[Federal Register Volume 90, Number 98 (Thursday, May 22, 2025)]
[Rules and Regulations]
[Pages 21855-21857]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-09205]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2024-1883; Project Identifier AD-2023-01120-E;
Amendment 39-23038; AD 2025-10-04]
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 all
General Electric Company (GE) Model CF34-10E2A1, CF34-10E5, CF34-
10E5A1, CF34-10E6, CF34-10E6A1, CF34-10E7, and CF34-10E7-B engines with
certain part-numbered high-pressure turbine (HPT) shroud/low pressure
turbine (LPT) nozzle assemblies installed. This AD was prompted by a
report of failed retention features of the inner and outer support air
ducts (commonly referred to as spoolies) discovered during engine
disassembly. This AD requires a visual inspection of the combustion
case for wear and gouges, repair if necessary, and rework of the
affected HPT shroud/LPT nozzle assemblies to add a positive retention
of the support air duct. The FAA is issuing this AD to address the
unsafe condition on these products.
DATES: This AD is effective June 26, 2025.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of June 26,
2025.
ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2024-1883; 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-2024-1883.
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 notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to all GE Model CF34-
10E2A1, CF34-10E6, CF34-10E6A1, CF34-10E7, and CF34-10E7-B engines with
an installed HPT shroud/LPT nozzle assembly having part number (P/N)
2205M38G01, 2205M38G02, 2205M38G03, 2205M38G04, or 2205M38G05. The NPRM
was published in the Federal Register on July 10, 2024 (89 FR 56674).
The NPRM was prompted by a report from the manufacturer that during
disassembly, the retention features of the inner and outer support air
ducts on GE Model CF34-10E series engines were found to have failed.
The retention features include a retaining ring, which becomes
plastically deformed during installation. Vibrations loosen the
retaining ring until it disengages. With the retaining ring disengaged,
the outer support air duct has no radial constraint, and releases and
migrates due to gravity, impacting the inner wall of the combustion
case causing case wall damage. If this damage has been repaired in the
past and after the repair
[[Page 21856]]
the support air duct liberates and causes more damage, then the
remaining wall thickness is not sufficient to sustain the loading from
a fan-blade-out or other extreme event. In the NPRM, the FAA proposed
to require a visual inspection of the combustion case for wear and
gouges, repair if necessary, and rework of the affected HPT shroud/LPT
nozzle assemblies to add a positive retention of the support air duct.
The FAA issued a supplemental notice of proposed rulemaking (SNPRM)
to amend 14 CFR part 39 by adding an AD that would apply to all GE
Model CF34-10E2A1, CF34-10E5, CF34-10E5A1, CF34-10E6, CF34-10E6A1,
CF34-10E7, and CF34-10E7-B engines with an installed HPT shroud/LPT
nozzle assembly having P/N 2205M38G01, 2205M38G02, 2205M38G03,
2205M38G04, or 2205M38G05. The SNPRM was published in the Federal
Register on January 23, 2025 (90 FR 7998). The SNPRM was prompted by
comments received on the NPRM from GE and Japan Airlines requesting the
addition of GE Model CF34-10E5 and CF34-10E5A1 engines to the
applicability of the NPRM. In response to these comments, the FAA
determined that additional model engines are affected by the unsafe
condition and, as a result, should be added to the applicability
paragraph of this AD. The SNPRM proposed to require a visual inspection
of the combustion case for wear and gouges, repair if necessary, and
rework of the affected HPT shroud/LPT nozzle assemblies to add a
positive retention of the support air duct. 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 one individual commenter. The
following presents the comments received on the SNPRM and the FAA's
response to the comments.
Request To Evaluate Economic Impact on Small Entities
An individual commenter requested that the FAA evaluate the
economic impact of compliance with the proposed AD, particularly on
smaller operators, and explore cost-effective solutions like
alternative repair procedures or extended compliance windows where
safety permits. The commenter also recommended that the FAA consider
additional guidance on streamlined approval processes for alternative
methods of compliance (AMOCs) in order to allow for flexibility in
addressing wear and damage while maintaining rigorous safety standards.
The commenter noted that the estimated cost of compliance, particularly
in cases requiring full combustion case replacement, could impose a
financial burden on affected carriers.
The FAA acknowledges the commenter's concerns and notes that
flexibility in compliance with an AD is allowed through a request for
an AMOC, allowed through the procedures in paragraph (i) of this AD.
The unsafe condition addressed in this AD includes failure of the
combustion case, which could result in possible engine separation and
loss of the airplane. Inspections and repairs are therefore necessary
to detect and repair any wear and gouges on the combustion case before
they lead to structural failure. The FAA did not change this AD as a
result of this comment.
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 72-0351 R01, dated
July 17, 2019, which specifies procedures for a visual inspection of
the combustion case for wear and gouges, repair if necessary, and
rework of the affected HPT shroud/LPT nozzle assemblies. This material
also introduces a new HPT shroud/LPT nozzle assembly P/N 2205M38G07
with welded retaining rings. 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 221 engines installed on
airplanes of U.S. registry.
The FAA estimates the following costs to comply with this AD:
Estimated Costs
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Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Visual inspection of the combustion case 8 work-hours x $85 per hour $0 $680 $150,280
inner shell surface. = $680.
Rework of the affected HPT shroud/LPT 8 work-hours x 85 per hour = 0 680 150,280
nozzle assembly. 680.
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The FAA estimates the following costs to do any necessary repairs
that would be required based on the results of the inspection. The
agency has no way of determining the number of engines that might need
these repairs.
On-Condition Costs
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Cost per
Action Labor cost Parts cost product
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Repair of the combustion case 8 work-hours x $0 $680
$85 per hour =
$680.
Replacement of the combustion 8 work-hours x $647,000 $647,680
case. $85 per hour =
$680.
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[[Page 21857]]
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:
2025-10-04 General Electric Company: Amendment 39-23038; Docket No.
FAA-2024-1883; Project Identifier AD-2023-01120-E.
(a) Effective Date
This airworthiness directive (AD) is effective June 26, 2025.
(b) Affected ADs
None.
(c) Applicability
This AD applies to General Electric Company (GE) Model CF34-
10E2A1, CF34-10E5, CF34-10E5A1, CF34-10E6, CF34-10E6A1, CF34-10E7,
and CF34-10E7-B engines with an installed high-pressure turbine
(HPT) shroud/low-pressure turbine (LPT) nozzle assembly having part
number (P/N) 2205M38G01, 2205M38G02, 2205M38G03, 2205M38G04, or
2205M38G05.
(d) Subject
Joint Aircraft System Component (JASC) Code 7250, Turbine
Section.
(e) Unsafe Condition
This AD was prompted by a report of failed retention features of
the inner and outer support air ducts (commonly referred to as
spoolies) discovered during engine disassembly. The FAA is issuing
this AD to prevent failure of the combustion case. The unsafe
condition, if not addressed, could result in the inner surface of
the combustion case having reduced load carrying capability for fan
blade out or other extreme event with possible engine separation and
loss of the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
(1) At the next engine shop visit after the effective date of
this AD, do a visual inspection of the combustion case inner shell
surface for wear and gouges in accordance with paragraphs 3.A.(1)
and (2) of the Accomplishment Instructions in GE CF34-10E Service
Bulletin (SB) 72-0351 R01, dated July 17, 2019 (GE CF34-10E SB 72-
0351 R01).
(i) If any wear or gouges are found during any inspection
required by paragraph (g)(1) of this AD, before further flight,
repair the combustion case in accordance with Table 1 of GE CF34-10E
SB 72-0351 R01.
(ii) If any wear or gouges exceed the maximum repairable limit
in accordance with Table 1 of GE CF34-10E SB 72-0351 R01, before
further flight, remove the combustion case from service.
(2) At the next engine shop visit after the effective date of
this AD, rework the affected HPT shroud/LPT nozzle assembly, in
accordance with paragraph 3.B. of the Accomplishment Instructions of
GE CF34-10E SB 72-0351 R01.
(h) Definition
For the purpose of this AD, an ``engine shop visit'' is defined
as when the HPT shroud/LPT nozzle assembly or the HPT rotor disk is
removed from the engine.
(i) 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 (j) 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.
(j) Related Information
For more information about this AD, contact Alexei Marqueen,
Aviation Safety Engineer, FAA, FAA, 2200 South 216th Street, Des
Moines, WA 98198; phone: (781) 238-7178; email:
[email protected].
(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 the AD specifies otherwise.
(i) GE CF34-10E Service Bulletin 72-0351 R01, dated July 17,
2019.
(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 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 www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].
Issued on May 8, 2025.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft
Certification Service.
[FR Doc. 2025-09205 Filed 5-21-25; 8:45 am]
BILLING CODE 4910-13-P