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

[Federal Register Volume 88, Number 97 (Friday, May 19, 2023)]
[Rules and Regulations]
[Pages 32092-32094]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-10763]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-0653; Project Identifier AD-2023-00280-E; 
Amendment 39-22429; AD 2023-09-06]
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 (LEAP-1A) model 
turbofan engines. This AD was prompted by a manufacturer investigation 
that revealed that certain high-pressure turbine (HPT) rotor stage 1 
disks (HPT stage 1 disks), forward outer seals, and compressor rotor 
stages 6-10 spools were manufactured from material suspected to have 
reduced material properties due to iron inclusion. This AD requires 
replacement of certain HPT stage 1 disks, forward outer seals, and 
compressor rotor stages 6-10 spools. The FAA is issuing this AD to 
address the unsafe condition on these products.

DATES: This AD is effective June 23, 2023.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of June 23, 
2023.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov by 
searching for and locating Docket No. FAA-2023-0653; 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 service information identified in this final rule, 
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].
    <bullet> 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 regulations.gov by searching for and locating Docket 
No. FAA-2023-0653.

FOR FURTHER INFORMATION CONTACT: Mehdi Lamnyi, Aviation Safety 
Engineer, Continued Operational Safety Branch, FAA, 2200 South 216th 
St., 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 by adding an AD that would apply to all CFM LEAP-1A model 
turbofan engines. The NPRM published in the Federal Register on March 
24, 2023 (88 FR 17753). The NPRM was prompted by notification from the 
manufacturer that iron inclusion was detected in three non-LEAP-1A HPT 
rotor disks. Further investigation by the manufacturer determined that 
the iron inclusion is attributed to deficiencies in the manufacturing 
process. The investigation by the manufacturer also determined that 
certain CFM LEAP-1A HPT stage 1 disks, forward outer seals, and 
compressor rotor stages 6-10 spools manufactured using the same process 
may have reduced material properties and a lower fatigue life 
capability due to iron inclusion, which may cause premature fracture 
and subsequent uncontained failure of certain HPT stage 1 disks, 
forward outer seals, and compressor rotor stages 6-10 spools. In the 
NPRM, the FAA proposed to require replacement of certain HPT stage 1 
disks, forward outer seals, and compressor rotor stages 6-10 spools. 
The FAA also proposed to prohibit installation of an HPT stage 1 disk, 
forward outer seal, or compressor rotor stages 6-10 spool that has a 
part number and serial number identified in the service information 
onto any engine. The FAA is issuing this AD to address the unsafe 
condition on these products.

Discussion of Final Airworthiness Directive

Comments

    The FAA received one comment, from Air Line Pilots Association, 
International (ALPA). ALPA supported the NPRM without change.

[[Page 32093]]

Additional Changes Made to This Final Rule

    Since the NPRM published, the FAA determined the need to change a 
part name in the final rule from ``stages 6-10 compressor rotor spool'' 
to ``compressor rotor stages 6-10 spool,'' to make the nomenclature 
consistent with the service information. The FAA has revised this final 
rule to incorporate this change.

Conclusion

    The FAA reviewed the relevant data, considered the 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, 
including the change described above and a change to the contact 
address for service information, 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 issued by CFM, 
which identify the part numbers and serial numbers of HPT stage 1 
disks, forward outer seals, and compressor rotor stages 6-10 spools 
with potentially reduced material properties and specify procedures for 
replacement of these parts. These documents are distinct since they 
apply to different engine serial numbers.
    <bullet> Service Bulletin LEAP-1A-72-00-0470-01A-930A-D, Issue 003, 
dated March 3, 2023.
    <bullet> Service Bulletin LEAP-1A-72-00-0493-01A-930A-D, Issue 002, 
dated November 17, 2022.
    <bullet> Service Bulletin LEAP-1A-72-00-0496-01A-930A-D, Issue 001, 
dated March 7, 2023.
    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 the ADDRESSES section.

Costs of Compliance

    The FAA estimates that this AD affects 38 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
----------------------------------------------------------------------------------------------------------------
Replace HPT stage 1 disk (38        8 work-hours x $85     $215,635 (pro-rated).        $216,315      $8,219,970
 affected parts).                    per hour = $680.
Replace forward outer seal (24      8 work-hours x $85     $47,500 (pro-rated)..          48,180       1,156,320
 affected parts).                    per hour = $680.
Replace compressor rotor stages 6-  8 work-hours x $85     $37,660 (pro-rated)..          38,340         575,100
 10 spool (15 affected parts).       per hour = $680.
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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:

2023-09-06 CFM International, S.A.: Amendment 39-22429; Docket No. 
FAA-2023-0653; Project Identifier AD-2023-00280-E.

(a) Effective Date

    This airworthiness directive (AD) is effective June 23, 2023.

(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; 7250, Turbine Section.

(e) Unsafe Condition

    This AD was prompted by a manufacturer investigation that 
revealed that certain HPT stage 1 disks, forward outer seals, and 
compressor rotor stages 6-10 spools were manufactured from material 
suspected to have reduced material properties due to iron inclusion. 
The FAA is issuing this AD to

[[Page 32094]]

prevent fracture and subsequent uncontained failure of certain high-
pressure turbine (HPT) stage 1 disks, forward outer seals, and 
compressor rotor stages 6-10 spools. 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) Required Actions

    (1) For engines with an installed HPT stage 1 disk, forward 
outer seal, or compressor rotor stages 6-10 spool having a part 
number (P/N) and serial number (S/N) identified in Compliance, 
paragraph 3.E., Tables 1 through 9, of CFM Service Bulletin (SB) 
LEAP-1A-72-00-0496-01A-930A-D, Issue 001, dated March 7, 2023 (CFM 
SB LEAP-1A-72-00-0496-01A-930A-D): At the next piece-part exposure 
of the HPT stage 1 disk, forward outer seal, or compressor rotor 
stages 6-10 spool, as applicable, or before exceeding the applicable 
cycles since new (CSN) threshold identified in Compliance, paragraph 
3.E., Tables 1 through 9, of CFM SB LEAP-1A-72-00-0496-01A-930A-D, 
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 flight cycles (FCs) from the effective 
date of this AD; remove the HPT stage 1 disk, forward outer seal, or 
compressor rotor stages 6-10 spool, as applicable, from service and 
replace with a part eligible for installation.
    (2) For engines with an installed forward outer seal having a P/
N and S/N identified in Compliance, paragraph 3.E., Tables 1 through 
2, of CFM SB LEAP-1A-72-00-0470-01A-930A-D, Issue 003, dated March 
3, 2023 (CFM SB LEAP-1A-72-00-0470-01A-930A-D): At the next piece-
part exposure of the forward outer seal, or before exceeding the 
applicable CSN threshold identified in Compliance, paragraph 3.E., 
Tables 1 through 2, of CFM SB LEAP-1A-72-00-0470-01A-930A-D, 
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 forward outer seal from service and replace with a part 
eligible for installation.
    (3) For engines with an installed HPT stage 1 disk having a P/N 
and S/N identified in Compliance, paragraph 3.E., Tables 1 through 
2, of CFM SB LEAP-1A-72-00-0493-01A-930A-D, Issue 002, dated 
November 17, 2022 (CFM SB LEAP-1A-72-00-0493-01A-930A-D): At the 
next piece-part exposure of the HPT stage 1 disk, or before 
exceeding the applicable CSN threshold identified in Compliance, 
paragraph 3.E., Tables 1 through 2, of CFM SB LEAP-1A-72-00-0493-
01A-930A-D, 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 stage 1 disk from service and replace with a 
part eligible for installation.

(h) Definition

    For the purpose of this AD, a ``part eligible for installation'' 
is an HPT stage 1 disk, forward outer seal, or compressor rotor 
stages 6-10 spool that does not have a P/N and S/N identified in the 
service information listed in paragraphs (g)(1) through (3) of this 
AD.

(i) Installation Prohibition

    After the effective date of this AD, do not install an HPT stage 
1 disk, forward outer seal, or compressor rotor stages 6-10 spool 
that has a P/N and S/N identified in the service information listed 
in paragraphs (g)(1) through (3) of this AD on any engine.

(j) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, 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 certification office, send it to the 
attention of the person identified in paragraph (k) 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.

(k) Related Information

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

(l) 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 International, S.A. Service Bulletin LEAP-1A-72-00-0470-
01A-930A-D, Issue 003, dated March 3, 2023.
    (ii) CFM International, S.A. Service Bulletin LEAP-1A-72-00-
0493-01A-930A-D, Issue 002, dated November 17, 2022.
    (iii) CFM International, S.A. Service Bulletin LEAP-1A-72-00-
0496-01A-930A-D, Issue 001, dated March 7, 2023.
    (3) For service information 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].
    (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: www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on May 8, 2023.
Michael Linegang,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2023-10763 Filed 5-18-23; 8:45 am]
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