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

<RULE> DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2025-0627; Project Identifier MCAI-2024-00608-E; Amendment 39-23135; AD 2025-18-08]</DEPDOC> <RIN>RIN 2120-AA64</RIN> <SUBJECT>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</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Federal Aviation Administration (FAA), DOT. <HD SOURCE="HED">ACTION:</HD> Final rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> 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. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> 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. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> <E T="03">AD Docket:</E> You may examine the AD docket at <E T="03">regulations.gov</E> 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. <E T="03">Material Incorporated by Reference:</E> • 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: <E T="03">ADs@easa.europa.eu;</E> website: <E T="03">easa.europa.eu.</E> You may find this material on the EASA website at <E T="03">ad.easa.europa.eu.</E> • 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 <E T="03">regulations.gov</E> under Docket No. FAA-2025-0627. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Robert Charbonneau, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (781) 238-7132; email: <E T="03">robert.d.charbonneau@faa.gov</E> . </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> <HD SOURCE="HD1">Background</HD> 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 <E T="04">Federal Register</E> 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 <E T="03">regulations.gov</E> under Docket No. FAA-2025-0627. <HD SOURCE="HD1">Discussion of Final Airworthiness Directive</HD> <HD SOURCE="HD1">Comments</HD> The FAA received no comments on the NPRM or on the determination of the costs. <HD SOURCE="HD1">Conclusion</HD> 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. <HD SOURCE="HD1">Material Incorporated by Reference Under 1 CFR Part 51</HD> 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 <E T="02">ADDRESSES</E> section. <HD SOURCE="HD1">Differences Between This AD and the MCAI</HD> 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. <HD SOURCE="HD1">Costs of Compliance</HD> 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: <GPOTABLE COLS="5" OPTS="L2,nj,i1" CDEF="s50,r50,10,10,12"> <TTITLE>Estimated Costs</TTITLE> <CHED H="1">Action</CHED> <CHED H="1">Labor cost</CHED> <CHED H="1">Parts cost</CHED> Cost on U.S. operators </CHED> <ROW> <ENT I="01">Inspect centrifugal compressor case</ENT> <ENT>1 work-hour × $85 per hour = $85</ENT> <ENT>$0</ENT> <ENT>$85</ENT> <ENT>$3,825</ENT> </ROW> <ROW> <ENT I="01">Report inspection results</ENT> <ENT>1 work-hour × $85 per hour = $85</ENT> <ENT>0</ENT> <ENT>85</ENT> <ENT>3,825</ENT> </ROW> </GPOTABLE> 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: <GPOTABLE COLS="4" OPTS="L2,nj,i1" CDEF="s50,r50,12,12"> <TTITLE>On-Condition Costs</TTITLE> <CHED H="1">Action</CHED> <CHED H="1">Labor cost</CHED> <CHED H="1">Parts cost</CHED> <ENT I="01">Replace centrifugal compressor case</ENT> <ENT>10 work-hours × $85 per hour = $850</ENT> <ENT>$5,000</ENT> <ENT>$5,850</ENT> </ROW> </GPOTABLE> 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. <HD SOURCE="HD1">Paperwork Reduction Act</HD> 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. <HD SOURCE="HD1">Authority for This Rulemaking</HD> 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. <HD SOURCE="HD1">Regulatory Fin ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 17k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━