2024-00993. Airworthiness Directives; The Boeing Company Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737–9 airplanes. This AD was prompted by a report of an in-flight departure of a mid cabin door plug, which resulted in a rapid decompression of the airplane. This AD prohibits further flight of affected airplanes, until the airplane is inspected and all applicable corrective actions have been performed. The FAA previously sent an emergency AD to all known U.S. owners and operators of these airplanes. The FAA is issuing this AD to address the unsafe condition on these products.

DATES:

This AD is effective on January 18, 2024. Emergency AD 2024–02–51, issued on January 6, 2024, which contained the requirements of this amendment, was effective with actual notice.

The FAA must receive comments on this AD by March 4, 2024.

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: [phone].

• 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 by searching for and locating Docket No. FAA–2024–0032; 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 final rule, any comments received, and other information. The street address for Docket Operations is listed above.

FOR FURTHER INFORMATION CONTACT:

Michael Linegang, Manager, Operational Safety Branch, FAA; phone: [phone]; email: [e-mail].

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to send any written relevant data, views, or arguments about this AD. Send your comments to an address listed under ADDRESSES . Include “Docket No. FAA–2024–0032; Project Identifier AD–2024–00021–T” at the beginning of your comments. The most helpful comments reference a specific portion of the final rule, 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 final rule 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 final rule.

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 AD 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 AD, 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 AD. Submissions containing CBI should be sent to Michael Linegang, Manager, Operational Safety Branch, FAA; phone: [phone]; email: [e-mail]. 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 issued Emergency AD 2024–02–51, dated January 6, 2024 (Emergency AD 2024–02–51), to address an unsafe condition on certain The Boeing Company Model 737–9 airplanes. The FAA sent the emergency AD to all known U.S. owners and operators of these airplanes. Emergency AD 2024–02–51 prohibits further flight until the airplane is inspected and all applicable corrective actions have been performed.

Emergency AD 2024–02–51 was prompted by a report of an in-flight departure of a mid cabin door plug, which resulted in a rapid decompression of the airplane. The FAA is issuing this AD to address the potential in-flight loss of a mid cabin door plug. This condition, if not addressed, could result in injury to passengers and crew, the door impacting the airplane, and/or loss of control of the airplane.

FAA's Determination

The FAA is issuing this AD because the agency has determined the unsafe condition described previously is likely to exist or develop in other products of the same type design.

AD Requirements

This AD prohibits further flight of affected airplanes, until the airplane is inspected and all applicable corrective actions have been performed using a method approved by the Manager, AIR–520, Continued Operational Safety Branch, FAA.

Interim Action

The FAA considers this AD to be an interim action. If final action is later identified, the FAA might consider further rulemaking then.

FAA's Justification and Determination of the Effective Date

Section 553(b)(3)(B) of the Administrative Procedure Act (APA) (5 U.S.C. 551 et seq.) authorizes agencies to dispense with notice and comment procedures for rules when the agency, for “good cause,” finds that those procedures are “impracticable, unnecessary, or contrary to the public interest.” Under this section, an agency, upon finding good cause, may issue a final rule without providing notice and seeking comment prior to issuance. Further, section 553(d) of the APA authorizes agencies to make rules effective in less than thirty days, upon a finding of good cause.

An unsafe condition exists that required the immediate adoption of Emergency AD 2024–02–51 issued on January 6, 2024, to all known U.S. owners and operators of these airplanes. The FAA found that the risk to the flying public justified waiving notice and comment prior to adoption of this rule because the in-flight loss of a mid cabin door plug could result in injury to passengers and crew, the door impacting the airplane, and/or loss of control of the airplane. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to 14 CFR 39.13 to make it effective to all persons. Given the significance of the risk presented by this unsafe condition, it must be immediately addressed. Accordingly, notice and opportunity for prior public comment are impracticable and contrary to the public interest pursuant to 5 U.S.C. 553(b)(3)(B). In addition, the FAA finds that good cause exists pursuant to 5 U.S.C. 553(d) for making this amendment effective in less than 30 days, for the same reasons the FAA found good cause to forgo notice and comment.

Regulatory Flexibility Act (RFA)

The requirements of the RFA do not apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt a rule without prior notice and comment. Because the FAA has determined that it has good cause to adopt this rule without notice and comment, RFA analysis is not required.

Costs of Compliance

The FAA estimates that this AD affects 144 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD:

Estimated Costs

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Inspection	Up to 8 work-hours × $85 per hour = Up to $680	$0	Up to $680	Up to $12,240.

The FAA has received no definitive data on which to base the cost estimates for the corrective actions specified in this 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

This AD will not have federalism implications under Executive Order 13132. This AD will 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 that this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866, and

(2) Will not affect intrastate aviation in Alaska.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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

[Amended]

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

2024–02–51 The Boeing Company: Amendment 39–22663; Docket No. FAA–2024–0032; Project Identifier AD–2024–00021–T.

(a) Effective Date

The FAA issued Emergency Airworthiness Directive (AD) 2024–02–51 on January 6, 2024, directly to affected owners and operators. As a result of such actual notice, the emergency AD was effective for those owners and operators on the date it was provided. This AD contains the same requirements as that emergency AD and, for those who did not receive actual notice, is effective on January 18, 2024.

(b) Affected ADs

None.

(c) Applicability

This AD applies to The Boeing Company Model 737–9 airplanes, certificated in any category, with a mid cabin door plug installed.

(d) Subject

Air Transport Association (ATA) of America Code 52, Doors.

(e) Unsafe Condition

This AD was prompted by a report of an in-flight departure of a mid cabin door plug, which resulted in a rapid decompression of the airplane. The FAA is issuing this AD to address the potential in-flight loss of a mid cabin door plug, which could result in injury to passengers and crew, the door impacting the airplane, and/or loss of control of the airplane.

(f) Compliance

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

(g) Inspection or Other Action

As of the effective date of this AD, further flight is prohibited until the airplane is inspected and all applicable corrective actions have been performed using a method approved by the Manager, AIR–520, Continued Operational Safety Branch, FAA.

(h) Special Flight Permits

Special flight permits, as described in 14 CFR 21.197 and 21.199, are allowed only for unpressurized flights.

(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 local Flight Standards District 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) of this AD. Information may be emailed to: [e-mail].

(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office.

(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

For further information about this AD, contact Michael Linegang, Manager, Operational Safety Branch, FAA; phone: [phone]; email: [e-mail].

(k) Material Incorporated by Reference

None.

Issued on January 12, 2024.

Caitlin Locke,

Director, Compliance & Airworthiness Division, Aircraft Certification Service.