Vol. 77 Monday, 

No. 117 June 18, 2012 

Part II 

Environmental Protection Agency 

40 CFR Parts 87 and 1068 

Control of Air Pollution From Aircraft and Aircraft Engines; Emission 

Standards and Test Procedures; Final Rule 


TKELLEY on DSK3SPTVN1PROD with RULES2
36342 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Parts 87 and 1068 

[EPA–HQ–OAR–2010–0687; FRL–9678–1] 

RIN 2060–AO70 

Control of Air Pollution From Aircraft 

and Aircraft Engines; Emission 

Standards and Test Procedures 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Final rule. 

SUMMARY: EPA is adopting several new 

aircraft engine emission standards for 

oxides of nitrogen (NOX), compliance 

flexibilities, and other regulatory 

requirements for aircraft turbofan or 

turbojet engines with rated thrusts 

greater than 26.7 kilonewtons (kN). We 

also are adopting certain other 

requirements for gas turbine engines 

that are subject to exhaust emission 

standards as follows. First, we are 

clarifying when the emission 

characteristics of a new turbofan or 

turbojet engine model have become 

different enough from its existing parent 

engine design that it must conform to 

the most current emission standards. 

Second, we are establishing a new 

reporting requirement for manufacturers 

of gas turbine engines that are subject to 

any exhaust emission standard to 

provide us with timely and consistent 

emission-related information. Third, 

and finally, we are establishing 

amendments to aircraft engine test and 

emissions measurement procedures. 

EPA actively participated in the United 

Nations’ International Civil Aviation 

Organization (ICAO) proceedings in 

which most of these requirements were 

first developed. These regulatory 

requirements have largely been adopted 

or are actively under consideration by 

its member states. By adopting such 

similar standards, therefore, the United 

States maintains consistency with these 

international efforts. 

DATES: These final rules are effective on 

July 18, 2012. The incorporation by 

reference of certain publications listed 

in this regulation is approved by the 

Director of the Federal Register as of 

July 18, 2012. 

ADDRESSES: EPA has established a 

docket for this action under Docket ID 

No. EPA–HQ–OAR–2010–0687. All 

documents in the docket are listed on 

the http://www.regulations.gov Web 

site. Although listed in the index, some 

information is not publicly available, 

e.g., confidential business information 

or other information whose disclosure is 

restricted by statute. Certain other 

material, such as copyrighted material, 

is not placed on the Internet and will be 

publicly available only in hard copy 

form. Publicly available docket 

materials are available electronically 

through http://www.regulations.gov or 

in hard copy at the EPA Docket Center, 

EPA/DC, EPA West, Room 3334, 1301 

Constitution Ave. NW., Washington, 

DC. The Public Reading Room is open 

from 8:30 a.m. to 4:30 p.m., Monday 

through Friday, excluding legal 

holidays. The telephone number for the 

Public Reading Room is (202) 566–1744, 

and the telephone number for the Air 

Docket is 202–566–1742. 

FOR FURTHER INFORMATION CONTACT: 

Richard Wilcox, Office of 

Transportation and Air Quality, Office 

of Air and Radiation, Environmental 

Protection Agency, 2000 Traverwood 

Drive, Ann Arbor, MI 48105; telephone 

number: (734) 214–4390; fax number: 

(734) 214–4816; email address: 

wilcox.rich@epa.gov. 

SUPPLEMENTARY INFORMATION: 

Does this action apply to me? 

Entities potentially regulated by this 

action are those that manufacture and 

sell aircraft engines and aircraft in the 

United States. Regulated categories 

include: 

Category NAICSa Codes SIC b Codes Examples of potentially affected entities 

Industry ................................................................... 336412 3724 Manufacturers of new aircraft engines. 

Industry ................................................................... 336411 3721 Manufacturers of new aircraft. 

a North American Industry Classification System (NAICS). 

bStandard Industrial Classification (SIC) system code. 

This table lists the types of entities 

that EPA is now aware could potentially 

be regulated by this action. Other types 

of entities not listed in the table could 

also be regulated. To determine whether 

your activities are regulated by this 

action, you should carefully examine 

the applicability criteria in 40 CFR 87.1 

(part 87). 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. 

Table of Contents 

I. Executive Summary 

II. Overview and Background 

A. Contents of the Final Rule 

B. EPA’s Authority and Responsibilities 

Under the Clean Air Act 

C. Interaction With the International 

Community 

D. Brief History of EPA’s Regulation of 

Aircraft Engine Emissions 

E. Brief History of ICAO Regulation of 

Aircraft Engine Emissions 

III. Why is EPA taking this action? 

A. Inventory Contribution 

B. Health, Environmental and Air Quality 

Impacts 

1. Background on Ozone, PM and NOX

a. What is ozone? 

b. What is particulate matter? 

c. What is NOX? 

2. Health Effects Associated With Exposure 

to Ozone, PM and NOX

a. What are the health effects of ozone? 

b. What are the health effects of PM? 

c. What are the health effects of NOX? 

3. Environmental Effects Associated With 

Exposure to Ozone, PM and NOX

a. Deposition of Nitrogen 

b. Visibility Effects 

c. Plant and Ecosystem Effects of Ozone 

4. Impacts on Ambient Air Quality 

IV. Details of the Final Rule 

A. NOX Standards for Newly-Certified 

Engines 

1. Tier 6 NOX Standards for NewlyCertified Engines 

a. Numerical Emission Limits for Higher 

Thrust Engines 

b. Numerical Emission Limits for Lower 

Thrust Engines 

2. Tier 8 NOX Standards for NewlyCertified Engines 

a. Numerical Emission Limits for Higher 

Thrust Engines 

b. Numerical Emission Limits for Lower 

Thrust Engines 

B. Application of NOX Standards for 

Newly-Manufactured Engines 

1. Phase-In of the Tier 6 NOX Standards for 

Newly-Manufactured Engines 

2. Carryover of Previously Generated 

Emission Data 

3. Exemptions and Exceptions From the 

Tier 6 Production Cutoff 

a. New Provisions for Spare Engines 

b. New Provisions for Engines Installed in 

New Aircraft 

i. Time-Frame and Scope 

ii. Production Limit 

iii. Exemption Requests 

iv. Coordination of Exemption Requests 

v. Low-Volume, Time-Limited Transitional 

Exception Program 

c. Voluntary Emission Offsets 

4. Potential Phase-In of New Tier 8 NOX

Standards for Newly-Manufactured 

Engines 


TKELLEY on DSK3SPTVN1PROD with RULES2
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36343 

C. Application of Standards for Derivative 

Engines 

D. Annual Reporting Requirement 

E. Standards for Supersonic Aircraft 

Turbine Engines 

F. Amendments to Test and Measurement 

Procedures 

G. Possible Future Revisions to Emission 

Standards for New Technology Turbine 

Engines and Supersonic Aircraft Turbine 

Engines 

V. Description of Other Revisions to the 

Regulatory Text 

A. Applicability Issues 

1. Military Engines 

2. Noncommercial Engines 

B. Non-Substantive Revisions 

C. Clarifying Language for Regulatory Text 

VI. Technical Feasibility and Cost Impacts 

VII. Consultation With FAA 

VIII. Public Participation 

IX. Statutory Provisions and Legal Authority 

X. Statutory and Executive Order Reviews 

A. Executive Order 12866: Regulatory 

Planning and Review, and Executive 

Order 13563: Improving Regulation and 

Regulatory Review 

B. Paperwork Reduction Act 

C. Regulatory Flexibility Analysis 

D. Unfunded Mandates Reform Act 

E. Executive Order 13132: Federalism 

F. Executive Order 13175: Consultation 

and Coordination With Indian Tribal 

Governments 

G. Executive Order 13045: Protection of 

Children From Environmental Health & 

Safety Risks 

H. Executive Order 13211: Actions That 

Significantly Affect Energy Supply, 

Distribution, or Use 

I. National Technology Transfer 

Advancement Act 

J. Executive Order 12898: Federal Actions 

To Address Environmental Justice in 

Minority Populations and Low Income 

Populations 

K. Congressional Review Act 

L. Executive Order 13609: Promoting 

International Regulatory Cooperation 

I. Executive Summary 

A. Purpose of the Regulatory Action 

The primary purpose of this rule is to 

adopt new oxides of nitrogen (NOX) 

emission standards for aircraft engines 

with rated thrusts greater than 26.7 kN 

thrust. These are mostly commercial 

passenger and freighter aircraft in 

common use at airports across the U.S. 

It does not include engines used on 

military aircraft. NOX is strongly 

correlated with NO2, for which EPA has 

established National Ambient Air 

Quality Standards (NAAQS), i.e., a 

criteria pollutant, and it is an important 

precursor gas in the formation of 

tropospheric ozone and secondary 

particulate matter which are common 

air pollutants in urban areas where 

airports are located. Currently, 

approximately 154 million people live 

in areas designated nonattainment for 

one or more of the current NAAQS. This 

rule will allow us to enforce in the U.S. 

the emission standards adopted by 

ICAO, and will be useful to states in 

attaining or maintaining the ozone, 

PM2.5, and NO2 NAAQS standards. This 

rule also contains several provisions to 

facilitate the implementation of EPA’s 

aircraft engine emission regulations and 

related requirements. It is also 

important to note that adoption of the 

provisions in this rule meets U.S. treaty 

obligations under the Chicago 

Convention of 1944 by aligning our 

regulations with those in the 

International Civil Aviation 

Organization Annex 16, Volume II 

(adopted in 2010) that the U.S. helped 

to develop and support as part of the 

international process. This rule is being 

implemented under the authority 

provided in section 231 of the Clean Air 

Act (42 U.S.C. 7571), which directs the 

Administrator of 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 her judgment causes 

or contributes to air pollution that may 

reasonably be anticipated to endanger 

public health or welfare. 

B. Summary of Major Provisions of the 

Regulatory Action 

The rule contains six major 

provisions. The first two provisions are 

new NOX emission standards for newly 

certified-engine models. The first 

standards, Tier 6, take effect when this 

rule becomes effective. These represent 

approximately a 12 percent reduction 

from current Tier 4 levels. They were 

actually adopted by ICAO in 2005 with 

an implementation date in 2008. The 

second standards, Tier 8, were adopted 

by ICAO in 2008 and take effect in 2014. 

These represent approximately a 15 

percent reduction from Tier 6 levels. As 

noted above, both tiers of emission 

standards are needed to address local air 

quality concerns (NAAQS) and to meet 

U.S. treaty obligations under the 

Chicago Convention. The third major 

provision is a production cut-off for 

newly-manufactured engines (as 

opposed to newly-certified engines) 

which basically requires that after 

December 31, 2012 all newlymanufactured engines must meet at 

least Tier 6 NOX emission standards. 

This is also needed to meet our 

obligations under the Chicago 

Convention. The production cut-off is 

needed to ensure that the emission 

reductions envisioned by the emission 

standards are achieved on new 

production engines. The fourth major 

provision is related to potential 

exemptions or exceptions to the 

production cut-off requirement. These 

include revised provisions allowing 

manufacturers to request that FAA in 

consultation with EPA grant exemptions 

from the production cut-off for a 

designated number of engines within a 

prescribed time frame. These also 

include a low-volume, time-limited 

exception provision that will exclude 

several engines from the production 

cutoff. Both of these provisions help to 

assure an orderly transition to the new 

standards for engines needing more time 

to comply or for a few engines at the 

end of their production life. Finally, the 

rule includes a set of provisions which 

may be considered as minor if viewed 

separately, but collectively are 

important in upgrading EPA’s 

regulations by incorporating some 

related agreements from our ICAO 

process and clarifying and improving 

existing provisions. Examples of this 

include special provisions for spare 

engines, provisions related to derivative 

engine models, test procedure 

specifications and reporting 

requirements. These changes are 

important for an effective 

implementation of the new 

requirements, and in many cases are 

also needed to meet our obligations 

under the Chicago Convention. 

C. Costs and Benefits 

This is not an economically 

significant regulatory action. Aircraft 

engines are international commodities 

used on aircraft manufactured and sold 

around the world. When developing 

new engine models manufacturers not 

only consider current emission 

requirements but also try to anticipate 

the stringency of future standards and 

respond appropriately. Engine 

manufacturers participated in the 

deliberations leading up to ICAO 

decisions on the aircraft engine NOX

emission standards and after the ICAO 

decisions they incorporated engine 

technology changes as needed to meet 

the new ICAO requirements. This helps 

to ensure the world wide acceptability 

of their products. Essentially all of these 

changes are now complete. Thus, while 

there is some cost to a manufacturer for 

responding to the new ICAO provisions, 

there is no significant further direct cost 

to the manufacturers created by EPA’s 

adopting the requirements into U.S 

regulations. In fact, it is likely that our 

adopting these requirements facilitates 

the acceptance of U.S. type certificates 

by aircraft manufacturers and airlines 

around the world. 

II. Overview and Background 

This section summarizes the major 

provisions of the final rule for aircraft 

gas turbine engines. It also contains 


TKELLEY on DSK3SPTVN1PROD with RULES2
36344 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

1Turbofan and turbojet engines will be 

collectively referred to as turbofan engines hereafter 

for convenience. 

2As previously mentioned, these new NOX

standards are identical to requirements established 

by ICAO. The stringency of any new emission 

standard is selected based on an assessment of the 

technical feasibility, cost, and environmental 

benefit of potential requirements. The NOX

standards we are promulgating today will not affect 

fuel economy or have any practical effect on CO2

emissions. (See International Civil Aviation 

Organization (ICAO), ‘‘Committee on Aviation 

Environmental Protection (CAEP), Eighth Meeting, 

Montreal, 1 to 12 February 2010, CAEP/8 NOX

Stringency Cost–Benefit Analysis Demonstration 

Using APMT–IMPACTS,’’ CAEP/8–IP/30, December 

1, 2010. A copy of this document is in docket 

number EPA–HQ–OAR–2010–0687.) 

3These exemption or exception provisions are 

conceptually the same as the ICAO exemption 

provisions and provide the same regulatory 

flexibilities to all engine manufacturers. 

4The term gas turbine engine includes turbofan, 

turbojet, and turboprop engines designs. The rated 

output for turbofan and turbojet engines is normally 

expressed as kilonewtons (kN) thrust. The rated 

output for turboprop engines is normally expressed 

as shaft horsepower (hp) or shaft kilowatt (kW). 

5This includes turbofan and turbojet engines less 

than 26.7 kN thrust and all turboprop engines that 

are subject to any emission standard, e.g., smoke. 

6As discussed further in section III.D., the 

voluntary emission data report to ICAO does not 

include turbofans at or below 26.7 kN or turboprops 

subject to any emission standard. 

7The functions of the Secretary of Transportation 

under part B of title II of the Clean Air Act (§§ 231– 

234, 42 U.S.C. 7571–7574) have been delegated to 

the Administrator of the FAA. 49 CFR 1.47(g). 

background on the EPA’s standard 

setting authority and responsibilities 

under the Clean Air Act, the connection 

between our emission standards and 

those of the international community, 

and a brief regulatory history for this 

source of emissions. 

A. Contents of the Final Rule 

We are adopting several new emission 

standards and other regulatory 

requirements for aircraft turbofan and 

turbojet engines 1 with rated thrusts 

greater than 26.7 kilonewtons (kN). 

First, we are establishing two new tiers 

of more stringent emission standards for 

oxides of nitrogen (NOX).2 The 

standards apply differently to two 

classes of these engines, i.e., ‘‘newlycertified engines’’ and ‘‘newlymanufactured engines.’’ The newlycertified engine standards apply to 

aircraft engines that have received a 

new type certificate and have never 

been manufactured prior to the effective 

date of the new emission standards. 

Requirements for newly-manufactured 

engines apply to aircraft engines that 

were previously certified and 

manufactured in compliance with 

preexisting standards, and they require 

manufacturers to either comply with the 

newer standards by a specified future 

date or cease production of the affected 

engine models. Newly-manufactured 

engine standards are also sometimes 

referred to as ‘‘production cutoff’’ 

standards. Second, we are adopting 

certain time-limited flexibilities, i.e., the 

potential for exemptions or exceptions 

as defined in the regulations for newlymanufactured engines that may not be 

able to comply with the first tier of the 

NOX standards because of specific 

technical or economic reasons.3

We are also making a number of 

additional changes that would apply to 

a wider range of aircraft gas turbine 

engines 4 than those that would be 

subject to the new emission standards.5

First, we are defining the meaning of a 

derivative engine for emissions 

certification purposes. The intent of this 

definition is to distinguish when the 

emission characteristics of a new 

turbofan engine model vary sufficiently 

from its existing parent engine design, 

and must show compliance with the 

emission standard for a newlycertificated engine. Second, we are 

establishing new reporting requirements 

for manufacturers that produce gas 

turbine engines subject to any exhaust 

emission standard. This will provide us 

with timely and consistent emission 

data and other information that is 

necessary to conduct emission 

inventory and air quality analyses and 

develop appropriate public policy for 

the aviation sector. Specifically, reports 

are required for turbofan engines with 

rated thrusts greater than 26.7 kN, 

which are subject to gaseous emission 

and smoke standards, in addition to 

turbofans less than or equal to 26.7 kN, 

and all turboprop engines, that are only 

subject to smoke standards.6 Third, we 

are adopting minor amendments to the 

test and measurement procedures for 

aircraft engines. Finally, as described in 

section IV, we are making minor 

amendments to regulator provisions 

addressing definitions, acronyms and 

abbreviations, general applicability and 

requirements, exemptions, and 

incorporation by reference. 

Most of these new regulatory 

requirements have already been adopted 

by the United Nation’s International 

Civil Aviation Organization (ICAO). The 

requirements contained in this final rule 

bring the United States into alignment 

with the international standards and 

recommended practices. 

B. EPA’s Authority and Responsibilities 

Under the Clean Air Act 

Section 231(a)(2)(A) of the Clean Air 

Act (CAA) directs the Administrator of 

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 her 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 EPA to consult with the 

Administrator of the Federal Aviation 

Administration (FAA) on such 

standards, and prohibits EPA from 

changing aircraft emission standards if 

such a change would significantly 

increase noise and adversely affect 

safety. 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.’’ 

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 EPA to 

adopt aircraft engine emission standards 

as the Agency determines are 

reasonable. NACAA v. EPA, 489 F.3d 

1221 (D.C. Cir. 2007). 

In addition, under CAA section 231(b) 

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. 

42 U.S.C. 7571(b). Section 232 then 

directs the FAA to prescribe regulations 

to ensure compliance with EPA’s 

standards. 42 U.S.C. 7572. Finally, 

section 233 of the CAA vests the 

authority to promulgate emission 

standards for aircraft or aircraft engines 

only in EPA. States are preempted from 

adopting or enforcing any standard 

respecting aircraft engine emissions 

unless such standard is identical to 

EPA’s standards. 42 U.S.C. § 7573. 

Section VI of today’s final rule further 

discusses our coordination with DOT 

through the FAA.7 It also describes 

DOT’s responsibility under the CAA to 

enforce the aircraft emission standards 

established by EPA. 

C. Interaction With the International 

Community 

We began regulating the air pollution 

emissions from aircraft engines in 1973. 

Since that time, we have worked with 

the FAA and later with the International 

Civil Aviation Organization (ICAO) to 

develop international standards and 

other recommended practices pertaining 

to aircraft engine emissions. ICAO was 

established in 1944 by the United 

Nations (by the Convention on 

International Civil Aviation, the 


TKELLEY on DSK3SPTVN1PROD with RULES2
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36345 

8 ICAO, ‘‘Convention on International Civil 

Aviation,’’ Ninth Edition, Document 7300/9, 2006. 

Copies of this document can be obtained from the 

ICAO Web site located at www.icao.int. 

9Members of ICAO’s Assembly are generally 

termed member States or contracting States. These 

terms are used interchangeably throughout this 

preamble. 

10There are currently 191 Contracting States 

according to ICAO Web site located at www.icao.int. 

11 ICAO, ‘‘Convention on International Civil 

Aviation,’’ Article 87, Ninth Edition, Document 

7300/9, 2006. Copies of this document can be 

obtained from the ICAO Web site located at 

www.icao.int/icaonet/arch/doc/7300/7300_9ed.pdf. 

12 ICAO, ‘‘Convention on International Civil 

Aviation,’’ Article 33, Ninth Edition, Document 

7300/9, 2006. Copies of this document can be 

obtained from the ICAO Web site located at 

www.icao.int/icaonet/arch/doc/7300/7300_9ed.pdf. 

13 ICAO, ‘‘Convention on International Civil 

Aviation,’’ Articles 38, Ninth Edition, Document 

7300/9, 2006. Copies of this document can be 

obtained from the ICAO Web site located at 

www.icao.int/icaonet/arch/doc/7300/7300_9ed.pdf. 

14Pursuant to the President’s memorandum of 

August 11, 1960 (and related Executive Order No. 

10883 from 1960), the Interagency Group on 

International Aviation (IGIA) was established to 

facilitate coordinated recommendations to the 

Secretary of State on issues pertaining to 

international aviation. The DOT/FAA is the chair of 

IGIA, and as such, the FAA represents the U.S. on 

environmental matters at CAEP. 

15 ICAO, ‘‘Aircraft Engine Emissions,’’ 

International Standards and Recommended 

Practices, Environmental Protection, Annex 16, 

Volume II, Second Edition, July 2008. A copy of 

this document is in docket number EPA–HQ–OAR– 

2010–0687. 

16CAEP develops new emission standards based 

on an assessment of the technical feasibility, cost, 

and environmental benefit of potential 

requirements. 

17U.S. EPA, ‘‘Emission Standards and Test 

Procedures for Aircraft;’’ Final Rule, 38 FR 19088, 

July 17, 1973. 

18U.S. EPA, ‘‘Control of Air Pollution from 

Aircraft and Aircraft Engines; Emission Standards 

and Test Procedures;’’ Final Rule, 62 FR 25356, 

May 8, 1997. While ICAO’s standards were not 

limited to ‘‘commercial’’ aircraft engines, our 1997 

standards were explicitly limited to commercial 

engines, as our finding that NOX and CO emissions 

from aircraft 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. As explained later in section 

IV.A.2. of today’s notice, we are expanding the 

scope of that finding and of our standards pursuant 

to section 231(a)(2)(A) of the Clean Air Act to 

include such emissions from both commercial and 

non-commercial aircraft engines based on the 

physical and operational similarities between 

commercial and noncommercial civilian aircraft 

and to bring our standards into full alignment with 

ICAO’s. 

19This does not mean that in 2005 we 

promulgated requirements for the re-certification or 

retrofit of existing in-use engines. 

20U.S. EPA, ‘‘Control of Air Pollution from 

Aircraft and Aircraft Engines; Emission Standards 

and Test Procedures;’’ Final Rule, 70 FR 2521, 

November 17, 2005. 

‘‘Chicago Convention’’) ‘‘* * * in order 

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.’’ 8 ICAO’s 

responsibilities include developing 

aircraft technical and operating 

standards, recommending practices, and 

generally fostering the growth of 

international civil aviation. The United 

States is currently one of 191 

participating member States of ICAO.9 10

In the interests of global 

harmonization and international air 

commerce, the Chicago Convention 

urges a high degree of uniformity by its 

member States. Nonetheless, the 

Convention also recognizes that member 

States may adopt their own unique 

airworthiness standards and that some 

may adopt standards that are more 

stringent than those agreed upon by 

ICAO. 

The Convention has a number of other 

features that govern international 

commerce. First, States that wish to use 

aircraft in international transportation 

must adopt emission standards and 

other recommended practices that are at 

least as stringent as ICAO’s standards. 

States may ban the use of any aircraft 

within their airspace that does not meet 

ICAO standards.11 Second, States are 

required to recognize the airworthiness 

certificates of any State whose standards 

are at least as stringent as ICAO’s 

standards, thereby assuring that aircraft 

of any member State will be permitted 

to operate in any other member State.12

Third, and finally, to ensure that 

international commerce is not 

unreasonably constrained, a 

participating nation which elects to 

adopt more stringent standards is 

obligated to notify ICAO of the 

differences between its standards and 

ICAO standards.13 However, if a nation 

sets tighter standards than ICAO, air 

carriers not based in that nation would 

only be required to comply with ICAO 

standards or more stringent standards 

imposed by their own nations, if 

applicable. 

ICAO’s Committee on Aviation 

Environmental Protection (CAEP) 

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 impact of international 

civil aviation. CAEP is composed of 

various task groups, work groups, and 

other committees whose contributing 

members include atmospheric, 

economic, aviation, environmental, and 

other professionals interested in 

aviation and environmental protection. 

At CAEP meetings, the United States is 

represented by the FAA, which plays an 

active role at these meetings.14 EPA has 

historically been a principal participant 

in the development of U.S. policy in 

various ICAO/CAEP working groups 

and other international venues, assisting 

and advising FAA on aviation 

emissions, technology, and policy 

matters. 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).15 16

D. Brief History of EPA’s Regulation of 

Aircraft Engine Emissions 

As mentioned above, we initially 

regulated gaseous exhaust emissions, 

smoke, and fuel venting from aircraft 

engines in 1973.17 Since that time, we 

have occasionally revised those 

regulations. Two of these revisions are 

most pertinent to today’s final rule. 

First, in a 1997 rulemaking, we made 

our emission standards and test 

procedures more consistent with those 

of ICAO for turbofan engines used in 

commercial aviation with rated thrusts 

greater than 26.7kN.18 These ICAO 

requirements are generally referred to as 

CAEP/2 standards. (The numbering 

nomenclature for CAEP requirements is 

discussed in the next section.) That 

action included new NOX emission 

standards for newly-manufactured 

commercial turbofan engines (those 

engines built after the effective date of 

the regulations that were already 

certified to pre-existing standards) 19

and for newly-certified commercial 

turbofan engines (those engine models 

that received their initial type certificate 

after the effective date of the 

regulations). It also included a CO 

emission standard for newlymanufactured commercial turbofan 

engines. Second, in our most recent 

rulemaking in 2005, we promulgated 

more stringent NOX emission standards 

for newly-certified commercial turbofan 

engines.20 That final rule brought the 

U.S. standards closer to alignment with 

ICAO CAEP/4 requirements that were 

effective in 2004. In ruling on a petition 

for judicial review of the 2005 rule filed 

by the National Association of Clean Air 

Agencies (NACAA), the U.S. Court of 

Appeals held that EPA’s approach of 

tracking the ICAO standards was 

reasonable and permissible under the 

CAA. NACAA v. EPA, 489 F.3d 1221, 

1230–32 (D.C. Cir. 2007). 

E. Brief History of ICAO Regulation of 

Aircraft Engine Emissions 

The first international standards and 

recommended practices for aircraft 

engine emissions was recommended by 

CAEP’s predecessor, the Committee on 

Aircraft Engine Emissions (CAEE), and 


TKELLEY on DSK3SPTVN1PROD with RULES2
36346 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

21 ICAO, Foreword of ‘‘Aircraft Engine 

Emissions,’’ International Standards and 

Recommended Practices, Environmental Protection, 

Annex 16, Volume II, Third Edition, July 2008. 

Copies of this document can be obtained from the 

ICAO Web site at www.icao.int. 22CAEP conducts its work over a period of years. 

Each work cycle is numbered sequentially and that 

identifier is used to differentiate the results from 

one CAEP to another by convention. The first 

technical meeting on aircraft emission standards 

was CAEP’s successor, i.e., CAEE. The first meeting 

of CAEP, therefore, is referred to as CAEP/2. 23CAEP/5 did not address new aircraft engine 

emission standards. 24 ICAO, ‘‘Aircraft Engine Emissions,’’ Annex 16, 

Volume II, Third Edition, July 2008, Amendment 4 

effective on July 20, 2008. Copies of this document 

can be obtained from the ICAO Web site at 

www.icao.int. 25CAEP/7 did not address new aircraft engine 

emission standards. 26 ICAO, ‘‘Committee on Aviation Environmental 

Protection (CAEP), Report of the Eighth Meeting, 

Montreal, February 1–12, 2010,’’ CAEP/8–WP/80. A 

copy of this document is in docket number EPA– 

HQ–OAR–2010–0687. 

27 ICAO, ‘‘Aircraft Engine Emissions,’’ Annex 16, 

Volume II, Third Edition, July 2008, Amendment 7 

effective on July 18, 2011. Copies of this document 

can be obtained from the ICAO Web site at 

www.icao.int. 

28 Ground-level ozone, the main ingredient in 

smog, is formed by complex chemical reactions of 

volatile organic compounds (VOC) and NOX in the 

presence of heat and sunlight. Standards that 

reduce NOX emissions will help address ambient 

ozone levels. They can also help reduce particulate 

matter (PM) levels as NOX emissions can also be 

part of the secondary formation of PM. See Section 

II.B below. 

29According to Airport Council International— 

North America and similar FAA databases, most 

commercial operations occur at airports that are in 

or near large cities or urbanized areas. There are 

about 130 commercial airports in 78 ozone and fine 

particulate nonattainment areas (based on the 

nonattainment areas status of 2008). There are about 

325 commercial airports in the U.S. 

30For a current list of nonattainment areas see: 

http://www.epa.gov/oar/oaqps/greenbk/index.html. 

31 ‘‘Historical Assessment of Aircraft Landing and 

Take-off Emissions (1986–2008),’’ Eastern Research 

Group, May 2011. A copy of this document can be 

found in public docket EPA–HQ–OAR–2010–0687. 

32The cumulative LTO NOX reduction associated 

with the new NOX standards is projected to be 

about 100,000 tons from 2014 to 2030 (2014 is the 

implementation date of the CAEP/8 NOX

standards). See ‘‘Historical Assessment of Aircraft 

Landing and Take-off Emissions (1986–2008),’’ 

Eastern Research Group, May 2011. A copy of this 

document can be found in public docket EPA–HQ– 

OAR–2010–0687. 

33U.S. EPA, ‘‘Comparison of Aircraft LTO and 

Full Flight NOX Emissions to Total Mobile Source 

NOX Emissions,’’ memorandum from John Mueller, 

Assessment and Standards Division, Office of 

Transportation and Air Quality, to docket EPA– 

HQ–OAR–2010–0687, May 10, 2011. 

adopted by ICAO in 1981.21 These 

standards limited aircraft engine 

emissions of HC, CO, and NOX. In 1994, 

ICAO adopted a CAEP/2 proposal to 

tighten the original NOX standard by 20 

percent and amend the test 

procedures.22 At the next CAEP meeting 

(CAEP/3) in 1995, the Committee 

recommended a further tightening of 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 on 

1998. The CAEP/4 standards applied 

only to new engine designs certified 

after December 31, 2003 (i.e., the 

requirements did not also apply to 

previously certified, newlymanufactured engines unlike the CAEP/ 

2 standards). In 2004, CAEP/6 

recommended a 12 percent NOX

reduction, which ICAO approved in 

2005.23 24 The CAEP/6 standards applied 

to new engine designs (newly-certified 

models) certified after December 31, 

2007. At the most recent meeting, 

CAEP/8 recommended a further 

tightening of the NOX standards by 15 

percent for newly-certified engines.25 26

The Committee also recommended that 

the CAEP/6 standards be applied to 

newly-manufactured engines. ICAO 

approved these recommendations in 

2011.27

III. Why is EPA taking this action? 

As mentioned above, section 

231(a)(2)(A) of the CAA authorizes the 

EPA Administrator to ‘‘from time to 

time, issue proposed emission standards 

applicable to the emission of any air 

pollution from any class or classes of 

aircraft or aircraft engines which in his 

judgment causes, or contributes to air 

pollution which may reasonably be 

anticipated to endanger public health or 

welfare.’’ 42 U.S.C. 7571(a)(2)(A). 

One of the principal components of 

aircraft exhaust emissions is NOX, a 

precursor to the formation of 

tropospheric ozone and secondary 

PM.28 Most commercial airports are 

located in urbanized areas 29 and many 

urbanized areas have ambient pollutant 

levels above the National Ambient Air 

Quality Standards (NAAQS) for ozone 

and fine particulate matter (PM2.5) (i.e., 

they are in nonattainment for ozone and 

PM2.5).30 This section discusses the 

contribution of aircraft engines used in 

commercial service with rated thrusts 

greater than 26.7kN to the national NOX

emissions inventory and to NOX

emission inventories in selected ozone 

and PM2.5 nonattainment areas, the 

potential effect of NOX emissions in the 

upper atmosphere on ground level PM2.5

in addition to the health and welfare 

impacts of NOX and PM emissions. 

A. Inventory Contribution 

In contrast to all other mobile sources, 

whose emissions occur completely at 

ground level, the emissions from aircraft 

and aircraft engines can be divided into 

two flight regimes. The first regime 

includes the emissions that are released 

in the lower layer of the atmosphere and 

directly affect local and regional 

ambient air quality. These emissions 

generally occur at or below 3,000 feet 

above ground level, i.e., during the 

landing and takeoff (LTO) cycle. The 

aircraft operations that comprise an LTO 

cycle are: engine idle at the terminal 

gate (and sometimes during ground 

delays while holding for the active 

runway); taxiing between the terminal 

and the runway; take-off; climb-out; and 

approach to the airport. The second 

regime includes emissions that occur 

above 3,000 feet above ground level, 

known as non-LTO emissions. 

Collectively, the emissions associated 

with all ground and flight operations are 

generally referred to as full flight 

emissions. 

In this section, we will discuss NOX

emission inventories for commercial 

turbine-engine aircraft, both nationally 

and for selected ozone and PM2.5

nonattainment areas (NAAs). These 

inventories reflect emissions during the 

landing and takeoff cycle only. The 

most recent comprehensive analysis of 

historical and current LTO emissions 

from aircraft engines comes from a 

study undertaken for us by Eastern 

Research Group (ERG).31 The study 

analyzed the national emissions of 

commercial aircraft operations in the 

United States, and showed that in the 

most recent year studied (2008), such 

aircraft LTO operations contributed 

about 97 thousand tons to the national 

NOX inventory.32 A summary of the 

national inventory of LTO NOX

emissions is shown in Table 1. 

When these nationwide LTO 

emissions are compared to the total U.S. 

mobile source inventory for 2009, they 

account for less than one percent of the 

total. However, such a comparison may 

be a bit misleading, as it only includes 

those aircraft emissions that occur 

below 3,000 feet altitude, while 

comparing them to the entirety of other 

mobile source emissions. In the U.S., 

LTO emissions account for only about 

ten percent of full flight NOX emissions. 

When considering full flight aircraft 

emissions (i.e., including both LTO and 

non-LTO emissions), the contribution of 

aircraft to the total mobile source NOX

inventory is approximately 7.7 

percent.33 It is also worth noting that 

these LTO emissions are more localized 

in that they occur near airports, which 

are mostly within urban areas. 


TKELLEY on DSK3SPTVN1PROD with RULES2
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36347 

34Although 41 NAAs were studied, the nonaircraft emissions data source that the aircraft 

emissions were compared to for this analysis did 

not distinguish between the Boston NAA in 

Massachusetts and the greater Boston NAA in New 

Hampshire. Thus, aircraft emissions from those two 

NAAs were combined into a single NAA for the 

purpose of this analysis, yielding 40 NAAs for 

study. 

35For a current list of nonattainment areas see: 

http://www.epa.gov/oar/oaqps/greenbk/index.html. 

36U.S. EPA, ‘‘Relative Contribution of Aircraft to 

Total Mobile Source NOX Emissions in Selected 

Ozone Nonattainment Areas,’’ memorandum from 

John Mueller, Assessment and Standards Division, 

Office of Transportation and Air Quality, to docket 

EPA–HQ–OAR–2010–0687, May 10, 2011. 

37U.S. EPA, ‘‘Addendum to ‘Relative 

Contribution of Aircraft to Total Mobile Source 

NOX Emissions in Selected Ozone Nonattainment 

Areas,’ ’’ memorandum from John Mueller, 

Assessment and Standards Division, Office of 

Transportation and Air Quality, to docket EPA– 

HQ–OAR–2010–0687, May 17, 2011. 

38U.S. EPA, ‘‘Update to ‘Relative Contribution of 

Aircraft to Total Mobile Source NOX Emissions in 

Selected Ozone Nonattainment Areas,’ ’’ 

memorandum from John Mueller, Assessment and 

Standards Division, Office of Transportation and 

Air Quality, to docket EPA–HQ–OAR–2010–0687, 

April 30, 2012. 

TABLE 1—CURRENT NATIONAL NOX

EMISSIONS FROM COMMERCIAL AIRCRAFT

Aircraft category 2008 Total NOX

(thousand tons) 

Air Carrier ....................... 86 

Commuter/Air Taxi .......... 11 

Total Commercial .... 97 

In addition, it is important to assess 

the contribution of commercial aircraft 

LTO NOX emissions on a local level, 

especially in areas containing or 

adjacent to airports. The historical 

analysis conducted by ERG also 

included an assessment of selected 

ozone nonattainment areas (NAAs). The 

NAAs selected for study were chosen as 

follows. First, the 25 NAAs with 

airports which had high commercial 

traffic volumes were identified. Second, 

the 25 NAAs with the largest population 

were identified. These lists were 

combined. However, there was some 

overlap, and this led to a total of 40 

NAAs being identified for the study.34

These NAAs collectively include 200 

airports, accounting for about 70 percent 

of commercial air traffic operations. 

Of the 40 NAAs originally studied by 

ERG as previously described, we 

identified the 30 areas that were in 

nonattainment for ozone or PM2.5 as of 

March 30, 2012.35 Current (2008) and 

projected (2020) NOX emissions for 

these 30 ozone and PM2.5 NAAs, as well 

as the percent contribution of aircraft to 

total mobile source inventories (as 

compared to 2005 and 2020 mobile 

source inventories), are shown in Table 

2.36 37 38 The relative contribution of 

aircraft in any given NAA varies based 

on activity in other transportation and 

industrial sectors. As can be seen from 

this table, expected growth in aircraft 

operations in many of these areas 

combined with anticipated reductions 

in NOX emissions from other mobile 

source categories results in the growth 

of the relative contribution of aircraft 

LTO emissions to mobile source NOX

emissions in NAAs. 

TABLE 2—NOX EMISSIONS IN SELECTED OZONE AND PM2.5 NONATTAINMENT AREAS

Nonattainment area 2008 Total NOX

(tons) 

2008 Aircraft 

percent of 

mobile 

source NOX

2020 Aircraft 

percent of 

mobile 

source NOX

Atlanta, GA ................................................................................................................ 5,808 2.6 8.2 

Baltimore, MD ............................................................................................................ 1,148 1.3 4.4 

Boston—including MA and NH NAAs ....................................................................... 2,032 1.0 2.7 

Charlotte-Gastonia-Rock Hill, NC-SC ........................................................................ 1,917 2.6 10.0 

Chicago-Gary-Lake County, IL-IN ............................................................................. 6,007 1.8 5.0 

Cleveland-Akron-Lorain, OH ...................................................................................... 680 0.5 1.3 

Dallas-Fort Worth, TX ................................................................................................ 3,880 1.7 6.9 

Denver-Boulder-Greeley-Fort Collins-Loveland, CO ................................................. 2,649 2.5 7.1 

Detroit-Ann Arbor, MI ................................................................................................. 2,312 1.1 3.0 

Greater Connecticut, CT ............................................................................................ 405 0.8 2.4 

Houston-Galveston-Brazoria, TX ............................................................................... 3,045 1.3 3.4 

Indianapolis, IN .......................................................................................................... 1,089 1.4 3.0 

Las Vegas, NV ........................................................................................................... 2,308 6.0 15.8 

Los Angeles South Coast Air Basin, CA ................................................................... 6,479 1.5 4.5 

Louisville, KY-IN ........................................................................................................ 1,211 1.9 6.2 

Milwaukee-Racine, WI ............................................................................................... 557 0.9 3.2 

New York-N. New Jersey-Long Island, NY-NJ-CT ................................................... 10,093 2.3 6.3 

Philadelphia-Wilmington-Atlantic City, PA-NY-MD-DE .............................................. 2,308 1.0 2.8 

Phoenix-Mesa, AZ ..................................................................................................... 2,298 1.4 3.3 

Pittsburgh-Beaver Valley, PA .................................................................................... 480 0.5 1.1 

Providence (entire State), RI ..................................................................................... 232 1.0 2.3 

Riverside County (Coachella Valley), CA .................................................................. 70 0.2 0.5 

Sacramento Metro, CA .............................................................................................. 603 1.0 2.0 

Salt Lake City, UT ..................................................................................................... 1,235 4.4 14.1 

San Diego, CA ........................................................................................................... 1,035 1.4 3.4 

San Francisco Bay Area, CA .................................................................................... 4,405 2.7 6.7 

San Joaquin Valley, CA ............................................................................................. 74 0.0 0.1 

Seattle-Tacoma, WA .................................................................................................. 1,958 1.4 3.9 

St. Louis, MO-IL ......................................................................................................... 810 0.6 1.6 

Washington, DC-MD-VA ............................................................................................ 2,983 2.0 6.2 

Table 3 shows how commercial 

aircraft operations are projected to rise 

in the future on a nationwide basis. As 

operations increase, the inventory 

impact of these aircraft on national and 

local NOX inventories will also increase. 


TKELLEY on DSK3SPTVN1PROD with RULES2
36348 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

39The discussion of PM health and welfare effects 

throughout this notice relates exclusively to the 

effects of the NOX emission standards on the 

formation of secondary PM from nitrate formation 

in the atmosphere. Presently, there are no emission 

standards for PM emitted directly from aircraft 

turbine engines. The current and planned future 

work programs for CAEP/ICAO are developing PM 

test procedures and information to characterize the 

amount and type of these emissions from aircraft 

engines that are in production. Ultimately, this 

information will be used to assess the need for an 

aircraft turbine engine PM standard (i.e., whether 

PM emissions from aircraft cause or contribute to 

air pollution which may reasonably be anticipated 

to endanger public health or welfare), with standard 

setting as appropriate. 

40U.S. EPA Air Quality Criteria for Ozone and 

Related Photochemical Oxidants (Final). U.S. 

Environmental Protection Agency, Washington, DC, 

EPA 600/R–05/004aF–cF, 2006. This document is 

available in Docket EPA–HQ–OAR–2010–0687. 

This document may be accessed electronically at: 

http://www.epa.gov/ttn/naaqs/standards/ozone/ 

s_o3_cr_cd.html. 

41U.S. EPA Air Quality Criteria for Ozone and 

Related Photochemical Oxidants (Final). U.S. 

Environmental Protection Agency, Washington, DC, 

EPA 600/R–05/004aF–cF, 2006. This document is 

available in Docket EPA–HQ–OAR–2010–0687. 

This document may be accessed electronically at: 

http://www.epa.gov/ttn/naaqs/standards/ozone/ 

s_o3_cr_cd.html. 

42U.S. EPA (2007) Review of the National 

Ambient Air Quality Standards for Ozone, Policy 

Assessment of Scientific and Technical 

Information. OAQPS Staff Paper.EPA–452/R–07– 

003. This document is available in Docket EPA– 

HQ–OAR–2010–0687. This document is available 

electronically at: http:www.epa.gov/ttn/naaqs/ 

standards/ozone/s_o3_cr_sp.html. 

TABLE 3—CURRENT AND PROJECTED COMMERCIAL AIRCRAFT OPERATIONS

Year 

Air carrier 

operations 

(millions) 

Commuter/air 

taxi operations 

(millions) 

Total commercial 

operations 

(millions) 

Total increase 

in commercial 

operations over 

2008 (percent) 

2008 ......................................................................................... 14.1 13.8 27.9 

2020 ......................................................................................... 16.5 14.1 30.5 9 

2030 ......................................................................................... 20.6 16.0 36.6 31 

Source: December 2010 FAA TAF, which is located at http://aspm.faa.gov/main/taf.asp. 

B. Health, Environmental and Air 

Quality Impacts 

NOX emissions from aircraft and other 

mobile and stationary sources 

contribute to the formation of ozone. In 

addition, NOX emissions at low altitude 

also react in the atmosphere to form 

secondary fine particulate matter 

(PM2.5), particularly ammonium nitrate. 

In the following sections we discuss the 

adverse health and welfare effects 

associated with NOX emissions, in 

addition to the current and projected 

levels of ozone and PM across the 

country. The ICAO NOX standards with 

which we are aligning will help reduce 

ambient ozone and secondary PM levels 

and thus will help areas with airports 

achieve or maintain attainment with the 

National Ambient Air Quality Standards 

(NAAQS).39

1. Background on Ozone, PM and NOX

a. What is ozone? 

Ground-level ozone pollution is 

typically formed through reactions 

involving VOC and NOX in the lower 

atmosphere in the presence of sunlight. 

These pollutants, often referred to as 

ozone precursors, are emitted by many 

types of pollution sources, such as 

highway and nonroad motor vehicles 

and engines, power plants, chemical 

plants, refineries, makers of consumer 

and commercial products, industrial 

facilities, and smaller area sources. 

The science of ozone formation, 

transport, and accumulation is 

complex.40 Ground-level ozone is 

produced and destroyed in a cyclical set 

of chemical reactions, many of which 

are sensitive to temperature and 

sunlight. When ambient temperatures 

and sunlight levels remain high for 

several days and the air is relatively 

stagnant, ozone and its precursors can 

build up and result in more ozone than 

typically occurs on a single hightemperature day. Ozone and its 

precursors can be transported hundreds 

of miles downwind from precursor 

emissions, resulting in elevated ozone 

levels even in areas with low local VOC 

or NOX emissions. 

b. What is particulate matter? 

The discussion includes PM2.5

because the NOX emitted by aircraft 

engines can react in the atmosphere to 

form nitrate, a component of PM2.5. 

Particulate matter is a generic term for 

a broad class of chemically and 

physically diverse substances. It can be 

principally characterized as discrete 

particles that exist in the condensed 

(liquid or solid) phase spanning several 

orders of magnitude in size. Since 1987, 

EPA has delineated that subset of 

inhalable particles small enough to 

penetrate to the thoracic region 

(including the tracheobronchial and 

alveolar regions) of the respiratory tract 

(referred to as thoracic particles). The 

current PM NAAQS uses PM2.5 as the 

indicator for fine particles (with PM2.5

generally referring to particles with a 

nominal mean aerodynamic diameter 

less than or equal to 2.5 micrometers 

(mm)), and use PM10 as the indicator for 

purposes of regulating the coarse 

fraction of PM10 (referred to as thoracic 

coarse particles or coarse-fraction 

particles; generally including particles 

with a nominal mean aerodynamic 

diameter greater than 2.5 mm and less 

than or equal to 10 mm, or PM10-2.5). 

Ultrafine particles are a subset of fine 

particles, generally less than 100 

nanometers (0.1 mm) in diameter. 

Fine particles are produced primarily 

by combustion processes and by 

transformations of gaseous emissions 

(e.g., SOX, NOX and VOC) in the 

atmosphere. The chemical and physical 

properties of PM2.5 may vary greatly 

with time, region, meteorology, and 

source category. Thus, PM2.5 may 

include a complex mixture of different 

components including sulfates, nitrates, 

organic compounds, elemental carbon 

and metal compounds. These particles 

can remain in the atmosphere for days 

to weeks and travel hundreds to 

thousands of kilometers. 

c. What is NOX? 

Nitrogen dioxide (NO2) is a member of 

the NOX family of gases. Most NO2 is 

formed in the air from the oxidation of 

nitric oxide (NO) emitted when fuel is 

burned at a high temperature. NO2 and 

its gas phase oxidation products can 

dissolve in water droplets and further 

oxidize to form nitric acid which reacts 

with ammonia to form nitrates, an 

important component of ambient PM. 

NOX and VOC are the two major 

precursors of ozone. The health effects 

of ozone, ambient PM and NOX are 

covered in section II.B.2. 

2. Health Effects Associated With 

Exposure to Ozone, PM and NOX

a. What are the health effects of ozone? 

The health and welfare effects of 

ozone are well documented and are 

assessed in EPA’s 2006 Air Quality 

Criteria Document and 2007 Staff 

Paper.41 42 People who are more 

susceptible to effects associated with 

exposure to ozone can include children, 


TKELLEY on DSK3SPTVN1PROD with RULES2
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36349 

43National Research Council (NRC), 2008. 

Estimating Mortality Risk Reduction and Economic 

Benefits From Controlling Ozone Air Pollution. The 

National Academies Press: Washington, DC A copy 

of this document is in docket number EPA–HQ– 

OAR–2010–0687. 

44U.S. EPA (2009) Integrated Science Assessment 

for Particulate Matter, EPA 600/R–08/139F. A copy 

of this document is in docket number EPA–HQ– 

OAR–2010–0687. 

45U.S. EPA (2009). Integrated Science 

Assessment for Particulate Matter (Final Report). 

U.S. Environmental Protection Agency, 

Washington, DC, EPA/600/R–08/139F, 2009. 

Section 2.3.1.1. 

46U.S. EPA (2009). Integrated Science 

Assessment for Particulate Matter (Final Report). 

U.S. Environmental Protection Agency, 

Washington, DC, EPA/600/R–08/139F, 2009. page 

2–12, Sections 7.3.1.1 and 7.3.2.1. 

47U.S. EPA (2009). Integrated Science 

Assessment for Particulate Matter (Final Report). 

U.S. Environmental Protection Agency, 

Washington, DC, EPA/600/R–08/139F, 2009. 

Section 2.3.2. 

48U.S. EPA (2008). Integrated Science 

Assessment for Oxides of Nitrogen—Health Criteria 

(Final Report). EPA/600/R–08/071. Washington, 

DC: U.S. EPA. A copy of this document is in docket 

number EPA–HQ–OAR–2010–0687. 

the elderly, and individuals with 

respiratory disease such as asthma. 

Those with greater exposures to ozone, 

for instance due to time spent outdoors 

(e.g., children and outdoor workers), are 

of particular concern. Ozone can irritate 

the respiratory system, causing 

coughing, throat irritation, and 

breathing discomfort. Ozone can reduce 

lung function and cause pulmonary 

inflammation in healthy individuals. 

Ozone can also aggravate asthma, 

leading to more asthma attacks that 

require medical attention and/or the use 

of additional medication. Thus, ambient 

ozone may cause both healthy and 

asthmatic individuals to limit their 

outdoor activities. In addition, there is 

suggestive evidence of a contribution of 

ozone to cardiovascular-related 

morbidity and highly suggestive 

evidence that short-term ozone exposure 

directly or indirectly contributes to nonaccidental and cardiopulmonary-related 

mortality, but additional research is 

needed to clarify the underlying 

mechanisms causing these effects. In a 

report on the estimation of ozonerelated premature mortality published 

by the National Research Council (NRC), 

a panel of experts and reviewers 

concluded that short-term exposure to 

ambient ozone is likely to contribute to 

premature deaths and that ozone-related 

mortality should be included in 

estimates of the health benefits of 

reducing ozone exposure.43 Animal 

toxicological evidence indicates that 

with repeated exposure, ozone can 

inflame and damage the lining of the 

lungs, which may lead to permanent 

changes in lung tissue and irreversible 

reductions in lung function. The 

respiratory effects observed in 

controlled human exposure studies and 

animal studies are coherent with the 

evidence from epidemiologic studies 

supporting a causal relationship 

between acute ambient ozone exposures 

and increased respiratory-related 

emergency room visits and 

hospitalizations in the warm season. In 

addition, there is suggestive evidence of 

a contribution of ozone to 

cardiovascular-related morbidity and 

non-accidental and cardiopulmonary 

mortality. 

b. What are the health effects of PM? 

Scientific studies show ambient PM is 

associated with a series of adverse 

health effects. These health effects are 

discussed in detail in EPA’s Integrated 

Science Assessment for Particulate 

Matter (ISA).44 The ISA summarizes 

health effects evidence associated with 

both short-term and long-term 

exposures to PM2.5, PM10–2.5, and 

ultrafine particles. 

The ISA concludes that health effects 

associated with short-term exposures 

(hours to days) to ambient PM2.5 include 

mortality, cardiovascular effects, such as 

altered vasomotor function and 

myocardial ischemia, and hospital 

admissions and emergency department 

visits for ischemic heart disease and 

congestive heart failure, and respiratory 

effects, such as exacerbation of asthma 

symptoms in children and hospital 

admissions and emergency department 

visits for chronic obstructive pulmonary 

disease and respiratory infections.45 The 

ISA notes that long-term exposure 

(months to years) to PM2.5 is associated 

with the development/progression of 

cardiovascular disease, premature 

mortality, and respiratory effects, 

including reduced lung function growth 

in children, increased respiratory 

symptoms, and asthma development.46

The ISA concludes that the currently 

available scientific evidence from 

epidemiologic, controlled human 

exposure, and toxicological studies 

supports a causal association between 

short- and long-term exposures to PM2.5

and cardiovascular effects and 

premature mortality. Furthermore, the 

ISA concludes that the collective 

evidence supports likely causal 

associations between short- and longterm PM2.5 exposures and respiratory 

effects. The ISA also concludes that the 

scientific evidence is suggestive of a 

causal association for reproductive and 

developmental effects including 

respiratory-related infant mortality and 

cancer, mutagenicity, and genotoxicity 

and long-term exposure to PM2.5.47

For PM10-2.5, the ISA concludes that 

the current evidence is suggestive of a 

causal relationship between short-term 

exposures and premature mortality, 

cardiovascular effects, and respiratory 

effects. Data are inadequate to draw 

conclusions regarding the health effects 

associated with long-term exposure to 

PM10-2.5. 

For ultrafine particles, the ISA 

concludes that there is suggestive 

evidence of a causal relationship 

between short-term exposures and 

cardiovascular effects, such as changes 

in heart rhythm and blood vessel 

function. It also concludes that there is 

suggestive evidence of association 

between short-term exposure to 

ultrafine particles and respiratory 

effects. Data are inadequate to draw 

conclusions regarding the health effects 

associated with long-term exposure to 

ultrafine particles. 

c. What are the health effects of NOX? 

Information on the health effects of 

NO2 can be found in the EPA Integrated 

Science Assessment (ISA) for Nitrogen 

Oxides.48 The EPA has concluded that 

the findings of epidemiologic, 

controlled human exposure, and animal 

toxicological studies provide evidence 

that is sufficient to infer a likely causal 

relationship between respiratory effects 

and short-term NO2 exposure. The ISA 

concludes that the strongest evidence 

for such a relationship comes from 

epidemiologic studies of respiratory 

effects including symptoms, emergency 

department visits, and hospital 

admissions. The ISA also draws two 

broad conclusions regarding airway 

responsiveness following NO2 exposure. 

First, the ISA concludes that NO2

exposure may enhance the sensitivity to 

allergen-induced decrements in lung 

function and increase the allergeninduced airway inflammatory response 

following 30-minute exposures of 

asthmatics to NO2 concentrations as low 

as 0.26 ppm. Second, exposure to NO2

has been found to enhance the inherent 

responsiveness of the airway to 

subsequent nonspecific challenges in 

controlled human exposure studies of 

asthmatic subjects. Small but significant 

increases in non-specific airway 

hyperresponsiveness were reported 

following 1-hour exposures of 

asthmatics to 0.1 ppm NO2. Enhanced 

airway responsiveness could have 

important clinical implications for 

asthmatics since transient increases in 

airway responsiveness following NO2

exposure have the potential to increase 

symptoms and worsen asthma control. 

Together, the epidemiologic and 

experimental data sets form a plausible, 

consistent, and coherent description of 


TKELLEY on DSK3SPTVN1PROD with RULES2
36350 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

49U.S. EPA. (2005). Review of the National 

Ambient Air Quality Standards for Particulate 

Matter: Policy Assessment of Scientific and 

Technical Information, OAQPS Staff Paper. 

Retrieved on April 9, 2009 from http:// 

www.epa.gov/ttn/naaqs/standards/pm/data/ 

pmstaffpaper_20051221.pdf. 

50U.S. EPA. (2004). Air Quality Criteria for 

Particulate Matter (AQCD). Volume I Document No. 

EPA600/P–99/002aF and Volume II Document No. 

EPA600/P–99/002bF. Washington, DC: U.S. 

Environmental Protection Agency. Retrieved on 

March 18, 2009 from http://cfpub.epa.gov/ncea/

cfm/recordisplay.cfm?deid=87903. 

51U.S. EPA (2009). Integrated Science 

Assessment for Particulate Matter (Final Report). 

U.S. Environmental Protection Agency, 

Washington, DC, EPA/600/R–08/139F, 2009. A 

copy of this document is in docket number EPA– 

HQ–OAR–2010–0687. 

52U. S. EPA (2010) Our Nation’s Air: Status and 

Trends through 2008. Office of Air Quality Planning 

and Standards, Research Triangle Park, NC. 

Publication No. EPA 454/R–09–002. This document 

can be accessed electronically at: http://www.epa.

gov/airtrends/2010/. 

53U.S. EPA, 2012. http://www.epa.gov/oar/oaqps/ 

greenbk/index.html 

a relationship between NO2 exposures 

and an array of adverse health effects 

that range from the onset of respiratory 

symptoms to hospital admission. 

Although the weight of evidence 

supporting a causal relationship is 

somewhat less certain than that 

associated with respiratory morbidity, 

NO2 has also been linked to other health 

endpoints. These include all-cause 

(non-accidental) mortality, hospital 

admissions or emergency department 

visits for cardiovascular disease, and 

decrements in lung function growth 

associated with chronic exposure. 

3. Environmental Effects Associated 

With Exposure to Ozone, PM and NOX

a. Deposition of Nitrogen 

Emissions of NOX from aircraft 

engines contribute to atmospheric 

deposition of nitrogen in the U.S. 

Atmospheric deposition of nitrogen 

contributes to acidification, altering 

biogeochemistry and affecting animal 

and plant life in terrestrial and aquatic 

ecosystems across the United States. 

The sensitivity of terrestrial and aquatic 

ecosystems to acidification from 

nitrogen deposition is predominantly 

governed by geology. Prolonged 

exposure to excess nitrogen deposition 

in sensitive areas acidifies lakes, rivers 

and soils. Increased acidity in surface 

waters creates inhospitable conditions 

for biota and affects the abundance and 

nutritional value of preferred prey 

species, threatening biodiversity and 

ecosystem function. Over time, 

acidifying deposition also removes 

essential nutrients from forest soils, 

depleting the capacity of soils to 

neutralize future acid loadings and 

negatively affecting forest sustainability. 

Major effects include a decline in 

sensitive forest tree species, such as red 

spruce (Picea rubens) and sugar maple 

(Acer saccharum); and a loss of 

biodiversity of fishes, zooplankton, and 

macro invertebrates. 

In addition to the role nitrogen 

deposition plays in acidification, 

nitrogen deposition also leads to 

nutrient enrichment and altered 

biogeochemical cycling. In aquatic 

systems increased nitrogen can alter 

species assemblages and cause 

eutrophication. In terrestrial systems 

nitrogen loading can lead to loss of 

nitrogen sensitive lichen species, 

decreased biodiversity of grasslands, 

meadows and other sensitive habitats, 

and increased potential for invasive 

species. 

Adverse impacts on soil chemistry 

and plant life have been observed for 

areas heavily influenced by atmospheric 

deposition of nutrients, metals and acid 

species, resulting in species shifts, loss 

of biodiversity, forest decline damage to 

forest productivity and reductions in 

ecosystem services. Potential impacts 

also include adverse effects to human 

health through ingestion of 

contaminated vegetation or livestock (as 

in the case for dioxin deposition), 

reduction in crop yield, and limited use 

of land due to contamination. 

Atmospheric deposition of pollutants 

can reduce the aesthetic appeal of 

buildings and culturally important 

articles through soiling, and can 

contribute directly (or in conjunction 

with other pollutants) to structural 

damage by means of corrosion or 

erosion.49 Atmospheric deposition may 

affect materials principally by 

promoting and accelerating the 

corrosion of metals, by degrading paints, 

and by deteriorating building materials 

such as concrete and limestone. 

Particles contribute to these effects 

because of their electrolytic, 

hygroscopic, and acidic properties, and 

their ability to adsorb corrosive gases 

(principally sulfur dioxide). 

b. Visibility Effects 

NOX emissions contribute to visibility 

impairment in the U.S. through the 

formation of secondary PM2.5.50

Visibility impairment is caused by light 

scattering and absorption by suspended 

particles and gases. Visibility is 

important because it has direct 

significance to people’s enjoyment of 

daily activities in all parts of the 

country. Individuals value good 

visibility for the well-being it provides 

them directly, where they live and 

work, and in places where they enjoy 

recreational opportunities. Visibility is 

also highly valued in significant natural 

areas, such as national parks and 

wilderness areas, and special emphasis 

is given to protecting visibility in these 

areas. For more information on visibility 

see the final 2009 PM ISA.51

c. Plant and Ecosystem Effects of Ozone 

Elevated ozone levels contribute to 

environmental effects, with impacts to 

plants and ecosystems being of most 

concern. Ozone can produce both acute 

and chronic injury in sensitive species 

depending on the concentration level 

and the duration of the exposure. Ozone 

effects also tend to accumulate over the 

growing season of the plant, so that even 

low concentrations experienced for a 

longer duration have the potential to 

create chronic stress on vegetation. 

Ozone damage to plants includes visible 

injury to leaves and impaired 

photosynthesis, both of which can lead 

to reduced plant growth and 

reproduction, resulting in reduced crop 

yields, forestry production, and use of 

sensitive ornamentals in landscaping. In 

addition, the impairment of 

photosynthesis, the process by which 

the plant makes carbohydrates (its 

source of energy and food), can lead to 

a subsequent reduction in root growth 

and carbohydrate storage below ground, 

resulting in other, more subtle plant and 

ecosystems impacts. These latter 

impacts include increased susceptibility 

of plants to insect attack, disease, harsh 

weather, interspecies competition and 

overall decreased plant vigor. The 

adverse effects of ozone on forest and 

other natural vegetation can potentially 

lead to species shifts and loss from the 

affected ecosystems, resulting in a loss 

or reduction in associated ecosystem 

goods and services. Lastly, visible ozone 

injury to leaves can result in a loss of 

aesthetic value in areas of special scenic 

significance like national parks and 

wilderness areas. The final 2006 Ozone 

Air Quality Criteria Document presents 

more detailed information on ozone 

effects on vegetation and ecosystems. 

4. Impacts on Ambient Air Quality 

The aircraft NOX emission standards 

we are promulgating would affect 

ambient concentrations of air pollutants. 

Nationally, levels of PM2.5, ozone, and 

NOX are declining.52 However as of 

March 30, 2012, over 15 million people 

live in areas designated nonattainment 

for one or more of the current NAAQS.53

These numbers do not include the 

people living in areas where there is a 

future risk of failing to maintain or 

attain the NAAQS. 

States with ozone nonattainment 

areas are required to take action to bring 


TKELLEY on DSK3SPTVN1PROD with RULES2
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36351 

54The Los Angeles South Coast Air Basin 8-hour 

ozone nonattainment area and the San Joaquin 

Valley Air Basin 8-hour ozone nonattainment area 

are designated as extreme and will have to attain 

before June 15, 2024. The Sacramento, Coachella 

Valley and Houston 8-hour ozone nonattainment 

areas are designated as severe and will have to 

attain by June 15, 2019. In addition, the Western 

Mojave 8-hour ozone nonattainment area has 

requested to be reclassified as severe. This request 

has not yet been acted on. 

55U.S. EPA, 2012. Proposed Rule— 

Implementation of the 2008 National Ambient Air 

Quality Standards for Ozone: Nonattainment Area 

Classifications Approach, Attainment Deadlines 

and Revocation of the 1997 Ozone Standards for 

Transportation Conformity Purposes. (77 FR 8107, 

February 14, 2012). 

56U.S. EPA (2010). Regulatory Impact Analysis: 

Final Rulemaking To Establish Greenhouse Gas 

Emission Standards and Fuel Efficiency Standards 

for Medium- and Heavy-Duty Engines and Vehicles. 

Chapter 8: Health and Environmental Impacts. EPA 

420–R–11–901. 

57U.S. EPA (2010). Regulatory Impact Analysis: 

Final Rulemaking To Establish Greenhouse Gas 

Emission Standards and Fuel Efficiency Standards 

for Medium- and Heavy-Duty Engines and Vehicles. 

Chapter 8: Health and Environmental Impacts. EPA 

420–R–11–901. 

58These figures are based on the results of EPA 

computer modeling, which is not affected by the 

upcoming 2008 ozone NAAQS nonattainment 

designations. 

59U.S. Environmental Protection Agency, 

‘‘Summary and Analysis of Comments: Control of 

Air Pollution From Aircraft and Aircraft Engines,’’ 

Office of Transportation and Air Quality, EPA–420– 

R–12–011, May 2012. A copy of this document is 

in docket number EPA–HQ–OAR–2010–0687. 

60The standards will apply to engines used in 

commercial and noncommercial aviation for which 

the FAA issues airworthiness certificates, e.g., nonrevenue, general aviation service. The vast majority 

of these engines are used in commercial 

applications. 

61 ICAO standards describe newly-certified 

engines as ‘‘* * * engines of a type or model for 

which the date of manufacture of the first 

individual production model was after. * * *’’ the 

effective date of the emission standards. See ICAO, 

‘‘Aircraft Engine Emissions,’’ Annex 16, Volume II, 

Third Edition, July 2008, Amendment 4 effective on 

July 20, 2008. Copies of this document can be 

obtained from the ICAO Web site at www.icao.int. 

The term ‘‘first individual production model’’ 

means the first engine ever produced of a unique 

model or type. 

62The standards for newly-manufactured engines 

are described in general regulatory terms as the date 

that the type or model was first certified and 

produced in conformance with specific emission 

standards, and the date beyond which an 

individual engine meeting those same requirements 

cannot be made. So ICAO standards describe 

newly-manufactured engines as ‘‘* * * engines of 

a type or model for which the date of manufacture 

of the first individual production model was after. 

* * *’’ the effective date of the applicable 

standards, and ‘‘* * * for which the date of 

manufacture of the individual engine was on or 

before. * * *’’ a specific date that is later than the 

first effective date of the standards. See ICAO, 

‘‘Aircraft Engine Emissions,’’ Annex 16, Volume II, 

Third Edition, July 2008, Amendment 4 effective on 

July 20, 2008. Copies of this document can be 

obtained from the ICAO Web site at www.icao.int. 

63These apply only to the first tier of NOX

standards. We are not adopting a production cutoff 

for the second tier of standards. 

those areas into attainment. The 

attainment date assigned to an ozone 

nonattainment area is based on the 

area’s classification. Most ozone 

nonattainment areas are required to 

attain the 1997 8-hour ozone NAAQS in 

the 2007 to 2013 time frame and then to 

maintain it thereafter.54 We anticipate 

designating areas for the 2008 ozone 

standards in late spring 2012; thus, the 

attainment dates for areas designated 

nonattainment for the 2008 8-hour 

ozone NAAQS would likely be in the 

2015 to 2032 timeframe, depending on 

the severity of the problem in each 

area.55

Areas designated as not attaining the 

1997 PM2.5 NAAQS will need to attain 

the 1997 standards in the 2010 to 2015 

time frame, and then maintain 

compliance with them thereafter. The 

2006 24-hour PM2.5 nonattainment areas 

will be required to attain the 2006 24- 

hour PM2.5 NAAQS in the 2014 to 2019 

time frame and then be required to 

maintain the 2006 24-hour PM2.5

NAAQS thereafter. 

EPA has already adopted many 

emission control programs that are 

expected to reduce ambient ozone and 

PM2.5 levels and which will assist in 

reducing the number of areas that fail to 

achieve the NAAQS. Even so, our air 

quality modeling projects that in 2030 

as many as 10 counties with a 

population of over 30 million may not 

attain the 2008 ozone standard of 0.075 

ppm (75 ppb) without additional 

controls.56 In addition, our air quality 

modeling projects that in 2030 at least 

four counties with a population of 

nearly 7 million may not attain the 1997 

annual PM2.5 standard of 15 mg/m3 and 

22 counties with a population of over 33 

million may not attain the 2006 24-hour 

PM2.5 standard of 35 mg/m3 without 

additional controls.57 58 These numbers 

do not account for those areas that are 

close to (e.g., within 10 percent of) the 

standards. These areas, although not 

violating the standards, would also 

benefit from any reductions in NOX

ensuring long-term maintenance of the 

NAAQS. 

In summary, the aircraft NOX

reductions resulting from these new 

aircraft engine emission standards will 

be useful to states in attaining or 

maintaining the ozone, PM2.5, and NO2

NAAQS standards. 

IV. Details of the Final Rule 

The following is a description of the 

regulations being adopted in this final 

rule, with any changes from the 

proposal also noted. The descriptions 

also include our response to the most 

significant comments received on the 

proposal. A full summary of the 

comments and our responses are 

contained in the response to comments 

document for the rule that is available 

in the public docket for this action.59

We are establishing two different 

levels or ‘‘tiers’’ of increasingly more 

stringent NOX emission standards for 

gas turbofan engines with maximum 

rated thrusts greater than 26.7 

kilonewtons (kN).60 Each of the tiers 

apply to newly-certified engines. 

Newly-certified aircraft engines are 

those that would receive a new type 

certificate after the effective date of the 

applicable standards. Such engine types 

or models would not have begun 

production prior to the effective date of 

the new requirement.61

We are also requiring newlymanufactured engines to comply with 

the first tier of the two tiers of 

standards. Newly-manufactured aircraft 

engines are those that have been 

previously certified and manufactured 

in compliance with preexisting 

standards, and will continue to be 

produced after the effective date of a 

new applicable standard. Normally, 

these newly-manufactured engines must 

comply with the same NOX limits as 

newly-certified engines, but at a later 

date or cease production.62 The end of 

this ‘‘phase-in’’ period for the newlymanufactured engine standards is 

sometimes referred to as a ‘‘production 

cutoff.’’. Again, we are adopting only 

the first of the two new tiers of NOX

standards for newly-manufactured 

engines. These provisions are described 

in detail below. 

Five other regulatory features are 

being established in this final rule. First, 

we are revising provisions for certain 

time-limited flexibilities, i.e., potential 

exemptions, for newly-manufactured 

engines that may not be able to comply 

with the first tier of the new NOX

standards because of specific technical 

or economic reasons.63 Second, we are 

defining ‘‘derivative engine’’ for 

emissions certification purposes. The 

intent of this definition is to distinguish 

when the emission characteristics of a 

new turbofan engine model vary 

substantially from its existing parent 

engine design, and must show 

compliance with the emission standards 

for a newly-certificated engine. Third, 

we are establishing new CO and NOX

standards for turbofan engines that are 

used to propel supersonic aircraft. 

These standards were adopted by ICAO 

in the 1980s, but were not previously 

added to our HC emission standard for 

these engines. Promulgating these 

standards meets our treaty obligation 

under the Convention on International 

Civil Aviation as previously described 


TKELLEY on DSK3SPTVN1PROD with RULES2
36352 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

64There are no gaseous emission standards, e.g., 

NOX, for gas turbine engines with maximum rated 

thrusts equal to or less than 26.7 kN. These engines 

are, however, subject to smoke and fuel venting 

standards. 

65The combustor is a chamber where a mixture 

of fuel and air is burned to form very hot, 

expanding gases. As these gases move through the 

combustion chamber, the walls of the combustor are 

cooled with dilution air to prevent thermal damage. 

Dilution air is also used to tailor the gas’ 

temperature profile as it exits the combustor so that 

the final temperatures will not exceed the allowable 

limit at the turbine inlet. 

in section I.C. Fourth, we are making 

several changes to the emission testing 

and measurement procedures in our 

regulations that are intended to 

implement ICAO’s Annex 16 and to 

incorporate the entire annex in our 

regulations by reference. Finally, as 

described in section IV, we are 

amending the current regulatory 

provisions that address definitions, 

acronyms and abbreviations, general 

applicability and requirements, 

exemptions, and incorporation by 

reference. These amendments are 

intended to clarify requirements, make 

them more consistent with other parts of 

the program, update the text to be 

consistent with current standard 

language conventions, or remove 

obsolete provisions. 

As discussed further below, with the 

exception of the annual reporting 

requirement described in section III.D, 

the amendments reflect those changes 

that were previously adopted by ICAO. 

This final rule also is consistent with 

our authority and obligations under the 

CAA as described in section I.B. More 

specifically, the technical feasibility and 

cost of the emission standards were well 

documented by our own analyses and 

CAEP as described later in this section 

and in section V, Technical Feasibility, 

Costs, and Emission Benefits. We think 

that the final rule provides adequate 

lead time for the development and 

application of the requisite technology 

with appropriate consideration to the 

cost of compliance. We have consulted 

with the Department of Transportation 

through the FAA regarding lead time, 

noise, safety, and the technical 

feasibility of the new standards. Today’s 

final rule is also consistent with U.S. 

treaty obligations under the Chicago 

Convention as described in section I.C., 

because the requirements are consistent 

with current ICAO standards. 

Except to the extent needed to make 

our standards conform to ICAO’s 

standards by making them applicable to 

both commercial and non-commercial 

engines, we are not revising exhaust 

emission standards for HC, CO, or 

smoke. All engines subject to the new 

NOX standards would also continue to 

be subject to the existing HC, CO, and 

smoke standards. It is worth 

emphasizing that although we are 

including these existing HC, CO, and 

smoke standards in a new section 87.23, 

which would also contain the new Tier 

6 and Tier 8 NOX standards, we are not 

actually adopting new standards for 

these three pollutants, since under the 

current form of part 87 these HC, CO 

and smoke standards would already 

continue to apply to new engine types 

subject to future revised NOX standards. 

As discussed above, we are adopting 

a new naming convention in this 

preamble and the regulatory text to 

more easily distinguish between the 

tiers of increasingly more stringent NOX

emission standards. This convention is 

also consistent with the numeric 

identifier that CAEP uses to differentiate 

the CAEP work cycle that produces new 

NOX standards. (The CAEP naming 

convention is described in section I.E.) 

As a result, the first tier of NOX

standards, which correspond to CAEP/ 

6, are referred to as Tier 6 in the 

remainder of today’s notice. The second 

tier of standards is referred to as Tier 8, 

which correspond to CAEP/8. We are 

also incorporating the new naming 

convention in the regulations for the 

existing NOX emission standards, i.e., 

Tier 0, Tier 2, and Tier 4. There is no 

material change to the existing NOX

standards themselves, except to the 

extent that when today’s final rule 

becomes effective, the existing NOX

standards would be superseded by Tier 

6 standards. 

We acknowledge that this new 

naming convention is a change from the 

past practice of not describing aircraft 

engine emission standards as tiers. 

However, we believe the new naming 

scheme is a valuable tool that makes 

referring to individual NOX standards 

much easier. It is also similar to the 

terminology we use for other mobile 

source sectors that are subject to 

environmental regulation and for which 

standards have become more stringent 

or have otherwise been amended over 

time. 

A. NOX Standards for Newly-Certified 

Engines 

We are adopting two different tiers of 

increasingly stringent NOX standards. 

These standards would apply for all for 

newly-certified turbofan aircraft engines 

with maximum rated thrusts greater 

than 26.7 kN.64 (See section III.B for a 

discussion of how these standards apply 

for newly-manufactured engines that are 

not considered to be newly certified.) 

The numerical value of the applicable 

standard for an individual engine model 

is defined by the engine’s thrust level 

and pressure ratio. Simply stated, the 

pressure ratio is the numerical ratio of 

the air pressure entering the engine to 

the air pressure at the entrance to the 

combustor, i.e., after the air has passed 

through the compressor section of the 

engine.65 The new tiers are described 

separately below. 

1. Tier 6 NOX Standards for NewlyCertified Engines 

This first tier of new standards is 

equivalent to the CAEP/6 NOX limits 

that were adopted by ICAO and became 

internationally applicable after 

December 31, 2007. Given that aircraft 

turbofan engines are international 

commodities, engine manufacturers 

introduced engine models after that date 

that demonstrate compliance with these 

international standards, or are already 

planning to do so for upcoming engine 

designs. Based on this, our evaluation of 

the necessary lead time, and the lack of 

any comments on this aspect of the 

proposal, this tier of standards takes 

effect immediately upon the effective 

date of this final rule. 

The basic form of the NOX standards 

for turbofan engines is different for 

higher- and lower-rated thrust engines. 

Higher output engines are defined as 

having rated thrusts equal to or greater 

than 89 kN, while lower output engines 

are defined as having rated thrusts less 

than 89 kN but greater than 26.7 kN. 

The new Tier 6 NOX standards for each 

of these power groupings are described 

separately below. 

a. Numerical Emission Limits for Higher 

Thrust Engines 

The Tier 6 NOX standards for newlycertified gas turbine engines with rated 

thrusts more than 89 kN are 

differentiated by pressure ratio as 

shown below. 

• For engines with a pressure ratio of 

30 or less: 

g/kN rated output = 16.72 + (1.4080 * 

engine pressure ratio) 

• For engines with a pressure ratio of 

more than 30 but less than 82.6: 

g/kN rated output = ¥1.04 + (2.0 * 

engine pressure ratio) 

• For engines with a pressure ratio of 

82.6 or more: 

g/kN rated output = 32 + (1.6 * engine 

pressure ratio) 

The new Tier 6 NOX standards for 

these higher thrust engines are 

presented in Figure 1 along with the 

previous EPA NOX standards, which 

were based on CAEP/4, for comparison. 


TKELLEY on DSK3SPTVN1PROD with RULES2
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36353 

66 ICAO/CAEP, ‘‘Report of Third Meeting, 

Montreal, Quebec, December 5–15, 1995,’’ 

Document 9675, CAEP/3. A copy of this paper can 

be found in Docket EPA–HQ–OAR–2010–0687. 

67 ICAO, ‘‘Combined Report of the Certification 

and Technology Subgroups,’’ section 2.3.6.1, CAEP 

Working Group 3 (Emissions). Presented by the 

Chairman of the Technology Subgroup, Third 

Meeting, Bonn, Germany, June 1995. A copy of this 

paper can be found in Docket EPA–HQ–OAR–2010– 

0687. 

As a matter of convention, the relative 

stringency from one CAEP standard to 

another is expressed relative to a 

pressure ratio of 30, because the 

percentage reduction is usually 

inconsistent across all of the possible 

pressure ratios, which otherwise makes 

a simple comparison difficult. Using 

that convention, the Tier 6 standards 

(CAEP/6) are referred to as being 12 

percent more stringent than the existing 

EPA NOX Tier 4 standards (CAEP/4). 

The relative stringency can also be 

illustrated at other pressure ratios. At 

pressure ratios less than 30 the 

reductions are also 12 percent. At 

pressure ratios above 30, however, the 

percent reduction decreases as the 

pressure ratio is increased. Based on the 

figure, the percent reduction for current 

technology engines ranges from about 8 

to 12 percent. 

b. Numerical Emission Limits for Lower 

Thrust Engines 

The new Tier 6 NOX standards for 

newly-certified gas turbine engines with 

rated thrusts between 26.7 and equal to 

or less than 89.0 kN are differentiated by 

both pressure ratio and rated thrust as 

shown below. 

• For engines with a pressure ratio of 

30 or less: 

g/kN rated output = 38.5486 + (1.6823 

* engine pressure ratio) ¥ (0.2453 

* kN rated thrust) ¥ (0.00308 * 

engine pressure ratio * kN rated 

thrust) 

• For engines with a pressure ratio of 

more than 30 but less than 82.6: 

g/kN rated output = 46.1600 + (1.4286 

* engine pressure ratio) ¥ (0.5303 

* kN rated thrust) + (0.00642 * 

engine pressure ratio * kN rated 

thrust) 

In developing the corresponding NOX

standards for lower thrust engines, 

CAEP recognized the technical 

challenges that physically smaller-sized 

engines sometimes present relative to 

incorporating some of the lowest NOX

technology approaches, which are 

otherwise available to their larger 

counterparts. These technical 

difficulties are well documented and 

increase progressively as size is reduced 

(from around 89 kN).66 For example, the 

relatively small combustor space and 

section height of these engines creates 

constraints on the use of low NOX fuelstaged combustor concepts which 

inherently require the availability of 

greater flow path cross-sectional area 

than conventional combustors. Also, 

fuel-staged combustors need more fuel 

injectors, and this need is not 

compatible with the relatively smaller 

total fuel flows of lower thrust engines. 

(Reductions in fuel flow per nozzle are 

difficult to attain without having 

clogging problems due to the small sizes 

of the fuel metering ports.) In addition, 

lower thrust engine combustors have an 

inherently greater liner surface-tocombustion volume ratio, and this 

requires increased wall cooling air flow. 

Thus, less air will be available to obtain 

acceptable turbine inlet temperature 

distribution and for emissions control.67

With these technological constraints in 

mind, CAEP fashioned the CAEP/6 NOX

standards across the range of thrusts 

represented by low-thrust engines to 

become comparatively less stringent, 

i.e., CAEP/6 relative to CAEP/4, as the 

rated output and physical size of the 

engines decrease. We agree with this 

approach. 

As mentioned, the new Tier 6 

standards depend on an individual 

engine’s rated thrust and pressure ratio. 

With two variables in the calculation, 

the standards cannot be represented in 

a simple figure, i.e., no single line graph 

showing the standards for all engines 

within the thrust range is possible as it 

was for higher thrust engines. 

Regardless of this complexity, however, 

some general observations are useful to 

characterize the Tier 6 NOX standards 

for lower thrust engines based on the 

engine size versus technological 

challenge described in the previous 

paragraph. 

Comparing the new lower and higher 

thrust standards at 89 kN, which is the 

demarcation point between the two sets 

of standards, shows that the standards 

for lower thrust engines are numerically 

equivalent to the limit for higher thrust 


TKELLEY on DSK3SPTVN1PROD with RULES2ER18JN12.000</GPH>
36354 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

engines at each pressure ratio. This is as 

expected because the engine sizes and 

ability to incorporate low-NOX

technologies are the same at 89.0 kN 

delineation point. 

Again focusing only on 89 kN 

engines, the new Tier 6 standards 

represent a 12 percent reduction from 

the existing EPA Tier 4 (CAEP/4 based 

standards) for pressure ratios of 30 or 

less as shown below in Figure 2. This 

includes the region represented by 

almost all current engine designs. At 

higher pressure ratios, the relative 

numerical reduction is progressively 

less because the slope of the two 

standards is essentially the same. 

At other thrust ratings the percent 

reduction between the new Tier 6 and 

existing EPA NOX standards at any 

pressure ratio becomes progressively 

smaller as thrust decreases. This is 

illustrated in Figure 3 for a pressure 

ratio of 30. This pressure ratio was 

chosen for the example because, as 

before, the relative stringency of CAEP 

NOX standards is generally compared at 

this point as a matter of convention. As 

shown in the figure for current engines, 

the reduction ranges from 12 percent at 

the upper end of the thrust range to 0 

percent at the lower end of the range. 

The pattern is similar for the other 

pressure ratios. Only the actual 

numerical value for percentage 

reduction at 89 kN, as shown on the far 

right of the figure, may vary by pressure 

ratio, as described at the beginning of 

this paragraph. However, in the region 

of pressure ratios represented by today’s 

engines, the results are identical to 

those shown in the figure, i.e., a 12 

percent reduction at 89 kN decreasing to 

0 percent at 26.7 kN. 


TKELLEY on DSK3SPTVN1PROD with RULES2ER18JN12.001</GPH>
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36355 

68CAEP/7 did not adopt new aircraft engine NOX

standards. 

69Leadtime in this context refers to the time 

between CAEP adoption of a new emission standard 

and the effective date of the requirement. ICAO 

emission standards are global in nature and 

designed to provide engine manufacturers with 

adequate time to develop and deploy the requisite 

technology. Manufacturers produce engines that 

comply with new ICAO standards to ensure their 

products can be sold and used worldwide even in 

the absence of specific U.S. regulations. Based on 

this response to the ICAO standard, we find that 

there is also adequate leadtime between EPA’s 

promulgation of the new requirement and the 

associated effective date. No public comments 

pertaining to leadtime were received. 

2. Tier 8 NOX Standards for NewlyCertified Engines 

The second tier of new standards, i.e., 

Tier 8, are equivalent to the NOX limits 

that were most recently recommended 

at CAEP/8 in February 2010 for 

adoption by ICAO.68 The CAEP/8 

recommended standards have a 

recommended applicable date after 

December 31, 2013. As discussed 

further in section V of today’s notice, we 

agree with CAEP that this provides 

engine manufacturers with adequate 

lead time to respond to these more 

stringent NOX standards considering the 

technical feasibility and cost associated 

with the requirements.69 Therefore, this 

tier of standards takes effect on January 

1, 2014. As with the new Tier 6 NOX

standards, the basic form of the new 

Tier 8 standards for turbofan engines is 

different for higher- and lower-rated 

thrust engines. Higher output engines 

are defined as having rated thrusts equal 

to or greater than 89 kN, while lower 

output engines are defined as having 

rated thrusts less than 89 kN but greater 

than 26.7 kN. The longer-term standards 

for each of these power grouping are 

described separately below. 

a. Numerical Emission Limits for Higher 

Thrust Engines 

The new Tier 8 NOX standards for 

newly-certified turbofan engines with 

rated thrusts of 89 N or more are 

differentiated by pressure ratio as 

shown below. 

• For engines with a pressure ratio of 

30 or less: 

g/kN rated output = 7.88 + (1.4080 * 

engine pressure ratio) 

• For engines with a pressure ratio of 

more than 30 but less than 104.7: 

g/kN rated output = ¥9.88 + (2.0 * 

engine pressure ratio) 

• For engines with a pressure ratio of 

104.7 or more: 

g/kN rated output = 32 + (1.6 * engine 

pressure ratio) 

The new Tier 8 NOX standards for 

these higher thrust engines are 

presented in Figure 4 along with the 

new Tier 6 standards for comparison. 


TKELLEY on DSK3SPTVN1PROD with RULES2ER18JN12.002</GPH>
36356 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

As noted previously, as a matter of 

convention the relative stringency from 

one CAEP standard to another is 

generally expressed relative to a 

pressure ratio of 30. Using that 

convention, the new Tier 8 standards 

(CAEP/8) are referred to as being 15 

percent more stringent than the new 

Tier 6 NOX standards (CAEP/6). The 

relative stringency can also be 

illustrated at other pressure ratios. At 

pressure ratios less than 30 the 

reductions increase. At pressure ratios 

above 30, however, the percent 

reduction decreases. Based on the 

figure, the percent reduction for current 

engine designs range from about 11 to 

19 percent. 

b. Numerical Emission Limits for Lower 

Thrust Engines 

The new Tier 8 NOX standards for 

newly-certified gas turbine engines with 

rated thrusts between 26.7 but less than 

or equal to 89.0 kN are differentiated by 

both pressure ratio and rated thrust as 

shown below. 

• For engines with a pressure ratio of 

30 or less: 

g/kN rated output = 40.052 + (1.5681 * 

engine pressure ratio) ¥ (0.3615 * 

kN rated thrust) ¥ (0.0018 * engine 

pressure ratio * kN rated thrust) 

• For engines with a pressure ratio of 

more than 30 but less than 104.7: 

g/kN rated output = 41.9435 + (1.505 * 

engine pressure ratio) ¥ (0.55823 * 

kN rated thrust) + (0.005562 * 

engine pressure ratio * kN rated 

thrust) 

In developing the corresponding 

CAEP/8 NOX standards for low thrust 

engines, CAEP recognized the technical 

challenges that physically smaller-sized 

engines represent relative to 

incorporating some of the lowest NOX

technology, which is otherwise 

available to their larger counterparts. 

These technical difficulties were 

described in the previous section for the 

Tier 6 low-thrust engine standards. 

Also as previously described, no 

single line graph showing the standards 

for all engines within the thrust range is 

possible as it was for higher thrust 

engines, because the equations have two 

variables. However, some general 

observations are useful to characterize 

the new Tier 8 NOX standards for lower 

thrust engines based on the engine size 

versus technological challenge 

described in the previous paragraph. 

First, the new Tier 8 NOX standards for 

lower thrust engines are numerically 

equivalent to the limit for higher thrust 

engines across all pressure ratios at the 

highest rating of 89 kN, where the 

engine sizes and ability to incorporated 

low-NOX technologies are comparable. 

This same characteristic was observed 

for the Tier 6 standards. Second, as 

shown below in Figure 5 for 89 kN 

engines, at this thrust rating the new 

Tier 8 standards represents a 15 percent 

reduction from the Tier 6 standards for 

a pressure ratio of 30. However, within 

the region of pressure ratios for all 

current engine designs, the reductions 

range from 19 to 23 percent. 


TKELLEY on DSK3SPTVN1PROD with RULES2ER18JN12.003</GPH>
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36357 

Third, at other thrust ratings the 

percent reduction between the new Tier 

6 and Tier 8 standards at any pressure 

ratio becomes progressively smaller as 

thrust decreases. This is illustrated in 

Figure 6 for a pressure ratio of 30, 

following the convention described 

above. Also as shown in the figure for 

current engines, the reduction ranges 

from 15 percent at the upper end of the 

thrust range to 5 percent at the lower 

end of the range. While not depicted in 

a figure, the pattern is similar for the 

other pressure ratios. However, the 

actual numerical values for percentage 

reductions at both ends of the thrust 

range, i.e., 26.7 to 89 kN, may vary by 

pressure ratio. In the region of pressure 

ratios represented by today’s engines, 

the results are identical to those shown 

in Figure 6 at 26.7 kN, i.e., a 5 percent 

reduction at all pressure ratios for that 

thrust rating. However, percent 

reductions increase linearly up to a 

maximum 23 percent reduction for 89 

kN engines with pressure ratios of about 

15. 


TKELLEY on DSK3SPTVN1PROD with RULES2ER18JN12.004</GPH> ER18JN12.005</GPH>
36358 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

70The requirement that newly-manufactured 

engines must meet the CAEP 6 NOX standard by a 

date certain applies only to engines that are 

intended to be installed on all new airframes. It 

would not apply to engines produced as ‘‘spares,’’ 

which are intended to be installed on existing 

airframes as replacements for maintenance or other 

reasons. See section III.B.2 for more information 

about new and spare engines. 

71After this date the production of any 

noncompliant engines would cease because the 

FAA would discontinue issuing an airworthiness 

approval tag (FAA Form 8130–3) to these engines. 

72 ICAO, Committee on Aviation Environmental 

Protection (CAEP), Eight Meeting, Montreal, 1 to 12 

February 2010, Agenda 2: Review of Technical 

Proposals Relating to Aircraft Engine Emissions, 

Adoption of Production Cutoff for Emission 

Standards, WP/56, Presented by the United States, 

December 12, 2009. A copy of this document is in 

docket number EPA–HQ–OAR–2010–0687. 

73The regulatory text specifies that engine models 

certified at or below the Tier 4 NOX standards may 

be produced through December 31, 2012 without 

meeting the Tier 6 NOX standards. Therefore, the 

effective date of the standards for newlymanufactured engines is effectively January 1, 2013. 

74 ICAO, Committee on Aviation Environmental 

Protection (CAEP), Steering Group Meeting, 

Salvador, Brazil, 22 to 26 June 2009, Agenda 6: 

Emissions Technical-WG3, Production Cutoffs and 

Associated Flexibilities for ICAO Engine Emission 

Standards, WP/39, Presented by U.S. 

Representative, August 6, 2009. A copy of this 

document is in docket number EPA–HQ–OAR– 

2010–0687. 

75 ICAO, Committee on Aviation Environmental 

Protection (CAEP), Steering Group Meeting, 

Salvador, Brazil, 22 to 26 June 2009, Agenda Item 

3: Forecasting and Economic Analysis Support 

Group (FESG), CAEP/6 NOX Production Cutoff Cost 

Analysis, WP/39, Presented by the FESG NOX

Stringency Task Group, February 6, 2009. A copy 

of this document is in docket number EPA–HQ– 

OAR–2010–0687. 

76 ICAO, Committee on Aviation Environmental 

Protection (CAEP), Steering Group Meeting, Seattle, 

22 to 26 September 2008, Agenda Item 3: 

Forecasting and Economic Analysis Support Group 

(FESG), Production Cutoff for NOX Standards, WP/ 

6, Presented by the FESG Rapporteurs, April 9, 

2008. A copy of this document is in docket number 

EPA–HQ–OAR–2010–0687. 

77The ICAO CAEP/6 NOX standards became 

effective after December 31, 2007. 

78This period of time is also consistent with the 

phase-in period associated with previous ICAO 

standards. CAEP’s predecessor, the Committee on 

Aircraft Engines Emissions, established the first 

international emission standards with an effective 

date four years after adoption, i.e., effectively a four 

year phase-in. CAEP2 included a phase-in period of 

4 years for newly-manufactured engines. 

B. Application of the Tier 6 NOX

Standards to Newly-Manufactured 

Engines 

This section describes the application 

of the new Tier 6 NOX standards to 

newly-manufactured engines, and our 

amended temporary flexibilities for 

newly-manufactured engines that show 

significant problems complying with 

these requirements. Also, consistent 

with CAEP/8, we are not applying the 

new Tier 8 NOX standards to newlymanufactured engines at this time. This 

section concludes with a description of 

future efforts to examine such a 

possibility. 

1. Phase-In of the Tier 6 NOX Standards 

for Newly-Manufactured Engines 

As described above, the new Tier 6 

NOX standards apply to all engine types 

or models that receive a new type 

certificate after the effective date of the 

final rule. We are also phasing in these 

same NOX limits for newlymanufactured engines for engine models 

(and their derivatives for emissions 

certification purposes) that were 

originally certified to less stringent 

requirements (i.e., Tier 2 or Tier 4) and 

were already being produced for 

installation on new aircraft prior to the 

effective date of the final rule.70 As a 

result, manufacturers need to bring 

newly-manufactured engines of these 

previously certified models into 

compliance with the applicable Tier 6 

standards by a future date or cease 

production of those engine models.71 As 

we discussed and described in our 

analysis of the need for a CAEP/6 

production cutoff during the CAEP 

process, establishing a date certain for 

compliance with any emission standard 

is necessary to ensure that the full 

benefits of newer, more stringent 

requirements will be achieved in a 

reasonable time.72 We are, however, 

adopting certain limited flexibilities for 

engines that cannot be made compliant 

because of specific technical or 

economic reasons, as discussed later in 

this section. 

As described in the proposal, the 

effective date of January 1, 2013 73 for 

the newly-manufactured engine 

standards is consistent with the 

expected market demand for these 

previously certified engine types. 

Historically, engine manufacturers have 

often responded to the adoption of more 

stringent NOX standards by bringing 

older engine types into compliance with 

the newer requirements well before the 

required date in anticipation of the 

likely market demand, or planning for 

the orderly withdrawal of these engines 

from the marketplace. Information 

developed during the ICAO process in 

2008 and 2009 74 75 76 and our more 

recent discussions with manufacturers 

indicate that: (1) All but a few models 

are already compliant with CAEP/6 

standards, (2) nearly without exception, 

all current production models will meet 

the CAEP/6 requirements by the 2012 

time frame, and (3) any noncompliant 

models will be phased out of production 

because of low market demand. 

We think that the five-year phase-in 

period from ICAO’s effective date of the 

CAEP/6 standards (corresponding to our 

new Tier 6 NOX standards) for newlymanufactured engines is adequate for 

manufacturers and their customers to 

respond to the new requirements 

without disrupting their future planning 

and purchasing decisions.77 78 This 

phase-in period for applying the Tier 6 

NOX standards to newly-manufactured 

engines is also identical to the date for 

this same requirement that was adopted 

by ICAO. No comments were received 

expressing concern with this phase-in 

period for newly-manufactured engines. 

We did, however, receive two 

comments expressing the view that the 

time between the date of our final rule 

and the January 1, 2013 effective date of 

the production cutoff would be too short 

if it is less than one year. General 

Electric Aviation (GE) was the most 

detailed and began by noting that most 

of the engine models currently in 

production were certified to the Tier 4 

standards and had demonstrated NOX

emissions below the Tier 6 at that time. 

They continued that if the original 

certification reports are sufficient for the 

FAA to formally certify these engines to 

the Tier 6 standards, then none of these 

engines would be adversely affected by 

the production cutoff. However, GE 

expressed the concern that if additional 

interactions or formal action by the FAA 

were needed, or revisions to the FAA’s 

FAR Part 34 were required, then having 

less than one year between EPA’s final 

rule and the production cutoff could 

disrupt current engine production. As a 

result, GE asked that the date of the 

production cutoff be delayed to take 

effect 12 months after the final rule, i.e., 

2013. The other joint comment from the 

Aerospace Industries Association (AIA) 

and the General Aviation Manufacturers 

Association (GAMA) was similar in 

nature, but without supporting details. 

The commenters’ concerns do not 

relate to the technical or economic 

feasibility of newly-manufactured 

engines achieving emission levels in 

compliance with the new Tier 6 

standards by the date of the production 

cutoff as proposed. The concerns 

expressed do not argue that additional 

time is necessary ‘‘to permit the 

development and application of the 

requisite technology’’ to comply with 

the standards under CAA section 231(b). 

Therefore, the date of the Tier 6 

production cutoff is appropriate and 

consistent with the Clean Air Act. 

Section 232(b) of the Act directly 

addresses our obligation relative to the 

effective date of the regulation. 

Specifically, it says: ‘‘Any regulation 

prescribed under this section (and any 

revision thereof) shall take effect after 

such period as the Administrator finds 

necessary (after consultation with the 


TKELLEY on DSK3SPTVN1PROD with RULES2
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36359 

79 ICAO, ‘‘Committee on Aviation Environmental 

Protection (CAEP), Report of the Eighth Meeting, 

Montreal, February 1–12, 2010,’’ CAEP/8–WP/80. A 

copy of this document is in docket number EPA– 

HQ–OAR–2010–0687. 

80Note that EPA has submitted a paper to amend 

the exemption provisions included in this ETM to 

be consistent with this rule. See ICAO, ‘‘Newly 

Produced Engine Exemptions for CAEP/6 NOX

Production Cutoff,’’ CAEP9_WG3–CTG–2_IP01, 

September 23, 2010. A copy of this document is in 

docket number EPA–HQ–OAR–2010–0687. 

Secretary of Transportation) to permit 

the development and application of the 

requisite technology, giving appropriate 

consideration to the cost of compliance 

within such period.’’ Based on the 

information provided above, the aircraft 

engine models described by GE are 

already capable of complying with the 

EPA Tier 6 NOX standards using already 

applied requisite technology, i.e., the 

cost of applying with has already been 

borne, as the effective date of the 

corresponding ICAO CAEP/6 NOX

standard has already passed. We do not 

believe there are any technical 

feasibility or economic implications 

arising from the continued application 

of the requisite technology for those 

engines to meet the Tier 6 NOX

standards. Also, consistent with our 

most recent previous amendment to the 

NOX standards, which similarly 

promulgated the standard at a level that 

was already being met by aircraft engine 

manufacturers who were already 

applying the requisite technology, the 

effective date does not need to include 

additional lead time for the 

development and application of 

additional technology that would be 

needed to comply with the standards. 

See, e.g., 70 FR 69604, 69674–76 (Nov. 

17, 2005). As a result, the 

implementation dates provide more 

than adequate lead time under the 

statute. Therefore, because aircraft 

engine manufacturers are already able to 

comply with the Tier 6 NOX standard 

through the continued use of already 

applied requisite technology, and 

because the effective date of the 

corresponding ICAO CAEP/6 NOX

standard has already passed (and also 

based on the assessment described in 

section V. Technical Feasibility, Cost, 

and Emission Benefits), we find that the 

dates provide more than adequate lead 

time under the statute for application of 

requisite technology. 

We also want to stress that the 

production cutoff is actually an ICAO 

standard and we think it is important to 

stay aligned with the CAEP production 

cutoff date. We note that this is also 

being adopted by the European Aviation 

Safety Agency (EASA) and perhaps 

other aviation certification authorities. 

Our adoption of the proposed date 

insures international consistency 

regarding the production cutoff date and 

avoids contradicting our international 

bilateral agreements with other 

governments, e.g., the European Union. 

Regarding the need for engine models 

to be formally recognized by the FAA as 

complying with the new Tier 6 

standard, this is completely within the 

purview of the FAA. In our previous 

most recent amendment to the NOX

standard, we provided just a one-month 

lead time period before the revised 

standard became effective, and FAA did 

not adopt corresponding implementing 

regulations until one year later, with no 

apparent disruption to the industry. 

(See 70 FR 69664, Nov. 17, 2005.) The 

new Tier 6 standards are the same as the 

CAEP/6 standards that were approved 

by ICAO in 2005 with an effective date 

of beginning after December 31, 2007. 

Therefore, just as for the 2005 revised 

NOX standard that we similarly 

promulgated significantly later than the 

effective date of the corresponding 

ICAO CAEP standard, we do not believe 

that it is necessary to delay the effective 

date based on a need for the FAA to 

revise its own implementation and 

enforcement regulations. 

Finally, section 232(a) of the Act 

directs the FAA to ensure compliance 

with our standards. In this regard, the 

FAA has developed a streamlined 

process to recognize compliance with 

Tier 6 and or Tier 8 as appropriate for 

currently type certified engine models 

which meet the emission standards and 

they have assured the regulated industry 

that they will dedicate the necessary 

resources to formally recognize 

conformance with the standards before 

the production cutoff date. 

For the reasons stated above, EPA is 

promulgating the Tier 6 production 

cutoff with the originally proposed 

effective date of January 1, 2013. 

2. Carryover of Previously Generated 

Emission Test Data 

Aircraft engine models normally 

receive type certificates, which include 

a determination that the model meets 

the emission standards in force at the 

time the type certificate is granted. EPA 

has not updated its aircraft emission 

standards or test procedure regulations 

since 2005. In this action we are 

adopting Tier 6 and Tier 8 NOX

emission standards and are adopting 

either in 40 CFR part 87 directly or 

through incorporation by reference of 

Annex 16, Volume II a number of minor 

changes to test procedures and related 

requirements. These changes will 

become effective on the date when the 

rule becomes effective. 

This leaves open a question regarding 

the future validity and acceptability for 

amended type certificates of emission 

tests and emission test data generated 

under previously specified test 

procedures and related requirements. 

For example, there may be an engine 

model tested in 2004 that demonstrated 

HC, CO, and NOX emission levels below 

the exhaust emission standards in effect 

at that time and also below the Tier 6 

or perhaps even the Tier 8 standards 

that are being promulgated in this final 

rule. We want to be clear that we do not 

intend minor changes to test procedures 

or related provisions and requirements 

to trigger the need for additional testing. 

Thus, in cases where a manufacturer has 

a valid current type certificate based on 

emissions information generated under 

the test procedures in force at the time 

the type certificate was granted, we 

consider that data to be valid for any 

formal FAA recognition of compliance, 

e.g., an amended type certificate, with 

the Tier 6 or Tier 8 NOX emission 

requirements if the original test data 

demonstrate such compliance. The same 

is true for the HC and CO emission 

standards. This clarification should 

greatly facilitate compliance 

determinations by the FAA and 

eliminate any uncertainty regarding the 

potential for otherwise minor test 

procedure changes to trigger new 

emissions testing for previously 

certificated engines with emission levels 

below the new NOX standards. 

3. Exemptions and Exceptions From the 

Tier 6 Production Cutoff 

In conjunction with the 

implementation of the new Tier 6 NOX

standards, we are establishing 

provisions which allow engine 

manufacturers to request an exemption 

or exception from meeting the Tier 6 

NOX standards for newly-manufactured 

engines. These provisions replace 

existing provisions addressing 

exemptions that were promulgated in 

section 87.7 of our aircraft engine 

regulations. (Any exemptions 

previously issued under section 87.7 

would not be affected by the revisions.) 

This section of the preamble describes 

these exemption and exception 

provisions, i.e., exemptions for engines 

installed in new aircraft and exceptions 

for spare engines used in existing 

aircraft for maintenance purposes. It 

also includes a description of a shortterm exception program (termed the 

low-volume, time-limited transitional 

exemption program). These provisions 

have largely been crafted to be 

consistent with exemption provisions in 

the ICAO Environmental Technical 

Manual (ETM).79 80 The provisions of 


TKELLEY on DSK3SPTVN1PROD with RULES2
36360 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

81EPA formally transferred the responsibility and 

authority for the evaluation of requests for 

exemptions from the emission standards to the 

Secretary of Transportation (DOT). See ‘‘Control of 

Air Pollution from Aircraft and Aircraft Engines; 

Emission Standards and Test Procedures;’’ Final 

Rule, 47 FR 58462, December 30, 1982. 

82U.S.EPA, ‘‘Control of Air Pollution from 

Aircraft and Aircraft Engines; Emission Standards 

and Test Procedures,’’ Final Rule, 47 FR 58462, 

December 30, 1982. 

83As used in 40 CFR part 87, as a practical matter 

the meanings of ‘‘exception’’ and ‘‘exemption’’ are 

essentially equivalent. However, under FAA 

regulations, the meanings of these terms are 

distinct, especially with respect to the manner in 

which they are administered. 

the ETM guidance were developed in 

the context of the CAEP/6 NOX

production cutoff deliberations leading 

up to the CAEP/8 meeting in February 

2010. 

While we are revising our regulations, 

the process for evaluating any request 

for an exemption, i.e., petition, and any 

final decision on its disposition would 

be unchanged. In this regard, the FAA 

is the process owner under its 

enforcement authority contained in 

section 232 of the Clean Air Act.81 The 

FAA must consult with EPA in 

evaluating the merits of the request, and 

the EPA must formally concur with any 

decision regarding the granting or denial 

of the request. 

We are deleting from our regulations 

the requirement in § 87.7(e) that the 

FAA publish a notice of the exemption 

in the Federal Register. The FAA has an 

established process in place for 

publishing requests for exemption that 

are filed in accordance with 14 CFR part 

11. Under § 87.7(b) of the existing 

regulations, the FAA, with EPA 

concurrence, may also exempt lowproduction volume engines from being 

fully compliant with the emission 

standards. Several such short-term 

exemptions were granted in the 1980s 

when emission standards were first 

applied. These exemptions have since 

expired, and requests for new 

exemptions under those provisions have 

not been submitted. We have 

determined that these provisions, which 

were adopted in conjunction with 

revised emission standards in 1982, are 

no longer of any utility.82 Therefore, we 

are deleting these provisions to avoid 

confusion. 

We are also deleting the time-limited 

exemption provision for in-use engines 

that is contained in section 87.7(d) of 

the existing regulations. This provision 

applies to fuel venting and smoke 

emission standards, which were new 

when the exemption was adopted in 

1973. The exemption allowance was 

limited to in-use engines that were 

unable to comply with the requirements 

when the regulation became effective in 

1974. The in-use fleet of engines was 

fully retrofitted to comply with the 

standards later in the 1970s. Therefore, 

this provision is now obsolete and we 

are deleting it to avoid confusion. We 

proposed to delete the existing 

provisions for temporary exemptions 

based on flights for short durations and 

infrequent intervals. This proposal was 

based on the EPA’s and FAA’s belief 

that the provisions were unnecessary 

because our standards apply to aircraft 

certificated by the FAA, and the FAA 

does not address in the certification 

process whether an aircraft will be used 

for short durations or infrequent 

intervals. Hence, the provisions 

appeared to have no utility. 

We received two comments from the 

Aerospace Industries Association (AIA) 

and the General Aviation Manufacturers 

Association (GAMA) requesting that the 

provision be retained. First, they argued 

that as in the past, a new aircraft may 

be produced at a commercial facility 

that is destined for immediate 

conversion to a military only 

application at a separate facility. These 

aircraft may require a small number of 

airworthiness flight tests before being 

delivered to the conversion facility and 

conceivably would be subject to EPA 

standards during flight testing. While 

these aircraft would generally utilize 

compliant engines, it may be possible 

that non-compliant engines could be 

used (our standards do not apply to 

engines used on military aircraft as 

discussed later) and temporary 

exemptions would be necessary. 

Second, AIA and GAMA commented 

that it would be helpful if the provision 

also allowed for granting a discrete 

number of exemptions over a specified 

time period, rather than having to 

request the exemption prior to each 

flight as currently required. 

In considering the commenters’ 

suggestion to retain the exemption 

provision, we note that allowing such 

operations will not have any significant 

adverse affect on the environment 

because of the infrequent nature and 

short duration of such flights. Retaining 

the exemption is also consistent with 

exempting military aircraft from 

emission control requirements as 

discussed later. Therefore, we have 

retained the provision with one change, 

made in response to the comments, as 

described below. 

The current provision calls for the 

Secretary of Transportation to consult 

with the EPA Administrator when 

considering any exemption request for 

infrequent interval and short duration 

flights not explicitly allowed by the 

regulations. Given the inconsequential 

nature of such flights on the 

environment, we believe that the 

Secretary should be able to consider and 

act on these petitions unilaterally to 

streamline the process. Therefore, we 

are deleting that portion of the previous 

exemption provision. Of course, we will 

consult with the Secretary if asked to do 

so. As for requesting a discrete number 

of temporary exemptions, we believe 

this is an issue that the Secretary of 

Transportation may address under its 

enforcement role as described in section 

232 of the CAA. 

The current regulations also provide 

for permanent exemptions for newlymanufactured engines based on 

consideration of the certain factors 

specified in section 87.7(c). We are 

replacing these provisions with new 

regulatory text generally consistent with 

the ETM that would provide for 

permanent exemptions or exceptions 83

for newly manufactured engines used 

on new aircraft and spare engines used 

for maintenance or replacement 

purposes. These are summarized below. 

(See § 87.50 of the regulations for 

additional details on these exemptions/ 

exceptions.) 

a. New Provisions for Spare Engines 

We are revising the regulations to 

allow the sale of a newly-manufactured 

engine for installation on an in-service 

aircraft, i.e., a spare engine that does not 

conform to the applicable emissions 

standards at the time it was produced. 

It does not allow for installing such an 

engine on a new aircraft. Spare engines 

are produced from time to time in order 

to keep an aircraft in revenue service 

when the existing in-service engine 

must be removed for maintenance or 

replacement purposes as needed. 

Otherwise removing these aircraft from 

active service would be very expensive 

and logistically difficult. 

As we explained in the proposal, 

explicitly allowing for the production of 

spare engines is not addressed in the 

existing regulations because there is no 

production cutoff for the current Tier 4 

NOX standards. Thus manufacturers 

have been allowed to continue 

production of older engine designs 

under type certificates first issued 

before the Tier 4 standards took effect 

(e.g., Tier 2). However, final regulations 

now apply a Tier 6 NOX production 

cutoff to all newly- manufactured 

engines. This means that if we did not 

also adopt a provision for the continued 

production of spare engines, 

manufacturers would be prohibited 

from producing Tier 4 engines under the 

existing type certificates for this 

purpose. We see no reason to change 

our policy of allowing manufacturers to 


TKELLEY on DSK3SPTVN1PROD with RULES2
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36361 

84The Air Transport Association has changed its 

name to Airlines for America (A4A). 

produce new engines for use as spares. 

Therefore, the final regulatory 

provisions allow this practice to 

continue. 

To ensure there would be no adverse 

environmental effect from allowing the 

use of a spare engine as a direct 

replacement for an existing engine, we 

proposed that the spare could be used 

only when the emissions for all 

pollutants of that engine were equal to 

or lower than those of the engine it 

replaced. This proposed requirement 

was consistent with the ETM, which 

also contains this allowance. We 

received a joint comment from AIA and 

GAMA stating that this is impractical 

because, while unlikely, a spare engine 

might have a different emissions profile 

for some pollutants than the engine it 

would replace. As an example, they 

stated that the two engines could have 

somewhat different combustion systems 

that might make one engine lower in 

NOX but higher in CO. They also 

suggested that EPA should consider the 

totality of the emissions in the decision, 

or delete the requirement in the final 

rule. 

These comments are surprising 

because this ETM provision, as well as 

the exception provisions, was subject to 

significant discussions within CAEP 

that included the engine manufacturers 

as well as a representative from AIA. 

Nonetheless, in this instance we believe 

the proposed provision should be 

modified to accommodate the potential 

for unusual circumstances as explained 

by the commenter. 

As noted above, AIA and GAMA 

suggested that EPA consider of the 

totality of emissions relative to their 

environmental effects as the basis for 

evaluating spare engine exemptions. 

This would entail understanding and 

comparing the environmental 

consequences of the different pollutants. 

We find that could be very complicated 

because different pollutants have 

different health and welfare end points 

and consequences. For example, in the 

illustration offered by the commenters, 

the effects of LTO NOX and CO are 

largely unrelated to one another. 

We think a preferred option to 

evaluating total environmental effects, 

or even dropping the provision entirely, 

is to incorporate an anti-backsliding 

requirement which ensures that at a 

minimum the excepted spare engine at 

least meets the same emission standards 

that are applicable to the engine it is 

replacing. For this reason, in response to 

the AIA and GAMA comment, we are 

modifying this provision in the final 

rule to allow an excepted spare engine 

to have different emission levels 

compared to the engine it replaces as 

long as it remains compliant with each 

of the applicable emission standards 

and any other requirements of its type 

certificate. Given the limited number of 

spare engines in the fleet, we expect 

allowing these engines to have 

somewhat different emissions profile 

from engines they are replacing will 

have no significant adverse 

environmental effect. This is especially 

true given that we expect the emissions 

of an excepted spare engine will be 

equal or better than the engine it is 

replacing in most cases in accordance 

with the basic tenant of the ETM. 

We are not requiring engine 

manufacturers to obtain FAA or EPA 

approval before producing spare 

engines. However, they must submit 

information about the production of 

spare engines in an annual report to 

EPA (see section III. D for more on the 

annual report). We proposed that 

because manufacturers are not required 

to seek or obtain formal approval to 

produce spare engines, this allowance 

was referred to as an ‘‘exception’’ rather 

than an ‘‘exemption’’. This terminology 

would be consistent with current FAA 

regulations. Furthermore, we proposed 

that the permanent record for each 

engine excepted under this provision 

would need to indicate that the engine 

is an excepted spare engine and the 

engine itself would need to be labeled 

as ‘‘EXCEPTED SPARE.’’ in accordance 

with FAA marking requirements of 14 

CFR. 

We received comments relating to 

allowing spare engines to be produced 

without requiring prior approval and 

the use of the terms ‘‘exceptions’’ or 

‘‘excepted.’’ The Air Transport 

Association (ATA) 84 appreciated that 

there would be no case-by-case 

approval, noting that it simplifies 

administering the provision for FAA 

without compromising the structure of 

the exemptions program set forth in the 

ETM. Regarding the terminology, AIA 

and GAMA noted that the terminology 

was inconsistent with current engine 

name plate labeling practices. They 

stated that engines are currently either 

marked ‘‘COMPLY’’ or ‘‘EXEMPT’’ for 

emissions. Both organizations generally 

felt the change in terminology for spare 

engines might be concerning to the 

operators holding an engine with a plate 

reading ‘‘EXCEPTED.’’ They concluded 

that the name plate for spare engines 

should continue to use ‘‘exempt.’’ The 

ATA appeared to give at least tacit 

approval to the new terminology by 

acknowledging without objection that 

spare engines would be labeled 

accordingly. 

First, we are puzzled that operators 

with a spare engine labeled as 

‘‘excepted spare’’ rather than ‘‘exempt’’ 

may have a concern, because AIA and 

GAMA did not elaborate on just what 

the concern might be. Without at least 

an example, we are unable to discern 

the nature of the concern and respond 

directly to it. We also find it puzzling 

that the two organizations that represent 

aerospace manufacturers expressed a 

concern regarding operators of aircraft 

and aircraft engines when the actual 

organization representing those 

companies, ATA, did not express such 

a concern. 

Second, regarding the terminology, 

the Tier 6 production cutoff does not 

apply to the continued production of 

engines that are designated spares. 

Spare engines are produced to replace a 

similar engine already in service that 

was removed from service for 

maintenance purposes. Accordingly, the 

production of a spare engine is not 

restricted by the production cutoff, and 

the regulation does not apply to these 

engines. The non-applicability of the 

cutoff eliminates the need to process an 

exemption for continued production of 

these engines beyond December 31, 

2012. 

Conversely, engines that are intended 

to be produced for new installations (i.e. 

not replacing an engine already in 

service) are subject to the production 

cutoff regulation and the continued 

production of such engines beyond the 

cutoff date would require a grant of 

exemption. Since the production of 

spare engines is not subject to the new 

cutoff regulations, the FAA proposed 

and the EPA accepted the idea that 

referring to these engines as exceptions 

to the regulation was more appropriate 

than requiring case-by-case 

consideration of exemptions when the 

regulation did not apply. 

Moreover, the word ‘‘exemption’’ is a 

meaningful regulatory term. It is used by 

the FAA in 14 CFR Part 11 to mean that 

an applicant is subject to a particular 

regulation and is requesting timelimited relief under a specific set of 

criteria. It is a specialized form of 

rulemaking. When an entity or its 

product is specifically left out of a 

regulatory provision, it is considered 

‘‘excepted’’. Any regulation adopted by 

the FAA would use these terms 

consistently. 

As already mentioned, assuming 

incorporation of these provisions by the 

FAA, engines meeting the requirements 

for spare engines could be produced and 

entered into commerce without prior 

approval from EPA or FAA. It is 


TKELLEY on DSK3SPTVN1PROD with RULES2
36362 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

85Engines certified only for compliance with 

earlier Tier 2 NOX standards would not be eligible 

for exemptions. This is also consistent with the 

exemption language in the ICAO ETM. Note that 

where such engines have emissions actually 

meeting the Tier 4 NOX standard, they may be 

recertified to the Tier 4 standards, but only before 

the effective date of the regulations. 

86For example, the hydrocarbon exhaust 

emission standards were adopted on December 30, 

1982. See 47 FR 58462. 

important to note that while spare 

engines would be excepted from the 

Tier 6 NOX standards being 

promulgated today, they still need to be 

produced under an FAA type certificate. 

(This FAA oversight would serve the 

same role as the exemption approval 

step envisioned by ICAO in its ETM 

language for spare engines.) We also 

expect minimal additional burden for 

manufacturers, since we are not 

establishing new restrictions, 

monitoring, recordkeeping, or reporting 

requirements other than the end of year 

report. 

b. New Provisions for Engines Installed 

in New Aircraft 

The primary purpose of allowing 

limited continued production of Tier 4 

engines is to provide for an orderly 

implementation of the Tier 6 NOX

production cutoff. It addresses engines 

reaching the end of their production 

cycles in the time frame when new 

emission standards take effect. The 

typical production cycle would have 

annual production volumes ramp up 

quickly, remain at relatively large 

volumes for several or many years, and 

then fall off over a few more years. 

When new emission standards are 

adopted in the middle of a production 

cycle to take effect a few years later, 

manufacturers generally devote 

technical resources to bring into 

compliance those engine models 

expected to be produced in large 

numbers in the time frame when the 

new standards are in effect. In contrast, 

they may plan not to invest in 

upgrading the emissions of engine 

models that would be very near the end 

of their normal production cycles when 

compliance with the new standards 

becomes required. The actual length and 

shape of this tail of production volumes 

can be affected by factors not fully 

within the engine manufacturers’ 

control, e.g., unexpected market 

demand. Thus, exemptions may be 

justified if a manufacturer does not 

complete the production cycle before 

the production cutoff date and projected 

production volumes are not adequate to 

justify investing the necessary resources 

to reduce emissions or there are other 

technological issues. 

Furthermore, in certain exceptional 

circumstances exemptions may also be 

appropriate. These are ‘‘hardship’’ 

situations that may arise as a result of 

unforeseen technical or economic 

circumstances or events beyond control 

of the manufacturer. For example, this 

could vary from unexpected problems 

with technology upgrade programs to 

labor disruptions or natural events 

disrupting production or parts 

availability. 

Our regulations currently address 

these kinds of situations in section 

87.7(c), entitled, ‘‘Exemptions for New 

Engines in Other Categories.’’ We are 

replacing this provision with a new set 

of provisions addressing exemptions for 

new engines. 

i. Time Frame and Scope 

The final regulations allow engine 

manufacturers to request an exemption 

for newly-manufactured engines not 

meeting the Tier 6 NOX standards so 

they may be installed in new aircraft. If 

granted, manufacturers may produce a 

limited number of these newlymanufactured engines in a four year 

time period beginning after December 

31, 2012 and going through December 

31, 2016. This four-year time period is 

consistent with the ETM. The period for 

any given approved exemption could be 

shorter depending on the specifics of 

the application, but it could not be 

longer. This exemption limits NOX

emissions from engines that are covered 

by a valid type certificate issued by 

FAA. The engines must meet all other 

applicable requirements. More 

specifically, an engine exempted from 

the Tier 6 NOX standards must be 

covered by a previously issued type 

certificate showing compliance with the 

Tier 4 NOX standards,85 as well as the 

current HC, CO, fuel venting, and smoke 

standards. 

As explained above, the scope of the 

exemption provisions are limited to 

newly-manufactured engines that do not 

comply with the Tier 6 NOX standards. 

No need has been identified to apply 

such exemption language to the other 

regulated exhaust pollutants, i.e., 

smoke, hydrocarbons and carbon 

monoxide. The emission standards for 

those pollutant species have remained 

unchanged for nearly three decades and 

present no technical issues for modern 

turbofan engines.86 If new emission 

standards for these pollutants are 

considered in the future, the potential 

need for exemption provisions will also 

be assessed at that time. 

We received comments requesting 

that exemptions be available for newlycertified engines in addition to newlymanufactured engines. General Electric 

Aviation (GE) stated that unforeseen 

circumstances may arise during the 

lengthy aircraft engine development 

process that necessitates a change in 

design, and that may affect the ability of 

that engine model to meet the prevailing 

Tier emission standard at certification. 

For that reason, GE concluded that 

exemptions for newly-certified engine 

would be beneficial. The AIA and 

GAMA jointly stated that the existing 

40 CFR 87.7(c) not only provides the 

flexibility to exempt newlymanufactured engines from a 

production cutoff, but also for newlycertificated engine models subject to 

any emission standards, e.g., the Tier 8 

NOX standards. They requested that this 

flexibility should be retained. 

Regarding the availability of 

exemptions for newly-certified engine 

models, the proposed regulatory text 

made clear that the exemption 

provisions would only apply to newlymanufactured engines. Specifically, the 

intent was to establish provisions for 

newly-manufactured engines to address 

the potential technology and economic 

adversities that may arise as part of 

adopting the Tier 6 production cutoff. 

The ICAO ETM provisions are clearly 

intended for that same purpose. Also, 

the original intent of EPA’s current 

exemption provisions in § 87.7(c), 

which we are modifying in this 

rulemaking, is clear from the proposed 

rulemaking and final rulemaking that 

resulted in those provisions. The March 

24, 1978 proposal described the concern 

as ‘‘* * * engines which are nearly [at] 

the end of their production life would 

be terminated prematurely because 

there would be insufficient future sales 

to justify incorporating emission 

controls.’’ (See 43 FR 12619, March 24, 

1978.) The December 30, 1982 final rule 

referenced ‘‘* * * the removal of an 

engine model from the market because 

of its failure to comply.’’ (See 47 FR 

58468, December 30, 1982.) Obviously, 

the intent of the existing exemption 

provision cited by AIA and GAMA was 

to make it apply only to newlymanufactured engines. 

As a general matter, we believe an 

exemption from the Tier 6 standard, or 

any other standard, for newly-certified 

engine models is speculative at this time 

and would undermine the goal of 

regulatory compliance by new engine 

designs. In any event, neither the 

current ICAO Annex 16, Volume II 

provisions nor the ETM provide for 

newly-certified engine exemptions. We 

believe that such would be a 

fundamental shift from Annex 16 and 

the ETM should be explored within the 

framework of ICAO/CAEP. Furthermore, 

engine manufacturers already have 


TKELLEY on DSK3SPTVN1PROD with RULES2
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36363 

87CAEP/8—WP/18, Environmental Technical 

Manual (ETM), Vol. II on the Use of Procedures in 

the Emission Certification of Aircraft Engines, 

Appendix ‘‘ICAO Emissions Environmental 

Technical Manual’’. 

significant leadtime between the date 

CAEP adopts a new emission standard 

and the standard’s effective date, e.g., 

usually 3–5 years. Finally, engine 

manufacturers historically design new 

engine models to comply with the most 

stringent future standard that also 

provides for a longer development time 

horizon. Therefore, we are promulgating 

the exemption provisions for newlymanufactured engines as proposed. 

ii. Production Limit 

As proposed, § 87.5 of the final 

regulations reflect the essence of the 

general exemption language for exhaust 

emission standards regarding how to 

determine the number of allowable 

exemptions that is embodied in existing 

§ 87.7(c) of the regulations. That 

provision generally that the FAA, with 

EPA’s concurrence, may grant 

exemptions to exhaust emission 

standards based on factors such as 

adverse economic impact on the engine 

manufacturer, aircraft manufacturer, or 

airline industry; in addition to the 

effects on public health and welfare. 

As a result, § 87.5 does not specify a 

nominal number of exemptions. Rather, 

each request for exemption would be 

evaluated on a case-by-case basis, using 

the information provided by the 

applicant and any other relevant 

information that is available to FAA and 

EPA at the time. Any approved 

exemption would include a specific 

limit on the number of such engines 

based on that information and is not 

defined on a basis such as type 

certificate. (See section III.B.b.iii for a 

description of what the request must 

contain.) The intent, of course, would be 

to exempt the minimum number of 

engines that can be clearly justified, 

including a consideration of the public 

health and welfare effect associated 

with the exemptions. 

In the proposal, we acknowledged 

that our approach to determining limits 

on the number of exempt engines differs 

from the language contained in the 

current ICAO ETM guidance. The ETM 

states that ‘‘[t]he number of engines 

exempted would normally not exceed 

75 per engine type * * *.’’ 87 We chose 

not to propose adopting this language 

on the nominal number of engines based 

on a single type certificate. Our reasons 

for this deviation were detailed in the. 

The interested reader is referred to the 

proposed rule for more detail. (See 76 

FR 45012. July 27. 2011.) We also want 

to emphasize that the exemption 

provisions as proposed and 

promulgated in this notice are not 

necessarily limited to the Tier 6 NOX

production cut-off, but could in fact be 

applied to future aircraft engine 

emission standards if a similar 

production cut-off was adopted. 

Therefore, we believe our approach is 

preferable because it more clearly leaves 

the number of exemptions that might be 

granted open, not limited to either more 

or less than 75 per engine type, and 

subject to the justification supplied by 

the engine manufacturer, both for the 

Tier 6 production cut-off and the future. 

We received several comments 

focusing primarily on the number of 

exemptions and the underlying process 

that is embodied in the ETM and our 

proposal. General Electric Aviation (GE) 

maintained that harmonization with the 

international community is not only 

required by the Chicago Convention, but 

also provides streamlined processes and 

procedures within the regulated 

industry. They contended that any 

purported benefits to EPA’s unique 

exemption scheme were outweighed by 

setting up a conflict with the remainder 

of the world. They also suggested that 

if EPA wants a different approach for 

evaluating exemptions, it would be 

more appropriate to work inside the 

ICAO/CAEP process toward that end. 

The ATA commented that EPA’s caseby-case approach to determining the 

number of engines is a rejection of the 

ICAO/ETM provisions that limit ‘‘* * * 

the number of exemptions * * * to 75 

engines per type certificate * * *.’’ 

They argued that this would create a 

serious discontinuity between the U.S. 

and the rest of the world, undermining 

ICAO’s objective of international 

uniformity. The ATA also argued that 

the ICAO exemption limits are intended 

to be coordinated among international 

aviation authorities, and that differing 

rules would make this impracticable. As 

evidence of this problem, ATA cited the 

European Aviation Safety Agency’s 

(EASA) proposed rulemaking, which 

they noted was based on the assumption 

that the ICAO proposals will be adopted 

unaltered by other aviation authorities 

of the world. The ATA also stated that 

the ICAO ETM guidance document 

supplements the official standards of 

Annex 16, Vol. II and, therefore, the 

ETM provides technical elaboration on 

the implementation of Annex 16. From 

this ATA concluded that differing 

practices in this regard are counter to 

the Chicago Convention. 

Regarding consistency with the 

Chicago Convention, our proposal 

thoroughly explained that the ETM is 

guidance material; not an ICAO 

standard or regulation of any type. 

While consistency is desirable, it is not 

compelled when a deviation is justified. 

Therefore, we disagree with the 

commenters on this point, and 

specifically with ATA’s comment that 

the ICAO guidance is effectively the 

equivalent of an ICAO Annex 16 

standard. 

Turning to ATA’s comment regarding 

the ETM cap of 75 engines per type 

certificate, we first want to point out 

that this is not a maximum limit on the 

number of potential exemptions per 

type certificate nor is it an implied 

entitlement. Rather the ETM provision 

is an expectation that ‘‘[T]he number of 

engines exempted would normally not 

exceed 75 per engine type certificate 

* * *.’’ as stated in the document. With 

this perspective both the ETM and our 

approach are similar in that the 

maximum number of exempted engines 

is based on a consideration of the 

petitioner’s justification for such 

exemptions. 

Finally, we disagree with the 

comment that the differences with the 

ETM make international coordination 

unworkable. In fact, one of the proposed 

justification elements, i.e., how many 

affected aircraft will be registered in the 

U.S. and other countries (estimate 

allowed), was described in the preamble 

for the proposal as being aimed at 

helping to facilitate consultation and 

coordination. Also, as noted above, the 

ETM’s expectation and our approach are 

similar in that the maximum number of 

exempted engines under both 

approaches is based on a consideration 

of the petitioner’s justification for such 

exemptions. We do not think 

coordination with foreign aviation 

authorities, with these few differences, 

should pose any problems. After 

considering the above comments on the 

number of exemptions and the 

underlying process embodied in the 

ETM and our approach, we are 

promulgating the provisions relating to 

the comments as originally proposed. 

iii. Exemption Requests 

We are establishing a process for 

requesting exemptions (for engines used 

on new aircraft) that would be more 

formal and structured than the current 

process. We are requiring manufacturers 

submit their request to the FAA, as 

currently required. The FAA will then 

share the submittal with EPA and 

execute the consultation process. 

To ensure that we have the 

information necessary to evaluate 

exemption requests in this specific 

manner, the requests need to include 

the following details to describe the 

specific engine model for which the 

manufacturer is requesting the 


TKELLEY on DSK3SPTVN1PROD with RULES2
36364 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

exemption. The final provisions 

contained in § 87.50, which are 

summarized below, are consistent with 

and in some areas expand on the 

provisions in the ETM: 

General Information 

• Corporate name and an authorized 

representative’s contact information 

(including a signed statement verifying 

the information); 

• Description of the engines for 

which you are requesting the 

exemption, including the engine model 

and sub-model names; 

• The number of engines that you 

would produce under the exemption 

and the period during which you would 

produce them; 

• Identify the authorizing type 

certificate (type certificate number and 

date); 

• Information about the aircraft in 

which the engines will be installed, 

including the airframe models and 

expected first purchasers/users of the 

aircraft, and the countries in which you 

expect the aircraft to be registered 

(including an estimate of how many will 

be registered in the U.S.); and 

• List of other certificating authorities 

from which you have requested (or 

expect to request) exemptions, and a 

summary of each request. 

Justification and Impacts Assessment 

• A detailed description and 

assessment of the environmental impact 

of granting the exemption; 

• Technical issues, from an 

environmental and airworthiness 

perspective, which may have caused a 

delay in compliance with a production 

cutoff, if any; 

• Any economic impacts on the 

manufacturer, operator(s), and aviation 

industry at large; and 

• Projected future production 

volumes and plans for producing a 

compliant version of the engine model 

in question. 

Other Factors 

• Hardship: Impact of unforeseen 

technical circumstances, business 

events, or other natural or manmade 

calamities beyond your control, and 

• Equity issues in administering the 

production cutoff among economically 

competing parties. 

It is important that any action on a 

potential exemption request be in the 

public interest; the fairly comprehensive 

list of application information in the 

regulations is intended to gather the 

information needed for this assessment. 

We would expect to take a broad 

perspective in evaluating what is or is 

not in the public interest. This is why 

a manufacturer’s justification needs to 

include a quantified description of the 

environmental effects of granting the 

exemption, as well as discussion of 

economic and technical issues related to 

bringing the engine into compliance. 

The analysis of environmental impacts 

needs to specify by how much the 

exempted engines would exceed the 

standards, the in-use effects in terms of 

lifetime tons of NOX, and estimate the 

emissions rates of engines/aircraft that 

could potentially be used if the 

exemption was not granted. Since 

exemptions granted under the 

regulations apply only to NOX

emissions, the analysis could also 

include possible benefits regarding 

noise levels or reduced emissions of 

pollutants other than NOX. Relevant 

economic impacts could include effects 

on the engine manufacturer, airframe 

manufacturer, airline(s), and the general 

public. 

As we detailed in the proposal, some 

manufacturers have requested 

exemptions in the past based on the 

largest number of engines they hoped to 

continue manufacturing without 

knowing how many they would actually 

be able to produce or who would 

purchase them. The new exemption 

language calls for manufacturers to 

target their requests more specifically 

based on likely production needs and 

time periods. While we expect a 

manufacturer to have this specific 

information when they submit a request, 

the final regulations allow us to process 

exemption requests with somewhat less 

specific information. However, we 

expect this to apply only for unusual 

circumstances. Manufacturers also are 

being required to notify the FAA if they 

determine after submitting a request that 

the information is not accurate, either 

from an error or from changing 

circumstances. 

The final regulations also allow 

manufacturers to revise their requests to 

justify covering additional engines at 

any time before approval. We would 

then review the revised request. 

Similarly, for exemptions that are 

already approved, manufacturers could 

request that additional engines be added 

after providing the justification for the 

increase. 

We received comments on the level of 

detail required in a request for 

exemption and the time needed to add 

more engines to such a request or an 

already approved exemption. First, ATA 

was concerned that requesting an 

increased amount of engine exemptions 

can take a significant amount of time. 

They stated that there may be 

insufficient time for a manufacturer to 

receive approval for additional engine 

exemptions if necessary to meet 

previously unknown market demands. 

In response, we find it unfortunate 

that the comment does not provide a 

specific example or other information 

that may illustrate this concern. As a 

general response, given the long 

leadtime between the initiation of 

discussions among aircraft purchasers 

and aircraft manufacturers, and actual 

orders and final deliveries, we expect 

that manufacturers will have enough 

time to request additional engine 

exemptions, and if appropriate, for the 

FAA and EPA to approve such a 

request. We expect that amending an 

already approved exemption would take 

less time to act upon than the original 

petition. Also, engine manufacturers 

may request an expedited review from 

the FAA, and by association the EPA, if 

circumstances warrant. Finally, to the 

extent that an engine manufacturer has 

specific concerns in this area, they 

could be ameliorated by improving the 

lines of communication with air frame 

manufacturers to increase the 

manufacturer’s awareness of market 

interest in potential new orders. 

Accordingly, we are promulgating the 

exemption provision relating to this 

comment as proposed. 

Second, ATA commented negatively 

that the exemption request for each 

individual engine be justified, ‘‘* * * 

including the exact number, initial 

purchasers/users, countries of registry 

and plans for bringing the product into 

compliance.’’ They claimed that this 

knowledge may not be known at the 

time of the exemption request because 

of market leadtime. As an example, 

ATA cited the 1998 Rolls Royce (RR) 

exemption request from the CAEP/2 

cutoff for 150 engines that was not 

based on that type of certainty, but was 

a prospective exemption for two years 

as protection against the uncertainties of 

technical development. They stated that 

RR did not know when the development 

process would be completed, and hence 

did not know the exact number of noncompliant engines that airlines would 

purchase. The ATA also added that the 

three affected airlines worked with RR 

to provide documentation of the 

financial and operational hardship that 

they would suffer based on their aircraft 

delivery schedules. 

In response to ATA’s second 

comment, we simply want to note that 

the information we would normally 

expect to be contained in the exemption 

application is actually not much 

different than the justification 

envisioned by the ETM. That guidance 

document explains that the petitioner 

should, to the extent possible, provide 

quantitative support to justify the 


TKELLEY on DSK3SPTVN1PROD with RULES2
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36365 

88 It is possible that applications for exemptions 

by foreign entities may be filed with their national 

certificating authorities for engines manufactured 

after December 31, 2012 and could be operated in 

the United States. The FAA has several 

international bilateral agreements in place that 

include provisions and obligations for technical 

assistance on environmental certification matters. 

The FAA plans to continue to coordinate with those 

foreign certificating authorities in their considering 

and granting petitions for exemptions and, likewise, 

those that are filed with the FAA and in 

consultation with EPA. 

89Memoranda documenting this supplemental 

information are located in docket number EPA– 

HQ–OAR–2010–0687. 

exemptions. Specifically, the ETM states 

that it ‘‘* * * provides guidelines on 

the process and criteria for issuing 

exemptions * * *.’’ These include some 

of the same elements as contained in 

our proposal and referenced above, i.e., 

the exact number of exemptions being 

requested, to whom the engines will be 

originally delivered, and plans for 

producing a compliant product. 

Therefore, the ETM envisions a 

consideration of specific information as 

part of the exemption request, in a 

similar fashion as EPA’s approach, in 

order to decide on the exact number of 

exemptions to grant. We are simply 

being more explicit in some areas 

concerning the type of information that 

should be included in any exemption 

request. We also note ATA’s comment 

that ‘‘[T]he airlines worked with Rolls 

Royce to provide documentation of the 

financial and operational hardship that 

they would suffer if there were an 

interruption in the supply of ICAOcompliant engines during their aircraft 

delivery schedules.’’ 

Given the long lead times generally 

associated with new aircraft orders and 

deliveries, we expect aircraft operators 

will work closely with aircraft 

manufacturers as their new aircraft 

needs are identified. Engine 

manufacturers should in turn work with 

aircraft manufacturers to stay aware of 

market interest in potential new orders. 

This appears to be reflected in the 

commenter’s example regarding the 

cooperation between airlines and RR in 

fashioning the exemption justification. 

Also, as explained in the proposed 

regulatory text, the petitioner should 

include information on the ‘‘expected’’ 

first purchasers/users of the aircraft. It 

also asked for information on the 

number of aircraft that will be registered 

in the U.S. versus other countries and 

that this may be estimated, if not 

known. Therefore, precise knowledge is 

not needed for certain elements of the 

justification. The preamble to the 

proposed requirements also stated that 

the regulations would allow us to 

process exemption requests with 

somewhat less specific information, 

although we expected that to apply only 

for unusual circumstances. We have 

made this clearer in the final 

regulations. 

In order to allow us to oversee these 

exempted engines, manufacturers are 

being required to also provide an annual 

report to EPA on exempt engines similar 

to the information about spare excepted 

engines. The permanent record for each 

engine exempted under this provision 

must indicate that the engine is an 

exempted engine and the engine itself 

must be labeled as ‘‘EXEMPT NEW.’’ 

iv. Coordination of Exemption Requests 

The limit on the number of 

potentially exempt engines as described 

in the ETM is intended to apply to 

overall worldwide production. Toward 

that end, the ETM envisions that 

certificating authorities and member 

states should coordinate whenever any 

authority receives an exemption request. 

Working with the FAA, we expect to 

consult with other aviation authorities 

whenever we receive an exemption 

request. This would include a 

consultation with other certificating 

authorities as well as coordination with 

the appropriate civil aviation authority 

of any country where the aircraft with 

the exempted engines will be registered. 

To facilitate this coordination, we are 

asking that manufacturers also include 

in their requests, a list of countries in 

which the aircraft are expected to be 

registered. While not specifically listed 

in the ETM, we believe that this 

information is consistent with the ETM 

as it would be necessary to ensure 

proper coordination. The ETM appears 

to presume that each member country 

will recognize exemptions granted by 

other countries. This presumption 

seems reasonable assuming that the 

exemption being granted is generally 

consistent with the guidelines of the 

ETM and that the consultation and 

coordination called for in the ETM was 

conducted in good faith. However, there 

should be no presumption that EPA 

would agree to an exemption for an 

engine model if the aforementioned 

collaboration, consultation, and 

coordination were not conducted. The 

Clean Air Act (which provides EPA 

with its authority to establish emission 

standards) includes no provisions that 

would allow any foreign country or 

other certificating authority to exempt 

subject aircraft engines, over the 

objection of FAA and EPA, from the 

applicable standards EPA 

promulgates.88 Nevertheless, because 

our final exemptions provisions are 

generally consistent with the procedures 

called for in the ETM, assuming 

appropriate consultation and 

coordination in accordance with the 

ETM and absent unforeseen 

complications, it is reasonable to believe 

that FAA and EPA would not object to 

exemptions for engines properly 

exempted by other countries under 

those procedures. The FAA would still 

need to take the certification action as 

called out in 14 CFR 91.203 and 14 CFR 

21.183. 

This, however, raises the question as 

to how we would respond to an 

exemption request when another 

certificating authority did not consult or 

coordinate on a previous request for the 

same engine model. A related concern 

arises if an FAA type certificate is 

sought under a reciprocity agreement for 

an engine which was previously 

certificated under an exemption by a 

foreign certificating authority, and the 

original exemption was not coordinated 

with the United States. Such requests 

would likely be viewed as new 

exemption requests if the anticipated 

collaboration, consultation, and 

coordination had not occurred. 

Thus to avoid these issues, in most 

cases, manufacturers may want to work 

with all relevant certificating authorities 

at the same time as well as the civil 

aviation authority of nation(s) where the 

aircraft will be initially registered or 

operated if that nation requires a type 

certificate issued under its own 

regulations to operate in its air space 

consistent with international 

agreements. 

v. Low-Volume, Time-Limited 

Transitional Exemption Program 

We received a comment from one 

manufacturer expressing concern that 

once the final rule becomes effective 

additional time may be required for EPA 

and FAA to establish and undertake 

procedures to review and act upon 

exemption requests. They stated that the 

time needed for this process could be 

very disruptive for engine 

manufacturers that have already 

contracted to delivery engines during 

the period which FAA/EPA would need 

to consider exemption requests. They 

also claimed it would be harmful to 

airplane manufacturers and airlines. To 

avoid such an undesirable outcome, the 

commenter suggested that EPA should 

grant a one-time, interim block of 

perhaps 20 exemptions. 

Based on supplemental information 

we received from the commenter,89 we 

find the concerns center on six engines 

for which they have contract 

commitments to build and deliver 

within several months of this final rule. 

These six engines belong to two engine 

models, with four engines in one model 


TKELLEY on DSK3SPTVN1PROD with RULES2
36366 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

90The FAA has stated to EPA that inadequate 

time exists for the required formal compliance 

determination before the production cutoff takes 

effect. 

91U.S. EPA, ‘‘Draft Regulatory Text for Voluntary 

Offset Program,’’ Memorandum from Charles 

Moulis, Assessment and Standards Division, Office 

of Air Quality and Transportation, June 2011. A 

copy of this document is in docket number EPA– 

HQ–OAR–2010–0687. 

and two engines in the other. The first 

model consisting of four engines is 

scheduled to begin shipping in January 

2013, shortly after the January 1, 2013 

Tier 6 production cut off. These engines 

are currently certificated to the Tier 4 

NOX standards. The commenter has 

stated, however, that the design of this 

engine model has been technically 

modified to achieve the Tier 6 

standards. Unfortunately, compliance 

testing of this model to meet the Tier 6 

standards cannot be performed until 

December of 2012 when the first 

production version is built. Assuming 

that this testing is successful, 

inadequate time remains for the FAA to 

formally recognize Tier 6 compliance 

based on those tests before the 

production cutoff becomes effective.90

The two new aircraft using these 

engines are being built and will be 

delivered to a foreign airline. 

The second model is comprised of 

two engines with a contracted delivery 

date in May 2013. They are also 

certificated to the Tier 4 NOX standards. 

These engines are at the end of their 

production life, i.e., no additional future 

deliveries for civilian uses are 

anticipated beyond these two contracted 

engines. For this reason, the commenter 

has stated that it is not economically 

feasible to redesign this model to 

conform with the Tier 6 NOX standards, 

even if it were technically feasible. The 

single new aircraft using these engines 

is also being built for delivery to a 

foreign airline. 

After assessing this concern, we are 

including an exception provision in the 

regulations that permits any aircraft 

engine manufacturer to produce and 

enter into commerce up to six newlymanufactured engines with a date of 

manufacture, as defined in the 

regulations, prior to August 31, 2013 

that are not certificated to meet Tier 6 

emission requirements. We find that a 

considerable amount of time will indeed 

be required between the time this final 

rule becomes effective and completing 

any formal FAA action using the normal 

exemption process as previously 

described in this notice. Specifically, 

time is needed for: (1) The FAA to 

amend 14 CFR part 34 through 

rulemaking to incorporate the 

production cutoff and procedures for 

granting exemption from the new 

standards; (2) the manufacturer to 

develop the information needed to 

support a request; (3) submitting the 

request for review by FAA and EPA; (4) 

coordination with other certificating 

authorities; and (5) EPA and FAA 

review and final action on the request, 

i.e., approval or disapproval. Regarding 

this review and final action, we note 

that FAA staff involved in reviewing the 

manufacturers request may also be 

engaged in conducting the processes to 

adopt this rule in 14 CFR part 34 and 

to review emission information on 

current type certificates to confirm that 

they meet either Tier 6 or Tier 8 

requirements, as previously described. 

Therefore, we conclude that inadequate 

time exists to act on an exemption 

request with certainty for these six 

engines before their contract deliver 

dates. Consequently, we conclude that a 

limited modification to the otherwise 

universal effective date of the final Tier 

6 compliance deadline is appropriate to 

accommodate the commenter’s situation 

and that for these six specific engines 

additional lead time is needed due to 

cost and technical feasibility factors. 

We also believe that disrupting the 

scheduled delivery dates of these 

engines could risk subjecting the 

commenter to possible financial 

penalties for late delivery, with possible 

follow-on effects for the aircraft 

manufacturer and airlines. We also find 

that there is no significant adverse effect 

on the environment in allowing these 

six engines to be produced and sold as 

compliant with Tier 4 standards, 

especially if four of the engines 

ultimately comply with the Tier 6 

standards. 

For the above reasons, and in 

response to the comments and under 

our authority under sections 231(a)(3) 

and (b) to issue final regulations with 

such modifications to the proposal as 

the Administrator deems appropriate 

and to make revised standards effective 

after such period as the Administrator 

finds necessary to permit the 

development and application or 

requisite technology, giving appropriate 

consideration to the cost of compliance 

within such period, we are including an 

exception provision in the regulations 

that permits any aircraft engine 

manufacturer to produce and enter into 

commerce up to six newly 

manufactured engines with a date of 

manufacture, as defined in the 

regulations, prior to August 31, 2013 

that are not certificated to meet Tier 6 

emission requirements. These engines 

must have a type certificate which 

indicates that they meet the 40 CFR part 

87 requirements last updated on 

October 30, 2009 (i.e., Tier 4). No formal 

exemption request or approval will be 

required for these six engines. These 

engines will be reported to EPA as part 

of the annual reporting requirement as 

described above for exempt engines. 

We know of no other engine 

manufacturer that is in this situation 

today, (i.e., contracted deliveries of 

engines not meeting the production cutoff within several months of the 

production cut-off date). However, as a 

matter of equity and to address 

situations which we may not be 

informed of at this time, we are 

extending this transitional flexibility to 

all manufacturers. 

c. Voluntary Emission Offsets 

We requested comment on 

establishing a voluntary EPA program 

by which manufacturers could receive 

emission credits for producing cleaner 

engines, which they could use to offset 

higher emissions from exempted 

engines. An example of such a program 

was summarized in a memorandum to 

the docket.91 The types of programs we 

were considering would be developed, 

promulgated, and administered by EPA. 

As described in the proposal and 

summarized here, we expected 

manufacturers to be interested in 

generating offsets for one of three 

purposes. First, manufacturers might 

choose to generate offsets as part of their 

justifications for exemptions. Second, 

manufacturers might choose to generate 

offsets as part of a justification for being 

allowed to exceed the numerical limit 

that FAA and EPA are willing to 

approve in an exemption request. Third, 

provided a provision was promulgated 

to allow this, a manufacturer might also 

be interested in generating offsets to 

bank for use for exemptions of engines 

to be produced after the credit 

generating engines are produced, or 

possibly against a future production 

cutoff. 

Under the proposed approach, 

generation of offsets would be voluntary 

and would be open to all certifying 

engine manufacturers. One concept was 

to allow credits to be generated only 

from engine models that are introduced 

after this rule and that had characteristic 

levels significantly below the otherwise 

applicable standard (e.g., at least 10 

percent below). There was a separate 

question, however, regarding how to 

calculate the credit. If we adopted, for 

example, a 10 percent threshold for 

eligibility, we would probably also 

allow credits only to the degree which 

the NOX characteristic level was more 

than 10 percent below the standard. 


TKELLEY on DSK3SPTVN1PROD with RULES2
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36367 

This would ensure a net improvement 

in emissions. Also, we could reserve the 

right to restrict the use of credits so that 

they were used in a manner that 

ensured there was no net adverse 

impact on air quality. Such a program 

would need to ensure that emission 

benefits from one aircraft model truly 

offset the higher emissions from another 

model. Equivalency factors could be 

developed to account for differences in 

the number of LTOs per year and the 

lifetime of the aircraft. 

We received a number of comments 

on the possibility of implementing a 

voluntary credit offset program. The 

ATA expressed significant doubt that 

EPA had the legal authority to adopt a 

voluntary emissions offset program. 

They argued that the standard setting 

authority under section 231 of the CAA 

does not appear to provide such 

authority. ATA further stated that where 

offsets or emissions trading schemes 

exist for other source categories, the 

authority is express. Examples cited 

were the CAA authority for the trading 

program under the acid rain program, 

and the Energy Independence and 

Security Act authorization for the offset 

program used under the Corporate 

Average Fuel Efficiency Standards. Pratt 

& Whitney provided comments very 

similar to ATA relative to the lack of 

EPA’s legal authority to create such a 

program. 

The ATA also commented that the 

voluntary offset program embodied in 

the proposal would be unworkable in 

the context of aviation. They noted that 

unlike cars or trucks, aircraft engine 

manufacturers have relatively low 

production volumes and few frequently 

updated models for generating credits. 

Also, some manufacturers have more 

models than others and this could 

possibly lead to competitive distortions 

in the market. The AIA and GAMA also 

raised concerns regarding potential 

market disruptions. Further, ATA 

argued that opportunities for generating 

offsets would be limited by the 

proposal’s high thresholds for 

generating those credits. In the context 

of using emission credits for exemptions 

ATA added that each situation would be 

unique and it would not be possible to 

match exemptions to credits, or to 

assess the further complexities of the 

‘‘equivalency factors’’ described in the 

proposal. Finally, they stated that an 

airline’s delivery schedule would be 

held hostage to the manufacturer’s 

ability to justify credits based on some 

other engine that the airline is not 

buying. For these reasons, ATA asked 

that no offset program be adopted. 

Pratt & Whitney stated that the EPA 

proposal assumes that an offset program 

would create an incentive for 

manufacturers to build lower-emissions 

engines. On the contrary they argued, 

manufacturers already have that 

incentive because using the lowestemitting technology that is available 

maximizes the life of the engine. Such 

a program would simply create a 

windfall to manufacturers whose 

product lines are already capable of 

generating credits. The AIA, GAMA, 

and GE jointly commented that the 

proposed emission offset program goes 

beyond the borders of CAEP, and any 

emissions offset program should be 

developed within ICAO. General 

Electric was interested in exploring a 

potential emission offset program, 

particularly if the program would be 

applicable to new engine designs and 

derivatives that are subject to the 

proposed Tier 8 standards, and if it 

created the incentive to adopt new 

technologies earlier than would 

otherwise be the case in the absence of 

such incentives. 

We appreciate the concerns raised by 

the commenters regarding the proposed 

voluntary offset emission program. We 

are also encouraged by GE’s interest in 

further discussions about how this 

program may be useful in the context of 

the Tier 8 standards and a possible 

future Tier 8 production cutoff. EPA 

agrees that the proposal needs to be 

further developed to address certain 

aspects of the offset program. We have 

determined that the time it would take 

to sufficiently develop the program is 

incompatible with the need to promptly 

promulgate the Tier 6 production cutoff 

standard with a near-term effective date 

of January 1, 2013. Therefore we are not 

including the voluntary emission offset 

program in the final rule at this time. 

Nonetheless, we continue to see value 

in such a program for the aviation 

industry and recommend continuing to 

consider such a regulatory flexibility in 

the future. 

Although we are deferring action on 

the proposed voluntary emission offset 

program for the time being, we believe 

that such programs are envisioned 

within the ETM language related to 

exemptions. Furthermore, we do not 

agree with the commenters who 

questioned the EPA’s legal authority for 

adopting a voluntary emissions offset 

program as part of the aircraft engine 

emission standards. We are somewhat 

surprised by the industry commenters 

who questioned the authority for 

averaging, banking, and trading (ABT) 

programs outside of the narrow 

examples cited in their comments, and 

we are not yet persuaded by their 

claims. Note that the U.S. Court of 

Appeals for the D.C. Circuit has clearly 

stated that EPA has substantial 

discretion under the CAA section 231 to 

adopt final aircraft emission standards 

as the agency deems appropriate 

(National Ass’n of Clean Air Agencies v. 

EPA 489 F.3d 1221 (D.C. Cir. 2007)). We 

also wonder to what extent their view 

represents the industry as a whole, 

including any aircraft engine 

manufacturers who also manufacture 

engines that are subject to other EPA 

regulations that provide for ABT 

without the ‘‘express’’ statutory 

authority the commenters claim is 

necessary. If in future actions we seek 

additional comments on the legality of 

ABT programs under our aircraft 

standards, we will be interested in 

receiving comments from other 

stakeholders in the mobile source arena 

who might have views regarding the 

arguments presented by the industry 

commenters above. 

In the meantime, we note that several 

of our mobile source regulations, in 

addition to the rule cited by industry 

commenters, have long provided 

regulated industry with the flexibilities 

inherent in an ABT program, under the 

authority of, for example CAA section 

213, and none of those subject 

industries have opposed the creation of 

such programs or questioned their legal 

basis. (See, e.g., 40 CFR part 89, subpart 

C (averaging, banking and trading 

provisions for nonroad compressionignition engines); 40 CFR part 90, 

subpart C (certification averaging, 

banking and trading provisions for 

nonroad spark-ignition engines at or 

below 19 kilowatts); 40 CFR part 91, 

subpart C (averaging, banking and 

trading provisions for marine sparkignition engines); 40 CFR part 92, 

subpart D (certification averaging, 

banking and trading provisions for 

locomotives and locomotive engines); 

40 CFR part 94, subpart D (certification 

averaging, banking and trading 

provisions for marine compressionignition engines).) EPA continues to 

believe that the legal basis of these ABT 

programs is sound. 

4. Potential Phase-In of New Tier 8 NOX

Standards for Newly-Manufactured 

Engines 

We did not propose a production 

cutoff for the Tier 8 NOX standards for 

newly-manufactured engines. This 

means that engine manufacturers may 

continue to produce Tier 6 compliant 

engines of previously certified models 

after the Tier 8 standards become 

effective for newly-certified engine 

models. As noted elsewhere, EPA is 

working within the ICAO/CAEP 

framework to develop harmonized 

international standards for aircraft 


TKELLEY on DSK3SPTVN1PROD with RULES2
36368 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

92 ICAO, ‘‘Committee on Aviation Environmental 

Protection (CAEP), Report of the Eighth Meeting, 

Montreal, February 1–12, 2010,’’ CAEP/8–WP–80. A 

copy of this document is in docket number EPA– 

HQ–OAR–2010–0687. 

turbine engines. At the February 2010 

meeting of CAEP, where the CAEP/8 

NOX standards were approved for 

recommendation to ICAO, the 

committee decided that further 

consideration could be given to a related 

newly-manufactured engine standard 

pending new information on technology 

and market responses, although no 

formal action was taken at the time to 

explicitly make this a future work item 

for CAEP.92

Assuming a CAEP/8 production cutoff 

is adopted at some time in the future, 

we will re-examine the permanent 

exemption provisions to ensure a timely 

and orderly phase-out of engine models 

that do not meet the CAEP/8 NOX

standards. We would expect this to be 

done through a notice and comment 

rulemaking process to amend our own 

regulations. 

C. Application of Standards for 

Derivative Engines 

It is very common for a manufacturer 

to make changes to an originally type 

certificated engine model that is in 

production while keeping the same 

basic engine core and combustor design. 

In some cases these modifications may 

affect emissions. As a result, the 

certificating authority (in our case the 

FAA) must decide whether the emission 

characteristics of the modified design 

were significant enough from the parent 

engine’s certification basis that a 

demonstration of compliance with more 

recent emission standards is necessary, 

or if the changes were minor relative to 

the parent engine’s emission 

certification basis so that it is 

considered a derivative version of the 

original model with no emissions 

changes. This may be further 

complicated because of the common 

practice of making iterative changes 

over time raises the question as to when 

the cumulative changes reach a point 

where a new demonstration of 

compliance is warranted. 

In the past, these determinations were 

made for turbofan engines by an 

engineering evaluation that was 

performed by the engine manufacturer 

and then reviewed by the FAA. As part 

of the ICAO/CAEP deliberations leading 

up to the February 2010 CAEP/8 

meeting, a new standardized guidance 

was agreed upon as described in the 

ETM. The guidance, which the U.S. 

fully supported, includes specific 

criteria that can be used to determine 

when a design modification requires a 

new demonstration of compliance with 

newer emission standards, or when a 

modification was simple enough to be 

considered a no emissions change. 

We are including the ETM 

requirements in our regulations to 

address the longstanding need to 

provide consistent standards for the 

decision process regarding derivative 

engines and applicable emission 

standards. The definition of ‘‘derivative 

engines for emissions certification 

purposes,’’ along with the criteria for 

making this determination, will provide 

engine manufacturers and the regulators 

with more certainty regarding emission 

standard requirements for future 

modifications made to certificated 

models. To ensure that the numerical 

decision criteria can be administered to 

allow for the consideration of unusual 

circumstances or special information, 

we are also providing the FAA with 

some flexibility to make adjustments to 

the specific criteria based on good 

engineering judgment. In summary, if 

the FAA determines that an engine 

model is sufficiently similar to its 

parent engine so as to meet the criteria 

established in § 87.48, the manufacturer 

may demonstrate certification 

compliance and continue production of 

the engine model to the same extent as 

allowed for the original engine model. 

However, if the FAA determines that an 

engine model is not a derivative for 

emission certification purposes, the 

manufacturer would be required to 

demonstrate compliance with the most 

recent emissions standards. This 

determination will be made using 

numerical criteria consistent with ICAO 

provisions, and a modified engine 

model can be considered a ‘‘derivative’’ 

only if it is: (1) Derived from an original 

engine that had received a U.S. 

certification, (2) the original engine was 

certified under title 14 of the CFR, and 

(3) one of the following conditions is 

met: 

(1) The FAA determined that a safety 

issue exists that requires an engine 

modification; or 

(2) Emissions from the derivative 

engines are equivalent to or lower than 

the original engine. 

The proposed rule provided that the 

engine manufacturer could show 

emissions equivalency by demonstrating 

that the difference between emission 

rates of a derivative engine and the 

original engine are within the following 

allowable ranges, unless otherwise 

adjusted using good engineering 

judgment as determined by the FAA: 

±3.0 g/kN for NOX

±1.0 g/kN for HC 

±5.0 g/kN for CO 

±2.0 SN for smoke 

The proposed rule also provided that 

engine models represented by 

characteristic levels at least five percent 

below all applicable standards would be 

allowed to demonstrate equivalency by 

engineering analysis. In all other cases, 

the manufacturer would be required to 

test the new engine model to show that 

its emissions met the equivalency 

criteria. 

We received three significant 

comments on the proposed derivative 

provisions. First, ATA, PW, and 

Dassault-Aviation (DA) pointed out that 

the proposed criteria contained a 

substantial deviation from the expressed 

intent of the proposal and the ETM 

guidance. Specifically, they noted that 

the ETM provides that ‘‘If a modified 

engine remains on the existing type 

certificate, it may retain the existing 

certification basis of the parent engine if 

the modification(s) * * * results in a 

decrease of the absolute emissions 

levels. * * * ’’ They pointed out, 

however, that the proposed rule 

provided that the certificate holder must 

demonstrate ‘‘ * * * the proposed 

derivative engine model’s emissions 

meet the applicable standards and differ 

from the original model’s emission rates 

only within * * * ’’ specified ranges for 

each pollutant. For example, the 

specified range is + or¥3 g/kN for NOX. 

The commenters stated that this is more 

stringent than the ETM, and could 

discourage cleaner engines that are not 

clean enough to meet the next tier of 

standards. They asked that the final rule 

be consistent with the ETM to prevent 

this untoward effect. 

We agree that the regulations should 

allow for such engines to be considered 

derivatives, even if the difference was 

outside the ‘‘no emission change’’ range. 

This allowance is clearly consistent 

with the ETM and was inadvertently left 

out of our proposed language. Therefore, 

the final regulations contain this 

allowance. 

Second, AIA and GAMA jointly 

commented that the term ‘‘new model’’ 

was inappropriate when used to 

determine which engine models could 

demonstrate equivalency by engineering 

analysis, and when the manufacturer 

would be required to test the new 

engine model to demonstrate 

compliance with the equivalency 

criteria. They argued that because this 

provision applies to changes made to an 

existing engine, it could cause an engine 

manufacturer to conduct an additional 

emissions test in cases where a very 

small change was made to the engine 


TKELLEY on DSK3SPTVN1PROD with RULES2
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36369 

93 ICAO, ‘‘Annex 16 to the Convention on 

International Civil Aviation, Environmental 

Protection, Volume II, Aircraft Engine Emissions,’’ 

Part III, Chapter 2, Section 2.4. A copy of this 

document is in docket number EPA–HQ–OAR– 

2010–0687. 

94United Kingdom, Civil Aviation Authority, 

‘‘ICAO Emissions Databank.’’ Available at the Civil 

Aviation Authority Web site www.caa.co.uk/ 

default.aspx?catid=702. 

95Under today’s regulations, a grouping of 

engines with an essentially identical emissionrelated design are defined to be an ‘‘engine submodel’’. Engines with slightly different designs are 

defined to be an ‘‘engine model’’. 

96The report would be submitted only to EPA. No 

separate submission or communication of any kind 

is required for the FAA. 

due to a performance or engine weight 

change. The commenters recommended 

that this be altered to allow a 

manufacturer to consider ‘‘* * * such 

emissions changes by analysis prior to 

this point, and only if such analysis 

revealed a deterioration that pushed the 

engine very close to the emission limits 

that the manufacturer be requested to 

complete an engine emissions test.’’ 

The AIA and GAMA also jointly 

commented on the proposed regulatory 

text that states if the characteristic level 

of the original certificated engine model 

before modification is at or above 95 

percent of the applicable standard for 

any pollutant, you must measure the 

proposed derivative engine model’s 

emissions for all pollutants to 

demonstrate the derivative engine’s 

resulting characteristic levels will not 

exceed the applicable emission 

standards. They claimed that the use of 

the term ‘‘you must measure’’ also 

implies further engine testing when 

additional analysis may likely prove 

sufficient. 

We agree that the term ‘‘new model’’ 

should be modified and have instead 

used the term ‘‘new engine 

configuration’’ in the final regulations. 

We want to clarify, however, that the 

regulations do explicitly require engine 

testing when an original engine’s 

emissions are within 5 percent of any 

emission standard. This text does not 

allow engineering analysis in such 

cases. We continue to believe this to be 

the appropriate policy. Given the greater 

uncertainty of engineering analysis 

relative to actual testing, we cannot rely 

on it for engines very close to the 

standard. This provision is also 

consistent with the ETM. Therefore, we 

are promulgating this requirement as 

proposed. 

Third, AIA, GAMA, and GE 

commented that as a general matter, 

EPA should not codify the ETM’s 

derivative engine decision criteria 

because the ETM guidance will evolve 

over time and the Agency’s rigid 

regulations will not, even allowing for 

the FAA flexibility to use good 

engineering judgment if necessary when 

deciding what is or is not a derivative 

engine. They concluded it was simply 

better to let the FAA rely on the ETM 

guidance in its decision making. As 

noted by the commenters, the ICAO 

ETM itself is a guidance document for 

use by aviation authorities. It does not 

represent a standard or any other 

enforceable regulatory requirement. In 

the particular case cited by the 

commenters, they appear to ask that 

FAA be given unlimited discretion to 

determine which engines are subject to 

each new tier of standards. 

In response to the comment, we also 

note that the Clean Air Act directs EPA 

to establish air pollution emission 

standards for aircraft engines. (See 42 

U.S.C. 7551(a)(2)(A).) Implementation of 

this statutory directive mandates that 

we specify enforceable air pollution 

emission standards and control 

requirements for aircraft engines in 

regulatory form. We believe that it is 

reasonable for us to also establish other 

associated requirements in regulatory 

form. Our final rule achieves an 

appropriate balance between providing 

FAA discretion to implement the 

standards, and the need to establish 

aircraft engine emission regulations that 

ensure consistency in application. 

We also disagree with the suggestion 

that the ETM will evolve over time, but 

that our regulations will not. As a 

working member of ICAO’s Committee 

on Aviation Environmental Protection, 

we will participate in developing any 

relevant revisions to the ETM and will 

make appropriate adjustments to our 

regulations as needed. 

We continue to believe that the ETM 

specifications for ‘‘no emissions 

change’’ are appropriate objective 

criteria for derivative engines. Thus, 

because we are codifying regulatory 

provisions to objectively specify when 

engines are considered to be ‘‘derivative 

engines’’, we are promulgating 

regulatory provisions consistent with 

the ICAO ETM guidance. 

D. Annual Reporting Requirements 

In May of 1980, ICAO’s Committee on 

Aircraft Engine Emissions (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 topics and Volume II addressing 

Aircraft Engine Emissions. Annex 16 

has continued to grow and today Annex 

16, Volume II includes a list of 

mandatory requirements to be satisfied 

in order for an aircraft engine to meet 

the ICAO emission standards.93 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 ‘‘Emissions 

Databank’’ (EDB) 94 for turbofan engines 

with maximum thrust ratings greater 

than 26.7 kN in order to aid with 

emission calculations and analysis as 

well as help inform the general public. 

In order to understand how current 

gaseous emission standards are affecting 

the current fleet, we need to have access 

to timely, representative emissions data 

of the engine fleet at the requisite model 

level. The EDB is a useful tool for 

providing a general overview of the 

aircraft fleet, as it contains information 

on engine exhaust emissions and 

performance tests. However, it is not 

updated on a consistent basis, it 

contains a varying amount of 

voluntarily reported data from each 

manufacturer, and it does not 

specifically list every engine submodel.95 It also does not contain 

information on smaller thrust category 

turbofans or turboprops, and contains 

no information on past or recent engine 

production volumes. We need this data 

to conduct accurate emission 

inventories and develop appropriate 

policy. Accordingly, we do not consider 

the EDB to be a sufficient tool upon 

which to base policy decisions or adopt 

future standards. Furthermore, in the 

context of EPA’s standards-setting role 

under the Clean Air Act 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. Under the Clean Air Act, 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).) 

Therefore, we proposed to require that 

each aircraft engine manufacturer 

submit a production report directly to 

EPA 96 with specific information for 

each individual engine sub-model that: 

(1) Is designed to propel subsonic 

aircraft, (2) is subject to our exhaust 

emission standards, and (3) has received 


TKELLEY on DSK3SPTVN1PROD with RULES2
36370 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

97See Regulation Part 87—Control of Air 

Pollution from Aircraft and Aircraft Engines, 

Subpart E, § 87.42 Production report to EPA for 

definitions. 

98 Dp/Foo: total gross emissions of each gaseous 

pollutant (mass)/rated thrust (g/kN). 

a U.S. type certificate. More specifically, 

the scope of the proposed production 

report would include turbofan engines 

as described above with maximum rated 

thrusts greater than 26.7 kN, i.e., those 

subject to gaseous emission and smoke 

standards. In addition, it would include 

turbofans with maximum rated thrusts 

less than or equal to 26.7 kN and all 

turboprop engines, i.e., those only 

subject to smoke standards. We also 

proposed that this specific exhaust 

emission related information be 

reported to us in a timely manner, 

which will allow us to conduct proper 

emissions inventory analyses of the 

existing fleet and to ensure that any 

public policy we create based on this 

information will be well informed. All 

of the specific reporting items we 

proposed were the same as requested for 

the EDB, with the exception of total 

annual engine production volumes, 

information on type certificates, and the 

emission standards to which the engine 

sub-model was certified. We anticipated 

that the new emissions database would 

be a significant improvement over the 

current EDB because the data reporting 

is mandatory, it will be comprehensive 

in that it covers all engine models, and 

it must be updated annually. 

In addition to some minor comments 

which are addressed in the analysis of 

comments document, we received 

comments from engine manufacturers 

addressing two specific areas of the 

proposed production reporting 

provision. First, the Aerospace 

Industries Association (AIA), General 

Aviation Manufacturers Association 

(GAMA) and Pratt & Whitney (PW) 

commented that annual production 

volume data is considered confidential 

business information (CBI) and as such, 

it should be exempt from Freedom of 

Information Act (FOIA) requests or 

other methods of public disclosure. 

Second, AIA, GAMA, PW and Williams 

International pointed out that for those 

engines which are only subject to smoke 

standards (turbofans with maximum 

thrust ratings less than or equal to 26.7 

kN, and turboprops), manufacturers are 

not required under current regulations 

to measure gaseous emissions (HC, CO, 

NOX, CO2). As such, data on these 

gaseous emissions, as well as 

information used to measure gaseous 

emissions (reference pressure ratio and 

fuel flow data) are not readily available 

for these engines. Further, smoke data 

by mode of the LTO cycle may not be 

available for these older engines. These 

manufacturers pointed out that new 

testing of such engines would be 

required to generate these data, and that 

appropriate test procedures for these 

engines do not currently exist. 

We understand and respect the needs 

of manufacturers to maintain the 

confidentiality of their legitimately 

proprietary data. However, we do not 

include in our regulations an up-front 

blanket CBI determination for any of the 

other mobile source sectors, and do not 

believe it is necessary here. As such, in 

response to the comments, we are 

including regulatory language patterned 

after existing regulations for several 

other mobile source categories which 

sets forth how we would treat—on a 

case by case basis—submitted data 

which is covered by a CBI claim from 

the manufacturer as provided by 40 CFR 

part 2. The addition of this provision 

will ensure that no information that is 

legitimately protected CBI gets 

inadvertently released to the public. 

We do not believe it is appropriate to 

require additional testing for turbofans 

with maximum thrust ratings less than 

or equal to 26.7 kN and turboprops 

specifically for production reporting 

purposes. Thus, for these engines, we 

will not be requiring the submission of 

HC, CO, NOX, CO2, reference pressure 

ratio or fuel rate data. Further, we will 

not require additional testing of older 

engines for which smoke data by 

specific LTO cycle segment is not 

currently available. 

We also noted in the proposal that the 

reported information would be used in 

conjunction with the NOX and CO2

emission data already required to be 

submitted to us under section 87.64 for 

purposes of greenhouse gas (GHG) 

reporting to establish. This would 

effectively provide us with a complete 

and comprehensive engine exhaust 

emissions database. We noted our 

expectation that most manufacturers 

would likely add the proposed 

information items to the annual GHG 

report. No comments were received on 

combining the two reports. After further 

deliberation, we have decided to require 

a single, integrated report in this final 

rule to eliminate any possible confusion 

regarding the two separate reports and 

make reporting more efficient. 

The incremental reporting elements 

for each affected gas turbine engine submodel are listed below. Although not 

proposed, we have added engine type to 

the list for completeness. The reporting 

elements of the existing GHG report are 

also identified for completeness. 

• Company corporate name as listed 

on the engine type certificate (GHG); 

• Engine Type (turbofan, mixed 

turbofan, or turboprop); 

• Calendar year for which reporting 

(GHG); 

• Complete sub-model name (This 

will generally include the model name 

and the sub-model identifier, but may 

also include an engine type certificate 

family identifier) (GHG); 

• The type certificate number, as 

issued by the FAA (Specify if the submodel also has a type certificate issued 

by a certificating authority other than 

the FAA) (GHG); 

• Date of issue of type certificate and/ 

or exemption, i.e. month and year 

(GHG); 

• Emission standards to which the 

engine is certified, i.e., the specific 

Annex 16, Volume II, edition number 

and publication date in which the 

numerical standards first appeared. 

• If this is a derivative engine for 

emissions certification purposes, 

identify the original certificated engine 

model. 

• Engine sub-model that received the 

original type certificate for the engine 

type certificate family; 

• Production volume of the submodel for the previous calendar year 

(even if zero). If an engine sub-model is 

no longer being produced, state that the 

engine sub-model is not in production 

and list the date of manufacture (month 

and year) of the last engine produced; 

• Regarding the above production 

volume report, specify (if known) the 

number of engines that are intended for 

use on new aircraft and the number 

intended for use as certified (nonexempt) spare engines on in-use aircraft; 

• Reference pressure ratio (GHG) (not 

applicable to turbofans with maximum 

thrust ratings less than or equal to 26.7 

kN, and turboprops); 

• Combustor description (type of 

combustor where more than one type 

available on an engine); 

• Engine maximum rated thrust 

output, in kilonewtons (kN) or kilowatts 

(kW) (depending on engine type) (GHG); 

• Unburned hydrocarbon (HC) mass 

(g) total (weighted) and over each 

segment of the Landing and Take-off 

Cycle (LTO), i.e. Take-off, Climb, 

Approach, Taxi/Ground Idle (not 

applicable to turbofans with maximum 

thrust ratings less than or equal to 26.7 

kN, and turboprops);97

• Unburned hydrocarbon (HC) 

characteristic level (i.e. mass of 

hydrocarbons over LTO cycle/Rated 

Thrust (Dp/Foo)) (not applicable to 

turbofans with maximum thrust ratings 

less than or equal to 26.7 kN, and 

turboprops);98


TKELLEY on DSK3SPTVN1PROD with RULES2
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36371 

99The CAEP position referred to by AIA and 

GAMA is based on the expectation that future 

designs for supersonic aircraft will be significantly 

different from past designs. The agreement was 

reached at CAEP/8 to evaluate emission standards 

for these engines as a future work item. 

100A strikeout and highlighted version of the 

amendments is contained in Attachment A to ICAO 

state letter AN 1/61.2, AN 1/62.2–07/32 entitled, 

‘‘Proposed Amendment to International Standards 

and Recommended Practices, Environmental 

Protection, Annex 16 to the Convention on 

International Civil Aviation, Volume II Aircraft 

Engine Emissions, May 27, 2007. A copy of this 

document is in docket number EPA–HQ–OAR– 

2010–0687. 

101 ICAO, ‘‘International Standards and 

Recommended Practices, Annex 16 to the 

Convention on International Civil Aviation, 

Environmental Protection, Volume II Aircraft 

Engine Emissions,’’ Third Edition, July 2008, 

International Civil Aviation Organization. This 

document contains the full text of ICAO standards 

and practices and is in docket number EPA–HQ– 

OAR–2010–0687. 

102 ICAO, ‘‘International Standards and 

Recommended Practices, Annex 16 to the 

Convention on International Civil Aviation, 

Environmental Protection, Volume II Aircraft 

Engine Emissions, Amendment 7, effective July 18, 

2011’’ Third. A copy of this document is in docket 

number EPA–HQ–OAR–2010–0687. 

• Carbon monoxide (CO) mass (g) 

total (weighted) and over each segment 

of the entire Landing and Take-off Cycle 

(LTO) (i.e. Take-off, Climb, Approach, 

Taxi/Ground Idle) (not applicable to 

turbofans with maximum thrust ratings 

less than or equal to 26.7 kN, and 

turboprops); 

• Carbon monoxide (CO) 

characteristic level (i.e. mass of CO over 

LTO cycle/Rated Thrust (Dp/Foo)) (not 

applicable to turbofans with maximum 

thrust ratings less than or equal to 26.7 

kN, and turboprops); 

• Nitrogen oxides (NOX) mass (g) total 

(weighted) and over each segment of the 

entire Landing and Take-off Cycle (LTO) 

(i.e. Take-off, Climb, Approach, Taxi/ 

Ground Idle) (GHG) (not applicable to 

turbofans with maximum thrust ratings 

less than or equal to 26.7 kN, and 

turboprops); 

• Nitrogen oxides (NOX) 

characteristic level (i.e. mass of NOX

over LTO cycle/Rated Thrust (Dp/Foo)) 

(GHG) (not applicable to turbofans with 

maximum thrust ratings less than or 

equal to 26.7 kN, and turboprops); 

• Smoke number total and over each 

segment of the entire Landing and Takeoff Cycle (LTO) (i.e. Take-off, Climb, 

Approach, Taxi/Ground Idle), if 

available; 

• Smoke number characteristic level; 

• Carbon dioxide (CO2) mass (g) total 

(weighted) and over each segment of the 

entire Landing and Take-off Cycle 

(LTO), (i.e. Take-off, Climb, Approach, 

Taxi/Ground Idle (GHG)) (not applicable 

to turbofans with maximum thrust 

ratings less than or equal to 26.7 kN, 

and turboprops); 

• Number of tests run per sub-model 

(GHG); 

• Number of engines tested per submodel (GHG); 

• Fuel flow (grams/second) total 

(weighted) and over each segment of the 

Landing and Take-off Cycle (LTO) (i.e. 

Take-off, Climb, Approach, Taxi/ 

Ground Idle) (GHG) (not applicable to 

turbofans with maximum thrust ratings 

less than or equal to 26.7 kN, and 

turboprops); and 

• Any additional remarks to the EPA. 

The annual report is required to be 

submitted for each calendar year in 

which a manufacturer produces any 

engine subject to emission standards as 

previously described. These reports will 

be due by February 28 of each year, 

starting with the 2014 calendar year, 

and cover the previous calendar year. 

This report shall be sent to the 

Designated EPA Program Officer. Where 

information provided for any previous 

year remains valid and complete, the 

engine manufacturer may report the 

production figures and 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 provide to 

each manufacturer. As noted previously, 

we intend to use the reports to help 

inform any policy approaches regarding 

aircraft engine emissions that we 

consider, including possible future 

emissions standards. The information 

will also enhance the general public’s 

understanding of the emission 

characteristics of aviation gas turbine 

engines and allow independent 

development of emission inventories 

and assessments of local environmental 

effects. 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 Web site and will 

be updated annually. We have assessed 

the potential reporting burden 

associated with this annual reporting 

requirement. That assessment is 

presented in sections V. and IX.B of this 

notice. 

E. Standards for Supersonic Aircraft 

Turbine Engines 

We proposed CO and NOX emission 

standards for turbine engines that are 

used to propel aircraft at sustained 

supersonic speeds, i.e., supersonic 

aircraft to complement our existing HC 

standard for these engines. These 

standards were originally adopted by 

ICAO in the 1980s, and our adoption of 

NOX and CO standards for commercial 

engines in 1997 omitted coverage of 

these pollutants for supersonic 

commercial engines that were then in 

use. The lack of EPA CO and NOX

standards for engines used by 

supersonic aircraft has had no practical 

effect, because no such engines have 

been certified by the FAA. Also, none of 

the engines used on these aircraft are 

currently in production. 

The Aerospace Industries Association 

(AIA) and the General Aviation 

Manufacturers Association (GAMA) 

commented that within CAEP it was 

agreed that these standards are ‘‘not 

appropriate for future products’’ and 

should not be adopted by EPA.99

However, to meet U.S. treaty obligations 

under the Convention on International 

Civil Aviation as previously described 

in section I.C, we believe it is necessary 

and appropriate to adopt these 

conforming standards. Therefore, we are 

promulgating the standards for 

supersonic aircraft as proposed. As 

previously noted, this action has no 

practical effect, and simply aligns EPA 

standards with the rest of the world. 

(See section III.G for a brief discussion 

of potential revised emission standards 

for future engine designs that may be 

used on supersonic aircraft.) 

F. Amendments To Test and 

Measurement Procedures 

We are incorporating by reference into 

the 40 CFR 87.60 regulatory text, 

amendments to ICAO’s International 

Standards and Recommended Practices 

for aircraft engine emissions testing and 

certification.100 101 102 These 

amendments to Annex 16, Volume II are 

primarily intended to ensure that the 

provisions reflect current certification 

practices. The amendments make 

clarifications or add flexibilities for 

engine manufacturers. They are 

described below. 

• Standardizing the terminology 

relating to engine thrust/power 

• Clarifying the need to correct 

measured results to standard reference 

day and reference engine conditions 

• Allowing a certificating authority to 

approve the use of test fuels other than 

those specified during certification 

testing 

• Allowing materials other than 

stainless steel in the sample collection 

equipment 

• Clarifying the appropriate value of 

fuel flow to be used at each LTO test 

point 

• Clarifying exhaust nozzle 

terminology for exhaust emissions 

sampling 

• Allowing an equivalent procedure 

for gaseous emission and smoke 


TKELLEY on DSK3SPTVN1PROD with RULES2
36372 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

103The CAEP Working Group 3 has taken the 

position that engine development programs for 

future supersonic aircraft applications should be 

focused on achieving the emission standards that 

are applicable to subsonic aircraft engines. Past 

supersonic aircraft engines required the use of 

afterburner technology to achieve supersonic 

speeds. Future supersonic aircraft are expected to 

use engines without that technology, making them 

more similar to their subsonic counterparts. 

measurement if approved by the 

certificating authority 

Manufacturers are either already 

voluntarily complying with these 

changes or will be even in the absence 

of a final rule. Our adoption of these test 

procedure amendments is, therefore, 

unlikely to require new action by 

manufacturers beyond what they have 

already done to meet ICAO’s adopted 

and recommended amendments. 

Our incorporation by reference of the 

ICAO test procedure makes most of the 

existing subpart G and all of subpart H 

of part 87 obsolete. Therefore, we are 

removing these sections from the 

regulation, as proposed. 

G. Possible Future Revisions to Emission 

Standards for New Technology Turbine 

Engines and Supersonic Aircraft 

Turbine Engines 

As a general matter, emission 

standards not only apply to all 

conventional turbofan aircraft engines 

greater than 26.7 kN, but also to all 

aircraft engines designed for 

applications that otherwise would have 

been fulfilled by turbofan aircraft 

engines. The high price of jet fuel, 

current emphasis on fuel economy, and 

need to reduce emissions have renewed 

interest in open rotor propulsion 

designs for future aircraft gas turbine 

engines. Essentially, the fan of an open 

rotor engine is not contained within an 

engine nacelle as it is with a 

conventional turbofan engine. This 

design has also been referred to as an 

unducted fan, propfan, or ultra-high 

bypass engine. At least two engine 

manufacturers are actively pursuing 

such designs for certification in the later 

part of this decade. 

It now appears that certain aspects of 

EPA’s gas turbine engine emission 

standards may be incompatible with 

these new designs. For example, the 

current landing and takeoff cycle for 

emissions certification is based on 

conventional engine designs where a 

significant amount of thrust is generated 

by an idling engine. Specifically, idle 

emissions are measured and calculated 

at seven percent of the engine’s rated 

thrust. However, the fan/prop blades of 

an open rotor engine may be variable in 

pitch and this may allow the blades to 

be ‘‘feathered’’ at idle. In that position, 

the blades are rotated so very little 

thrust is generated as the engine idles 

and generates emissions. Also, future 

aircraft using these engine designs may 

fly at somewhat slower speeds. This 

might affect the time these aircraft 

spend during the climbout mode of the 

landing and takeoff cycle. Therefore, the 

traditional landing and takeoff cycle 

used in turbofan engine emissions 

certification may need to be revised in 

the future to accommodate open rotor 

engines. 

We will be working within CAEP to 

evaluate the differences between 

conventional turbine engine and open 

rotor engine technologies, and to revise 

the emission standards and test 

procedures as appropriate for these 

latter engines. If any changes are 

required, EPA will undertake 

rulemaking to revise our regulations 

accordingly. 

There may also be changes in the 

emission standards and test procedures 

for engines used to power future 

supersonic transport aircraft designs. 

The emission standards for these 

engines were originally developed in 

the early 1970s in response to the 

Aerospatiale-BAC Concorde. Since that 

time, there have been varying levels of 

interest in developing a new generation 

of supersonic transport. As a result, the 

current CAEP work program is 

evaluating the status of supersonic 

aircraft engine development and the 

potential need for new emission 

standards and test procedures.103 Our 

recent discussions with engine 

manufacturers indicate that no 

substantive work is being undertaken at 

this time, however. We will continue to 

work within CAEP on this issue and 

undertake rulemaking to revise the 

regulations for supersonic aircraft 

engines as appropriate. 

V. Description of Other Revisions to the 

Regulatory Text 

In addition to the changes discussed 

above, we are including a number of 

other changes to the regulatory program. 

Most of these changes are designed to 

bring the program into conformity with 

current technology and current 

technical or policy practice. Each of 

these is discussed below. 

A. Applicability Issues 

This section discusses how this final 

rule relates to engines used in military 

and noncommercial civilian aircraft. We 

do not believe these changes will have 

practical significance for current engine 

models because the changes align with 

manufacturers’ current practice in 

certifying their engines. 

1. Military Engines 

We do not intend today’s action to 

have any impact on engines installed on 

military aircraft, or new aircraft that are 

destined to be converted for military 

use. Military aircraft are not required to 

have FAA standard airworthiness 

certificates, and our 1997 endangerment 

finding for NOX and CO emissions and 

resulting standards did not cover 

military aircraft (see 62 FR at 25359). As 

such, engines used in military aircraft 

are not required to meet EPA emission 

standards, since our current regulations 

define ‘‘aircraft’’ subject to our rules as 

any airplane for which a U.S. standard 

airworthiness certificate (or foreign 

equivalent) is issued. (See 40 CFR 

87.1(a) of the existing regulations.) 

Currently, manufacturers certificate 

some engine models used in military 

aircraft with the FAA (with respect to 

emissions), because these engine models 

also have commercial applications and 

have to be certificated for such use. Our 

new standards and requirements will 

continue to apply only to engines used 

in aircraft for which standard 

airworthiness certificates are required, 

and thus are not applicable to engines 

used in military aircraft. It is not our 

intent to interfere with current practice 

with regard to engine models with joint 

commercial/military applications to the 

extent such engines are used in military 

aircraft. Although civilian aircraft 

applications of all such engines would 

be subject to the new standards and 

production cutoff, in the NPRM we 

proposed to include a statement in the 

regulations to clarify that the proposed 

production cutoff would not apply for 

previously certificated engines that are 

installed and used in military aircraft. 

One manufacturer commented that the 

definition of ‘‘military aircraft’’ we 

proposed should extend to sales of 

military aircraft outside of the U.S. 

While we believe the regulations as 

written do not apply to foreign sales of 

military aircraft, we are nonetheless 

revising our proposed definition of 

‘‘military aircraft’’ to clarify that foreign 

aircraft considered military under 

international laws and agreements are 

not covered by 40 CFR part 87. 

2. Noncommercial Engines 

Prior to this action, section 87.21(d) 

specified that gaseous emission 

standards applied to engines used in 

commercial applications with rated 

thrusts greater than 26.7 kN. These are 

engines intended for use by an air 

carrier or a commercial operator as 

defined in the Chapter I, Title 49 of the 

United States Code and Title 14 of the 

Code of Federal Regulations. Therefore, 


TKELLEY on DSK3SPTVN1PROD with RULES2
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36373 

104U.S. EPA, ‘‘Final Finding for Commercial and 

Noncommercial Turbofan and Turbojet Aircraft 

Emissions,’’ memorandum from John Mueller, 

Assessment and Standards Division, Office of 

Transportation and Air Quality, March 2012. A 

copy of this document is in docket EPA–HQ–OAR– 

2010–0687. 

engines of equivalent thrust ratings that 

are used in aircraft certificated by the 

FAA that are used in non-revenue, 

general aviation service were not 

required to comply with our current HC, 

CO, and NOX exhaust emission 

standards in § 87.21(d). They were and 

are subject, however, to the current 

standards for smoke and fuel venting. 

In today’s action we are applying the 

gaseous emission standards for 

commercial engines to their 

noncommercial civilian counterparts 

that are required to obtain standard 

airworthiness certificates. There are a 

couple of reasons for this action. First, 

the ICAO Annex 16, Volume II 

standards and recommended practices 

apply equally to commercial and 

noncommercial engines, and our rules’ 

previous failure to reflect this meant 

that our requirements did not fully 

conform to ICAO’s standards. Second, 

manufacturers already emissions certify 

engines that are used in non-revenue, 

general aviation service to these 

standards. Therefore, this provision 

simply incorporates the status quo. 

In order to make EPA standards 

conform to ICAO’s, we needed to, in 

addition to promulgating the necessary 

regulatory amendments, update the 

underlying finding regarding the need to 

limit gaseous emissions from 

commercial and non-commercial 

civilian aircraft, pursuant to CAA 

section 231(a)(2)(A). In 1997, our 

analysis and finding, and hence our 

regulations, were limited to commercial 

aircraft emissions. (See 62 FR at 25358.) 

In conjunction with the NPRM for this 

final rule, we proposed to expand that 

analysis and finding to include gaseous 

emissions from both commercial and 

non-commercial civilian aircraft engines 

with rated thrusts greater than 26.7 kN. 

We received no comments on that 

proposed finding, and are therefore 

finalizing our emissions assessment 

supporting this finding, which is 

contained in the docket for this 

rulemaking.104

B. Non-Substantive Revisions 

We are also taking the opportunity to 

revisit the clarity of other regulatory 

provisions in part 87. Many of these 

provisions were first written 30 or 40 

years ago with little or no change since 

then. We are revising the text related to 

some of these provisions to better 

organize, clarify, and update the 

regulations. Our goal is to revise the 

regulations in part 87 to properly 

organize the content of the regulation, 

use clearer language to describe the 

applicable requirements, clarify some 

definitions, and clear up a variety of 

terms and current practices that have 

not been adequately addressed. 

Except as discussed in previous 

sections, the changes to part 87 are not 

intended to significantly change the 

certification and compliance program. 

We did not reopen for comment the 

substance of any part of the program 

that remains unchanged substantively. 

This rule includes the following 

definitions and other minor changes in 

addition to those changes described 

earlier in this section or in section III. 

The definition of the term ‘‘aircraft’’ is 

being revised to be consistent with its 

meaning under FAA regulations in 14 

CFR 1.1. The existing part 87 definition 

limits ‘‘aircraft’’ to be only those aircraft 

issued an airworthiness certificate. This 

was done as a way to specify the 

applicability of the standards. However, 

this can cause confusion in a variety of 

ways. For example, this departs from 

the plain meaning of ‘‘aircraft,’’ as well 

as from the meaning given under the 

Clean Air Act and Title 49 of the United 

States Code. The revised definition 

aligns with these statutory definitions. 

The changed wording is intended to 

clarify the existing policy without 

changing it. 

Text specifying general applicability 

is being added to part 87.3 to be 

consistent with the new definition of 

‘‘aircraft’’ and maintain the effective 

applicability of the existing regulations, 

which uses narrow definitions to limit 

applicability. For example, the existing 

regulations limit the applicability of the 

standards by defining ‘‘aircraft’’ to only 

include fixed-wing airplanes with 

airworthiness certificates. They exclude 

non-propulsion engines from the 

definition of ‘‘aircraft engine’’ and 

turboshaft engines from the definition of 

‘‘aircraft gas turbine engine.’’ We believe 

it is more appropriate to explicitly 

exclude these engines in an 

applicability section than to rely on 

readers finding these exclusions in the 

definitions section. We are also 

renaming part 87.3 as ‘‘General 

applicability and requirements’’ and 

reorganizing the content for clarity. 

Finally, we are replacing the existing 

regulatory text related to federal 

preemption for exempted engines in 

part 87.7(f) with a codification of the 

statutory preemption language in part 

87.3 and an explanatory note that the 

statutory preemption applies to 

exempted engines because they are 

certified to prior-tier standards. 

ICAO Annex 16, Volume II is being 

incorporated by reference for test 

procedures. This involves a broader 

reference to Annex 16, with less content 

repeated in part 87. However, this does 

not substantively change the test 

procedures that apply since the existing 

procedures are based directly on Annex 

16, Volume II. As part of this change, we 

are adding the ICAO definition of 

‘‘characteristic level’’ to properly 

describe how manufacturers 

demonstrate that they meet applicable 

standards. 

Definitions are being added for ‘‘date 

of introduction,’’ ‘‘date of manufacture,’’ 

and ‘‘derivative engine for emissions 

certification purposes,’’ and the 

definition of ‘‘engine model’’ is being 

revised, to more carefully describe when 

new emission standards apply to 

specific aircraft engines. These 

definitions are generally consistent with 

the most common understandings of 

these terms by industry and FAA, and 

with the CAEP/8 recommendation for 

adoption by ICAO. Except for engines 

subject to exemptions, there will be no 

more engines required to be certified to 

the standards specified in part 87.21, so 

changing the definition of ‘‘engine 

model’’ will not change the 

requirements for engines certified to the 

Tier 4 or earlier standards. For the 

benefit of the reader, we are also 

reprinting the following definitions that 

remain unchanged: 

• Aircraft engine 

• Aircraft gas turbine engine 

• Class TP 

• Class TF 

• Class T3 

• Class T8 

• Class TSS 

• Commercial aircraft gas turbine 

engine 

• Fuel venting emissions 

Specific provisions are being added to 

define and require the use of ‘‘good 

engineering judgment.’’ This applies for 

instances where the regulation cannot 

spell out every technical detail of how 

a manufacturer should comply with the 

regulation. For example, the regulations 

rely on good engineering judgment 

being used on the engineering analysis 

of emissions equivalency for derivative 

engines (part 87.48(b)(2)), and for 

applying the turbofan test procedures to 

turboprop engines (part 87.60(a)). The 

general approach for implementing good 

engineering judgment is to allow 

manufacturers to exercise well 

substantiated and explained technical 

judgment subject to potential EPA and 

FAA review (as appropriate). The 

consequences of disagreements with a 

manufacturer’s decision would depend 


TKELLEY on DSK3SPTVN1PROD with RULES2
36374 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

on whether we believe the manufacturer 

made the decision in good faith. Where 

the manufacturer makes its decision in 

good faith, EPA or FAA could require a 

different approach for future work if we 

believe it would represent better 

engineering judgment. We believe these 

provisions reflect the spirit of the 

approach being used today to interpret 

the applicable regulations. 

Provisions are being added specifying 

rounding practices for rated output, 

rated pressure ratio, and calculated 

emission standards; generally specifying 

that they be expressed to at least three 

significant figures. The primary 

exception to this is the specification that 

smoke numbers be expressed to one 

decimal place. These specifications are 

consistent with how manufacturers are 

generally certifying engines today. 

Defining how to round these values 

would prevent manufacturers in the 

future from effecting small changes in 

the level of the emission standards to 

which they certify their engines. This is 

because standards are calculated using 

the numerical values of the rated output 

and rated pressure ratio. Without these 

specifications, manufacturers could 

subject themselves to a slightly less 

stringent standard by selectively 

rounding or truncating an engine 

model’s rated output to be low and its 

rated pressure ratio to be high, or by 

strategically rounding the calculated 

standard itself. While this has not been 

an issue in the past, it is important to 

maintain a level playing field for all 

manufacturers as standards become 

more stringent. We do not expect any 

more engines type-certificated to the 

standards specified in part 87.21, so the 

specified procedures for rounding these 

values will not change the requirements 

for engines certified to the Tier 4 or 

earlier standards 

Definitions are being added for 

‘‘turbofan engine,’’ ‘‘turbojet engine,’’ 

‘‘turboprop engine,’’ ‘‘turboshaft 

engine,’’ ‘‘supersonic,’’ and ‘‘subsonic’’ 

to avoid any uncertainty about how the 

standards apply to different types of 

engines. The definitions are intended to 

reflect the plain meaning of these terms. 

The regulations include the following 

additional amendments: 

Regulation cite Description of amendment Notes 

87.1 ......................... Add definition of ‘‘characteristic level’’ .. The characteristic level is established by ICAO Annex 16 as a means of calculating a statistical adjustment to measured emission results to take into account the level of uncertainty corresponding to the number of tests run for a 

given pollutant. 

87.1 ......................... Remove definitions for ‘‘emission measurement system’’, ‘‘power setting’’, 

‘‘sample system’’, ‘‘shaft power’’, 

‘‘taxi/idle (in)’’, and ‘‘taxi/idle (out)’’.

These terms will no longer be used in part 87. There will be no more engines 

certified to the standards specified in § 87.21, so removing these definitions 

will not change the requirements for engines certified to the Tier 4 or earlier 

standards. 

87.1 ......................... Revise definition of ‘‘exhaust emissions’’ and ‘‘smoke’’.The new language references the emission testing procedures, since that is the 

practical meaning of these terms in part 87. This clarifies, for example, that 

emissions from the nozzle of an aircraft or aircraft engine count as exhaust 

emissions only if they are measured using the specified test procedures. 

There will be no more engines certified to the standards specified in § 87.21, 

so revising these definitions will not change the requirements for engines certified to the Tier 4 or earlier standards. 

87.1 ......................... Define ‘‘new’’ instead of defining ‘‘new 

aircraft turbine engine’’.

The regulations also refer to new turboprop engines and new engines used for 

supersonic aircraft, so it is appropriate to define the adjective as it relates to 

these different kinds of engines. This approach does not change the meaning 

of the applicable terms and therefore has no bearing on the requirements 

that applied under the standards specified in § 87.21. 

87.1 ......................... Revise the definition of ‘‘standard day 

condition’’: (1) Remove the reference 

to the 1976 U.S. Standard Atmosphere, (2) correct a typographical 

error in the humidity specification, 

and (3) change the atmospheric 

pressure units from Pa to kPa.

The editorial changes do not involve any substantive change in the specified 

conditions. 

87.2 ......................... Remove FAA from the list of acronyms 

in § 87.2 and add it to the set of defined terms in § 87.1.

This is intended to not involve a change in emission standards or implementation. 

87.3 ......................... Add provisions describing the scope of 

applicability of part 87.

The broad statement in § 87.3 is not intended to conflict with the applicability 

statements in individual subparts, since those additional statements indicate 

that certain requirements in part 87 apply more narrowly. All applicability 

statements in the rule are intended to be consistent with current policy. 

87.3 ......................... Remove the provision related to preemption of state standards for exempted aircraft and replace it with 

the preemption provision in the Clean 

Air Act.

This change more carefully tracks the statutory provisions related to preemption. 

87.5 ......................... Move the provisions related to special 

test procedures to § 87.60.

This provision, and the similar provision from § 87.3(a), should be described together in the context of the testing requirements in subpart G. 

87.21 ....................... Identify the specific date when the 

smoke standard started to apply for 

turbofan engines with rated output 

less than 26.7 kilonewtons.

This corrects a typographical error from the Federal Register. 

87.21 ....................... Revise paragraph (f) to correctly reference the regulatory sections that 

describe the applicable test procedures.

This change is strictly editorial. 


TKELLEY on DSK3SPTVN1PROD with RULES2
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36375 

105CAEP/6 NOX standards: CAEP Forecasting and 

Economic Analysis Support Group, Economic 

Analysis of NOX Emissions Stringency Options, 

CAEP/6–IP/13 (Information Paper 13), January 15, 

2004. A copy of this document is in docket number 

EPA–HQ–OAR–2010–0687. 

106CAEP/8 NOX standards: CAEP Working Group 

3, NOX Stringency Technology Response 

Assessment, CAEP–SG/20082–WP/18 (Working 

Paper 18), September 25, 2008. CAEP Forecasting 

and Economic Analysis Support Group, Economic 

Assessment of the NOX Stringency Scenarios, 

CAEP/8–IP/14, November 30, 2009. Modeling Task 

Force, MODTF NOX .Stringency Assessment, CAEP/ 

8–IP/13, December 11, 2009. United States, 

Aviation Environmental Portfolio Management Tool 

for Economics (APMT-Economics) and Its 

Application in the CAEP/8 NOX Stringency 

Analysis, CAEP/8–IP/29, January 6, 2010. A copy of 

these documents are in docket number EPA–HQ– 

OAR–2010–0687. 

Regulation cite Description of amendment Notes 

87.60 ....................... Revise the description of test procedures to rely broadly on the procedures specified in ICAO Annex 16. 

This includes a variety of recent 

changes to the Annex 16 procedures.

There will be no more engines certified to the standards specified in § 87.21, so 

any changes to the test procedures will not change the requirements for engines certified to the Tier 4 or earlier standards. Moreover, engine manufacturers are expected to perform all their testing based on the current test procedures from ICAO Annex 16, regardless of the standards that apply. 

C. Clarifying Language for Regulatory 

Text 

The regulations incorporate the 

changes described in this preamble. The 

following table highlights and clarifies 

several provisions that may not be 

obvious to the reader. 

Regulation cite Note 

87.1, Definition of ‘‘aircraft’’ ................................ This definition would revert to the normal FAA definition of aircraft, rather than the much narrower current definition in part 87. To understand this change, the definition needs to be 

considered along with the changes to applicability in 87.3(a). 

87.1, Definition of ‘‘date of manufacture’’ ........... This is generally the same definition as given in ICAO Annex 16. However, our definition addresses certain specific circumstances that could possibly occur, but that are not addressed 

by the Annex. For example, our definition would provide a date of manufacture for an engine not previously documented by a manufacturer. 

87.1, Definition of ‘‘derivative engine for emissions certification purposes’’.It is important to consider this definition in combination with the definition of ‘‘engine type certificate family’’. 

87.1, Definition of ‘‘engine model’’ ..................... A manufacturer or FAA may further divide an engine model into sub-models. Engines from an 

engine model must be contained within a single engine type certificate family. Where FAA 

determines that engines are not sufficiently similar to be included under a single type certificate, they will not be considered to be the same engine model for purposes of part 87. 

87.1, Definition of ‘‘military aircraft’’ and 

87.23(d).

In § 87.23(d) we clarify that the production cutoff does not apply for military aircraft engines 

(even if they have been certificated). In § 87.1, we define military aircraft to primarily mean 

‘‘aircraft owned by, operated by, or produced for sale to the armed forces or other agency of 

the federal government responsible for national security (including but not limited to the Department of Defense).’’ For example, aircraft owned by the U.S. Coast Guard would be military aircraft. In response to comments, we added a clarification that military aircraft also include ‘‘other aircraft considered to be military aircraft under international law and conventions.’’ 

87.1, Definition of ‘‘production cutoff date’’ ........ The production cutoff date for the Tier 6 NOX standards is December 31, 2012. 

87.1, Definition of ‘‘spare engine’’ ...................... Newly manufactured spare engines may be excepted under § 87.50. 

87.1, Definitions of tiers ...................................... As specified in the definitions of ‘‘Tier 0’’ through ‘‘Tier 8’’, tiers apply only for NOX standards. 

Tiers do not apply for HC, CO, and smoke standards because these continue to apply, independent of the NOX standards. 

87.23(d)(2) .......................................................... The allowance to continue production of Tier 6 engines after the Tier 8 standards start to 

apply is not necessary for engines with rated pressure ratio at or above 104.7 because the 

Tier 6 and Tier 8 standards are numerically identical at these thrust levels. 

87.42(c)(1) .......................................................... § 87.42 requires that a manufacturer report the engines it produces by sub-model. The manufacturer must specify the manufacturer’s unique sub-model name, which will generally include a model name and a sub-model name. It may also include a family name. 

87.50 ................................................................... This provision specifies that EPA must provide written concurrence for exemptions. 

87.50(a)(1)(iv)(F) ................................................. This provision states that manufacturers requesting exemptions should describe equity issues. 

As an example of equity issues related to an exemption request, a manufacturer might provide a rationale for granting the exemption when another manufacturer has a compliant engine and does not need an exemption, taking into account the implications for operator fleet 

composition, commonality, and related issues in the absence of the engine model in question. 

87.50(a)(6) .......................................................... This provision requires manufacturers to promptly notify the FAA if new or changed information could have affected approval of an exemption. For corrections to an exemption request 

that would not affect the approval of the exemption, manufacturers may include the updated 

information in the annual report described in § 87.50(e). 

VI. Technical Feasibility and Cost 

Impacts 

During the CAEP process, the 

technical feasibility and cost of 

compliance of the CAEP/6 and CAEP/8 

NOX standards were thoroughly 

assessed and documented.105 106 EPA 

participated in these analyses and 

supported the results. Generally, CAEP 

considered certain factors as pertinent 

to the cost estimates of a technology 

level for engine changes, and these 

factors or technology levels are 


TKELLEY on DSK3SPTVN1PROD with RULES2
36376 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

107As discussed in section III.D, we are requiring 

a single report that integrates the new reporting 

requirement contained in this final rule with the 

existing mandatory greenhouse gas (GHG) reporting 

of NOX and CO2 as already required under § 87.64. 

Combining the existing GHG report with the new 

reporting requirement will not increase an engine 

manufacturer’s reporting burden. A single, 

integrated report may actually reduce a 

manufacturer’s total reporting burden somewhat 

because of the efficiency inherent in reporting to 

EPA once instead of twice. 

described below. The first technology 

level was regarded as a minor change, 

and it could include modeling work, 

minor design changes, and additional 

testing and re-certification of emissions. 

The second technology level was 

considered a scaled proven technology. 

At this level an engine manufacturer 

applies its best-proven, combustion 

technology that was already certified in 

at least one other engine type to another 

engine type. This second technology 

level would include substantial 

modeling, design, combustion rig 

testing, modification and testing of 

development engines, and flight testing. 

The third technology level was regarded 

as new technology or current industry 

best practice, and it was considered 

where a manufacturer has no proven 

technology that can be scaled to provide 

a solution and some technology 

acquisition activity is required. (One or 

more manufacturers have demonstrated 

the necessary technology, while the 

remaining manufacturers would need to 

acquire the technology to catch up.) 

Since the effective date for the CAEP/6 

NOX standard was January 1, 2008 and 

nearly all in-production engines 

currently meet this standard, we believe 

this clearly demonstrates the technical 

feasibility of those standards. Therefore, 

we will limit our discussion below to 

applying these technology levels to 

engines that need to comply with the 

CAEP/8 NOX standard. 

At the time of the CAEP reports, the 

CAEP/8 NOX standard for higher thrust 

engines, i.e., 89.0 kN or more would 

apply to a total of 15 engine types. For 

these types the following technology 

level response was anticipated: six types 

would require no change, one type 

would need the first technology level 

change, five would require the second 

technology level, and three would need 

the third technology level. For lower 

thrust engines, i.e., greater that 26.7 but 

less than 89.0 kN, CAEP listed a total of 

13 engine types in their analysis of the 

CAEP/8 NOX standard. The following 

technology level response was estimated 

for these types: 11 types would require 

no change, 1 type would need the first 

technology level change, and 1 type 

would require a second technology. 

Based on these analyses, CAEP 

concluded that the CAEP/8 NOX

standards were technically feasible 

within the lead time and time frame 

identified in the action. 

Regarding the costs of this final rule, 

aircraft turbofan engines are designed 

and built for use on aircraft that are sold 

and operated throughout the world. As 

a result, engine manufacturers respond 

to this market reality by designing and 

building engines that conform to ICAO 

international standards and practices. 

This normal business practice means 

that engine manufacturers are 

compelled to make the necessary 

business decisions and investments to 

maximize their international markets 

even in the absence of U.S. regulations 

that would otherwise codify ICAO 

standards and practices. Indeed, engine 

manufacturers have developed or are 

already developing improved 

technology in response to ICAO 

standards that match the standards 

being promulgated in this final rule. 

Also, the recommended practices, e.g., 

test procedures, needed to demonstrate 

compliance are being adhered to by 

manufacturers during current engine 

certification tests, or will be even in the 

absence this final rule. Therefore, EPA 

believes that today’s standards and 

practices that conform with ICAO 

standards and practices will impose no 

real additional burden on engine 

manufacturers. This finding regarding 

no incremental burden, is also 

consistent with past EPA rulemakings 

that adopted ICAO requirements. ((See 

62 FR 25356 (May 8, 1997) and 70 FR 

69664 (November 11, 2005). 

In fact, engine manufacturers have 

suggested that certain benefits accrue for 

compliant products when the U.S. 

adopts ICAO standards and practices, 

but have not provided detailed 

information regarding these benefits. 

Primarily, such action makes FAA 

certification more straightforward and 

transparent. That in turn is 

advantageous when marketing their 

products to potential customers, 

because compliance with ICAO 

standards is an important consideration 

in purchasing decisions. It simply 

removes any question that their engines 

comply with international requirements. 

There will be some cost, however, 

associated with our annual reporting 

requirement for emission related 

information. (See section III.D for a 

description of the reports.) There are a 

total of 10 engine manufacturers that 

would be affected. Eight of these 

produce turbofan engines with rated 

thrusts greater than 26.7 kN, which are 

already voluntarily reported to the 

ICAO-related Emissions Databank 

(EDB).107 We expect the incremental 

reporting burden for these 

manufacturers to be very small because 

we: (1) Have significantly reduced the 

number of reporting elements from 

those requested in the EDB, and (2) are 

adding only three basic reporting 

categories to those already requested by 

the EDB. Also, four of the eight 

manufacturers make smaller turbofan 

and turboprop engines that will be 

reporting for the first time. This will add 

a small incremental burden for these 

four manufacturers that otherwise 

already voluntarily report to the EDB. 

There are also two engine manufacturers 

that only produce turbofan engines with 

rated thrusts less than or equal to 26.7 

kN and they will be reporting for the 

first time. For these two manufacturers 

we believe that the reporting burden 

will be small because all of the 

information we are requiring should be 

readily available, and these 

manufacturers have a very limited 

number of engine models. 

We have estimated the annual burden 

and cost to be about six hours and $365 

per manufacturer. With 10 

manufacturers submitting reports, the 

total burden of this reporting 

requirement is estimated to be 60 hours, 

for a total cost of $3,646. 

VII. Consultation With FAA 

The requirements contained in this 

action were developed in consultation 

with the Federal Aviation 

Administration (FAA). Section 

231(a)(2)(B)(i) of the CAA requires EPA 

to ‘‘consult with the Administrator of 

the [FAA] on aircraft engine emission 

standards’’ 42 U.S.C. 7571(a)(2)(B)(i), 

and section 231(a)(2)(B)(ii) indicates 

that EPA ‘‘shall not change the aircraft 

engine emission standards if such 

change would significantly increase 

noise. * * *’’ 42 U.S.C. 

7571(a)(2)(B)(ii). Section 231(b) of the 

CAA states that ‘‘[a]ny regulation 

prescribed under this section (and any 

revision thereof) shall take effect after 

such period as the Administrator finds 

necessary (after consultation with the 

Secretary of Transportation) to permit 

the development and application of the 

requisite technology, giving appropriate 

consideration to the cost of compliance 

within such period.’’ 42 U.S.C. 7571(b). 

Section 231(c) provides that any 

regulation under section 231 ‘‘shall not 

apply if disapproved by the President 

* * * on the basis of a finding by the 

Secretary of Transportation that any 

such regulation would create a hazard to 

aircraft safety.’’ 42 U.S.C. 7571(c). 

Under section 232 of the CAA, the 

Department of Transportation (DOT) has 

the responsibility to enforce the aircraft 

emission standards established by EPA 


TKELLEY on DSK3SPTVN1PROD with RULES2
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36377 

108The functions of the Secretary of 

Transportation under part B of title II of the Clean 

Air Act (§§ 231–234, 42 U.S.C. 7571–7574) have 

been delegated to the Administrator of the FAA. 

49 CFR 1.47(g). 

109The Sixth Meeting of CAEP (CAEP/6) occurred 

in Montreal, Quebec from February 2 through 12 in 

2004. 

under section 231.108 As in past 

rulemakings and pursuant to the above 

referenced sections of the CAA, EPA has 

coordinated with the FAA, i.e., DOT, 

with respect to today’s action. 

Moreover, FAA is the official U.S. 

delegate to ICAO. FAA agreed to the 

amendments at ICAO’s Sixth and Eighth 

Meetings of the Committee on Aviation 

Environmental Protection (CAEP/6) 

after advisement from EPA.109 FAA and 

EPA were both members of the CAEP’s 

Working Group 3 (among others), whose 

objective was to evaluate emissions 

technical issues and develop 

recommendations on such issues for 

CAEP/6 and CAEP/8. After assessing 

emissions test procedure amendments 

and new NOX standards, Working 

Group 3 made recommendations to 

CAEP on these elements. These 

recommendations were approved by 

CAEP/6 meetings prior to their adoption 

by ICAO in 2004. Similarly, the more 

recent Working Group 3 

recommendations were approved by 

CAEP/8 and have been adopted ICAO. 

In addition, as discussed above, FAA 

will have the duty to enforce today’s 

requirements. As a part of these duties, 

the FAA witnesses the emission tests or 

delegates aspects of that responsibility 

to the engine manufacturer, which is 

then monitored by the FAA. 

VIII. Public Participation 

We proposed this regulation on July 

27, 2011 (76 FR 45012). A public 

hearing was held on August 11, 2011 in 

Chicago, IL. The public was invited to 

submit written comments on the 

proposal during the formal comment 

period, which ended on September 26, 

2011. We received eight public 

comments from aircraft and aircraft 

engine manufacturers, airline operators 

and an individual. 

The vast majority of commenters 

supported the central tenets of the 

proposed regulations. That is, there was 

broad support for the adoption of these 

standards and the alignment of U.S. and 

international emissions regulations. We 

received specific comments on several 

aspects of the proposal. 

Throughout this notice, we discussed 

the key issues arising from the public 

comment and our responses. In 

addition, we have addressed all of the 

public comments in the analysis of 

comments document associated with 

this final action and located in the 

docket (Docket ID EPA–HQ–OAR–2010– 

0687). 

IX. Statutory Provisions and Legal 

Authority 

The statutory authority for today’s 

proposal is provided by sections 114, 

231–234 and 301(a) of the Clean Air 

Act, as amended, 42 U.S.C. §§ 7414, 

7571–7574 and 7601(a). See section II of 

today’s rule for discussion of how EPA 

meets the CAA’s statutory requirements. 

X. Statutory and Executive Order 

Reviews 

A. Executive Order 12866: Regulatory 

Planning and Review, and Executive 

Order 13563: Improving Regulation and 

Regulatory Review 

Under Executive Order (EO) 12866 

(58 FR 51735, October 4, 1993), this 

action is a ‘‘significant regulatory 

action.’’ This action promulgates new 

aircraft engine emissions regulations 

and as such, requires consultation and 

coordination with the Federal Aviation 

Administration (FAA). OMB has 

determined that this action raises 

‘‘* * * novel legal or policy issues 

arising out of legal mandates, the 

President’s priorities, or the principles 

set forth in the EO.’’ Accordingly, EPA 

submitted this action to the Office of 

Management and Budget (OMB) for 

review under EO 12866 and 13563 (76 

FR 3821, January 21, 2011) and any 

changes made in response to OMB 

recommendations have been 

documented in the docket for this 

action. 

As discussed further in section V, we 

do not attribute any costs to the 

compliance with today’s regulations 

that conform to ICAO standards and 

recommended practices. Aircraft 

turbofan engines are international 

commodities. As a result, engine 

manufacturers respond to this market 

reality by designing and building 

engines that conform to ICAO 

international standards and practices. 

Therefore, engine manufacturers are 

compelled to make the necessary 

business decisions and investments to 

maximize their international markets 

even in the absence of U.S. action. 

Indeed, engine manufacturers have or 

are already responding, or will in the 

future, to ICAO requirements that match 

the standards and practices adopted 

here. Therefore, EPA believes that 

today’s requirements that conform with 

ICAO standards and practices will 

impose no real additional burden on 

engine manufacturers. This finding is 

also consistent with past EPA 

rulemakings that adopted ICAO 

requirements. 

There is, nonetheless, a small burden 

associated with the reporting 

requirements, as discussed in section 

IX.B. 

B. Paperwork Reduction Act 

The information collection 

requirements in this rule have been 

submitted for approval to the Office of 

Management and Budget (OMB) under 

the Paperwork Reduction Act, 44 U.S.C. 

3501 et seq. The information collection 

requirements are not enforceable until 

OMB approves them. 

Manufacturers keep substantial 

records to document their compliance 

with emission standards. We need to be 

able to access this data to conduct 

accurate emission inventories, 

understand how emission standards 

affect the current fleet, and develop 

appropriate policy in the form of future 

emission standards. Most manufacturers 

are already accustomed to reporting 

much of this information to ICAO. 

However, these reports are voluntary 

and aperiodic. As part of this action, we 

are requiring that engine manufacturers 

send this information to EPA on an 

annual basis. We are also requiring 

manufacturers to send us their annual 

production volumes, which we would 

treat as confidential business 

information. Under the Clean Air Act, 

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 execute our 

functions under the Act. See 42 U.S.C. 

7414(a)(1). We will simply require 

manufacturers to add the required 

information items to the annual report 

they are already required to submit with 

information about NOX and CO2

emission levels. See section III.D for a 

more complete description of the annual 

reporting requirement. 

We have estimated the total annual 

burden of the reporting requirement to 

be 60 hours, and the total cost to be 

$3,646. The annual burden and cost per 

respondent is estimated to be 6 hours 

and $365. Burden is defined at 5 CFR 

1320.3(b). 

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 EPA’s regulations in 40 

CFR are listed in 40 CFR part 9. When 

this ICR is approved by OMB, the 

Agency will publish a technical 

amendment to 40 CFR part 9 in the 

Federal Register to display the OMB 

control number for the approved 


TKELLEY on DSK3SPTVN1PROD with RULES2
36378 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

110 ‘‘Small Business Impact Memo, Proposed 

Aircraft Engine Emission Standards—Determination 

of No SISNOSE,’’ EPA memo from Solveig Irvine to 

Alexander Cristofaro, November, 2010. 

information collection requirements 

contained in this final rule. 

C. Regulatory Flexibility Analysis 

The Regulatory Flexibility Act (RFA) 

generally requires an agency to prepare 

a regulatory flexibility analysis of any 

rule subject to notice and comment 

rulemaking requirements under the 

Administrative Procedure Act or any 

other statute unless the agency certifies 

that the rule will not have a significant 

economic impact on a substantial 

number of small entities. Small entities 

include small businesses, small 

organizations, and small governmental 

jurisdictions. 

For purposes of assessing the impacts 

of today’s rule on small entities, small 

entity is defined as: (1) A small business 

as defined by SBA size standards; (2) a 

small governmental jurisdiction that is a 

government of a city, county, town, 

school district or special district with a 

population of less than 50,000; and (3) 

a small organization that is any not-forprofit enterprise which is independently 

owned and operated and is not 

dominant in its field. The following 

Table 4 provides an overview of the 

primary SBA small business categories 

potentially affected by this regulation. 

TABLE 4—PRIMARY POTENTIALLY AFFECTED SBA SMALL BUSINESS CATEGORIES

Industry NAICSa Codes Defined by SBA as a 

small business if: b

Manufacturers of new aircraft engines .................................................................................................. 336412 <1,000 employees. 

Manufacturers of new aircraft ................................................................................................................ 336411 <1,500 employees. 

a North American Industry Classification System (NAICS). 

bAccording to SBA’s regulations (13 CFR part 121), businesses with no more than the listed number of employees or dollars in annual receipts are considered ‘‘small entities’’ for purposes of a regulatory flexibility analysis. 

After considering the economic 

impacts of today’s rule on small entities, 

I certify that this action will not have a 

significant economic impact on a 

substantial number of small entities. 

Small governmental jurisdictions and 

small organizations as described above 

will not be impacted. We have 

determined that the estimated effect of 

the rule’s reporting requirement is to 

affect one small entity turbofan engine 

manufacturer with costs less than one 

percent of revenues. This one company 

represents all of the small businesses 

affected by the regulations. An analysis 

of the impacts of the proposed rule on 

small businesses has been prepared and 

placed in the docket for this 

rulemaking.110 Since this final rule is 

largely unchanged from the proposal, 

that analysis remains valid for the final 

rule. 

D. Unfunded Mandates Reform Act 

This rule does not contain a Federal 

mandate that may result in expenditures 

of $100 million or more for State, local, 

and tribal governments, in the aggregate, 

or the private sector in any one year. As 

discussed in section III, today’s action 

will establish consistency between U.S. 

and existing international emission 

standards. The engine manufacturers are 

already developing the technology to 

meet the existing ICAO standards, and 

we do not believe it is appropriate to 

attribute the costs of that technology to 

this action. Thus, this rule is not subject 

to the requirements of sections 202 or 

205 of UMRA. 

This rule is also not subject to the 

requirements of section 203 of UMRA 

because it contains no regulatory 

requirements that might significantly or 

uniquely affect small governments. The 

provisions of this rule apply to the 

manufacturers of aircraft and aircraft 

engines, and as such would not affect 

small governments. 

E. 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, as specified in 

Executive Order 13132. As discussed 

earlier, section 233 of the CAA preempts 

states from adopting or enforcing 

aircraft engine emission standards that 

are not identical to our standards. This 

rule revises the Code of Federal 

Regulations to more accurately reflect 

the statutory preemption established by 

the Clean Air Act. This rule does not 

impose any new preemption of State 

and local law. Thus, Executive Order 

13132 does not apply to this action. 

F. Executive Order 13175: Consultation 

and Coordination With Indian Tribal 

Governments 

These rules regulate aircraft 

manufacturers and aircraft engine 

manufacturers. We do not believe that 

Tribes own any of these businesses nor 

are there other implications for Tribes. 

Thus, Executive Order 13175 does not 

apply to this action. 

G. Executive Order 13045: Protection of 

Children From Environmental Health 

and Safety Risks 

This rule is not subject to Executive 

Order 13045 (62 FR 19885, April 23, 

1997) because it is not economically 

significant as defined in EO 12866 and 

the Agency does not believe the 

environmental health risks or safety 

risks addressed by this action present a 

disproportionate risk to children. See 

section II.B.2 for a discussion of the 

health impacts of NOX emissions. 

H. Executive Order 13211: Actions That 

Significantly Affect Energy Supply, 

Distribution, or Use 

This action is not a ‘‘significant 

energy action’’ as defined in Executive 

Order 13211 (66 FR 28355 (May 22, 

2001)), because it is not likely to have 

a significant adverse effect on the 

supply, distribution, or use of energy. 

These aircraft engine emissions 

regulations are not expected to result in 

any changes to aircraft fuel 

consumption. 

I. National Technology Transfer 

Advancement Act 

Section 12(d) of the National 

Technology Transfer and Advancement 

Act of 1995 (‘‘NTTAA’’), Public Law 

104–113 (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 EPA to provide 


TKELLEY on DSK3SPTVN1PROD with RULES2
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36379 

111 ICAO International Standards and 

Recommended Practices Environmental Protection, 

Annex 16, Volume II, ‘‘Aircraft Engine Emissions,’’ 

Second Edition, July 1993—Amendment 3, March 

20, 1997. Copies of this document can be obtained 

from ICAO (www.icao.int). 

Congress, through OMB, explanations 

when the Agency decides not to use 

available and applicable voluntary 

consensus standards. 

This rulemaking involves technical 

standards for testing emissions for 

aircraft gas turbine engines. EPA is 

using test procedures contained in 

ICAO’s International Standards and 

Recommended Practices Environmental 

Protection, Annex 16, Volume II along 

with the modifications contained in this 

rulemaking.111 These procedures are 

currently used by all manufacturers of 

aircraft gas turbine engines (with thrust 

greater than 26.7 kN) to demonstrate 

compliance with ICAO emissions 

standards. 

J. Executive Order 12898: Federal 

Actions To Address Environmental 

Justice in Minority Populations and 

Low-Income Populations 

Executive Order (EO) 12898 (59 FR 

7629 (Feb. 16, 1994)) establishes federal 

executive policy on environmental 

justice. Its main provision directs 

federal agencies, to the greatest extent 

practicable and permitted by law, to 

make environmental justice part of their 

mission by identifying and addressing, 

as appropriate, disproportionately high 

and adverse human health or 

environmental effects of their programs, 

policies, and activities on minority 

populations and low-income 

populations in the United States. 

EPA has determined that this rule will 

not have disproportionately high and 

adverse human health or environmental 

effects on minority or low-income 

populations because it increases the 

level 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. 

K. Congressional Review Act 

The Congressional Review Act, 5 

U.S.C. 801 et seq., as added by the Small 

Business Regulatory Enforcement 

Fairness Act of 1996, generally provides 

that before a rule may take effect, the 

agency promulgating the rule must 

submit a rule report, which includes a 

copy of the rule, to each House of the 

Congress and to the Comptroller General 

of the United States. EPA will submit a 

report containing this rule and other 

required information to the U.S. Senate, 

the U.S. House of Representatives, and 

the Comptroller General of the United 

States prior to publication of the rule in 

the Federal Register. A major rule 

cannot take effect until 60 days after it 

is published in the Federal Register. 

This action is not a ‘‘major rule’’ as 

defined by 5 U.S.C. 804(2). This rule 

will be effective July 18, 2012. 

L. Executive Order 13609: Promoting 

International Regulatory Cooperation 

Executive Order (EO) 13609 

(77 FR 26413, May 4, 2012) promotes 

international regulatory cooperation in 

order to identify approaches that are at 

least as protective as those that are or 

would be adopted in the absence of 

such cooperation in meeting shared 

challenges involving health, safety, 

labor, security, environmental, and 

other issues. International regulatory 

cooperation can also reduce, eliminate, 

or prevent unnecessary differences in 

regulatory requirements. 

These final standards are identical to 

the international standards developed 

through EPA’s active participation in 

the United Nation’s International Civil 

Aviation Organization (ICAO) activities. 

EPA has historically been a principal 

participant in the development of U.S. 

policy in various ICAO working groups 

and other international venues, assisting 

and advising the Federal Aviation 

Administration on aviation emissions, 

technology, and policy matters. These 

provisions provide a means by which 

the United States can meet its 

obligations under the Chicago 

Convention and ensure that engine 

manufacturers maintain worldwide 

acceptability of their products. 

List of Subjects 

40 CFR Part 87 

Environmental protection, Air 

pollution control, Aircraft, 

Incorporation by reference. 

40 CFR Part 1068 

Environmental protection, 

Administrative practice and procedure, 

Confidential business information, 

Imports, Motor vehicle pollution, 

Penalties, Reporting and recordkeeping 

requirements, Warranties. 

Dated: June 1, 2012. 

Lisa P. Jackson, 

Administrator. 

For the reasons described in the 

preamble, title 40, chapter I, of the Code 

of Federal Regulations is amended as set 

forth below. 

PART 87—CONTROL OF AIR 

POLLUTION FROM AIRCRAFT AND 

AIRCRAFT ENGINES 

■ 1. The authority citation for part 87 is 

revised to read as follows: 

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

Subpart A—[Amended] 

■ 2. Revise § 87.1 to read as follows: 

§ 87.1 Definitions. 

The definitions in this section apply 

to this part. The definitions apply to all 

subparts. Any terms not defined in this 

section have the meaning given in the 

Clean Air Act. The definitions follow: 

Act means the Clean Air Act, as 

amended (42 U.S.C. 7401 et seq). 

Administrator means the 

Administrator of the Environmental 

Protection Agency and any other officer 

or employee of the Environmental 

Protection Agency to whom authority 

involved may be delegated. 

Aircraft has the meaning given in 14 

CFR 1.1, which defines aircraft to mean 

a device used or intended to be used for 

flight in the air. Note that under § 87.3, 

the requirements of this part generally 

apply only to propulsion engines used 

on certain airplanes for which U.S. 

airworthiness certificates are required. 

Aircraft engine means a propulsion 

engine which is installed in or which is 

manufactured for installation in an 

aircraft. 

Aircraft gas turbine engine means a 

turboprop, turbofan, or turbojet aircraft 

engine. 

Characteristic level has the meaning 

given in Appendix 6 of ICAO Annex 16 

(as of July 2008). The characteristic level 

is a calculated emission level for each 

pollutant based on a statistical 

assessment of measured emissions from 

multiple tests. 

Class TP means all aircraft turboprop 

engines. 

Class TF means all turbofan or 

turbojet aircraft engines or aircraft 

engines designed for applications that 

otherwise would have been fulfilled by 

turbojet and turbofan engines except 

engines of class T3, T8, and TSS. 

Class T3 means all aircraft gas turbine 

engines of the JT3D model family. 

Class T8 means all aircraft gas turbine 

engines of the JT8D model family. 

Class TSS means all aircraft gas 

turbine engines employed for 

propulsion of aircraft designed to 

operate at supersonic flight speeds. 

Commercial aircraft engine means 

any aircraft engine used or intended for 

use by an ‘‘air carrier,’’ (including those 

engaged in ‘‘intrastate air 

transportation’’) or a ‘‘commercial 


TKELLEY on DSK3SPTVN1PROD with RULES2
36380 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

operator’’ (including those engaged in 

‘‘intrastate air transportation’’) as these 

terms are defined in subtitle 7 of title 49 

of the United States Code and title 14 of 

the Code of Federal Regulations. 

Commercial aircraft gas turbine 

engine means a turboprop, turbofan, or 

turbojet commercial aircraft engine. 

Date of introduction or introduction 

date means the date of manufacture of 

the first individual production engine of 

a given engine model or engine type 

certificate family to be certificated. This 

does not include test engines or other 

engines not placed into service. 

Date of manufacture means the date 

on which a manufacturer is issued 

documentation by FAA (or other 

competent authority for engines 

certificated outside the United States) 

attesting that the given engine conforms 

to all applicable requirements. This date 

may not be earlier that the date on 

which assembly of the engine is 

complete. Where the manufacturer does 

not obtain such documentation from 

FAA (or other competent authority for 

engines certificated outside the United 

States), date of manufacture means the 

date of final assembly of the engine. 

Derivative engine for emissions 

certification purposes means an engine 

that has the same or similar emissions 

characteristics as an engine covered by 

a U.S. type certificate issued under 14 

CFR part 33. These characteristics are 

specified in § 87.48. 

Designated EPA Program Officer 

means the Director of the Assessment 

and Standards Division, 2000 

Traverwood Drive, Ann Arbor, 

Michigan 48105. 

DOT Secretary means the Secretary of 

the Transportation and any other officer 

or employee of the Department of 

Transportation to whom the authority 

involved may be delegated. 

Engine means an individual engine. A 

group of identical engines together make 

up an engine model or sub-model. 

Engine model means an engine 

manufacturer’s designation for an 

engine grouping of engines and/or 

engine sub-models within a single 

engine type certificate family, where 

such engines have similar design, 

including being similar with respect to 

the core engine and combustor designs. 

Engine sub-model means a 

designation for a grouping of engines 

with essentially identical design, 

especially with respect to the core 

engine and combustor designs and other 

emission-related features. Engines from 

an engine sub-model must be contained 

within a single engine model. For 

purposes of this part, an original engine 

model configuration is considered a 

sub-model. For example, if a 

manufacturer initially produces an 

engine model designated ABC and later 

introduces a new sub-model ABC–1, the 

engine model consists of two submodels: ABC and ABC–1. 

Engine type certificate family means a 

group of engines (comprising one or 

more engine models, including submodels and derivative engines for 

emissions certification purposes of 

those engine models) determined by 

FAA to have a sufficiently common 

design to be grouped together under a 

type certificate. 

EPA means the U.S. Environmental 

Protection Agency. 

Except means to routinely allow 

engines to be produced and sold that do 

not meet (or do not fully meet) 

otherwise applicable standards. (Note 

that this definition applies only with 

respect to spare engines and that the 

term ‘‘except’’ has its plain meaning in 

other contexts.) Excepted engines must 

conform to regulatory conditions 

specified for an exception in this part 

and other applicable regulations. 

Excepted engines are deemed to be 

‘‘subject to’’ the standards of this part 

even though they are not required to 

comply with the otherwise applicable 

requirements. Engines excepted with 

respect to certain standards must 

comply with other standards from 

which they are not excepted. 

Exempt means to allow (through a 

formal case-by-case process) engines to 

be produced and sold that do not meet 

(or do not fully meet) otherwise 

applicable standards. Exempted engines 

must conform to regulatory conditions 

specified for an exemption in this part 

and other applicable regulations. 

Exempted engines are deemed to be 

‘‘subject to’’ the standards of this part 

even though they are not required to 

comply with the otherwise applicable 

requirements. Engines exempted with 

respect to certain standards must 

comply with other standards as a 

condition of the exemption. 

Exhaust emissions means substances 

emitted to the atmosphere from exhaust 

discharge nozzles, as measured by the 

test procedures specified in subpart G of 

this part. 

FAA means the U.S. Department of 

Transportation, Federal Aviation 

Administration. 

Fuel venting emissions means raw 

fuel, exclusive of hydrocarbons in the 

exhaust emissions, discharged from 

aircraft gas turbine engines during all 

normal ground and flight operations. 

Good engineering judgment involves 

making decisions consistent with 

generally accepted scientific and 

engineering principles and all relevant 

information, subject to the provisions of 

40 CFR 1068.5. 

ICAO Annex 16 means Volume II of 

Annex 16 to the Convention on 

International Civil Aviation 

(incorporated by reference in § 87.8). 

In-use aircraft gas turbine engine 

means an aircraft gas turbine engine 

which is in service. 

Military aircraft means aircraft owned 

by, operated by, or produced for sale to 

the armed forces or other agency of the 

federal government responsible for 

national security (including but not 

limited to the Department of Defense) 

and other aircraft considered to be 

military aircraft under international law 

and conventions. 

New means relating to an aircraft or 

aircraft engine that has never been 

placed into service. 

Operator means any person or 

company that owns or operates an 

aircraft. 

Production cutoff date or date of the 

production cutoff means the date on 

which interim phase-out allowances 

end. 

Rated output (rO) means the 

maximum power/thrust available for 

takeoff at standard day conditions as 

approved for the engine by FAA, 

including reheat contribution where 

applicable, but excluding any 

contribution due to water injection, 

expressed in kilowatts or kilonewtons 

(as applicable) and rounded to at least 

three significant figures. 

Rated pressure ratio (rPR) means the 

ratio between the combustor inlet 

pressure and the engine inlet pressure 

achieved by an engine operating at rated 

output, rounded to at least three 

significant figures. 

Round has the meaning given in 40 

CFR 1065.1001. 

Smoke means the matter in exhaust 

emissions that obscures the 

transmission of light, as measured by 

the test procedures specified in subpart 

G of this part. 

Smoke number means a 

dimensionless value quantifying smoke 

emissions calculated in accordance with 

ICAO Annex 16. 

Spare engine means an engine 

installed (or intended to be installed) on 

an in-service aircraft to replace an 

existing engine and that is excepted as 

described in § 87.50(c). 

Standard day conditions means the 

following ambient conditions: 

temperature = 15 °C, specific humidity 

= 0.00634 kg H2O/kg dry air, and 

pressure = 101.325 kPa. 

Subsonic means relating to aircraft 

that are not supersonic aircraft. 


TKELLEY on DSK3SPTVN1PROD with RULES2
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36381 

Supersonic means relating to aircraft 

that are certificated to fly faster than the 

speed of sound. 

Tier 0 means relating to an engine that 

is subject to the Tier 0 NOX standards 

specified in § 87.21. 

Tier 2 means relating to an engine that 

is subject to the Tier 2 NOX standards 

specified in § 87.21. 

Tier 4 means relating to an engine that 

is subject to the Tier 4 NOX standards 

specified in § 87.21. 

Tier 6 means relating to an engine that 

is subject to the Tier 6 NOX standards 

specified in § 87.23. 

Tier 8 means relating to an engine that 

is subject to the Tier 8 NOX standards 

specified in § 87.23. 

Turbofan engine means a gas turbine 

engine designed to create its propulsion 

from exhaust gases and from air that 

bypasses the combustion process and is 

accelerated in a ducted space between 

the inner (core) engine case and the 

outer engine fan casing. 

Turbojet engine means a gas turbine 

engine that is designed to create all of 

its propulsion from exhaust gases. 

Turboprop engine means a gas turbine 

engine that is designed to create most of 

its propulsion from a propeller driven 

by a turbine, usually through a gearbox. 

Turboshaft engine means a gas 

turbine engine that is designed to drive 

a rotor transmission system or a gas 

turbine engine not used for propulsion. 

U.S.-registered aircraft means an 

aircraft that is on the U.S. Registry. 

We (us, our) means the Administrator 

of the Environmental Protection Agency 

and any authorized representatives. 

■ 3. Revise § 87.2 to read as follows: 

§ 87.2 Abbreviations. 

The abbreviations used in this part 

have the following meanings: 

% percent 

° degree 

CO carbon monoxide 

CO2 carbon dioxide 

g gram 

HC hydrocarbon(s) 

kN kilonewton 

kW kilowatt 

LTO landing and takeoff 

NOX oxides of nitrogen 

rO rated output 

rPR rated pressure ratio 

SN smoke number 

■ 4. Revise § 87.3 to read as follows: 

§ 87.3 General applicability and 

requirements. 

(a) The regulations of this part apply 

to engines on all aircraft that are 

required to be certificated by FAA under 

14 CFR part 33 except as specified in 

this paragraph (a). These regulations do 

not apply to the following aircraft 

engines: 

(1) Reciprocating engines (including 

engines used in ultralight aircraft). 

(2) Turboshaft engines such as those 

used in helicopters. 

(3) Engines used only in aircraft that 

are not airplanes. For purposes of this 

paragraph (a)(3), ‘‘airplane’’ means a 

fixed-wing aircraft that is heavier than 

air. 

(4) Engines not used for propulsion. 

(b) Under section 232 of the Act, the 

Secretary of Transportation issues 

regulations to ensure compliance with 

the standards and related requirements 

of this part (42 U.S.C. 7572). 

(c) The Secretary of Transportation 

shall apply these regulations to aircraft 

of foreign registry in a manner 

consistent with obligations assumed by 

the United States in any treaty, 

convention or agreement between the 

United States and any foreign country or 

foreign countries. 

(d) No State or political subdivision of 

a State may adopt or attempt to enforce 

any aircraft or aircraft engine standard 

respecting emissions unless the 

standard is identical to a standard 

applicable to such aircraft under this 

part (including prior-tier standards 

applicable to exempt engines). 

§ 87.5 [Removed] 

■ 5. Remove § 87.5. 

■ 6. Revise § 87.6 to read as follows: 

§ 87.6 Aircraft safety. 

The provisions of this part will be 

revised if at any time the DOT Secretary 

determines that an emission standard 

cannot be met within the specified time 

without creating a hazard to aircraft 

safety. 

§ 87.7 [Removed] 

■ 7. Remove § 87.7. 

■ 8. Revise § 87.8 to read as follows: 

§ 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 notice of change 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 and 

Information Center, 1301 Constitution 

Ave. NW., Room B102, EPA West 

Building, Washington, DC 20460, (202) 

202–1744, and is available from the 

sources listed below. It is also available 

for inspection at the National Archives 

and Records Administration (NARA). 

For information on the availability of 

this material at NARA, call 202–741– 

6030 or go to http://www.archives.gov/ 

federal_register/ 

code_of_federal_regulations/ 

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 II— 

Aircraft Engine Emissions, Third 

Edition, July 2008 (ICAO Annex 16). 

IBR approved for §§ 87.1, 87.42(c), and 

87.60(a) and (b). 

(2) [Reserved] 

Subpart C—[Amended] 

■ 9. Amend § 87.21 as follows: 

■ a. By revising the section heading. 

■ b. By adding introductory text. 

■ c. By revising paragraphs (d)(1)(iii), 

(d)(1)(iv), (d)(1)(vi) introductory text, 

(e)(1), and (f). 

§ 87.21 Exhaust emission standards for 

Tier 4 and earlier engines. 

This section describes the emission 

standards that apply for Tier 4 and 

earlier engines that apply for aircraft 

engines manufactured before July 18, 

2012 and certain engines exempted 

under § 87.50. Note that the tier of 

standards identified for an engine 

relates to NOX emissions and that the 

specified standards for HC, CO, and 

smoke emissions apply independent of 

the changes to the NOX emission 

standards. 

(d) * * * 

(1) * * * 

(iii) The following Tier 0 emission 

standard applies for engines of a type or 

model of which the date of manufacture 

of the first individual production model 

was on or before December 31, 1995 and 

for which the date of manufacture of the 

individual engine was on or before 

December 31, 1999. 

Oxides of Nitrogen: (40 + 2(rPR)) grams/ 

kilonewton rO. 

(iv) The following Tier 2 emission 

standard applies for engines of a type or 

model of which the date of manufacture 

of the first individual production model 

was after December 31, 1995 or for 

which the date of manufacture of the 

individual engine was after December 

31, 1999: 

Oxides of Nitrogen: (32 + 1.6(rPR)) 

grams/kilonewton rO. 

* * * * * 


TKELLEY on DSK3SPTVN1PROD with RULES2
36382 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

(vi) The following Tier 4 emission 

standards apply for engines of a type or 

model of which the date of manufacture 

of the first individual production model 

was after December 31, 2003: 

* * * * * 

(e) * * * 

(1) Class TF of rated output less than 

26.7 kilonewtons manufactured on or 

after August 9, 1985: 

SN = 83.6(rO)¥0.274 (rO is in 

kilonewtons) not to exceed a 

maximum of SN = 50. 

* * * * * 

(f) The standards in this section refer 

to a composite emission sample 

measured and calculated in accordance 

with the procedures described in 

subpart G of this part. 

■ 10. Add a new § 87.23 to subpart C to 

read as follows: 

§ 87.23 Exhaust emission standards for 

Tier 6 and Tier 8 engines. 

This section describes the emission 

standards that apply for Tier 6 and Tier 

8 engines. The standards of this section 

apply for aircraft engines manufactured 

on or after July 18, 2012, except where 

we specify that they apply differently by 

year, or where the engine is exempt 

from one or more standards of this 

section. Except as specified in 

paragraph (d) of this section, these 

standards apply based on the date the 

engine is manufactured. Where a 

gaseous emission standard is specified 

by a formula, calculate and round the 

standard to three significant figures or to 

the nearest 0.1 g/kN (for standards at or 

above 100 g/kN). Where a smoke 

standard is specified by a formula, 

calculate and round the standard to the 

nearest 0.1 SN. Engines comply with an 

applicable standard if the testing results 

show that the engine type certificate 

family’s characteristic level does not 

exceed the numerical level of that 

standard, as described in § 87.60. The 

tier of standards identified for an engine 

relates to NOX emissions and that the 

specified standards for HC, CO, and 

smoke emissions apply independent of 

the changes to the NOX emission 

standards. 

(a) New turboprop aircraft engines 

with rated output at or above 1,000 

kilowatts must comply with a smoke 

standard of 187 · rO¥0.168. 

(b) New supersonic engines must 

comply with the standards shown in the 

following table: 

TABLE 1 TO § 87.23—SMOKE AND GASEOUS EMISSION STANDARDS FOR NEW SUPERSONIC ENGINES

Rated output Smoke number HC (g/kN rated 

output) 

NOX (g/kN rated 

output) 

CO (g/kN rated 

output) 

rO < 26.7 kN .............. ......................................................................... 140 · 0.92rPR 36 + 2.42 · rPR 4550 · rPR¥1.03

rO ≥ 26.7 kN .............. 83.6 · rO¥0.274 or 50.0, whichever is smaller 140 · 0.92rPR 36+2.42 · rPR 4550 · rPR¥1.03

(c) New turbofan or turbojet aircraft 

engines that are installed in subsonic 

aircraft must comply with the following 

standards: 

(1) The applicable smoke, HC, and CO 

standards are shown in the following 

table: 

TABLE 2 TO § 87.23—SMOKE, HC, AND CO STANDARDS FOR NEW SUBSONIC TURBOFAN OR TURBOJET ENGINES

Rated output (kN) Smoke standard 

Gaseous emission standards 

(g/kN rated output) 

HC CO 

rO < 26.7 kN ................................. 83.6 · rO¥0.274 or 50.0, whichever is smaller ...................................... ............................ ............................

rO ≥ 26.7 kN ................................. 83.6 · rO¥0.274 or 50.0, whichever is smaller ...................................... 19.6 118 

(2) The Tier 6 NOX standards apply as 

described in this paragraph (c)(2). See 

paragraph (d) of this section for 

provisions related to models introduced 

before these standards started to apply 

and engines determined to be derivative 

engines for emissions certification 

purposes under the requirements of this 

part. 

TABLE 3 TO § 87.23—TIER 6 NOX STANDARDS FOR NEW SUBSONIC TURBOFAN OR TURBOJET ENGINES WITH RATED

OUTPUT ABOVE 26.7 KN 

If the rated pressure ratio is . . . and the rated output (in kN) is . . . The NOX emission standard (in g/kN rated output) is 

. . . 

rPR ≤ 30 ..................................................... 26.7 < rO ≤ 89 ........................................... 38.5486 + 1.6823 · PR¥0.2453 · rO¥0.00308 · rPR · 

rO 

rO > 89 ...................................................... 16.72 + 1.4080 · rPR 

30 < rPR < 82.6 ......................................... 26.7 < rO ≤ 89 ........................................... 46.1600 + 1.4286 · rPR ¥ 0.5303 · rO + 0.00642 · rPR 

· rO 

rO > 89 ...................................................... ¥1.04 + 2.0 · rPR 

rPR ≥ 82.6 .................................................. all ............................................................... 32 + 1.6 · rPR 

(3) The Tier 8 NOX standards apply as 

described in this paragraph (c)(3) 

beginning January 1, 2014. See 

paragraph (d) of this section for 

provisions related to models introduced 

before January 1, 2014 apply and 

engines determined to be derivative 

engines for emissions certification 

purposes under the requirements of this 

part. 


TKELLEY on DSK3SPTVN1PROD with RULES2
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36383 

TABLE 4 TO § 87.23—TIER 8 NOX STANDARDS FOR NEW SUBSONIC TURBOFAN OR TURBOJET ENGINES WITH RATED

OUTPUT ABOVE 26.7 KN 

If the rated pressure ratio is . . . and the rated output (in kN) is . . . The NOX emission standard (in g/kN rated 

output) is . . . 

rPR ≤ 30 ............................................................. 26.7 < rO ≤ 89 ................................................. 40.052 + 1.5681 · rPR ¥ 0.3615 · rO ¥ 

0.0018 · rPR · rO 

rO > 89 ............................................................. 7.88 + 1.4080 · rPR 

30 < rPR < 104.7 ............................................... 26.7 < rO ≤ 89 ................................................. 41.9435 + 1.505 rPR¥0.5823 · rO + 

0.005562¥rPR · rO 

rO > 89 ............................................................. –9.88 + 2.0 · rPR 

rPR ≥ 104.7 ........................................................ all ...................................................................... 32 + 1.6 · rPR 

(d) This paragraph (d) specifies phasein provisions that allow continued 

production of certain engines after the 

Tier 6 and Tier 8 standards begin to 

apply. 

(1) Engine type certificate families 

certificated with characteristic levels at 

or below the Tier 4 NOX standards of 

§ 87.21 (as applicable based on rated 

output and rated pressure ratio) and 

introduced before July 18, 2012 may be 

produced through December 31, 2012 

without meeting the Tier 6 NOX

standards of paragraph (c)(2) of this 

section. This also applies for engines 

that are covered by the same type 

certificate and are determined to be 

derivative engines for emissions 

certification purposes under the 

requirements of this part. Note that after 

this production cutoff date for the Tier 

6 NOX standards, such engines may be 

produced only if they are covered by an 

exemption under § 87.50. This 

production cutoff does not apply to 

engines installed (or delivered for 

installation) on military aircraft. 

(2) Engine type certificate families 

certificated with characteristic levels at 

or below the Tier 6 NOX standards of 

paragraph (c)(2) of this section with an 

introduction date before January 1, 2014 

may continue to be produced. This also 

applies for engines that are covered by 

the same type certificate and are 

determined to be derivative engines for 

emissions certification purposes under 

the requirements of this part. 

(3) An engine manufacturer may 

produce up to six newly manufactured 

Tier 4 engines on or after July 18, 2012, 

subject to the provisions of this 

paragraph (d)(3). Tier 4 engines meeting 

the criteria of this paragraph (d)(3) are 

excepted without request from the 

otherwise applicable Tier 6 NOX

emission standard. To be eligible for 

this exception the engines must have a 

date of manufacture prior to August 31, 

2013 and be fully compliant with all 

requirements applicable to Tier 4 

engines. The manufacturer must include 

these engines in the report required by 

§ 87.50. This exception is void for any 

manufacturer that produces more than 

six excepted engines under this 

paragraph. 

■ 11. Add a new subpart E containing 

§§ 87.40, 87.42, 87.46, and 87.48 to read 

as follows: 

Subpart E—Certification Provisions 

Sec. 

87.40 General certification requirement. 

87.42 Production report to EPA. 

87.46 Recordkeeping. 

87.48 Derivative engines for emissions 

certification purposes. 

Subpart E—Certification Provisions 

§ 87.40 General certification requirement. 

Manufacturers of engines subject to 

this part must meet the requirements of 

title 14 of the Code of Federal 

Regulations as applicable. 

§ 87.42 Production report to EPA. 

Engine manufacturers must submit an 

annual production report as specified in 

this section. This requirement applies 

for engines produced on or after January 

1, 2013. 

(a) You must submit the report for 

each calendar year in which you 

produce any engines subject to emission 

standards under this part. The report is 

due by February 28 of the following 

calendar year. Note that § 87.64 requires 

you to report CO2 emission rates to EPA 

in addition to NOX. Include these data 

in the report required by this section. If 

you produce exempted or excepted 

engines, you may submit a single report 

with information on exempted/excepted 

and normally certificated engines. 

(b) Send the report to the Designated 

EPA Program Officer. 

(c) In the report, specify your 

corporate name and the year for which 

you are reporting. Include information 

as described in this section for each 

engine sub-model subject to emission 

standards under this part. List each 

engine sub-model produced or 

certificated during the calendar year, 

including the following information for 

each sub-model: 

(1) The type of engine (turbofan, 

turboprop, etc.) and complete submodel name, including any applicable 

model name, sub-model identifier, and 

engine type certificate family identifier. 

(2) The certificate under which it was 

produced. Identify all the following: 

(i) The type certificate number. 

Specify if the sub-model also has a type 

certificate issued by a certificating 

authority other than FAA. 

(ii) Your corporate name as listed in 

the certificate. 

(iii) Emission standards to which the 

engine is certificated. 

(iv) Date of issue of type certificate 

(month and year). 

(v) Whether or not this is a derivative 

engine for emissions certification 

purposes. If so, identify the original 

certificated engine model. 

(vi) The engine sub-model that 

received the original type certificate for 

an engine type certificate family. 

(3) Identify the combustor of the submodel, where more than one type of 

combustor is available. 

(4) The calendar-year production 

volume of engines from the sub-model 

that are covered by an FAA type 

certificate. Record zero for sub-models 

with no engines produced during the 

calendar year, or state that the engine 

model is no longer in production and 

list the date of manufacture (month and 

year) of the last engine produced. 

Specify the number of these engines that 

are intended for use on new aircraft and 

the number that are intended for use as 

non-exempt engines on in-use aircraft. 

For engines delivered without a final 

sub-model status and for which the 

manufacturer has not ascertained the 

engine’s sub-model when installed 

before submitting its production report, 

the manufacturer may do any of the 

following in its initial report, and 

amend it later: 

(i) List the sub-model that was 

shipped or the most probable submodel. 

(ii) List all potential sub-models. 

(iii) State ‘‘Unknown Sub-Model.’’ 

(5) The number of engines tested and 

the number of test runs for the 

applicable type certificate. 


TKELLEY on DSK3SPTVN1PROD with RULES2
36384 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

(6) The applicable test data and 

related information specified in Part III, 

Section 2.4 of ICAO Annex 16 

(incorporated by reference in § 87.8), 

except as otherwise allowed by this 

paragraph. For purposes of this 

paragraph (c)(6), applicable test data 

means data required to certify the 

engine sub-model, which would 

typically include NOX, HC, CO and 

smoke number. However, applicable test 

data would not include NOX, HC, or CO 

emissions for engines subject to only 

smoke standards. Note that § 87.64 also 

requires you to report CO2 emissions. 

Specify thrust in kW for turboprop 

engines. You may omit the following 

items specified in Part III, Section 2.4 of 

ICAO Annex 16: 

(i) Fuel specifications including fuel 

specification reference and hydrogen/ 

carbon ratio. 

(ii) Methods used for data acquisition, 

correcting for ambient conditions, and 

data analysis. 

(iii) Intermediate emission indices 

and rates, however you may not omit 

the final characteristic level for each 

regulated pollutant in units of g/kN or 

g/kW. 

(d) Clearly show what information 

you consider confidential by marking, 

circling, bracketing, stamping, or some 

other method. We will store your 

confidential information as described in 

40 CFR part 2. Also, we will disclose it 

only as specified in 40 CFR part 2. If 

you send us information without 

claiming it is confidential, we may make 

it available to the public without further 

notice to you, as described in 40 CFR 

2.204. 

(e) Include the following signed 

statement and endorsement by an 

authorized representative of your 

company: ‘‘We submit this report under 

40 CFR 87.42. 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. 

§ 87.46 Recordkeeping. 

(a) You must keep a copy of any 

reports or other information you submit 

to us for at least three years. 

(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. 

§ 87.48 Derivative engines for emissions 

certification purposes. 

(a) General. A type certificate holder 

may request from the FAA a 

determination that an engine 

configuration is considered a derivative 

engine for emissions certification 

purposes. This would mean that the 

engine configuration is determined to be 

similar in design to a previously 

certificated engine (the ‘‘original’’ 

engine) for purposes of compliance with 

exhaust emission standards (gaseous 

and smoke). In order for the engine 

configuration to be considered a 

derivative engine for emission purposes 

under this part, it must have been 

derived from an original engine that was 

certificated to the requirements of 

14 CFR part 33, and one of the following 

conditions must be met: 

(1) The FAA determined that a safety 

issue exists that requires an engine 

modification. 

(2) Emissions from the derivative 

engines are determined to be similar. In 

general, this means the emissions must 

meet the criteria specified in paragraph 

(b) of this section. FAA may adjust these 

criteria in unusual circumstances, 

consistent with good engineering 

judgment. 

(3) All of the regulated emissions from 

the derivative engine are lower than the 

original engine. 

(b) Emissions similarity. (1) The type 

certificate holder must demonstrate that 

the proposed derivative engine model’s 

emissions meet the applicable standards 

and differ from the original model’s 

emission rates only within the following 

ranges: 

(i) ±3.0 g/kN for NOX. 

(ii) ±1.0 g/kN for HC. 

(iii) ±5.0 g/kN for CO. 

(iv) ±2.0 SN for smoke. 

(2) If the characteristic level of the 

original certificated engine model (or 

any other sub-models within the 

emission type certificate family tested 

for certification) before modification is 

at or above 95% of the applicable 

standard for any pollutant, you must 

measure the proposed derivative engine 

model’s emissions for all pollutants to 

demonstrate that the derivative engine’s 

resulting characteristic levels will not 

exceed the applicable emission 

standards. If the characteristic levels of 

the originally certificated engine model 

(and all other sub-models within the 

emission type certificate family tested 

for certification) are below 95% of the 

applicable standard for each pollutant, 

then, you may use engineering analysis 

to demonstrate that the derivative 

engine will not exceed the applicable 

emission standards, consistent with 

good engineering judgment. The 

engineering analysis must address all 

modifications from the original engine, 

including those approved for previous 

derivative engines. 

(c) Continued production allowance. 

Where we allow continued production 

of an engine model after new standards 

begin to apply, you may also produce 

engine derivatives if they conform to the 

specifications of this section. 

(d) Non-derivative engines. If the FAA 

determines that an engine model does 

not meet the requirements for a 

derivative engine for emissions 

certification purposes, the type 

certificate holder is required to 

demonstrate that the engine complies 

with the emissions standards applicable 

to a new engine type. 

■ 12. Add a new subpart F containing 

§ 87.50 to read as follows: 

Subpart F—Exemptions and 

Exceptions 

§ 87.50 Exemptions and exceptions. 

This section specifies provisions 

related to exempting/excepting engines 

from some or all of the standards and 

requirements of this part 87. Exempted/ 

excepted engines must conform to 

regulatory conditions specified for an 

exemption in this section and other 

applicable regulations. Exempted/ 

excepted engines are deemed to be 

‘‘subject to’’ the standards of this part 

even though they are not required to 

comply with the otherwise applicable 

requirements. Engines exempted/ 

excepted with respect to certain 

standards must comply with other 

standards. Exemption requests under 

paragraph (a) of this section must be 

approved by the FAA, with the written 

concurrence of EPA, to be effective. 

Exemption requests under paragraph (b) 

of this section must be approved only by 

the FAA to be effective. Exceptions do 

not require a case-by-case FAA 

approval. 

(a) Engines installed in new aircraft. 

Type certificate holders may request an 

exemption to produce a limited number 

of newly manufactured engines through 

December 31, 2016, to be installed in 

new aircraft as specified in this 

paragraph (a). This exemption is limited 

to NOX emissions from engines that are 

covered by a valid type certificate 

issued by FAA. 

(1) Submit your request for an 

exemption to the FAA before producing 

the engines to be exempted, who will 

provide a copy to the Designated EPA 

Program Officer. Exemption by an 

authority outside the United States does 

not satisfy this requirement. Unless EPA 

and FAA allow otherwise, all requests 

must include the following: 


TKELLEY on DSK3SPTVN1PROD with RULES2
Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 36385 

(i) Your corporate name and an 

authorized representative’s contact 

information. 

(ii) A description of the engines for 

which you are requesting the exemption 

including the type certificate number 

and date it was issued by the FAA. 

Include in your description the engine 

model and sub-model names and the 

types of aircraft in which the engines 

are expected to be installed. Specify the 

number of engines that you would 

produce under the exemption and the 

period during which you would 

produce them. 

(iii) Information about the aircraft in 

which the engines will be installed. 

Specify the airframe models and 

expected first purchasers/users of the 

aircraft. Identify all countries in which 

you expect the aircraft to be registered. 

Specify how many aircraft will be 

registered in the United States and how 

many will be registered in other 

countries; you may estimate this if it is 

not known. 

(iv) A justification of why the 

exemption is appropriate. Justifications 

must include a description of the 

environmental impact of granting the 

exemption. Include other relevant 

information such as the following: 

(A) Technical issues, from an 

environmental and airworthiness 

perspective, which may have caused a 

delay in compliance with a production 

cutoff. 

(B) Economic impacts on the 

manufacturer, operator(s), and aviation 

industry at large. 

(C) Environmental effects. This 

should consider the amount of 

additional air pollutant emissions that 

will result from the exemption. This 

could include consideration of items 

such as: 

(1) The amount that the engine model 

exceeds the standard, taking into 

account any other engine models in the 

engine type certificate family covered by 

the same type certificate and their 

relation to the standard. 

(2) The amount of the applicable air 

pollutant that would be emitted by an 

alternative engine for the same 

application. 

(3) The impact of changes to reduce 

the applicable air pollutant on other 

environmental factors, including 

emission rates of other air pollutants, 

community noise, and fuel 

consumption. 

(4) The degree to which the adverse 

impact would be offset by cleaner 

engines produced in the same time 

period (unless we decide to consider 

earlier engines). 

(D) Impact of unforeseen 

circumstances and hardship due to 

business circumstances beyond your 

control (such as an employee strike, 

supplier disruption, or calamitous 

events). 

(E) Projected future production 

volumes and plans for producing a 

compliant version of the engine model 

in question. 

(F) Equity issues in administering the 

production cutoff among economically 

competing parties. 

(G) List of other certificating 

authorities from which you have 

requested (or expect to request) 

exemptions, and a summary of the 

request. 

(H) Any other relevant factors. 

(v) A statement signed by your 

authorized representative attesting that 

all information included in the request 

is accurate. 

(2) In consultation with the EPA, the 

FAA may specify additional conditions 

for the exemption. 

(3) You must submit the annual report 

specified in paragraph (d) of this 

section. 

(4) The permanent record for each 

engine exempted under this paragraph 

(a) must indicate that the engine is an 

exempted new engine. 

(5) Engines exempted under this 

paragraph (a) must be labeled with the 

following statement: ‘‘EXEMPT NEW’’. 

(6) You must notify the FAA if you 

determine after submitting your request 

that the information is not accurate, 

either from an error or from changing 

circumstances. If you believe the new or 

changed information could have 

affected approval of your exemption 

(including information that could have 

affected the number of engines we 

exempt), you must notify the FAA 

promptly. The FAA will consult with 

EPA as needed to address any concerns 

related to this new or corrected 

information. 

(b) Temporary exemptions based on 

flights for short durations at infrequent 

intervals. The emission standards of this 

part do not apply to engines which 

power aircraft operated in the United 

States for short durations at infrequent 

intervals. Such operations are limited 

to: 

(1) Flights of an aircraft for the 

purpose of export to a foreign country, 

including any flights essential to 

demonstrate the integrity of an aircraft 

prior to its flight to a point outside the 

United States. 

(2) Flights to a base where repairs, 

alterations or maintenance are to be 

performed, or to a point of storage, and 

flights for the purpose of returning an 

aircraft to service. 

(3) Official visits by representatives of 

foreign governments. 

(4) Other flights the Secretary 

determines to be for short durations at 

infrequent intervals. A request for such 

a determination shall be made before 

the flight takes place. 

(c) Spare engines. Newly 

manufactured engines meeting the 

definition of ‘‘spare engine’’ are 

excepted as follows: 

(1) This exception allows production 

of a newly manufactured engine for 

installation on an in-service aircraft. It 

does not allow for installation of a spare 

engine on a new aircraft. 

(2) Each spare engine must be 

identical to a sub-model previously 

certificated to meet all requirements 

applicable to Tier 4 engines or later 

requirements. 

(3) Spare engines excepted under this 

paragraph (c) may be used only where 

the emissions of the spare engines are 

certificated to equal to or lower 

emission standards than those of the 

engines they are replacing, for all 

regulated pollutants. 

(4) No prior approval is required to 

produce spare engines. Engine 

manufacturers must include information 

about their production of spare engines 

in the annual report specified in 

paragraph (d) of this section 

(5) The permanent record for each 

engine excepted under this paragraph 

(c) must indicate that the engine was 

produced as an excepted spare engine. 

(6) Engines excepted under this 

paragraph (c) must be labeled with the 

following statement: ‘‘EXCEPTED 

SPARE’’. 

(d) Annual reports. If you produce 

engines with an exemption/exception 

under this section, you must submit an 

annual report with respect to such 

engines. 

(1) You must send the Designated 

EPA Program Officer a report describing 

your production of exempted/excepted 

engines for each calendar year in which 

you produce such engines by February 

28 of the following calendar year. You 

may include this information in the 

certification report described in § 87.42. 

Confirm that the information in your 

initial request is still accurate, or 

describe any relevant changes. 

(2) Provide the information specified 

in this paragraph (d)(2). For purposes of 

this paragraph (d), treat spare engine 

exceptions separate from other new 

engine exemptions. Include the 

following for each exemption/exception 

and each engine model and sub-model: 

(i) Engine model and sub-model 

names. 

(ii) Serial number of each engine. 

(iii) Use of each engine (for example, 

spare or new installation). 


TKELLEY on DSK3SPTVN1PROD with RULES2
36386 Federal Register / Vol. 77, No. 117 / Monday, June 18, 2012 / Rules and Regulations 

(iv) Types of aircraft in which the 

engines were installed (or are intended 

to be installed for spare engines). 

(v) Serial number of the new aircraft 

in which engines are installed (if 

known), or the name of the air carriers 

(or other operators) using spare engines. 

(3) Include information in the report 

only for engines having a date of 

manufacture within the specific 

calendar year. 

Subpart G—Test Procedures 

■ 13. The heading for subpart G is 

revised as set forth above. 

■ 14. Revise § 87.60 to read as follows: 

§ 87.60 Testing engines. 

(a) Use the equipment and procedures 

specified in Appendix 3, Appendix 5, 

and Appendix 6 of ICAO Annex 16 

(incorporated by reference in § 87.8), as 

applicable, to demonstrate whether 

engines meet the gaseous emission 

standards specified in subpart C of this 

part. Measure the emissions of all 

regulated gaseous pollutants. Similarly, 

use the equipment and procedures 

specified in Appendix 2 and Appendix 

6 of ICAO Annex 16 to determine 

whether engines meet the smoke 

standard specified in subpart C of this 

part. The compliance demonstration 

consists of establishing a mean value 

from testing some number of engines, 

then calculating a ‘‘characteristic level’’ 

by applying a set of statistical factors 

that take into account the number of 

engines tested. Round each 

characteristic level to the same number 

of decimal places as the corresponding 

emission standard. For turboprop 

engines, use the procedures specified 

for turbofan engines, consistent with 

good engineering judgment. 

(b) Use a test fuel meeting the 

specifications described in Appendix 4 

of ICAO Annex 16 (incorporated by 

reference in § 87.8). The test fuel must 

not have additives whose purpose is to 

suppress smoke, such as organometallic 

compounds. 

(c) Prepare test engines by including 

accessories that are available with 

production engines if they can 

reasonably be expected to influence 

emissions. The test engine may not 

extract shaft power or bleed service air 

to provide power to auxiliary gearboxmounted components required to drive 

aircraft systems. 

(d) Test engines must reach a steady 

operating temperature before the start of 

emission measurements. 

(e) In consultation with the EPA, the 

FAA may approve alternate procedures 

for measuring emissions as specified in 

this paragraph (e). This might include 

testing and sampling methods, 

analytical techniques, and equipment 

specifications that differ from those 

specified in this part. Manufacturers 

and operators may request this approval 

by sending a written request with 

supporting justification to the FAA and 

to the Designated EPA Program Officer. 

Such a request may be approved only if 

one of the following conditions is met: 

(1) The engine cannot be tested using 

the specified procedures. 

(2) The alternate procedure is shown 

to be equivalent to or better (e.g., more 

accurate or precise) than the specified 

procedure. 

(f) The following landing and take-off 

(LTO) cycles apply for emission testing 

and calculating weighted LTO values: 

TABLE 1 TO § 87.60—LTO TEST CYCLES

Mode 

Turboprop Subsonic turbofan Supersonic turbofan 

Percent of 

rated output 

Time in mode 

(minutes) 

Percent of 

rated output 

Time in mode 

(minutes) 

Percent of 

rated output 

Time in mode 

(minutes) 

Take-off .................................................. 100 0.5 100 0.7 100 1 .2 

Climb ...................................................... 90 2.5 85 2.2 65 2 .0 

Descent .................................................. ........................ ........................ ........................ ........................ 15 1 .2 

Approach ................................................ 30 4.5 30 4.0 34 2 .3 

Taxi/ground idle ..................................... 7 26.0 7 26.0 5.8 26 .0 

(g) Engines comply with an applicable 

standard if the testing results show that 

the engine type certificate family’s 

characteristic level does not exceed the 

numerical level of that standard, as 

described in § 87.60. 

§§ 87.61–87.63 [Removed] 

■ 15. Remove §§ 87.61–87.63. 

§ 87.64 [Amended] 

■ 16. In § 87.64, remove and reserve 

paragraph (a). 

§§ 87.65–87.71 [Removed] 

■ 17. Remove §§ 87.65–87.71. 

Subpart H—[Removed] 

■ 18. Remove subpart H. 

PART 1068—GENERAL COMPLIANCE 

PROVISIONS FOR HIGHWAY, 

STATIONARY, AND NONROAD 

PROGRAMS 

■ 19. The authority citation for part 

1068 continues to read as follows: 

Authority: 42 U.S.C. 7401–7671q. 

Subpart A—[Amended] 

■ 20. Amend § 1068.1 by revising 

paragraph (b) to read as follows: 

§ 1068.1 Does this part apply to me? 

* * * * * 

(b) This part does not apply to any of 

the following engine or vehicle 

categories: 

(1) Light-duty motor vehicles (see 40 

CFR part 86). 

(2) Heavy-duty motor vehicles and 

motor vehicle engines, except as 

specified in 40 CFR part 86. 

(3) Aircraft engines, except as 

specified in 40 CFR part 87. 

(4) Land-based nonroad compressionignition engines we regulate under 40 

CFR part 89. 

(5) Small nonroad spark-ignition 

engines we regulate under 40 CFR part 

90. 

(6) Marine spark-ignition engines we 

regulate under 40 CFR part 91. 

(7) Locomotive engines we regulate 

under 40 CFR part 92. 

(8) Marine compression-ignition 

engines we regulate under 40 CFR parts 

89 or 94. 

* * * * * 

[FR Doc. 2012–13828 Filed 6–15–12; 8:45 am] 

BILLING CODE 6560–50–P 


TKELLEY on DSK3SPTVN1PROD with RULES2