Airworthiness Directives; ATR-GIE Avions de Transport Régional Airplanes

DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2025-1354; Project Identifier MCAI-2025-00012-T]</DEPDOC> <RIN>RIN 2120-AA64</RIN> <SUBJECT>Airworthiness Directives; ATR—GIE Avions de Transport Régional Airplanes</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 adopt a new airworthiness directive (AD) for certain ATR—GIE Avions de Transport Régional Model ATR42-500 and ATR72 airplanes. This proposed AD was prompted by an investigation indicating that an erroneous monitoring of the travel limitation unit (TLU) could occur when the airplane is flying above a certain speed as a result of the logic input from either air data computer (ADC) 1 or ADC2 input. This proposed AD would require modifying airplanes by installing one or two relays and associated wiring, and testing of the TLU monitoring logic. The FAA is proposing this AD to address the unsafe condition on these products. </SUM> <HD SOURCE="HED">DATES:</HD> The FAA must receive comments on this proposed AD by August 21, 2025. <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-2025-1354; 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. <E T="03">Material Incorporated by Reference:</E> • For European Union Aviation Safety Agency (EASA) material identified in this proposed AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone +49 221 8999 000; email <E T="03">ADs@easa.europa.eu.</E> You may find this material on the EASA website at <E T="03">ad.easa.europa.eu.</E> It is also available at <E T="03">regulations.gov</E> under Docket No. FAA-2025-1354. • You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Jonathan Duong, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: 516-228-7362; email: <E T="03">9-AVS-AIR-BACO-COS@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 relevant data, views, or arguments about this proposal. Send your comments to an address listed under the <E T="02">ADDRESSES</E> section. Include “Docket No. FAA-2025-1354; Project Identifier MCAI-2025-00012-T” 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 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 Jonathan Duong, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: 516-228-362; email: <E T="03">9-AVS-AIR-BACO-COS@faa.gov.</E> Any commentary that the FAA receives that is not specifically designated as CBI will be placed in the public docket for this rulemaking. <HD SOURCE="HD1">Background</HD> EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2025-0004, dated January 7, 2025 (EASA AD 2025-0004) (also referred to as the MCAI), to correct an unsafe condition for certain ATR—GIE Avions de Transport Régional Model ATR42-400, ATR42-500, ATR72-101, ATR72-102, ATR72-201, ATR72-202, ATR72-211, ATR72-212, and ATR72-212A airplanes. Model ATR42-400 airplanes are not certificated by the FAA and are not included on the U.S. type certificate data sheet; this proposed AD therefore does not include those airplanes in the applicability. The MCAI states that an ATR internal review of the TLU new avionics suite design identified an erroneous behavior of core processing module (CPM) 2, hosting the data concentration application (DCA) 2, that might affect the TLU command, monitoring, and indication. Further investigation results indicated that an erroneous monitoring of the TLU could occur when the airplane is flying above a certain speed due to the logic input from either ADC1 or ADC2 input. The FAA is proposing this AD to address erroneous behavior of CPM 2, hosting the DCA 2, that could affect the TLU command, monitoring, and indication. This condition, if not corrected, could result in the rudder deflection not being limited at high airplane speed, which, if combined with a large rudder pedal input, could lead to the loss of control of the airplane. You may examine the MCAI in the AD docket at <E T="03">regulations.gov</E> under Docket No. FAA-2025-1354. <HD SOURCE="HD1">Material Incorporated by Reference Under 1 CFR Part 51</HD> EASA AD 2025-0004 specifies procedures for modifying airplanes by installing one or two relays and associated wiring. EASA AD 2025-0004 also specifies procedures for an operational test of the TLU monitoring logic after the modification, a functional test of the rudder travel limiter unit, and obtaining and following instructions to correct any failed test. For airplanes on which a previous revision of the applicable service information has been accomplished, EASA AD 2025-0004 specifies accomplishing “Additional Work,” which consists of a functional test of the rudder travel limiter unit. 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> This product has been approved by the aviation authority of another country and is 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 referenced above. The FAA is issuing this NPRM after determining that the unsafe condition described previously is likely to exist or develop in other products of the same type design. <HD SOURCE="HD1">Proposed AD Requirements in This NPRM</HD> This proposed AD would require accomplishing the actions specified in EASA AD 2025-0004 described previously, except for any differences identified as exceptions in the regulatory text of this proposed AD. <HD SOURCE="HD1">Explanation of Required Compliance Information</HD> In the FAA's ongoing efforts to improve the efficiency of the AD process, the FAA developed a process to use some civil aviation authority (CAA) ADs as the primary source of information for compliance with requirements for corresponding FAA ADs. The FAA has been coordinating this process with manufacturers and CAAs. As a result, the FAA proposes to incorporate EASA AD 2025-0004 by reference in the FAA final rule. This proposed AD would, therefore, require compliance with EASA AD 2025-0004 in its entirety through that incorporation, except for any differences identified as exceptions in the regulatory text of this proposed AD. Using common terms that are the same as the heading of a particular section in EASA AD 2025-0004 does not mean that operators need comply only with that section. For example, where the AD requirement refers to “all required actions and compliance times,” compliance with this AD requirement is not limited to the section titled “Required Action(s) and Compliance Time(s)” in EASA AD 2025-0004. Material required by EASA AD 2025-0004 for compliance will be available at <E T="03">regulations.gov</E> under Docket No. FAA-2025-1354 after the FAA final rule is published. <HD SOURCE="HD1 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 19k characters. 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