Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 1 of 207 **ENVIRONMENTAL PROTECTION AGENCY 40 CFR Parts 87 and 1068**  **[EPA -**  **HQ -**  **OAR -**  **2010 -**  **0687; FRL -**  **XXXX -**  **X] RIN 2060**  **- AO70**  **Control of Air Pollution From Aircraft and Aircraft Engines; Emission Standards and Test Procedures**  **AGENCY** : Environmental Protection Agency (EPA). **ACTION** : Final rule. **SUMMARY** : EPA is adopting several new aircraft engine emission standards for oxides of nitrogen (NOx) , compliance flexibilities, and other regulatory requirements for aircraft turbofan or turbojet engines with rated thrusts greater than 26.7 kilonewtons (kN). We also are adopting certain other requirements for gas turbine engines that are subject to exhaust emission standards as follows . First, we are clarifying when the emission characteristics of a new turbofan or turbojet engine mod el have become different enough from its existing parent engine design that it must conform to the most current emission standards. Second, we are establishing a new reporting requirement for manufacturers of gas turbine engines that are subject to an y ex haust emission standard to provide us with timely and consistent emission - related information. Third,Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 2 of 207 and finally , we are establishing amendments to aircraft engine test and emissions measurement procedures. EPA actively participated in the United Nation ’s International Civil Aviation Organization (I CAO) proceedings in which most of these requirements were first developed. These regulatory

requirements have largely been adopted or are actively under consideration by its member states. By

adopting such s imilar standards, therefore, the United States maintains consistency

with these international efforts. EXECUTIVE SUMMARY: A. Purpose of the Regulatory Action The primary

purpose of this rule is to adopt new oxides of nitrogen (NOx) emission standards fo r aircraft engines with rated thrusts greater than 26.7 kN thrust. These are mostly commercial passenger and freighter aircraft in common use at airports across the U.S. It does not include engines used on military aircraft. NOx is strongl y correlated wi th NO 2 , for which EPA has established National Ambient Air Quality Standards, i.e., a criteria pollutant, and it is an important precursor gas in the formation of tropospheric ozone and secondary particulate matter which are common air pollutants in urban areas where airports are located. This rule also contains several provisions to facilitate the implementation of EPA’s aircraft engine emission regulations and related requirements. It is also important to note that adoption of the provisions in this rul e meets U.S. treaty obligations under the Chicago Convention of 1944 by aligning our regulations with those in the International Civil Aviation Organization Annex 16 , Volume IIDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 3 of 207 (adopted in 2010) that the U.S. helped to develop and support as part of the international process. This rule is being implemented under the authority provided in section 231 of the Clean Air Act (42 USC 7571). B. Summary

of Major Provisions of the Regulatory Action The rule contains six major provisions. The first two provisi ons are new NOx emission standards for newl y certified engine models. The first standards, Tier 6, take effect when this rule becomes effective. These represent approximately a 12 percent reduction from current Tier 4 levels. They

were actually

adopted by ICAO in 200 5 with an implementation date in 2008 . The second, Tier 8, takes effect in 2014. These represent approximately a 15 percent reduction from Tier 6 levels. B oth tiers of emission standards are needed to address local air quality concerns and, as noted above, to meet U.S. treat y obligations under the Chicago Convention. The third major provision is a production cut - off for newl y manufactured engines which basicall y requires that after December 31, 20 12 all newly manufactured engines must meet at least Tier 6 NOx emission standards. This is also consistent with our obligations under the Chicago Convention. The production cut - off is needed to ensure that the emission reductions envisioned by the emission standards are achieved on new production e ngines. The fourth major provision is related to potential exemptions or exceptions to the production cut - off requirement. These include revised provisions allowing manufacturers to request that FAA in consultation with EPA grant exemptions from the production cut - off for a designated number of engines within aDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 4 of 207 prescribed time frame. Th ese also include a low - volume, time - limited exception provision that will exclude several engines from the production cutoff. Both of these provisions help to assure an orderl y transition to the new standards for engines needing more time to comply or fo r a few engines at the end of their production life. Finally, the rule includes a set of provisions which may be considered as minor if viewed separatel y, but collectively are important in upgrading EPA’s regulations b y incorporating some related agreements from our ICAO process and clarifying and improving existing provisions. Examples of this include special provisions for spare engines, provisions related to derivative engine models, test procedure specifications and reporting requirements. These chan ges are important for an effective implementation of the new requirements . C. Costs and Benefits This is not an economically significant regulatory

action. Aircraft engines are international commodities used on aircraft manufactured and sold around the wo rld. When developing new engine models manufacturers not only consider current emission requirements but also try

to anticipate the stringency of future standards and respond appropriatel y. Engine manufacturers participated in the deliberations leading up to ICAO decisions on the aircraft engine NOx emission standards and after the IC AO decisions they incorporated engine technology

changes as needed to meet the new ICAO requirements. This helps to ensure the world wide acceptabilit y of their products. Ess entially all of these changes are now complete.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 5 of 207 Thus, while there is some cost to a manufacturer for responding to the new ICAO provisions, there is no significant further direct cost to the manufacturers created b y EPA’s adopting the requirements into U. S regulations. In fact, it is likely that our adopting these requirements facilitates the acceptance of U.S. ty pe certificates by

aircraft manufacturers and airlines around the world. Since the majority of engine models slated for future production met the new emission standards when adopted b y ICAO the emission gains are modest. EPA projects that landing and takeoff cycle NOx emissions will be reduced by about 100,000 tons between 2014 and 2030. **DATES:** These final rules are effective on [insert date 3 0 day s after publication in the Federal Register.] The incorporation b y reference of certain publications listed in this regulation is approved b y the Director of the Federal Register as of [insert date 3 0 day s after publication in the Federal Register.] **ADDRESSES:** EPA has established a docket for this action under Docket ID No. EPA HQ - OAR - 2010 - 0687 **.** All documents in the docket are listed on the http://www.regulations.gov Web site. Although listed in the index, s ome information is not publicly available, e.g., confidential business information or other information whose disclosure is restricted by statute. Certain other material, such as cop yri ghted material, is not placed on the Internet and will be publicly ava ilable only

in hard copy

form. Publicly

available docket materials are available electronically

through http://www.regulations.gov or in hard cop y at the EPA Docket Center,Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 6 of 207 EPA/DC, EPA West, Room 3334, 1301 Constitution Ave., NW, Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holiday s. The telephone number for the Public Reading Room is (202) 566 - 1744, and the telephone number for the Air Docket is 202 - 566 - 1742 . **FOR FURTHER INFORMATION CONTACT** : Richard Wilcox , Office of Transportation and Air Quality , Office of Air and Radiation, Environmental Protection Agency , 2000 Traverwood Drive, Ann Arbor, MI 481 05 ; telephone number: (734) 214 - 4 390 ; fax number: (734) 214 - 4816; email address: wilcox.rich@epa.gov. SUPPL EMENTARY INFORMATION: Does This Action Apply

to Me? Entities potentially

regulated by

this action are those that manufacture and sell aircraft engines and aircraft in the United States. Regulated categories include: Category NAI CS a Codes SI C b Codes Examples of potentially affected entities Industry .......... 336412 3724 Manufacturers of new aircraft engines Industry .......... 336411 3721 Manufacturers of new aircraft

a North American Industry Classification System (NAICS) b Standard Industrial Classification (SIC) system code This table lists the ty

pes of entities that EPA is now aware could potentially be regulated by this action. Other ty

pes 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 theDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 7 of 207 applicability

criteria in 40 CFR 87. 1 (part 87). If y ou have any questions regarding the applicability

of this action to a particular entity , consult the person listed in the preceding **FO R**  **FURTHER INFORMATION CONTACT** section. Table of Contents I. Overview and Background A. Contents of the Final Rule B . EPA’s Responsibilities Under the Clean Air Act C . Interaction with the International Community D. Brief History

of EPA’s Regulation of Aircraft Engine Emissions E . Brief History

of ICAO Regulation of Aircraft Engine Emissions II. Why is EPA Taking this Action? A. Inventory

Contribution B. Health, Environmental and Air Quality Impacts 1. Background on Ozone, PM and NOx a. What is Ozone?Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 8 of 207 b. What is Particulate Matter? c. What is NOx? 2. Health Effects Associated with Exposure to Ozone, PM and NOx a. What are the Health Effects of Ozone? b. What are the Health Effects of PM? c. What are the Health Effects of NOx? 3. Environmental Effects Associated with Exposure to Ozon e, PM and NOx a. Deposition of Nitrogen b. Visibility

Effects c. Plant and Ecos ys tem Effects of Ozone 4 . Impacts on Ambient Air Quality III. Details of the Final Rule A. NOx Standards for Newly - Certified EnginesDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 9 of 207 1. Tier 6 NOx Standards for Newl y - Certified Engines a. Numerical Emission Limits for Higher Thrust Engines b. Numerical Emission Limits for Lower Thrust Engines 2 . Tier 8 NOx Standards for Newl y - Certified Engines

a. Numerical Emission Limits for Higher Thrus t Engines b. Numerical Emission Limits for Lower Thrust Engines B . Application of NOx Standards for Newl y - Manufactured Engines 1. Phase - In of the Tier 6 NOx Standards for Newly Manufactured Engines 2. Carry over of Previously Generated Emission Data 3. Exemptions and Exceptions from the Tier 6 Production Cutoff

a . New Provisions for Spare Engines b . New Provisions for Engines Installed in New Aircraft i. Time - Frame and Scope ii. Production L imitDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 10 of 207 iii. Exemption Re quests iv. Coordination of Exemption Requests

v. Lo w - V olume , T ime - L imited T ransitional E x c eption program c. Voluntary Emission Offsets 4 . Potential Phase - Inof New Tier 8 NOx Standards for Newl y Manufactured Engines C. Application of Standards for Derivative Engines for Emission Certification Purposes D. Annual Reporting Requirement E. Standards for Supersonic Aircraft Turbine Engines F . Amendments to Test and Measurement Procedures G. Possible Future Revisions to Emis sion Standards for New Technology Turbine Engines and Supersonic Aircraft Turbine Engines IV . Description of Other Revisions to the Regulatory Text A. Applicability

I ssuesDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 11 of 207 1. Military

Engines 2. Noncommercial Engines B. Non - Substantive Revisions C. Clarifying Language for Regulatory Text V. Technical Feasibility , Costs , and Emission Benefits V I. Consultation with FAA V I I. Public Participation VIII. Statutory

Provisions and Legal Authorit y IX . Statutory

and Executive Orders Re view A. Executive Order 12866: Regulatory Planning and Review B. Paperwork Reduction Act C. Regulatory

Flexibility

Analy sis D. Unfunded Mandates Reform Act E. Executive Order 13132: FederalismDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 12 of 207 F. Executive Order 13175: Consultation and Coordi nation with Indian Tribal Governments G. Executive Order 13045: Protection of Children from Environmental Health & Safet y Risks H. Executive Order 13211: Actions that Significantly Affect Energy Supply , Distribution, or Use I. National Technology

Transfer Advancement Act J. Executive Order 12898: Federal Actions to Address Environmental Justice in Minority Populations and L ow Income Populations K. Congressional Review Act I. Overview and Background This section summarizes the major provisions of the final rule for aircraft gas turbine engines . It also contains background on the EPA’s standard setting authority and responsibilities under the Clean Air Act, the connection between our emission standards and those of the internati onal community , and a brief regulatory history for this source of emissions.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 13 of 207 A. Contents of the Final Rule We are adopting several new emission standards and other regulatory requirements for aircraft turbofan and turbojet engines 1 with rated thrusts greater than 26.7 kilonewtons (kN). First, we are establishing two new tiers of more stringent emission standards for oxides of nitrogen (NO x ) . T he standards appl y differentl y to two classes of these engines, i.e., “newl y certified engines” and “newly - manufactured engines.” The newl y - certified engine standards apply to aircraft engines that have received a new ty pe certificate and have never been manufactured prior to the effective date o f the new emission standards. Requirements for n ewly manu factured engines apply to aircraft engines that were previously certified and manufactured in compliance with preexisting standards, and they require manufacturers to either compl y with the newer standards b y a specified future date or cease production of the affected engine models . Newl y - manufactured engine standards are also sometimes referred to as “production cutoff ” standards. Second, we are adopting certain time - limited flexibilities, i.e., the potential for exemptions or exceptions as defined in th e regulations for newl y - manufactured engines that may not be able to compl y with the first tier of the NOx standards because of specific technical or economic reasons.

1 Turbofan and turbojet engines will be collectively referred to as turbofan engines hereafter for convenience.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 14 of 207 We are also making a number of additional changes that would apply to a wider range of aircraft gas turbine engines 2 than those that would be subject to the new emission standards. 3 First, we are defining the meaning of a derivative engine for emissions certification purposes. The intent of this definition is to distinguish when the emiss ion characteristics of a new turbofan engine model vary

sufficiently

from its existing parent engine design, and must show compliance with the emission standard for a newly - certificated engine. Second, we are establishing new reporting requirements for manufacturers that produce gas turbine engines subject to any exhaust emission standard. This will provide us with timely and consistent emission data and other information that is necessary to conduct emission inventory and air quality anal ys es and develop appropriate public policy for the aviation sector. Specificall y, reports are required for turbofan engines with rated thrusts greater than 26.7 kN, which are subject to gaseous emission and smoke standards, in addition to turbofans less than or equal to 26.7 kN, and all turboprop engines, that are only

subject to smoke standards. Third, we are adopting minor amendments to the test and measurement procedures for aircraft engines . Finally , as described in section IV, we are making minor amendments to regu lator provisions addressing definitions, acron ym s and abbreviations, general applicability and requirements, exemptions, and incorporation b y reference.

2 The term gas turbine engine includes turbofan, turbojet, and turboprop engines designs. The rated output for turbofan and turbojet engines is normally expressed as kilonewtons (kN) thrust. The rated output for turboprop engines is normally expressed as shaft horsepow er (hp) or shaft kilowatt (kW).

3 This includes turbofan and turbojet engines less than 26.7 kN thrust and all turboprop engines that are subject to any emission standard, e.g., smoke.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 15 of 207 Most of these new regulatory requirements have already been adopted by the United Nation ’ s Internatio nal Civil Aviation Organization (I CAO) . The requirements contained in this final rule bring the United States into al ignment with the international standards and recommended practices . B. EPA’s Authority and Responsibilities under the Clean Air Act Section 231 (a)(2)(A) of the Clean Air Act (CAA) directs the Administrator of EPA to , from time to time, propose aircraft engine emission standards applicable to the emission of any air pollutant from classes of aircraft engines which in her judgment causes or contributes to air pollution that may

reasonably

be anticipated to endanger public health or welfare. (See 42 U.S.C . § 7571(a)(2)(A).) Section 231(a)(2)(B) directs EPA to consult with the Administrator of the Federal Aviation Administration (FAA) on such standards, and prohibits EPA from changing aircraft emission standards if such a change would significantl y increase noise and adversel y affect safety . 42 U.S.C. § 7571(a)( 2)(B ) (i) - (ii) . Section 231(a)(3) provides that after we propose standards, the Administrator shall issue such standards “with such modifications as he deems appropriat e.” 42 U.S.C. § 7571(a)(3). The U.S. Court of App eals for the D.C. Circuit has held that this provision confers an unusually broad degree of discretion on EPA to adopt aircraft engine emission standards as the Agency determines are reasonable. NACAA v. EPA , 489 F.3d 1221 (D.C. Cir. 2007).Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 16 of 207 In addition, under CAA section 231(b) EPA is required to ensure, in consultation with the U.S. Department of Transportation (DOT), that the effective date of an y standard provide s the necessary time to permit the development and application of the requisite technology , gi ving appropriate consideration to the cost of compl iance. 42 U.S.C . § 7571(b). Section 232 then directs the FAA to prescribe regulations to ensure compliance with EPA’s standards. 42 U.S.C. § 7572. Finally , section 233 of the CAA vests the authority to promulgate e mission standards for aircraft or aircraft engines only in EPA. States are preempted from adopting or enforcing an y standard respecting aircraft engine emissions unless such standard is identical to EPA’s standards. 42 U.S.C. § 7573. Sec tion VI of today 's final rule further discusses our coordination with DOT through the FAA . 4 It also describes DOT’s responsibility under the CAA to enforce the aircraft emission standards established b y EP A. C. Interaction w ith the International Community We began regulating the air pollution emissions from aircraft engines in 1973 . Since that time, we have worked with the FAA and later with the International Civil Aviation Organization (I CAO) to develop international standards and other recommended practi ces pertaining to aircr aft engine emissions. IC AO 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 or derl y manner and that international

4 The functions of the Secretary of Transportation unde r 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).Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 17 of 207 air transport services may be established on the basis of equality of opportunity

and operated soundly and economically .” 5 IC AO’s responsibilities include developing aircraft technical and operating standards, recommend ing practices, and generall y fostering the growth of international civil aviation. The United States is currentl y one of 19 1 participating member States of ICAO. 6 , 7 In the interests of global harmonization and international air commerce, the Chicago Convention urges a high degree of uniformit y by its member States. Nonetheless , the Convention also recognizes that member States may adopt their own unique airworthiness standards and that some may adopt standards that are more stringent than those agree d upon by ICAO. The Convention has a number of other features that govern international commerce. First, States that wish to use aircraft in international transportation must adopt emission standards and other recommended practices that are at least as stringent as ICAO ’s standards . States may ban the use of an y aircraft within their airspace that does not meet I CAO standards. 8 Second,

5 International Civil Aviation Organization (ICAO), “Convention on International Civil Aviation,” Ninth Editio n, Document 7300/9, 2006. Copies of this document can be obtained from the ICAO w ebsite located at www.icao.int .

6 Mem bers of ICAO’s Assembly are generally termed member States or contracting States. These terms are used interchangeably throughout this preamble.

7 There are currently 191 Contracting States according to ICAO w ebsite located at www.icao.int . 8 ICAO, “Convention on International Civil Aviation,” Article 87, Ninth Edition, Document 7300/9, 2006. Copies of this document can be obtained from the ICAO website located at www.icao.int/icaonet/arch/doc/7300/7300_9ed.pdf .Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 18 of 207 States are required to recognize the airworthiness certificates of an y State whose standards are at least as stringent as ICAO ’s standards , thereby assuring that aircraft of an y member State will be pe rmitted to operate in any other member State. 9 Third, and finall y, t o ensure that international commerce is not unreasonably constraine d , a participating nation which elec ts to adopt more stringent standards is obligated to notify I CAO of the differences between its standards and ICAO standards. 10 However, if a nation sets tighter standards than IC AO, air carriers not based in that nation would only be required to comply with I CAO standards or more stringent standards imposed b y their own nations, if applicable . ICAO ’s Committee on Aviation Environmental Protection (CAEP) undertakes I CAO’s technical work in the environmental field. The C ommittee is responsible for evaluating, researching, and recommending measures to the ICAO Council that address the environmental impact of international civil aviation. CAEP is composed of various task groups, work groups, and other committees whose contributing members include atmospheric, economic, aviation, environmental, and other professionals interested in aviation and environmental protection . At CAEP meetings, the United States is represented by the FAA, which play s an active role at these meetings. EPA has historically been a principal participant in the development of U.S. policy in

9 ICAO, “Convention on International Civil Aviation,” Article 33, Ninth Edition, Document 7300/9, 2 006. Copies of this document can be obtained from the ICAO website located at www.icao.int/icaonet/arch/doc/7300/7300_9ed.pdf . 10 ICAO, “Convention on International Civil Aviation,” Articles 38, Ninth Edition, Document 7300/9, 2006. Copies of this document can be obtained from the ICAO website located at www.icao.int/icaonet/arch/doc/7300/7300_9ed.pdf .Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 19 of 207 various IC AO/CAEP working groups and other international venues, assisting and adv ising FAA on aviation emissions, technology , and policy matters. If ICAO adopts a CAEP pr oposal for a new environmental standard, it then becomes part of I CAO standards and recommended practices (Annex 16 to the Chicago Convention). 11 D. Brief History of EPA’s Regulation of Aircraft Engine Emissions As mentioned above, we initially regulated gase ous exhaust emissions, smoke, and fuel venting from aircraft engines in 1973. 12 Since that time, we have occasionally revised those regulations. Two of these revisions are most pertinent to today ’s final rule . First, in a 1997 rulemaking, we made our emi ssion standards and test procedures more consistent with those of ICAO for turbofan engines used in commercial aviation with rated thrusts greater than 26.7kN. 13 These ICAO requirements are generall y referred to as CAEP/2 standards. (The numbering nomen clature for CAEP requirements is discussed in the next section.) That action included new NO x emission standards for newl y - manufactured commercial turbofan engines (those engines

11 ICAO, “Aircraft Engine Emissions,” International Standards and Recommended Practices, Environmental Protection, Annex 16, Volume II, Second Edition, July 2 008 . A c op y of this document is in docket number EPA - HQ - OAR - 2010 - 0687.

12 U.S. EPA, **“** Emission Standards and Test Procedures for Aircraft; ” Final Rule, 38 FR 19088 , July 17, 1973 . 13 U.S. EPA, “Control of Air Pollution from Aircraft and Aircraft Engines; Emission Standards and Test Procedures;” Final Rule, 62 FR 25356, May 8, 1997 . While ICAO’s standards w ere not limited to “commercial” aircraft engines, our 1997 standards w ere explicitly limited to commercial engines, as our finding that NOx and CO emissions from aircraft engines cause or contribute to air pollution which may reasonably be anticipated to endanger public health or w elfare was so limited, See 62 FR 25358. As explained lat er in today’s notice, w e are expand ing the scope of that finding and of our standards to include such emissions from both commercial and non - commercial aircraft engines, in order to bring our standards into full alignment with ICAO’s.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 20 of 207 built after the effective date of the regulations that were already certifie d to pre - existing standards) 14 and for newl y - certified commercial turbofan engines (those engine models that received their initial ty

pe certificate after the effective date of the regulations). It also included a CO emission standard for newl y - manufactur ed commercial turbofan engines. Second, in our most recent rulemaking in 2005, we promulgated more stringent NO x emission stand ards for newly - certi fied commercial turbofan engines . 15 That final rule brought the U.S. standards closer to alignment with ICAO CAEP/4 requirements that were effective in 2004 . In ruling on a petition for judicial review of the 2005 rule filed by the National Association of Clean Air Agencies (NACAA), the U.S. Court of Appeals held that EPA’s approach of tracking the ICAO standar ds was reasonable and permissible under the CAA. NACAA v. EPA , 489 F.3d 1221, 1230 - 32 (D.C. Cir. 2007). E. Brief History of ICAO Regulation of Aircraft Engine Emissions The first international standards and recommended practices for aircraft engine emissions was recommended b y C AEP’s predecessor, the Committee on Aircraft Engine Emissions (CAEE), and adopted b y ICAO in 1981 . 16 These standards limited aircraft engine emissions of

14 This does not mean that in 2005 w e promulgated requirements for the re - certification or retrofit of existing in - use engines.

15 U.S. EPA, “Control of Air Pollution from Aircraft and Aircraft Engines; Emission Standards and Test Procedures;” Final Rule, 70 FR 2521, November 1 7, 2005.

16 ICAO, Forew ord of “Aircraft Engine Emissions,” International Standards and Recommended Practices, Environmental Protection, Annex 16, Volume II, Third Edition, July 2008. Copies of this document can be obtained from the ICAO website at www.icao.int .Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 21 of 207 HC, CO, and NO x . In 1994, I CAO adopted a CAEP /2 propos al to tighten the original NO x standard b y 20 percent and amend the test procedures. 17 At the next CAEP meeting (CAEP/3) in 1995, the Committee recommended a further tightening of 16 percent and additional test procedure amendments, but in 1997 the I CAO Co uncil rejected this stringency proposal and approved onl y the test procedure amendments. At the CAEP/4 meeting in 1998, the Committee adopted a similar 16 percent NO x reduction proposal, which ICAO approved on 1998. The CAEP/4 standard s applied only to n ew engine designs certified after December 31, 2003 (i.e., the requirements did not also apply to previously certified, newl y - manufactured engines unlike the CAEP/2 standards). In 2004, CAEP/6 recommend ed a 12 percent NOx reduction , which I CAO approved in 200 5 . 18 , 19 The CAEP/6 standard s applied to new engine designs ( newly - certified models ) certified after December 31, 2007. At the most recent meeting, CAEP/8 recommended a further tightening of the NOx standards b y 15 percent for newl y - certified engines. 20 , 21 The

17 CAEP conducts its w ork over a period of years. Each work cy cle is numbered sequentially and that identifier is used to differentiate the results from one CAEP to another by convention. The first technical meeting on aircraft emission standards was CAEP’s successor, i.e., CAEE. The first meeting of CAEP, therefore, is referred to as CAEP/2.

18 CAEP/5 did not address new aircraft engine emission standards. 19 ICAO, “Aircraft Engine Emissions,” Annex 16, Volume II, Third Edition, July 2008, Amendment 4 effective on July 20, 2008. Copies of this document can be obtained from the ICAO website at www.icao.int .

20 CAEP/7 did not add

ress new aircraft engine emission standards. 21 ICAO, “Committee on Aviation Environmental Protection (CAEP), Report of the Eighth Meeting, Montreal, February 1 - 12 , 2010,” CAEP/8 - WP/80. A copy of this document is in docket number EPA - HQ - OAR 2010 - 0687.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 22 of 207 Committee also recommended that the CAEP/6 standards be applied to newly - manufactured engines. ICAO approved these recommendations in 2011. 22 II. Why I s EPA Taking This Action? As mentioned above, section 231(a)(2)(A) of the CAA authorizes the EPA Administrator to “from time to time, issue proposed emission standards applicable to the emission of any air pollution from any

class or classes of aircraft or aircraft engines which in his judgment causes, or contributes to air pollution which may reasona bl y 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 NO x , a precursor to the formation of tropospheric ozone and secondary PM . 23 M ost commercial airports ar e located in urban areas and man y of these areas have ambient pollutant levels above the National Ambient Air Quality

Standards (NAAQS) for ozone and fine particulate matter (PM 2.5 ) (i.e., they are in nonattainment for ozone and PM 2.5 ) . This section dis cusses the contribution of aircraft engines used in commercial service with rated thrusts greater than 26.7kN to the national NO x emissions inventory and to NO x emission inventories in selected ozone nonattainment areas, the potential

22 22 ICAO, “Aircraft Engine Emissions,” Annex 16, Volume II, Third Edition, July 2008, Amendment 7 effective on July 18, 2011. Copies of this document can be obtained from the ICAO website at www.icao.int .

23 Ground - level ozone, the m ain ingredient in smog, is formed by complex chemical reactions of volatile organic compounds (VOC) and NO x in the presence of heat and sunlight. Standards that reduce NO x emissions will help address ambient ozone levels. They can also help reduce particulate matter (PM) levels as NO x emissions can also be part of the secondary formation of PM. See Section II.B below .Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 23 of 207 effect of NO x emissio ns in the upper atmosphere on ground level PM 2.5 in addition to the health and welfare impacts of NO x and PM emissions . A. Inventory

Contribution In contrast to all other mobile sources, whose emissions occur completel y at ground level, the emissions from aircraft and aircraft engines can be divided into two flight regimes. The first regime includes the emissions that are released in the lower lay er of the atmosphere and directly affect local and regional ambient air quality . These emiss ions generall y occur at or below 3,000 feet above ground level , i.e., during the landing and takeoff (LTO) cy cle. The aircraft operations that comprise an LTO cycle are: engine idle at the terminal gate (and sometimes during ground delay s while holding fo r the active runway); taxiing between the terminal and the runway ; take - off; climb - out; and approach to the airport. The second regime includes emissions that occur above 3,000 feet above ground level, known as non - LTO emissions . Collectively , the emissi ons associated with all ground and flight operations are generall y referred to as full flight emissions. In this section, we will discuss NO X emission inventories for commercial turbine - engine aircraft, both nationally

and for selected ozone nonattainment areas (NAAs). These inventories reflect emissions during the land ing and t akeoff cycle only . The most recent comprehensive anal ys is of hist orical and current LTO emissions from aircraft engines comes from a studyDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 24 of 207 undertaken for us b y Eastern Research Group (ERG). 24 The study analyzed the national emissions of commercial aircraft operations in the United States, and showed that in the most re cent ye ar studied (2008), such aircraft LTO operations contributed about 97 thousand tons to the national NO X inventory . A summary of the national inventory of LTO NO X emissions is shown in Table 1 . When these nationwide LTO emissions are compared to th e total U.S. mobile source inventory for 2009, they

account for less than one percent of the total. However, such a comparison may

be a bit misleading, as it onl y includes those aircraft emissions that occur below 3,000 feet altitude, while comparing them to the entirety of other mobile source emissions. In the U.S., L TO emissions account for only about ten percent of full flight NO X emissions. When considering full flight aircraft emissions (i.e., including both LTO and non - LT O emissions), the contribut ion of aircraft to the total mobile source NO X inventory is approximately

7.7 percent. 25 It is also worth noting that these LTO emissions are more localized in that they occur near airports, which are mostly within urban areas. Table 1 : Current National NO X Emissions from Commercial Aircraft Aircraft Category 2008 Total NO X (thousand tons)

24 “Historical Assessment of Aircraft Landing and Take - of f Emissions (1986 - 2008),” Eastern Research Group, May 2011. A copy of this document can be found in public docket EPA - HQ - OAR - 2010 - 0687.

25 U.S. EPA, “Comparison of Aircraft LTO and Full Flight NO X Emissions to Total Mobile Source NO X Emissions,” memorandum from John Mueller, Assessment and Standards Division, Office of Transport ation and Air Quality, to docket EPA - HQ - OAR - 2010 - 0687, May 10, 2011.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 25 of 207 Air Carrier 86 Commuter/Air Taxi 11 **Total Commercial**  **97** In addition, it is important to assess the contribution of commercial aircraft LTO NO X emissions on a local level, especiall y in areas containing or adjacent to airports. Th e historical anal ys is conducted b y ERG also included an assessment of selected ozone nonattainment areas (NAAs). The NAAs selected for study were chosen as follows. First, the 25 ozone NAAs with airports which had high commercial traffic volumes were identified. Second, the 25 ozone NAAs with the largest population were identified. These lists were combined. How ever, there was some overlap, and this led to a total of 4 0 NAAs being identified for the study . 26 These NAAs collectivel y include 200 airports, accounting for about 70 percent of commercial air traffic operations . Current (2008) and projected (2020) NO X emissions for these 4 0 NAAs , as well as the percent contribution of aircraft to total mobile source inventories (as compared to 2005 and 2020 mobile source inventories), are shown in Table 2 . 27 , 28 The relative contribution of aircraft

26 Although 41 NAAs were studied, the non - aircraft emissions data source that the aircraft emissions were compared to for this analysis did not distinguish between the Boston NAA in Massac husetts and the greater Boston NAA in New Hampshire. Thus, aircraft emissions from those tw o NAAs were combined into a single NAA for the purpose of this analysis, yielding 40 NAAs for study.

27 U.S. EPA, “Relative Contribution of Aircraft to Total Mobi le Source NO X Emissions in Selected Ozone Nonattainment Areas,” memorandum from John Mueller, Assessment and Standards Division, Office of Transportation and Air Quality, to docket EPA - HQ - OAR - 2010 - 0687, May 10, 2011.

28 U.S. EPA, “Addendum to “Relative Contribution of Aircraft to Total Mobile Source NO X Emissions in Selected Ozone Nonattainment Areas,”” memorandum from John Mueller, Assessment and Standards Division, Office of Transportation and Air Quality, to docket EPA - HQ - OAR - 2010 - 0687, May 17, 2011.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 26 of 207 in any given NAA var ie s based on activit y in other transportation and industrial sectors. As can be seen from this table, expected growth in aircraft operations in many of these areas combined with anticipated reductions in NO X emissions from other mobile source categories re sults in the growth of the relative contribution of aircraft LTO emissions to mobile source NO X emissions in NAAs.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 27 of 207 Table 2 : Current NO X Emissions in Selected Ozone Nonattainment Areas

Nonattainment Area 2008 Total NO X (tons) 2008 Aircraft Percent of Mobile Source NO X 2020 Aircraft Percent of Mobile Source NO X Albuquerque, NM 380 1.6 4.3 Anchorage, AK 2,538 23. 4 49.3 Aspen 16 2.0 6.6 Atlanta, GA 5,808 2.6 8.2 Baltimore, MD 1,148 1.3 4. 4 Boston - including MA and NH NAAs 2, 0 3 2 1.0 2. 7 Charlotte - Gastonia - Rock Hill, NC - SC 1,917 2.6 10.0 Chicago - Gary - Lake County, IL - IN 6,007 1.8 5.0 Cincinnati - Hamilton, OH - KY IN 1,287 1.5 3.3 Cleveland - Akron - Lorain, OH 680 0. 5 1. 3 Dallas - Fort Worth, TX 3,880 1.7 6.9 Denver - Boulder - Greeley - Fort Collins - Loveland, CO 2,649 2.5 7.1 Detroit - Ann Arbor, MI 2,312 1.1 3.0 El Paso, TX 223 0.9 1.1 Gr eater Connecticut, CT 405 0.8 2.4 Houston - Galveston - Brazoria, TX 3,045 1.3 3. 4 Indianapolis, I

N 1,089 1.4 3.0 La s Vegas, NV 2,308 6.0 15.8 Los Angeles South Coast Air Basin, CA 6,479 1. 5 4. 5 Louisville, KY - IN 1,211 1.9 6.2 Memphis, TN - AR 2,988 6.3 16.8 Milwaukee - Racine, WI 557 0.9 3.2 Minneapolis - St Paul, MN 2,154 1.0 5.1 New York - N. New Jersey Long Island, NY - NJ - CT 10,093 2.3 6. 3 Philadelphia - Wilmington Atlantic City, PA - NY - MD - DE 2,308 1.0 2.8 Phoenix - Mesa, AZ 2,298 1.4 3.3 Pittsburgh - Beaver Valley, PA 480 0.5 1.1 Providence (entire State), RI 232 1.0 2. 3 Raleigh - Durham - Chapel Hill, NC 565 1.0 3.2 Reno, NV 246 1.9 4.4 Riverside County (Coachella Valley), CA 70 0.2 0.5 Sacramento Metro, CA 603 1.0 2.0 Salt Lake City, UT 1,235 4.4 14.1 San Diego, CA 1,035 1.4 3. 4 San Francisco Bay Area, CA 4,405 2. 7 6.7 San Joaquin Valley, CA 74 0.0 0.1 Seattle - Tacoma, WA 1,958 1. 4 3.9 St. L ouis, MO - IL 810 0.6 1.6 Syracuse, NY 139 0.8 1.9 Washington, DC - MD - VA 2,983 2.0 6. 2Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 28 of 207 Table 3 shows how commercial aircraft operations are projected to rise in the future on a nationwide basis . As operations increase, the inventory impact of these aircraft on national and local NO X inventories will also increase. Table 3 : Current and Projected Commercial Aircraft Operations Year Air Carrier

Operations (millions) Commuter/

Air Taxi Operations (millions) Total

Commercial Operations (millions) Total increase in

commercial operations over 2008 (percent) 2008 14.1 13.8 27.9 -- 2020 16.5 14.1 30.5 9 2030 20.6 16.0 36.6 31

Source: December 2010 FAA TAF, which is located at http://aspm.faa.gov/main/taf.asp . B. Heal th, Environmental and Air Quality Impacts NO x emissions from aircraft and other mobile and stationary sources contribute to the formation of ozone. In addition, NO x emissions at low altitude also react in the atmosphere to form secondary

fine particulate matter (PM 2.5 ), particularly ammonium nitrate. In the following sections we discuss the adverse health and welfare effects associated with NO x emissions, in additio n to the current and projected levels of ozone and PM across the country . The ICAO NO x standards with which we are align ing will help reduce ambient ozone and secondary PM levelsDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 29 of 207 and thus will help areas with airports achieve or maintain attainment with the National Ambient Air Quality

Standards (NAAQS). 29 1. Background on Ozone, PM and NO X a. What is Ozone? Ground - level ozone pollution is ty pically formed through reaction s involving VOC and NO X in the lower atmosphere in the presence of sunlight. These po llutants, often referred to as ozone precursors, are emitted by man y t ypes of pollution sources, such as highway and nonroad motor vehicles and engines, power plants, chemical plants, refineries, makers of consumer and commercial products, industrial facil ities, and smaller area sources. The science of ozone formation, transport, and accumulation is complex. 30 Ground - level ozone is produced and destroy ed in a cyclical set of chemical reactions, many of which are sensitive to temperature and sunlight. When ambient temperatures and sunlight levels remain

29 The discussion of PM health and w elfare effects throughout this notice relates exclusively to the effects of the NOx emission standards on the formation of secondary PM from nitrate formation in the atmosphere. Presently, there are no emission standards f or PM emitted directly from aircraft turbine engines. The current and planned future w ork programs for CAEP/ICAO are developing PM test procedures and information to characterize the amount and type of these emissions from aircraft engines that are in pro duction. Ultimately, this information will be used to assess the need for an aircraft turbine engine PM standard (i.e., whether PM emissions from aircraft cause or contribute to air pollution which may reasonably be anticipated to endanger public health o r welfare), with standard setting as appropriate.

**30** U.S. EPA Air Quality Criteria for Ozone and Related Photochemical Oxidants (Final). U.S. Environmental Protection Agency, Washington, D.C., EPA 600/R - 05/004aF - cF, 2006. This document is available in D ocket EPA - HQ - OAR - 2010 - 0687. This document may be accessed electronically at: http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_cr_cd.html.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 30 of 207 high for several day s and the air is relativel y stagnant, ozone and its precursors can build up and result in more ozone than ty picall y occurs on a single high - temperature day. Ozone and its precursors can b e transported hundreds of miles downwind from precursor emissions , resulting in elevated ozone levels even in areas with low local VOC or NO X emissions. b . W hat is Particulate Matter? The discussion includes PM 2.5 because the NO X emitted by aircraft engines can react in the atmosphere to form nitrate, a component of PM 2.5 . Particulate matter is a generic term for a broad class of chemically and phy sically diverse substances. It can be principally characterized as discrete particl es that exist in the condensed (liquid or solid) phase spanning several orders of magnitude in size. Since 1987, EPA has delineated that subset of inhalable particles small enough to penetrate to the thoracic region (including the tracheobronchial and alv eolar regions) of the respiratory

tract (referred to as thoracic particles). The c urrent PM NAAQS use s PM 2.5 as the indicator for fine particles (with PM 2.5 generally referring to particles with a nominal mean aerod ynamic diameter less than or equal to 2. 5 micrometers (μm)), and use PM 10 as the indicator for purposes of regulating the coarse fraction of PM 10 (referred to as thoracic coarse particles or coarse - fraction particles; generall y including particles with a nominal mean aerod ynamic diameter greater than 2.5 μm and less than or equal to 10 μm, or PM 10 - 2.5 ). Ultrafine particles are a subset of fine particles, generall y less than 100 nanometers (0.1 μm) in diameter.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 31 of 207 Fine particles are produced primaril y b y combustion processes and b y transformations of gaseous emissions (e.g., SO X , NO X and VOC) in the atmosphere. The chemical and phy sical properties of PM 2.5 may

vary greatly with time, region, meteorology , and source category . Thus, PM 2.5 may

include a complex mixture of different components includ ing sulfates, nitrates, organic compounds, elemental carbon and metal compounds. These particles can remain in the atmosphere for day s to weeks and travel hundreds to thousands of kilometers.

c . What is NO

X? Nitrogen dioxide (NO 2 ) is a member of the N O X family of gases. Most NO 2 is formed in the air from the oxidation of nitric oxide (NO) emitted when fuel is burned at a high temperature. NO 2 and its gas phase oxidation products can dissolve in water droplets and further oxidize to form nitric acid which reacts with ammonia to form nitrates, an important component of ambient PM. NO X and VOC are the two major precursors of ozone. The health effects of ozone, ambient PM and NO X are covered in section II.B.2. 2. Health Effects Associated with Exposure to Ozone, PM and NO X a. W hat are the Health Effects of Ozone?Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 32 of 207 The health and welfare effects of ozone are well documented and are assessed in EPA’s 2006 Air Quality

Criteria Document and 2007 Staff Paper. 31 , 32 People who are more susceptible to effects associated with exposure to ozone can include children, the elderl y, and individuals with respiratory

disease such as asthma. Those with greater exposures to ozone, for instance due to time spent outdoors (e.g., children and outdoor workers), are of particular concern. Ozone can irritate the respiratory

s ystem, causing coughing, throat irritation, and breathing discomfort. Ozone can reduce lung function and cause pulmonary inflammation in healthy

individuals. Ozone can also aggravate asthma, leading to more asthma attacks that require medical attention and/or the use of additional medication. Thus, ambient ozone may cause both healthy

and asthmatic individuals to limit their outdoor activities. In addition, there is suggestive evidence of a contribution of ozone to cardiovascular - related morbidity and highly

suggestive evidence that short - term ozone exposure directl y or indirectly contributes to non - accidental and cardiopulmonary - related mortality , but additional research is needed to clarify the underl yi ng mechanisms causing these effects. In a report on the estimation of ozone - related premature mortality published by

the National Research Council (NRC), a panel of experts and reviewers concluded that short - term exposure to ambient ozone is likely to contribute to premature deaths **31** U.S. EPA Air Quality Criteria for Ozone and Related Photochemical Oxidants (Final). U.S. Environmental Protection Agency, Washington, D.C., EPA 600/R - 05/004aF - cF, 2006. This document is available in Docket EPA - HQ - OAR - 2010 - 0687. This document may be accessed electronically at: http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_cr_cd.html.

32 U.S. EPA (2007) Review of the National Ambient Air Quality Standards for Ozone, Policy Assessment of Scientific and Technical Information. OAQPS Staff Paper.EPA - 452/R - 07 - 003. This document is available in Docket EPA - HQ - OAR - 2010 - 0687. This document is available electronically at: http:www.epa.gov/ttn/naaqs/standards/ozone/s_o3_cr_sp.html.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 33 of 207 and that ozone - related mortality should be included in estimates of the health benefits of reducing ozone exposure. 33 Animal toxicological evidence indicates that with repeated exposure, ozone can inflame and damag e the lining of the lungs, which may lead to permanent changes in lung tissue and irreversible reductions in lung function. The respiratory effects observed in controlled human exposure studies and animal studies are coherent with the evidence from epidem iologic studies supporting a causal relationship between acute ambient ozone exposures and increased respiratory - related emergency room visits and hospitalizations in the warm season. In addition, there is suggestive evidence of a contribution of ozone to cardiovascular - related morbidity and non - accidental and cardiopulmonary mortality . b. W hat are the Health Effects of PM? Scientific studies show ambient PM is associated with a series of adverse health effects. These health effects are discussed in det ail in EPA’s Integrated Science Assessment for Particulate Matter (I SA) . 34 The I SA summarizes health effects evidence associated with both short - term and long - term exposures to PM 2.5 , PM 10 - 2.5 , and ultrafine particles. The I SA concludes that health effects associated with short - term exposures (hours to day s) to ambient PM 2.5 include mortality, cardiovascular effects, such as altered vasomotor

33 National Research Council (NRC), 2008. Estimating Mortality Risk Reduction and Economic Benefits from Controlling Ozone Air Pollution . The National Academies Press: Washington, D.C. A copy of this document is in docket number EPA - HQ - OAR - 2010 - 0687. **34** U.S. EPA (2009) Integrated Science Assessment for Particulate Matter, EPA 600/R - 08/139F. A copy of this document is in docket number EPA - HQ - OAR - 2010 - 0687.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 34 of 207 function and my ocardial ischemia, and hospital admissions and emergency department visits for ischemic heart disease and congestive heart failure, and respiratory effects, such as exacerbation of asthma s ymptoms in children and hospital admissions and emergency department visits for chronic obstructive pulmonary disease and respiratory

infections . 35 The ISA notes that l ong term exposure (months to y ears) to PM 2.5 is associated with the development/progression of cardiovascular disease, premature mortality , and respiratory effects, including reduced lung function growth in children, increased respiratory sy mptoms, and asthma development. 36 The ISA concludes that the currentl y available scientific evidence from epidemiologic, controlled human exposure, and toxicological studies supports a causal association between short - and long - term exposures to PM 2.5 and cardiovascular effects and premature mortality . Furthermore, the I SA concludes that the collective evidence supports likely causal associations between short and long - term PM 2.5 exposures and respiratory effects. The ISA also concludes that the scientific evidence is suggestive of a causal association for reproductive and developmental effects including respiratory - related infant mortality and cancer, mutagenicit y, and genotoxicity and long - term exposure to PM 2. 5 . 37 For PM 10 - 2.5 , the I SA concludes that the current evid ence is suggestive of a causal relationship between short - term exposures and premature mortalit y, cardiovascular effects, and

35 U.S. EPA (2009). Integrated Science As sessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R - 08/139F, 2009. Section 2.3.1.1. 36 U.S. EPA (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Prote ction Agency, Washington, DC, EPA/600/R - 08/139F, 2009. page 2 - 12, Sections 7.3.1.1 and 7.3.2.1. 37 U.S. EPA (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R - 08/139F, 2009. Section 2.3.2.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 35 of 207 respiratory

effects. Data are inadequate to draw conclusions regarding the health effects associated with long - term exposure to P M 10 - 2.5 . For ultrafine particles, the I SA concludes that there is suggestive evidence of a causal relationship between short - term exposures and cardiovascular effects, such as changes in heart rhy thm and blood vessel function. It also concludes that ther e is suggestive evidence of association between short - term exposure to ultrafine particles and respiratory effects. Data are inadequate to draw conclusions regarding the health effects associated with long - term exposure to ultrafine particles. c. What are the Health Effects of NO X? In formation on the health effects of NO 2 can be found in the EPA Integrated Science Assessment (I SA) for Nitrogen Oxides. 38 The EPA has concluded that the findings of epidemiologic, controlled human exposure, and animal toxicological studies provide evidence that is sufficient to infer a likely causal relationship between respiratory effects and short - term NO 2 exposure. The I SA concludes that the strongest evidence for such a relationship comes from epidemiologic studies of respiratory effects including s ymptoms, emergency department visits, and hospital admissions. The I SA also draws two broad conclusions regarding airway re sponsiveness following NO 2 exposure. First, the I SA concludes that NO 2 exposure may

38 U.S. EPA (2008). Integrated Science Assessment for Oxides of Nitrogen

– Health Criteria (Final Report). EPA/600/R - 08/071. Washington, DC: U.S.EPA. A copy of this document is in docket number EPA - HQ - OAR - 2010 - 0687.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 36 of 207 enhance the sensitivity

to allergen - induced decrements in lung function and increase the allergen - induced airway

inflammatory

response following 30 - minute exposures of asthmatics to NO 2 concentrations as low as 0.26 ppm . Second, exposure to NO 2 has been found to enhance the inherent responsiveness of the airway to subsequent nonspecific challenges in controlled human exposure studies of asthmatic subjects. S mall but s ignificant increases in non - specific airway hy perresponsiveness were reported following 1 - hour exposures of asthmatics to 0.1 ppm NO 2 . Enhanced airway

responsiveness could have important clinical implications for asthmatics since transient increases in ai rway responsiveness following NO 2 exposure have the potential to increase sy

mptoms and worsen asthma control. Together, the epidemiologic and experimental data sets form a plausible, consistent, and coherent description of a relationship between NO 2 expos ures and an array

of adverse health effects that range from the onset of respiratory sy mptoms to hospital admission. Although the weight of evidence supporting a causal relationship is somewhat less certain than that associated with respiratory morbidit y , NO 2 has also been linked to other health endpoints. These include all - cause (non - accidental) mortality , hospital admissions or emergency department visits for cardiovascular disease, and decrements in lung function growth associated with chronic exposur e. 3. Environmental Effects Associated with Exposure to Ozone, PM and NO X

a. Deposition of NitrogenDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 37 of 207 Emissions of NO X from aircraft engines contribute to atmospheric deposition of nitrogen in the U.S. Atmospheric deposition of nitrogen contributes to acidi fication, altering biogeochemistry

and affecting animal and plant life in terrestrial and aquatic ecos ys tems across the United S tates . The sensitivity of terrestrial and aquatic ecosy stems to acidification from nitrogen deposition is predominantly governe d by

geology . Prolonged exposure to excess nitrogen deposition in sensitive areas acidifies lakes, rivers and soils. Increased acidity in surface waters creates inhospitable conditions for biota and affects the abundance and nutritional value of preferre d prey

species, threatening biodiversity and ecos ys tem function. Over time, acidifying deposition also removes essential nutrients from forest soils, depleting the capacit y of soils to neutralize future acid loadings and negatively affecting forest sustai nability . Major effects include a decline in sensitive forest tree species, such as red spruce (Picea rubens ) and sugar maple (

Acer saccharum ); and a loss of biodiversity of fishes, zooplankton, and macro invertebrates . In addition to the role nitrogen deposition play s in acidification, nitrogen deposition also leads to nutrient enrichment and altered biogeochemical cycling. In aquatic sy stems increased nitrogen can alter species assemblages and cause eutrophication. In terrestrial sy stems nitrogen loading can lead to loss of nitrogen sensitive lichen species, decreased biodiversity of grasslands, meadows and other sensitive habitats, and increased potential for invasive species.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 38 of 207 Adverse impacts on soil chemistry and plant life have been observed for areas heavil y influenced b y atmospheric deposition of nutrients, metals and acid species, resulting in species shifts, loss of biodiversity, forest decline damage to forest productivity and reductions in ecos ys tem services . Potential impacts also include adverse effects to human health through ingestion of contaminated vegetation or livestock (as in the case for dioxin deposition), reduction in crop yield, and limited use of land due to contamination. Atmospheric deposit ion of pollutant s can reduce the aesthetic appeal of buildings and culturally important articles through soiling, and can contribute directly (or in conjunction with other pollutants) to structural damage b y m eans of corrosion or erosion. 39 Atmospheric de position may affect materials principall y b y promoting and accelerating the corrosion of metals, by

degrading paints, and by deteriorating building materials such as concrete and limestone. Particles contribute to these effects because of their electrol yt ic, hygroscopic, and acidic properties, and their ability to adsorb corrosive gases (principally sulfur dioxide). b. Visibility Effects

39 U.S. EPA. (2005). Review of the National Ambient Air Quality Standards for Particulate Matter: Policy Assessment of Scientific and Technical Information, OAQPS Staff Paper. Retrieved on April 9, 2009 from http://www.epa.gov/ttn/naaqs/standards/pm/data/pmstaffpaper_2005122 1.pdf.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 39 of 207 NOx emissions contribute to visibility impairment in the U.S. through the formation of secondary PM 2.5 . 40 Visibility impairment is caused by light scattering and absorption by suspended particles and gases. Visibility is important because it has direct significance to people’s enjoyment of daily activities in all parts of the country . Individuals value good visibility for the well - being it provides them directl y, where they live and work, and in places where they enjoy recreational opportunities. Visibility is also highl y valued in significant natural areas , such as national parks and wilderness areas , and special emph asis is given to protecting visibility in these areas. For more information on visibility see the final 200 9 PM I SA. 41 c. Plant and Ecosystem Effects of Ozone Elevated ozone levels contribute to environmental effects, with impacts to plants and ecos ys tems being of most concern. Ozone can produce both acute and chronic injury in sensitive species depending on the concentration level and the duration of the expos ure. Ozone effects also tend to accumulate over the growing season of the plant, so that even low concentrations experienced for a longer duration have the potential to create chronic stress on vegetation. Ozone damage to plants includes visible injury t o leaves and impaired photosy nthesis, both of

40 U.S. EPA. (2004). Air Quality Criteria for Particulate Matter (AQCD). Volume I Document No. EPA600/P - 99/002aF and Volume II Document No. EPA600/P - 99/002bF. Washington, DC: U.S. Environmental Protection Agency. Retrieved on March 18, 2009 from http ://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=87903. 41 U.S. EPA (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R - 08/139F, 2009. A copy of this document is in doc ket number EPA - HQ - OAR - 2010 - 0687.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 40 of 207 which can lead to reduced plant growth and reproduction, resulting in reduced crop yi elds, forestry production, and use of sensitive ornamentals in landscaping. In addition, the impairment of photosy

nthesis, the process b y which the plant makes carboh ydrates (its source of energy and food), can lead to a subsequent reduction in root growth and carboh ydrate storage below ground, resulting in other, more subtle plant and ecos ys tems impacts. These latter impacts include increased susceptibility

of plants to insect attack, disease, harsh weather, interspecies competition and overall decreased plant vigor. The adverse effects of ozone on forest and other natural vegetation can potentially lead to species shifts and loss from the affected ecos ys tems, resulting in a loss or reduction in associated ecosystem goods and services. L astl y, visible ozone injury to leaves can result in a loss of aesthetic value in areas of special scenic significance like national parks and wilderness areas. The final 2006 Ozone Air Quality Criteria Document presents more detailed information on ozone effects on vegetation and ecosy stems. 4. Impacts on Ambient Air Quality Th e aircraft NOx emission standards we are promulgating would a ffect ambient concentrations of air pollutants. Nationally , levels of PM 2.5 , ozone, and NO X are declining. 42 However approximately

1 44 million people currently live in areas designated nonattainment for

42 U. S. EPA (2010) Our Nation’s Air: Status and Trends through 2008. Office of Air Quality Planning and Standards, Research Triangle Park, NC. Publication No. EPA 454/R - 09 - 002. This document can be accessed electronically at: http://www.epa.gov/airtrends/2010/.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 41 of 207 one or more of the current NAAQS. 43 These numbers do not include the people living in areas where there is a future risk of failing to maintain or attain the NAAQS. States with ozone nonattainment areas are required to take action to bring those areas into attainment . The attainment date assigned to an ozone nonattainment area is based on the area’s classification. Most ozone nonattainment areas are required to attain the 1997 8 - hour ozone NAAQS in the 2007 to 2013 time frame and then to maintain it thereafter. 44 We anticipate designating areas for the 2008 o zone standards in late spring 2012; thus, the attainment dates for areas designated nonattainment for the 2008 8 - hour ozone NAAQS would likely be in the 2015 to 203 2 timeframe, depending on the severit y of the problem in each area. In addition, EPA is wor king to complete the current review of the ozone NAAQS b y mid - 2014. If EPA revises the ozone standards in 2014 pursuant to that review, the attainment dates associated with areas designated nonattainment for that NAAQS would likely be in the 2019 to 2036 timeframe, depending on the severity of the problem in each area. Areas designated as not attaining the 1997 PM 2.5 NAAQS will need to attain the 1997 standards in the 2010 to 2015 time frame, and then maintain compliance with them thereafter. The 2006 24 - hour PM 2.5 nonattainment areas will be required to attain the 2006 24 - hour PM 2.5 43 U.S. EPA, “ Development of Population Currently Living in Non attainment Areas ,” m emorandum from Margaret Zawacki, Assessment and Stand ards Division, Office of Transportation and Air Quality, January 19, 2012 . A copy of this document is in docket EPA - HQ - OAR - 2010 - 0687. 44 The Los Angeles South Coast Air Basin 8 - hour ozone nonattainment area and the San Joaquin Valley Air Basin 8 - hour oz one nonattainment area are designated as extreme and will have to attain before June 15, 2024. The Sacramento, Coachella Valley and Houston 8 - hour ozone nonattainment areas are designated as severe and will have to attain by June 15, 2019. In addition, the Western Mojave 8 - hour ozone nonattainment area has requested to be reclassified as severe. This request has not yet been acted on.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 42 of 207 NAAQS in the 2014 to 2019 time frame and then be required to maintain the 2006 24 - hour PM 2.5 NAAQS thereafter. EPA has alread y adopted many emission control programs that are expected to reduce ambient ozone and PM 2.5 levels and which will assist in reducing the number of areas that fail to achieve the NAAQS . Even so, our air quality modeling projects that in 2030 as many as 1 0 counties with a population of over 3 0 million may not attain the 2008 ozone standard of 0.075 ppm (75 ppb) without additional controls. 45 In addition, our air quality modeling projects that in 2030 at least four counties with a population of nearly 7 million may not attain the 1997 annual PM 2 .5 standard of 15 μg/m 3 and 2 2 counties with a population of over 33 million may not attain the 2006 24 - hour PM 2.5 standard of 35 μg/m 3 without additional controls . 46 Th ese numbers do not account for those areas that are close to (e.g., within 10 percent o f) the standards. These areas, although not violating the standards, would also benefit from an y reductions in NO X ensuring long - term maintenance of the NAAQS. The primary

NAAQS for NO 2 was revised in January 2010. EPA completed area designations in Janu ary 2012 and there are currently no nonattainment areas. The designations

45 U.S. EPA (2010). Regulatory Impact Analysis: Final Rulemaking to Establish Greenhouse Gas Emission Standards and Fuel Efficiency Standards for Medium - and Heavy - Duty Engines and Vehicles. Chapter 8: Health and Environmental Impacts. EPA 420 - R - 11 - 901.

46 U.S. EPA (2010). Regulatory Impact Analysis: Final Rulemaking to Establish Greenhouse Gas Emission Standards and Fuel Efficiency Standards for Medium - and Heavy - Duty Engines and Vehicles. Chapter 8: Health and Environmental Impacts. EPA 420 - R - 11 - 901.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 43 of 207 were based on the existing communit y - wide monitoring network. Once the expanded network of NO 2 monitors is fully

deploy ed and three ye ars of air quality data have been collected, E PA intends to redesignate areas after 2015, as appropriate, based on the air quality data from the new monitoring network . 47 In summary , the aircraft NOx reductions resulting from the se new aircraft engine emission standards will be useful to states in attaining or maintaining the ozone, PM 2.5 , and NO 2 NAAQS standards. I II. Details of the Fina l Rule The following is a description of the regulations being adopted in this final rule , with an y changes from the proposal also noted. The descriptions also include our response to the most significant comments received on the proposal. A full summary of the comments and our responses are contained in the r esponse to c omments document for the rule that is available in the public docket f

or this action . 48 We are establishing two different levels or “ tiers ” of increasingl y more stringent NOx emission standards for gas turbofan engines with maximum rated thrusts greater than 26.7

47 EPA 2010. Fact Sheet: Final Revisions to the National Ambient Air Quality Standards for Nitrogen Dioxide. http://www.epa.gov/air/nitrogenoxides/pdfs/20100122fs.pdf

48 U.S. Environmental Protection Agency, “Summary and Analysis of Comments: Control of Ai r Pollution from Aircraft and Aircraft Engines,” Office of Transportation and Air Quality, **[insert report number and date here]**  . A copy of this document is in docket number EPA - HQ - OAR - 2010 - 0687.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 44 of 207 kilonewtons (kN). 49 Each of the tiers appl y to newly - certified engines. Newly - certified aircraft engines are those that would receive a new t yp e certificate after the effective date of the applicable standards. Such engine t ypes or models would not have begun production prior to the effective date of the new requir ement. 50 We are also requiring newly - manufactured engines to comply with the first tier of the two tiers of standards. Newly - manufactured aircraft engines are those that have been previously certified and manufactured in compliance with preexisting stand ards, and will continue to be produced after the effective date of a new applicable standard. Normally , these newl y manufactured engines must comply with the same NOx limits as newly - certified engines, but at a later date or cease production. 51 The end of this “phase - in” period for the newly - manufactured engine standards is sometimes referred to a “production cutoff . ”. Again, we are adopting only

49 The standards will apply to engines used in commercial an d noncommercial aviation for which the FAA issues airworthiness certificates, e.g., non - revenue, general aviation service. The vast majority of these engines are used in commercial applications.

50 ICAO standards describe newly - certified engines as “...eng ines of a type or model for which the date of manufacture of the first individual production model was after....” the effective date of the emission standards. See ICAO, “Aircraft Engine Emissions,” Annex 16, Volume II, Third Edition, July 2008, Amendment 4 effective on July 20, 2008. Copies of this document can be obtained from the ICAO website at www.icao.int .

51 The standards for newly - manufactured engines are described in general regulatory terms as the date that the type or model was first certified and produced in conformance with specific emission standards, and the date beyond which an individual engine meet ing those same requirements cannot be made. So ICAO standards describe newly - manufactured engines as “...engines of a type or model for which the date of manufacture of the first individual production model wa s after....” the effective date of the applicable standards, and “...for which the date of manufacture of the individual engine wa s on or before....” a specific date that is later than the first effective date of the standards. See ICAO, “Aircraft Engine Emissions,” Annex 16, Volume II, Third Edition, July 2008, Amendment 4 effective on July 20, 2008. Copies of this document can be obtained from the ICAO website at www.icao.int .Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 45 of 207 the first of the two new tiers of NOx standards for newly - manufactured engines. These provisions are describ ed in detail below. Five other regulatory

features are being established in this final rule . First, we are revis ing provisions for certain time - limited flexibilities, i.e., potential exemptions, for newl y manufactured engines that may not be able to comply

with the first tier of the new NOx standards because of specific technical or economic reasons . 52 Second, we are defining “derivative engine” for emissions certification purposes. T he intent of this definition is to distinguish when the emission characteristics of a new turbofan engine model vary substantially from its existing parent engine design, and must show compliance with the emission standards for a newly - certificated engine. Third, we are establishing new CO and NOx standards for turbofan engines that are used to propel supersonic aircraft. These standards were adopted b y ICAO in the 1980s, but were not previously added to our HC emission standard for these engines . Promul gating the se standards meet s our treat y obligation under the Convention on International Civil Aviation as previousl y described in section I . C . Fourth, we are making several changes to the emission testing and measurement procedures in our regulations th at are intended to implement ICAO’s Annex 16 and to incorporate the entire annex in our regulations by reference. Finally , as described in s ection IV , we are amend ing the current regulatory provisions that address definitions, acron ym s and abbreviations, general applicability and

52 These apply only to the first tier of NOx standards. We are not adopting a production cutoff for the second tier of standards.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 46 of 207 requirements, exemptions, and incorporation by reference. These amendments are intended to clarify requirements, make them more consistent with other parts of the program, update the text to be consistent with current standard la nguage conventions, or remove obsolete provisions. As discussed further below, with the exception of the annual reporting requirement describ ed in section III.D, the amendments reflect those changes that were previously adopted by ICAO . This final rule also is consistent with our authority and obligations under the CAA as described in s ection I. B . More specificall y, the technical feasibility and cost of the emission standards were well documented by our own analyses and CAEP as described later in this section and in s ection V, Technical Feasibility , Costs, and Emission Benefits . We think that the final rule provides adequate lead time for the development and application of the requisite technology

with appropriate consideration to the cost of complian ce. W e have consulted with the Department of Transportation through the FAA regarding lead time, noise, safet y, and the technical feasibility of the new standards. Today ’s final rule is also consistent with U.S. treaty obligations under the Chicago Convention as described in section I. C ., because the requirements are consistent with current I CAO standards. Except to the extent needed to make our standards conform to ICAO’s standard s by making them applicable to both commercial and non - commercial engines, we are not revis ing exhaust emission standards for HC, CO, or smoke . Those standards remain in effect as currentl yDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 47 of 207 promulgated. All engines subject to the new NOx standards would a lso continue to be subject to the existing HC, CO, and smoke standards. It is worth emphasizing that although we are includ ing these existing HC, CO, and smoke standards in a new section 87.23, which would also contain the new Tier 6 and Tier 8 NOx stand ards, we are not actuall y adopting new standards for these three pollutants , since under the current form of part 87 these HC, CO and smoke standards would alread y continue to apply to new engine t ypes subject to future revised NOx standards. As discusse d above, w e are adopt ing a new naming convention in this preamble and the regulatory

text to more easily

distinguish between the tiers of increasingly more stringent NOx emission standards. This convention is also consistent with the numeric identifier th at CAEP uses to differentiate the CAEP work cy cle that produces new NOx standards. (The CAEP naming convention is described in section I.E.) As a result, the first tier of NOx standards, which correspond to CAEP/6, are referred to as Tier 6 in the remain der of today ’s notice. The second tier of standards is referred to as Tier 8, which correspond to CAEP/8. We are also incorporating the new naming convention in the regulations for the existing NOx emission standards, i.e., Tier 0, Tier 2, and Tier 4. T here is no material change to the existing NOx standards themselves, except to the extent that when today ’s final rule becomes effective, the existing NOx standards would be superseded b y Tier 6 standards. We acknowledge that this new naming convention i s a change from the past practice of not describing aircraft engine emission standards as tiers. However, we believe the new namingDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 48 of 207 scheme is a valuable tool that makes referring to individual NOx standards much easier. Itis also similar to the terminol ogy we use for other mobile source sectors that are subject to environmental regulation and for which standards have become more stringent or have otherwise been amended over time . A. NOx Standards for Newly - Certified Engines W e are adopting two differ ent tiers of increasingl y stringent NOx standards. These standards would appl y for all for newl y - certified turb ofan aircraft engines with maximum rated thrusts greater than 26.7 kN . 53 (See section III.B for a discussion of how these standards appl y for ne wl y - manufactured engines that are not con sidered to be newl y certified.) The numerical value of the applicable standard for an individual engine model is defined by the engine’s thrust level and pressure ratio. Simply stated, the pressure ratio is the numerical ratio of the air pressure entering the engine to the air pressure at the entrance to the combustor, i.e., after the air has passed through the compressor section of the engine. 54 The new tiers are described separately below. 1. Tier 6 NOx Standards for Newl y - Certified Engines

53 There are no gaseous emission standards, e.g., NOx, for gas turbine engines with maximum rated thrusts equal to or less than 26.7kN. These engines are, however, subject to smoke and fuel venting standards.

54 The combus tor is a chamber where a mixture of fuel and air is burned to form very hot, expanding gases. As these gases move through the combustion chamber, the walls of the combustor are cooled with dilution air to prevent thermal damage. Dilution air is also use d to tailor the gas’ temperature profile as it exits the combustor so that the final temperatures will not exceed the allowable limit at the turbine inlet.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 49 of 207 This first tier of new standards is equivalent to the CAEP/6 NOx limits that were adopted by I CAO and became internationall y applicable after December 31, 2007. Given that aircraft turb ofan engines are international c ommodities, engine manufacturers introduced engine models after that date that demonstrate compliance with these international standards , or are alread y planning to do so for upcoming engine designs. Based on this, our evaluation of the necessary lead tim e, and the lack of any comments on this aspect of the proposal, this tier of standards take s effect immediatel y upon the effective date of this final rule . The basic form of the NOx standards for turbofan engines is different for higher - and lower - rat ed thrust engines. Higher output engines are defined as having rated thrusts equal to or greater than 89 kN , while lower output engines are defined as having rated thrusts less than 89 kN but greater than 26.7 kN . The new Tier 6 NOx standards for each of these power grouping are described separatel y below. a. Numerical Emission Limits for Higher Thrust Engines The Tier 6 NOx standards for newl y - certified gas turbine engines with rated thrusts of 89 kN or more are differentiated b y pressure ratio as shown below. • For engines with a pressure ratio of 30 or less: g/kN rated output = 16.72 + (1.4080 * engine pressure ratio) • For engines with a pressure ratio of more than 30 but less than 82.6:Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 50 of 207 g/kN rated output = - 1.04 + (2.0 * engine pressure rat io) • For engines with a pressure ratio of 82.6 or more: g/kN rated output = 32 + (1.6 * engine pressure ratio) The new Tier 6 NOx standards for these higher thrust engines are presented in Figure 1 along with the previous EPA NOx standards, which were b ased on CAEP/4, for comparison.

As a matter of convention, the relative stringency from one CAEP standard to another is expressed relative to a pressure ratio of 30, because the percentage reduction is usually

0 20 40 60 80 100 120 140 160 180

10 30 50 70 90**g /** **k N** **T h** **r u** **s t** 

**Pressure Ratio (PR)**  **Figure 1: Tier 6 NOx Standards for Higher** 

**Thrust Engines** Existing Tier 4 Standard Tier 6

8% Reduction Current Engine PRs

12% ReductionDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 51 of 207 inconsistent across all of the possible p ressure ratios, which otherwise makes a simple comparison difficult. Using that convention, the Tier 6 standards (CAEP/6) are referred to as being 12 percent more stringent than the existing EPA NOx Tier 4 standards (CAEP/4). The relative stringency

can also be illustrated at other pressure ratios. At pressure ratios less than 30 the reductions are also 12 percent. At pressure ratios above 30, however, the percent reduction decreases as the pressure ratio is increased. Based on the figure, the percent reduction for current technology

engines ranges from about 8 to 12 percent. b. Numerical Emission Limits for Lower Thrust Engines The new Tier 6 NOx standards for newl y - certified gas turbine engines with rated thrusts between 26.7 and less than 89.0 kN are differentiated by both pressure ratio and rated thrust as shown below. • For engines with a pressure ratio of 30 or less: g/kN rated output = 38.5486 + (1.6823 * engine pressure ratio) - (0.2453 * kN rated thrust) - (0.00308 * eng ine pressure r atio * kN rated thrust) • For engines with a pressure ratio of more than 30 but less than 82.6: g/kN rated output = 46.1504 + (1.4285 * engine pressure ratio) - (0.5298 * kN rated thrust) + (0.00642 * engine pressure ratio * kN rated thrust)Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 52 of 207 In developing the corresponding NOx standards for low er thrust engines, CAEP recognized the technical challenges that ph ys ically smaller - sized engines sometimes present relative to incorporating some of the lowest NOx technology approaches , which are otherwis e available to their larger counterparts. These technical difficulties are well documented and increase progressively

as size is reduced (from around 89 kN ). 55 For example, the relativel y small combustor space and section height of these engines creates c onstraints on the use of low NO x fuel - staged combustor concepts which inherently require the availability

of greater flow path cross - sectional area than conventional combustors. Also, fuel - staged combustors need more fuel injectors, and this need is not c ompatible with the relativel y smaller total fuel flows of lower thrust engines. (Reductions in fuel flow per nozzle are difficult to attain without having clogging problems due to the small sizes of the fuel metering ports.) In addition, lower thrust eng ine combustors have an inherently greater liner surface - to - combustion 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. 56 With these technological constraints in mind, CAEP fashioned the CAEP/6 NOx standards across the range of thrusts represented b y low - thrust engines to become comparativel y less stringent, i.e., CAEP/6 relative

55 ICAO/CAEP, “Report of Third Meeting, Montreal, Quebec, December 5 - 15, 1995,” Document 9675, CAEP/3 . A copy of this paper can be found in Docket EPA - HQ - OAR - 2010 - 0687 .

56 ICAO, “Combined Report of the Certification and Technology Subgroups,” section 2.3.6.1, CAEP Working Group 3 (Emissions). Presented by the Chairman of the Technology Subgroup, Third Me eting, Bonn, Germ any, June 1995. A copy of this paper can be found in Docket EPA - HQ - OAR - 2010 - 0687 .Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 53 of 207 to CAEP/4, as the rated output and phy sical size of the engines decrease. We agree with this approach. As mentioned, the new Tier 6 standards depend on an individual engine’s rated thrust and pressure ratio. With two variables in the calculation, the standards cannot be represented in a simple figure, i.e., no single line graph showing the standards for all engines within the thrust range is possible as it was for higher thrust engines. Regardless of this complexity , however, some general observations are useful to characterize the Tier 6 NOx stan dards for lower thrust engines based on the engine size versus technological challenge described in the previous paragraph. C omparing the new lower and higher thrust standards at 89 kN , which is the demarcation point between the two sets of standards, shows that the standards for lower thrust engines are numericall y equivalent to the limit for higher thrust engines at each pressure ratio. This is as expected because the engine sizes and ability to incorporate low - NOx technologies are the same at 89.0 k N delineation point. Again focusing onl y on 89 kN engines, the new Tier 6 standards represent a 12 percent reduction from the existing EPA Tier 4 ( CAEP/4 based standards ) for pressure ratios of 30 or less as shown below in Figure 2. This includes the re gion represented b y almost all current engine designs. At higher pressure ratios, the relative numerical reduction is progressivel y less because the slope of the two standards is essentially the same.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 54 of 207 At other thrust ratings the percent reduction be tween the new Tier 6 and existing EPA NOx standards at an y pressure ratio becomes progressively smaller as thrust decreases. This is illustrated in Figure 3 for a pressure ratio of 30. This pressure ratio was chosen for the example because , as before, the relative stringency of CAEP NOx standards is generally compared at this point as a matter of convention. As shown in the figure for current engines, the reduction ranges from 12 percent at the upper end of the thrust range to 0 percent at the lower end of the range. The pattern is similar for the other pressure ratios. Only the actual numerical value for percentage reduction at 89 kN , as shown on the far right of the figure, may vary by pressure ratio, as described at the beginning of this paragraph. However, in the region of pressure ratios

0 20 40 60 80 100 120 140 160 180

10 20 30 40 50 60**g /** **k N** **T h** **r u** **s t** 

**Pressure Ratio (PR)**  **Figure 2: Tier 6 NOx Standards for Low**  **er Thrust Engines Rated at 89.0 kN** 

Existing Standard Proposed Tier 6

12% Reduction Current Engine PRsDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 55 of 207 represented b y today’s engines, the results are identical to those shown in the figure, i.e., a 12 percent reduction at 89 kN decreasing to 0 percent at 26.7 kN .

2. Tier 8 NOx Standards for Newl y - Certified Eng ines The second tier of new standards, i.e., Tier 8, are equivalent to the NOx limits that were most recentl y recommended at CAEP/ 8 in February 2010 for adoption b y ICAO. 57 The CAEP/8 recommended standards have a recommended applicable date after December 31, 2013. As discussed further in section V of today ’s notice, we agree with CAEP that this provides engine

57 CAEP/7 did not adopt new aircraft engine NOx standards. 40 50 60 70 80 90 100

20 40 60 80 100**g /** **k N** **T h** **r u** **s t** 

**Thrust (kN)**  **Figure 3: Tier 6 NOx Standards for Low**  **er Thrust** 

**Engines A**

**t Pressure Ratio 30** 

Existing Tier 4 Standard Tier 6

0% Reduction at 26.7kN 12% Reduction at 89kN Current Engine ThrustsDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 56 of 207 manufacturers with adequate lead time to respond to these more stringent NOx standards considering the technical feasibility and cost asso ciated with the requirements. Therefore, this tier of standards take s effect on January 1, 2014 . As with the new Tier 6 NOx standards, the basic form of the new Tier 8 standards for turb ofan engines is different for higher - and lower rated thrust engines . Higher output engines are defined as having rated thrusts equal to or greater than 89 kN , while lower output engines are defined as having rated thrusts less than 89 kN but greater than 26.7 kN . The longer - term standards for each of these power groupin g are described separately below. a. Numerical Emission Limits for Higher Thrust Engines The new Tier 8 NOx standards for newl y - certified turb ofan engines with rated thrusts of 89 N or more are differentiated by pressure ratio as shown below. • For engin es with a pressure ratio of 30 or less: g/kN rated output = 7.88 + (1.4080 * engine pressure ratio ) • For engines with a pressure ratio of more than 30 but less than 104.7: g/kN rated output = - 9.88+ (2.0 * engine pressure ratio) • For engines wi th a pressure ratio of 104.7 or more: g/kN rated output = 32 + (1.6 * engine pressure ratio)Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 57 of 207 The new Tier 8 NOx standards for these higher thrust engines are presented in Figure 4 along with the new Tier 6 standards for comparison.

As noted previousl y , as a matter of convention the relative stringency from one CAEP standard to another is generall y expressed relative to a pressure ratio of 30. Using that convention, the new Tier 8 standards (CAEP/8) are referred to as being 15 percent more stringent than the new Tier 6 NOx standards (CAEP/6). The relative stringency can also be illustrated at other pressure ratios. At pressure ratios less than 30 the reductions increase. At pressure ratios

0 20 40 60 80 100 120 140 160 180

10 30 50 70 90**g /** **k N** **T h** **r u** **s t** 

**Pressure Ratio (PR)**  **Figure 4: Tier 8 NOx Standards for Higher** 

**Thrust Engines**

Tier 6 Tier 8 Current Engine PRs

19% Reduction

15% Reduction 11% ReductionDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 58 of 207 above 30, however, the percent reduction decreases. Based on the figure, the percent reduction for current engine design s range from about 11 to 19 percent. b. Numerical Emission Limits for Lower Thrust Engines The new Tier 8 NOx stand ards for newl y - certified gas turbine engines with rated thrusts between 26.7 but less than 89.0 kN are differentiated by both pressure ratio and rated thrust as shown below. • For engines with a pressure ratio of 30 or less: g/kN rated output = 40.052 + (1.5681 * engine pressure ratio) - (0.3615 * kN rated thrust) - (0.0018 * eng ine pressure ratio * kN rated thrust) • For engines with a pressure ratio of more than 30 but less than 104.7: g/kN rated output = 41.9435 + (1.505 * engine pressure ratio) - (0.55823 * kN rated thrust) + (0.005562 * engine pressure ratio * kN rated thrust) In developing the corresponding CAEP/8 NOx standards for low thrust engines, CAEP recognized the technical challenges that ph ys ically smaller - sized engines repre sent relative to incorporating some of the lowest NOx technology, which is otherwise available to their larger counterparts. These technical difficulties were described in the previous section for the Tier 6 low - thrust engine standards.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 59 of 207 Also as previously described, no single line graph showing the standards for all engines within the thrust range is possible as it was for higher thrust engines, because the equations have two variables. However, some general observations are useful to characterize the new Tier 8 NOx standards for lower thrust engines based on the engine size versus technological challenge described in the previous paragraph. First, the new Tier 8 NOx standards for lower thrust engines are numerically

equivalent to the limit for higher thr ust engines across all pressure ratios at the highest rating of 89 kN , where the engine sizes and ability to incorporated low - NOx technologies are comparable. This same characteristic was observed for the Tier 6 standards. Second, as shown below in Figur e 5 for 89 kN engines, at this thrust rating the new Tier 8 standards represents a 15 percent reduction from the Tier 6 standards for a pressure ratio of 30. However, within the region of pressure ratios for all current engine designs, the reductions rang e from 19 to 23 percent.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 60 of 207 Third, at other thrust ratings the percent reduction between the new Tier 6 and Tier 8 standards at an y pressure ratio becomes progressively smaller as thrust decreases. This is illustrated in Figure 6 for a pressure ratio o f 30, following the convention described above. A lso a s shown in the figure for current engines, the reduction ranges from 15 percent at the upper end of the thrust range to 5 percent at the lower end of the range. While not depicted in a figure, the pattern is similar for the other pressure ratios . H owever, the actual numerical values for percentage reductions at both ends of the thrust range, i.e., 26.7 to 89 kN , may vary by pressure ratio . In the region of pressure ratios represented by today ’s eng ines, the results are identical to those shown in F igure 6 at 26.7 kN , i.e., a 5 percent reduction at all pressure ratios for that thrust

0 20 40 60 80 100 120 140 160 180

10 20 30 40 50 60**g /** **k N** **T h** **r u** **s t** 

**Pressure Ratio**  **Figure 5: Tier 8 NOx Standards for Low**  **er Thrust Engines Rated at 89.0 kN** 

Tier 6 Tier 8 Current Engine PRs 15% Reduction 23% Reduction 19% ReductionDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 61 of 207 rating . However , percent reductions increase linearly up to a maximum 23 percent reduction for 89 kN engines with pressure ratios of about 15.

B. Application of the Tier 6 NOx Standards to Newly - Manufactured Engines This section describes the application of the new Tier 6 NOx standards to newly manufactured engines, and our amended temporary flexibilities for newly - manufactured engines that show significant problems complying with these requirements. Also , consistent with CAEP/8, we are not applying the new Tier 8 NOx standards to newl y - manufactured engines at

40 50 60 70 80 90

20 40 60 80 100**g /** **k N** **T h** **r u** **s t** 

**Thrust (kN)**  **Figure 6: Tier 8 NOx Standards for Low**  **er Thrust** 

**Engines at Pressure Ratio 30**

Tier 6 Tier 8

Current Engine Thrusts 15% Reduction at 89 kN 5% Reduction at 26.7 kNDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 62 of 207 this time . T his secti on concludes with a description of future efforts to examine such a possibility . 1. Phase - In of the Tier 6 NOx Standards for Newly - Manufactured Engines As described above, the new Tier 6 NOx standards apply to all engine t yp es or models that receive a new ty

pe certificate after the effective date of the final rule. We are also phas ing in these same NOx limits for newl y - manufactured engines for engine models (and their derivatives for emissions certification purposes ) that were originall y certified to l ess stringent requirements (i.e., Tier 2 or Tier 4) and were already being produced for installation on new aircraft prior to the effective date of the final rule . 58 As a result, manufacturers need to bring newly manufactured engines of these previousl y ce rtified models into compliance with the applicable Tier 6 standards b y a future date or cease production of those engine models. 59 As we discussed and described in our analysis of the need for a CAEP/ 6 production cutoff during the CAEP process, establishing a date certain for compliance with any emission standard is necessary to ensure that the full benefits of newer, more stringent requirements will be achieved in a

58 The requirement that newly - manufactured engines must meet the CAEP 6 NOx standard by a date cert ain applies only to engines that are intended to be installed on all new airframes. It would not apply to engines produced as “spares,” which are intended to be installed on existing airframes as replacements for maintenance or other reasons. See section III.B.2 for more information about ne w and spare engines.

59 After this date the production of any noncompliant engines would cease because the FAA w ould discontinue issuing an airworthiness approval tag (FAA Form 8130 - 3) to these engines.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 63 of 207 reasonable time. 60 We are, however, adopting certain limited flexibilities for engines that cannot be made compliant because of specific technical or economic reasons, as discussed later in this section. As described in the propos al, the effective date of January 1, 2013 61 for the newly manufactured engine s tandards is consistent with the expected market demand for these previously

certified engine ty

pes. Historicall y, engine manufacturers have often responded to the adoption of more stringent NOx standards by bringing older engine t ypes i nto compliance with the newer requirements well before the required date in anticipation of the likely market demand, or planning for the orderly withdrawal of these engines from the marketplace. Information developed during the IC AO process in 2008 and 2 009 62 , 63 , 64 and our more recent discussions

60 ICAO, Committee on Aviation Environmental Protection (CAEP), Eight Meeting, Montreal, 1 to 12 February 2010, Agenda 2: Review of Technical Proposals Relating to Aircraft Engine Emissions, Adoption of Production Cutoff for Emission Standards, WP/56, Presented by the United States, December 12, 2009. A copy of this document is in docket number EPA - HQ - OAR - 2010 - 0687.

61 The regulatory text specifies that engine models certified at or below the Tier 4 NOx standards may be produced through December 31, 2012 without meetin g the Tier 6 NOx standards. Therefore, the effective date of the standards for new ly - ma nufactured engines is effectively January 1, 2013.

62 ICAO, Committee on Aviation Environmental Protection (CAEP), Steering Group Meeting, Salvador, Brazil, 22 to 26 June 2009, Agenda 6: Emissions Technical - WG3, Production Cutoffs and Associated Flexibilities for ICAO Engine Emission Standards, WP/39, Presented by U.S. Representative, August 6, 2009. A copy of this document is in docket number EPA - HQ - OAR - 2010 - 0687.

63 ICAO, Committee on Aviation Environmental Protection (CAEP), Steering Group Meeting, Salvador, Brazil, 22 to 26 June 2009, Agenda Item 3: Forecasting and Economic Analysis Support Group (FESG), CAEP/6 NOx Production Cutoff Cost Analysis, WP/39, Presented by the FESG NOx Stringency Task Group, February 6, 2009. A copy of this document is in docket number EPA - HQ - OAR - 2010 - 0687.

64 ICAO, Committee on Aviation Environmental Protection (CAEP), Steering Group Meeting, Seattle, 22 to 26 September 2008, Agenda Item 3: Forecasting and Economic Analysis Support Group (FESG),Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 64 of 207 with manufacturers indicate that : 1) all but a few models are alread y compliant with CAEP/6 standards, 2) nearl y without exception, all current production models will meet the CAEP / 6 requirements b y the 201 2 time f rame, and 3) any

noncompliant models will be phased out of production because of low market demand. W e think that the five - ye ar phase - in p eriod from ICAO’s effective date of the CAEP/6 standards (corresponding to our new Tier 6 NOx standards ) for newl y - m anufactured engines is adequate for manufacturers and their customers to respond to the new requirements without d isrupting their future planning and purchasing decisions. 65 , 66 T his phase - in period for appl yi ng the Tier 6 NOx standards to newly - manufactured engines is also identical to the date for this same requirement that was adopted b y ICAO. N o comments were received expressing concern with this phase - in period for newl y - manufactured engines. We did, however, receive two comments expressing the view that the time between the date of our final rule and the January 1, 2013 effective date of the production cutoff would be to o short if it is less than one y ear. G eneral E lectric Aviation (GE) was the most detailed and began by noting that most o f the engine models currently in production were certified to the Tier 4 Production Cutoff for NOx Standards, WP/6, Presented by the FESG Rapporteurs, April 9, 2008. A copy of this document is in docket number EPA - HQ - OAR - 20 10 - 0687.

65 The ICAO CAEP/6 NOx standards became effective after December 31, 2007. 66 This period of time is also consistent with the phase - in period associated with previous ICAO standards. CAEP’s predecessor, the Committee on Aircraft Engines Emissions, established the first international emission standards with an effective date four years after adoption, i.e., effectively a four year phase - in. CAEP2 included a phase - in period of 4 years for newly - manufactured engines.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 65 of 207 standards and had demonstrated NOx emissions below the Tier 6 at that time. They continued that if the original certification reports are sufficient for the FAA to formally certify these engines to the Tier 6 standards, th e n none of these engines would be adversely affected by

the production cutoff. However, GE expressed the concern that if additional interactions or formal action by the FAA were needed, or revisions to the FAA’s FAR Part 34 were required, then having less than one ye ar between EPA’s final rule and the production cutoff could disrupt current engine production. As a result, GE asked that the date of the production cutoff be delay ed to take effect 12 months after the f inal rule. The other joint comment from the Aerospace Industries Association (AIA) and the General Aviation Manufacturers Association (GAMA) was similar in nature , but without supporting detail s . The commenters’ concerns do not relate to the technical or economic feasibility of newly - manufactured engines achieving emission levels in compliance with the new Tier 6 standards b y the date of the production cutoff as proposed. The concerns expressed do not argue that additional time is necess ary “to permit the development and application of the requisite technology” to compl y with the standards under CAA section 231(b). Therefore, the date of the Tier 6 production cutoff is appropriate and consistent with the Clean Air Act. Section 232(b) of the Act directly addresses our obligation relative to the effective date of the regulation. Specifically , it say s: “Any regulation prescribed under this section (and an y revision thereof) shall take effect after such period as the Administrator finds necessary (afterDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 66 of 207 con sultation 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.” Based on the information provided above , the aircraft en gine models described b y GE are alread y capable of complying with the EPA Tier 6 NOx standards using alread y applied requisite technology , i.e., the cost of appl yi ng with has alread y been borne, as the effective date of the corresponding ICAO CAEP/6 NOx st andard has alread y passed. We do not believe there are an y t echnical feasibility or economic implications arising from the continued application of the requisite technology

for those engines to meet the Ti er 6 NOx standards. Also, c onsistent with our most recent previous amendment to the NOx standards, which similarly promulgated the standard at a level that was already being met by aircraft engine manufacturers who were alread y applying the requisite technology , the effective date does not need to in clude additional lead time for the development and application of additional technology that would be needed to comply with the standards. See, e.g., 70 FR 69604, 69674 - 76 (Nov. 17, 2005). As a result, the implementation dates provide more than adequate lead t ime under the statute. Therefore, because aircraft engine manufacturers are already able to comply with the Tier 6 NOx standard through the continued use of alread y applied requisite technology, and because the effective date of the corresponding ICAO CAE P/6 N Ox standard has alread y passed ( and also based on the assessment described in section V. Technical Feasibility , Cost, and Emission Benefits ) , w e find that the dates provide more than adequate lead time under the statute for application of requisite te chnol o gy .Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 67 of 20 7 We also want to stress that the production cutoff i s actually an ICAO standard and we think it is important to stay aligned with th e CAEP production cutoff date. We note that this is also being adopted b y the European Aviation Safety Agency (EASA ) and perha

ps other aviation certification authorities. Our adoption of the proposed d ate insures international consistency regarding the production cutoff date and avoids contradicting our international bilateral agreements with other governments, e.g., the European Union . Regarding the need for engine models to be formally recognized by

the FAA as complying with the new Tier 6 standard, this is completely within the purview of the FAA. In our previous most recent amendment to the NOx standard, we provid ed just a one - month lead time period before the revised standard became effective, and FAA did not adopt corresponding implementing regulations until one y ear later, with no apparent disruption to the industry . ( See 70 FR 69664 , Nov. 17, 2005. ) The new T ier 6 standards are the same as the CAEP/6 standards that were approved b y IC AO in 2005 with an effective date of beginning after December 31, 2007. Therefore, just as for the 2005 revised NOx standard that we similarly promulgated significantl y later than the effective date of the corresponding I CAO CAEP standard, we do not believe that it is necessary to delay the effective date based on a need for the FAA to revise its own implementation and enforcement regulations. Finally , section 23 2(a) of the Act directs the FAA to e nsure compliance with our standards. In this regard , the FAA has developed a streamlined process to recognize complianceDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 68 of 207 with Tier 6 and or Tier 8 as appropriate for currently t ype certified engine models which meet th e emission standards and they have assured the regulated industry that they will dedicate the necessary resources to formally recognize conformance with the standards before the production cutoff date . This process will rely on part 87 rather than the FAA ’s FAR part 34, due to the time needed to amend its current regulations through formal rulemaking. Further, the FAA has informed us that they are pursuing the use of an expedited regulatory process, called a direct final rule to promulgate the necessary amendments to FAR part 34 in a timely manner. Based on the FAA’s assurances and description of the streamline d process to formally recognize conformance with the new standards, engine manufacturers now support promulgating the production cutoff date as pro posed . 67 For the reasons stated above, EPA is promulgating the Tier 6 production cutoff with the originall y proposed effective date of January 1, 2013 . 2. 2. Carry over of Previously Generated Emission Test Data Aircraft engine models normally receive ty pe certificates, which include a determination that the model meets the emission standards in force at the time the t ype certificate is granted. EPA has not updated its aircraft emission standards or test procedure regulations since 2005. In

67 Reference letter from AIA to FAA that is expected by February 2012. Also reference any letters directly from the engine manufacturersDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 69 of 207 this action we are adopting Tier 6 and Tier 8 NOx emission standards and are adopting either in 40 CFR part 87 directl y or through incorporation by reference of Annex 16, Volume II a number of minor changes to test procedures and related requirements. These changes will become effective on the date when the rule becomes effective. This leaves open a question regarding the future validity and acceptability

for amended ty pe certificates of emission tests and emission test data generated under previously specified test proc edures and related requirements. For example, there may be an engine model tested in 2004 that demonstrated HC, CO, and NOx emission levels below the exhaust emission standards in effect at that time and also below the Tier 6 or perhaps even the Tier 8 st andards that are being promulgated in this final rule . We want to be clear that we do not intend minor changes to test procedures or related provisions and requirements to trigger the need for additional testing. Thus, in cases where a manufacturer has a valid current t ype certificate based on emissions information generated under the test procedures in force at the time the ty pe certificate was granted, we consider that data to be valid for an y formal FAA recognition of compliance, e.g., an amended t ype certificate , with the Tier 6 or Tier 8 NOx emission requirements if the original test data demonstrate such compliance. The same is true for the HC and CO emission standards. This clarification should greatl y facilitate compliance determinations by the FAA and eliminate any uncertainty

regarding the potential for otherwise minor test procedure changes to trigger new emissions testing for previously certificated engines with emission levels below the new NOx standards.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 70 of 207 3 . Exemption s and Exceptions from the Tier 6 Production Cutoff In conjunction with the implementation of the new Tier 6 NOx standards, we are establishing provisions which allow engine manufacturers to request an exemption or exception from meeting the Tier 6 NOx standards for newl y - manufactured engines . These provisions replace existing provisions addressing exemptions that are currentl y promulgated in section 87.7 of our aircraft engine regulations. (Any exemptions previously

issued under section 87.7 would not be affected b y the revision s.) This section of the preamble describes these exemption and exception provisions , i.e., exemptions for engines installed in new aircraft and exceptions for spare engines used in existing aircraft for maintenance purposes. It also in cludes a descripti on of a short - term ex c eption program (termed the low - volume , time - limited transitional exemption program). These provisions have largely been crafted to be consistent with exemption provisions in the I CAO Environmental Technical Manual (ETM). 68 , 69 The prov isions of the ETM guidance were developed in the context of the CAEP/6 NOx production cutoff deliberations leading up to the CAEP /8 meeting in February 2010.

68 ICAO, “Committee on Aviation Environmental Protection (CAEP), Report of the Eighth Meeting, Montreal, February 1 - 12, 20 10,” CAEP/8 - WP/80. A copy of this document is in docket number EPA - HQ - OAR 2010 - 0687.

69 N ote that EPA has submitted a paper to amend the exemption provisions included in this ETM to be consistent with this rule. See ICAO, “Newly Produced Engine Exemption s for CAEP/6 NOx Production Cutoff,” CAEP9_WG3 - CTG - 2_IP01, September 23, 2010. A copy of this document is in docket number EPA - HQ - OAR 2010 - 0687.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 71 of 207 While we are revis ing our regulations, the process for evaluating any request for an exemption, i .e., petition, and an y final decision on its disposition would be unchanged. In this regard, the FAA is the process owner under its enforcement authority contained in section 232 of the Clean Air Act . 70 T he FAA must consult with EPA in evaluating the merits of the request, and the EPA must formally concur with an y decision regarding the granting or denial of the request. We are deleting from our regulations the requirement in §87.7(e) that the FAA publish a notice of the exemption in the Federal Register. This provision was originally adopted in 1982 when publication in the Federal Register was the most reliable method to ensure the public was notified. We now believe it is more appropriate to allow the FAA to determine how best to notify the public of exemption action s. We note that removing this provision from our regulations does not preclude the FAA from keeping such a requirement in its regulations , which we strongly

support . Under the existing regu lations, the FAA , with EPA concurrence, may also exempt low production volume engines from being full y compliant with the emission st andards. Several such short - term exemptions were granted in the 1980s when emission standards were first applied. These e xemptions have since expired, and requests for new exemptions under those provisions have not been submitted . We have determined that these provisions, which were

70 EPA formally transferred the responsibility and authority for the evaluation of requests for exemptions fro m the emission standards to the Secretary of Transportation (DOT). See “Control of Air Pollution from Aircraft and Aircraft Engines; Emission Standards and Test Procedures;” Final Rule, 47 FR 58462 , December 30, 1982.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 72 of 207 adopted in conjunction with revised emission standards in 1982, are no longer of an y utility . 71 Therefore , we are delet ing these provisions to avoid confusion . W e are also delet ing the time - limited exemption provisions for in - use engines that are contained in section 87.7(d). These provisions, which were intended for when the standards of sections 87.11(a), 87.31(a), and 87.31(c) first took effect, are now obsolete. We propos ed to delete the existing provisions for temporary exemptions based on flights for short durations and infrequent intervals. Th is proposal was based on the EPA’s and FAA’s belief that the provisions were unnecessary because our standards appl y to aircraft certificated b y the FAA, and the FAA does not address in the certification process whether an aircraft will be used for short durations or infrequent intervals. Henc e, the provisions appeared to have no utility . We received two comments from the Aerospace Industries Association (AIA) and the General Aviation Manufacturers Association (GAMA) requesting that the provision be retained. First, they

argued that as in the past, a new aircraft may be produced at a commercial facility that is destined for immediate conversion to a military only application at a separate facility . These aircraft may

require a small number of airworthiness flight tests before being delivered to the conversion facility and conceivabl y would be subject to EPA standards during flight testing .

71 U.S.EPA, “Control of Air Pollution from Aircraft and Aircraft Engines; Emission Standards and Test Procedures,” Final Rule, 47 FR 58462, December 30, 1982.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 73 of 207 While these aircraft would generall y utilize compliant engines, it may be possible that non compliant engines could be used (our standards do not apply to engines used on military aircraft as discussed later) and temporary exemptions would be necessary . Second, AIA and GAMA commented that it would be helpful if the provision also allowed for granting a discrete number of exemptions over a specified time period, rather than having to request the exemption prior to each flight as currently

required. In considering the commenters’ suggestion to retain the exemption provision , we note that a llowing such operations will not have any significant adverse affect o n the environment because of the infrequent nature and short duration of such flights . Retaining the exemption is also consistent with exempt ing military aircraft from emission control requirements as discussed later. Therefore , we have retain ed the prov ision with one change , made in response to the comments, as described below . The current provision calls for the Secretary of Transportation to consult with the EPA Administrator when considering an y exemption request for infrequent interval and short duration flights not explicitly

allowed by

the regulations . Given the inconsequential nature of such flights on the environment, we believe that the Secretary should be able to consider and act on these petitions unilaterally

to streamline the process. Therefore, we are delet ing that portion of the previous exemption provision . Of course, we will consult with the Secretary if asked to do so. As for requesting a discrete number of temporary exemptions, we believe this is an issue that theDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 74 of 207 Secretary of Tr ansportation may address under its enforcement role as described in s ection 232 of the CAA. The current regulations also provide for permanent exemptions for newly - manufactured engines based on consideration of the certain factors specified in section 8 7.7(c). We are replac ing these provisions with new regulatory text generall y consistent with the ETM that would provide for permanent exemptions or exceptions 72 for newl y manufactured engines used on new aircraft and spare engines used for maintenance or r eplacement purposes. These are summarized below. ( See §87.50 of the regulations for additional details on these exemptions /exceptions . ) a. New Provisions for Spare Engines We are revising the regulations to allow the sale of a newl y - manufactured en gine for installation on an in - service aircraft , i.e., a spare engine that does not conform to the applicable emissions standards at the time it was produced. It does not allow for installing such an engine on a new aircraft. Spare engines are produced from time to time in order to keep an aircraft in revenue service when the existing in - service engine must be removed for maintenance or

72 As used in 40 CFR part 87, as a practical matter the meanings of “exception” and “exemption” are essentially equivalent. How ever, under FAA regulations, the meanings of these terms are distinct, especially with respect to the manner in which they are administered.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 75 of 207 replacement purposes as needed. Otherwise removing these aircraft from active service would be very expensive and logisticall y difficult. As we explained in the proposal, explicitly allowing for the production of spare engines is not addressed in the existing regulations because there is no production cutoff for the current Tier 4 NOx standard s. Thus manufacturers have been allowed to continue production of older engine designs under t yp e certificates first issued before the Tier 4 standards took effect (e.g., Tier 2). However, final regulations now appl y a Tier 6 NOx production cutoff to all newl y manufactured engines . This means that if we did not also adopt a provision for the continued production of spare engines, manufacturers would be prohibited from producing Tier 4 engines under the existing ty

pe certificates for this purpose . We se e no reason to change our policy of allowing manufacturers to produce new engines for use as spares. Therefore, the final regulatory provisions allow this practice to continue. To ensure there would be no adverse environmental effect from allowing the use of a spare engine as a direct replacement for an existing engine, we proposed that the spare could be used only whe n the emissions for all pollutants of th at engine were equal to or lower than those of the engine it replac ed . This proposed requirement wa s consistent with the ETM, which also contains this allowance. We received a joint comment from AIA and GAMA stating that this is impractical because, while unlikely , a spare engine might have a different emissions profile for some pollutants than the eng ine it would replace. As an example, they stated that the twoDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 76 of 207 engines could have somewhat different combustion sy stems that might make one engine lower in NOx but higher in CO. They also suggested that EPA should consider the totality of the emissions in the decision, or delete the requirement in the final rule. These comments are surprising because this ETM provision, as well as the exemption provisions, was subject to significant discussions within CAEP that included the engine manufacturers as well as a representative from AIA. Nonetheless, i n this instance we believe the proposed provision should be modified to accommodate the potential for unusual circumstances as explained by

the commenter . As noted above, AIA and GAMA suggested that EPA consider of the totality of emissions relative to their environmental effects as the basis for evaluating spare engine exemptions . This would entail understanding and comparing the environmental consequences of the different pollutants. We find that could be very c omplicated because different pollutants have different health and welfare end points and consequences. For example , in the illustration offered b y the commenter s , the effects of LTO NOx and CO are largely unrelated to one another. We think a preferred option to evaluating total environmental effects, or even dropping the provision entirely , is to incorporate an anti - backsliding requirement which ensure s that at a minimum the excepted spare engine at least m eets the same emission standards that are applicable to the engine it is replacing . For this reason, in response to the AIA and GAMA comment, we are modify ing this provision in the final rule to allow an excepted spare engine toDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 77 of 207 have different emission levels compared to the engine it replaces as long as it remains compliant with each of the applicable emission standards and any other requirements of its ty pe certificate. Given the limited number of spare engines in the fleet, we expect allowing these engines to have somewhat diffe rent emissions profile from engines they are replacing will have no significant adv erse environmental effect. This is especially true given that we expect the emissions of an excepted spare engine will be equal or better than the engine it is replacing in most cases in accordance with the basic tenant of the ETM. We are not requiring engine m anufacturers to obtain FAA or EPA approval before producing spare engines . However, they must submit information about the production of spare engines in an annual report to EPA (see s ection III. D for more on the annual report) . We proposed that because manufacturers are not required to seek or obtain formal approval to produce spare engines, this allowance was referred to as an “exception” rather than an “exemptio n”. This terminology would be consistent with current FAA regulations. Furthermore, we proposed that the permanent record for each engine ex cep ted under this provision would need to indicate that the engine is an excepted spare engine and the engine itself would need to be labeled as “ EXCEPTED SPARE . ” in accordance with FAA marking requirements of 14 CFR . We received comments relating to allowing spare engines to be produced without requiring prior approval and the use of the terms “exceptions” or “excepted.” The Air TransportDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 78 of 207 Association (ATA) 73 appreciated that there would be no case - by - case approval, noting that it simplifies administering the provision for FAA with out compromising the structure of the exemptions program set forth in the ETM. Regarding the terminology , AIA and GAMA noted that the terminology

was inconsistent with current engine name plate labeling practices. They stated that engines are currentl y either marked “COM PLY” or “EXEMPT” for emissions. Both o rganizations generall y felt the change in terminology for spare engines might be concerning to the operators holding an engine with a plate reading “EXCEPTED .” The y concluded that the name plate for spare engines should continue to use “exempt . ” The ATA appeared to give at least tacit approval to the new terminology by acknowledging without objection that spare engines would be labeled accordingl y. First, w e are puzzled that operators with a spare engine labeled as “excepted spare” rather than “exempt” m ay

have a concern, because AIA and GAMA did not elaborate on just what the concern might be. Without at least an example, we are unable to discern the nature of the concern and respond directly to it . We also find it puzzling that the two organization s that represent aerospace manufacturers expressed a concern regarding operators of aircraft and aircraft engines when the actual organization representing those companies, ATA, did not express such a concern.

73 The Air Transport Association has changed its name to Airlines for America (A4A).Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 79 of 207 Second, regarding the terminology , the Tier 6 pro duction cutoff does not apply to the continued production of engines that are designated spares. Spare engines are produced to replace a similar engine alread y in service that was removed from service for maintenance purposes. Accordingly , the production o f a spare engine is not restricted by the production cutoff, and the regulation does not apply to these engines. The non - applicability of the cutoff eliminates the need to process an exemption for continued production of these engines beyond December 31, 2012. Conversel y, engines that are intended to be produced for new installations (i.e. not replacing an engine already in service) are subject to the production cutoff regulation and the continued production of such engines bey ond the cutoff date would re quire a grant of exemption. Since the production of spare engines is not subject to the new cutoff regulations, the FAA proposed and the EPA accepted the idea that referring to these engines as exceptions to the regulation was more appropriate than requiri ng case - by - case consideration of exemptions when the regulation did not apply . Moreover, the word “exemption” is a meaningful regulatory term. Itis used by the FAA in 14 CFR Part 11 to mean that an applicant is subject to a particular regulation and is r equesting time - limited relief under a specific set of criteria. It is a specialized form of rulemaking. When an entity or its product is specificall y left out of a regulatory provision, it is considered

“ excepted ” . An y regulation adopted by the FAA woul d use these terms consistently .Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 80 of 207 As alread y m entioned, assuming incorporation of these provisions by the FAA, engines meeting the requirements for spare engines could be produced and entered into commerce without prior approval from EPA or FAA . It is impo rtant to note that while spare engines would be excepted from the Tier 6 NOx standards being promulgated today , they still need to be produced under an FAA type certificate . ( This FAA oversight w ould serve the same role as the exemption approval step envisioned by IC AO in its ETM language for spare engines.) We also expect little or no additional burden for manufacturer s, since we are not establishing new restrictions, monitoring, recordkeeping, or reporting requirements other than the e nd of ye ar report. b. New Provisions for Engines Installed in New Aircraft The primary

purpose of allowing limited continued production of Tier 4 engines is to provide for an orderly

implementation of the Tier 6 NOx production cutoff . It addresses engi nes reaching the end of their production cycles in the time frame when new emission standards take effect. The t ypical production cycle would have annual production volumes ramp up quickly, remain at relatively

large volumes for several or many y ears, and then fall off over a few more ye ars. When new emission standards are adopted in the middle of a production cycle to take effect a few ye ars later, manufacturers generall y devote technical resources to bring into compliance those engine models expected to be produced in large numbers in the time frame when the new standards are in effect. In contrast, they may plan not to invest in upgrading theDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 81 of 207 emissions of engine models that would be very near the end of their normal production cycles when compliance wi th the new standards becomes required. The actual length and shape of this tail of production volumes can be affected b y factors not fully within the engine manufacturers’ control , e.g., unexpected market demand . Thus , exemptions may be justified if a manufacturer does not complete the production cycle before the production cutoff date and projected production volumes are not adequate to justify invest ing the necessary

resources to reduce emissions or there are other technological issues . Furthermore, i n certain exceptional circumstances exemptions may also be appropriate. These are “hardship” situations that may arise as a result of unforeseen technical or economic circumstances or events bey ond control of the manufacturer. For example, this could vary from unexpected problems with technology upgrade programs to labor disruptions or natural events disrupting production or parts availability . Our regulations currentl y address these kinds of situations in section 87.7(c), entitled , “Exemptions for New E ngines in Other Categories . ” We are replac ing this provision with a new set of provisions addressing exemptions for new engines. i. Time Frame and Scope The final regulations allow engine manufacturers to request an exemption for newl y manufacture d eng ines not meet ing the Tier 6 NOx standards so they may be installed in new aircraft. If granted, manufacturers may pr oduce a limited number of these newly - manufacturedDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 82 of 207 engines in a four ye ar time period beginning after December 31, 2012 and going through December 31, 2016. This four - ye ar time period is consistent with the ETM. The period for an y given approved exemption could be shorter depending on the specifics of the application , but it c ould not be longer. This exemption limit s NOx emissions from engines that are covered b y a valid ty pe certificate issued by

FAA. The engines must meet all other applicable requirements. More specificall y, an engine exempted from the Tier 6 NOx standards must be covered b y a previously

issued ty pe certificate showing compliance with the Tier 4 NOx standards, 74 as well as the current HC, CO, fuel venting, and smoke standards. As explained above, the scope of the exemption provisions are limited to newly manufactured engines that do not comply with the Tier 6 NOx standards. No need has been identified to apply such exemption language to the other regulated exhaust pollutants, i.e., smoke, hydrocarbons and carbon monoxide. The emission standards for those po llutant species have remained unchanged for nearly three decades and present no technical issues for modern turbofan engines. 75 If new emission standards for these pollutants are considered in the future, the potential need for exemption provisions will a l so be assessed at that time.

74 Engines certified only for complian ce with earlier Tier 2 NOx standards w ould not be eligible for exemptions. This is also consistent with the exemption language in the ICAO ETM. Note that where such engines have emissions actually meeting the Tier 4 NOx standard, they may be recertified to the Tier 4 standards, but only before the effective date of the regulations.

75 For example, the hydrocarbon exhaust emission standards were adopted on December 30, 1982. See 47 FR 58462.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 83 of 207 We received comments requesting that exemptions be available for newl y - certified engines in addition to newly - manufactured engines. General Electric Aviation (GE) stat ed that unforeseen circumstances may arise during the lengthy aircraft engine development process that necessitates a change in design , and that may affect the ability of that engine model to meet the prevailing Tier emission standard at certification. For that reason, GE concluded that exemptions for newly - cert ified engine would be beneficial. The AIA and GAMA jointly stated that the existing 40 CFR section 87.7(c) not onl y provides the flexibility to exempt newly manufactured engines from a production cutoff, but also for newl y - certificated engine models subje ct to any

emission standards, e.g., the Tier 8 NOx standards. They requested that this flexibility should be retained. Regarding the availability of exemptions for newly - certified engine models, the proposed regulatory

text made clear that the exemption provisions would only apply to newly manufactured engines. Specificall y, the intent was to establish provisions for newl y manufactured engines to address the potential technology and economic adversities that may arise as part of adopting the Tier 6 prod uction cutoff. The ICAO ETM provisions are clearl y intended for that same purpose. Also, the original intent of EPA’s current exemption provisions in section 87.7(c), which we are modifying in this rulemaking, is clear from the proposed rulemaking and fin al rulemaking that resulted in those provisions. The March 24, 1978 proposal described the concern as “...engines which are nearly [at] the end of their production life would be terminated prematurely because there would be insufficient future sales to justi fyDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 84 of 207 incorporating emission controls.” (See 43 FR 12619, March 24, 1978.) The December 30, 1982 final rule referenced “...the removal of an engine model from the market because of its failure to comply .” (See 47 FR 58468, December 30, 1982.) Obviously , the intent of the existing e xemption provision cited by AIA and GAMA was to make it apply onl y to newly - manufactured engines. As a general matter, we believe an exemption from the Tier 6 standard, or any other standard, for newl y - certified engine models is speculative at this time and would undermine the goal of regulatory

compliance by

new engine designs. In any event, neither the current ICAO Annex 16 , Volume II provisions nor the ETM provide for newl y - certified en gine exemptions. We believe that such would be a fundamental shift from Annex 16 and the ETM should be explored within the framework of IC AO/CAEP. Furthermore, engine manufacturers already have significant leadtime between the date CAEP adopts a new emis sion standard and the standard’s effective date, e.g., usually 3 - 5 y ears. Finally , engine manufacturers historicall y design new engine models to comply with the most stringent future standard that also provides for a longer development time horizon. There fore, we are promulgating the exemption provisions for newl y - manufactured engines as proposed.

ii. Production Limit The final regulations reflect the essence of the general exemption language for exhaust emission standards regarding how to determine the number of allowable exemptions that isDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 85 of 207 embodied in current section 87.7(c) of the regulations. That provision generally states that the FAA, with EPA ’s concurrence , may grant exemptions to exhaust emission standards based on factors such as adverse ec onomic impact on the engine manufacturer, aircraft manufacturer, or airline industry ; in addition to the effects on public health and welfare. As a result, section 87.7(c) does not specify a nominal number of exemptions. Rather, e ach request for exemption would be evaluated on a case - by - case basis, using the information provided b y the applicant and an y other relevant information that is available to FAA and EPA at the time. Any

approved exemption would include a specific limit on the number of s uch engines based on that information and is not defined on a basis such as ty pe certificate. (See section III.B.b.iii for a description of what the request must contain.) The intent, of course, would be to exempt the minimum number of engines that can b e clearly justified, including a consideration of the public health and welfare effect associated with the exemptions. In the proposal, w e acknowledged that our approach to determining limits on the number of exempt engines differs from the language contained in the current ICAO ETM guidance. The ETM states that “[t]he number of engines exempted would normally not exceed 75 per engine ty pe....” 76 We chose not to propose adopting this language on the nominal number of engines based on a single t ype certif icate. Our reasons for this deviation were detailed in the proposal and are summarized below.

76 CAEP/8

– WP/18, Environmental Technical Manual (ETM), Vol II on the Use of Procedures in the Emission Certification of Aircraft Engines , Appendix ”ICAO Emissions Environmental Technical Manual”.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 86 of 207 At the time of the CAEP deliberations, the ICAO Emissions Data Bank identified 20 unique engine models/sub models that could have been affected b y the productio n cutoff. Those models had valid ty

pe certificates and , therefore , were consid er ed to be “in production.” 77 During further discussions the engine manufacturers clarified that most of these 20 were not in active production because the airlines normall y purchase new aircraft with engines meeting the latest emission standards. Nonetheless , it was stated that if the demand arose , 14 of these 20 models could potentially be produced under the exemption provisions since they had valid ty

pe certificates and met the previously mentioned exemption emission requirements. 78 , 79 , 80 , 81 After much deliberation, the CAEP technic al working group settled on a value of 75 engines per t ype

77 U.S. EPA, “Simplified Working Copy of ICAO EDB, Issue 16A,” memorandum from Glenn Passavant, Assessment and Standards Division, Office of Air Quality and Transportation, March 25, 2010. A copy of this document is in docket num ber EPA - HQ - OAR - 2010 - 0687. 78 ICAO, “Committee on Aviation Environmental Protection (CAEP), Response to EPA Paper 14 and 16,” WG - 3 Flimsy 6 - 2, ICCAIA, London, UK, April 13, 2009. A copy of this document is in docket num ber EPA - HQ OAR - 2010 - 0687.

79 ICAO, “Committee on Aviation Environme ntal Protection (CAEP), Production Cut - Off for Engine NOx Standards,” CAEP - SG/20082 - WP/6, Presented by FESG, September 4, 2008. A copy of this document is in docket n umber EPA - HQ - OAR - 2010 - 0687.

80 ICAO, “Committee on Aviation Environmental Protection (CAEP ), CAEP/6 NOx Production Cut - Off Analysis,” CAEP - SB/20093 - IP/19, Presented by FESG NOx Stringency Task Group, June 2, 2009. A copy of this document is in docket num ber EPA - HQ - OAR - 2010 - 0687. 81 ICAO, “Committee on Aviation Environmental Protection (CAEP), P roduction Cut - Off and Associated Flexibilities for ICAO Engine Emission Standards,” CAEP - SG/20093 - WP/39, U.S.EPA, June 8, 2009. A copy of this document is in docket num ber EPA - HQ - OAR - 2010 - 0687.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 87 of 207 certificate over the four years for the ICAO ETM guidance based on the information available at the time . 82 This value and the maximum number of engines it could represent were of immediate concern to EPA. First, in a hy pothetical worst case, the number of potentially exempted engines was very large relative to average annual engine sales Second, it was unclear to us if that number of potential exemptions, i.e., 75 per ty pe certificate, was necess ary. Both of these gave the appearance that the ETM nominal limit was potentially very excessive. We also noted that, from a broader perspective, while EPA regulations normally include hardship ty

pe provisions, it is ab normal for EPA to include specific transitional exemptions of this magnitude in our regulations. As we continued efforts to identify how man y exemptions might potentially be needed for the CAEP/6 production cutoff , three new pieces of information became available during the development o f th e proposed rule that were not considered during the deliberations leading up to the I CAO decision for the ETM guidance . First , a review of previousl y unavailable information on past exemption requests to FAA under the previous less specific ICAO langu age indicated that of the eight requests granted since 1983, onl y three involved exemptions during standards transition ( two related to smoke for turboprop engines and one related to NOx for a turbo fan

82 ICAO, “Committee on Aviation Environmental Protection (CAEP ), Report of the Eighth Meeting, Montreal, February 1 - 12, 2010,” CAEP/8 - WP - 80, Appendix B. A copy of this document is in docket n umber EPA HQ - OAR - 2010 - 0687.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 88 of 207 engine). These three exemption petitions in combinati on ultimately affected less than 50 engines. 83 Second , engine manufacturers indicated individually that the potential need for exemptions was not as large as EPA understood during the technical working group deliberations, and that absent unforeseen events , a much smaller value was workable on a per manufacturer bas is as opposed to a per t ype certificate basis. 84 , 85 , 86 Third, our most recent discussions with the engine manufacturers that are directly affected by

the proposed Tier 6 NOx standards, i.e., CAEP/6 standards, concluded that only one or two engine models may be candidates for exemptions. Those discussions a lso concluded that the likely potential number of justifiable exemptions would be less than 75 in total. 87

83 U.S. EPA , "Historical Exemptions from Gas Turbine Aircraft Emission Standards," me mo randum from Glenn Passavant, Assessment and Standards Division, Office of Air Quality and Transportation, March 28, 2011. A copy of this document is in docket num ber EPA - HQ - OAR - 2010 - 0687. 84 ICAO, “Committee on Aviation Environmental Protection (CAEP), Response to EPA Paper 14 and 16,” WG - 3 Flimsy 6 - 2, ICCAIA, London, UK, April 13, 2009. A copy of this document is in docket num ber EPA - HQ OAR - 2010 - 0687.

85 ICAO, “Committee on Aviation Environmental Protection (CAEP), Production Cut - Off for Engine NOx Standards,” CAEP - SG/20082 - WP/6, Presented by FESG, September 4, 2008. A copy of this document is in docket n umber EPA - HQ - OAR - 2010 - 0687.

86 ICAO, “Committee on Aviation Environmental Protection (CAEP), CAEP/6 NOx Production Cut - Off Analysis,” CAEP - SB/20093 - IP/19, Presented by FESG NOx Stringency Task Group, June 2, 2009. A copy of this document is in docket num ber EPA - HQ - OAR - 2010 - 0687. 87 U.S. EPA, “Results of Discussions with Aviation Gas Turbine Manufactures on the Potential Number of Exemptions from the Tier 6 Production Cutoff for the Proposed Rulemaking on Aircraft Engine Emission Standards,” memorandum from Richard S. Wilcox, Assessment and Standards Division, Office of Air Quality and Transportation, May 19, 2011. A copy of this document is in docket number EPA - HQ - OAR - 2 010 - 0687.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 89 of 207 Considering all of these factors and the basic intent of the CAEP ETM exemption provisions , we proposed to adopt language in our new regulatory tex t addressing exemptions that reflects the essence of the general exemption language for exhaust emission standards embodied in current section 87.7(c) of the regulations. As stated above, that provision generall y states that the FAA, with EPA ’s concurrenc e , may grant exemptions to exhaust emission standards based on factors such as adverse economic impact on the engine manufacturer, aircraft manufacturer, or airline industry ; in addition to the effects on public health and welfare. We also noted that th e proposed exemption provision ha d no cost associated with it for the government or industry , and there is no difference in potential cost savings under either approach. Both were designed to provide manufacturers with an opportunity to reduce costs or other adverse effects should the need for exemptions arise. Finally , w e concluded th at the proposed approach addresse d the intent of the I CAO guidance in addition to the potential need s of the engine manufacturers, while minimizing the potential for adverse environmental impacts from exemptions and aligning with EPA’s general approach with regard to exemptions and hardship provisions. We received several comments focusing primarily on the number of exemptions and the underlying process that is embodied in th e ETM and our propos al . General Electric Aviation (GE) maintained that harmonization with the international community is not only

required b y the Chicago Convention, but also provides streamlined processes and procedures within theDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 90 of 207 regulated industry . T hey argued that an y purported benefits to EPA’s unique exemption scheme were outweighed b y setting up a conflict with the remainder of the world. They also suggested that if EPA wants a different approach for evaluating exemptions, it would be more approp riate to work inside the I CAO/CAEP process toward that end. The ATA commented that EPA ’s case - by - case approach to determining the number of engines is a rejection of the I CAO/ETM provisions that limit “...the number of exemptions ... to 75 engines per t ype certificate...”. They argued that this would create a serious discontinuity between the U.S. and the rest of the world, undermining I CAO’s objective of international uniformity . The ATA also argued that the ICAO exemption limits are intended to be coordinated among international aviation authorities , and that d iffering rules would make this impracticable. As evidence of this problem, ATA cited the European Aviation Safet y Agency’s (EASA) proposed rulemaking , which they noted was based on the assumption that the I CAO proposals will be adopted unaltered by other aviation authorities of the world. The ATA also stated that the I CAO ETM guidance document supplements the official standards of Annex 16, Vol. II and, therefore, the ETM provides technical elaboration on the implementation of Annex 16. From this ATA concluded that differing practices in this regard are counter to the Chicago Convention. Regarding consistency

with the Chicago Convention , our proposal thoroughly explain ed that the ETM is guidance material; not an ICAO standard or regulation of any t ype. Moreover, even if the ETM were wrongl y considered a standard , consistency is not compelled when aDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 91 of 207 deviation is justified, and we were comfortable with our proposed exemp tion provision for those reasons. Therefore, we disagree with the commenters on this point, and specificall y with ATA’s comment that the I CAO guidance is effectivel y the equivalent of an ICAO Annex 16 standard. Turning to ATA’s comment regarding the ETM cap of 75 engines per t ype certificate, we first want to point out that this is not a maximum limit on the number of potential exemptions per ty pe certificate. Rather the ETM provision is an expectation that “[T]he number of engines exempted would normal ly not exceed 75 per engine ty pe certificate ....” as stated in the document. With this perspective both the ETM and our approach are similar in that the maximum number of exempted engines is based on a consideration of the petitioner’s justification for su ch exemptions. Finally , we disagree with the comment that the differences with the ETM make international coordination unworkable. In fact, one of the proposed justification elements, i.e., how many

affected aircraft will be registered in the U.S. and o ther countries (estimate allowed), was described in the preamble for the proposal as being aimed at helping to facilitate consultation and coordination. Also, as noted above, the ETM’s expectation that exemptions would normally

not exceed 75 per t ype cert ificate and our proposal are similar in that the maximum number of exempted engines under both approaches is based on a consideration of the petitioner’s justification for such exemptions. As we described in the proposal, it now appears that only one or two engine models may be candidates for exemptions, and that the potentialDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 92 of 207 number of justifiable exemptions would be less than 75 in total. We do not think coordination with foreign aviation authorities, most likely EASA, with these few exemptions should p ose any problems. Therefore, we find nothing in the justification elements that should impinge upon the ability to internationall y collaborate and consult on exemptions. After considering the above comments on the number of exemptions and the underl yi ng process embodied in the ETM and our approach, we are promulgating the provisions relating to the comments as originally proposed. iii. Exemption Requests We are establishin g a process for requesting exemptions (for engines used on new aircraft) that would be more formal and structured than the current process. We are requiring manufacturers submit their request to the FAA , as currentl y required. The FAA will then share the submittal with EPA and execute the consultation process . To ensure that we have the information necessary to evaluate exemption requests in this specific manner, the requests need to include the following details to describe the specific engine model for which the manufacturer i s requesting the exemption. The final provisions contain ed in §87.50, which are summarized below , are consistent with and in some areas expand on the provisions in the ETM: General InformationDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 93 of 207 • Corporate name and an authorized repre sentative’s contact information (including a signed statement verifying the i nformation);

• Description of the engines for which you are requesting the exemption, including the e ngine model and sub - model names;

• The number of engines that y ou would produce under the exemption and the period duri ng which you would produce them;

• Id entify the authorizing t ype certificate (t y pe certificate number and date);

• In formation about the aircraft in which the engines will be installed, including the airframe models and expected first purchasers/users of the aircraft, and the countries in which you expect the aircraft to be registered (including an estimate of how many will be registered in the U.S.); and

• Li st of other certificating authorities from which y ou have requested (or expect to request) exemptions, and a summary of each request. Justification and Impacts Assessment

• A detailed description and assessment of the environmental i mpact of granting the exemption;Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 94 of 207 • Technical issues, from an environmental and airworthiness perspective, which may have caused a delay

in compliance w ith a production cutoff, if an y;

• Any economic impacts on the manufacturer, operator(s), and aviation industry at large; and

• Projected future production volumes and plans for producing a compliant version of the engine model in question. Other Factors

• Hardship: Impact of unforeseen technical circumstances , business events, or other natural or manmade calamities beyond your control, and

• Equity issues in administering the production cutoff among economically competing parties . It i s important that an y action on a potential exemption request be in the public interest; the fairl y comprehensive list of application information in the regulations is intended to gather the information needed for this assessment. We would expect to take a broad perspective in evaluating what is or is not in the public interest. This is why a manufacturer ’s justification need s to include a quantified description of the environmental effects of granting the exemption, as well as discussion of economic and technical issues related to bringing the engine into compliance. The anal ys is of environmental impacts need s to specify by how much the exemptedDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 95 of 207 engines would exceed the standards, the in - u se effects in terms of lifetime tons of NOx, and estimate the emissions rates of engines/aircraft that could potentially be used if the exemption was not granted. Since exemptions granted under the regulations appl y only to NOx emissions, the anal ys is cou ld also include possible benefits regarding noise levels or reduced emissions of pollutants other than NOx. Relevant economic impacts could include effects on the engine manufacturer, airframe manufacturer, airline(s), and the general public. As we detail ed in the proposal, some manufacturers have requested exemptions in the past based on the largest number of engines they hoped to continue manufacturing without knowing how man y they

would actuall y be able to produce or who would purchase them. The new ex emption language calls for manufacturers to target their requests more specificall y based on likely production needs and time periods. While we expect a manufacturer to have this specific information when they submit a request, the final regulations allow us to process exemption requests with somewhat less specific information. However, we expect this to apply only for unusual circumstances. Manufacturers also are being required to notify the FAA if they determine after submitting a request that the info rmation is not accurate, either from an error or from changing circumstances. The final regulations also allow manufacturers to revise their requests to justify cover ing additional engines at an y time before approval . We would then review the revised re quest.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 96 of 207 Similarly , for e xemptions that are alread y approved , manufacturers could request that additional engines be added after providing the justification for the increase . We received comments on the level of detail required in a request for exemption and the time needed to add more engines to such a request or an already approved exemption. First, ATA was concerned that r equesting an increased amount of engine exemptions can take a significant amount of time . They stated that there may

be ins ufficient time for a manufacturer to receive approval for additional engine exemption s if necessary to meet previously

unknown market demands. In response, we find it unfortunate that the comment does not provide a specific example or other information that may il lustrate this concern. As a general response, given the long leadtime between the initiation of discussions among aircraft purchasers and aircraft manufacturers, and actual orders and final deliveries, we expect that manufacturers will have enough time t o request additional engine exemptions, and if appropriate, for the FAA and EPA to approve such a request. We expect that amending an already approved exemption would take less time to act upon than the original petition. Also, engine manufacturers may r equest an expedited review from the FAA, and b y association the EPA, if circumstances warrant. Finally, to the extent that an engine manufacturer has specific concerns in this area, they could be ameliorated b y improving the lines of communication with ai r frame manufacturers to increaseDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 97 of 207 the manufacturer’s awareness of market interest in potential new orders. Accordingl y, we are promulgating the exemption provision relating to this comment as proposed. Second, ATA commented negativel y that the exemption r equest for each individual engine be justified, “...including the exact number, initial purchasers/users, countries of registry and plans for bring ing the product into compliance.” They claimed that this knowledge may not be known at the time of the exemptio n request because of market leadtimes. As an example, ATA cited the 1998 Rolls Roy ce (RR) exemption request from the CAEP / 2 cutoff for 150 engines that was not based on that ty pe of certainty , but was a prospective exemption for two ye ars as protection against the uncertainties of technical development. They stated that RR did not know when the development process would be c ompleted, and hence did not know the exact number of non - compliant engines that airlines would purchase. The ATA also added that the three affected airlines worked with RR to provide documentation of the financial and operational hardship that they

would suffer based on their aircraft delivery schedules. In response to ATA’s second comment, we simply want to note that the information we would normally

expect to be contained in the exemption application is actually not much different than the justification envisioned by the ETM. That guidance document explains that the petitioner should, to the extent possible, provide quantitative support to justify the exemptions. Specifically, the ETM states that it “...provides guidelines on the process and criteria for issuing exemptions....” These include some of the same elements as contained in ourDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 98 of 207 proposal and referenced above, i.e., the exact number of exemptions being requested, to whom the engines will be originally delivered, and plans for producing a compliant p roduct. Therefore, the ETM envisions a consideration of specific information as part of the exemption request, in a similar fashion as EPA’s approach, in order to decide on the exact number of exemptions to grant. We are simpl y being more explicit in som e areas concerning the t ype of information that should be included in any exemption request. We also note ATA’s comment that “[T]he airlines did work with Rolls Royce to provide documentation of the financial and operational hardship that they would suffe r if there were an interruption in the supply of ICAO - compliant engines during their aircraft delivery schedules . ” G iven the long lead times generall y associated with new aircraft orders and deliveries, we expect aircraft operators will work closely with aircraft manufacturers as their new aircraft needs are identified. Engine manufacturers should in turn work with aircraft manufacturers to stay aware of market interest in potential new orders. This appears to be reflected in the commenter’s example regarding the cooperation between airlines and RR in fashioning the exemption justification. Also, as explained in the proposed regulatory text, the petitioner should include information on the “ expected” first purchasers/users of the aircraft. It also ask ed for information on the number of aircraft that will be registered in the U.S. versus other countries and that this may be estimated if not known. Therefore, precise knowledge is not needed for certain elements of the justification. The preamble to the p roposed requirements also stated that the regulations would allow us to process exemption requests with somewhat less specific information, althoughDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 99 of 207 we expected that to appl y only for unusual circumstances. We have made this clearer in the final regulatio ns. Returning to the final exemption provisions, if after consult ing with FAA we determine that the exemption request is fully documented and approval would be in the public interest, we will concur with approv ing the request if the FAA also concluded that the request should be granted . Note that we could approve the exemption for a smaller number of engines than the manufacturer requested, or we could include certain other conditions. In order to allow us to oversee these exempted engines, manufacturers are being required to also provide an annual report to EPA on exempt engines similar to the information about spare ex cepted engines. The permanent record for each engine exempted under this provision must indicate that the engine is an exempted engine a nd the engine itself must to be labeled as

“ exempt new ” in accordance with FAA marking requirements of 14 CFR . iv. Coordination of Exemption Requests The limit on the number of potentially exempt engines as described in the ETM is intended to apply

to overall worldwide production. Toward that end, the ETM envisions that certificating authorities and member states should coordinate whenever an y authority receives an exemption request.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 100 of 207 Working with the FAA, we expect to consult with other aviation authorities whenever we receive an exemption request. This would include a consultation with other certificating authorities as well as coordination with the appropriate civil aviation authority of an y country where the aircraft with the exempted engines will be registered. To facilitate this coordination we are asking that manufacturers also include in their requests , a list of countries in which the aircraf t are expected to be registered. While not specificall y listed in the ETM, we believe that this information is consistent with the ETM as it would be necessary

to ensure proper coordination. The ETM appears to presume that each member country

will recogn ize exemptions granted by other countries. This presumption seems reasonable assuming that the exemption being granted is generall y consistent with the guidelines of the ETM and that the consultation and coordination called for in the ETM was conducted in good faith. However, there should be no presumption that EPA would agree to an exemption for an engine model if the aforementioned collaboration, consultation, and coordination were not conducted. The Clean Air Act (which provides EPA with its authori ty to establish emission standards) includes no provisions that would allow an y foreign country or other certificating authority to exempt subject aircraft engines, over the objection of FAA and EPA, from the applicable standards EPA promulgates. Neverthe less, because our final exemptions provisions are generally consistent with the procedures called for in the ETM, assuming appropriate consultation and coordination in accordance with the ETM and absent unforeseen complications, it is reasonable to believe that FAA and EPA would not object to exemptions for enginesDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 101 of 207 properl y exempted b y other countries under those procedures. The FAA would still need to take the certification action as called out in 14 CFR 91.203 and 14 CFR 21.183. This, however, raises th e question as to how we would respond to an exemption request when another certificating authorit y did not consult or coordinate on a previous request for the same engine model. A related concern arises if an FAA ty pe certificate is sought under a recipro city

agreement for an engine which was previously certificated under an exemption by a foreign certificating authority , and the original exemption was not coordinated with the United States. Such requests would likely be viewed as new exemption requests i f the anticipated collaboration, consultation, and coordination had not occurred. Thus to avoid these issues, in most cases, manufacturers may want to work with all relevant certificating authorities at the same time as well as the civil aviation authority of nation(s) where the aircraft will be initially registered or operated if that nation requires a t yp e certificate issued under its own regulations to operate in its air space consistent with international agreements.

v . L ow - volume, time - limited transitional ex ce ption program We r eceived a comment from one manufacturer expressing concern that once the final rule becomes effective additional time may be required for EPA and FAA to establish and undertake procedures to review and act upon exemption requests. They stated that the time needed for this process could be very dis ruptive for engine manufacturers that have alread yDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 102 of 207 contracted to deliver engines during th e period which FAA/EPA would need to consider exemption requests . They also claimed it would be harmful to airplane manufacturers and airlines. To avoid such an undesirable outcome, the commenter suggested that EPA should grant a one - time, interim block of perhaps 20 exemptions. Based on supplemental information we received from the commenter , 88 we find the concerns center on six engines for which they have contract commitments to build and deliver within several months of this final rule. T hese six engines belong to two engine models, with four engines in one model and two engines in the other . The first model co nsist ing of four engines is scheduled to begin shipping in January 2013, shortly

after the January

1, 2013 Tier 6 production cut off. These engines are currentl y certificated to the Tier 4 NOx standards . The commenter ha s stated, however, that the design of this engine model has b een technically modif ied to achieve the Tier 6 standards. Unfortunately , compliance testing of th is model to meet the Tier 6 standards cannot be performed until December of this y ear when the first production version is built . Assuming that this testing is successful, inadequate time remains for the FAA to formally

recognize Tier 6 compliance based on those tests before the production

88 Mem oranda documenting this supplemental information are located in docket n umber EPA - HQ - OAR 2010 - 0687 .Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 103 of 207 cutoff becomes effective. 89 The two new aircraft using these engines are being built and will be delivered to a foreign ai rline. The second model is comprised of two engines with a contracted deliver date in May 2013. They are also certificated to the Tier 4 NOx standards. These engines are at the end of their production life, i.e., no additional future deliveries for civilian uses are anticipated beyond these two contracted engines . For this reason, the commenter has stated that it is not economicall y feasible to redesign this model to conform with the Tier 6 standards, even if it were technicall y feasible. The single new aircraft using these engine s is also being built for delivery to a foreign airline. In assessing this concern, we find that a considerable amount of time will indeed be required between the time this final rule becomes effectiv e and completing any formal FAA action using the normal exemption process as previously described in this notice . Specificall y, t ime is needed for : 1) the FAA to amend 14 CFR part 34 through rulemaking to incorporate the production cutoff and procedures for granting exemption from the new standards ; 2) the manufacturer to develop the information needed s to s upport a request ; 3) submitting the request for review by

FAA and EPA ; 4) c oordination with other certificating authorities ; and 5) EPA and FAA review and final action on the request, i.e., approval or disapproval. Regarding this review

89 The FAA has stated to EPA that inadequate time exists for the required formal compliance determination before the production cutoff takes effect.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 104 of 207 and final action, we note that FAA staff involved in reviewing the manufacturers request may also be engaged in conducting the processes to adopt this rule in 14 CFR part 34 and to review emission information on current t ype certificates to confirm that they meet either Tier 6 or Tier 8 requirements , as previously described . Therefore, we conclud e that inadequate time exists to act on an exemption request with certaint y for these six engines before their contract deliver dates. Consequently , we conclude that a limited modification to the otherwise universal effective date of the final Tier 6 comp liance deadline is appropriate to accommodate the commenter’s situation, and that for these six specific engines additional lead time is needed due to cost and technical feasibility factors. We also believe that disrupting the scheduled delivery dates of these engines could risk subject ing the commenter to possible financial penalties for late delivery , with possible follow on effects for the aircraft manufacturer and airlines. We also find that there is no significant adverse effect on the environment in allowing these six engines to be produced and sold as compliant with Tier 4 standards , especially if four of the engines ultimately comply with the Tier 6 standards. For the above reasons, and in response to the comments and under our authority under sections 231(a)(3 ) and (b) to issue final regulations with such modifications to the proposal as the Administrator deems appropriate and to make revised standards effective after such period as the Administrator finds necessary to permit the development and application or requisiteDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 105 of 207 technology , giving appropriate consideration to the cost of compliance within such period , we are including an exception provision in the regulations that permits any aircraft engine manufacturer t o produce and enter into commerce up to six newly manufactured engines with a date of manufacture , as defined in the regulations, prior to August 3 1, 2013 that are not certificated to meet Tier 6 emission requirements . These engines must have a t ype certi ficate which indicates that they

meet the 40 CFR 87 requirements last updated on October 30 , 2009 (i.e., Tier 4) . No formal exemption request or approval will be required for these six engines. T hese engines will be labeled as specified by the FAA and reported to EPA as part of the annual reporting requirement as described above for exempt engines. We know of no other engine manufacturer that is in this situation today , (i.e., contracted deliveries of engines not meeting the production cut - off with in several months of the production cut - off date). However, as a matter of equity and to address situations which we may not be informed of at this time, we are extending this transitional flexibility to all manufacturers. c. Voluntary Emission Offs ets We requested comment on establishing a voluntary EPA program by which manufacturers could receive emission credits for producing cleaner engines, which they could use to offset higher emissions from exempted engines. An example of such a program wasDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 106 of 207 s ummarized in a memorandum to the docket . 90 The ty pes of programs we were considering would be developed, promulgated, and administered by EPA. As described in the proposal and summarized here, w e expect ed manufacturers to be interested in generating offs ets for one of three purposes. First, manufacturers might choose to generate offsets as part of their justifications for exemptions. Second, manufacturers might choose to generate offsets as part of a justification for being allowed to exceed the numeric al limit that FAA and EPA are willing to approve in an exemption request . Third , provided a provision was promulgated to allow this, a manufacturer might also be interested in generating offsets to bank for use for exemptions of engines to be produced aft er the credit generating engines are produced, or possibly against a future production cutoff . Under th e proposed approach, generation of offsets would be voluntary and would be open to all certifying engine manufacturers. One concept was to allow c redi ts to be generated only from engine models that are introduced after this rule and that had characteristic level s significantl y below the otherwise applicable standard (e.g., at least 10 percent below) . There was a separate question, however, regarding how to calculate the credit. If we adopted, for example, a 10 percent threshold for eligibility , we would probably also allow credits only

to the degree which the NOx characteristic level was more than 1 0 percent below the standard. This would

90 U.S. EPA, “Draft Regulatory Text for Voluntary Offset Program,” Memorandum from Charles Moulis, Assessment and Standards Division, Office of Air Quality and Transportation, June 2011. A copy of this document is in docket number EPA - HQ - OAR - 2010 - 0687.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 107 of 207 ensure a net improvement in emissions. Also , we could reserve the right to restrict the use of credits so that they

were used in a manner that ensured there was no net adverse impact on air quality . Such a program would need to ensure that emission benefits from one aircraft model truly offset the higher emissions from another model. Equivalency factors could be developed to account for differences in the number of LTOs per y ear and the lifetime of the aircraft . We received a number of comments on the possibility of implementing a voluntary credit offset program. The ATA expressed significant doubt that EPA had the legal authority to adopt a voluntary

emissions offset program. They argued that the standard setting authorit y under section 231 of the CAA does not appear to provide such authorit y. ATA f urther stated that where offsets or emissions trading scheme s exist for other source categories, the authorit y is express. E xamples cited were the CAA authorit y f or the trading program under the acid rain program, and the Energy

Independence and Security Act authorization for the offset program used under the Corporate Average Fuel Efficiency Standards. Pratt & Whitney provided comments very similar to ATA relativ e to the lack of EPA’s legal authorit y to create such a program. The ATA also commented that the voluntary offset program embodied in the proposal would be unworkable in the context of aviation. They noted that unlike car s or trucks, aircraft engine manufa cturers have relativel y low production volumes and few frequently updated models for generating credits. Also, some manufacturers have more models than others and thisDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 108 of 207 could possibly

lead to competitive distortions in the market. The AIA and GAMA also rai sed concerns regarding potential market disruptions. Further, ATA argued that opportunities for generating offsets would be limited by the proposal’s high thresholds for generating those credits. In the context of using emission credits for exemptions AT A added that each situation would be unique and it would not be possible to match exemptions to credits, or to assess the further complexities of the “equivalency factors” described in the proposal. Finally , they stated that an airline’s delivery

schedule would be held hostage to the manufacturer’s ability to justify credits based on some other engine that the airline is not buying. For these reasons, ATA asked that no offset program be adopted. Pratt & Whitney

stated that the EPA proposal assumes that an offset program would create an incentive for manufacturers to build lower - emissions engines. On the contrary they argued, manufacturers alread y have that incentive because using the lowest - emitting technology that is available maximizes the life of the engine. Such a program would simply create a windfall to manufacturers whose produc t lines are alread y capable of generating credits. The AIA , GAMA , and GE jointly commented that the proposed emission offset program goes beyond the borders of CAEP, and any emissions offset program should be developed within ICAO. G eneral E lectric was interested in exploring a potential emission offset program , particularl y if the program would be applicable to new engine designs and derivatives that are subject to the pr oposed Tier 8 standards, and if it created the incentive to adopt new technologies earlier than would otherwise be the case in the absence of such incentives.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 109 of 207 We appreciate the concerns raised b y the commenters regarding the proposed voluntary offset emiss ion program. We are also encouraged by GE’s interest in further discussions about how this program may

be useful in the context of the Tier 8 standards and a possible future Tier 8 production cutoff. EPA agrees that the proposal needs to be further develo ped to address certain aspects of the offset program. We have determined that the time it would take to sufficiently

develop the program is incompatible with the need to promptly promulgate the Tier 6 production cutoff standard with a near - term effective date of January 1, 2013. Therefore we are not including the voluntary emission offset program in the final rule at this time. Nonetheless, we continue to see value in such a program for the aviation industry and recommend continuing to consider such a regu latory flexibility

in the future. Although we are deferring action on the proposed voluntary emission offset program for the time being, we believe that such programs are envisioned within the ETM language related to exemptions. Furthermore, we do not agr ee with the commenters who questioned the EPA's l egal auth ority for adopting a voluntary

emissions offset program as part of the aircraft engine emission standards. W e are somewhat surprised by the industry commenters who questioned the authority for averaging, banking, and trading ( ABT ) programs outside of the narrow examples cited in their comments, and we are not yet persua ded by their claims. Note that the U.S. Court of Appeals for the D.C. Circuit has clearl y stated that EPA has substantial discr etion under the CAA section 231 to adopt final aircraft emission standards as the agency deems appropriate (National Ass’n of Clean Air Agencies v. EPA 489 F.3d 1221 (D.C. Cir. 2007)) . We alsoDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 110 of 207 wonder to what extent their view represents the industry as a whole, including an y aircraft engine manufacturers who also manufacture engines that are subject to other EPA regulations that provide for ABT without the “express” statutory authority the commenters claim is necessary . If in future actions we seek additi onal comments on the legality of ABT programs under our aircraft standards, we will be interested in receiving comments from other stakeholders in the mobile source arena who might have views regarding the arguments presented by the industry commenters abo ve. In the meantime, we note that several of our mobile source regulations, in addition to the rule cited b y industry

commenters, have long provided regulated industry with the flexibilities inherent in an ABT program, under the authority of, for example CAA section 213, and none of those subject industrie s have opposed the creation of such programs or questioned their legal basis. ( See, e.g., 40 C.F.R. part 89, subpart C (averaging, banking and trading provisions for nonroad compression - ignition engines ); 40 C.F.R. part 90, subpart C (certification averaging, banking and trading provisions for nonroad spark - ignition engines at or below 19 kilowatts); 40 C.F.R. part 91, subpart C (averaging, banking and trading provisions for marine spark - ignition engines ); 40 C.F.R. part 92, subpart D (certification averaging, banking and trading provisions for locomotives and locomotive engines); 40 C.F.R. part 94, subpart D (certification averaging, banking and trading provisions for marine compression - ignition engines) . ) EPA continues to believe that the legal basis of these ABT programs is sound.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 111 of 207 4 . Potential Phase - Inof New Tier 8 NOx Standards for Newl y - Manufactured Engines We did not propose a production cutoff for the Tier 8 NOx standards for newly manufactured e ngines. This means that engine manufacturers may continue to produce Tier 6 compliant engines of previously certified models after the Tier 8 standards become effective for newly - certified engine models. As noted elsewhere, EPA is working within the I CAO /CAEP framework to develop harmonized international standards for aircraft turbine engines. At the February 2010 meeting of CAEP, where the CAEP/8 NOx standards were approved for recommendation to ICAO , the committee decided that further consider ation cou ld be given to a related newly - manufactured engine standard pending new information on technology and market responses , although no formal action was taken at the time to explicitly make this a future work item for CAEP . 91 Assuming a CAEP/8 production cut off is adopted at some time in the future, we will re examine the permanent exemption provisions to ensure a timel y and orderly phase - out of engine models that do not meet the CAEP/8 NOx standards. We would expect this to be done through a notice and comm ent rulemaking process to amend our own regulations .

91 IC AO, “Committee on Aviation Environmental Protection (CAEP), Report of the Eighth Meeting, Montreal, February 1 - 12, 2010,” CAEP/8 - WP - 80. A copy of this document is in docket n umber EPA - HQ - OAR 2010 - 0687.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 112 of 207 C. Application of Standards for Derivative Engines I t is very common for a manufacturer to make changes to an originall y t yp e certificated engine model that is in production while keeping the same basic engine core and combustor design. In some cases these modifications may affect emissions. As a resu lt, the certificating authority (in our case the FAA) must decide whether the emission characteristics of the modified design were significant enough from the parent engine’s certification basis that a demonstration of compliance with more recent emission standards is necessary , or if the changes were minor relative to the parent engine’s emission certification basis so that it is considered a derivative ver sion of the original model with no emissions changes. This may be further complicated because of the common practice of making iterative changes over time raises the question as to when the cumulative changes reach a point where a new demonstration of compliance is warranted. In the past, these determinations were made for turbofan engines by an engineering evaluation that was performed by the engine manufacturer and then review ed by the FAA. As part of the ICAO/CAEP deliberations leading up to the Feb ruary 2010 CAEP/8 meeting, a new standardized guidance was agreed upon as described in the ETM . The guidance, which the U.S. fully supported, includ es specific criteria that can be used to determine when a design modification require s a new demonstration of compliance with newer emission standards , or when a modification was simple enough to be considered a no emissions change .Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 113 of 207 W e are including the ETM requirements in our regulations to address the longstanding need to provide consistent standards for the decision process regarding derivative engines and applicable emission standards. The definition of “derivative engines for emissions certification purposes,” along with the criteria for making this determination, will provide engine manufacturers and the regulators with more certainty regarding emission standard requirements for future modifications made to certificated models. To ensure that the numerical decision criteria can be administered to allow for the consideration of unusual circumstances or special information, we are also providing the FAA wi th some flexibility to make adjustments to the specific criteria based on good engineering judgment. In summary , if the FAA determine s that an engine model is sufficiently similar to its parent engine s o as to m eet the criteria established in part 87.48 , the manufacturer may demonstrate certification compliance and continue production of the engine model to the same extent as allowed for the original engine model. However, if the FAA determines that an engine model is not a derivative for emission certification purposes, the manufacturer would be required to demonstrate compliance with the most recent emissions standards. This determination will be made using numerical criteria consistent with I CAO prov isions, and a modified engine model can be considered a “derivative” only if it is: 1) derived from an original engine that had received a U.S. certification, 2) the original engine was certified under title 14 of the CFR , and 3) one of the following con ditions is met: (1) The FAA determined that a safet y issue exists that requires an engine modification; orDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 114 of 207 (2) Emissions from the derivative engines are equivalent to or lower than the original engine. The proposed rule provided that the engine manufacturer could show emissions equivalency

by demonstrat ing that the difference between emission rates of a derivative engine and the original engine are within the following allowable ranges , unless otherwise adjusted using good engineering judgment as determined by the FAA : ± 3.0 g/kN for NOx. ± 1.0 g/kN for HC. ± 5.0 g/kN for CO. ± 2.0 SN for smoke. The proposed rule also provided that engine models represented b y characteristic levels at least five percent below all applicable standards would be allowed to demonstrate equivalency by engineering anal ys is. In all other cases, the manufacturer would be required to test the new engine mod el to show that its emissions met the equivalency criteria. We received three significant comments on the proposed derivative provisions. First, ATA, PW, and Dassault - Aviation (DA) pointed out that the proposed criteria contained a substantial deviation from the expressed intent of the proposal and the ETM guidance.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 115 of 20 7 Specificall y, they noted that the ETM provides that “If a modified engine remains on the existing ty pe certificate, it may

retain the existing certification basis of the parent engine if the modification(s) ...results in a decrease of the absolute emissions levels....” They pointed out, however , that the proposed rule provide d that the certificate holder must demonstrate “...the proposed derivative engine model’s emissions meet the applicable stan dards and differ from the original model’s emission rates onl y within...” specified ranges for each pollutant. For example, the specified range is + or

– 3 g/kN for NOx . The commenters stated that this is more stringent than the ETM, and could discourage cl eaner engines that are not clean enough to meet the next tier of standards. The y asked that the final rule be consistent with the ETM to prevent this untoward effect. W e agree that the regulations should allow for such engines to be considered derivatives, even if the difference was outside the “no emission change ” range. This allowance is clearl y consistent with the ETM and was inadvertentl y left out of our proposed language. Therefore, the final regulations contain this allowance. Second, AIA and GAMA joi ntly commented that the term “new model” was inappropriate when used to determin e which engine models could demonstrate equivalency by engineering anal ys is , and when the manufacturer would be required to test the new engine model to demonstrate compliance with the equivalency criteria. They

argued that because this provision applies to changes made to an existing engine , it could cause an engine manufacturerDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 116 of 207 to conduct an additional emissions test in cases where a very small change w as made to the engine due to a performance or engine weight change. The commenters recommend ed that this be altered to allow a manufacturer to consider “...such emissions changes by anal ys is prior to this point, and only

if such anal ys is revealed a deterioration that pushed the engine very close to the emission limits that the manufacturer be requested to complete an engine emissions test.” The AIA and GAMA also jointly commented on the proposed regulatory text that states if the characteristic level of the o riginal certificated engine model before modification is at or above 95 percent of the applicable standard for any pollutant, you must measure the proposed derivative engine model’s emissions for all pollutants to demonstrate the derivative engine ’ s result ing characteristic levels will not exceed the applicable emission standards. The y cl aimed that the use of the term “ yo u must measure” also implies further engine testing when additional anal ys is may

likel y prove sufficient. We agree that the term “new mo del” should be modified and have instead used the term “new engine configuration” in the final regulations. We want to clarify , however, that th e regulations do explicitly

require engine testing when an original engine’s emission s are with in 5 percent of an y emission standard. This text does not allow engineering analysis in such cases . We continue to believe this to be the appropriate policy . Given the greater uncertaint y of engineering anal ys is relative to actual testing, we cannot rel y on it for engi nes very close to theDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 117 of 207 standard. This provision is also consistent with the ETM. Therefore, we are promulgating this requirement as proposed. Third, AIA, GAMA, and GE commented that as a general matter, EPA should not codify the ETM’s derivative engine dec ision criteria because the E TM guidance will evolve over time and the Agency ’s rigid regulations will not, even allowing for the FAA flexibility to use good engineering judgment if necessary when deciding what is or is not a derivative engine. They conclu ded it was simply

better to let the FAA rel y on the ETM guidance in its decision making. As noted by

the commenters, the ICAO ETM itself is a guidance document for use by aviation authorities. It does not represent a standard or any other enforceable regulatory requirement. In the particular case cited by the commenters, they

appear to ask that FAA be given unlimited discretion to determine which engines are subject to each new tier of standards. In response to the comment, we also note that the Clean Air Act directs EPA to establish air pollution emission standards for aircraft engines. (See 42 U.S.C. 7551 (a)(2)(A).) Implementation of this statutory directive mandates that we specify enforceable air pollution emission standards and control requirements for aircraft engines in regulatory form . We believe that it is reasonable for us to also establish other associated requirements in regulatory form. Our final rule achieves an appropriate balance between providing FAA discretion to implement the standards, and the need to establish aircraft engine emission regulations that ensure consistency in application.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 118 of 207 We also disagree with the suggestion that the ETM will evolve over time, but th at our regulations will not. As a working member of ICAO’s Committee on Aviation Environmental Protection, we will participate in developing an y relevant revisions to the ETM and will make appropriate adjustments to our regulations as needed. We continue to believe that the ETM specifications for “no emissions change” are appropriate objective criteria for derivative engines. Thus, because we are codifying regulatory provisions to objectively

specify when engines are c onsidered to be “derivative engines”, we are promulgating regulatory

provisions consistent with the I CAO ETM guidance. D. Annual Reporting Requirements In May of 1980, ICAO’s Committee on Aircraft Engine Emissions (CAEE) recognized that certain informati on relating to environmental aspects of aviation should be organized into one document. This document became IC AO’s “Annex 16 to the Convention on International Civil Aviation, International Standards and Recommended Practices, Environmental Protection” and was split into two volumes

– Volume I addressing Aircraft Noise topics and Volume II addressing Aircraft Engine Emissions. Annex 16 has continued to grow and today Annex 16 , Volume II includes a list of mandatory requirements to be satisfied in order f or an aircraft engine to meet the I CAO emission standards . 92 These requirements include information relating to

92 ICAO, “ Annex 16 to the Convention on International Civil Aviation, Environmental Protection, Volume II, Aircraft Engine Emissions , ” Part III, Chapter 2, Section 2.4 . A copy of this document is in docket number EPA HQ - OAR - 2010 - 0687.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 119 of 207 engine identification and characteristics, fuel usage, data from engine testing, data anal ys is, and the results derived from the test data. Add itionally , this list of aircraft engine requirements is supplemented with voluntarily reported information which has been assembled into an electronic spreadsheet entitled “Emissions Databank” (EDB) 93 for turbofan engines with maximum thrust ratings greater than 26.7 kN in order to aid with emission calculations and anal ys is as well as help inform the general public. In order to understand how current gaseous emission standards are affecting the current fleet, we need to have access to timely , representativ e emissions data of the engine fleet at the requisite model level. The EDB is a useful tool for providing a general overview of the aircraft fleet, as it contains information on engine exhaust emissions and performance tests . H owever, it is not updated o n a consistent basis, it contains a varying amount of voluntarily reported data from each manufacturer, and it does not specifically list every engine sub - model . 94 Italso does not contain information on smaller thrust category turbofans or turboprops, and contains no information on past or recent engine production volumes. We need this data to conduct accurate emission inventories and develop appropriate policy. Accordingl y, we do not consider the EDB to be a sufficient tool upon which to base policy decisions or adopt future standards. Furthermore, in the context of EPA ’s standards - setting role under the Clean Air Act with regar d

93 United Kingdom, Civil Aviation Authority, “ICAO Emissions Databank.” Av ailable at the Civil Aviation Authority website www.caa.co.uk/default.aspx?catid=702 .

94 Under today’s regulations, a grouping of engines with an essentially identical emission - related design are defined to be an “e ngine sub - mo del ”. Engines with slightly different designs are defined to be an “engine model”.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 120 of 207 to aircraft engine emission s , it is consistent with our policy and practice to ask for timely and reasonable reporting of emission certification testing and other information that is relevant to our mission . Under the Clean Air Act, we are authorized to require manufacturers to establish and maintain necessary

records, make reports, and provide such other information as we may reasonabl y require to discharge our functions under the Act. ( See 42 U.S.C. § 7414(a)(1). ) T herefore, we propos ed to require that each aircraft engine manufacturer submit a production report directly to EPA 95 with specific information for each individual engine sub model that: 1) is designed to propel subsonic aircraft, 2) is subject to our exhaust emission standards, and 3) has rec eived a U.S. t ype certificate. More specifically, the scope of the proposed production report would include turbofan engines as described above with maximum rated thrusts greater than 26.7 kN, i.e., those subject to gaseous emission and smoke standards. In addition, it would include turbofans with maximum rated thrusts less than or equal to 26.7 kN and all turboprop engines, i.e., those only subject to smoke standards. We also propos ed that this specific exhaust emission related information be reported t o us in a timely manner , which will allow us to conduct proper emissions inventory analy ses of the existing fleet and to ensure that any public policy

we create based on this information will be well informed. A ll of the specific reporting items we propos ed were the same as requested for the EDB, with the exception of total annual engine production volumes, information on ty pe certificates, and the emission standards

95 The report w ould be submitted only to EPA. No separate submission or communication of any kind is required for the FAA.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 121 of 207 to which the engine sub - model was certified . We anticipated that the new emissions databa se would be a significant improvement over the current EDB because the data reporting is mandatory , it will be comprehensive in that it covers all engine models, and it must be updated annually . In addition to some minor comments which are addressed in the analy sis of c omments document, we received comments from engine manufacturers addressing two specific areas of the proposed production reporting provision. First, the Aerospace Industries Association (AIA), General Aviation Manufacturers Association (GAM A) and Pratt & Whitney (PW) commented that annual production volume data is considered confidential business information (CBI) and as such, it should be exempt from Freedom of Information Act (FOIA) requests or other methods of public disclosure. Second, AIA, GAMA, PW and Williams International pointed out that for those engines which are only subject to smoke standards (turbofans with maximum thrust ratings less than or equal to 26.7 kN, and turboprops), manufacturers are not required under current regulations to measure gaseous emissions (HC, CO, NOx, CO 2 ). As such, data on these gaseous emissions, as well as information used to measure gaseous emissions (reference pressure ratio and fuel flow data) are not readily available for these engines. Further, smoke data b y mode of the LT O cy cle may

not be available for these older engines. These manufacturers pointed out that new testing of such engines would be required to generate these data, and that appropriate test procedures for these engines do not curr ently exist.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 122 of 207 We understand and respect the needs of manufacturers to maintain the confidentiality of their legitimatel y proprietary data. However, we do not include in our regulations an up - front blanket CBI determination for an y of the other mobile source sectors, and do not believe it is necessary here. As such, in response to the comments, we are including regulatory language patterned after existing regulations for several other mobile source categories which sets forth how we would treat

– on a case b y case basis

– submitted data which is covered b y a CBI claim from the manufacturer as provided b y 40 CFR part 2. The addition of this provision will ensure that no information that is legitimat el y protected CBI gets inadvertently released to the public. We do not believe it is appropriate to require additional testing for turbofans with maximum thrust ratings less than or equal to 26.7 kN and turboprops specifically for production reporting purp oses. Thus, for these engines, we will not be requiring the submission of HC, CO, NOx, CO 2 , reference pressure ratio or fuel rate data. Further, we will not require additional testing of older engine s for which smoke data b y s pecific LTO cy cle segment is not currently available. We also noted in the proposal that the reported information would be used in conjunction with the NOx and CO 2 emission data alread y required to be submitted to us under section 87.64 for purposes of greenhouse gas (GHG) reporting to establish . This would effectivel y provide us with a complete and comprehensive engine exhaust emissions database. We noted our expect ation that most manufacturers would likel y add the proposed information items to theDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 123 of 207 annual GHG report. No comments we re received on combining the two reports. After further deliberation, we have decided to require a single, integrated report in this final rule to eliminate any possible confusion regarding the two separate reports and make reporting more efficient. Th e incremental reporting elements for each affected gas turbine engine sub - model are listed below. Although not proposed, we have added engine t ype to the list for completeness. The reporting elements of the existing GHG report are also identified for completeness.

• Company corporate name as listed on the engine ty pe certificate (GHG);

• Engine T yp e (turbofan, mixed turbofan, or turboprop)

• Calendar y ear for which reporting (GHG);

• Complete sub - model name ( This will generally include the model name and the sub model identifier, but may also include an engine t ype certificate family identifier) (GHG);

• The ty pe certificate number, as issued by the FAA ( Specify if the sub - model also has a ty pe certificate issued by

a certifi cating authorit y oth er than the FAA) (GHG);

• Date of issue of t yp e certificate and/or exemption, i.e. month and y ear (GHG);

• Emission standards to which the engine is certified, i.e. , the specific Annex 16, Volume II, edit ion number and publication date in which the numerical standards first appeared.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 124 of 207 • If this is a derivative engine for emissions certification purposes , identify the original certificated engine model.

• Engine sub - model that received the original t ype certificate for the engine type certificate famil y ;

• P roduction volume of the sub - model for the previous calendar ye ar (even if zero). If an engine sub - model is no longer being produced, state that the engine sub - model is not in production and list the date of manufacture (month and y ear) of the last eng ine produced;

• Regarding the above production volume report, specify ( if known) the number of engines that are intended for use on new aircraft and the number intended for use as certified (non - exempt) spare engines on in - use aircraft;

• Reference press ure r atio (GHG) (not applicable to turbofans with maximum thrust ratings less than or equal to 26.7 kN, and turboprops);

• Combustor d escription (ty pe of combustor where more than one t yp e available on an engine) ;

• Engine maximum rated thrust output, in kilo n ewtons (kN) ) or kilowatts (kW) (depending on engine t yp e) (GHG);Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 125 of 207 • Unburned h ydrocarbon (HC) mass (g) total (weighted) and over each segment of the Landing and Take - off C ycle (LTO), i.e. Take - off, Climb, Approach, Taxi/Ground Idle (not applicable to turbofans with maximum thrust ratings less than or equal to 26.7 kN, and turboprops); 96

• Unburned h ydrocarbon (HC) characteristic level (i.e. mass of h ydrocarbons over LTO cycle/Rated Thrus t (Dp/Foo)) (not applicable to turbofans with maximum thrust ratings less than or equal to 26.7 kN, and turboprops); 97

• Carbon m onoxide (CO) mass (g) total (weighted) and over each segment of the entire Landing and Take - off C ycle (LTO) (i.e. Take - off, Climb, Approach, Taxi/Ground Idle) (not applicable to turbofans w ith maximum thrust ratings less than or equal to 26.7 kN, and turboprops);

• Carbon m onoxide (CO) characteristic level (i.e. mass of CO over LTO cycle/Rated Thrust (Dp/Foo)) (not applicable to turbofans with maximum thrust ratings less than or equal to 26 .7 kN, and turboprops);

• Nitrogen o xides (NOx) mass (g) total (weighted) and o ver each segment of the entire Landing and T ake - off C ycle (LTO) (i.e. Take - off, Climb, Approach, Taxi/ Ground Idle) (GHG)

96 See Regulation Part 87 - Control of Air Pollution from Aircraft and Aircraft Engines , Subpart E , §87.42 Production report to EPA for definitions.

97 Dp/Foo : total gross emissions of each gaseous pollutant (mass) / rated thrust (g/kN).Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 126 of 207 (not applicable to turbofans with maximum thrust rating s less than or equal to 26.7 kN, and turboprops);

• Nitrogen o xides (NOx) characteristic level (i.e. mass of NOx over LTO cy cle/Rated Thrust (Dp/Foo)) (GHG) (not applicable to turbofans with maximum thrust ratings less than or equal to 26.7 kN, and turbop rops);

• Smoke number total and over each segment of the entire Landing and Take - off C ycl e (L TO) (i.e. Take - off, Climb, Approach, Taxi/Ground I dle) , if available ;

• Smoke number characteristic level;

• Carbon d ioxide (CO 2 ) mass (g) total (weighted) and over each segment of the entire L anding and Take - off C ycle (LTO), ( i.e. Take - off, Climb, Approach, Taxi/Ground Idle (GHG)) (not applicable to turbofans with maximum thrust ratings less than or equal to 26.7 kN, and turboprops);

• Number of tests run per sub - model (GHG);

• Number of engines tested per sub - model (GHG);

• Fuel flow (grams / second) total (weighted) and over each segment of the Landing and Take - off Cy cle (LTO) (i.e. Take - off, Climb, Approach, Taxi/Ground Idle) (GHG) (notDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 127 of 207 applicable to turbofans with maximum thrust ratings less than or equal to 26.7 kN, and turboprops); and

• Any a dditional r emarks to the EPA . The annual report is required to be submitted for each calendar ye ar in which a manufacturer produces any engine subject to em ission standards as previously described. These reports will be due by

February 28 of each ye ar, starting with the 2014 calendar year, and cover the previous calendar ye ar. This report shall be sent to the Designated EPA Program Officer. Where informati on provided for an y previous y ear remains valid and complete, the engine manufacturer may

report the production figures and state that there are no changes instead of resubmitting the original information . To facilitate and standardize reporting , we expec t to specify a particular format for this reporting in the form of a spreadsheet or database template that we provide to each manufacturer. As noted previously , we inten d to use the report s to help inform an y further public policy approaches regarding air craft engine emissions that we consider , including possible future emissions standards, as well as help provide transparency to the general public. Subject to the applicable requirements of 42 U.S.C. 7414(c), 18 U.S.C. 1905, and 40 CF R part 2, all data received b y the Administrator that is not confidential business information may be posted on our website and will be updated annuall y. We have assessed the potential repor

ting burden associated with this annual reporting requirement. T hat assessment is presented in section s V and IX.B of this notice.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 128 of 207 E. Standards for Supersonic Aircraft Turbine Engines We pro posed CO and NOx emission standards for turbine engines that are used to propel aircraft at sustained supersonic speeds, i.e., su personic aircraft to complement our existing HC standard for these engines. These standards were originall y adopted b y IC AO in the 1980s , and our adoption of NOx and CO standards for commercial engines in 1997 omitted coverage of the se pollutants for supe rsonic commercial engines that were then in use. The lack of EPA CO and NOx standards for engines used b y supersonic aircraft has had no practical effect, because no such engines have been certified b y the FAA. Also, none of the engines used on these air craft are currentl y in production . (See section III.G for a brief discussion of potential revised emission standards for future engine designs that may be used on supersonic aircraft.) The Aerospace Industries Association (AIA) and the General Aviation Manufacturers Association (GAMA) commented that within CAEP it was agreed that these standards are “not appropriate for future products” and should not be adopted b y EPA. However, to meet U.S. treat y obligations under the Convention on International Civi l Aviation as previously described in section I . C, we believe it is necessary and appropriate to adopt these conforming standards. Therefore, we are promulgating the standards for supersonic aircraft as proposed. As previousl y noted, this action has no p ractical effect, and simply aligns EPA standards with the rest of the world. F . Amendments to Test and Measurement ProceduresDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 129 of 207 We are incorporat ing by

reference into the 40 CFR § 87.6 0 regulatory text, amendments to I CAO’s International Standards and Recommended Practices for aircraft engine emissions testing and certification. 98 , 99 , 100 These amendments to Annex 16, Volume II are primarily intended to ensure that the provisions reflect current certification practices. The amendments make clarifications or add flexibilities for engine manufacturers. They are described below. • Standardizing the terminology relating to engine thrust/power • Clarifying the need to correct measured results to standard reference day and reference engine conditions • Allowing a certificating authorit y to approve the use of test fuels other than those specified during certification testing • Allowing materi als other than stainless steel in the sample collection equipment

98 A strikeout and highlighted version of the amendments is contained in Attachment A to ICAO state letter AN 1/61. 2, AN 1/62.2 - 07/32 entitled, “Proposed Amendment to International Standards and Recommended Practices, Environmental Protection, Annex 16 to the Convention on International Civil Aviation, Volume II Aircraft Engine Emissions, May 27, 2007. A copy of thi s document is in docket n umber EPA - HQ - OAR - 2010 - 0687. 99 ICAO, “International Standards and Recommended Practices, Annex 16 to the Convention on International Civil Aviation, Environmental Protection, Volume II Aircraft Engine Emissions,” Third Edition, July 2008, International Civil Aviation Organization. This document contains the full text of ICAO standards and practices and is in docket number EPA - HQ - OAR - 2010 - 0687.

100 ICAO, “International Standards and Recommended Practices, Annex 16 to the Convention on International Civil Aviation, Environmental Protection, Volume II Aircraft Engine Emissions, Amendment 7, effective July 18, 2011” Third . A copy of this document is i n docket number EPA - HQ - OAR - 2010 - 0687.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 130 of 207 • Clarifying the appropriate value of fuel flow to be used at each LTO test point • Clarifying exhaust nozzle terminology for exhaust emissions sampling • Allowing an equivalent procedure for gaseous emission and smoke measurement if approved by

the certificating authorit y Manufacturers are either alread y voluntarily complying with these changes or will be even in the absence of a final rule. Our adoption of these test procedure amendme nts is, therefore , un likel y to require new action by manufacturers bey ond what they have already done to meet I CAO’s adopted and recommended amendments. Our incorporation by

reference of the IC AO test procedure makes most of the existing subpart G and al l of subpart H of part 87 obsolete. Therefore, we are removing these sections from the regulation, as proposed. G . Possible Future Revisions to Emission Standards for New Technology Turbine Engines and Supersonic Aircraft Turbine Engines As a general matter, emission standards not only apply to all conventional turbofan aircraft engines greater than 26.7 kN, but also to all aircraft engines designed for applications that otherwise would have been fulfilled by turbofan aircraft engines. The high price of jet fuel, current emphasis on fuel econom y, and need to reduce emissions have renewed interest in open rotor propulsion designs for future aircraft gas turbine engines. Essentiall y, the fan of an openDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 131 of 207 rotor engine is not contained within an engine nacelle as it is with a conventional turbofan engine. This design has also been referred to as an unducted fan, propfan, or ultra - high by pass engine. At least two engine manufacturers are actively pursuing such designs for certification in the later part of thi s decade . It now appears that certain aspects of EPA’s gas turbine engine emission standards may be incompatible with these new designs. For example, the current landing and takeoff cycle for emissions certification is based on conventional engine designs where a significant amount of thrust is generated b y an idling engine. Specifically , idle emissions are measured and calculated at seven percent of the engine’s rated thrust. However, the fan/prop blades of an open rotor engine may

be variable in pitch and this may allow the blades to be “feathered” at idle. In that position, the blades are rotated so very little thrust is generated as the engine idles and generates emissions. Also, future aircraft using these engine designs may fly at somewhat slower speeds. This might affect the time these aircraft spend during the climbout mode of the landing and takeoff cycl e. Therefore, the traditional landing and takeoff cycle used in turb ofan engine emissions certification may need to be revised in the future to accommodate open rotor engines. We will be working within CAEP to evaluate the differences between convention al turbine engine and open rotor engine technologies, and to revise the emission standards and test procedures as appropriate for these latter engines. If an y changes are required, EPA will undertake rulemaking to revise our regulations accordingl y.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 132 of 207 There may

also be changes in the emission standards and test procedures for engines used to power future supersonic transport aircraft designs. The emission standards for these engines were originally

developed in the earl y 1970s in response to the Aerospatial e - BAC Concorde. Since that time, there have been varying levels of interest in developing a new generation of supersonic transport. As a result, the current CAEP work program is evaluating the status of supersonic aircraft engine development and the pote ntial need for new emission standards and test procedures. 101 Our recent discussions with engine manufacturers indicate that no substantive work is being undertaken at this time, however. We will continue to work within CAEP on this issue and undertake r ulemaking to revise the regulations for supersonic aircraft engines as appropriate. IV . Description of Other Revisions to the Regulatory Text In addition to the changes discussed above, we are including a number of other changes to the regulatory

program . Most of these changes are designed to bring the program into conformity

with current technology

and current technical or policy practice. Each of these is discussed below.

101 The CAEP Working Group 3 has taken the position that engine development programs for future supersonic aircraft applications should be focused on achieving the emission standards that are applicable to subsonic air craft engines. Past supersonic aircraft engines required the use of afterburner technology to achieve supersonic speeds. Future supersonic aircraft are expected to use engines without that technology, making them mo re similar to their subsonic counterpart s.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 133 of 207 A. Applicability

I ssues This section discusses how this final rule relates to engines used in military and noncommercial civilian aircraft . We do not believe these changes will have practical significance for current engine models because the changes align with manufacturers’ current practice in certifying their engines. 1. Mi litary

Engines We do not intend today ’s action to have an y impact on engines installed on military aircraft , or new aircraft that are destined to be converted for military use . Military

aircraft are not required to have FAA standard airworthiness certific ates , and our 1997 endangerment finding for NOx and CO emissions and resulting standards did not cover military aircraft (see 62 FR at 25359). As such, engines used in military aircraft are not required to meet EPA emission standards, since our current re gulations define “aircraft” subject to our rules as an y airplane for which a U.S. standard airworthiness certificate (or foreign equivalent) is issued. (See 40 C.F.R. § 87.1(a) of the existing regulations.) Currentl y, manufacturers certificate some engin e models used in military

aircraft with the FAA (with respect to emissions), because these engine models also have commercial applications and have to be certificated for such use. Our new standards and requirements w ill continue to apply onl y to engines used in aircraft for which standard airworthiness certificates are required , and thus are not applicable to engines used in military aircraft. I t is not our intent to interfere with current practice with regard to engine models withDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 134 of 207 joint commercial/milit ary applications to the extent such engines are used in military aircraft. Although civilian aircraft applications of all such engines would be subject to the new standards and production cutoff

, in the NPRM we propos ed to include a statement in the regul ations to clarify that the proposed production cutoff would not apply for previousl y certificated engines that are installed and used in military aircraft. One manufacturer commented that the definition of “military

aircraft” we proposed should extend to sales of military aircraft outside of the U.S. While we believe the regulations as written do not apply to foreign sales of military aircraft, we are nonetheless revising our proposed definition of “military aircraft” to clarify

that foreign aircraft cons idered military under international laws and agreements are not covered by 40 CFR part 87. 2. Noncommercial Engines Prior to this action, section 87.21 (d) specifie d that gaseous emission standards appl ied to engines used in commercial applications with rated thrusts greater than 26.7 kN. These are engines intended for use by an air carrier or a commercial operator as defined in the Chapter I, Title 49 of the United States Code and Title 14 of the Code of Federal Regulations . Therefore, e ngines of equivalent thrust ratings that are used in aircraft certifi cat ed by the FAA that are use d in non - revenue, general aviation service were not required to compl y with our current HC, CO, and NOx exhaust emission standards in §87.21(d). They were and are subject, however, to the current standards for smoke and fuel venting.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 135 of 207 In today ’s action we are applying the gaseous emission standards for commercial engines to their noncommercial civilian counterparts that are required to obtain standard airworthiness c ertificates. There are a couple of reasons for this action. First, the ICAO Annex 16 , Volume II standards and recommended practices appl y equally to commercial and noncommercial engines, and our rules’ previous failure to reflect this meant that our requ irements did not fully conform to ICAO’s standards. Second, manufacturers already emissions certify engines that are used in non - revenue, general aviation service to these standards . Therefore, this provision simply incorporates the status quo. In order to make EPA standards conform to I CAO’s, we need ed to , in addition to promulgating the necessary regulatory

amendments, update the underl yi ng finding regarding the need to limit gaseous emissions from commercial and non - commercial civilian aircraft , pursuant to CAA section 231(a)(2)(A) . In 1997, our analy sis and finding, and hence our regulations, were limited to commercial aircraft emissions. (See 62 FR at 25358.) In conjunction with the NPRM for this final rule, we propos ed to expand that analysis and finding to include gaseous emissions from both commercial and non - commercial civilian aircraft engines with rated thrusts greater than 26.7 kN. We received no comments on that proposed finding, and are therefore finalizingDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 136 of 207 our emissions assessment support ing this finding, which is contained in the docket for this rulemaking. 102 B. Non - substantive Revisions We are also taking the opportunity to revisit the clarity

of other regulatory

provisions in part 87. Man y of these provisions were first written 30 or 40 ye ars ago with little or no change since then. We are revising the text related to some of these pro visions to better organize, clarify , and update the regulations. Our goal is to revise the regulations in part 87 to properl y organize the content of the regulation, use clearer language to describe the applicable requirements, clarify

some definitions, and clear up a variet y of terms and current practices that have not been adequatel y addressed. Except as discussed in previous sections, the changes to part 87 are not intended to significantl y change the certification and compliance program. We did not reopen for comment the substance of an y part of the program that remains unchanged substantively. Th is rule includes the following definitions and other minor changes in addition to those changes described earlier in this section or in s ection III .

102 U.S. EPA, “ Final Finding for Commercial and Noncommercial Turbofan and Turbojet Aircraft Emissions,” memorandum from John Mueller , Assessment and Standards Division, Office of Transportation and Air Quality, February 2012. A copy of this document is in docket EPA - HQ - OAR - 2010 - 0687Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 137 of 207 The definition of the term “aircraft” is being revised to be consistent with its meaning under FAA regulations in 14 CFR 1.1. The existing part 87 definition limits “aircraft” to be onl y those air craft issued an airworthiness certificate. This was done a s a way to specify

the applicability

of the standards. However, this can cause confusion in a variety of way s. For example, this departs from the plain meaning of “aircraft , ” as well as from the meaning given under the Clean Air Act and Title 49 of the United States Code . The revised definition aligns with these statutory

definitions. The changed wording is intended to clarify the existing policy without changing it . Text specifying general applicability is being added to part 87.3 to be consistent with the new definition of “aircraft” and maintain the effective applicability of the existing regulations, which uses narrow definitions to limit applicability. For example, the existing regulation s limit the applicability

of the standards b y defining “aircr aft” to onl y include fixed - wing airplanes with airworthiness certificates. They exclude non - propulsion engines from the definition of “aircraft engine” and turboshaft engines from the definition of “aircraft gas turbine engine . ” We believe it is more app ropriate to explicitly exclude these engines in an applicability section than to rely

on readers finding these exclusions in the definitions section. We are also renaming part 87.3 as “General applicability

and requirements” and reorganizing the content f or clarity . Finally , we are replacing the existing regulatory text related to federal preemption for exempted engines in part 87.7(f) with a codification of the statutory preemption language in part 87.3 and anDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 138 of 207 explanatory

note that the statutory

preempti on applies to exempted engines because they are certified to prior - tier standards . ICAO Annex 16 , Volume II is being incorporated by reference for test procedures . This involves a broader reference to Annex 16, with less content repeated in part 87. Howe ver, this does not substantively

change the test procedures that apply since the existing procedures are based directly

on Annex 16 , Volume II . As part of this change, we are adding the ICAO definition of “characteristic level” to properly describe how manufacturers demonstrate that they meet applicable standards. Definitions are being added for “date of introduction , ” “date of manufacture , ” and “derivative engine for emissions certification purposes, ” and the definition of “engine model” is being revised, to more carefull y describe when new emission standards apply to specific aircraft engines. These definitions are generall y consistent with the most common understandings of these terms b y industry and FAA, and with the CAEP / 8 recommendation for adoption by I CAO. Except for engines subject to exemptions, there will be no more engines required to be certified to the standards specified in part 87.21, so c hanging the definition of “engine model” will not change the requirements for engines certified to the Tier 4 or earlier standards. For the benefit of the reader, we are also reprinting the following definitions that remain unchanged :

• Aircraft engine • Aircraft gas turbine engineDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 139 of 207 • Class TP • Class TF • Class T3 • Class T8 • Class TSS • Commercial aircraft gas turbine engine • Fuel venting emissions Specific provisions are being added to define and require the use of “good engineering judgment.” This applies for instances where the regulation cannot spell out every technical detail of ho w a manufacturer should compl y with the regulation. For example, the regulations rely on good engineering judgment being used on the engineering anal ys is of emissions equivalency

for derivative engines (part 87.48(b)(2)), and for appl yi ng the turbofan tes t procedures to turboprop engines (part 87.60(a)). The general approach for implementing good engineering judgment is to allow manufacturers to exercise well substantiated and explained technical judgment subject to potential EPA and FAA review (as approp riate). The consequences of disagreements with a manufacturer’s decision would depend on whether we believe the manufacturer made the decision in good faith. Where the manufacturer makes its decision in good faith, EPA or FAA could require a different a pproach for future work if we believe it would represent better engineering judgment. We believe these provisions reflect the spirit of the approach being used today to interpret the applicable regulations.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 140 of 207 Provisions are being added specifying rounding p ractices for rated output, rated pressure ratio, and calculated emission standards; generally specifying that they

be expressed to at least three significant figures. The primary exception to this is the specification that smoke numbers be expressed to on e decimal place. These specifications are consistent with how manufacturers are generally

certifying engines today . Defining how to round these values would prevent manufacturers in the future from effecting small changes in the level of the emission standards to which they

certify their engines. This is because standards are calculated using the numerical values of the rated output and rated pressure ratio. Without these specifications, manufacturers could subject themselves to a slightly less stringen t standard b y selectivel y rounding or truncating an engine model’s rated output to be low and its rated pressure ratio to be high, or b y strategicall y rounding the calculated standard itself. While this has not been an issue in the past, it is important t o maintain a level playing field for all manufacturers as standards become more stringent. We do not expect any more engines t yp e - certificated to the standards specified in part 87.21, so the specified procedures for rounding these values will not change the requirements for engines certified to the Tier 4 or earlier standards Definitions are being added for “turbofan engine , ” “turbojet engine , ” “turboprop engine , ” “turboshaft engine , ” “supersonic , ” and “subsonic” to avoid any uncertainty

about how the standards appl y to different ty pes of engines. The definitions are intended to reflect the plain meaning of these terms.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 141 of 207 The regulations include the following additional amendments: Regulation cite Description of

Am endment Notes

87.1 Add definition of

“characteristic level”. The characteristic level is established by ICAO Annex 16 as a means of calculating a statistical adjustment to measured emission results to take into account the level of uncertainty corresponding to the number of tests run for a gi ven pollutant. 87.1 Remove definitions for

“emission measurement system”, “power setting”, “sample system”, “shaft power”, “taxi/idle (in)”, and “taxi/idle (out).” These terms will no longer be used in part 87. There will be no more engines certified to the standards specified in §87.21, so removing these definitions will not change the requirements for engines certified to the Tier 4 or earlier standards. 87.1 Revise definition of

“exhaust emissions” and “smoke ”. The new language references the emission testing procedures, since that is the practical meaning of these terms in part 87. This clarifies, for example, that emissions from the nozzle of an aircraft or aircraft engine count as exhaust emissions only if they are measured using the specified test procedures. There will be no more engines certified to the standards specified in §87.21, so revising these definitions will not change the requirements for engines certified to the Tier 4 or earlier standards. 87.1 Define “new” instead of

defining “new aircraft turbine engine”. The regulations also refer to new turboprop engines and new engines used for supersonic aircraft, so it is appropriate to define the adjective as it relates to these different kinds of e ngines. This approach does not change theDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 142 of 207 meaning of the applicable terms and therefore has no bearing on the requirements that applied under the standards specified in §87.21. 87.1 Revise the definition of

“standard day condition”: (1) remove the reference to the 1976 U.S. Standard Atmosphere, (2) correct a typographical error in the humidity specification, and (3) change the atmospheric pressure units from Pa to kPa. The editorial changes do not involve any substantive change in the specified cond itions.

87.2 Remove FAA from the

list of acronyms in §87.2 and add it to the set of defined terms in §87.1. This is intended to not involve a change in emission standards or implementation.

87.3 Add provisions

describing the scope of applicability of part 87. The broad statement in §87.3 is not intended to conflict with the applicability statements in individual subparts, since those additional statements indicate that certain requirements in part 87 apply more narrowly. All applicability statements in the rule are intended to be consistent with current policy. 87.3 Remove the provision

related to preemption of state standards for exempted aircraft and replace it with the preemption provision in the Clean Air Act. This change more carefully tracks the statutory provisions related to preemption.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 143 of 207 87.5 Move the provisions

related to special test procedures to §87.60. This provision, and the similar provision from §87.3(a), should be described together in the context of the testing requirements in subpart G. 87.21 Identify the specific

date when the smoke standard started to apply for turbofan engines with rated output less than 26.7 kilonewtons. This corrects a typographical error from the Federal Register .

87.21 Revise paragraph (f) to

correctly reference the regulatory sections that describe the applicable test procedures. This change is strictly editorial.

87.60 Revise the description

of test procedures to rely broadly on the procedures specified in ICAO Annex 16. This includes a variety of re cent changes to the Annex 16 procedures. There will be no more engines certified to the standards specified in §87.21, so any changes to the test procedures will not change the requirements for engines certified to the Tier 4 or earlier standards. Moreove r, engine manufacturers are expected to perform all their testing based on the current test procedures from ICAO Annex 16, regardless of the standards that apply.

C. Clarifying Language for Regulatory Text The regulations incorporate the changes describ ed in this preamble. The following table highlights and clarifies several provisions that may not be obvious to the reader.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 144 of 207 Regulation cite Note 87.1, Definition of “aircraft” This definition would revert to the normal FAA definition of aircraft, rather than the much narrower current definition in part 87. To understand this change, the definition needs to be considered along with the changes to applicability in 87.3(a). 87.1, Definition of “date of manufacture” This is generally the same definition as given in ICAO Annex 16. However, our definition addresses certain specific circumstances that could possibly occur, but that are not addressed by the Annex. For example, our definition would provide a date of manufacture for an engine not previously doc umented by a manufacturer. 87.1, Definition of “ d erivative engine for emissions certification purposes ” Itis important to consider this definition in combination with the definition of “engine type certificate family”. 87.1 Definition of “ e ngine model” A manufacturer or FAA may further divide an engine model into sub - models. Engines from an engine model must be contained within a single engine type certificate family. Where FAA determines that engines are not sufficiently similar to be included under a single type certificate, they will not be considered to be the same engine model for purposes of part 87. 87.1, Definition of “ military aircraft” and 87.23(d). In §87.23(d) we clarify that the production cutoff does not apply for military aircraft engines (even if they have been certificated). In §87.1, we define military aircraft to primarily mean “aircraft owned by, operated by, or produced for sale to the arm ed forces or other agency of the federal government responsible for national security (including but not limited to the Department of Defense).” For example, a ircraft owned by the U.S. Coast Guard would be military aircraft. In response to comments, we a dded a clarification that military aircraft also include “ other aircraft considered to be military aircraft under international law andDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 145 of 207 conventions .” 87.1, Definition of “ p roduction cutoff date” The production cutoff date for the Tier 6 NOx standards is D ecember 31, 2012. 87.1, Definition of “ s pare engine” Newly manufactured spare engines may be ex ce pt ed under §87.50. 87.1, Definitions of tiers As specified in the definitions of “Tier 0” through “Tier 8”, tiers apply only for NOx standards. Tiers do not apply for HC, CO, and smoke standards because these continue to apply, independent of the NOx standards. 87.23(d)(2) The allowance to continu e production of Tier 6 engines after the Tier 8 standards start to apply is not necessary for engines with rated pressure ratio at or above 104.7 because the Tier 6 and Tier 8 standards are numerically identical at these thrust levels . 87.42(c)(1) §87.42 requires that a manufacturer report the engines it produces by sub - model. The manufacturer must specify the manufacturer’s unique sub - model name, which will generally include a model name and a sub - model name. It may also include a family name. 87. 50 Th is provision specifies that EPA must provide written concurrence for exemptions. 87. 50 ( a ) (1 ) (iv)(F) This provision states that manufacturers requesting exemptions should describe equity issues. As an example of equity issues related to an exemption req uest, a manufacturer might provide a rationale for granting the exemption when another manufacturer has a compliant engine and does not need an exemption, taking into account the implications for operator fleet composition, commonality, and related issues in the absence of the engine model in question.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 146 of 207 87. 50 ( a ) (6 ) This provision requires manufacturers to promptly notify the FAA if new or changed information could have affected approval of an exemption. For corrections to an exemption request that would no t affect the approval of the exemption, manufacturers ma y include the updated information in the annual report described in §87.50(e).

V. Technical Feasibility , Cost Impacts, Emission Benefits During the CAEP process , the technical feasibility and cost of compliance of the CAEP/6 and CAEP/8 NOx standards were thoroughly assessed and documented. 103 , 104 EPA participated in these anal ys es and supported the results. Generally , CAEP considered certain factors as pertinent to the cost estimates of a technology level for engine changes, and these factors or technology

levels are described below. The first technology level was regarded as a minor change, and it could include modeling work, minor design changes, and additional testing and re certification of emis sions. The second technology level was considered a scaled proven technology . At this level an engine manufacturer applies its best - proven, combustion technology

103 CAEP/6 NOx standards: CAEP Forecasting and Economic Analysis Support Group , Economic Analysis of NOx Emissions Stringency Options , CAEP/6 - IP/13 (Information Paper 13), January 15, 2004. A copy of this document is in docket num ber EPA - HQ - OAR - 2010 - 0687. 104 CAEP/8 NOx standards: CAEP Working Group 3, NOx Stringency Technology Response Assessment , CAEP - SG/20082 - WP/18 (Working Paper 18), September 25, 2008. CAEP Forecasting and Economic Analysis Support Group, Economic Assessme nt of the NOx Stringency Scenarios , CAEP/8 - IP/14, November 30, 2009. Modeling Task Force, MODTF NOx Stringency Assessment , CAEP/8 - IP/13 , December 11, 2009. United States, Aviation Environmental Portfolio Management Tool for Economics (APMT -Economics) and Its Application in the CAEP/8 NOx Stringency Analysis , CAEP/8 - IP/29 , January 6, 2010. A copy of these documents are in docket n umber EPA - HQ - OAR - 2010 - 0687.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 147 of 207 that was alread y certified in at least one other engine ty pe to another engine ty

pe. This s econd technology

level would include substantial modeling, design, combustion rig testing, modification and testing of development engines, and flight testing. The third technology level was regarded as new technology or current industry

best practice, and it was considered where a manufacturer has no proven technology that can be scaled to provide a solution and some technology

acquisition activity

is required. (One or more manufacturers have demonstrated the necessary technology , while the remaining manufacturers would need to acquire the technology to catch up.) Since the effective date for the CAEP/6 NOx standard was January 1, 2008 and nearl y al l in - production engines currentl y meet this standard , we believe this clearl y demonstrates the technica l feasibility of those standards. Therefore, we will limit our discussion below to applying these technology levels to engines that need to compl y with the CAEP/8 NOx standard. At the time of the CAEP reports, the CAEP/8 NOx standard f or higher thrust e ngines, i.e., 89.0 kN or more would apply to a total of 15 engine ty pes . For these ty

pes the following technology

level response was anticipated: six ty pes would require no change, one ty pe would need the first technology

level change, five would require the second technology level, and three would need the third technology level. For lower thrust engines, i.e., greater that 26.7 but less than 89.0 kN , CAEP listed a total of 13 engine ty pes in their anal ys is of the CAEP/8 NOx standard. The following technology level response was estimated for these ty pes : 11 ty pes would require no change, 1 ty pe would need the first technology level change, and 1 ty

pe wouldDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 148 of 207 require a second technology . Based on th e s e analy s e s, CAEP concluded that the CAEP/8 NOx standards were technically feasible within the lead time and time frame identified in the action . Regarding the costs of this final rule , a ircraft turbofan engines are designed and buil t for use on aircraft that are sold and operated throughout the world. As a result, engine manufacturers respond to this market realit y b y designing and building engines that conform to ICAO international standards and practices. This normal business practice means that engine manufacturers are compell ed to make the necessary business decisions and investments to maximize their international markets even in the absence of U.S. regulations that would otherwise codify

I CAO standards and practices. Indeed, engine manufacturers have developed or are alread y developing improved technology in response to ICAO standards that match the standards being promulgated in this final rule . Also, the recommended practices, e.g., test procedures, needed to demonstrate compliance are being adhered to b y manufacturers during current engine certification tests, or will be even in the absence this final rule. Therefore, EPA believes that today ’s standards and practices that conform with I CAO standards and practices will impose no real additional burden on engine manufactur ers. This finding regarding no incremental burden, is also consistent with past EPA rulemakings that adopted I CAO requirements. ((See 62 FR 25356 (May 8, 1997) and 70 FR 69664 (November 11, 2005)) . In fact, engine manufacturers have suggested that certain benefits accrue for compliant products when the U.S. adopt s IC AO standards and practices , but have not provided detailedDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 149 of 207 information regarding these benefits . Primarily , such action makes FAA certification more straightforward and transparent . That in turn is advantageous when marketing their products to potential customers , because compliance with ICAO standards is an important consideration in purchasing decisions. It simply removes an y question that their engines comply with international requirements . There will be some cost, however, associated with our annual reporting requirement for emission re lated information. (See s ection III.D for a description of the reports.) There are a total of 10 engine manufacturers that would be affected . Eight of these produce turbofan engines with rated thrusts greater than 26.7 kN, which are already voluntarily reported to the ICAO - related Emissions Databank (EDB) 105 . We expect the incremental reporting burden for these manufacturers to be very small b ecause we: 1) have significantl y reduced the number of reporting elements from those requested in the EDB, and 2) are adding only three basic reporting categories to those already requested by

the EDB. Also, four of the eight manufacturers make smaller turbofan and turboprop engines that will be reporting for the first time. This will add a small incremental burden for these four manufacturers that otherwise alread y voluntarily

report to the EDB. There are also two engine manufacturers that onl y produce turbofan engines with rated thrusts less than or equal to 26.7 kN and they will be reporting for the first time. For these two manufacturers we believe that the reporting burden

105 As discussed in section III. D, w e are requiring a single report that integrates the new reportin g requirement contained in this final rule with the existing mandatory greenhouse gas (GHG) reporting of NOx and CO 2 as already required under §87. 64. Combining the existing GHG report with the new reporting requirement will not increase an engine ma nufacturer’s reporting burden. A single, integrated report may actually reduce a manufacturers total reporting burden somewhat because of the efficiency inherent in reporting to EPA once instead of twice.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 150 of 207 will be small because all of the information we are requiring should be readi ly available, and these manufacturers have a very limited number of engine models. We have estimated the annual burden and cost to be about six hours and $365 per manufacturer. With 10 manufacturers submitting reports, the total burden of this reporting requirement is estimated to be 60 hours, for a total cost of $3,646. Turning to emission benefits , CAEP’s assessments indicated that the CAEP/8 NOx standards would provide global NOx reductions, which would translate to emission reductions in the U.S. The global LTO NOx reductions were estimated to be about 5.5 percent in 2026 and 7 percent in 2036 relative to the baseline. 106 According to an anal ys is conducted for comparable percent NOx reductions in the U.S., it was estimated that this would translate to L TO NOx reductions in the U.S. of about 5,200 tons in 2020 and 8,700 tons in 2030, 107 and the cumulative LTO NOx reductions from 2014 to 2030 (2014 is the implementation date of the CAEP/8 NOx standards) were projected to be about 100,000 NOx tons. V I . Coordination with FAA The requirements contained in this action were developed in consultation with the Federal Aviation Administration (FAA). Section 231(a)(2)(B)(i) of the CAA requires EPA to

106 CAEP Rapporteurs of Modeling Task Force and Fo recasting and Economic Analysis Support Group, Enviro n mental and Economic Assessment of the NOx Stringency Scenarios , CAEP/8 - WP/15, December 2 , 2009 .

107 “Historical Assessment of Aircraft Landing and Take - of f Emissions (1986 - 2008),” Eastern Research Group, May 2011. A copy of this document can be found in public docket EPA - HQ - OAR - 2010 - 0687.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 151 of 207 “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 23 1(b) of the CAA states that “[a]ny regulation prescribed under this section (and an y revision thereof) shall take effect after such period as the Administrator finds necessary (after consultation with the Secretary of Transportation) to permit the developm ent 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 an y regulation under section 231 “shall not apply if disapproved by

the Presi dent...on the basis of a finding by the Secretary

of Transportation that any such regulation would create a hazard to aircraft safet y.” 42 U.S.C. 7571(c). Under section 232 of the CAA, the Department of Transportation (DOT) has the responsibility

to enforc e the aircraft emission standards established by EPA under section 231. 108 As in past rulemakings and pursuant to the above referenced sections of the CAA, EPA has coordinated with the FAA , i.e., DOT , with respect to today 's action. Moreover, FAA is the off icial U.S. delegate to IC AO. FAA agreed to the amendments at ICAO's Sixth and Eighth Meetings of the Committee on Aviation Environmental Protection (CAEP/6) after advisement from EPA. 109 FAA and EPA were both members of the CAEP’s

108 The 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 Ad ministrator of the FAA. 49 CFR 1.47(g).

109 The Sixth Meeting of CAEP (CAEP/6) occurred in Montreal, Quebec from February 2 through 12 in 2004.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 152 of 207 Working Group 3 (among others), whose objective was to evaluate emissions technical issues and develop recommendations on such issues for CAEP/6 and CAEP/8 . After assessing emissions test procedure amendments and new NO x standards, Working Group 3 made recommendations to CAEP on these elements. These recommendations were approved b y CAEP/6 meetings prior to their adoption by I CAO in 2004. Similarly , the more recent Working Group 3 recommendations were approved b y CAEP/8 and have been adopted IC AO. In addition, as discussed abov e, FAA will have the duty to enforce today 's requirements . As a part of these duties , the FAA witnesses the emission tests or delegates aspects of that responsibility

to the engine manufacturer, which is then monitored by the FAA. VII. Public Participat ion We proposed this regulation on July 27, 2011 (76 FR 45012). A public hearing was held on August 11, 2011 in Chicago, IL. The public was invited to submit written comments on the proposal during the formal comment period, which ended on September 26, 2011. We received eight public comments from aircraft and aircraft engine manufacturers, airline operators and an individual. The vast majority

of commenters supported the central tenets of the proposed regulations. That is, there was broad support for the adoption of these standards and the alignment of U.S. and international emissions regulations. We received specific comments on several aspects of the proposal.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 153 of 207 Throughout this notice, we discuss ed the key issues arising from the public comment and our responses. In addition, we have addressed all of the public comments in the anal ys is of c omments document associated with this final action and located in the docket (Docket ID EPA HQ - OAR - 2010 - 0687). VIII. Statutory

Provisions and Legal Authorit y The st atutory

authorit y for today's proposal is provided by sections 114, 231 - 234 and 301(a) of the Clean Air Act, as amended, 42 U.S.C. §§ 7414, 7571 - 7574 and 7601(a). See section II of today 's rule for discussion of how EPA meets the CAA's statutory requirements. IX . Statutory

and Executive Order Reviews A. Executive Order 12866: Regulatory Planning and Review Under Executive Order (EO) 12866 (58 FR 51735, October 4, 1993), this action is a "significant regulatory

action.” This action pro mulgates new aircraf t engine emissions regulations and as such, require s consultation and coordination with the Federal Aviation Administration (FAA). OMB has determined that this action raises “... novel legal or policy issues arising out of legal mandates, the President’s priorities, or the principles set forth in the EO.” Accordingl y, EPA submitted this action to the Office of Management and Budget (O MB) for review under EO 12866 and an y changes made in response to OMB recommendations have been documented in the docket for this action.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 154 of 207 As discussed further in section V, we do not attribute an y costs to the compliance with today ’s regulations that confo rm to IC AO standards and recommended practices. A ircraft turbofan engines are international commodities . As a result, engine manufacturers respond to this market realit y b y designing and building engines that conform to ICAO international standards and p ractices. Therefore, e ngine manufacturers are compelled to make the necessary business decisions and investments to maximize their international markets even in the absence of U.S. action. Indeed, engine manufacturers have or are alread y responding, or w ill in the future, to ICAO requirements that match the standards and practices adopted here. Therefore, EPA believes that today ’s requirements that conform with I CAO standards and practices will impose no real additional burden on engine manufacturers. T his finding is also consistent with past EPA rulemakings that adopted ICAO requirements. T here is , nonetheless, a small burden associated with the reporting requirements, as discussed in section IX.B. B. Paperwork Reduction Act The information collection requirements in this rule have been submitted for approval to the Office of Management and Budget (OMB) under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. The Information Collection Request (I CR) document prepared by EPA has been assigned EPA I CR Number 2427.01 .Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 155 of 207 Manufacturers keep substantial records to document their compliance with emission standards. We need to be able to access this data to conduct accurate emission inventories , understand how emission standards affect the current fleet, and de velop appropriate policy in the form of future emission standards. Most manufacturers are alread y accustomed to reporting much of this information to I CAO. However, these reports are voluntary and aperiodic. As part of this action, w e are requiring that engine manufacturers send this information to EPA on an annual basis. We are also requiring manufacturers to send us their annual production volumes, which we would treat as confidential business information. Under the Clean Air Act, we are authorized t o require manufacturers to establish and maintain necessary records, make reports, and provide such other information as we may reasonably require to execute our functions under the Act. See 42 U.S.C. 7414(a)(1). We will simply require manufacturers to a dd the required information items to the annual report they are alread y required to submit with information about NOx and CO 2 emission levels. See section III.D for a more complete description of the annual reporting requirement. We have estimated the tot al annual burden of th e reporting requirement to be 60 hours, and the total cost to be $3,646. The annual burden and cost per respondent is estimated to be 6 hours and $365. Burden is defined at 5 CFR 1320.3(b). An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it display s a currentl y valid OMB control number. The OMB control numbers for EPA's regulations in 40 CFR are listed in 40 CFR part 9.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 156 of 207 C. Regulatory

Flexibility

Analy sis The Regu latory

Flexibility

Act (RFA) generall y requires an agency to prepare a regulatory

flexibility

analy sis of any

rule subject to notice and comment rulemaking requirements under the Administrative Procedure Act or an y other statute unless the agency certifies that the rule will not have a significant economic impact on a substantial number of small entities. Small entities include small businesses, small organizations, and small governmental jurisdictions. For purposes of assessing the impacts of today 's rule on small entities, small entity is defined as: (1) a small business as defined b y SBA size standards; (2) a small governmental jurisdiction that is a government of a cit y, count y, town, school district or special district with a population of less than 50 ,000; and (3) a small organization that is an y not - for - profit enterprise which is independentl y owned and operated and is not dominant in its field. The following Table 4 provides an overview of the primary SBA small business categories potentially affect ed by this regulation. Table 4: Primary Potentially Affected SBA Small Business Categories Industry NAI CS a Codes Defined b y SBA as a small

business if: b Manufacturers of new aircraft engines 336412 < 1,000 employ ees Manufacturers of new aircraft 336411 < 1,500 employ ees a North American Industry Classification System (NAICS)Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 157 of 207 b According to SBA's regulations (13 CFR part 121), businesses with no more than the listed number of employees or dollars in annual receipts are considered “small entities” for purposes of a regulatory flexibility analysis . After considering the economic impacts of today ’s rule on small entities, I certify that this action will not have a significant economic impact on a substantial number of small entities. Small governmental jurisdictions and small organizations as described above will not be impacted. We have determined that the estimated effect of the rule ’s reporting requirement is to affect one small entity turbofan engine manufacturer with costs less than one percent of revenues. This one company represents all of the small businesses affected by the regulations. An anal ys is of the impacts of the proposed rule on small businesses has been prepared and placed in the docket for this rulemaking. 110 Since this final rule is largel y unchanged from the proposal, that anal ys is remains valid for the final rule. D. Unfunded Mandates Reform Act This rule does not contain a Federal mandate that may result in expenditures of $100 million or more for State, local, and tribal governme nts, in the aggregate, or the private sector in any one y ear. As discussed in s ection III , today ’s action will establish consistency between U.S. and existing international emission standards. The engine manufacturers are already developing the technolog y to meet the existing I CAO standards, and we do not believe it is appropriate to

110 “ Small Business Impact Memo, Proposed Aircraft Engine Emission Standards

– Determination of No SISNOSE ,” EPA memo from Solveig Irvine to Alexander Cristofaro, November, 2010.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 1 58 of 207 attribute the costs of that technology to this action. Thus, this rule is not subject to the requirements of sections 202 or 205 of UMRA. This rule is also not subject to th e requirements of section 203 of UMRA because it contains no regulatory

requirements that might significantly or uniquel y affect small governments. The provisions of this rule apply to the manufacturers of aircraft and aircraft engines, and as such would not affect small governments. E. Executive Order 13132: Federalism This action does not have federalism implications. It will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government, as specified in Executive Order 13132. As discussed earlier, section 233 of the CAA preempts states from adopting or enforcing aircraft engine emission standards that are not identical to our standards. This rule revise s the Code of Feder al Regulations to more accuratel y reflect the statutory preemption established by the Clean Air Act. This rule does not impose any new preemption of State and local law. Thus, Executive Order 13132 does not apply to this a c tion. F. Executive Order 1317 5: Consultation and Coordination with Indian Tribal GovernmentsDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 159 of 207 These rules regulate aircraft manufacturers and aircraft engine manufacturers. We do not believe that Tribes own any of these businesses nor are there other implications for Tribes. Thus, Ex ecutive Order 13175 does not apply to this action. G. Executive Order 13045: Protection of Children from Environmental Health & Safety Risks This rule is not subject to Executive Order 13045 (62 FR 19885, April 23, 1997) because the Agency

does not believe the environmental health risks or safet y risks addressed b y this action present a disproportionate risk to children. See section II.B.2 for a discussion of the health impacts of NO X emissions. H. Executive Order 13211: Actio ns that Significantly Affect Energy

Supply , Distribution, or Use This action is not a “significant energy action” as defined in Executive Order 13211 (66 FR 28355 (May

22, 2001)), because it is not likely to have a significant adverse effect on the supply , distribution, or use of energy . The se aircraft engine emissions regulations are not expected to result in an y changes to aircraft fuel consumption. I. National Technology

Transfer Advancement Act Section 12(d) of the National Technology Transfer and Adv ancement Act of 1995 (“NTTAA”), Public Law No. 104 - 113 (15 U.S.C. 272 note) directs EPA to use voluntaryDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 160 of 207 consensus standards in its regulatory activities unless to do so would be inconsistent with applicable law or otherwise impractical. Voluntary consensu s standards are technical standards (e.g., materials specifications, test methods, sampling procedures, and business practices) that are developed or adopted b y voluntary consensus standards bodies. NTTAA directs EPA to provide Congress, through OMB, expl anations when the Agency decides not to use available and applicable voluntary

consensus standards. This rulemaking involves technical standards for testing emissions for aircraft gas turbine engines. EPA is using te st procedures contained in IC AO’s Inter national Standards and Recommended Practices Environmental Protection, Annex 16, Volume II along with the modifications contained in this rulemaking. 111 These procedures are currentl y used by all manufacturers of aircraft gas turbine engines (with thrust gr eater than 26.7 kN) to demonstrate compliance with ICAO emissions standards. J. EO 12898: Federal Actions to Address Environmental Justice in Minority Populations and L ow - Income Populations Executive Order (EO) 12898 (59 FR 7629 (Feb. 16, 1994)) establ ishes federal executive policy on environmental justice. Its main provision directs federal agencies, to the greatest extent practicable and permitted by law, to make environmental justice part of their mission by

111 ICAO International Standards and Recommended Practices Environmental Protection, Annex 16, Volume II, “Aircraft Engine Emissions,” Second Edition, July 1993 -- Amendment 3, March 20, 1997 . Copies of this document can be obtained from ICAO ( www.icao.int ).Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 161 of 207 identifying and addressing, as appropriat e, disproportionately high and adverse human health or environmental effects of their programs, policies, and activities on minority populations and low income populations in the United States. EPA has determined that this rule will not have disproportio natel y high and adverse human health or environmental effects on minority or low - income populations because it increases the level of environmental protection for all affected populations without having any disproportionately

high and adverse human health or environmental effects on any population, including an y minorit y or l ow - income population. K. Congressional Review Act The Congressional Review Act, 5 U.S.C. 801 et seq., as added b y the Small Business Regulatory

Enforcement Fairness Act of 1996, gener all y provides that before a rule may take effect, the agency

promulgating the rule must submit a rule report, which includes a cop y 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 m ajor rule cannot take effect until 60 day s 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 [insert date 30 day s after publ ication in the Federal Register ] .Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 162 of 207 List of Subjects 40 CFR Part 87 Environmental p rotection, Air pollution control, Aircraft, Incorporation by reference. 40 CFR Part 1068 Environmental protection, Administrative practice and procedure, Confidential business information, Imports, Incorporation by reference, Motor vehicle pollution, Penal ties, Reporting and recordkeeping requirements, Warranties. Dated: Lisa P. Jackson , AdministratorDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 163 of 207 PART 87 - CONTROLOF AIR POLLUTION FROM AI RCRAFT AND AIRCRAFT ENGINES

1. The authorit y citation for part 87 is revised to read as follows: Authority : 42 U.S.C. 7401 et seq . **Subpart A -**  **[Amended]**

2. Revise §87.1 to read as follows: **§87. 1**  **Definitions.** The definitions in this section apply to this part. The definitions apply to all subparts. Any terms not defined in this section have the meaning given in the Clean Air Act . The definitions follow: Act means the Clean Air Act , as amended ( 42 U.S.C. 7401 et seq ) .Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 164 of 207 Administrator means the Administrator of the Environmental Protection Agency and any other officer or employ ee of the Environmental Protection Agency to whom authority

involved may be delegated. Aircraft has the meaning given in 14 CFR 1.1, which defines aircraft to me an a device used or intended to be used for flight in the air. Note that under §87.3, the requirements of this part generall y appl y onl y to propulsion engines used on certain airplanes for which U.S. airworthiness certificates are required. Aircraft engin e means a propulsion engine which is installed in or which is manufactured for installation in an aircraft. Aircraft gas turbine engine means a turboprop, turbofan, or turbojet aircraft engine. Characteristic level has the meaning given in Appendix 6 of I CAO Annex 16 (as of July 2008) . The characteristic level is a calculated emission level for each pollutant based on a statistical assessment of measured emissions from multiple tests. Class TP means all aircraft turboprop engines. Class TF means all turb ofan or turbojet aircraft engines or aircraft engines designed for applications that otherwise would have been fulfilled by turbojet and turbofan engines except engines of class T3, T8, and TSS.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 165 of 207 Class T3 means all aircraft gas turbine engines of the JT3D m odel family . Class T8 means all aircraft gas turbine engines of the JT8D model family . Class TSS means all aircraft gas turbine engines employed for propulsion of aircraft designed to operate at supersonic flight speeds. Commercial aircraft engine means an y aircraft engine used or intended for use by an “air carrier,” (including those engaged in “intrastate air transportation”) or a “commercial operator” (including those engaged in “intrastate air transportation”) as these terms are defined in subt itle 7 of title 49 of the United States Code and title 14 of the Code of Federal Regulations . Commercial aircraft gas turbine engine means a turboprop, turbofan, or turbojet commercial aircraft engine. Date of introduction or introduction date means the date of manufacture of the first individual production engine of a given engine model or engine ty pe certificate family to be certifi cat ed. This does not include test engines or other engines not placed into service. Date of manufacture means the date on wh ich a manufacturer is issued documentation by FAA (or other competent authority for engines certifi cat ed outside the United States) attesting that the given engine conforms to all applicable requirements . This date may not be earlier that the date on whic h assembly of the engine is complete. Where the manufacturer does not obtainDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 166 of 207 such documentation from FAA (or other competent authority for engines certifi cat ed outside the United States), date of manufacture means the date of final assembly of the engine. Derivative engine for emissions certification purposes means an engine that has the same or similar emissions characteristics as an engine covered b y a U.S. t ype certificate issued under 14 CFR part 33. These characteristics are specified in §87.48. D esignated EPA Program Officer means the Director of the Assessment and Standards Division, 2000 Traverwood Drive, Ann Arbor, Michigan 48105. DOT S ecretary means the Secretary of the Transportation and an y other officer or employee of the Department of Transportation to whom the authority involved may

be delegated. Engine means an individual engine. A group of identical engines together make up an engine model or sub - model. Engine model means an engine manufacturer’s designation for an engine grouping o f engines and/or engine sub - models within a single engine ty pe certificate family , where such engines have similar design , including being similar with respect to the core engine and combustor designs . Engine sub - model means a designation for a grouping of engines with essentially identical design , especiall y with respect to the core engine and combustor designs and other emission related features . Engines from an engine sub - model must be contained within a single engine model . For purposes of this part, an original engine model configuration is considered a sub -Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 167 of 207 model. For example, if a manufacturer initially produces an engine model designated ABC and later introduces a new sub - model ABC - 1, the engine model consists of two sub - models: ABC and ABC - 1. Engine ty pe certificate family means a group of engines ( comprising one or more engine models , including sub - models and derivative e ngines for emissions certification purpose s of those engine models ) determined b y FAA to have a sufficientl y common design to be grouped together under a t ype certificate . EPA means the U.S. E nvironmental Protection Agency . Ex cept means to routinely allow engines to be produced and sold that do not m eet (or do not fully meet) otherwise applicable standards. (Note that this de finition applies only with respect to spare engines and that the term “except” has its plain meaning in other contexts.) Ex cept ed engines must conform to regulatory conditions specified for an ex cep tion in this part and oth er applicable regulations. Excep t ed engines are deemed to be “subject to” the standards of this part even though they

are not required to compl y with the otherwise appli cable requirements. Engines exce pted with respect to certain standards must comply with other standards from which they are not excepted . Exempt means to allow (through a formal case - by - case process) engines to be produced and sold that do not m eet (or do not fully meet) otherwise applicable standards. Exempted engines must conform to regulatory conditions specified for an exemption in this part and otherDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 168 of 207 applicable regulations. Exempted engines are deemed to be “subject to” the standards of this part even though they

are not required to compl y with the otherwise applicable requirements. Engines exempted with respect to cert ain standards must comply with other standards as a condition of the exemption. E xhaust emissions means substances emitted to the atmosphere from exhaust discharge nozzles, as measured by

the test procedures specified in subpart G of this part. FAA means the U.S. Department of Transportation, Federal Aviation Administration. Fuel venting emissions means raw fuel, exclusive of h ydrocarbons in the exhaust emissions, discharged from aircraft gas turbine engines during all normal ground and flight operations . Good engineering judgment involves making decisions consistent with generall y accepted scientific and engineering principles and all relevant information, subject to the provisions of 40 CFR 1068.5. ICAO Annex 16 means Volume II of Annex 16 to the Convention on International Civil Aviation (incorporated by reference in §87.8). In - use aircraft gas turbine engine means an aircraft gas turbine engine which is in service.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 169 of 207 Military aircraft means aircraft owned b y, operated by, or produced for sale to the armed forces or other agency

of the federal government responsible for national security ( including but not limited to the Department of Defense ) and other aircraft considered to be military aircraft under international law and conventions . New means relating to an aircraft or aircraft engine that has never been placed into service. Operator means any

person or company

that owns or operates an aircraft. Productio n cutoff date or date of the production cutoff means the date on which interim phase - out allowances end . Rated output (rO) means the maximum power/thrust available for takeoff at standard day conditions as approved for the engine b y FAA , including reheat contribution where applic able, but excluding an y contribution due to water injection, expressed in kilowatts or kilonewtons (as applicable) and rounded to at least three significant figures. Rated pressure ratio (rPR) means the ratio between the combustor inlet pressure and the en gine inlet pressure achieved b y an engine operating at rated output, rounded to at least three significant figures. Round means to round numbers according to NIST SP 811 (March 2008), unless otherwise specified.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 170 of 207 Smoke means the matter in exhaust emissions that obscures the transmission of light, as measured b y the test procedures specified in subpart G of this part. Smoke number means a dimensionless value quantifying smoke emissions calculated in accordance with I CAO Annex 16. Spare engine means an engine installed (or intended to be installed) on an in - service aircraft to replace an existing engine and that is excepted as described in §87.50(c). . Standard day

conditions means the following ambient conditions: temperature =15 °C, spec ific humidity

= 0.00634 kg H 2 O/kg dry air, and pressure =101.325 kPa. Subsonic means relating to aircraft that are not supersonic aircraft. Supersonic m eans relating to aircraft that are certificated to fl y faster than the speed of sound. Tier 0 means relating to an engine that is subject to the Tier 0 NOx standards specified in §87.21. Tier 2 means relating to an engine that is subject to the Tier 2 NOx standards specified in §87.21. Tier 4 means relating to an engine that is subject to the Tier 4 NOx standards specified in §87.21.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 171 of 207 Tier 6 means relating to an engine that is subject to the Tier 6 NOx standards specified in §87.23. Tier 8 means relating to an engine that is subject to the Tier 8 NOx standards specified in §87.23. Turbofan engine me ans a gas turbine engine designed to create its propulsion from exhaust gases and from air that by passes the combustion process and is accelerated in a ducted space between the inner (core) engine case and the outer engine fan casing. Turbojet engine mean s a gas turbine engine that is designed to create all of its propulsion from exhaust gases. Turboprop engine means a gas turbine engine that is designed to create most of its propulsion from a propeller driven by a turbine, usuall y through a gearbox. Turb oshaft engine means a gas turbine engine that is designed to drive a rotor transmission sy stem or a gas turbine engine not used for propulsion . U.S. - registered aircraft means an aircraft that is on the U.S. Registry . We (us, our) means the Administrator of the Environmental Protection Agency and any authorized representatives.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 172 of 207 3. Revise §87.2 to read as follows: **§87. 2**  **Abbreviations.** The abbreviations used in this part have the following meanings: % p ercent ° d egree CO c arbon m onoxide CO 2 carbon dioxide g gram HC hydrocarbon(s) kN kilonewton kW kilow att LTO l anding and takeoff NO x o xides of nitrogen rO r ated output rPR r ated pressure ratio SN s moke number

4. Revise §87.3 to read as follows: **§87. 3**  **General a pplicability and requirements.**  (a) The regulations of this part appl y to engines on all aircraft that are required to be certificated b y FAA under 14 CFR part 3 3 except as specified in this paragraph (a). These regulations do not apply

to the following aircraft engines: (1) Reciprocati ng engines (including engines used in ultralight aircraft).Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 173 of 207 ( 2 ) T urboshaft engines such as those used in helicopters . (3) Engines used onl y in aircraft that are not airplanes. For purposes of this paragraph (a)(3), “airplane” means a fixed - wing aircraft that is heavier than air. (4 ) Engines not used for propulsion. (b) Under section 232 of the Act, the Secretary of Transportation issues regulations to e nsure compliance with the standards and related requirements of this part (42 U.S.C. 7572) . (c) The Se cretary

of Transportation shall apply these regulations to aircraft of foreign registry in a manner consistent with obligations assumed by the United States in any

treat y, convention or agreement between the United States and an y foreign country or foreign countries. ( d) No State or political subdivision of a State may adopt or attempt to enforce an y aircraft or aircraft engine standard respecting emissions unless the standard is identical to a standard applicable to such aircraft under this part (includi ng prior - tier standards applicable to exempt engines) . **§87.5 —**  **[Removed]** 5. Remove §87.5.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 174 of 207 6. Revise §87.6 to read as follows: **§87. 6**  **Aircraft safety.** The provisions of this part will be revised if at any time the DOT Secretary determines that an emission standard cannot be met within the specified time without creating a hazard to aircraft safety . **§87.7 —**  **[Removed]** 7. Remove §87.7.

8. Revise §87.8 to read as follows: **§87.8 Incorporation by reference.** (a) Certain material is incorporated by reference into this part with the approval of the Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. To enforce an y edition other than that specif ied in this section, the Environmental Protection Agency must publish notice of change in the Federal Register and the material must be available to the public.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 175 of 207 All approved material is available for inspection at U.S. EPA, Air and Radiation Docket and In formation Center, 1301 Constitution Ave., NW., Room B102, EPA West Building, Washington, DC 20460 , (202) 202 - 1744, and is available from the sources listed below. It is also available for inspecti on at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202 - 741 - 6030 or go tohttp://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. (b ) Internation al Civil Aviation Organization , Document Sales Unit, 999 University Street, Montreal, Quebec, Canada H3C 5H7 , (514) 954 - 8022, www.icao.int , or sales@icao.int .

(1) Annex 16 to the Convention on International Civil Aviation, Environmental Protection, Volume II

– Aircraft Engine Emissions, Third Edition, July 2008. [Update for CAEP8 changes]; IBR approved for §§87.2, 87.40, 87.42(d) and (f), and 87.60(a) and (b). (2) [Reserved] ( c ) National Institute of Standards and Technology , 100 Bureau Drive, Stop 1070, Gaithersburg, MD 20899 - 1070 , (301) 975 - 6478, www.nist.gov , or inquiries@nist.gov . An yone may also purchas e copies of these materials from the Government Printing Office, Washington, DC 20402 , (202) 512 - 0916, www.gpo.gov , or prntproc@gpo.gov .Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 176 of 207 (1) NI ST Special Publication 811, 1995 Edition , Guide for the Use of the International S ys tem of Units (SI ), Barry N. Taylor, Phy sics Laboratory ; IBR approved for §87.2. (2) [Reserved]Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 177 of 207 **Subpart C —**  **[Amended]**

9. Amend §87.21 as follows: a. By revising the section heading. b. By adding introductory

text.

c. By revising paragraphs (d)(1)(iii), (d)(1)(iv), (d)(1)(vi) introductory text, (e)(1), and (f). **§87.21 Exhaust emission standards for Tier 4 and earlier engines.**  This section describes the emission standard s that apply for Tier 4 and earlier engines that apply for air craft engines manufactured before [I NSERT DATE 30 DAYS AFTER PUBLICATION IN THE FEDERAL REGISTER ] and certain engines exempted under §87.50. Note that the tier of standards identified for an engine relates to NOx emissions and that the s pecified standards for HC, CO, and smoke emissions apply independent of the changes to the NOx emission standards. (d) * * * (1) * * *Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 178 of 207 (iii) The following Tier 0 emission standard applies for e ngines of a t ype or model of which the date of manufacture of the first individual production model was on or before December 31, 1995 and for which the date of manufacture of the individual engine was on or before December 31, 1999. Oxides of Nitrogen: (40 + 2(rPR)) grams/kilonewton rO. (iv) The following Tier 2 emi ssion standard applies for e ngines of a t ype or model of which the date of manufacture of the first individual production model was after December 31, 1995 or for which the date of manufacture of the individual engine was after December 31, 1999: Oxides of Nitrogen: (32 + 1.6(rPR)) grams/kilonewton rO.

* * * * * (vi) The following Tier 4 emission standards apply for e ngines of a t ype or model of which the date of manufacture of the first individual production model was after December 31, 2003: (e) * * * (1) Class TF of rated output less than 26.7 kilonewtons manufactured on or aft er August 9, 1985:Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 179 of 20 7 SN=83.6(rO) - 0.274 (rO is in kilonewtons) not to exceed a maximum of SN=50.

* * * * * (f) The standards in this section refer to a composite emission sample me asured and calculated in accordance with the procedures described in subpart G of this part .

10. Add a new §87.23 to read as follows: **§87.23 Exhaust emission standards for Tier 6 and Tier 8**  **engines.** This section describes the emission standards that apply for Tier 6 and Tier 8 engines. The standards of this section apply for aircraft engines manufactured on or after [INSERT DATE 30 DAYS AFTER PUBLICATION IN THE FEDERALREGISTER ], except wher e we specify that they apply differently

by y ear , or where the engine is exempt from one or more standards of this section . Except as specified in paragraph (d) of this section , these standards appl y based on the date the engine is manufactured. Where a gaseous emission standard is specified b y a formula, calculate and round the standard to three significant figures or to the nearest 0.1 g/kN (for standards at or above 100 g/kN). Where a smoke standard is specified by a formula, calculate and round the s tandard to the nearest 0.1 SN. Engines compl y with an applicable standard if the testing results show that the engine ty pe certificate family ’s characteristic level does not exceed the numerical level of that standard, as described in §87.60. The tier ofDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 180 of 207 standards identified for an engine relates to NOx emissions and that the specified standards for HC, CO, and smoke emissions apply independent of the changes to the NOx emission standards. (a) New turboprop aircraft engines with rated output at or above 1 ,000 k ilowatts must comply with a smoke standard of 187• rO - 0.168

. (b) New supersonic engines must comply with the standards shown in the following table :

Table 1 to §87.23

– Smoke and Gaseous Emission Standards for New Supersonic Engines

Rated Output Sm o ke

Number HC

(g/kN rated output) NOx

(g/kN rated output) CO

(g/kN rated output) rO < 26.7 kN

— 140•0.92 rPR 36+2.42•rPR 4550•rPR - 1.03 rO > 26.7 kN 83.6•rO - 0.274 or 50 .0 ,

whichever is smaller 140•0.92 rPR 36+2.42•rPR 4550•rPR - 1.03

(c) New turbofan or turbojet aircraft engines that are installed in subsonic aircraft must comply with the following standards:Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 181 of 207 (1) The applicable smoke, HC, and CO standards are shown in the following table:

Table 2 to §87.23

– Smoke, HC, and CO Standards for New Subsonic T urbofan or Turbojet Engines

Rated Output (kN) Sm oke

Standard Gaseous Emission Standards (g/kN rated output)

HC CO

rO < 26.7 kN 83.6•rO - 0.274 or 50 .0 ,

whichever is smaller — —

rO > 26.7 kN 83.6•rO - 0.274 or 50 .0 ,

whichever is smaller 19.6 118

(2) The Tier 6 NOx standards appl y as described in this paragraph (c)(2). See paragraph (d) of this section for provisions related to models introduced before these standards started to appl y and engines determined to be derivative engines for emissions certification purposes under the requirements of this part .Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 182 of 207 Table 3 to §87.23

– Tier 6 NOx Standards for New Subsonic Turbofan or Turbojet Engines with Rated Output Above 26.7 kN

I f the rated pressure ratio is... and the rated output

(in k N ) is... T he NO x emission standard (in g/k N rated output) is....

rPR < 30 26.7 < rO < 89 38.5486 + 1.6823•rPR - 0.2453•rO - 0.00308•rPR•rO

rO > 89 16.72 + 1.4080•rPR

30 < rPR < 82.6 26.7 < rO < 89 46.1600 + 1.4286•rPR - 0.5303•rO + 0.00642•rPR•rO

rO > 89

– 1.04 + 2.0•rPR

rPR > 82.6 all 32 + 1.6•rPR (3) The Tier 8 NOx standards appl y as described in this paragraph (c)(3) beginning January 1, 2014. See paragraph (d) of this section for provisions related to modelsDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 183 of 207 introduced before January 1, 2014 appl y and engines determined to be derivative engines for emissions certification purposes under the requirements of this part .

Table 4 to §87.23

– Tier 8 NOx Standards for New Subsonic T urbofan or Turbojet Engines with Rated Output Above 26.7 kN

I f the rated pressure ratio is... and the rated output

(in k N ) is... T he NO x emission standard (in g/k N rated output) is....

rPR < 30 26.7 < rO < 89 40.052 + 1.5681•rPR - 0.3615•rO - 0.0018•rPR•rO

rO > 89 7.88 + 1.4080•rPR

30 < rPR < 104.7 26.7 < rO < 89 41.9435 + 1.505•rPR - 0.5823•rO + 0.005562•rPR•rO

rO > 89 – 9.88 + 2.0•rPR

rPR > 104.7 all 32 + 1.6•rPRDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 184 of 207 (d) This paragraph specifies phase - in provisions that allow continued production of certain engines after the Tier 6 and Tier 8 standards begin to appl y.

(1) Engine ty

pe certificate families certifi cat ed with characteristic levels at or below the Tier 4 NOx standards of §87.21 (as applicable based on rated o utput and rated pressure ratio) and introduced before [INSERT DATE 30 DAYS AFTER PUBLICATION IN THE FEDERAL REGISTER ] may be produced through December 31, 2012 without meeting the Tier 6 NOx standards of paragraph (c)(2) of this section . This also applies for engines that are covered by

the same ty

pe certificate and are determined to be derivative engines for emissions certification purposes under the requirements of this part . Note that a fter this production cutoff date for the Tier 6 NOx standards, such engines may be produced onl y if they are covered by

an exemption under §87.50. This production cutoff does not apply to engines installed (or delivered for installation) on military aircraft. (2 ) Engine ty

pe certificate families certifi cat ed with charact eristic levels at or below the Tier 6 NOx standards of paragraph (c)( 2 ) of this section with an introduction date before January 1, 2014 may

continue to be produced. This also applies for engines that are covered by the same ty

pe certificate and are determined to be derivative engines for emissions certification purposes under the requirements of this part.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 185 of 207 (3) An engine manufacturer may produce up to six newly

manufactured Tier 4 engines on or after [INSERT DATE 30 DAYS AFTER PUBLICATION IN THE FEDERAL REGI STER] , subject to the provisions of this paragraph (d)(3) . Tier 4 engines meeting the criteria of this paragraph (d)(3) are excepted without request from the otherwise applicable Tier 6 NOx emission standard. T o be eligible for this exce ption the engines must have a date of manufacture prior to August 3 1, 2013, be fully compliant with all requirements applicable to Tier 4 engines, and be labeled as specified by the FAA . The manufacturer must include these engines in the report required b y §87.50. This ex cep tion is void for any manufacturer that produces more than six ex cep ted engines under this paragraph.

11. Add a new subpart E containing §§87.40, 87.42, 87.44, 87.46, and 87.48 to part 87 to read as follows:

**Subpart E —**  **Certification Provisions** 

Sec. 87.40 General certification requirement.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 186 of 207 87.42 Certification report to EPA. 87.4 4 Reporting CO 2 emissions. 87.46 Recordkeeping. 87.4 8 Derivative engines for emissions certification purposes . **§87.40 General certification requirement.**  Manufacturers of engines subject to this part must meet the requirements of title 14 of the Code of Federal Regulations as applicable.

**§87.42 Production**  **report to EPA.** Engine manufacturers must submit an annual production report as specified in this se ction. This requirement applies for engines produced on or after January 1, 2013. (a) You must submit the report for each calendar year in which you produce an y engines subject to emission standards under this part. The report is due b y February 28 of the following calendar year. Note that §87.64 requires you to report CO 2 emission rates to EPA in addition to NOx . Include these data in the report required b y this section. I f you produce exempted orDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 187 of 207 excepted engines, you may submit a single report with information on exempted/excepted and normally certificated engines. (b) Send the report to the Designated EPA Program Officer. ( c ) In the report, specify

your corporate name and the y ear for which you are reporting. In clude information as described in this section for each engine sub - model subject to emission standards under this part. L ist each engine sub - model produced or certific ated during the calendar year, including the following information for each sub - model:

(1) The t ype of engine (turbofan, turboprop, etc.) and complete sub - model name, including an y applicable model name , sub - model identifier, and engine t ype certificate family identifier. (2) The certificate under which it was produced. Identify all the following: (i) The t ype certificate number. Specify if the sub - model also has a t ype certificate issued b y a certificating authority other than FAA. (ii) Your corporate name as listed in the certificate. (i ii ) Emission s tandards to which the engine is certifi cat ed. (iv ) Date of issue of t ype certificate (month and ye ar) .Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 188 of 207 (v ) Whether or not this is a derivative engine for emissions certification purposes . If so, identify

th e original certifi cat ed engine model. ( v i ) The engine sub - model that received the original ty pe certificate for an engine ty pe certificate family . (3) Identify

the combustor of the sub - model, where more than one t yp e of combustor is available. ( 4 ) The calendar - ye ar production volume of engines from the sub - model that are covered b y an FAA t ype certificate. Record zero for sub - models with no engines produced during the calendar ye ar, or state that the engine model is no longer in production and list the date of manufacture (month and y ear) of the last engine produced. Specify the number of these engines that are intended for use on new aircraft and the number that are intended for use as non - exempt engines on in - use aircraft. For engines delivered witho ut a final sub model status and for which the manufacturer has not ascertained the engine’s sub - model when installed before submitting its production report, the manufacturer may do any of the following in its initial report, and amend it later:

(i) L ist the sub - model that was shipped or the most probable sub - model. (ii) L ist all potential sub - models. (iii) State “Unknown Sub - Model”.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 189 of 207 (5) The number of engines tested and the number of test runs for the applicable ty pe certificate. (6) T he applicable test data and related information specified in Part III, Section 2.4 of I CAO Annex 16 (incorporated by reference in §87.8) , except as otherwise allowed b y this paragraph . For purposes of this paragraph (c)(6), applicable test data means data required to certify the engine sub - model, which would ty pically include NOx, HC, CO and smoke number. However, applicable test data would not include NOx, HC, or CO emissions for engines subject to only

smoke standards. Note that §87.64 also requires you to report CO 2 emiss ions. Specify

thrust in kW for turboprop engines. You may omit the following items specified in Part III, Section 2.4 of I CAO Annex 16 :

(i) Fuel specifications including fuel specification reference and h ydrogen/carbon ratio. (ii) Methods used for data a cquisition, correcting for ambient conditions, and data anal ys is. (iii) Intermediate emission indices and rates, however y ou may not omit the final characteristic level for each regulated pollutant in units of g/kN or g/kW. (d) Clearl y show what informatio n you consider confidential by marking, circling, bracketing, stamping, or some other method. We will store y our confidential information asDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 190 of 207 described in 40 CFR part 2. Also, we will disclose it only as specified in 40 CFR part 2. If y ou send us informat ion without claiming it is confidential, we may make it available to the public without further notice to you, as described in 40 CFR 2.204. ( e ) Include the following signed statement and endorsement by an authorized representative of your company : “We sub mit this report under 40 CFR 87.42. All the information in this report is true and accurate to the best of m y knowledge. ” ( f ) Where information provided for the previous year remains valid and complete, you may report your production volumes and state that there are no changes , without resubmitting the other information specified in this section.

**§87.4 6**  **Recordkeeping .**  (a) You must keep a copy of any reports or other information you submit t o us for at least three ye ars. (b ) Store these records in any format and on any

media, as long as you can promptly send us organized, written records in English if we ask for them. You must keep these records readily available. We may

review them at any

time.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 191 of 207 **§ 87.48**  **Derivative engine s**  **for emissions certification purposes .**  (a) General . A ty

pe certificate holder may

request from the FAA a determination that an engine configuration is considered a derivative engine for emissions certification purposes . This would mean that the engine configuration is determined to be similar in design to a previously certifi cat ed engine (the “original” engine) for purposes of compliance with exhaust emission standards (gaseous and smoke) . In order for the engine confi guration to be considered a derivative engine for emission purposes under this part, it must have been derived from an original engine that was certifi cat ed to the requirements of 14 CFR part 33 , and one of the following conditions must be met:

(1) The FAA determined that a safet y issue exists that requires an engine modification. (2) Emissions from the derivative engines are determined to be similar. In general, this means the emissions must meet the criteria specified in paragraph (b) of this section. FAA may adjust these criteria in unusual circumstances, consistent with good engineering judgment. (3) All of the regulated emissions from the derivative engine are lower than the original engine.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 192 of 207 (b) Emissions similarity . (1) The ty pe certificate holder must demonstrate that the proposed derivative engine model ’s emission s meet the applicable standards and differ from the original model ’s emission rates onl y within the following ranges :

(i) ± 3.0 g/kN for NOx. (ii) ± 1.0 g/kN for HC. (iii) ± 5.0 g/kN for CO. (iv) ± 2.0 SN for smoke. (2) If the characteristic level of the original certificated engine model (or any other sub - models within the emission ty pe certificate family

tested for certification) before modification is at or above 95% of the applicable standard for an y pollutant, you must measure the proposed derivative engine model’s emissions for all pollutants to demonstrate that the derivative engine’s resulting characteristic levels will not exceed the applicable emission standards. If the charact eristic level s of the originally certificated engine model (and all other sub - models within the emission ty pe certificate family

tested for certification) are below 95% of the applicable standard for each pollutant , then, you may use engineering anal ys is to demonstrate that the derivative engine will not exceed the applicable emission standards, consistent with good engineering judgment. The engineering analy sis mustDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 193 of 207 address all modifications from the original engine, including those approved for previous derivative engines. (c) Continued production allowance . Where we allow continued production of an engine model after new standards begin to appl y, you may also produce engine derivatives if they conform to the specifications of this section. (d) Non - deri vative engines . If the FAA d etermines that an engine model does not meet the requirements for a derivative engine for emissions certification purposes, the ty pe certificate holder is required to demonstrate that the engine complies with the emissions stan dards applicable to a new engine ty pe.

12. Add a new subpart F containing §87.50 to part 87 to read as follows:

**Subpart F —** **Exemptions and exceptions** 

**§87.50 Exemptions and exceptions**  **.**Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 194 of 207 This section specifies provisions related to exempting/excepting engines from some or all of the standards and requirements of this part 87. Exempted /excepted engines must conform to regulatory

conditions specified for an exemption in this section and other applicable regulations. Exempted/excepted engines are deemed to be “subject to” the standards of this part even though they are not required to comply with the otherwise applicable requirements. Engines exempted/excepted with respect to certain standards must comply with other standards. Exemption requests under para graph (a) of this section must be approved by the FAA, with the written concurrence of EPA, to be effective. Exemption requests under paragraph (b) of this section must be approved only by the FAA to be effective. Exceptions do not require a case - by case FAA approval. (a) Engines installed in new aircraft. Ty pe certificate holders may request an exemption to produce a limited number of newly manufactured engines through December 31, 2016 , to be installed in new aircraft as specified in this paragraph (a) . This exemption is limited to NOx emissions from engines that are covered b y a valid type certificate issued by FAA.

( 1 ) Submit y our request for an exemption before producing the engines to be exempted to the FAA who will provide a cop y to the Desi gnated EPA Program Officer. Exemption by

an authority

outside the United States does not satisfy this requirement. Unless EPA and FAA allow otherwise, a ll requests must include the following:

(i) Your corporate name and an authorized representative’s contact information.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 195 of 207 (ii) A description of the engines for which you are requesting the exemption including the t ype certificate number and date it was issued b y the FAA . Include in your description the engine model and sub - model names and the t ypes of aircr aft in which the engines are expected to be installed. Specify the number of engines that yo u would produce under the exemption and the period during which you would produce them. (iii) Information about the aircraft in which the engines will be install ed. Specify the airframe models and expected first purchasers/users of the aircraft. Identify all countries in which you expect the aircraft to be registered . Specify how many

aircraft will be registered in the United States and how many will be registered in other countries ; yo u may estimate this if it is not known . (iv) A justification of why the exemption is appropriate. Justifications must include a description of the environmental impact of granting the exemption. Include other relevant i nformation such as the following.

(A) Technical issues, from an environmental and airworthiness perspective, which may

have caused a delay

in compliance with a production cutoff. (B) Economic impacts on the manufacturer, operator(s), and aviation industry at large.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 196 of 207 (C) Environmental effects. This should consider the amount of additional air pollutant emissions that will result from the exemption. This could include consideration of items such as:

( 1 ) The amount that the engine model exceeds the standard, t aking into account an y other engine models in the engine t yp e certificate family covered by the same ty

pe certificate and their relation to the standard. ( 2 ) The amount of the applicable air pollutant that would be emitted by an alternative engine for the same application. ( 3 ) The impact of changes to reduce the applicable air pollutant on other environmental factors, including emission rates of other air pollutants, community

noise , and fuel consumption . ( 4 ) The degree to which the adverse impact would be offset b y cl eaner engines produced in the same time period (unless we decide to consider earlier engines). (D) Impact of unforeseen circumstances and hardship due to business circumstances bey ond your control (such as an employ ee strike, supplier disruptio n, or calamitous events).Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 197 of 207 (E) Projected future production volumes and plans for producing a compliant version of the engine model in question. (F) Equit y issues in administering the production cutoff among economically competing parties. (G) List of other certificating authorities from which you have requested (or expect to request) exemptions, and a summary of the request. (H) An y other relevant factors. (v) A statement signed by yo ur authorized representative attesting that all information included in the request is accurate. ( 2 ) In consultation with the EPA, the FAA may specify additional conditions for the exemption. The FAA may also require a dditional information pursuant to 14 CFR Parts 11 and 34, as applicable to exemption requests made to the FAA . ( 3 ) You must submit the annual report specified in paragraph ( d ) of this section. ( 4 ) The permanent record for each engine exempted under this paragraph (a) must indicate that the engine is an exempted new engine. ( 5 ) Engines exempted under this paragraph (a) must be labeled with the following statement: “EXEMPT NEW”.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 198 of 207 ( 6 ) You must notify the FAA if you determine after submitting your request that the information is not accurate, either from an error or from changing circumstances. If you believe the new o r changed information c ould have affected approval of your exemption (including information that could have affected the number of engines we exempt) , you must notify the FAA promptl y. The FAA will consult with EPA as needed to address an y concerns relate d to this new or corrected information. (b) Temporary

exemptions based on flights for short durations at infrequent intervals. The emission standards of this part do not apply to engines which power aircraft operated in the United States for short durations at infrequent intervals. Such operations are limited to:

(1) Flights of an aircraft for the purpose of export to a foreign c ountry , including any flights essential to demonstrate the integrity of an aircraft prior to its flight to a point outside the United States. (2) Flights to a base where repairs, alterations or maintenance are to be performed, or to a point of storage, and flights for the purpose of returning an aircraft to service. (3) Official visits by representatives of foreign governments. (4) Other flights the Secretary determines to be for short durations at infrequent intervals. A request for such a determination shall be made before the flight takes place.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 199 of 207 ( c ) S pare engines . Newly manufactured engines meeting the definition of “spare engine” are excepted as follows:

(1) This ex ce ption allow s production of a newly manufactured engine for installation on an in - s ervice aircraft. It does not allow for install ation of a spare engine on a new aircraft. (2) Each spare engine must be identical to a sub - model previously certificated to meet all requirements applicable to Tier 4 engines or later requirements. (3) Spare engines ex ce pt ed under this paragraph ( c ) may be used only

where the emissions of the spare engines are certificated to equal to or lower emission standards than those of the engines they

are replacing, for all regulated pollutants. ( 4 ) No prior approval i s required to produce spare engines. E ngine manufacturers must include information about their production of spare engines in the annual report specified in paragraph ( d ) of this section ( 5 ) The permanent record for each engine ex ce pted under this paragra ph (c) must indicate that the engine was produced as an ex ce pted spare engine. ( 6 ) Engines ex ce pted under this paragraph (c) must be labeled with the following statement: “EX CE PT ED SPARE”.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 200 of 207 ( d) Annual reports. If you produce engines with an exemption/exception under this section, y ou must submit an annual report with respect to such engines.

(1) You must send the Designated EPA Program Officer a report describing your p roduction of exempted

/excepted engines for each calendar y ear in which y ou produce such engines b y February 28 of the following calendar year. You may include this information in the certification report described in §87.42. Confirm that the information in your initial request is still accurate, or describe an y relevant changes. (2) Pr ovide the information specified in this paragraph ( d )(2). For purposes of this paragraph ( d), treat spare engine ex ce ptions separate from other new engine exemptions. In clude the following for each exemption/exception and each engine model and sub - model:

(i) Engine model and sub - model names. (ii) Serial number of each engine. (iii) Use of each engine (for example, spare or new installation). (iv) Ty pes of aircraft in which the engines were installed (or are intended to be installed for spare engines). (v) Serial number of the new aircraft in which engines are installed (if known) , or the name of the air carriers (or other operators) using spare engines.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 201 of 207 (3) Include information in the report onl y for engines having a date of manufacture within the speci fic calendar year.

**Subpart G**

**— Test Procedures**  13. The heading for subpart G is revised as set forth above.

14. Revise §87.60 to read as follows: **§87.60 Testing engines.** (a) Use the equipment and procedures specified in Appendix 3, Appendix 5, and Appendix 6 of IC AO Annex 16 (incorporated b y reference in §87.8), as applicable, to demonstrate whether engines meet the gaseous emission standards specified in subpart C of this part . Measure the emissions of all regulated gaseous pollutants. Similarly , use the equi pment and procedures specified in Appendix 2 and Appendix 6 of I CAO Annex 16 to determine whether engines meet the smoke standard specified in subpart C of this part . The compliance demonstration consists of establishing a mean value from testing some num ber of engines, then calculating a “characteristic level” b y appl yi ng a set of statistical factors that take into account the number of engines tested. Round each characteristic level to the same number of decimalDeliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 202 of 207 places as the corresponding emission stan dard. For turboprop engines, use the procedures specified for turbofan engines, consistent with good engineering judgment. (b) Use a test fuel meeting the specifications described in Appendix 4 of I CAO Annex 16 (incorporated b y reference in §87.8). The t est fuel must not have additives whose purpose is to suppress smoke, such as organometallic compounds. (c) Prepare test engines by including accessories that are available with production engines if they

can reasonably

be expected to influence emissions. The test engine may not extract shaft power or bleed service air to provide power to auxiliary gearbox - mounted components required to drive aircraft s ys tems. (d) Test engines must reach a stead y operating temperature before the start of emission measurements. (e) In consultation with the EPA , the FAA may approve alternate procedures for measuring emissions as specified in this paragraph (e) . This might include testing and sampling methods, analy

tical techniques, and equipment specifications that differ from those specified in this part. Manufacturers and operators may request this approval by

sending a written request with supporting justi fication to the FAA and to the Designated EPA Program Officer . Such a request may

be approved only

if one of the following conditions is met: (1) The engine cannot be tested using the specified procedures.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 203 of 207 (2) The alternate procedure is shown to be equi valent to or better (e.g., more accurate or precise) than the specified procedure.Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 204 of 207 (f) The following landing and take - off (LTO) cycles apply for emission testing and calculating weighted LTO values :

Table 1 to § 87.60

– LTO Test Cy cles

Mode Turboprop Su bsonic Turbofan Supersonic Turbofan

Percent of Rated Output Tim e in

Mode (minutes) Perc

ent of Rated Output Tim e in

Mode (minutes) Percent of

Rated Output Tim e in

Mode (minutes)

Take - o ff 100 0.5 100 0.7 100 1.2

Climb 90 2.5 85 2.2 65 2.0

Descent

— — — — 15 1.2 Approach 30 4.5 30 4.0 34 2.3 Taxi/ground idle 7 26.0 7 26.0 5.8 26.0Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 205 of 207 (g) Engines compl y with an applicable standard if the testing results show that the engine ty pe certificate family ’s characteristic level does not exceed the numerical level of that standard, as described in §87.60.

**§§87.61 -**  **87.63 —**  **[Removed]** 15. Remove §§87.61 - 87.63.

**§87.64 —**  **[Revised]** 16. Remove and reserve paragraph (a).

**§§87.65 -**  **87.71 —**  **[Removed]** 17. Remove §§87.65 - 87.71.

**Subpart H —**  **[Removed]**Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 206 of 207 18. Remove subpart H.

**PART 1068 --**  **GENERAL COMPLIANCE PROVISIONS FOR ENGINE PROGRAMS** 

19. The authorit y citation for part 1068 continues to read as follows: Authority : 42 U.S.C. 7 401 - 7671q . **Subpart A —**  **[Amended]**

20. Amend §1068.1 by

revising paragraph (b) to read as follows: **§1068.1 Does this part apply to me?**

* * * * * (b) This part does not apply to an y of the following engine or vehicle categories: (1) L ight - duty

motor vehicles (see 40 CFR part 86).Deliberative and Confidential Do Not Cite or Quote EO12866_Aircraft_NOx_2060 - A070_FRN_20120209.doc

Page 207 of 207 (2) Heav y - dut y motor vehicles and motor vehicle engines, exc ept as specified in 40 CFR part 86. (3) Aircraft engines, except as specified in 40 CFR part 87. (4) Land - based nonroad compression - ignition engines we regulate under 40 CFR part 89. (5) Small nonroad spark - ignition engines we regulate under 40 CFR part 90 . (6) Marine spark - ignition engines we regulate under 40 CFR part 91. (7) Locomotive engines we regulate under 40 CFR part 92. (8) Marine compression - ignition engines we regulate under 40 CFR parts 89 or 94.

* * * * *