[Federal Register Volume 90, Number 71 (Tuesday, April 15, 2025)]
[Proposed Rules]
[Pages 15670-15673]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-06382]
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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]
RIN 2120-AA64
Airworthiness Directives; CFM International, S.A. Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD)
2023-23-12, which applies to 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 (LEAP-1B) engines. AD 2023-23-12 requires 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 proposed AD. This proposed AD would
retain the requirements to replace certain HPT rotor stage 1 disks and
a certain compressor rotor stages 6-10 spool. This proposed AD would
also 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
proposing this AD to address the unsafe condition on these products.
DATES: The FAA must receive comments on this proposed AD by May 30,
2025.
ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to regulations.gov. Follow
the instructions for submitting comments.
Fax: (202) 493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
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 NPRM, any comments received, and other
information. The street address for Docket Operations is listed above.
Material Incorporated by Reference:
For CFM material identified in this proposed AD, contact
CFM, GE Aviation Fleet Support, 1 Neumann Way, M/D Room 285,
Cincinnati, OH 45215; phone: (877) 432-3272; email:
[email protected].
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.
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:
Comments Invited
The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under the ADDRESSES section. Include ``Docket No. FAA-2025-0621;
Project Identifier AD-2024-00796-E'' at the beginning of your comments.
The most helpful comments reference a specific portion of the proposal,
explain the reason for any recommended change, and include supporting
data. The FAA will consider all comments received by the closing date
and may revise this proposal because of those comments.
Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
regulations.gov, including any personal information you provide. The
agency will also post a report summarizing each substantive verbal
contact received about this NPRM.
Confidential Business Information
CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this NPRM contain commercial
or financial information that is customarily treated
[[Page 15671]]
as private, that you actually treat as private, and that is relevant or
responsive to this NPRM, it is important that you clearly designate the
submitted comments as CBI. Please mark each page of your submission
containing CBI as ``PROPIN.'' The FAA will treat such marked
submissions as confidential under the FOIA, and they will not be placed
in the public docket of this NPRM. Submissions containing CBI should be
sent to Mehdi Lamnyi, Aviation Safety Engineer, FAA, 2200 South 216th
Street, Des Moines, WA 98198. Any commentary that the FAA receives
which is not specifically designated as CBI will be placed in the
public docket for this rulemaking.
Background
The FAA issued AD 2023-23-12, Amendment 39-22614 (88 FR 85836,
December 11, 2023), (AD 2023-23-12), for all CFM Model LEAP-1B engines.
AD 2023-23-12 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. AD 2023-23-12
requires replacing certain HPT rotor stage 1 disks and a certain
compressor rotor stages 6-10 spool. The agency issued AD 2023-23-12 to
prevent fracture and subsequent uncontained failure of certain HPT
rotor stage 1 disks and a certain compressor rotor stages 6-10 spool.
Actions Since AD 2023-23-12 Was Issued
Since the FAA issued AD 2023-23-12, the manufacturer has identified
additional affected HPT rotor stage 1 disks that were manufactured from
material suspected to have reduced material properties due to iron
inclusion. This condition, if not addressed, could result in
uncontained debris release, damage to the engine, and damage to the
aircraft.
FAA's Determination
The FAA is issuing this NPRM after determining that the unsafe
condition described previously is likely to exist or develop on other
products of the same type design.
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.
Proposed AD Requirements in This NPRM
This proposed AD would retain all of the requirements of AD 2023-
23-12. This proposed AD would require replacement of certain HPT rotor
stage 1 disks and a certain compressor rotor stages 6-10 spool. This
proposed AD would also 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.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 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 proposed
AD:
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 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.
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The new requirements of this proposed 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.
Regulatory Findings
The FAA determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 the proposed
regulation:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Would not affect intrastate aviation in Alaska, and
(3) Would 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.
[[Page 15672]]
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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 2023-23-12, Amendment 39-22614 (88
FR 85836, December 11, 2023); and
0
b. Adding the following new airworthiness directive:
CFM International, S.A.: Docket No. FAA-2025-0621; Project
Identifier AD-2024-00796-E.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by May 30, 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. Information may be
emailed 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].
(2) Service material identified in this AD that is not
incorporated by reference is available at the addresses specified in
paragraphs (n)(5) and (6) 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 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
[[Page 15673]]
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 April 10, 2025.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft
Certification Service.
[FR Doc. 2025-06382 Filed 4-14-25; 8:45 am]
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