envision the future air traffic system as having all classes of vehicles sharing principally the same airspace and that airways, approach routes, and technology will sort the traffic out and prevent conflicts. Ultimately, routine “file and fly” access—the ability to operate “at will” without the need for one-off special approval for each operation—to all classes of airspace, subject to constraints of airspace design and airspace use by other traffic, is essential to the success of later applications of advanced aerial mobility.
The scale of activity in the National Airspace System, at least with respect to commercial airline operations, has grown substantially over recent decades. The scalability of the National Airspace System is closely related to the density of operations it can support, and technological advances in traffic management, precision flight path following, and new procedures have increased the tempo of operations in the terminal area around large airports as well as in the en route structure. However, a major limiting factor in scalability remains the limitations of human operators throughout the system to safely manage the demands of handling additional density.
Overcoming these limits necessarily involves increasingly replacing human responsibilities in these roles with automation. This is a complex undertaking, as detailed in this report’s coverage of the challenges around autonomy, and involves technical, systems engineering, and human factors, among other considerations, in order to succeed. The expectation is that early applications of advanced aerial mobility will thus work within the scale limitations of today’s National Airspace System. However, a successful approach to advanced air mobility must have the capability to scale as markets for various applications emerge and grow. Technologies, operational procedures, and adjacent services will have to be flexible and capable to grow from the current levels of today to a robust global ecosystem.
Today’s airspace system is designed around very defined and well-understood flight operations and air vehicle types. The dominant mission types flown in the national airspace have remained relatively static over recent decades. Advanced aerial mobility fundamentally expands the viable applications for flight, and many of these applications remain unforeseen.
Flexibility is critical as new use cases are tried and tested and as operational concepts emerge. As new technologies are developed, changes to the system must integrate them such that maximum economic benefit can be realized without compromising safety or environmental responsibility. A flexible advanced air mobility system
will include a need for flight rules and procedures for routine operation in all classes of airspace as well as for ground operations.
Surface infrastructure to support aviation is built around the aircraft currently in the airspace, predominantly airplanes and helicopters. The majority of journeys are intercity trips of distances longer than what is convenient via automobile. Today’s air transportation mobility system is physically partitioned from other modes of transport, with passengers passing into and out of this system through highly controlled structures at airports and with the air-side of the infrastructure thoroughly segmented away from all external factors.
Likewise, the route structure, navigation aids, and approach and departure procedures are designed with today’s aircraft and travel patterns as assumptions. For example, airways and terminal approach procedures are designed for longer routes and do not support or envision short urban flights. Instrument routes for flights in inclement weather send aircraft on long roundabout routes and often require higher minimum altitudes than would be usable or practical for advanced aerial mobility vehicles on short urban trips.
Advanced aerial mobility, with its vehicle types ranging from small parcel delivery drones to larger cargo and passenger vehicles and with its different and varying movement patterns, presents significant changes to the types of infrastructure that will support it. More ground locations may be served using advanced aerial mobility systems than with airports today. These ground locations will be smaller and far more numerous than airports and will necessarily be more seamlessly combined with other transportation modes and in closer proximity to the general public, less able to partition and segment.
Yet today’s airports may see increased activity and undergo changes to optimize around new advanced aerial mobility traffic flows. Trip distances, routes, and altitudes will likely vary significantly from aviation today. Among the many configurations to explore for various applications, a common aspect is that a scalable system will be dependent on design and standards for ground infrastructure (e.g., vertiport design and spacing) and the ways that infrastructure connects and interfaces with the rest of the National Airspace System.
Financing for air transportation infrastructure is well-established, combining a mix of public and private sources to address both the airside (e.g., runways) and terminal-side (e.g., gates, concourses, etc.) for airports. Similar financing will evolve for new advanced aerial mobility infrastructure but will likely have different requirements and needs for support.
Airspace and Flight Data
For operations, there is a need for flight data gathering and dissemination specific to autonomous system operations, including microweather forecasting and reporting.
The committee did not focus on vehicles per se. However, propulsion system limitations were noted, including battery and hybrid technology options and recharging infrastructure. The recharging requirements will place demands on local infrastructure, although currently electric ground vehicles are placing demands on infrastructure and will continue to do so, providing an experience and industrial base that could benefit electric-powered aerial systems.
Barriers to Executing the Vision
The barriers to executing the vision relate to the coordination required in order to introduce innovation into the National Airspace System in a way that preserves safety and addresses the needs of all stakeholders. Given the increasing complexity of operations envisioned in the National Airspace System as well as the pace of innovation across the many disciplines relevant to advanced aerial mobility, this coordination is instrumental in determining
the pace of realizing the vision for advanced aerial mobility and the ultimate success it is likely to achieve. Some examples of these barriers are discussed below.
Advanced air mobility is a multidisciplinary challenge. The system-level complexities are daunting in many respects. Overcoming the hurdles will require collaboration between stakeholders from across different areas of specialty, both within and outside traditional aviation. No single entity will solve all the issues ahead. Government and private sectors will have to coordinate closely to enable each other and to achieve progress.
Aside from safety, one of the most important barriers to adoption of advanced aerial mobility applications and services is societal acceptance of this new technology and perception that the benefits it delivers outweigh the impacts it has on bystanders, the environment, and overall quality of life. The public’s perception of the various contributing factors to acceptance is as important as the factors themselves, and the interplay between them is very complex and can be subjective in certain circumstances. Environmental factors such as noise and visual annoyance from air vehicles to perceptions about privacy and a sense of trust in these new systems are all very important to plan for accordingly.
Studies conducted by Booz Allen Hamilton yielded some interesting data related to passenger acceptance and expectations.3 There is a perceived concern from the public about ride sharing in an aircraft with other unknown individuals. Survey data show public reticence to the idea of flying without an onboard pilot. There were overall personal security and privacy concerns among potential users of advanced air mobility.
The public brings preconceived notions about aspects of advanced aerial mobility that are important to consider. Noise and annoyance from commercial airliners or consumer drones disturbing the peace for beachgoers may be the baseline experiences for forming perceptions about advanced aerial mobility services that remain only in the planning phase today.
Debates over privacy have impacted progress in early applications, including drones. The number of state and local regulations in play have imposed a “patchwork quilt” of limitations and prohibitions, making expansion of advanced aerial mobility difficult.
Over time, the benefits to the public in overall cost and time savings as well as greater productivity and convenience could help overcome many of these concerns. However, they do need to be addressed upfront and in a purposeful coordinated way.
There are several barriers to executing on the vision that relate to the regulatory function. Regulations play an integral role in coordinating, standardizing, and ensuring safety throughout all parts of the National Airspace System. In the gradually evolving National Airspace System of the past 60 years that has supported the relatively static dominant application of commercial aviation, the existing regulatory function has succeeded in driving exceptional safety and improving efficiency.
Primum non nucere (first, do no harm) is the mantra of regulators across the globe. Regulators will want technology developed to support advanced air mobility to be compliant with all current and foreseeable future regulations and meet universally accepted performance criteria. But beyond this, advanced aerial mobility brings changes to the assumptions under which today’s regulatory function evolved and with it requires a new way that the regulatory function must work.
3 Booz Allen Hamilton, 2018, Final Report: Urban Air Mobility (UAM) Market Study, submitted to NASA on November 21, https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190001472.pdf.
Regulations will have to change to accommodate a new wave of innovation in aviation. New technologies must find a way to be certified. New, diverse, and constantly evolving applications of flight will displace the gradual evolution of commercial aviation. Flight will take place between highly granular destinations and over short distances that were never before considered economically or technically feasible.
Many changes are required to enable this, but regulations are notoriously difficult to change and implement. It is not uncommon for a decade or longer to pass before a new rule or requirement is adopted. Regulators are working around this by adopting a posture of risk-based approval for certain unmanned operations while operating within the current regulatory framework. The major concern is that at present, the risk cannot be determined for non-stochastic processes and designs that are new and have no historical basis.
These changes to enable advanced aerial mobility cannot occur on their own and cannot be accomplished by a single party—not even a regulator with the authority to do so. The recent rewrite of the Federal Aviation Regulations Part 23 certification rules is an example, bringing together regulators, industry and trade associations, standards development organizations, and others to complete it.4 Experience, data, and coordination between the public and private sectors are critical requirements to enacting change, and standardization plays a central role. The mandate within the public sector and regulatory function to pursue the technological progress that comes with advanced aerial mobility is the single most critical enabler to successful execution.
With respect to aircraft certification, this is one existing capability area that transfers well into the future requirements. However, changing flight standards or airspace architecture is a wholly different undertaking.
The large number of new entrants is notable in that a variety of firms are offering aircraft concepts targeting the advanced aerial mobility market. Many of these have never certified an aircraft for commercial (i.e., passenger or cargo) transportation. A new certification construct could greatly improve advanced air mobility market participation by these new, especially non-aviation, entrants, though it must be designed so that current safety standards are maintained within these new platforms.
The NASA UAM National Campaign program is a step in the right direction, especially the objective to “Accelerate Certification and Approval. Develop and assess an integrated approach to vehicle certification and operational approval.”5 This is especially important because the introduction of a new safety risk can stem from the vehicle design as well as the way in which it is being operated in the airspace.
The committee received information from the FAA showing that, in some cases, noise and other environmental concerns had delayed or totally prevented implementation of the Next Generation Air Transportation System (NextGen) needed to modernize U.S. air transportation. It was clear that noise concerns, founded on health and welfare impacts, are complex psychoacoustic issues. It is important to understand the direct environmental impact characteristics of advanced air mobility vehicles. It is just as important to understand the public reaction to these technologies.
Several presenters provided evidence about the importance of community outreach when implementing new aviation capabilities. Being able to communicate a vision that squarely addresses societal benefits is critical to successful implementations of advanced air mobility. The committee was briefed by several organizations on studies on the potential benefits and market size of implementing advanced air mobility. While elements of a compelling vision were evident, the assumptions were not always realistic, and the ability to accurately model the costs and benefits was not clear. Having a clear understanding of societal effects will enhance community outreach and help lessen the barriers to advanced air mobility implementation.
Finding: While certification of advanced air mobility vehicles and integration into the airspace system will be challenging, there are additional barriers to consider. Public acceptance of advanced air mobility, particularly noise
4 Part 23 establishes airworthiness standards for normal, utility, acrobatic, and commuter category airplanes.
5 See “UAM Coordination and Assessment Team (UCAT), NASA UAM Update for ARTR.” Presentation by NASA to the committee, May 22, 2019, p. 18. (Note: ARTR refers to the Academies’ NASA Aeronautics Research and Technology Roundtable.)
aspects, is perhaps one of the biggest challenges along with safety. Failure to address these issues could hinder advanced air mobility implementation.
Finding: Noise from aircraft, and other transportation modes, is a complex topic spanning acoustics, the physiological way humans experience noise, and the psychological perceptions listeners have of the source of the noise and what it represents to them. A large body of research spanning this area has been conducted over the past century, with learning outcomes relevant to modern aviation.6 Admittedly, noise from advanced aerial mobility vehicles will be different from noise from commercial aircraft or helicopters. Many of these vehicles will be powered by electric motors, which will be inherently quieter than jet engines or rotorcraft. However, aircraft noise originates from many sources including aerodynamic sources, propeller or rotor blades, and the complex and highly dynamic interactions between these. Electric propulsion does enable new propulsion possibilities that promise to change the character of aircraft noise and to reduce it overall. The degree to which this falls below the public’s threshold for annoyance remains to be determined and depends on additional operational and contextual factors. Annoyance caused by noise is not strictly related to noise levels. “New noise”—that is, noise in places where there was no noise before—causes high levels of annoyance to the public that experiences it. So it is to be expected that the introduction of advanced aerial mobility vehicles will lead to annoyance and adverse health and welfare effects. Understanding the nature of these effects is critical to successfully mitigate them.
Finding: Early applications of enhanced aerial mobility may include operations with a less intense acoustical impact on bystanders (e.g., less frequent operations in rural areas) and with strong positive social impact (e.g., emergency medical services, search and rescue, and disaster relief). These applications can be a valuable test bed to learn and refine low-noise operations as well as to actively shape positive public perception of the technology.
Finding: Advanced aerial mobility can bring about transformation in a number of industries (transportation, emergency response, and cargo/package logistics). However, it is important to ensure that societal benefits and costs of advanced aerial mobility implementation are well understood using scenario-based analyses to assist, as all the applications will most likely not be evident until deployment is under way and users adapt to new capabilities. Being able to communicate benefits will aid in public acceptance and community outreach.
Recommendation: Research should be performed to quantify and mitigate public annoyance due to noise, including psychoacoustic and health aspects, from different types of advanced aerial mobility operations. NASA should facilitate a collaboration between relevant government agencies—including FAA, Department of Defense, National Institutes of Health, academia, state and local governments, industry, original equipment manufacturers, operators, and nonprofit organizations—to prioritize and conduct the research, with responsibility allocated per a coordinated plan and accountability for delivery incorporated. The research should be completed in 2 years.
Recommendation: NASA should facilitate a collaboration with other relevant government agencies—the FAA, Department of Commerce, and Environmental Protection Agency—and industry—original equipment manufacturers and operators as well as academia and nonprofit organizations—to conduct scenario-based studies to assess societal impacts (e.g., privacy, intrusion, public health and welfare, transparency, environmental, inequity) of advanced aerial mobility vehicles and associated infrastructure. These studies should recommend a path to implementation that prioritizes maximum public benefits.
6 See M. Basner, C. Clark, A. Hansell, J.I. Hileman, S. Janssen, K. Shepherd, and V. Sparrow, 2017, Aviation noise impacts: State of the science, Noise Health 19(87):41-50. See, generally, the Pennsylvania State University website “NoiseQuest” at https://www.noisequest.psu.edu/. See, for example, National Research Council, 2002, For Greener Skies: Reducing Environmental Impacts of Aviation, The National Academies Press, Washington, D.C., https://doi.org/10.17226/10353.
Most, if not all, of the economic concerns relate to the scalability of advanced aerial mobility operations. Business case closure will be largely dependent on the cost associated with solving the aforementioned barriers and bringing cost to the consumer in line with traditional modes of ground-based transportation or by creating value with respect to the new locations it can uniquely serve or the time it can save. The value delivered to the consumer by utilizing advanced aerial mobility, whether it be for simple package delivery or point-to-point personal transportation, will define acceptance and economic viability. Value per seat-mile or freight cost per mile will be the metric by which businesses will be built. For air taxi operations, current estimates of per-seat mile cost for a two-person aircraft (like the example in Figure 2.1) average approximately $11 per mile.7 Early versions of air taxi operations using a five-seat electrically powered vertical takeoff and landing (eVTOL) air vehicle have an estimated cost of approximately $6.25 per mile.8 These costs are presently higher than a luxury car ride share. If the time savings to the consumer has value, the higher cost may be acceptable.
7 Booz Allen Hamilton, 2018, Final Report: Urban Air Mobility (UAM) Market Study, submitted to NASA on November 21, https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190001472.pdf; McKinsey & Company, 2019, Urban Air Mobility (UAM) Market Study, submitted to NASA in November.
The gaps and barriers outlined above address the differences between the National Airspace System today and what the community envisions it potentially evolving to in the long term. Taken as a whole, these challenges can appear dauntingly difficult to surmount from today’s perspective. The technologies that must be proven and integrated, the system-level considerations and input from stakeholders that are required, the coordination across public and private sectors, and the operational experimentation and buildup of experience that will inform the optimal working of the future National Airspace System can make it difficult to identify and agree on a starting point to begin moving forward.
Finding: It is important to consider a phased, iterative approach to development, testing, and introduction of new capabilities. It is not reasonable for a system of this degree of multidisciplinary complexity, with as many stakeholders involved (including the general public) and with regulatory involvement at every step, to self-assemble out of a mass of uncoordinated innovation efforts. Rather, coordination leading to interoperability and standards is essential.
The committee heard evidence to believe that viable applications of the technology and airspace system capability can likely be exploited even at the increments that are introduced. These incremental capabilities are directly constructive toward the systems required for UAM and the sooner they are fielded, the sooner experience with them is gained and further capability can then be introduced. The approach should, however, be flexible to react to and accommodate entrepreneurial advances that bring advanced capability faster than anticipated.
If a well-thought-out strategy is created to approach these challenges and break them down into more manageable pieces, then a coordinated effort is more easily achieved and several benefits result from easier coordination of stakeholders and standards development through to collaboration with regulators and the benefit of experience gained at each step to inform the next. However, for this approach to succeed, it must balance the need to coordinate around an organized plan with the need to be flexible to entrepreneurial approaches producing unexpected leaps forward in capability.
As a roadmap is created to guide coordinated efforts to overcome the gaps and barriers, due consideration should be given to defining each milestone such that it supports meaningful and usable new capabilities in the National Airspace System and that it generates practical data, experience, capability, and insights that inform the next milestone. Guiding priorities at each milestone should include safety, environmental responsibility, societal acceptance, flexibility, scalability, and open access.
The committee envisions a National Airspace System that continues to evolve as a system of systems. Its complexity, the diverse and evolving applications it will support, and its multidisciplinary nature means that its structure favors a modular and standards-driven architecture rather than being designed and built as a monolith. This is further reinforced because enhancements to the National Airspace System necessarily require development by stakeholders across the private and public sectors. As such, it must evolve on the back of standards that support coordination across stakeholders. Standards also serve to support future expansion of capability and growth while managing and encapsulating complexity.
The private sector possesses the resources, capital, and capability to execute on addressing the challenges posed by implementation of advanced aerial mobility at increasing levels of complexity and density. The private sector will have to be mobilized to deliver these innovations. However, they need clarity in terms of coordination and standards in order to define their own product roadmaps and allocate resources and capital to their implementation.
The public sector will have to engage with the private sector to proactively deliver the clarity that mobilizes private sector innovation. This can include (but is not limited to) the following:
- Defining National Airspace System capability milestones in terms of requirements sets.
- Defining agreed-upon detailed requirements that support technical implementations of systems in the National Airspace System and that support increasing capability and complexity of operations. These may
- include requirements describing automation levels, system structure, system component responsibilities, and so on.
- Driving creation of standards, in collaboration with industry, based on system requirements to detail the system protocols, data exchange, communications, interoperability, and other areas.
- Identifying and managing long lead-time research to support future capabilities.
For the public sector to succeed in this new mission, it will need to realign itself in terms of its mandate, capabilities, and authority. This aspect is covered further in Chapter 5 of this report.
If the right framework is created to enable private sector innovation, it will be possible to move faster to break down the complexity of advanced aerial mobility systems and build U.S. competitiveness in the process. The experience gained in applying advanced aerial mobility at each capability milestone to missions for which it delivers value will constructively feed into insights that inform development of the next level of capability. This follows historic precedent of other complex systems society has adopted and fulfills on the guiding principles of the vision.
The committee heard from a broad cross section of industry experts across a wide variety of fields, disciplines, and areas of expertise. Over the course of this study, it has become clear that the advanced aerial mobility market is poised for massive and rapid evolution and growth over the coming decade and that many other countries are viewing the advanced aerial mobility opportunity space as a potentially transformative societal element and emergent driving force of their economy. Mastery of advanced aerial mobility, given its wide-ranging impacts on society and the economy, will be one of the highlights of civilization. The size and importance of this vision means that governments are viewing it as strategic and taking various approaches to compete for leadership and prepare for its adoption. U.S. leadership in advanced aerial mobility is in no way assured, despite the nation’s strong legacy in aerospace. The new technologies enabling advanced aerial mobility are widespread across developed and developing countries. Their fundamental nature lowers the barrier to entry, despite the complex systems engineering involved. The subject of competitiveness is further explored in Chapter 3.
In sum, the national vision for advanced aerial mobility is an airspace system that can support high-scale flight operations supporting any number of applications, using vehicles small and large, carrying passengers or cargo, and operating over cities or in remote areas. This system will maintain the highest levels of safety yet be designed to be inherently flexible, supporting a diverse array of flight operations for any number of customized applications. It will be environmentally responsible, including minimizing noise effects, and be accepted by society and embraced as a new transportation mode. It will support the particular needs and characteristics of electrically propelled flight and eVTOL-capable flight. It will support both manned and unmanned aircraft as well as aircraft of all sizes. It will support a very large number of ground destinations and fluid flight operations between them. It will support all-weather operations tailored to the needs of this type of transportation system.
Fully realizing this vision may take many years. However, there are high-impact victories to be had at milestones along the way that will create valuable new markets, grow industries, and positively impact society. Progress will be achieved through a succession of increasingly complex and high-scale flight operations types, with each building upon the standards, technologies, and experience gained from those that preceded it. This succession will not be spontaneously self-assembled but rather will have to be designed and agreed upon by all stakeholders such that they build constructively upon each other and such that the private sector is given the clarity from regulators and national and international standards development organizations needed for them to deploy resources and capital toward these goals.