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

[Federal Register Volume 90, Number 177 (Tuesday, September 16, 2025)]
[Rules and Regulations]
[Pages 44489-44491]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-17852]



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Rules and Regulations
                                                Federal Register
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Federal Register / Vol. 90, No. 177 / Tuesday, September 16, 2025 / 
Rules and Regulations

[[Page 44489]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2025-0627; Project Identifier MCAI-2024-00608-E; 
Amendment 39-23135; AD 2025-18-08]
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: Final rule.

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

SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2024-06-02 
for 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 
required 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 AD requires 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. The FAA is issuing this AD to address the unsafe 
condition on these products.

DATES: This AD is effective October 21, 2025.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of October 21, 
2025.

ADDRESSES: 
    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 final rule, the mandatory continuing airworthiness 
information (MCAI), any comments received, and other information. The 
address for Docket Operations is U.S. Department of Transportation, 
Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 
New Jersey Avenue SE, Washington, DC 20590.
    Material Incorporated by Reference:
    <bullet> For European Union Aviation Safety Agency (EASA) material 
identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 
Cologne, Germany; phone: +49 221 8999 000; email: [email protected]; 
website: easa.europa.eu. You may find this material on the EASA website 
at ad.easa.europa.eu.
    <bullet> 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. It is also available at 
regulations.gov under Docket No. FAA-2025-0627.

FOR FURTHER INFORMATION CONTACT: Robert Charbonneau, Aviation Safety 
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; 
phone: (781) 238-7132; email: [email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to supersede AD 2024-06-02, Amendment 39-22707 (89 FR 
21196, March 27, 2024) (AD 2024-06-02). AD 2024-06-02 applied to all 
GEAC Model M601D-11, M601E-11, M601E-11A, M601E-11AS, M601E-11S, and 
M601F engines. AD 2024-06-02 required a one-time DVI 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.
    The NPRM was published in the Federal Register on April 23, 2025 
(90 FR 17022). The NPRM was prompted by EASA AD 2024-0194, dated 
October 15, 2024 (EASA AD 2024-0194) (also referred to as the MCAI) 
issued by EASA, which is Technical Agent for the Member States of the 
European Union. The MCAI states that 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.
    In the NPRM, the FAA proposed to 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.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2025-0627.

Discussion of Final Airworthiness Directive

Comments

    The FAA received no comments on the NPRM or on the determination of 
the costs.

Conclusion

    These products have been approved by the civil 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, that authority has notified the FAA of the unsafe condition 
described in the MCAI referenced above. The FAA reviewed the relevant 
data and determined that air safety requires adopting this AD as 
proposed. Accordingly, the FAA is issuing this AD to address the unsafe 
condition on these products. Except for minor editorial changes, to 
include allowing the use of a part eligible for installation, this AD 
is adopted as proposed in the NPRM. None of the changes will increase 
the economic burden on any operator.

Material Incorporated by Reference Under 1 CFR Part 51

    The FAA reviewed EASA AD 2024-0194, which 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.

[[Page 44490]]

Differences Between This 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 AD does not include those engines in the applicability.

Costs of Compliance

    The FAA estimates that this AD affects 45 engines installed on 
airplanes of U.S. registry.
    The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                       Cost per    Cost on U.S.
                  Action                            Labor cost           Parts cost    product       operators
----------------------------------------------------------------------------------------------------------------
Inspect centrifugal compressor case......  1 work-hour x $85 per hour            $0          $85          $3,825
                                            = $85.
Report inspection results................  1 work-hour x $85 per hour             0           85           3,825
                                            = $85.
----------------------------------------------------------------------------------------------------------------

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

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replace centrifugal compressor case...........  10 work-hours x $85 per hour =            $5,000          $5,850
                                                 $850.
----------------------------------------------------------------------------------------------------------------

    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some of the costs of this 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 has determined that this AD will not have federalism 
implications under Executive Order 13132. This AD will 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 this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) Will 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 Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 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:
0
a. Removing Airworthiness Directive 2024-06-02, Amendment 39-22707 (89 
FR 21196, March 27, 2024); and
0
b. Adding the following new airworthiness directive:

2025-18-08 GE Aviation Czech s.r.o. (Type Certificate Previously 
Held by WALTER Engines a.s., Walter a.s., and MOTORLET a.s.): 
Amendment 39-23135; Docket No. FAA-2025-0627; Project Identifier 
MCAI-2024-00608-E.

(a) Effective Date

    This airworthiness directive (AD) is effective October 21, 2025.

(b) Affected ADs

    This AD replaces AD 2024-06-02, Amendment 39-22707 (89 FR 21196, 
March 27, 2024) (AD 2024-06-02).

[[Page 44491]]

(c) Applicability

    This AD applies to 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, M601E-11, M601E-11A, M601E-11AS, 
M601E-11S, and M601F engines.

(d) Subject

    Joint Aircraft System Component (JASC) Codes 7120, Engine Mount 
Section; 7230, Turbine Engine Compressor Section.

(e) Unsafe Condition

    This AD 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). The FAA is issuing this AD to prevent 
failure of the centrifugal compressor case. The unsafe condition, if 
not addressed, could result in crack propagation, possibly resulting 
in engine separation and reduced control of the airplane.

(f) Compliance

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

(g) Required Actions

    Except as specified in paragraph (h) of this AD, perform all 
required actions within the compliance times specified in, and in 
accordance with, European Union Aviation Safety Agency (EASA) AD 
2024-0194, dated October 15, 2024 (EASA AD 2024-0194).

(h) Exceptions to EASA AD 2024-0194

    (1) Where EASA AD 2024-0194 requires compliance from its 
effective date, this AD requires using the effective date of this 
AD.
    (2) Where EASA AD 2024-0194 defines serviceable part as 
``Centrifugal compressor case, eligible for installation in 
accordance with GEAC instructions, which is not an affected part'', 
this AD requires replacing that text with ``centrifugal compressor 
case, eligible for installation, which is not an affected part''.
    (3) Where EASA AD 2024-0194 specifies ``Replacing the affected 
part of an engine with a centrifugal compressor case, eligible for 
installation in accordance with GEAC instructions, which is not an 
affected part'', this AD requires replacing that text with 
``Replacing the affected part of an engine with a centrifugal 
compressor case, eligible for installation, which is not an affected 
part''.
    (4) Where EASA AD 2024-0194 specifies to contact the 
manufacturer for approved instructions if any crack is detected on 
an affected part, this AD requires replacement of the compressor 
case.
    (5) This AD does not adopt the ``Remarks'' paragraph of EASA AD 
2024-0194.

(i) Alternative Methods of Compliance (AMOCs)

    The Manager, AIR-730 International Validation 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 AIR-730 International Validation 
Branch, send it to the attention of the person identified in 
paragraph (j) of this AD and email to: [email protected].

(j) Additional Information

    For more information about this AD, contact Robert Charbonneau, 
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; phone: (781) 238-7132; email: 
[email protected].

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference of the material listed in this paragraph 
under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this material as applicable to do the actions 
required by this AD, unless the AD specifies otherwise.
    (i) European Union Aviation Safety Agency (EASA) AD 2024-0194, 
dated October 15, 2024.
    (ii) [Reserved]
    (3) For EASA material identified in this AD, contact EASA, 
Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 
000; email: [email protected]; website: easa.europa.eu. You may 
find this material on the EASA website at ad.easa.europa.eu.
    (4) You may view this material at FAA, 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 material at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].

    Issued on September 3, 2025.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2025-17852 Filed 9-15-25; 8:45 am]
BILLING CODE 4910-13-P

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