2025-06157: Airworthiness Directives; The Boeing Company Airplanes

Federal Register, Volume 90 Issue 69 (Friday, April 11, 2025) [Federal Register Volume 90, Number 69 (Friday, April 11, 2025)] [Proposed Rules] [Pages 15417-15419] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 2025-06157] ======================================================================== Proposed Rules Federal Register ________________________________________________________________________ This section of the FEDERAL REGISTER contains notices to the public of the proposed issuance of rules and regulations. The purpose of these notices is to give interested persons an opportunity to participate in the rule making prior to the adoption of the final rules. ======================================================================== Federal Register / Vol. 90, No. 69 / Friday, April 11, 2025 / Proposed Rules [[Page 15417]] DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2025-0349; Project Identifier AD-2024-00208-T] RIN 2120-AA64 Airworthiness Directives; The Boeing Company Airplanes

Agency

Federal Aviation Administration (FAA), DOT.

Action

Notice of proposed rulemaking (NPRM). -----------------------------------------------------------------------

Summary

The FAA proposes to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 737-700, 737-800, 737-900, 737- 900ER, 737-8, and 737-9 series airplanes. This proposed AD was prompted by a report of a passenger being unable to exit the lavatory during flight due to a broken latch that prevented toggling of the lock. This proposed AD would require replacing lavatory bifold door latches with latches having an improved design. This proposed AD would also prohibit the installation of affected parts. The FAA is proposing this AD to address the unsafe condition on these products.

Dates

The FAA must receive comments on this proposed AD by May 27, 2025.

Addresses

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods: Federal eRulemaking Portal: Go to regulations.gov. Follow the instructions for submitting comments. Fax: 202-493-2251. Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590. Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2025-0349; 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.

For Further Information Contact

Nicole Tsang, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206- 231-3959; email: [email protected].

Supplementary Information

Comments Invited 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 ADDRESSES section. Include ``Docket No. FAA-2025-0349; Project Identifier AD-2024-00208-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 regulations.gov, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this NPRM. Confidential Business Information 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 Nicole Tsang, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3959; email: [email protected]. Any commentary that the FAA receives that is not specifically designated as CBI will be placed in the public docket for this rulemaking. Background The FAA has received a report indicating that during flight, a passenger was unable to exit the lavatory due to a broken latch that prevented toggling of the lock. Flight attendants were unable to open the bifold door, leading the flightcrew to accomplish an unscheduled landing. It was determined that bifold door latches failed in service, preventing the bifold door from opening without mechanic assistance. The root cause was material fatigue of the plastic structure of the bifold door latch. The material fatigue was caused primarily by excessive stress combined with weld-line and machining marks from drilling holes for inserts into the plastic structure. In an otherwise survivable emergency event (e.g., severe turbulence, medical emergency, or emergency egress), potential damages to the lavatory lock could impede access to the passenger and impede egress during an emergency evacuation, which may result in serious injury to the trapped occupant. FAA's Determination 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. Proposed AD Requirements in This NPRM This proposed AD would require replacing the lavatory bifold door latch having part number (P/N) SC1L500031-3/20218-3, SC1L500031-4/ 20218-4, SC1L500031-5/20218-5/20218-7, or SC1L500031-6/20218-6/20218-8 with lavatory bifold door latch having P/N SC1L500031-9/20218-9 or SC1L500031-10/20218-10. This proposed AD would also prohibit the installation of the affected part. [[Page 15418]] Costs of Compliance The FAA estimates that this AD, if adopted as proposed, would affect 2,612 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD: Estimated Costs ---------------------------------------------------------------------------------------------------------------- Cost on U.S. Action Labor cost Parts cost Cost per product operators ---------------------------------------------------------------------------------------------------------------- Replacement..................... 2 work-hours x $85 Up to $481 per Up to $1,302 (Up Up to $3,400,824. per hour = $170 latch. to 2 latches per per latch. airplane). ---------------------------------------------------------------------------------------------------------------- The FAA has included all known costs in its cost estimate. According to the manufacturer, however, some or all of the costs of this proposed AD may be covered under warranty, thereby reducing the cost impact on affected operators. Authority for This Rulemaking 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. Regulatory Findings 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 this 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. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. The Proposed Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows: PART 39--AIRWORTHINESS DIRECTIVES 0