### U.S. EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866 Interagency Review.[rcvd February 17 2011]

Subject to Further Policy Review.

Page 1 of 13 1) Comment : Please provide a detailed outline of the provisions of this rulemaking that deviate from the recommendations of I CAO and provide a detailed justification and policy rationale for why EPA is proposing to deviate from these recommended standards. The Uni ted States has an obligation under the Article 2.4 TBT Agreement to follow international standards unless those standards would be ineffective and inappropriate. Specificall y, Article 2.4 states, “Where technical regulations are required and relevant int ernational standards exist or their completion is imminent, Members shall use them, or the relevant parts of them, as a basis for their technical regulations except when such international standards or relevant parts would be an ineffective or inappropriat e means for the fulfillment of the legitimate objectives pursued, for instance because of fundamental climatic or geographical factors or fundamental technological problems.” Response : There are only two provisions in this draft proposed rule which are di fferent than those adopted b y ICAO or its Committee on Aviation Environmental Protection (CAEP). The first is related to how potential exemptions from meeting Tier 6 (CAEP/6) NOx standards are defined and the second is related to reporting requirements. Each of these is discussed below. This proposal implements a new requirement limiting the number of legacy engines that can continue to be sold even though they onl y comply

with the previous NOx emission standards to 75 engines per ty

pe certificate holder (e.g., per manufacturer) . The ICAO Working Group responsible for this issue developed similar language that limited the number of potential exemptions to 75 per ty

pe certificate rather than per ty pe certificate holder

. In our outreach to stakeholders preceding the drafting of th is proposed rule , it became apparent that while the ICAO process resulted in 75 exemptions per ty pe certificate the actual need expressed b y the industry was for 75 ex e mptions per ty pe certificate holder with some flexibility i n case of unanticipated hardship as we have proposed. We worked th ese idea s with all of the manufacturers and the y support the language we are proposing

. The European Aviation Safety Agency ( EASA ) did not object to th ese idea s either , but they did indicate that their regulation to adopt IC AO’s production cut

- off and exemptions was already too far along to be modified to align with the newl y agreed upon interpretation of 75

. The 75 per ty pe certificate holder approach is the correct outcome ; it helps to assure that the emission benefit of the standard is achieved, it meets the needs of industry, and it sets an appropriate basis (i.e. per ty pe certificate holder) for future considerations. We plan to continue our dialogue with EASA with the goal of harmonizing ICAO’s ETM and their regulation with our draft proposal. Regarding reporting requirements, IC AO sponsors an emissions data bank (EDB) to provide information to the public on aircraft engines and their HC, CO, NOx and smoke emission levels. This information is reported to the I CAO point of contact voluntarily and

### U.S. EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866 Interagency Review.[rcvd February 17 2011]

Subject to Further Policy Review.

Page 2 of 13 aperiodicall y b y the manufacturers. The point of contact has retired and despite our overtures to ICAO to address the EDB’s incompleteness we identified in the EDB , I CAO has taken no definitive steps to identify a new point of contact or to resolve the lack of currency and completeness o f the EDB. As part of the mandatory GHG reporting rule (http://www.epa.gov/climatechange/emissions/ghgrulemaking.html ) , we adopted mandatory reporting requirements in 40 CFR P art 87 which require manufacturers to report aircraft engine CO2 emissions together with more general information describing the engine model and its characteristics. The provisions in this draft proposal simply add a separate requirement to report HC, CO, NOx, and smoke emissions , consistent with the existing IC AO dat abase , includes the relativel y few smaller thrust turbofan or turboprop engines not included in the EDB and ask s for information on annual production and production status . It adds no significant burden on the manufacturers beyond what is required to resp ond to the EDB or required separately in the GHG reporting rule

. Any incremental burden is minimal

. The collection of this information is authorized under section 114(a)(1) of the Clean Air Act (CAA). Specifically, under the CAA, we are authorized to require any person who is subject to the Act to establish and maintain necessary records,
make reports, and provide such other information as we may reasonably require in discharging our obligations under the Act

. (See 4 2 U.S.C. § 7414(a)(1)) S uch a reporting requirement is appropriate because we are the regulatory authority for aircraft engine emissions standards , and we need this information to work with FAA to develop the U.S. positions for emissions standards at ICAO. We also require it to review exemption requests, for example, by examining the history of production

. Examples of how this type of information has already been used to develop ICAO policy are contained in the following recent ICAO/CAEP papers :

 CAEP/8

- W G3

- WP6

- 14, Production Cut

- Off W orking Paper, March 2009

 CAEP WG3 Presentation, Production Cut

- Off Provisions for Jet Engines , April 2009

 CAEP WG3 Presentation, Change in Average NOx Emissions , April 2009

 ICAO Steering Group, WP39, Production Cut

- Offs and Associated Flexibilities for ICAO Engine Emission Standards W orking Paper , June 2009

 ICAO Forecasting and Economic Anal ys is Support Group, IP Paper, Aircraft NOx Emissions Control Information Paper, October 2009

 CAEP/8

- WP/52, NOx Stringency Working Paper , February 2010

 CAEP/8

- WP/15, Environmental and Economic Assessment of the NOx Stringency Scenarios Working Paper , February 2010

 CAEP/8

–IP /14, Economic Assessment of the NOx Stringency Scenarios Information Paper , February

2010 2) Comment : How did EPA cho ose which non

- attainment areas to display in Table 4 on page 25? Why are areas that encompass some of the Nation’s larger “hub” airports (such as Boston, New York and Dallas

- Fort Worth) not included?

### U.S. EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866 Interagency Review.[rcvd February 17 2011]

Subject to Further Policy Review.

Page 3 of 13 Response : We chose the nonattainment areas for illustrative purposes and have since expand ed the number of nonattainment areas described in the proposal

. These now include the airports identified by

the commenter. A draft of this list is attached. We anticipate that a total of 4 1
n onattainment areas will be identified in the proposal . To select these nonattainment areas, commercial service aircraft emissions inventories were anal yz ed for areas where airports had either a high number of commercial service operations or large populati on s in the nearb y vicinity . We identified the top 25 nonattainment areas in each of these two categories, and after eliminating duplicates , 4 1 nonattainment areas remained for the assessment. Collectively these 4 1 nonattainment areas include 20 0 airports that account for 7 0 percent of commercial air traffic. 3) Comment : Itis acknowledged that section 233 of the Clean Air Act preempts States from adopting or enforcing any aircraft engine emissions standard unless such standard is identical to EPA’s. Nonetheless, because EPA is proposing to revise text in the Code of Federal Regulations with respect to this statutory preemption, additional discussion addressing EPA’s argument that this rule will not have federalism implications under Executive Order 13132 would be helpful. At a minimum, EPA should clarify the explanation provided on page 131 to remove some apparent inconsistencies in the text. Suggested revisions are: This action does not have federalism implications. It will not have sub stantial 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 proposes to revise the Code of Federal Regulations to more accuratel y reflect the statutory preemption established by the Clean Air Act. This rule does not impose any new preemption merely

modifies existing EPA aircraft engine emission standards and test procedures and therefore will merel y continue an existing preemption of State and local law. Thus, Executive Order 13132 does not apply to this action. Response : We agree, and we made this change as the commenter indicated

. 4) Comment : Inthe discussion in the preamble about military engines, EPA states that it is "not proposing any specific provisions with respect to engines installed on military aircraft," explaining that such aircraft fall outside the scope of the emissions rules by operation of the regulatory

language that brings covered aircraft within the rules (because the FAA rules do not require the certification of military engines). In the table on page 114, however, EPA suggests that proposed § 87.1 ("Definitions") contains a definition of "military aircraft." In fact, consistent with the earlier discussion, there is no such definition in § 87.1.

### U.S. EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866 Interagency Review.[rcvd February 17 2011]

Subject to Further Policy Review.

Page 4 of 13 Response : Th e language in the draft proposal clarifies that our standards do not apply to military engines. Th e definition is required to ensure that the regulations are not misinterpreted to mean that civilian aircraft engines produced for military applications are subject to the production cutoff, as described in our response to comments 1 and 5. 5) Comment : Recommend revising the table to cite § 87.3 ("General applicability and requirements"), since it really pertains to applicability

and since it doesn't actually refer to any particular definition in § 87.1. For consistency with the statutory

FAA provisions, EPA may also wish to use the terminology in 49 USC § 40125(c), i.e. "aircraft owned or operated by the armed forces." The note in the table on page 114 might be revised to say , for instance, "The regulations of this part do not apply

to aircraft owned or operated by the Armed Forces, including aircraft owned b y the U.S. Coast Guard, as well as some other aircraft not owned by DoD." Whether or not EPA changes the cite or uses the terminology in 49 U.S.C., EPA's clarification in the preamble that military /armed forces aircraft are not covered by the rules and that such aircraft includes non

- DoD aircraft is very helpful and much appreciated. Response : The definition states that military aircraft means "aircraft owned by , operated b y, 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)." The table entry has been revised accordingl y. 6) Comment : Recommend adding the words "that are required to be" to § 87.3(a) to read: "The regulations of this part apply to engines on all aircraft that are required to be certificated by FAA under 14 CFR P art 34 except as specified...." In the preamble, EPA points out that manufacturers sometimes voluntarily certify engines that FAA does not require to be certificated and clarifies that it is EPA's intent to exclude engines which FAA does not require to be certificated, whether or not they are, in fact, certificated. The proposed language does not, however, say

that and could be read that voluntary certification brings an engine within the purview of the regulations. Response : We have made the change

. The new language is below: §87.3 General applicability 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 33 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 ultra light aircraft). (2) Turboshaft engines such as those used in helicopters. (3) Engines used onl y in aircraft that are not airplanes. For purposes of this paragraph (a)(4), “airplane” means a fixed

- wing aircraft that is heavier than air.

### U.S. EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866 Interagency Review.[rcvd February 17 2011]

Subject to Further Policy Review.

Page 5 of 13 (4) Engines not used for propulsion. 7) Comment : Recommend checking the internal cross

- reference in §87.1 to ensure it is the correct cite. Response : We validated the cross reference

. 8) Comment : The draft rule contains provisions that may exceed reasonable interpretations of the statutory

phrase “standards applicable to the emission of any air pollutant” (standards). If every thing in the draft rule is considered a standard, an obligation would be created under CAA section 7572 for other agencies besides EPA to adopt and implement through their authorities. Response : Without specifying the provisions in question or even examples of such provisions, it is not possible for us to provide a specific response to th is comment. However, the definition of a standard in section 302(k) of the CAA broadl y defines “emission standard” to mean “a requirement established by the State or the Administrator which limits the quantity , rate, o r concentration of emissions of air pollutants on a continuous basis, including any requirement relating to the operation or maintenance of a source to assure continuous emission reduction, and any design, equipment, work practice or operational standard p romulgated under this chapter.” Within this context, provisions that are not simply a numerical expression of an emission limit or standard, but are necessary to make the numeric limit enforceable may be broadly considered as part of the “ standard s ” EPA i s directed to promulgate . Such provisions have historically been included in EPA programs, including emission standards for aircraft engines. Therefore, we believe that all of the provisions of the draft proposed rule are appropriate ly within the scope o f EPA’s authority

to promulgate emission standards. The U.S. Court of Appeals for the D.C. Circuit has read EPA’s aircraft engine emissions standard

- setting authority to be particularly broad. No one has challenged EPA’s authority to include in such standards provisions addressing exemptions (existing section 87.7) ; incorporation by reference of ICAO technical materials (existing section 87.8) ; or test procedures and emissions measurement, and determination of compliance (existing subparts G and H). 9 ) Comment : The EPA has proposed that a new annual report be submitted by engine manufacturers detailing the production of various engine models. Much of this infor mation is available elsewhere. Response : See our response to comment 1) above. Some of the information that EPA is seeking is already submitted to the FAA. However, we have been informed that this information is unavailable to us because of FAA’s confidentiall y agreements with the engine manufacturers. Comment : Itis unclear wheth er the report can be viewed as a standard ....

### U.S. EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866 Interagency Review.[rcvd February 17 2011]

Subject to Further Policy Review.

Page 6 of 13 Response: Please refer to our discussion on the meaning of the term standard in our response to comment number 8 )

. Our authority to request such information is discussed in response to comment 1 )

. Comment : ... there does not appear to be a clear regulatory need for the report. Can EPA provide a clear rationale for why this report would be required, or consider not requiring this report? What specifically would the information be used for? Response: S ee our response to comment 1)

. Comment : Would collecting this information require approval under the Paperwork Reduction Act? Response : Yes , w e have prepared a draft ICR for this purpose , S ee our response to comment 1 ) for details on our authority

. 10 ) Comment : The EPA has proposed a new “exemption” process under which manufacturers could continue to produce certain engines after the standards have changed. In general, industry usage of exemptions has remained low. The new process includes joint filings and unclear lines of authority

and decision. Response : The exemption process is not new . Exemption provisions have been included in the EPA and FAA regulations for decades. Th e proposed revisions to the existing exemption provisions are virtuall y identical in all material respects to the process specified in I CAO’s Annex 16 and ET M

. The draft proposal would require that a manufacturer submit its exemption request simultaneously

to EPA and to FAA. We believe that this would facilitate a more timely consultation process between the two agencies. We think that a manufacturer would be very willing to do this in order to help expedite this review. There should be no real burden associated with a duplicate submission because the contents would be identical, except perhaps for the addressee on the cover letter and the cost of mailing. Finall y, both EPA’s current regulations and FAA’s require that exemption requests be submitted in duplicate to the FAA , presumabl y to facilitate dispatching a cop y t o EPA . Our proposal simply eliminates this two step handling process. We are unsure what could be unclear about the lines of authority and decision. The draft regulations clearly

state that exemptions must be approved by the FAA under 14 CFR part 34. W e have made the preamble clearer relative to the FAA being the process owner. Regarding EPA’s role in granting exemptions, our current § 87.7(c) regulations and current § 34.7(c) FAA regulations state that EPA must concur with the DOT/FAA decision to grant an exemption. The

### U.S. EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866 Interagency Review.[rcvd February 17 2011]

Subject to Further Policy Review.

Page 7 of 13 draft proposal clarifies that this would be a “written” concurrence to prevent any misunderstanding s and to provide a historical record of our decision

. Comment : It [the exemption process] appears inconsistent in its use of terms that are well known in the industry , and attaches new concepts to them. Response : We are unaware any significant term inology in the draft proposal regarding exemption s that is inconsistent with terms that are well known in the industry, or attaches new concepts to them. Further, the lack of any specific examples in th is comment makes it difficult for us to respond. We have retained the word “ exemption ” in the draft proposal because it is used in the current EPA regulation, in IC AO’s Annex 16, and in IC AO’s ETM. Thus it is very familiar to stakeholders and is unambiguous

. Comment : No attempt has been made to detail the costs of the new process to other agencies, or to industry

applicants. Response : Addressing the other agencies first, o ur draft proposal does not describe the costs of the exemption process to any other government entity

. As noted above, the exemption process i s not new. We have proposed some revisions to clarify what a manufacturer should include in the petition for exemption, which in large part is what is currentl y required or has generally been submitted by

manufacturers in previous exemption requests. We b elieve the only definite incremental change in the process is differentiating spare engines from new engines (as discussed in our response to Comment 11)

. This differentiation should not represent substantial change relative to the status quo. The United States ’ position at CAEP fully supported the spare engine versus new engine exemptions provisions , which were adopted b y CAEP. The United States’ Interagency

Group on International Aviation ( IG IA ) concurred on the United States’ position to support the a doption of these provisions at I CAO/CAEP. Thus , in following the United States’ position at CAEP, we have proposed these provisions, based upon I CAO’s Annex 16 and ETM

. Regarding cost to the industry , exemptions are a voluntary regulatory flexibility f

or the benefit of the engine manufacturers directly , and the airframe manufacturers and airlines indirectly . Exemptions can avoid costs that may otherwise be incurred b y these entities if they had to comply

with certain emission standards. EPA and the in dustry consider these provisions to be useful voluntary flexibilities

. 11) Comment : Similarly, the EPA proposes a new designation of “exempt

- spare” engines that may be produced outside of production limits. The draft rule does not account for how this would impact certification processes and regulations of other agencies. The draft rule does not acknowledge the regulatory requirements or their costs that would fall on other agencies from adopting a new category

of engine marking ....”

### U.S. EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866 Interagency Review.[rcvd February 17 2011]

Subject to Further Policy Review.

Page 8 of 13 Response : Please refer to our response to Comment 10 on accounting for other agencies process es and costs with regard to spares

. Comment: “... and a new sy stem by which the EPA expects them [spares] to be traceable. The concept of installing a “spare” engine presumes there is a s ys tem in place by which individual engines are tracked on individual aircraft by operation (emphasis added) . The reality is that there is no such s ys tem in place to track eng ines with this new designation. The rule contains no acknowledgement of the cost that could result from a full consideration of such a requirement, including the tremendous cost on the FAA to promulgate and implement such a s ys tem. Response : The current EPA and FAA regulations provide for exemptions regardless of the intended use of an engine, i.e., whether it is intended to be attached to an all new aircraft , or for temporary

use as a spare engine when the original engine is removed for maintenance. Further, ICAO’s current Annex 16 specifies that such engines shall have their identification plates marked “EXEMPT” and the exemption noted in the permanent engine record. The FAA Part 45 regulations currently require both of these. The draft proposal follo ws IC AO’s ETM , which splits the overall exemption category described above into “new” and “spare” engines. This division was made to recognize that spare engines have no adverse effect on the environment because a spare must have emissions that are equivalent or better than the engine it is replacing. Making this distinction al lowed the exemption provisions for spare engine s to be streamlined to the point that engine manufacturers are not required to obtain prior approval to produce or ship spare engines. Only an annual report containing such items as the engine serial number, ty pe of aircraft receiving the engine(s), and use of each engine (spare or new installation) are to be reported to EPA. The streamlined requirements for spare engines do not require that “... individual engines are [be] tracked on individual aircraft b y operations

. ” The draft proposal does not contemplate a new s ys tem by which spare engines would be traceable. 12) Comment : EPA requests comment on a proposed “voluntary” emissions credit program. EPA has not acknowledged the lack of regulatory infrastructure on which to overlay such a program, or the fact that they intend for other agencies to administer it under its own regulations. Moreover, the offset program applies to engine manufacturers getting credit for producing a certain number of better engines in trade for ones that pollute more. However, manufacturers do not know or control where their engines are operated, n or can the presumption be made that all are operated the same amount, producing a comparable amount of pollutant. The idea is based on an unstated presumption that there will be some benefit in the United States, or even in certain domestic areas. It is further tied into the unclear exemption process described previousl y. The cost of such a s ys tem is not described, nor is the presumed benefit of its existence.

### U.S. EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866 Interagency Review.[rcvd February 17 2011]

Subject to Further Policy Review.

Page 9 of 13 Response : Voluntary

e missions credit programs such as emissions credit averaging, banking, and trading are a part of almost every EPA mobile source vehicle/equipment and fuel regulation. In all cases, p articipation in these programs is voluntary , as they are an optional compliance flexibility a manufacturer may

elect to exercise if the manufacturer determines an advantage in doing so . It is simply

the intent of these ty

pes of provisions to encourage engine manufacturers to certify and sell engines with emissions technology better than that required by the emission standards. These provisions essenti ally reward these efforts through a market

- based emission credit program , which can be used to offset higher emissions from other models , which may more difficult or more expensive to control. This flexibility is commonly

used by manufacturers in sectors where it is available and is highl y valued by them. As noted in the comment at this point we are not proposing specific provisions; rather, in the Preamble to this draft proposal we are seeking comment and input on how such a program could be structured to enhance future compliance efforts and reduce compliance costs. We are including additional descriptive detail in a memo to the docket. The comment asserts that there is an unclear link to possible future exemption allowances. While the viability of an emissions credit program for aircraft engines remains to be
seen (hence the request for comment) , one potential use of such credits could be substi tution for exemptions or as part of a justification for an increase of the number allowed exemptions above a set maximum. Furthermore, the comment asserts that some other agency would implement such a program if ultimatel y enacted. Such an assertion is premature and unsubstantiated because we are onl y seeking comment at this time. 13 ) Comment : It is unclear why EPA is proposing to include ICAO guidance material (known as the Environmental Technical Manual or ETM for emissions) in the regulatory text. Adoption of international guidance material eliminates valid means of regulatory guidance already in place, changes it from advisory

to mandatory

(which was not I CAO’s intent) and eliminates compliance flexibility . A clear example is EPA’s proposal regardin g what constitutes a derivative engine, which was clearl y intended as guidance. No accounting for costs to other Agencies for implementing this requirement or industry compliance is accounted for. From a broader governmental perspective, this is an issue that goes beyond emissions, and would set a dangerous precedent. ICAO guidance material is not designed to function as mandatory regulation, and often embodies compromises that the U.S. agrees to onl y because it is adopted as guidance. If the U.S. turns guidance into regulations, it could tempt others to adopt, as regulations, I CAO guidance material that we object to. It would also undermine countries' willingness to adopt guidance material in the future. Response : This comment raises issues with regar d to regulatory text in EPA’s draft NPRM , which would incorporate language on when a derivative engine version is to be treated as new

### U.S. EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866 Interagency Review.[rcvd February 17 2011]

Subject to Further Policy Review.

Page 10 of 13 for emissions purposes. EPA and FAA worked closely within ICAO/CAEP Working Group 3 (WG3) C ertification T ask Group (CTG) in crafting this language . The United States position at CAEP supported this language , and the provisions were adopted at ICAO/ CAEP. Provisions such as these with regard to de rivative engine s are needed in regulations to define the scope and applicability of the regulations ; to give them context and clarity for the manufacturers ; and to allow for their unambiguous and equitable implementation. I f one examines the draft regulatory language, it is clear that it explains under what conditions new standards appl y and under what conditions they do not. With respect to the specific comment on the definition of a derivative engine, we are adopting the definition and related provisions agreed to b y ICAO. In response to the comment,
we have revised th e regulatory text to provide the certificating authority (i.e. FAA) with the discretion to apply good engineering judgment in the implementation of these provisions

. However, we would assert that this definition is still necessary in the regulations becau se it is necessary

to implement the provisions agreed to at I CAO and address es a long standing shortcoming in the regulations by more fully

prescribing the applicability of the standards in these situations

. We cannot regulate through guidance.
14 ) Comment : In discussing the inclusion of ICAO materials, the draft rule engages in a discussion of “commercial” and “non

- commercial” aircraft engines. The distinction between an engine used in commercial operation vs. non

- commercial operation has no basis in the reality of regulated aircraft operations. An individual aircraft, for example, can switch status between flights. From a broader perspective, creating commercial and non

- commercial definitions by classes of equipment rather than usage would also s et a dangerous precedent, and would conflict with existing statutory

and regulatory

definitions. Response : The commenter may be unaware that the distinction between commercial and non

commercial aircraft turbine engines already exists i n the current EPA regulations. This distinction was made in our 1982 final rule after consultation with the FAA. The draft proposal would actuall y do what the commenter prefers by applying the turbine engine standards without regard to operation category . Perhaps the commenter’s confusion arises from the fact that current FAA regulations already apply the standards without distinction. In other words , the draft proposal actuall y updates and harmonizes EPA regulations to align with current FAA regulation s. 15) Comment : The draft rule includes the adoption of technical appendices to I CAO standards and recommended practices. EPA’s adoption of these standards through incorporation b y reference (IBR) is inappropriate as there are legal implications of proper notice, the req uirement to access a foreign publication to properl y understand the requirements of a codified standard,

### U.S. EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866 Interagency Review.[rcvd February 17 2011]

Subject to Further Policy Review.

Page 11 of 13 and even language and format. There are also issues of cost in adopting the technical changes that the EPA does not acknowledge. Response : The Office of the Federal Register is charged b y Congress to publish regulations. As part of this charge, Congress has specificall y directed the Federal Register to work with federal agencies to use Incorporation by Reference to properly

and efficientl y communicate regulatory requirements. We routinely use this approach in our regulatory text. 16) Comment : In several places, the proposed rule discusses military aircraft engines. While certain engine manufacturers certify engines that have both military and civilian applications, these are generall y treated as civilian and under existing regulatory authorities. I f the EPA finds that their authority

extends to engines produced only for installation on military airplanes, then that regulation should remain within the ir sole jurisdiction and not be considered a standard that other agencies will adopt or enforce. Response : To clarify , we are not intending to assert authority over exclusively military engines , and as needed , we have modified and clarified any text we thought the commenter could have found misleading

. Our interest in addressing this issue in th e proposal is discussed in the response s to comments 4) and 5). 17) Comment : Itis several reviewers’ view that the EPA draft would require another federal agency to change its regulatory

approach, add scope and costs to regulatory oversight with unclear benefits, incorporate practices not endorsed by aviation’s international standard

- setting body , and produce confusion and misunderstanding in a global indus try . There is no acknowledgment of the costs associated with such regulations, the changes to the current regulations, the burdens placed on other agencies for adoption and implementation, and no consideration of what benefits from the changes might accru e. If the EPA chooses to adopt them as its regulations alone, the provisions would be at considerable odds with the current regulatory sy stem of aircraft engine certification in place under existing regulations. One approach at least one reviewer recommen ds would be for EPA to limit its rulemaking proposal to adopting onl y the I CAO oxides of nitrogen (NOx) emissions standards agreed upon at the CAEP/6 and CAEP/8 meetings. This approach could be implemented similarly to other historical I CAO CAEP outcomes. Response : The comment er suggests that EPA is proposing sweeping changes from current practice. In our response to comment 1 ) we identified only one diversion from the outcome at CAEP/8 and one additional provision which EPA is proposing to implement under its own authority . Furthermore, while none of these are inconsistent with the basic I CAO provisions, there a few instances where we are adding clarifications and detail to help ensure the proper

### U.S. EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866 Interagency Review.[rcvd February 17 2011]

Subject to Further Policy Review.

Page 12 of 13 implementation of the program. ICAO is not a regulatory body and thus has not included these details. 18) Comment : The proposed rule does not indicate the fact that this EPA CAA rulemaking is subject to CAA section 307(d), 42 USC 7607(d). Response : W e do not find this necessary because the CAA itself makes the proposed rule subject to 307(d) . (See section 307(d)(1)(F))

. Otherwise, EPA rules that are subject to section 307(d) similarly

do not specify

as such, but rather cite to the entire CAA as their authority . See, e.g., Primary

National Air Quality

Stand ard for Sulfur Dioxide; Final Rule, 75 FR 35520, 35592/col.1 (June 22, 2010). However, we have no objection to adding his citation if it adds clarity

. 19) Comment : “...§87.44 Reporting CO 2 emissions. (a)(1) For any type certificates involving compliance with NOx emission standards that are issued on or after January 1, 2014, you must report CO 2 emissions to the Designated EPA Program Officer. You may include this information in the certification report described in §87.42 or in a separate submission. (2) For any type certificates involving compliance with NOx emission standards that are issued before January

1, 2014, you must report CO 2 emissions along with your emission levels of regulated NOx to the Designated EPA Program Officer. (b) Determine CO2 emis sion rates b y direct measurement or b y calculation from measured fuel mass flow rates for CO 2 emissions from fossil and biogenic sources separately

. These methods are described in Appendices 3 and 5 to I CAO Annex 16 (incorporated by reference in §87.8). Report CO2 emissions separately for each operating mode. If you test more than one engine, report the average value of e missions for each operating mode. Round CO2 emissions of CO 2 emissions from fossil and biogenic sources to the nearest whole gram and gram/kilo

-N ewton...”

Response : We d o not intend to revise the CO2 reporting requirements. The collection of information for CO2 under the mandatory GHG rules and the new information we are proposing to require for other pollutants is authorized under separate authorities. To make this clear and in response to the comment , we propose creating a new section in the regulations to cover these new requirements and leave the existing CO2 reporting requirements untouched in § 87.64.

### U.S. EPA Response to Summary of Interagency Working Comments on Draft

Language under EO12866 Interagency Review.[rcvd February 17 2011]

Subject to Further Policy Review.

Page 13 of 13 Attachment for Response to C omment 2

Nonattainment Area Albuquerque, NM Anchorage, AK Aspen Atlanta, GA Baltimore, MD Boston

- Lawrence

- Worcester (eastern MA), MA Boston

- Manchester

- Portsmouth (southeast NH), NH Charlotte

- Gastonia

- Rock Hill, NC

- SC Chicago

- Gary

- Lake County, IL

- IN Cincinnati

- Hamilton, OH

- KY

- IN Cleveland

- Akron

- Lorain, OH Dallas

- Fort Worth, TX Denver

- Boulder

- Greeley

- Fort Collins

- Loveland, CO Detroit

- Ann Arbor, MI El Paso, TX Greater Connecticut, CT Houston

- Galveston

- Brazoria, TX Indianapolis, IN Las Vegas, NV Los Angeles South Coast Air Basin, CA Louisville, KY

- IN Memphis, TN

- AR Milwaukee

- Racine, WI Minneapolis

- St Paul, MN New York

- N. New Jersey

- Long Island, NY

- NJ

- CT Philadelphia

- Wilmington

- Atlantic City, PA

- NY

- MD

- DE Phoenix

- Mesa, AZ Pittsburgh

- Beaver Valley, PA Providence (entire State), RI Raleigh

- Durham

- Chapel Hill, NC Reno, NV Riverside County (Coachella Valley), CA Sacramento Metro, CA Salt Lake City, UT San Diego, CA San Francisco Bay Area, CA San Joaquin Valley, CA Seattle

- Tacoma, WA St. Louis, MO

- IL Syracuse, NY Washington, DC

- MD

- VA