[Federal Register Volume 89, Number 162 (Wednesday, August 21, 2024)]
[Rules and Regulations]
[Pages 67535-67538]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-18628]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-1001; Project Identifier MCAI-2023-01129-T; 
Amendment 39-22787; AD 2024-14-06]
RIN 2120-AA64


Airworthiness Directives; Airbus SAS Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
Airbus SAS Model A350-941 and -1041 airplanes. This AD was prompted by 
reports that certain engine bleed air system (EBAS) T-Ducts may not 
conform to the type design due to a quality escape not detected during 
the manufacturing process on Rolls-Royce Trent XWB-75, Trent XWB-84, 
and Trent XWB-97 engines. This AD requires replacement of affected EBAS 
T-Ducts and limits the installation of affected parts under certain 
conditions, as specified in a European Union Aviation Safety Agency 
(EASA) AD, which is incorporated by reference (IBR). The FAA is issuing 
this AD to address the unsafe condition on these products.

DATES: This AD is effective September 25, 2024.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of September 
25, 2024.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2024-1001; 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 
address for Docket Operations is U.S. Department of Transportation, 
Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 
New Jersey Avenue SE, Washington, DC 20590.
    Material Incorporated by Reference:

[[Page 67536]]

     For EASA material identified in this AD, contact EASA, 
Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone +49 221 8999 
000; email [email protected]; website easa.europa.eu. You may find 
this material on the EASA website at ad.easa.europa.eu. It is also 
available at regulations.gov under Docket No. FAA-2024-1001.
     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. It is also available at regulations.gov under 
Docket No. FAA-2024-1001.

FOR FURTHER INFORMATION CONTACT: Dat Le, Aviation Safety Engineer, FAA, 
1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone: 516-228-
7300; email: [email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to all Airbus SAS Model 
A350-941 and -1041 airplanes. The NPRM published in the Federal 
Register on April 10, 2024 (89 FR 25191). The NPRM was prompted by EASA 
AD 2023-0189, dated October 31, 2023, issued by EASA, which is the 
Technical Agent for the Member States of the European Union (referred 
to after this as the MCAI). The MCAI states a sub-supplier to Rolls-
Royce for bleed ducts on Trent XWB-75, Trent XWB-84, and Trent XWB-97 
engines reported that certain EBAS T-Ducts may not conform to the type 
design due to a quality escape not detected during the manufacturing 
process. Affected EBAS T-Ducts have Part Number RR03-11011-001 and 
serial number listed in the Appendix 1 of Rolls-Royce Alert Non-
Modification Service Bulletin (NMSB) Trent XWB 36-AK870, dated 
September 29, 2023.
    In the NPRM, the FAA proposed to require replacement of affected 
EBAS T-Ducts and limit the installation of affected parts under certain 
conditions, as specified in a European Union Aviation Safety Agency 
(EASA) AD. The FAA is issuing this AD to address cracking of certain 
EBAS T-Ducts on Rolls-Royce (RR) Trent XWB-75, Trent XWB-84 and Trent 
XWB-97 engines. The unsafe condition, if not addressed, could result in 
cracking of the affected part with consequent air leakage, which could 
result in high energy debris release (uncontained engine rotor 
failure), an uncontrolled engine fire, and subsequent loss of control 
of the airplane.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2024-1001.

Discussion of Final Airworthiness Directive

Comments

    The FAA received a comment from the Air Line Pilots Association, 
International (ALPA), who supported the NPRM without change.
    The FAA received additional comments from Delta Air Lines. The 
following presents the comments received on the NPRM and the FAA's 
response to each comment.

Request for Removal of Step in Exceptions Paragraph

    Delta considered the exception in paragraph (h)(3) of the proposed 
AD unnecessary, and stated that this exception only restricts the use 
of later-approved revisions of Rolls-Royce Alert Non-Modification 
Service Bulletin TRENT XWB-36-AK870 (the NMSB). Delta stated that 
putting the date of the NMSB in the proposed AD limits the revision 
that can be used to comply with the AD, and use of later revisions will 
require approval of alternative methods of compliance (AMOCs). Delta 
noted that EASA AD 2023-0189 already defines the NMSB in the 
Definitions and Ref. Publications sections, and allows the use of 
later-approved revisions of the NMSB to comply with the EASA AD.
    The FAA disagrees with removing paragraph (h)(3) of this AD. 
Appendix 1 of the NMSB defines affected EBAS T-Ducts by part and serial 
number. Because Appendix 1 may change in future revisions of the NMSB, 
this AD defines the acceptable NMSB version to control for the identity 
of the affected parts. Paragraph (h)(3) of this AD does not otherwise 
affect the use of later-approved versions for the actions required by 
paragraph (1) or (2) of the EASA AD2023-0189. The FAA agrees that AMOC 
approvals may be necessary to use a future NMSB version if the 
definition of affected parts changes. The FAA has not changed this AD 
in this regard.

Request for Reporting Clarification

    Delta requested adding a new subparagraph to the ``Exceptions'' 
section of the NPRM to clarify reporting requirements. Delta stated 
that paragraphs 3.A.(4) and 3.B.(4) of Trent Service Bulletin XWB 36-
AK870 require the operator to complete an Appendix 3 form and submit it 
to Rolls-Royce. Delta claims the ``reporting requirement'' in an AD 
typically requests findings from an inspection to enable the 
manufacturer to learn more about the cause of the unsafe condition and 
determine appropriate corrective actions. Furthermore, the Trent 
Service Bulletin XWB 36-AK870, Appendix 3, merely requests that 
operators inform Rolls-Royce that the service bulletin is completed for 
their airplanes and does not specify submitting specific information 
such as test or inspection results.
    The FAA agrees and has added paragraph (i) of this AD in order to 
clarify that no reporting is required.

Conclusion

    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 reviewed the relevant data, considered the 
comments received, and determined that air safety requires adopting 
this AD as proposed. Accordingly, the FAA is issuing this AD to address 
the unsafe condition on this product. Except for minor editorial 
changes, and any other changes described previously, this AD is adopted 
as proposed in the NPRM. None of the changes will increase the economic 
burden on any operator.

Material Incorporated by Reference Under 1 CFR Part 51

    EASA AD 2023-0189 specifies procedures for replacement of affected 
EBAS T-Ducts. EASA AD 2023-0189 also limits the installation of 
affected parts. 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.

Costs of Compliance

    The FAA estimates that this AD affects 32 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:

[[Page 67537]]



                                      Estimated Costs for Required Actions
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            Labor cost               Parts cost           Cost per product            Cost on U.S. operators
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Up to 2 work-hours x $85 per hour        $128,555  Up to $128,725...............  Up to $4,119,200.
 = $170.
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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

    This AD will not have federalism implications under Executive Order 
13132. This AD will 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 that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) Will 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 Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

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


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

2024-14-06 Airbus SAS: Amendment 39-22787; Docket No. FAA-2024-1001; 
Project Identifier MCAI-2023-01129-T.

(a) Effective Date

    This airworthiness directive (AD) is effective September 25, 
2024.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Airbus SAS Model A350-941 and -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 reports that certain engine bleed air 
system (EBAS) T-Ducts on Rolls-Royce Trent XWB-75, Trent XWB-84, and 
Trent XWB-97 engines may not conform to the type design due to a 
quality escape not detected during the manufacturing process. The 
FAA is issuing this AD to address cracking of certain EBAS T-Ducts 
on Rolls-Royce (RR) Trent XWB-75, Trent XWB-84 and Trent XWB-97 
engines. The unsafe condition, if not addressed, could result in 
cracking of the affected part with consequent air leakage, which 
could result in high energy debris release (uncontained engine rotor 
failure), an uncontrolled engine fire, and subsequent loss of 
control of the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Requirements

    Except as specified in paragraphs (h) and (i) of this AD: Comply 
with all required actions and compliance times specified in, and in 
accordance with, European Union Aviation Safety Agency (EASA) AD 
2023-0189, dated October 31, 2023 (EASA AD 2023-0189).

(h) Exceptions to EASA AD 2023-0189

    (1) Where EASA AD 2023-0189 refers to its effective date, this 
AD requires using the effective date of this AD.
    (2) This AD does not adopt the ``Remarks'' section of EASA AD 
2023-0189.
    (3) Where the definition of affected part in EASA AD 2023-0189 
specifies ``as listed in the APPENDIX 1 of the NMSB,'' replace that 
text with ``as listed in the APPENDIX 1 of Rolls-Royce ALERT Non-
Modification Service Bulletin TRENT XWB 36-AK870, dated September 
29, 2023.''

(i) No Reporting Requirement

    Although certain material referenced in EASA AD 2023-0189 
specifies to submit certain information to the manufacturer, this AD 
does not include that requirement.

(j) Special Flight Permit

    Special flight permits may be issued in accordance with 14 CFR 
21.197 and 21.199 to operate the airplane to a location where an 
EBAS T-Duct can be replaced, provided only one EBAS T-Ducts requires 
replacement.

(k) 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 (l) of this AD. Information may be emailed to: [email protected]. 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 
paragraph (k)(2) of this AD, if any material contains procedures or 
tests that are identified as RC, those procedures and tests must be 
done to comply with this AD; any procedures or tests that are not 
identified as RC are recommended. Those procedures and tests that 
are 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

[[Page 67538]]

procedures and tests identified as RC can be done and the airplane 
can be put back in an airworthy condition. Any substitutions or 
changes to procedures or tests identified as RC require approval of 
an AMOC.

(l) 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: [email protected].

(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 this AD specifies otherwise.
    (i) European Union Aviation Safety Agency (EASA) AD 2023-0189, 
dated October 31, 2023.
    (ii) [Reserved]
    (3) For EASA AD 2023-0189, contact EASA, Konrad-Adenauer-Ufer 3, 
50668 Cologne, Germany; telephone +49 221 8999 000; email 
[email protected]; 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 [email protected].

    Issued on July 12, 2024.
Suzanne Masterson,
Deputy Director, Integrated Certificate Management Division, Aircraft 
Certification Service.
[FR Doc. 2024-18628 Filed 8-20-24; 8:45 am]
BILLING CODE 4910-13-P