Airworthiness Directives; The Boeing Company Airplanes

DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2025-0196; Project Identifier AD-2024-00250-T]</DEPDOC> <RIN>RIN 2120-AA64</RIN> <SUBJECT>Airworthiness Directives; The Boeing Company 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 supersede Airworthiness Directive (AD) 2019-12-13, which applies to all The Boeing Company Model 757 airplanes. AD 2019-12-13 requires repetitive checks of the aileron trim actuator bearing for free rotation, repetitive detailed inspections of the aileron trim actuator attachment lug for damage and cracking, and applicable on-condition actions. Since the FAA issued AD 2019-12-13, the FAA has determined that a modification must be done to address the unsafe condition. This proposed AD would continue to require the actions in AD 2019-12-13. This proposed AD would also require for certain airplanes changing the lateral control box support assembly and installing an aileron trim actuator bracket, and for certain other airplanes replacing the existing actuator lateral control fitting with an aileron trim actuator bracket, which terminates the repetitive checks and inspections. 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 March 31, 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-2025-0196; 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. <E T="03">Material Incorporated by Reference:</E> • For the material identified in this proposed AD, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600; telephone 562-797-1717; website <E T="03">myboeingfleet.com.</E> • 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. It is also available at <E T="03">regulations.gov</E> under Docket No. FAA-2025-0196. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Katherine Venegas, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 562-627-5353; email: <E T="03">katherine.venegas@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-2025-0196; Project Identifier AD-2024-00250-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 Katherine Venegas, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 562-627-5353; email: <E T="03">katherine.venegas@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> The FAA issued AD 2019-12-13, Amendment 39-19668 (84 FR 30577, June 27, 2019) (AD 2019-12-13), for all Boeing 757 airplanes. AD 2019-12-13 was prompted by a report of the failure of the aileron trim actuator attachment lug. AD 2019-12-13 requires repetitive checks of the aileron trim actuator bearing for free rotation, repetitive detailed inspections of the aileron trim actuator attachment lug for damage and cracking, and applicable on-condition actions. The agency issued AD 2019-12-13 to address failure of the aileron trim actuator attachment lug and subsequent loss of feel force, wheel centering, and lateral trim, which, if not corrected, could cause over-control of the airplane and subsequent lateral pilot-induced oscillations that could adversely affect continued safe flight and landing. <HD SOURCE="HD1">Actions Since AD 2019-12-13 Was Issued</HD> Since the FAA issued AD 2019-12-13, the FAA has determined that a modification must be done to address the unsafe condition. The preamble to AD 2019-12-13 specifies that the FAA considers that AD “interim action” and that the FAA might consider further rulemaking if a modification is developed, approved, and available. The manufacturer has since developed such a modification, which would terminate the repetitive inspections required by AD 2019-12-13. <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">Material Incorporated by Reference Under 1 CFR Part 51</HD> The FAA reviewed Boeing Alert Requirements Bulletin 757-27A0159 RB, Revision 1, dated April 29, 2020. This material describes procedures for repetitive checks of the aileron trim actuator bearing for free rotation, repetitive detailed inspections of the aileron trim actuator attachment lug for damage or cracking, and applicable on-condition actions. On-condition actions include high frequency eddy current (HFEC) inspections of the aileron trim actuator attachment lug for cracking, repair, and replacement. This revision only adds references to AD 2019-12-13 and does not add any new actions. The FAA also reviewed Boeing Alert Requirements Bulletin 757-27A0160 RB, dated April 1, 2024. This material specifies procedures for modifying the affected airplanes, which includes for certain airplanes changing the lateral control box support assembly (which includes doing a portable method C penetrant inspection of the machined surface of the lug for any crack, and repair as applicable) and installing an aileron trim actuator bracket, and for certain other airplanes replacing the existing actuator lateral control fitting with an aileron trim actuator bracket. Accomplishment of the modification terminates the repetitive checks and inspections specified in Boeing Alert Requirements Bulletin 757-27A0159 RB. This proposed AD would also require Boeing Alert Requirements Bulletin 757-27A0159 RB, dated March 29, 2019, which the Director of the Federal Register approved for incorporation by reference as of July 12, 2019 (84 FR 30577, June 27, 2019). 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">Proposed AD Requirements in This NPRM</HD> This proposed AD would retain all of the requirements of AD 2019-12-13 and would refer to Boeing Alert Requirements Bulletin 757-27A0159 RB, Revision 1, dated April 29, 2020, as the appropriate source of service information for accomplishing the retained actions. This proposed AD would also require doing the actions described in Boeing Alert Requirements Bulletin 757-27A0160 RB, dated April 1, 2024, above, except for any differences identified as exceptions in the regulatory text of this proposed AD. For information on the procedures and compliance times, see this material at <E T="03">regulations.gov</E> under Docket No. FAA-2025-0196. <HD SOURCE="HD1">Costs of Compliance</HD> The FAA estimates that this AD, if adopted as proposed, would affect 460 airplanes of U.S. registry. The FAA estimates ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 23k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━