Airworthiness Directives; CFM International, S.A. Engines

DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2025-1725; Project Identifier AD-2025-00583-E]</DEPDOC> <RIN>RIN 2120-AA64</RIN> <SUBJECT>Airworthiness Directives; CFM International, S.A. Engines</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Federal Aviation Administration (FAA), DOT. <HD SOURCE="HED">ACTION:</HD> Notice of proposed rulemaking (NPRM). <SUM> <HD SOURCE="HED">SUMMARY:</HD> The FAA proposes to supersede Airworthiness Directive (AD) 2018-19-16, which applies to all CFM International, S.A. (CFM) Model LEAP-1A23, -1A24, -1A24E1, -1A26, -1A26E1, -1A26CJ, -1A29, -1A29CJ, -1A30, -1A32, -1A33, -1A33B2, and -1A35A engines with certain full authority digital engine control (FADEC) and prognostic health monitoring (PHM) software installed. AD 2018-19-16 requires removing certain FADEC and PHM software and installing versions eligible for installation. Since the FAA issued AD 2018-19-16, the manufacturer has developed a new pressure subsystem (PSS) with a heater element to evaporate potential moisture on the PSS manifold/transducer interface and prevent freezing at low temperature. This proposed AD would require replacing certain FADEC and PHM software with new versions that are eligible for installation, replacement of certain harnesses with newly designed harnesses, and replacement of the PSS with a newly designed heated PSS. The FAA is proposing this AD to address the unsafe condition on these products. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> The FAA must receive comments on this proposed AD by September 22, 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-2025-1725; 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, any comments received, and other information. The street address for Docket Operations is listed above. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Mehdi Lamnyi, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: (781) 238-7743; email: <E T="03">mehdi.lamnyi@faa.gov.</E> </FURINF> <SUPLINF> <REGTEXT> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> <HD SOURCE="HD1">Comments Invited</HD> The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments using a method listed under the <E T="02">ADDRESSES</E> section. Include “Docket No. FAA-2025-1725; Project Identifier AD-2025-00583-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 revise this 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 <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 NPRM. <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 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 Mehdi Lamnyi, 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. <HD SOURCE="HD1">Background</HD> The FAA issued AD 2018-19-16, Amendment 39-19416 (83 FR 50818, October 10, 2018) (AD 2018-19-16), for certain CFM Model LEAP-1A23, -1A24, -1A24E1, -1A26, -1A26E1, -1A26CJ, -1A29, -1A29CJ, -1A30, -1A32, -1A33, -1A33B2, and -1A35A engines. AD 2018-19-16 was prompted by aborted takeoffs after engines did not advance to the desired takeoff fan speed due to icing in the pressure sensor line. AD 2018-19-16 requires removing certain FADEC and PHM software and installing versions eligible for installation. The agency issued AD 2018-19-16 to prevent icing in the pressure sensor lines and inaccurate pressure sensor readings, which could result in failure of one or more engines, loss of thrust control, and loss of the airplane. <HD SOURCE="HD1">Actions Since AD 2018-19-16 Was Issued</HD> The preamble to AD 2018-19-16 specifies that the FAA considers that AD “interim action,” that the manufacturer was developing a modification to address the unsafe condition, and that the FAA might consider further rulemaking once the modification is developed, approved, and available. Since the FAA issued AD 2018-19-16, the manufacturer has developed a new pressure subsystem with a heater element to evaporate potential moisture on the PSS manifold/transducer interface and prevent freezing at low temperature, which would mitigate the unsafe condition specified in AD 2018-19-16. The FAA has determined that this modification should be required. <HD SOURCE="HD1">FAA's Determination</HD> 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. <HD SOURCE="HD1">Proposed AD Requirements in This NPRM</HD> This proposed AD would retain none of the requirements of AD 2018-19-16. This proposed AD would require replacing certain FADEC and PHM software with new versions that are eligible for installation, replacement of the HJ6A and HJ6B harnesses with newly designed harnesses, and replacement of the PSS with a newly designed heated PSS. <HD SOURCE="HD1">Costs of Compliance</HD> The FAA estimates that this AD, if adopted as proposed, would affect 306 engines installed on airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed 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">Install electronic engine control software</ENT> <ENT>1 work-hour × $85 per hour = $85</ENT> <ENT>$0</ENT> <ENT>$85</ENT> <ENT>$26,010</ENT> </ROW> <ROW> <ENT I="01">Replace PSS with heated PSS</ENT> <ENT>1 work-hours × $85 per hour = $85</ENT> <ENT>185,950</ENT> <ENT>186,035</ENT> <ENT>56,926,710</ENT> </ROW> <ROW> <ENT I="01">Replace HJ6A and HJ6B harnesses</ENT> <ENT>1 work-hour × $85 per hour = $85</ENT> <ENT>57,510</ENT> <ENT>57,595</ENT> <ENT>17,624,070</ENT> </ROW> </GPOTABLE> <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 Findings</HD> 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. <LSTSUB> <HD SOURCE="HED">List of Subjects in 14 CFR Part 39</HD> Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. </LSTSUB> <HD SOURCE="HD1">The Proposed Amendment</HD> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 16k characters. 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