Amping Airpower — Electric Vertical Takeoff and Landing for the U.S. Air Force

These discussions provided information, insights, and perspectives that were critical to our research. Conversations with and in-person visits to eVTOL companies were eye-opening and provided a tangible view into the industry that we could not have gained otherwise. We also are grateful to major eVTOL investors who gave us their time and provided a contrasting set of concerns from those we heard otherwise. Within RAND, we want to extend special thanks to Thomas Light for his contributions to our eVTOL aircraft cost modeling; to Jan Osburg for his analytic review of this report; to Jeff Hagen, Michael Kennedy, and Jim Leftwich, who provided interim analytic reviews and advice that were extremely helpful; to Evan Smith, who took copious and careful notes for each of our discussions; and to Regina Kalasky for her careful review of the report and tireless copy editing. Outside RAND, we also thank Daniel DeLaurentis for his analytic review of this report. Finally, we extend gratitude to Frank Delsing, who came to us from the Agility Prime Program and advised our work as a RAND Project Air Force Fellow. Frank not only was able to provide insights into Agility Prime’s work prior to the start of this project but also joined with an extensive background on eVTOL technology and suppliers. This was invaluable and catapulted our baseline understanding of the eVTOL industry. That we received help and insights from those acknowledged here should not be taken to imply that they concur with the views expressed in this report. v Summary Background Billions of dollars from industry have been poured into the development of electric vertical takeoff and landing (eVTOL) aircraft for future urban mobility. The Air Force Research Laboratory founded Agility Prime to shape and accelerate the eVTOL market. In this report, we evaluate the utility the U.S. Air Force (USAF) might get from eVTOL aircraft, how much influence the USAF has on technical development and supply chains, and options for transitioning emerging commercial technology to the USAF to recommend an eVTOL strategy for the USAF. Approach This research involved a literature review, expert discussions, operation modeling, aircraft performance modeling, strategic modeling, and case studies. We leveraged eVTOL performance parameters, economic data, policy statutes, and background literature. The main outputs are measures of eVTOL military utility, forecasted military market share, the future eVTOL supply chain geography, and feasible transition routes that the USAF could use to adopt eVTOL aircraft. Key Findings • State of the technology and market: A revenue-generating eVTOL market is on the brink of emerging. Commercial viability hinges on sufficient charging infrastructure, pilot training, safety, and public trust. State-of-the-art eVTOL aircraft can carry a 1,000-lb payload for 150 to 200 nmi. Plausible future solid-state lithium batteries, lightweight hydrogen fuel cells, or a hybrid fuel-electric aircraft model could significantly increase that range or payload. • Utility to the USAF: eVTOL aircraft could benefit select USAF missions today, including replacing car transport of security forces at the Malmstrom Air Force Base missile fields. In a future high-end fight, such aircraft could provide operational support airlift for agile combat employment, for which transport aircraft, such as C-130s, are in short supply. eVTOL also confers resilience through runway and jet fuel independence. However, historical analysis suggests that eVTOL aircraft are unlikely to be transformational today, and we did not find a major command ready to sponsor an eVTOL capability today. Stakeholders suggested that autonomous flight and increased range, payload, and hover would enhance eVTOL attractiveness. • USAF influence on the market: USAF eVTOL demand will constitute a fraction of a percent of the projected total 2050 market, limiting the USAF’s ability to induce eVTOL company production of aircraft with defense-unique specifications or to mitigate various supply chain vi vulnerabilities. We found that future eVTOL supply chains will not be dominated by a single foreign nation but that certain countries dominate the manufacturing of important inputs, introducing security and reliability vulnerabilities. We also assessed that the USAF lacks other significant mechanisms to shape the future eVTOL market. • Strategic framework to inform future USAF investment: We developed a model to inform USAF strategy based on the technology’s military value and market sensitivity to military investment (a function of market share and opportunities for first-mover advantage). Agility Prime’s goals most align to a shape-the-market strategy, but the eVTOL market is not a good fit. Instead, a survey-the-market strategy is appropriate and low risk for eVTOL today. • Options to transition eVTOL technology to the warfighter: Technologies that do not align with a capability gap have limited transition options. Experimenting and using eVTOL aircraft for small-scale operations is the best path forward to collect feedback and showcase the technology. Many barriers exist to transitioning emerging commercial technologies, suggesting a need for the USAF to develop and test new acquisition processes before the next game- changing commercial technology is discovered. Recommendations Injecting capital into eVTOL firms is not likely to have Agility Prime’s desired effect of shaping the domestic eVTOL industry. Instead, Agility Prime should focus on two lines of effort (LOEs): • LOE 1 should lead acquisition and experimentation efforts and buy, lease, or acquire as a service a few of the most-capable eVTOL aircraft for small-scale operational use and live experiments. The aircraft can transport security forces at Malmstrom Air Force Base and maintain flexibility so that aircraft can participate in live exercises. Additionally, eVTOL aircraft can be used in virtual exercises and wargames. Feedback can be solicited from users and results can be socialized to avoid the defense valley of death. • LOE 2 should sustain relationships with eVTOL companies to foster nonmonetary collaboration in pursuit of autonomous flight. It can monitor the technology and market and share knowledge with interested government entities. Along with the Air Force Life Cycle Management Center Airworthiness Office, this LOE should support government entities working on eVTOL Federal Aviation Administration certifications, air traffic control regulations, and pilot requirements. Finally, it should broadly share knowledge about eVTOL supply chain risks to improve supply chain risk management for key inputs that are also critical for broader national security objectives. In addition, Air Force Research Laboratory’s AFWERX should use our strategic framework to weigh the next commercial technology to “prime.” The next technology should have high projected military utility and market sensitivity to military investment. Given finite resources, the USAF should take a utility maximization portfolio approach. Finally, the Office of the Secretary of the Air Force for Acquisition and Air Force Futures should develop tools and processes to prepare for adoption of the next game-changing emerging commercial technologies, especially ones that do not immediately align with a capability gap. vii Contents About This Report ........................................................................................................................................................... iii Summary ............................................................................................................................................................................. v Figures and Tables ............................................................................................................................................................ ix CHAPTER 1 ........................................................................................................................................................................................ 1 Introduction........................................................................................................................................................................ 1 Research Approach ....................................................................................................................................................... 5 Strengths and Limitations of This Approach ........................................................................................................... 7 Organization of This Report ....................................................................................................................................... 8 CHAPTER 2 ...................................................................................................................................................................................... 10 eVTOL Aircraft Today .................................................................................................................................................. 10 2022 Market Overview and Future Projections...................................................................................................... 10 Commercial Business Cases....................................................................................................................................... 13 2022 eVTOL Aircraft Capabilities and Limitations ............................................................................................. 14 Other Factors for Commercial Success .................................................................................................................... 18 Future eVTOL Capabilities ...................................................................................................................................... 21 eVTOL Technology Prospects ................................................................................................................................. 26 CHAPTER 3 ...................................................................................................................................................................................... 27 eVTOL Aircraft Utility for the USAF ......................................................................................................................... 27 Past Work.................................................................................................................................................................... 27 Our Findings of Operational Community Perspectives on eVTOL Aircraft .................................................... 27 Surface Transport at the Nevada Test and Training Range ................................................................................. 29 Missile Field Support Transportation ..................................................................................................................... 32 Agile Combat Employment ....................................................................................................................................... 39 Major Command Support Today............................................................................................................................. 44 Initial Conclusions ...................................................................................................................................................... 45 CHAPTER 4 ...................................................................................................................................................................................... 47 eVTOL Market Considerations for the USAF ........................................................................................................... 47 To What Extent Do USAF Technical and Supply Chain Requirements Overlap with Those of the Commercial Market?........................................................................................................................................... 47 What Is the Proportion of USAF Demand Relative to the Commercial Market? ............................................ 50 Where Will eVTOL Supply Chains Be Located? ................................................................................................. 54 CHAPTER 5 ...................................................................................................................................................................................... 63 A Strategic Approach to Future USAF Engagement with eVTOL Technology ................................................... 63 A Strategic Framework for Commercial Technology Opportunities .................................................................. 63 How Does eVTOL Technology Rate on the Military Value Scale for the USAF? .......................................... 68 Will eVTOL Transform Military Operations in the Future? .............................................................................. 70 How Does the eVTOL Market Rate on the Sensitivity Scale? ............................................................................ 72 viii How Does the eVTOL Market Compare with the sUAS Market? .................................................................... 73 Implications for Agility Prime................................................................................................................................... 75 CHAPTER 6 ...................................................................................................................................................................................... 79 Options to Transition eVTOL Technology to the Warfighter ................................................................................ 79 Options to Transition Emerging Commercial Technologies to the Warfighter ................................................ 80 Feasible Transition Routes for eVTOL Technology............................................................................................. 86 Applying Experimentation and Prototyping Lessons to eVTOL Technology .................................................. 87 Implementing a Survey-the-Market Approach....................................................................................................... 89 Improving DoD Acquisition Processes for Commercial Technology ................................................................. 91 Transition Conclusions .............................................................................................................................................. 91 CHAPTER 7 ...................................................................................................................................................................................... 93 Findings and Recommendations .................................................................................................................................... 93 Major Findings ............................................................................................................................................................ 93 Recommendations ...................................................................................................................................................... 97 Conclusion ................................................................................................................................................................ 102 APPENDIX A .................................................................................................................................................................................. 103 Previous USAF Analysis of eVTOL Utility ............................................................................................................. 103 APPENDIX B .................................................................................................................................................................................. 106 Stakeholder Input ......................................................................................................................................................... 106 APPENDIX C .................................................................................................................................................................................. 111 eVTOL Cost and Capability ....................................................................................................................................... 111 APPENDIX D .................................................................................................................................................................................. 118 Use Case Assessment ................................................................................................................................................... 118 APPENDIX E................................................................................................................................................................................... 131 Emerging Technology Case Studies ........................................................................................................................... 131 APPENDIX F ................................................................................................................................................................................... 139 Transition Mechanisms ............................................................................................................................................... 139 Abbreviations ................................................................................................................................................................ 141 References ...................................................................................................................................................................... 144 ix Figures and Tables Figures Figure 1.1. Timeline of U.S.-Based eVTOL Development and USAF and NASA Engagement.......................... 4 Figure 1.2. Overview of Project Approach ..................................................................................................................... 5 Figure 2.1. Cost to Move a Passenger 50 nmi as a Function of Total Passengers Moved ...................................... 17 Figure 2.2. eVTOL Range and Payload Trade-Offs Using State-of-the-Art Battery Technology ...................... 23 Figure 2.3. eVTOL Range and Payload Trade-Offs Using Future Battery Technology ....................................... 23 Figure 2.4. Future Hydrogen Fuel Cell Technology Compared with Current Battery Technology .................... 24 Figure 2.5. Future Hydrogen Fuel Cell Technology Compared with Projected Future Battery Technology ..... 25 Figure 2.6. Range and Payload Trade-Offs Using Hybrid-Electric Technology with Aviation Fuel................... 25 Figure 3.1. Locations of NTTR Entry Points, Associated Destination Locations, by Type, and Envisioned Vertiports at the NTTR with 75 nmi Range Rings ..................................................................... 30 Figure 3.2. Minuteman III Missile Fields ..................................................................................................................... 33 Figure 3.3. Location of Missile Silos and Missile Alert Facilities Relative to Malmstrom AFB ........................... 34 Figure 3.4. Missile Silo and Notional MAF-Based eVTOL Locations, by Squadron ........................................... 37 Figure 3.5. Potential Inspection Routes, Grouped by USAF Squadron Flight....................................................... 38 Figure 3.6. Locations of Airports in the Analysis, Philippines .................................................................................. 42 Figure 3.7. Locations of Airfields in the Analysis, Poland.......................................................................................... 43 Figure 4.1. World eVTOL Demand in 2030 and 2050, by Region and Sector, at Time of Writing .................. 53 Figure 4.2. 2018 Motor Vehicle Production, by Region ............................................................................................ 58 Figure 4.3. Motor Vehicle Supply Chains for the United States, China, and the World ...................................... 59 Figure 5.1. Emerging Technology Strategic Framework and Four Scenarios.......................................................... 65 Figure 6.1. Possible Transition Routes for Emerging Commercial Technologies .................................................. 81 Figure C.1. Passenger Movement Cost for Various Aircraft Within 25 nmi ....................................................... 114 Figure C.2. Passenger Movement Cost for Various Aircraft Within 100 nmi..................................................... 115 Figure C.3. Passenger Movement Cost for Various Aircraft Within 250 nmi..................................................... 115 Figure C.4. Cost Versus Capacity for Nevada Electric Highway Charging Stations .......................................... 116 Figure D.1. Distribution of Driving and Flying Times Between NTTR Entry Points and Destinations ........ 121 Figure D.2. Time Savings When Flying Versus Driving from NTTR Entry Points.......................................... 122 Figure D.3. Distribution of Travel Times by Mode, from MAFs .......................................................................... 123 Figure D.4. Distribution of Travel Times, by Mode, from Malmstrom AFB ...................................................... 124 Figure D.5. Time Savings When Flying Versus Driving from Malmstrom AFB ................................................ 125 Figure D.6 Distribution of Travel Times by Mode, Philippines ............................................................................ 126 Figure D.7. Time Savings when Flying Versus Driving from Bancasi Airport, Philippines............................... 128 Figure D.8. Distribution of Travel Times by Mode, Poland .................................................................................. 129 Figure D.9. Time Savings when Flying Versus Driving from Powidz Military Air Base, Poland ..................... 130 x Tables Table 2.1. Countries with at Least Four eVTOL Concepts Listed in the Vertical Flight Society Directory ................................................................................................................................................................. 11 Table 2.2. eVTOL Startups That Have Held Initial Public Offerings as of the Time of Writing ...................... 12 Table 2.3. Summary of Various Transport Aircraft, Helicopters, a Generic eVTOL, and a Ford F-150 Truck ........................................................................................................................................................... 16 Table 2.4. Estimated Vertiport Construction Costs ................................................................................................... 18 Table 2.5. Cost Estimates for Electric Charger Levels ................................................................................................ 19 Table 2.6. Estimated Vertiport and Charger Construction Costs ............................................................................ 20 Table 2.7. Estimated Performance Characteristics for eVTOL Aircraft ................................................................. 22 Table 3.1. Potential USAF eVTOL Aircraft Military Use Cases ............................................................................ 28 Table 3.2. Electricity Budgets at NTTR or NTTR-Adjacent Sites......................................................................... 32 Table 4.1. Overlap in Requirements Between USAF and Commercial eVTOL Customers and Implications for USAF Objectives....................................................................................................................... 49 Table 4.2. Financial and Consulting Firm Forecasts of eVTOL Demand............................................................... 51 Table 6.1. Emerging Technology Transition Case Studies ........................................................................................ 80 Table 6.2. Select Mechanisms for Routes to Transition ............................................................................................ 85 Table A.1. Agility Prime Requirements for Innovative Capability-Opening Areas of Interest ......................... 103 Table B.1. Summary of Interviews with USAF and Combatant Command eVTOL Aircraft Stakeholders ........................................................................................................................................................ 108 Table C.1. Summary of eVTOL Aircraft Capability for Leading U.S. Companies ............................................ 112 Table C.2. Sources and Assumptions for Other Platform Costs and Capabilities .............................................. 113 Table C.3. Costs for Nevada Electric Highway Charging Stations ....................................................................... 117 Table D.1. Time Savings for Each NTTR Entry Point, in Hours ........................................................................ 121 Table D.2. Drive Time, Flight Time, and Time Savings, NTTR ......................................................................... 121 Table D.3. Time Savings for Each MAF, in Hours ................................................................................................. 123 Table D.4. Drive Time, Flight Time, and Time Savings, from MAFs to Missile Silos ...................................... 124 Table D.5. Drive Time, Flight Time, and Time Savings, Missile Fields ............................................................... 124 Table D.6. Estimated Inspection Times for Each Route ........................................................................................ 125 Table D.7. Drive Time, Flight Time, and Time Savings, Philippines ................................................................... 127 Table D.8. Drive Time, Flight Time, and Time Savings, Poland .......................................................................... 129 Table F.1. Key Features of Select Mechanisms for Routes to Transition ............................................................. 140 1 Chapter 1 Introduction The Jetsons, an animated television show, premiered in 1962 and featured flying cars for character travel. In 1985, Back to the Future, a science fiction comedy, came out, positing a variety of prospective technologies, including flying cars for city travel. But the concept of small air vehicles for personal travel goes even further back—in 1939 the VS-300 helicopter took flight, and light personal aircraft, such as the Cessna 172 Skyhawk, have been flying since the 1950s. Individuals can obtain general aviation pilot licenses, but doing so is expensive and time consuming and requires runway availability. Helicopters allow vertical takeoff and landing (VTOL), but they are loud, notoriously difficult to fly, energy inefficient, and expensive to operate and maintain. Consequently, none of these aircraft matched, or match, the vision of the screenwriters, in which the general population can enter a vehicle near their homes and personally fly wherever they want to go without disturbing their neighbors. Although we still do not see cars flying around, there has been much quiet progress over the past 15 years in developing distributed electric propulsion and novel airframes that allow both vertical lift and cruise flight.1 Combined with a dramatic decrease in lithium-ion battery costs, progress toward battery-powered, light, VTOL aircraft has been rapidly accelerating and may very well lead to a new market in short-distance air mobility in the coming years, which has particular application to urban mobility. November 2009 marked a paradigm shift when the National Aeronautics and Space Administration (NASA) published a YouTube video showcasing a conceptual single-flyer electric VTOL (eVTOL) aircraft called the Puffin (Barnstorff, 2010). Two months earlier, JoeBen Bevirt had founded Joby Aero (now Joby Aviation) to explore the potential of electric aviation and, along with several other companies, set off to demonstrate that distributed electric propulsion could be useful and could one day become a commercially viable form of aviation. In 2016, Uber Elevate, a unit of Uber, focused on airborne urban mobility, published an on- demand aviation concept that would employ a fleet of VTOL aircraft to shuttle people around and between nearby cities, bypassing chronic traffic. These aircraft would be faster and safer than cars yet inexpensive enough to be used by the regular commuter. Critically, these VTOL aircraft would harness a large network of vertiports (hubs that would enable multiple takeoff and landing pads, along with fueling or charging infrastructure) and vertistops (single VTOL pads with minimal infrastructure). Unlike cars, these aircraft would be road-independent. Finally, these aircraft would be electric, allowing them to fly quietly over residential areas and be environmentally sustainable, 1 Aircraft powered by distributed electric propulsion have multiple propellers providing thrust and/or lift, each of which is driven by an electric motor. Some advantages of distributed electric propulsion include a higher motor power-to-weight ratio, higher efficiency than standard turbine engines, no need for a transmission, lighter weight, and environmental benefits. Because they have multiple simple electric motors instead of one or a few complex turbines, as on legacy aircraft, these aircraft also have more redundancy against failures, if designed right. If a motor does fail, it should be relatively simple to replace (Moore, 2016). 2 situating them for a future less dependent on fossil fuels (Holden and Goel, 2016).2 The Uber name gave the eVTOL aircraft taxi concept an air of legitimacy, and it generated buzz and excitement (e.g., Hirschberg, 2021). Uber Elevate did not go so far as to suggest that everyone would be flying their own eVTOL aircraft (thus, not actually reaching the level of personal flying cars) but did plant the seeds of real-life airborne urban mobility just around the time that commercial experimentation with eVTOL engineering designs was taking off. Since then, there has been a flurry of commercial activity in the eVTOL space. There have been multiple prototype eVTOL aircraft that, in combination, have flown tens of thousands of test flights,3 and more than one company has transitioned from prototype to production phase. Dozens of companies have eVTOL plans; as of June 2022, six companies had sufficiently mature technology and production capability to have gone public through mergers and special purpose acquisition companies, yielding a combined market capitalization of $15 billion (Esqué and Riedel, 2022).4 eVTOL engineering designs that enable both vertical lift and thrust throughout flight vary across companies but all feature the aforementioned battery-powered electric propulsion systems and, in theory, will one day fly autonomously. While the commercial success of any new industry or technology is not a guarantee, eVTOL companies and investors are pushing to bring the technology to large-scale production and are working with regulatory agencies, such as the Federal Aviation Administration (FAA) and local governments, to actually fly the novel aircraft in U.S. cities. The question of whether or not eVTOL aircraft will have a significant role to play for the U.S. Air Force (USAF), however, remained open. Answering this question is a principal purpose of this report. Historically, military investment in new technology has been an important source of innovation affecting both military capability and the broader civilian economy. Over time, the nature of this investment has changed: In 1969, the Mansfield Amendment was passed (National Science Board, 2000), limiting U.S. Department of Defense (DoD) investment in fundamental research. Particularly in the post–Cold War era, DoD has increasingly relied on contractors; and, in recent years, new technology pipelines have increasingly flowed from commercial industry to the military.5 Supply chains and financial markets have also become more global in recent decades, introducing an additional complication to the task of developing and procuring military capabilities: how to ensure a new capability provides an asymmetric advantage rather than a vulnerability through supply chain dependency on a potential adversary. 2 A recent acoustic flight test conducted by NASA on Joby Aviation’s eVTOL aircraft registered below 65 dBA at a distance of 100 m, which is consistent with the noise signature of a normal conversation and less than, for example, a vacuum cleaner, at 75 dBA (Boyer, 2022). 3 Now-defunct Kittyhawk claimed to have made over 25,000 test flights with its ultralight Flyer prototypes (Korosec, 2022). Wisk also claims to have made over 1,000 test flights (Wisk Aero, 2020). Beta and Archer have each conducted a small number of test flights in hover. International companies have also begun flight testing, including Lilium (Germany), Volocopter (Germany), and eHang (Japan) (Gettinger, 2022b). 4 Unless otherwise indicated, all amounts are in U.S. dollars. 5 For instance, according to data since 1953 from the U.S. Bureau of Economic Analysis and the National Science Foundation, the federal government’s share of total U.S. research and development spending peaked at a ten-year average of 65 percent from 1957 to 1966. Since then, it has declined to a ten-year average of just over 25 percent from 2010 to 2019. Over the same period, the U.S. business sector’s share of total U.S. research and development spending increased from an average of just under 33 percent to an average of 67 percent for the same ten-year periods (National Science Foundation, 2021). 3 History, however, may be reversing course. In 2015, DoD launched the Defense Innovation Unit Experimental (now the Defense Innovation Unit [DIU]) to facilitate adoption of, and investment in, emerging commercial technologies with military applications. In 2017, the USAF founded AFWERX to accelerate technology transition from the private sector to the USAF through partnerships with companies developing innovative technologies with potential military applications. Recent U.S. national security guidance has focused on technological superiority and leadership via investing in cutting-edge technologies (Biden, 2021). This may seem natural, given the realities of technology development being dominated by commercial markets, but it has also forced DoD to work closely with U.S. commercial entities to promote emerging commercial technologies and to shape, acquire, field, and sustain commercially developed technology for its own benefit. eVTOL aircraft represent a potential example of an emerging technology that the services could employ for military-specific missions. Recognizing this possibility, AFWERX issued a Request for Information on eVTOL technology to the fledgling industry in December 2019 to better understand the state of eVTOL development at the time (Swartz, 2021a). The Air Force Research Laboratory (AFRL) launched the Agility Prime Program within AFWERX just a few months later (April 2020) to “[e]xpand technology transition paths to accelerate emerging dual-use transformative vertical lift markets by leveraging government resources for rapid and affordable fielding” (AFWERX, undated). Will Roper, Chief Scientist of the USAF at the time, was a big proponent of Agility Prime, heavily motivated by Chinese domination of small unmanned aircraft systems (sUASs). Dr. Roper did not want to see the United States pushed out of the eVTOL space.6 Agility Prime was thus tasked with supporting the development of eVTOL technology within the United States and accelerating its transition to USAF operational use (see e.g., Hitchens, 2020b; Hitchens, 2020e). Today, this new model is the prime model,7 and Agility Prime was the first instantiation of it. A newer program, Orbital Prime, launched to reinvigorate the on-orbit servicing, assembly, and manufacturing market (SpaceWERX, undated). Figure 1.1 is a more detailed timeline of eVTOL development, emphasizing USAF and NASA engagement with the industry. As a part of the Agility Prime effort, AFRL asked RAND Project AIR FORCE to provide an assessment of the commercial eVTOL market and the technological status of eVTOL aircraft and their potential to enhance military missions and to provide recommendations on how Agility Prime and the USAF should proceed with eVTOL industry engagement. In this report, we focus primarily on eVTOL—the heart of Agility Prime’s work—although we do consider the increase in performance that hybrid fuel-electric aircraft could have, noting that these hybrid aircraft are not at the same level of maturity as eVTOL aircraft and are not options for near-term use. From the outset, policy options ranged from “do nothing” to “pursue a formal eVTOL acquisition program.” 6 We explore whether or not the Chinese domination of the sUAS market is an appropriate cautionary tale for eVTOL in later chapters of this report. 7 There is an equivalent program, called Space Prime, within SpaceWERX, the innovation arm of the U.S. Space Force. 4 Figure 1.1. Timeline of U.S.-Based eVTOL Development and USAF and NASA Engagement SOURCES: Features information from AFWERKS, undated; AFRL Public Affairs, 2021a; AFRL Public Affairs, 2021b; Barnstorff, 2010; Cohen, 2021; Guisbond, 2021a; Hawkins, 2021; Head and Ostrower, 2022; Hitchens, 2020a; Hitchens, 2020b; Hitchens, 2020c; Hitchens, 2020d; Hitchens, 2020e; Insinna, 2021; Kolodny and Josephs, 2021; Milligan, 2022a; Milligan, 2022b; Pritchard, 2020; Reed, 2022a; Reed, 2022b; Reichmann, 2021; Swartz, 2021a; Swartz, 2021b; Trick, 2020; and “USAF Initiative Agility Prime Demonstrates eVTOL Advances,” 2020. NOTE: AFSOC = Air Force Special Operations Command; AP = Agility Prime; Archer = Archer Aviation; Beta = Beta Technologies; ICO = Innovative Capabilities Opening; Lift = Lift Aircraft; NYSE = New York Stock Exchange; OSTP = Office of Science and Technology Policy; RFI = request for information; STTR = Small Business Technology Transfer program; TAA = Technical Airworthiness Authority. We also note that, while it is focused on USAF requirements for eVTOL technology, Agility Prime took a novel approach that could more generally help the USAF and the Department of the Air Force (DAF) address a set of challenges it faces with increasing frequency: how to (1) adapt a commercially developed technology with potential military applications, (2) proactively tackle risks stemming from globalized and commercially oriented supply chains, and (3) navigate the adoption of the technology by the warfighter. The Agility Prime legacy may therefore very well outlast its mission of facilitating USAF eVTOL adoption. 2017 2020 2021 2022 2023 AFWERX founded USAF began engaging with eVTOL industry Summer AFSOC suggested eVTOL to support distributed operations December February April May AFWERX releases ICO document AP virtual launch event AFWERX transitions to AFRL Joby and Beta move to ICO Phase III June USAF eVTOL TAA plan developed July AFWERX and AFRL host virtual TeamUp event August First demo flight through AP Due date for STTR program proposals September AFWERX relaunched as AFWERX 2.0 Winners of Civil Air Patrol AP competition announced October Expected date for awarding $150k Phase 1 awards Late 2020 AP team reaches 75 full or part-time members AFWERX "Accelerate" event Initial deadline for competitors to complete test flight Joby is first AP competitor awarded airworthiness approval December January March Potential OSTP interest in eVTOL Detachment 62 (Air Education and Training Command) stood up for eVTOL operation and maintenance training May First operational exercise using eVTOL system Beta is first AP competitor awarded airworthiness approval for crewed flight July USAF airworthiness approval for Kitty Hawk Heaviside system announced December Deadline for 2nd group of competitors to complete test flight First USAF remotely piloted eVTOL flight (Kitty Hawk) Anticipated start of full eVTOL production September 2019 Lift receives USAF airworthiness approval USAF transports eVTOL system on C- 130 August Joby goes public on NYSE September Archer Aviation goes public on NYSE 2009 NASA engineer develops “Puffin” eVTOL concept March May February Detachment 62 begins researching eVTOL pilot training First USAF onboard- piloted eVTOL flight (Beta) FAA revises eVTOL certification approach December “Air Race to Certification” application process closes AFWERX issues RFI on eVTOL capabilities USAF publicly expresses interest in eVTOL 5 Research Approach Figure 1.2 provides an overview of our approach. The blue boxes represent research tasks we executed; the green boxes represent an analytic activity; and the pink boxes contain data inputs for the tasks. As can be seen, we used a varied set of methods, ranging from purely qualitative, to purely quantitative, to mixed. We leveraged policy and literature reviews, discussions with key stakeholders and subject-matter experts (SMEs), quantitative and qualitative modeling, and case studies. Following this flow chart, we briefly describe how we approached each task. Full methodological details are provided in the subsequent chapters and in the appendixes in this report. Figure 1.2. Overview of Project Approach NOTE: MATE = multi-attribute tradespace exploration; OECD = Organisation for Economic Co-operation and Development; OICA = International Organization of Motor Vehicle Manufacturers; SIPRI = Stockholm International Peace Research Institute; USG = U.S. government;. Assessing Current and Future eVTOL Technology and Commercial Business Plans We started by investigating the current landscape of eVTOL aircraft by answering such questions as the following: How far can these aircraft travel? How does their cost compare with the costs of other aircraft or surface vehicles that have comparable performance capabilities? How close are these aircraft to gaining government approval for commercial flight? What does the current commercial market look like? We talked to experts and reviewed key references to enumerate the different 6 business plans and operational rollouts that companies are working toward. We surveyed publicly available eVTOL company data to delineate which companies are industry leaders, what entities have funded them and in what magnitude, and the level of maturity of their eVTOL aircraft. Finally, we modeled how much solid-state lithium ion batteries, hydrogen fuel, or a hybrid-electric propulsion system could increase aircraft performance parameters. Modeling eVTOL Aircraft Military Utility to USAF Use Cases Next, we interviewed a wide range of stakeholders across DoD and the U.S. government and reviewed prior reports commissioned by Agility Prime to determine a possible set of USAF use cases for eVTOL aircraft. We then modeled the trade-offs between eVTOL aircraft and other forms of transportation (helicopter or surface vehicle) for three particularly promising use cases that were of interest to the USAF operational community: test range mobility, missile field mobility, and agile combat employment (ACE) operations. The main outcome parameters we considered were time saved and cost accrued. The details of this model are located in Appendix D. We also investigated the cost and projected availability of vertiports (including requisite charging infrastructure) for both peacetime and wartime scenarios. Evaluating USAF Influence on eVTOL Market Simultaneously with the military use case and infrastructure modeling task, we used economic modeling to project the ratio of USAF (and military) demand to total commercial demand for eVTOL aircraft in 2030 and 2050. The relative scale of the commercial market to an upper bound of military demand illuminated to us how much influence the USAF could expect to have on eVTOL companies’ aircraft designs and supply chains. This is important because the USAF may desire different technical specifications than would naturally be included for commercial use cases. The USAF might also have more-stringent supply chain security requirements than a typical commercial consumer. Finally, while commercial entities will care about having reliable access to aircraft, the USAF must try to ensure it even during the most trying of times, when demand might actually escalate, such as during a war. We also modeled what a future eVTOL supply chain might look like geographically for both final production and for different inputs along the supply chain by drawing an analogy with automotive supply chains. Finally, we sought to understand whether there is a significant first-mover advantage for early successful companies in the eVTOL marketplace. If there is, USAF influence on these companies could have positive downstream effects in terms of inducing aircraft technical specifications or shaping the supply chain. Furthermore, much of the impetus of Agility Prime and its approach to the commercial eVTOL market stems from the assumption that there are significant opportunities for first-mover advantage within the eVTOL market. 7 Strategizing How the USAF Should Proceed with eVTOL First, for this task, we proposed a general framework that highlights distinct characteristics across emerging technology markets that, in turn, affect the USAF’s strategic choices. The framework employs two variables—military value and market sensitivity to military investment—to create four ideal-type scenarios, with each scenario driving a different strategy for engaging with a commercial market. Second, we applied this strategic framework to the case of the commercial eVTOL market specifically for the USAF, assessing the market along both variables. Toward this end, we relied heavily on our research from the previous two tasks. Market sensitivity to military investment was directly taken from the work on eVTOL market dynamics and first-mover advantage. Military value draws on our eVTOL modeling results across all three use cases and is augmented by review of the historical and theoretical literature focused on technological revolutions in military affairs. Proponents of Agility Prime have argued that eVTOL technology represents a revolution in aviation that will fundamentally alter future military operations. We looked to the relevant historical and theoretical literature to help weigh these claims. From this, we identified a strategy for how the USAF should engage with the commercial eVTOL market moving forward. Transition Mechanisms Given the results of the strategy task, we sought to determine the best routes to transition eVTOL technology to the USAF. To do this, we studied relevant policy and statute to enumerate all of the possible routes, which illuminated distinct entry points for eVTOL adoption. We also conducted a series of case studies to better understand how other commercial technologies have been or are being successfully transitioned to the warfighter. Each of these case studies mirrors elements of the eVTOL case and provides valuable lessons for how to succeed along the different technology transition routes. Finally, we considered different eVTOL purchasing options: outright buying, leasing, or acquiring as a service. Strengths and Limitations of This Approach While we believe our work is methodologically sound and defensible and provides a strong, relevant set of recommendations, no approach is without its limitations. To this end, we provide detailed caveats and assumptions throughout the report and provide broad strengths and limitations of our approach: • Strengths — Our overall approach and the strategic framework we propose that ties together military utility and market factors are systematic and repeatable and could be used again for other emerging commercial technologies. - Some insights are likely generalizable across commercial technologies—particularly those related to successful technology-to-warfighters transitions. 8 - We reviewed many assessments of the future eVTOL market, each of which had its own strengths, weaknesses, and assumptions. Not relying on one forecast increased our confidence in market predictions and eVTOL commercial viability. - We engaged a very wide array of stakeholders (across DoD, the Coast Guard, NASA, private eVTOL investors, and eVTOL companies). This was key to getting a balanced assessment of the current state of eVTOL technology and possible use cases for the USAF and commercially. - An interdisciplinary research team conducted the research, drawing from more than half a dozen disciplines including aeronautical science, chemical physics, economics, engineering, operations research, and political science. This synthesis facilitated a nuanced policy analysis and helps offset priors of different academic backgrounds. • Limitations - Every emerging commercial technology is unique. Many of our models and specific recommendations are not directly transferable to any other technologies. - Staff stakeholders shared their thoughts with us but were not able to share an official, staff-coordinated position on eVTOL technology. - Companies and investors have large stakes in the eVTOL industry and try to paint it in as positive a light as possible. It is not always possible to uncover the entire picture as an outsider. - Our access to economic data about the supply chains of other industries was limited. - The research scope was limited to U.S. eVTOL companies and USAF missions. Organization of This Report Chapter 2 describes the state of eVTOL technology today, the commercial business case, and how capabilities could evolve in the future. Chapter 3 presents our assessment of eVTOL military utility to the USAF and discusses infrastructure and charging costs and requirements. Chapter 4 contains economic modeling of USAF versus commercial eVTOL demand and an analysis of future eVTOL supply chains. Chapter 5 builds on Chapters 2 and 3, contextualizing eVTOL technology historically and assessing first-mover advantage. It draws on the sum of this analysis and applies the framework introduced above to identify an eVTOL strategy for Agility Prime. Chapter 6 presents transition routes for the USAF to adopt commercial technologies and suggests the best options for the USAF with respect to eVTOL. Chapter 6 also highlights lessons learned from a set of case studies that should help to optimize transition execution and considers different procurement options. Finally, Chapter 7 presents a summary of the major findings from the previous chapters and our set of recommendations to the USAF and to the U.S. government regarding future eVTOL engagement and policy. Five appendixes provide additional details. Appendix A presents a summary of previous USAF analysis of eVTOL utility. Appendix B provides a summary of our stakeholder inputs to this research. Appendix C provides assumptions and calculations used to determine eVTOL and other platform cost and capability, as well as more information on electric infrastructure requirements. Appendix D contains methods for calculating eVTOL aircraft utility for our use cases and 9 supplementary results of these analyses. Appendix E provides additional details of our emerging technology case studies. Finally, Appendix F imparts further details on transition mechanisms. 10 Chapter 2 eVTOL Aircraft Today Throughout this report, we attempt to analyze the role eVTOL aircraft could play for the USAF and answer the core question: “What should the USAF do with state-of-the-art eVTOL aircraft?” In this chapter, we start the process by laying out the state of eVTOL technological development, of eVTOL industry leaders’ business plans, and of other factors that we believe are important to successful deployment of eVTOL aircraft in a commercial setting. Although eVTOL companies have come a long way since 2009, when NASA published a video of a conceptual eVTOL, the fact remains that there are still many dimensions across which these companies must achieve further progress (that go beyond large-scale production of their aircraft) before people or cargo are going to be flying in them. One detail that is important to clarify at the outset is the eVTOL aircraft are a subset of the broader advanced air mobility (AAM) market.8 While there is no official definition for AAM, the basic premise is the integration of novel aircraft designs and flight technologies into airspace operations. Several types of aircraft fall under the AAM umbrella, including small, medium, and large unmanned aircraft systems (UAS) and medium-altitude long-endurance; high-altitude long- endurance; conventional electric; electric short-takeoff-and-landing; and, as we have already noted, eVTOL aircraft. While we focused our research on eVTOL aircraft (and briefly touched on hybrid VTOL aircraft), the eVTOL market picture can become blurred with bigger AAM data and statistics. 2022 Market Overview and Future Projections By many accounts, a revenue-generating eVTOL market is on the brink of emerging. Between 2010 and 2020, an estimated total of $4.5 billion was invested in eVTOL companies (Vertical Flight Society [VFS], 2022b). Perhaps even more striking, investment in eVTOL-focused companies went from $40 million in 2016 (Hader et al., 2020) to around $6 billion in 2021 alone (VFS, 2022a). As we will discuss in more detail, six eVTOL companies have held initial public offerings (IPOs), and at least eight companies across the world anticipate launching services that use eVTOL aircraft by 2025. Here we present a view of the 2022 eVTOL market first by platform design and then by investment in eVTOL companies. 8 While NASA is commonly associated with space exploration, its predecessor, the National Advisory Committee for Aeronautics, endowed NASA with a long history of aeronautical expertise. It is in this vein that NASA is an AAM pioneer: “NASA’s vision for Air Mobility Pathfinders (AMP) is to help emerging aviation markets to safely develop an air transportation system that moves people and cargo between places previously not served or underserved by aviation—local, regional, intraregional, urban—using revolutionary new aircraft that are only just now becoming possible” (NASA, undated). 11 Surveying the eVTOL Market by Platform Design VFS, an international nonprofit forum for the exchange of information on vertical flight technology, maintains a directory of known eVTOL projects (VFS, undated-a).9 As of January 14, 2022, the VFS directory identified “over 590 different electric VTOL concepts from nearly 350 companies and innovators” (VFS, 2022a). We used the data in the VFS directory to estimate the distribution of eVTOL projects by country and entity type. Forty-eight countries spanning the globe have at least one entity with an eVTOL concept listed on the VFS directory. Table 2.1 lists the number of concepts for the 16 countries offering at least four unique concepts. Table 2.1. Countries with at Least Four eVTOL Concepts Listed in the Vertical Flight Society Directory Country Number of Concepts United States 123 Great Britain 23 Germany 19 China 18 Canada 16 Russia 14 Japan 11 France 11 India 8 Italy 6 Australia 6 Turkey 5 South Africa 4 South Korea 4 Austria 4 Israel 4 SOURCE: RAND analysis of data provided by VFS. Thirty-seven percent of all listed entities are located in the United States. Approximately 87 percent of entities worldwide are for-profit, with the rest split about equally between academic and government entities. Just over one-half of worldwide entities were established specifically for the purpose of advancing eVTOL-related technologies or concepts. The rapid proliferation of eVTOL technology by companies worldwide is a promising sign for the future eVTOL market. A weakness of these data is that they do not provide details about the underlying engineering or aircraft designs for each project. Our general assessment of eVTOL companies’ intent (based on public claims, our interactions with certain firms, and our discussions with major eVTOL investors) is 9 VFS considers the directory authoritative (VFS, 2022b). It is located at VFS (undated-b). 12 that their aircraft will be quiet, nonpolluting, likely human-piloted in the near term but eventually autonomous. Surveying eVTOL Market by Investment Data Next, we looked at the best-financed and most-developed firms in the space—a mix of existing firms and startups dedicated to eVTOL technology. The information cited here was accurate as of this writing. Many of the world’s largest companies in the aerospace and technology sectors have invested in either internal or external eVTOL endeavors. A multitude of large aerospace and motor vehicle companies have invested heavily in the eVTOL space, including Boeing, Airbus, Lockheed Martin, Toyota, and Hyundai (Head, 2021a; Leonardo, 2021); major technology companies, such as Amazon, Google, Apple, and Facebook, have also thrown dollars at the industry (Doo et al., 2021). As already discussed, Uber played a major role in spearheading industry development early on through its Uber Elevate initiative in 2016 (Hirschberg, 2021). Where is this investment going? eVTOL-focused startups that are actually building aircraft have attracted a significant amount of capital. Table 2.2 lists the six eVTOL aircraft companies that went public between 2019 and 2022, for a total valuation at offering exceeding $14.5 billion. Additionally, some leading firms were private, such as Vermont-based Beta Technologies, which was valued at $2.4 billion in 2022 and had partnered with UPS and Amazon (Ohnsman, 2022). The German company Volocopter (whose eVTOL prototypes date back to 2011), had recently finished a massive funding round leading to a valuation of $1.87 billion and major partnerships with Honeywell, Mercedes-Benz, and Volvo owner Geely Holdings (Lunden, 2022). Table 2.2. eVTOL Startups That Have Held Initial Public Offerings as of the Time of Writing Company Headquarters IPO Date Approximate Value at IPO ($B) Archer Aviation United States September 2021 1.7 EHang Holdings Limited China December 2019 0.7 Eve Air Mobility Brazil May 2022 2.4 Joby Aviation United States August 2021 4.5 Lilium Air Mobility Germany September 2021 3.3 Vertical Aerospace United Kingdom December 2021 2.2 SOURCES: Archer Aviation (Mozée, 2021); EHang Holdings Limited (Renaissance Capital, 2019); Eve Air Mobility (“Eve Urban Air Mobility, LLC Completed the Acquisition of Zanite . . . ,” 2022); Joby Aviation (Alamalhodaei, 2021b); Lilium Air Mobility (Quell Acquisition Corp., 2021); Vertical Aerospace (Manthey, 2021). NOTE: EHang also sells a UAS, but its primary objective is to supply passenger eVTOL platforms. 13 No firm had substantial revenue-generating eVTOL operations, and a majority of industry executives were anticipating operational rollout somewhere between 2025 and 2030 (Hader et al., 2020). At least eight eVTOL suppliers anticipated commencing operations by 2026.10 There has also been substantial investment in other technologies and services needed to commercialize eVTOL aircraft. Consulting firm Roland Berger delineates the “eVTOL ecosystem” into five distinct elements (Hader et al., 2020): 1. aircraft 2. maintenance, repair, and overhaul 3. flight operations 4. building and maintenance, repair, and overhaul of physical infrastructure, including for takeoff and landing, charging, and passenger hubs 5. digital infrastructure for air traffic control, navigation, and customer ticketing. Existing and new companies have entered each of these ecosystem elements.11 For example, Raytheon and Harris are targeting eVTOL air traffic control technology (Jonas et al., 2018), and helicopter and charter jet booking company Blade Urban Air Mobility is partnering with Beta (Blade Urban Air Mobility, Inc., 2021), Wisk (Alamalhodaei, 2021a), and Eve (“Blade to Use eVTOL Air Taxis from Eve . . . ,” 2021) to lay the groundwork for eVTOL operations (Head, 2020). Despite all this investment in eVTOL companies and eVTOL adjacent technologies, analysts anticipate that global eVTOL markets will take decades to scale (Jonas et al., 2021). There are many reasons for this. The National Academies of Sciences national blueprint for AAM identifies numerous developments to air systems management technology and infrastructure needed to expand operations beyond the small-scale initial rollouts (National Academies of Sciences, Engineering, and Medicine, 2020). Analysts also anticipate a dramatic consolidation in the number of firms in the marketplace as certain eVTOL aircraft models start to outperform and/or outsell others and as successful operations, or lack thereof, catapult some companies to victory or failure (Hader et al., 2020). Commercial Business Cases As companies developing eVTOL aircraft have matured and attempted to distinguish themselves from one another, operational rollout plans have become further refined. Dominant use cases can be broadly categorized into (1) passenger and (2) cargo movement. Where, exactly, people will fly, whether or not aircraft will be shared by passengers who do not know each other, and the type of the 10 EHang anticipated commencing commercial operations in China by the end of 2022 (Patterson, 2022a). Eve anticipates commencing commercial operations in 2026 (Araujo, 2022). Six firms anticipate commencing commercial operations in 2024: Archer (Garsten, 2021), Beta (Ohnsman, 2022), Joby (Shepardson, 2022), Lilium (Quell Acquisition Corp., 2021), Vertical Aerospace (Manthey, 2021), and Volocopter (Lunden, 2022). 11 While many eVTOL makers are highly vertically integrated at this early stage of development, an increasing number of suppliers are being drawn to the sector. Honeywell, BAE Systems, and Garmin are some of the conventional aerospace suppliers that have announced agreements with eVTOL developers (Gettinger, 2023). Startups focused on enabling technologies are also working in the eVTOL space; for example, Daedalean, a Swiss company, is developing autonomy systems based on computer vision (Whittle, 2020). 14 cargo carried all depend on the vision of the eVTOL company. In this section, we highlight publicly stated business plans of eVTOL industry leaders that were current as of this writing. Passenger Movement Going forward, urban mobility remains a core business case for eVTOL companies in the United States and abroad. Joby Aviation says its S4 aircraft will provide “electric aerial ride sharing,” primarily in urban areas, such as Los Angeles and New York City (Joby Aviation, undated). This is quite similar to the Uber Elevate vision published in 2016.12 Archer Aviation’s stated mission is to “advance the benefits of sustainable air mobility” (Archer, 2021a). In 2021, United Airlines announced a $1 billion deal to purchase a fleet of Archer aircraft (pending FAA certification and realized aircraft performance) for its vision of “using zero-emission air taxis to ferry passengers on short flights over gridlocked cities to hub airports” (Patterson, 2022b). Wisk Aero describes itself as “an urban air mobility company dedicated to delivering safe, everyday flight for everyone. Wisk’s self-flying, eVTOL . . . air taxi, will make it possible for passengers to skip the traffic and get to their destination faster” (Wisk Aero, undated). Cargo Movement Beta Aviation is planning to use its aircraft to deliver time-sensitive cargo, including human organs. United Parcel Service (UPS) agreed to purchase of up to 150 Beta Alia aircraft. Beta’s CEO was quoted as saying that UPS plans to use the piloted eVTOL aircraft to transport time-sensitive deliveries that would otherwise fly on small conventional airplanes. Rather than relying on airports, the fully electric aircraft will take off and land on property at UPS facilities, creating a “micro air feeder network without the noise or operating emissions of traditional aircraft” (Head, 2021a). Another Beta investor, United Therapeutics, plans to use the Alia to move lifesaving organs (Head, 2021b). Elroy Air has also developed a VTOL aircraft it calls Chaparral to “carry cargo in lightweight, aerodynamic pods which are preloaded by ground personnel and picked up autonomously by the aircraft before takeoff. The result is a conveyor belt through the sky for high-throughput express shipping” (Elroy Air, 2022). In 2022, FedEx Express announced a partnership with Elroy to “develop plans to test Elroy Air’s Chaparral autonomous air cargo system within the company’s middle-mile logistics operations, moving shipments between sortation locations” (FedEx, 2022). 2022 eVTOL Aircraft Capabilities and Limitations Investors and technologists are obviously excited by the prospects of eVTOL technology and how it will transform urban mobility and logistics. But can today’s state-of-the-art eVTOL aircraft execute 12 This is hardly surprising: Joby Aviation bought Uber Elevate in late 2020. 15 the vision people have for them? How far can one expect to fly in them, how much will it cost, and how many family members can come along? In 2022, battery-powered eVTOL aircraft could transport about four people, or approximately 1,500 lbs of cargo taking up 200 ft3 of space, between 100 and 200 nmi at 100 to 150 knots on a single charge. Recharging took about one hour. eVTOL aircraft are significantly quieter than traditional helicopters but can sustain hovering flight only for a few minutes without draining their batteries. Thus, eVTOL aircraft are less capable than traditional turbine-powered helicopters in terms of range, capacity, and hover, but both eVTOL companies and independent analyses project that they will be significantly cheaper to buy, operate, and sustain than helicopters (e.g., Jonas et al., 2021; Joby Aviation, 2021; Booz Allen Hamilton, 2018; Mihara et al., 2021).13 In general, batteries do not perform well in extremely cold environments. Current battery-powered electric cars lose range in cold conditions, and it is likely that eVTOL aircraft will also suffer from this limitation. At present, the magnitude of this effect remains to be determined. Finally, it should be noted that, unlike turbine or piston-powered engines, electric motors do not lose power with increasing altitude (and decreasing air density); however, as air density decreases, the air mass available to assist with battery cooling goes down, necessitating additional cooling. Table 2.3 compares basic performance and cost parameters across a range of platforms, including a generic eVTOL, based on analysis from Agility Prime’s Lifecycle Cost Model (see Appendix C for details). 13 For example, Booz Allen Hamilton (2018) projected the price per passenger-mile of a five-seat eVTOL aircraft to be about 33 percent higher than luxury ridesharing, while Jonas et al. (2021) states that many eVTOL companies “are targeting prices comparable to an Uber Black ride” (p. 19). 16 Table 2.3. Summary of Various Transport Aircraft, Helicopters, a Generic eVTOL, and a Ford F-150 Truck Vehicle Type Passengers Range (nmi) Speed (knots) Turn Time (min) Acquisition Price ($M) O&S Cost per Hour ($) Cost per nmi ($) Cost per Passenger Seat per nmi ($) C-17A Turbofan 102 3,500 450 165 361.0 17,247 38.33 0.38 C-130J-30 Turboprop 128 2,500 320 120 89.9 6,691 20.91 0.16 HH-60G Turbine helicopter 12 504 159 25 52.1 11,266 70.86 5.90 UH-1N Turbine helicopter 10 290 95 25 5.5 5,750 60.53 6.05 H-130 Turbine helicopter 7 327 128 20 3.3 4,752 37.13 5.30 MD-500E Turbine helicopter 4 290 135 20 1.9 1,009 7.47 1.87 R-66 Turbine helicopter 4 350 110 20 0.9 1,100 10.00 2.50 Generic eVTOL Electric VTOL 4 100 low 200 high 145 10 1.3 low 6.1 high 1,000 low 1,500 high 9.56 low 12.64 high 2.39 low 3.41 high Ford F-150 Gas V-6 truck 5 625 39 5 0.05 26 0.67 0.14 SOURCES: See Appendix C. NOTE: Operations and sustainment (O&S). 17 We used these parameters to ascertain the cost-competitiveness of moving people via a generic eVTOL aircraft as opposed to other vehicles. Figure 2.1 shows the cost to move a passenger 50 nmi as a function of the total number of passengers moved for all the vehicles in Table 2.3 as compared with the C-130J-30 (we chose this as the throughput baseline because it is the most common mobility aircraft that the USAF employs).14 This type of comparison is important; proponents of eVTOL technology highlight the low cost of moving people. To calculate the curves in Figure 2.1, we first determined how many of each aircraft or ground vehicle would be needed to match the theoretical daily passenger throughput of the C-130J-30 (1,318 passengers per 24 hours).15 We then calculated the cost to fly or drive this number of vehicles, divided by the number of passengers. Of course, there is no such thing as a generic eVTOL, and estimates of what it will cost to buy one vary greatly. To account for this variability, we show results for a low- ($1.3 million) and high-end estimate ($6.14 million) of eVTOL purchase price in 2023-year dollars. The table note supplies other details relevant to the assumptions underlying the graph. Figure 2.1. Cost to Move a Passenger 50 nmi as a Function of Total Passengers Moved NOTE: We assumed that aircraft fly at their nominal cruise speed for 50 nmi between origin and destination and that they fly out fully loaded and return empty. In the case of the truck, we multiplied the straight-line distance by a factor of 1.3 to account for the fact that road networks do not travel in straight lines. Appendix D contains model details and assumptions about time required for fueling or recharging, loading and unloading passengers, and checklists. It also includes our cost model, which allowed us to estimate how much it costs to purchase, operate, and sustain these vehicles. 14 Appendix C provides the data for 25 nmi, 100 nmi, and 250 nmi. 15 The legend of Figure 2.1 contains the number of each aircraft required to match C-130J-30 throughput. 18 The eVTOL performance data we collected answer the original question posed in this section: the generation of eVTOL aircraft we studied do appear to be capable enough to provide urban mobility, some short-distance intercity travel, and short-hop flights aimed at logistics of relatively lightweight cargo. However, our analysis suggests that, to make a compelling economic case for their aircraft, eVTOL companies must bring the purchase price down. How cheap does eVTOL travel need to be per nautical mile? It probably does not need to be as cheap as going by car because flying confers significant time savings but would certainly be more economical than helicopters, which are known to be prohibitively expensive for large-scale transportation services. Other Factors for Commercial Success As we have already suggested, eVTOL company commercial viability ultimately depends on more than being well capitalized or having mature technology ready to execute business plans. This is not a comprehensive discussion of additional factors that must succeed for eVTOL aircraft to become significant players in the urban mobility market, but we expound on three particularly important ones in this section: takeoff, landing, and charging infrastructure; aircraft certification and safety; and pilot training. Infrastructure Requirements All eVTOL companies, irrespective of business plan or precise range or cruise speed, will require takeoff and landing areas, still often referred to as vertiports, as in Uber Elevates’ original report. At least some of these vertiports will need battery charging capabilities. Several of the companies we spoke with had already started building proto-infrastructure networks for their future operations or have well laid-out plans to do so. No company was fully ready to launch. Here, we present estimates for cost and space to build vertiports and charging stations and the electric grid requirements. Table 2.4 shows construction costs for some different vertiports as estimated by Taylor, Saldanli, and Park (2021). Table 2.4. Estimated Vertiport Construction Costs Vertiport Design Description Area (acres) Estimated Construction Cost ($000s, 2021) Single multifunction pad 0.66 350 One landing/takeoff pad, two staging areas 1.75 750 One landing/takeoff pad, three staging areas 1.75 950 One landing pad, one takeoff pad, one staging area 2.90 1,150 One landing pad, one takeoff pad, two staging areas 2.90 1,600 SOURCE: Information extracted from Taylor, Saldanli, and Park (2021). 19 Pure eVTOL aircraft will also require an electrical power source to charge their batteries. A representative pure eVTOL might have 150 kWh of battery capacity. However, several AAM manufacturers are either building or considering building a hybrid eVTOL aircraft, which would carry an onboard generator and burn fuel to charge its own batteries and power its electric motors. Such a hybrid eVTOL would be fueled in the same way as traditional aircraft and would require a source of aviation fuel. As with electric ground vehicles, eVTOL aircraft can be charged at faster or slower rates depending on the power capacity of the charger. Table 2.5 shows cost estimates for different charger levels (Redwood Coast Energy Authority, 2018; McDonald, 2021). The most powerful chargers that are currently commercially available have 360 kW capacity (Kane, 2022). CharIN is currently developing a Megawatt Charging System (MCS) standard that will theoretically deliver megawatt charging levels to large electric trucks and eVTOL aircraft (Blain, 2021a). To take full advantage of MCS chargers, eVTOL battery systems will have to be designed to accommodate higher charging currents and have adequate cooling. However, the MCS is intended to support a wide range of possible vehicle systems, by operating at voltages from 500 VDC to 1250 VDC (CharIN, 2022). Table 2.5. Cost Estimates for Electric Charger Levels Charger Type Electric Grid Connection Required Power Capacity (kW) Typical Cost of Charger ($) Typical Cost to Install ($) Time to Fully Charge Representative eVTOL Level 1 Any 120 V outlet 1.5–2.0 200 0 75–100 hrs Level 2 208 V three-phase or 240 V single-phase 19 500–8,000 600–13,000 8 hrs Level 3a 480 V three-phase 50 30,000 27,500 3 hrs 480 V three-phase 100 55,000 50,000 90 min 480 V three-phase 180 90,000 105,000 50 min 480 V three-phase 350 160,000 160,000 26 min SOURCES: Redwood Coast Energy Authority (2018); McDonald (2021). a Direct current fast charging. We analyzed the reported construction costs of 30 electric charging stations that are part of the Nevada Electric Highway and concluded from that data that $240,000 is a typical cost for a charging station with a total 300 kW power capacity, with the cost of additional power capacity being about $365/kW on average. (For the data and analysis, see Appendix C.) Finally, these numbers are roughly consistent with costs that Tesla reported in the past when building out its Supercharger network (Tesla Motors, Inc., 2016) and are also consistent with conversations we had with eVTOL companies. Table 2.6 shows the combined estimates of charging costs along with the architectural costs of the vertiport, assuming that one 300 kW charger is supplied for each eVTOL staging area. 20 Table 2.6. Estimated Vertiport and Charger Construction Costs Vertiport Design Description Vertiport Construction Cost ($000s) Cost for 300 kW Chargers at Each Staging Area ($000s) Total Cost ($000s) Single multifunction pad 350 240 590 One landing/takeoff pad, two staging areas 750 480 1,230 One landing/takeoff pad, three staging areas 950 720 1,670 One landing pad, one takeoff pad, one staging area 1,150 240 1,390 One landing pad, one takeoff pad, two staging areas 1,600 480 2,080 SOURCES: Taylor, Saldanli, and Park (2021); Nevada Governor’s Office of Energy (2021). Existing heliports in some cities might allow limited testing of eVTOL aircraft use cases if the heliports are usefully located and can hold a charging station. However, eVTOL company success will ultimately depend on having access to sufficient locations for landing and takeoff pads to support their business plans, which will not be cheap. Additional costs not included in these figures are those due to yearly maintenance and sustainment. Safety, Aircraft Certifications, Air Traffic Control, and Other Commercialization Factors Regulatory requirements for aviation are major drivers of the timing of operational rollout: “One of the greatest challenges facing the eVTOL industry is that the regulations for certifying these novel aircraft do not yet exist, and neither do the airspace management paradigms to enable operations at scale” (Head, 2021b). Several firms are in the process of obtaining certification from the relevant regulatory authorities in the United States, European Union, the United Kingdom, and China, among others. Industry analysts and eVTOL suppliers alike anticipate rolling out operations in selected urban environments first, for both intracity on-demand transport and airport shuttle, with subsequent rollout to intercity and other environments (Hader et al., 2020). Unsurprisingly, American eVTOL companies are currently laser focused on achieving FAA certifications (e.g., type certification, production certification, airworthiness certification, air carrier certification) for their aircraft.16 Without these, the companies’ commercial business plans deteriorate. Certification ultimately lies in proof that distributed electric propulsion is safe and that eVTOL aircraft can avoid collisions with each other and other aircraft types. In May 2022 the FAA updated its plans to certify eVTOL aircraft, now classifying them as powered-lift aircraft under the “special class” process in 14 Code of Federal Regulations (CFR) 21.17(b), while using 14 CFR Part 23’s small 16 An FAA production certificate “is an approval . . . to manufacture duplicate products under an FAA-approved type design” and a “Parts Manufacture Approval” is “a combined design and production approval for modification and replacement articles [that] allows a manufacturer to produce and sell these articles for installation on type certificated products” (FAA, 2016; FAA, 2020). 21 airplane regulations for performance-based airworthiness standards. In addition to obtaining FAA certification, eVTOL companies will need to convince the public, insurers, and other implementation partners that eVTOL aircraft are sufficiently safe. What is safe enough? Uber Elevate originally postulated that the aircraft must be twice as safe as cars on a fatalities-per-passenger-mile basis (Holden and Goel, 2016). However, only time will tell what accident rate the market will bear. Pilot Training Finally, at least in the short term, eVTOL aircraft adoption will also increase the demand on pilots. (In the long term, as eVTOL aircraft move toward autonomous flight, this demand should decrease.) The FAA recently announced that eVTOL aircraft will be classified as powered-lift category aircraft (Reed, 2022b). According to 14 CFR 61.129(e), “For a powered-lift rating, except as provided in paragraph (i) of this section, a person who applies for a commercial pilot certificate with a powered-lift category rating must log at least 250 hours of flight time as a pilot.” Facile transition pathways for people who already have general aviation pilot licenses to acquire eVTOL licenses could also help lessen the pilot burden, at least at first. eVTOL companies will have to facilitate pilot training if they are going to scale operations as imagined, both in the United States and worldwide. Future eVTOL Capabilities eVTOL, like all technologies, will not remain static. In fact, eVTOL companies we spoke with discussed directing their efforts and investment toward improving aircraft capabilities. While these companies did not discuss developing new battery systems themselves, they will certainly use future batteries,17 which should improve eVTOL performance attributes by increasing hover time, range, and payload. To estimate how future battery improvements would improve the performance envelope of eVTOL aircraft, we adapted the eVTOL performance model in Sripad and Viswanathan (2021). This model calculates the power and energy demands on the battery system of an eVTOL to perform a nominal flight, given publicly stated performance specifications or estimated aerodynamic parameters for various eVTOL designs. Table 2.7 lists the estimated performance parameters for some of the eVTOL designs. The parameter sets were intended to correspond with certain actual eVTOL aircraft, but to avoid suggesting that every parameter estimate is entirely accurate, we have avoided labeling the design points with actual eVTOL names. Sripad and Viswanathan (2021) assumed that between 45 percent and 55 percent of the total takeoff mass of the aircraft could be available for either payload or battery energy storage. 17 A Reuters analysis (Lienert and Bellon, 2021) found that global automakers plan to invest over $500 billion in battery- powered vehicle technology by 2030, including recent investments in next-generation batteries that are solid state, semisolid state, or lithium-metal (Blois, 2022). 22 Table 2.7. Estimated Performance Characteristics for eVTOL Aircraft eVTOL Design A B C D Maximum takeoff weight (lbs) 4,800 6,999 3,318 869 Nominal range (nmi) 130 150 with 1,200-lb payload 250 with 600-lb payload 52 86 Lift-to-drag ratio 18 18 12 17 Disk loading (lbs/ft2) 9.4 13.2 15.3 9.2 Area loading (lbs/ft2) 18.4 14.3 12.3 12.3 CD0 minimum drag coefficient 0.015 0.015 0.015 0.012 SOURCES: Information extracted from Sripad and Viswanathan (2021) and Sripad (2021). Figures 2.2 and 2.3 illustrate the trade-offs between payload and range for the eVTOL designs in Table 2.7 using the Sripad and Viswanathan model. These calculations assume that the eVTOL chooses its cruise speed to maximize range. For these figures, we supposed that batteries could be freely added to or subtracted from the aircraft in exchange for payload. We also supposed that the eVTOL has one 220-lb pilot who is not included in payload. Figure 2.2 shows the range-payload diagram assuming battery packs with specific energy of 230 Wh/kg and specific power of 1 kW/kg, roughly corresponding to the limit of existing lithium-ion battery technology. The battery pack must be able to supply enough power for vertical takeoff; for short-range flights, this is the dominant requirement determining the mass of the battery pack; therefore, the mass of the battery pack (and, indirectly, the mass of the payload) is constant for ranges under about 120 nmi. If longer flights are intended, more batteries are needed to support the cruise portion of the flight, and the achievable payload decreases. Figure 2.3 shows the same performance calculations, with the change that lithium-ion battery packs (230 Wh/kg, 1 kW/kg) are replaced with more-advanced batteries providing 400 Wh/kg and 2 kW/kg, which are projected to be possible using solid lithium-metal technology (QuantumScape, 2022). If batteries of this energy density become practical and available for use in eVTOL applications and if the eVTOL designs otherwise remained unchanged, the larger eVTOL aircraft could deliver 1,000-lb payloads to a range of 300 nmi or, if packed with extra batteries, could deliver a small payload more than 400 nmi. For comparison, dashed lines in the figure indicate the state-of-the-art performance regions that were previously plotted in Figure 2.2. Figure 2.4 repeats these performance calculations with the eVTOL battery replaced by a future hydrogen fuel cell system. The company HyPoint, for example, claims to have developed a prototype turbo air-cooled fuel cell system in the lab, such that the fuel cell system would have a specific power of 1,500 W/kg, while the hydrogen storage tanks would have an energy density of 1,000 Wh/kg (HyPoint, 2021). If realized, the hydrogen system would enable modestly greater payloads at short ranges but would have substantially greater range than current batteries. 23 Figure 2.2. eVTOL Range and Payload Trade-Offs Using State-of-the-Art Battery Technology SOURCE: RAND analysis using the model in Sripad and Viswanathan (2021). Figure 2.3. eVTOL Range and Payload Trade-Offs Using Future Battery Technology 24 Figure 2.4. Future Hydrogen Fuel Cell Technology Compared with Current Battery Technology Figure 2.5 compares the hydrogen system with the posited future batteries previously plotted in Figure 2.3. The batteries are expected to be superior to the hydrogen system for flights up to about 250 nmi. However, the hydrogen fuel cell system would enable longer-range flights. Note that these calculations reflect only the weight of payloads and not their volume—hydrogen storage tanks will be relatively bulky for the energy stored and, therefore, would consume more of the available interior space of the eVTOL aircraft. For the foreseeable future, standard aviation fuel will continue to have much higher specific energy than electric batteries and will require much lighter fuel tanks to contain than hydrogen. Therefore, a hybrid design that relies on aviation fuel for long-range energy can be expected to have greater total range while retaining many of the advantages of an electric system. Figure 2.6 shows the expected range and payload graph for an eVTOL aircraft using current state-of-the-art lithium-ion batteries (230 Wh/kg, 1 kW/kg) to provide electric power during vertical lift, and a generator with a specific power of 1.5 kW/kg burning aviation fuel to provide power during cruise. To be conservative, we assumed that the generator is only 25 percent efficient. Aviation fuel has a specific energy of 12 kWh/kg, and we assumed a tankage weight factor of 10 percent. As seen in Figure 2.6, this solution enables dramatically greater ranges than the other technologies considered (although it does not have zero emissions at altitude, so it is arguably less green). Several eVTOL companies that we interviewed are either pursuing or considering pursuing hybrid designs of this type. 25 Figure 2.5. Future Hydrogen Fuel Cell Technology Compared with Projected Future Battery Technology Figure 2.6. Range and Payload Trade-Offs Using Hybrid-Electric Technology with Aviation Fuel 26 eVTOL Technology Prospects In sum, eVTOL companies in 2022 were well capitalized and diverse and were supported by a remarkable range of some of the most successful companies in the world. The aircraft could already carry out a set of operations that appear potentially commercially viable, and performance parameters should improve over time. Many other firms—both startups and mature entities—are also entering the space to provide eVTOL-adjacent capabilities, such as future eVTOL air traffic control. How, precisely, the structure of the industry shakes out is currently unknowable, but, by all appearances, the emergence of eVTOL-driven urban mobility is primed to become a global phenomenon. 27 Chapter 3 eVTOL Aircraft Utility for the USAF In this chapter, we present our evaluation of eVTOL military utility for the USAF for three use cases—test range transport, missile range transport, and agile combat employment (ACE)—in notional Poland and Philippine scenarios. These use cases were selected based on interviews across a very broad range of stakeholders (see Appendix B) and past work that sought to identify USAF applications for eVTOL aircraft. Probably unsurprisingly, the use cases that seemed most compelling are rooted in mobility and do not require aircraft performance that exceeds eVTOL aircraft capabilities today or such features as weapons, stealth, and specialized reconnaissance sensors. We also consider the costs and availability of vertiports and charging infrastructure for USAF eVTOL use. Past Work We are not the first researchers to assess the potential value of eVTOL aircraft to the USAF. The USAF has engaged directly with eVTOL companies through AFWERX and, later, the Agility Prime program, providing business plans; a tremendous amount of engineering design; and, eventually, test flight data. Appendix A provides more details on early USAF engagement with the eVTOL industry to comprehensively assess the state-of-the-art of eVTOL technology. Agility Prime also contracted Perduco and LinQuest to conduct a detailed evaluation of the military utility of a variety of AAM aircraft, including eVTOL aircraft, which led to the development of a detailed MATE. Additionally, a group of internal experts from around the USAF formed a commission to explore the mission areas for which eVTOL aircraft would most likely show promise. Appendix A also includes summaries of the MATE results and commission report. The MATE work is technical and focused on capturing the current state of the art with respect to eVTOL aircraft. The authors of the commission report took a more subjective approach, surveying SMEs to identify USAF mission areas in which eVTOL aircraft might be useful. Our approach was to develop a few operational concepts (derived from talking to a large range of potential stakeholders) and analyze eVTOL performance within each and to assess the broader economic market and potential USAF acquisition strategies. Our Findings of Operational Community Perspectives on eVTOL Aircraft As part of this project, we also interviewed many potential eVTOL aircraft stakeholders within the USAF and joint community (see Appendix B for a complete list). These discussions revealed various possible missions and use cases for eVTOL aircraft, including personnel recovery, short-range logistics and resupply, and last-mile tactical delivery. However, we were largely told that current 28 eVTOL capabilities do not align with capability gaps,18 although there was certainly interest in observing how the technology evolves and matures. There was general consensus that increased range, payload, and hover times would make eVTOL aircraft more useful. There was also widespread support for autonomous eVTOL aircraft and a desire to be able to use them in both austere and contested environments. Appendix B contains more details. A few use cases, listed in Table 3.1, came up repeatedly in our interviews. We added test and training range transportation to the list, as inspired by both the commission report and our own ideas. We found it useful to think about eVTOL aircraft through two lenses: as fast cars and as cheap helicopters. However, eVTOL aircraft lack other characteristics that the USAF typically values, such as weapons, stealth, and sensors. We used this general description of eVTOL capabilities to further narrow down the set of use cases to the ones that appeared promising enough to analyze. In the next section, we describe how eVTOL aircraft could be used to transport personnel in place of surface transport at the Nevada Test and Training Range (NTTR) and the intercontinental ballistic missile (ICBM) field around Malmstrom Air Force Base (AFB). We also assess how eVTOL aircraft could support notional ACE scenarios. Table 3.1. Potential USAF eVTOL Aircraft Military Use Cases Use Case Our Thoughts Personnel recovery over land—particularly in contested environments—enabled by autonomy Do not analyze. Existing eVTOL aircraft are still human- piloted, although certain companies intend their first- generation aircraft to be autonomous. None have defenses, and hover times are insufficient. Test and training range transportation Analyze (see “Surface Transport at the Nevada Test and Training Range” in this chapter). Missile field transportation Analyze (see “Missile Field Support Transportation” in this chapter). Operational support airlift (OSA) in ACE Analyze (see “Agile Combat Employment” in this chapter). Medical evacuation, particularly in response to an airfield attack where the runways are damaged These are specific examples of OSA missions. RAND investigated these within the context of the ACE concept of operation (CONOP). Emergency medical team transport On-call logistics—particularly Classes I, V, and IXa Sensor movement Do not analyze. eVTOL aircraft could, in theory, take the place of other vehicles with sensors (e.g., MQ-9); however, this would require tremendously more range and hover ability than current models allow. Aircraft also do not currently carry weapons and are not stealthy, so not ideal for moving sensors in