Airworthiness Directives; CFM International, S.A. Engines

[Federal Register Volume 90, Number 137 (Monday, July 21, 2025)]
[Rules and Regulations]
[Pages 34165-34168]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-13660]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2025-0621; Project Identifier AD-2024-00796-E; 
Amendment 39-23086; AD 2025-14-08]
RIN 2120-AA64


Airworthiness Directives; CFM International, S.A. Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2023-23-12 
for all CFM International, S.A. (CFM) Model LEAP-1B21, LEAP-1B23, LEAP-
1B25, LEAP-1B27, LEAP-1B28, LEAP-1B28B1, LEAP-1B28B2, LEAP-1B28B2C, 
LEAP-1B28B3, LEAP-1B28BBJ1, and LEAP-1B28BBJ2 engines. AD 2023-23-12 
required replacing certain high-pressure turbine (HPT) rotor stage 1 
disks and a certain compressor rotor stages 6-10 spool. Since the FAA 
issued AD 2023-23-12, the manufacturer has identified additional parts 
that were manufactured from material suspected to have reduced material 
properties due to iron inclusion, which prompted this AD. This AD 
retains the requirements to replace certain HPT rotor stage 1 disks and 
a certain compressor rotor stages 6-10 spool. This AD also expands the 
applicability to include additional affected HPT rotor stage 1 disks 
that were manufactured from the same material suspected to have reduced 
material properties due to iron inclusion. 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.
    The Director of the Federal Register approved the incorporation by 
reference of a certain other publication listed in this AD as of 
January 16, 2024 (88 FR 85836, December 11, 2023).

[[Page 34166]]


ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2025-0621; 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 CFM material identified in this AD, contact CFM, GE 
Aviation Fleet Support, 1 Neumann Way, M/D Room 285, Cincinnati, OH 
45215; phone: (877) 432-3272; email: [email protected].
    <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-2025-0621.

FOR FURTHER INFORMATION CONTACT: Mehdi Lamnyi, Aviation Safety 
Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: 
(781) 238-7743; email: [email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to supersede AD 2023-23-12, Amendment 39-22614 (88 FR 
85836, December 11, 2023) (AD 2023-23-12). AD 2023-23-12 applied to all 
CFM Model LEAP-1B21, LEAP-1B23, LEAP-1B25, LEAP-1B27, LEAP-1B28, LEAP-
1B28B1, LEAP-1B28B2, LEAP-1B28B2C, LEAP-1B28B3, LEAP-1B28BBJ1, and 
LEAP-1B28BBJ2 engines. The NPRM was published in the Federal Register 
on April 15, 2025 (90 FR 15670). The NPRM was prompted by a 
manufacturer investigation that revealed that certain HPT rotor stage 1 
disks and a certain compressor rotor stages 6-10 spool were 
manufactured from material suspected to have reduced material 
properties due to iron inclusion. Since the FAA issued AD 2023-23-12, 
the manufacturer has identified additional parts that were manufactured 
from material suspected to have reduced material properties due to iron 
inclusion, which prompted this AD. In the NPRM, the FAA proposed to 
continue to require replacement of certain HPT rotor stage 1 disks and 
a certain compressor rotor stages 6-10 spool. In the NPRM, the FAA also 
proposed to expand the applicability to include additional affected HPT 
rotor stage 1 disks that were manufactured from the same material 
suspected to have reduced material properties due to iron inclusion. 
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 three commenters. Commenters 
included the Air Line Pilots Association, International (ALPA), ProTech 
Aero Services Limited (ProTech), and United Airlines. ALPA and ProTech 
supported the NPRM without change. United Airlines had no comments or 
objections to the NPRM.

Conclusion

    The FAA reviewed the relevant data, considered any comments 
received, and determined that air safety requires adopting the 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 CFM Service Bulletin (SB) LEAP-1B-72-00-0402-01A-
930A-D, Issue 001, dated January 23, 2024. This material specifies the 
part numbers and serial numbers of additional affected HPT rotor stage 
1 disks and includes procedures for replacement of HPT rotor stage 1 
disks.
    The FAA also reviewed CFM SB LEAP-1B-72-00-0392-01A-930A-D, Issue 
002, dated September 5, 2023, which the Director of the Federal 
Register approved for incorporation by reference as of January 16, 2024 
(88 FR 85836, December 11, 2023).
    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 51 engines installed on 
airplanes of U.S. registry. These 51 engines require replacement of the 
HPT stage 1 disk. The FAA estimates that there are no engines installed 
on airplanes of U.S. registry that require replacement of the 
compressor rotor stages 6-10 spool.
    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
----------------------------------------------------------------------------------------------------------------
Replace HPT rotor stage 1 disk....  8 work-hours x $85     $215,635 (pro-rated).        $216,315     $11,032,065
                                     per hour = $680.
Replace compressor rotor stages 6-  8 work-hours x $85     $37,660 (pro-rated)..          38,340               0
 10 spool (0 affected US engines).   per hour = $680.
----------------------------------------------------------------------------------------------------------------

    The new requirements of this AD add no additional economic burden.

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.

[[Page 34167]]

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:
0
a. Removing Airworthiness Directive AD 2023-23-12, Amendment 39-22614 
(88 FR 85836, December 11, 2023); and
0
b. Adding the following new airworthiness directive:

2025-14-08 CFM International, S.A.: Amendment 39-23086; Docket No. 
FAA-2025-0621; Project Identifier AD-2024-00796-E.

(a) Effective Date

    This airworthiness directive (AD) is effective August 25, 2025.

(b) Affected ADs

    This AD replaces AD 2023-23-12, Amendment 39-22614 (88 FR 85836, 
December 11, 2023) (AD 2023-23-12).

(c) Applicability

    This AD applies to CFM International, S.A. (CFM) Model LEAP-
1B21, LEAP-1B23, LEAP-1B25, LEAP-1B27, LEAP-1B28, LEAP-1B28B1, LEAP-
1B28B2, LEAP-1B28B2C, LEAP-1B28B3, LEAP-1B28BBJ1, and LEAP-1B28BBJ2 
engines.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7230, Turbine Engine 
Compressor Section; 7250, Turbine Section.

(e) Unsafe Condition

    This AD was prompted by a manufacturer investigation that 
revealed that certain high-pressure turbine (HPT) rotor stage 1 
disks and a certain compressor rotor stages 6-10 spool were 
manufactured from material suspected to have reduced material 
properties due to iron inclusion. The FAA is issuing this AD to 
prevent fracture and subsequent uncontained failure of certain HPT 
rotor stage 1 disks and a certain compressor rotor stages 6-10 
spool. The unsafe condition, if not addressed, could result in 
uncontained debris release, damage to the engine, and damage to the 
aircraft.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Retained Required Actions

    (1) For engines with an installed HPT rotor stage 1 disk having 
a part number (P/N) and serial number (S/N) identified in 
Compliance, paragraph 3.E., Tables 1 through 2, of CFM Service 
Bulletin (SB) LEAP-1B-72-00-0392-01A-930A-D, Issue 002, dated 
September 5, 2023 (CFM SB LEAP-1B-72-00-0392-01A-930A-D, Issue 002): 
At the next piece-part exposure of the HPT rotor stage 1 disk, or 
before exceeding the applicable cycles since new (CSN) threshold 
identified in Compliance, paragraph 3.E., Tables 1 through 2, of CFM 
SB LEAP-1B-72-00-0392-01A-930A-D, Issue 002, whichever occurs first 
after January 16, 2024 (the effective date of AD 2023-23-12); or if 
the applicable CSN threshold has been exceeded as of January 16, 
2024 (the effective date of AD 2023-23-12), within 50 flight cycles 
(FCs) from January 16, 2024 (the effective date of AD 2023-23-12); 
remove the HPT rotor stage 1 disk from service and replace with a 
part eligible for installation.
    (2) For engines with an installed compressor rotor stages 6-10 
spool having a P/N and S/N identified in Compliance, paragraph 3.E., 
Table 3, of CFM SB LEAP-1B-72-00-0392-01A-930A-D, Issue 002: At the 
next piece-part exposure of the compressor rotor stages 6-10 spool, 
or before exceeding the applicable CSN threshold identified in 
Compliance, paragraph 3.E., Table 3, of CFM SB LEAP-1B-72-00-0392-
01A-930A-D, Issue 002, whichever occurs first after January 16, 2024 
(the effective date of AD 2023-23-12); or if the applicable CSN 
threshold has been exceeded as of January 16, 2024 (the effective 
date of AD 2023-23-12), within 50 FCs from January 16, 2024 (the 
effective date of AD 2023-23-12); remove the compressor rotor stages 
6-10 spool from service and replace with a part eligible for 
installation.

(h) New Required Actions

    For engines with an installed HPT rotor stage 1 disk having a P/
N and S/N identified in Compliance, paragraph 3.E., Table 1, of CFM 
SB LEAP-1B-72-00-0402-01A-930A-D, Issue 001, dated January 23, 2024 
(CFM SB LEAP-1B-72-00-0402-01A-930A-D, Issue 001): At the next 
piece-part exposure of the HPT rotor stage 1 disk, or before 
exceeding the applicable CSN threshold identified in Compliance, 
paragraph 3.E., Table 1, of CFM SB LEAP-1B-72-00-0402-01A-930A-D, 
Issue 001, whichever occurs first after the effective date of this 
AD; or if the applicable CSN threshold has been exceeded as of the 
effective date of this AD, within 50 FCs from the effective date of 
this AD; remove the HPT rotor stage 1 disk from service and replace 
with a part eligible for installation.

(i) Retained Definition, With Updated Service Information Reference

    For the purpose of this AD, a ``part eligible for installation'' 
is an HPT rotor stage 1 disk or compressor rotor stages 6-10 spool 
that does not have a P/N and S/N identified in Compliance, paragraph 
3.E., Tables 1 through 3, of CFM SB LEAP-1B-72-00-0392-01A-930A-D, 
Issue 002; or Compliance, paragraph 3.E., Table 1, of CFM SB LEAP-
1B-72-00-0402-01A-930A-D, Issue 001.

(j) Retained Installation Prohibition, With Updated Service Information 
Reference

    After the effective date of this AD, do not install an HPT rotor 
stage 1 disk or compressor rotor stages 6-10 spool that has a P/N 
and S/N identified in Compliance, paragraph 3.E., Tables 1 through 
3, of CFM SB LEAP-1B-72-00-0392-01A-930A-D, Issue 002; or 
Compliance, paragraph 3.E., Table 1, of CFM SB LEAP-1B-72-00-0402-
01A-930A-D, Issue 001, on any engine.

(k) Retained Credit for Previous Actions

    This paragraph provides credit for the actions required by 
paragraph (g) of this AD, if those actions were performed prior to 
January 16, 2024 (the effective date of AD 2023-23-12) by following 
the Accomplishment Instructions specified in CFM SB LEAP-1B-72-00-
0392-01A-930A-D, Issue 001, dated March 7, 2023.

(l) 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 (m)(1) 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.

(m) Additional Information

    (1) For more information about this AD, contact Mehdi Lamnyi, 
Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, 
WA 98198; phone: (781) 238-7743; email: [email protected].

[[Page 34168]]

    (2) Service material identified in this AD that is not 
incorporated by reference is available at the addresses specified in 
paragraph (n)(5) of this AD.

(n) 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.
    (3) The following material was approved for IBR on [DATE 35 DAYS 
AFTER PUBLICATION OF THE FINAL RULE].
    (i) CFM International, S.A. (CFM) Service Bulletin (SB) LEAP-1B-
72-00-0402-01A-930A-D, Issue 001, dated January 23, 2024.
    (ii) [Reserved]
    (4) The following material was approved for IBR on January 16, 
2024 (88 FR 85836, December 11, 2023).
    (i) CFM SB LEAP-1B-72-00-0392-01A-930A-D, Issue 002, dated 
September 5, 2023.
    (ii) [Reserved]
    (5) For CFM material identified in this AD, contact CFM 
International, S.A., GE Aviation Fleet Support, 1 Neumann Way, M/D 
Room 285, Cincinnati, OH 45215; phone: (877) 432-3272; email: 
[email protected].
    (6) 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.
    (7) 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 9, 2025.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft 
Certification Service.
[FR Doc. 2025-13660 Filed 7-18-25; 8:45 am]
BILLING CODE 4910-13-P

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