[4910-13-P]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2024-1701; Project Identifier MCAI-2024-00153-T]
RIN 2120-AA64
Airworthiness Directives; Airbus SAS Airplanes
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 SAS Model A350-941 and A350-1041 airplanes. This proposed AD was
prompted by a report the thrust reverser and pylon thermal blankets were found damaged
due to air leaking from the pre-cooler exchanger (PCE). This proposed AD would require
repetitively testing the PCE for air leaks and reporting the results, and depending on
findings, replacing the PCE and inspecting the thermal blankets for damage, as 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 proposed AD by [INSERT DATE 45
DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER].
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. FAA2024-1701; 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 EASA material, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne,
Germany; telephone +49 221 8999 000; email ADs@easa.europa.eu; website
easa.europa.eu. You may find this material on the EASA website ad.easa.europa.eu. It is
also available at regulations.gov under Docket No. FAA-2024-1701.
• You may view this material at the FAA, Airworthiness Products Section,
Operational Safety Branch, 2200 South 216th Street, Des Moines, WA. For information
on the availability of this material at the FAA, call 206-231-3195.
FOR FURTHER INFORMATION CONTACT: Dat Le, Aviation Safety Engineer,
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7317;
email dat.v.le@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-2024-1701; Project Identifier MCAI-2024-00153-T” 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 Dat Le, Aviation
Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone
516-228-7317; email dat.v.le@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 EASA AD 2024-0058R1, dated April 16, 2024 (EASA AD 20240058R1) (also referred to as the MCAI), to correct an unsafe condition for all Airbus SAS
Model A350-941 and A350-1041 airplanes. The MCAI states that during a maintenance

inspection, thrust reverser and pylon thermal blankets were found damaged due to air
leaking from the PCE. This condition, if not detected and corrected, could result in
thermal blanket damage that, if combined with an independent event of engine fire, could
lead to a temporary uncontrolled fire.
The FAA is proposing this AD to address the unsafe condition on these products.
You may examine the MCAI in the AD docket at regulations.gov under Docket
No. FAA-2024-1701.
Related Material Under 1 CFR Part 51
EASA AD 2024-0058R1 specifies a repetitive air leak test of the PCE and
reporting the results. If a leak is detected, EASA AD 2024-0058R1 specifies to replace
the PCE and visually inspect the thrust reverser and pylon thermal blankets and replace if
damaged. EASA AD 2024-0058R1 also requires performing an air leak test on any newly
installed PCE.
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 ADDRESSES
section.
FAA’s Determination
This product has been approved by the aviation authority of another country and
is 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 in
other products of the same type design.

Proposed AD Requirements in this NPRM
This proposed AD would require accomplishing the actions specified in EASA
AD 2024-0058R1 described previously, except for any differences identified as
exceptions in the regulatory text of this proposed AD.
Explanation of Required Compliance Information
In the FAA’s ongoing efforts to improve the efficiency of the AD process, the
FAA developed a process to use some civil aviation authority (CAA) ADs as the primary
source of information for compliance with requirements for corresponding FAA ADs.
The FAA has been coordinating this process with manufacturers and CAAs. As a result,
the FAA proposes to incorporate EASA AD 2024-0058R1 by reference in the FAA final
rule. This proposed AD would, therefore, require compliance with EASA AD 20240058R1 in its entirety through that incorporation, except for any differences identified as
exceptions in the regulatory text of this proposed AD. Using common terms that are the
same as the heading of a particular section in EASA AD 2024-0058R1 does not mean
that operators need comply only with that section. For example, where the AD
requirement refers to “all required actions and compliance times,” compliance with this
AD requirement is not limited to the section titled “Required Action(s) and Compliance
Time(s)” in EASA AD 2024-0058R1. Service information required by EASA AD 20240058R1 for compliance will be available at regulations.gov under Docket No. FAA2024-1701 after the FAA final rule is published.
Interim Action
The FAA considers that this proposed AD would be an interim action. If final
action is later identified, the FAA might consider further rulemaking then.

Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would affect 32
airplanes of U.S. registry. The FAA estimates the following costs to comply with this
proposed AD:
Estimated costs for required actions
Labor cost

Parts cost

Cost per product

Cost on U.S. operators

3 work-hours X $85
per hour = $255

$0

$255

$8,160

Estimated costs of on-condition actions
Labor cost

Parts cost

Cost per product

Up to 24 work-hours X $85 per
hour = Up to $2,040

Up to $18,844

Up to $20,884

Paperwork Reduction Act
A federal agency may not conduct or sponsor, and a person is not required to
respond to, nor shall a person be subject to a penalty for failure to comply with a
collection of information subject to the requirements of the Paperwork Reduction Act
unless that collection of information displays a current valid OMB Control Number. The
OMB Control Number for this information collection is 2120-0056. Public reporting for
this collection of information is estimated to take approximately 1 hour per response,
including the time for reviewing instructions, searching existing data sources, gathering
and maintaining the data needed, and completing and reviewing the collection of
information. All responses to this collection of information are mandatory. Send
comments regarding this burden estimate or any other aspect of this collection of
information, including suggestions for reducing this burden, to: Information Collection
Clearance Officer, Federal Aviation Administration, 10101 Hillwood Parkway, Fort
Worth, TX 76177-1524.

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
(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:
Airbus SAS: Docket No. FAA-2024-1701; Project Identifier MCAI-2024-00153-T.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive (AD) by
[INSERT DATE 45 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL
REGISTER].
(b) Affected ADs
None.
(c) Applicability
This AD applies to all Airbus SAS Model A350-941 and A350-1041 airplanes,
certificated in any category.
(d) Subject
Air Transport Association (ATA) of America Code 36, Pneumatic.
(e) Unsafe Condition
This AD was prompted by a report the thrust reverser and pylon thermal blankets
were found damaged due to air leaking from the pre-cooler exchanger (PCE). The FAA is
issuing this AD to address the PCE leaking air. The unsafe condition, if not addressed,
could result in thermal blanket damage that, if combined with an independent event of
engine fire, could lead to a temporary uncontrolled fire.

(f) Compliance
Comply with this AD within the compliance times specified, unless already done.
(g) Requirements
Except as specified in paragraph (h) of this AD: Comply with all required actions
and compliance times specified in, and in accordance with, European Union Aviation
Safety Agency (EASA) AD 2024-0058R1, dated April 16, 2024 (EASA AD 20240058R1).
(h) Exceptions to EASA AD 2024-0058R1
(1) Where EASA AD 2024-0058R1 refers to its effective date, this AD requires
using the effective date of this AD.
(2) Where paragraph (4) of EASA AD 2024-0058R1 specifies “if any discrepancy
is detected, before next flight, contact Airbus for approved instructions and accomplish
those instructions accordingly,” this AD requires replacing that text with “if any
discrepancy is detected, the discrepancy 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) Paragraph (6) of EASA AD 2024-0058R1 specifies to report air leak test
results to Airbus within a certain compliance time. For this AD, report test results at the
applicable time specified in paragraph (h)(3)(i) or (ii) of this AD.
(i) If the test was done on or after the effective date of this AD: Submit the report
within 30 days after the test.
(ii) If the test was done before the effective date of this AD: Submit the report
within 30 days after the effective date of this AD.
(4) This AD does not adopt the “Remarks” section of EASA AD 2024-0058R1.

(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: 9-AVS-AIR-730-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 DOA. If approved by the DOA, the approval must include the DOAauthorized signature.
(3) Required for Compliance (RC): Except as required by paragraph (i)(2) of this
AD, if any material referenced in EASA AD 2024-0058R1 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 516-228-7317;
email dat.v.le@faa.gov.
(k) 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 this AD specifies otherwise.
(i) European Union Aviation Safety Agency (EASA) AD 2024-0058R1, dated
April 16, 2024.
(ii) [Reserved]
(3) For EASA AD 2024-0058R1, contact EASA, Konrad-Adenauer-Ufer 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 ad.easa.europa.eu.
(4) You may view this material at the FAA, Airworthiness Products Section,
Operational Safety Branch, 2200 South 216th Street, 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 June 25, 2024.

Suzanne Masterson,
Deputy Director, Integrated Certificate Management Division,
Aircraft Certification Service.
[FR Doc. 2024-14437 Filed: 6/28/2024 8:45 am; Publication Date: 7/1/2024]