[Federal Register Volume 88, Number 140 (Monday, July 24, 2023)]
[Proposed Rules]
[Pages 47404-47407]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-15378]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-1216; Project Identifier AD-2023-00502-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 adopt a new airworthiness directive (AD) 
for 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. This 
proposed AD was prompted by a manufacturer investigation that revealed 
that certain high-pressure turbine (HPT) rotor stage 1 disks (HPT 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. This proposed AD would require 
replacement of certain HPT stage 1 disks and a certain compressor rotor 
stages 6-10 spool. 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 September 
7, 2023.

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-

[[Page 47405]]

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 by 
searching for and locating Docket No. FAA-2023-1216; 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 service information identified in this NPRM, 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].
     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.

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 ADDRESSES. Include ``Docket No. FAA-2023-1216; Project Identifier 
AD-2023-00502-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 amend 
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 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 was notified by the manufacturer of the detection of iron 
inclusion in three non-LEAP-1B 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 LEAP-1B HPT stage 1 disks and 
a certain compressor rotor stages 6-10 spool 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 and a certain compressor rotor stages 6-10 spool. 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.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed CFM Service Bulletin LEAP-1B-72-00-0392-01A-930A-
D, Issue 001, dated March 7, 2023. This service information identifies 
the part numbers and serial numbers of HPT stage 1 disks and a 
compressor rotor stages 6-10 spool with potentially reduced material 
properties and specifies procedures for replacement of these parts. 
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.

Proposed AD Requirements in This NPRM

    This proposed AD would require replacement of certain HPT stage 1 
disks and a certain compressor rotor stages 6-10 spool. This proposed 
AD would also prohibit installation of an HPT stage 1 disk or 
compressor rotor stages 6-10 spool that has a part number and serial 
number identified in the service information onto any engine.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 39 engines installed on airplanes of U.S. registry. These 39 
engines would require replacement of the HPT stage 1 disk. The FAA 
estimates that there are no engines installed on airplanes of U.S. 
registry that would require replacement of the compressor rotor stages 
6-10 spool.
    The FAA estimates the following costs to comply with this proposed 
AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
              Action                      Labor cost             Parts cost           product        operators
----------------------------------------------------------------------------------------------------------------
Replace HPT stage 1 disk..........  8 work-hours x $85     $215,635 (pro-rated).        $216,315      $8,436,285
                                     per hour = $680.
Replace compressor rotor stages 6-  8 work-hours x $85     $37,660 (pro-rated)..          38,340               0
 10 spool.                           per hour = $680.
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[[Page 47406]]

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 this 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.

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 adding the following new airworthiness 
directive:

CFM International, S.A.: Docket No. FAA-2023-1216; Project 
Identifier AD-2023-00502-E.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by September 7, 2023.

(b) Affected ADs

    None.

(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 (HPT 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 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) Required Actions

    (1) For engines with an installed HPT 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 001, dated March 7, 2023 (CFM 
SB LEAP-1B-72-00-0392-01A-930A-D): At the next piece-part exposure 
of the HPT 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, 
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 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: 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, 
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 compressor rotor stages 6-10 spool 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 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.

(i) Installation Prohibition

    After the effective date of this AD, do not install an HPT 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.

(j) 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 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, FAA, 2200 South 216th Street, 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-1B-72-00-0392-
01A-930A-D, Issue 001, dated March 7, 2023.
    (ii) [Reserved]
    (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].

[[Page 47407]]

    (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 June 12, 2023.
Ross Landes,
Deputy Director for Regulatory Operations, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2023-15378 Filed 7-21-23; 8:45 am]
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