Airworthiness Directives; The Boeing Company Airplanes

DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2025-1114; Project Identifier AD-2025-00314-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) 2023-08-04, which applies to certain The Boeing Company Model 787-8, 787-9, and 787-10 airplanes. AD 2023-08-04 requires a detailed visual inspection of all door 1 and door 3 lavatory and galley potable water systems for any missing or incorrectly installed clamshell couplings, and applicable on-condition actions. Since the FAA issued AD 2023-08-04, Boeing has discovered that some couplings did not have the required safety strap and has developed a design solution that replaces the couplings with couplings that have safety straps. This proposed AD would retain the requirements of AD 2023-08-04 and require, for certain airplanes, a detailed inspection of all clamshell couplings for the presence and correct installation of safety straps at door 1 and door 3 lavatories and galleys with a potable water system, and applicable on-condition actions, which would terminate the existing requirements. The AD would also prohibit the installation of affected parts at inspection locations. 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 August 18, 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-2025-1114; 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 Boeing 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-2025-1114. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Courtney Tuck, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3986; email: <E T="03">courtney.k.tuck@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 using a method listed under the <E T="02">ADDRESSES</E> section. Include “Docket No. FAA-2025-1114; Project Identifier AD-2025-00314-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 Courtney Tuck, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3986; email: <E T="03">courtney.k.tuck@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 2023-08-04, Amendment 39-22419 (88 FR 33823, May 25, 2023) (AD 2023-08-04), for certain The Boeing Company Model 787-8, 787-9, and 787-10 airplanes. AD 2023-08-04 was prompted by reports of a loss of water pressure during flight and water leaks that affected multiple pieces of electronic equipment. AD 2023-08-04 requires a detailed visual inspection of all door 1 and door 3 lavatory and galley potable water systems for any missing or incorrectly installed clamshell couplings, and applicable on-condition actions. The agency issued AD 2023-08-04 to address incorrectly installed or missing lavatory and galley clamshell couplings that could lead to water leaks and water migration to critical flight equipment, which may affect the continued safe flight and landing of the airplane. The FAA previously issued an NPRM on July 15, 2024 (89 FR 57374) for certain The Boeing Company Model 787-8 and 787-9 airplanes to address the unsafe condition. The FAA subsequently withdrew that NPRM on February 4, 2025 (90 FR 8914) due to a determination that the identified service information may not have adequately addressed the unsafe condition on one of the galleys, and the Model 787-10 airplanes should have been included in the applicability. This NPRM includes the Model 787-10 airplane and will address the unsafe condition. <HD SOURCE="HD1">Actions Since AD 2023-08-04 Was Issued</HD> The preamble to AD 2023-08-04 explains that the FAA considers the requirements “interim action” and was considering further rulemaking. Since the FAA issued AD 2023-08-04, Boeing has determined that some clamshell couplings do not have the required safety straps and has since developed procedures to ensure that affected clamshell couplings have correctly installed safety straps. The FAA has now determined that further rulemaking is necessary, and this proposed AD follows from that determination. The FAA is proposing this AD to prevent a loss of water pressure during flight and water leaks that can affect multiple pieces of electronic equipment. The unsafe condition, if not addressed, could lead to water migration to critical flight equipment, which may affect the continued safe flight and landing of the airplane. <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 B787-81205-SB250299-00 RB, Issue 002, dated February 28, 2025. This material specifies procedures for a detailed inspection for the presence and correct installation of safety straps at the clamshell couplings at door 1 and door 3 lavatories and galleys with a potable water system. The material also specifies applicable on-condition actions including correcting the installation of the safety strap, replacing any clamshell coupling that does not have a strap with a new clamshell coupling that has a safety strap, and performing a water leak test. This proposed AD would also require Boeing Alert Requirements Bulletin B787-81205-SB380021-00 RB, Issue 001, dated August 12, 2022, which the Director of the Federal Register approved for incorporation by reference as of June 29, 2023 (88 FR 33823, May 25, 2023). 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 2023-08-04. This proposed AD would require accomplishing the actions specified in the material already described, except for any differences identified as exceptions in the regulatory text of this proposed AD. This proposed AD would also prohibit the installation of affected parts at inspection locations. For information on the procedures and compliance times, see this material at <E T="03">re ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 23k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━