79480 Federal Register / Vol. 89, No. 189 / Monday, September 30, 2024 / Proposed Rules 

accomplish those instructions accordingly,’’ 

this AD requires replacing that text with ‘‘if 

any crack or damage is detected, the crack or 

damage must be repaired before further flight 

using a method approved by the Manager, 

International Validation Branch, FAA; or 

EASA; or Airbus SAS’s EASA Design 

Organization Approval (DOA). If approved by 

the DOA, the approval must include the 

DOA-authorized signature.’’ 

(3) This AD does not adopt the ‘‘Remarks’’ 

section of EASA AD 2024–0129. 

(i) Additional AD Provisions 

The following provisions also apply to this 

AD: 

(1) Alternative Methods of Compliance 

(AMOCs): The Manager, International 

Validation Branch, FAA, has the authority to 

approve AMOCs for this AD, if requested 

using the procedures found in 14 CFR 39.19. 

In accordance with 14 CFR 39.19, send your 

request to your principal inspector or 

responsible Flight Standards Office, as 

appropriate. If sending information directly 

to the manager of the International Validation 

Branch, mail it to the address identified in 

paragraph (j) of this AD. Information may be 

emailed to: AMOC@faa.gov. Before using any 

approved AMOC, notify your appropriate 

principal inspector, or lacking a principal 

inspector, the manager of the responsible 

Flight Standards Office. 

(2) Contacting the Manufacturer: For any 

requirement in this AD to obtain instructions 

from a manufacturer, the instructions must 

be accomplished using a method approved 

by the Manager, International Validation 

Branch, FAA; or EASA; or Airbus SAS’s 

EASA Design Organization Approval (DOA). 

If approved by the DOA, the approval must 

include the DOA-authorized signature. 

(3) Required for Compliance (RC): Except 

as required by paragraphs (h)(2) and (i)(2) of 

this AD, if any material referenced in EASA 

AD 2024–0129 contains paragraphs that are 

labeled as RC, the instructions in RC 

paragraphs, including subparagraphs under 

an RC paragraph, must be done to comply 

with this AD; any paragraphs, including 

subparagraphs under those paragraphs, that 

are not identified as RC are recommended. 

The instructions in paragraphs, including 

subparagraphs under those paragraphs, not 

identified as RC may be deviated from using 

accepted methods in accordance with the 

operator’s maintenance or inspection 

program without obtaining approval of an 

AMOC, provided the instructions identified 

as RC can be done and the airplane can be 

put back in an airworthy condition. Any 

substitutions or changes to instructions 

identified as RC require approval of an 

AMOC. 

(j) Additional Information 

For more information about this AD, 

contact Dat Le, Aviation Safety Engineer, 

FAA, 1600 Stewart Avenue, Suite 410, 

Westbury, NY 11590; telephone 516–228– 

7300; email dat.v.le@faa.gov. 

(k) Material Incorporated by Reference 

(1) The Director of the Federal Register 

approved the incorporation by reference of 

the material listed in this paragraph under 5 

U.S.C. 552(a) and 1 CFR part 51. 

(2) You must use this material as 

applicable to do the actions required by this 

AD, unless this AD specifies otherwise. 

(i) European Union Aviation Safety Agency 

(EASA) AD 2024–0129, dated July 5, 2024. 

(ii) [Reserved] 

(3) For EASA AD 2024–0129 identified in 

this AD, contact EASA, Konrad-AdenauerUfer 3, 50668 Cologne, Germany; telephone 

+49 221 8999 000; email ADs@

easa.europa.eu; website easa.europa.eu. You 

may find this EASA AD on the EASA website 

at ad.easa.europa.eu. 

(4) You may view this material at the FAA, 

Airworthiness Products Section, Operational 

Safety Branch, 2200 South 216th St., Des 

Moines, WA. For information on the 

availability of this material at the FAA, call 

206–231–3195. 

(5) You may view this material at the 

National Archives and Records 

Administration (NARA). For information on 

the availability of this material at NARA, 

visit www.archives.gov/federal-register/cfr/ 

ibr-locations or email fr.inspection@nara.gov. 

Issued on September 23, 2024. 

Peter A. White, 

Deputy Director, Integrated Certificate 

Management Division, Aircraft Certification 

Service. 

[FR Doc. 2024–22180 Filed 9–27–24; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2024–2322; Project 

Identifier MCAI–2024–00065–Q] 

RIN 2120–AA64 

Airworthiness Directives; THOMMEN 

AIRCRAFT EQUIPMENT AG Digital Air 

Data Computers 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to adopt a 

new airworthiness directive (AD) for 

certain THOMMEN AIRCRAFT 

EQUIPMENT AG (THOMMEN) AC32 

Digital Air Data Computers. This 

proposed AD results from occurrences 

of AC32 Digital Air Data Computers 

(ADCs) that stop functioning below 

certain temperatures. This proposed AD 

would require replacing an affected 

AC32 Digital ADC with a serviceable 

part. The FAA is proposing this AD to 

address the unsafe condition on these 

products. 

DATES: The FAA must receive comments 

on this NPRM by November 14, 2024. 

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–2024–2322; 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 NPRM, 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 THOMMEN AIRCRAFT 

EQUIPMENT material identified in this 

proposed AD, contact THOMMEN 

AIRCRAFT EQUIPMENT AG, 

Hofackerstrasse 48, 4132 Muttenz, 

Switzerland; phone: +41 (0) 61 965 22 

22; email: sales@thommen.aero; 

website: thommen.aero. 

• You may view this material at the 

FAA, Airworthiness Products Section, 

Operational Safety Branch, 901 Locust, 

Kansas City, MO 64106. For information 

on the availability of this material at the 

FAA, call (817) 222–5110. 

FOR FURTHER INFORMATION CONTACT: 

William Reisenauer, Aviation Safety 

Engineer, FAA, 1600 Stewart Avenue, 

Suite 410, Westbury, NY 11590; phone: 

(516) 228–7301; email: 9-AVS-AIRBACO-COS@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

The FAA invites you to send any 

written relevant data, views, or 

arguments about this proposal. Send 

your comments to an address listed 

under ADDRESSES. Include ‘‘Docket No. 

FAA–2024–2322; Project Identifier 

MCAI–2024–00065–Q’’ at the beginning 

of your comments. The most helpful 

comments reference a specific portion of 

the proposal, explain the reason for any 

recommended change, and include 

supporting data. The FAA will consider 

all comments received by the closing 

date and may amend this proposal 

because of those comments. 

Except for Confidential Business 

Information (CBI) as described in the 

following paragraph, and other 


ddrumheller on DSK120RN23PROD with PROPOSALS1
Federal Register / Vol. 89, No. 189 / Monday, September 30, 2024 / Proposed Rules 79481 

information as described in 14 CFR 

11.35, the FAA will post all comments 

received, without change, to 

regulations.gov, including any personal 

information you provide. The agency 

will also post a report summarizing each 

substantive verbal contact received 

about this NPRM. 

Confidential Business Information 

CBI is commercial or financial 

information that is both customarily and 

actually treated as private by its owner. 

Under the Freedom of Information Act 

(FOIA) (5 U.S.C. 552), CBI is exempt 

from public disclosure. If your 

comments responsive to this NPRM 

contain commercial or financial 

information that is customarily treated 

as private, that you actually treat as 

private, and that is relevant or 

responsive to this NPRM, it is important 

that you clearly designate the submitted 

comments as CBI. Please mark each 

page of your submission containing CBI 

as ‘‘PROPIN.’’ The FAA will treat such 

marked submissions as confidential 

under the FOIA, and they will not be 

placed in the public docket of this 

NPRM. Submissions containing CBI 

should be sent to William Reisenauer, 

Aviation Safety Engineer, FAA, 1600 

Stewart Avenue, Suite 410, Westbury, 

NY 11590. Any commentary that the 

FAA receives which is not specifically 

designated as CBI will be placed in the 

public docket for this rulemaking. 

Background 

The European Union Aviation Safety 

Agency (EASA), which is the Technical 

Agent for the Member States of the 

European Union, has issued EASA AD 

2024–0024, dated January 24, 2024 (also 

referred to as the MCAI), to correct an 

unsafe condition on certain THOMMEN 

AC32 Digital ADCs. The MCAI states 

that there have been occurrences of 

certain AC32 Digital ADCs stopping 

functioning at temperatures below ¥20 

degrees Celsius. The error is detectable 

and does not transmit erroneous data. 

The problem is caused by the power 

module and the affected units have been 

identified. This condition, if not 

addressed, could result in insufficient 

navigational data provided to the flight 

crew, resulting in reduced control of the 

aircraft. The MCAI requires removing 

from service each affected part and 

specifies that only serviceable parts as 

defined in the MCAI may be installed. 

You may examine the MCAI in the 

AD docket at regulations.gov under 

Docket No. FAA–2024–2322. 

Material Incorporated by Reference 

Under 1 CFR Part 51 

The FAA reviewed THOMMEN 

AIRCRAFT EQUIPMENT Service 

Bulletin SB AC32/07, Revision 1.0, 

dated August 31, 2023 (THOMMEN SB 

AC32/07, Revision 1.0). This material 

specifies procedures for determining if 

an aircraft is equipped with an affected 

AC32 Digital ADC listed in Appendix A, 

determining if the actions specified in 

THOMMEN SB AC32/07, Revision 1.0, 

were already accomplished, and 

replacing any affected THOMMEN 

AC32 Digital ADC. 

This material is reasonably available 

because the interested parties have 

access to it through their normal course 

of business or by the means identified 

in the ADDRESSES section. 

FAA’s Determination 

These products have been approved 

by the aviation authority of another 

country and are approved for operation 

in the United States. Pursuant to the 

FAA’s bilateral agreement with this 

State of Design Authority, it has notified 

the FAA of the unsafe condition 

described in the MCAI referenced 

above. The FAA is issuing this NPRM 

after determining that the unsafe 

condition described previously is likely 

to exist or develop on other products of 

the same type design. 

Proposed AD Requirements in This 

NPRM 

This proposed AD would require 

replacing affected AC32 Digital ADCs 

with serviceable parts. This proposed 

AD would also prohibit the installation 

of an affected AC32 Digital ADC on any 

aircraft. 

Costs of Compliance 

The FAA estimates that this AD, if 

adopted as proposed, would affect 401 

AC32 Digital ADCs that are installed on 

aircraft worldwide. The FAA has no 

way of determining how many of these 

ADC are installed on aircraft of U.S. 

registry. 

The FAA estimates the following 

costs to comply with this proposed AD. 

These costs assume all 401 AC32 Digital 

ADCs are installed on aircraft of U.S. 

registry. The FAA expects a portion of 

the affected population to exist outside 

of the U.S. and the estimated costs to be 

lower. 

ESTIMATED COSTS

Action Labor cost Parts cost Cost per 

product 

Cost on U.S. 

operators 

Replace affected AC32 Digital ADC ............... 12 work-hours × $85 per hour = $1,020 ........ $4,477 $5,497 $2,204,297 

The FAA has included all known 

costs in its cost estimate. According to 

the manufacturer, however, some of the 

costs of this proposed AD may be 

covered under warranty, thereby 

reducing the cost impact on affected 

operators. 

Authority for This Rulemaking 

Title 49 of the United States Code 

specifies the FAA’s authority to issue 

rules on aviation safety. Subtitle I, 

section 106, describes the authority of 

the FAA Administrator. Subtitle VII: 

Aviation Programs, describes in more 

detail the scope of the Agency’s 

authority. 

The FAA is issuing this rulemaking 

under the authority described in 

Subtitle VII, Part A, Subpart III, Section 

44701: General requirements. Under 

that section, Congress charges the FAA 

with promoting safe flight of civil 

aircraft in air commerce by prescribing 

regulations for practices, methods, and 

procedures the Administrator finds 

necessary for safety in air commerce. 

This regulation is within the scope of 

that authority because it addresses an 

unsafe condition that is likely to exist or 

develop on products identified in this 

rulemaking action. 

Regulatory Findings 

The FAA determined that this 

proposed AD would not have federalism 

implications under Executive Order 

13132. This proposed AD would not 

have a substantial direct effect 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. 

For the reasons discussed above, I 

certify this proposed regulation: 

(1) Is not a ‘‘significant regulatory 

action’’ under Executive Order 12866, 

(2) Would not affect intrastate 

aviation in Alaska, and 


ddrumheller on DSK120RN23PROD with PROPOSALS1
79482 Federal Register / Vol. 89, No. 189 / Monday, September 30, 2024 / Proposed Rules 

(3) Would not have a significant 

economic impact, positive or negative, 

on a substantial number of small entities 

under the criteria of the Regulatory 

Flexibility Act. 

List of Subjects in 14 CFR Part 39 

Air transportation, Aircraft, Aviation 

safety, Incorporation by reference, 

Safety. 

The Proposed Amendment 

Accordingly, under the authority 

delegated to me by the Administrator, 

the FAA proposes to amend 14 CFR part 

39 as follows: 

PART 39—AIRWORTHINESS 

DIRECTIVES 

■ 1. The authority citation for part 39 

continues to read as follows: 

Authority: 49 U.S.C. 106(g), 40113, 44701. 

§ 39.13 [Amended] 

■ 2. The FAA amends § 39.13 by adding 

the following new airworthiness 

directive: 

Thommen Aircraft Equipment AG: Docket 

No. FAA–2024–2322; Project Identifier 

MCAI–2024–00065–Q. 

(a) Comments Due Date 

The FAA must receive comments on this 

airworthiness directive (AD) by November 

14, 2024. 

(b) Affected ADs 

None. 

(c) Applicability 

(1) This AD applies to THOMMEN 

AIRCRAFT EQUIPMENT AG (THOMMEN) 

AC32 Digital Air Data Computers (ADCs) 

having an affected part as defined in 

paragraph (f)(1) of this AD. 

(2) This appliance is installed on, but not 

limited to, the following aircraft models 

specified in Table 1 to paragraph (c)(2) of this 

AD, certificated in any category. 

TABLE 1 TO PARAGRAPH (C)(2)—APPLICABLE AIRCRAFT MODELS

Type certificate holder Aircraft model 

Airbus Defense and Space S.A. (type certificate previously held by 

Construcciones Aeronauticas, S.A.).

CN–235, CN–235–100, CN–235–200, and CN–235–300. 

Airbus Helicopters .................................................................................... AS332C, AS332C1, AS332L, AS332L1, AS3323L2. 

Airbus Helicopters Deutschland GmbH (AHD) ........................................ EC635T2+. 

Bell Textron Inc ........................................................................................ 212, 412, and 412EP. 

Bombardier Inc ......................................................................................... CL–600–1A11 (600). 

Columbia Helicopters Inc ......................................................................... 234. 

General Atomics Aerotek Systems GmbHl (type certificate formerly 

held by DORNIER LUFTFAHRT Inc.).

228–100, 228–101, 228–200, 228–201, 228–202, and 228–212. 

Gulfstream Aerospace LP ........................................................................ Westwind Astra 1124 (serial numbers 004–0410). 

International Air Response ....................................................................... C–130A. 

Leonardo S.p.a ......................................................................................... A109, A10A, A109A II, A109C, A109K2, A109S, 1099SP, and AW139. 

Textron Aviation Inc .................................................................................. 200, 300, 500, 501, 550, and 551. 

Viking Air Limited ...................................................................................... CL–215–6B11 (CL–215T Variant). 

(3) This appliance is approved for 

installation and could be installed on various 

aircraft modified by Supplemental Type 

Certificate (STC) No. SR09595RC or 

ST01523WI. 

(d) Subject 

Joint Aircraft System Component (JASC) 

Code 3417, Air Data Computer. 

(e) Unsafe Condition 

This AD was prompted by occurrences of 

AC32 Digital ADCs stopping functioning due 

to the power module failing at temperatures 

below –20 degrees Celsius. The unsafe 

condition, if not addressed, could result in 

insufficient navigational data provided to the 

flight crew, resulting in reduced control of 

the aircraft. 

(f) Definitions 

For the purpose of this AD the definitions 

in paragraphs (f)(1) through (4) of this AD 

apply: 

(1) Affected part: THOMMEN AC32 Digital 

ADCs, part numbers (P/N) AC32.10.21.10.XX, 

AC32.10.21.11.XX, AC32.11.21.10.XX, and 

AC32.11.21.11.XX (where XX represents any 

alpha/numerical sequence), and having a 

serial number (S/N) listed in Appendix A of 

THOMMEN AIRCRAFT EQUIPMENT Service 

Bulletin SB AC32/07, Revision 1.0, dated 

August 31, 2023 (THOMMEN SB AC32/07 

Revision 1.0). 

(2) Serviceable part: Any AC32.(X) Digital 

ADC that is not an affected part; or an 

affected part where the power module has 

been replaced by THOMMEN, in accordance 

with the instructions of THOMMEN SB 

AC32/07 Revision 1.0. 

(3) Group 1 aircraft: Have an affected part 

installed. 

(4) Group 2 aircraft: Do not have an 

affected part installed but are eligible for 

AC32.(X) Digital ADC installation. 

(g) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(h) Required Actions 

For Group 1 aircraft: Within 12 months 

after the effective date of this AD, remove 

each affected part from service and replace it 

with a serviceable part in accordance with 

paragraph 3.A. of the Accomplishment 

Instructions in THOMMEN SB AC32/07 

Revision 1.0, except where this material 

specifies to send the removed affected part to 

the manufacturer, this AD does not require 

that action. 

(i) Parts Installation Prohibition 

For Group 1 and 2 aircraft: As of the 

effective date of this AD, do not install an 

affected part on any aircraft. 

(j) Special Flight Permits 

A one-time special flight permit may be 

issued in accordance with 14 CFR 21.197 and 

21.199 in order to fly to a maintenance base 

to perform the required action in this AD, 

provided a flight profile above ¥15 degrees 

Celsius (5 degrees Fahrenheit) is maintained. 

(k) Alternative Methods of Compliance 

(AMOCs) 

(1) The Manager, International Validation 

Branch, FAA, has the authority to approve 

AMOCs for this AD, if requested using the 

procedures found in 14 CFR 39.19. In 

accordance with 14 CFR 39.19, send your 

request to your principal inspector or local 

Flight Standards District Office, as 

appropriate. If sending information directly 

to the International Validation Branch, send 

it to the attention of the person identified in 

paragraph (l) of this AD and email to: 

AMOC@faa.gov. Before using any approved 

AMOC, notify your appropriate principal 

inspector, or lacking a principal inspector, 

the manager of the responsible Flight 

Standards Office. 

(l) Additional Information 

For more information about this AD, 

contact William Reisenauer, Aviation Safety 

Engineer, FAA, 1600 Stewart Avenue, Suite 

410, Westbury, NY 11590; phone: (516) 228– 

7301; email: 9-AVS-AIR-BACO-COS@faa.gov. 

(m) Material Incorporated by Reference 

(1) The Director of the Federal Register 

approved the incorporation by reference 

(IBR) of the material listed in this paragraph 

under 5 U.S.C. 552(a) and 1 CFR part 51. 

(2) You must use this material as 

applicable to do the actions required by this 

AD, unless the AD specifies otherwise. 


ddrumheller on DSK120RN23PROD with PROPOSALS1
Federal Register / Vol. 89, No. 189 / Monday, September 30, 2024 / Proposed Rules 79483 

(i) THOMMEN AIRCRAFT EQUIPMENT 

Service Bulletin SB AC32/07, Revision 1.0, 

dated August 31, 2023. 

(ii) [Reserved] 

(3) For THOMMEN AIRCRAFT 

EQUIPMENT material in this AD, contact 

THOMMEN AIRCRAFT EQUIPMENT AG, 

Hofackerstrasse 48, 4132 Muttenz, 

Switzerland; phone: +41 (0) 61 965 22 22; 

email: sales@thommen.aero; website: 

thommen.aero. 

(4) You may view this material at the FAA, 

Airworthiness Products Section, Operational 

Safety Branch, 901 Locust, Kansas City, MO 

64106. For information on the availability of 

this material at the FAA, call (817) 222–5110. 

(5) You may view this material at the 

National Archives and Records 

Administration (NARA). For information on 

the availability of this material at NARA, 

visit www.archives.gov/federal-register/cfr/ 

ibr-locations or email fr.inspection@nara.gov. 

Issued on September 24, 2024. 

Steven W. Thompson, 

Acting Deputy Director, Compliance & 

Airworthiness Division, Aircraft Certification 

Service. 

[FR Doc. 2024–22251 Filed 9–27–24; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2024–2147; Project 

Identifier MCAI–2022–01515–R] 

RIN 2120–AA64 

Airworthiness Directives; Airbus 

Helicopters 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to adopt a 

new airworthiness directive (AD) for all 

Airbus Helicopters Model EC 155B, 

EC155B1, SA–365N, SA–365N1, AS– 

365N2, and AS 365 N3 helicopters. This 

proposed AD was prompted by an 

engine compartment fire where the 

upper stiffener of the central firewall in 

the engine compartment was found 

damaged. This proposed AD would 

require replacing the aluminum central 

firewall stiffener with a titanium central 

firewall stiffener and prohibit installing 

an aluminum central firewall stiffener. 

These actions are specified in a 

European Union Aviation Safety Agency 

(EASA) AD, which is proposed for 

incorporation by reference. The FAA is 

proposing this AD to address the unsafe 

condition on these products. 

DATES: The FAA must receive comments 

on this NPRM by November 14, 2024. 

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–2024–2147; 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 NPRM, the EASA AD, 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 

proposed AD, contact EASA, KonradAdenauer-Ufer 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, Office of the Regional Counsel, 

Southwest Region, 10101 Hillwood 

Pkwy., Room 6N–321, Fort Worth, TX 

76177. For information on the 

availability of this material at the FAA, 

call (817) 222–5110. The EASA material 

is also available at regulations.gov under 

Docket No. FAA–2024–2147. 

Other Related Material: For Airbus 

Helicopters material identified in this 

proposed AD, contact Airbus 

Helicopters, 2701 North Forum Drive, 

Grand Prairie, TX 75052; phone (972) 

641–0000 or (800) 232–0323; fax (972) 

641–3775; or at airbus.com/en/ 

products-services/helicopters/hcareservices/airbusworld. 

FOR FURTHER INFORMATION CONTACT: Hye 

Yoon Jang, Aviation Safety Engineer, 

FAA, 1600 Stewart Avenue, Suite 410, 

Westbury, NY 11590; phone: (206) 231– 

3758; email: Hye.Yoon.Jang@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

The FAA invites you to send any 

written relevant data, views, or 

arguments about this proposal. Send 

your comments to an address listed 

under ADDRESSES. Include ‘‘Docket No. 

FAA–2024–2147; Project Identifier 

MCAI–2022–01515–R’’ at the beginning 

of your comments. The most helpful 

comments reference a specific portion of 

the proposal, explain the reason for any 

recommended change, and include 

supporting data. The FAA will consider 

all comments received by the closing 

date and may amend this proposal 

because of those comments. 

Except for Confidential Business 

Information (CBI) as described in the 

following paragraph, and other 

information as described in 14 CFR 

11.35, the FAA will post all comments 

received, without change, to 

regulations.gov, including any personal 

information you provide. The agency 

will also post a report summarizing each 

substantive verbal contact received 

about this NPRM. 

Confidential Business Information 

CBI is commercial or financial 

information that is both customarily and 

actually treated as private by its owner. 

Under the Freedom of Information Act 

(FOIA) (5 U.S.C. 552), CBI is exempt 

from public disclosure. If your 

comments responsive to this NPRM 

contain commercial or financial 

information that is customarily treated 

as private, that you actually treat as 

private, and that is relevant or 

responsive to this NPRM, it is important 

that you clearly designate the submitted 

comments as CBI. Please mark each 

page of your submission containing CBI 

as ‘‘PROPIN.’’ The FAA will treat such 

marked submissions as confidential 

under the FOIA, and they will not be 

placed in the public docket of this 

NPRM. Submissions containing CBI 

should be sent to Hye Yoon Jang, 

Aviation Safety Engineer, FAA, 1600 

Stewart Avenue, Suite 410, Westbury, 

NY 11590; phone: (206) 231–3758; 

email: Hye.Yoon.Jang@faa.gov. Any 

commentary that the FAA receives 

which is not specifically designated as 

CBI will be placed in the public docket 

for this rulemaking. 

Background 

EASA, which is the Technical Agent 

for the Member States of the European 

Union, has issued European Union 

Aviation Safety Agency AD 2022–0231, 

dated November 28, 2022 (EASA AD 

2022–0231), to correct an unsafe 

condition on Airbus Helicopters Model 

EC 155B, EC155B1, SA–365N, SA– 

365N1, AS–365N2, and AS 365 N3 

helicopters. 

This proposed AD was prompted by 

an engine fire where the upper stiffener 

of the central firewall, made of 

aluminum, in the engine compartment 

was found damaged. The FAA is 

proposing this AD to address failure of 


ddrumheller on DSK120RN23PROD with PROPOSALS1