Airworthiness Directives: The Boeing Company Airplanes

Airworthiness Directives; The Boeing Company Airplanes

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-2024-2008; Project Identifier AD-2024-00122-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 Joseph Hodgin, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3962; 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 from Boeing that during manufacture of four drag brace lower lock link assemblies for the MLG, a fluorescent penetrant inspection was not performed. The subsequent investigation determined that the quality escape was caused by human error and has been isolated to a single technician. Undetected cracks could lead to fracture of the drag brace lower lock link assembly. This condition, if not addressed, could lead to MLG collapse, which could result in loss of directional control while the airplane is on the ground, with the potential for off-runway excursion or penetration of the wing box fuel tank.

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 B787-81205-SB320048-00 RB, Issue 001, dated November 20, 2023. This material specifies procedures for doing a check of maintenance records or an inspection of the drag brace lower lock link assembly on the right and left MLG for affected serial numbers and applicable on-condition actions. On-condition actions include replacing any affected drag brace lower lock link assembly on the MLG with a serviceable drag brace lower lock link assembly. 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 as discussed under "Differences Between this Proposed AD and the Referenced Material," and except for any differences identified as exceptions in the regulatory text of this proposed AD. This proposed AD would also prohibit the installation of affected parts. For information on the procedures and compliance times, see this material at regulations.gov under Docket No. FAA-2024-2008.

Differences Between This Proposed AD and the Referenced Material

The effectivity of Boeing Alert Requirements Bulletin B787-81205-SB320048-00 RB, Issue 001, dated November 20, 2023, is limited to Model 787-8, 787-9, and 787-10 airplanes, line numbers 6 through 1168 inclusive. However, the applicability of this proposed AD includes all The Boeing Company Model 787-8, 787-9, and 787-10 airplanes. Because the affected drag brace lower lock link assemblies are rotable parts, the FAA has determined that these parts could later be installed on airplanes that were initially delivered with acceptable drag brace lower lock link assemblies, thereby subjecting those airplanes to the unsafe condition.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 156 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD:

The FAA estimates the following costs to do any necessary replacement 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:

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.

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

The Boeing Company: Docket No. FAA-2024-2008; Project Identifier AD-2024-00122-T.

(a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by September 16, 2024.

(b) Affected ADs

None.

(c) Applicability

This AD applies to all The Boeing Company Model 787-8, 787-9, and 787-10 airplanes, certificated in any category.

(d) Subject

Air Transport Association (ATA) of America Code 32, Landing gear.

(e) Unsafe Condition

This AD was prompted by a report that during manufacture of drag brace lower lock link assemblies for the main landing gear (MLG), a certain inspection was not performed. The FAA is issuing this AD to address undetected cracks that could lead to fracture of the drag brace lower lock link assembly. The unsafe condition, if not addressed, could result in MLG collapse, which could result in loss of directional control while the airplane is on the ground, with the potential for off-runway excursion or penetration of the wing box fuel tank.

(f) Compliance

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

(g) Required Actions

For airplanes with an original airworthiness certificate or original export certificate of airworthiness issued on or before the effective date of this AD: Except as specified by paragraph (h) of this AD, at the applicable times specified in the "Compliance" paragraph of Boeing Alert Requirements Bulletin B787-81205-SB320048-00 RB, Issue 001, dated November 20, 2023, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin B787-81205-SB320048-00 RB, Issue 001, dated November 20, 2023. The actions specified in Boeing Alert Requirements Bulletin B787-81205-SB320048-00 RB, Issue 001, dated November 20, 2023, apply to airplanes not listed in Boeing Alert Requirements Bulletin B787-81205-SB320048-00 RB, Issue 001, dated November 20, 2023.

Note 1 to paragraph (g): Guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletin B787-81205-SB320048-00, Issue 001, dated November 20, 2023, which is referred to in Boeing Alert Requirements Bulletin B787-81205-SB320048-00 RB, Issue 001, dated November 20, 2023.

(h) Exceptions to Service Information Specifications

Where the Compliance Time column of the table in the "Compliance" paragraph of Boeing Alert Requirements Bulletin B787-81205-SB320048-00 RB, Issue 001, dated November 20, 2023, refers to the Issue 001 date of Requirements Bulletin B787-81205-SB320048-00 RB, this AD requires using the effective date of this AD.

(i) Parts Installation Prohibition

As of the effective date of this AD, no person may install a drag brace lower lock link assembly, part number 531Z2010-501 and serial number 19ZHQ00772, 19ZHQ00773, 19ZHQ00890, or 19ZHQ00891, on any airplane.

(j) 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 (k)(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.

(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.

(k) Related Information

(1) For more information about this AD, contact Joseph Hodgin, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3962; email: [email protected].

(2) Material identified in this AD that is not incorporated by reference is available at the address specified in paragraph (l)(3) of this AD.

(l) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference (IBR) 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 B787-81205-SB320048-00 RB, Issue 001, dated November 20, 2023.

(ii) [Reserved]

(3) For the 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].