2023-20399. Airworthiness Directives; Airbus SAS Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede Airworthiness Directive (AD) 2022–07–15, which applies to all Airbus SAS Model A318, A319, A320, and A321 series airplanes. AD 2022–07–15 requires replacing affected braking and steering control units (BSCUs) and revising the operator's existing FAA-approved minimum equipment list (MEL). Since the FAA issued AD 2022–07–15, a type 1 relay combined with an affected BSCU would induce BSCU freezing. This proposed AD would remove certain airplanes from the applicability, retain the requirements of AD 2022–07–15, require an inspection for the relay type installed and replacement of type 1 relays with type 2 relays, and prohibit the installation of affected relays at certain locations, limit the installation of affected BSCUs on certain airplanes, and prohibit the installation of affected BSCUs for certain other airplanes, 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 November 13, 2023.

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 under Docket No. FAA–2023–1882; 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 the EASA AD identified in this NPRM, 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. It is also available at regulations.gov under Docket No. FAA–2023–1882.

• For Airbus service information identified in this NPRM, contact Airbus SAS, Airworthiness Office—EIAS, Rond-Point Emile Dewoitine No: 2, 31700 Blagnac Cedex, France; telephone [phone]; fax [phone]; email [e-mail]; website airbus.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.

FOR FURTHER INFORMATION CONTACT:

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

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–2023–1882; Project Identifier MCAI–2023–00651–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 Timothy Dowling, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone [phone]; email [e-mail]. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking.

Background

The FAA issued AD 2022–07–15, Amendment 39–22003 (87 FR 22438, April 15, 2022), for all Airbus SAS Model A318–111, –112, –121, and –122 airplanes; Model A319–111, –112, –113, –114, –115, –131, –132, –133, –151N, –153N, and –171N airplanes; Model A320–211, –212, –214, –216, –231, –232, –233, –251N, –252N, –253N, –271N, –272N, –273N airplanes; and Model A321–111, –112, –131, –211, –212, –213, –231, –232, –251N, –251NX, –252N, –252NX, –253N, –253NX, –271N, –271NX, –272N, and –272NX airplanes. AD 2022–07–15 was prompted by an MCAI originated by EASA, which is the Technical Agent for the Member States of the European Union. EASA issued AD 2022–0032, dated March 3, 2022 (EASA AD 2022–0032), to correct an unsafe condition.

AD 2022–07–15 requires replacing affected BSCUs and revising the operator's existing FAA-approved MEL. The FAA issued AD 2022–07–15 to address loss of braking performance with significant increase in airplane stopping distance, possibly resulting in runway excursion.

Actions Since AD 2022–07–15 Was Issued

Since the FAA issued AD 2022–07–15, EASA superseded AD 2022–0032 and issued EASA AD 2023–0093, dated May 5, 2023, which was subsequently revised. EASA AD 2023–0093R1, dated May 15, 2023 (EASA AD 2022–0093R1) (also referred to as the MCAI), retains the requirements of EASA AD 2023–0032 and requires replacement of type 1 relays with type 2 relays.

The MCAI noted that BSCU channel failures could induce, in the event of dual channel failures, loss of anti-skid function together with the reversion to the alternate braking mode, and loss of nose wheel steering, and lead to loss of braking performance with significant increase in airplane stopping distance, possibly resulting in runway excursion.

The MCAI states that further investigation identified a type 1 relay installed in a position where a type 2 relay should have been installed. The combination of a type 1 relay with an affected BSCU could induce BSCU freezing. EASA therefore determined that it is necessary to replace type 1 relays with type 2 relays.

The MCAI also states that type 1 relays are no longer installed on Model A320 Current Engine Option (CEO) airplanes ( i.e., Model A318 series airplanes; A319–111, –112, –113, –114, –115, –131, –132, and –133 airplanes; A320–211, –212, –214, –216, –231, –232, and –233 airplanes; and A321–111, –112, –131, –211, –212, –213, –231, and –232 airplanes). Type 1 relays were required to be replaced on Model A320 CEO airplanes by AD 96–04–06, Amendment 39–9518 (61 FR 6927, February 23, 1996). AD 96–04–06 corresponded to DGAC France AD F–1993–163–043, dated September 29, 1993. Model A320 CEO airplanes are therefore not included in the applicability of this proposed AD.

Further, EASA stated that some relays installed at functional item number (FIN) locations 24GG and 25GG were not in conformity with the Airplane Inspection Report on certain airplanes.

In addition, it was determined that certain airplanes have been delivered with a BSCU P/N E21327107.

Explanation of Retained Requirements

Although this proposed AD does not explicitly restate the requirements of AD 2022–07–15, this proposed AD would retain all the requirements of AD 2022–07–15. Those requirements are referenced in EASA AD 2023–0093R1, which, in turn, is referenced in paragraph (g) of this proposed AD.

Related Service Information Under 1 CFR Part 51

EASA AD 2023–0093R1 specifies procedures for replacing affected BSCUs if a fault signature is triggered, and implementing the instructions of master minimum equipment list (MMEL) updates on the basis of which the operator's existing MEL must be amended–that is, procedures for revising the operator's existing FAA-approved MEL with the provisions in the MMEL updates specified in the EASA AD. EASA AD 2023–0093R1 also specifies procedures for a general visual inspection of the FINs 24GG and 25GG to identify the relay type installed, and replacement of each type 1 relay with a type 2 relay. EASA AD 2023–0093R1 also limits the installation of affected parts.

Airbus Alert Operators Transmission A32N025–22, Rev 01, dated May 10, 2023, including Appendixes 1 through 3, dated May 2023, defines BSCU fault signatures that may be triggered on the airplane, and specifies procedures for replacing affected parts, among other actions.

This proposed AD would also require Airbus Alert Operators Transmission A32N025–22, Rev 00, dated February 24, 2022, including Appendixes 1 through 4, dated February 21, 2022, which the Director of the Federal Register approved for incorporation by reference as of May 2, 2022 (87 FR 22438, April 15, 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 the 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 all requirements of AD 2022–07–15. This proposed AD would remove airplanes from the applicability and require accomplishing the actions specified in EASA AD 2023–0093R1 described previously, except for any differences identified as exceptions in the regulatory text of this proposed AD.

Compliance With MEL Revisions

EASA AD 2023–0093R1 requires operators to “inform all flight crews” of revisions to the MEL, and thereafter to “operate the airplane accordingly.” However, this proposed AD would not specifically require those actions as those actions are already required by FAA regulations. FAA regulations (14 CFR 121.628 (a)(2)) require operators to provide pilots with access to all of the information contained in the operator's MEL. Furthermore, 14 CFR 121.628 (a)(5) requires airplanes to be operated under all applicable conditions and limitations contained in the operator's MEL. Therefore, including a requirement in this proposed AD to operate the airplane according to the revised MEL would be redundant and unnecessary.

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 2023–0093R1 by reference in this AD. This proposed AD would, therefore, require compliance with EASA AD 2023–0093R1 entirety 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 2023–0093R1 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 2023–0093R1. Service information required by EASA AD 2023–0093R1 for compliance will be available at regulations.gov under Docket No. FAA–2023–1882 after the FAA final rule is published.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 349 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD:

Estimated Costs for Required Actions

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Retained actions from AD 2022–07–15	Up to 5 work-hours × $85 per hour = $425	$0	Up to $425	Up to $148,325.
Relay inspection and replacement (new proposed actions)	Up to 9 work-hours × $85 per hour = $765	0	Up to 765	Up to 266,985.

According to the manufacturer, some or all of the costs of this proposed AD may be covered under warranty, thereby reducing the cost impact on affected individuals. The FAA does not control warranty coverage for affected individuals. As a result, the FAA has included all known costs in the cost estimate.

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

[Amended]

2. The FAA amends § 39.13 by:

a. Removing Airworthiness Directive (AD) 2022–07–15, Amendment 39–22003 ( 87 FR 22438, April 15, 2022); and

b. Adding the following new AD:

Airbus SAS: Docket No. FAA–2023–1882; Project Identifier MCAI–2023–00651–T.

(a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by November 13, 2023.

(b) Affected ADs

This AD replaces AD 2022–07–15, Amendment 39–22003 (87 FR 22438, April 15, 2022) (AD 2022–07–15).

(c) Applicability

This AD applies to the Airbus SAS airplanes, certificated in any category, identified in paragraphs (c)(1) through (3) of this AD.

(1) All Model A319–151N, A319–153N, and A319–171N airplanes.

(2) All Model A320–251N, A320–252N, A320–253N, A320–271N, A320–272N, and A320–273N airplanes.

(3) All Model A321–251N, A321–251NX, A321–252N, A321–252NX, A321–253N, A321–253NX, A321–271N, A321–271NX, A321–272N, and A321–272NX airplanes.

(d) Subject

Air Transport Association (ATA) of America Code 32, Landing Gear; and America Code 92, Electrical System Installation.

(e) Unsafe Condition

This AD was prompted by the detection of several channel failures on the braking and steering control unit (BSCU), inducing, in case of dual channel failures, loss of anti-skid function together with the reversion to the alternate braking mode, and loss of nose wheel steering. This AD was further prompted by the determination that a type 1 relay combined with an affected BSCU could induce BSCU freezing. The FAA is issuing this AD to address these conditions, which could lead to loss of braking performance with significant increase in airplane stopping distance, possibly resulting in runway excursion.

(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, European Union Aviation Safety Agency (EASA) 2023–0093R1, dated May 15, 2023 (EASA AD 2023–0093R1).

(h) Exceptions to EASA AD 2023–0093R1

(1) Where EASA AD 2023–0093R1 refers to “10 March 2022 [the effective date of EASA AD 2022–0032 at original issue],” this AD requires using May 2, 2022 (the effective date of AD 2022–07–15).

(2) Where EASA AD 2023–0093R1 refers to its effective date, this AD requires using the effective date of this AD.

(3) Where EASA AD 2023–0093R1 defines “the AOT 1” as “Airbus Alert Operators Transmission (AOT 1) A32N025–22,” this AD requires using Airbus Alert Operators Transmission A32N025–22, Rev 00, dated February 24, 2022, including Appendixes 1 through 4, dated February 21, 2022, or Airbus Alert Operators Transmission A32N025–22, Rev 01, dated May 10, 2023, including Appendixes 1 through 3, dated May 2023.

(4) Where paragraphs (2) and (3) of EASA AD 2023–0093R1 specify “in accordance with the instructions of the AOT 1,” replace those words with “in accordance with the `Remove and replace BSCU P/N E21327307' step in paragraph 5.6., `Instructions,' of Airbus Alert Operators Transmission A32N025–22, Rev 00, dated February 24, 2022, including Appendixes 1 through 4, dated February 21, 2022, or of Airbus Alert Operators Transmission A32N025–22, Rev 01, dated May 10, 2023, including Appendixes 1 through 3, dated May 2023.” No other actions in Airbus Alert Operators Transmission A32N030–23, Rev 00, dated February 27, 2023, including Appendixes 1 and 2, dated February 21, 2023 (referenced in EASA AD 2023–0093R1 and not incorporated by reference in this AD), or Airbus Alert Operators Transmission A32N025–22, Rev 01, dated May 10, 2023, including Appendixes 1 through 3, dated May 2023, are required for compliance for the replacement.

(5) Where paragraph (4) of EASA AD 2023–0093R1 requires operators to “implement the instructions of the MMEL [master minimum equipment list] update,” this AD requires replacing those words with “implement the operator's existing FAA-approved minimum equipment list (MEL) with the provisions specified in `The MMEL update' as identified in EASA AD 2023–0093R1.”

(6) Where paragraph (4) of EASA AD 2023–0093R1 specifies to “inform all flight crews, and, thereafter, operate the airplane accordingly,” this AD does not require those actions as those actions are already required by existing FAA operating regulations.

(7) This AD does not adopt the “Remarks” section of EASA AD 2023–0093R1.

(i) No Reporting Requirement

Although certain service information specified in EASA AD 2023–0093R1 specifies to report certain information and send affected parts to the manufacturer, this AD does not require those actions.

(j) 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 (k) of this AD. Information may be emailed to: [e-mail].

(i) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the responsible Flight Standards Office.

(ii) AMOCs approved previously for AD 2022–07–15 are approved as AMOCs for the corresponding provisions of EASA AD 2023–0093R1 that are required by paragraph (g) of this AD.

(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 (j)(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.

(k) Additional Information

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

(l) 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 2023–0093R1, dated May 15, 2023.

(ii) Airbus Alert Operators Transmission A32N025–22, Rev 01, dated May 10, 2023, including Appendixes 1 through 3, dated May 2023.

(4) The following service information was approved for IBR on May 2, 2022 (87 FR 22438, April 15, 2022).

(i) Airbus Alert Operators Transmission A32N025–22, Rev 00, dated February 24, 2022, including Appendixes 1 through 4, dated February 21, 2022.

(ii) [Reserved]

(5) For EASA AD 2023–0093R1, 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.

(6) For Airbus service information identified in this AD, contact Airbus SAS, Airworthiness Office—EIAS, Rond-Point Emile Dewoitine No: 2, 31700 Blagnac Cedex, France; telephone [phone]; fax [phone]; email [e-mail]; website airbus.com.

(7) 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.

(8) You may view this service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, email [e-mail], or go to: www.archives.gov/​federal-register/​cfr/​ibr-locations.html.

Issued on September 15, 2023.

Victor Wicklund,

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