BREAKING THE SOUND BARRIER: NAVIGATING THE LEGAL TURBULENCE OF SUPERSONIC AND HYPERSONIC AIRCRAFT DEVELOPMENT BY - SHUBHADIP GHATAK & APOORVA SAXENA

BREAKING THE SOUND BARRIER: NAVIGATING THE LEGAL TURBULENCE OF SUPERSONIC AND HYPERSONIC AIRCRAFT DEVELOPMENT
 
AUTHORED BY - SHUBHADIP GHATAK.
CO-AUTHOR - APOORVA SAXENA.
INSTITUTE’S - CHRIST ACADEMY INSTITUTE OF LAW, BENGALURU.
PROGRAM- BBA LLB.
YEAR OF STUDY- 4TH YEAR.
 
 
I. INTRODUCTION
The aviation industry's pursuit of supersonic and hypersonic flight promises to revolutionize transportation and military capabilities. However, this technological leap faces complex legal and regulatory challenges. This article explores the intricate legal landscape surrounding high-speed aircraft development and deployment, examining issues from noise pollution and environmental impact to airspace management in congested skies.
 
Through analysis of international regulations, national laws, landmark cases, and future developments, we provide a comprehensive overview of legal hurdles in this field. We consider the balance between progress and compliance, the need for international cooperation in establishing new regulatory frameworks, and potential solutions for next-generation aircraft.
 
Understanding these legal complexities will help industry stakeholders, policymakers, and legal professionals prepare for the future of air travel beyond the sound barrier.
 
II. HISTORICAL CONTEXT AND CURRENT DEVELOPMENTS
A. The Birth of Supersonic Flight
The dream of supersonic flight became a reality on October 14, 1947, when U.S. Air Force pilot Chuck Yeager broke the sound barrier in the Bell X-1 aircraft[1]. This milestone ushered in a new era of aviation, sparking both military and civilian interest in high-speed flight. The subsequent decades saw the development of military supersonic aircraft, culminating in the creation of civilian supersonic transport (SST) aircraft like the iconic Concorde.
 
B. The Concorde Era and Its Legal Legacy
The Anglo-French Concorde, which entered commercial service in 1976, represented the pinnacle of civilian supersonic travel. However, its operation was marred by legal challenges, particularly regarding noise pollution. The case of Concorde-Heathrow Airport Users Committee v. British Airports Authority (1981)[2] highlighted the tension between technological advancement and environmental concerns. The UK Court of Appeal ruled that while the Concorde's noise levels exceeded statutory limits, its unique status justified special consideration, setting a precedent for balancing innovation with regulatory compliance.
 
C. The Sonic Boom Problem and Regulatory Response
One of the most significant legal hurdles faced by supersonic aircraft has been the issue of sonic booms. In response to public concerns, the U.S. Federal Aviation Administration (FAA) implemented Federal Aviation Regulation (FAR) Part 91.817 in 1973, effectively banning overland supersonic flight for civil aircraft[3]. This regulation, which remains in effect today, has been a major obstacle to the widespread adoption of supersonic travel.
 
D. The Hypersonic Frontier
While supersonic technology has been around for decades, hypersonic flight defined as speeds of Mach 5 and above represents the next frontier. Military applications, such as hypersonic missiles and aircraft, are driving much of the current research and development. However, the potential for civilian hypersonic travel is also being explored, with companies like Boeing and Reaction Engines Ltd. working on concepts for hypersonic passenger aircraft[4].
 
E. Current Developments and Industry Players
Today, a new wave of companies is seeking to overcome the challenges that grounded the Concorde and usher in a new era of supersonic and hypersonic travel. Firms like Boom Supersonic, Spike Aerospace, and Hermeus are developing aircraft designed to fly at speeds ranging from Mach 1.4 to Mach 5[5]. These endeavours have reignited discussions about the legal and regulatory frameworks necessary to accommodate such revolutionary technology.
 
F. Renewed Regulatory Interest
In response to these developments, regulatory bodies have begun to revisit their stance on supersonic flight. In 2020, the FAA proposed a new rule to establish noise certification standards for supersonic aircraft[6]. Similarly, the International Civil Aviation Organization (ICAO) has initiated discussions on developing standards for supersonic aircraft, signalling a shift in the global regulatory landscape[7].
 
III. REGULATORY FRAMEWORK
The development and operation of supersonic and hypersonic aircraft are subject to a complex web of international and national regulations.
 
A. International Civil Aviation Organization (ICAO) Standards
The ICAO, a specialized agency of the United Nations, plays a crucial role in establishing global aviation standards. While ICAO has not yet developed specific standards for supersonic or hypersonic aircraft, it has taken steps to address this emerging technology.
  1. Annex 16 to the Chicago Convention: This annex, which deals with environmental protection, is particularly relevant to supersonic aircraft. Volume I of Annex 16 sets standards for aircraft noise, while Volume II addresses engine emissions[8]. The challenge lies in adapting these standards to accommodate the unique characteristics of supersonic and hypersonic flight.
  2. CAEP Initiatives: The ICAO's Committee on Aviation Environmental Protection (CAEP) has established a task group to develop noise and emissions standards for supersonic aircraft. This group is working on creating a new chapter in Annex 16 specifically for supersonic aircraft[9].
  3. Future Sonic Boom Standard: ICAO is considering the development of a sonic boom standard, which would be crucial for enabling overland supersonic flight. This standard would need to balance technological capabilities with environmental and public health concerns[10].
 
B. National Regulations
While ICAO provides a global framework, individual countries have their own regulations governing supersonic and hypersonic flight.
 
1.      UNITED STATES
The U.S. has been at the forefront of developing regulations for supersonic flight, given its historical leadership in aerospace technology.
a)      FAA Modernization and Reform Act of 2012: This act directed the FAA to review its position on supersonic flight over land. Section 911 of the act required the FAA to study the impact of supersonic flight and consider revising the current ban[11].
b)      FAA Reauthorization Act of 2018: This legislation further pushed for the development of supersonic regulations. Section 181 directed the FAA to exercise leadership in the creation of federal and international policies, regulations, and standards relating to the certification and safe and efficient operation of civil supersonic aircraft[12].
c)      Noise Standards for Supersonic Aircraft: In 2020, the FAA proposed a new rule (Notice of Proposed Rulemaking, NPRM) to establish noise certification standards for supersonic airplanes. This rule aims to provide a means for supersonic aircraft to be certificated for subsonic operation in the U.S., a crucial step towards the eventual certification of supersonic flight[13].
d)      Overland Flight Ban: Despite these developments, the ban on civil supersonic flight over land (14 CFR Section 91.817) remains in effect. Any change to this regulation would require significant evidence that supersonic aircraft can operate without causing unacceptable environmental impact.
 
  1. EUROPEAN UNION
The EU has taken a more cautious approach to supersonic flight, with a focus on environmental protection.
a)      Regulation (EU) No 598/2014: This regulation establishes rules and procedures for noise-related operating restrictions at EU airports. While not specifically addressing supersonic aircraft, it sets a stringent framework for noise management that would apply to any future supersonic operations[14].
b)      Clean Sky 2 Joint Undertaking: This public-private partnership between the European Commission and the European aeronautics industry includes research into low-noise aircraft technologies, which could be applicable to supersonic aircraft[15].
c)      SENECA Project: The EU-funded SENECA (Silent Engine Concept for Civil Aviation) project aims to develop technologies for ultra-low noise aircraft engines, potentially paving the way for more environmentally friendly supersonic flight[16].
 
  1. OTHER KEY JURISDICTIONS
a)      Japan: As a country with a history of high-speed rail, Japan has shown interest in supersonic aviation. The Japan Aerospace Exploration Agency (JAXA) has conducted research on reducing sonic booms, which could inform future regulations[17].
b)      Russia: With its own supersonic aircraft program, Russia has regulations governing supersonic flight, primarily for military purposes. The development of civil supersonic aircraft may necessitate updates to these regulations[18].
c)      China: As an emerging leader in aerospace technology, China is developing its own regulatory framework for high-speed flight. The Civil Aviation Administration of China (CAAC) has expressed interest in supersonic and hypersonic technologies, though specific regulations are still in development[19].
 
The regulatory landscape for supersonic and hypersonic aircraft is dynamic and evolving. As technology advances, regulatory bodies worldwide are grappling with the challenge of creating frameworks that promote innovation while ensuring safety and environmental protection.
 
 
IV. KEY LEGAL CHALLENGES
The advancement of supersonic and hypersonic aircraft technology presents a myriad of legal challenges that span environmental, safety, and international law concerns.
 
A. Noise Pollution and Sonic Booms
One of the most significant legal hurdles for supersonic and hypersonic aircraft is the issue of noise pollution, particularly the phenomenon of sonic booms.
1.      Legal Framework: In the U.S., the Noise Control Act of 1972 empowers the Environmental Protection Agency (EPA) to regulate noise that jeopardizes public health and welfare[20]. This act, along with FAA regulations, forms the basis for restrictions on supersonic flight over land.
2.      The landmark case of Sierra Club v. Department of Transportation (1989)[21] challenged the FAA's decision to allow limited supersonic operations of the Concorde at Dulles International Airport. The court upheld the FAA's decision, but the case highlighted the tension between technological advancement and environmental protection.
3.      International Considerations: The Convention on International Civil Aviation (Chicago Convention) requires member states to adopt measures to ensure that aircraft noise does not exceed levels established by ICAO[22]. This presents a challenge for supersonic aircraft, which inherently produce more noise than subsonic aircraft.
4.      Potential Solutions: Recent research into "low-boom" supersonic designs offers hope for overcoming noise restrictions. NASA's X-59 Quesst (Quiet Supersonic Technology) demonstrator aims to reduce the sonic boom to a mere "thump," potentially paving the way for new regulations[23].
 
B. Environmental Impact
Beyond noise pollution, supersonic and hypersonic aircraft face scrutiny over their broader environmental impact.
1.      Emissions Regulations: The EPA has the authority to regulate aircraft emissions under the Clean Air Act[24]. In 2016, the EPA issued a finding that greenhouse gas emissions from certain aircraft engines contribute to air pollution that endangers public health and welfare[25].
2.      International Framework: The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA), developed by ICAO, aims to address the growth in international civil aviation CO2 emissions[26]. Supersonic aircraft manufacturers will need to demonstrate compliance with these evolving standards.
3.      In Center for Biological Diversity v. EPA (2019)[27], environmental groups challenged the EPA's delay in regulating greenhouse gas emissions from aircraft. The court's decision to allow the lawsuit to proceed underscores the legal pressure to address aviation's environmental impact.
4.      Stratospheric Ozone Depletion: Hypersonic aircraft, which fly at higher altitudes, face unique environmental challenges. The potential impact on the ozone layer could lead to new regulations under the Montreal Protocol on Substances that Deplete the Ozone Layer[28].
 
C. Airspace Management and Air Traffic Control
The integration of supersonic and hypersonic aircraft into existing air traffic systems presents complex legal and operational challenges.
1.      Regulatory Framework: In the U.S., the NextGen air traffic control system, mandated by the FAA Modernization and Reform Act of 2012, aims to modernize airspace management[29]. However, it was not designed with supersonic or hypersonic aircraft in mind.
2.      International Coordination: The Chicago Convention requires states to collaborate on air navigation facilities[30]. The introduction of high-speed aircraft will necessitate new international agreements on airspace management.
3.      Legal Liability: Questions of liability in the event of accidents or incidents involving supersonic or hypersonic aircraft in shared airspace remain largely unresolved. The Warsaw Convention and Montreal Convention, which govern international air carrier liability, may need to be revisited[31].
4.      While not directly related to supersonic flight, the ongoing legal battles over drone integration into national airspace, such as Taylor v. FAA (2017)[32], provide insights into the challenges of incorporating new technologies into existing airspace regulations.
 
D. Safety and Certification
Ensuring the safety of supersonic and hypersonic aircraft presents unique legal and regulatory challenges.
1.      Certification Standards: The FAA's existing airworthiness standards (14 CFR Part 25) were not designed for supersonic or hypersonic aircraft. New standards will need to be developed, a process that has begun with the FAA's 2020 Notice of Proposed Rulemaking on noise certification for supersonic aircraft[33].
2.      International Harmonization: ICAO's Airworthiness Manual (Doc 9760) provides guidance for national aviation authorities on certification[34]. However, it will need to be updated to address the unique characteristics of high-speed aircraft.
3.      Legal Precedent: The case of In re Air Crash Disaster at Sioux City, Iowa (1991)[35], which dealt with the certification of the DC-10 aircraft, demonstrates the potential legal ramifications of certification decisions. Similar scrutiny can be expected for supersonic and hypersonic aircraft.
4.      Hypersonic Challenges: The extreme speeds and temperatures involved in hypersonic flight present unprecedented safety challenges. The lack of established safety standards could lead to legal disputes over what constitutes "reasonable care" in the design and operation of these aircraft.
 
E. Intellectual Property Rights
The development of supersonic and hypersonic technologies involves significant intellectual property considerations.
1.      Patent Law: The novelty and non-obviousness requirements for patents, as outlined in 35 U.S.C. Section 102 and 103, present challenges for supersonic and hypersonic technologies that may build on existing aerospace innovations[36].
2.      Trade Secrets: The case of United States v. Hsu (1999)[37], which involved the attempted theft of trade secrets related to anti-cancer drugs, highlights the legal risks associated with protecting valuable technical information. Similar concerns apply to advanced aerospace technologies.
3.      International IP Protection: The Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) provides a framework for international IP protection[38]. However, the strategic importance of supersonic and hypersonic technologies may lead to tensions between IP rights and national security concerns.
4.      Collaborative Development: Joint ventures and international collaborations in aerospace development, such as the Concorde project, raise complex IP ownership issues. The case of Rolls-Royce plc v United Technologies Corp (2011)[39] demonstrates the potential for disputes in collaborative aerospace projects.
 
F. Export Control and National Security
The dual-use nature of many supersonic and hypersonic technologies presents significant legal challenges related to export control and national security.
1.      U.S. Export Control Reform: The Export Control Reform Act of 2018 updated U.S. export control laws, with implications for aerospace technologies[40]. Supersonic and hypersonic technologies may fall under stricter control categories.
2.      International Traffic in Arms Regulations (ITAR): Many advanced aerospace technologies are subject to ITAR, which imposes strict controls on the export of defense and military related technologies[41].
3.      Wassenaar Arrangement: This multilateral export control regime, which includes 42 participating states, aims to prevent the proliferation of technologies with potential military applications[42]. Supersonic and hypersonic technologies are likely to fall under its purview.
4.      Case Study: The ongoing legal dispute between Boom Supersonic and Rolls-Royce over engine technology for supersonic aircraft highlights the intersection of commercial interests and national security concerns in high-speed aviation development[43].
 
V. CASE STUDIES AND LANDMARK LEGAL DECISIONS
The development of supersonic and hypersonic aircraft has been influenced by a series of important legal cases and decisions.
 
A. United States v. Causby (1946)[44]
While predating the supersonic era, this landmark U.S. Supreme Court case established crucial principles regarding airspace rights that continue to influence aviation law today.
1.      Background: The case involved a chicken farmer whose land was frequently overflown by military aircraft at low altitudes, causing distress to his chickens and economic loss.
2.      Decision: The Court ruled that landowners have property rights in the airspace above their land, but these rights are limited by the public's right to travel through navigable airspace.
3.      Implications for Supersonic/Hypersonic Flight: This case set a precedent for balancing private property rights with the needs of aviation. As supersonic and hypersonic aircraft seek to operate at various altitudes, this balance will need to be reassessed.
 
B. British Airways Board v Laker Airways Ltd (1985)[45]
This case, involving the collapse of Laker Airways, highlighted the complex interplay between national regulations and international competition in the aviation industry.
1.      Background: Laker Airways, a budget airline, accused major carriers of predatory pricing and conspiracy, leading to a series of legal battles in the U.S. and UK.
2.      Decision: The House of Lords ruled on jurisdictional issues, emphasizing the importance of international comity in aviation disputes.
3.      Relevance to Supersonic/Hypersonic Aviation: As new high-speed aircraft enter the market, similar issues of fair competition and international jurisdiction may arise, particularly given the high costs and potential market disruption associated with these technologies.
 
C. Concorde-Heathrow Airport Users Committee v. British Airports Authority (1981)[46]
This case, previously mentioned, deserves a more detailed examination due to its significance for supersonic aircraft operations.
1.      Background: The case challenged the British Airports Authority's decision to allow Concorde to operate from Heathrow Airport despite noise concerns.
2.      Decision: The UK Court of Appeal ruled that while Concorde's noise levels exceeded statutory limits, its unique status justified special consideration.
3.      Impact: This decision set a precedent for balancing technological innovation with environmental regulations, a balance that will be crucial for future supersonic and hypersonic aircraft.
 
D. Center for Biological Diversity v. EPA (2019)[47]
This recent case underscores the growing legal pressure to address aviation's environmental impact.
1.      Background: Environmental groups sued the EPA for failing to regulate greenhouse gas emissions from aircraft engines.
2.      Decision: The D.C. Circuit Court allowed the lawsuit to proceed, rejecting the EPA's argument that it had unreviewable discretion in the timing of its regulatory actions.
3.      Implications: This case signals increased scrutiny of aviation's environmental impact, which will likely extend to supersonic and hypersonic aircraft. Manufacturers and operators will need to demonstrate compliance with evolving environmental standards.
 
E. In re Air Crash Near Peggy's Cove, Nova Scotia on September 2, 1998 (2001)[48]
While not directly related to supersonic flight, this case involving the crash of Swissair Flight 111 illustrates the complex liability issues that can arise in international aviation accidents.
1.      Background: The case involved multiple lawsuits filed in various jurisdictions following the crash of a McDonnell Douglas MD-11 aircraft.
2.      Decision: The U.S. District Court for the Eastern District of Pennsylvania consolidated the cases and addressed issues of jurisdiction and applicable law.
3.      Relevance to Supersonic/Hypersonic Aviation: As these high-speed aircraft begin international operations, similar complex liability issues may arise, potentially complicated by the unique characteristics of supersonic and hypersonic flight.
F. Griggs v. Allegheny County (1962)[49]
This U.S. Supreme Court case built upon the Causby decision, further refining the concept of "taking" as it relates to airport operations.
1.      Background: The case involved a homeowner near an airport who claimed that low-flying aircraft constituted a "taking" of his property.
2.      Decision: The Court ruled that the county, as the airport operator, was responsible for acquiring sufficient air easements to operate the airport without infringing on property rights.
3.      Implications for Supersonic/Hypersonic Flight: As these aircraft may require different approach and departure paths, this case highlights the potential need for reassessment of air easements and potential compensation to affected property owners.
 
G. Massachusetts v. Environmental Protection Agency (2007)[50]
While not specific to aviation, this landmark climate change case has broad implications for the regulation of greenhouse gas emissions, including those from aircraft.
1.      Background: Several states sued the EPA for failing to regulate greenhouse gases under the Clean Air Act.
2.      Decision: The Supreme Court ruled that the EPA has the authority to regulate greenhouse gases and must ground its reasons for action or inaction in the statute.
3.      Relevance to Supersonic/Hypersonic Aviation: This decision underpins the EPA's authority to regulate aircraft emissions, which will be a crucial consideration for supersonic and hypersonic aircraft manufacturers and operators.
 
H. Save Our Heritage Organisation v. San Diego City Council (2021)[51]
This recent case demonstrates the ongoing tension between development and environmental/historical preservation, which may be relevant to the construction of new facilities for supersonic and hypersonic aircraft.
1.      Background: The case involved a challenge to the approval of a development project near a historic district in San Diego.
2.      Decision: The California Court of Appeal upheld the project approval, finding that the city had adequately considered environmental and historical impacts.
3.      Implications: As new infrastructure may be needed to support supersonic and hypersonic operations, similar challenges balancing development with environmental and historical preservation may arise.
These case studies illustrate the complex legal landscape that supersonic and hypersonic aviation must navigate. From environmental concerns to property rights, from liability issues to regulatory authority, the development of high-speed aircraft will continue to intersect with various areas of law.
 
VI. FUTURE OUTLOOK AND POTENTIAL SOLUTIONS
As the aerospace industry continues to push the boundaries of speed and efficiency, the legal landscape must evolve to accommodate these advancements while safeguarding public interests.
 
A. Adaptive Regulatory Frameworks
1.      Performance-Based Regulations: Rather than prescriptive rules, regulatory bodies may adopt performance-based standards that focus on desired outcomes. This approach could provide flexibility for innovative technologies while maintaining safety and environmental standards[52].
2.      Regulatory Sandboxes: Following the model used in fintech, aviation authorities could create "regulatory sandboxes" that allow for controlled testing of supersonic and hypersonic technologies under relaxed regulatory conditions[53].
 
B. International Harmonization
1.      ICAO Leadership: ICAO could play a pivotal role in developing globally harmonized standards for supersonic and hypersonic flight. The organization's ongoing work on a new supersonic noise standard is a step in this direction[54].
2.      Bilateral Agreements: Countries may pursue bilateral agreements to facilitate the development and operation of high-speed aircraft, similar to the US-EU Bilateral Aviation Safety Agreement[55].
 
 
C. Environmental Solutions
1.      Sustainable Aviation Fuels: The development of sustainable aviation fuels could help address emissions concerns associated with high-speed flight. Legal frameworks may need to be adjusted to incentivize their use in supersonic and hypersonic aircraft[56].
2.      Carbon Offsetting: Expanding programs like CORSIA to specifically address high-speed flight could provide a mechanism for mitigating the environmental impact of these aircraft[57].
 
D. Noise Mitigation Strategies
1.      Route Optimization: Advanced algorithms and AI could be employed to optimize flight paths, minimizing noise impact on populated areas. This would require updates to air traffic management regulations[58].
2.      Community Engagement: Developing legal frameworks that mandate community engagement and compensation schemes could help address noise concerns, drawing lessons from cases like Griggs v. Allegheny County[59].
 
E. Safety and Certification
1.      International Certification Standards: Developing harmonized international certification standards for supersonic and hypersonic aircraft could streamline the approval process and ensure global safety standards[60].
2.      Digital Twin Technology: The use of digital twin technology for virtual testing and certification could accelerate the approval process while maintaining rigorous safety standards. This would require updates to certification regulations[61].
 
F. Airspace Integration
1.      Dynamic Airspace Management: Implementing flexible, dynamic airspace management systems could accommodate the unique flight profiles of supersonic and hypersonic aircraft. This would necessitate updates to air traffic control regulations and international agreements[62].
2.      Space Traffic Management: As hypersonic flights may operate at the edge of space, integrating space traffic management principles into aviation law could become necessary[63].
 
G. Intellectual Property and Export Control
1.      International IP Agreements: Developing specific international agreements on IP protection for aerospace technologies could facilitate innovation while protecting national interests[64].
2.      Targeted Export Control: Refining export control regulations to distinguish between military and civilian applications of high-speed flight technologies could support commercial development while safeguarding national security[65].
 
VII. CONCLUSION
The development of supersonic and hypersonic aircraft represents a new frontier in aviation, promising to revolutionize global transportation and defense capabilities. The noise pollution concerns that grounded the Concorde continue to pose significant hurdles, but advancements in "low-boom" technology offer hope for overcoming these obstacles. Environmental impacts remain a critical issue, with the need to balance the benefits of high-speed travel against the imperative of addressing climate change and protecting the ozone layer.
 
As we look to the future, it is clear that the development of supersonic and hypersonic aircraft will require not only technological breakthroughs but also legal ingenuity. Adaptive regulatory frameworks, international harmonization, and novel approaches to environmental mitigation will be key to unlocking the full potential of high-speed flight.
The journey beyond the sound barrier is as much a legal odyssey as it is a technological one. By addressing these challenges head-on, the global community can pave the way for a new era of aviation that connects the world faster than ever before, while respecting the principles of safety, environmental stewardship, and international cooperation.

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[2] Concorde-Heathrow Airport Users Comm. v. British Airports Auth., [1981] QB 64.
[3] 14 C.F.R. Section 91.817 (2024).
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[12] FAA Reauthorization Act of 2018, Pub. L. No. 115-254, Section 181, 132 Stat. 3186, 3459-60 (2018).
[13] Noise Certification of Supersonic Airplanes, 85 Fed. Reg. 20431 (Apr. 13, 2020) (to be codified at 14 C.F.R.   pt. 36).
[14] Regulation 598/2014, 2014 O.J. (L 173) 65.
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[16] European Comm'n, SENECA Project, CORDIS EU RESEARCH RESULTS (2021).
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[19] CIV. AVIATION ADMIN. OF CHINA, DEVELOPMENT OF CHINA'S CIVIL AVIATION INDUSTRY: 2019 ANNUAL REPORT (2019).
[20] Noise Control Act of 1972, 42 U.S.C. Section 4901-4918.
[21] Sierra Club v. Dep't of Transp., 753 F.2d 120 (D.C. Cir. 1985).
[22] Convention on International Civil Aviation, Dec. 7, 1944, 61 Stat. 1180, 15 U.N.T.S. 295.
[23] NAT'L AERONAUTICS & SPACE ADMIN., X-59 QUESST: THE FUTURE OF FLIGHT (2021).
[24] Clean Air Act, 42 U.S.C. Section 7571.
[25] Finding That Greenhouse Gas Emissions From Aircraft Cause or Contribute to Air Pollution That May  Reasonably Be Anticipated To Endanger Public Health and Welfare, 81 Fed. Reg. 54422 (Aug. 15, 2016) (to be codified at 40 C.F.R. pts. 87, 1068).
[26] INT'L CIV. AVIATION ORG., CARBON OFFSETTING AND REDUCTION SCHEME FOR   INTERNATIONAL AVIATION (CORSIA) (2016).
[27] Ctr. for Biological Diversity v. EPA, No. 16-1363 (D.C. Cir. 2019).
[28] Montreal Protocol on Substances that Deplete the Ozone Layer, Sept. 16, 1987, 1522 U.N.T.S. 3.
[29] FAA Modernization and Reform Act of 2012, Pub. L. No. 112-95, 126 Stat. 11 (2012).
[30] Convention on International Civil Aviation, supra note 22, art. 28.
[31] Convention for the Unification of Certain Rules for International Carriage by Air, May 28, 1999, T.I.A.S. No.  13,038, 2242 U.N.T.S. 309.
[32] Taylor v. FAA, 856 F.3d 1089 (D.C. Cir. 2017).
[33] Noise Certification of Supersonic Airplanes, 85 Fed. Reg. 20431 (Apr. 13, 2020) (to be codified at 14 C.F.R.   pt. 36).
[34] INT'L CIV. AVIATION ORG., AIRWORTHINESS MANUAL, DOC 9760 (3d ed. 2014).
[35] In re Air Crash Disaster at Sioux City, Iowa, on July 19, 1989, 781 F. Supp. 1307 (N.D. Ill. 1991).
[36] 35 U.S.C. Section 102, 103.
[37] United States v. Hsu, 155 F.3d 189 (3d Cir. 1998).
[38] Agreement on Trade-Related Aspects of Intellectual Property Rights, Apr. 15, 1994, Marrakesh Agreement Establishing the World Trade Organization, Annex 1C, 1869 U.N.T.S. 299.
[39] Rolls-Royce plc v. United Techs. Corp. [2011] EWCA (Civ) 1589 (Eng.).
[40] Export Control Reform Act of 2018, Pub. L. No. 115-232, 132 Stat. 2208 (2018).
[41] International Traffic in Arms Regulations, 22 C.F.R. Section 120-130 (2024).
[42] Wassenaar Arrangement on Export Controls for Conventional Arms and Dual-Use Goods and Technologies (July 12, 1996).
[43] Boom Supersonic and Rolls-Royce End Engine-development Relationship, FLIGHT GLOBAL, Sept. 19, 2022.
[44] United States v. Causby, 328 U.S. 256 (1946).
[45] British Airways Bd. v. Laker Airways Ltd. [1985] AC 58 (HL) (appeal taken from Eng.).
[46] Concorde-Heathrow Airport Users Comm. v. British Airports Auth., [1981] QB 64.
[47] Ctr. for Biological Diversity v. EPA, No. 16-1363 (D.C. Cir. 2019).
[48] In re Air Crash Near Peggy's Cove, Nova Scotia on Sept. 2, 1998, 210 F. Supp. 2d 570 (E.D. Pa. 2002).
[49] Griggs v. Allegheny County, 369 U.S. 84 (1962).
[50] Massachusetts v. EPA, 549 U.S. 497 (2007).
[51] Save Our Heritage Org. v. San Diego City Council, 11 Cal. 5th 1071 (2021).
[52] INT'L CIV. AVIATION ORG., SAFETY MANAGEMENT MANUAL (SMM), DOC 9859 (4th ed. 2018).
[53] Dirk A. Zetzsche et al., Regulating a Revolution: From Regulatory Sandboxes to Smart Regulation, 23   FORDHAM J. CORP. & FIN. L. 31 (2017).
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