Document ID: EPA-HQ-OAR-2018-0276-0001
Agency: epa
Document Type: Proposed Rule
Title: Control of Air Pollution From Airplanes and Airplane Engines: Greenhouse Gas Emission Standards and Test Procedures
Posted Date: 2020-08-20T04:00Z

[Federal Register Volume 85, Number 162 (Thursday, August 20, 2020)]
[Proposed Rules]
[Pages 51556-51594]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-16271]

[[Page 51555]]

Vol. 85

Thursday,

No. 162

August 20, 2020

Part II

Environmental Protection Agency

-----------------------------------------------------------------------

40 CFR Parts 87 and 1030

-----------------------------------------------------------------------

Control of Air Pollution From Airplanes and Airplane Engines: GHG 
Emission Standards and Test Procedures; Proposed Rule

  Federal Register / Vol. 85, No. 162 / Thursday, August 20, 2020 / 
Proposed Rules  

[[Page 51556]]

-----------------------------------------------------------------------

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 CO2 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, 
CO2 and nitrous oxide (N2O). 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, CO2 and N2O.

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 CO2 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)

[[Page 51557]]

    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:

------------------------------------------------------------------------
                                                       Examples of
              Category                  NAICS     potentially  affected
                                       code \a\          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 CO2 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 
CO2 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 CO2 
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 
CO2 Emission Standards, U.S. civil airplane manufacturers 
could be forced to seek CO2 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 CO2 
emissions. The ICAO Airplane CO2 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 
CO2 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 CO2 emissions. The 
proposed GHG standards are equivalent to the CO2 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

[[Page 51558]]

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 CO2 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 (NOX) 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 CO2 
Emission Standards, which ICAO approved in 2017. The EPA is proposing 
to adopt GHG standards that are equivalent to the international 
Airplane CO2 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--CO2 and N2O--have non-
zero emissions for total civil subsonic airplanes and U.S. covered 
airplanes. CO2 represents 99 percent of all GHGs emitted 
from both total U.S. civil airplanes and U.S. covered airplanes, and 
N2O 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 CO2 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 CO2 Emission Standards adopted by ICAO.\11\ This 
proposed rule incorporates the same compliance schedule as the ICAO

[[Page 51559]]

Airplane CO2 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 CO2 emissions are based on the consumption of 
fuel (or fuel burn) under prescribed conditions at optimum cruise 
altitude. ICAO uses the term, CO2, 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 CO2 is 3.16 
kilograms of CO2 per kilogram of fuel burn (or 3,160 
grams of CO2 per kilogram of fuel burn). Thus, to convert 
an airplane's rate of fuel burn to a CO2 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, NOX, 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 CO2 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

[[Page 51560]]

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 (NOX). 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 NOX 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 NOX 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 NOX 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 NOX 
reduction, which ICAO approved in 2005.24 25 The CAEP/6 
standards applied

[[Page 51561]]

to new engine designs certificated after December 31, 2007. In 2010, 
CAEP/8 recommended a further tightening of the NOX 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 CO2 emission standards, which ICAO approved in 
2017. The CAEP/10 CO2 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 
NOX 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 NOX 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 NOX emission standards for newly certificated and in-
production commercial and non-commercial turbofan engines, and these 
NOX 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 NOX 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 CO2 Emission Standards. In this action, we are 
proposing to adopt GHG standards equivalent to the ICAO Airplane 
CO2 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 CO2 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 CO2 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 
CO2 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 CO2 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 CO2 emissions test procedures based on measuring the 
performance of the whole airplane rather than the

[[Page 51562]]

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 CO2 emissions. Rather than measuring a single 
chemical compound, the ICAO CO2 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 
CO2 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 CO2 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 
CO2 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--CO2, methane, 
N2O, 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

[[Page 51563]]

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 CO2 Emissions Inventory for 
Aircraft Below ICAO CO2 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 CO2 Emissions Inventory for 
Aircraft Below ICAO CO2 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. Schl[ouml]mer, 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. Schl[ouml]mer, 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, CO2 and N2O, are emitted from covered 
aircraft. CO2 represents 99 percent of all GHGs emitted from 
both total U.S. aircraft and U.S. covered aircraft, and N2O 
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--
CO2 and N2O-- 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 CO2 Emissions Inventory for 
Aircraft Below ICAO CO2 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 CO2 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 CO2 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 CO2 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

[[Page 51564]]

Section III and in the 2016 Findings,\60\ only two of the six well-
mixed GHGs--CO2 and N2O--are emitted from covered 
aircraft. Both CO2 and N2O 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, NOX, 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 
CO2 standards adopted by ICAO. The EPA and the FAA worked 
within ICAO to help establish the international CO2 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 
CO2 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 CO2 
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 
CO2 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 CO2 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 CO2 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 CO2 emissions metric, it is a measure of fuel 
efficiency, which is directly related to CO2 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 CO2 emissions. In 
addition, the international metric system accommodates a wide range of 
technologies and designs that manufacturers may choose to implement to 
reduce CO2 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

[[Page 51565]]

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 CO2 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 CO2 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 CO2 
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.
[GRAPHIC] [TIFF OMITTED] TP20AU20.000

    The ICAO CO2 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 CO2 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 
CO2 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[supcaret]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 CO2 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 CO2 emissions metric is correlated against 
MTOM, it has a positive slope. The international Airplane 
CO2 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 CO2 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 CO2 and N2O, 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 CO2 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

[[Page 51566]]

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 CO2 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 
CO2 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: CO2 Analysis of CO2-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 CO2-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: CO2 Analysis of CO2-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, CO2 Analysis of CO2-Reducing Technologies for 
Airplane, Final Report, EPA Contract Number EP-C-12-011, March 17, 
2015.)

---------------------------------------------------------------------------

[[Page 51567]]

    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 CO2 
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 NOX 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

[[Page 51568]]

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 CO2 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.
[GRAPHIC] [TIFF OMITTED] TP20AU20.001

    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 CO2 Emission 
Standards.

[[Page 51569]]

[GRAPHIC] [TIFF OMITTED] TP20AU20.002

[[Page 51570]]

[GRAPHIC] [TIFF OMITTED] TP20AU20.003

    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 CO2 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 CO2 
Emissions Standard, Montr[eacute]al, 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 
CO2 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.

[[Page 51571]]

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 CO2 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 CO2 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.
[GRAPHIC] [TIFF OMITTED] TP20AU20.004

    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

[[Page 51572]]

Figure V-3 to better show the first two segments of the limit line. 
These plots below show the airplane CO2 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 CO2 Emission 
Standards.
[GRAPHIC] [TIFF OMITTED] TP20AU20.005

[[Page 51573]]

[GRAPHIC] [TIFF OMITTED] TP20AU20.006

    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 CO2 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.\99\
---------------------------------------------------------------------------

    \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.

---------------------------------------------------------------------------

[[Page 51574]]

    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 Sec.  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 CO2 Emission Standards, 
a new version of an existing CO2-certificated airplane is 
one that incorporates modifications to the type design that increase 
the MTOM or increase its CO2 Metric Value more than the No-
CO2-Change Threshold (described in V.F.1 below). ICAO's 
standards provide that once an airplane is CO2 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 CO2 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 CO2 emissions change thresholds 
was developed for the ICAO Airplane CO2 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 CO2 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.

[[Page 51575]]

[GRAPHIC] [TIFF OMITTED] TP20AU20.007

    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 CO2 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

[[Page 51576]]

II includes a list of reporting requirements for an aircraft engine to 
comply with the ICAO emission standards.\103\ 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 CO2 Emission Standards 
adopted by ICAO in 2017 are prescribed in ICAO Annex 16, Volume III 
titled, Aeroplane CO2 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 CO2 Emission Standards, and this 
database is referred to as the ICAO CO2 Certification 
Database (CO2DB). The information requested by ICAO to go in 
the CO2DB will include only information that is not 
considered by industry to be commercially sensitive. This means that 
the ICAO CO2DB 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 data to conduct accurate 
technology assessments, compile airplane emission inventories, and 
develop appropriate policy. While the FAA would have access to 
technical information during certification, the EPA would not be able 
to access this information provided to FAA, and these circumstances 
reinforce the need for the EPA reporting requirement.
    Having the information updated each year would allow the EPA to 
assess technology trends. It would also assist the EPA to stay abreast 
of any developments in the characteristics of the industry. The EPA 
would begin to collect data as airplanes start to become certificated. 
The EPA does not expect a full dataset on all in-production airplanes 
until shortly after the in-production applicability date of January 1, 
2028. In the context of EPA's standard-setting role under the CAA with 
regard to aircraft engine emissions, it is consistent with our policy 
and practice to ask for timely and reasonable reporting of emission 
certification testing and other information that is relevant to our 
mission.\106\ Under the CAA, we are authorized to require manufacturers 
to establish and maintain necessary records, make reports, and provide 
such other information as we may reasonably require to discharge our 
functions under the Act. (See 42 U.S.C. 7414(a)(1).)
---------------------------------------------------------------------------

    \106\ The FAA already requires much of the information EPA is 
seeking through the certification process but is unable to share it 
because of confidentiality agreements with engine manufacturers. 
Also, that information is part of a much larger submission, making 
it difficult to extract the specific reporting elements for EPA.
---------------------------------------------------------------------------

    We are proposing to require that airplane manufacturers submit an 
annual production report directly to the EPA \107\ with specific 
information for each individual airplane sub-model that (1) is designed 
to operate at subsonic speeds, (2) is subject to EPA's GHG emission 
standards, and (3) has received a type certificate. More specifically, 
the scope of the proposed production report would include subsonic jet 
powered airplanes with certificated MTOM over 5,700 kg and turboprop 
powered airplanes with certificated MTOM over 8,618 kg. We are also 
proposing that this information be reported to us in a timely manner, 
which would allow us to ensure that any public policy that we create 
based on this information will be well informed.
---------------------------------------------------------------------------

    \107\ The proposed report would be submitted only to EPA. No 
separate submission or communication of any kind is required for the 
FAA.
---------------------------------------------------------------------------

    The proposed reporting elements for each affected airplane sub-
model are listed below.
     Company corporate name as listed on the airplane type 
certificate;
     Calendar year for which reporting;
     Complete airplane sub-model name (this would generally 
include the model name and the sub-model identifier, but may also 
include a type certificate family identifier);
     The airplane type certificate number, as issued by the FAA 
(specify if the sub-model also has a type certificate issued by a 
certificating authority other than the FAA);
     Date of issue of airplane type certificate and/or 
exemption (i.e. month and year);
     Number of engines on the airplane;
     Company corporate name, as listed on the engine type 
certificate;
     Complete engine sub-model name (this would generally 
include the model name and the sub-model identifier, but may also 
include an engine type certificate family identifier);
     Company corporate name as listed on the propeller type 
certificate--as applicable;
     Complete propeller sub-model name (this would generally 
include the model name and the sub-model identifier, but may also 
include propeller an engine type certificate family identifier);
     Date of application for certification to airplane GHG 
standards;
     Emission standard to which the airplane is certificated 
(i.e., the specific Annex 16, Volume III, edition number and 
publication date in which the numerical standards first appeared);
     If this is a modified airplane for emissions certification 
purposes, identify the original certificated airplane model;
     Production volume of the airplane sub-model for the 
previous calendar year, or if zero, state that the airplane model is 
not in production and list the date of manufacture (month and year) of 
the last airplane produced;
     Number of exempt airplanes produced,\108\ if applicable;
---------------------------------------------------------------------------

    \108\ Airplanes produced under an exemption would still be 
required to report all information for all fields. In the case new 
type designs that are built and fixed (or changed) in the same year, 
separate lines should be used to record the exempt and complaint 
configurations and metric values.

---------------------------------------------------------------------------

[[Page 51577]]

     Certificated MTOM;
     GHG Emissions Metric Value;
     Regulatory level;
     Margin to regulatory level;
     RGF.
    The EPA is proposing to collect additional elements or information 
beyond what ICAO will request for the voluntary CO2DB. These 
additional elements are the RGF and annual production volume. From the 
list above, the ICAO CO2DB will only include the airplane 
identification information, MTOM, and Metric Value. ICAO limited the 
information in the public CO2DB for the following reasons: 
(a) To recognize the concerns of manufacturers to exclude commercially 
sensitive information and (b) to expedite manufacturers' voluntary 
submissions for populating the dataset. These reasons would not pertain 
to the EPA reporting requirement because (a) the EPA's CBI regulations 
would prevent the disclosure of confidential business information (see 
V.G.1 below), and (b) the EPA reporting of information would be 
required, preventing delays in manufacturers' submissions. The EPA 
requests comment on the scope of this proposed information request 
including any concerns related to reporting any of this information. 
The EPA also requests comment on whether we should require reporting of 
additional information.
    The proposed annual report would be submitted for each calendar 
year in which a manufacturer produces any airplane subject to emission 
standards as previously described. These reports would be due by 
February 28 of each year, starting with the 2020 calendar year, and 
cover the previous calendar year. This report would be sent to the 
Designated EPA Program Officer. Where information provided for any 
previous year remains valid and complete, the manufacturer would be 
allowed to report the production figures and to state that there are no 
changes instead of resubmitting the original information. To facilitate 
and standardize reporting, we expect to specify a particular format for 
this reporting in the form of a spreadsheet or database template that 
we would provide to each manufacturer. As noted previously, we intend 
to use the proposed reports to help inform any further public policy 
approaches regarding airplane GHG emissions that we consider, including 
possible future emissions rules, as well as to help provide 
transparency to the general public. Subject to the applicable 
requirements of 42 U.S.C. 7414(c), 18 U.S.C. 1905, and 40 CFR part 2, 
all data received by the Administrator that is not confidential 
business information may be posted on our website and would be updated 
annually. By collecting and publicly posting this information on EPA's 
website, we believe that this information would be useful to the 
general public to help inform public knowledge regarding airplane GHG 
emissions.
    We have assessed the potential reporting burden associated with the 
proposed annual reporting requirement. That assessment is presented in 
Sections VII.D.4 and IX.C of this proposed rule.
1. Confidentiality
    In general, emission data and related technical information 
collected under CAA section 114 cannot be treated as confidential 
business information (CBI). Consistent with governing EPA regulations, 
however, where manufacturers show what information they consider 
confidential by marking, circling, stamping or some other method, and 
if the EPA determines that the information is confidential, the EPA 
would store said information as CBI pursuant to 40 CFR part 2 and 40 
CFR 1068.10. If manufacturers send the EPA information without marking 
it is CBI, the EPA may make it available to the public without further 
notice to the manufacturer. Although CBI determinations are usually 
made on a case-by-case basis, the EPA has issued guidance on what 
constitutes emission data that cannot be considered CBI (56 FR 7042, 
February 21, 1991).

H. Test and Measurement Procedures

    The international certification test procedures have been developed 
based upon industry's current best practices for establishing the 
cruise performance of their airplanes and on input from certification 
authorities. These procedures include specifications for airplane 
conformity, weighing, fuel specifications, test condition stability 
criteria, required confidence intervals, measurement instrumentation 
required, and corrections to reference conditions. In this action, we 
are proposing to incorporate by reference the test procedures for the 
ICAO Airplane CO2 Emission Standards. Adoption of these test 
procedures would maintain consistency among all ICAO member States.
    Airplane flight tests, or FAA approved performance models, would be 
used to determine SAR values that form the basis of the GHG metric 
value. Under the proposed rule, flight testing to determine SAR values 
shall be conducted within the approved normal operating envelope of the 
airplane, when the airplane is steady, straight, level, and trim, at 
manufacturer-selected speed and altitude.\109\ The rule would provide 
that flight testing must be conducted at the ICAO-defined reference 
conditions where possible,\110\ and that when testing does not align 
with the reference conditions, corrections for the differences between 
test and reference conditions shall be applied.\111\
---------------------------------------------------------------------------

    \109\ It is expected that manufacturers will choose conditions 
that result in the highest SAR value for a given certification mass. 
Manufacturers may choose other than optimum conditions to determine 
SAR; however, doing so will be at their detriment.
    \110\ Annex 16, Vol. III, sec. 2.5. ICAO, 2017: Annex 16 Volume 
III--Environmental Protection--Aeroplane CO2 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.
    \111\ Annex 16, Vol. III, Appendix 1. ICAO, 2017: Annex 16 
Volume III--Environmental Protection--Aeroplane CO2 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.
---------------------------------------------------------------------------

    We are proposing to incorporate by reference, in proposed Sec.  
1030.23(d), certain procedures found in ICAO Annex 16, Volume III.

I. Controlling Two of the Six Well-Mixed GHGs

    As described earlier in Section V.A and V.H, we are proposing to 
adopt the ICAO test procedures and fuel efficiency metric.\112\ The 
ICAO test procedures for the international Airplane CO2 
Emission Standards measure fuel efficiency (or fuel burn), and ICAO 
uses fuel efficiency in the metric (or equation) for determining 
compliance. As explained earlier in Section III and in the 2016 
Findings,\113\ only two of the six well-mixed GHGs--CO2 and 
N2O--are emitted from covered aircraft. Although there is 
not a standardized test procedure for directly measuring airplane 
CO2 or N2O emissions, the test

[[Page 51578]]

procedure for fuel efficiency scales with the limiting of both 
CO2 and N2O emissions, as they both can be 
indexed on a per-unit-of-fuel-burn basis. Therefore, both 
CO2 and N2O emissions can be controlled as 
airplane fuel burn is limited.\114\ Since limiting fuel burn is the 
only means by which airplanes control their GHG emissions, the fuel-
burn-based metric (or fuel-efficiency-based metric) reasonably serves 
as a surrogate for controlling both CO2 and N2O.
---------------------------------------------------------------------------

    \112\ ICAO's certification standards and procedures for airplane 
CO2 emissions are based on the consumption of fuel (or 
fuel burn). ICAO uses the term CO2 for its standards and 
procedures, but ICAO is actually regulating or measuring the rate of 
an airplane's fuel burn (or fuel efficiency). As described earlier, 
to convert an airplane's rate of fuel burn (for jet fuel) to a 
CO2 emissions rate, a 3.16 kilograms of CO2 
per kilogram of fuel burn emission index needs to be applied.
    \113\ 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).
    \114\ For jet fuel, the emissions index or emissions factor for 
CO2 is 3.16 kilograms of CO2 per kilogram of 
fuel burn (or 3,160 grams of CO2 per kilogram of fuel 
burn). For jet fuel, the emissions index for nitrous oxide is 0.1 
grams of nitrous oxide per kilogram of fuel burn (which is 
significantly less than the emissions index for CO2). 
Since CO2 and nitrous oxide emissions are indexed to fuel 
burn, they are both directly tied to fuel burn. Controlling 
CO2 emissions means controlling fuel burn, and in turn 
this leads to limiting nitrous oxide emissions. Thus, controlling 
CO2 emissions would scale with limiting nitrous oxide 
emissions.
    SAE, 2009, Procedure for the Calculation of Airplane Emissions, 
Aerospace Information Report, AIR5715, 2009-07 (pages 45-46). The 
nitrous oxide emissions index is from this report.
    ICAO, 2016: ICAO Environmental Report 2016, Aviation and Climate 
Change, 250 pp. The CO2 emissions index is from this 
report. Available at https://www.icao.int/environmental-protection/Documents/ICAO%20Environmental%20Report%202016.pdf (last accessed 
March 16, 2020).
---------------------------------------------------------------------------

    Since CO2 emissions represent nearly all GHG emissions 
from airplanes and ICAO's CO2 test procedures measure fuel 
efficiency by using a fuel-efficiency-based metric, we propose to 
harmonize with the ICAO CO2 standard--by proposing to adopt 
an aircraft engine GHG \115\ standard that also employs a fuel 
efficiency metric that will also scale with both CO2 and 
N2O emissions. The proposed aircraft engine GHG standard 
would control both CO2 and N2O emissions, without 
the need for adoption of engine exhaust emissions rates for either 
CO2 or N2O. However, the air pollutant regulated 
by these standards would remain the aggregate of the six well-mixed 
GHGs.\116\
---------------------------------------------------------------------------

    \115\ See section II.E (Consideration of Whole Airplane 
Characteristics) of this proposed rule for a discussion on 
regulating emissions from the whole airplane.
    \116\ Although compliance with the proposed GHG standard would 
be measured in terms of fuel efficiency, the EPA considers the six 
well-mixed GHGs to be the regulated pollutant for the purposes of 
the proposed standard.
---------------------------------------------------------------------------

VI. Aggregate GHG and Fuel Burn Methods and Results

    This section describes the EPA's emission impacts analysis for the 
proposed standards. This section also describes the assumptions and 
data sources used to develop the baseline GHG emissions inventories and 
the potential consequences of the proposed standards on aviation 
emissions. Consistent with Executive Order 12866, we analyzed the 
impacts of alternatives (using similar methodologies), and the results 
for these alternatives are described in chapters 4 and 5 of the Draft 
Technical Support Document (TSD).
    As described earlier in Section II, the manufacturers of affected 
airplanes and engines have already developed or are developing 
technologies that meet the 2017 ICAO Airplane CO2 Emission 
Standards. The EPA expects that the manufacturers will comply with the 
ICAO Airplane CO2 Emission Standards even in advance of 
member States' adoption into domestic regulations. Therefore, the EPA 
expects that the proposed GHG standards would not, beyond limited 
reporting costs, impose an additional burden on manufacturers. In 
keeping with the ICAO/CAEP need to consider technical feasibility in 
standard setting, the ICAO Airplane CO2 Emission Standards 
reflect demonstrated technology that will be available in 2020.
    As described below, the analysis for the proposed GHG standards 
considered individual airplane types and market forces. We have 
assessed GHG emission reductions needed for airplane types (or airplane 
models) to meet the proposed GHG standards compared to the improvements 
that are driven by market competition and are expected to occur in the 
absence of any standard (business as usual improvements). A summary of 
these results is described later in this section. Additional details 
can be found in chapter 5 of the accompanying Draft TSD for the 
proposed standards.

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

    The EPA participated in ICAO/CAEP's standard-setting process for 
the international Airplane CO2 Emission Standards. CAEP 
provided a summary of the results from this analysis in the report of 
its tenth meeting,\117\ which occurred in February 2016. However, due 
to the commercial sensitivity of the data used in the analysis, much of 
the underlying information is not available to the public. For the U.S. 
domestic GHG standards, however, we are making our analysis, data 
sources, and model assumptions transparent to the public so all 
stakeholders affected by the proposed standards can understand how the 
agency derives its decisions. Thus, the EPA has conducted an 
independent impact analysis based solely on publicly available 
information and data sources. An EPA report detailing the methodology 
and results of the emissions inventory analysis \118\ was peer-reviewed 
by multiple independent subject matter experts, including experts from 
academia and other government agencies, as well as independent 
technical experts.\119\
---------------------------------------------------------------------------

    \117\ ICAO, 2016: Doc 10069--Report of the Tenth Meeting, 
Montreal,1-12 February 2016, Committee on Aviation Environmental 
Protection, CAEP 10, 432pp., pages 271 to 308, is found on page 27 
of the ICAO Products & Services English Edition 2020 Catalog and is 
copyright protected. For purchase available at: https://www.icao.int/publications/Pages/catalogue.aspx (last accessed March 
16, 2020). The summary of technological feasibility and cost 
information is located in Appendix C (starting on page 5C-1) of this 
report.
    \118\ U.S. EPA, 2020: Technical Report on Aircraft Emissions 
Inventory and Stringency Analysis, July 2020, 52pp.
    \119\ RTI International and EnDyna, EPA Technical Report on 
Aircraft Emissions Inventory and Stringency Analysis: Peer Review, 
July 2019, 157pp.
---------------------------------------------------------------------------

    The methodologies the EPA uses to assess the impacts of the 
proposed GHG standards are summarized in a flow chart shown in Figure 
VI-1. This section describes the impacts of the proposed GHG standards. 
Essentially, the approach is to compare the GHG emissions of the 
business as usual baseline in the absence of standards with those 
emissions under the proposed GHG standards.

[[Page 51579]]

[GRAPHIC] [TIFF OMITTED] TP20AU20.008

    The first step of the EPA analysis is to create a baseline, which 
is constructed from the unique airport origin-destination (OD) pairs 
and airplane combinations in the 2015 base year. As described further 
in the next section, these base year operations are then evolved to 
future year operations, 2016-2040, by emulating the market driven fleet 
renewal process to define the baseline (without the proposed GHG 
regulatory requirements). The same method then is applied to define the 
fleet evolution under the proposed GHG standards, except that different 
potential technology responses are defined for the airplanes impacted 
by the proposed GHG standards. Specifically, they are either modified 
to meet the standards or removed from production. Once the flight 
activities for all analysis scenarios are defined by the fleet 
evolution module, then fuel burn and GHG \120\ emissions are modelled 
for all the scenarios with a physics-based airplane performance model 
known as PIANO.\121\ A brief account of the methods, assumptions, and 
data sources used is given below, and more details can be found in 
chapter 4 of the Draft TSD.
---------------------------------------------------------------------------

    \120\ To convert fuel burn to CO2 emissions, we used 
the conversion factor of 3.16 kg/kg fuel for CO2 
emissions, and to convert to the six well-mixed GHG emissions, we 
used 3.19 kg/kg fuel for CO2 equivalent emissions. Our 
method for calculating CO2 equivalent emissions is based 
on SAE AIR 5715, 2009: Procedures for the Calculation of Aircraft 
Emissions and the EPA publication: Emissions Factors for Greenhouse 
Gas Inventories, EPA, last modified 4, April 2014, https://www.epa.gov/sites/production/files/2015-07/documents/emission-factors_2014.pdf (last accessed March 16, 2020).
    \121\ PIANO is the Aircraft Design and Analysis Software by Dr. 
Dimitri Simos, Lissys Limited, UK, 1990-present; Available at 
www.piano.aero (last accessed March 16, 2020). PIANO is a 
commercially available airplane design and performance software 
suite used across the industry and academia.
---------------------------------------------------------------------------

1. Fleet Evolution Module
    To develop the baseline, the EPA used FAA 2015 operations data as 
the basis to project future fleet operations out to 2040. The year-to-
year activity growth rate was determined by the FAA 2015-2040 Terminal 
Area Forecast \122\ (TAF) based on airport OD-pairs, route groups 
(domestic or international), and airplane types. The retirement rate of 
a specific airplane is determined by the age of the airplane and the 
retirement curve of its associated airplane type. Retirement curves of 
major airplane types are derived statistically based on data from the 
FlightGlobal Fleets Analyzer database \123\ (also known as ASCEND 
Online Fleets Database--hereinafter ``ASCEND'').
---------------------------------------------------------------------------

    \122\ FAA 2015-2040 Terminal Area Forecast, the Terminal Area 
Forecast (TAF) is the official FAA forecast of aviation activity for 
U.S. airports. It contains active airports in the National Plan of 
Integrated Airport Systems (NPIAS) including FAA-towered airports, 
Federal contract-towered airports, non-Federal towered airports, and 
non-towered airports. Forecasts are prepared for major users of the 
National Airspace System including air carrier, air taxi/commuter, 
general aviation, and military. The forecasts are prepared to meet 
the budget and planning needs of the FAA and provide information for 
use by state and local authorities, the aviation industry, and the 
public.
    \123\ FlightGlobal Fleets Analyzer is a subscription based 
online data platform providing comprehensive and authoritative 
source of global airplane fleet data (also known as ASCEND database) 
for manufacturers, suppliers and Maintenance, Repair, Overhaul (MRO) 
providers. https://signin.cirium.com (last accessed December 16, 
2019).
---------------------------------------------------------------------------

    EPA then linked the 2015 FAA operations data to the TAF and ASCEND-
based growth and retirement rates by matching the airport and airplane 
parameters. Where the OD-pair and airplane match between the operations 
data and the TAF, then the exact TAF year-on-year growth rates were 
applied to grow 2015 base year activities to future years. For cases 
without exact matches, growth rates from progressively more aggregated 
levels were used to grow the future year activities.\124\
---------------------------------------------------------------------------

    \124\ For example, in the absence of exact airplane match, the 
aggregated growth rate of airplane category is used; in case of no 
exact OD-pair match, the growth rate of route group is used. Outside 
the U.S. the non-US flights were modelled with global average growth 
rates from ICAO for passenger and freighter operations and from the 
Bombardier forecast for business jets. See chapter 5 of the Draft 
TSD for details.
---------------------------------------------------------------------------

    The retirement rate was based on the exact age of the airplane from 
ASCEND for airplanes with a known tail number. When the airplane tail 
number was not known, the aggregated retirement rate of the next level 
matching fleet (e.g., airplane type or category as defined by

[[Page 51580]]

ASCEND) was used to calculate the retirement rates for future years.
    Combining the growth and retirement rates together, we calculate 
the future year growth and replacement (G&R) market demands. These 
future year G&R market demands are aligned to each base year flight, 
and the future year flights are allocated with available G&R airplanes 
\125\ using an equal-product market-share selection process.\126\ The 
market demand allocation is made based on ASK (Available Seat 
Kilometer) for passenger operations, ATK (Available Tonne Kilometer) 
for freighter operations, and number of operations for business jets.
---------------------------------------------------------------------------

    \125\ The airplane G&R database contains all the EPA-known in-
production and in-development airplanes that are projected to grow 
and replace the global base-year fleet over the 2015-2040 analysis 
period. This airplane G&R database, the annual continuous 
improvements, and the technology responses are available in the 2018 
ICF Report.
    \126\ EPA uses equal product market share (for all airplane 
present in the G&R database), but attention has been paid to make 
sure that competing manufacturers have reasonable representative 
products in the G&R database.
---------------------------------------------------------------------------

    For the 2015 base-year analysis, the baseline (no regulation) 
modelling includes continuous (2016-2040) annual fuel efficiency 
improvements. The modelling tracks the year airplanes enter the fleet 
and applies the type-specific fuel efficiency improvement \127\ via an 
annual adjustment factor based on the makeup of the fleet in a 
particular year. Since there is uncertainty associated with the fuel-
efficiency improvement assumption, the analysis also includes a 
sensitivity scenario without this assumption in the baseline.\128\ The 
EPA fleet evolution model focuses on U.S. aviation, including both 
domestic and international flights (with U.S. international flights 
defined as flights departing from the U.S. but landing outside the 
U.S.). This is the same scope of operations used for the EPA Inventory 
of U.S. Greenhouse Gas Emissions and Sinks.\129\ However, because 
aviation is an international industry and manufacturers of covered 
airplanes sell their products globally, the analysis also covers the 
global fleet evolution and emissions inventories for reference (but at 
a much less detailed level for traffic growth and fleet evolution 
outside of the U.S.).
---------------------------------------------------------------------------

    \127\ ICF, 2018: Aircraft CO2 Cost and Technology Refresh and 
Industry Characterization, Final Report, EPA Contract Number EP-C-
16-020, September 30, 2018.
    \128\ Note that the ICAO analysis did not use a continuous 
improvement assumption, but instead technology was assumed to stay 
at its current state. Specifically, current airplane types would 
have the same metric value in 2040 as they did in 2016, unless they 
were changed to meet the ICAO CO2 standards.
    \129\ U.S. EPA, 2018: Inventory of U.S. Greenhouse Gas Emissions 
and Sinks: 1990-2016, 1,184 pp., U.S. EPA Office of Air and 
Radiation, EPA 430-R-18-003, April 2018. Available at: https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2016 (last accessed March 16, 2020).
---------------------------------------------------------------------------

    The fleet evolution modelling for the proposed regulatory scenarios 
defines available G&R airplanes for various market segments based on 
the technology responses identified by ICF, a contractor for EPA, as 
described later in Section VII.\130\
---------------------------------------------------------------------------

    \130\ ICF, 2018: Aircraft CO2 Cost and Technology Refresh and 
Industry Characterization, Final Report, EPA Contract Number EP-C-
16-020, September 30, 2018.
---------------------------------------------------------------------------

2. Full Flight Simulation Module
    PIANO version 5.4 was used for all the emissions modelling. PIANO 
v5.4 (2017 build) has 591 airplane models (including many project 
airplanes still under development, e.g., the B777-9X) and 56 engine 
types in its airplane and engine databases. PIANO is a physics-based 
airplane performance model used widely by industry, research 
institutes, non-governmental organizations and government agencies to 
model airplane performance metrics such as fuel consumption and 
emissions characteristics based on specific airplane and engine types. 
We use it to model airplane performance for all phases of flight from 
gate to gate including taxi-out, takeoff, climb, cruise, descent, 
approach, landing, and taxi-in in this analysis.
    To simplify the computation, we made the following modeling 
assumptions: (1) Assume airplanes fly great circle distance (which is 
the shortest distance along the surface of the earth between two 
airports) for each origin-destination (OD) pair. (2) Assume still air 
flights and ignore weather or jet stream effects. (3) Assume no delays 
in takeoff, landing, enroute, and other flight-related operations. (4) 
Assume a load factor of 75 percent maximum payload capacity for all 
flights except for business jet where 50 percent is assumed. (5) Use 
the PIANO default reserve fuel rule \131\ for a given airplane type. 
(6) Assume a one-to-one relationship between metric value improvement 
and fuel burn improvement for airplanes with better fuel-efficiency 
technology insertions (or technology responses).
---------------------------------------------------------------------------

    \131\ For typical medium/long-haul airplanes, the default 
reserve settings are 200 NM diversion, 30 minutes hold, plus 5% 
contingency on mission fuel. Depending on airplane types, other 
reserve rules such as U.S. short-haul, European short-haul, National 
Business Aviation Association--Instrument Flight Rules (NBAA-IFR) or 
Douglas rules are used as well.
---------------------------------------------------------------------------

    Given the flight activities defined by the fleet evolution module 
in the previous section, we generated a unit flight matrix to summarize 
all the PIANO outputs of fuel burn, flight distance, flight time, 
emissions, etc. for all flights uniquely defined by a combination of 
departure and arrival airports (OD-pairs), airplane types, and engine 
types. This matrix includes millions of flights and forms the basis for 
our analysis (including the sensitivity studies).
3. Emissions Module
    The GHG emissions calculation involves summing the outputs from the 
first two modules for every flight in the database. This is done 
globally, and then the U.S. portion is segregated from the global 
dataset. The same calculation is done for the baseline and the proposed 
GHG standard. When a surrogate airplane is used to model an airplane 
that is not in the PIANO database, or when a technology response is 
required for an airplane to pass a standard level, an adjustment factor 
is also applied to model the expected performance of the intended 
airplane and technology responses.
    The differences between the proposed GHG standards and the baseline 
provide quantitative measures to assess the emissions impacts of the 
proposed GHG standards. A brief summary of these results is described 
in the next two sections. More details can be found in chapter 5 of the 
Draft TSD.

B. What are the baseline CO2 emissions?

    The commercial aviation marketplace is continually changing, with 
new origin-destination markets and new, more fuel-efficient airplanes 
growing in number and replacing existing airplanes in air carrier (or 
airline) fleets. This behavior introduces uncertainty to the future 
implications of this rulemaking. Since there is uncertainty, multiple 
baseline/scenarios may be analyzed to explore a possible range of 
implications of the proposed rule.
    For the analysis in this proposed rulemaking and consistent with 
our regulatory impact analyses for all other sectors, the EPA is 
analyzing additional baseline/scenarios that reflect a business-as-
usual continually improving baseline with respect to fleet fuel 
efficiency. We also evaluated a baseline scenario that is fixed to 
reflect 2016 technology levels (i.e., no continual improvement in fuel-
efficient technology), and this baseline scenario

[[Page 51581]]

is consistent with the approach used by ICAO.\132\
---------------------------------------------------------------------------

    \132\ A comparison of the EPA and ICAO modeling approaches and 
results is available in chapter 5 and 6 of the Draft TSD.
---------------------------------------------------------------------------

    For the EPA analysis, the baseline GHG emissions are assessed for 
2015, 2020, 2023, 2025, 2028, 2030, 2035, and 2040. The projected 
baseline GHG emissions for all U.S. flights (domestic and 
international) are shown in Figure VI-2 and Figure VI-3, both with and 
without the continuous (2016-2040) fuel-efficiency improvement 
assumption. More detailed breakdowns for the passenger, freighter, and 
business market segments can be found in chapter 5 of the Draft TSD. It 
is worth noting that the U.S. domestic market is relatively mature, 
with a lower growth rate than those for most international markets. The 
forecasted growth rate for the U.S. domestic market combined with the 
Continuous Improvement Assumption results in a low GHG emissions growth 
rate in 2040 for the U.S. domestic market. However, it should be noted 
that this is one set of assumptions combined with a market forecast. 
Actual air traffic and emissions growth may vary as a result of a 
variety of factors.\133\
---------------------------------------------------------------------------

    \133\ To convert fuel burn to CO2 emissions, we used 
the conversion factor of 3.16 kg/kg fuel for CO2 
emissions, and to convert to the six well-mixed GHG emissions, we 
used 3.19 kg/kg fuel for CO2 equivalent emissions. Our 
method for calculating CO2 equivalent emissions is based 
on SAE AIR 5715, 2009: Procedures for the Calculation of Aircraft 
Emissions and the EPA publication: Emissions Factors for Greenhouse 
Gas Inventories, EPA, last modified 4, April 2014. https://www.epa.gov/sites/production/files/2015-07/documents/emission-factors_2014.pdf (last accessed March 16, 2020).
[GRAPHIC] [TIFF OMITTED] TP20AU20.009

[[Page 51582]]

[GRAPHIC] [TIFF OMITTED] TP20AU20.010

    Conceptually, the difference between the EPA and ICAO baselines is 
illustrated in Figure VI-4. The solid line represents the historical 
growth of emissions from the dawn of the jet age in 1960s to the 
present (2016). In this time, air traffic and operations have increased 
and offset the technology improvements. The long-dashed line (__) and 
dot-dash-dot (_. _) lines represent different assumptions used by the 
EPA and ICAO to create baseline future inventories to compare the 
benefits of potential standards. The two baselines start in 2016, but 
their different assumptions lead to very different long-term forecasts. 
The EPA method (long dash) uses the input from an independent analysis 
conducted by ICF \134\ to develop a Projected Continuous Improvement 
baseline to model future improvements similar to historical trends. The 
ICAO method creates a baseline using a Constant Technology Assumption 
that freezes the airplane technology going forward. This means that the 
in-production airplanes at that date will be built with no changes 
indefinitely into the future. The dot-dot-dash (_. . _) line compares 
this Constant Technology Assumption to the solid historical emissions 
growth. Thus, the projected benefits of any standards will be different 
depending upon the baseline that is assumed. We believe all these 
baselines are valid relative to their assumptions. To understand the 
true meaning of the analysis and make well-informed policy decisions, 
one must consider the underlying assumptions carefully.
---------------------------------------------------------------------------

    \134\ ICF, 2018: Aircraft CO2 Cost and Technology Refresh and 
Industry Characterization, Final Report, EPA Contract Number EP-C-
16-020, September 30, 2018.

---------------------------------------------------------------------------

[[Page 51583]]

[GRAPHIC] [TIFF OMITTED] TP20AU20.011

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

    Based on the technology response described in Section VII.C and the 
baseline Continuous Improvement Assumption, the proposed GHG standards 
are not expected to result in reductions in fuel burn and GHG emissions 
beyond the baseline. This result makes sense because all of the 
airplanes in the G&R fleet either will meet the standard level 
associated with the proposed GHG standards or are expected to be out of 
production by the time the standards take effect, according to our NPRM 
technology responses.\135\ In other words, the existing or expected 
fuel efficiency technologies from airplane and engine manufacturers 
that were the basis of the ICAO standards, which match the proposed 
standards, demonstrate technological feasibility. Thus, we do not 
project a cost (except for limited reporting costs as described in 
Section VII) or benefit for the proposed GHG standards (further 
discussion on the rationale for no expected reductions and no costs is 
provided later in this section and Section VII).
---------------------------------------------------------------------------

    \135\ ICF, 2018: Aircraft CO2 Cost and Technology Refresh and 
Industry Characterization, Final Report, EPA Contract Number EP-C-
16-020, September 30, 2018.
---------------------------------------------------------------------------

    The projected zero reduction in GHG emissions is quite different 
from the results of the ICAO analysis mentioned in VI.A, which bounds 
the range of analysis exploration given the uncertainties involved with 
predicting the implications of this proposed rule. The agency has 
conducted sensitivity studies around our main analysis to understand 
the differences \136\ between our analysis and ICAO's (further detail 
on the differences in the analyses and the sensitivity studies is 
provided in the Draft TSD). These sensitivity studies show that the no 
cost-no benefit conclusion is quite robust. For example, even if we 
assume no continuous improvement, the projected GHG emissions 
reductions for the proposed standards would still be zero since all the 
non-compliant airplanes (A380 and 767 freighters) are assumed to be out 
of production by 2028 (according to ICF analysis), the proposed 
standard effective year. Furthermore, even if we

[[Page 51584]]

assume A380 and 767 freighters will continue production till 2030 and 
not making any improvement between 2015 and 2027, the GHG emissions 
reductions will still be an order of magnitude lower than the ICAO 
results since all emissions reductions will come from just 3 years' 
worth of production (2028 to 2030) of A380 and 767 freighters.\137\ 
Considering that both airplanes are close to the end of their 
production life cycle by 2028 and low market demands for them, these 
limited emissions reductions may not be realized at all if the 
manufacturers are granted exemptions. Thus, the agency analysis results 
in a no cost-no benefit conclusion that is reasonable for the proposed 
GHG standards. At the same time, we note that this is distinct from the 
ICAO analysis, which did not use production end dates for airplanes nor 
a continually improving baseline.
---------------------------------------------------------------------------

    \136\ The differences in the analyses include different 
assumptions. Our analysis assumes continuous improvement and ICAO's 
analysis does not. Also, we make different projections about the end 
of production of the A380 and 767 compared to ICAO.
    \137\ On February 14, 2019, Airbus made an announcement to end 
A380 production by 2021 after Emirates airlines reduced its A380 
order by 39 and replaced them with A330 and A350. (The Airbus press 
release is available at: https://www.airbus.com/newsroom/press-
releases/en/2019/02/airbus-and-emirates-reach-agreement-on-a380-
fleet_sign-new-widebody-orders.html, last accessed on February 10, 
2020). EPA's analysis was conducted prior to Airbus's announcement, 
so the analysis does not consider the impact of the A380 ending 
production in 2021. The early exit of A380, compared to the modeled 
scenarios, fits the general trend of reduced demands for large quad 
engine airplanes projected by the ICF technology responses and is 
consistent with our conclusion of no cost and no benefit for this 
rule.
---------------------------------------------------------------------------

    In summary, the ICAO Airplane CO2 Emission Standards, 
which match the proposed GHG standards, were predicated on 
demonstrating technological feasibility; i.e. that manufacturers of 
affected airplanes and engines have already developed or are developing 
technologies that meet the 2017 ICAO Airplane CO2 Emission 
Standards. The EPA expects that the manufacturers will comply with the 
ICAO Airplane CO2 Emission Standards even in advance of 
member States' adoption into domestic regulations. Therefore, the EPA 
expects that the proposed airplane GHG standards would not, beyond 
limited reporting costs, impose an additional burden on manufacturers.

VII. Technological Feasibility and Economic Impacts

    This section describes the technological feasibility and costs of 
the proposed airplane GHG rule. This section describes the agency's 
methodologies for assessing technological feasibility and estimated 
costs of the proposed standards. Consistent with Executive Order 12866, 
we analyzed the technological feasibility and costs of alternatives 
(using similar methodologies), and the results for these alternatives 
are described in chapter 6 of the Draft TSD.
    The EPA and FAA participated in the ICAO analysis that informed the 
adoption of the international Airplane CO2 Emission 
Standards. A summary of that analysis was published in the report of 
ICAO/CAEP's tenth meeting,\138\ which occurred in February 2016. 
However, due to the commercial sensitivity of much of the underlying 
data used in the ICAO analysis, the ICAO-published report (which is 
publicly available) provides only limited supporting data for the ICAO 
analysis. The EPA Draft TSD for this proposed rulemaking compares the 
ICAO analysis to the EPA analysis.
---------------------------------------------------------------------------

    \138\ ICAO, 2016: Report of Tenth Meeting, Montreal, 1-12 
February 2016, Committee on Aviation Environmental Protection, 
Document 10069, CAEP/10, 432pp, is found on page 27 of the English 
Edition of the ICAO Products & Services 2020 Catalog and is 
copyright protected; Order No. 10069. For purchase available at: 
https://www.icao.int/publications/Pages/catalogue.aspx (last 
accessed March 16, 2020). The summary of technological feasibility 
and cost information is located in Appendix C (starting on page 5C-
1) of this report.
---------------------------------------------------------------------------

    For the purposes of evaluating the proposed GHG regulations based 
on publicly available and independent data, the EPA had an analysis 
conducted of the technological feasibility and costs of the 
international Airplane CO2 Emission Standards through a 
contractor (ICF) study.139 140 The results, developed by the 
contractor, include estimates of technology responses and non-recurring 
costs for the proposed domestic GHG standards, which are equivalent to 
the international Airplane CO2 Emission Standards. 
Technologies and costs needed for airplane types to meet the proposed 
GHG regulations were analyzed and compared to the improvements that are 
anticipated to occur in the absence of regulation. In addition, costs 
were evaluated for EPA's proposed annual reporting requirement that was 
described earlier in Section V.G. The methods used in and the results 
from the analysis are described in the following paragraphs--and in 
further detail in chapter 2 of the Draft TSD for this proposed 
rulemaking.
---------------------------------------------------------------------------

    \139\ ICF, 2018: Aircraft CO2 Cost and Technology Refresh and 
Industry Characterization, Final Report, EPA Contract Number EP-C-
16-020, September 30, 2018.
    \140\ ICF International, 2015: CO2 Analysis of CO2-Reducing 
Technologies for Aircraft, Final Report, EPA Contract Number EP-C-
12-011, March 17, 2015.
---------------------------------------------------------------------------

A. Market Considerations

    Prior to describing our technological feasibility and cost 
analysis, potential market impacts of the proposed GHG regulations are 
discussed in this section. As described earlier, airplanes and airplane 
engines are sold around the world, and international airplane emission 
standards help ensure the worldwide acceptability of these products. 
Airplane and airplane engine manufacturers make business decisions and 
respond to the international market by designing and building products 
that conform to ICAO's international standards. However, ICAO's 
standards need to be implemented domestically for products to prove 
such conformity. Domestic action through EPA rulemaking and subsequent 
FAA rulemaking enables U.S. manufacturers to obtain internationally 
recognized FAA certification, which for the proposed GHG standards 
would ensure type certification consistent with the requirements of the 
international Airplane CO2 Emission Standards. This is 
important, as compliance with the international standards (via FAA type 
certification) is a critical consideration in airlines' purchasing 
decisions. By implementing the requirements that conform to ICAO 
requirements in the United States, we would remove any question 
regarding the compliance of airplanes certificated in the United 
States. The proposed rule, if adopted, would facilitate the acceptance 
of U.S. airplanes and airplane engines by member States and airlines 
around the world. Conversely, U.S. manufacturers would be at a 
competitive disadvantage compared with their international competitors 
without this domestic action.
    In considering the aviation market, it is important to understand 
that the international Airplane CO2 Emission Standards were 
predicated on demonstrating technological feasibility; i.e., that 
manufacturers have already developed or are developing improved 
technology that meets the 2017 ICAO CO2 standards, and that 
the new technology will be integrated in airplanes throughout the fleet 
in the time frame provided before the implementation of the standards' 
effective date. Therefore, as described in Section VI.C, the EPA 
projects that these proposed standards would impose no additional 
burden on manufacturers beyond the proposed reporting requirement.
    While recognizing that the international agreement was predicated 
on demonstrated technological feasibility, without access to the 
underlying ICAO/CAEP data it is informative to evaluate individual 
airplane models relative to the proposed equivalent U.S. regulations. 
Therefore,

[[Page 51585]]

the technologies and costs needed for airplane types to meet the 
proposed rule were compared to the improvements that are expected to 
occur in the absence of standards (business as usual improvements). A 
summary of these results is described later in this section.

B. Conceptual Framework for Technology

    As described in the 2015 ANPR, the EPA contracted with ICF to 
develop estimates of technology improvements and responses needed to 
modify in-production airplanes to comply with the international 
Airplane CO2 Emission Standards. ICF conducted a detailed 
literature search, performed a number of interviews with industry 
leaders, and did its own modeling to estimate the cost of making 
modifications to in-production airplanes.\141\ Subsequently, for this 
proposed rulemaking, the EPA contracted with ICF to update its analysis 
(herein referred to as the ``2018 ICF updated analysis'').\142\ It had 
been three years since the initial 2015 ICF analysis was completed, and 
the EPA had ICF update the assessment to ensure that the analysis 
included in this proposed rulemaking reflects the current status of 
airplane GHG technology improvements. Therefore, ICF's assessment of 
technology improvements was updated since the 2015 ANPR was 
issued.\143\
---------------------------------------------------------------------------

    \141\ ICF International, 2015: CO2 Analysis of CO2-Reducing 
Technologies for Aircraft, Final Report, EPA Contract Number EP-C-
12-011, March 17, 2015.
    \142\ ICF, 2018: Aircraft CO2 Cost and Technology Refresh and 
Industry Characterization, Final Report, EPA Contract Number EP-C-
16-020, September 30, 2018.
    \143\ As described earlier in section V, the ICAO test 
procedures for the international airplane CO2 standards 
measure fuel efficiency (or fuel burn). Only two of the six well-
mixed GHGs--CO2 and N2O are emitted from 
airplanes. The test procedures for fuel efficiency scale with the 
limiting of both CO2 and N2O emissions, as 
they both can be indexed on a per-unit-of-fuel-burn basis. 
Therefore, both CO2 and N2O emissions can be 
controlled as airplane fuel burn is limited. Since limiting fuel 
burn is the only means by which airplanes control their GHG 
emissions, the fuel burn (or fuel efficiency) reasonably serves as a 
surrogate for controlling both CO2 and N2O.
---------------------------------------------------------------------------

    The long-established ICAO/CAEP terms of reference were taken into 
account when deciding the international Airplane CO2 
Emission Standards, principal among these being technical feasibility. 
``For the ICAO CO2 certification standard setting, technical 
feasibility refers to any technology expected to be demonstrated to be 
safe and airworthy proven to Technology Readiness Level \144\ (TRL) 8 
by 2016 or shortly thereafter (per CAEP member guidance; approximately 
2017), and expected to be available for application in the short term 
(approximately 2020) over a sufficient range of newly certificated 
airplanes.'' \145\ This means that the analysis that informed the 
international standard considered the emissions performance of in-
production and on-order or in-development \146\ airplanes, including 
types that would first enter into service by about 2020. (ICAO/CAEP's 
analysis was completed in 2015 for the February 2016 ICAO/CAEP 
meeting.)
---------------------------------------------------------------------------

    \144\ TRL is a measure of Technology Readiness Level. CAEP has 
defined TRL8 as the ``actual system completed and `flight qualified' 
through test and demonstration.'' TRL is a scale from 1 to 9, TRL1 
is the conceptual principle, and TRL9 is the ``actual system `flight 
proven' on operational flight.'' The TRL scale was originally 
developed by NASA. ICF International, CO2 Analysis of CO2-Reducing 
Technologies for Aircraft, Final Report, EPA Contract Number EP-C-
12-011, see page 40, March 17, 2015.
    \145\ ICAO, 2016: Report of the Tenth Meeting, Montreal, 1-12 
February 2016, Committee on Aviation Environmental Protection, 
Document 10069, CAEP10, 432pp, is found on page 27 of the English 
Edition of the ICAO Products & Services 2020 Catalog and is 
copyright protected: Order No. 10069. For purchase available at: 
https://www.icao.int/publications/Pages/catalogue.aspx (last 
accessed March 16, 2020). The statement on technological feasibility 
is located in Appendix C (page 5C-15, paragraph 6.2.1) of this 
report.
    \146\ Aircraft that are currently in-development, but were 
anticipated to be in production by about 2020.
---------------------------------------------------------------------------

    In assessing the airplane GHG rule proposed in this action, the 
2018 ICF updated analysis, which was completed a few years after the 
ICAO analysis, was able to use a different approach for technology 
responses. ICF based these responses on technology that would be 
available at TRL8 by 2017 and assumed continuous improvement of 
CO2 metric values for in-production and in-development (or 
on-order) airplanes from 2010 to 2040 based on the incorporation of 
these technologies onto these airplanes over this same timeframe. Also, 
ICF considered the end of production of airplanes based on the expected 
business-as-usual status of airplanes (with the continuous improvement 
assumptions). This approach is described in further detail later in 
Section VII.C. The ICF approach differed from ICAO's analysis for years 
2016 to 2020 and diverged even more for years 2021 and after. Since ICF 
was able to use the proposed effective dates in their analysis of the 
proposed airplane GHG standard (for new type design airplanes 2020, or 
2023 for airplanes with less than 19 seats, and for in-production 
airplanes 2028), ICF was able to differentiate between airplane GHG 
technology improvements that would occur in the absence of the proposed 
standard (business as usual improvements) compared against technology 
improvements/responses that would be needed to comply with the proposed 
standard. ICF's approach is appropriate for the EPA-proposed GHG 
standard because it is based on more up-to-date inputs and assumptions.

C. Technological Feasibility

1. Technology Principles and Application
i. Short- and Mid-Term Methodology
    ICF analyzed the feasible technological improvements to new in-
production airplanes and the potential GHG emission reductions they 
could generate. For this analysis, ICF created a methodological 
framework to assess the potential impact of technology introduction on 
airplane GHG emissions for the years 2015-2029 (upcoming short and mid-
term). This framework included five steps to estimate annual metric 
value (baseline metric values were generated using PIANO data \147\) 
improvements for technologies that are being or will be applied to in-
production airplanes. First, ICF identified the technologies that could 
reduce GHG emissions of new in-production airplanes. Second, ICF 
evaluated each technology for the amount of potential GHG reduction and 
the mechanisms by which this reduction could be achieved. These first 
two steps were analyzed by airplane category. Third and fourth, the 
technologies were passed through technical success probability and 
commercial success probability screenings, respectively. Finally, 
individual airplane differences were assessed within each airplane 
category to generate GHG emission reduction projections by technology 
by airplane model--at the airplane family level (e.g., 737 family). ICF 
refers to their methodological framework for projection of the metric 
value improvement or reduction as the expected value methodology. The 
expected value methodology is a projection of the annual fuel 
efficiency metric value improvement \148\ from 2015-2029 for all the 
technologies that would be applied to each airplane (or

[[Page 51586]]

business as usual improvement in the absence of a standard).
---------------------------------------------------------------------------

    \147\ To generate metric values, the 2015 ICF analysis and 2018 
ICF updated analysis used PIANO (Project Interactive Analysis and 
Optimization) data so that their analyses results can be shared 
publicly. Metric values developed utilizing PIANO data are similar 
to ICAO metric values. PIANO is the Aircraft Design and Analysis 
Software by Dr. Dimitri Simos, Lissys Limited, UK, 1990-present; 
Available at www.piano.aero (last accessed March 16, 2020). PIANO is 
a commercially available aircraft design and performance software 
suite used across the industry and academia.
    \148\ Also referred to as the constant annual improvement in 
CO2 metric value.
---------------------------------------------------------------------------

    As a modification to the 2015 ICF analysis, the 2018 ICF updated 
analysis extended the metric value improvements at the airplane family 
level (e.g., 737 family) to the more specific airplane variant level 
(e.g., 737-700, 737-800, etc.). Thus, to estimate whether each airplane 
variant complied with the proposed GHG standard, ICF projected airplane 
family metric value reductions to a baseline (or base year) metric 
value of each airplane variant. ICF used this approach to estimate 
metric values for 125 airplane models allowing for a comparison of the 
estimated metric value for each airplane model to the level of the 
proposed GHG standard at the time the standard would go into effect.
    In addition, ICF projected which airplane models would end their 
production runs (or production cycle) prior to the effective date of 
the proposed GHG standard. These estimates of production status, at the 
time the standard would go into effect, further informed the projected 
response of airplane models to the proposed standard. Further details 
of the short- and mid-term methodology are provided in chapter 2 of the 
Draft TSD.
ii. Long-Term Methodology
    To project metric value improvements for the long-term, years 2030-
2040, ICF generated a different methodology compared with the short- 
and mid-term methodology. The short- and mid-term methodology is based 
on forecasting metric value improvements contributed by specific 
existing technologies that are implemented, and ICF projects that about 
the 2030 timeframe a new round of technology implementation would begin 
that leads to developing a different method for predicting metric value 
improvements for the long term. For 2030 or later, ICF used a 
parametric approach to project annual metric value improvements. This 
approach included three steps. First, for each airplane type, technical 
factors were identified that drive fuel burn and metric value 
improvements in the long-term (i.e., propulsive efficiency, friction 
drag reduction), and the fuel burn reduction prospect index \149\ was 
estimated on a scale of 1 to 5 for each technical factor (chapter 2 of 
the Draft TSD describes these technical factors in detail). Second, a 
long-term market prospect index was generated on a scale of 1 to 5 
based on estimates of the amount of potential research and development 
(R&D) put into various technologies for each airplane type. Third, the 
long-term market prospect index for each airplane type was combined 
with its respective fuel burn reduction prospect index to generate an 
overall index score for its metric value improvements. A low overall 
index score would indicate that the airplane type will have a reduced 
annual metric value reduction (the metric value decreases yearly at a 
slower rate relative to an extrapolated short- and mid-term annual 
metric value improvement), and a high overall index score would 
indicate an accelerated annual metric value improvement (the metric 
value decreases yearly at a quicker rate relative to an extrapolated 
short- and mid-term annual metric value improvement). Further details 
of the long-term methodology are provided in chapter 2 of the Draft 
TSD.
---------------------------------------------------------------------------

    \149\ The fuel burn reduction prospect index is a projected 
ranking of the feasibility and readiness of technologies (for 
reducing fuel burn) to be implemented for 2030 and later. There are 
three main steps to determine the fuel burn reduction prospect 
index. First, the technology factors that mainly contribute to fuel 
burn were identified. These factors included the following engine 
and airframe technologies as described below: (Engine) sealing, 
propulsive efficiency, thermal efficiency, reduced cooling, and 
reduced power extraction and (Airframe) induced drag reduction and 
friction drag reduction. Second, each of the technology factors were 
scored on the following three scoring dimensions that will drive the 
overall fuel burn reduction effectiveness in the outbound forecast 
years: Effectiveness of technology in reducing fuel burn, likelihood 
of technology implementation, and level of research effort required. 
Third, the scoring of each of the technical factors on the three 
dimensions were averaged to derive an overall fuel burn reduction 
prospect index.
---------------------------------------------------------------------------

2. What technologies did the EPA consider to reduce GHG emissions?
    ICF identified and analyzed seventy different aerodynamic, weight, 
and engine (or propulsion) technologies for fuel burn reductions. 
Although weight-reducing technologies affect fuel burn, they do not 
affect the metric value for the proposed GHG rule.\150\ Thus, ICF's 
assessment of weight-reducing technologies was not included in this 
proposed rule, which excluded about one-third of the technologies 
evaluated by ICF for fuel burn reductions. In addition, based on the 
methodology described earlier in Section VII.C, ICF utilized a subset 
of the about fifty aerodynamic and engine technologies they evaluated 
to account for the improvements to the metric value for the proposed 
standard (for in-production and in-development airplanes \151\).
---------------------------------------------------------------------------

    \150\ The metric value does not directly reward weight reduction 
technologies because such technologies are also used to allow for 
increases in payload, equipage and fuel load. Thus, reductions in 
empty weight can be canceled out or diminished by increases in 
payload, fuel, or both; and, this varies by operation. Empty weight 
refers to operating empty weight. It is the basic weight of an 
airplane including the crew, all fluids necessary for operation such 
as engine oil, engine coolant, water, unusable fuel and all operator 
items and equipment required for flight, but excluding usable fuel 
and the payload.
    \151\ Airplanes that are currently in-development but will be in 
production by the applicability dates. These could be new type 
designs or redesigned airplanes.
---------------------------------------------------------------------------

    A short list of the aerodynamic and engine technologies that were 
considered to improve the metric value of the proposed rule is provided 
below. Chapter 2 of the Draft TSD provides a more detailed description 
of these technologies.
     Aerodynamic technologies: The airframe technologies that 
accounted for the improvements to the metric values from airplanes 
included aerodynamic technologies that reduce drag. These technologies 
included advance wingtip devices, adaptive trailing edge, laminar flow 
control, and riblet coatings.
     Engine technologies: The engine technologies that 
accounted for reductions to the metric values from airplanes included 
architecture and cooling technologies. Architecture technologies 
included ultra-high bypass engines and the fan drive gear, and cooling 
technologies included compressor airfoil coating and turbine air 
cooling.
3. Technology Response and Implications of the Proposed Standard
    The EPA does not project that the proposed GHG rule would cause 
manufacturers to make technical improvements to their airplanes that 
would not have occurred in the absence of the rule. The EPA projects 
that the manufacturers would meet the proposed standards independent of 
the EPA standards, for the following reasons (as was described earlier 
in Section VII.A):
     Manufacturers have already developed or are developing 
improved technology in response to the ICAO standards that match the 
proposed GHG regulations;
     ICAO decided on the international Airplane CO2 
Emission Standards, which are equivalent to the proposed GHG standards, 
based on proven technology by 2016/2017 that was expected to be 
available over a sufficient range of in-production and on-order 
airplanes by approximately 2020. Thus, most or nearly all in-production 
and on-order airplanes already meet the levels of the proposed 
standards;
     Those few in-production airplane models that do not meet 
the levels of the proposed GHG standards are at the end of their 
production life and are expected to go out of production in the near 
term; and

[[Page 51587]]

     These few in-production airplane models anticipated to go 
out of production are being replaced or are expected to be replaced by 
in-development airplane models (airplane models that have recently 
entered service or will in the next few years) in the near term--and 
these in-development models have much improved metric values compared 
to the in-production airplane model they are replacing.
    Based on the approach described above in Sections VII.C.1 and 
VII.C.2, ICF assessed the need for manufacturers to develop technology 
responses for in-production and in-development airplane models to meet 
the proposed GHG standards (for airplane models that were projected to 
be in production by the effective dates of the proposed standards and 
would be modified to meet these standards, instead of going out of 
production). After analyzing the results of the approach/methodology, 
ICF estimated that all airplane models (in-production and in-
development airplane models) would meet the levels of the proposed 
standard or be out of production by the time the standard would become 
effective. Thus, a technology response is not necessary for airplane 
models to meet the proposed rule. This result confirms that the 
international Airplane CO2 Emission Standards are 
technology-following standards, and that the EPA's proposed GHG 
standards as they would apply to in-production and in-development 
airplane models would also be technology following.\152\
---------------------------------------------------------------------------

    \152\ As described earlier, this result is different from the 
ICAO analysis, which did not use continuous improvement 
CO2 metric values nor production end dates for products.
---------------------------------------------------------------------------

    For the same reasons, a technology response is not necessary for 
new type design airplanes to meet the GHG rule proposed in this action. 
The EPA is currently not aware of a specific model of a new type design 
airplane that is expected to enter service after 2020. Additionally, 
any new type design airplanes introduced in the future would have an 
economic incentive to improve their fuel burn or metric value at the 
level of or less than the proposed rule.

D. Costs Associated With the Program

    This section provides the elements of the cost analysis for 
technology improvements, including certification costs, and recurring 
costs. As described, above, the EPA does not anticipate new technology 
costs due to the proposed GHG rule; however, there would be some costs 
associated with our annual reporting requirement. While recognizing 
that the proposed GHG rule does not have non-recurring costs (NRC), 
certification costs, or recurring costs, it is informative to describe 
the elements of these costs.
1. Non-Recurring Costs
    Non-recurring cost (NRC) consists of the cost of engineering and 
integration,\153\ testing (flight and ground testing) and tooling, 
capital equipment, and infrastructure. As described earlier for the 
technology improvements and responses, ICF conducted a detailed 
literature search, conducted a number of interviews with industry 
leaders, and did its own modeling to estimate the NRC of making 
modifications to in-production airplanes. The EPA used the information 
gathered by ICF for assessing the cost of individual technologies, 
which were used to build up NRC for incremental improvements (a bottom-
up approach). These improvements would be for 0 to 10 percent 
improvements in the airplane CO2 metric value, and this 
magnitude of improvements is typical for in-production airplanes (the 
focus of our analysis). In the initial 2015 ICF analysis, ICF developed 
NRC estimates for technology improvements to in-production airplanes, 
and in the 2018 ICF updated analysis these estimates have been brought 
up to date. The technologies available to make improvements to 
airplanes are briefly listed earlier in Section VII.C.2.
---------------------------------------------------------------------------

    \153\ Engineering and Integration includes the engineering and 
Research & Development (R&D) needed to progress a technology from 
its current level to a level where it can be integrated onto a 
production airframe. It also includes all airframe and technology 
integration costs.
---------------------------------------------------------------------------

    The methodology for the development of the NRC for in-production 
airplanes consisted of six steps. First, technologies were categorized 
either as minor performance improvement packages (PIPs) with 0 to 2 
percent (or less than 2 percent) fuel burn improvements or as larger 
incremental updates with 2 to 10 percent improvements. Second, the 
elements of non-recurring cost were identified (e.g., engineering and 
integration costs), as described earlier. Third, these elements of non-
recurring cost are apportioned by incremental technology category for 
single-aisle airplanes (e.g., for the category of an airframe minor 
PIP, 85 percent of NRC is for engineering of integration costs, 10 
percent is for testing, and 5 percent is for tooling, capital 
equipment, and infrastructure).\154\ Fourth, the NRC elements were 
scaled to the other airplane size categories (from the baseline single-
aisle airplane category). Fifth, we estimated the NRC costs for single-
aisle airplane and applied the scaled costs to the other airplane size 
categories.\155\ Sixth, we compiled technology supply curves by 
airplane model, which enabled us to rank incremental technologies from 
most cost effective to the least cost effective. For determining 
technical responses by these supply curves, it was assumed that the 
manufacturer would invest in and incorporate the most cost-effective 
technologies first and go on to the next most cost-effective technology 
to attain the metric value improvements needed to meet the standard. 
Chapter 2 of the Draft TSD provides a more detailed description of this 
NRC methodology for technology improvements and results.
---------------------------------------------------------------------------

    \154\ For the incremental technology category of an engine minor 
PIP, 35 percent of NRC is for engineering of integration costs, 50 
percent is for testing, and 15 percent is for tooling, capital 
equipment, and infrastructure. For the category of a large 
incremental upgrade, 55 percent of NRC is for engineering of 
integration costs, 40 percent is for testing, and 5 percent is for 
tooling, capital equipment, and infrastructure.
    \155\ Engineering and integration costs and tooling, capital 
equipment, and infrastructure costs were scaled by airplane realized 
sale price from the single-aisle airplane category to the other 
airplane categories. Testing costs were scaled by average airplane 
operating costs.
---------------------------------------------------------------------------

2. Certification Costs
    After the EPA issues the final rulemaking for the proposed GHG 
standards, the FAA would issue a rulemaking to enforce compliance to 
these standards, and any potential certification costs for the GHG 
standards would be attributed to the FAA rulemaking. However, it is 
informative to discuss certification costs.
    As described earlier, manufacturers have already developed or are 
developing technologies to respond to ICAO standards that are 
equivalent to the proposed standards, and they will comply with the 
ICAO standards in the absence of U.S. regulations. Also, this proposed 
rulemaking would potentially provide for a cost savings to U.S. 
manufacturers since it would enable them to domestically certify their 
airplane (via subsequent FAA rulemaking) instead of having to certify 
with foreign certification authorities (which would occur without this 
EPA rulemaking). If the proposed GHG standards, which match the ICAO 
standards, are not adopted in the U.S., the U.S. civil airplane 
manufacturers would have to certify to the ICAO standards at higher 
costs because they would have to move their entire certification 
program(s) to a non-U.S.

[[Page 51588]]

certification authority.\156\ Thus, there are no new certification 
costs for the proposed rule. However, it is informative to describe the 
elements of the certification cost, which include obtaining an 
airplane, preparing an airplane, performing the flight tests, and 
processing the data to generate a certification test report (i.e., test 
instrumentation, infrastructure, and program management).
---------------------------------------------------------------------------

    \156\ In addition, European authorities charge fees to airplane 
manufacturers for the certification of their airplanes, but FAA does 
not charge fees for certification.
---------------------------------------------------------------------------

    The ICAO certification test procedures to demonstrate compliance 
with the international Airplane CO2 Emission Standards--
incorporated by reference in this proposed rulemaking--were based on 
the existing practices of airplane manufacturers to measure airplane 
fuel burn (and to measure high-speed cruise performance).\157\ 
Therefore, some manufacturers already have or would have airplane test 
data (or data from high-speed cruise performance modelling) to certify 
their airplane to the standard, and they would not need to conduct 
flight testing for certification to the standard. Also, these data 
would already be part of the manufacturers' fuel burn or high-speed 
performance models, which they can use to demonstrate compliance with 
the international Airplane CO2 Emission Standards. In the 
absence of the standard, the relevant CO2 or fuel burn data 
would be gathered during the typical or usual airplane testing that the 
manufacturer regularly conducts for non-GHG standard purposes (e.g., 
for the overall development of the airplane and to demonstrate its 
airworthiness). In addition, such data for new type design airplanes 
(where data has not been collected yet) would be gathered in the 
absence of a standard. Also, the EPA is not making any attempt to 
quantify the costs associated with certification by the FAA.
---------------------------------------------------------------------------

    \157\ ICAO, 2016: Report of Tenth Meeting, Montreal, 1-12 
February 2016, Committee on Aviation Environmental Protection, 
Document 10069, CAEP/10, 432pp, is found on page 27 of the English 
Edition of the ICAO Products & Services 2020 Catalog and is 
copyright protected; Order No. 10069. See Appendix C of this report. 
For purchase available at: https://www.icao.int/publications/Pages/catalogue.aspx (last accessed March 16, 2020).
---------------------------------------------------------------------------

3. Recurring Operating Costs
    For the same reasons there are no NRC and certification costs for 
the proposed rule as discussed earlier, there would be no recurring 
costs (recurring operating and maintenance costs) for the proposed 
rule; however, it is informative to describe elements of recurring 
costs. The elements of recurring costs for incorporating fuel saving 
technologies would include additional maintenance, material, labor, and 
tooling costs. Our analysis shows that airplane fuel efficiency 
improvements typically result in net cost savings through the reduction 
in the amount of fuel consumed. If technologies add significant 
recurring costs to an airplane, operators (e.g., airlines) would likely 
reject these technologies.
4. Reporting Requirement Costs
    There would be some costs for the proposed annual reporting 
requirement for GHG emissions-related information. (See Section V.G for 
a description of the reports.) There is a total of 10 civil airplane 
manufacturers that would be affected. It is expected that these 
manufacturers will voluntarily report to the ICAO-related 
CO2 Certification Database (CO2DB). We expect the 
incremental reporting burden for these manufacturers to be small 
because we would be adding only 2 basic reporting categories to those 
already requested by the CO2DB, as described earlier in 
Section V.G. Also, the reporting burden would be small because all of 
the information we would be requiring will be readily available--since 
it would be gathered for non-GHG standard purposes (as noted earlier in 
this Section VII).
    We have estimated the annual burden and cost would be about 6 hours 
and $543 per manufacturer. With ten manufacturers submitting reports, 
the total burden for manufacturers of this proposed reporting 
requirement (for three years) \158\ would be estimated to be 180 hours, 
for a total cost of $16,290.
---------------------------------------------------------------------------

    \158\ Information Collection Requests (ICR) for reporting 
requirements are renewed triennially.
---------------------------------------------------------------------------

E. Summary of Benefits and Costs

    Should the proposed airplane GHG emission standards, which match 
the ICAO Airplane CO2 Emission Standards, be finalized, all 
U.S. airplane models (in-production and in-development airplane models) 
should be in compliance with the proposed standards, by the time the 
standards would become applicable. Therefore, there would only be 
limited costs from the proposed annual reporting requirement and no 
additional benefits from complying with these proposed standards--
beyond the benefits from maintaining consistency or harmonizing with 
the international standards.

VIII. Aircraft Engine Technical Amendments

    The EPA, through the incorporation by reference of ICAO Annex 16, 
Volume II, Third Edition (July 2008), requires the same test and 
measurement procedures as ICAO for emissions from aircraft engines. See 
our regulations at 40 CFR 87.8(b)(1). At the CAEP/10 meeting in 
February 2016, several minor technical updates and corrections to the 
test and measurement procedures were approved and ultimately included 
in a Fourth Edition of ICAO Annex 16, Volume II (July 2017). The EPA 
played an active role in the CAEP process during the development of 
these revisions and concurred with their adoption. Thus, we are 
proposing to update the incorporation by reference in Sec.  87.8(b) of 
our regulations to refer to the new Fourth Edition of ICAO Annex 16, 
Volume II (July 2017), replacing the older Third Edition.
    Most of these ICAO Annex 16 updates and corrections to the test and 
measurement procedures were editorial in nature and merely served to 
clarify the procedures rather than change them in any substantive 
manner. Additionally, some updates served to correct typographical 
errors and incorrect formula formatting. However, there is one change 
contained in these ICAO Annex 16 updates that warrants additional 
discussion here: A change to the certification test fuel 
specifications.
    Fuel specification bodies establish limits on jet fuels properties 
for commercial use so that aircraft are safe and environmentally 
acceptable in operation. For engine emissions certification testing, 
the ICAO fuel specification prior to CAEP10 was a minimum 1 percent 
volume of naphthalene content and a maximum content of 3.5 percent 
(1.0-3.5%). However, the ASTM International specification is 0.0-3.0 
percent naphthalene, and an investigation found that it is challenging 
to source fuels for engine emissions certification testing that meet 
the minimum 1% naphthalene level. In many cases, engine manufacturers 
were forced to have fuels custom blended for certification testing 
purposes at a cost premium well above that of commercial jet fuel. 
Additionally, such custom blended fuels needed to be ordered well in 
advance and shipped by rail or truck to the testing facility. In order 
to potentially alleviate the cost and logistical burden that the 
naphthalene specification of certification fuel presented, CAEP 
undertook an effort to analyze and consider whether it would be 
appropriate to align the ICAO Annex

[[Page 51589]]

16 naphthalene specification for certification fuel with that of in-use 
commercial fuel.
    Prior to the CAEP10 meeting, technical experts (including the EPA) 
reviewed potential consequences of a test fuel specification change and 
concluded that there would be no effect on gaseous emissions levels and 
a negligible effect on the `Smoke Number' (SN) level as long as the 
aromatic and hydrogen content remains within the current emissions test 
fuel specification limits. ICAO subsequently adopted the ASTM 
International specification of 0.0-3.0 percent naphthalene for the 
engine emissions test fuel specification and no change to the aromatic 
and hydrogen limits, which was incorporated into the Fourth Edition of 
ICAO Annex 16, Volume II, (July 2017).
    The EPA is proposing, through the incorporation of the Annex 
revisions in Sec.  87.8(b), to adopt the new naphthalene specification 
for certification testing into U.S. regulations. This proposed change 
will have the benefit of more closely aligning the certification fuel 
specification for naphthalene with actual in-use commercial fuel 
properties while reducing the cost and logistical burden associated 
with certification fuel procurement for engine manufacturers. As 
previously mentioned, all the other changes associated with updating 
the incorporation by reference of ICAO Annex 16, Volume II, are 
editorial or typographical in nature and merely intended to clarify the 
requirements or correct mistakes and typographical errors in the Annex.

IX. Statutory Authority and Executive Order Reviews

    Additional information about these statutes and Executive orders 
can be found at http://www2.epa.gov/laws-regulations/laws-and-executive-orders.

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

    This action is a significant regulatory action that was submitted 
to the Office of Management and Budget (OMB) for review. The OMB has 
determined that this proposed action raises ``. . . novel legal or 
policy issues arising out of legal mandates, the President's 
priorities, or the principles set forth in this Executive Order.'' This 
proposed action addresses novel policy issues due to the international 
nature of civil aviation and the development of related emissions 
standards. Accordingly, the EPA submitted this proposed action to the 
OMB for review under E.O. 12866 and E.O. 13563. Any changes made in 
response to OMB recommendations have been documented in the docket. 
Sections I.C.3 and VII.E of this preamble summarize the cost and 
benefits of this action. The supporting information is available in the 
docket.

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

    This action is expected to be an Executive Order 13771 regulatory 
action. Sections I.C.3. and VII.E. of this preamble summarize the cost 
and benefits of this action. The supporting information is available in 
the docket.

C. Paperwork Reduction Act (PRA)

    The information collection activities in this proposed rule have 
been submitted for approval to the Office of Management and Budget 
(OMB) under the PRA. The Information Collection Request (ICR) document 
that the EPA prepared has been assigned EPA ICR number 2626.01. You can 
find a copy of the ICR in the docket for this rule, and it is briefly 
summarized here.
    In order to understand how the proposed GHG standards are affecting 
the in-production fleet, we need access to timely, representative 
emissions data of the fleet at the requisite model level. The EPA needs 
the information on technology, performance parameters, and emissions 
data to conduct accurate technology assessments, compile airplane 
emission inventories, and develop appropriate policy. The ICAO 
CO2DB (discussed in Section V.G) will only include the 
airplane identification information, MTOM, and Metric Value. The EPA 
proposes to collect additional elements or information beyond what ICAO 
will request for the voluntary CO2DB. These additional 
elements would be the RGF and the annual production volume. In general, 
we would expect the manufacturers to claim this additional information 
as confidential business information (CBI), and under such 
circumstances we would treat it accordingly under 40 CFR part 2 and 40 
CFR 1068.10. The EPA does not expect a full dataset on all in-
production airplanes until shortly after the in-production 
applicability date of January 1, 2028. In the context of EPA's 
standard-setting role under the CAA with regard to aircraft engine 
emissions, it is consistent with our policy and practice to ask for 
timely and reasonable reporting of emission certification testing and 
other information that is relevant to our mission.\159\ Under the CAA, 
we are authorized to require manufacturers to establish and maintain 
necessary records, make reports, and provide such other information as 
we may reasonably require to discharge our functions under the Act. 
(See 42 U.S.C. 7414(a)(1).)
---------------------------------------------------------------------------

    \159\ The FAA already requires much of the information EPA is 
seeking through the certification process but is unable to share it 
because of confidentiality agreements with engine manufacturers. 
Also, that information is part of a much larger submission, making 
it difficult to extract the specific reporting elements for EPA.
---------------------------------------------------------------------------

    Respondents/affected entities: Airplane manufacturers.
    Respondent's obligation to respond: Mandatory, under the authority 
of 42 U.S.C. 7414(a)(1).
    Estimated number of respondents: Ten.
    Frequency of response: Annual.
    Total estimated burden: 60 hours (per year). Burden is defined at 5 
CFR 1320.3(b).
    Total estimated cost: $5,430 (per year), includes $0 annualized 
capital or operation & maintenance costs.
    An agency may not conduct or sponsor, and a person is not required 
to respond to, a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for the 
EPA's regulations in 40 CFR are listed in 40 CFR part 9.
    Submit your comments on the Agency's need for this information, the 
accuracy of the provided burden estimates and any suggested methods for 
minimizing respondent burden to the EPA using the docket identified at 
the beginning of this rule. The EPA will respond to any ICR-related 
comments in the final rule. Additionally, written comments and 
recommendations for the proposed information collection should be sent 
within 30 days of publication of this notification to www.reginfo.gov/public/do/PRAMain. Find this particular information collection by 
selecting ``Currently under 30-day Review--Open for Public Comments'' 
or by using the search function.

D. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA. In 
making this determination, the impact of concern is any significant 
adverse economic impact on small entities. An agency may certify that a 
rule will not have a significant economic impact on a substantial 
number of small entities if the rule relieves regulatory burden, has no 
net burden or otherwise has a positive economic effect on the small 
entities subject to the rule. Among the potentially affected entities 
(manufacturers of covered airplanes and

[[Page 51590]]

engines for those airplanes) there is one small business potentially 
affected by this proposed action. This one small business is a 
manufacturer of aircraft engines. The costs we are projecting 
associated with this proposal is that associated with the annual 
reporting requirement discussed in Section IX.C. However, that 
reporting requirement would apply to the manufacturers of covered 
airplanes, not to the manufacturers of aircraft engines. Thus, the 
reporting burden would not impact the one small business potentially 
affected by these proposed regulations. We have therefore concluded 
that this action will have no net regulatory burden for all directly 
regulated small entities.

E. Unfunded Mandates Reform Act (UMRA)

    This action does not contain an unfunded mandate of $100 million or 
more as described in UMRA, 2 U.S.C. 1531-1538, and does not 
significantly or uniquely affect small governments. The action imposes 
no enforceable duty on any state, local or tribal governments or the 
private sector.

F. Executive Order 13132: Federalism

    This action does not have federalism implications. It will not have 
substantial direct effects on the states, on the relationship between 
the National Government and the states, or on the distribution of power 
and responsibilities among the various levels of government.

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

    This action does not have tribal implications as specified in 
Executive Order 13175. This proposed action would regulate the 
manufacturers of airplanes and aircraft engines and would not have 
substantial direct effects on one or more Indian tribes, on the 
relationship between the Federal Government and Indian tribes, or on 
the distribution of power and responsibilities between the Federal 
Government and Indian tribes. Thus, Executive Order 13175 does not 
apply to this action.

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

    This action is not subject to Executive Order 13045 because it is 
not economically significant as defined in Executive Order 12866, and 
because the EPA does not believe the environmental health or safety 
risks addressed by this action present a disproportionate risk to 
children.

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

    This action is not a ``significant energy action'' because it is 
not likely to have a significant adverse effect on the supply, 
distribution or use of energy. These proposed airplane GHG regulations 
are not expected to result in any changes to airplane fuel consumption 
beyond what would have otherwise occurred in the absence of this 
proposed rule, as discussed in Section VI.C.

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

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (``NTTAA''), Public Law 104-113, 12(d) (15 U.S.C. 272 note) 
directs EPA to use voluntary consensus standards in its regulatory 
activities unless to do so would be inconsistent with applicable law or 
otherwise impractical. Voluntary consensus standards are technical 
standards (e.g., materials specifications, test methods, sampling 
procedures, and business practices) that are developed or adopted by 
voluntary consensus standards bodies. NTTAA directs agencies to provide 
Congress, through OMB, explanations when the Agency decides not to use 
available and applicable voluntary consensus standards. This action 
involves technical standards.
    In accordance with the requirements of 1 CFR 51.5, we are proposing 
to incorporate by reference the use of test procedures contained in 
ICAO's International Standards and Recommended Practices Environmental 
Protection, Annex 16, Volumes II and III, along with the modifications 
contained in this rulemaking. This includes the following standards and 
test methods:

------------------------------------------------------------------------
   Standard or test method         Regulation              Summary
------------------------------------------------------------------------
ICAO 2017, Aircraft Engine    40 CFR 87.1, 40 CFR   Test method
 Emissions, Annex 16, Volume   87.42(c), and 40      describes how to
 II, Fourth Edition, July      CFR 87.60(a) and      measure gaseous and
 2017.                         (b).                  smoke emissions
                                                     from airplane
                                                     engines.
ICAO 2017, Aeroplane CO       40 CFR 1030.23(d),    Test method
 Emissions, Annex 16, Volume   40 CFR 1030.25(d),    describes how to
 III, First Edition, July      40 CFR 1030.90(d),    measure the fuel
 2017.                         and 40 CFR 1030.105.  efficiency of
                                                     airplanes.
------------------------------------------------------------------------

    The material from the ICAO Annex 16, Volume II is an updated 
version of the document that is already incorporated by reference in 40 
CFR 87.1, 40 CFR 87.42(c), and 40 CFR 87.60(a) and (b). For both this 
document and ICAO Annex 16, Volume III, we intend to include in the 
final rule any amendments adopted subsequent to the referenced 2017 
publications.
    The referenced standards and test methods may be obtained through 
the International Civil Aviation Organization, Document Sales Unit, 999 
University Street, Montreal, Quebec, Canada H3C 5H7, (514) 954-8022, 
www.icao.int, or sales@icao.int.

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

    The EPA believes that this action does not have disproportionately 
high and adverse human health or environmental effects on minority 
populations, low-income populations and/or indigenous peoples, as 
specified in Executive Order 12898 (59 FR 7629, February 16, 1994). It 
provides similar levels of environmental protection for all affected 
populations without having any disproportionately high and adverse 
human health or environmental effects on any population, including any 
minority or low-income population.

List of Subjects

40 CFR Part 87

    Air pollution control, Aircraft, Environmental protection, 
Incorporation by reference.

40 CFR Part 1030

    Air pollution control, Aircraft, Environmental protection, 
Greenhouse gases, Incorporation by reference.

Andrew Wheeler,
Administrator.

    For the reasons set forth above, EPA proposes to amend 40 CFR 
chapter I as follows:

[[Page 51591]]

PART 87--CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT 
ENGINES

0
1. The authority citation for part 87 continues to read as follows:

    Authority: 42 U.S.C. 7401 et seq.

0
2. Section 87.8 is amended by revising paragraphs (a) and (b)(1) to 
read as follows:

Sec.  87.8  Incorporation by reference.

    (a) Certain material is incorporated by reference into this part 
with the approval of the Director of the Federal Register under 5 
U.S.C. 552(a) and 1 CFR part 51. To enforce any edition other than that 
specified in this section, the Environmental Protection Agency must 
publish a document in the Federal Register and the material must be 
available to the public. All approved material is available for 
inspection at U.S. EPA, Air and Radiation Docket Center, WJC West 
Building, Room 3334, 1301 Constitution Ave. NW, Washington, DC 20004, 
www.epa.gov/dockets, (202) 202-1744, and is available from the sources 
listed in this section. It is also available for inspection at the 
National Archives and Records Administration (NARA). For information on 
the availability of this material at NARA, email fedreg.legal@nara.gov 
or go to http://www.archives.gov/federal-register/cfr/ibr-locations.html.
    (b) * * *
    (1) Annex 16 to the Convention on International Civil Aviation, 
Environmental Protection, Volume II--Aircraft Engine Emissions, Fourth 
Edition, July 2017 (ICAO Annex 16, Volume II). IBR approved for 
Sec. Sec.  87.1, 87.42(c), and 87.60(a) and (b).
* * * * *
0
3. Add part 1030 to read as follows:

PART 1030--CONTROL OF GREENHOUSE GAS EMISSIONS FROM ENGINES 
INSTALLED ON AIRPLANES

Scope and Applicability
Sec.
1030.1 Applicability.
1030.5 State standards and controls.
1030.10 Exemptions.
Subsonic Airplane Emission Standards and Measurement Procedures
1030.20 Fuel efficiency metric.
1030.23 Specific air range (SAR).
1030.25 Reference geometric factor (RGF).
1030.30 GHG emission standards.
1030.35 Change criteria.
Reporting and Recordkeeping
1030.90 Airplane production report to the EPA.
1030.95 Recordkeeping.
1030.98 Confidential business information.
Reference Information
1030.100 Abbreviations.
1030.105 Definitions.
1030.110 Incorporation by reference.

    Authority: 42 U.S.C. 7401-7671q.

Scope and Applicability

Sec.  1030.1  Applicability.

    (a) Except as provided in paragraph (c) of this section, when an 
aircraft engine subject to 40 CFR part 87 is installed on an airplane 
that is described in this section and subject to title 14 of the Code 
of Federal Regulations, the airplane may not exceed the Greenhouse Gas 
(GHG) standards of this part when certification under title 14 is 
sought.
    (1) A subsonic jet airplane that has--
    (i) A type certificated maximum passenger seating capacity of 20 
seats or more;
    (ii) A maximum take-off mass (MTOM) greater than 5,700 kg; and
    (iii) An application for original type certification that is 
submitted on or after January 1, 2020.
    (2) A subsonic jet airplane that has--
    (i) A type certificated maximum passenger seating capacity of 19 
seats or fewer;
    (ii) A MTOM greater than 5,700 kg, but not greater than 60,000 kg; 
and
    (iii) An application for original type certification that is 
submitted on or after January 1, 2023.
    (3) A propeller-driven airplane that has--
    (i) A MTOM greater than 8,618 kg; and
    (ii) An application for original type certification that is 
submitted on or after January 1, 2020.
    (4) A subsonic jet airplane that is a modified version of an 
airplane whose original type certificated version was not required to 
have GHG emissions certification under this part and has--
    (i) A MTOM greater than 5,700 kg; and
    (ii) An application for certification that is submitted on or after 
January 1, 2023.
    (5) A propeller-driven airplane that is a modified version of an 
airplane whose original type certificated version was not required to 
have GHG emissions certification under this part and has--
    (i) A MTOM greater than 8,618 kg; and
    (ii) An application for certification that is submitted on or after 
January 1, 2023.
    (6) A subsonic jet airplane that has--
    (i) A MTOM greater than 5,700 kg; and
    (ii) An original certificate of airworthiness issued on or after 
January 1, 2028.
    (7) A propeller-driven airplane that has--
    (i) A MTOM greater than 8,618 kg; and
    (ii) An original certificate of airworthiness issued on or after 
January 1, 2028.
    (b) An airplane that incorporates modifications that change the 
fuel efficiency metric value of a prior version of airplane may not 
exceed the GHG standards of this part when certification under 14 CFR 
is sought. The criteria for modified airplanes are described in Sec.  
1030.35. A modified airplane may not exceed the metric value limit of 
the prior version under Sec.  1030.30.
    (c) The requirements of this part do not apply to:
    (1) Subsonic jet airplanes having a MTOM at or below 5,700 kg.
    (2) Propeller-driven airplanes having a MTOM at or below 8,618 kg.
    (3) Amphibious airplanes.
    (4) Airplanes initially designed, or modified and used, for 
specialized operations. These airplane designs may include 
characteristics or configurations necessary to conduct specialized 
operations that the EPA and the FAA have determined may cause a 
significant increase in the fuel efficiency metric value.
    (5) Airplanes designed with a reference geometric factor of zero.
    (6) Airplanes designed for, or modified and used for, firefighting.

Sec.  1030.5  State standards and controls.

    No State or political subdivision of a State may adopt or attempt 
to enforce any airplane or aircraft engine standard with respect to 
emissions unless the standard is identical to a standard that applies 
to airplanes under this part.

Sec.  1030.10  Exemptions.

    Each person seeking relief from compliance with this part at the 
time of certification must submit an application for exemption to the 
FAA in accordance with the regulations of 14 CFR parts 11 and 38. The 
FAA will consult with the EPA on each exemption application request 
before the FAA takes action.

Subsonic Airplane Emission Standards and Measurement Procedures

Sec.  1030.20  Fuel efficiency metric.

    For each airplane subject to this part, including an airplane 
subject to the change criteria of Sec.  1030.35, a fuel efficiency 
metric value must be calculated, using the following equation, rounded 
to three decimal places:

[[Page 51592]]

Fuel Efficiency metric value = (1/SAR)avg/(RGF[supcaret]0.24)

    Where the specific air range (SAR) is determined in accordance with 
Sec.  1030.23, and the reference geometric factor is determined in 
accordance with Sec.  1030.25. The fuel efficiency metric value is 
expressed in units of kilograms of fuel consumed per kilometer.

Sec.  1030.23  Specific air range (SAR).

    (a) For each airplane subject to this part the SAR of an airplane 
must be determined by either--
    (1) Direct flight test measurements.
    (2) Using a performance model that is:
    (i) Validated by actual SAR flight test data; and
    (ii) Approved by the FAA before any SAR calculations are made.
    (b) For each airplane model, establish a 1/SAR value at each of the 
following reference airplane masses:
    (1) High gross mass: 92 percent maximum takeoff mass (MTOM).
    (2) Low gross mass: (0.45 * MTOM) + (0.63 * (MTOM[supcaret]0.924)).
    (3) Mid gross mass: Simple arithmetic average of high gross mass 
and low gross mass.
    (c) Calculate the average of the three 1/SAR values described in 
paragraph (b) of this section to calculate the fuel efficiency metric 
value in Sec.  1030.20. Do not include auxiliary power units in any 1/
SAR calculation.
    (d) All determinations under this section must be made according to 
the procedures applicable to SAR in Paragraphs 2.5 and 2.6 of Annex 16, 
Volume III and Appendix 1 of Annex 16, Volume III (incorporated by 
reference in Sec.  1030.110).

Sec.  1030.25   Reference geometric factor (RGF).

    For each airplane subject to this part, determine the airplane's 
nondimensional reference geometric factor (RGF) for the fuselage size 
of each airplane model, calculated as follows:
    (a) For an airplane with a single deck, determine the area of a 
surface (expressed in m[supcaret]2) bounded by the maximum width of the 
fuselage outer mold line projected to a flat plane parallel with the 
main deck floor and the forward and aft pressure bulkheads except for 
the crew cockpit zone.
    (b) For an airplane with more than one deck, determine the sum of 
the areas (expressed in m[supcaret]2) as follows:
    (1) The maximum width of the fuselage outer mold line, projected to 
a flat plane parallel with the main deck floor by the forward and aft 
pressure bulkheads except for any crew cockpit zone.
    (2) The maximum width of the fuselage outer mold line at or above 
each other deck floor, projected to a flat plane parallel with the 
additional deck floor by the forward and aft pressure bulkheads except 
for any crew cockpit zone.
    (c) Determine the non-dimensional RGF by dividing the area defined 
in paragraph (a) or (b) of this section by 1 m[supcaret]2.
    (d) All measurements and calculations used to determine the RGF of 
an airplane must be made according to the procedures for determining 
RGF in Appendix 2 of ICAO Annex 16, Volume III (incorporated by 
reference in Sec.  1030.110).

Sec.  1030.30  GHG emission standards.

    (a) The greenhouse gas emission standards in this section are 
expressed as maximum permitted values fuel efficiency metric values, as 
calculated under Sec.  1030.20.
    (b) The fuel efficiency metric value may not exceed the following, 
rounded to three decimal places:

------------------------------------------------------------------------
For airplanes defined in . . .                     The standard is . . .
                                 With MTOM . . .
------------------------------------------------------------------------
(1) Section 1030.1(a)(1) and    5,700 < MTOM <=    10 (-2.73780 +
 (2).                            60,000 kg.         (0.681310 *
                                                    log10(MTOM)) + (-
                                                    0.0277861 *
                                                    (log10(MTOM))[supcar
                                                    et]2))
(2) Section 1030.1(a)(3)......  8,618 < MTOM <=    10 (-2.73780 +
                                 60,000 kg.         (0.681310 *
                                                    log10(MTOM)) + (-
                                                    0.0277861 *
                                                    (log10(MTOM))[supcar
                                                    et]2)):
(3) Section 1030.1(a)(1) and    60,000 < MTOM <=   0.764
 (3).                            70,395 kg.
(4) Section 1030.1(a)(1) and    MTOM > 70,395 kg.  10 (-1.412742 + (-
 (3).                                               0.020517 *
                                                    log10(MTOM)): +
                                                    (0.0593831 *
                                                    (log10(MTOM))[supcar
                                                    et]2))
(5) Section 1030.1(a)(4) and    5,700 < MTOM <=    10 (-2.57535 +
 (6).                            60,000 kg.         (0.609766 *
                                                    log10(MTOM)) + (-
                                                    0.0191302 *
                                                    (log10(MTOM))[supcar
                                                    et]2))
(6) Section 1030.1(a)(5) and    8,618 < MTOM <=    10 (-2.57535 +
 (7).                            60,000 kg.         (0.609766 *
                                                    log10(MTOM)) + (-
                                                    0.0191302 *
                                                    (log10(MTOM))[supcar
                                                    et]2)):
(7) Section 1030.1(a)(4)        60,000 <= MTOM <   0.797
 through (7).                    70,107 kg.
(8) Section 1030.1(a)(4)        MTOM > 70,107 kg.  10 (-1.39353 + (-
 through (7).                                       0.020517 *
                                                    log10(MTOM)) +
                                                    (0.0593831 *
                                                    (log10(MTOM))[supcar
                                                    et]2))
------------------------------------------------------------------------

Sec.  1030.35  Change criteria.

    (a) For an airplane that has demonstrated compliance with Sec.  
1030.30, any subsequent version of that airplane must demonstrate 
compliance with Sec.  1030.30 if the subsequent version incorporates a 
modification that either increases--
    (1) The maximum take-off mass; or
    (2) The fuel efficiency metric value by more than:
    (i) For airplanes with a MTOM greater than or equal to 5,700 kg, 
the value decreases linearly from 1.35 to 0.75 percent for an airplane 
with a MTOM of 60,000 kg.
    (ii) For airplanes with a MTOM greater than or equal to 60,000 kg, 
the value decreases linearly from 0.75 to 0.70 percent for airplanes 
with a MTOM of 600,000 kg.
    (iii) For airplanes with a MTOM greater than or equal to 600,000 
kg, the value is 0.70 percent.
    (b) For an airplane that has demonstrated compliance with Sec.  
1030.30, any subsequent version of that airplane that incorporates 
modifications that do not increase the MTOM or the fuel efficiency 
metric value in excess of the levels shown in paragraph (a) of this 
section, the fuel efficiency metric value of the modified airplane may 
be reported to be the same as the value of the prior version.
    (c) For an airplane that meets the criteria of Sec.  1030.1(a)(4) 
or (5), after January 1, 2023 and until January 1, 2028, the airplane 
must demonstrate compliance with Sec.  1030.30 if it incorporates any 
modification that increases the fuel efficiency metric value by more 
than 1.5 per cent from the prior version of the airplane.

Reporting and Recordkeeping

Sec.  1030.90  Airplane production report to the EPA.

    Manufacturers of airplanes subject to Sec.  1030.1 must submit an 
annual report as specified in this section.
    (a) You must submit the report for each calendar year in which you 
produce any airplanes that are subject to GHG emission standards under 
this part. The report is due by the following February 28. Include 
exempted airplanes in your report.
    (b) Send the report to the Designated EPA Program Officer.
    (c) In the report, identify your corporate name as listed on the 
airplane type certificate and the year for which you are reporting.
    (d) Identify the complete name for each of your airplane sub-models 
and include the following information for each airplane sub-model that 
is covered by an FAA type certificate:

[[Page 51593]]

    (1) Type certificate number from the FAA. Also identify type 
certificates issued by any organization other than the FAA. Identify 
the issue date of each type certificate (month and year).
    (2) Submission date for the application to certify to the GHG 
emission standards in Sec.  1030.30.
    (3) Edition number and publication date of the applicable standards 
under Annex 16, Volume III.
    (4) For modified airplanes under Sec.  1030.35, the most recently 
certificated version.
    (5) Maximum take-off mass and reference geometric factor.
    (6) The number of installed engines for each airplane. Include the 
following information for each engine:
    (i) The corporate name as listed on the engine type certificate.
    (ii) The complete name for each of engine model.
    (7) Include the following information from the propeller type 
certificate, if applicable:
    (i) The corporate name as listed on the propeller type certificate.
    (ii) The complete name for each propeller model.
    (8) Fuel efficiency metric value and the calculated GHG emission 
standard.
    (9) Identify the number of airplanes produced during the reporting 
period. If the number is zero, identify the date of manufacture for the 
last airplane you produced and state whether the airplane is out of 
production.
    (10) For airplanes exempted under Sec.  1030.10, identify the 
approval date for the exemption and the number of exempt airplanes.
    (e) Include the following signed statement and endorsement by an 
authorized representative of your company: ``We submit this report 
under 40 CFR 1030.90. All the information in this report is true and 
accurate to the best of my knowledge.''
    (f) Where information provided for the previous year remains valid 
and complete, you may report your production volumes and state that 
there are no changes, without resubmitting the other information 
specified in this section.

Sec.  1030.95   Recordkeeping.

    (a) You must keep a copy of any reports or other information you 
submit to us for at least three years. If you use the same emissions 
data or other information to support a new certification, the three-
year period restarts with each year that you continue to rely on the 
information.
    (b) Store these records in any format and on any media, as long as 
you can promptly send us organized, written records in English if we 
ask for them. You must keep these records readily available. We may 
review them at any time.

Sec.  1030.98  Confidential business information.

    The provisions of 40 CFR 1068.10 apply for information you consider 
confidential.

Reference Information

Sec.  1030.100  Abbreviations.

    The abbreviations used in this part have the following meanings:

                       Table 1 to Sec.   1030.100
------------------------------------------------------------------------
 
------------------------------------------------------------------------
EPA..........................  U.S. Environmental Protection Agency.
FAA..........................  U.S. Federal Aviation Administration.
GHG..........................  greenhouse gas.
IBR..........................  incorporation by reference.
ICAO.........................  International Civil Aviation
                                Organization.
MTOM.........................  maximum take-off mass.
RGF..........................  reference geometric factor.
SAR..........................  specific air range.
------------------------------------------------------------------------

Sec.  1030.105  Definitions.

    The following definitions in this section apply to this part. Any 
terms not defined in this section have the meaning given in the Clean 
Air Act. The definitions follow:
    Aircraft has the meaning given in 14 CFR 1.1, a device that is used 
or intended to be used for flight in the air.
    Aircraft engine means a propulsion engine that is installed on or 
that is manufactured for installation on an airplane for which 
certification under 14 CFR is sought.
    Airplane has the meaning given in 14 CFR 1.1, an engine-driven 
fixed-wing aircraft heavier than air, that is supported in flight by 
the dynamic reaction of the air against its wings.
    Designated EPA Program Officer means the Director, Compliance 
Division, U.S. Environmental Protection Agency, 2000 Traverwood Dr., 
Ann Arbor, MI 48105; complianceinfo@epa.gov.
    Exempt means to allow, through a formal case-by-case process, an 
airplane to be certificated and operated that does not meet the 
applicable standards of this part.
    Greenhouse Gas (GHG) means an air pollutant that is the aggregate 
group of six greenhouse gases: Carbon dioxide, nitrous oxide, methane, 
hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride.
    ICAO Annex 16, Volume III means Volume III of Annex 16 to the 
Convention on International Civil Aviation.
    Maximum take-off mass (MTOM) is the maximum allowable take-off mass 
as stated in the approved certification basis for an airplane type 
design. Maximum take-off mass is expressed in kilograms.
    Performance model is an analytical tool (or a method) validated 
using corrected flight test data that can be used to determine the 
specific air range values for calculating the fuel efficiency metric 
value.
    Reference geometric factor is a non-dimensional number derived from 
a two-dimensional projection of the fuselage.
    Round has the meaning given in 40 CFR 1065.1001.
    Specific air range is the distance an airplane travels per unit of 
fuel consumed. Specific air range is expressed in kilometers per 
kilogram of fuel.
    Subsonic means an airplane that has not been certificated under 14 
CFR to exceed Mach 1 in normal operation.
    Type certificated maximum passenger seating capacity means the 
maximum number of passenger seats that may be installed on an airplane 
as listed on its type certificate data sheet, regardless of the actual 
number of seats installed on an individual airplane.
    We (us, our) means the Administrator of the Environmental 
Protection Agency and any authorized representatives.

Sec.  1030.110  Incorporation by reference.

    (a) Certain material is incorporated by reference into this part 
with the approval of the Director of the Federal Register under 5 
U.S.C. 552(a) and 1 CFR part 51. To enforce any edition other than that 
specified in this section, the Environmental Protection Agency must 
publish a document in the Federal Register and the material must be 
available to the public. All approved material is available for 
inspection at EPA Docket Center, WJC West Building, Room 3334, 1301 
Constitution Ave. NW, Washington, DC 20004, www.epa.gov/dockets, (202) 
202-1744, and is available from the sources listed in this section. It 
is also available for inspection at the National Archives and Records 
Administration (NARA). For information on the availability of this 
material at NARA, email fedreg.legal@nara.gov or go to: 
www.archives.gov/federal-register/cfr/ibr-locations.html.
    (b) International Civil Aviation Organization, Document Sales Unit, 
999 University Street, Montreal, Quebec, Canada H3C 5H7, (514) 954-
8022, www.icao.int, or sales@icao.int.
    (1) Annex 16 to the Convention on International Civil Aviation, 
Environmental Protection, Volume III--Aeroplane CO2 Emissions, First 
Edition,

[[Page 51594]]

July 2017 (ICAO Annex 16, Volume III). IBR approved for Sec. Sec.  
1030.23(d) and 1030.25(d).
    (2) [Reserved]

[FR Doc. 2020-16271 Filed 8-19-20; 8:45 am]
BILLING CODE 6560-50-P