DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-2149; Project Identifier MCAI-2023-00136-E]
RIN 2120-AA64

Airworthiness Directives; GE Aviation Czech s.r.o. (Type
Certificate Previously Held by WALTER Engines a.s., Walter a.s., and
MOTORLET a.s.) Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD)
2022-13-16, which applies to all GE Aviation Czech s.r.o. (GEAC) (type
certificate previously held by WALTER Engines a.s., Walter a.s., and
MOTORLET a.s.) Model M601D-11 engines; and AD 2022-14-12, which applies
to certain GEAC Model M601D-11, M601E-11, M601E-11A, M601E-11AS, M601E-
11S, and M601F engines. AD 2022-13-16 requires revising the
airworthiness limitations section (ALS) of the existing engine
maintenance manual (EMM) to incorporate a visual inspection of the
centrifugal compressor case for cracks. AD 2022-14-12 requires
replacing the propeller shaft for Model M601F engines. AD 2022-14-12
also requires calculating the accumulated life of the propeller shaft
and replacing the propeller shaft, if necessary, for model M601D-11,
M601E-11, M601E-11A, M601E-11AS, and M601E-11S engines. Since the FAA
issued AD 2022-13-16 and AD 2022-14-12, the manufacturer revised the
ALS of the existing EMM to introduce new and more restrictive tasks and
limitations, expand the applicability to all Model M601 engines, and
incorporate certain requirements addressed by AD 2021-13-07 and AD
2023-01-10, which prompted this proposed AD. This proposed AD would
require revising the ALS of the existing EMM and the operator's
existing approved engine maintenance or inspection program, as
applicable, to incorporate new and more restrictive tasks and
limitations, as specified in a European Union Aviation Safety Agency
(EASA) AD, which is proposed for incorporation by reference (IBR). The
FAA is proposing this AD to address the unsafe condition on these
products.

DATES: The FAA must receive comments on this NPRM by December 29, 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 under
Docket No. FAA-2023-2149; 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, the mandatory continuing airworthiness
information (MCAI), 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
EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221
8999 000; email: ADs@easa.europa.eu; website: easa.europa.eu. You may
find this material on the EASA website at ad.easa.europa.eu. It is also
available at regulations.gov under Docket No. FAA-2023-2149.
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: Barbara Caufield, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
phone: (781) 238-7146; email: barbara.caufield@faa.gov.

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-2023-2149; Project Identifier
MCAI-2023-00136-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
the 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
Barbara Caufield, Aviation Safety Engineer, FAA, 1600 Stewart Avenue,
Suite 410, Westbury, NY 11590. 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 issued AD 2021-13-07, Amendment 39-21612 (86 FR 31601, June
15, 2021) (AD 2021-13-07) for all GEAC Model M601D-11, M601E-11, M601E-
11A, M601E-11AS, M601E-11S, and M601F engines. AD 2021-13-07 was
prompted by an MCAI originated by EASA. EASA issued EASA Emergency AD
2021-0125-E, dated May 7, 2021 (EASA Emergency AD 2021-0125-E) to
correct an unsafe condition identified as the manufacturer finding
errors in the ALS of the existing EMM, including errors in the formula
to determine the consumed equivalent flight cycles of critical parts
and errors with certain part numbers. The manufacturer also determined
that the life limit of a certain compressor case installed on Model
M601E engines was not listed in the ALS of the applicable EMM.
AD 2021-13-07 requires recalculating the life of critical parts and
replacing critical parts, if necessary. AD 2021-13-
07 also requires replacing a certain compressor case. The FAA issued AD
2021-13-07 to prevent failure of the engine.
The FAA issued AD 2022-13-16, Amendment 39-22102 (87 FR 37986, June
27, 2022) (AD 2022-13-16), for all GEAC Model M601D-11 engines. AD
2022-13-16 was prompted by an MCAI originated by EASA, which is the
Technical Agent for the Member States of the European Union. EASA
issued AD 2021-0060, dated March 3, 2021 (EASA AD 2021-0060) to correct
an unsafe condition identified as the manufacturer revising the ALS to
introduce a visual inspection of the centrifugal compressor case for
cracks.
AD 2022-13-16 requires revising the ALS of the existing EMM to
incorporate a visual inspection of the centrifugal compressor case for
cracks. The FAA issued AD 2022-13-16 to prevent failure of the
centrifugal compressor case.
The FAA issued AD 2022-14-12, Amendment 39-22117 (87 FR 42066, July
14, 2022) (AD 2022-14-12), for certain GEAC Model M601D-11, M601E-11,
M601E-11A, M601E-11AS, M601E-11S, and M601F engines. AD 2022-14-12 was
prompted by an MCAI originated by EASA. EASA issued AD 2021-0154, dated
July 1, 2021 (EASA AD 2021-0154) to correct an unsafe condition
identified as the absence of life limits for the propeller shaft part
number M601-6081.6 in the ALS of the applicable EMM, as well as a lack
of data necessary for operators to determine the accumulated life of
certain propeller shafts, resulting in a propeller shaft life limit
that may not have been implemented correctly.
AD 2022-14-12 requires replacing the propeller shaft for Model
M601F engines. AD 2022-14-12 also requires calculating the accumulated
life of the propeller shaft and replacing the propeller shaft, if
necessary, for model M601D-11, M601E-11, M601E-11A, M601E-11AS, and
M601E-11S engines. The FAA issued AD 2022-14-12 to prevent failure of
the propeller shaft.
The FAA issued AD 2023-01-10, Amendment 39-22304 (88 FR 7578,
February 6, 2023) (AD 2023-01-10) for certain GEAC Model M601E-11,
M601E-11A, M601E-11AS, M601E-11S, and M601F engines. AD 2023-01-10 was
prompted by an MCAI originated by EASA. EASA issued EASA AD 2021-0264,
dated November 22, 2021 (EASA AD 2021-0264) to correct an unsafe
condition identified as the exclusion of life limits for certain
compressor cases and compressor drums from the ALS of the EMM and
certain compressor cases that, following rework, were improperly re-
identified and had incomplete engine logbook entries.
AD 2023-01-10 requires recalculating the consumed life for certain
compressor cases and compressor drums and replacing certain compressor
cases and compressor drums, if necessary. The FAA issued AD 2023-01-10
to prevent failure of the compressor case and compressor drum.

Actions Since the Previous ADs Were Issued

Since the FAA issued AD 2021-13-07, AD 2022-13-16, AD 2022-14-12,
and AD 2023-01-10, EASA superseded EASA AD 2021-0060 and EASA AD 2021-
0154 and issued EASA AD 2023-0020, dated January 23, 2023 (EASA AD
2023-0020) (also referred to as the MCAI). The MCAI states that the
manufacturer revised the ALS to incorporate new and more restrictive
tasks and limitations, expand the applicability to all model M601
series engines, and include certain requirements that were previously
addressed by EASA Emergency AD 2021-0125-E and EASA AD 2021-0264. The
MCAI also states that the manufacturer published service information
that specifies instructions to determine the accumulated life of
certain propeller shafts.
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2023-2149.

Related Service Information Under 1 CFR Part 51

The FAA reviewed EASA AD 2023-0020, which specifies procedures for
accomplishment of the actions specified in the ALS, including
performing maintenance tasks, replacing life-limited parts, and
revising the existing approved maintenance or inspection program, as
applicable, by incorporating the instructions and associated thresholds
and intervals described in the ALS, as applicable to engine model and
depending on engine configuration.
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.

FAA's Determination

These products have been approved by the aviation authority of
another country and are approved for operation in the United States.
Pursuant to the FAA's bilateral agreement with this State of Design
Authority, it has notified the FAA of the unsafe condition described in
the MCAI referenced above. 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.

Proposed AD Requirements in This NPRM

This proposed AD would require accomplishing the actions specified
in the MCAI described previously, except for any differences identified
as exceptions in the regulatory text of this proposed AD and as
discussed under ``Differences Between this Proposed AD and the MCAI.''
This proposed AD would terminate the requirements of paragraphs
(g)(1) through (3) of AD 2021-13-07 for model M601D-11, M601E-11,
M601E-11A, M601E-11AS, M601E-11S, and M601F engines only.
This proposed AD would terminate the requirements of paragraphs
(g)(1) through (3) of AD 2023-01-10 for model M601E-11, M601E-11A,
M601E-11AS, M601E-11S, and M601F engines only.
The owner/operator (pilot) holding at least a private pilot
certificate may revise the ALS of the existing EMM and must enter
compliance with the applicable paragraph of this proposed AD into the
engine maintenance records in accordance with 14 CFR 43.9(a) and
91.417(a)(2)(v). The pilot may perform this action because it only
involves revising the pilot's manual. This action could be performed
equally well by a pilot or a mechanic. This is an exception to the
FAA's standard maintenance regulations.

Explanation of Required Compliance Information

In the FAA's ongoing efforts to improve the efficiency of the AD
process, the FAA developed a process to use some civil aviation
authority (CAA) ADs as the primary source of information for compliance
with requirements for corresponding FAA ADs. The FAA has since
coordinated with other manufacturers and CAAs to use this process. As a
result, the FAA proposes to incorporate by reference EASA AD 2023-0020
in the FAA final rule. This proposed AD would, therefore, require
compliance with EASA AD 2023-0020 in its entirety through that
incorporation, except for any differences identified as exceptions in
the regulatory text of this proposed AD. Using common terms that are
the same as the heading of a particular section in the EASA AD does not
mean that operators need comply only with that section. For example,
where the AD requirement refers to ``all required actions within the
compliance times,'' compliance with this AD requirement is not limited
to the section titled ``Required Action(s) and Compliance Time(s)'' in EASA
AD 2023-0020.
Service information required by the EASA AD for compliance will be
available at regulations.gov under Docket No. FAA-2023-2149 after the
FAA final rule is published.

Differences Between This Proposed AD and the MCAI

Where the MCAI applies to Model M601D, M601D-1, M601D-2, M601D-
11NZ, M601E, M601E-21, M601FS, and M601Z engines, this proposed AD does
not, as these engine models are not type certificated in the United
States.
Where the MCAI defines the AMP as the approved Aircraft Maintenance
Programme containing the tasks on the basis of which the scheduled
maintenance is conducted to ensure the continuing airworthiness of each
operated engine, this proposed AD defines the AMP as the aircraft
maintenance program containing the tasks on the basis of which the
scheduled maintenance is conducted to ensure the continuing
airworthiness of each operated airplane.
Where the MCAI specifies the ALS of GEAC EMM No. 0982309, Revision
21, dated November 18, 2022, this proposed AD specifies the ALS of GEAC
EMM No. 0982309, Revision 22, dated March 10, 2023. The ALS in Revision
22 of GEAC EMM No. 0982309 is unchanged from Revision 21.
Where paragraph (3) of the MCAI specifies revising the approved
Aircraft Maintenance Programme within 12 months after the effective
date of EASA AD 2023-0020, this proposed AD would require revising the
ALS of the existing approved engine maintenance or inspection program,
as applicable, within 90 days after the effective date of this AD.
This proposed AD would not require compliance with paragraphs (1),
(2), (4), and (5) of the MCAI.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would
affect 42 engines installed on airplanes of U.S. registry.
The FAA estimates the following costs to comply with this proposed
AD:

Estimated Costs

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 that the 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

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]

2. The FAA amends Sec. 39.13 by:

a. Removing Airworthiness Directive 2022-13-16, Amendment 39-22102 (87
FR 37986, June 27, 2022); and Airworthiness Directive 2022-14-12,
Amendment 39-22117 (87 FR 42066, July 14, 2022); and

b. Adding the following new airworthiness directive: