Airworthiness Directives; General Electric Company Engines

[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]


-----------------------------------------------------------------------

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.

-----------------------------------------------------------------------

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:
    <bullet> 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.
    <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 
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
----------------------------------------------------------------------------------------------------------------
                                                                                        Cost per   Cost on U.S.
                  Action                             Labor cost            Parts cost   product      operators
----------------------------------------------------------------------------------------------------------------
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.
----------------------------------------------------------------------------------------------------------------

    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
------------------------------------------------------------------------
                                                               Cost per
            Action                Labor cost     Parts cost    product
------------------------------------------------------------------------
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.
------------------------------------------------------------------------


[[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

The complete text was extracted from the official GovInfo HTML edition for this publication. Acquired 2026-10-09T01:24:15.444594+00:00. Text extraction preserves the recorded source wording; it does not determine current requirements.

Open the captured official edition

Source SHA-256

f77a22cc132bad7d57c887f4215750a2aeffe06087d04541412434afce295d2c

Text SHA-256

58581d81f1cb5f34734025cbc806402e7dbe40a50268b9f32699c51b6ed05f10