DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2025-0627; Project Identifier MCAI-2024-00608-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)
2024-06-02, which applies to all GE Aviation Czech s.r.o. (GEAC) Model
M601D-11, M601E-11, M601E-11A, M601E-11AS, M601E-11S, and M601F
engines. AD 2024-06-02 was prompted by a report of a crack on the
centrifugal compressor case mount pad weld area caused by a non-
conforming weld (lack of welding penetration). AD 2024-06-02 requires a
one-time detailed visual inspection (DVI) of the compressor case pad
welds for any crack, and replacement of the compressor case if
necessary. Since the FAA issued AD 2024-06-02, the manufacturer
determined that the compliance time for the DVI can be extended, and
repetitive inspections of the centrifugal compressor case must be
accomplished. This proposed AD would require performing repetitive DVIs
of the compressor case pad welds for any crack, replacing the
compressor case if necessary, and sending certain inspection results to
the manufacturer, as specified in a European Union Aviation Safety
Agency (EASA) AD, which is proposed for incorporation by reference. The
FAA is proposing this AD to address the unsafe condition on these
products.

DATES: The FAA must receive comments on this NPRM by June 9, 2025.

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-2025-0627; 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 EASA material identified in this proposed AD, 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.

You may view this material 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: Robert Charbonneau, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
phone: (781) 238-7132; email: robert.d.charbonneau@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-2025-0627; Project Identifier
MCAI-2024-00608-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
Robert Charbonneau, 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 issued AD 2024-06-02, Amendment 39-22707 (89 FR 21196,
March 27, 2024) (AD 2024-06-02), for GEAC Model M601D-11, M601E-11,
M601E-11A, M601E-11AS, M601E-11S, and M601F engines. AD 2024-06-02 was
prompted by an MCAI originated by EASA, which is the Technical Agent
for the Member States of the European Union. EASA issued EASA AD 2024-
0040-E, dated February 8, 2024 (EASA AD 2024-0040-E), to correct an
unsafe condition identified as a crack on the
centrifugal compressor case mount pad weld area caused by a non-
conforming weld (lack of welding penetration).

AD 2024-06-02 requires a one-time detailed visual inspection of the
compressor case pad welds for any crack and replacement of the
compressor case, if necessary. The FAA issued AD 2024-06-02 to prevent
failure of the centrifugal compressor case.

Actions Since AD 2024-06-02 Was Issued

Since the FAA issued AD 2024-06-02, EASA superseded EASA AD 2024-
0040-E and issued EASA AD 2024-0194, dated October 15, 2024 (EASA AD
2024-0194) (also referred to as the MCAI). EASA AD 2024-0194 states
since that AD was issued, it has been confirmed that the compliance
time for the DVI can be extended, and that repetitive DVIs of the
affected part must be accomplished.

You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2025-0627.

Material Incorporated by Reference Under 1 CFR Part 51

EASA AD 2024-0194 specifies procedures for performing repetitive
DVIs of the compressor case pad welds for any crack, replacement of the
compressor case if necessary, and sending certain inspection results to
the manufacturer.
This material is reasonably available because the interested
parties have access to it through their normal course of business or by
the means identified in the ADDRESSES section.

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 and material 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 retain none of the requirements of AD 2024-
06-02. 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.

Differences Between This Proposed AD and the MCAI

GEAC Model M601D, M601D-1, M601D-2, M601D-11NZ, M601E, M601E-21,
M601FS, and M601Z engines do not have an FAA type certificate,
therefore this proposed AD does not include those engines in the applicability.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would
affect 45 engines installed on airplanes of U.S. registry.

The FAA estimates the following costs to comply with this proposed AD:

Estimated Costs

The FAA estimates the following costs to do any necessary
replacements that would be required based on the results of the
proposed inspection. The agency has no way of determining the number of
engines that might need this replacement:

On-Condition Costs

The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some of the costs of this
proposed AD may be covered under warranty, thereby reducing the cost
impact on affected operators.

Paperwork Reduction Act

A federal agency may not conduct or sponsor, and a person is not
required to respond to, nor shall a person be subject to a penalty for
failure to comply with a collection of information subject to the
requirements of the Paperwork Reduction Act unless that collection of
information displays a currently valid OMB Control Number. The OMB
Control Number for this information collection is 2120-0056. Public
reporting for this collection of information is estimated to be
approximately 1 hour per response, including the time for reviewing
instructions, searching existing data sources, gathering and
maintaining the data needed, and completing and reviewing the
collection of information. All responses to this collection of
information are mandatory. Send comments regarding this burden estimate
or any other aspect of this collection of information, including
suggestions for reducing this burden, to: Information Collection
Clearance Officer, Federal Aviation Administration, 10101 Hillwood
Parkway, Fort Worth, TX 76177-1524.

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 2024-06-02, Amendment 39-22707 (89
FR 21196, March 27, 2024); and

b. Adding the following new airworthiness directive: