[Federal Register Volume 87, Number 108 (Monday, June 6, 2022)]
[Proposed Rules]
[Pages 34221-34223]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-11897]



[[Page 34221]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-0515; Project Identifier AD-2022-00287-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 model turbofan 
engines. This proposed AD was prompted by multiple commanded in-flight 
shutdowns (IFSDs) due to inner radial drive shaft (RDS) failure. This 
proposed AD would require initial and repetitive inspections of the 
transfer gearbox (TGB) scavenge screens and, depending on the results 
of the inspections, replacement or rework of the affected inner RDS. As 
a mandatory terminating action to the initial and repetitive 
inspections of the TGB scavenge screens, this proposed AD would require 
replacement or rework of the affected inner RDS. This proposed AD would 
also prohibit the installation of an engine with an affected inner RDS 
onto an airplane that already has one engine with an affected inner RDS 
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 July 21, 
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-2022-0515; 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-2022-0515; Project Identifier 
AD-2022-00287-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 received reports of multiple IFSDs on CFM 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) model 
turbofan engines beginning in August 2018. The manufacturer's 
investigations determined that some of these IFSD events were the 
result of inadequate oil flow to the RDS bearing, which caused the RDS 
bearing and RDS bearing cage to fail. The FAA issued AD 2019-12-01, 
Amendment 39-19656 (84 FR 28202, June 18, 2019), which required initial 
and repetitive inspections of the TGB scavenge screens and, depending 
on the results of the inspection, possible removal of the engine from 
service.
    After the FAA issued AD 2019-12-01, further investigation by the 
manufacturer identified an additional contributing factor to the RDS 
bearing failures. The manufacturer revised the service information to 
include a repetitive TGB screen inspection until the RDS accumulates 
1,500 flight hours (FHs) since new and borescope inspections of the RDS 
bearing at 1,500 FHs since new and 6,000 FHs since new. The FAA 
superseded AD 2019-12-01 by issuing AD 2020-06-01, Amendment 39-21103 
(85 FR 14413, March 12, 2020), which requires revision to the 
airworthiness limitations section (ALS) of the applicable engine shop 
manual to incorporate the new inspections.
    Since the FAA issued AD 2020-06-01, the FAA received further 
reports of commanded IFSDs due to inner RDS failure. The manufacturer 
initiated an investigation and identified a subpopulation of inner RDS 
susceptible to rivet fatigue failure occurring after the inspection 
thresholds required by the ALS revision in AD 2020-06-01. This 
condition, if not addressed, could result in failure of one or more 
engines, loss of thrust control, and loss of the airplane.

[[Page 34222]]

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 (SB) LEAP-1B-72-00-0365-01A-
930A-D, Issue 003-00, dated April 26, 2022 (CFM LEAP-1B-72-00-0365-01A-
930A-D). This SB identifies the affected serial numbers of the inner 
RDS susceptible to rivet fatigue failure and specifies procedures for 
performing inspections of TGB1 and TGB2 scavenge screens. This SB also 
specifies procedures for accomplishing applicable corrective actions if 
metallic particles are found. The FAA also reviewed CFM SB LEAP-1B-72-
00-0258-01A-930A-C, Issue 002, dated September 15, 2020. This SB 
specifies procedures for replacement or rework of the inner RDS. 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 initial and repetitive inspections 
of the TGB1 and TGB2 scavenge screens and, depending on the results of 
the inspections, replacement or rework of the affected inner RDS. As a 
mandatory terminating action to the initial and repetitive inspections 
of the TGB1 and TGB2 scavenge screens, this proposed AD would require 
replacement or rework of the affected inner RDS. This proposed AD would 
also prohibit the installation of an engine with an affected inner RDS 
onto an airplane that already has one engine with an affected inner RDS 
installed.

Differences Between This Proposed AD and the Service Information

    The Accomplishment Instructions, paragraph 5.A.(3), of CFM LEAP-1B-
72-00-0365-01A-930A-D specifies removing the engine if certain 
conditions exist, whereas this proposed AD would require replacement or 
rework of the affected inner RDS if certain conditions exist.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 34 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
----------------------------------------------------------------------------------------------------------------
Inspect TGB1 and TGB 2 scavenge         1 work-hour x $85 per                 $0             $85          $2,890
 screens.                                hour = $85.
----------------------------------------------------------------------------------------------------------------

    For either replacement or rework of the inner RDS, depending on the 
option selected by the operator to comply with this AD, the FAA 
estimates the following costs:

----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replace inner RDS.............................  600 work-hours x $85 per hour =          $60,000        $111,000
                                                 $51,000.
Rework inner RDS..............................  600 work-hours x $85 per hour =           54,000         105,000
                                                 $51,000.
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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.

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-2022-0515; Project 
Identifier AD-2022-00287-E.

[[Page 34223]]

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by July 21, 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 with an installed inner radial drive shaft 
(RDS) with a serial number listed in Additional Information, 
paragraph 6.A., Table 1, of CFM Service Bulletin (SB) LEAP-1B-72-00-
0365-01A-930A-D, Issue 003-00, dated April 26, 2022 (CFM LEAP-1B-72-
00-0365-01A-930A-D).

(d) Subject

    Joint Aircraft System Component (JASC) Code 7260, Turbine Engine 
Accessory Drive.

(e) Unsafe Condition

    This AD was prompted by multiple commanded in-flight shutdowns 
(IFSDs) due to inner RDS failure. The FAA is issuing this AD to 
prevent failure of the inner RDS and subsequent IFSDs. The unsafe 
condition, if not addressed, could result in failure of one or more 
engines, 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) Before exceeding 50 flight hours (FHs) after the effective 
date of this AD, and thereafter at intervals not to exceed 50 FHs 
from the previous inspection, inspect the transfer gearbox (TGB) 
TGB1 and TGB2 scavenge screens in accordance with the Accomplishment 
Instructions, paragraph 5.A.(1), of CFM LEAP-1B-72-00-0365-01A-930A-
D.
    (2) If, during any inspection required by paragraph (g)(1) of 
this AD, any metallic particles are found, before further flight, 
perform the actions in the Accomplishment Instructions, paragraphs 
5.A.(2) and (3), of CFM LEAP-1B-72-00-0365-01A-930A-D. Where 
paragraph 5.A.(3)(b) of CFM LEAP-1B-72-00-0365-01A-930A-D specifies 
to remove the engine, this AD instead requires replacement or rework 
of the inner RDS in accordance with the Accomplishment Instructions, 
paragraph 5.A., of CFM SB LEAP-1B-72-00-0258-01A-930A-C Issue 002, 
dated September 15, 2020 (CFM SB LEAP-1B-72-00-0258-01A-930A-C).

(h) Mandatory Terminating Action

    As a mandatory terminating action to the initial and repetitive 
inspections of the TGB1 and TGB2 scavenge screens required by 
paragraph (g)(1) of this AD, at the next piece-part exposure after 
the effective date of this AD, replace or rework the inner RDS in 
accordance with the Accomplishment Instructions, paragraph 5.A., of 
CFM SB LEAP-1B-72-00-0258-01A-930A-C.

(i) Installation Prohibition

    After the effective date of this AD, do not install an engine 
with an affected inner RDS onto an airplane that already has one 
engine with an affected inner RDS installed.

(j) Definitions

    For the purpose of this AD, ``piece-part exposure'' is when the 
fan frame shroud is separated from the fan hub.

(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)(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.

(l) 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 May 5, 2022.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2022-11897 Filed 6-3-22; 8:45 am]
BILLING CODE 4910-13-P