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

[Federal Register Volume 87, Number 94 (Monday, May 16, 2022)]
[Rules and Regulations]
[Pages 29651-29654]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-10447]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-1183; Project Identifier AD-2021-01193-E; 
Amendment 39-22029; AD 2022-09-09]
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-1A23, LEAP-1A24, LEAP-1A24E1, LEAP-
1A26, LEAP-1A26CJ, LEAP-1A26E1, LEAP-1A29, LEAP-1A29CJ, LEAP-1A30, 
LEAP-1A32, LEAP-1A33, LEAP-1A33B2, and LEAP-1A35A 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 interstage seals, 
HPT rotor stage 2 disks, low pressure turbine (LPT) stage 1 disks, LPT 
stage 2 disks, LPT stage 3 disks, and LPT stage 4 disks. This AD 
requires revising the airworthiness limitations section (ALS) of the 
applicable CFM LEAP-1A Engine Shop Manual (ESM) and the operator's 
existing approved continuous airworthiness maintenance program (CAMP) 
to incorporate reduced life limits for these parts. This AD also 
requires the removal of certain LPT stage 4 disks identified by serial 
number (S/N) prior to their new life limits. The FAA is issuing this AD 
to address the unsafe condition on these products.

DATES: This AD is effective June 21, 2022.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of June 21, 
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-2021-1183.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-1183; 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; fax: (781) 238-7199; 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-1A23, 
LEAP-1A24, LEAP-1A24E1, LEAP-1A26, LEAP-1A26CJ, LEAP-1A26E1, LEAP-1A29, 
LEAP-1A29CJ, LEAP-1A30, LEAP-1A32, LEAP-1A33, LEAP-1A33B2, and LEAP-
1A35A model turbofan engines. The NPRM published

[[Page 29652]]

in the Federal Register on January 18, 2022 (87 FR 2563). The NPRM was 
prompted by the manufacturer's detection of melt-related freckles in 
the billet, which may reduce the life of certain compressor rotor 
stages 6-10 spools, HPT rotor interstage seals, HPT rotor stage 2 
disks, LPT stage 1 disks, LPT stage 2 disks, LPT stage 3 disks, and LPT 
stage 4 disks (life-limited parts (LLPs)). Through the manufacturer's 
investigation, it was determined that these LLPs may have subsurface 
anomalies that developed during the manufacturing process, resulting in 
a lower life capability. In the NPRM, the FAA proposed to require 
revising the ALS of the CFM LEAP-1A ESM, as applicable to each affected 
engine model, and the operator's existing approved CAMP to incorporate 
reduced life limits for certain LLPs. In the NPRM, the FAA also 
proposed to require operators to remove certain LPT stage 4 disks, 
identified by S/N, before reaching their new life limits. The LPT stage 
4 disks, identified by S/N in Figure 1 to paragraph (g)(2) of the NPRM, 
were discovered by the manufacturer after publication of the ALS 
revision.
    After the NPRM was issued, CFM revised its service information by 
including additional part numbers for newly manufactured parts that did 
not exist prior to NPRM publication. Accordingly, the FAA has revised 
paragraph (g)(1)(iii) of this AD to require operators to update the ALS 
of the applicable CFM LEAP-1A ESM and the operator's existing approved 
CAMP to include CFM Low Pressure Turbine Rotor Life Limits LEAP 1A-05-
11-04-01A-0B1B-C, Issue 010-00, dated February 15, 2022, instead of CFM 
Low Pressure Turbine Rotor Life Limits LEAP 1A-05-11-04-01A-0B1B-C, 
Issue 009-00, dated June 1, 2021.
    The FAA has also added a credit for previous actions paragraph to 
this AD, providing credit to operators that incorporated CFM Low 
Pressure Turbine Rotor Life Limits LEAP 1A-05-11-04-01A-0B1B-C, Issue 
009-00, dated June 1, 2021, into the ALS of the applicable ESM and the 
operator's existing approved CAMP prior to the effective date of this 
AD.
    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 two commenters. The commenters were 
American Airlines (AA) and Air Line Pilot Association, International 
(ALPA). The following presents the comments received on the NPRM and 
the FAA's response to each comment.

Request To Include Future Revisions to ESM

    AA requested that the FAA add `` . . . or later'' to the following 
ALS references in paragraph (g) of this AD to allow for the use of 
future revisions;
    (i) CFM High Pressure Compressor Rotor Life Limits LEAP 1A-05-11-
02-01A-0B1B-C, Issue 010-00, dated September 15, 2021, or later;
    (ii) CFM High Pressure Turbine Rotor Life Limits LEAP 1A-05-11-03-
01A-0B1B-C, Issue 007-00, dated September 15, 2021, or later; and
    (iii) CFM Low Pressure Turbine Rotor Life Limits LEAP 1A-05-11-04-
01A-0B1B-C, Issue 009-00, dated June 1, 2021, or later.
    AA stated that they are currently using Issues 7, 9, and 10 of the 
referenced service information and their ALS and CAMP are already in 
compliance with this AD. AA also stated that CFM continues to update 
the referenced service information and Issues 7, 9, and 10 will be 
further revised. As a result, the requirements of this AD will cause AA 
to use outdated service information.
    The FAA disagrees with adding ``or later'' when referencing the 
service information in paragraph (g) of this AD. Future revisions of 
the service information have not yet been published by the manufacturer 
or reviewed by the FAA. 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 Add Credit for Previous Actions

    AA requested that the FAA add a new paragraph (h)(3) to this AD to 
allow credit for previous actions associated with the required actions 
proposed in paragraph (g)(1)(iii) of the NPRM, similar to the credit 
paragraphs proposed in (h)(1) and (h)(2) of the NPRM. AA requested that 
the new paragraph (h)(3) provide credit to operators if CFM Low 
Pressure Turbine Rotor Life Limits LEAP 1A-05-11-04-01A-0B1B-C, Issue 
008-00 was incorporated into the ALS of the applicable ESM and the 
operator's existing approved CAMP prior to the effective date of this 
AD.
    The FAA notes that CFM Low Pressure Turbine Rotor Life Limits LEAP 
1A-05-11-04-01A-0B1B-C, Issue 009-00, dated June 1, 2021, was the first 
issue of this service information to include the reduced life limits 
for that module as a result of the investigation into melt-related 
freckles in the billet. Issue 008-00 and earlier issues do not include 
the reduced life limits so the FAA will not provide credit for issues 
released prior to Issue 009-00. Since the FAA issued the NPRM, the 
manufacturer published CFM Low Pressure Turbine Rotor Life Limits LEAP 
1A-05-11-04-01A-0B1B-C, Issue 010-00, dated February 15, 2022. As a 
result, the FAA has added paragraph (h)(3) to this AD, providing credit 
for actions required by paragraph (g)(1)(iii) of this AD if CFM Low 
Pressure Turbine Rotor Life Limits LEAP 1A-05-11-04-01A-0B1B-C, Issue 
009-00, dated June 1, 2021, was incorporated into the ALS of the 
applicable ESM and the operator's existing approved CAMP prior to the 
effective date of this AD.

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 CFM High Pressure Compressor Rotor Life Limits 
LEAP 1A-05-11-02-01A-0B1B-C, Issue 010-00, dated September 15, 2021 
(CFM LEAP 1A-05-11-02-01A-0B1B-C); CFM High Pressure Turbine Rotor Life 
Limits LEAP 1A-05-11-03-01A-0B1B-C, Issue 007-00, dated September 15, 
2021 (CFM LEAP 1A-05-11-03-01A-0B1B-C); and CFM Low Pressure Turbine 
Rotor Life Limits LEAP 1A-05-11-04-01A-0B1B-C, Issue 010-00, dated 
February 15, 2022 (CFM LEAP 1A-05-11-04-01A-0B1B-C). CFM LEAP 1A-05-11-
02-01A-0B1B-C provides the new life limits for the high-pressure 
compressor, CFM LEAP 1A-05-11-03-01A-0B1B-C provides the new life 
limits for the HPT rotor, and CFM LEAP 1A-05-11-04-01A-0B1B-C

[[Page 29653]]

provides the new life limits for the LPT 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 LEAP 1A-05-11-02-01A-0B1B-C, Issue 009-00, 
dated July 26, 2021; CFM LEAP 1A-05-11-03-01A-0B1B-C, Issue 006-00, 
dated July 26, 2021, and CFM LEAP 1A-05-11-04-01A-0B1B-C, Issue 009, 
dated June 1, 2021. This service information provides the new life 
limits for the LLPs.
    The FAA also reviewed CFM Service Bulletin (SB) LEAP-1A-72-00-0413-
01A-930A-D, Issue 004-00, dated December 11, 2021 (CFM SB LEAP-1A-72-
00-0413-01A-930A-D). CFM SB LEAP-1A-72-00-0413-01A-930A-D specifies 
procedures for removing and replacing the LLPs, and provides new life 
limits for certain S/Ns of the LLPs.

Costs of Compliance

    The FAA estimates that this AD affects 256 engines installed on 
airplanes of U.S. registry. The FAA estimates that 256 engines 
installed on airplanes of U.S. registry require revising the ALS of the 
CFM LEAP-1A ESM and the operator's existing approved CAMP. The FAA 
estimates that zero airplanes of U.S. registry require replacement of 
the LPT stage 4 disk.
    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 Engine Manual and the     1 work-hour x $85 per                 $0             $85         $21,760
 operator's existing approved CAMP.      hour = $85.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to replace the LPT stage 4 
disk:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Replace LPT Stage 4 disk..............  225 work-hours x $85 per        $129,000        $148,125              $0
                                         hour = $19,125.
----------------------------------------------------------------------------------------------------------------

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:

2022-09-09 CFM International, S.A.: Amendment 39-22029; Docket No. 
FAA-2021-1183; Project Identifier AD-2021-01193-E.

(a) Effective Date

    This airworthiness directive (AD) is effective June 20, 2022.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to CFM International, S.A. (CFM) LEAP-1A23, 
LEAP-1A24, LEAP-1A24E1, LEAP-1A26, LEAP-1A26CJ, LEAP-1A26E1, LEAP-
1A29, LEAP-1A29CJ, LEAP-1A30, LEAP-1A32, LEAP-1A33, LEAP-1A33B2, and 
LEAP-1A35A 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 interstage 
seals, HPT rotor stage

[[Page 29654]]

2 disks, low pressure turbine (LPT) stage 1 disks, LPT stage 2 
disks, LPT stage 3 disks, and LPT stage 4 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

    (1) Within 60 days after the effective date of this AD, revise 
the airworthiness limitations section (ALS) of the applicable CFM 
LEAP-1A Engine Shop Manual (the ESM) and the operator's existing 
approved continuous airworthiness maintenance program (CAMP) by 
incorporating the following service information:
    (i) CFM High Pressure Compressor Rotor Life Limits LEAP 1A-05-
11-02-01A-0B1B-C, Issue 010-00, dated September 15, 2021; and
    (ii) CFM High Pressure Turbine Rotor Life Limits LEAP 1A-05-11-
03-01A-0B1B-C, Issue 007-00, dated September 15, 2021; and
    (iii) CFM Low Pressure Turbine Rotor Life Limits LEAP 1A-05-11-
04-01A-0B1B-C, Issue 010-00, dated February 15, 2022.
    (2) Before the LPT stage 4 disk, part number (P/N) 362-039-520-
0, with serial numbers identified in Figure 1 to paragraph (g)(2) of 
this AD (Figure 1) accumulates the cycles in Figure 1, or within 100 
cycles after the effective date of this AD, whichever occurs later, 
remove the affected LPT stage 4 disk from service and replace with a 
part eligible for installation.
[GRAPHIC] [TIFF OMITTED] TR16MY22.000

(h) Credit for Previous Actions

    (1) You may take credit for the action required by paragraph 
(g)(1)(i) of this AD if the following service information was 
incorporated into the ALS of the applicable ESM and the operator's 
existing approved CAMP prior to the effective date of this AD: CFM 
High Pressure Compressor Rotor Life Limits LEAP 1A-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)(1)(ii) of this AD if the following service information was 
incorporated into the ALS of the applicable ESM and the operator's 
existing approved CAMP prior to the effective date of this AD: CFM 
High Pressure Turbine Rotor Life Limits LEAP 1A-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)(1)(iii) of this AD if the following service information was 
incorporated into the ALS of the applicable ESM and the operator's 
existing approved CAMP prior to the effective date of this AD: CFM 
Low Pressure Turbine Rotor Life Limits LEAP 1A-05-11-04-01A-0B1B-C, 
Issue 009-00, dated June 1, 2021.

(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. You may email your request 
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; fax: (781) 238-7199; 
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 1A-05-
11-02-01A-0B1B-C, Issue 010-00, dated September 15, 2021.
    (ii) CFM High Pressure Turbine Rotor Life Limits LEAP 1A-05-11-
03-01A-0B1B-C, Issue 007-00, dated September 15, 2021.
    (iii) CFM Low Pressure Turbine Rotor Life Limits LEAP 1A-05-11-
04-01A-0B1B-C, Issue 010-00, dated February 15, 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 April 15, 2022.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2022-10447 Filed 5-13-22; 8:45 am]
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