Rule2025-02204
Airworthiness Directives; CFM International, S.A. Engines
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
February 4, 2025
Effective
March 11, 2025
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for certain CFM International, S.A. (CFM) Model LEAP-1A and LEAP-1C engines. This AD was prompted by an investigation of an in-flight shut down event that revealed the aft arm of the high-pressure turbine (HPT) rotor interstage seal had failed. This AD requires removal from service and replacement of the HPT rotor interstage seal for LEAP-1A engines. Since the HPT rotor interstage seal part number is interchangeable between LEAP-1A and LEAP-1C engines, this AD also prohibits installation of these affected parts onto any LEAP-1A or LEAP-1C engine. The FAA is issuing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 90 Issue 22 (Tuesday, February 4, 2025)</title>
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[Federal Register Volume 90, Number 22 (Tuesday, February 4, 2025)]
[Rules and Regulations]
[Pages 8889-8891]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-02204]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2024-2325; Project Identifier AD-2024-00412-E;
Amendment 39-22927; AD 2025-01-03]
RIN 2120-AA64
Airworthiness Directives; CFM International, S.A. Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain CFM International, S.A. (CFM) Model LEAP-1A and LEAP-1C
engines. This AD was prompted by an investigation of an in-flight shut
down event that revealed the aft arm of the high-pressure turbine (HPT)
rotor interstage seal had failed. This AD requires removal from service
and replacement of the HPT rotor interstage seal for LEAP-1A engines.
Since the HPT rotor interstage seal part number is interchangeable
between LEAP-1A and LEAP-1C engines, this AD also prohibits
installation of these affected parts onto any LEAP-1A or LEAP-1C
engine. The FAA is issuing this AD to address the unsafe condition on
these products.
DATES: This AD is effective March 11, 2025.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of March 11,
2025.
ADDRESSES:
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2024-2325; 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, 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:
<bullet> For CFM material identified in this AD, contact CFM, GE
Aviation Fleet Support, 1 Neumann Way, M/D Room 285, Cincinnati, OH
45215; phone: (877) 432-3272; email: <a href="/cdn-cgi/l/email-protection#9cfdeaf5fde8f5f3f2b2faf0f9f9e8efe9ececf3eee8dcfbf9b2fff3f1"><span class="__cf_email__" data-cfemail="80e1f6e9e1f4e9efeeaee6ece5e5f4f3f5f0f0eff2f4c0e7e5aee3efed">[email protected]</span></a>.
<bullet> You may view this material at the FAA, Airworthiness
Products Section, Operational Safety Branch, 1200 District Avenue,
Burlington, MA 01803. For information on the availability of this
material at the FAA, call (817) 222-5110. It is also available at
<a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2024-2325.
FOR FURTHER INFORMATION CONTACT: Mehdi Lamnyi, Aviation Safety
Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone:
(781) 238-7743; email: <a href="/cdn-cgi/l/email-protection#bdd0d8d5d9d493d1dcd0d3c4d4fddbdcdc93dad2cb"><span class="__cf_email__" data-cfemail="fc9199949895d2909d91928595bc9a9d9dd29b938a">[email protected]</span></a>.
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 certain CFM Model LEAP-
1A and LEAP-1C engines. The NPRM published in the Federal Register on
October 2, 2024 (89 FR 80155). The NPRM was prompted by a report of an
in-flight shutdown caused by turbine blades that had broken and metal
that entered the exhaust. A manufacturer investigation later revealed
that the aft arm of the HPT rotor interstage seal had failed due to a
non-conforming surface condition in the fillet area coupled with
higher-than-expected operating stress due to friction. In the NPRM, the
FAA proposed to require removal from service and replacement of the HPT
rotor interstage seal. Since the HPT rotor interstage seal part number
is interchangeable between LEAP-1A and LEAP-1C engines, the NPRM also
proposed to prohibit installation of these affected parts onto any
LEAP-1A or LEAP-1C engine. The FAA is issuing this AD to address the
unsafe condition on these products.
Discussion of Final Airworthiness Directive
Comments
The FAA received comments from Airline Pilots Association
International (ALPA), StandardAero, an individual commenter, and an
anonymous commenter. All commenters supported the NPRM without change.
Conclusion
The FAA reviewed the relevant data, considered the comments
received, and determined that air safety requires adopting the AD as
proposed. Accordingly, the FAA is issuing this AD to address the unsafe
condition on these products. Except for minor editorial changes, this
AD is adopted as proposed in the NPRM.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed the following CFM material:
<bullet> CFM Service Bulletin (SB) LEAP-1A-72-00-0525-01A-930A-D,
Issue 002-00, dated June 28, 2024, which provides the serial numbers
(S/Ns) of the affected HPT rotor interstage seals for LEAP-1A engines.
<bullet> CFM SB LEAP-1C-72-00-0124-01A-930A-D, Issue 001-00, dated
September 5, 2024, which provides the S/Ns of the affected HPT rotor
interstage seals that are excluded from installation onto LEAP-1C
engines.
This material also includes instructions for removal and
installation of the HPT rotor interstage seal. 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 56 engines installed on
airplanes of U.S. registry.
The FAA estimates the following costs to comply with this AD:
[[Page 8890]]
Estimated costs
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Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Replace HPT rotor interstage seal..... 12 work-hours x $85 per $195,000 $196,020 $10,977,120
hour = $1,020.
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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:
2025-01-03 CFM International, S.A.: Amendment 39-22927; Docket No.
FAA-2024-2325; Project Identifier AD-2024-00412-E.
(a) Effective Date
This airworthiness directive (AD) is effective March 11, 2025.
(b) Affected ADs
None.
(c) Applicability
This AD applies to the following CFM International, S.A. (CFM)
engines:
(1) Model LEAP-1A23, LEAP-1A24, LEAP-1A24E1, LEAP-1A26, LEAP-
1A26CJ, LEAP-1A26E1, LEAP-1A29, LEAP-1A29CJ, LEAP-1A30, LEAP-1A32,
LEAP-1A33, LEAP-1A33B2, and LEAP-1A35A engines.
(2) Model LEAP-1C28, LEAP-1C30, and LEAP-1C30B1 engines.
(d) Subject
Joint Aircraft System Component (JASC) Code 7250, Turbine
Section.
(e) Unsafe Condition
This AD was prompted by an investigation of an in-flight shut
down event that revealed the aft arm of the high-pressure turbine
(HPT) rotor interstage seal had failed. The FAA is issuing this AD
to prevent failure of the HPT rotor interstage seal. The unsafe
condition, if not addressed, could result in failure of one or more
engines, loss of thrust control, and loss of the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
(1) For LEAP-1A engines having an HPT rotor interstage seal
installed with a part number (P/N) and serial number (S/N) listed in
Table 1 of CFM Service Bulletin (SB) LEAP-1A-72-00-0525-01A-930A-D,
Issue 002-00, dated June 28, 2024 (CFM SB LEAP-1A-72-00-0525-01A-
930A-D Issue 002-00), at the next engine shop visit or before
exceeding the applicable cyclic threshold in table 1 to paragraph
(g)(1) of this AD, whichever occurs first after the effective date
of this AD, remove the affected HPT rotor interstage seal from
service and replace with a part eligible for installation.
Table 1 to Paragraph (g)(1)--Removal Thresholds for Each Engine Model
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Engine model Removal cyclic threshold
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LEAP-1A23, LEAP-1A24, LEAP-1A24E1, LEAP- 11,100 cycles since new (CSN)
1A26, LEAP-1A26E1, LEAP-1A29, LEAP- accumulated on the affected
1A30, LEAP-1A32, LEAP-1A33, LEAP- part.
1A33B2, and LEAP-1A35A.
LEAP-1A26CJ and LEAP-1A29CJ............ 9,700 CSN accumulated on the
affected part.
------------------------------------------------------------------------
(2) For LEAP-1A engines having an HPT rotor interstage seal
installed with a P/N and S/N listed in Table 2 of CFM SB LEAP-1A-72-
00-0525-01A-930A-D Issue 002-00, at the next piece part exposure or
before exceeding the applicable cyclic threshold in table 1 to
paragraph (g)(1) of this AD, whichever occurs first after the
effective date of this AD, remove the affected HPT rotor interstage
seal from service and replace with a part eligible for installation.
(h) Installation Prohibition
(1) After the effective date of this AD, do not install an HPT
rotor interstage seal having a P/N and S/N listed in Table 1 or
Table 2 of CFM SB LEAP-1A-72-00-0525-01A-930A-D Issue 002-00, in any
LEAP-1A engine.
(2) After the effective date of this AD, do not install an HPT
rotor interstage seal having a P/N and S/N listed in Table 1 of CFM
SB LEAP-1C-72-00-0124-01A-930A-D, Issue 001-00, dated September 5,
2024, in any LEAP-1C engine.
(i) Definitions
For the purpose of this AD:
[[Page 8891]]
(1) ``LEAP-1A engines'' are CFM Model LEAP-1A23, LEAP-1A24,
LEAP-1A24E1, LEAP-1A26, LEAP-1A26CJ, LEAP-1A26E1, LEAP-1A29, LEAP-
1A29CJ, LEAP-1A30, LEAP-1A32, LEAP-1A33, LEAP-1A33B2, LEAP-1A35A
engines.
(2) ``LEAP-1C engines'' are CFM Model LEAP-1C28, LEAP-1C30, and
LEAP-1C30B1 engines.
(3) A ``part eligible for installation'' is any HPT rotor
interstage seal having a P/N and S/N that is not listed in Table 1
or Table 2 of CFM SB LEAP-1A-72-00-0525-01A-930A-D Issue 002-00.
(4) An ``engine shop visit'' is the induction of an engine into
the shop for maintenance involving the separation of major mating
engine flanges, except for the separation of engine flanges solely
for the purposes of transportation without subsequent engine
maintenance.
(5) A ``piece-part exposure'' is when the HPT rotor interstage
seal is separated from the HPT rotor assembly.
(j) Alternative Methods of Compliance (AMOCs)
(1) The Manager, AIR-520 Continued Operational Safety 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 manager of AIR-520 Continued Operational
Safety Branch, send it to the attention of the person identified in
paragraph (k) of this AD and email to: <a href="/cdn-cgi/l/email-protection#094844464a496f6868276e667f"><span class="__cf_email__" data-cfemail="bffef2f0fcffd9dede91d8d0c9">[email protected]</span></a>.
(2) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the local flight standards district office/certificate holding
district office.
(k) Additional Information
For more information about this AD, contact Mehdi Lamnyi,
Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines,
WA 98198; phone: (781) 238-7743; email: <a href="/cdn-cgi/l/email-protection#98f5fdf0fcf1b6f4f9f5f6e1f1d8fef9f9b6fff7ee"><span class="__cf_email__" data-cfemail="e9848c818d80c7858884879080a98f8888c78e869f">[email protected]</span></a>.
(l) 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.
(i) CFM Service Bulletin LEAP-1A-72-00-0525-01A-930A-D, Issue
002-00, dated June 28, 2024.
(ii) CFM Service Bulletin LEAP-1C-72-00-0124-01A-930A-D, Issue
001-00, dated September 5, 2024.
(3) For CFM material identified in this AD, contact CFM, GE
Aviation Fleet Support, 1 Neumann Way, M/D Room 285, Cincinnati, OH
45215; phone: (877) 432-3272; email: <a href="/cdn-cgi/l/email-protection#9cfdeaf5fde8f5f3f2b2faf0f9f9e8efe9ececf3eee8dcfbf9b2fff3f1"><span class="__cf_email__" data-cfemail="c5a4b3aca4b1acaaabeba3a9a0a0b1b6b0b5b5aab7b185a2a0eba6aaa8">[email protected]</span></a>.
(4) You may view this material at the FAA, Airworthiness
Products Section, Operational Safety Branch, 1200 District Avenue,
Burlington, MA 01803. 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 <a href="http://www.archives.gov/federal-register/cfr/ibr-locations">www.archives.gov/federal-register/cfr/ibr-locations</a> or email <a href="/cdn-cgi/l/email-protection#7f190d5116110c0f1a1c0b1610113f111e0d1e51181009"><span class="__cf_email__" data-cfemail="4325316d2a2d30332620372a2c2d032d2231226d242c35">[email protected]</span></a>.
Issued on January 30, 2025.
Suzanne Masterson,
Deputy Director, Integrated Certificate Management Division, Aircraft
Certification Service.
[FR Doc. 2025-02204 Filed 2-3-25; 8:45 am]
BILLING CODE 4910-13-P
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