Airworthiness Directives; CFM International, S.A. Turbofan Engines

[Federal Register Volume 87, Number 107 (Friday, June 3, 2022)]
[Rules and Regulations]
[Pages 33621-33623]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-11926]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-0094; Project Identifier AD-2021-01251-E; 
Amendment 39-22052; AD 2022-11-02]
RIN 2120-AA64


Airworthiness Directives; CFM International, S.A. Turbofan 
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 all 
CFM International, S.A. (CFM) LEAP-1B21, LEAP-1B23, LEAP-1B25, LEAP-
1B27, LEAP-1B28, LEAP-1B28B1, LEAP-1B28B2, LEAP-1B28B2C, LEAP-1B28B3, 
LEAP-1B28BBJ1, and LEAP-1B28BBJ2 model turbofan engines. This AD was 
prompted by the detection of melt-related freckles in the billet, which 
may reduce the life of certain compressor rotor stages 6-10 spools, 
high pressure turbine (HPT) rotor mid seals, HPT rotor stage 2 disks, 
low pressure turbine (LPT) stage 2 disks, and LPT stage 3 disks. This 
AD requires revising the airworthiness limitations section (ALS) of the 
applicable CFM LEAP-1B Engine Shop Manual (ESM), and the operator's 
existing approved maintenance or inspection program, as applicable, to 
incorporate reduced life limits for these parts. The FAA is issuing 
this AD to address the unsafe condition on these products.

DATES: This AD is effective July 8, 2022.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of July 8, 2022.

ADDRESSES: For service information identified in this final rule, 
contact CFM International, S.A., Aviation Operations Center, 1 Neumann 
Way, M/D Room 285, Cincinnati, OH 45125; phone: (877) 432-3272; email: 
[email protected]. You may view this service information 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 https://www.regulations.gov by searching for and 
locating Docket No. FAA-2022-0094.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2022-0094; 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.

FOR FURTHER INFORMATION CONTACT: Mehdi Lamnyi, Aviation Safety 
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; 
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 by adding an AD that would apply to all CFM LEAP-1B21, 
LEAP-1B23, LEAP-1B25, LEAP-1B27, LEAP-1B28, LEAP-1B28B1, LEAP-1B28B2, 
LEAP-1B28B2C, LEAP-1B28B3, LEAP-1B28BBJ1, and LEAP-1B28BBJ2 model 
turbofan engines. The NPRM published in the Federal Register on 
February 15, 2022 (87 FR 8434). The NPRM was prompted by the engine 
manufacturer notifying the FAA of the detection of melt-related 
freckles in the billet, which may reduce the life of certain compressor 
rotor stages 6-10 spools, HPT rotor mid seals, HPT rotor stage 2 disks, 
LPT stage 2 disks, and LPT stage 3 disks (life-limited parts (LLPs)). 
The manufacturer's investigation determined that, as a result of such 
freckles forming in the billet, these LLPs may have undetected 
subsurface anomalies that developed during the manufacturing process, 
resulting in reduced material properties and a lower fatigue life 
capability. Reduced material properties may cause premature LLP 
fracture, which could result in uncontained debris release. As a result 
of its investigation, the manufacturer determined the need to reduce 
the life limits of these LLPs. To reflect these reduced life limits, 
the manufacturer revised the CFM ALS, Chapter 05 of LEAP-1B ESM. 
Additionally, the manufacturer published service information that 
specifies procedures for the removal and replacement of these LLPs 
before reaching their new life limits. In the NPRM, the FAA proposed to 
require revising the ALS of the CFM LEAP-1B ESM, as applicable to each 
affected engine model, and the operator's existing approved maintenance 
or inspection program, as applicable, to incorporate reduced life 
limits for certain LLPs. 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 four commenters. The commenters were 
Air Line Pilots Association, International (ALPA), American Airlines 
(AA), CFM, and United Airlines (UAL). The following presents the 
comments received on the NPRM and the FAA's response to each comment.

Request To Update Service Information Revisions

    CFM requested that the FAA update the service information issue 
numbers and dates to reflect the current revisions.
    The FAA agrees and updated the service information issue numbers 
and dates throughout this AD. The FAA also added a Credit For Previous 
Actions paragraph to this AD, allowing operators to take credit for 
required actions if accomplished prior to the effective date of this AD 
using prior versions of the service information. This change imposes no 
additional burden on operators who are required to comply with this AD.

[[Page 33622]]

Request To Include Future Revisions to Service Information

    AA and UAL requested that the FAA revise the required actions of 
the AD to allow the use of future approved revisions of the specified 
service information. AA added that when the FAA publishes an AD that 
incorporates an EASA AD by reference, the EASA AD includes language 
stating the use of later revisions is acceptable for compliance. AA 
suggested that since the FAA already approves future approved revisions 
of documents that are incorporated by reference in a foreign AD, it is 
reasonable and logical that this FAA AD allows future approved 
revisions.
    The FAA disagrees with revising the required actions of this AD to 
allow for the use of future approved revisions of the service 
information. Future revisions of the service information have not yet 
been published by the manufacturer or reviewed by the FAA. In the case 
of a foreign AD incorporated by reference in an FAA AD, the service 
information referenced by EASA is a second-tier document. A request for 
an alternative method of compliance can be submitted to the FAA if 
future revisions of the service information referenced in paragraph (g) 
of this AD are published. Additionally, if future revisions of the 
service information are published by the manufacturer and approved by 
the FAA, the FAA may consider further rulemaking.

Request To Clarify the Intent of the AD

    AA requested the FAA clarify if the AD requires the incorporation 
of the LLP life limits in CFM Service Bulletin (SB) LEAP-1B-72-00-0342-
01A-930A-D, Issue 002-00, dated July 26, 2021 (CFM SB LEAP-1B-72-00-
0342-01A-930A-D), identified in Other Related Service Information, or 
if the AD requires revisions to the ESM.
    The FAA notes that this AD does not require any actions using CFM 
SB LEAP-1B-72-00-0342-01A-930A-D. This AD requires only revising the 
ALS of the applicable CFM LEAP-1B ESM, and the operator's existing 
approved maintenance or inspection program, as applicable, to 
incorporate reduced life limits for these parts using CFM High Pressure 
Compressor Rotor Life Limits LEAP-1B-05-11-02-01A-0B1B-C, Issue 010-00, 
dated March 17, 2022, CFM High Pressure Turbine Rotor Life Limits LEAP-
1B-05-11-03-01A-0B1B-C, Issue 007-00, dated March 17, 2022, and CFM Low 
Pressure Turbine Rotor Life Limits LEAP-1B-05-11-04-01A-0B1B-C, Issue 
008-00, dated February 16, 2022. The revised life limits include 
references to CFM SB LEAP-1B-72-00-0342-01A-930A-D for lists of 
specific part serial numbers.

Support for the AD

    ALPA expressed support for the AD as written.

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, and 
any other changes described previously, this AD is adopted as proposed 
in the NPRM. None of the changes will increase the economic burden on 
any operator.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed the following service information:
    <bullet> CFM High Pressure Compressor Rotor Life Limits LEAP-1B-05-
11-02-01A-0B1B-C, Issue 010-00, dated March 17, 2022 (CFM LEAP-1B-05-
11-02-01A-0B1B-C). CFM LEAP-1B-05-11-02-01A-0B1B-C provides the new 
life limits for the high pressure compressor rotor.
    <bullet> CFM High Pressure Turbine Rotor Life Limits LEAP-1B-05-11-
03-01A-0B1B-C, Issue 007-00, dated March 17, 2022 (CFM LEAP-1B-05-11-
03-01A-0B1B-C). CFM LEAP-1B-05-11-03-01A-0B1B-C provides the new limits 
for the high pressure turbine rotor.
    <bullet> CFM Low Pressure Turbine Rotor Life Limits LEAP-1B-05-11-
04-01A-0B1B-C, Issue 008-00, dated February 16, 2022 (CFM LEAP-1B-05-
11-04-01A-0B1B-C). CFM LEAP-1B-05-11-04-01A-0B1B-C provides the new 
life limits for the low pressure turbine rotor.
    This service information is reasonably available because the 
interested parties have access to it through their normal course of 
business or by the means identified in ADDRESSES.

Other Related Service Information

    The FAA reviewed CFM SB LEAP-1B-72-00-0342-01A-930A-D. CFM SB LEAP-
1B-72-00-0342-01A-930A-D specifies procedures for removing and 
replacing the LLPs, and provides new life limits for certain serial 
numbers of the LLPs.

Costs of Compliance

    The FAA estimates that this AD affects 378 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
----------------------------------------------------------------------------------------------------------------
Revise ALS of the ESM and the         1 work-hour x $85 per                $0              $85          $32,130
 operator's existing approved          hour = $85.
 maintenance or inspection program.
----------------------------------------------------------------------------------------------------------------

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:

[[Page 33623]]

    (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:

2022-11-02 CFM International, S.A.: Amendment 39-22052; Docket No. 
FAA-2022-0094; Project Identifier AD-2021-01251-E.

(a) Effective Date

    This airworthiness directive (AD) is effective July 8, 2022.

(b) Affected ADs

    None.

(c) Applicability

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

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by the detection of melt-related freckles 
in the billet, which may reduce the life of certain compressor rotor 
stages 6-10 spools, high pressure turbine (HPT) rotor mid seals, HPT 
rotor stage 2 disks, low pressure turbine (LPT) stage 2 disks, and 
LPT stage 3 disks. The FAA is issuing this AD to prevent the failure 
of the high pressure compressor, HPT rotor, and LPT rotor. The 
unsafe condition, if not addressed, could result in release of 
uncontained debris, 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

    Within 60 days after the effective date of this AD, revise the 
airworthiness limitations section (ALS) of the applicable CFM LEAP-
1B Engine Shop Manual (ESM) and the operator's existing approved 
maintenance or inspection program, as applicable, by incorporating 
the following service information:
    (1) CFM High Pressure Compressor Rotor Life Limits LEAP-1B-05-
11-02-01A-0B1B-C, Issue 010-00, dated March 17, 2022;
    (2) CFM High Pressure Turbine Rotor Life Limits LEAP-1B-05-11-
03-01A-0B1B-C, Issue 007-00, dated March 17, 2022; and
    (3) CFM Low Pressure Turbine Rotor Life Limits LEAP-1B-05-11-04-
01A-0B1B-C, Issue 008-00, dated February 16, 2022.

(h) Credit for Previous Actions

    (1) You may take credit for the action required by paragraph 
(g)(1) of this AD if the following service information was 
incorporated into the ALS of the applicable ESM and the operator's 
existing approved maintenance or inspection program, as applicable, 
prior to the effective date of this AD: CFM High Pressure Compressor 
Rotor Life Limits LEAP-1B-05-11-02-01A-0B1B-C, Issue 009-00, dated 
July 26, 2021.
    (2) You may take credit for the action required by paragraph 
(g)(2) of this AD if the following service information was 
incorporated into the ALS of the applicable ESM and the operator's 
existing approved maintenance or inspection program, as applicable, 
prior to the effective date of this AD: CFM High Pressure Turbine 
Rotor Life Limits LEAP-1B-05-11-03-01A-0B1B-C, Issue 006-00, dated 
July 26, 2021.
    (3) You may take credit for the action required by paragraph 
(g)(3) of this AD if the following service information was 
incorporated into the ALS of the applicable ESM and the operator's 
existing approved maintenance or inspection program, as applicable, 
prior to the effective date of this AD: CFM Low Pressure Turbine 
Rotor Life Limits LEAP-1B-05-11-04-01A-0B1B-C, Issue 006-00, dated 
June 1, 2021, or Issue 007, dated February 15, 2022.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, ECO 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 
certification office, 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 Mehdi Lamnyi, 
Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: (781) 238-7743; email: 
[email protected].

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) CFM High Pressure Compressor Rotor Life Limits LEAP-1B-05-
11-02-01A-0B1B-C, Issue 010-00, dated March 17, 2022.
    (ii) CFM High Pressure Turbine Rotor Life Limits LEAP-1B-05-11-
03-01A-0B1B-C, Issue 007-00, dated March 17, 2022.
    (iii) CFM Low Pressure Turbine Rotor Life Limits LEAP-1B-05-11-
04-01A-0B1B-C, Issue 008-00, dated February 16, 2022.
    (3) For service information identified in this AD, contact CFM 
International, S.A., Aviation Operations Center, 1 Neumann Way, M/D 
Room 285, Cincinnati, OH 45125; phone: (877) 432-3272; email: 
[email protected].
    (4) You may view this service information at 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 service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, email: [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on May 13, 2022.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2022-11926 Filed 6-2-22; 8:45 am]
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