2023-28848. Airworthiness Directives; Airbus SAS Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

The FAA is superseding Airworthiness Directive (AD) 2020–24–12, which applied to certain Airbus SAS Model A350–941 airplanes. AD 2020–24–12 required replacing certain center wing box (CWB) fasteners with fasteners having improved friction efficiency. This AD was prompted by reports that certain CWB fasteners had rotated inside the fastener holes due to insufficient friction for the application, and by the determination that additional work is necessary to ensure the correct application of the fuel vapor barrier structure paint on the outside of the CWB. This AD continues to require the actions in AD 2020–24–12; and requires the additional work; as specified in European Union Aviation Safety Agency (EASA) AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products.

DATES:

This AD is effective February 7, 2024.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of February 7, 2024.

ADDRESSES:

AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA–2023–1887; 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, the mandatory continuing airworthiness information (MCAI), any comments received, and other information. The address for Docket Operations is U.S. Department of Transportation, Docket Operations, M–30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue SE, Washington, DC 20590.

Material Incorporated by Reference:

• For material incorporated by reference in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone [phone]; email [e-mail]; website easa.europa.eu. You may find this material on the EASA website at ad.easa.europa.eu.

• 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 in the AD docket at regulations.gov under Docket No. FAA–2023–1887.

FOR FURTHER INFORMATION CONTACT:

Dat Le, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone [phone]; email [e-mail].

SUPPLEMENTARY INFORMATION:

Background

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2020–24–12, Amendment 39–21342 (85 FR 76949, December 1, 2020) (AD 2020–24–12). AD 2020–24–12 applied to certain Airbus SAS Model A350–941 airplanes. AD 2020–24–12 required replacing certain CWB fasteners with fasteners having improved friction efficiency. The FAA issued AD 2020–24–12 to address CWB fastener rotation. This condition, if not corrected, could lead to cracking of the fastener head sealant cover, followed by fuel vapor leakage inside the cabin, possibly resulting in injury to airplane occupants.

The NPRM published in the Federal Register on September 26, 2023 (88 FR 65831). The NPRM was prompted by AD 2023–0068, dated March 30, 2023, issued by EASA, which is the Technical Agent for the Member States of the European Union (EASA AD 2023–0068) (also referred to as the MCAI). The MCAI states that during flight and fatigue testing it was discovered that some fasteners can rotate inside their CWB fastener holes. Further investigation identified insufficient friction for the application. After EASA issued AD 2020–0123 (which corresponds to FAA AD 2020–24–12), it was determined that additional work is necessary to ensure the correct application of the fuel vapor barrier structure paint on the outside of the CWB. CWB fastener rotation, if not corrected, can lead to a crack of the fastener head sealant cover, followed by fuel vapor leakage inside the cabin, possibly resulting in injury to airplane occupants.

In the NPRM, the FAA proposed to continue to require the actions in AD 2020–24–12 and to require the additional work, as specified in EASA AD 2023–0068. The FAA is issuing this AD to address the unsafe condition on these products.

You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA–2023–1887.

Discussion of Final Airworthiness Directive

Comments

The FAA received no comments on the NPRM or on the determination of the cost to the public.

Additional Changes Made to This AD

In the NPRM, the FAA inadvertently omitted an exception allowing the use of the effective date of this AD in lieu of the effective date of the EASA AD. The FAA has added paragraph (h)(2) of this AD to include that exception.

Conclusion

This product has been approved by the aviation authority of another country and is approved for operation in the United States. Pursuant to the FAA's bilateral agreement with this State of Design Authority, it has notified the FAA of the unsafe condition described in the MCAI referenced above. The FAA reviewed the relevant data and determined that air safety requires adopting this AD as proposed. Accordingly, the FAA is issuing this AD to address the unsafe condition on this product. Except for minor editorial changes, and any other changes described previously, this AD is adopted as proposed in the NPRM. None of the changes will increase the economic burden on any operator.

Related Service Information Under 1 CFR Part 51

EASA AD 2023–0068 specifies procedures for replacing the affected CWB fasteners with fasteners having improved friction efficiency, and for doing additional work on previously modified airplanes to ensure the correct application of the fuel vapor barrier structure paint from outside the CWB.

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.

Costs of Compliance

The FAA estimates that this AD affects 13 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD:

Estimated Costs for Required Actions

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Retained actions from AD 2020–24–12	307 work-hours × $85 per hour = $26,095	$5,900	$31,995	$415,935
New actions	174 work-hours × $85 per hour = $14,790	900	15,690	203,970

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,

(2) Will not affect intrastate aviation in Alaska, and

(3) Will 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 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:

a. Removing Airworthiness Directive (AD) 2020–24–12, Amendment 39–21342 ( 85 FR 76949, December 1, 2020); and

b. Adding the following new AD:

2023–25–15 Airbus SAS: Amendment 39–22642; Docket No. FAA–2023–1887; Project Identifier MCAI–2023–00543–T.

(a) Effective Date

This airworthiness directive (AD) is effective February 7, 2024.

(b) Affected ADs

This AD replaces AD 2020–24–12, Amendment 39–21342 (85 FR 76949, December 1, 2020) (AD 2020–24–12).

(c) Applicability

This AD applies to Airbus SAS Model A350–941 airplanes, certificated in any category, as identified in European Union Aviation Safety Agency (EASA) AD 2023–0068, dated March 30, 2023 (EASA AD 2023–0068).

(d) Subject

Air Transport Association (ATA) of America Code 57, Wings.

(e) Unsafe Condition

This AD was prompted by reports that certain center wing box (CWB) fasteners had rotated inside the fastener holes due to insufficient friction for the application, and by the determination that additional work is necessary to ensure the correct application of the fuel vapor barrier structure paint on the outside of the CWB. The FAA is issuing this AD to address CWB fastener rotation. The unsafe condition, if not corrected, could lead to cracking of the fastener head sealant cover, followed by fuel vapor leakage inside the cabin, possibly resulting in injury to airplane occupants.

(f) Compliance

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

(g) Requirements

Except as specified in paragraph (h) of this AD: Comply with all required actions and compliance times specified in, and in accordance with, EASA AD 2023–0068.

(h) Exceptions to EASA AD 2023–0068

(1) This AD does not adopt the “Remarks” section of EASA AD 2023–0068.

(2) Where EASA AD 2023–0068 refers to its effective date, this AD requires using the effective date of this AD.

(i) Additional AD Provisions

The following provisions also apply to this AD:

(1) Alternative Methods of Compliance (AMOCs): The Manager, International Validation 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 International Validation Branch, send it to the attention of the person identified in paragraph (j) of this AD. Information may be emailed to: [e-mail]. Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the responsible Flight Standards Office.

(2) Contacting the Manufacturer: For any requirement in this AD to obtain instructions from a manufacturer, the instructions must be accomplished using a method approved by the Manager, International Validation Branch, FAA; or EASA; or Airbus SAS's EASA Design Organization Approval (DOA). If approved by the DOA, the approval must include the DOA-authorized signature.

(3) Required for Compliance (RC): Except as required by paragraph (i)(2) of this AD, if any service information contains procedures or tests that are identified as RC, those procedures and tests must be done to comply with this AD; any procedures or tests that are not identified as RC are recommended. Those procedures and tests that are not identified as RC may be deviated from using accepted methods in accordance with the operator's maintenance or inspection program without obtaining approval of an AMOC, provided the procedures and tests identified as RC can be done and the airplane can be put back in an airworthy condition. Any substitutions or changes to procedures or tests identified as RC require approval of an AMOC.

(j) Additional Information

For more information about this AD, contact Dat Le, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone [phone]; email [e-mail].

(k) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference (IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) You must use this service information as applicable to do the actions required by this AD, unless this AD specifies otherwise.

(i) European Union Aviation Safety Agency (EASA) AD 2023–0068, dated March 30, 2023.

(ii) [Reserved]

(3) For EASA AD 2023–0068, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone [phone]; email [e-mail]; website easa.europa.eu. You may find this EASA AD on the EASA website at ad.easa.europa.eu.

(4) You may view this service information 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 [e-mail].

Issued on December 14, 2023.

Victor Wicklund,

Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.