Given the key barriers to advancement, the evolution path and timeline for advanced aerial mobility applications remains ambiguous. There are many perspectives regarding the scope and size of the potential market space from which a few common themes have been extracted and correlated. The committee was presented with a wide range of various projected times in the future for advanced aerial mobility operational implementations of different types, each a snapshot of an isolated scenario. For example, initial urban air mobility (UAM) operations in 2022/2023, to 2028 to 2030 for viable markets for air metro and “last-mile” delivery operations, respectively.1 Advanced aerial mobility operations like those of a taxi service were not envisioned in the National Aeronautics and Space Administration (NASA)-sponsored UAM market studies as having a viable market in the 2030 time frame.2 However, these projections have significant sensitivity to their underlying assumptions and should not be taken at face value but rather considered as a tool for deeper thought about the steps required to achieve them. Rather than debate the timing, it is more informative to look inside the process and journey to get the milestone. From this we can more clearly articulate the challenges and thereby work to better affect the outcome.
While the committee has not developed predictions about the pace of advanced aerial mobility market evolution, it is likely that the market will develop in step with new capabilities that are incrementally introduced, such as when necessary vehicles, infrastructure, and operational procedures are developed, tested, and certified by airworthiness authorities. The Federal Aviation Administration (FAA) has endorsed the use of a “safety continuum,” in which the level of airworthiness certification is varied as a function of the risk of operations in which a manned or an unmanned aircraft will engage. Given that the FAA puts its highest priority on aviation safety, advanced aerial mobility operational implementation will most likely be evolutionary, slow and methodical, with regard to an increased operational risk profile, not revolutionary.
1 As characterized in marketing studies presented to the committee, air metro operations have predetermined routes and schedules, much like a bus network. “Last mile” is the final delivery of a product or service to the consumer. Delivering mail or a package to a door step dispatched from a nearby distribution site or even a delivery vehicle is the most common vision. “Middle mile” is movement of cargo or people to or from a terminal location to an intermediate location for further transport. Carrying a FedEx package from Memphis International airport to a distribution center for further delivery action is a good example.
2 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.
For example, air metro operations may well have their initial operational implementation with a pilot in the vehicle, working within existing regulations with regard to, for instance, “see and avoid” requirements and using the generally less sophisticated advanced aerial mobility traffic management infrastructure available in the early days. The committee was provided input from several participants in the advanced aerial mobility industry that are consistent with such an approach. As sufficient confidence is earned in air metro operations (via current operators such as UberCopter, VOOM, Blade, and others), as well as in their certified vehicles and the supporting infrastructure through operational implementation and experience, the stage will be set for greater autonomy of advanced aerial mobility vehicle operation.
In order to accelerate the eventual operational implementation of advanced aerial mobility, related research, development, and experimentation activities should have this type of market evolution in mind and seek to reduce uncertainties where they exist. Four particular opportunities are described below for this purpose.
As noted previously, a key infrastructure requirement for operational implementation of advanced aerial mobility is one or more systems that supply effective air traffic management (ATM) for operations not presently covered by voice-centric FAA ATM services.
The committee was provided updated information on NASA’s multiyear Unmanned Aircraft System Traffic Management (UTM) program. The UTM program has demonstrated four increasingly challenging technical capability levels for unmanned aircraft system (UAS) operations in low altitude airspace, most recently (in the summer of 2019) complex beyond visual line-of-sight operations in an urban environment for both nominal and contingency situations.
NASA is now looking at expansion of the UTM system concepts to advanced aerial mobility as a whole, including for emerging electric aircraft that could be “dually capable” to interact within the low-altitude UTM environment using the UTM construct as well as inside the current ATM environment with traditional (heretofore almost exclusively manned aviation) FAA air traffic control (ATC). Initially, support of such expanded operations might be achieved through effective interfaces between UTM and the ATM system. Long term, an integrated National Airspace System will be most efficient when capable of supporting aircraft operations of all types without the need for segregation to separate airspace for manned and unmanned traffic.
Alongside system architectural integration of UTM with the ATM system, the policy barrier of how UTM is to be financed has been a question that the FAA’s Drone Advisory Committee is addressing. As a roadmap to an integrated air traffic system is laid out, this issue remains relevant.
Finding: NASA has developed a promising concept for UTM, but is still in the process of extending this concept to include general advanced aerial mobility operations and integration with existing air traffic. Routine advanced aerial mobility operations above 400 feet in all classes of controlled airspace will require key infrastructure for operations not presently covered by voice-centric FAA ATM services. The committee is encouraged by early coordination with the FAA and industry on UTM.
Recommendation: NASA, in coordination with the FAA, should perform research to extend Unmanned Aircraft System Traffic Management concepts to accommodate emerging advanced aerial mobility traffic in all classes of airspace.
While the maturation and evolution of this overall market will take time, patience, skill, and investment in order to bring it to fruition, many of the stakeholders and early adopters appear ready now. They will not wait the decade or more that historically it could take the public sector for things to start moving. One potential solution might be to focus solely on a portion of the market that is more mature and potentially viable in the near term.
The cargo transport market for remote areas or over water may represent such an opportunity for advanced aerial mobility, providing realistic operations in lower-risk geographical areas. It frames many of the key seminal challenges that face this emerging market in a manner that makes them tractable and surmountable for test/implementation in a real-world environment—for example, reduced population density and minimal air traffic density. This forms the basis of a risk-based approach that begins with vehicle operations in remote areas or over water, later incorporating vehicles with people on board. Operations are then tested in more populated areas and last evolve to support passenger operations over urban areas.
The committee was briefed by several representatives of U.S. package delivery services, all with enthusiastic discussions of current investments and flight demonstrations. These are commercially driven entities that stand to profit from the increased delivery capability and reduced personnel costs of the envisioned systems. These briefings included discussion of the initial small aircraft, rural operations as experiments in vertical, autonomous operations that allowed development in more benign environments. But all of the representatives indicated that their plans included entry into suburban and urban environments as soon as FAA approval was granted.3
The committee found that the commercial entities already had significant sophistication as to cargo size needs and market forces that they had to respond to. The committee concluded that these commercial operators and investors were far more capable of defining the market size for each class of vehicle and that the fundamental issues to be defined and solved were universal to virtually all autonomous vertical vehicles.
Large Cargo Advanced Aerial Mobility operations. Current business plans for at least one original equipment manufacturer include developing a universal vehicle agnostic autonomous control and servo package that can retrofit into existing airframes, created partly by the Defense Advanced Research Projects Agency Aircrew Labor In-Cockpit Automation System program and currently in a convincing flight demonstration program. “Platform agnostic design supports multiple vehicles enabling mission tailoring,” according to one press release, so that there is strong market participation in creating autonomous air vehicles that, by dint of their current piloted participation in large cargo operations, will easily answer questions of the infrastructure for loading/unloading, and meshing of these autonomous operations with manned operations.4 While initial operations do not seem to be planned as electrically powered vertical takeoff and landing, these large autonomous vehicles will need to be part of the autonomous vehicle overall integration into the National Airspace System that is part and parcel of this report’s scope.
Small Cargo Advanced Aerial Mobility operations. The committee was briefed by the United Parcel Service (UPS) and shown video of current “drone” package delivery systems integrated into the classic UPS brown delivery trucks.5 It is clear that the market will define the payload capacity, range, and speed of small drones. As far as delivery methods in the “last mile,” (i.e., to the customer, which could be a household or business) the committee saw several examples. The commercial delivery experts who are developing the vehicles are certainly aware of the issues, and several innovative methods of home delivery in suburban environments are currently being flown.
In addition, this initial implementation could benefit from an inherent acceptance of baseline business cases owing to these clear advantages of demonstrating deployment on a realistic scale in communities that stand to derive credible value proposition. This idea has been developed, matured, and endorsed by key stakeholders such as UPS, Federal Express, and Amazon.6 These operators have initially explored these markets and unmanned cargo operations in detail, establishing a baseline perspective that these markets can be viably sustained. This greatly increases the committee’s confidence that these specific implementation areas are viable and promising first adopters of large-scale advanced aerial mobility deployment and associated technologies that enable the cargo delivery market.
3 A recent example of testing involves Federal Express; see FedEx, 2019, “Wing Drone Deliveries Take Flight in First-of-its-Kind Trial with FedEx,” October 18, https://about.van.fedex.com/newsroom/wing-drone-deliveries-take-flight-in-first-of-its-kind-trial-with-fedex/.
5 UPS, 2019, “UPS Flight Forward Attains FAA’s First Full Approval for Drone Airline,” October 1, https://pressroom.ups.com/pressroom/ContentDetailsViewer.page?ConceptType=PressReleases&id=1569933965476-404.
6 UPS has an approved but limited Part 135 approval to deliver medical supplies at the WakeMed facilities in North Carolina. The Federal Aviation Administration grants the authority to operate on-demand, unscheduled air service in the form of a Part 135 certificate. Air carriers authorized to operate with a 135 certificate vary from small single aircraft operators to large operators that often provide a network to move cargo to larger Part 121 air carriers. Many Part 135 operators offer critical passenger and cargo service to remote areas.
Focusing on a rural cargo delivery system could provide a number of benefits in the establishment of a broader advanced aerial mobility market. First, there is a compelling need to cover significant distances and circuitous routes with a reduced number of cargo assets. Second, several major air carriers have explored the viability of utilizing advanced aerial mobility vehicles for rural cargo delivery already. Some have even demonstrated how small drones and conventional delivery trucks can work in concert in order to achieve superior overall efficiency system-wide, reducing time and cost in delivering goods to rural customers (see Box 3.1).
Although the example above involving a pilot project in Raleigh, North Carolina demonstrates that test projects in urban areas are possible, they still present more hurdles than rural areas. The operation of rural cargo delivery service could allow operators to explore the societal acceptance levels of operating such vehicles on a regular recurring tempo and with increasing frequency. On a much larger and more impactful scale, these drones will face the same challenges but in a dense urban environment.
Last, rural areas offer the reduced population, vehicle density, and air traffic density that should lend themselves well to refining complex operations, allowing prototype UAS cargo logistics services to “work out the kinks” in cargo operations. This simultaneously provides a great benefit to the local community and allows a true advanced aerial mobility operation to be tested and vetted for future use.
Finding: A risk-approach to operations rollout can include a progression starting with cargo in rural areas and moving to people in urban areas. The rural cargo market appears to be a good match for early autonomous drone operations due to reduced population and spectrum density, minimal air traffic volume, reduced ground clutter
and ground obstacles, reduced operational risk, and the need to often cover long distances between points with minimal logistics footprint.
Finding: The commercial cargo market is ready to adopt an operationalized advanced aerial mobility capability as a cost-saving measure in order to derive greater efficiencies within its business space, particularly focused on deployment in rural markets and as a hybrid capability with its ground cargo distribution infrastructure.
Finding: The commercial cargo industry is potentially willing to fund/invest in technology development as required to do so. These operators have already conducted economic analysis that highlights potential break-even points within the next 1-2 years.
Finding: The economics and compelling value propositions to support the deployment of a cargo carrier UAS exists and has been quantified by commercial cargo operators.
Finding: The commercial cargo market appears to be a receptive, prepared, and very promising “initial adopter” of autonomous cargo drone technology/capability for rural domestic cargo operations. This posture is fueled by the need to enhance delivery throughput, increase cargo velocities, and define future competitive discriminators.
Recommendation: NASA should, within the next year, establish strategic partnerships with first adopter cargo logistics providers and relevant manufacturers. The partners should focus on maturation of technologies aimed at deploying autonomous cargo drone delivery of small, medium, and large size within 3 years.
RESEARCHING OPERATIONAL CONCEPTS OF INCREASING COMPLEXITY TO DISCOVER EMERGENT EFFECTS AND REDUCE UNCERTAINTY ON STANDARDS FOR OPERATIONS
Having heard from many technology providers, service providers, regulatory agencies, academicians, and original equipment manufacturers seeking to enable the emergence of a UAM marketplace, the committee is well-positioned to combine these pieces and assess the overall robustness and viability of the marketplace as a whole. In considering the various facets of this enormously complex technical, regulatory, and societal transformation, there is a disparity between stakeholders who have framed their perspective upon past lessons learned, proven standards of safety, and regulatory discipline, and ambitious “first movers” who are taking a principled (i.e., responsible and not reckless) yet far more aggressive approach to prove the viability of this emerging market.
This dichotomy is both empowering and concerning. The intersection between these two disparate perspectives is at the heart of the advanced aerial mobility marketplace emergence and revolves around approaches to managing risk in the pursuit of safety and system capability. Perspectives differ on where system-wide risks are expected, how experience mitigating risks applies, and how new technologies change sources of risk or instigate known and qualified risks. While there is broad agreement on safety objectives, the approaches to the underlying factors and components differ markedly, primarily driven by differences in past experience and familiarity with the various best practices, design and operating methodologies, and new technologies involved. Ultimately, the constructive intersection of these perspectives may define this sector’s ability to evolve to its full potential. There are many viable and impressive technology/platform providers but because they are new to the heavily regulated aviation industry, many of them do not have experience working with the authorities that will ultimately determine the fate of their autonomous mobility product offering.
Further, when considering matters from a global lens, the committee is concerned that the U.S.-based aviation industry may actually be at a distinct competitive disadvantage precisely because the domestic U.S. commercial aviation industry is itself so mature and well developed. Given its maturity, long track record of safety, and the high standards of regulatory management, the country may actually be at a disadvantage as this market emerges. One reason for this potential disadvantage is the possibility that early adopters across the globe may not feel as encumbered or obligated to operate these platforms and systems with the same rigor and discipline as will be likely required and mandated for operation in the United States. Much is still unknown about large-scale operations, the
robustness of the technological solutions being fielded, and ultimately the level of safety that can be achieved. As the industry gathers these data, it is imperative that sharing and collaboration take place on a global basis in order to ensure that all adopting regions have the benefit of the learning that is going on in any one portion of the market.
Finding: There is real risk that the United States may not act quickly enough from a regulatory standpoint to achieve the full potential of advanced aerial mobility. This may result in the nation essentially ceding a leadership role in the definition of the enhanced aerial mobility market segment in the near term if things are done as they have always been done or if this new air mobility paradigm is forced to fit within the current airspace system regulatory framework.
Beyond new air vehicles, advanced aerial mobility requires a vastly more capable flight environment. As discussed in Chapter 2, gaps exist between today’s National Airspace System and what the community will build. The task touches systems tying together air vehicles, airspace, surveillance, communications, and infrastructure. One question is where to begin and how to coordinate the process, given innumerable system interdependencies and needs of different stakeholders. Further, there is a question of how each participant gains the clarity needed to commit resources to build and contribute their part.
Clarity comes from an agreed goal and understanding of the big picture. The plan must be collaborative, involving public and private stakeholders. Beginning at system-wide scope, the community should create a high-level roadmap describing a progression of milestones, each a new capability for the airspace system (see Figure 3.1).
Systems in other industries have enjoyed a more passive evolution, converging on design by letting innovations compete, with the best rising to the top. However, the realities of the National Airspace System—with its low risk tolerance, public and private stakeholders, and strong regulatory involvement—make it unworkable to self-assemble new capability out of a mass of independent innovation efforts.
A capability roadmap guides to the standards that are needed. Standards are important for bridging from high-level requirements to detailed implementation. Through ongoing work, standards development organizations like ASTM, RTCA, SAE, ANSI (American National Standards Institute), and others are developing system and operational performance requirements leading to operational approvals and certification of UAS. Existing standards development processes include the creation of foundational concepts of operation and scenarios that describe an integrated airspace model supporting advanced air mobility.
While standards define specifics, they depend on the external context of a bigger picture for their requirements and constraints. A well-defined, high-level architecture that describes the system of systems, subsidiary roles and responsibilities, and the points of interface is critical to identifying where standards are needed and what they need to achieve.
It follows that the starting point is to collaborate on the capability roadmap. As a clarifying example, instrument flight is a capability the community has already built. Autonomous flight, in various forms, could be a future capability. The roadmap drives agreement on the vision and setting of priorities; it helps to identify gaps, while providing the clarity to enable commitment of resources to execution. However, balanced against clarity should be flexibility, in particular with respect to how the capability might be applied to new operations or business models.
Building new capabilities into the airspace system will be a stepwise journey. The historical progression of capability supporting instrument flight reflects this. Each future advance, whether for drones or piloted flight, can be thought of as a capability milestone. Milestones can break the larger problem down, reducing complexity, while the experience gained at each step can inform the definition and development of the next.
Getting the milestones right is critical. The selection of a milestone (i.e., the capability it delivers) is as important as clarity in requirements and the collaborative process by which they are derived. How feasible is the milestone? How useful will the milestone be in enabling new operations in the airspace? These considerations should be balanced. Each milestone must define critical requirements including roles and responsibilities, high-level architecture, and required performance levels.
The process to define a milestone should take input from all key stakeholders, including regulators, other affected parts of the public sector, and the private sector. The process should be conducted by those with authority to make decisions for the National Airspace System, and they should be held accountable for timely delivery of the milestone and its full set of requirements. A coordinated, purposeful approach to requirements and the roadmap can identify needs for standards earlier, yielding a better end result and saving years of time.
A goal should be to achieve consensus through a collaborative process that is held accountable for its progress, in order to move fastest. A goal should be to supply the private sector with the clarity needed to commit resources. With clarity, the private sector has proven able to define product and strategy and to deliver rapid innovation through commitment of financial and human capital.
A goal should also be to provide regulators with a structured performance-based safety case to enable them to commit to milestones and requirements early, thus driving further clarity for all other stakeholders. This buy-in early in the process is crucial.
Finally, milestones and their respective requirements should be very clear in support of the above goals but remain flexible to technical implementations, striking a balance between the need for an organized plan and the need to iterate and be flexible to entrepreneurial approaches that produce unexpected leaps forward. Through a performance-based approach to requirements, this can be achieved while also providing a clear pathway to integrating future improved capabilities.
In summary, the challenge becomes more manageable when the community first agrees on a roadmap of high-level requirements. Requirements can design-in safety by construction and build a performance-based safety case that regulators can get behind from the beginning. Clarity from the plan gains buy-in from the private sector, unlocking investment and creating a host of opportunities. The right plan is the biggest success factor to integrating autonomous flight into the airspace system in a timely manner.
Through ongoing work, standards development organizations like ASTM, RTCA, SAE, ANSI, and others are developing system and operational performance requirements leading to operational approvals and certification of UAS. The existing standards development process includes the creation of foundational concepts of operation and scenarios that describe an integrated airspace model supporting advanced aerial mobility.
Finding: Advanced aerial mobility will commercialize only based on clarity from regulators and the perceived risk of timely regulatory progress, which will be required to support given new flight operation types or applications. This is particularly true where operation types or applications depend on regulatory approval of new technology, increased automation, or other changes to the National Airspace System necessary to support the required scale or sophistication.
Finding: Urban air taxi service for the general public, due to its requirements for vehicle performance, safety, sophisticated operations, infrastructure, operating costs, and system scale and tempo, is one of the most demanding applications of advanced aerial mobility. However, it is an attractive application once the system capabilities are in place.
Finding: Numerous other applications that are less demanding can serve as opportunities to build experience and refine technology on the way to establishing the full set of capabilities required for urban air taxi services. These applications can also play an important role in establishing societal acceptance of the technology.
Finding: Near-term applications can include cargo delivery and surveillance operations in less densely populated areas. Applications can include emergency medical services (see Figure 3.2), first responders, disaster relief, corporate transport, cargo logistics, inspection of electric power facilities (e.g., transmission lines) in remote areas, and others. Given the new capabilities technology delivers to flight, the applications of advanced aerial mobility are wide-reaching and difficult to foresee.
Finding: A National Airspace System that delivers safety, access for increasingly autonomous systems, and scalability, yet that makes few constraining assumptions about specific anticipated flight operations, will deliver flexibility to explore applications of advanced aerial mobility and to adapt gracefully to future increases in scale and capability.
Finding: A definition of a series of successively more complex capability milestones and associated requirements sets including the architectural components of the system that will support them is needed. These requirements sets embody progressively more sophisticated operations in the National Airspace System that deliver increased capabilities and scale to the system and may touch vehicles, airspace, and infrastructure (see Figure 3.3). These requirements sets serve as a target for standards development and the systems based on them and ultimately
new flight rules sets for the National Airspace System. Architectural decisions include specifications sufficient for future standards and implementation development in areas such as the following:
- System architecture framework—defining the principal elements, functions, and interfaces of the system;
- Roles and responsibilities throughout the system;
- Communications—assumed communications capabilities including decisions for spectrum, data exchange, and cybersecurity standards;
- Approaches to adapting architectural function and components over time; and
- Evolution of existing safety evaluation approaches.
Recommendation: NASA should prioritize research that develops architectures, requirements, and supporting technologies to enable integrating advanced aerial mobility into a future National Airspace System.
NASA’s desire to develop a robust portfolio of technologies that enable mission agencies and commercial firms to create safe and effective advanced aerial mobility is challenged by significant market uncertainty, including uncertainty sourced from the emergence of nontraditional participants and their novel approaches, objective functions, and constraints derived from unique business models. By definition, highly entrepreneurial approaches are distinguished by their disruptive approach to perform some key function in advanced aerial mobility.
Therefore, it is important for NASA to document categories of disruptive effects and their interactions among effects to create a foundation for learning about, and then accommodating, these effects in NASA’s investment portfolio. NASA’s recognition of this appears to be a driver for creating the UAM National Campaign program.7
7 NASA changed the name of the program from Grand Challenge to National Campaign soon after this report was first released. The new name has been used in the final version of this report.
The stated goal of NASA’s UAM National Campaign program is to improve advanced aerial mobility safety and accelerate scalability through integrated demonstrations of candidate operational concepts and scenarios. This goal is supported by the following overarching objectives:
- Accelerate Certification and Approval
- Develop Flight Procedure Guidelines
- Evaluate the Communications, Navigation, and Surveillance Trade-Space
- Demonstrate an Airspace Operations Management Architecture
- Characterize Vehicle Noise
Flight experiments under the National Campaign are coordinated in design and execution with the FAA and industry participants. In particular, the experiments are structured around scenarios with specific outcomes that support the five overarching objectives. These scenarios are as follows:
- Scenario 1—Trajectory Planning and Compliance
- Scenario 2—Aircraft and Airspace Operations Management Data Exchange and Coordination
- Scenario 3—UAM Port Operations
- Scenario 4—Noise Evaluation and Response
- Scenario 5—Communication, Navigation, and Surveillance Contingencies
- Scenario 6—Air-to-Air Conflict Management
- Scenario 7—Constrained Conflict Management
The potentially large number of new entrants is perhaps most striking in the variety of firms offering aircraft concepts that target the advanced aerial mobility market. Many of these have never applied for certification for commercial (i.e., passenger or cargo) transportation; thus, they will find it challenging to deal with the FAA, and the FAA will also find it difficult to deal with these inexperienced companies. The NASA National Campaign program will be successful if it continues to evolve to accommodate these new entrants. This is especially important because new entrants can introduce new safety risks.
Finding: NASA’s continual refinement of the National Campaign program and scenarios based on feedback of industry as central players in the National Campaign experimentation is commendable (and essential) given the many opportunities (but unknowns) related to new entrants and entrepreneurial approaches.
Finding: One of NASA’s priorities for the National Campaign program is to pioneer the research, systems, and concepts of operations to enable advanced aerial mobility in the National Airspace System. This is a critical enabler with benefits for all, as it will assist in driving clarity from regulators with respect to system architecture, operations, and regulatory requirements. However, the structure and schedule of the National Campaign program to drive these goals means that many companies are either unable or unwilling to participate.
Finding: An additional outgrowth of NASA’s work in the National Campaign program is the generation of data, best practices, resources focused on advanced aerial mobility, and other findings that are valuable to all U.S. participants in the industry. If captured and disseminated effectively, these assets can accelerate progress across the industry and promote continued U.S. leadership in aerospace.
Recommendation: In partnership with industry, NASA should continue building on and enhancing the National Campaign program and develop its learning outcomes into formalized best practices, tools, resources, and training programs available to all U.S. stakeholders.
The next chapter addresses some of the most difficult issues that will face participants in advanced aerial mobility systems, notably how to achieve safety, security, and contingency management within the cyber environment.