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###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. FAA-2023-2004; Project Identifier MCAI-2023-00977-T]
          - RIN 2120-AA64

# AGENCY:

Federal Aviation Administration (FAA), DOT.

# ACTION:

Notice of proposed rulemaking (NPRM).

# SUMMARY:

The FAA proposes to supersede Airworthiness Directive (AD) 2022-01-07, which applies to certain Airbus SAS Model A350-941 and -1041 airplanes. AD 2022-01-07 requires revising the existing maintenance or inspection program, as applicable, to incorporate new or more restrictive airworthiness limitations. Since the FAA issued AD 2022-01-07, the FAA has determined that new or more restrictive airworthiness limitations are necessary. This proposed AD would retain the actions required by AD 2022-01-07 and also require revising the existing maintenance or inspection program, as applicable, to incorporate new or more restrictive airworthiness limitations, as specified in a European Union Aviation Safety Agency (EASA) AD, which is proposed for incorporation by reference (IBR). 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 December 11, 2023.

      ( print page 73546)    

# 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-2023-2004; 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, the mandatory continuing airworthiness information (MCAI), any comments received, and other information. The street address for Docket Operations is listed above.                    

*Material Incorporated by Reference:*
      - For EASA ADs identified in this NPRM, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone +49 221 8999 000; email ADs@easa.europa.eu;                          website                          easa.europa.eu.                          You may find this material on the EASA website                          ad.easa.europa.eu.                          It is also available at                          regulations.gov                          under Docket No. FAA-2023-2004.                    
      - You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 2200 South 216th Street, Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195.

# FOR FURTHER INFORMATION CONTACT:

                        Dat Le, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone: 562-627-5357; email:                         *dat.v.le@faa.gov*.                    

# 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                     **ADDRESSES**                    . Include “Docket No. FAA-2023-2004; Project Identifier MCAI-2023-00977-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 Dat Le, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone: 562-627-5357; email:                     *dat.v.le@faa.gov.*                     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 AD 2022-01-07, Amendment 39-21895 (87 FR 5391, February 1, 2022) (AD 2022-01-07), for certain Airbus SAS Model A350-941 and -1041 airplanes. AD 2022-01-07 was prompted by an MCAI originated by EASA, which is the Technical Agent for the Member States of the European Union. EASA issued AD 2021-0209, dated September 15, 2021 (EASA AD 2021-0209) (which corresponds to FAA AD 2022-01-07), to correct an unsafe condition.

AD 2022-01-07 requires revising the existing maintenance or inspection program, as applicable, to incorporate new or more restrictive airworthiness limitations. The FAA issued AD 2022-01-07 to address the potential of ignition sources inside fuel tanks, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.

## Actions Since AD 2022-01-07 Was Issued

Since the FAA issued AD 2022-01-07, EASA superseded AD 2021-0209 and issued EASA AD 2023-0162, dated August 17, 2023 (EASA AD 2023-0162) (referred to after this as the MCAI), for certain Airbus SAS Model A350-941 and -1041 airplanes. The MCAI states that new or more restrictive airworthiness limitations have been developed.

Airplanes with an original airworthiness certificate or original export certificate of airworthiness issued after June 1, 2023, must comply with the airworthiness limitations specified as part of the approved type design and referenced on the type certificate data sheet; this proposed AD therefore does not include those airplanes in the applicability.

                    The FAA is proposing 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-2023-2004.                

## Related Service Information Under 1 CFR Part 51

The FAA reviewed EASA AD 2023-0162. This service information specifies new or more restrictive airworthiness limitations related to fuel tank ignition prevention and fuel tank flammability reduction.

This proposed AD would also require EASA AD 2021-0209, which the Director of the Federal Register approved for incorporation by reference as of March 8, 2022 (87 FR 5391, February 1, 2022).

                    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                     **ADDRESSES**                     section.                

## FAA's Determination

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 is issuing this NPRM after determining that the unsafe condition described previously is likely to exist or develop in other products of the same type design.

## Proposed AD Requirements in This NPRM

                    This proposed AD would retain the requirements of AD 2022-01-07. This proposed AD would require revising the existing maintenance or inspection                           ( print page 73547)                        program, as applicable, to incorporate new or more restrictive airworthiness limitations, which are specified in EASA AD 2023-0162 described previously, as incorporated by reference. Any differences with EASA AD 2023-0162 are identified as exceptions in the regulatory text of this AD.                

                    This proposed AD would require revisions to certain operator maintenance documents to include new actions (                    *e.g.,*                     inspections) and Critical Design Configuration Control Limitations (CDCCLs). Compliance with these actions is required by 14 CFR 91.403(c). For airplanes that have been previously modified, altered, or repaired in the areas addressed by this proposed AD, the operator may not be able to accomplish the actions described in the revisions. In this situation, to comply with 14 CFR 91.403(c), the operator must request approval for an alternative method of compliance (AMOC) according to paragraph (m)(1) of this proposed AD.                

## Explanation of Required Compliance Information

                    In the FAA's ongoing efforts to improve the efficiency of the AD process, the FAA developed a process to use some civil aviation authority (CAA) ADs as the primary source of information for compliance with requirements for corresponding FAA ADs. The FAA has been coordinating this process with manufacturers and CAAs. As a result, the FAA proposes to incorporate EASA AD 2023-0162 by reference in the FAA final rule. This proposed AD would, therefore, require compliance with EASA AD 2023-0162 through that incorporation, except for any differences identified as exceptions in the regulatory text of this proposed AD. Using common terms that are the same as the heading of a particular section in EASA AD 2023-0162 does not mean that operators need comply only with that section. For example, where the AD requirement refers to “all required actions and compliance times,” compliance with this AD requirement is not limited to the section titled “Required Action(s) and Compliance Time(s)” in EASA AD 2023-0162. Service information required by EASA AD 2023-0162 for compliance will be available at                     *regulations.gov*                     by searching for and locating Docket No. FAA-2023-2004 after the FAA final rule is published.                

## Airworthiness Limitation ADs Using the New Process

The FAA's process of incorporating by reference MCAI ADs as the primary source of information for compliance with corresponding FAA ADs has been limited to certain MCAI ADs (primarily those with service bulletins as the primary source of information for accomplishing the actions required by the FAA AD). However, the FAA is now expanding the process to include MCAI ADs that require a change to airworthiness limitation documents, such as airworthiness limitation sections.

For these ADs that incorporate by reference an MCAI AD that changes airworthiness limitations, the FAA requirements are unchanged. Operators must revise the existing maintenance or inspection program, as applicable, to incorporate the information specified in the new airworthiness limitation document. The airworthiness limitations must be followed according to 14 CFR 91.403(c) and 91.409(e).

                    The previous format of the airworthiness limitation ADs included a paragraph that specified that no alternative actions (                    *e.g.,*                     inspections), intervals, or CDCCLs may be used unless the actions, intervals, and CDCCLs are approved as an AMOC in accordance with the procedures specified in the AMOCs paragraph under “Additional AD Provisions.” This new format includes a “New Provisions for Alternative Actions, Intervals, and CDCCLs” paragraph that does not specifically refer to AMOCs, but operators may still request an AMOC to use an alternative action or interval.                

## Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 31 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD:

The FAA has determined that revising the existing maintenance or inspection program takes an average of 90 work-hours per operator, although the agency recognizes that this number may vary from operator to operator. Since operators incorporate maintenance or inspection program changes for their affected fleet(s), the FAA has determined that a per-operator estimate is more accurate than a per-airplane estimate.

The FAA estimates the total cost per operator for the new proposed actions to be $7,650 (90 work-hours × $85 per work-hour).

## 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: 

a. Removing Airworthiness Directive 2022-01-07, Amendment 39-21895 ( 87 FR 5391, February 1, 2022); and

b. Adding the following new Airworthiness Directive: 

**Airbus SAS:**                         Docket No. FAA-2023-2004; Project Identifier MCAI-2023-00977-T.                              ( print page 73548)    

## (a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by December 11, 2023.

## (b) Affected ADs

This AD replaces AD 2022-01-07, Amendment 39-21895 (87 FR 5391, February 1, 2022) (AD 2022-01-07).

## (c) Applicability

This AD applies all Airbus SAS Model A350-941 and -1041 airplanes, certificated in any category, with an original airworthiness certificate or original export certificate of airworthiness issued on or before June 1, 2023.

## (d) Subject

Air Transport Association (ATA) of America Code 05, Time Limits/Maintenance Checks.

## (e) Unsafe Condition

This AD was prompted by a determination that new or more restrictive airworthiness limitations are necessary. The FAA is issuing this AD to address the potential of ignition sources inside fuel tanks, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.

## (f) Compliance

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

## (g) Retained Revision of the Existing Maintenance or Inspection Program, With AD 2022-01-07, With No Changes

This paragraph restates the requirements of paragraph (g) of AD 2022-01-07, with no changes. For airplanes with an original airworthiness certificate or original export certificate of airworthiness issued on or before June 30, 2021: Except as specified in paragraph (h) of this AD: Comply with all required actions and compliance times specified in, and in accordance with, European Union Aviation Safety Agency (EASA) AD 2021-0209, dated September 15, 2021 (EASA AD 2021-0209). Accomplishing the revision of the existing maintenance or inspection program required by paragraph (j) of this AD terminates the requirements of this paragraph.

## (h) Retained Exceptions to EASA AD 2021-0209, With No Changes

This paragraph restates the exceptions specified in paragraph (h) of AD 2022-01-07, with no changes.

(1) The requirements specified in paragraphs (1) and (2) of EASA AD 2021-0209 do not apply to this AD.

(2) Paragraph (3) of EASA AD 2021-0209 specifies revising “the AMP [aircraft maintenance program]” within 12 months after its effective date, but this AD requires revising the existing maintenance or inspection program, as applicable, to incorporate the “limitations, tasks and associated thresholds and intervals” specified in paragraph (3) of EASA AD 2021-0209 within 90 days after March 8, 2022 (the effective date of AD 2022-01-07).

(3) The initial compliance time for doing the tasks specified in paragraph (3) of EASA AD 2021-0209 is at the applicable “associated thresholds” specified in paragraph (3) of EASA AD 2021-0209, or within 90 days after March 8, 2022 (the effective date of AD 2022-01-07), whichever occurs later.

(4) The provisions specified in paragraphs (4) and (5) of EASA AD 2021-0209 do not apply to this AD.

(5) The “Remarks” section of EASA AD 2021-0209 does not apply to this AD.

## (i) Retained Restrictions on Alternative Actions, Intervals, and Critical Design Configuration Control Limitations (CDCCLs), With No Changes

                        This paragraph restates the requirements of paragraph (i) of AD 2022-01-07, with no changes. Except as required by paragraph (j) of this AD, after the maintenance or inspection program has been revised as required by paragraph (g) of this AD, no alternative actions (                        *e.g.,*                         inspections), intervals, and critical design configuration control limitations (CDCCLs) are allowed unless they are approved as specified in the provisions of the “Ref. Publications” section of EASA AD 2021-0209.                    

## (j) New Revision of the Existing Maintenance or Inspection Program

Except as specified in paragraph (k) of this AD: Comply with all required actions and compliance times specified in, and in accordance with, EASA AD 2023-0162, dated August 17, 2023 (EASA AD 2023-0162). Accomplishing the revision of the existing maintenance or inspection program required by this paragraph terminates the requirements of paragraph (g) of this AD.

## (k) Exceptions to EASA AD 2023-0162

(1) This AD does not adopt the requirements specified in paragraphs (1) and (2) of EASA AD 2023-0162.

(2) Where paragraph (3) of EASA AD 2023-0162 specifies “Within 12 months after the effective date of this AD, revise the AMP,” this AD requires replacing those words with “Within 90 days after the effective date of this AD, revise the existing maintenance or inspection program, as applicable.”

(3) The initial compliance time for doing the tasks specified in paragraph (3) of EASA AD 2023-0162 is at the applicable “limitations” and “associated thresholds” as incorporated by the requirements of paragraph (3) of EASA AD 2023-0162, or within 90 days after the effective date of this AD, whichever occurs later.

(4) This AD does not adopt the provisions specified in paragraphs (4) and (5) of EASA AD 2023-0162.

(5) This AD does not adopt the “Remarks” section of EASA AD 2023-0162.

## (l) New Provisions for Alternative Actions and Intervals

                        After the existing maintenance or inspection program has been revised as required by paragraph (j) of this AD, no alternative actions (                        *e.g.,*                         inspections), intervals, and CDCCLs are allowed unless they are approved as specified in the provisions of the “Ref. Publications” section of EASA AD 2023-0162.                    

## (m) 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 manager of the International Validation Branch, mail it to the address identified in paragraph (n) of this AD or email to:                         *9-AVS-AIR-730-AMOC@faa.gov.*                         If mailing information, also submit information by email. 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.                    

## (n) Additional Information

                        For more information about this AD, contact Dat Le, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone: 562-627-5357; email:                         *dat.v.le@faa.gov.*

## (o) 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.

(3) The following service information was approved for IBR on [DATE 35 DAYS AFTER PUBLICATION OF THE FINAL RULE].

(i) European Union Aviation Safety Agency (EASA) AD 2023-0162, dated August 17, 2023.

(ii) [Reserved]

(4) The following service information was approved for IBR on March 8, 2022 (87 FR 5391, February 1, 2022).

(i) European Union Aviation Safety Agency (EASA) AD 2021-0209, dated September 15, 2021.

(ii) [Reserved]

                        (5) For EASA AD 2023-0162 and EASA AD 2021-0209, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone +49 221 8999 000; email                         *ADs@easa.europa.eu;*                         website                         *easa.europa.eu.*                         You may find this EASA AD on the EASA website                         *ad.easa.europa.eu.*

                        (6) You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 2200 South 216th Street, Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195.                              ( print page 73549)    

                        (7) 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                         *fr.inspection@nara.gov.*

Issued on October 19, 2023.

Ross Landes,

Deputy Director for Regulatory Operations, Compliance & Airworthiness Division, Aircraft Certification Service.

[FR Doc. 2023-23517 Filed 10-25-23; 8:45 am]

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