[Federal Register Volume 90, Number 105 (Tuesday, June 3, 2025)]
[Rules and Regulations]
[Pages 23432-23435]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-10024]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-0015; Project Identifier AD-2024-00615-E;
Amendment 39-23049; AD 2025-11-03]
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 GEnx-1B64, GEnx-1B64/P1,
GEnx-1B64/P2, GEnx-1B67, GEnx-1B67/P1, GEnx-1B67/P2, GEnx-1B70, GEnx-
1B70/75/P1, GEnx-1B70/75/P2, GEnx-1B70/P1, GEnx-1B70/P2, GEnx-1B70C/P1,
GEnx-1B70C/P2, GEnx-1B74/75/P1, GEnx-1B74/75/P2, GEnx-1B76/P2, GEnx-
1B76A/P2, and GEnx-2B67/P engines. This AD was prompted by a
manufacturer's investigation that revealed certain high-pressure
turbine (HPT) stage 1 and HPT stage 2 disks were manufactured from
powder metal material suspected to contain iron inclusion. This AD
requires replacement of affected HPT stage 1 and HPT stage 2 disks with
parts eligible for installation. The FAA is issuing this AD to address
the unsafe condition on these products.
DATES: This AD is effective July 8, 2025.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of July 8, 2025.
ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2025-0015; 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,
[[Page 23433]]
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-2025-0015.
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 certain GE Model GEnx-
1B64, GEnx-1B64/P1, GEnx-1B64/P2, GEnx-1B67, GEnx-1B67/P1, GEnx-1B67/
P2, GEnx-1B70, GEnx-1B70/75/P1, GEnx-1B70/75/P2, GEnx-1B70/P1, GEnx-
1B70/P2, GEnx-1B70C/P1, GEnx-1B70C/P2, GEnx-1B74/75/P1, GEnx-1B74/75/
P2, GEnx-1B76/P2, GEnx-1B76A/P2, and GEnx-2B67/P engines. The NPRM was
published in the Federal Register on January 31, 2025 (90 FR 8687). The
NPRM was prompted by a manufacturer's investigation that revealed the
detection of iron inclusion in turbine disks manufactured from the same
powder metal material used to manufacture certain HPT stage 1 and HPT
stage 2 disks for the above-referenced engines. Further investigation
by the manufacturer revealed that the iron inclusion is attributed to
deficiencies in the manufacturing process and may cause reduced
material properties and a lower fatigue life capability, which may
result in premature fracture and uncontained failure. The manufacturer
also informed the FAA that additional risk assessments determined that
there were no failed events associated with the discovery of this iron
inclusion material; however, concluded that replacement of the affected
HPT stage 1 and HPT stage 2 disks is necessary to prevent any future
failed events. In the NPRM, the FAA proposed to require replacement of
affected HPT stage 1 and HPT stage 2 disks with parts eligible for
installation. 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 six commenters. The commenters were
the Air Line Pilots Association, International (ALPA), The Boeing
Company (Boeing), Cathay Pacific Airways, Thai Airways, United
Airlines, and an individual commenter. ALPA and Boeing supported the
NPRM without change. The following presents the comments received from
Cathay Pacific Airways, Thai Airways, United Airlines, and the
individual commenter and the FAA's response.
Request To Clarify Reinstallation of Affected Part
Cathay Pacific Airways requested that the FAA clarify whether the
affected part may be reinstalled after being removed from an engine if
the part has not reached the cyclic removal threshold identified in GE
GEnx-1B Service Bulletin 72-0542 R00, dated April 15, 2024 (GE GEnx-1B
SB 72-0542 R00) and GE GEnx-2B SB 72-0471 R00, dated April 15, 2024 (GE
GEnx-2B Service Bulletin 72-0471 R00).
The FAA agrees to clarify. Because the compliance time of this
final rule is at a certain number of cycles or at the next piece part
exposure after the effective date of the AD, whichever occurs first,
the affected part must be removed from service and is not eligible to
be re-installed during piece part exposure. The FAA did not change this
AD as a result of this comment.
Request To Clarify Affected Engines
Thai Airways noted that GE Model GEnx-1b engines with engine serial
numbers 958136, 958164, and 958949 are not affected by GE GEnx-1B SB
72-0542 R00.
The FAA clarifies that the applicability for this AD is not
designated by engine serial number, but it is designated by specific
part numbers and serial numbers of affected parts. The FAA did not
change this AD as a result of this comment.
Request To Update Proposed AD Requirements
United Airlines requested that the FAA update the language in the
``Proposed AD Requirements in This NPRM'' paragraph of the proposed AD
to the following: ``Depending on the part numbers and serial numbers of
the affected HPT stage 1 disks and HPT stage 2 disks, this NPRM
proposes to require these actions to be accomplished at the next piece-
part exposure after the effective date of this proposed AD or before
the affected HPT stage 1 disks and HPT stage 2 disks reach the cyclic
removal threshold of up to 10,100 cycles since new, whichever occurs
first.''
The FAA agrees with the content in the requested language. However,
this section is not included in the final rule. Therefore, the FAA did
not change this AD as a result of this comment.
Request for New Part Design Details
An individual commenter requested that the FAA provide information
on what material the new HPT stage 1 and HPT stage 2 disks that are
eligible for installation will be composed of, how long these parts
will take to deteriorate, and how these new parts will be tested to
assure they will be more viable than the affected HPT stage 1 and HPT
stage 2 disks.
The FAA clarifies that the design of the HPT stage 1 and HPT stage
2 disks is unchanged by this AD. The iron inclusions are a result of a
deficiency in the manufacturing process, which has since been addressed
by the manufacturer. 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 NPRM. 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 GEnx-1B SB 72-0542 R00. The FAA also reviewed
GE GEnx-2B SB 72-0471 R00. This material specifies the affected part
numbers, serial numbers, and cyclic removal thresholds for the HPT
stage 1 and HPT stage 2 disks. 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 one engine installed on an
airplane of U.S. registry. The FAA estimates that no engines installed
on airplanes of U.S. registry require replacement of the HPT stage 2
disk.
The FAA estimates the following costs to comply with this AD:
[[Page 23434]]
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 stage 1 disk...... 8 work-hours x $757,416 (prorated)............. $758,096 $758,096
$85 per hour =
$680.
Replace HPT stage 2 disk...... 8 work-hours x $278,101 (prorated)............. 278,781 0
$85 per hour =
$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:
2025-11-03 General Electric Company: Amendment 39-23049; Docket No.
FAA-2025-0015; Project Identifier AD-2024-00615-E.
(a) Effective Date
This airworthiness directive (AD) is effective July 8, 2025.
(b) Affected ADs
None.
(c) Applicability
This AD applies to General Electric Company Model GEnx-1B64,
GEnx-1B64/P1, GEnx-1B64/P2, GEnx-1B67, GEnx-1B67/P1, GEnx-1B67/P2,
GEnx-1B70, GEnx-1B70/75/P1, GEnx-1B70/75/P2, GEnx-1B70/P1, GEnx-
1B70/P2, GEnx-1B70C/P1, GEnx-1B70C/P2, GEnx-1B74/75/P1, GEnx-1B74/
75/P2, GEnx-1B76/P2, GEnx-1B76A/P2, and GEnx-2B67/P engines with at
least one of the following installed:
(1) High Pressure Turbine (HPT) stage 1 disk having part number
(P/N) 2383M83G03 and a serial number (S/N) listed in Table 1 of GE
GEnx-1B Service Bulletin 72-0542 R00, dated April 15, 2024 (GE GEnx-
1B SB 72-0542 R00);
(2) HPT stage 2 disk having P/N 2300M84P02 and a S/N listed in
Table 2 of GE GEnx-1B SB 72-0542 R00;
(3) HPT stage 1 disk having P/N 2383M83G03 and a S/N listed in
Table 1 of GE GEnx-2B Service Bulletin 72-0471 R00, dated April 15,
2024 (GE GEnx-2B SB 72-0471 R00); or
(4) HPT stage 2 disk having P/N 2300M84P02 and a S/N listed in
Table 2 of GE GEnx-2B SB 72-0471 R00.
(d) Subject
Joint Aircraft System Component (JASC) Code 7250, Turbine
Section.
(e) Unsafe Condition
This AD was prompted by a manufacturer investigation that
revealed certain HPT stage 1 disks and HPT stage 2 disks were
manufactured from powder metal material suspected to contain iron
inclusion. The FAA is issuing this AD to prevent premature fracture
and uncontained failure. The unsafe condition, if not addressed,
could result in uncontained debris release, 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
At the applicable time specified in paragraphs (g)(1) through
(4) of this AD, remove each affected HPT stage 1 disk and HPT stage
2 disk from service and replace with a part eligible for
installation.
(1) For engines identified in paragraph (c)(1) of this AD, at
the next piece-part exposure after the effective date of this AD or
before the affected HPT stage 1 disk exceeds the cyclic removal
threshold listed in Table 1 of GE GEnx-1B SB 72-0542 R00, whichever
occurs first.
(2) For engines identified in paragraph (c)(2) of this AD, at
the next piece-part exposure after the effective date of this AD or
before the affected HPT stage 2 disk exceeds the cyclic removal
threshold listed in Table 2 of GE GEnx-1B SB 72-0542 R00, whichever
occurs first.
(3) For engines identified in paragraph (c)(3) of this AD, at
the next piece-part exposure after the effective date of this AD or
before the affected HPT stage 1 disk exceeds the cyclic removal
threshold listed in Table 1 of GE GEnx-2B SB 72-0471 R00, whichever
occurs first.
(4) For engines identified in paragraph (c)(4) of this AD, at
the next piece-part exposure after the effective date of this AD or
before the affected HPT stage 2 disk exceeds the cyclic removal
threshold listed in Table 2 of GE GEnx-2B SB 72-0471 R00, whichever
occurs first.
(h) Definitions
For the purpose of this AD:
(1) A ``part eligible for installation'' is any HPT stage 1 disk
or HPT stage 2 disk with a P/N and S/N that is not listed in Table 1
or Table 2 of either GEnx-1B SB 72-0542 R00 or GEnx-2B SB 72-0471
R00.
(2) A ``piece-part exposure'' is when the affected HPT stage 1
disk or HPT stage 2 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 AIR-520 Continued Operational
Safety Branch, send it to the attention of the person identified in
[[Page 23435]]
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) Additional 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].
(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 GEnx-1B Service Bulletin (SB) 72-0542 R00, dated April
15, 2024.
(ii) GE GEnx-2B SB 72-0471 R00, dated April 15, 2024.
(3) For GE material identified in this AD, contact General
Electric Company, 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 21, 2025.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft
Certification Service.
[FR Doc. 2025-10024 Filed 6-2-25; 8:45 am]
BILLING CODE 4910-13-P