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

[Federal Register Volume 87, Number 169 (Thursday, September 1, 2022)]
[Rules and Regulations]
[Pages 53651-53654]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-18923]



[[Page 53651]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-0160; Project Identifier AD-2022-00009-E; 
Amendment 39-22150; AD 2022-17-12]
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 
certain CFM International, S.A. (CFM) LEAP-1A model turbofan engines. 
This AD was prompted by reports of two in-flight shutdowns (IFSDs) and 
subsequent investigation by the manufacturer that revealed cracks in 
the high-pressure turbine (HPT) rotor stage 1 blades. This AD requires 
initial and repetitive borescope inspections (BSIs) of the HPT rotor 
stage 1 blades. Depending on the results of the BSIs, this AD requires 
either additional BSIs at reduced intervals or replacement of the HPT 
rotor stage 1 blades. This AD also requires sending the inspection 
results to CFM if any unserviceable finding is found. The FAA is 
issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective October 6, 2022.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of October 6, 
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 www.regulations.gov by searching for and locating 
Docket No. FAA-2022-0160.

Examining the AD Docket

    You may examine the AD docket at www.regulations.gov by searching 
for and locating Docket No. FAA-2022-0160; 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 certain 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. The NPRM published in the 
Federal Register on March 21, 2022 (87 FR 15896). The NPRM was prompted 
by reports of two single-engine IFSDs on airplanes powered by LEAP-1A 
model turbofan engines, operating extensively in the Middle East and 
North Africa (MENA) region. A post-flight BSI of the HPT module 
revealed that the engine failures were due to cracks in the HPT rotor 
stage 1 blades. After investigation, the manufacturer determined that 
engines operating in the MENA region are susceptible to accelerated HPT 
rotor stage 1 blade deterioration and airfoil distress due to the 
build-up of dust. In the NPRM, the FAA proposed to require initial and 
repetitive BSIs of the HPT rotor stage 1 blades and HPT stator stage 1 
nozzle set and, depending on the results of the inspections, additional 
BSIs at reduced intervals or replacement of the HPT rotor stage 1 
blades or HPT stator stage 1 nozzle set. In the NPRM, the FAA proposed 
to require a BSI of the HPT rotor stage 1 blades and HPT stator stage 1 
nozzle set installed on the sister engine of the same airplane if 
certain criteria are met. In the NPRM, the FAA also proposed to require 
sending the inspection results to CFM if any unserviceable finding is 
found. 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. The commenters 
were Air Line Pilots Association, International (ALPA), CFM, and an 
individual commenter. The following presents the comments received on 
the NPRM and the FAA's response to each comment.

Support for the AD

    ALPA expressed support for the AD as written.

Use of a Proprietary Ground Operation System as an Alternate Means of 
Compliance

    An individual commenter stated that using a specific ground 
operation taxi system could provide an alternate means of compliance 
for this AD. The commenter reasoned that limiting engine operation 
during ground operations would increase the interval between 
inspections from 150 cycles to 450 cycles and from 300 cycles to 900 
cycles. The commenter also stated that use of this ground operation 
taxi system would reduce costs on operators, result in fuel burn 
reduction, and reduce carbon emissions.
    The FAA did not change this AD as a result of this comment. The 
compliance timing for the actions required by this AD are based on the 
accumulated number of takeoffs and flight cycles, not on engine 
operating hours. In addition, it has not been demonstrated that 
variation in operation of the engine on the ground and during taxi has 
any impact on the unsafe condition addressed by this AD.

Availability of Revised Service Information

    CFM commented that revised service information, CFM Service 
Bulletin (SB) LEAP-1A-72-00-0461-01A-930A-D, Issue 003-00, dated July 
13, 2022, has been published. CFM identified that this revised service 
information removes references to the HPT stator stage 1 nozzle set, 
adds an inspection credit for the engines for which the conditional 
inspection of the sister engine installed on the same airplane is 
applicable, updates the BSI guidance for the HPT stator stage 1 blades, 
and removes the requirement to share all videos and images with CFM.
    In response to this comment, the FAA revised this AD to reference 
CFM SB LEAP-1A-72-00-0461-01A-930A-D, Issue 003-00, dated July 13, 
2022. The FAA also removed all references to the HPT stator stage 1 
nozzle set and associated SB paragraph references as proposed in the 
NPRM. The FAA has also added paragraph (i), Credit for Previous 
Actions, to this AD to provide credit for the initial BSI required by 
paragraph (g)(1)(i) or (2)(i) of this AD if the initial BSI was 
performed before the

[[Page 53652]]

effective date of this AD using CFM SB LEAP-1A-72-00-0461-01A-930A-D, 
Issue 002-00, dated December 21, 2021.

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 SB LEAP-1A-72-00-0461-01A-930A-D, Issue 003-
00, dated July 13, 2022. This service information specifies procedures 
for performing a BSI of the HPT rotor stage 1 blades for LEAP-1A model 
turbofan engines operating in the MENA region, performing all 
applicable corrective actions, and reporting any unserviceable HPT 
rotor stage 1 blade findings to CFM.
    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.

Interim Action

    The FAA considers this AD to be an interim action. The inspection 
reports that are required by this final rule will enable the 
manufacturer to obtain better insight into the nature, cause, and 
extent of the cracking, and eventually to develop final action to 
address the unsafe condition. Once final action has been identified, 
the FAA might consider additional rulemaking.

Costs of Compliance

    The FAA estimates that this AD affects 0 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
----------------------------------------------------------------------------------------------------------------
BSI the HPT rotor stage 1 blades....  4 work-hours x $85 per               $0             $340               $0
                                       hour = $340.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary reporting 
and replacements that would be required based on the results of the 
inspection. The agency has no way of determining the number of aircraft 
that might need these replacements:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replace the HPT rotor stage 1 blades..........  150 work-hours x $85 per hour =         $988,200      $1,000,950
                                                 $12,750.
BSI the HPT rotor stage 1 blades (on the        4 work-hours x $85 per hour =                  0             340
 sister engine).                                 $340.
Report BSI results to CFM.....................  1 work-hour x $85 per hour = $85               0              85
----------------------------------------------------------------------------------------------------------------

Paperwork Reduction Act

    A federal agency may not conduct or sponsor, and a person is not 
required to respond to, nor shall a person be subject to a penalty for 
failure to comply with a collection of information subject to the 
requirements of the Paperwork Reduction Act unless that collection of 
information displays a currently valid OMB Control Number. The OMB 
Control Number for this information collection is 2120-0056. Public 
reporting for this collection of information is estimated to take 
approximately 1 hour per response, including the time for reviewing 
instructions, searching existing data sources, gathering and 
maintaining the data needed, and completing and reviewing the 
collection of information. All responses to this collection of 
information are mandatory. Send comments regarding this burden estimate 
or any other aspect of this collection of information, including 
suggestions for reducing this burden to: Information Collection 
Clearance Officer, Federal Aviation Administration, 10101 Hillwood 
Parkway, Fort Worth, TX 76177-1524.

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.

[[Page 53653]]

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:

2022-17-12 CFM International, S.A.: Amendment 39-22150; Docket No. 
FAA-2022-0160; Project Identifier AD-2022-00009-E.

(a) Effective Date

    This airworthiness directive (AD) is effective October 6, 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 with an installed high-pressure 
turbine (HPT) rotor stage 1 blade, having part number (P/N) 
2747M92P01, P/N 2553M91G03, P/N 2553M91G05, P/N 2553M91G06, P/N 
2553M91G07, or P/N 2553M91G08 that has accumulated more than 800 
Middle East and North Africa (MENA) takeoffs.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7250, Turbine 
Section.

(e) Unsafe Condition

    This AD was prompted by reports of two in-flight shutdowns and 
subsequent investigation by the manufacturer that revealed cracks in 
the HPT rotor stage 1 blades. The FAA is issuing this AD to prevent 
failure of the HPT rotor stage 1 blades. The unsafe condition, if 
not addressed, could result in failure of the engine, in-flight 
shutdown, loss of thrust control, and loss of the airplane.

(f) Compliance

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

(g) Required Actions

    (1) Group 1 Engines: Borescope Inspection (BSI) of HPT Rotor 
Stage 1 Blades
    For Group 1 engines with an affected HPT rotor stage 1 blade 
installed:
    (i) Within 100 flight cycles (FCs) after accumulating 800 MENA 
takeoffs on the HPT rotor stage 1 blade, before the HPT rotor stage 
1 blade accumulates 1,750 cycles since new (CSN), or within 100 FCs 
after the effective date of this AD, whichever occurs later, perform 
an initial BSI of the HPT rotor stage 1 blades in accordance with 
the Accomplishment Instructions, paragraphs 5.E.(1)(c), of CFM 
Service Bulletin LEAP-1A-72-00-0461-01A-930A-D, Issue 003-00, dated 
July 13, 2022 (the SB).
    (ii) Thereafter, at intervals not to exceed 150 FCs since the 
last BSI, perform a repetitive BSI of the HPT rotor stage 1 blades 
in accordance with the Accomplishment Instructions, paragraphs 
5.E.(1)(c), of the SB.
    (2) Group 2 Engines: BSI of HPT Rotor Stage 1 Blades
    For Group 2 engines with an affected HPT rotor stage 1 blade 
installed:
    (i) Within 100 FCs after accumulating 800 MENA takeoffs on the 
HPT rotor stage 1 blade, before the HPT rotor stage 1 blade 
accumulates 2,600 CSN, or within 100 FCs after the effective date of 
this AD, whichever occurs later, perform an initial BSI of the HPT 
rotor stage 1 blades in accordance with the Accomplishment 
Instructions, paragraphs 5.E.(1)(c), of the SB.
    (ii) Thereafter, at intervals not to exceed 300 FCs since the 
last BSI, perform a repetitive BSI of the HPT rotor stage 1 blades 
in accordance with the Accomplishment Instructions, paragraphs 
5.E.(1)(c), of the SB.
    (3) BSI Results Disposition
    Based on the results of the BSI required by paragraph (g)(1) or 
(2) of this AD, as applicable, either re-inspect or replace the HPT 
rotor stage 1 blades set using the criteria, compliance times, and 
procedures referenced in the Accomplishment Instructions, paragraph 
5.E.(1)(f), of the SB.
    (4) Conditional Inspection of the Sister Engine on the Same 
Airplane
    (i) Based on the BSI results disposition required by paragraph 
(g)(3) of this AD, if re-inspection or replacement of the HPT rotor 
stage 1 is required within 50 FCs based on the criteria, compliance 
times, and procedures referenced in the Accomplishment Instructions, 
paragraph 5.E.(1)(f), of the SB, then perform the actions required 
in paragraph (g)(4)(ii) of this AD.
    (ii) Within 5 FCs after performing the inspection required by 
paragraph (g)(1) or (2) of this AD, as applicable, either inspect or 
replace the HPT rotor stage 1 blades on the sister engine using the 
procedures and compliance times in the Accomplishment Instructions, 
paragraph 5.E.(1)(g), of the SB. Where the SB specifies to remove 
the engine, this AD requires replacement of the HPT rotor stage 1 
blades.
    (5) Reporting Requirements
    If, during any inspection required by paragraph (g)(1), (2), 
(3), or (4) of this AD, as applicable, any HPT unserviceable finding 
is found on an engine as identified in the Accomplishment 
Instructions, paragraph 5.E.(1)(f) of the SB, within 30 days of 
performing the inspection, report the HPT rotor stage 1 blade 
unserviceable finding to CFM in accordance with the Accomplishment 
Instructions, paragraph 5.E.(1)(f)1, of the SB.

    Note 1 to paragraph (g):  The Accomplishment Instructions in 
paragraph 5.E.(1)(f) of the SB reference applicable aircraft 
maintenance manual tasks for procedures and compliance times for the 
actions required by paragraphs (g)(3) through (5) of this AD.

(h) Definitions

    (1) Group 1 engines are CFM LEAP-1A29, LEAP-1A29CJ, LEAP-1A30, 
LEAP-1A32, LEAP-1A33, LEAP-1A33B2, and LEAP-1A35A model turbofan 
engines.
    (2) Group 2 engines are CFM LEAP-1A23, LEAP-1A24, LEAP-1A24E1, 
LEAP-1A26, LEAP-1A26CJ, and LEAP-1A26E1 model turbofan engines.
    (3) For the purpose of this AD, a ``MENA takeoff'' is any 
takeoff accomplished in the MENA region, as defined in the Planning 
Information, paragraph 3.D., of the SB.
    (4) For the purpose of this AD, ``sister engine'' refers to the 
other engine installed on the same airplane.

(i) Credit for Previous Actions

    You may take credit for the initial BSI required by paragraph 
(g)(1)(i) or (2)(i) of this AD if you performed the initial BSI 
before the effective of this AD using CFM Service Bulletin LEAP-1A-
72-00-0461-01A-930A-D, Issue 002-00, December 21, 2021.

(j) 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 (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, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; 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 Service Bulletin LEAP-1A-72-00-0461-01A-930A-D, Issue 
003-00, dated July 13, 2022.
    (ii) [Reserved]
    (3) For service information identified in this AD, contact CFM 
International, S.A.,

[[Page 53654]]

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: www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on August 12, 2022.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2022-18923 Filed 8-31-22; 8:45 am]
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