[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]


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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
1. The authority citation for part 39 continues to read as follows:

    Authority:  49 U.S.C. 106(f), 40113, 44701.


Sec.  39.13   [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

The Boeing Company: Docket No. FAA-2025-0349; Project Identifier AD-
2024-00208-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by May 27, 2025.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to certain The Boeing Company Model 737-700, 
737-800, 737-900, 737-900ER, 737-8, and 737-9 series airplanes, 
certificated in any category, with lavatory bifold door latch 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.

(d) Subject

    Air Transport Association (ATA) of America Code 25; Equipment/
Furnishings.

(e) Unsafe Condition

    This AD was prompted by a report that a passenger was unable to 
exit the lavatory during flight due to a broken latch that prevented 
toggling of the lock. The FAA is issuing this AD to address bifold 
door latch failure during service preventing the bifold door from 
opening without mechanic assistance. 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.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Replace Lavatory Bifold Door Latch

    Within 4 months after the effective date of this AD. Replace 
lavatory bifold door latch having part number 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 part number 
SC1L500031-9/20218-9 or SC1L500031-10/20218-10.
    Note 1 to paragraph (g): Guidance for accomplishing the actions 
required by this AD can be found in B/E Aerospace Service Bulletin 
1L3-25-0069, Revision 4, dated April 18, 2024.
    Note 2 to paragraph (g): For airplanes modified via Supplemental 
Type Certificate (STC) ST02574SE, guidance for accomplishing the 
actions required by this AD can be found in B/E Aerospace Service 
Bulletin 1L3-25-0083, Revision 2, dated August 26, 2020.
    Note 3 to paragraph (g): For airplanes modified via STC 
ST02582SE, guidance for accomplishing the actions required by this 
AD can be found in B/E Aerospace Service Bulletin 1L3-25-0112, 
Revision 1, dated August 26, 2020.

(h) Parts Installation Prohibition

    As of the effective date of this AD, no person may install, on 
any airplane, a lavatory bifold door latch having part number 
SC1L500031-3/20218-3, SC1L500031-4/20218-4, SC1L500031-5/20218-5/
20218-7, or SC1L500031-6/20218-6/20218-8.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, AIR-520, Continued Operational Safety Branch, 
FAA, has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19. In accordance with 14 
CFR 39.19, send your request to your principal inspector or 
responsible Flight Standards Office, as appropriate. If sending 
information directly to the manager of the certification office, 
send it to the attention of the person identified in paragraph 
(j)(1) of this AD. Information may be emailed to: [email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the responsible Flight Standards Office.

[[Page 15419]]

    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair, modification, or alteration required by this AD 
if it is approved by The Boeing Company Organization Designation 
Authorization (ODA) that has been authorized by the Manager, AIR-
520, Continued Operational Safety Branch, FAA, to make those 
findings. To be approved, the repair method, modification deviation, 
or alteration deviation must meet the certification basis of the 
airplane, and the approval must specifically refer to this AD.

(j) Related Information

    (1) For more information about this AD, contact Nicole Tsang, 
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 
98198; phone: 206-231-3959; email: [email protected].
    (2) For B/E Aerospace material identified in this AD that is not 
incorporated by reference, contact Collins Aerospace, Interiors--B/E 
Aerospace--ALCI, 11404 Commando Road, Suite B, Everett, WA 98204, 
United States; telephone +1-888-232-2594; email 
[email protected]; website 
customers.collinsaerospace.com.

(k) Material Incorporated by Reference

    None.

    Issued on March 13, 2025.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft 
Certification Service.
[FR Doc. 2025-06157 Filed 4-10-25; 8:45 am]
BILLING CODE 4910-13-P