   1) Please provide a detailed outline of the provisions of this rulemaking that deviate from the recommendations of ICAO and provide a detailed justification and policy rationale for why EPA is proposing to deviate from these recommended standards.  The United States has an obligation under the Article 2.4 TBT Agreement to follow international standards unless those standards would be ineffective and inappropriate.  Specifically, Article 2.4 states, 
            "Where technical regulations are required and relevant international 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 inappropriate means for the fulfilment of the legitimate objectives pursued, for instance because of fundamental climatic or geographical factors or fundamental technological problems."

   2) How did EPA choose 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?

   3) It is 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 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 proposes to revise the Code of Federal Regulations to more accurately reflect the statutory preemption established by the Clean Air Act.  This rule does not impose any new preemption of merely modifies existing EPA aircraft engine emission standards and test procedures and therefore will merely continue an existing preemption of State and local law.   Thus, Executive Order 13132 does not apply to this action.
   4) In the 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. 

   5) 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 by 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.

   6) 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 part 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.

   7) Recommend checking the internal cross-reference in §87.1 to ensure it is the correct cite. 

   8) 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 everything 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.    

   9) The EPA has proposed that a new annual report be submitted by engine manufacturers detailing the production of various engine models.  Much of this information is available elsewhere.  It is unclear whether the report can be viewed as a standard, and 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?  Would collecting this information require approval under the Paperwork Reduction Act?   

   10) 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.  It appears inconsistent in its use of terms that are well known in the industry, and attaches new concepts to them.  No attempt has been made to detail the costs of the new process to other agencies, or to industry applicants.  

   11) 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, and a new system by which the EPA expects them to be traceable. The concept of installing a "spare" engine presumes there is a system in place by which individual engines are tracked on individual aircraft by operations.  The reality is that there is no such system in place to track engines 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 system.

   12) 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, nor 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 previously.  The cost of such a system is not described, nor is the presumed benefit of its existence.  

   13) 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 ICAO's intent) and eliminates compliance flexibility.  A clear example is EPA's proposal regarding what constitutes a derivative engine, which was clearly 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 only because it is adopted as guidance.  If the U.S. turns guidance into regulations, it could tempt others to adopt, as regulations, ICAO guidance material that we object to.  It would also undermine countries' willingness to adopt guidance material in the future.

   14) 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 set a dangerous precedent, and would conflict with existing statutory and regulatory definitions.

   15) The draft rule includes the adoption of technical appendices to ICAO standards and recommended practices.  EPA's adoption of these standards through incorporation by reference (IBR) is inappropriate as there are legal implications of proper notice, the requirement to access a foreign publication to properly understand the requirements of a codified standard, and even language and format. There are also issues of cost in adopting the technical changes that the EPA does not acknowledge. 

   16) 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 generally treated as civilian and under existing regulatory authorities.  If the EPA finds that their authority extends to engines produced only for installation on military airplanes, then that regulation should remain within their sole jurisdiction and not be considered a standard that other agencies will adopt or enforce.  

   17) It is 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 industry.  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 accrue.  If the EPA chooses to adopt them as its regulations alone, the provisions would be at considerable odds with the current regulatory system of aircraft engine certification in place under existing regulations. One approach at least one reviewer recommends would be for EPA to limit its rulemaking proposal to adopting only the ICAO 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 ICAO CAEP outcomes.

   18)  The proposed rule does not indicate the fact that this EPA CAA rulemaking is subject to CAA section 307(d), 42 USC 7607(d). 

   19) "...§87.44 Reporting CO2 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 CO2 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 CO2 emissions along with your emission levels of regulated NOx to the Designated EPA Program Officer. 
   (b) Determine CO2 emission rates by direct measurement or by calculation from measured fuel mass flow rates for CO2 emissions from fossil and biogenic sources separately.  These methods are described in Appendices 3 and 5 to ICAO 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 CO2 emissions for each operating mode.  Round CO2 emissions of CO2 emissions from fossil and biogenic sources to the nearest whole gram and gram/kilonewton..."
Typos
   Page 12:  Specifically, reports would be required for turbofan engines with rated thrusts greater than 26.7 kN , which are subject to gaseous emission and smoke standards.....
   Page 15:  States may ban the use of any aircraft within their airspace that does not meet ICAO standards.   Second, States are required to recognize the airworthiness certificates of any State whose standards are at least as stringent as ICAO's standards, thereby assuring that it's the aircraft of any member State will be permitted to operate in any other member State.  
   Page 28:  The ICAO NOx standards that with which we propose are proposing to align with will help reduce ambient ozone and secondary PM levels and thus will help areas with airports achieve and/or maintain compliance with the National Ambient Air Quality Standards (NAAQS).
