[Federal Register Volume 87, Number 230 (Thursday, December 1, 2022)]
[Proposed Rules]
[Pages 73686-73688]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-26121]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-1422; Project Identifier AD-2022-01208-E]
RIN 2120-AA64


Airworthiness Directives; CFM International, S.A. Turbofan 
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 certain CFM International, S.A. (CFM) LEAP-1B turbofan engines. 
This proposed AD was prompted by a report of multiple aborted takeoffs 
and air turn-backs (ATBs) caused by high-pressure compressor (HPC) 
stall, which was induced by high levels of non-synchronous vibration 
(NSV). A subsequent investigation by the manufacturer revealed that 
wear on the No. 3 bearing spring finger housing can lead to high levels 
of NSV. This proposed AD would require repetitive calculations of the 
oil filter delta pressure (OFDP) data and, depending on the results of 
the calculation, replacement of the No. 3 bearing spring finger 
housing. This proposed AD would also prohibit installation of an engine 
with an affected No. 3 bearing spring finger housing onto an airplane 
that already has one engine with an affected No. 3 bearing spring 
finger housing installed. 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 January 17, 
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-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-2022-1422; 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 CFM service information identified in this NPRM, 
contact CFM International Inc., 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.

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:

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-2022-1422; Project Identifier 
AD-2022-01208-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

[[Page 73687]]

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, ECO Branch, FAA, 1200 District 
Avenue, Burlington, MA 01803. 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 engine manufacturer of three aborted 
takeoffs and two ATBs caused by HPC stall. A subsequent investigation 
by the manufacturer revealed that wear on the No. 3 bearing spring 
finger housing can lead to high levels of NSV, which could induce HPC 
stall. This wear manifests itself early on as higher than typical OFDP 
loading. As a result of its investigation, the manufacturer published 
service information that specifies procedures for calculating the OFDP 
data and replacing the affected No. 3 bearing spring finger housing. 
This condition, if not addressed, could result in engine power loss at 
a critical phase of flight such as takeoff or climb, loss of thrust 
control, reduced controllability of the airplane, and loss of the 
airplane.

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-72-00-0369-01A-930A-
D, Issue 001-00, dated August 22, 2022. This service information 
specifies procedures for calculating the OFDP data and replacing the 
affected No. 3 bearing spring finger housing. This service information 
also identifies the serial numbers of the affected No. 3 bearing spring 
finger housings installed on LEAP-1B turbofan engines. 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 a calculation of the OFDP data and, 
depending on the results of the calculation, replacement of the No. 3 
bearing spring finger housing. This proposed AD would also prohibit the 
installation of an engine with an affected No. 3 bearing spring finger 
housing onto an airplane that already has one engine with an affected 
No. 3 bearing spring finger housing installed.

Interim Action

    The FAA considers that this proposed AD would be an interim action. 
The design approval holder is currently developing a modification that 
will address the unsafe condition identified in this proposed AD. Once 
this modification is developed, approved, and available, the FAA might 
consider additional rulemaking.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 8 engines installed on airplanes of U.S. registry.
    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
----------------------------------------------------------------------------------------------------------------
Calculate OFDP data...................  1 work-hour x $85 per                 $0             $85            $680
                                         hour = $85.
Replace No. 3 bearing spring finger     17 work-hours x $85 per           64,590          66,035         528,280
 housing.                                hour = $1,445.
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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

    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.

[[Page 73688]]

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-2022-1422; Project 
Identifier AD-2022-01208-E.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by January 17, 2023.

(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 with an installed No. 3 bearing spring finger 
housing, part number (P/N) 2542M54G01, and serial number (S/N) 
identified in Table 1 of CFM Service Bulletin (SB) LEAP-1B-72-00-
0369-01A-930A-D, Issue 001-00, dated August 22, 2022 (CFM LEAP-1B-
72-00-0369-01A-930A-D).

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by a report of multiple aborted takeoffs 
and air turn-backs (ATBs) caused by high-pressure compressor (HPC) 
stall, which was induced by high levels of non-synchronous vibration 
(NSV), and a subsequent investigation by the manufacturer that 
revealed wear on the No. 3 bearing spring finger housing. The FAA is 
issuing this AD to prevent HPC stall. The unsafe condition, if not 
addressed, could result in engine power loss at a critical phase of 
flight such as takeoff or climb, loss of thrust control, reduced 
controllability of the airplane, and loss of the airplane.

(f) Compliance

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

(g) Required Actions

    (1) Before the affected No. 3 bearing spring finger housing 
accumulates 125 flight cycles (FCs) since new, but not before 
accumulating 75 FCs since new, or within 50 FCs after the effective 
date of this AD, whichever occurs later, calculate the oil filter 
delta pressure (OFDP) data in accordance with the Accomplishment 
Instructions, paragraphs 5.A.(1) through 5.A.(2) or 5.B.(1) through 
5.B.(2), of CFM LEAP-1B-72-00-0369-01A-930A-D.
    (2) Thereafter, at intervals not to exceed 100 FCs from the last 
calculation of the OFDP data, and until the affected No. 3 bearing 
spring finger housing accumulates 1,000 FCs since new, repeat the 
calculation required by paragraph (g)(1) of this AD.
    (3) If, during the calculation required by paragraph (g)(1) or 
(2) of this AD, the OFDP data exceed the limits specified in the 
Accomplishment Instructions, paragraph 5.A.(3) or 5.B.(3), of CFM 
LEAP-1B-72-00-0369-01A-930A-D, as applicable, within 25 FCs of 
performing the calculation, replace the affected No. 3 bearing 
spring finger housing with a part eligible for installation.
    (4) During the next engine shop visit after the effective date 
of this AD, replace the affected No. 3 bearing spring finger housing 
with a part eligible for installation.

(h) Terminating Action

    Replacement of the affected No. 3 bearing spring finger housing 
with a part eligible for installation, as specified in paragraphs 
(g)(3) and (g)(4) of this AD, constitutes terminating action for the 
calculations required by paragraphs (g)(1) and (2) of this AD.

(i) Installation Prohibition

    After the effective date of this AD, do not install an engine 
with an affected No. 3 bearing spring finger housing onto an 
airplane that already has one engine with an affected No. 3 bearing 
spring finger housing installed.

(j) Definition

    For the purpose of this AD, a ``part eligible for installation'' 
is a No. 3 bearing spring finger housing that is not identified in 
Table 1 of CFM LEAP-1B-72-00-0369-01A-930A-D.

(k) 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 (l) of this AD and email it 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.

(l) 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].

(m) 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-1B-72-00-0369-01A-930A-D, Issue 
001-00, dated August 22, 2022.
    (ii) [Reserved]
    (3) For CFM service information identified in this AD, contact 
CFM International Inc., 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 November 9, 2022.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2022-26121 Filed 11-30-22; 8:45 am]
BILLING CODE 4910-13-P


