[Federal Register Volume 90, Number 137 (Monday, July 21, 2025)]
[Rules and Regulations]
[Pages 34178-34180]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-13644]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2024-1885; Project Identifier AD-2023-00995-E;
Amendment 39-23081; AD 2025-14-03]
RIN 2120-AA64
Airworthiness Directives; General Electric Company 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 General Electric Company (GE) Model CF34-10E2A1, CF34-10E6,
CF34-10E6A1, CF34-10E7, CF34-10E7-B, CF34-10E5, and CF34-10E5A1
engines. This AD was prompted by a report of cracks found in the high-
pressure turbine (HPT) front rotating air seal. This AD requires
performing repetitive fluorescent penetrant inspections (FPIs) to
detect indications or linear indications (any indication which is four
times longer than the width of that same indication) in the HPT front
rotating air seal and, if necessary, replacing the HPT front rotating
air seal or HPT rotor disk with parts eligible for installation as
applicable. This AD also includes an optional terminating action to the
repetitive FPIs. The FAA is issuing this AD to address the unsafe
condition on these products.
DATES: This AD is effective August 25, 2025.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of August 25,
2025.
ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2024-1885; 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:
For GE material identified in this AD, contact GE, 1
Neumann Way, Cincinnati, OH 45215; phone: (513) 552-3272; email:
ge.com">aviation.fleetsupport@ge.com; website: ge.com.
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
regulations.gov under Docket No. FAA-2024-1885.
FOR FURTHER INFORMATION CONTACT: Alexei Marqueen, Aviation Safety
Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone:
(781) 238-7178; email: [email protected].
SUPPLEMENTARY INFORMATION:
Background
The FAA issued a supplemental notice of proposed rulemaking (SNPRM)
to amend 14 CFR part 39 by adding an AD that would apply to certain GE
Model CF34-10E2A1, CF34-10E6, CF34-10E6A1, CF34-10E7, CF34-10E7-B,
CF34-10E5, and CF34-10E5A1 engines. The SNPRM was published in the
Federal Register on April 25, 2025 (90 FR 17345). The SNPRM was
prompted by a report of indications found in certain HPT front rotating
air seals at the rabbet surface where the affected part interacts with
the HPT rotor disk tabs. The manufacturer investigated and determined
that the indications were caused by high edge contact stress at the
interface between the HPT rotor disk and the rabbet surface of the HPT
front rotating air seal. The SNPRM proposed to require repetitive FPIs
to detect indications or linear indications (any indication that is
four times longer than the width of that same indication) in the HPT
front rotating air seal and, if necessary, replacement of the HPT front
rotating air seal or HPT rotor disk with parts eligible for
installation. Additionally, replacing the HPT front rotating air seal
with an updated design part constitutes as a terminating action for the
proposed AD. The FAA has also determined that changes to the
applicability are necessary, primarily based on comments received on
the notice of proposed rulemaking (NPRM) (89 FR 59860; July 24, 2024)
from several commenters and additional review by the FAA. The FAA is
issuing this AD to address the unsafe condition on these products.
Discussion of Final Airworthiness Directive
Comments
The FAA received a comment from one individual commenter. The
commenter supported the SNPRM without change.
Conclusion
The FAA reviewed the relevant data, considered any 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 these products. Except for minor editorial changes, this
AD is adopted as proposed in the SNPRM. None of the changes will
increase the economic burden on any operator.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed GE CF34-10E Service Bulletin 72-0341 R02, dated
September 24, 2021 (GE SB 72-0341 R02). This material specifies
procedures for repetitive FPIs and eddy current inspections of certain
HPT front rotating air seals for indications or linear
[[Page 34179]]
indications and, if necessary, replacement of the affected HPT front
rotating air seals or the HPT rotor disk with parts eligible for
installation. 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 228 engines installed on
airplanes of U.S. registry.
The FAA estimates the following costs to comply with this AD:
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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FPI of the HPT front rotating air seal... 8 work-hours x $85 per hour $0 $680 $155,040
= $680.
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The FAA estimates the following costs to do any necessary
replacements that would be required based on the results of the
inspections. The agency has no way of determining the number of engines
that might need these replacements:
On-Condition Costs
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Action Labor cost Parts cost Cost per product
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Replace HPT front rotating air seal.......... 8 work-hours x $85 per hour = $332,000 $332,680
$680.
Replace HPT rotor disk....................... 8 work-hours x $85 per hour = 341,800 342,480
$680.
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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:
2025-14-03 General Electric Company: Amendment 39-23081; Docket No.
FAA-2024-1885; Project Identifier AD-2023-00995-E.
(a) Effective Date
This airworthiness directive (AD) is effective August 25, 2025.
(b) Affected ADs
None.
(c) Applicability
This AD applies to General Electric Company (GE) Model CF34-
10E2A1, CF34-10E6, CF34-10E6A1, CF34-10E7, CF34-10E7-B, CF34-10E5,
and CF34-10E5A1 engines with an installed high-pressure turbine
(HPT) front rotating air seal having part number (P/N) 1865M49P04,
2448M30P02, or 2448M30P03.
(d) Subject
Joint Aircraft System Component (JASC) Code 7250, Turbine
Section.
(e) Unsafe Condition
This AD was prompted by a report of cracks found in the HPT
front rotating air seal. The FAA is issuing this AD to detect
indications and linear indications (any indication which is four
times longer than the width of that same indication) of the HPT
front rotating air seal. The FAA is issuing this AD to prevent
failure of the HPT front rotating air seal or HPT rotor disk. The
unsafe condition, if not addressed, could result in uncontained
release of the HPT front rotating air seal or HPT rotor disk, damage
to the engine, and damage to the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
(1) At the next exposure of the HPT rotor assembly after the
effective date of this AD and each exposure thereafter, perform a
fluorescent penetrant inspection (FPI) of the HPT front rotating air
seal for indications or linear indications in accordance with
paragraphs 3.B.(1)(a) through (f), of GE CF34-10E Service Bulletin
(SB) 72-0341 R02, dated September 24, 2021 (GE CF34-10E SB 72-0341
R02).
(2) If during any FPI required by paragraph (g)(1) of this AD,
any indication greater than 0.015 in. (0.38mm) or any linear
indication is found, before further flight, remove the HPT front
rotating air seal from service and replace with a part eligible for
installation, in
[[Page 34180]]
accordance with paragraphs 3.B.(1)(g) and (h) of GE CF34-10E SB 72-
0341 R02.
(3) If during any FPI required by paragraph (g)(1) of this AD,
any indication is found that extends beyond the rabbet diameter M,
as specified in paragraph 3.B.(1)(i), Figure 1, and Figure 4 (Sheet
2) of GE CF34-10E SB 72-0341 R02, before further flight, remove the
HPT rotor disk from service and replace with a part eligible for
installation, in accordance with paragraph 3.B.(1)(i)2 of GE CF34-
10E SB 72-0341 R02.
(h) Optional Terminating Action
Replacing the HPT front rotating air seal with an HPT front
rotating air seal having P/N 2929M57P01 terminates the requirements
of this AD.
(i) Definitions
For the purpose of this AD, the definitions in paragraphs (i)(1)
through (3) of this AD apply:
(1) An ``exposure of the HPT rotor assembly'' is when the HPT
rotor assembly
is removed from the core module assembly.
(2) A ``linear indication'' is any indication whose length is at
least four times greater than its width.
(3) A ``part eligible for installation'' is defined as the
following, as applicable:
(i) An HPT front rotating air seal that is eligible for
installation is an HPT front rotating air seal having P/N
1865M49P04, P/N 2448M30P02, or P/N 2448M30P03 that has passed the
inspection required by paragraph (g)(1) of this AD, or an HPT front
rotating air seal having P/N 2929M57P01.
(ii) An HPT rotor disk that is eligible for installation is an
HPT rotor disk having P/N 1865M51P03 or P/N 1865M51P04 that has not
been removed from service as a result of the actions required by
paragraph (g)(3) of this AD.
(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 the AIR-520 Continued
Operational Safety Branch, send it to the attention of the person
identified in paragraph (k) of this AD and email to: [email protected].
(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) Related Information
For more information about this AD, contact Alexei Marqueen,
Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines,
WA 98198; phone: (781) 238-7178; email: [email protected].
(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) General Electric Company (GE) CF34-10E Service Bulletin 72-
0341 R02, dated September 24, 2021.
(ii) [Reserved]
(3) For GE material identified in this AD, contact GE, 1 Neumann
Way, Cincinnati, OH 45215; phone: (513) 552-3272; email:
ge.com">aviation.fleetsupport@ge.com; website: ge.com.
(4) You may view this material at 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 www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].
Issued on July 10, 2025.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft
Certification Service.
[FR Doc. 2025-13644 Filed 7-18-25; 8:45 am]
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