Airworthiness Directives; The Boeing Company Airplanes

DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2025-1103; Project Identifier AD-2024-00141-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) 2024-01-01, which applies to certain The Boeing Company Model 787-8, 787-9, and 787-10 airplanes. AD 2024-01-01 requires repetitive general visual inspections (GVIs) of the area under all lavatory washbasins for evidence of intermittent and active leaks at the faucet control module (FCM) and applicable on-condition actions. The FAA has determined that the affected FCMs must be replaced with an improved design FCM to address the unsafe condition. This proposed AD would continue to require the actions of AD 2024-01-01 and would require replacing the FCM as terminating action for the repetitive GVIs, performing a leak test, installing moisture management devices, and performing applicable on-condition actions. 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 July 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-2025-1103; 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 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-2025-1103. <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 to an address listed under the <E T="02">ADDRESSES</E> section. Include “Docket No. FAA-2025-1103; Project Identifier AD-2024-00141-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 2024-01-01, Amendment 39-22652 (89 FR 6422, February 1, 2024) (AD 2024-01-01), for The Boeing Company Model 787-8, 787-9, and 787-10 airplanes with certain line numbers. AD 2024-01-01 was prompted by reports of undetected water leaks from the FCM migrating below the passenger floor in multiple lavatory locations during flight, and into the electronic equipment bay(s). AD 2024-01-01 requires repetitive GVIs of the area under all lavatory washbasins for evidence of intermittent and active leaks at the FCM. If there are leaks, AD 2024-01-01 requires replacing the FCM with a new or serviceable FCM and doing a leak test. The agency issued AD 2024-01-01 to address undetected water leaks, which could damage flight critical equipment. Investigation identified the o-ring seal at the top of the FCM mixing chamber as the source of the leaking. As a result, Boeing developed an FCM with an improved design that is not susceptible to leaking. The FAA has determined that replacing FCM part number (P/N) AFUT000200A0001 or AFUT000200A0002 with the new FCM P/N AFUT000200A0004 is necessary to address the unsafe condition and would be terminating action for the GVIs required by AD 2024-01-01. <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-SB250290-00 RB, Issue 002, dated January 31, 2025. This material specifies procedures for a repetitive general visual inspection of the area under all lavatory washbasins for evidence of intermittent and active leaks at the FCM and applicable on-condition actions. On-condition actions include replacing the affected FCM with new or serviceable FCM at affected lavatory washbasin(s) and performing a leak test. If a leak is found during the leak test, this material specifies completing applicable corrective action, repeating the leak test, and making sure no leak is found. The FAA reviewed Boeing Alert Requirements Bulletin B787-81205-SB250291-00 RB, Issue 002, dated November 22, 2024. This material specifies procedures for replacing the FCM, performing a leak test and repairing any leaks, and installing moisture management devices if not previously installed. This material also specifies procedures for reviewing and updating, if necessary, the existing maintenance program documentation to include Maintenance Review Board Report item number 38-025-00. This material specifies that replacement of the FCM terminates the repetitive inspections (which are required by AD 2024-01-01). This proposed AD would also require Boeing Alert Requirements Bulletin B787-81205-SB250290-00 RB, Issue 001, dated November 1, 2022, which the Director of the Federal Register approved for incorporation by reference as of March 7, 2024 (89 FR 6422, February 1, 2024). 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 the repetitive inspections and all other requirements in AD 2024-01-01. This proposed AD would also require replacing the FCM as specified in the material already described, except for any differences identified as exceptions in the regulatory text of this proposed AD. The FCM replacement would be terminating action for the repetitive inspections. For information on the procedures and compliance times, see this material at <E T="03">regulations.gov</E> under Docket No. FAA-2025-1103. <HD SOURCE="HD1">Costs of Compliance</HD> The FAA estimates that this AD, if adopted as proposed, would affect 155 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,r50,8,xs72,xs72"> <TTITLE>Estimated Costs</TTITLE> <CHED H="1">Action</CHED> <CHED H="1">Labor cost</CHED> Cost on U.S. operators </CHED> <ROW> <ENT I="01">GVI of area under all lavatory washbasins (retained actions from AD 2024-01-01)</ENT> <ENT>2 work-hour × $85 per hour = $170 per inspect ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 24k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━