This section of the FEDERAL REGISTER

contains regulatory documents having general

applicability and legal effect, most of which

are keyed to and codified in the Code of

Federal Regulations, which is published under

50 titles pursuant to 44 U.S.C. 1510.

The Code of Federal Regulations is sold by

the Superintendent of Documents.

Rules and Regulations Federal Register

92787 

Vol. 89, No. 227 

Monday, November 25, 2024 

1 87 FR 72312 (Nov. 23, 2022), Control of Air 

Pollution From Aircraft Engines: Emission 

Standards and Test Procedures. 

2 89 FR 37971 (May 7, 2024), Control of NonVolatile Particulate Matter From Aircraft Engines: 

Emissions Standards and Test Procedures; 

Correction. 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 34 

[Docket No.: FAA–2023–2434; Amdt. No. 

34–7] 

RIN 2120–AL83 

Control of Non-Volatile Particulate 

Matter From Aircraft Engines: 

Emission Standards and Test 

Procedures 

AGENCY: Federal Aviation 

Administration (FAA), Department of 

Transportation (DOT). 

ACTION: Final rule; confirmation of 

effective date and response to public 

comments. 

SUMMARY: This action confirms the 

effective date of the final rule published 

on April 24, 2024, and responds to the 

comments received on that final rule. 

The FAA published a correction on May 

7, 2024, to the final rule that established 

a compliance date of 90 days after the 

effective date. The rule adopts standards 

for measuring non-volatile particulate 

matter (nvPM) exhaust emissions from 

aircraft engines. With this rulemaking, 

the FAA implemented the nvPM 

emissions standards adopted by the 

Environmental Protection Agency 

(EPA), allowing manufacturers to 

certificate engines to the new nvPM 

emissions standards in the United 

States, and fulfilling the statutory 

obligations of the FAA under the Clean 

Air Act. 

DATES: The effective date of the final 

rule published on April 24, 2024 (89 FR 

31078), is confirmed as May 24, 2024. 

Compliance was required by August 22, 

2024. 

ADDRESSES: For information on where to 

obtain copies of rulemaking documents 

and other information related to this 

action, see ‘‘How To Obtain Additional 

Information’’ in the SUPPLEMENTARY

INFORMATION section of this document. 

FOR FURTHER INFORMATION CONTACT: For 

technical questions concerning this 

action, contact Ralph Iovinelli, Office of 

Environment and Energy (AEE–300), 

Federal Aviation Administration, 800 

Independence Ave. SW, Washington, 

DC 20591; telephone (202) 267–3566; 

email Ralph.Iovinelli@faa.gov. 

For legal questions concerning this 

action, contact Jacob Keohane, Office of 

the Chief Counsel (AGC–200), Federal 

Aviation Administration, 800 

Independence Ave. SW, Washington, 

DC 20591; telephone (202) 355–5491; 

email jacob.w.keohane@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Background 

Non-volatile Particulate Matter 

(nvPM) is a standard for measuring the 

amount of solid particles (e.g. soot, etc.) 

emitted by an aircraft. The 

Environmental Protection Agency (EPA) 

has adopted nvPM-based standards for 

aircraft engine emissions and 

certification test procedures to replace 

the old ‘‘Smoke Number’’ (SN) 

standard.1 On May 24, 2024, the Federal 

Aviation Administration (FAA) 

implemented EPA’s nvPM standard in 

Control of Non-Volatile Particulate 

Matter From Aircraft Engines: Emission 

Standards and Test Procedures (89 FR 

31078). 

The FAA was statutorily required (see 

42 U.S.C. 7572; Clean Air Act sec. 232) 

to incorporate the EPA’s nvPM 

emissions standards into its own 

regulations and apply the regulatory 

requirements that will allow applicants 

to demonstrate compliance with the 

emissions standards at the time of 

engine airworthiness certification. 

Because the FAA does not have 

authority to make changes to the 

standards or procedures adopted by the 

EPA, and because the EPA issued its 

proposed rule for notice and sought 

public comment on these standards and 

test procedures prior to promulgating 

them on November 23, 2022, the FAA 

published the standards as a final rule 

with request for comment instead of 

seeking comment beforehand (see 5 

U.S.C. 533(b)(3)(B), outlining the 

requirements under the Administrative 

Procedure Act for waiving prior notice 

and comment in informal rulemaking). 

In its final rule, the FAA requested 

comment from interested parties 

regarding the parts of that rulemaking 

that adopted the certification 

regulations in 14 CFR part 34 and 

implemented them at the time of aircraft 

engine certification. This document is a 

response to those comments. 

Discussion of Comments 

The FAA received six comments on 

the rule, addressing several issues. The 

FAA received comments from five 

organizations and an individual. 

Many comments raised the issue of 

compliance dates. The rule was 

originally published without a 

compliance date, but a compliance date 

of 90 days after the effective date of May 

24, 2024, was added to the rule when 

the FAA published a correction to the 

final rule on May 7, 2024.2 A trade 

association wrote a comment in support 

of the standard. One commenter raised 

issues of environmental justice that are 

out of scope regarding this FAA 

rulemaking, as the FAA lacks authority 

to change EPA emissions standards. 

The FAA has determined that no 

changes to the final rule are necessary 

based on the comments received. 

A. Ultrafine Particles and 

Environmental Justice Issues 

One commenter suggested that the 

FAA’s Aviation Environmental Design 

Tool (AEDT) model include all 

particulate matter including ultrafine 

particulates (UFP) for mass and made 

additional comments on other various 

subjects including: EPA addressing 

environmental justice, EPA certification 

of engines, EPA technology following 

regulations, EPA regulation of UFP, 

limiting engines that may operate at a 

single location, health analysis for 

airports, and data input to models. 

The nvPM standards adopted by the 

FAA include UFP, which are defined as 

particles in the atmosphere smaller than 

100 nanometers in diameter. Particulate 

emissions from aircraft engines covered 

by this rule range from approximately 5 

to 40 nanometers (nm) in diameter. The 

EPA and FAA worked together to 

implement nvPM regulations per the 

Clean Air Act (CAA) and the United 

States’ responsibilities under the 


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92788 Federal Register / Vol. 89, No. 227 / Monday, November 25, 2024 / Rules and Regulations 

3 87 FR 72312 (Nov. 23, 2022), Control of Air 

Pollution From Aircraft Engines: Emission 

Standards and Test Procedures. 

International Civil Aviation 

Organization (ICAO) Conventions. The 

other subjects this commenter raised are 

beyond the FAA’s authority and are 

addressed in the EPA final rule.3

B. Purported Change in Emissions 

Standards 

One commenter stated that the FAA 

does not have the authority to change 

the emissions standards adopted by the 

EPA. That commenter argued that the 

FAA ‘‘changed the nvPM standard set 

by the EPA in 40 CFR 1031.140(f)’’ by 

adopting thrust (FN) as the correlating 

factor instead of the combustor inlet 

temperature (T3) as adopted by the 

International Civil Aviation 

Organization (ICAO). It referenced 

‘‘Section 4.2.2 of ICAO ETM Doc 9501, 

Fifth Edition, 2023 and EPA 40 CFR 

1031.140(f)’’ as evidence. 

The EPA limits are based on thrust, 

not combustor inlet temperature. See 40 

CFR 1031.140(f). The EPA limits for 

nvPM are contained in 40 CFR 

1030.60(b), which sets particulate limits 

in terms of particulate mass per 

kilonewton (maximum rated thrust 

output). These regulations do not set T3

as the correlating factor. 

Furthermore, in ICAO Annex 16 

Volume II, Section 4.2.2, all applicable 

limits are stated in terms of ‘‘maximum 

rated thrust’’ not ‘‘T3’’. In 40 CFR 

1031.140(f) of the EPA regulations, only 

the equipment and procedures of Annex 

16 Volume II are incorporated by 

reference. The regulation states: ‘‘Use 

the equipment and procedures specified 

in ICAO Appendix 7 and ICAO 

Appendix 6, as applicable.’’ There is no 

mention of any limits in this section. 

Emissions testing using T3 is 

acceptable when an approved thrust vs 

T3 correlation curve is available for the 

engine being tested. 

C. Showing of Compliance, Foreign 

Emissions Standards 

Two commenters made the following 

identical statement: ‘‘Regarding the rule 

being effective May 24, 2024; this does 

not provide adequate time to compile, 

submit, approve, and revise the required 

FAA paperwork given the multiple 

engines in production by multiple 

Aircraft Engine manufacturers feeding 

into one FAA office.’’ In addition, the 

same two commenters also stated 

concerns about compiling the 

information required by 14 CFR 34.73(e) 

for submittal. 

Although the initial rule did lack an 

implementation timeframe for 

manufacturers to show compliance, the 

FAA subsequently issued an 

amendment to the rule change, 

Amendment 7A, that added an 

implementation requirement time of 90 

days after the effectivity date of the rule 

as 14 CFR 34.25(d). 

The data reporting requirements 

shown in § 34.73(e) list the data 

currently needed to show compliance. 

This is the same data needed to 

determine the final approved values for 

ICAO Annex 16 Volume II. The FAA 

needs this data to verify the results and 

conduct appropriate oversight when 

reviewing submitted reports for 

approval. Reports showing compliance 

should include the data used for that 

showing and how it was obtained. 

Manufacturers that have already 

submitted compliance reports to a 

foreign authority can use data compiled 

for those reports to show compliance 

with this requirement. Therefore, the 

FAA concludes 90 days to be sufficient. 

In response to Amendment 7A, 

another commenter stated, ‘‘Most engine 

manufactures have already shown 

EASA that their in-production aircraft 

engines meet ICAO CAEP/10 and CAEP/ 

11 nvPM standards equivalent to the 

nvPM limits described in 14 CFR 34.25 

at Amendment 7A.’’ The commenter 

requested that the compliance deadline 

be extended to 240 days after the 

effectivity date, arguing that, since most 

manufacturers have already shown 

EASA that their engines meet ICAO 

Annex 16 Volume II, an even later 

deadline to show compliance with the 

FAA rule would not harm the public. 

The commenter also stated its 

perception that this rule amendment 

was intended to apply to in-production 

aircraft as well as engines. 

This rule does not hold up shipment 

of aircraft, because part 34 applies only 

to engines, not aircraft. Once the 

engines were type certificated and 

shipped, they became valid engines. 

There is a misperception that this 

requirement extends to airplane 

manufacturing as well as engines. The 

applicability section in 14 CFR 34.25 

only considers the manufacturer date of 

the engines. These requirements are 

only applicable to engines produced by 

the engine manufacturer after January 1, 

2023. 

Moreover, as noted above, 

manufacturers that have already 

submitted compliance reports to a 

foreign authority can use data compiled 

for those reports to show compliance 

with this requirement. Therefore, the 

FAA concludes the 90-day deadline to 

show compliance with this rule to be 

sufficient. 

D. 90% Confidence Interval 

A commenter asked why the FAA 

included a requirement for a 90% 

confidence interval at 14 CFR 34.73(d), 

since this requirement is not included 

in ICAO Annex 16 Volume II, Appendix 

1. 

The FAA concludes it is in harmony 

with the international community 

because ICAO Annex 16 Volume II, 

Appendix 6, ‘‘Compliance Procedure for 

Gaseous Emissions, Smoke, and 

Particulate Matter Emissions,’’ 

recommends demonstrating a 90% 

confidence interval. The FAA concludes 

this recommendation should be 

mandatory to ensure that the data 

provided to the FAA is appropriately 

representative of the population. Under 

United States domestic law, all 

mandatory regulations must be in the 

CFR, not supplementary guidance 

documents. Therefore, the FAA has 

included this requirement here. 

E. Standard Temperature Correction 

One commentor questioned the 

necessity of correcting for standard 

temperature and pressure, as indicated 

in the preamble of the rule, and the 

commentor posed the same comment on 

14 CFR 34.73. 

The FAA notes that 14 CFR 34.73 

correctly refers to the standard 

temperature and pressure (STP) 

corrections detailed in ICAO Annex 16 

Volume II, Appendix 7. Section 3.1 of 

that Appendix requires the applicant to 

‘‘determine nvPM at STP’’. Per this 

requirement, nvPM must be corrected to 

STP. The FAA also notes that 

corrections to standard temperature and 

pressure are generally automatically 

included in the instrumentation. 

F. Typographical Errors 

Some commenters pointed out several 

typographical errors (‘‘typos’’) in the 

preamble of the final rule, which the 

FAA acknowledges. They are: 

• The preamble refers to ICAO Annex 

16 Volume II, Appendix 1, rather than 

to the correct reference of Appendix 7. 

(89 FR 31082) 

• The end applicability date of the SN 

standard is given as January 1, 2023, as 

opposed to January 1, 2020. (89 FR 

31087) 

• The FAA preamble reads 

‘‘manufactures’’ in a line of text that 

should read manufacturers.’’ (89 FR 

31083) 

A commenter also observed that the 

definition for ‘‘reference day condition’’ 

includes the phrase ‘‘. . . the measured 

smoke, nvPM, and gaseous emissions 

must be corrected.’’ 14 CFR. 34.1 

(‘‘Reference day condition’’). The FAA 


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Federal Register / Vol. 89, No. 227 / Monday, November 25, 2024 / Rules and Regulations 92789 

acknowledges that ‘‘smoke’’ was 

erroneously included in this definition, 

as there are no corrections to reference 

day conditions required for smoke 

measurements. However, regarding 

nvPM emissions, the FAA notes that 

corrections to reference day conditions 

are required, and that the measurement 

instrumentation corrects to reference 

day corrections. 

For clarity, a commenter suggested 

that the internal references in 

§ 34.73(c)(1) include a greater level of 

detail, specifically: 

• Paragraph (c)(1)(i)(B), when 

referencing ‘‘paragraph (c)(1),’’ should 

reference ‘‘paragraph (c)(1)(i)(A).’’ 

• Paragraph (c)(1)(ii)(B), when 

referencing ‘‘paragraph (c)(1),’’ should 

reference ‘‘paragraph (c)(1)(ii)(A).’’ 

• Paragraph (c)(1)(ii)(C), when 

referencing ‘‘paragraph (c)(1),’’ should 

reference ‘‘paragraph (c)(1)(ii)(B).’’ 

• Paragraph (c)(1)(iii)(B), when 

referencing ‘‘paragraph (c)(1),’’ should 

reference ‘‘paragraph (c)(1)(iii)(A).’’ 

The FAA thanks this commentor for 

its detailed and accurate suggestions. 

The FAA is declining to make these 

suggestions at this time, as such changes 

are not necessary. 

G. Average of One 

A commenter noted that 14 CFR 

37.73(c)(1)(iii)(D) requires an ‘‘average’’ 

of engines tested, but ‘‘[w]hat is missing 

is saying that this average has to be done 

if several engines have been tested.’’ 

The FAA concludes that adding 

additional text to § 34.73(c)(1)(iii)(D) is 

not necessary as taking the average of a 

single engine does not change the 

results of the calculations. 

H. Comments in Support 

Finally, the FAA received positive 

feedback from multiple organizations. 

Conclusion 

After consideration of the comments 

submitted in response to the final rule 

with request for comment, the FAA has 

determined that no further rulemaking 

action is necessary. Therefore, 

amendment 34–7 remains in effect. 

How To Obtain Additional Information 

A. Rulemaking Documents 

An electronic copy of a rulemaking 

document may be obtained by using the 

internet— 

1. Search the Federal eRulemaking 

Portal (www.regulations.gov); 

2. Visit the FAA’s Regulations and 

Policies web page at www.faa.gov/ 

regulations_policies/ or 

3. Access the Government Printing 

Office’s web page at www.gpo.gov/fdsys/. 

Copies may also be obtained by 

sending a request (identified by notice, 

amendment, or docket number of this 

rulemaking) to the Federal Aviation 

Administration, Office of Rulemaking, 

ARM–1, 800 Independence Avenue SW, 

Washington, DC 20591, or by calling 

(202) 267–9680. 

B. Comments Submitted to the Docket 

Comments received may be viewed by 

going to www.regulations.gov and 

following the online instructions to 

search the docket number for this 

action. Anyone is able to search the 

electronic form of all comments 

received into any of the FAA’s dockets 

by the name of the individual 

submitting the comment (or signing the 

comment, if submitted on behalf of an 

association, business, labor union, etc.). 

C. Small Business Regulatory 

Enforcement Fairness Act 

The Small Business Regulatory 

Enforcement Fairness Act (SBREFA) of 

1996 requires FAA to comply with 

small entity requests for information or 

advice about compliance with statutes 

and regulations within its jurisdiction. 

A small entity with questions regarding 

this document may contact its local 

FAA official or the person listed under 

the FOR FURTHER INFORMATION CONTACT

heading at the beginning of the 

preamble. To find out more about 

SBREFA on the internet, visit 

www.faa.gov/regulations_policies/ 

rulemaking/sbre_act/. 

Issued under authority provided 49 U.S.C. 

40101, et seq., in Washington, DC, on 

November 18, 2024. 

Brandon Roberts, 

Executive Director, Office of Rulemaking. 

[FR Doc. 2024–27390 Filed 11–22–24; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2024–2537; Project 

Identifier MCAI–2024–00631–E; Amendment 

39–22892; AD 2024–24–02] 

RIN 2120–AA64 

Airworthiness Directives; Safran 

Helicopter Engines, S.A. (Type 

Certificate Previously Held by 

Turbomeca S.A.) 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule; request for 

comments. 

SUMMARY: The FAA is adopting a new 

airworthiness directive (AD) for all 

Safran Helicopter Engines, S.A. (Safran) 

Model ARRIUS 2F engines. This AD 

was prompted by a report of an 

uncommanded in-flight shut-down 

(IFSD) of a Safran Model ARRIUS 2F 

engine, followed by an investigation 

that revealed the IFSD was due to a 

missing lubricating and balancing 

groove on one of the bearings of the fuel 

control unit (FCU) fuel pump related to 

a non-conforming manufacturing 

process. This AD requires removal of 

the affected fuel pump from service and 

replacement with a serviceable part, as 

specified in a European Union Aviation 

Safety Agency (EASA) AD, which is 

incorporated by reference. The FAA is 

issuing this AD to address the unsafe 

condition on these products. 

DATES: This AD is effective December 

10, 2024. 

The Director of the Federal Register 

approved the incorporation by reference 

of a certain publication listed in this AD 

as of December 10, 2024. 

The FAA must receive comments on 

this AD by January 9, 2025. 

ADDRESSES: You may send comments, 

using the procedures found in 14 CFR 

11.43 and 11.45, by any of the following 

methods: 

• Federal eRulemaking Portal: Go to 

regulations.gov. Follow the instructions 

for submitting comments. 

• Fax: (202) 493–2251. 

• Mail: U.S. Department of 

Transportation, Docket Operations, M– 

30, West Building Ground Floor, Room 

W12–140, 1200 New Jersey Avenue SE, 

Washington, DC 20590. 

• Hand Delivery: Deliver to Mail 

address above between 9 a.m. and 5 

p.m., Monday through Friday, except 

Federal holidays. 

AD Docket: You may examine the AD 

docket at regulations.gov under Docket 

No. FAA–2024–2537; or in person at 

Docket Operations between 9 a.m. and 

5 p.m., Monday through Friday, except 

Federal holidays. The AD docket 

contains this final rule, the mandatory 

continuing airworthiness information 

(MCAI), any comments received, and 

other information. The street address for 

Docket Operations is listed above. 

Material Incorporated by Reference: 

• For EASA material identified in this 

AD, contact EASA, Konrad-AdenauerUfer 3, 50668 Cologne, Germany; phone: 

+49 221 8999 000; email: ADs@

easa.europa.eu; website: 

easa.europa.eu. You may find this 

material on the EASA website at 

ad.easa.europa.eu. 

• You may view this material at the 

FAA, Operational Safety Branch, 1200 


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