Airworthiness Directives; General Electric Company Engines

[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]


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

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.

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

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:
    <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,

[[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
----------------------------------------------------------------------------------------------------------------
                                                                                       Cost per    Cost on U.S.
            Action                  Labor cost                Parts cost               product       operators
----------------------------------------------------------------------------------------------------------------
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.
----------------------------------------------------------------------------------------------------------------

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

The complete text was extracted from the official GovInfo HTML edition for this publication. Acquired 2026-10-09T01:23:56.489536+00:00. Text extraction preserves the recorded source wording; it does not determine current requirements.

Open the captured official edition

Source SHA-256

7e3700e7cf7202b60057f4f5134f952f8ac15e9a6752630d61d767806419347b

Text SHA-256

72b5e09f78bf625288b741a802008cf9919bde0bd5b6cef8d5f6970355187956