Airworthiness Directives; Continental Aerospace Technologies GmbH Engines

<RULE> DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2025-3432; Project Identifier MCAI-2024-00743-E; Amendment 39-23171; AD 2025-20-18]</DEPDOC> <RIN>RIN 2120-AA64</RIN> <SUBJECT>Airworthiness Directives; Continental Aerospace Technologies GmbH Engines</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Federal Aviation Administration (FAA), DOT. <HD SOURCE="HED">ACTION:</HD> Final rule; request for comments. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The FAA is adopting a new airworthiness directive (AD) for all Continental Aerospace Technologies GmbH (Continental) Model TAE 125-02-125 engines. This AD was prompted by multiple reports of cracks in the cylinder heads, which can cause engine coolant to leak into the combustion chamber. This AD requires a one-time inspection of the engine coolant for contamination and, depending on the inspection results, replacement of the coolant and replacement of the cylinder heads. This AD also prohibits installing a cylinder head on any engine unless it is a serviceable part. 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 30, 2025. The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of October 30, 2025. The FAA must receive comments on this AD by December 1, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods: • <E T="03">Federal eRulemaking Portal:</E> Go to <E T="03">regulations.gov</E> . Follow the instructions for submitting comments. • <E T="03">Fax:</E> (202) 493-2251. • <E T="03">Mail:</E> 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">Hand Delivery:</E> Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. <E T="03">AD Docket:</E> You may examine the AD docket at <E T="03">regulations.gov</E> under Docket No. FAA-2025-3432; 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 street address for Docket Operations is listed above. <E T="03">Material Incorporated by Reference:</E> • For Continental material identified in this AD, contact Continental, Platanenstrasse 14, 09356 Sankt Egidien, Germany; phone: +49 37204 696 0; email: <E T="03">support@continentaldiesel.com;</E> website: <E T="03">continentaldiesel.com.</E> • You may view this material at the 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. It is also available at <E T="03">regulations.gov</E> under Docket No. FAA-2025-3432. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Rawle Thomas, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (404) 474-5576; email: <E T="03">rawle.f.thomas@faa.gov</E> . </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> <HD SOURCE="HD1">Comments Invited</HD> The FAA invites you to send any written data, views, or arguments about this final rule. Send your comments using a method listed under the <E T="02">ADDRESSES</E> section. Include “Docket No. FAA-2025-3432; Project Identifier MCAI-2024-00743-E” at the beginning of your comments. The most helpful comments reference a specific portion of the final rule, 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 final rule 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 <E T="03">regulations.gov</E> , including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this final rule. <HD SOURCE="HD1">Confidential Business Information</HD> 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 AD 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 AD, 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 AD. Submissions containing CBI should be sent to Rawle Thomas, 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. <HD SOURCE="HD1">Background</HD> The European Union Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2024-0236, dated December 10, 2024 (EASA AD 2024-0236) (also referred to as the MCAI), to correct an unsafe condition on all Continental Model TAE 125-02-125 engines. The MCAI states that several cases of cracks in cylinder heads have been reported. The MCAI further states that these cracks may cause leakage of engine coolant into the combustion chamber(s), causing loss of coolant, which could lead to engine overheat and eventual engine failure or seizure. Additionally, the MCAI states that contamination of the engine coolant, especially with potassium, triggers certain critical types of chemical corrosion, depending on the nature of such contamination. The investigation of the root cause for the cylinder head ruptures is still ongoing. Accordingly, the MCAI is considered an interim action. This condition, if not addressed, could result in an uncommanded in-flight shutdown of the engine and a forced landing, which could result in damage to the airplane and injury to occupants. You may examine the MCAI in the AD docket at <E T="03">regulations.gov</E> under Docket No. FAA-2025-3432. <HD SOURCE="HD1">Material Incorporated by Reference Under 1 CFR Part 51</HD> The FAA reviewed Continental Service Bulletin (SB) CG 125-1030 P1, Revision 4, dated January 10, 2025. This material specifies procedures for a one-time inspection of the engine coolant for contamination using the minimum and maximum acceptable ranges for the two coolant types as specified in the material. This material also specifies procedures for labeling the coolant samples. 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">FAA's Determination</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 and material referenced above. The FAA is issuing this AD after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design. <HD SOURCE="HD1">AD Requirements</HD> This AD requires a one-time inspection of the engine coolant for contamination and, depending on the results, replacing the cylinder heads with a serviceable part for engines in which the coolant sample has aluminum or fluoride that exceeds the acceptable range; or draining and flushing the engine cooling system and refilling it with new coolant for engines in which the coolant sample exceeds any acceptable range, except for aluminum and fluoride. This AD also prohibits installing a cylinder head on any engine unless it is a serviceable part. <HD SOURCE="HD1">Interim Action</HD> The FAA considers this AD interim action. The unsafe condition is still under investigation by the manufacturer. If final action is later identified, the FAA might consider further rulemaking. <HD SOURCE="HD1">Justification for Immediate Adoption and Determination of the Effective Date</HD> Section 553(b) of the Administrative Procedure Act (APA) (5 U.S.C. 551 <E T="03">et seq.</E> ) authorizes agencies to dispense with notice and comment procedures for rules when the agency, for “good cause,” finds that those procedures are “impracticable, unnecessary, or contrary to the public interest.” Under this section, an agency, upon finding good cause, may issue a final rule without providing notice and seeking comment prior to issuance. Further, section 553(d) of the APA authorizes agencies to make rules effective in less than thirty days, upon a finding of good cause. An unsafe condition exists that requires the immediate adoption of this AD without providing an opportunity for public comments prior to adoption. The FAA has found that the risk to the flying public justifies forgoing notice and comment prior to adoption of this rule because contamination of the engine coolant can cause chemical corrosion, which could lead to cracks in the cylinder heads and allow engine coolant ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 22k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━