# [Amended]
**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 737-8, 737-9, and 737-8200 (737 MAX) airplanes. This proposed AD was prompted by reports indicating cracks in the bear strap and stub frame at the forward galley door cutout. This proposed AD would require inspections for existing repairs; an inspection for any crack of the fuselage skin, bear strap, and stub frame; repetitive inspections for any crack of the bear strap and stub frame; and applicable on-condition actions. 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 January 9, 2026.
**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-2025-3439; 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.
*Material Incorporated by Reference:*
• 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 *myboeingfleet.com.*
• 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 *regulations.gov* under Docket No. FAA-2025-3439.
**FOR FURTHER INFORMATION CONTACT:**
Luis Cortez-Muniz, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3958; 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 using a method listed under the *ADDRESSES* section. Include “Docket No. FAA-2025-3439; Project Identifier AD-2025-00463-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 Luis Cortez-Muniz, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3958; 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 reports indicating that cracking was found in the bear strap and stub frame at the forward galley door cutout, from station (STA) 290 to STA 296 and between stringer S-8R and stringer S-9R, on certain Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes (737NG airplanes). Boeing investigated and found surface scratches on the bear strap, which were inadvertently created while removing sealant and adhesive during hot bonding process of fuselage skin and bear strap. The presence of these scratches, along with local elevated stresses in the bear strap, cause a reduction in fatigue life and early cracking. Although no cracks have been reported in the same areas on The Boeing Company Model 737 MAX airplanes, The Boeing Company Model 737 MAX airplanes have similar design and build process, making The Boeing Company Model 737 MAX airplanes susceptible to the same crack condition. This condition, if not addressed, may result in the inability of a principal structural element to sustain limit load, which could adversely affect the structural integrity of the airplane.
Boeing issued Requirements Bulletin 737-53A1383 to address the identified unsafe condition for The Boeing Company Model 737NG airplanes. Subsequently, the FAA issued AD 2021-02-13, Amendment 39-21396 (86 FR10776, February 23, 2021) to require inspections of the fuselage skin and bear strap at the forward galley door between certain stations for cracks, and applicable on-condition actions, in accordance with Boeing Alert Requirements Bulletin 737-53A1383 RB, Revision 1, dated February 19, 2020.
**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.
**Material Incorporated by Reference Under 1 CFR Part 51**
The FAA reviewed Boeing Alert Requirements Bulletin 737-53A1420 RB, dated February 13, 2025. This material specifies procedures for doing Option 1 or Option 2 actions as specified below, and applicable on-condition actions. On-condition actions include replacing the stub frame, doing alternative inspections, and doing a repair.
• Option 1—Perform initial external general visual inspection (GVI) of the fuselage skin and gap cover for any repair, initial internal GVI of the bear strap and stub frame for any repair, and repetitive internal high frequency eddy current (HFEC) inspections of the bear strap and stub frame for any crack.
• Option 2—Perform initial external GVI of the fuselage skin and gap cover for any repair, initial internal GVI of the stub frame for any repair, initial external HFEC inspection of the fuselage skin for any crack, initial external low frequency eddy current (LFEC) inspection of the bear strap for any crack, initial internal HFEC inspection of the stub frame for any crack, and repetitive internal HFEC inspections of the bear strap and stub frame for any crack.
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 *ADDRESSES* section.
**Proposed AD Requirements in This NPRM**
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. For information on the procedures and compliance times, see this material at *regulations.gov* under Docket No. FAA-2025-3439.
**Costs of Compliance**
The FAA estimates that this AD, if adopted as proposed, would affect 476 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD:
| Action | Labor cost | Parts cost | Cost per product | Cost on U.S. |
| --- | --- | --- | --- | --- |
| Option 1—Initial inspections | 31 work-hours × $85 per hour = $2,635 | $0 | $2,635 | $1,254,260. |
| Option 2—Initial inspections | 7 work-hours × $85 per hour = $595 | 0 | $595 | $283,220. |
| Repetitive internal HFEC inspections of the bear strap and stub frame per Option 1 or Option 2 | 29 work-hours × $85 per hour = $2,465 per inspection cycle | 0 | $2,465 per inspection cycle | $1,173,340 per inspection cycle. |
The FAA estimates the following costs to do any necessary replacements that would be required based on the results of the proposed inspection. The agency has no way of determining the number of aircraft that might need this replacement:
| Action | Labor cost | Parts cost | Cost per |
| --- | --- | --- | --- |
| Replace the stub frame | 35 work-hours × $85 per hour = $2,975 | $1,359 | $4,334 |
The FAA has received no definitive data that would enable the agency to provide cost estimates for the on-condition repairs specified in this proposed AD.
**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**
1. The authority citation for part 39 continues to read as follows:
**Authority:**
49 U.S.C. 106(g), 40113, 44701.
§ 39.13
2. The FAA amends § 39.13 by adding the following new airworthiness directive:
*The Boeing Company:* Docket No. FAA-2025-3439; Project Identifier AD-2025-00463-T.
**(a) Comments Due Date**
The FAA must receive comments on this airworthiness directive (AD) by January 9, 2026.
**(b) Affected ADs**
None.
**(c) Applicability**
This AD applies to The Boeing Company Model 737-8, 737-9, and 737-8200 airplanes, certificated in any category, as identified in Boeing Alert Requirements Bulletin 737-53A1420 RB, dated February 13, 2025.
**(d) Subject**
Air Transport Association (ATA) of America Code 53, Fuselage.
**(e) Unsafe Condition**
This AD was prompted by reports indicating cracks in the bear strap and stub frame at the forward galley door cutout, from station (STA) 290 to STA 296 and between stringer S-8R and stringer S-9R. The FAA is issuing this AD to address any crack in the fuselage skin, bear strap, and stub frame at the forward galley door cutout from STA 290 to STA 296 and between stringer S-8R and stringer S-9R, before it reaches critical length. The unsafe condition, if not addressed, may result in the inability of a principal structural element to sustain limit load, which could adversely affect the structural integrity of the airplane.
**(f) Compliance**
Comply with this AD within the compliance times specified, unless already done.
**(g) Required Actions**
Except as specified in paragraph (h) of this AD: At the applicable times specified in the “Compliance” paragraph of Boeing Alert Requirements Bulletin 737-53A1420 RB, dated February 13, 2025, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin 737-53A1420 RB, dated February 13, 2025.
*Note 1 to paragraph (g):* Guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletin 737-53A1420, dated February 13, 2025, which is referred to in Boeing Alert Requirements Bulletin 737-53A1420 RB, dated February 13, 2025.
**(h) Exceptions to Requirements Bulletin Specifications**
(1) Where the Compliance Time columns of the tables in the “Compliance” paragraph of Boeing Alert Requirements Bulletin 737-53A1420 RB, dated February 13, 2025, refers to the original issue date of Requirements Bulletin 737-53A1420 RB, this AD requires using the effective date of this AD.
(2) Where Boeing Alert Requirements Bulletin 737-53A1420 RB, dated February 13, 2025, specifies contacting Boeing for repair instructions or for alternative inspections: This AD requires doing the repair, or doing the alternative inspections and applicable on-condition actions using a method approved in accordance with the procedures specified in paragraph (i) of this AD.
**(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 Continued Operational Safety Branch, send it to the attention of the person identified in paragraph (j) of this AD. Information may be emailed to: *[email protected].* Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the responsible Flight Standards Office.
(2) 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**
For more information about this AD, contact Luis Cortez-Muniz, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3958; email: *[email protected].*
**(k) Material Incorporated by Reference**
(1) The Director of the Federal Register approved the incorporation by reference of the material listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this material as applicable to do the actions required by this AD, unless the AD specifies otherwise.
(i) Boeing Alert Requirements Bulletin 737-53A1420 RB, dated February 13, 2025.
(ii) [Reserved]
(3) For Boeing material identified in this 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 *myboeingfleet.com.*
(4) 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.
(5) You may view this material at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, visit *www.archives.gov/federal-register/cfr/ibr-locations* or email *[email protected].*
Issued on October 20, 2025.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft Certification Service.