Document ID: FAA-2022-0094-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: CFM International, S.A. Turbofan Engines
Posted Date: 2022-02-15T05:00Z

[Federal Register Volume 87, Number 31 (Tuesday, February 15, 2022)]
[Proposed Rules]
[Pages 8434-8436]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-03041]

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 Proposed Rules
                                                 Federal Register
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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 

  Federal Register / Vol. 87, No. 31 / Tuesday, February 15, 2022 / 
Proposed Rules  

[[Page 8434]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-0094; Project Identifier AD-2021-01251-E]
RIN 2120-AA64

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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for all 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. This 
proposed 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 mid seals, HPT 
rotor stage 2 disks, low pressure turbine (LPT) stage 2 disks, and LPT 
stage 3 disks. This proposed AD would require revising the 
airworthiness limitations section (ALS) of the applicable CFM LEAP-1B 
Engine Shop Manual (ESM), and the operator's existing approved 
continuous airworthiness maintenance program (CAMP) to incorporate 
reduced life limits for these parts. 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 April 1, 
2022.

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 https://www.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.
    For service information identified in this NPRM, 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.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2022-0094; 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.

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-2022-0094; Project Identifier 
AD-2021-01251-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 
https://www.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 the detection of 
melt-related freckles in the billet, which may reduce the life of 
certain compressor rotor stages 6-10 spools, HPT rotor mid seals, HPT 
rotor stage 2 disks, LPT stage 2 disks, and LPT stage 3 disks (life-
limited parts (LLPs)). The manufacturer's investigation determined 
that, as a result of such freckles forming in the billet, these LLPs 
may have undetected subsurface anomalies that developed during the 
manufacturing process, resulting in reduced material properties and a 
lower fatigue life capability. Reduced material properties may cause 
premature LLP fracture, which could result in uncontained debris 
release. As a result of its investigation, the manufacturer determined 
the need to reduce the life limits of these LLPs. To reflect these 
reduced life limits, the manufacturer revised the CFM ALS, Chapter 05 
of

[[Page 8435]]

LEAP-1B ESM. Additionally, the manufacturer published service 
information that specifies procedures for the removal and replacement 
of these LLPs before reaching their new life limits. The FAA is 
proposing to require operators to update the ALS of the applicable CFM 
LEAP-1B ESM, with the reduced life limits for these LLPs.
    This condition, if not addressed, could result in uncontained 
debris release, damage to the engine, and damage to 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 High Pressure Compressor Rotor Life Limits 
LEAP-1B-05-11-02-01A-0B1B-C, Issue 009-00, dated July 26, 2021 (CFM 
LEAP-1B-05-11-02-01A-0B1B-C); CFM High Pressure Turbine Rotor Life 
Limits LEAP-1B-05-11-03-01A-0B1B-C, Issue 006-00, dated July 26, 2021 
(CFM LEAP-1B-05-11-03-01A-0B1B-C); and CFM Low Pressure Turbine Rotor 
Life Limits LEAP-1B-05-11-04-01A-0B1B-C, Issue 006-00, dated June 1, 
2021 (LEAP-1B-05-11-04-01A-0B1B-C). CFM LEAP-1B-05-11-02-01A-0B1B-C 
provides new high pressure compressor rotor life limits. CFM LEAP-1B-
05-11-03-01A-0B1B-C provides new HPT rotor life limits. CFM LEAP-1B-05-
11-04-01A-0B1B-C provides new LPT rotor life limits. 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 Service Bulletin LEAP-1B-72-00-0342-01A-930A-
D, Issue 002-00, dated July 26, 2021 (LEAP-1B-72-00-0342-01A-930A-D). 
LEAP-1B-72-00-0342-01A-930A-D specifies procedures for removing and 
replacing the LLPs, and provides new life limits for certain serial 
numbers of the LLPs.

Proposed AD Requirements in This NPRM

    This proposed AD would require revising the ALS of the CFM LEAP-1B 
ESM, as applicable to each affected engine model, and the operator's 
existing approved CAMP to incorporate reduced life limits for certain 
LLPs.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 378 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
----------------------------------------------------------------------------------------------------------------
Revise ALS of Engine Manual and the     1 work-hour x $85 per                 $0             $85         $32,130
 operator's existing approved CAMP.      hour = $85.
----------------------------------------------------------------------------------------------------------------

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-2022-0094; Project 
Identifier AD-2021-01251-E.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by April 1, 2022.

(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.

(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 mid seals, HPT 
rotor stage 2

[[Page 8436]]

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

    Within 60 days after the effective date of this AD, revise the 
airworthiness limitations section of the applicable CFM LEAP-1B 
Engine Shop Manual and the operator's existing approved continuous 
airworthiness maintenance program by incorporating the following 
service information:
    (1) CFM High Pressure Compressor Rotor Life Limits LEAP-1B-05-
11-02-01A-0B1B-C, Issue 009-00, dated July 26, 2021; and
    (2) CFM High Pressure Turbine Rotor Life Limits LEAP-1B-05-11-
03-01A-0B1B-C, Issue 006-00, dated July 26, 2021; and
    (3) CFM Low Pressure Turbine Rotor Life Limits LEAP-1B-05-11-04-
01A-0B1B-C, Issue 006-00, dated June 1, 2021.

(h) 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 (i)(1) 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.

(i) Related Information

    (1) 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].
    (2) 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]. You may view this referenced 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.

    Issued on February 3, 2022.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2022-03041 Filed 2-14-22; 8:45 am]
BILLING CODE 4910-13-P