# Control of Air Pollution From Airplanes and Airplane Engines: GHG Emission Standards and Test Procedures

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URL: https://www.frixlaw.com/law-library/documents/fr%3A2020-16271

## Record

- **Collection:** Federal Register
- **Document type:** Proposed Rule
- **Published:** August 20, 2020
- **Citation:** 85 FR 51556

## Text

ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 87 and 1030
[EPA-HQ-OAR-2018-0276; FRL-10010-88-OAR]
RIN 2060-AT26
Control of Air Pollution From Airplanes and Airplane Engines: GHG Emission Standards and Test Procedures

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule.

SUMMARY:

The Environmental Protection Agency (EPA) is proposing greenhouse gas (GHG) emission standards applicable to certain classes of engines used by certain civil subsonic jet airplanes with a maximum takeoff mass greater than 5,700 kilograms and by certain civil larger subsonic propeller-driven airplanes with turboprop engines having a maximum takeoff mass greater than 8,618 kilograms. These proposed standards are equivalent to the airplane CO
2
standards adopted by the International Civil Aviation Organization (ICAO) in 2017 and would apply to both new type design airplanes and in-production airplanes. The standards proposed in this rule are the equivalent of the ICAO standards, consistent with U.S. efforts to secure the highest practicable degree of uniformity in aviation regulations and standards. The proposed standards would, if finalized, also meet the EPA's obligation under section 231 of the Clean Air Act to adopt GHG standards for certain classes of airplanes as a result of the 2016 “Finding That Greenhouse Gas Emissions From Aircraft Cause or Contribute to Air Pollution That May Reasonably Be Anticipated To Endanger Public Health and Welfare” (hereinafter “2016 Findings”)—for six well-mixed GHGs emitted by certain classes of airplane engines. Airplane engines emit only two of the six well-mixed GHGs, CO
2
and nitrous oxide (N
2
O). Accordingly, EPA is proposing to use the fuel-efficiency-based metric established by ICAO, which reasonably serves as a surrogate for controlling both the GHGs emitted by airplane engines, CO
2
and N
2
O.

DATES:

Comments:
Written comments on this proposal must be received on or before October 19, 2020. Under the Paperwork Reduction Act (PRA), comments on the information collection provisions are best assured of consideration if the Office of Management and Budget (OMB) receives a copy of your comments on or before September 21, 2020.

Public Hearing:
EPA will announce the public hearing date and location for this proposal in a supplemental
Federal Register
document.

ADDRESSES:

Submit your comments, identified by Docket ID No. EPA-HQ-OAR-2018-0276, at
http://www.regulations.gov
(our preferred method), or the other methods identified in the
ADDRESSES
section. Once submitted, comments cannot be edited or removed from the docket. The EPA may publish any comment received to its public docket. Do not submit to EPA's docket at
https://www.regulations.gov
any information you consider to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Multimedia submissions (audio, video, etc.) must be accompanied by a written comment. The written comment is considered the official comment and should include discussion of all points you wish to make. The EPA will generally not consider comments or comment contents located outside of the primary submission (
i.e.
on the web, cloud, or other file sharing system). For additional submission methods, the full EPA public comment policy, information about CBI or multimedia submissions, and general guidance on making effective comments, please visit
https://www.epa.gov/dockets/commenting-epa-dockets
.

EPA solicits comments on all aspects of the proposed standards. However, we do not seek and do not intend to respond to comments on any aspect of EPA's 2016 Findings.

The EPA is temporarily suspending its Docket Center and Reading Room for public visitors, with limited exceptions, to reduce the risk of transmitting COVID-19. Our Docket Center staff will continue to provide remote customer service via email, phone, and webform. We encourage the public to submit comments via
https://www.regulations.gov/
as there may be a delay in processing mail and faxes. Hand deliveries or couriers will be received by scheduled appointment only. For further information and updates on EPA Docket Center services, please visit us online at
https://www.epa.gov/dockets
.

The EPA continues to carefully and continuously monitor information from the Centers for Disease Control and Prevention (CDC), local area health departments, and our Federal partners so that we can respond rapidly as conditions change regarding COVID-19.

FOR FURTHER INFORMATION CONTACT:

Bryan Manning, Office of Transportation and Air Quality, Assessment and Standards Division (ASD), Environmental Protection Agency, 2000 Traverwood Drive, Ann Arbor, MI 48105; telephone number: (734) 214-4832; email address:
manning.bryan@epa.gov
.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. General Information

A. Does this action apply to me?

B. Did EPA conduct a peer review before issuing this proposed rule?

C. Executive Summary

II. Introduction: Overview and Context for This Proposed Action

A. Summary of Proposed Rule

B. EPA Statutory Authority and Responsibilities Under the Clean Air Act

C. Background Information Helpful to Understanding This Proposed Action

D. U.S. Airplane Regulations and the International Community

E. Consideration of Whole Airplane Characteristics

III. Summary of the 2016 Findings

IV. Summary of Advance Notice of Proposed Rulemaking and Comments Received

A. Summary

V. Details for the Proposed Rule

A. Airplane Fuel Efficiency Metric

B. Covered Airplane Types and Applicability

C. GHG Standard for New Type Designs

D. GHG Standard for In-Production Airplane Types

E. Exemptions From the Proposed GHG Rules

F. Application of Rules for New Version of an Existing GHG-Certificated Airplane

G. Annual Reporting Requirement

H. Test and Measurement Procedures

I. Controlling Two of the Six Well-Mixed GHGs

VI. Aggregate GHG and Fuel Burn Methods and Results

A. What methodologies did the EPA use for the emissions inventory assessment?

B. What are the baseline CO
2
emissions?

C. What are the projected effects in fuel burn and GHG emissions?

VII. Technological Feasibility and Economic Impacts

A. Market Considerations

B. Conceptual Framework for Technology

C. Technological Feasibility

D. Costs Associated With the Program

E. Summary of Benefits and Costs

VIII. Aircraft Engine Technical Amendments

IX. Statutory Authority and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive Order 13563: Improving Regulation and Regulatory Review

B. Executive Order 13771: Reducing Regulation and Controlling Regulatory Costs

C. Paperwork Reduction Act (PRA)

D. Regulatory Flexibility Act (RFA)

E. Unfunded Mandates Reform Act (UMRA)

F. Executive Order 13132: Federalism

G. Executive Order 13175: Consultation and Coordination With Indian Tribal Governments

H. Executive Order 13045: Protection of Children From Environmental Health Risks and Safety Risks

I. Executive Order 13211: Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution or Use

J. National Technology Transfer and Advancement Act (NTTAA) and 1 CFR part 51

K. Executive Order 12898: Federal Actions To Address Environmental Justice in Minority Populations and Low-Income Populations

I. General Information

A. Does this action apply to me?

This proposed action would affect companies that manufacture civil subsonic jet airplanes that have a maximum takeoff mass (MTOM) of greater than 5,700 kilograms and civil subsonic propeller driven airplanes (
e.g.,
turboprops) that have a MTOM greater than 8,618 kilograms, including the manufacturers of the engines used on these airplanes. Affected entities include the following:

Category

NAICS code
a

Examples of
potentially
affected entities

Industry
336412
Manufacturers of new aircraft engines

Industry
336411
Manufacturers of new aircraft

a
North American Industry Classification System (NAICS).

This table lists the types of entities that EPA is now aware could potentially be affected by this action. Other types of entities not listed in the table might also be subject to these proposed regulations. To determine whether your activities are regulated by this action, you should carefully examine the relevant applicability criteria in 40 CFR parts 87 and 1030. If you have any questions regarding the applicability of this action to a particular entity, consult the person listed in the preceding
FOR FURTHER INFORMATION CONTACT
section.

For consistency purposes across the United States Code of Federal Regulations (CFR), the terms “airplane,” “aircraft,” and “civil aircraft” have the meanings found in title 14 CFR and are used as appropriate throughout the new proposed regulation under 40 CFR part 1030.

B. Did EPA conduct a peer review before issuing this proposed rule?

This regulatory action is supported by influential scientific information. Therefore, the EPA conducted peer reviews consistent with the Office of Management and Budget's (OMB's) Final Information Quality Bulletin for Peer Review.
1

Two different reports used in support of this proposed action underwent peer review; a report detailing the technologies likely to be used in compliance with the proposed standards and their associated costs
2

and a report detailing the methodology and results of the emissions inventory modeling.
3

These reports were each peer-reviewed through external letter reviews by multiple independent subject matter experts (including experts from academia and other government agencies, as well as independent technical experts).
4 5

The peer review reports and the Agency's response to the peer review comments are available in Docket ID No. EPA-HQ-OAR-2018-0276.

1
OMB, 2004: Memorandum for Heads of Departments and Agencies,
Final Information Quality Bulletin for Peer Review.
Available at
https://www.whitehouse.gov/sites/whitehouse.gov/files/omb/memoranda/2005/m05-03.pdf
.

2
ICF, 2018:
Aircraft CO
2
Cost and Technology Refresh and Industry Characterization, Final Report, EPA Contract Number EP-C-16-020, September 30, 2018.

3
U.S. EPA, 2020:
Technical Report on Aircraft Emissions Inventory and Stringency Analysis,
July 2020, 52pp.

4
RTI International and EnDyna,
Aircraft CO2 Cost and Technology Refresh and Aerospace Industry Characterization: Peer Review,
June 2018, 114pp.

5
RTI International and EnDyna,
EPA Technical Report on Aircraft Emissions Inventory and Stringency Analysis: Peer Review,
July 2019, 157pp.

C. Executive Summary

1. Purpose of the Proposed Regulatory Action

One of the core functions of ICAO is to adopt Standards and Recommended Practices on a wide range of aviation-related matters, including aircraft emissions. As a member State of the ICAO, the United States seeks to secure the highest practicable degree of uniformity in aviation regulations and standards.
6

ICAO adopted airplane CO
2
standards in 2017. The adoption of these aviation standards into U.S. law will align with the ICAO standards. For reasons discussed herein, the EPA is proposing to adopt standards for GHG emissions from certain classes of engines used on covered airplanes (hereinafter “covered airplanes” or “airplanes”) that are equivalent in scope, stringency and timing to the CO
2
standards adopted by ICAO.

6
ICAO, 2006: Convention on International Civil Aviation, Ninth Edition, Document 7300/9, Article 37, 114 pp. Available at:
http://www.icao.int/publications/Documents/7300_9ed.pdf
(last accessed March 16, 2020).

These proposed standards would allow U.S. manufacturers of covered airplanes to remain competitive in the global marketplace. In the absence of U.S. standards for implementing the ICAO Airplane CO
2
Emission Standards, U.S. civil airplane manufacturers could be forced to seek CO
2
emissions certification from an aviation certification authority of another country (not the Federal Aviation Administration (FAA)) in order to market and operate their airplanes internationally. U.S. manufacturers would be presumed to be at a significant disadvantage if the U.S. fails to adopt standards that are at least as stringent as the ICAO standards for CO
2
emissions. The ICAO Airplane CO
2
Emission Standards have been adopted by other ICAO member states that certify airplanes. The action to adopt in the U.S. GHG standards that match the ICAO Airplane CO
2
Emission Standards will help ensure international consistency and acceptance of U.S. manufactured airplanes worldwide.

In August 2016, the EPA issued two findings regarding GHG emissions from aircraft engines (the 2016 Findings).
7

First, the EPA found that elevated concentrations of GHGs in the atmosphere endanger the public health and welfare of current and future generations within the meaning of section 231(a)(2)(A) of the Clean Air Act (CAA). Second, EPA found that emissions of GHGs from certain classes of engines used in certain aircraft are contributing to the air pollution that endangers public health and welfare under CAA section 231(a)(2)(A). Additional details of the 2016 Findings are described in Section III. As a result of the 2016 Findings, CAA sections 231(a)(2)(A) and (3) obligate the EPA to propose and adopt, respectively, GHG standards for these covered aircraft engines.

7
U.S. EPA, 2016:
Finding That Greenhouse Gas Emissions From Aircraft Cause or Contribute To Air Pollution That May Reasonably Be Anticipated To Endanger Public Health and Welfare; Final Rule,
81 FR 54422 (August 15, 2016).

2. Summary of the Major Provisions of the Proposed Regulatory Action

The EPA is proposing to regulate GHG emissions from covered airplanes through the adoption of domestic GHG regulations that match international standards to control CO
2
emissions. The proposed GHG standards are equivalent to the CO
2
standards adopted by ICAO and will be implemented and enforced in the U.S. The proposed standards would apply to covered airplanes: Civil subsonic jet airplanes (those powered by turbojet or turbofan engines and with a

MTOM greater than 5,700 kilograms), as well as larger civil subsonic propeller-driven airplanes (those powered by turboprop engines and with a MTOM greater than 8,618 kilograms). The timing and stringencies of the standards would differ depending on whether the covered airplane is a new type design (
i.e.,
a design that has not previously been type certificated under title 14 CFR) or an in-production model (
i.e.,
an existing design that had been type certificated under title 14 CFR prior to the effective date of the GHG standards). The standards for new type designs would apply to covered airplanes for which an application for certification is submitted to the FAA on or after January 1, 2020 (January 1, 2023, for new type designs that have a maximum takeoff mass (MTOM) of 60,000 kilograms MTOM or less and have 19 passenger seats or fewer). The in-production standards would apply to covered airplanes beginning January 1, 2028. Additionally, consistent with ICAO standards, the EPA is proposing that, before the in-production standards otherwise apply in 2028, certain modifications made to airplanes (
i.e.,
changes that result in an increase in GHG emissions) would trigger a requirement to certify to the in-production regulation beginning January 1, 2023.

The EPA is proposing to adopt the ICAO CO
2
metric, which measures fuel efficiency, for demonstrating compliance with the GHG emission standards. This metric is a mathematical function that incorporates the specific air range (SAR) of an airplane/engine combination (a traditional measure of airplane cruise performance in units of kilometer/kilogram of fuel) and the reference geometric factor (RGF), a measure of fuselage size. The metric is further discussed in Section V.A.

To measure airplane fuel efficiency, the EPA is proposing to adopt the ICAO test procedures whereby the airplane/engine SAR value is measured at three specific operating test points, and a composite of those results is used in the metric to determine compliance with the proposed GHG standards. The test procedures are discussed in Section V.H.

Consistent with the current annual reporting requirement for engine emissions, the EPA is proposing to require the annual reporting of the number of airplanes produced, airplane characteristics, and test parameters. Further information on all aspects of the proposed GHG standards can be found in Section V.

Finally, the EPA is proposing to update the existing incorporation by reference of the ICAO test procedures for hydrocarbons (HC), carbon monoxide (CO), oxides of nitrogen (NO
X
) and smoke to reference the most recent edition of the ICAO procedures. This update would improve clarity in the existing test procedures and includes a minor change to the composition of the test fuel used for engine certification. Further details on this technical amendment can be found in Section VIII.

3. Cost and Benefits

U.S. manufacturers have already developed or are developing technologies that will allow affected airplanes to comply with the ICAO standards, in advance of EPA's adoption of standards. Furthermore, based on the manufacturers' expectation that the ICAO standards will be implemented globally, the EPA anticipates nearly all affected airplanes to be compliant by the respective effective dates for new type designs and for in-production airplanes. This includes the expectation that existing in-production airplanes that are non-compliant will either be modified and re-certificated as compliant or will likely go out of production before the production compliance date of January 1, 2028. For these reasons, the EPA is not projecting emission reductions associated with these proposed GHG regulations. We do, however, project a small cost associated with the proposed annual reporting requirement. For further details on the benefits and costs associated with these proposed GHG standards, see Sections VI and VII, respectively.

II. Introduction: Overview and Context for This Proposed Action

This section provides a summary of the proposed rule. This section describes the EPA's statutory authority, the U.S. airplane engine regulations and the relationship with ICAO's international standards, and consideration of the whole airplane in addressing airplane engine GHG emissions.

A. Summary of Proposed Rule

In February 2016, ICAO's Committee on Aviation Environmental Protection (CAEP) agreed to international Airplane CO
2
Emission Standards, which ICAO approved in 2017. The EPA is proposing to adopt GHG standards that are equivalent to the international Airplane CO
2
Emission Standards promulgated by ICAO in Annex 16.
8

8
ICAO, 2006: Convention on International Civil Aviation, Ninth Edition, Document 7300/9, 114 pp. Available at:
http://www.icao.int/publications/Documents/7300_9ed.pdf
(last accessed March 16, 2020).

As a result of the 2016 findings,
9 10

the EPA is obligated under section 231(a) of the CAA to propose and issue emission standards applicable to GHG emissions from the classes of engines used by covered aircraft included in the 2016 Findings. As described later in further detail in Section III, we are proposing to regulate the air pollutant that is the aggregate of the six well-mixed GHGs. Only two of the six well-mixed GHGs—CO
2
and N
2
O—have non-zero emissions for total civil subsonic airplanes and U.S. covered airplanes. CO
2
represents 99 percent of all GHGs emitted from both total U.S. civil airplanes and U.S. covered airplanes, and N
2
O represents 1 percent of GHGs emitted from total airplanes and U.S. covered airplanes. Promulgation of the proposed GHG emission standards for the certain classes of engines used by covered airplanes would fulfill EPA's obligations under the CAA and is the next step for the United States in implementing the ICAO standards promulgated in Annex 16 under the Chicago Convention. We are proposing a new rule that controls aircraft engine GHG emissions through the use of the ICAO regulatory metric that quantifies airplane fuel efficiency.

9
U.S. EPA, 2016:
Finding That Greenhouse Gas Emissions From Aircraft Cause or Contribute To Air Pollution That May Reasonably Be Anticipated To Endanger Public Health and Welfare and Advance Notice of Proposed Rulemaking; Final Rule,
81 FR 54422 (August 15, 2016).

10
Covered airplanes are those airplanes to which the international CO
2
standards and the proposed GHG standards would apply: Subsonic jet airplanes with a maximum takeoff mass (MTOM) greater than 5,700 kilograms and subsonic propeller-driven (
e.g.,
turboprop) airplanes with a MTOM greater than 8,618 kilograms. Section V describes covered and non-covered airplanes in further detail.

ICAO, 2016:
Tenth Meeting Committee on Aviation Environmental Protection Report,
Doc 10069, CAEP/10, 432 pp, Available at:
http://www.icao.int/publications/Pages/catalogue.aspx
(last accessed March 16, 2020). The ICAO CAEP/10 report is found on page 27 of the English Edition 2020 catalog and is copyright protected; Order No. 10069.

The proposed rule would establish GHG standards applicable to U.S. airplane manufacturers that are no less stringent than the ICAO Airplane CO
2
Emission Standards adopted by ICAO.
11

This proposed rule incorporates the same compliance schedule as the ICAO

Airplane CO
2
Emission Standards. The proposed standards would apply to both new type designs and in-production airplanes. The in-production standards would have later applicability dates and different emission levels than for the standards for new type designs. The different emission levels for new type designs and in-production airplanes depend on the airplane size, weight, and availability of fuel efficiency technologies.

11
ICAO's certification standards and test procedures for airplane CO
2
emissions are based on the consumption of fuel (or fuel burn) under prescribed conditions at optimum cruise altitude. ICAO uses the term, CO
2
, for its standards and procedures, but ICAO is actually regulating or measuring the rate of an airplane's fuel burn (fuel efficiency). For jet fuel, the emissions index or emissions factor for CO
2
is 3.16 kilograms of CO
2
per kilogram of fuel burn (or 3,160 grams of CO
2
per kilogram of fuel burn). Thus, to convert an airplane's rate of fuel burn to a CO
2
emissions rate, this emission index needs to be applied.

Apart from the proposed GHG requirements, we are also proposing to update the engine emissions testing and measurement procedures applicable to HC, NO
X
, CO, and smoke in current regulations. The updates would implement recent amendments to ICAO standards in Annex 16, Volume II, and these updates would be accomplished by incorporating provisions of the Annex by reference, as has historically been done.

B. EPA Statutory Authority and Responsibilities Under the Clean Air Act

Section 231(a)(2)(A) of the CAA directs the Administrator of the EPA to, from time to time, propose aircraft engine emission standards applicable to the emission of any air pollutant from classes of aircraft engines which in the Administrator's judgment causes or contributes to air pollution that may reasonably be anticipated to endanger public health or welfare. (See 42 U.S.C. 7571(a)(2)(A)). Section 231(a)(2)(B) directs the EPA to consult with the Administrator of the FAA on such standards, and it prohibits the EPA from changing aircraft engine emission standards if such a change would significantly increase noise and adversely affect safety (see 42 U.S.C. 7571(a)(2)(B)(i)-(ii)). Section 231(a)(3) provides that after we propose standards, the Administrator shall issue such standards “with such modifications as he deems appropriate.” (see 42 U.S.C. 7571(a)(3)). The U.S. Court of Appeals for the D.C. Circuit has held that this provision confers an unusually broad degree of discretion on the EPA to adopt aircraft engine emission standards as the Agency determines are reasonable.
Nat'l Ass'n of Clean Air Agencies
v.
EPA,
489 F.3d 1221, 1229-30 (D.C. Cir. 2007) (
NACAA
).

In addition, under CAA section 231(b) the EPA is required to ensure, in consultation with the U.S. Department of Transportation (DOT), that the effective date of any standard provides the necessary time to permit the development and application of the requisite technology, giving appropriate consideration to the cost of compliance (see 42 U.S.C. 7571(b)). Section 232 then directs the Secretary of Transportation to prescribe regulations to ensure compliance with the EPA's standards (see 42 U.S.C. 7572). Finally, section 233 of the CAA vests the authority to promulgate emission standards for aircraft engines only in the Federal Government. States are preempted from adopting or enforcing any standard respecting emissions from aircraft or aircraft engines unless such standard is identical to the EPA's standards (see 42 U.S.C. 7573).

C. Background Information Helpful To Understanding This Proposed Action

Civil airplanes and associated engines are international commodities that are manufactured and sold around the world. The member States of ICAO and the world's airplane and engine manufacturers participated in the deliberations leading up to ICAO's adoption of the international Airplane CO
2
Emission Standards. However, ICAO's standards are not directly applicable to and enforceable against member States' airplane and engine manufacturers. Instead, after adoption of the standards by ICAO, a member State is required (as described later in Section II.D.1) to adopt domestic standards at least as stringent as ICAO standards and apply them, as applicable, to subject airplane and engine manufacturers in order to ensure recognition of their airworthiness and type certificate by other civil aviation authorities. This proposed rulemaking is a necessary step to meet this obligation for the United States.

D. U.S. Airplane Regulations and the International Community

The EPA and the FAA work within the standard-setting process of ICAO's CAEP to help establish international emission standards and related requirements, which individual member States adopt into domestic law and regulations. Historically, under this approach, international emission standards have first been adopted by ICAO, and subsequently the EPA has initiated rulemakings under CAA section 231 to establish domestic standards that are at least as stringent as ICAO's standards. After EPA promulgates aircraft engine emission standards, CAA section 232 requires the FAA to issue regulations to ensure compliance with the EPA aircraft engine emission standards when issuing airworthiness certificates pursuant to its authority under Title 49 of the United States Code. This proposed rule continues this historical rulemaking approach.

1. International Regulations and U.S. Obligations

The EPA has worked with the FAA since 1973, and later with ICAO, to develop domestic and international standards and other recommended practices pertaining to aircraft engine emissions. The Convention on International Civil Aviation (commonly known as the ‘Chicago Convention') was signed in 1944 at the Diplomatic Conference held in Chicago. The Chicago Convention establishes the legal framework for the development of international civil aviation. The primary objective is “that international civil aviation may be developed in a safe and orderly manner and that international air transport services may be established on the basis of equality of opportunity and operated soundly and economically.”
12

In 1947, ICAO was established, and later in that same year ICAO became a specialized agency of the United Nations (UN). ICAO sets international standards for aviation safety, security, efficiency, capacity, and environmental protection and serves as the forum for cooperation in all fields of international civil aviation. ICAO works with the Chicago Convention's member States and global aviation organizations to develop international Standards and Recommended Practices (SARPs), which member States reference when developing their domestic civil aviation regulations. The United States is one of 193 currently participating ICAO member States.
13 14

12
ICAO, 2006:
Convention on International Civil Aviation, Ninth Edition,
Document 7300/9, 114 pp. Available at:
http://www.icao.int/publications/Documents/7300_9ed.pdf
(last accessed March 16, 2020).

13
Members of ICAO's Assembly are generally termed member States or contracting States. These terms are used interchangeably throughout this preamble.

14
There are currently 193 contracting states according to ICAO's website:
https://www.icao.int/MemberStates/Member%20States.English.pdf
(last accessed March 16, 2020).

In the interest of global harmonization and international air commerce, the Chicago Convention urges its member States to “collaborate in securing the highest practicable degree of uniformity in regulations, standards, procedures and organization in relation to aircraft, . . . in all matters which such uniformity will facilitate and improve air navigation.” The Chicago Convention also recognizes that member States may adopt national standards that are more or less stringent than those agreed upon by ICAO or standards that are different in character or comply with the ICAO standards by other means. Any member State that finds it impracticable to comply in all respects

with any international standard or procedure, or that determines it is necessary to adopt regulations or practices differing in any particular respect from those established by an international standard, is required to give notification to ICAO of the differences between its own practice and that established by the international standard.
15

15
ICAO, 2006:
Doc 7300-Convention on International Civil Aviation, Ninth Edition,
Document 7300/9, 114 pp. Available at
http://www.icao.int/publications/Documents/7300_9ed.pdf
(last accessed March 16, 2020).

ICAO's work on the environment focuses primarily on those problems that benefit most from a common and coordinated approach on a worldwide basis, namely aircraft noise and engine emissions. SARPs for the certification of aircraft noise and aircraft engine emissions are contained in Annex 16 to the Chicago Convention. To continue to address aviation environmental issues, in 2004, ICAO established three environmental goals: (1) Limit or reduce the number of people affected by significant aircraft noise; (2) limit or reduce the impact of aviation emissions on local air quality; and (3) limit or reduce the impact of aviation GHG emissions on the global climate.

The Chicago Convention has a number of other features that govern international commerce. First, member States that wish to use aircraft in international transportation must adopt emission standards that are at least as stringent as ICAO's standards if they want to ensure recognition of their airworthiness certificates. Member States may ban the use of any aircraft within their airspace that does not meet ICAO standards.
16

Second, the Chicago Convention indicates that member States are required to recognize the airworthiness certificates issued or rendered valid by the contracting State in which the aircraft is registered provided the requirements under which the certificates were issued are equal to or above ICAO's minimum standards.
17

Third, to ensure that international commerce is not unreasonably constrained, a member State that cannot meet or deems it necessary to adopt regulations differing from the international standard is obligated to notify ICAO of the differences between its domestic regulations and ICAO standards.
18

16
ICAO, 2006:
Convention on International Civil Aviation, Article
33,
Ninth Edition,
Document 7300/9, 114 pp. Available at
http://www.icao.int/publications/Documents/7300_9ed.pdf
(last accessed March 16, 2020).

17
ICAO, 2006:
Convention on International Civil Aviation, Article 33, Ninth Edition,
Document 7300/9, 114 pp. Available at
http://www.icao.int/publications/Documents/7300_9ed.pdf
(last accessed March 16, 2020).

18
ICAO, 2006:
Convention on International Civil Aviation, Article 38, Ninth Edition,
Document 7300/9, 114 pp. Available at
http://www.icao.int/publications/Documents/7300_9ed.pdf
(last accessed March 16, 2020).

ICAO's CAEP, which consists of members and observers from states, intergovernmental and non-governmental organizations representing the aviation industry and environmental interests, undertakes ICAO's technical work in the environmental field. The Committee is responsible for evaluating, researching, and recommending measures to the ICAO Council that address the environmental impacts of international civil aviation. CAEP's terms of reference indicate that “CAEP's assessments and proposals are pursued taking into account: Technical feasibility; environmental benefit; economic reasonableness; interdependencies of measures (for example, among others, measures taken to minimize noise and emissions); developments in other fields; and international and national programs.”
19

The ICAO Council reviews and adopts the recommendations made by CAEP. It then reports to the ICAO Assembly, the highest body of the organization, where the main policies on aviation environmental protection are adopted and translated into Assembly Resolutions. If ICAO adopts a CAEP proposal for a new environmental standard, it then becomes part of ICAO standards and recommended practices (Annex 16 to the Chicago Convention).
20 21

19
ICAO: CAEP Terms of Reference. Available at
http://www.icao.int/environmental-protection/Pages/Caep.aspx#ToR
(last accessed March 16, 2020).

20
ICAO, 2017:
Aircraft Engine Emissions,
International Standards and Recommended Practices, Environmental Protection, Annex 16, Volume II, Fourth Edition, July 2017, 174 pp. Available at
http://www.icao.int/publications/Pages/catalogue.aspx
(last accessed March 16, 2020). The ICAO Annex 16 Volume II is found on page 16 of the ICAO Products & Services English Edition 2020 catalog and is copyright protected; Order No. AN16-2.

21
CAEP develops new emission standards based on an assessment of the technical feasibility, cost, and environmental benefit of potential requirements.

The FAA plays an active role in ICAO/CAEP, including serving as the representative (member) of the United States at annual ICAO/CAEP Steering Group meetings, as well as the ICAO/CAEP triennial meetings, and contributing technical expertise to CAEP's working groups. The EPA serves as an advisor to the U.S. member at the annual ICAO/CAEP Steering Group and triennial ICAO/CAEP meetings, while also contributing technical expertise to CAEP's working groups and assisting and advising FAA on aviation emissions, technology, and environmental policy matters. In turn, the FAA assists and advises the EPA on aviation environmental issues, technology and airworthiness certification matters.

CAEP's predecessor at ICAO, the Committee on Aircraft Engine Emissions (CAEE), adopted the first international SARPs for aircraft engine emissions that were proposed in 1981.
22

These standards limited aircraft engine emissions of hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NO
X
). The 1981 standards applied to newly manufactured engines, which are those engines built after the effective date of the regulations—also referred to as in-production engines. In 1993, ICAO adopted a CAEP/2 proposal to tighten the original NO
X
standard by 20 percent and amend the test procedures.
23

These 1993 standards applied both to newly certificated turbofan engines (those engine models that received their initial type certificate after the effective date of the regulations, referred to as newly certificated engines or new type design engines) and to in-production engines; the standards had different effective dates for newly certificated engines and in-production engines. In 1995, CAEP/3 recommended a further tightening of the NO
X
standards by 16 percent and additional test procedure amendments, but in 1997 the ICAO Council rejected this stringency proposal and approved only the test procedure amendments. At the CAEP/4 meeting in 1998, the Committee adopted a similar 16 percent NO
X
reduction proposal, which ICAO approved in 1998. Unlike the CAEP/2 standards, the CAEP/4 standards applied only to new type design engines after December 31, 2003. In 2004, CAEP/6 recommended a 12 percent NO
X
reduction, which ICAO approved in 2005.
24 25

The CAEP/6 standards applied

to new engine designs certificated after December 31, 2007. In 2010, CAEP/8 recommended a further tightening of the NO
X
standards by 15 percent for new engine designs certificated after December 31, 2013.
26 27

The Committee also recommended that the CAEP/6 standards be applied to in-production engines, which cut off the production of CAEP/4 compliant engines with the exception of spare engines; ICAO adopted these as standards in 2011.
28

22
ICAO, 2017:
Aircraft Engine Emissions: Foreword,
International Standards and Recommended Practices, Environmental Protection, Annex 16, Volume II, Fourth Edition, July 2017, 174pp. Available at
https://www.icao.int/publications/Pages/catalogue.aspx
(last accessed March 16, 2020). The ICAO Annex 16 Volume II is found on page 16 of the ICAO Products & Services English Edition 2020 catalog and is copyright protected; Order No. AN16-2.

23
CAEP conducts its work triennially. Each 3-year work cycle is numbered sequentially and that identifier is used to differentiate the results from one CAEP meeting to another by convention. The first technical meeting on aircraft emission standards was CAEP's predecessor,
i.e.,
CAEE. The first meeting of CAEP, therefore, is referred to as CAEP/2.

24
CAEP/5 did not address new airplane engine emission standards.

25
ICAO, 2017:
Aircraft Engine Emissions,
International Standards and Recommended Practices, Environmental Protection, Annex 16,Volume II, Fourth Edition, July 2017, 174pp. Available at
https://www.icao.int/publications/Pages/catalogue.aspx
(last accessed March 16, 2020). The ICAO Annex 16 Volume II is found on page 16 of the ICAO Products & Services English Edition 2020 catalog and is copyright protected; Order No. AN16-2.

26
CAEP/7 did not address new aircraft engine emission standards.

27
ICAO, 2010:
Committee on Aviation Environmental Protection (CAEP), Report of the Eighth Meeting, Montreal, February 1-12, 2010,
CAEP/8-WP/80 Available in Docket EPA-HQ-OAR-2010-0687.

28
ICAO, 2017:
Aircraft Engine Emissions,
International Standards and Recommended Practices, Environmental Protection, Annex 16, Volume II, Fourth Edition, July 2017, Amendment 9, 174 pp. CAEP/8 corresponds to Amendment 7 effective on July 18, 2011. Available at
https://www.icao.int/publications/Pages/catalogue.aspx

(last accessed March 16, 2020). The ICAO Annex 16 Volume II is found on page 16 of the ICAO Products & Services English Edition 2020 catalog and is copyright protected; Order No. AN16-2.

At the CAEP/10 meeting in 2016, the Committee agreed to the first airplane CO
2
emission standards, which ICAO approved in 2017. The CAEP/10 CO
2
standards apply to new type design airplanes for which the application for a type certificate will be submitted on or after January 1, 2020, some modified in-production airplanes on or after January 1, 2023, and all applicable in-production airplanes built on or after January 1, 2028.

2. EPA's Regulation of Aircraft Engine Emissions and the Relationship to International Aircraft Standards

As required by the CAA, the EPA has been engaged in reducing harmful air pollution from airplane engines for over 40 years, regulating gaseous exhaust emissions, smoke, and fuel venting from engines.
29

We have periodically revised these regulations. In a 1997 rulemaking, for example, we made our emission standards and test procedures more consistent with those of ICAO's CAEP for turbofan engines used in commercial aviation with rated thrusts greater than 26.7 kilonewtons.
30

These ICAO requirements are generally referred to as CAEP/2 standards.
31

The 1997 rulemaking included new NO
X
emission standards for newly manufactured commercial turbofan engines
32 33

and for newly certificated commercial turbofan engines.
34 35

It also included a CO emission standard for in-production commercial turbofan engines.
36

In 2005, we promulgated more stringent NO
X
emission standards for newly certificated commercial turbofan engines.
37

That final rule brought the U.S. standards closer to alignment with ICAO CAEP/4 requirements that became effective in 2004. In 2012, we issued more stringent two-tiered NO
X
emission standards for newly certificated and in-production commercial and non-commercial turbofan engines, and these NO
X
standards align with ICAO's CAEP/6 and CAEP/8 standards that became effective in 2013 and 2014, respectively.
38 39

The EPA's actions to regulate certain pollutants emitted from aircraft engines come directly from the authority in section 231 of the CAA, and we have aligned the U.S. emissions requirements with those promulgated by ICAO. All of these previous emission standards have generally been considered anti-backsliding standards (most aircraft engines meet the standards), which are technology following.

29
U.S. EPA, 1973: Emission Standards and Test Procedures for Aircraft; Final Rule, 38 FR 19088 (July 17, 1973).

30
U.S. EPA, 1997:
Control of Air Pollution from Aircraft and Aircraft Engines; Emission Standards and Test Procedures; Final Rule,
62 FR 25355 (May 8, 1997).

31
The full CAEP membership meets every three years and each session is denoted by a numerical identifier. For example, the second meeting of CAEP is referred to as CAEP/2, and CAEP/2 occurred in 1994.

32
This does not mean that in 1997 we promulgated requirements for the re-certification or retrofit of existing in-use engines.

33
Those engines built after the effective date of the regulations that were already certificated to pre-existing standards are also referred to as in-production engines.

34
In the existing EPA regulations, 40 CFR part 87, newly certificated aircraft engines are described as engines of a type or model of which the date of manufacture of the first individual production model was after the implementation date. Newly manufactured aircraft engines are characterized as engines of a type or model for which the date of manufacturer of the individual engine was after the implementation date.

35
Those engine models that received their initial type certificate after the effective date of the regulations are also referred to as new engine designs.

36
U.S. EPA, 1997:
Control of Air Pollution from Aircraft and Aircraft Engines; Emission Standards and Test Procedures; Final Rule,
62 FR 25355 (May 8, 1997).

37
U.S. EPA, 2005:
Control of Air Pollution from Aircraft and Aircraft Engines; Emission Standards and Test Procedures; Final Rule,
70 FR 69664 (November 17, 2005).

38
U.S. EPA, 2012:
Control of Air Pollution from Aircraft and Aircraft Engines; Emission Standards and Test Procedures; Final Rule,
77 FR 36342 (June 18, 2012).

39
While ICAO's standards were not limited to “commercial” airplane engines, our 1997 standards were explicitly limited to commercial engines, as our finding that NO
X
and carbon monoxide emissions from airplane engines cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare was so limited. See 62 FR 25358 (May 8, 1997). In the 2012 rulemaking, we expanded the scope of that finding and of our standards pursuant to CAA section 231(a)(2)(A) to include such emissions from both commercial and non-commercial airplane engines based on the physical and operational similarities between commercial and noncommercial civilian airplane and to bring our standards into full alignment with ICAO's.

The EPA and FAA worked from 2009 to 2016 within the ICAO/CAEP standard-setting process on the development of the international Airplane CO
2
Emission Standards. In this action, we are proposing to adopt GHG standards equivalent to the ICAO Airplane CO
2
Emission Standards. As stated earlier in this Section II, the standards established in the United States need to be at least as stringent as the ICAO Airplane CO
2
Emission Standards in order to ensure global acceptance of FAA airworthiness certification. Also, as a result of the 2016 Findings, as described later in Section V, the EPA is obligated under section 231 of the CAA to propose and issue emission standards applicable to GHG emissions from the classes of engines used by covered aircraft included in the 2016 Findings.

When the EPA proposed the aircraft GHG findings in 2015, we included an aircraft greenhouse gas emission standards advance notice of proposed rulemaking (henceforth the “2015 ANPR”)
40

that provided information on the international process for setting the ICAO Airplane CO
2
Emission Standards. Also, the 2015 ANPR described and sought input on the potential use of section 231 of the CAA to adopt and implement the corresponding international Airplane CO
2
Emission Standards domestically as a CAA section 231 GHG standard. Section IV provides a summary of the ANPR comments that we received.

40
U.S. EPA, 2015:
Proposed Finding that Greenhouse Gas Emissions from Aircraft Cause or Contribute to Air Pollution that May Reasonably Be Anticipated to Endanger Public Health and Welfare and Advance Notice of Proposed Rulemaking,
80 FR 37758 (July 1, 2015).

E. Consideration of Whole Airplane Characteristics

In addressing CO
2
emissions, ICAO adopted an approach that measures the fuel efficiency from the perspective of whole airplane design—an airframe and engine combination. Specifically, ICAO adopted CO
2
emissions test procedures based on measuring the performance of the whole airplane rather than the

airplane engines alone.
41

The ICAO standards account for three factors: Aerodynamics, airplane weight, and engine propulsion technologies. These airplane performance characteristics determine the overall CO
2
emissions. Rather than measuring a single chemical compound, the ICAO CO
2
emissions test procedures measure fuel efficiency based on how far an airplane can fly on a single unit of fuel at the optimum cruise altitude and speed.

41
ICAO, 2016:
Report of Tenth Meeting, Montreal, 1-12 February 2016, Committee on Aviation Environmental Protection,
Document 10069, 432pp. Available at:
https://www.icao.int/publications/Pages/catalogue.aspx
(last accessed March 16, 2020). ICAO Document 10069 is found on page 27 of the ICAO Products & Services English Edition 2020 Catalog, and it is copyright protected; Order No. 10069. See Appendix C (starting on page 5C-1) of this report.

The three factors—and technology categories that improve these factors—are described as follows:
42

42
ICAO,
Environmental Report 2010—Aviation and Climate Change,
2010, which is located at
http://www.icao.int/environmental-protection/Pages/EnvReport10.aspx
(last accessed March 16, 2020).

•
Weight:
Reducing basic airplane weight
43

via structural changes to increase the commercial payload or extend range for the same amount of thrust and fuel burn;

43
Although weight reducing technologies affect fuel burn, they do not affect the metric value for the proposed GHG standard. The standard is a function of maximum takeoff mass (MTOM). Reductions in airplane empty weight (excluding usable fuel and the payload) can be canceled out or diminished by a corresponding increase in payload, fuel, or both—when MTOM is kept constant. Section V and VII provide a further description of the metric value and the effects of weight reducing technologies.

•
Propulsion (thermodynamic and propulsion efficiency):
Advancing the overall specific performance of the engine, to reduce the fuel burn per unit of delivered thrust; and

•
Aerodynamic:
Advancing the airplane aerodynamics to reduce drag and its associated impacts on thrust.

As examples of technologies that support addressing aircraft engine CO
2
emissions accounting for the airplane as a whole, manufacturers have already achieved significant weight reduction with the introduction of advanced alloys and composite materials and lighter weight control systems (
e.g.,
fly-by-wire)
44

and aerodynamic improvements with advanced wingtip devices such as winglets.

44
Fly-by-wire refers to a system which transmits signals from the cockpit to the airplane's control surfaces electronically rather than mechanically. AirlineRatings.com, Available at
https://www.airlineratings.com/did-you-know/what-does-the-term-fly-by-wire-mean/
(last accessed on March 16, 2020).

The EPA agrees with ICAO's approach to measure the fuel efficiency based on the performance of the whole airplane. Accordingly, under section 231 of the CAA, the EPA is proposing regulations that are consistent with this approach. We are proposing GHG test procedures that are the same as the ICAO CO
2
test procedures. (See Section V.H for details on the proposed test procedures.)

As stated earlier in Section II, section 231(a)(2)(A) of the CAA directs the Administrator of the EPA to, from time to time, propose aircraft engine emission standards applicable to the emission of any air pollutant from classes of aircraft engines which in the Administrator's judgment causes or contributes to air pollution that may reasonably be anticipated to endanger public health or welfare. For a standard promulgated under CAA section 231(a)(2)(A) to be “applicable to” emissions of air pollutants from aircraft engines, it could take many forms and include multiple elements in addition to a numeric permissible engine exhaust rate. For example, EPA rules adopted pursuant to CAA section 231 have addressed fuel venting to prevent the discharge of raw fuel from the engine and have adopted test procedures for exhaust emission standards. See 40 CFR part 87, subparts B and G.

Given both the absence of a statutory directive on what form a CAA section 231 standard must take (in contrast to, for example, CAA section 129(a)(4), which requires numerical emissions limitations for emissions of certain pollutants from solid waste incinerators) and the D.C. Circuit's 2007
NACAA
ruling that section 231 of the CAA confers an unusually broad degree of discretion on the EPA in establishing airplane engine emission standards, the EPA proposes to control GHG emissions in a manner identical to how ICAO's standards control CO
2
emissions—with a fuel efficiency standard based on the characteristics of the whole airplane. While this proposed standard incorporates characteristics of airplane design as adopted by ICAO, the EPA is not asserting independent regulatory authority over airplane design.

III. Summary of the 2016 Findings

On August 15, 2016,
45

the EPA issued two findings regarding GHG emissions from aircraft engines. First, the EPA found that elevated concentrations of GHGs in the atmosphere endanger the public health and welfare of current and future generations within the meaning of section 231(a)(2)(A) of the CAA. The EPA made this finding specifically with respect to the same six well-mixed GHGs—CO
2
, methane, N
2
O, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride—that together were defined as the air pollution in the 2009 Endangerment Finding under section 202(a) of the CAA and that together were found to constitute the primary cause of climate change. Second, the EPA found that emissions of those six well-mixed GHGs from certain classes of engines used in certain aircraft
46

cause or contribute to the air pollution—the aggregate group of the same six GHGs—that endangers public health and welfare under CAA section 231(a)(2)(A).

45
U.S. EPA, 2016:
Finding That Greenhouse Gas Emissions From Aircraft Cause or Contribute To Air Pollution That May Reasonably Be Anticipated To Endanger Public Health and Welfare; Final Rule,
81 FR 54422 (August 15, 2016).

46
Certain aircraft in this context are referred to interchangeably as “covered airplanes,” “US covered airplanes,” or airplanes throughout this notice of proposed rulemaking.

The EPA identified U.S. covered aircraft as subsonic jet aircraft with a maximum takeoff mass (MTOM) greater than 5,700 kilograms and subsonic propeller-driven (
e.g.,
turboprop) aircraft with a MTOM greater than 8,618 kilograms. See Section V of this proposed rule for examples of airplanes that correspond to the U.S. covered aircraft identified in the 2016 Findings.
47

The EPA did not at that time make findings regarding whether other substances emitted from aircraft engines cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare. The EPA also did not make a cause or contribute finding regarding GHG emissions from engines not used in U.S. covered aircraft (
i.e.,
those used in smaller turboprops, smaller jet aircraft, piston-engine aircraft, helicopters and military aircraft).

47
81 FR 54423, August 15, 2016.

The EPA explained that the collective GHG emissions from the classes of engines used in U.S. covered aircraft contribute to the national GHG emission inventories
48

and estimated global GHG

emissions.
49 50 51 52

The 2016 Findings accounted for the majority (89 percent) of total U.S. aircraft GHG emissions.
53 54

48
In 2014, classes of engines used in U.S. covered airplanes contribute to domestic GHG inventories as follows: 10 percent of all U.S. transportation GHG emissions, representing 2.8 percent of total U.S. emissions.

U.S. EPA, 2016:
Finding That Greenhouse Gas Emissions From Aircraft Cause or Contribute To Air Pollution That May Reasonably Be Anticipated To Endanger Public Health and Welfare; Final Rule,
81 FR 54422 (August 15, 2016).

U.S. EPA, 2016:
Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2014,
1,052 pp., U.S. EPA Office of Air and Radiation, EPA 430-R-16-002, April 2016. Available at:
https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2014
(last accessed March 16, 2020).

ERG, 2015:
U.S. Jet Fuel Use and CO
2

Emissions Inventory for Aircraft Below ICAO CO
2

Standard Thresholds,
Final Report, EPA Contract Number EP-D-11-006, 38 pp.

49
In 2010, classes of engines used in U.S. covered airplanes contribute to global GHG inventories as follows: 26 percent of total global airplane GHG emissions, representing 2.7 percent of total global transportation emissions and 0.4 percent of all global GHG emissions.

U.S. EPA, 2016:
Finding That Greenhouse Gas Emissions From Aircraft Cause or Contribute To Air Pollution That May Reasonably Be Anticipated To Endanger Public Health and Welfare; Final Rule,
81 FR 54422 (August 15, 2016).

U.S. EPA, 2016:
Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2014,
1,052 pp., U.S. EPA Office of Air and Radiation, EPA 430-R-16-002, April 2016. Available at:
https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2014
(last accessed March 16, 2020).

ERG, 2015:
U.S. Jet Fuel Use and CO
2

Emissions Inventory for Aircraft Below ICAO CO
2

Standard Thresholds,
Final Report, EPA Contract Number EP-D-11-006, 38 pp.

IPCC, 2014:
Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change
[Edenhofer, O., R. Pichs-Madruga, Y. Sokona, E. Farahani, S. Kadner, K. Seyboth, A. Adler, I. Baum, S. Brunner, P. Eickemeier, B. Kriemann, J. Savolainen, S. Schlömer, C. von Stechow, T. Zwickel and J.C. Minx (eds.)]. Cambridge University Press, 1435 pp.

50
U.S. EPA, 2016:
Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2014,
1,052 pp., U.S. EPA Office of Air and Radiation, EPA 430-R-16-002, April 2016. Available at:
https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2014
(last accessed March 16, 2020).

51
IPCC, 2014:
Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change
[Edenhofer, O., R. Pichs-Madruga, Y. Sokona, E. Farahani, S. Kadner, K. Seyboth, A. Adler, I. Baum, S. Brunner, P. Eickemeier, B. Kriemann, J. Savolainen, S. Schlömer, C. von Stechow, T. Zwickel and J.C. Minx (eds.)]. Cambridge University Press, 1435 pp.

52
The domestic inventory comparisons are for the year 2014, and global inventory comparisons are for the year 2010. The rationale for the different years is described in section V.B.4 of the 2016 Findings, 81 FR 54422 (August 15, 2016).

53
Covered U.S. aircraft GHG emissions in the 2016 Findings were from airplanes that operate in and from the U.S. and thus contribute to emissions in the U.S. This includes emissions from U.S. domestic flights, and emissions from U.S. international bunker flights (emissions from the combustion of fuel used by airplanes departing the U.S., regardless of whether they are a U.S. flagged carrier—also described as emissions from combustion of U.S. international bunker fuels). For example, a flight departing Los Angeles and arriving in Tokyo, regardless of whether it is a U.S. flagged carrier, is considered a U.S. international bunker flight. A flight from London to Hong Kong is not.

54
U.S. EPA, 2016:
Inventory of U.S. Greenhouse Gas Emissions and Sinks:
1990-2014, 1,052 pp., U.S. EPA Office of Air and Radiation, EPA 430-R-16-002, April 2016. Available at:
https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2014
(last accessed March 16, 2020).

As explained in the 2016 Findings,
55

only two of the six well-mixed GHGs, CO
2
and N
2
O, are emitted from covered aircraft. CO
2
represents 99 percent of all GHGs emitted from both total U.S. aircraft and U.S. covered aircraft, and N
2
O represents 1 percent of GHGs emitted from total U.S. aircraft and U.S. covered aircraft.
56

Modern aircraft are overall consumers of methane.
57

Hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride are not products of aircraft engine fuel combustion. (Section V.I discusses controlling two of the six well-mixed GHGs—CO
2
and N
2
O— in the context of the details of the proposed rule.)

55
U.S. EPA, 2016:
Finding That Greenhouse Gas Emissions From Aircraft Cause or Contribute To Air Pollution That May Reasonably Be Anticipated To Endanger Public Health and Welfare; Final Rule,
81 FR 54422 (August 15, 2016).

56
U.S. EPA, 2016:
Finding That Greenhouse Gas Emissions From Aircraft Cause or Contribute To Air Pollution That May Reasonably Be Anticipated To Endanger Public Health and Welfare; Final Rule,
81 FR 54422 (August 15, 2016).

U.S. EPA, 2016:
Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2014,
1,052 pp., U.S. EPA Office of Air and Radiation, EPA 430-R-16-002, April 2016. Available at:
https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2014
(last accessed March 16, 2020).

ERG, 2015:
U.S. Jet Fuel Use and CO
2
Emissions Inventory for Aircraft Below ICAO CO
2
Standard Thresholds,
Final Report, EPA Contract Number EP-D-11-006, 38 pp.

57
Methane emissions are no longer considered to be emitted from aircraft gas turbine engines burning jet fuel A at higher power settings. Modern aircraft jet engines are typically net consumers of methane (Santoni et al. 2011). Methane is emitted at low power and idle operation, but at higher power modes aircraft engines consume methane. Over the range of engine operating modes, aircraft engines are net consumers of methane on average.

IV. Summary of Advance Notice of Proposed Rulemaking and Comments Received

A. Summary

As described earlier in Section II, the 2015 ANPR
58

discussed the issues arising from the ICAO/CAEP proceedings for the international Airplane CO
2
Emission Standards. The ANPR requested public comment on a variety of issues to help ensure transparency and to obtain views on airplane engine GHG emission standards that the EPA might potentially adopt under the CAA section 231. This section provides a summary of the ANPR comments that the EPA received in 2015.

58
80 FR 37758 (July 1, 2015).

All major stakeholders (airplane manufacturers, engine manufacturers, airlines, states, and environmental organizations) expressed their support for the United States' efforts in ICAO/CAEP for the adoption of the international Airplane CO
2
Emission Standards, as well as the subsequent EPA adoption of a domestic GHG standard.

The states and environmental organizations commented that the U.S. aircraft sector is the single largest GHG emissions source yet to be regulated among the domestic transportation sectors. They indicated that the EPA should adopt airplane GHG emission standards that materially reduce GHG emissions from the U.S. airplane sector in the near- to mid-term, beyond the expected “business-as-usual” improvement absent GHG emission standards. These commenters stated that the airplane GHG emission standards should be technology-forcing standards.

The airplane manufacturers, aircraft engine manufacturers, and airlines commented that the U.S. should adopt airplane GHG emission standards that are equivalent to ICAO/CAEP's standards. These commenters indicated that aviation is a global industry which requires common, world-wide standards. Airplanes are uniquely mobile assets that are designed to fly anywhere in the world, and consistency amongst national rules makes sure there is a level playing field globally for the aviation industry. In addition, they asserted that the CAEP terms of reference for adopting airplane emission standards (which include technical feasibility, environmental benefit, and economic reasonableness
59

), as described earlier in Section II.D.1, line up with the criteria for adopting such standards under section 231 of the CAA. Therefore, the U.S. should align with those terms and criteria in continuing their efforts in the ICAO/CAEP proceedings and in subsequently adopting the ICAO/CAEP Airplane CO
2
Emission Standards domestically.

59
CAEP's terms of reference indicate that “CAEP's assessments and proposals are pursued taking into account: technical feasibility; environmental benefit; economic reasonableness; interdependencies of measures (for example, among others, measures taken to minimize noise and emissions); developments in other fields; and international and national programs.” ICAO: CAEP Terms of Reference. Available at
http://www.icao.int/environmental-protection/Pages/Caep.aspx#ToR
(last accessed March 16, 2020).

All of the comments received on the 2015 ANPR are located in the docket for the 2016 Findings under Docket ID No. EPA-HQ-OAR-2014-0828. See the ANPR phase of that docket.

V. Details for the Proposed Rule

For the proposed rule, this section describes the fuel efficiency metric that would be used as a measure of airplane GHG emissions, the size and types of airplanes that would be affected, the emissions levels, the applicable test procedures, and the associated reporting requirements. As explained earlier in

Section III and in the 2016 Findings,
60

only two of the six well-mixed GHGs—CO
2
and N
2
O—are emitted from covered aircraft. Both CO
2
and N
2
O emissions scale with fuel burn, thus allowing them to be controlled through fuel efficiency.

60
U.S. EPA, 2016:
Finding That Greenhouse Gas Emissions From Aircraft Cause or Contribute To Air Pollution That May Reasonably Be Anticipated To Endanger Public Health and Welfare; Final Rule,
81 FR 54422 (August 15, 2016).

We are proposing that the GHG emission regulations for this proposed rule would be specified in a new part in title 40 of the CFR—40 CFR part 1030. The existing aircraft engine regulations applicable to HC, NO
X
, CO, and smoke would remain in 40 CFR part 87.

In order to promote international harmonization of aviation standards and to avoid placing U.S. manufacturers at a competitive disadvantage that likely would result if EPA were to adopt standards different from the standards adopted by ICAO, the EPA is proposing to adopt standards for GHG emissions from certain classes of engines used on airplanes that match the scope, stringency, and timing of the CO
2
standards adopted by ICAO. The EPA and the FAA worked within ICAO to help establish the international CO
2
emission standards, which under the Chicago Convention individual member States then adopt into domestic law and regulations in order to implement and enforce them against subject manufacturers. A member State that adopts domestic regulations differing from the international standard—in either scope, stringency or timing—is obligated to notify ICAO of the differences between its domestic regulations and the ICAO standards.
61

61
ICAO, 2006:
Convention on International Civil Aviation, Article 38, Ninth Edition,
Document 7300/9, 114 pp. Available at
http://www.icao.int/publications/Documents/7300_9ed.pdf
(last accessed March 16, 2020).

Under the longstanding EPA and FAA rulemaking approach to regulate airplane emissions, international emission standards have been adopted by ICAO, with significant involvement from the FAA and the EPA, and subsequently the EPA has undertaken rulemakings under CAA section 231 to establish domestic standards that are the same as or at least as stringent as ICAO's standards. Then, CAA section 232 requires the FAA to issue regulations to ensure compliance with the EPA standards. In 2015, EPA issued an advance notice of proposed rulemaking
62

which noted EPA and FAA's engagement in ICAO to establish an international CO
2
standard and EPA's potential use of section 231 to adopt corresponding airplane GHG emissions standards domestically. This proposed rulemaking continues this statutory paradigm.

62
U.S. EPA, 2015:
Proposed Finding That Greenhouse Gas Emissions From Aircraft Cause or Contribute to Air Pollution That May Reasonably Be Anticipated To Endanger Public Health and Welfare and Advance Notice of Proposed Rulemaking; Proposed Rule,
80 FR 37758 (July 1, 2015).

The proposed rule, if adopted, would facilitate the acceptance of U.S. manufactured airplanes and airplane engines by member States and airlines around the world. We anticipate U.S. manufacturers would be at a significant competitive disadvantage if the U.S. fails to adopt standards that are aligned with the ICAO standards for CO
2
emissions. Member States may ban the use of any airplane within their airspace that does not meet ICAO standards.
63

If the EPA were to adopt no standards or standards that were not as stringent as ICAO's standards, U.S. civil airplane manufacturers could be forced to seek CO
2
emissions certification from an aviation certification authority of another country (other than the FAA) in order to market their airplanes for international operation.

63
ICAO, 2006:
Convention on International Civil Aviation, Article
33,
Ninth Edition,
Document 7300/9, 114 pp. Available at
http://www.icao.int/publications/Documents/7300_9ed.pdf
(last accessed March 16, 2020).

Having invested significant effort and resources, working with FAA and the Department of State, to gain international consensus to adopt the first-ever CO
2
standards for airplanes, the EPA believes that meeting the United States' obligations under the Chicago Convention by aligning domestic standards with the ICAO standards, rather than adopting more stringent standards, will have substantial benefits for future international cooperation on airplane emission standards, and such cooperation is the key for achieving worldwide emission reductions. Nonetheless, the EPA also analyzed the impacts of two more stringent alternatives, and the results of our analyses are described in chapters 4, 5, and 6 of the Draft Technical Support Document (TSD) which can be found in the docket for this rulemaking. The analyses show that one alternative would result in limited additional costs, but no additional GHG emission reductions compared to the proposed standards. The other alternative would have further limited additional costs and some additional GHG emission reductions compared to the proposed standards, but the additional emission reductions are relatively small from this alternative and do not justify differentiating from the international standards and disrupting international harmonization. ICAO intentionally established its standards at a level which is technology following, to adhere to its definition of technical feasibility that is meant to consider the emissions performance of in-production and in-development airplanes, including types that would first enter into service by about 2020. Thus, the additional emission reductions associated with the more stringent alternatives are relatively small because all but one of the affected airplanes either meet the stringency levels or are expected to go out of production by the effective dates. In addition, requiring U.S. manufacturers to certify to a different standard than has been adopted internationally (even one more stringent) could have disruptive effects on manufacturers' ability to market planes for international operation. Consequently, the EPA is not proposing either of these alternatives.

A. Airplane Fuel Efficiency Metric

For the international Airplane CO
2
Emission Standards, ICAO developed a metric system to allow the comparison of a wide range of subsonic airplane types, designs, technology, and uses. While ICAO calls this a CO
2
emissions metric, it is a measure of fuel efficiency, which is directly related to CO
2
emitted by aircraft engines. The ICAO metric system was designed to differentiate between fuel-efficiency technologies of airplanes and to equitably capture improvements in propulsive and aerodynamic technologies that contribute to a reduction in the airplane CO
2
emissions. In addition, the international metric system accommodates a wide range of technologies and designs that manufacturers may choose to implement to reduce CO
2
emissions from their airplanes. However, because of an inability to define a standardized empty weight across manufacturers and types of airplanes, the metric is based on the MTOM of the airplane. This metric does not directly reward weight reduction technologies because the MTOM of an airplane will not be reduced when weight reduction technologies are applied so that cargo carrying capacity or range can be increased. Further, while weight reduction technologies can be used to improve airplane fuel efficiency, they may also be used to allow increases in

payload,
64

equipage, and fuel load.
65

Thus, even though weight reducing technologies increase the airplane fuel efficiency, this improvement in efficiency frequently would not be reflected in operation.

64
Payload is the weight of passengers, baggage, and cargo.

FAA Airplane Weight & Balance Handbook (Chapter 9, page 9-10, file page 82)
https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/media/FAA-H-8083-1.pdf
(x)(last accessed on March 16, 2020).

65
ICF, 2018:
Aircraft CO
2
Cost and Technology Refresh and Industry Characterization,
Final Report, EPA Contract Number EP-C-16-020, September 30, 2018.

The ICAO metric system consists of a CO
2
emissions metric (Equation V-1) and a correlating parameter.
66

66
Annex 16 Volume III Part II Chapter 2 sec. 2.2. ICAO, 2017:
Annex 16 Volume III—Environmental Protection—Aeroplane CO
2
Emissions, First Edition,
40 pp. Available at:
http://www.icao.int/publications/Pages/catalogue.aspx
(last accessed July 15, 2020). The ICAO Annex 16 Volume III is found on page 16 of English Edition 2020 catalog and is copyright protected; Order No. AN 16-3.

EP20AU20.000

The ICAO CO
2
emissions metric uses an average of three Specific Air Range (SAR) test points that is normalized by a geometric factor representing the physical size of an airplane. SAR is a measure of airplane cruise performance, which measures the distance an airplane can travel on a unit of fuel. Here the inverse of SAR is used (1/SAR), which has the units of kilograms of fuel burned per kilometer of flight; therefore, a lower metric value represents a lower level of airplane CO
2
emissions (
i.e.,
better fuel efficiency). The SAR data are measured at three gross weight points used to represent a range of day-to-day airplane operations (at cruise).
67

67
. ICAO, 2016:
Tenth Meeting Committee on Aviation Environmental Protection Report,
Doc 10069, CAEP/10, 432 pp, AN/192, Available at:
https://www.icao.int/publications/Pages/catalogue.aspx
(last accessed March 16, 2020). The ICAO Report of the Tenth Meeting report is found on page 27 of the ICAO Products & Services English Edition 2020 catalog and is copyright protected; Order No. 10069.

(1/SAR)
avg

68

is calculated at 3 gross weight fractions of Maximum Take Off Mass (MTOM):
69

68
Avg means average.

69
Annex 16 Vol. III Part II Chapter 2 sec. 2.3. ICAO, 2017:
Annex 16 Volume III—Environmental Protection—Aeroplane CO
2
Emissions, First Edition,
40 pp. Available at:
http://www.icao.int/publications/Pages/catalogue.aspx
(last accessed July 15, 2020). The ICAO Annex 16 Volume III is found on page 16 of English Edition 2020 catalog and is copyright protected; Order No. AN 16-3.

•
High gross mass:
92% MTOM

•
Mid gross mass:
Average of high gross mass and low gross mass

•
Low gross mass:
(0.45 * MTOM) + (0.63 * (MTOM^0.924))

The Reference Geometric Factor (RGF) is a non-dimensional measure of the fuselage size of an airplane normalized by 1 square meter, generally considered to be the shadow area of the airplane's pressurized passenger compartment.
70

70
Annex 16 Vol. III Appendix 2. ICAO, 2017:
Annex 16 Volume III—Environmental Protection—Aeroplane CO
2
Emissions, First Edition,
40 pp. Available at:
http://www.icao.int/publications/Pages/catalogue.aspx
(last accessed July 15, 2020). The ICAO Annex 16 Volume III is found on page 16 of English Edition 2020 catalog and is copyright protected; Order No. AN 16-3.

When the ICAO CO
2
emissions metric is correlated against MTOM, it has a positive slope. The international Airplane CO
2
Emission Standards use the MTOM of the airplane as an already certificated reference point to compare airplanes. In this action, we propose to use MTOM as the correlating parameter as well.

We are proposing to adopt ICAO's airplane CO
2
emissions metric (shown in Equation V-1) as the measure of airplane fuel efficiency as a surrogate for GHG emissions from covered airplanes (hereafter known as the “fuel efficiency metric” or “fuel burn metric”). This is because the fuel efficiency metric controls emissions of both CO
2
and N
2
O, the only two GHG emitted by airplane engines (see Section V.I for further information). Consistent with ICAO, we are also proposing to adopt MTOM as a correlating parameter to be used when setting emissions limits.

B. Covered Airplane Types and Applicability

1. Maximum Takeoff Mass Thresholds

The proposed GHG rule would apply to civil subsonic jet airplanes (turbojet or turbofan airplanes) with certificated MTOM over 5,700 kg (12,566 lbs.) and propeller-driven civil airplanes (turboprop airplanes) over 8,618 kg (19,000 lbs.). These applicability criteria are the same as those in the ICAO Airplane CO
2
Emission Standards and correspond to the scope of the 2016 Findings. The applicability of the proposed rule is limited to civil subsonic airplanes and does not extend to civil supersonic airplanes.
71

Through this action, as described earlier in Section II, the EPA is fully discharging its obligations under the CAA that were triggered by the 2016 Findings. Once EPA and FAA fully promulgate the airplane GHG emission standards domestically, the United States regulations will align with ICAO Annex 16 standards.

71
Currently, civilian supersonic airplanes are not in operation. The international standard did not consider the inclusion of supersonic airplanes in the standard. More recently, there has been renewed interest in the development of civilian supersonic airplanes. This has caused ICAO to begin considering how existing emission standards should be revised for new supersonic airplanes. The US is involved in these discussions and at this point plans to work with ICAO to develop emission standards on the international stage prior to adopting them domestically.

Examples of covered airplanes under the proposed GHG rules include smaller civil jet airplanes such as the Cessna Citation CJ3+, up to and including the largest commercial jet airplanes—the Boeing 777 and the Boeing 747. Other examples of covered airplanes include larger civil turboprop airplanes, such as the ATR 72 and the Viking Q400.
72 73

The proposed GHG rules would not apply to smaller civil jet airplanes (
e.g.,
Cessna Citation M2), smaller civil turboprop airplanes (
e.g.,
Beechcraft King Air 350i), piston-engine airplanes, helicopters, and military airplanes.

72
This was previously owned by Bombardier and was sold to Viking in 2018, November 8, 2018 (Forbes).

73
It should be noted that there are no US domestic manufacturers that produce turboprops that meet the MTOM thresholds. These airplanes are given as examples but will be expected to be certificated by their national aviation certification authority.

2. Applicability

The proposed rule would apply to all covered airplanes, in-production and new type designs, produced after the respective effective dates of the standards except as provided in V.B.3. There are different regulatory emissions levels and/or applicability dates depending on whether the covered airplane is in-production before the

applicability date or is a new type design.

The proposed in-production standards would only be applicable to previously type certificated airplanes, newly-built on or after the applicability date (described in V.D.1), and would not apply retroactively to airplanes that are already in-service.

3. Exceptions

Consistent with the applicability of the ICAO standards, the EPA is proposing applicability language that excepts the following airplanes: Amphibious airplanes, airplanes initially designed or modified and used for specialized operational requirements, airplanes designed with an RGF of zero,
74

and those airplanes specifically designed or modified and used for fire-fighting purposes. Airplanes in these categories proposed to be excepted are generally designed or modified in such a way that their designs are well outside of the design space of typical passenger or freight carrying airplanes. For example, amphibious airplanes are by necessity designed with fuselages that resemble boats as much as airplanes. As such, their aerodynamic efficiency characteristics fall well outside of the range of airplanes used in developing the ICAO Airplane CO
2
Emission Standards and our proposed GHG rules.

74
RGF refers to the pressurized compartment of an airplane, generally meant for passengers and/or cargo. If an airplane is unpressurized, the calculated RGF of the airplane would be zero (0). These airplanes are very rare, and the few that are in service are used for special missions. An example is Boeing's Dreamlifter.

Airplanes designed or modified for specialized operational requirements could include a wide range of activities, but all of them require performance that was outside of the scope considered during the development of the ICAO standards. Such airplanes could include

• airplanes that required capacity to carry cargo that is not possible by using less specialized airplanes (
e.g.
civil variants of military transports);
75

75
This is not expected to include freight versions of passenger airplanes such as the Boeing 767F, Boeing 747-8F, or Airbus A330F. Rather, this is intended to except airplanes such as the Lockheed L-100.

• airplanes that required capacity for very short or vertical take-offs and landings;

• airplanes that required capacity to conduct scientific,
76

research, or humanitarian missions exclusive of commercial service; or

76
For example, the NASA SOFIA airborne astronomical observatory.

• airplanes that required similar factors.

The EPA requests comments on proposed exceptions for specialized operational requirements. Some exceptions are based on the use of the airplane after civil certification (
e.g.,
use for firefighting). The EPA requests comment on the proposed definitions of these excepted airplanes.

4. New Airplane Types and In-Production Airplane Designations

The proposed rule recognizes differences between previously type certificated airplanes that are in production and new type designs presented for original certification.

•
In-production airplanes:
Those airplane types which have already received a Type Certificate
77

from the FAA, and for which manufacturers either have existing undelivered sales orders or would be willing and able to accept new sales orders. The term can also apply to the individual airplane manufactured according to the approved design Type Certificate, and for which an Airworthiness Certificate is required before the airplane is permitted to operate.
78 79

77
A Type Certificate is a design approval whereby the FAA ensures that the manufacturer's designs meet the minimum requirements for airplane safety and environmental regulations. According to ICAO Cir 337, a Type Certificate is “[a] document issued by a Contracting State to define the design of an airplane type and to certify that this design meets the appropriate airworthiness requirements of that State.” A Type Certificate is issued once for each new type design airplane, and modified as an airplane design is changed over the course of its production life.

78
ICAO, 2016:
Tenth Meeting Committee on Aviation Environmental Protection Report,
Doc 10069, CAEP/10, 432 pp, AN/192, Available at:
http://www.icao.int/publications/Pages/catalogue.aspx
(last accessed March 16, 2020). The ICAO Report of the Tenth Meeting report is found on page 27 of the ICAO Products & Services English Edition 2020 catalog and is copyright protected; Order No. 10069.

79
In existing U.S. aviation emissions regulations, in-production means newly-manufactured or built after the effective date of the regulations—and already certificated to pre-existing rules. This is similar to the current ICAO definition for in-production airplane types for purposes of the international CO
2
standard.

•
New type designs:
Airplane types for which original certification is applied for (to the FAA) on or after the compliance date of a rule, and which have never been manufactured prior to the compliance date of a rule.

Certificated designs may subsequently undergo design changes such as new wings, engines, or other modifications that would require changes to the type certificated design. These modifications happen more frequently than the application for a new type design. For example, a number of airplanes have undergone significant design changes (including the Boeing 747-8, Boeing 737 Max, Airbus 320 Neo, Airbus A330 Neo, and Boeing 777-X). As with a previous series of redesigns, which included the Boeing 777-200LR in 2004, 777-300ER in 2006, Airbus 319 in 1996, and Airbus 330-200 in 1998, incremental improvements are expected to continue to be more frequent than major design changes over the next decade—following these more recent major programs.
80 81

80
ICF International, 2015:
CO
2
Analysis of CO
2
-Reducing Technologies for Airplane,
Final Report, EPA Contract Number EP-C-12-011, March 17, 2015.

81
Insofar as we are going through a wave of major redesign and service entry now, prospects for further step-function improvements will be low in the coming 10-15 years. (ICF International,
CO2 Analysis of CO2-Reducing Technologies for Airplane,
Final Report, EPA Contract Number EP-C-12-011, March 17, 2015.)

New type designs are infrequent, and it is not unusual for new type designs to take 8-10 years to develop, from preliminary design to entry into service.
82

The most recent new type designs introduced in service were the Airbus A350 in 2015,
83

the Airbus A220 (formerly known as the Bombardier C-Series) in 2016,
84

and the Boeing 787 in 2011.
85 86

However, it is unlikely more than one new type design will be presented for certification in the next ten years.
87

New type designs (and some redesigns) typically yield large fuel burn reductions—10 percent to 20 percent over the prior generation they replace (considered a step-change in fuel burn improvement). As one might expect, these significant fuel burn reductions do not happen frequently. Also, airplane development programs are expensive.
88

82
ICF International, 2015:
CO2 Analysis of CO
2
-Reducing Technologies for Airplane,
Final Report, EPA Contract Number EP-C-12-011, March 17, 2015.

83
The Airbus A350 was announced in 2006 and received its type certification in 2014. The first model, the A350-900 entered service with Qatar Airways in 2015.

84
The Bombardier C-series was announced in 2005 and received its type certification in 2015. The first model, the C100 entered service with Swiss Global Air Lines in 2016.

85
Boeing, 2011: Boeing Unveils First 787 to Enter Service for Japan Airlines, December 14. Available at
http://boeing.mediaroom.com/2011-12-14-Boeing-Unveils-First-787-to-Enter-Service-for-Japan-Airlines
(last accessed March 16, 2020).

86
ICF International, 2015:
CO
2
Analysis of CO
2
-Reducing Technologies for Airplane,
Final Report, EPA Contract Number EP-C-12-011, March 17, 2015.

87
Ibid.

88
Analysts estimate a new single aisle airplane would have cost $10-12 billion to develop. The A380 and 787 are estimated to each have cost around $20 billion to develop; the A350 is estimated to have cost $15 billion, excluding engine development. Due to the large development cost of a totally new airplane design, manufacturers are opting to re-wing or re-engine their airplane. Boeing is said to have budgeted $5 billion for the re-wing of the 777, and Airbus and Boeing have budgeted

$1-2 billion each for the re-engine of the A320 and the 737, respectively (excluding engine development costs). Embraer has publicly stated that it will need to spend $1-2 billion to re-wing the EMB-175 and variants. (ICF International,
CO
2
Analysis of CO
2
-Reducing Technologies for Airplane,
Final Report, EPA Contract Number EP-C-12-011, March 17, 2015.)

At ICAO, the difference between in-production airplanes and new type designs has been used to differentiate two different pathways by which fuel efficiency technologies can be introduced into civil airplane designs.

When a new requirement is applied to an in-production airplane, there may be a real and immediate effect on the manufacturer's ability to continue to build and deliver it in its certificated design configuration and to make business decisions regarding future production of that design configuration. Manufacturers need sufficient notice to make design modifications that allow for compliance and to have those modifications certificated by their certification authorities. In the United States, applying a new requirement to an in-production airplane means that a newly produced airplane subject to this rule that does not meet the GHG standards would likely be denied an airworthiness certificate after January 1, 2028. As noted above in V.B.2, in-service airplanes are not subject to the ICAO CO
2
standards and likewise would not be subject to these proposed GHG standards.

For new type designs, this proposed rule would have no immediate effect on airplane production or certification for the manufacturer. The standards that a new type design must meet are those in effect when the manufacturer applies for type certification. The applicable design standards at the time of application remain frozen over the typical 5-year time frame provided for completing the type certification process. Because of the investments and resources necessary to develop a new type design, manufacturers have indicated that it is important to have knowledge of the level of future standards at least 8 years in advance of any new type design entering service.
89

Because standards are known early in the design and certification process, there is more flexibility in how and what technology can be incorporated into a new type design. (See Section VII describing the Technology Response for more information on this).

89
ICAO policy is that the compliance date of an emissions standard must be at least 3 years after it has been agreed to by CAEP. Adding in the 5-year certification window, this means that the level of the standard can be known 8 years prior to entry into service date for a new type design. Manufacturers also have significant involvement in the standard development process at ICAO, which begins at least 3 years before any new standard is agreed to.

To set standards at levels that appropriately reflect the feasibility to incorporate technology and lead time, the level and timing of the proposed standards would be different for in-production airplanes and new type designs. This is discussed further in Sections V.C and V.D below, describing standards for new type designs and in-production airplanes, and Section VII, discussing the technology response.

C. GHG Standard for New Type Designs

1. Applicability Dates for New Type Designs

The EPA is proposing that the GHG standards would apply to the same airplanes as those identified as within the scope of the international standards adopted by ICAO in 2017, in terms of maximum take-off weight thresholds, passenger capacity, and reference to dates of applications for original type certificates. In this way, EPA's standards would align with ICAO's in defining those airplanes that will become subject to our standards. Consequently, for subsonic jet airplanes over 5,700 kg MTOM and certificated with more than 19 passenger seats, and for turboprop airplanes over 8,618 kg MTOM, the proposed regulations would apply to all airplanes for which application for an original type certificate is made to the FAA on or after January 1, 2020. For subsonic jet airplanes over 5,700 kg MTOM with 19 passenger seats or fewer, the proposed regulations would apply to all airplanes for which an original type certification application was made to the FAA on or after January 1, 2023.

Consistency with international standards is important for manufacturers, as they noted in comments to our ANPR in 2017, and to propose criteria to identify those airplanes to be covered by our standards that differ from those covered by ICAO's standards—either in terms of maximum take-off mass, passenger capacity, or dates of applications for new original type certificates—would not be expected by airplane manufacturers and engine manufacturers, and would introduce unnecessary uncertainty into the airplane type certification process.

The EPA understands that by adopting the same effective date as ICAO, January 1, 2020, for defining those type certification applications subject to the standards, we are employing a date that has already passed. Since no airplane manufacturer has in fact yet submitted an application for a new type design certification since January 1, 2020, no manufacturer would currently need to amend any already submitted application to address the GHG standards. Neither the EPA nor the FAA is aware of any anticipated original new type design application expected to be submitted before the EPA's standards are promulgated and effective that would need amendment to reflect the GHG standards. Therefore, no airplane manufacturer is expected to be adversely affected by adoption of the same applicability dates as ICAO's applicability dates for new type design certification applications, including the January 1, 2020, date.

The EPA recognizes that new regulatory requirements have differing impacts on items that are already in production and those yet to be built. Airplane designs that have yet to undergo original type certification can more easily be adapted for new regulatory requirements, compared with airplanes already being produced subject to older, existing design standards. The agency has experience adopting regulations that acknowledge these differences, such as in issuing emission standards for stationary sources of hazardous air pollutants (which often impose more stringent standards for new sources, defined based on dates that precede dates of final rule promulgation, than for existing sources). See,
e.g.,
42 U.S.C. 7412(a)(4), defining “new source” to mean a stationary source the construction or reconstruction of which is commenced after the EPA proposes regulations establishing an emission standard. In addition, the EPA has previously, for the Tier 4 NO
X
aircraft engine standards, defined the scope of aircraft engines that were to become subject to the standards based on a date that preceded the effective date of the final standards, while at the same time providing that the standards applied as prescribed after the effective date of the rule. See,
e.g.,
40 CFR 87.23(d)(1)(vi) and (vii).

Here, the U.S. airplane manufacturers that would be subject to these GHG standards participated in the development of them at ICAO and have been aware of and supported ICAO's use of the January 1, 2020, date for new type design certificate applications as triggering applicability of the international standards, knowing for several years that any as-yet undetermined new designs would have to comply with the international standards in order to be marketable internationally. Consequently, EPA proposes that adoption of the January 1, 2020, date to define which future new type design certification applications

would need to meet the GHG standards is reasonable and in harmony with the 2017 ICAO Airplane CO2 Emission Standards. Adoption of the same dates for new type design certification applications, as well as for maximum take-off mass thresholds and passenger capacity cutoffs, will also prevent any need for the United States to file a difference with ICAO as would be required under the Chicago Convention.

2. Regulatory Limit for New Type Designs

The EPA proposes that the GHG emissions limit for new type designs would be a function of the airplane certificated MTOM and consist of three levels described below in Equation V-2, Equation V-3, and Equation V-4.
90

90
Annex 16 Vol. III Part II Chapter 2 sec. 2.4.2 (a), (b), and (c). ICAO, 2017:
Annex 16 Volume III—Environmental Protection—Aeroplane CO
2

Emissions, First Edition,
40 pp. Available at:
http://www.icao.int/publications/Pages/catalogue.aspx
(last accessed July 15, 2020). The ICAO Annex 16 Volume III is found on page 16 of English Edition 2020 catalog and is copyright protected; Order No. AN 16-3.

EP20AU20.001

Figure V-1 and Figure V-2 show the numerical limits of the proposed new type design rules and how the airplane types analyzed in Sections VI and VII relate to this limit. Figure V-2 shows only the lower MTOM range of Figure V-1 to better show the first two segments of the limit line. These plots below show the airplane fuel efficiency metric values as they were modeled. This includes all anticipated/modeled technology responses, improvements, and production assumptions in response to the market and the proposed rules. (See Section VI and VII for more information about this.) These proposed GHG emission limits are the same as the limits of the ICAO Airplane CO
2
Emission Standards.

EP20AU20.002

EP20AU20.003

When analyzing potential levels of the standard, ICAO determined, based on assessment of available data, that there were significant performance differences between large and small airplanes. Airplanes with an MTOM less than 60 tons
91

are either business jets or regional jets. The physical size of smaller airplanes presents scaling challenges that limit technology improvements that can readily be made on larger airplanes.
92

This leads to requiring higher capital costs to implement the technology relative to the sale price of the airplanes.
93

Business jets (generally less than 60 tons MTOM) tend to operate at higher altitudes and faster speeds than larger commercial traffic.

91
In this rulemaking, 60 tons means 60 metric tons (or tonnes), which is equal to 60,000 kilograms (kg). 1 ton means 1 metric ton (or tonne), which is equal to 1,000 kg.

92
ICF, 2018:
Aircraft CO
2

Cost and Technology Refresh and Industry Characterization,
Final Report, EPA Contract Number EP-C-16-020, September 30, 2018.

93
U.S.,
United States Position on the ICAO Aeroplane CO
2

Emissions Standard,
Montréal, Canada, CAEP10 Meeting, February 1-12, 2016, Presented by United States, CAEP/10-WP/59. Available in the docket for this proposed rulemaking, Docket EPA-HQ-OAR-2018-0276.

Based on these considerations, when developing potential levels for the international standards, ICAO further realized that curve shapes of the data differed for large and small airplanes (on MTOM versus metric value plots). Looking at the dataset, there was originally a gap in the data at 60 tons.
94

This natural gap allowed a “kink” point (
i.e.,
change in the slope of the proposed standard) to be established between larger commercial airplanes and smaller business jets and regional jets. The introduction of this kink point provided flexibility at ICAO to consider standards at appropriate levels for airplanes above and below 60 tons.

94
Initial data that were reviewed at ICAO did not include data on the Bombardier C-Series airplane. Once data were provided for this airplane, it was determined by ICAO that while the airplane did cross the 60 tons kink point, this did not pose a problem for analyzing stringency options, because the airplane passes all options considered.

The level proposed to apply to new type designs was set to reflect the performance for the latest generation of airplanes. The CO
2
emission standards agreed to at ICAO, and the GHG standards proposed here, are meant to be technology following standards. This means the rule reflects the performance and technology achieved by existing airplanes (in-production and in-development airplanes
95

).
96

95
In-development airplanes are airplanes that were in-development when setting the standard at ICAO but will be in production by the applicability dates. These could be new type designs (
e.g.
Airbus A350) or redesigned airplanes (
e.g.
Boeing 737Max).

96
Note: Figure V-1 and Figure V-2 show the metric values used in the EPA modeling for this action. These values differ from those used at ICAO. The rationale for this difference is discussed below in section VII of this proposed rule, and in chapter 2 of the Draft TSD.

Airplanes of less than 60 tons with 19 passenger seats or fewer have additional economic challenges to technology development compared with similar sized commercial airplanes. ICAO sought to reduce the burden on manufacturers of airplanes with 19 seats or fewer, and thus ICAO agreed to delay the applicability of the new type designs for 3 years. In maintaining consistency with the international decision, the applicability dates in this proposed rule reflect this difference determined by ICAO (see Section VII for further information).

As described earlier in Section II, consistency with the international standards would facilitate the acceptance of U.S. airplanes by member States and airlines around the world, and it would ensure that U.S.

manufacturers would not be at a competitive disadvantage compared with their international competitors. Consistency with the international standards would also place an anti-backsliding cap on future emissions of airplanes by ensuring that all new type design airplanes are at least as efficient as today's airplanes.

The EPA requests comment on all aspects of the proposed new type design rule, including the level of the standard, timing, and differentiation between airplane categories.

D. GHG Standard for In-Production Airplane Types

1. Applicability Dates for In-Production Airplane Types

The EPA is proposing the same compliance dates for the proposed GHG rule as those adopted by ICAO for its CO
2
emission standards. Section V.D.2 below describes the rationale for these proposed dates and the time provided to in-production types.

All airplanes type certificated prior to January 1, 2020, and newly built after January 1, 2028, would be required to comply with the proposed in-production rule. This proposed GHG regulation would function as a production cutoff for airplanes that do not meet the fuel efficiency levels described below.

i. Changes for Non-GHG Certificated Airplane Types

After January 1, 2023, and until January 1, 2028, an applicant that submits a modification to the type design of a non-GHG certificated airplane that increases the Metric Value of the airplane
97

would be required to demonstrate compliance with the in-production rule. This proposed earlier applicability date for in-production airplanes, of January 1, 2023, is the same as that adopted by ICAO and is similarly designed to capture modifications to the type design of a non-GHG certificated airplanes newly manufactured prior to the January 1, 2028, production cut-off date. The January 1, 2028 production cut-off date was introduced by ICAO as an anti-backsliding measure that gives notice to manufacturers that non-compliant airplanes will not receive airworthiness certification after this date.

97
Note that V.D.1.i, Changes for non-GHG certified Airplane Types, is different than the No GHG Change Threshold described in V.F.1 below. V.F.1 applies only to airplanes that
have previously been
certificated to a GHG rule. V.D.1.i only applies only to airplane types that
have not been
certificated for GHG.

An application for certification of a modified airplane on or after January 1, 2023, would trigger compliance with the in-production GHG emissions limit provided that the airplane's GHG emissions metric value for the modified version increases by more than 1.5 percent from the prior version of the airplane. As with changes to GHG certificated airplanes, introduction of a modification that does not adversely affect the airplane fuel efficiency Metric Value would not be required to comply with this GHG rule at the time of that change. Manufacturers may seek to certificate any airplane to this standard, even if the criteria do not require compliance.

As an example, if a manufacturer chooses to shorten the fuselage of a type certificated airplane, such action would not automatically trigger the requirement to certify to the in-production GHG rule. The fuselage shortening of a certificated type design would not be expected to adversely affect the metric value, nor would it be expected to increase the certificated MTOM. Again, a manufacturer may choose to recertificate this change in type design for GHG compliance.

This earlier effective date for in-production airplanes is expected to help encourage some earlier compliance for new airplanes. However, it is expected that manufacturers would likely volunteer to certify to the in-production rule when applying to the FAA for these types of changes.

2. Regulatory Limit for In-Production Type Designs

The EPA proposes that the emissions limit for in-production airplanes be a function of airplane certificated MTOM and consist of three MTOM ranges as described below in Equation V-5, Equation V-6, and Equation V-7.
98

98
Annex 16 Vol. III Part II Chapter 2 sec. 2.4.2 (d), (e), and (f). ICAO, 2017:
Annex 16 Volume III—Environmental Protection—Aeroplane CO
2

Emissions, First Edition,
40 pp. Available at:
http://www.icao.int/publications/Pages/catalogue.aspx
(last accessed July 15, 2020). The ICAO Annex 16 Volume III is found on page 16 of English Edition 2020 catalog and is copyright protected; Order No. AN 16-3.

EP20AU20.004

Figure V-3 and Figure V-4 show the numerical limits of the proposed in-production rules and the relationship of the airplane types analyzed in Sections VI and VII to this limit. Figure V-4 shows only the lower MTOM range of

Figure V-3 to better show the first two segments of the limit line. These plots below show the airplane CO
2
metric values as they were modeled. This includes all anticipated/modeled technology responses, improvements, and production assumptions in response to the market and the proposed rules. (See Sections VI and VII for more information about this.) These proposed GHG emission limits are the same as the limits of the ICAO Airplane CO
2
Emission Standards.

EP20AU20.005

EP20AU20.006

As discussed in Section V.C above, a kink point was added at 60 tons to accommodate a change in slope observed between large and small airplanes. The flat section starting at 60 tons is used as a transition to connect the curves for larger and smaller airplanes.

While the same technology is considered for both new type design and in-production airplanes, there would be a practical difference in compliance for in-production airplanes. Manufacturers would need to test and certify each type design to the GHG standard prior to January 1, 2028, or else newly produced airplanes would likely be denied an airworthiness certificate. In contrast, new type design airplanes have yet to go into production, but these airplanes would need to be designed to comply with the standards for new type designs (for an application for a new type design certificate on or after January 1, 2020). This poses a challenge for setting the level of the in-production standard, because sufficient time needs to be provided to allow for the GHG certification process and the engineering and airworthiness certifications needed for improvements. The more stringent the in-production standard is, the more time that is necessary to provide manufacturers to modify production of their airplanes. ICAO determined that while the technology to meet the proposed in-production level is available in 2020 (the new type design applicability date), additional time beyond the new type design applicability date was necessary to provide sufficient time for manufacturers to certify all of their products. The EPA agrees that additional time is appropriate.

Section VII describes the analysis that the EPA conducted to determine the cost and benefits of adopting this standard. Consistent with the ICAO standard, this proposed rule would apply to all in-production airplanes built on or after January 1, 2028, and to all in-production airplanes that have any modification that trigger the change criteria after January 1, 2023.

The proposed levels of the in-production GHG standards are the same as ICAO's CO
2
standards, and they reflect the emission performance of current in-production and in-development airplanes. As discussed in Section V.B.4 above and in Section VII, the regulations reflect differences in economic feasibility for introducing modifications to in-production airplanes and new type designs. The standards adopted by ICAO, and proposed here, for in-production airplanes were developed to reflect these differences.

The EPA requests comment on all aspects of the proposed in-production rule, including the level, timing, and differentiation between airplane categories.

E. Exemptions From the Proposed GHG Rules

On occasion, manufacturers may need additional time to comply with a standard. The reasons for needing a temporary exemption from regulatory requirements vary and may include circumstances beyond the control of the manufacturer. The FAA is familiar with these actions, as it has handled the similar engine emission standards under its CAA authority to enforce the standards adopted by the EPA. The FAA has considerable authority under its authorizing legislation and its regulations to deal with these events.
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99
Title 49 of the United States Code, sec. 44701(f), vests power in the FAA Administrator to issue exemptions as long as the public interest condition is met, and, pursuant to sec. 232(a) of the CAA, the Administrator may use that power “in the execution of all powers and duties vested in him under this section” “to insure compliance” with emission standards.

Since requests for exemptions are requests for relief from the enforcement of these standards (as opposed to a request to comply with a different standard than set by the EPA), this rule would continue the relationship between the agencies by proposing that any request for exemption be filed with the FAA under its established regulatory paradigm. The instructions for a submitting a petition for exemption to the FAA can be found in 14 CFR part 11, specifically § 11.63. Section 11.87 lists the information that must be filed in a petition, including a reason “why granting your petition is in the public interest.” Any request for exemption would need to cite the regulation that the FAA will adopt to carry out its duty of enforcing the standard set by the EPA. A list of requests for exemption received by the FAA is routinely published in the
Federal Register
.

The primary criterion for any exemption filed with the FAA is whether a grant of exemption would be in the public interest. The FAA will continue to consult with EPA on all petitions for exemption that the FAA receives regarding the enforcement of aircraft engine and emission standards adopted under the CAA.

F. Application of Rules for New Version of an Existing GHG-Certificated Airplane

Under the international Airplane CO
2
Emission Standards, a new version of an existing CO
2
-certificated airplane is one that incorporates modifications to the type design that increase the MTOM or increase its CO
2
Metric Value more than the No-CO
2
-Change Threshold (described in V.F.1 below). ICAO's standards provide that once an airplane is CO
2
certificated, all subsequent changes to that airplane must meet at least the regulatory level of the parent airplane. For example, if the parent airplane is certificated to the in-production level, then all subsequent versions must also meet the in-production level. This would also apply to voluntary certifications under ICAO's standards. If a manufacturer seeks to certificate an in-production airplane type to the level applicable to a new type design, then future versions of that airplane must also meet the same regulatory level. Once certificated, subsequent versions of the airplane may not fall back to a less stringent regulatory GHG level.

If the FAA finds that a new original type certificate is required for any reason, the airplane would need to comply with the regulatory level applicable to a new type design.

The EPA is proposing provisions for versions of existing GHG-certificated airplanes that are the same as the ICAO requirements for the international Airplane CO
2
Emission Standards. These provisions would reduce the certification burden on manufacturers by clearly defining when a new metric value must be established for the airplane.

1. No Fuel Efficiency Change Threshold for GHG-Certificated Airplanes

There are many types of modifications that could be introduced on an airplane design that could cause slight changes in GHG emissions (
e.g.
changing the fairing on a light,
100

adding or changing an external antenna, changing the emergency exit door configuration, etc.). To reduce burden on both certification authorities and manufacturers, a set of no CO
2
emissions change thresholds was developed for the ICAO Airplane CO
2
Emission Standards as to when new metric values would need to be certificated for changes. The EPA proposes to adopt these same thresholds in its GHG rules.

100
A fairing is
“a structure on the exterior of an aircraft or boat, for reducing drag.” https://www.dictionary.com/browse/fairing.

Under this proposal, an airplane would be considered a modified version of an existing GHG certificated airplane, and therefore have to recertify, if it incorporates a change in the type design that either (a) increases its maximum take-off mass, or (b) increases its GHG emissions evaluation metric value by more than the no-fuel efficiency change threshold percentages described below and in Figure V-5:
101

101
Annex 16, Volume III, Part 1, Chapter 1. ICAO, 2017:
Annex 16 Volume III—Environmental Protection—Aeroplane CO
2

Emissions, First Edition,
40 pp. Available at:
http://www.icao.int/publications/Pages/catalogue.aspx
(last accessed July 15, 2020). The ICAO Annex 16 Volume III is found on page 16 of English Edition 2020 catalog and is copyright protected; Order No. AN 16-3.

• For airplanes with a MTOM greater than or equal to 5,700 kg, the threshold value decreases linearly from 1.35 to 0.75 percent for an airplane with a MTOM of 60,000 kg.

• For airplanes with a MTOM greater than or equal to 60,000 kg, the threshold value decreases linearly from 0.75 to 0.70 percent for airplanes with a MTOM of 600,000 kg.

• For airplanes with a MTOM greater than or equal to 600,000 kg, the threshold value is 0.70 percent.

EP20AU20.007

The threshold is dependent on airplane size, because the potential fuel efficiency changes to an airplane are not constant across all airplanes. For example, a change to the fairing surrounding a wing light, or the addition of an antenna to a small business jet, may have greater impacts on the airplane's metric value than a similar change would on a large twin aisle airplane.

These GHG changes would be assessed on a before-change and after-change basis. If there is a flight test as part of the certification, the metric value (MV) change could be assessed based on the change in calculated metric value of flights with and without the change.

A modified version of an existing GHG certificated airplane would be subject to the same regulatory level as the airplane from which it was modified. A manufacturer may also choose to voluntarily comply with a later or more stringent standard.
102

102
ETM Vol. III sec. 2.2.3. ICAO, 2018:
Environmental Technical Manual Volume III—Procedures for the CO
2

Emissions Certification of Aeroplanes, First Edition, Doc 9501,
64 pp. Available at:
http://www.icao.int/publications/Pages/catalogue.aspx
(last accessed July 15, 2020). The ICAO Environmental Technical Manual Volume III is found on page 77 of the English Edition 2020 catalog and is copyright protected; Order No. 9501-3.

Under this proposed rule, when a change is made to an airplane type that does not exceed the no-change threshold, the fuel efficiency metric value would not change. There would be no method to track these changes to airplane types over time. This feature of the proposed rule would not remove the requirement for a manufacturer to demonstrate that the airplane type would still meet the rule after a given change. If an airplane type has, for example, a 10 percent compliance margin under the rule, then a small adverse change less than the threshold may not require the re-evaluation of the airplane metric value. However, if the compliance margin for a type design is less than the no GHG change criteria, a manufacturer would be required to prove that it meets the rule to certify the adverse change.

Under the proposed rule, a manufacturer that introduces modifications that reduce GHG emissions can request voluntary recertification from the FAA. There would be no required tracking or accounting of GHG emissions reductions made to an airplane unless it is voluntarily re-certificated.

The EPA proposes to adopt as part of the GHG rules the no-change thresholds for modifications to airplanes discussed above, which are the same as the provisions in the international standard. We believe that these thresholds would maintain the effectiveness of the rule while limiting the burden on manufacturers to comply. The proposed regulations reference specific test and other criteria that were adopted internationally in the ICAO standards setting process.

G. Annual Reporting Requirement

As described later in this section, the EPA proposes to collect information about airplane GHG emissions and related parameters to help inform the development of future policy, assessments of emissions inventories, and specific technologies.

In May of 1980, ICAO's CAEE recognized that certain information relating to environmental aspects of aviation should be organized into one document. This document became ICAO's “Annex 16 to the Convention on International Civil Aviation, International Standards and Recommended Practices, Environmental Protection” and was split into two volumes—Volume I, addressing Aircraft Noise, and Volume II, addressing Aircraft Engine Emissions. Annex 16 has continued to grow since its inception, and today Annex 16 Volume

II includes a list of reporting requirements for an aircraft engine to comply with the ICAO emission standards.
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These requirements include information relating to engine identification and characteristics, fuel usage, data from engine testing, data analysis, and the results derived from the test data. Additionally, this list of aircraft engine requirements is supplemented with voluntarily reported information which has been assembled into an electronic spreadsheet, entitled ICAO Aircraft Engine Emissions Databank (EDB),
104

in order to aid with criteria pollutant emission calculations and analysis as well as help inform the general public.

103
ICAO, Annex 16 to the Convention on International Civil Aviation, Environmental Protection, Volume II, Aircraft Engine Emissions, Part III, Chapter 2, Section 2.4. ICAO, 2017:
Annex 16 Volume II—Environmental Protection—Aircraft Engine Emissions, Fourth Edition,
Incorporating Amendments 1-9, 174 pp. Available at:
http://www.icao.int/publications/Pages/catalogue.aspx
(last accessed July 15, 2020). The ICAO Annex 16 Volume II is found on page 16 of English Edition 2020 catalog and is copyright protected; Order No. AN 16-2.

104
The European Aviation Safety Agency (EASA) hosts the ICAO Aircraft Engine Emissions Databank on behalf of ICAO. Available at:
https://www.easa.europa.eu/easa-and-you/environment/icao-aircraft-engine-emissions-databank
(last accessed March 16, 2020).

The new international Airplane CO
2
Emission Standards adopted by ICAO in 2017 are prescribed in ICAO Annex 16, Volume III titled, Aeroplane CO
2
Emissions. Building on the precedent from ICAO Annex 16 Volume I and II and the ICAO Aircraft Engine Emissions Databank, ICAO is planning to develop a similar public database of voluntarily reported information related to the international Airplane CO
2
Emission Standards, and this database is referred to as the ICAO CO
2
Certification Database (CO
2
DB). The information requested by ICAO to go in the CO
2
DB will include only information that is not considered by industry to be commercially sensitive. This means that the ICAO CO
2
DB will include only information to identify the airplane type (manufacturer, engine type(s), MTOM, etc.), the regulatory limit, and certified emissions metric value (and only where voluntarily reported by manufacturers). This will not include the individual components of the metric equation (
e.g.
RGF or SAR values described in Equation V-1). (Note later in this section (V.G.1) we describe the manner in which the EPA treats information that has been claimed to be confidential business information. Further information is also included in the Information Collection Request Supporting Statement.
105

)

105
Draft ICR Supporting Statement 2626.01, available in the public Docket.

In order to assess the GHG emission impacts of the proposed standards and to inform future actions, the EPA needs to understand how the proposed GHG standards affect the in-production fleet. Thus, we need access to timely, representative emissions data of the fleet at the requisite model level. The EPA needs information on technology, performance parameters, and emissions da

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2020-16271. Public record. Not legal advice.