69664 Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 

tribal governments are known to own or 

operate BSCP manufacturing facilities. 

Thus, Executive Order 13175 does not 

apply to the final rule or today’s action. 

G. Executive Order 13045: Protection of 

Children From Environmental Health 

and Safety Risks 

Executive Order 13045 (62 FR 19885, 

April 23, 1997) applies to any rule that: 

(1) Is determined to be ‘‘economically 

significant’’ as defined under Executive 

Order 12866, and (2) concerns the 

environmental health or safety risk that 

EPA has reason to believe may have a 

disproportionate effect on children. If 

the regulatory action meets both criteria, 

the EPA must evaluate the 

environmental health or safety effects of 

the planned rule on children, and 

explain why the planned regulation is 

preferable to other potentially effective 

and reasonably feasible alternatives 

considered by EPA. 

The EPA interprets Executive Order 

13045 as applying only to those 

regulatory actions that are based on 

health or safety risks, such that the 

analysis required under section 5–501 of 

the Executive Order has the potential to 

influence the rule. Today’s action is not 

subject to Executive Order 13045 

because the final BSCP rule, which 

today’s action does not change, is based 

on technology performance and not on 

health or safety risks. 

H. Executive Order 13211: Actions That 

Significantly Affect Energy Supply, 

Distribution, or Use 

Executive Order 13211 (66 FR 28355, 

May 22, 2001) provides that agencies 

shall prepare and submit to the 

Administrator of the Office of 

Information and Regulatory Affairs, 

OMB, a Statement of Energy Effects for 

certain actions identified as ‘‘significant 

energy actions.’’ Section 4(b) of 

Executive Order 13211 defines 

‘‘significant energy actions’’ as ‘‘any 

action by an agency (normally 

published in the Federal Register) that 

promulgates or is expected to lead to the 

promulgation of a final rule or 

regulation, including notices of inquiry, 

advance notices of proposed 

rulemaking, and notices of proposed 

rulemaking: (1)(i) That is a significant 

regulatory action under Executive Order 

12866 or any successor order, and (ii) is 

likely to have a significant adverse effect 

on the supply, distribution, or use of 

energy; or (2) that is designated by the 

Administrator of the Office of 

Information and Regulatory Affairs as a 

significant energy action.’’

Today’s action is not subject to 

Executive Order 13211 because it is not 

a significant regulatory action under 

Executive Order 12866 nor is it likely to 

have a significant adverse effect on the 

supply, distribution, or use of energy. 

I. National Technology Transfer and 

Advancement Act 

Section 12(d) of the National 

Technology Transfer and Advancement 

Act (NTTAA) of 1995 (Pub. L. 104–113; 

15 U.S.C. 272 note) directs EPA to use 

voluntary consensus standards in its 

regulatory and procurement 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, business 

practices) developed or adopted by one 

or more voluntary consensus bodies. 

The NTTAA directs EPA to provide 

Congress, through annual reports to 

OMB, with explanations when an 

agency does not use available and 

applicable voluntary consensus 

standards. 

Today’s action does not involve 

technical standards. Therefore, EPA is 

not considering the use of any voluntary 

consensus standards. 

List of Subjects for 40 CFR Part 63 

Environmental protection, 

Administrative practice and procedures, 

Air pollution control, Hazardous 

substances, Intergovernmental relations, 

Reporting and recordkeeping 

requirements. 

Dated: November 10, 2005. 

Stephen L. Johnson, 

Administrator. 

[FR Doc. 05–22805 Filed 11–16–05; 8:45 am] 

BILLING CODE 6560–50–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 87 

[OAR–2002–0030; FRL–7997–3] 

RIN 2060–AK01 

Control of Air Pollution From Aircraft 

and Aircraft Engines; Emission 

Standards and Test Procedures 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Final rule. 

SUMMARY: In this action, we are 

amending the existing United States 

regulations governing the exhaust 

emissions from new commercial aircraft 

gas turbine engines. Under the authority 

of section 231 of the Clean Air Act 

(CAA), 42 U.S.C. 7571, the 

Environmental Protection Agency (EPA) 

is establishing new emission standards 

for oxides of nitrogen (NOX) for newly 

certified commercial aircraft gas turbine 

engines with rated thrust greater than 

26.7 kilonewtons (kN). This action 

adopts standards equivalent to the NOX

standards of the United Nations 

International Civil Aviation 

Organization (ICAO), and thereby brings 

the United States emission standards 

into alignment with the internationally 

adopted standards (ICAO standards for 

newly certified engines were effective 

beginning in 2004). In addition, today’s 

action amends the test procedures for 

gaseous exhaust emissions to 

correspond to recent amendments to the 

ICAO test procedures for these 

emissions. 

On December 19, 2005, the new NOX

standards will apply to newly certified 

gas turbine engines—those engines 

designed and certified after the effective 

date of the regulations (for purposes of 

this action, the date of manufacture of 

the first individual production model 

means the date of type certification). 

Newly manufactured engines of already 

certified models (i.e., those individual 

engines that are part of an already 

certified engine model, but are built 

after the effective date of the regulations 

for such engines and have never been in 

service) will not have to meet these 

standards. 

Today’s amendments to the emission 

test procedures are those recommended 

by ICAO and are widely used by the 

aircraft engine industry. Thus, today’s 

action will help establish consistency 

between U.S. and international 

standards, requirements, and test 

procedures. Since aircraft and aircraft 

engines are international commodities, 

there is commercial benefit to 

consistency between U.S. and 

international emission standards and 

control program requirements. In 

addition, today’s action ensures that 

domestic commercial aircraft meet the 

current international standards, and 

thus, the public can be assured they are 

receiving the air quality benefits of the 

international standards. 

DATES: This final rule is effective 

December 19, 2005. 

The incorporation by reference of 

certain publications listed in this 

regulation is approved by the Director of 

the Federal Register as of December 19, 

2005. 

ADDRESSES: EPA has established a 

docket for this action under Docket ID 

No. OAR–2002–0030. All documents in 

the docket are listed in the EDOCKET 

index at http://www.epa.gov/edocket. 

Although listed in the index, some 

information is not publicly available, 

Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 69665 

i.e., CBI 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 either electronically in 

EDOCKET or in hard copy at the Air 

Docket in the EPA Docket Center, EPA/ 

DC, EPA West, Room B102, 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: Mr. 

Bryan Manning, Assessment and 

Standards Division, Office of 

Transportation and Air Quality, 

Environmental Protection Agency, 2000 

Traverwood Drive, Ann Arbor, MI 

48105; telephone number: (734) 214–

4832; fax number: (734) 214–4816; email address: manning.bryan@epa.gov, 

or Assessment and Standards Division 

Hotline; telephone number: (734) 214–

4636; e-mail address: asdinfo@epa.gov. 

SUPPLEMENTARY INFORMATION: 

Does This Action Apply to Me? 

Entities potentially regulated by this 

action are those that manufacture and 

sell commercial aircraft engines and 

aircraft in the United States. Regulated 

categories include: 

Category NAICSa codes SIC codes b 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 is not intended to be 

exhaustive, but rather provides a guide 

for readers regarding entities likely to be 

regulated by this action. 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 87.20 

(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. 

How Can I Get Copies of This 

Document and Other Related 

Information? 

Docket. EPA has established an 

official public docket for this action 

under Docket ID No. OAR–2002–0030 at 

http://www.epa.gov/edocket. The 

official public docket consists of the 

documents specifically referenced in 

this action, any public comments 

received, and other information related 

to this action. The public docket does 

not include Confidential Business 

Information (CBI) or other information 

whose disclosure is restricted by statute. 

The official public docket is the 

collection of materials that is available 

for public viewing at the Air Docket in 

the EPA Docket Center, (EPA/DC) EPA 

West, Room B102, 1301 Constitution 

Ave., NW., Washington, DC. The EPA 

Docket Center 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 

Reading Room is (202) 566–1742, and 

the telephone number for the Air Docket 

is (202) 566–1742. 

Electronic Access. You may access 

this Federal Register document 

electronically through the EPA Internet 

under the ‘‘Federal Register’’ listings at 

http://www.epa.gov/fedrgstr/. 

An electronic version of the public 

docket is available through EPA’s 

electronic public docket and comment 

system, EPA Dockets. You may use EPA 

Dockets at http://www.epa.gov/edocket/ 

to view public comments, access the 

index listing of the contents of the 

official public docket, and to access 

those documents in the public docket 

that are available electronically. 

Although not all docket materials may 

be available electronically, you may still 

access any of the publicly available 

docket materials through the docket 

facility identified above. Once in the 

system, select ‘‘search,’’ then key in the 

appropriate docket identification 

number. 

Outline of This Preamble 

I. Introduction 

A. Brief History of EPA’s Regulation of 

Aircraft Engine Emissions 

B. Interaction With the International 

Community 

C. EPA’s Responsibilities Under the Clean 

Air Act 

II. Why is EPA Taking This Action? 

A. Inventory Contribution 

B. Health and Welfare Effects 

1. Ozone 

a. What Are the Health Effects of Ozone 

Pollution? 

b. What Are the Current and Projected 8- 

hour Ozone Levels? 

2. Particulate Matter 

a. What Is Particulate Matter? 

b. What Are the Health Effects of PM2.5? 

c. What Are Current and Projected Level of 

PM? 

C. Other Environmental Effects 

1. Acid Deposition 

2. Eutrophication and Nitrification 

3. Plant Damage from Ozone 

4. Visibility 

III. Aircraft Engine Standards 

A. What Are The NOX Standards For 

Newly Certified Engines? 

1. Today’s NOX Standards 

a. For Engines With a Pressure Ratio of 30 

or less 

i. For engines with a maximum rated 

output of more than 89.0 kN 

ii. For engines with a maximum rated 

output of more than 26.7 kN but not 

more than 89.0 kN 

b. For Engines With A Pressure Ratio of 

More Than 30 But Less than 62.5 

i. For engines with a maximum rated 

output of more than 89.0 kN 

ii. For engines with a maximum rated 

output of more than 26.7 kN but not 

more than 89.0 kN 

c. For Engines With a Pressure Ratio of 

62.5 or More 

2. NOX Standards of Newly Certified Midand High-Thrust Engines 

3. NOX Standards for Newly Certified LowThrust Engines 

4. Rationale for Today’s NOX Standards for 

Newly Certified Low-, Mid-, and HighThrust Engines 

5. Future NOX Standards for Newly 

Certified Low-, Mid-, and High-Thrust 

Engines 

B. Newly Manufactured Engines of Already 

Certified Models 

1. What Is the Status of Engines? 

2. What Are The Issues With Applying 

Today’s NOX Standards to Newly 

Manufactured Engines of Already 

Certified Models? 

IV. Amendments to Criteria on Calibration 

and Test Gases for Gaseous Emissions 

Test and Measurement Procedures 

V. Correction of Exemptions for Very Low 

Production Models 

VI. Coordination with FAA 

VII. Possible Future Aviation Emissions 

Reduction (EPA/FAA Voluntary 

Aviation Emissions Reduction Initiative) 

VIII. Regulatory Impacts 

IX. Public Participation 

X. Statutory Provisions and Legal Authority 

XI. Statutory and Executive Order Reviews 

A. Executive Order 12866: Regulatory 

Planning and Review 

69666 Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 

1 In the proposal, we referred to such engines as 

already certified, newly manufactured engines or 

already certified engines; however, this terminology 

may need some clarification for the final 

rulemaking (thus, we use the term ‘‘newly 

manufactured engines of already certified models’’). 

2This does not mean that in 1997 we 

promulgated requirements for the re-certification or 

retrofit of existing in-use engines. 

3Throughout this rule, the date of manufacture of 

the first individual production model means the 

date of type certification. 

4U.S. EPA, ‘‘Control of Air Pollution from 

Aircraft and Aircraft Engines; Emission Standards 

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

May 8, 1997. 

5 ICAO, ‘‘Convention on International Civil 

Aviation,’’ Sixth Edition, Document 7300/6, 1980. 

Copies of this document can be obtained from the 

ICAO Web site located at http://www.icao.int. 

6 International Civil Aviation Organization 

(ICAO), Foreword of ‘‘Aircraft Engine Emissions,’’

International Standards and Recommended 

Practices, Environmental Protection, Annex 16, 

Volume II, Second Edition, July 1993. Copies of this 

document can be obtained from the ICAO Web site 

located at http://www.icao.int. 

7 ICAO, ‘‘Assembly—35th Session, Report of the 

Executive Committee on Agenda Item 15,’’

Presented by the Chairman of the Executive 

Committee, A35–WP/32, October 12, 2004. 

8As of March 2, 2005 there were 188 Contracting 

States according to the ICAO Web site located at 

http://www.icao.int. 

9Text of Article 38 of Chicago Convention: 

Any State which finds it impracticable to comply 

in all respects with any such international standard 

or procedure, or to bring its own regulations or 

practices into full accord with any international 

standard or procedure after amendment of the 

latter, or which deems it necessary to adopt 

regulations or practices differing in any particular 

respect from those established by an international 

standard, shall give immediate notification to the 

International Civil Aviation Organization of the 

differences between its own practice and that 

established by the international standard * * * In 

any such case, the Council shall make immediate 

notification to all other states of the difference 

which exists between one or more features of an 

international standard and the corresponding 

national practice of that State. 

10Text of Article 33 of Chicago Convention: 

Certificates of airworthiness and certificates of 

competency and licenses issued or rendered valid 

by the contracting State in which the aircraft is 

registered, shall be recognized as valid by the other 

contracting States, provided that the requirements 

under which such certificates or licenses were 

issued or rendered valid are equal to or above the 

minimum standards which may be established from 

time to time pursuant to this Convention. 

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. Congressional Review Act 

I. Introduction 

A. Brief History of EPA’s Regulation of 

Aircraft Engine Emissions 

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

Act (CAA) directs the EPA 

Administrator to ‘‘issue proposed 

emission standards applicable to the 

emission of any air pollutant 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). In addition, 

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). Under this 

authority EPA has conducted several 

rulemakings since 1973 establishing 

emission standards and related 

requirements for several classes 

(commercial and general aviation 

engines) of aircraft and aircraft engines. 

Most recently, in 1997 EPA promulgated 

NOX emission standards for newly 

manufactured gas turbine engines of 

already certified models 1 (those 

individual engines that are part of an 

already certified engine model, but are 

built after the effective date of the 

regulations for such engines and have 

never been in service) 2 and for newly 

certified gas turbine engines (those 

engines designed and certified after the 

effective date of the regulations 3).4 In 

addition, EPA promulgated a carbon 

monoxide (CO) emission standard for 

newly manufactured gas turbine engines 

in this same 1997 rulemaking. At the 

time, the 1997 rulemaking established 

consistency between the U.S. and 

international standards. (See 40 CFR 

part 87 for a description of EPA’s 

aircraft engine emission control 

requirements and 14 CFR part 34 for the 

Department of Transportation’s 

regulations for ensuring compliance 

with these standards in accordance with 

section 232 of the Clean Air Act.) 

B. Interaction With the International 

Community 

Since publication of the initial 

standards in 1973, EPA, together with 

the Federal Aviation Administration 

(FAA), has worked with the 

International Civil Aviation 

Organization (ICAO) on the 

development of international aircraft 

engine emission standards. ICAO was 

established in 1944 by the United 

Nations (by the Convention on 

International Civil Aviation, the 

‘‘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.’’ 5 ICAO’s 

responsibilities include developing 

aircraft technical and operating 

standards, recommending practices, and 

generally fostering the growth of 

international civil aviation. 

In 1972 at the United Nations 

Conference on the Human Environment, 

ICAO’s position on the human 

environment was developed to be the 

following: ‘‘[i]n fulfilling this role ICAO 

is conscious of the adverse 

environmental impact that may be 

related to aircraft activity and its 

responsibility and that of its member 

States to achieve maximum 

compatibility between the safe and 

orderly development of civil aviation 

and the quality of the human 

environment.’’ Also, in 1972 ICAO 

established the position to continue 

‘‘* * * with the assistance and 

cooperation of other bodies of the 

Organization and other international 

organizations * * * the work related to 

the development of Standards, 

Recommended Practices and Procedures 

and/or guidance material dealing with 

the quality of the human environment 

* * *.’’ 6 At the 35th Assembly in 

October 2004, ICAO’s 188 Contracting 

States affirmed that ICAO should 

continue to take the leadership role in 

all international civil aviation matters 

relating to the environment.7

The United States is one of 188 

participating member States of ICAO.8

Under the basic ICAO treaty established 

in 1944 (the Chicago Convention), a 

participating nation which elects not to 

adopt the ICAO standards must provide 

a written explanation to ICAO 

describing why a given standard is 

impractical to comply with or not in its 

national interest.9 ICAO standards 

require States to provide written 

notification and failure to provide such 

notification could have negative 

consequences as detailed below. 

If a Contracting State files a written 

notification indicating that it does not 

meet ICAO standards, other Contracting 

States are absolved of their obligations 

to ‘‘recognize as valid’’ the certificate of 

airworthiness issued by that Contracting 

State, since that certificate will not have 

been issued under standards ‘‘equal to 

or above’’ ICAO standards. In other 

words, other Contracting States do not 

have to allow aircraft belonging to that 

Contracting State to travel through their 

airspace.10 Further, if it fails to file a 

written notification, it will be in default 

of its obligations, and risks mandatory 

exclusion of its aircraft from the 

airspace of other Contracting States and 

Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 69667 

11Articles 87 and 88 of Chicago Convention. 

12Article 33 of Chicago Convention. 

13Article 38 of Chicago Convention. 

14 ICAO, ‘‘Aircraft Engine Emissions,’’

International Standards and Recommended 

Practices, Environmental Protection, Annex 16, 

Volume II, Second Edition, July 1993. Copies of this 

document can be obtained from ICAO (http:// 

www.icao.int). 

15 ICAO, Foreword of ‘‘Aircraft Engine 

Emissions,’’ International Standards and 

Recommended Practices, Environmental Protection, 

Annex 16, Volume II, Second Edition, July 1993. 

Copies of this document can be obtained from ICAO 

(http://www.icao.int). 

16 International Civil Aviation Organization 

(ICAO), Aircraft Engine Emissions, Annex 16, 

Volume II, Second Edition, July 1993, Amendment 

4 effective on July 19, 1999. Copies of this 

document can be obtained from ICAO (http:// 

www.icao.int). 

17These NOX standards will be interchangeably 

be referred to as the 1998 CAEP/4 standards and the 

1999 ICAO standards throughout this Notice. 

18Newly manufactured engines of already 

certified models are those individual engines that 

are part of an already certified engine model, but 

are built after the effective date of the regulations 

for such engines and have never been in service. 

This does not mean the re-certification or retrofit of 

existing in-use engines. 

19CAA section 233 entitled ‘‘State Standards and 

Controls’’ states that ‘‘No State or political 

subdivision thereof may adopt or attempt to enforce 

any standard respecting emissions of any air 

Continued 

the loss of its voting power in the 

Assembly and Council.11

The Chicago Convention does not 

require all Contracting States to adopt 

identical airworthiness standards. 

Although the Convention urges a high 

degree of uniformity, it is expected that 

States will adopt their own 

airworthiness standards, and it is 

anticipated that some states may adopt 

standards that are more stringent than 

those agreed upon by ICAO. However, 

because any State can ban use within its 

airspace of any aircraft that does not 

meet ICAO standards, States that wish 

to use aircraft in international air 

transportation have agreed to adopt 

standards that meet or exceed the 

stringency levels of ICAO standards.12

Because States are required to recognize 

certificates of any State whose standards 

meet or exceed ICAO standards, a State 

is assured its aircraft will be permitted 

to operate in any other Contracting State 

if its standards meet or exceed the 

minimum stringency levels of ICAO 

standards. 

As long as a participating nation of 

ICAO adopts aircraft emission standards 

that are equal to or more stringent than 

ICAO’s standards, the certificates of 

airworthiness for such nations are valid. 

Thus, aircraft belonging to countries 

with more stringent standards are 

permitted to travel through the airspace 

of other countries without any 

restriction. To ensure operation 

internationally without constraints, 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 

(foreign-flag carriers) would only be 

required to comply with the ICAO 

standards. 

The ICAO Council’s Committee on 

Aviation Environmental Protection 

(CAEP) undertakes ICAO’s technical 

work in the environmental field. The 

CAEP 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 Study Groups, 

Work Groups, Committees and other 

contributing memberships that include 

atmospheric, economic, aviation, 

environmental, and other professionals 

committed to ICAO’s previously stated 

position regarding aviation and the 

environment. At CAEP meetings, the 

United States is represented by the 

FAA, which plays an active role at these 

meetings (see section VI for further 

discussion of FAA’s role). EPA has 

historically been a principal participant 

in the development of U.S. policy in 

ICAO/CAEP and other international 

venues, assisting and technically 

advising FAA on aviation emissions 

matters. If the ICAO Council adopts a 

CAEP proposal to adopt a new 

environmental standard, it then 

becomes part of the ICAO standards and 

recommended practices (Annex 16 to 

the Chicago Convention).14

On June 30, 1981, the ICAO Council 

adopted its first international standards 

and recommended practices covering 

aircraft engine emissions.15 These 

standards limit aircraft engine emissions 

of NOX, CO, and hydrocarbons (HC), in 

relation to other engine performance 

parameters, and are commonly known 

as stringency standards. On March 24, 

1993, the ICAO Council approved a 

proposal adopted at the second meeting 

of the CAEP (CAEP/2) to tighten the 

original NOX standard by 20 percent 

and amend the test procedures. At the 

next CAEP meeting (CAEP/3) in 

December 1995, the CAEP 

recommended a further tightening of 16 

percent and additional test procedure 

amendments, but on March 20, 1997 the 

ICAO Council rejected this stringency 

proposal and approved only the test 

procedure amendments. At its next 

meeting (CAEP/4) in April 1998, the 

CAEP adopted a similar 16 percent NOX

reduction proposal, which the ICAO 

Council approved on February 26, 

1999.16 The CAEP/4 16 percent NOX

reduction standard applies to new 

engine designs certified after December 

31, 2003 (i.e., it applies only to newly 

certified engines, rather than to newly 

manufactured engines of already 

certified models).17 18

As discussed earlier, in 1997 EPA 

amended its regulations to adopt the 

1981 ICAO NOX and CO emission 

standards, as well as the NOX emission 

standards and test procedures revised 

by ICAO in 1993. As discussed above, 

the U.S. has an obligation under the 

Convention on International Civil 

Aviation to notify ICAO regarding 

differences between U.S. standards and 

ICAO standards, and to provide 

notification on the date by which the 

program requirements will be 

consistent. In response to the recent 

actions by ICAO and for the reasons 

discussed below, in today’s rulemaking 

EPA is adopting standards for newly 

certified engines that are equivalent to 

ICAO’s 1999 amendment to the NOX

emission standard and the test 

procedure changes approved by ICAO in 

1997, and EPA is adopting other 

technical amendments to further align 

EPA and ICAO requirements. 

C. EPA’s Responsibilities Under the 

Clean Air Act 

As discussed earlier, section 231 of 

the CAA directs EPA, from time to time, 

to propose aircraft engine emission 

standards applicable to the emission of 

any air pollutant from classes of aircraft 

engines which in its 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). 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). In addition, EPA is required 

to ensure, in consultation with the 

Secretary of Transportation, that such 

standards’ effective dates provide the 

necessary time to permit the 

development and application of the 

requisite technology, giving appropriate 

consideration to compliance cost. 42 

U.S.C. 7571(b). Also, EPA must consult 

with the FAA before proposing or 

promulgating emission standards. 42 

U.S.C. 7571(a)(2)(B)(i). (See section VI of 

today’s proposal for further discussion 

of EPA’s coordination with FAA and 

FAA’s responsibilities under the CAA.) 

In addition, section 233 of the CAA 

vests authority to implement emission 

standards for aircraft or aircraft engines 

only in EPA.19 States are preempted 

69668 Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 

pollutant from any aircraft or engine thereof unless 

such standard is identical to a standard applicable 

to such aircraft under this part.’’ 42 U.S.C. 7573. 

20 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. 

21For additional information on the inventory 

impacts of our new rules, see Tables IV–A–1 and 

IV–A–2 in our Advance Notice of Proposed 

Rulemaking for an additional tier of standards for 

locomotives and marine diesel engines below 30 

liters per cylinder displacement (69 FR 39276, June 

29, 2004). 

22Commercial aircraft include those aircraft used 

for scheduled service transporting passengers, 

freight, or both. Air taxis also fly scheduled service 

carrying passengers, freight or both, and they 

usually are smaller aircraft than those operated by 

air carriers. Air taxis have played an increasing role 

in the operations of the U.S. aviation system, and 

by 2015, such operations are forecast to represent 

54 percent of operations (see Table II.A–2 and the 

FAA website http://www.apo.data.faa.gov/main/ 

taf.asp). General aviation includes most other 

aircraft used for recreational flying and personal 

transportation. Aircraft that support business travel, 

usually on an unscheduled basis, are included in 

the category of general aviation. Military aircraft 

cover a wide range of sizes, uses, and operating 

missions. While they are often similar to civil 

aircraft, they are modeled separately because they 

often operate primarily out of military bases and 

frequently have distinctive flight profiles. 

23U.S. EPA, ‘‘Average Annual Emissions, All 

Criteria Pollutants Years Including 1970–2001,’’

Updated August 2003. A copy of this document can 

be found in Docket No. OAR–2002–0030. 

U.S. EPA, ‘‘Documentation for Aircraft, 

Commercial Marine Vessel, Locomotive, and other 

Nonroad Components of the National Emissions 

Inventory, Volume I—Methodology,’’ Prepared for 

EPA by Eastern Research Group, Inc., October 7, 

2003. A copy of this document can be found in 

Docket No. OAR–2002–30. 

24The earlier military estimates are based on 

emission inventories from the Final Rule for 

Control of Emissions from Land-based Nonroad 

Diesel Engines, 69 FR 38958, June 29, 2004. Also, 

see the following memorandum for further 

discussion of the contribution of military aircraft to 

total aircraft emissions and related references: U.S. 

EPA, ‘‘Earlier and Current Estimates of Military 

Aircraft Emissions (Updated),’’ Memorandum to 

Docket OAR–2002–0030 from Bryan Manning 

(Document No. OAR–2002–0030–0214), May 11, 

2005. 

from adopting or enforcing any standard 

respecting aircraft engine emissions 

unless such standard is identical to 

EPA’s standards. 42 U.S.C. 7573. 

II. Why Is EPA Taking This Action? 

As mentioned above, section 

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

Administrator to ‘‘from time to time, 

issue proposed emission standards 

applicable to 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. NOX

is a precursor to the formation of 

ozone.20 Many commercial airports are 

located in urban areas and many of 

these areas have ambient ozone levels 

above the National Ambient Air Quality 

Standards (NAAQS) for ozone (i.e., they 

are in nonattainment for ozone). This 

section discusses the contribution of 

aircraft engines to the national NOX

emissions inventory and the health and 

welfare impacts of these emissions. 

A. Inventory Contribution 

EPA’s estimate of the contribution of 

aircraft to the national NOX emission 

inventory is set out in Table II.A–1. 

Note that this table provides the 

inventory contributions only for 2001, 

and therefore does not take into account 

the impacts of our recent mobile source 

emission control programs for highway 

vehicles and nonroad engines and 

equipment which will go into effect in 

the coming years.21 Those new 

standards are expected to reduce NOX

emissions from highway and nonroad 

engines by 90 percent or more on a perengine basis. (Nor does the table 

account for aviation’s reduced NOX

emissions due to slower growth and 

changes in fleet composition after 2001.) 

Nonetheless, as these new programs go 

into effect, the relative size of the 

contribution of aircraft to national NOX

levels may increase due to the decrease 

in the contribution of those other mobile 

sources. 

TABLE II.A–1.—ANNUAL NOX BASELINE LEVELS a FROM EPA’S NATIONAL AIR QUALITY AND EMISSIONS

TRENDS REPORT, AUGUST 2003 

[Short tons, 2001] 

Category NOX

(Thous. Tons) 

Aircraft b c ................... 81 0.7% 

Nonroad .................... 4,075 32.8% 

Highway .................... 8,249 66.5% 

Total Mobile Source 12,405 

aSource: U.S. EPA, ‘‘Average Annual Emissions, All Criteria Pollutants Years Including 

1970–2001,’’ Updated August 2003. A copy of 

this document can be found in Docket No. 

OAR–2002–0030. bThese aircraft emissions are a conservative estimate as they reflect military operations only at FAA and FAA-contracted facilities and not at military bases. See the following memo for further discussion of the contribution of military aircraft to total aircraft 

emissions: U.S. EPA, ‘‘Earlier and Current Estimates of Military Aircraft Emissions (Updated),’’ Memorandum to Docket OAR–2002– 

0030 from Bryan Manning, May 11, 2005. cThere is a new draft version of the national 

emissions inventories (for 2002), and the percentage contribution of the above sources to 

the total mobile source NOX inventory remains 

essentially the same. 

Aircraft emissions are emitted from a 

variety of aircraft types used for public, 

private, and military purposes including 

commercial aircraft, air taxis, general 

aviation, and military aircraft.22

Commercial aircraft emissions 

contribute from 74 to 99 percent of the 

NOX aircraft emissions in the U.S. The 

high end of this range represents 

commercial aircraft’s fraction of 

national aircraft NOX emissions when 

current estimates for all aircraft types 

(commercial aircraft, air taxis, general 

aviation, and military aircraft) are added 

together.23 The lower end of the range 

is commercial aircraft’s contribution of 

NOX aircraft emissions in the U.S. when 

combining earlier 24 military aircraft 

estimates with current emission 

estimates for the three other aircraft 

types (the earlier and current estimates 

were based on different methods or 

models for calculating aircraft emissions 

in 2001). This range was provided since 

the current estimates of military aircraft 

emission have limitations—i.e., military 

aircraft estimates are a conservative 

estimate as they reflect military 

operations only at FAA and FAAcontracted facilities and not at military 

bases. For a discussion on obtaining 

improved military aircraft emission 

estimates, see Section 5 of the Summary 

and Analysis of Comments for this 

rulemaking. (See the following 

memorandum for a further description 

of the contribution of military aircraft to 

total aircraft emissions: U.S. EPA, 

‘‘Earlier and Current Estimates of 

Military Aircraft Emissions (Updated),’’

Memorandum to Docket OAR–2002–

0030 from Bryan Manning (Document 

No. OAR–2002–0030–0214), May 11, 

2005.) 

While the current contribution of 

aircraft to nationwide NOX is less than 

one percent, their contribution on a 

local level, especially in areas 

containing or adjacent to airports can be 

much larger and is also expected to 

grow. This is illustrated by EPA’s 1999 

study that examined NOX emissions 

from aircraft for ten cities: Atlanta, 

Boston-Lawrence-Worcester, CharlotteGastonia, Chicago-Gary-Lake County, 

Houston-Galveston-Brazoria, New YorkNew Jersey-Long Island, Philadelphia, 

Phoenix, Los Angeles Air Basin and 

Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 69669 

25U.S. EPA, ‘‘Evaluation of Air Pollutant 

Emissions from Subsonic Commercial Jet Aircraft,’’

April 1999, EPA420–R–99–013. A copy of this 

document is available at http://www.epa.gov/otaq/ 

aviation.htm. It can also be found in Docket No. 

OAR–2002–0030, Document No. OAR–2002–0030–

0002. As indicated in the report, comments 

received from reviewers of this study indicated that 

uncertainty may exist in the national forecasts of 

growth in aircraft activity, on future composition of 

the aircraft fleet, and on the accuracy of a default 

mixing height. Such uncertainties carry over into 

projections of future emissions, and resolution of 

uncertainties may result in higher or lower groundlevel emissions estimates from future aircraft. 

26Based on the one-hour ozone standard, nine of 

the ten metropolitan areas are currently not in 

attainment of NAAQS for one-hour ozone; the tenth 

city has attained the one-hour ozone standard and 

is considered an one-hour ozone ‘‘maintenance’’

area. Based on the 8-hour ozone standard, all ten 

metropolitan areas are currently not in attainment 

of NAAQS for 8-hour ozone. See section II.B.1 of 

this rule for further discussion on the ozone 

NAAQs. Also, for more detailed information on the 

8-hour ozone standard, see the following EPA Web 

sites: http://www.epa.gov/airlinks/ozpminfo.html, 

http://www.epa.gov/airlinks/airlinks4.html or 

http://www.epa.gov/ttn/naaqs/ozone/o3imp8hr. 

27U.S. Department of Transportation, Office of 

Inspector General, ‘‘Airline Industry Metrics,’’ CC–

2203–007, January 7, 2003. A copy of this document 

can be found in Docket No. OAR–2002–0030, 

Document No. OAR–2002–0030–0012. 

28U.S. General Accounting Office, ‘‘Aviation and 

the Environment: Strategic Framework Needed to 

Address Challenges Posed by Aircraft Emissions,’’

GAO–03–252, February 2003. This document is 

available at http://www.gao.gov/cgi-bin/ 

getrpt?GAO-03-252, and it can also be found in the 

Docket No. OAR–2002–0030, Document No. OAR–

2002–0030–0005. 

29U.S. FAA, ‘‘APO Terminal Area Forecast 

Summary Report,’’ Aircraft Operations, December 

14, 2000. A copy of this document can be found in 

Docket No. OAR–2002–0030. 

30U.S. FAA, ‘‘APO Terminal Area Forecast 

Summary Report,’’ Aircraft Operations, June 30, 

2005. The flight forecast data is based on FAA’s 

Terminal Area Forecast System (TAFS). TAFs is the 

official forecast of aviation activity at FAA facilities. 

This includes FAA-towered airports, federallycontracted towered airports, nonfederal towered 

airports, and many non-towered airports. For 

detailed information on TAFS and the air carrier 

activity forecasts see the following FAA Web site: 

http://www.apo.data.faa.gov/main/taf.asp. The 

June 30, 2005 aviation forecasts contained in TAFS 

for Fiscal Years 2002–2020 included the impact of 

the terrorists’ attacks of September 11, 2001 and the 

recent economic downturn. Currently, the aviation 

industry is undergoing significant structural and 

economic changes. These changes may necessitate 

revisions to forecasts for a number of large hub 

airports prior to the update of the entire TAF next 

year. A copy of the June 30, 2005 forecast summary 

report can also be found in Docket No. OAR–2002–

0030. 

Washington DC.25 26 Nineteen airport 

facilities with significant commercial jet 

aircraft activity were identified within 

these selected areas. On average for 

these ten cities, commercial aircraft’s 

contribution is expected to increase 

from about 2 percent of regional total 

NOX emissions in 1990 to about 5 

percent in 2010. 

It should be noted that the above 

study of the impacts of airports on 

regional air quality was conducted 

before the tragic events of September 11, 

2001, and the economic downturn in 

the aircraft transportation sector and 

resulting slowing of emissions growth. 

A report by the Department of 

Transportation in 2003 indicated that 

the combination of the September 11, 

2001 terrorist attacks and cut-backs in 

business travel have had a significant 

effect on air transportation demand.27

The FAA expects the demand for air 

travel to recover and then continue a 

long-term trend of annual growth, 

though from a lower base and a slower 

rate in the United States.28 Thus, there 

is both a short-term decrease in aircraft 

transportation activity as a result of 9/ 

11, with negative growth for a few years 

and associated decreases in aircraft 

emission contributions and lower 

emissions growth than originally 

anticipated over the time period 

assessed. This is illustrated in Table 

II.A–2, which compares the results of an 

earlier, pre-9/11 FAA activity forecast to 

a recent, post-9/11 forecast. As 

operations increase, the inventory 

impact of these aircraft on national and 

local NOX inventories and on ozone 

levels will also increase. 

TABLE II.A–2.—FAA TERMINAL AREA FORECAST SUMMARY REPORT OF NATIONWIDE AIR CARRIER AND COMMUTER/AIR

TAXI OPERATIONS abcde

Year 

Air carrier & 

commuter/air 

taxi operations 

12/14/00 forecast (pre-9/11) 

Percent 

change 12/14/ 

00 forecast 

between years 

listed 

Air carrier & 

commuter/air 

taxi operations 

6/30/05 

forecast 

(post-9/11) 

Percent 

change 6/30/ 

05 forecast 

between years 

listed 

Percent 

change versus 

earlier forecast 

1999 ..................................................................................... 28,860,731 ........................ 28,947,500 ........................ 0.3 

2000 ..................................................................................... 29,445,619 2.0 29,714,995 2.7 0.9 

2001 ..................................................................................... 30,033,967 2.0 29,366,221 ¥1.2 ¥2.2 

2002c .................................................................................... 30,663,508 2.1 27,803,970 ¥5.3 ¥9.3 

2005 ..................................................................................... 32,619,194 6.4 29,877,529 7.5 ¥8.4 

2010 ..................................................................................... 36,015,595 10 33,118,411 11 ¥8.0 

2015 ..................................................................................... 39,549,526 10 36,280,526 10 ¥8.3 

2020 ..................................................................................... N/A ........................ 39,695,796 9 

aSource: U.S. FAA, ‘‘APO Terminal Area Forecast Summary Report,’’ Aircraft Operations, December 14, 2000; and ‘‘APO Terminal Area Forecast Summary Report,’’ Aircraft Operations, June 30, 2005. See the following FAA Web site: http://www.apo.data.faa.gov/main/taf.asp. A copy of 

these reports can be found in Docket No. OAR–2002–0030. bOperations means the number of arrivals and departures (see Docket No. OAR–2002–0030, Document No. OAR–2002–0030–0258). cAir carrier operations refers to flights of commercial aircraft with seating capacity of more than 60 seats. 

d Commuter/air taxi operations refers to aircraft with 60 or fewer seats conducting scheduled commercial flights/non-scheduled or for-hire 

flights. eThe change in operations from 2000 to 2002 was +4.1% for the 12/14/2000 forecast, and it was ¥6.4% for the 6/30/2005 forecast. 

The data in Table II.A–2 show that 

prior to 9/11 growth in air carrier and 

commuter/air taxi operations was 

expected to increase by 34 percent from 

2000 to 2015.29 The revised growth 

forecast for this period estimates that 

aircraft activity will now increase only 

22 percent in the period 2000–2015. In 

fact, the originally anticipated operation 

levels in 2015 are now forecast not to be 

reached until 2020.30

Aircraft emissions are a large portion 

of total emissions associated with 

airports. Air pollutants resulting from 

airport operations are emitted from 

several types of sources including 

aircraft main engines and auxiliary 

power units (APUs); ground support 

equipment (GSE), which includes 

vehicles such as aircraft tugs, baggage 

tugs, fuel trucks, maintenance vehicles, 

and other miscellaneous vehicles used 

to support aircraft operations; and 

ground access vehicles (GAV), which 

include vehicles used by passengers, 

employees, freight operators, and other 

persons to enter and leave an airport. 

69670 Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 

31The California FIP, signed by the Administrator 

2/14/95, is located in EPA Air Docket A–94–09, 

item number V–A–1. The FIP was vacated by an act 

of Congress before it became effective. 

32For comparison, the 1997 EPA Draft Final 

Report entitled, ‘‘Analysis of Techniques to Reduce 

Air Emission at Airports’’ (prepared by Energy and 

Environmental Analysis, Inc), estimated that for the 

four airports studied (which are large air traffic 

hubs) on average aircraft comprise approximately 

35 percent of NOX emissions from airport 

operations; GAV account for another 35 percent, 

and APUs and GSE contribute about 15 percent 

each for the remaining 30 percent. For NOX and 

VOC together, aircraft contribute about 35 percent; 

GAV account for another 40 percent, and APUs and 

GSE combined make up the remaining 25 percent. 

This document can be found in Docket No. OAR–

2002–0030, Document No. OAR–2002–0030–0071. 

33As described later in section II.B.2, fine 

particles refer to those particles with an 

aerodynamic diameter less than or equal to a 

nominal 2.5 micrometers (also known as PM2.5). 

34The NOX standards being set today will also 

help reduce levels of nitrogen dioxide (NO2), for 

which NAAQS have been established. Currently, 

every area in the United States has been designated 

to be in attainment with the NO2 NAAQS. 

35U.S. EPA (1996). Air Quality Criteria for Ozone 

and Related Photochemical Oxidants, EPA/600/P–

93/004aF. This document can be found in Docket 

No. OAR–2002–0030. Document Nos. OAR–2002–

0030–0165 through OAR–2002–0030–0194. (U.S. 

EPA (2005), Air Quality Criteria for Ozone and 

Related Photochemical Oxidants (First External 

Review Draft), EPA/600/R–05/004aA–cA. This 

document can be found in Docket No. OAR–2002–

0030, Document Nos. OAR–2002–0030–0202, 

–0210, and –0211.) U.S. EPA (2004). Final 

Regulatory Assessment: Control of Emissions from 

Nonroad Diesel Engines, EPA420–R–04–007. This 

document can be found in Docket No. OAR–2002–

0030, Document No. OAR–2002–0030–0128. 

36U.S. EPA (1996). Review of National Ambient 

Air Quality Standards for Ozone, Assessment of 

Scientific and Technical Information, OAQPS Staff 

Paper, EPA–452/R–96–007. Docket No. A–99–06. 

Document No. II–A–22. 

37U.S. EPA (1996). Air Quality Criteria for Ozone 

and Related Photochemical Oxidants, EPA/600/P–

93/004aF. This document can be found in Docket 

No. OAR–2002–0030, Document Nos. OAR–2002–

0030–0165 through OAR–2002–0030–0194. (U.S. 

EPA (2005). Air Quality Criteria for Ozone and 

Related Photochemical Oxidants (First External 

Review Draft), EPA/600/R–05/004aA–cA. This 

document can be accessed electronically at: 

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

s_o3_cr_cd.html. This document can also be found 

in Docket No. OAR–2002–0030, Doc. Nos. OAR–

2002–0030–0202, –0210, and –0211.) 

38New Ozone Health and Environmental Effects 

References, Published Since Completion of the 

Previous Ozone AQCD, National Center for 

Environmental Assessment, Office of Research and 

Development, U.S. Environmental Protection 

Agency, Research Triangle Park, NC 27711 (7/2002). 

This document can be found in Docket No. OAR–

2002–0030, Document No. OAR–2002–0030–0131. 

39U.S. EPA (2005), Air Quality Criteria for Ozone 

and Related Photochemical Oxidants (First External 

Review Draft), Volume I Document No. EPA/600/R–

05/004aA, Volume II Document No. EPA/600/R–05/ 

004bA, Volume III Document No. EPA/600/R–05/ 

004cA. This document can be found in Docket No. 

OAR–2002–0030, Document Nos. OAR–2002–0030–

0202, –0210, and –0211. 

40U.S. EPA, National Ambient Air Quality 

Standards for Ozone; Final Rule. 62 FR 38855 (July 

18, 1997). U.S. EPA, ‘‘Final Rule to Implement the 

8-Hour Ozone National Ambient Air Quality 

Standard—Phase 1,’’ Final Rule, 69 FR 23951 (April 

30, 2004). 

EPA estimates that aircraft engines 

comprise approximately 45 percent of 

total air pollutant emissions from 

airport operations. GAV account for 

another 45 percent and APUs and GSE 

combined make up the remaining 10 

percent.31 32 Since EPA has established 

stringent emission standards for GAVs 

and other highway and nonroad 

vehicles used at airports, overall 

emissions from these vehicles will 

continue to decline for many years. This 

means that aircraft will contribute an 

increasing portion of total emissions 

associated with airport operations. 

B. Health and Welfare Effects 

NOX emissions from commercial 

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 

particulate matter (PM2.5), particularly 

ammonium nitrate, and contribute to 

regional haze.33 The NOX standards 

adopted in this rule will help reduce 

ambient ozone and potentially 

secondary PM levels and thus will help 

areas with airports achieve and/or 

maintain compliance with the NAAQS 

for ozone and potentially PM.34 In the 

following section we discuss the 

adverse health and welfare effects 

associated with NOX emissions. 

1. Ozone 

a. What are the health effects of ozone 

pollution? 

NOX is a precursor in the 

photochemical reaction which forms 

tropospheric ozone. Ground-level 

ozone, the main ingredient in smog, is 

formed by complex chemical reactions 

of VOCs and NOX in the presence of 

heat and sunlight. The health effects of 

ozone pollution are described in detail 

in EPA’s Air Quality Criteria Document 

for Ozone and Other Photochemical 

Oxidants and are also described in the 

Final Regulatory Analysis for our recent 

Clean Air Nonroad Diesel rule.35 The 

following is a summary of those effects. 

Ozone can irritate the respiratory 

system, causing coughing, throat 

irritation, and/or uncomfortable 

sensation in the chest. In addition, 

ozone can reduce lung function and 

make it more difficult to breathe deeply, 

and breathing may become more rapid 

and shallow than normal, thereby 

limiting a person’s normal activity. 

Ozone also can aggravate asthma, 

leading to more asthma attacks that 

require a doctor’s attention and/or the 

use of additional medication. In 

addition, ozone can inflame and damage 

the lining of the lungs, which may lead 

to permanent changes in lung tissue, 

irreversible reductions in lung function, 

and a lower quality of life if the 

inflammation occurs repeatedly over a 

long time period. People who are of 

particular concern with respect to ozone 

exposures include children and adults 

who are active outdoors. Those people 

particularly susceptible to ozone effects 

are people with respiratory disease, 

such as asthma, people with unusual 

sensitivity to ozone, and children. 

Beyond its human health effects, ozone 

has been shown to injure plants, which 

has the effect of reducing crop yields 

and reducing productivity in forest 

ecosystems.36 37

New research suggests additional 

serious health effects beyond those that 

were known when the ozone NAAQS 

was revised in 1997. Between 1997 and 

a 2002 literature review, over 1,700 new 

health and welfare studies relating to 

ozone have been published in peerreviewed journals.38 Many of these 

studies investigate the impact of ozone 

exposure on such health effects as 

changes in lung structure and 

biochemistry, inflammation of the 

lungs, exacerbation and causation of 

asthma, respiratory illness-related 

school absence, hospital and emergency 

room visits for asthma and other 

respiratory causes, and premature 

mortality. EPA is currently evaluating 

these and other studies as part of the 

ongoing review of the air quality criteria 

and NAAQS for ozone. A revised Air 

Quality Criteria Document for Ozone 

and Other Photochemical Oxidants will 

be prepared in consultation with EPA’s 

Clean Air Science Advisory Committee 

(CASAC).39 Key new health information 

falls into four general areas: 

development of new-onset asthma, 

hospital admissions for young children, 

school absence rate, and premature 

mortality. In all, the new studies that 

have become available since the 8-hour 

ozone standard was adopted in 1997 

continue to demonstrate the harmful 

effects of ozone on public health and the 

need for areas with high ozone levels to 

attain and maintain the NAAQS. 

b. What are the current and projected 8- 

hour ozone levels? 

There is currently one ozone NAAQS, 

an 8-hour standard. The 8-hour ozone 

standard is met when the fourth highest 

daily maximum 8-hour average ozone 

concentration measured over a 3-year 

period is less than or equal to 0.084 

parts per million (ppm). The former 1- 

hour ozone standard was revoked in 

June 2005.40

Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 69671 

41U.S. EPA, ‘‘Air Quality Designations and 

Classifications for the 8-hour Ozone National 

Ambient Air Quality Standards; Early Action 

Compact Areas With Deferred Effective Dates,’’

Final Rule, 69 FR 23858 (April 30, 2004). 

42A map that shows the current 8-hour ozone and 

PM2.5 nonattainment areas, federal Class I areas, and 

a list of affected counties can be found in Docket 

No. OAR–2002–0030, Document No. OAR–2002–

0030–0209. 

43U.S. EPA, ‘‘Rule To Reduce Interstate Transport 

of Fine Particulate Matter and Ozone (Clean Air 

Interstate Rule); Revisions to Acid Rain Program; 

Revisions to the NOX SIP Call,’’ Final Rule, 70 FR 

25162, May 12, 2005. 

44U.S. EPA, ‘‘Proposed Rule to Implement the 8- 

hour Ozone National Ambient Air Quality 

Standard,’’ Proposed Rule, 68 FR 32802 (June 2, 

2003). 

45U.S. EPA, ‘‘Final Rule to Implement the 8-Hour 

Ozone National Ambient Air Quality Standard—

Phase 1,’’ Final Rule, 69 FR 23951 (April 30, 2004). 

46See the Regulatory Impact Analysis: ‘‘Final 

Regulatory Analysis: Control of Emissions from 

Nonroad Diesel Engines,’’ EPA420–R–04–007, May 

2004. This document is available at http:// 

www.epa.gov/nonroad/ and in Docket No. OAR–

2002–0030, Document No. OAR–2002–0030–0128. 

47U.S. EPA, Air Quality Criteria for Particulate 

Matter (OCT 2004), Volume I Document No. 

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

EPA600/P–99/002bF. This document is available in 

Docket No. OAR–2002–0030, Document No. OAR–

2002–0030–0129 and OAR–2002–0030–0130. 

On June 15, 2004, the 8-hour ozone 

nonattainment designations became 

effective.41 Nationwide, there are 

approximately 159 million people living 

in 126 areas that are designated as not 

attaining the 8-hour ozone NAAQS 

based upon the monitored data from 

2001–2003 and other factors. The CAA 

defines a nonattainment area as an area 

that is violating an ambient standard or 

is contributing to a nearby area that is 

violating the standard. All or part of 474 

counties are designated as 

nonattainment for the 8-hour ozone 

NAAQS. These counties are spread over 

wide geographic areas, including most 

of the nation’s major population centers, 

which include much of the eastern half 

of the U.S. and large areas of 

California.42

From air quality modeling performed 

for the recent Clean Air Interstate Rule 

(CAIR),43 we anticipate that without 

emission reductions beyond those 

already required under promulgated 

regulation and approved State 

Implementation Plans (SIPs), ozone 

nonattainment will likely persist into 

the future. With reductions from 

programs already in place, including the 

CAIR, the number of counties in the 

eastern U.S. violating the ozone 8-hour 

standard is expected to decrease in 2015 

to 16 counties where 12 million people 

are projected to live. 

On June 2, 2003 (68 FR 32802), EPA 

issued a proposal for the 

implementation process to bring the 

nation’s air into attainment with the 8- 

hour ozone NAAQS, including 

proposed requirements that States 

submit SIPs that address how areas will 

attain the 8-hour ozone standard.44 The 

second phase (Phase II) of this proposed 

implementation process for the 8-hour 

ozone NAAQS will be finalized in the 

next few months, and it will describe 

the SIP submittal date requirements. 

(Phase I of the proposed implementation 

process was finalized on April 30, 2004 

(69 FR 23951), but it did not include 

these SIP submittal date 

requirements.) 45

The Act (Title I, Part D) contains two 

sets of requirements for State plans 

implementing the national ozone air 

quality standards in nonattainment 

areas. Subpart 1 contains general 

requirements for SIPs for nonattainment 

areas for any pollutant, including ozone, 

governed by a NAAQS. Subpart 2 

provides more specific requirements for 

ozone nonattainment SIPs. Under 

subpart 1, a state must demonstrate that 

its nonattainment areas will attain the 

ozone 8-hour standard as expeditiously 

as practicable, but no later than five 

years from the date that the area was 

designated nonattainment. However, 

based on the severity of the air quality 

problem and the availability and 

feasibility of control measures, the 

Administrator may extend the 

attainment date ‘‘for a period of no 

greater than 10 years from the date of 

designation as nonattainment.’’ Based 

on these provisions, we expect that most 

or all areas covered under subpart 1 will 

attain the 8-hour ozone standard in the 

2007 to 2014 time frame. For areas 

covered under subpart 2, the maximum 

attainment dates provided under the Act 

range from 3 to 20 years after 

designation, depending on an area’s 

classification. Thus, we anticipate that 

areas covered by subpart 2 will attain 

the 8-hour ozone standard in the 2007 

to 2024 time period. 

Since the emission reductions 

expected from the standards we are 

adopting in this rule will occur during 

the time period when areas will need to 

attain the standard under either option, 

projected reductions in aircraft engine 

emissions will assist States in their 

efforts to attain and maintain the 8-hour 

ozone NAAQS. 

2. Particulate Matter 

a. What is particulate matter? 

Particulate matter represents 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. PM10 refers to 

particles with an aerodynamic diameter 

less than or equal to a nominal 10 

micrometers. Fine particles refer to 

those particles with an aerodynamic 

diameter less than or equal to a nominal 

2.5 micrometers (also known as PM2.5). 

The emission sources, formation 

processes, chemical composition, 

atmospheric residence times, transport 

distances and other parameters of fine 

and coarse particles are distinct. This 

discussion focuses on fine PM since the 

NOX emitted by aircraft engines can 

react in the atmosphere to form fine PM 

as discussed below. 

Fine particles are directly emitted 

from combustion sources and are 

formed secondarily from gaseous 

precursors such as oxides of nitrogen 

(NOX). Fine particles are generally 

composed of sulfate, nitrate, chloride, 

ammonium compounds, organic carbon, 

elemental carbon, and metals. Aircraft 

engines emit NOX which reacts in the 

atmosphere to form secondary PM2.5

(namely ammonium nitrate). 

Combustion of coal, oil, diesel, gasoline, 

and wood, as well as high temperature 

process sources such as smelters and 

steel mills, produce emissions that 

contribute to fine particle formation. 

Fine particles can remain in the 

atmosphere for days to weeks and travel 

through the atmosphere hundreds to 

thousands of kilometers. Thus 

emissions from aircraft, as well as those 

from other sources, could affect 

nonattainment areas far from their 

source. 

The relative contribution of various 

chemical components to PM2.5 varies by 

region of the country. Data on PM2.5

composition are available from the EPA 

Speciation Trends Network in 2001 and 

the Interagency Monitoring of 

PROtected Visual Environments 

(IMPROVE) network in 1999 covering 

both urban and rural areas in numerous 

regions of the U.S. These data show that 

nitrates formed from NOX play a major 

role in the western U.S., especially in 

the California area where it is 

responsible for about a quarter of the 

ambient PM2.5 concentrations.46

(However, the majority of NOX involved 

in this process does not come from 

aircraft.) 

b. What are the health effects of PM2.5? 

Scientific studies show ambient PM is 

associated with a series of adverse 

health effects. These health effects are 

discussed in detail in the recently 

released EPA Criteria Document for 

PM.47 They are also described in the 

Final Regulatory Analysis for our recent 

69672 Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 

48U.S. EPA (2004). Final Regulatory Assessment: 

Control of Emissions from Nonroad Diesel Engines, 

EPA420–R–04–007. This document can be found in 

Docket No. OAR–2002–0030, Document No. OAR–

2002–0030–0128. 

49 Dockery, DW; Pope, CA, III; Xu, X; et al. (1993) 

An association between air pollution and mortality 

in six U.S. cities. N Engl J Med 329:1753–1759. 

50Pope, CA, III; Thun, MJ; Namboordiri, MM; et 

al. (1995) Particulate air pollution as a predictor of 

mortality in a prospective study of U.S. adults. Am 

J Respir Crit Care Med 151:669–674. 

51Hoek, G; Brunekreef, B; Goldbohm, S; et al. 

(2002) Association between mortality and 

indicators of traffic-related air pollution in the 

Netherlands: a cohort study. Lancet 360:1203–1209. 

52Laden F; Neas LM; Dockery DW; et al. (2000) 

Association of fine particulate matter from different 

sources with daily mortality in six U.S. cities. 

Environ Health Perspect 108(10):941–947. 

53Schwartz J; Laden F; Zanobetti A. (2002) The 

concentration-response relation between PM(2.5) 

and daily deaths. Environ Health Perspect 110(10): 

1025–1029. 

54A map that shows the current 8-hour ozone and 

PM2.5 nonattainment areas, federal Class I areas, and 

a list of affected counties can be found in Docket 

No. OAR–2002–0030, Document No. OAR–2002–

0030–0209. The final PM2.5 designations were 

effective on April 5, 2005. (U.S. EPA, ‘‘Air Quality 

Designations and Classifications for the Fine 

Particles (PM2.5) National Ambient Air Quality 

Standards,’’ Final Rule, January 5, 2005 (70 FR 944); 

‘‘Air Quality Designations for the Fine Particles 

(PM2.5) National Ambient Air Quality Standards,’’

Supplemental Notice, April 5, 2005, located at 

http://www.epa.gov/pmdesignations/.) 

55U.S. EPA, ‘‘Rule To Reduce Interstate Transport 

of Fine Particulate Matter and Ozone (Clean Air 

Interstate Rule); Revisions to Acid Rain Program; 

Revisions to the NOX SIP Call,’’ Final Rule, 70 FR 

25162, May 12, 2005. 

56U.S. EPA (2004). Final Regulatory Assessment: 

Control of Pollution from Nonroad Diesel Engines, 

EPA420–R–04–007. This document can be found in 

Docket No. OAR–2002–0030, Document No. OAR–

2002–0030–0128. 

57Much of the information in this subsection was 

excerpted from the EPA document, Human Health 

Benefits from Sulfate Reduction, written under Title 

IV of the 1990 Clean Air Act Amendments, U.S. 

EPA, Office of Air and Radiation, Acid Rain 

Division, Washington, DC 20460, November 1995. 

A copy of this document is available in Docket No. 

OAR 2002–0030, Document No. OAR–2002–0030–

0028. 

Clean Air Nonroad Diesel rule.48 The 

following is a summary of those effects. 

The health effects associated with 

short-term variation in ambient 

particulate matter (PM) have been 

indicated by epidemiologic studies 

showing associations between exposure 

and increased hospital admissions for 

ischemic heart disease, heart failure, 

respiratory disease, including chronic 

obstructive pulmonary disease (COPD) 

and pneumonia. Short-term elevations 

in ambient PM have also been 

associated with increased cough, lower 

respiratory symptoms, and decrements 

in lung function. Additional studies 

have associated changes in heart rate 

and/or heart rhythm in addition to 

changes in blood characteristics with 

exposure to ambient PM. Short-term 

variations in ambient PM have also been 

associated with increases in total and 

cardiorespiratory mortality. Studies 

examining populations exposed to 

different levels of air pollution over a 

number of years, including the Harvard 

Six Cities Study and the American 

Cancer Society Study, suggest an 

association between exposure to 

ambient PM2.5 and premature 

mortality.49 50 Additionally, one longterm study provides evidence for 

premature mortality specifically 

associated with PM generated by mobile 

sources.51 Two studies further analyzing 

the Harvard Six Cities Study’s air 

quality data have also established a 

specific influence of mobile sourcerelated PM2.5 on daily mortality 52 and a 

concentration-response function for 

mobile source-associated PM2.5 and 

daily mortality.53

c. What are current and projected levels 

of PM? 

The NAAQS for PM2.5 were 

established by EPA in 1997 (62 FR 

38651, July 18, 1997). The short-term 

(24-hour) standard is set at a level of 65 

μg/m3 based on the 98th percentile 

concentration averaged over three years. 

The long-term standard specifies an 

expected annual arithmetic mean not to 

exceed 15 ug/m3 averaged over three 

years. 

Approximately 88 million people live 

in 208 full and partial counties and 39 

areas which EPA has designated 

nonattainment for the PM2.5 NAAQS.54

In addition, tens of millions of people 

live in areas where there is a significant 

future risk of failing to maintain or 

achieve the PM2.5 NAAQS. 

This is illustrated by the air quality 

modeling performed recently in 

connection with our CAIR rule, which 

suggests that elevated PM2.5 levels are 

likely to continue to exist in the future 

in many areas in the absence of 

additional emission controls.55 For 

example in the eastern U.S. in 2015, 

based on emission controls currently 

adopted, we project that 16 million 

people will live in 18 counties with 

average PM2.5 levels above 15 μ/m3. 

While the final implementation 

process for bringing the nation’s air into 

attainment with the PM2.5 NAAQS is 

still being completed in a separate 

rulemaking action, the basic framework 

is well defined by the statute. EPA 

designated PM2.5 nonattainment areas 

on April 5, 2005. Following designation, 

section 172(b) of the Clean Air Act 

allows states up to three years to submit 

a revision to their state implementation 

plan (SIP) that provides for the 

attainment of the PM2.5 standard. Based 

on this provision, states could submit 

these SIPs as late as the end of 2007. 

Section 172(a)(2) of the Clean Air Act 

requires that these SIP revisions 

demonstrate that the nonattainment 

areas will attain the PM2.5 standard as 

expeditiously as practicable but no later 

than five years from the date that the 

area was designated nonattainment. 

However, based on the severity of the 

air quality problem and the availability 

and feasibility of control measures, the 

Administrator may extend the 

attainment date ‘‘for a period of no 

greater than 10 years from the date of 

designation as nonattainment.’’

Therefore, based on this information, we 

expect that most or all are as will need 

to attain the PM2.5 NAAQS in the 2009 

to 2014 time frame, and then be 

required to maintain the NAAQS 

thereafter. 

Potentially, today’s aircraft NOX

standards may contribute to attainment 

and maintenance of the existing PM 

NAAQS since NOX contributes to the 

secondary formation of PM2.5. 

C. Other Environmental Effects 

This section presents information on 

four categories of public welfare and 

environmental impacts related to NOX

and fine PM emissions: Acid deposition, 

eutrophication of water bodies, plant 

damage from ozone, and visibility 

impairment. These environmental 

effects are described in detail in the 

Final Regulatory Assessment for our 

recent Clean Air Nonroad Diesel rule.56

1. Acid Deposition 

Acid deposition, or acid rain as it is 

commonly known, occurs when NOX

and SO2 react in the atmosphere with 

water, oxygen, and oxidants to form 

various acidic compounds that later fall 

to earth in the form of precipitation or 

dry deposition of acidic particles.57

Acid rain contributes to damage of trees 

at high elevations and in extreme cases 

may cause lakes and streams to become 

so acidic that they cannot support 

aquatic life. In addition, acid deposition 

accelerates the decay of building 

materials and paints, including 

irreplaceable buildings, statues, and 

sculptures that are part of our nation’s 

cultural heritage. To reduce damage to 

automotive paint caused by acid rain 

and acidic dry deposition, some 

manufacturers use acid-resistant paints, 

at an average cost of $5 per vehicle for 

a total of $80–85 million per year when 

applied to all new cars and trucks sold 

in the U.S. each year. 

The NOX reductions from today’s 

action will help reduce acid rain and 

acid deposition, thereby helping to 

reduce acidity levels in lakes and 

Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 69673 

58 Deposition of Air Pollutants to the Great 

Waters, Third Report to Congress, June 2000, EPA–

453/R–00–005. This document can be found in 

Docket No. OAR–2002–0030, Document No. OAR–

2002–0030–0025. It is also available at http:// 

www.epa.gov/oar/oaqps/gr8water/3rdrpt/ 

obtain.html. 

59U.S. EPA (1996). Air Quality Criteria for Ozone 

and Related Photochemical Oxidants, EPA/600/P–

93/004aF. This document can be found in Docket 

No. OAR–2002–0030. Document Nos. OAR–2002–

0030–0165 through OAR–2002–0030–0194. (U.S. 

EPA (2005), Air Quality Criteria for Ozone and 

Related Photochemical Oxidants (First External 

Review Draft), EPA/600/R–05/004aA—cA. This 

document can be found in Docket No. OAR–2002–

0030, Document Nos. OAR–2002–0030–0202, 

–0210, and –0211.) 

60National Research Council, 1993. Protecting 

Visibility in National Parks and Wilderness Areas. 

National Academy of Sciences Committee on Haze 

in National Parks and Wilderness Areas. National 

Academy Press, Washington, DC. This book can be 

viewed on the National Academy Press Web site at 

http://www.nap.edu/books/0309048443/html/. See 

also U.S. EPA Air Quality Criteria Document for 

Particulate Matter (2004). This document is 

available in Docket No. OAR–2002–0030, Document 

No. OAR–2002–0030–0129 and OAR–2002–0030–

0130. See also Review of the National Ambient Air 

Quality Standards for Particulate Matter: Policy 

Assessment of Scientific and Technical 

Information, 2nd Draft. This document can be 

found in Docket No. OAR–2002–0030, Document 

Nos. OAR–2002–0030–0198 through—0201. It is 

also available electronically at http://www.epa.gov/ 

ttn/naaqs/standards/pm/data/ 

pm_staff_paper_2nddraft.pdf. 

61A map that shows the current 8-hour ozone and 

PM2.5 nonattainment areas, federal Class I areas, and 

a list of affected counties can be found in Docket 

No. OAR–2002–0030, Document No. OAR–2002–

0030–0209. 

62 In the proposal, we stated that no general 

aviation or military engines are covered by the 

proposal; however, this statement may need some 

clarification in today’s final rulemaking. See the 

Section 5.2 of the Summary and Analysis of 

Comments of this rulemaking for further discussion 

of general aviation and military aircraft. 

streams throughout the country and 

helping to accelerate the recovery of 

acidified lakes and streams and the 

revival of ecosystems adversely affected 

by acid deposition. Reduced acid 

deposition levels will also help reduce 

stress on forests, thereby accelerating 

reforestation efforts and improving 

timber production. Deterioration of our 

historic buildings and monuments, and 

of buildings, vehicles, and other 

structures exposed to acid rain and dry 

acid deposition will be reduced, and the 

costs borne to prevent acid-related 

damage may also decline. 

2. Eutrophication and Nitrification 

In recent decades, human activities 

have greatly accelerated nutrient 

impacts, such as nitrogen and 

phosphorus, causing excessive growth 

of algae and leading to degraded water 

quality and associated impairment of 

fresh water and estuarine resources for 

human uses.58 Eutrophication is the 

accelerated production of organic 

matter, particularly algae, in a water 

body. This increased growth can cause 

numerous adverse ecological effects and 

economic impacts, including nuisance 

algal blooms, dieback of underwater 

plants due to reduced light penetration, 

and toxic plankton blooms. Algal and 

plankton blooms can also reduce the 

level of dissolved oxygen, which can 

also adversely affect fish and shellfish 

populations. 

Deposition of nitrogen from aircraft 

engines contributes to elevated nitrogen 

levels in waterbodies. The NOX

reductions from today’s promulgated 

standards will help reduce the airborne 

nitrogen deposition that contributes to 

eutrophication of watersheds, 

particularly in aquatic systems where 

atmospheric deposition of nitrogen 

represents a significant portion of total 

nitrogen loadings. 

3. Plant Damage From Ozone 

Ground-level ozone can also cause 

adverse welfare or environmental 

effects.59 Specifically, ozone enters the 

leaves of plants where it interferes with 

cellular metabolic processes. This 

interference can be manifest either as 

visible foliar injury from cell injury or 

death, and/or as decreased plant growth 

and yield due to a reduced ability to 

produce food. With fewer resources, the 

plant reallocates existing resources 

away from root storage, growth and 

reproduction toward leaf repair and 

maintenance. Plants that are stressed in 

these ways become more susceptible to 

disease, insect attack, harsh weather and 

other environmental stresses. Because 

not all plants are equally sensitive to 

ozone, ozone pollution can also exert a 

selective pressure that leads to changes 

in plant community composition. 

As discussed earlier, aircraft engine 

emissions of NOX contribute to ozone. 

The final standards will aid in the 

reduction of ozone and, therefore, help 

reduce crop damage and stress from 

ozone on vegetation. 

4. Visibility 

Visibility can be defined as the degree 

to which the atmosphere is transparent 

to visible light.60 Fine particles with 

significant light-extinction efficiencies 

include organic matter, sulfates, 

nitrates, elemental carbon (soot), and 

soil. 

Visibility is important because it 

directly affects people’s enjoyment of 

daily activities in all parts of the 

country. Individuals value good 

visibility for the well-being it provides 

them directly, both in 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, 

because of the special emphasis given to 

protecting these lands now and for 

future generations. 

As discussed previously, aircraft 

engine emissions of NOX are precursors 

to PM2.5. In 1997, EPA established the 

secondary (welfare-based) PM2.5

NAAQS as equal to the primary (healthbased) NAAQS of 15 ug/m3 (based on a 

3-year average of the annual mean) and 

65 ug/m3 (based on a 3-year average of 

the 98th percentile of the 24-hour 

average value) (62 FR 38669, July 18, 

1997). EPA concluded that PM2.5 causes 

adverse effects on visibility in various 

locations, depending on PM 

concentrations and factors such as 

chemical composition and average 

relative humidity. In 1997, EPA 

demonstrated that visibility impairment 

is an important effect on public welfare 

and that unacceptable visibility 

impairment is experienced throughout 

the U.S., in multi-state regions, urban 

areas, and remote federal Class I areas.61

Furthermore, in setting the PM2.5

NAAQS, EPA acknowledged that levels 

of fine particles below the NAAQS may 

also contribute to unacceptable 

visibility impairment and regional haze 

problems in some areas, and section 169 

of the Act provides additional 

authorities to remedy existing 

impairment and prevent future 

impairment in the 156 national parks, 

forests and wilderness areas labeled as 

mandatory Federal Class I areas (62 FR 

38680–81, July 18, 1997). 

Taken together with other programs, 

potential reductions from this final rule 

may help to improve visibility across 

the nation, including mandatory Federal 

Class I areas. 

III. Aircraft Engine Standards 

Under the authority of section 231 of 

the CAA, EPA today adopts standards 

equivalent to ICAO’s February 1999 

NOX emission standards (these NOX

standards were adopted at CAEP/4 in 

1998 and approved by the ICAO Council 

in 1999) and March 1997 test procedure 

amendments. Today’s emission 

standards and test procedure 

amendments apply to commercial 

aircraft engines, and these standards do 

not apply to aircraft engines used only 

for general aviation or military 

applications.62 (General aviation and 

military aircraft can use commercial 

aircraft engines subject to these 

standards—e.g., small regional jet 

engines are also utilized in executive 

general aviation aircraft and larger 

commercial aircraft engines may also be 

used in military transport aircraft). The 

69674 Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 

63Applying standards to newly manufactured 

engines of already certified models does not mean 

the re-certification or retrofit of existing in-use 

engines. Instead such a provision would require the 

ongoing production of engines that have already 

been certified to meet the new standards. However, 

we are not adopting this provision in today’s 

rulemaking 

64 ICAO, CAEP, Fourth Meeting, Montreal, 

Quebec, April 6–8, 1998, Report, Document 9720, 

CAEP/4. Copies of this document can be obtained 

from the ICAO Web site located at http:// 

www.icao.int. 

65As described later, more information and 

greater lead time would be necessary to require 

more stringent standards. 

66This includes standards for low-, mid-, and 

high-thrust engines (see below for further 

discussion of the different standards based on the 

thrust of the engines). 

67 ICAO’s CAEP/4 NOX standards became 

effective July 19, 1999, and applicable as of 

November 4, 1999. December 31, 2003 is the 

implementation date for these standards. However, 

for the purpose of this Notice the effective date is 

considered the implementation date. (ICAO, 

‘‘Aircraft Engine Emissions,’’ International 

Standards and Recommended Practices, 

Environmental Protection, Annex 16, Volume II, 

Second Edition, July 1993—Amendment 4, July 19, 

1999.) 

commercial aircraft engines subject to 

today’s NOX standards are those gas 

turbine engines that are newly certified 

(and newly designed) after the effective 

dates of the regulations. (Newly 

manufactured engines of already 

certified models—i.e., those individual 

engines that are part of an already 

certified engine model, but are built 

after the effective date of the regulations 

for such engines and have never been in 

service—will not have to meet these 

standards).63 The NOX emission 

standards and their effective dates are 

described below in this section, and the 

test procedure amendments are 

discussed later in section IV. 

A. What Are The NOX Standards For 

Newly Certified Engines? 

As discussed earlier in sections I and 

II of today’s notice, section 231(a)(2)(A) 

of the CAA authorizes EPA to establish 

emission standards for aircraft engine 

emissions ‘‘ * * * which in his 

judgment causes, or contributes to, air 

pollution which may reasonably be 

anticipated to endanger public health or 

welfare.’’ The Administrator may revise 

such standards from ‘‘time to time.’’ 42 

U.S.C. 7571(a)(2). CAA section 231(b) 

requires that any emission standards 

provide sufficient lead time ‘‘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). 

Today’s rule adopts near-term 

standards that will go into effect 

December 19, 2005 to ensure future 

engines do not jeopardize recent or past 

technology gains. These standards are 

equivalent to the CAEP/4 NOX

international consensus emissions 

standards for aircraft engines adopted 

by ICAO’s CAEP in 1998.64 This final 

rule to promulgate aircraft engine NOX

standards equivalent to CAEP/4 

standards is consistent with U.S. 

obligations under ICAO. By issuing 

standards that meet or exceed ICAO 

CAEP/4 standards, we satisfy these 

obligations. As indicated earlier in 

section I of today’s rule, the 

implementation date, December 31, 

2003, has already occurred for the 

CAEP/4 standards, and we need to 

promulgate the standards in accordance 

with U.S. obligations under ICAO. At 

the same time, EPA anticipates 

establishing more stringent NOX

standards in the future. In February 

2004, CAEP/6 (sixth meeting of CAEP) 

agreed to establish more stringent 

international consensus emission 

standards for aircraft engines. Such 

standards will be a central consideration 

in a future EPA regulation of aircraft 

engine emissions. 

We believe this approach is the most 

appropriate means to address emissions 

from aircraft engines in this rulemaking. 

It codifies current practice, with no 

significant lead time, as a near-term 

approach.65 EPA has authority to revise 

emission standards from ‘‘time to time.’’

EPA intends to address more stringent 

emission standards requiring more lead 

time in a future rulemaking (see section 

III.A.5 for further discussion of future 

standards), as the ICAO and CAEP 

process develops progressively more 

stringent standards. 

1. Today’s NOX Standards 

EPA is adopting standards equivalent 

to ICAO’s 1999 NOX emission standards 

for newly certified aircraft gas turbine 

engines (turbofan and turbojet engines) 

of rated thrust or output greater than 

26.7 kilonewtons (kN) with compliance 

dates as follows:66

For engines of a type or model of 

which that date of manufacture of the 

first individual production model was 

after December 31, 2003 (see below for 

further discussion on the effective date 

of these standards): 

(a) For engines with a pressure ratio 

of 30 or less: 

(i) For engines with a maximum rated 

output of more than 89.0 kN: 

NOX = (19 + 1.6(rated pressure ratio)) 

g/kN rated output 

(ii) For engines with a maximum rated 

output of more than 26.7 kN but not 

more than 89.0 kN: 

NOX = (37.572 + 1.6(rated pressure 

ratio)—0.2087(rated output))g/kN rated 

output 

(b) For engines with a pressure ratio 

of more than 30 but less than 62.5: 

(i) For engines with a maximum rated 

output of more than 89.0 kN: 

NOX = (7 + 2.0(rated pressure ratio)) 

g/kN rated output 

(ii) For engines with a maximum rated 

output of more than 26.7 kN but not 

more than 89.0 kN: 

NOX = (42.71 + 1.4286(rated pressure 

ratio)—0.4013(rated output) + 

0.00642(rated pressure ratio × rated 

output))g/kN rated output 

(c) For engines with a pressure ratio 

of 62.5 or more: 

NOX = (32 + 1.6(rated pressure ratio)) 

g/kN rated output. 

The NOX emission standards 

presented above are equivalent to the 

ICAO NOX standards that have an 

implementation date of December 31, 

2003.67 However, since this date has 

passed, the NOX emission standards 

prescribed above for newly certified 

engines shall take effect as prescribed 

beginning December 19, 2005. 

2. NOX Standards for Newly Certified 

Mid- and High-Thrust Engines 

EPA is adopting NOX standards for 

newly certified mid- and high-thrust 

engines (those engines designed and 

certified after the effective date of the 

regulations, which have a rated output 

or thrust greater than 89 kN) that 

generally represent about a 16 percent 

reduction (or increase in stringency) 

from the existing standard. (See section 

III.A.1(a)(i) and III.A.1(b)(i) above for the 

standards for mid- and high-thrust 

engines.) More specifically, at a rated 

pressure ratio of 30 the NOX standards 

represent a 16 percent reduction from 

the existing standard. At rated pressure 

ratios of 10 and 20, the standards 

correspond to 27 and 20 percent 

reductions, respectively. In addition, at 

rated pressure ratios of 40 and 50, the 

NOX standards signify 9 and 4 percent 

reductions, respectively. Also, today’s 

and existing standards are equivalent at 

a rated pressure ratio of 62.5. See Figure 

III.B–1 in section III.B for a comparison 

of today’s NOX standards (equivalent to 

CAEP/4 standards) to the existing 

standards (equivalent to CAEP/2 

standards) . 

3. NOX Standards for Newly Certified 

Low-Thrust Engines 

For newly certified low-thrust engines 

(engines with a thrust or rated output of 

more than 26.7 kN but not more than 

89.0 kN), EPA is adopting near-term 

Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 69675 

68Today’s NOX standards for low thrust or small 

engines specify that engines with a rated output or 

thrust at 26.7 kN meet the existing standard, and 

engines with a rated output at 89 kN meet today’s 

(or CAEP/4) standards. For engines with rated 

outputs or thrust levels between 26.7 and 89 kN, 

a linear interpolation was made between the low 

range of the existing standard and the high range 

of today’s standard based upon the rated output to 

determine the NOX limits for such engines. Thus, 

thrust dependent standards are being adopted for 

engines with rated output or thrust between 26.7 kN 

and 89 kN. 

69The standards for mid- and high-thrust engines 

are dependent only on an engine’s rated pressure 

ratio. 

70Additional examples of the standards for lowthrust engines in comparison to the standards for 

mid- and high-thrust engines are provided below. 

At rated pressure ratios of 10 and 20 with a thrust 

of 58 kN, today’s low-thrust engine standards are 

a 14 and 10 percent reduction from the existing 

standard, respectively. Whereas, at these same rated 

pressure ratios, today’s standards for mid- and highthrust engines are 27 and 20 percent reductions. In 

addition, at rated pressure ratios of 40 and 50 with 

a thrust of 58 kN, these low-thrust engine standards 

signify a 5 and 2 percent reduction from the 

existing standard, respectively. In comparison, at 

these same rated pressure ratios, today’s standards 

for mid- and high-thrust engines are 9 and 4 percent 

reductions. 

71 ICAO/CAEP, Report of Third Meeting, 

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

9675, CAEP/3. 

72 ‘‘The burner section of an aircraft engine, 

which contains the combustion chamber, burns a 

mixture of fuel and air, and delivers the resulting 

gases to the turbine at a temperature which will not 

exceed the allowable limit at the turbine inlet.’’

(United Technologies Pratt and Whitney, ‘‘The 

Aircraft Gas Turbine Engine and Its Operation,’’

August 1998.) 73 ICAO/CAEP Working Group 3 (Emissions), 

‘‘Combined Report of the Certification and 

Technology Subgroups,’’ section 2.3.6.1, Presented 

by the Chairman of the Technology Subgroup, 

Third Meeting, Bonn, Germany, June 1995. A copy 

of this paper can be found in Docket OAR–2002–

0030. 

NOX standards that are equivalent to 

CAEP/4 standards for such engines, and 

these standards are different than 

today’s standards for mid- and highthrust engines (engines with thrust 

greater than 89.0 kN).68 In addition to 

rated pressure ratio, the standards for 

low-thrust engines will also be 

dependent on an engine’s thrust or rated 

output.69 (See section III.A.1(a)(ii) and 

III.A.1(b)(ii) for a description of these 

different standards.) For example, at a 

rated pressure ratio of 30 and a thrust 

of 58 kN (thrust level in the middle of 

26.7 kN and 89 kN), these standards are 

an 8 percent reduction (or increase in 

stringency) from the existing standard 

compared to a 16 percent reduction for 

the standards for mid- and high-thrust 

engines.70

The existing standards were not set at 

a stringency level that created a need for 

low-thrust engines to have different 

requirements, but at the level of NOX

stringency adopted today different 

requirements are considered necessary 

for such engines. Due to their physical 

size, it is difficult to apply the best NOX

reduction technology to low thrust or 

small engines. The difficulty increases 

progressively as size is reduced (from 

around 89 kN).71 For example, the 

relatively small combustor space and 

section height of these engines creates 

constraints on the use of low NOX fuel 

staged combustor concepts which 

inherently require the availability of 

greater flow path cross-sectional area 

than conventional combustors.72 Also, 

fuel staged combustors need more fuel 

injectors, and this need is not 

compatible with the relatively lower 

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.73

Since the difficulties increase 

progressively as engine thrust size is 

reduced, EPA believes it is appropriate 

to make a graded change in stringency 

of today’s NOX standards for low-thrust 

engines. 

4. Rationale for Today’s NOX Standards 

for Newly Certified Low-, Mid-, and 

High-Thrust Engines 

Today’s standards for low-, mid-, and 

high-thrust engines, which are 

equivalent to the CAEP/4 standards, 

ensure that new engine designs will 

incorporate the existing combustor 

technology and will not perform worse 

than today’s current engines. This final 

rule to promulgate aircraft engine NOX

standards equivalent to CAEP/4 

standards is consistent with U.S. 

obligations under ICAO. By issuing 

standards that meet or exceed the 

minimum stringency levels of ICAO 

CAEP/4 standards, we satisfy these 

obligations. (See section I.B for a 

discussion of the obligation of ICAO’s 

participating nations). As indicated 

earlier, the implementation date, 

December 31, 2003, has already 

occurred for the CAEP/4 standards, and 

we need to promulgate the standards to 

meet our obligations for the CAEP/4 

standards. Moreover, since we have 

already gone past the implementation 

date of the ICAO/CAEP/4 standards, 

there is not sufficient lead time to 

require more stringent emission 

standards in the very near term. As 

discussed later in section III.A.5 for 

future standards, we plan to address 

whether to take action on more stringent 

NOX standards in the future because 

pursuant to section 231(b) of the CAA 

we need more time to better understand 

the cost of compliance with such 

standards (see section III.A.5 for further 

discussion regarding lead time). Also, 

see the Summary and Analysis of 

Comments for this rulemaking for 

further discussion of this near-term 

approach. 

EPA believes that today’s standards 

will not impose any additional burden 

on manufacturers, because 

manufacturers are already designing 

new engines to meet the ICAO 

international consensus standards by 

2004 (see section VIII of today’s action 

for further discussion of regulatory 

impact). Even though the U.S. did not 

immediately adopt the ICAO NOX

standards after 1999, engine 

manufacturers have continued to make 

progress in reducing these emissions. 

Today’s standards are aimed at assuring 

that this progress is not reversed in the 

future. 

We received a number of comments 

from state and local governments and 

environmental groups stating that the 

NOX standards should be technologyforcing standards (a performance level 

that is beyond what sources are 

currently achieving). They stated that 

the standards are not technology forcing 

since 94 percent of all engine models 

currently in production already meet 

the standards (85 percent did in 1999 

when the ICAO adopted the standards). 

Also, state and local governments and 

environmental groups stated that since 

the standards are not technology-forcing 

and most engines already meet the 

standards, aircraft engine NOX will 

increase. They expressed concern the 

many states are facing air quality 

challenges with implementation of the 

new 8-hour ozone national ambient air 

quality standards (NAAQS). Decreases 

in ozone and its precursors, including 

NOX, requires controls of emissions 

from all sectors, in addition to controls 

already implemented for 1-hour ozone 

NAAQS. For nonattainment areas, 

aircraft emissions are problematic, and 

the standards will not reduce aircraft 

emissions or address aircraft NOX

pollution. 

Engine and airframe manufacturers 

and airlines supported the standards 

and opposed the concept of technologyforcing standards. Airlines indicated 

that the rulemaking would codify 

aircraft emission standards determined 

to be technologically feasible. In 

addition, airlines expressed that 

technology-forcing standards would be 

contrary to the CAA. Aircraft engine 

emission standards adopted according 

69676 Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 

74The projected growth in aircraft emissions is 

not simply from the number of operations, but it 

could also be attributed to the change in the types 

of aircraft being operated. For example, regional 

aircraft activity is growing (regional aircraft are 

generally referred to as those aircraft with more 

than 19 but fewer than 100 seats—regional jets and 

turboprops). In the U.S., traffic flown by regional 

airlines increased about 20 percent in 1999 and is 

expected to grow approximately 7 percent annually 

during the next ten years, compared to 4 to 6 

percent for the major airlines. In addition, regional 

jets comprised about 25 percent of the regional 

aircraft fleet in 2000, up from only 4.2 percent in 

1996, and their fraction of the fleet is expected to 

increase to nearly 50 percent by 2011. (R. Babikian, 

S. P. Lukachko and I. A. Waitz, ‘‘Historical Fuel 

Efficiency Characteristics of Regional Aircraft from 

Technological, Operational, and Cost Perspectives,’’

Journal of Air Transport Management, Volume 8, 

No. 6, pp. 389–400, Nov. 2002.) 

75U.S. EPA, ‘‘Evaluation of Air Pollutant 

Emissions from Subsonic Commercial Jet Aircraft,’’

April 1999, EPA420–R–99–013. This study is 

section 231 of the CAA must be based 

on what is technologically feasible, and 

the standards cannot be amended if the 

change would significantly increase 

noise or adversely affect safety. They 

suggested that a technology-forcing NOX

standard could adversely affect noise 

and safety. In addition, they indicated 

that section 231 of the Act is different 

from other sections of the CAA that call 

for technology-forcing standards. 

Airlines expressed that section 231 

requires that standards already be 

technologically feasible and not 

compromise noise and safety. In 

addition, airlines expressed that 

whether a ‘‘standard is technologically 

feasible depends not just on whether it 

can be achieved in a laboratory setting, 

but whether it can be achieved on a 

range of actual aircraft engine and 

airframe combinations that are certified 

as airworthy, safe, and fully operable 

under flight conditions. Moreover, such 

demonstrated technology must be 

available for application over a 

sufficient range of newly certificated 

aircraft, not just on a few airframe/ 

engine combinations.’’ (See the 

Summary and Analysis of Comments of 

this rulemaking for further discussion of 

comments.) 

In response to these comments, we 

refer to sections 231(a)(2)(B) and (b) of 

the CAA. Section 231(b) requires that 

any emission standards ‘‘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 

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

Section 231(a)(2)(B) provides that the 

Administrator shall consult with the 

Administrator of the FAA on standards, 

and ‘‘shall not change the aircraft engine 

emission standards if such change 

would significantly increase noise and 

adversely affect safety.’’ 42 U.S.C. 

7571(a)(2)(B). Future aircraft emission 

standards will involve appropriate 

consultations between EPA and the 

FAA in applying these provisions of the 

CAA. 

EPA also needs to have a technical 

basis for expecting the standards will be 

achievable in a specific period of time. 

While the statutory language of section 

231 is not identical to other provisions 

in title II of the CAA that direct EPA to 

establish technology-based standards for 

various types of engines, EPA interprets 

its authority under section 231 to be 

somewhat similar to those provisions 

that require us to identify a reasonable 

balance of specified emissions 

reduction, cost, safety, noise, and other 

factors. See, e.g., Husqvarna AB v. EPA, 

254 F.3d 195 (DC Cir. 2001) (upholding 

EPA’s promulgation of technology-based 

standards for small non-road engines 

under section 213(a)(3) of the CAA). 

However, we are not compelled under 

section 231 to obtain the ‘‘greatest 

degree of emission reduction 

achievable’’ as per sections 213 and 202 

of the CAA, and so EPA does not 

interpret the Act as requiring the agency 

to give subordinate status to factors such 

as cost, safety, and noise in determining 

what standards are reasonable for 

aircraft engines. Rather, EPA has greater 

flexibility under section 231 in 

determining what standard is most 

reasonable for aircraft engines, and is 

not required to achieve a ‘‘technologyforcing’’ result. The fact that most 

engines already meet standards would 

not in itself mean that the standard is 

inappropriate, provided the agency has 

a reasonable basis after considering all 

the relevant factors for setting the 

standard (with an appropriate period of 

lead time for that standard) at a level 

that results in no actual emissions 

reduction from the baseline. 

By the same token, EPA does not 

agree that a technology-forcing standard 

would be precluded by section 231, in 

light of section 231(b)’s forward-looking 

language. Nor would EPA have to 

demonstrate that a technology is 

currently available universally or over a 

broad range of aircraft in order to base 

a standard on the emissions 

performance of such technology—the 

Agency is not limited in identifying 

what is ‘‘technologically feasible’’ as 

what is already technologically 

achieved. However, EPA would, after 

consultation with the Secretary of 

Transportation, need to provide 

manufacturers sufficient lead time to 

develop and implement requisite 

technology. As section 231 conveys, 

there is an added emphasis on the 

consideration of safety (see, e.g., 

sections 231(a)(2)(B)(ii) (‘‘The 

Administrator shall not change the 

aircraft engine emission standards if 

such change would [* * *] adversely 

affect safety’’), 42 U.S.C. 

7571(a)(2)(B)(ii), and 231(c) (‘‘Any 

regulations in effect under this section 

[* * *] shall not apply if disapproved 

by the President, after notice and 

opportunity for public hearing, 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). Therefore, it 

is reasonable for EPA to give greater 

weight to considerations of safety in this 

context than it might in balancing 

emissions reduction, cost, and energy 

factors under other title II provisions. 

EPA is aware that many states face air 

quality challenges in light of the new 

ozone NAAQS, and since section 233 of 

the CAA vests authority only in EPA to 

set aircraft emission standards, we 

understand their perspective regarding 

the importance of setting more stringent 

NOX standards in the future. For these 

future standards, we expect to adopt 

standards developed through the CAEP 

process in ICAO. Further, federal 

agencies plan on working through the 

environmental Integrated Product Team 

for the Next Generation Air 

Transportation System (NGATS), to 

conduct a review of technology for 

aircraft engines and the resulting trend 

in aircraft emissions as well as 

interrelationships with noise (e.g., 

standards effect on projected aircraft 

emissions growth and expected effects 

on noise). See section III.A.5 below for 

further discussion of future NOX

standards. (See the Summary and 

Analysis of Comments of this 

rulemaking for further discussion of our 

responses to comments.) 

5. Future NOX Standards for Newly 

Certified Low-, Mid-, and High-Thrust 

Engines 

More stringent standards for low-, 

mid-, and high-thrust engines will likely 

be necessary and appropriate in the 

future. As discussed earlier in section II, 

the growth in aircraft emissions is 

projected to occur at a time when other 

mobile source categories are reducing 

emissions.74 The 1999 EPA study of 

commercial aircraft activity in ten cities 

projected that the aircraft NOX

emissions would double in some of 

these cities by 2010, and the aircraft 

component of the regional mobile 

source NOX emissions in the ten cities 

would grow from a range of 1 to 4 

percent that existed in 1990 to a range 

of 2 to 10 percent in 2010.75 As 

Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 69677 

available at http://www.epa.gov/otaq/aviation.htm. 

It can also be found in Docket No. OAR–2002–0030. 

76U.S. FAA, ‘‘APO Terminal Area Forecast 

Summary Report,’’ Aircraft Operations, June 30, 

2005. The flight forecast data is based on FAA’s 

Terminal Area Forecast System (TAFS). TAFs is the 

official forecast of aviation activity at FAA facilities. 

This includes FAA-towered airports, federallycontracted towered airports, nonfederal towered 

airports, and many non-towered airports. For 

detailed information on TAFS and the air carrier 

activity forecasts see the following FAA website: 

http://www.apo.data.faa.gov/main/taf.asp. The 

June 30, 2005 aviation forecasts contained in TAFS 

for Fiscal Years 2002–2020 included the impact of 

the terrorists’ attacks of September 11, 2001 and the 

recent economic downturn. Currently, the aviation 

industry is undergoing significant structural and 

economic changes. These changes may necessitate 

revisions to forecasts for a number of large hub 

airports prior to the update of the entire TAF next 

year. A copy of the June 30, 2005 forecast summary 

report can also be found in Docket No. OAR–2002–

0030. 

77For information on the geographic location of 

airports, see the following U.S. Department of 

Transportation (Bureau of Transportation Statistics) 

website: http://www.bts.gov/oai. The report or 

database provided on the website entitled, ‘‘Airport 

Activity Statistics of Certificated Air Carriers: 

Summary Tables 2000,’’ lists airports by 

community. In addition, see the following EPA 

website for information on nonattainment areas for 

criteria pollutants: http://www.epa.gov/oar/oaqps/ 

greenbk. 

78 ICAO News Release, ‘‘ICAO Council Adopts 

New Standards for Aircraft Emissions,’’ PIO 03/05, 

March 2, 2005. Copies of this document can be 

obtained at the ICAO website located at http:// 

www.icao.int. 

79 ICAO, CAEP, Sixth Meeting, Montreal, Quebec, 

February 2–12, 2004, Report, Letter of Transmittal 

to the President of the Council From the Chairman 

of the Sixth Meeting of CAEP, CAEP/6–WP/57 

(Report on Agenda Item 1). Copies of this document 

can be obtained from ICAO (http://www.icao.int). It 

can also be found in Docket No. OAR–2002–0030. 

80 ICAO, CAEP, Sixth Meeting, Montreal, Quebec, 

February 2–12, 2004, Report, Letter of Transmittal 

to the President of the Council From the Chairman 

of the Sixth Meeting of CAEP, CAEP/6–WP/57 

(Report on Agenda Item 4). Copies of this document 

can be obtained from ICAO (http://www.icao.int). It 

can also be found in Docket No. OAR–2002–0030. 

81For the purposes of setting long-term 

technology goals for aircraft emission reductions, 

the CAEP/6 (occurred in February 2004) future 

work program included the following items: 

(a) Implement a CAEP-approved process to set, 

periodically review and update technology goals 

and identify environmental benefits, taking into 

account progress in ongoing research and 

development efforts toward reducing aircraft 

emissions, environmental interdependencies and 

trade-offs, and scientific understanding of the 

effects of aircraft engine emissions; 

(b) Support and monitor development and 

methods for understanding the inter-relationship of 

technology goals targeting individual emissions 

performance improvements; and 

(c) Develop the inputs appropriate for use of air 

quality and climate impact models to be used by 

CAEP to quantify the value of emissions reduction 

and to estimate the benefit from long-term goals. 

ICAO, CAEP, Sixth Meeting, Montreal, Quebec, 

February 2–12, 2004, Report, Letter of Transmittal 

to the President of the Council From the Chairman 

of the Sixth Meeting of CAEP, CAEP/6–WP/57 

(Appendix A to the Report on Agenda Item 4—

Revised Work Program for CAEP, page 4A–7). 

Copies of this document can be obtained from ICAO 

(http://www.icao.int). It can also be found in Docket 

No. OAR–2002–0030. 

82 ICAO, CAEP, Fourth Meeting, Montreal, 

Quebec, April 6–8, 1998, Report, Document 9720, 

CAEP/4, see Appendix A to the Report on Agenda 

Item 4 (page 4–A–1). Copies of this document can 

be obtained from ICAO (http://www.icao.int). 

indicated earlier, the above projections 

were made prior to the tragic events of 

September 11, 2001, and the economic 

downturn. A January 2003 report by the 

Department of Transportation indicated 

that the combination of the September 

11, 2001 terrorist attacks and a cut-back 

in business travel had a significant and 

perhaps long-lasting effect on air traffic 

demand. While, the FAA expects the 

demand for air travel to recover, and 

then continue a long-term trend of 

annual growth in the United States, it 

will grow at a lower rate and from a 

lower base than originally forecast. 

More recently, as discussed earlier, FAA 

reports that flights (or activity) of 

commercial air carriers and commuters/ 

air taxis will increase by 22 percent 

from 2000 to 2015, about 12 percent less 

than what was forecast before 

September 11th.76 While flight activity, 

and thus NOX emissions, will be lower 

than originally anticipated, the relative 

size of the contribution of aircraft to 

national NOX levels may increase due to 

the potential decreased contribution 

from other mobile sources; hence, 

further action may be necessary in the 

future to reduce aircraft NOX emissions 

in nonattainment areas. 

Further stringency of the NOX

standards would reduce the expected 

growth in commercial aircraft NOX

emissions. The importance of 

controlling aircraft emissions has grown 

in many areas (especially areas not 

meeting the 1-hour and 8-hour ozone 

NAAQS) as controls on other sources 

become more stringent and attainment 

of the NAAQS’s has still not been 

achieved. (Many airports in the U.S. are 

located in nonattainment areas.77) As 

activity increases, aircraft would emit 

increasing amounts of NOX in many 

nonattainment areas, and thus, aircraft 

NOX emissions would further aggravate 

the problems in these areas (either by 

emitting pollutants directly within a 

nonattainment area or by contributing to 

regional transport emissions in an area 

upwind of a nonattainment area). More 

stringent aircraft engine NOX standards 

may assist in alleviating these problems 

in nonattainment areas, and they may 

aid in preventing future concerns in 

areas currently designated as attainment 

(or maintenance) areas. In addition, 

attainment or maintenance of the 

NAAQS may depend upon aircraft 

engines being subject to a program of 

control compatible with their 

significance as pollution sources. (See 

the Summary and Analysis of 

Comments for this rulemaking for 

further discussion of future standards 

and the environmental need for control.) 

EPA, therefore, is considering the 

exploration of more stringent future 

standards, beyond today’s standards. 

Earlier this year, the ICAO Council 

adopted more stringent international 

consensus NOX emission standards for 

newly certified aircraft engines 

(implementation date of after December 

31, 2007).78 The CAEP/6 NOX standards 

generally represent about a 12 percent 

increase in stringency from the 

standards promulgated in this final rule 

(or the CAEP/4 NOX standards).79

(These standards were accompanied by 

more stringent standards for low-thrust 

engines). Moreover, CAEP agreed to 

review the stringency of the NOX

standards again during the work 

program for the eighth meeting of CAEP, 

which will commence in early 2007 and 

is expected to culminate in early 2010. 

Such standards will be a central 

consideration in a future EPA regulation 

of aircraft engine emissions. Thus, it 

will be important that the U.S. continue 

to actively participate in the technical 

emissions work activity that will 

endeavor to establish the technological 

basis for any increase in stringency that 

CAEP will contemplate. We believe this 

ongoing phased approach is the most 

appropriate means to address emissions 

from aircraft engines. 

As we discussed in the proposal, 

activity is also underway in CAEP to 

identify and assess the potential for 

long-term technology goals to be 

established for further emission 

reductions, including implementing a 

CAEP-approved process to set and 

review these goals.80 81 The aim of the 

goal setting activity is to complement 

the ICAO CAEP standard setting process 

with information to aid the engine and 

airframe manufacturer’s design process. 

The goals are expected to take into 

account the results of recently 

completed emissions reduction 

technology programs such as those 

conducted by National Aeronautics and 

Space Administration (NASA) and the 

European Commission and the timeline 

necessary to carry those technologies 

from the research phase through 

commercialization.82 We support this 

CAEP work item for establishing goals. 

However, this should not be interpreted 

as agreement on our part that the CAEP 

process is the exclusive appropriate 

process for setting aircraft emissions 

reduction goals or for encouraging the 

development of better performing 

technology. For example, the Next 

Generation Air Transportation System 

69678 Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 

83For low-thrust engines, deferring regulatory 

action on more stringent future standards until after 

CAEP/6 would also enable us to obtain additional 

information on the technological feasibility of such 

standards. 

84This provision does not mean the recertification or retrofit of existing in-use engines. 

Instead the provision would require the ongoing 

production of engines that have already been 

certified to meet the new standards, rather than 

following CAEP/4 and merely applying today’s 

standards to future engine designs and allowing 

currently produced engine models to meet the 

previous standards. 

85 ICAO, CAEP, Sixth Meeting, Montreal, Quebec, 

February 2–12, 2004, Report, Letter of Transmittal 

to the President of the Council From the Chairman 

of the Sixth Meeting of CAEP, CAEP/6–WP/57 

(Report on Agenda Item 1). A copy of this document 

can be found in Docket No. OAR–2002–30. 

86CAEP/6 noted that industry ‘‘pointed out that 

introduction of a production cut-off now would 

cause the manufacturer to modify engines to meet 

the CAEP/4 standards, whereas if no cut-off were 

imposed it was likely that they could be modified 

to meet the new standards agreed at this meeting.’’

(ICAO, CAEP, Sixth Meeting, Montreal, Quebec, 

February 2–12, 2004, Report, Letter of Transmittal 

to the President of the Council From the Chairman 

of the Sixth Meeting of CAEP, CAEP/6–WP/57, 

Report on Agenda Item 1, pages 1–13.) 

87 ICAO, CAEP/6, Information Paper 28—

Appendix B, ‘‘FESG Economic Assessment of 

Applying a Production Cut-off to the CAEP/4 NOX

Standard’’ Presented by the FESG Rapporteur, 

January 29, 2004 (Same as CAEP–SG20031–IP/9, 

which was presented at June 10, 2003 CAEP 

Steering Group Meeting). A copy of this document 

can be found in Docket No. OAR–2002–30. 

88 ICAO, CAEP/6, Information Paper 28—

Appendix B, ‘‘FESG Economic Assessment of 

Applying a Production Cut-off to the CAEP/4 NOX

Standard’’ Presented by the FESG Rapporteur, 

January 29, 2004 (Same as CAEP–SG20031–IP/9, 

which was presented at June 10, 2003 CAEP 

Steering Group Meeting). A copy of this document 

can be found in Docket No. OAR–2002–30. 

89 International Civil Aviation Organization 

(ICAO), Aircraft Engine Exhaust Emissions Data 

Bank, July 26, 2004. This data bank is available at 

http://www.caa.co.uk/ 

default.aspx?categoryid=702&pagetype=90. In 

addition, a copy of a table including data of engine 

NOX emissions from the ICAO data bank and their 

margin to today’s NOX standards can be found in 

Docket OAR–2002–0030. 

(NGATS) plan was released in 

December 2004—a Congressionally 

chartered and Administration endorsed 

activity to develop research and plans to 

transform the air transportation system. 

Efforts there will include assessment of 

various technological and operational 

procedures to reduce aircraft emissions, 

including NOX, as well as a thorough 

assessment of interrelationships 

between noise and emissions and 

amongst emissions to enable 

maximizing environmental benefit 

derived from mitigating actions. 

Further, in EPA’s long history of mobile 

source regulation, we have found that 

performance-based standards have been 

successfully used to stimulate 

technological development resulting in 

cleaner, cost-effective, and safe engines. 

Manufacturers should be able to 

achieve additional reductions with more 

lead time than is provided by today’s 

action. As we discussed in the proposal, 

in the future we intend to assess, in 

coordination with the NGATS 

Environmental Integrated Product Team 

(IPT) whether or not the new 

international consensus and longer-term 

standards, CAEP/6 NOX standards, 

would be stringent enough to protect the 

U.S. public health and welfare. If so, we 

would plan to propose to adopt the 

CAEP/6 NOX standards. EPA in 

consultation with the Secretary of 

Transportation retains the discretion to 

adopt more stringent NOX standards in 

the future if the international consensus 

standards ultimately prove insufficient 

to protect U.S. air quality. As discussed 

earlier, the implementation date, 

December 31, 2003, has already 

occurred for the CAEP/4 standards, and 

we need to promulgate today’s 

standards to meet our obligations for the 

CAEP/4 standards. This final rule to 

promulgate aircraft engine NOX

standards equivalent to CAEP/4 

standards is consistent with U.S. 

obligations under ICAO. We would not 

be able to quickly adopt a more 

stringent standard. However, we intend 

to consider further stringency in a future 

rulemaking. In addition, we have not yet 

assessed the costs (and emission 

benefits) of more stringent standards, 

but we anticipate doing so in the future 

for such standards. 

Consideration of more stringent NOX

standards in the future will allow us to 

obtain important additional information 

on the costs of such standards.83 As 

described earlier, section 231 of the 

CAA authorizes EPA from ‘‘time to 

time’’ to revisit emission standards, and 

it requires that any standards’ effective 

dates permit the development of 

necessary technology, giving 

appropriate consideration to the cost. 

We did not propose more stringent NOX

standards primarily because we needed 

more time to better understand the cost 

of compliance of such standards. Cost 

data is now available from CAEP/6 

(meeting occurred in February 2004), 

but we need to first adopt the standards 

equivalent to CAEP/4 today since we 

have already gone past the CAEP/4 

implementation date. Although, as we 

described earlier, the CAEP/6 NOX

standards will be a central consideration 

in a future aircraft engine emission 

standards, other levels of further 

stringency would also be under 

consideration, and additional cost 

information for such standards would 

need to be evaluated. 

As we discussed in the proposal, 

producing (and/or developing) new 

engines or engine technologies requires 

significant financial investments from 

engine manufacturers, which takes time 

to recoup (the amount of time depends 

upon sales of engines, replacement 

parts, etc.). After evaluating additional 

cost information for future standards as 

well as other emissions reduction 

approaches, we would then be better 

situated to make decisions on an 

appropriate level of stringency and 

implementation timing that maximizes 

NOX reductions from aircraft engines, 

taking into consideration cost, safety, 

and noise. 

B. Newly Manufactured Engines of 

Already Certified Models 

We requested comment on whether 

the NOX standards would apply to 

newly manufactured engines of already 

certified models (i.e., those individual 

engines that are part of an already 

certified engine model, but are built 

after the effective date of the regulations 

for such engines and have never been in 

service),84 but after careful 

consideration and reviewing comments 

from stakeholders, we have decided not 

to include such engines in today’s final 

rulemaking. It is important to mention 

that CAEP/6 did not adopt provisions to 

apply the CAEP/4 NOX standards to 

newly manufactured engines of already 

certified models (a production cut-off). 

CAEP/6 noted the industry view that 

market forces are the primary drivers of 

the development and incorporation of 

new technology (asserting voluntary 

compliance would suffice), and an 

understanding at CAEP/4 that a 

production cut-off would not be 

introduced in the future. CAEP/6, after 

reviewing that commitment, decided 

that ‘‘* * *this should not be 

interpreted as meaning that production 

cut-offs would not be introduced in the 

future if the situation so warranted.’’85 86

(As we discussed in the proposal, 

CAEP’s Forecasting and Economic 

Analysis Support Group (FESG) further 

analyzed applying CAEP/4 NOX

standards to newly manufactured 

engines of already certified models for 

CAEP/6, and assessed effective dates of 

2, 4, and 6 years after December 31, 

2003, which is the implementation date 

for newly certified engines.87 FESG 

estimated that the cost per ton of NOX

reduced would range from $3,800 to 

$11,200 for the three effective dates.88

The emission benefits and costs of this 

provision are discussed further below.) 

1. What Is the Status of Engines? 

According to the ICAO Aircraft 

Engine Exhaust Emissions Data Bank,89

nearly all already certified engine 

models (95 percent of already certified 

Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 69679 

90Based on the ICAO Data Bank, 151 out of 159 

(95 percent) engine models that are currently in 

production perform better than the CAEP/4 NOX

standards. The 8 engine models (which are midand high-thrust engines) that are not achieving the 

CAEP/4 NOX standards are from three different 

Pratt and Whitney (PW) engine types or families 

(engines and their thrust variants with the same 

build standard). These engines are the following: (1) 

JT8D–217C E-kit and JT8D–219 E-kit; (2) PW4077D, 

PW4084D, and PW4090; and (3) PW4164, PW4168, 

and PW4168A. (See Figure III.B–1 below that 

specifically shows these 8 in-production models in 

relation to the CAEP/4 or proposed NOX standards.) 

For the year 2000, these 8 engine models were 

found on approximately 751 out of 20,137 (3.7 

percent) aircraft owned by U.S. carriers and 

accounted for approximately 1,541,172 out of 

11,505,063 (13.4 percent) of U.S. domestic flights. 91For Figure III.B–1, the Allison, Pratt and 

Whitney (does not include JT8D–217C E-kit and 

JT8D–219 E-kit), Rolls-Royce, and Textron 

Lycoming engines with rated pressure ratios less 

than or equal to 20 and NOX levels above the CAEP/ 

4 NOX standards actually perform better than the 

standards, since there are different CAEP/4 NOX

standards for these low-thrust engines (see section 

III.A.3 for further discussion of NOX standards for 

low thrust engines). (47 of the 159 engines, 30 

percent of engine models in production, in Figure 

IV.B–1 and the ICAO Aircraft Engine Exhaust 

Emissions Data Bank are low-thrust engines—

engines with thrust greater than 26.7 kN but not 

more than 89 kN.) 

92 ICAO, CAEP/4, Working Paper 4, ‘‘Economic 

Assessment of the EPG NOX Stringency Proposal,’’

March 12, 1998, Presented by the Chairman of 

Forecasting and Economic Analysis Support Group 

(FESG), Agenda Item 1: Review of proposals 

relating to NOX emissions, including the 

amendment of Annex 16, Volume II, See Table 3.1 

of paper. A copy of this paper can be found in 

Docket OAR–2002–0030. 

93 ICAO, CAEP/6, Working Paper 34, ‘‘NOX

Production Cut-off Consideration,’’ Presented by the 

International Coordinating Council of Aerospace 

Industries Associations (ICCAIA), January 6, 2004. 

A copy of this document can be found in Docket 

No. OAR–2002–30. 

94 ICAO, CAEP/6, Information Paper 28—

Appendix B, ‘‘FESG Economic Assessment of 

Applying a Production Cut-off to the CAEP/4 NOX

Standard’’ Presented by the FESG Rapporteur, 

January 29, 2004 (Same as CAEP–SG20031–IP/9, 

which was presented at June 10, 2003 CAEP 

Steering Group Meeting). A copy of this document 

can be found in Docket No. OAR–2002–30. 

95The PW Canada growth engines are the one 

remaining type of newly designed engines. The 

ICAO Aircraft Engine Exhaust Emissions Data Bank 

currently does not have emissions certification data 

for such an engine, but Working Paper 34 presented 

at CAEP/6 indicated it would be compliant. (ICAO, 

CAEP/6, Working Paper 34, ‘‘NOX Production Cutoff Consideration,’’ Presented by the International 

Coordinating Council of Aerospace Industries 

Associations (ICCAIA), January 6, 2004. A copy of 

this document can be found in Docket No. OAR–

2002–30.) 

96 ICAO, CAEP/4, Information Paper 3, 

‘‘Clarification of the Definition of Derivative 

Version,’’ Agenda Item 4—Future Work, Presented 

by United States, April 3, 1998. A copy of this 

document can be found in Docket No. OAR–2002–

30. 

97Chapter 1 of Part I of the ICAO Annex 16, 

Volume II, Aircraft Engine Emissions, defines 

derivative version as follows: ‘‘an aircraft gas 

turbine engine of the same generic family as an 

originally type-certificated engine and having 

features which retain the basic core engine and 

combustor design of the original model and for 

which other factors, as judged by the certificating 

authority, have not changed.’’

and in-production engine models in the 

Data Bank) currently meet or perform 

better than the standards we are 

adopting today.90 (See Figure III.B–1 

below for a comparison of the NOX

emission levels of current in-production 

engines to the CAEP/4 NOX

standards.91) At the time the CAEP/4 

NOX standards were adopted in 1998, 

all but 11 in-production engines and 5 

newly designed engine models (these 5 

engines were in the design and 

development process in 1998) had NOX

emission levels that would perform 

better than the CAEP/4 standards.92

Today, nearly all of the engines that did 

not meet the CAEP/4 NOX standard in 

1998 now comply, except for the JT8D–

200 engine family.93 The other engine 

models have either, through additional 

testing or modifications, been improved 

to meet the standards or the engines are 

no longer in-production. Although, as 

described earlier, the ICAO Data Bank 

shows that eight engine models or three 

different Pratt and Whitney engine types 

or families do not meet the NOX

standards, we now know that except for 

the JT8D–217 and JT8D–219, six of the 

engine models or two of the engine 

types are compliant. 

(The above reference for the fleet 

fraction is BACK Aviation Solutions, 

http://www.backaviation.com/ 

Information_Services/default.htm. 

The domestic flight information is 

based on SAGE, the System for 

Assessing Aviation Emissions. SAGE is 

an FAA model that estimates aircraft 

emissions through the full flight profile 

using non-proprietary input data, such 

as BACK, FAA’s Enhanced Traffic 

Management System (ETMS), and the 

Official Airline Guide (OAG). The year 

2000 air traffic movements database 

portion of SAGE was used to estimate 

the number of flights using the subject 

engines.) 

The PW4090 family of engines 

(PW4077D, PW4084D, and PW4090) 

now has the means to eventually meet 

the standards utilizing technology that 

would meet the lower ranges of 

stringency options for the NOX

standards considered at CAEP/6, 

although the manufacturer has projected 

it would be some years before it expects 

to meet CAEP/6 levels (the 

manufacturer has not provided us with 

a projected necessary lead-time to meet 

CAEP/4). The engine family that 

includes the PW4164, PW4168 and 

PW4168A engines is now certified with 

the PW 4168 Technologically Affordable 

Low NOX (Talon) II engine combustor 

technology, which performs 

significantly better than the CAEP/4 

standards. Also, the JT8D–200 engine 

powers the MD–80 aircraft, which is no 

longer in production. Yet, the JT8D–200 

engine (JT8D–217C and JT8D–219 inproduction engines) could potentially 

apply to future supersonic business jets. 

As stated in the proposal, the resulting 

NOX emission benefits of applying the 

standards to the JT8D–200 (for these 

possible supersonic business jets) would 

be expected to be very small, and the 

costs would also likely be relatively 

small on an industry wide basis, 

although as discussed further below we 

do not feel we have a sufficient record 

at this point—nor have we presented it 

for public comment—to state our 

definitive views on these issues. 

However, the direct (development) costs 

would most likely be borne by one 

engine manufacturer.94 As discussed in 

the proposal, there is only one 

remaining newly designed engine 

model—out of the five identified in 

1998—that would be certified after 

2003, and it also has been made 

compliant with today’s or CAEP/4 NOX

standards.95

In addition, as we indicated in the 

proposal, if an already certified engine 

design meets the standards that we are 

adopting today, then it is unlikely that 

either existing or future engine designs 

built to that design or type (derivatives 

or thrust variants with the same build 

standard) would not meet these 

standards. However, we may have been 

imprecise by stating in the proposal that 

when design modifications are made to 

an existing engine type, then this engine 

type would likely need to be recertified. 

Derivative versions of engines are not 

typically required to meet new 

standards for newly certified (and newly 

designed) engines, but they usually 

need to comply with the same standards 

as were applied to the original engine 

model.96 97 Thus, derivative versions of 

engines typically do not need to be 

recertified. However, an engine type 

that does need to recertified will be 

required to comply with the CAEP/4 

and today’s NOX standards. 

69680 Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 

2. What Are the Issues With Applying 

Today’s NOX Standards to Newly 

Manufactured Engines of Already 

Certified Models? 

One commenter expressed that EPA 

conceded in the proposed rule that it 

has historically applied aircraft 

emission standards to newly 

manufactured engines of already 

certified models, and doing so this time 

would prohibit the indefinite continued 

production of aircraft engines that 

would meet only the previous 

standards. ‘‘EPA does not explain why 

it is proposing a sudden departure from 

the past practice of regulating already 

certified, newly manufactured engines—

i.e., what is different about this 

particular rulemaking that justifies the 

exemption of such engines.’’ With the 

long life of aircraft engines and the 

availability of newly manufactured 

engines of already certified models in 

the future, there is a need to apply the 

proposed NOX standards to this category 

of aircraft engines. 

State and local governments 

recommended that the standards for 

newly manufactured engines of already 

certified models should be implemented 

one year after the effective date of the 

final rulemaking. At a minimum, EPA 

should have an implementation date 

that prohibits engine manufacturers 

from selling already certified engines 

unless the engines were recertified or 

redesigned to meet the proposed 

standards. Such a provision would be 

consistent with a stated objective of the 

rulemaking, which is to assure that 

progress in reducing aircraft engine 

emissions is not reversed in the future. 

Without such standards high-emitting 

engines can continue to be produced 

and brought into service, further adding 

to the long-term growth in aircraft 

emissions that is anticipated without a 

more aggressive approach to regulating 

this source. 

Airlines commented that as the 

proposal acknowledges, market 

incentives lead manufacturers to bring 

their engines to the levels of the CAEP/ 

4 NOX standards as soon as possible 

once the standards take effect. Airlines 

investing in costly, long-lasting assets 

prefer to buy engines that meet the latest 

standards, and demand engines that 

perform better than the standard 

without regulatory intervention of a 

production cut-off (applying standards 

to newly manufactured engines of 

already certified models). Such market 

forces together with EPA’s four-year 

delay in proposing to adopt the CAEP/ 

4 NOX standards, account for the fact 

that 94 percent of in-production engines 

already meet the standard. 

In addition, airlines expressed that for 

the same reasons that the Agency 

should generally align with ICAO 

standards, it should be consistent with 

ICAO on whether to apply CAEP/4 

standards to newly manufactured 

engines of already certified models. If 

EPA differed from ICAO on this 

provision, there would be the very 

inconsistency between domestic and 

international practice that aligning with 

ICAO requirements avoids. 

Furthermore, if EPA adopts such a 

provision prior to ICAO, such action 

would potentially place U.S. 

manufacturers and airlines at a 

competitive disadvantage for what EPA 

acknowledges to be minimal 

environmental benefit. 

In addition, one airline expressed that 

it presently has the JT8D–219 engine on 

some of its commercial jets. The 

proposal indicated that the JT8D–219 

would be used in supersonic business 

jets, which the airline does not operate; 

however, it (and maybe other domestic 

airlines) operates this engine in our 

commercial aircraft fleet. Therefore, the 

implication of these provisions has not 

been fully investigated by EPA as 

mandated by the CAA. (See the 

Summary and Analysis of Comments for 

this rulemaking for further discussion of 

comments.) 

In response, as indicated earlier, the 

implementation date applicable to 

newly designed and certified engines 

under CAEP/4, December 31, 2003, has 

already occurred for the CAEP/4 

standards, and at this late date to 

promulgate a provision to apply today’s 

standards to newly manufactured 

engines of already certified models (a 

production cut-off) could be disruptive 

to the production planning of engine 


ER17NO05.001</GPH>
Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 69681 

98Such engines include newly manufactured 

engines of already certified models. 

99Russian Federation, ‘‘Corrections to Annex 16, 

Volume II,’’ Agenda Item 2: Review of reports of 

working groups relating to engine emissions and the 

development of recommendations to the Council 

thereon, Working Paper 19, Presented by A.A. 

Gorbatko, November 11, 1995 (distributed 

November 30, 1995), CAEP/3, Montreal, December 

5 to 15, 1995. A copy of this paper can be found 

in Docket OAR–2002–0030. 

100United Kingdom, ‘‘Amendments to Annex 16, 

Volume II, Attachment D to Appendices 3 and 5 

(Calibration and Test Gases),’’ Agenda Item 2: 

Review of reports of working groups relating to 

engine emissions and the development of 

recommendations to the Council thereon, Working 

Paper 20, Presented by M.E. Wright, November 14, 

1995 (distributed November 30, 1995), CAEP/3, 

Montreal, December 5 to 15, 1995. A copy of this 

paper can be found in Docket OAR–2002–0030. 

101 ICAO/CAEP, Report of Third Meeting, 

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

9675, CAEP/3. Copies of this document can be 

obtained from ICAO (http://www.icao.int). 

manufacturers. EPA and ICAO (as we 

mentioned in the proposal and as one 

commenter noted in its comments) have 

historically adopted production cut-offs 

for previous standards, but in today’s 

unique case the lateness of the rule may 

not provide manufacturers enough lead 

time for such planning. However, as we 

discussed earlier, we intend to consider 

more stringent NOX standards in a 

future rulemaking, and similar to CAEP/ 

6’s future plans described above, we 

also intend to consider applying more 

stringent standards to newly 

manufactured engines of already 

certified models for such a future 

rulemaking. This provision is an 

important issue that we expect to fully 

consider for future standards. 

While we solicited comment on 

extending the CAEP/4 standards to 

newly manufactured engines of already 

certified models, we did not develop a 

record that fully analyzes the emissions 

benefits (if any) and the implementation 

costs of going beyond CAEP in this 

manner. Therefore, the public has not 

been provided an opportunity to 

analyze and comment upon these 

important factors. We believe that our 

analysis of these factors would need to 

be weighed through a notice-andcomment process in determining 

whether a production cut-off, with a 

specific lead-time period, would be 

appropriate under CAA section 231 in 

this case. Particularly regarding the cost 

of compliance within necessary leadtime issue, we are concerned that there 

is insufficient data that specifically 

addresses the appropriate lead time for 

subjecting the few remaining inproduction engine models to the CAEP/ 

4 standards, and that our selection of a 

production cut-off date could therefore 

be viewed as arbitrarily chosen. 

Since we have not yet provided that 

opportunity for public comment on our 

analysis of this issue, and since 

attempting to do so now would in our 

view unacceptably slow down this 

rulemaking, in the interests of 

expediency and of bringing U.S. 

domestic law into conformity with our 

obligations under the Chicago 

Convention (albeit tardily), we have 

decided that the most appropriate 

course for now, under CAA section 231 

(a), is to simply update our regulations 

to track CAEP/4 in terms of both 

stringency levels and scope of 

applicability. Similarly, without having 

developed the necessary record and 

analysis, at this time we are unable to 

respond to the substantive comments 

offered by commenters regarding the 

production-cutoff issue, and our 

decision today should in no way be 

viewed as either endorsing or rejecting 

the concept of a production cut-off. 

Given the need to quickly promulgate 

standards that are at least as stringent as 

CAEP/4, we must decline to resolve the 

numerous issues raised either in favor of 

or in opposition to applying the CAEP/ 

4 standards to newly manufactured 

engines of already certified models. 

IV. Amendments to Criteria on 

Calibration and Test Gases for Gaseous 

Emissions Test and Measurement 

Procedures 

In today’s rulemaking, EPA will 

incorporate by reference ICAO’s 1997 

amendments to the criteria on 

calibration and test gases for the test 

procedures of gaseous emissions (ICAO 

International Standards and 

Recommended Practices Environmental 

Protection, Annex 16, Volume II, 

‘‘Aircraft Engine Emissions,’’ Second 

Edition, July 1993; Amendment 3, 

March 20, 1997, Appendices 3 and 5) in 

40 CFR 87.64. ICAO’s amendments, 

which became effective on March 20, 

1997, apply to subsonic (newly certified 

and newly manufactured engines 98) and 

supersonic gas turbine engines. The 

technical changes will correct a few 

inconsistencies between the 

specifications for carbon dioxide (CO2) 

analyzers (Attachment B of Appendices 

3 and 5) and the calibration and test 

gases (Attachment D of Appendices 3 

and 5) of gaseous emissions. The test 

procedure amendments incorporated by 

reference will be effective 30 days after 

the publication of the final rule. 

For CAEP/3 in 1995, the Russian 

Federation presented a working paper 

entitled, ‘‘Corrections to Annex 16, 

Volume II,’’ that stated the following: 99

According to CAEP/2 recommendations, in 

the list of calibration and test gases (see the 

table in Attachment of Appendices 3 and 5) 

‘‘CO2 in N2’’ was replaced with ‘‘CO2 in air’’

gas. At the same time the following subparagraph was newly introduced into 

Attachment B (Appendices 3 and 5) : 

(g) The effect of oxygen (O2) on the CO2

analyzer response shall be checked. For a 

change from 0 percent O2 to 21 percent O2

the response of a given CO2 concentration 

shall not change by more than 2 per cent of 

reading. If this limit cannot be met an 

appropriate correction factor shall be 

applied. 

Since the best way to carry out this 

checking procedure is to calibrate the 

analyzer first with CO2 in nitrogen and then 

with CO2 in air, both ‘‘CO2 in N2’’ and ‘‘CO2

in air’’ gases have to be retained in the list. 

It seems then that ‘‘CO in air,’’ ‘‘CO2 in air,’’

‘‘NO in N2’’ and now ‘‘CO2 in N2’’ have to 

be replaced with ‘‘CO in zero air,’’ ‘‘CO2 in 

zero air,’’ ‘‘CO2 in zero nitrogen’’ and ‘‘NO in 

zero nitrogen’’ just by analogy with the 

gaseous mixtures of different hydrocarbons 

diluted by zero air and listed in the same 

table. 

In addition, at CAEP/3 the United 

Kingdom then presented a working 

paper on this same issue.100 They 

indicated that CAEP’s Working Group 3 

(Emissions Working Group) had 

accepted the above proposals of the 

Russian Federation paper on correcting 

inconsistencies in the list of calibration 

and test gases specified in Annex 16, 

Volume II, Attachment D to Appendices 

3 and 5, and Working Group 3 had 

recommended that these proposals be 

presented at CAEP/3. The United 

Kingdom also recommended the 

adoption of these Russian Federation 

proposals—to utilize CO2 in nitrogen 

gas mixture to check the effect of oxygen 

on CO2 analyzers. In addition, they 

recommended the specification of all 

calibration and test gases required for all 

the gaseous emissions tests required in 

Annex 16. 

At CAEP/3, the CAEP members agreed 

that the above amendments to the 

calibration and test gases were justified, 

and thus, these amendments were then 

adopted.101 Today, EPA will incorporate 

by reference the amendments to the 

criteria on calibration and test gases for 

the test procedures of gaseous 

emissions, because the changes improve 

the test procedures by correcting 

inconsistencies and distinguishing 

between calibration and test gases. The 

amendments will include the following: 

(1) Listing all calibration gases 

separately from test gases for HC, CO2, 

CO and NOX analyzers, (2) changing 

‘‘N2’’ to ‘‘zero nitrogen’’ in relation to 

the test gases for the HC and NOX

analyzers, (3) adding ‘‘CO2 in zero 

nitrogen’’ as a test gas for CO2 analyzer, 

(4) changing ‘‘air’’ to ‘‘zero air’’ in 

relation to the test gas for CO and CO2

analyzers, (5) revising the accuracy to ‘‘± 

1 percent’’ for the ‘‘propane in zero air’’

69682 Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 

102This action was taken in 1984 to provide 

greater flexibility to manufacturers for scheduling 

engine production rates during the final years. 

103The 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). 

104The Third Meeting of CAEP (CAEP/3) 

occurred in Montreal, Quebec from December 5 

through 15 in 1995. CAEP/4 took place in Montreal 

from April 6 through 8, 1998. 

105FAA and EPA, ‘‘Agreement Between Federal 

Aviation Administration and Environmental 

Protection Agency Regarding Environmental 

Matters Relation to Aviation,’’ signed on March 24, 

1998 by FAA’s Acting Assistant Administrator for 

Policy, Planning, and International Aviation, Louise 

Maillet, and EPA’s Acting Assistant Administrator 

for Air and Radiation, Richard Wilson. A copy of 

this document can be found in Docket OAR–2002–

0030. 

test gas of HC analyzer, (6) amending 

the accuracy to ‘‘± 1 percent’’ for the 

‘‘CO2 in zero air’’ test gas of CO2

analyzer, (7) adding the accuracy ‘‘± 1 

percent’’ for the ‘‘CO2 in zero nitrogen’’

test gas of CO2 analyzer, (8) changing 

accuracy to ‘‘± 1 percent’’ for test gas of 

CO analyzer, and (9) revising accuracy 

to ‘‘± 1 percent’’ for test gas of NOX

analyzer. 

Manufacturers are already voluntarily 

complying with ICAO’s 1997 

amendments to the criteria on 

calibration and test gases for the test 

procedures of gaseous emissions. Thus, 

formal adoption of these ICAO test 

procedure amendments will require no 

new action by manufacturers. In 

addition, the existence of ICAO’s 

requirements will ensure that the costs 

of compliance (as well as the air quality 

impact) with these test procedures will 

be minimal. (In the 1982 and 1997 final 

rules on aircraft engine emissions (47 

FR 58462, December 30, 1982 and 62 FR 

25356, May 8, 1997, respectively), EPA 

incorporated by reference the thenexisting ICAO testing and measurement 

procedures for aircraft engine emissions 

(ICAO International Standards and 

Recommended Practices Environmental 

Protection, Annex 16, Volume II, 

‘‘Aircraft Engine Emissions,’’ First and 

Second Editions, Appendices 3 and 5 

were incorporated by reference in 40 

CFR 87.64) in order to eliminate 

confusion over minor differences in 

procedures for demonstrating 

compliance with the U.S. and ICAO 

standards.) 

V. Correction of Exemptions for Very 

Low Production Models 

Because of an editorial error, the 

section in the aircraft engine emission 

regulations regarding exemptions for 

very low production models is 

incorrectly specified (see section 40 CFR 

87.7(b)(1) and (2)). In the October 18, 

1984 final rulemaking (49 FR 41000), 

EPA intended to amend the low 

production engine provisions of the 

aircraft regulations by revising 

paragraph (b) and deleting paragraphs 

(b)(1) and (b)(2) in order to eliminate the 

maximum annual production limit of 20 

engines per year. In the revisions to 

paragraph (b), EPA retained the 

maximum total production limit of 200 

units for aircraft models certified after 

January 1, 1984.102 For § 87.7(b), today, 

EPA will correct this editorial error by 

eliminating paragraph (b)(1) and (b)(2). 

As discussed further in the 1984 final 

rulemaking, this action will provide 

more flexibility for engine 

manufacturers in scheduling during the 

last few engine production years. Also, 

the air quality impact of eliminating the 

annual production limit will be very 

small. 

VI. Coordination With FAA 

The requirements contained in this 

action are being promulgated after 

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 

under section 231.103 As in past 

rulemakings and pursuant to the above 

referenced sections of the CAA, EPA has 

coordinated with the FAA of the DOT 

with respect to today’s action. 

Moreover, FAA is the official U.S. 

delegate to ICAO. FAA agreed to the 

1997 and 1999 amendments at ICAO’s 

Third and Fourth Meetings of the 

Committee on Aviation Environmental 

Protection (CAEP/3 and CAEP/4) after 

advisement from EPA.104 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/3 and CAEP/4. After assessing 

emissions test procedure amendments 

and new NOX standards, Working 

Group 3 made recommendations to 

CAEP on these elements. These 

recommendations were then considered 

at the CAEP/3 and CAEP/4 meetings, 

respectively, prior to their adoption by 

ICAO in 1997 and 1999. 

In addition, as discussed above, FAA 

will have the responsibility to enforce 

today’s requirements. As a part of its 

compliance responsibilities, FAA 

conducts the emission tests or delegates 

that responsibility to the engine 

manufacturer, which is then monitored 

by the FAA. Since the FAA does not 

have the resources or the funding to test 

engines, FAA selects engineers at each 

plant to serve as representatives (called 

designated engineering representatives 

(DERs)) for the FAA while the 

manufacturer performs the test 

procedures. DERs’ responsibilities 

include evaluating the test plan, the test 

engine, the test equipment, and the final 

testing report sent to FAA. DERs’

responsibilities are determined by the 

FAA and today’s rulemaking will not 

affect their duties. 

VII. Possible Future Aviation Emission 

Reductions (EPA/FAA Voluntary 

Aviation Emissions Reduction 

Initiative) 

As discussed in the proposal, there is 

growing interest, particularly at the state 

and local level, in addressing emissions 

from aircraft and other aviation-related 

sources. Such interest is often related to 

plans for airport expansion which is 

occurring across the country. It is 

possible that other approaches may 

provide effective avenues to achieve 

additional aviation emission reductions, 

beyond EPA establishing aircraft engine 

emission standards. 

Concerns by state and local air 

agencies and environmental and public 

health organizations about aviation 

emissions, led to EPA and FAA signing 

a memorandum of understanding 

(MOU) in March 1998 agreeing to work 

to identify efforts that could reduce 

aviation emissions.105 FAA and EPA 

participated in a national stakeholder 

initiative led by states and industry 

whose goal was to develop a voluntary 

program to reduce pollutants from 

aircraft and other aviation sources that 

Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 69683 

106Two engine models were indeed certificated 

with emissions retrofit kits, and a number of these 

engines have been purchased for aircraft with the 

retrofit kits installed in their stock configuration. 

However, retrofit kits have not to date provided 

widescale emissions improvements because it 

seems they may have limited applicability to 

certain engine types, small emission benefits, and 

cost issues. 

107The stakeholders considered the impact, 

operation and design of GSE at airports, and 

whether to undertake projects at several airports to 

reduce overall emissions. 

108Operational strategies, such as reducing the 

time in which aircraft are in idle and taxi modes 

and the impact of auxiliary power units (APUs) 

were also considered. 

109The Vision 100-Century of Aviation 

Reauthorization Act, signed into law on December 

12, 2003 (Pub. L. 108–176), directs the FAA to 

establish a national program to reduce airport 

ground emissions at commercial service airports 

located in air quality nonattainment and 

maintenance areas. The new Voluntary Airport Low 

Emissions (VALE) program will allow airport 

sponsors to use the Airport Improvement Program 

(AIP) and Passenger Facility Charges (PFCs) to 

finance low-emission vehicles, refueling and 

recharging stations, gate electrification, and other 

airport air quality improvements. See the FAA 

website located at http://www.faa.gov/arp/ 

environmental/vale. 

110CAEP’s Forecasting and Economic Analysis 

Support Group (FESG) concluded at CAEP/4 that 

their assessment of these new NOX standards 

indicates that the direct costs of the standards 

would be minimal, and the benefits would be 

modest. (ICAO, CAEP/4, Working Paper 4, 

‘‘Economic Assessment of the EPG NOX Stringency 

Proposal,’’ March 12, 1998, Presented by the 

Chairman of FESG, Agenda Item 1: Review of 

proposals relating to NOX emissions, including the 

amendment of Annex 16, Volume II. A copy of this 

paper can be found in Docket OAR–2002–0030. 

contribute to local and regional air 

pollution in the United States. The 

major stakeholders that participated in 

this initiative included representatives 

of the aviation industry (passenger and 

cargo airlines and engine 

manufacturers), airports, state and local 

air pollution control officials, 

environmental organizations, and 

NASA. 

Initially, the discussions with 

stakeholders focused on the prospect of 

aircraft engine emission reduction 

retrofit kits, which might be applied to 

certain existing aircraft engines.106

However, as the initiative evolved, the 

focus was expanded by the stakeholders 

to identify strategies for various types of 

ground service equipment (GSE) in use 

at airports,107 in addition to strategies to 

reduce aircraft emissions.108 (At the 

same time, FAA developed a program, 

with Congressional approval, to fund 

conversion of airport infrastructure and 

ground support vehicles to alternative 

fuels technologies.109) Unfortunately, 

the state and industry stakeholders did 

not reach consensus on a national 

aviation emissions reduction program. 

The Agencies are currently 

contemplating next steps following from 

the national stakeholder initiative and 

discussions of potential voluntary 

programs. 

In addition, in the proposal EPA 

invited comment on the national 

stakeholder initiative and any other 

approaches for aviation emission 

reductions, and we received many 

suggestions from commenters. We may 

consider these suggested approaches 

during our current reflection on the 

stakeholder initiative and for future 

voluntary programs. 

Finally, FAA has two other initiatives 

that will assist in addressing concerns 

with respect to emissions from aircraft. 

First, in September 2003 it created a 

Center of Excellence—Partnership for 

Reduction of Air Transportation Noise 

and Emissions Reduction (PARTNER)—

a consortium of 8 universities, 29 

industry representatives as well as 

NASA and Transport Canada-to develop 

new approaches and solutions to reduce 

aviation’s environmental impacts. 

Second, with the assistance of the 

National Academy of Sciences, FAA is 

developing the next generation of 

aviation noise and emissions models 

and analytical tools improve 

measurement, understanding, and 

targeted solutions. See the Summary 

and Analysis of Comments for further 

discussion of approaches to additional 

aviation emission reductions. 

VIII. Regulatory Impacts 

Aircraft engines are international 

commodities, and thus, they are 

designed to meet international 

standards. Today’s action will have the 

benefit of establishing consistency 

between U.S. and international emission 

standards and test procedures. Thus, an 

emission certification test which meets 

U.S. requirements will also be 

applicable to all ICAO requirements. 

Engine manufacturers are already 

developing improved technology in 

response to the ICAO standards that 

match standards promulgated here, and 

EPA does not believe that the costs 

incurred by the aircraft industry as a 

result of the existing ICAO standards 

should be attributed to today’s 

regulations. Also, the test procedure 

amendments (revisions to criteria on 

calibration and test gases) necessary to 

determine compliance are already being 

adhered to by manufacturers during 

current engine certification tests. 

Therefore, EPA believes that today’s 

regulations will impose no additional 

burden on manufacturers. 

The existence of ICAO’s requirements 

results in minimal cost as well as air 

quality benefits from today’s 

requirements.110 Since aircraft and 

aircraft engines are international 

commodities, there is commercial 

benefit to consistency between U.S. and 

international emission standards and 

control program requirements. Also, the 

adoption of the ICAO standards and 

related test procedures is consistent 

with our treaty obligations. 

IX. Public Participation 

A number of interested parties 

participated in the rulemaking process 

that culminates with this final rule. This 

process provided opportunity for 

submitting written public comments 

following the proposal that we 

published on September 30, 2003 (68 FR 

56226). We considered these comments 

in developing the final rule. In addition, 

we held a public hearing on the 

proposed rulemaking on November 13, 

2003, and we have considered 

comments presented at the hearing. 

We have prepared a detailed 

Summary and Analysis of Comments 

document, which describes comments 

we received on the proposal and our 

response to each of these comments. 

The Summary and Analysis of 

Comments is available in the e-docket 

for this rule, as well as on the Office of 

Transportation and Air Quality 

homepage (http://www.epa.gov/otaq/ 

aviation.htm). In addition, comments 

and responses for key issues are 

included throughout this preamble. 

X. Statutory Provisions and Legal 

Authority 

The statutory authority for today’s 

proposal is provided by sections 231 

and 301(a) of the Clean Air Act, as 

amended, 42 U.S.C. 7571 and 7601(a). 

See section II of today’s rule for 

discussion of how EPA meets the CAA’s 

statutory requirements. 

XI. Statutory and Executive Order 

Reviews 

A. Executive Order 12866: Regulatory 

Planning and Review 

Under Executive Order 12866 (58 FR 

51735, October 4, 1993), the Agency 

must determine whether this regulatory 

action is ‘‘significant’’ and therefore 

subject to Office of Management and 

Budget (OMB) review and the 

requirements of the Executive Order. 

The Order defines ‘‘significant 

regulatory action’’ as one that is likely 

to result in a rule that may: 

(1) Have an annual effect on the 

economy of $100 million or more or 

adversely affect in a material way the 

economy, a sector of the economy, 

productivity, competition, jobs, the 

environment, public health or safety, or 

State, local, or tribal governments or 

communities; 

69684 Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 

(2) Create a serious inconsistency or 

otherwise interfere with an action taken 

or planned by another agency; 

(3) Materially alter the budgetary 

impact of entitlements, grants, user fees, 

or loan programs or the rights and 

obligations of recipients thereof; or 

(4) Raise novel legal or policy issues 

arising out of legal mandates, the 

President’s priorities, or the principles 

set forth in the Executive Order. 

Pursuant to the terms of Executive 

Order 12866, OMB has notified EPA 

that it considers this a ‘‘significant 

regulatory action’’ within the meaning 

of the Executive Order. EPA has 

submitted this action to OMB for 

review. Changes made in response to 

OMB suggestions or recommendations 

will be documented in the public 

record. 

B. Paperwork Reduction Act 

This action does not impose an 

information collection burden under the 

provisions of the Paperwork Reduction 

Act, 44 U.S.C. 3501 et seq. Any 

reporting and recordkeeping 

requirements associated with these 

standards would be defined by the 

Secretary of Transportation in 

enforcement regulations issued later 

under the provisions of section 232 of 

the Clean Air Act. Since most if not all 

manufacturers already measure NOX

and report the results to the FAA, any 

additional reporting and record keeping 

requirements associated with FAA 

enforcement of today’s regulations 

would likely be very small. 

Burden means the total time, effort, or 

financial resources expended by persons 

to generate, maintain, retain, or disclose 

or provide information to or for a 

Federal agency. This includes the time 

needed to review instructions; develop, 

acquire, install, and utilize technology 

and systems for the purposes of 

collecting, validating, and verifying 

information, processing and 

maintaining information, and disclosing 

and providing information; adjust the 

existing ways to comply with any 

previously applicable instructions and 

requirements; train personnel to be able 

to respond to a collection of 

information; search data sources; 

complete and review the collection of 

information; and transmit or otherwise 

disclose the information. 

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. 

C. Regulatory Flexibility Analysis 

EPA has determined that it is not 

necessary to prepare a regulatory 

flexibility analysis in connection with 

this final rule. 

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; or (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 XI–C–1 provides an overview of 

the primary SBA small business 

categories potentially affected by this 

regulation. 

TABLE XI–C–1.—PRIMARY SBA SMALL BUSINESS CATEGORIES POTENTIALLY AFFECTED BY THIS REGULATION

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, 

EPA has concluded that this action will 

not have a significant economic impact 

on a substantial number of small 

entities. This rule will not impose any 

requirements on small entities. Our 

review of the list of manufacturers of 

commercial aircraft gas turbine engines 

with rated thrust greater than 26.7 kN 

and manufacturers of aircraft with such 

engines indicates that there are no U.S. 

manufacturers that qualify as small 

businesses. We are unaware of any 

foreign manufacturers with a U.S.-based 

facility that will qualify as a small 

business. 

As discussed earlier, today’s action 

will codify emission standards that 

manufacturers currently adhere to 

(nearly all in-production engines 

already meet the standards). These 

standards are equivalent to the ICAO 

international consensus standards. 

Today’s emission standards will not 

impose any additional burden on 

manufacturers because they are already 

designing engines to meet the ICAO 

standards. Also, the test procedure 

amendments (revisions to criteria on 

calibration and test gases) necessary to 

determine compliance are already being 

adhered to by manufacturers during 

current engine certification tests. 

D. Unfunded Mandates Reform Act 

Title II of the Unfunded Mandates 

Reform Act of 1995 (UMRA), Public 

Law 104–4, establishes requirements for 

Federal agencies to assess the effects of 

their regulatory actions on State, local, 

and tribal governments and the private 

sector. Under section 202 of the UMRA, 

EPA generally must prepare a written 

statement, including a cost-benefit 

analysis, for proposed and final rules 

with ‘‘Federal mandates’’ that may 

result in expenditures to State, local, 

and tribal governments, in the aggregate, 

or to the private sector, of $100 million 

or more in any one year. Before 

promulgating an EPA rule for which a 

written statement is needed, section 205 

of the UMRA generally requires EPA to 

identify and consider a reasonable 

number of regulatory alternatives and 

adopt the least costly, most costeffective or least burdensome alternative 

that achieves the objectives of the rule. 

The provisions of section 205 do not 

apply when they are inconsistent with 

applicable law. Moreover, section 205 

allows EPA to adopt an alternative other 

than the least costly, most cost-effective 

or least burdensome alternative if the 

Administrator publishes with the final 

rule an explanation why that alternative 

was not adopted. Before EPA establishes 

any regulatory requirements that may 

significantly or uniquely affect small 

governments, including tribal 

governments, it must have developed 

under section 203 of the UMRA a small 

government agency plan. The plan must 

provide for notifying potentially 

affected small governments, enabling 

officials of affected small governments 

to have meaningful and timely input in 

the development of EPA regulatory 

Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 69685 

proposals with significant Federal 

intergovernmental mandates, and 

informing, educating, and advising 

small governments on compliance with 

the regulatory requirements. 

EPA has determined that this rule 

does not contain a Federal mandate that 

may result in expenditure of $100 

million or more for State, local, or tribal 

governments, in the aggregate or the 

private sector in any one year. This rule 

contains no regulatory requirements that 

might significantly or uniquely affect 

small governments. Today’s action will 

codify emission standards that 

manufacturers currently adhere to 

(nearly all in-production engines 

already meet the standards). These 

standards are equivalent to the ICAO 

international consensus standards. 

Today’s emission standards will not 

impose any additional burden on 

manufacturers because they are already 

designing new engines to meet the ICAO 

standards. Thus, the annual effect on 

the economy of today’s standards will 

be minimal. Today’s rule is not subject 

to the requirements of sections 202 and 

205 of the UMRA. 

E. Executive Order 13132: Federalism 

Executive Order 13132, entitled 

‘‘Federalism’’ (64 FR 43255, August 10, 

1999), requires EPA to develop an 

accountable process to ensure 

‘‘meaningful and timely input by State 

and local officials in the development of 

regulatory policies that have federalism 

implications.’’ ‘‘Policies that have 

federalism implications’’ is defined in 

the Executive Order to include 

regulations that 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.’’

Today’s rule 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 merely modifies existing EPA 

aircraft engine emission standards and 

test procedures and therefore will 

merely continue an existing preemption 

of State and local law. Thus, Executive 

Order 13132 does not apply to this rule. 

In the spirit of Executive Order 13132, 

and consistent with EPA policy to 

promote communications between EPA 

and State and local governments, EPA 

specifically solicited comment on the 

proposed rule from State and local 

officials. 

F. Executive Order 13175: Consultation 

and Coordination With Indian Tribal 

Governments 

Executive Order 13175, entitled 

‘‘Consultation and Coordination with 

Indian Tribal Governments’’ (65 FR 

67249, November 6, 2000), requires EPA 

to develop an accountable process to 

ensure ‘‘meaningful and timely input by 

tribal officials in the development of 

regulatory policies that have tribal 

implications.’’

This rule does not have tribal 

implications, as specified in Executive 

Order 13175. The promulgated emission 

standards and other related 

requirements for private industry in this 

rule have national applicability and 

therefore do not uniquely affect the 

communities of Indian Tribal 

Governments. 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 final 

rule merely modifies existing EPA 

aircraft engine emission standards and 

test procedures and therefore will 

merely continue an existing preemption 

of State and local law. In addition, 

today’s rule will be implemented at the 

Federal level and impose compliance 

obligations only on engine 

manufacturers. Thus, Executive Order 

13175 does not apply to this rule. 

G. Executive Order 13045: Protection of 

Children From Environmental Health & 

Safety Risks 

Executive Order 13045, ‘‘Protection of 

Children from Environmental Health 

Risks and Safety Risks’’ (62 FR 19885, 

April 23, 1997) applies to any rule that 

(1) is determined to be ‘‘economically 

significant’’ as defined under Executive 

Order 12866, and (2) concerns an 

environmental health or safety risk that 

EPA has reason to believe may have a 

disproportionate effect on children. If 

the regulatory action meets both criteria, 

Section 5–501 of the Order directs the 

Agency to evaluate the environmental 

health or safety effects of the planned 

rule on children, and explain why the 

planned regulation is preferable to other 

potentially effective and reasonably 

feasible alternatives considered by the 

Agency. 

This rule is not subject to Executive 

Order 13045 because the Agency does 

not have reason to believe the 

environmental health risks or safety 

risks addressed by this action present a 

disproportionate risk to children. EPA 

believes that the NOX emission 

reductions (NOX is a precursor to the 

formation of ozone and PM) from this 

rulemaking will further improve air 

quality and will further improve 

children’s health. 

H. Executive Order 13211: Actions That 

Significantly Affect Energy Supply, 

Distribution, or Use 

This rule is not a ‘‘significant energy 

action’’ as defined in Executive Order 

13211, ‘‘Actions Concerning Regulations 

That Significantly Affect Energy Supply, 

Distribution, or Use’’ (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. 

As discussed earlier, today’s action will 

codify emission standards that 

manufacturers currently adhere to 

(nearly all in-production engines 

already meet the standards). These 

standards are equivalent to the ICAO 

international consensus standards. The 

final standards will have no likely 

adverse energy effects because 

manufacturers are already designing 

engines to meet the ICAO standards. 

Also, the test procedure amendments 

(revisions to criteria on calibration and 

test gases) necessary to determine 

compliance are already being adhered to 

by manufacturers during current engine 

certification tests. Thus, we have 

concluded that this rule is not likely to 

have any adverse energy effects. 

I. National Technology Transfer 

Advancement Act 

Section 12(d) of the National 

Technology Transfer and Advancement 

Act of 1995 (‘‘NTTAA’’), Public Law 

104–113, section 12(d) (15 U.S.C. 272 

note) directs EPA to use voluntary 

consensus standards in its regulatory 

activities unless to do so would be 

inconsistent with applicable law or 

otherwise impractical. Voluntary 

consensus standards are technical 

standards (e.g., materials specifications, 

test methods, sampling procedures, and 

business practices) that are developed or 

adopted by voluntary consensus 

standards bodies. NTTAA directs EPA 

to provide Congress, through OMB, 

explanations when the Agency decides 

not to use available and applicable 

voluntary consensus standards. 

This final rulemaking involves 

technical standards for testing emissions 

for commercial aircraft gas turbine 

engines. EPA will use test procedures 

contained in ICAO International 

Standards and Recommended Practices 

Environmental Protection, with the 

modifications contained in this 

69686 Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 

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 (http://www.icao.int). 

rulemaking.111 These procedures are 

currently used by all manufacturers of 

commercial aircraft gas turbine engines 

(with thrust greater than 26.7 kN) to 

demonstrate compliance with ICAO 

emissions standards. 

J. 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 December 19, 2005. 

List of Subjects in 40 CFR Part 87 

Environmental protection, Air 

pollution control, Aircraft, 

Incorporation by reference. 

Dated: November 9, 2005. 

Stephen L. Johnson, 

Administrator. 

■ For the reasons set out in the 

preamble, title 40, chapter I of the Code 

of Federal Regulations is amended as 

follows: 

PART 87—CONTROL OF AIR 

POLLUTION FROM AIRCRAFT AND 

AIRCRAFT ENGINES 

■ 1. The authority citation for part 87 

continues to read as follows: 

Authority: Secs. 231, 301(a), Clean Air Act, 

as amended (42 U.S.C 7571, 7601(a)). 

Subpart A—[Amended] 

■ 2. Section 87.7 is amended by 

removing paragraphs (b)(1) and (b)(2). 

■ 3. A new § 87.8 is added to read as 

follows: 

§ 87.8 Incorporation by reference. 

We have incorporated by reference 

the documents listed in this section. 

The Director of the Federal Register 

approved the incorporation by reference 

as prescribed in 5 U.S.C. 552(a) and 1 

CFR part 51. Anyone may inspect copies 

at the U.S. EPA, Air and Radiation 

Docket and Information Center, 1301 

Constitution Ave., NW., Room B102, 

EPA West Building, Washington, DC 

20460 or 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. 

(a) ICAO material. Table 1 of § 87.8 

lists material from the International 

Civil Aviation Organization that we 

have incorporated by reference. The first 

column lists the number and name of 

the material. The second column lists 

the sections of this part where we 

reference it. Anyone may purchase 

copies of these materials from the 

International Civil Aviation 

Organization, Document Sales Unit, 999 

University Street, Montreal, Quebec, 

Canada H3C 5H7. Table 1 follows: 

TABLE 1 OF § 87.8.—ICAO MATERIALS

Document number and name Part 87 reference 

International Civil Aviation Organization Annex 16, Environmental Protection, Volume II, Aircraft Engine 

Emissions, Second Edition, July 1993, Including Amendment 3 of March 20, 1997 (as indicated in 

footnoted pages.).

87.8, 87.64, 87.71, 87.82, 87.89. 

(b) [Reserved] 

Subpart C—[Amended] 

■ 4. Section 87.21 is amended by adding 

paragraphs (d)(1)(vi) and (d)(1)(vii) to 

read as follows: 

§ 87.21 Standards for exhaust emissions. 

* * * * * 

(d) * * * 

(1) * * * 

(vi) Engines of a type or model of 

which the date of manufacture of the 

first individual production model was 

after December 31, 2003: 

(A) Engines with a rated pressure ratio 

of 30 or less: 

(1) Engines with a maximum rated 

output greater than 89 kilonewtons: 

Oxides of Nitrogen: (19 + 1.6(rPR)) 

grams/kilonewtons rO. 

(2) Engines with a maximum rated 

output greater than 26.7 kilonewtons 

but not greater than 89 kilonewtons: 

Oxides of Nitrogen: (37.572 + 1.6(rPR) 

¥ 0.2087(rO)) grams/kilonewtons rO. 

(B) Engines with a rated pressure ratio 

greater than 30 but less than 62.5: 

(1) Engines with a maximum rated 

output greater than 89 kilonewtons: 

Oxides of Nitrogen: (7 + 2(rPR)) 

grams/kilonewtons rO. 

(2) Engines with a maximum rated 

output greater than 26.7 kilonewtons 

but not greater than 89 kilonewtons: 

Oxides of Nitrogen: (42.71 + 

1.4286(rPR) ¥ 0.4013(rO) + 0.00642(rPR 

× rO)) grams/kilonewtons rO. 

(C) Engines with a rated pressure ratio 

of 62.5 or more: 

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

grams/kilonewtons rO. 

(vii) The emission standards 

prescribed in paragraph (d)(1)(vi) of this 

section shall apply as prescribed 

beginning December 19, 2005. 

* * * * * 

Subpart G—[Amended] 

■ 5. Section 87.64 is revised to read as 

follows: 

§ 87.64 Sampling and analytical 

procedures for measuring gaseous exhaust 

emissions. 

The system and procedures for 

sampling and measurement of gaseous 

emissions shall be as specified by 

Appendices 3 and 5 to ICAO Annex 16 

(incorporated by reference in § 87.8). 

■ 6. Section 87.71 is revised to read as 

follows: 

§ 87.71 Compliance with gaseous 

emission standards. 

Compliance with each gaseous 

emission standard by an aircraft engine 

shall be determined by comparing the 

pollutant level in grams/kilonewton/ 

thrust/cycle or grams/kilowatt/cycle as 

calculated in § 87.64 with the applicable 

emission standard under this part. An 

acceptable alternative to testing every 

Federal Register / Vol. 70, No. 221 / Thursday, November 17, 2005 / Rules and Regulations 69687 

engine is described in Appendix 6 to 

ICAO Annex 16 (incorporated by 

reference in § 87.8). Other methods of 

demonstrating compliance may be 

approved by the Secretary with the 

concurrence of the Administrator. 

Subpart H—[Amended] 

■ 7. Section 87.82 is revised to read as 

follows: 

§ 87.82 Sampling and analytical 

procedures for measuring smoke exhaust 

emissions. 

The system and procedures for 

sampling and measurement of smoke 

emissions shall be as specified by 

Appendix 2 to ICAO Annex 16 

(incorporated by reference in § 87.8). 

■ 8. Section 87.89 is revised to read as 

follows: 

§ 87.89 Compliance with smoke emission 

standards. 

Compliance with each smoke 

emission standard shall be determined 

by comparing the plot of SN as a 

function of power setting with the 

applicable emission standard under this 

part. The SN at every power setting 

must be such that there is a high degree 

of confidence that the standard will not 

be exceeded by any engine of the model 

being tested. An acceptable alternative 

to testing every engine is described in 

Appendix 6 to ICAO Annex 16 

(incorporated by reference in § 87.8). 

[FR Doc. 05–22704 Filed 11–16–05; 8:45 am] 

BILLING CODE 6560–50–U 

DEPARTMENT OF THE INTERIOR 

Bureau of Land Management 

43 CFR Part 1820 

[WO 630–1610–EI–25–2Z] 

RIN 1004–AD77 

Application Procedures, Execution and 

Filing of Forms: Correction of State 

Office Address for Filings and 

Recordings, Proper Offices for 

Recording of Mining Claims 

AGENCY: Bureau of Land Management, 

Interior. 

ACTION: Final rule. 

SUMMARY: This final rule amends the 

regulations pertaining to execution and 

filing of forms in order to reflect the 

new address of the Arizona State Office 

of the Bureau of Land Management 

(BLM), which moved on October 5, 

2005. All filings and other documents 

relating to public lands in Arizona must 

be filed at the new address of the State 

Office. 

EFFECTIVE DATE: November 17, 2005. 

FOR FURTHER INFORMATION CONTACT: 

Diane Williams, Regulatory Affairs 

Group, (202) 452–5030. Persons who 

use a telecommunications device for the 

deaf (TDD) may call the Federal 

Information Relay Service (FIRS) at 1–

800–877–8339, 24 hours a day, 7 days 

a week. 

ADDRESSES: You may send inquiries or 

suggestions to Director (630), Bureau of 

Land Management, Eastern States 

Office, 7450 Boston Boulevard, 

Springfield, Virginia 22153; Attention: 

RIN 1004–AD77. 

SUPPLEMENTARY INFORMATION: 

I. Background 

II. Procedural Matters 

I. Background 

This final rule reflects the 

administrative action of changing the 

address of the Arizona State Office of 

the BLM. It changes the street address 

for the personal filing of documents 

relating to public lands in Arizona, but 

makes no other changes in filing 

requirements. The BLM has determined 

that it has no substantive impact on the 

public, imposes no costs, and merely 

updates a list of addresses included in 

the Code of Federal Regulations for the 

convenience of the public. The 

Department of the Interior, therefore, for 

good cause finds under 5 U.S.C. 553 

(b)(B) and 553 (d)(3) that notice and 

public comment procedures are 

unnecessary and that the rule may take 

effect upon publication. 

II. Procedural Matters 

Regulatory Planning and Review 

(Executive Order 12866) 

This final rule is an administrative 

action to change the address for one 

BLM State Office. This rule was not 

subject to review by the Office of 

Management and Budget under 

Executive Order 12866. It imposes no 

costs, and merely updates a list of 

addresses included in the Code of 

Federal Regulations for the convenience 

of the public. 

National Environmental Policy Act 

This final rule is a purely 

administrative regulatory action having 

no effect upon the public or the 

environment, it has been determined 

that the rule is categorically excluded 

from review under section 102(2)(C) of 

the National Environmental Policy Act 

of 1969 (42 U.S.C. 4332(2)(C)). 

Regulatory Flexibility Act 

Congress enacted the Regulatory 

Flexibility Act of 1980 (5 U.S.C. 601, et 

seq.) to ensure that Government 

regulations do not unnecessarily or 

disproportionately burden small 

entities. This final rule is a purely 

administrative regulatory action having 

no effects upon the public or the 

environment, it has been determined 

that the rule will not have a significant 

effect on the economy or small entities. 

Small Business Regulatory Enforcement 

Fairness Act 

This final rule is a purely 

administrative regulatory action having 

no effects upon the public or the 

economy. This is not a major rule under 

Small Business Regulatory Enforcement 

Fairness Act (5 U.S.C. 804(2)). It should 

not have an annual effect on the 

economy of $100 million or more. The 

rule will not cause a major increase in 

costs of prices for consumers, individual 

industries, Federal, State, or local 

government agencies, or geographic 

regions. It will not have significant 

adverse effects on competition, 

employment, investment, productivity, 

innovation, or the ability of United 

States-based enterprises to compete 

with foreign-based enterprises. 

Unfunded Mandate Reform Act of Act 

The BLM has determined that the 

final rule is not significant under the 

Unfunded Mandates Reform Act of 1995 

because it will not result in the 

expenditure by State, local, and tribal 

governments, in the aggregates, or by the 

private sector, of $100 million or more 

in any one year. 

Further, the final rule will not 

significantly or uniquely affect small 

governments. It does not require action 

by any non-federal government entity. 

Therefore, the information required by 

the Unfunded Mandates Reform Act (2 

U.S.C. 1531 et. seq.), is not required. 

Executive Order 12630, Government 

Action and Interference With 

Constitutionally Protected Property 

Rights (Takings) 

As required by Executive Order 

12630, the Department of the Interior 

has determined that the rule would not 

cause a taking of private property. No 

private property rights would be 

affected by a rule that merely reports an 

address change for the Arizona State 

Office. The Department therefore 

certifies that this final rule does not 

represent a governmental action capable 

of interference with constitutionally 

protected property rights.