This section of the FEDERAL REGISTER

contains regulatory documents having general

applicability and legal effect, most of which

are keyed to and codified in the Code of

Federal Regulations, which is published under

50 titles pursuant to 44 U.S.C. 1510.

The Code of Federal Regulations is sold by

the Superintendent of Documents.

Rules and Regulations Federal Register

233 

Vol. 89, No. 2 

Wednesday, January 3, 2024 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2023–1711; Project 

Identifier MCAI–2023–00093–T; Amendment 

39–22639; AD 2023–25–12] 

RIN 2120–AA64 

Airworthiness Directives; Airbus SAS 

Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: The FAA is adopting a new 

airworthiness directive (AD) for all 

Airbus SAS Model A318–112 airplanes; 

Model A319–115, –132, –133, –151N, 

–153N, and –171N airplanes; Model 

A320–211, –212, –214, –231, –232, 

–251N, –252N, –253N, –271N, –272N, 

and –273N airplanes; and Model A321– 

112 airplanes. This AD was prompted 

by a report that the fatigue life limit of 

the motoreductor installed on the onboard entrance stairs is not 

demonstrated for the complete airplane 

design service goal (DSG). This AD 

requires repetitive replacement of the 

motoreductor for onboard entrance 

stairs, and it limits the installation of 

affected parts under certain conditions, 

as specified in a 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–2023–1711; 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 +49 221 

8999 000; email ADs@easa.europa.eu; 

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– 

2023–1711. 

FOR FURTHER INFORMATION CONTACT: Tim 

Dowling, Aviation Safety Engineer, 

FAA, 1600 Stewart Avenue, Suite 410, 

Westbury, NY 11590; telephone 206– 

231–3667; email timothy.p.dowling@

faa.gov. 

SUPPLEMENTARY INFORMATION: 

Background 

The FAA issued a notice of proposed 

rulemaking (NPRM) to amend 14 CFR 

part 39 by adding an AD that would 

apply to all Airbus SAS Model A318– 

112 airplanes; Model A319–115, –132, 

–133, –151N, –153N, and –171N 

airplanes; Model A320–211, –212, –214, 

–231, –232, –251N, –252N, –253N, 

–271N, –272N, and –273N airplanes; 

and Model A321–112 airplanes. The 

NPRM published in the Federal 

Register on August 17, 2023 (88 FR 

55953). The NPRM was prompted by 

AD 2023–0014, dated January 18, 2023, 

issued by EASA, which is the Technical 

Agent for the Member States of the 

European Union (EASA AD 2023–0014) 

(also referred to as the MCAI). The 

MCAI states that computations 

conducted on the Model A320 family 

program showed that the fatigue life 

limit of the motoreductor, installed on 

the on-board entrance stairs and acting 

as one of the two (stair) immobilization 

systems, is not demonstrated for the 

complete airplane design service goal 

(DSG). Therefore, a motoreductor failure 

could remain undetected during the 

period between the demonstrated life 

limit of the motoreductor and the 

airplane DSG (and subsequent extended 

service goal). A failed motoreductor, if 

not corrected, could lead to an airstairs 

deployment in flight, possibly resulting 

in loss of control of the airplane. 

In the NPRM, the FAA proposed to 

require repetitive replacement of the 

motoreductor for onboard entrance 

stairs, and limit the installation of 

affected parts under certain conditions, 

as specified in EASA AD 2023–0014. 

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–2023–1711. 

Discussion of Final Airworthiness 

Directive 

Comments 

The FAA received comments from a 

commenter, American Airlines (AAL). 

The following presents the comments 

received on the NPRM and the FAA’s 

response to each comment. 

Request for Revision of the 

Applicability Paragraph 

AAL requested revising paragraph (c) 

of the proposed AD to narrow the scope 

of affected airplanes to only those that 

have had certain modifications 

accomplished for installing airstairs on 

the affected Airbus SAS model airplanes 

(identified as Group 1 airplanes in 

EASA AD 2023–0014). AAL 

acknowledged that the FAA carried over 

EASA AD 2023–0014’s applicability 

statement on all serial numbers of the 

affected Airbus SAS models. AAL also 

noted that the replacement action is 

only necessary if the airplane is 

equipped with the airstairs. 

The FAA agrees that the replacement 

actions are only required for airplanes 

equipped with the affected airstairs 

(Group 1 airplanes). However, the FAA 

has determined it is necessary to retain 

the proposed applicability that is based 

on EASA’s determination of the 

effectivity of EASA AD 2023–0014. 

Airplanes that have airstairs installed 

after the effective date would be subject 

to the requirements of this AD. 

Removing airplanes identified as Group 

2 airplanes in EASA AD 2023–0014 

(airplanes not equipped with the 


ddrumheller on DSK120RN23PROD with RULES1
234 Federal Register / Vol. 89, No. 2 / Wednesday, January 3, 2024 / Rules and Regulations 

affected airstairs) would remove this AD 

from those airplanes’ records and 

possibly increase the risk that the 

affected airstair part could be installed 

during a later modification of the Group 

2 airplane into a Group 1 airplane 

without the operator’s awareness that 

the requirements of this AD would then 

apply to that airplane. A Group 2 

airplane with on-board entrance stairs 

becomes a Group 1 airplane. Operators 

can check the airplane’s maintenance 

records to monitor the Group status and 

determine the applicable requirements 

for that airplane. The FAA has not 

changed this AD as a result of this 

comment. 

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, considered 

the comment received, 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, 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 2023–0014 specifies 

procedures for repetitive replacement of 

the motoreductor for Airbus on-board 

entrance stairs, including a detailed 

inspection to determine the threshold 

for replacement. 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 will 

affect 954 airplanes of U.S. registry. The 

FAA estimates the following costs to 

comply with this AD: 

ESTIMATED COSTS FOR REQUIRED ACTIONS

Labor cost Parts cost Cost per product Cost on U.S. 

operators 

Up to 8 work-hours × $85 per hour = $680 per replacement cycle.$49,590 per replacement 

cycle.

Up to $50,270 per replacement cycle.Up to $47,957,580 per replacement cycle. 

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 adding 

the following new airworthiness 

directive: 

2023–25–12 Airbus SAS: Amendment 39– 

22639; Docket No. FAA–2023–1711; 

Project Identifier MCAI–2023–00093–T. 

(a) Effective Date 

This airworthiness directive (AD) is 

effective February 7, 2024. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to all Airbus SAS 

airplanes identified in paragraphs (c)(1) 

through (4) of this AD, certificated in any 

category. 

(1) Model A318–112 airplanes. 

(2) Model A319–115, –132, –133, –151N, 

–153N, and –171N airplanes. 

(3) Model A320–211, –212, –214, –231, 

–232, –251N, –252N, –253N, –271N, –272N, 

and –273N airplanes. 

(4) Model A321–112 airplanes. 

(d) Subject 

Air Transport Association (ATA) of 

America Code 52, Doors. 

(e) Unsafe Condition 

This AD was prompted by a report that the 

fatigue life limit of the motoreductor, 

installed on the on-board entrance stairs, is 

not demonstrated for the complete airplane 

design service goal (DSG). The FAA is 

issuing this AD to address a motoreductor 

failure, which could be undetected until DSG 

is reached. The unsafe condition, if not 

addressed, could result in an airstairs 

deployment in flight, possibly resulting in 

loss of control of the airplane. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Requirements 

Except as specified in paragraphs (h) and 

(i) of this AD: Comply with all required 

actions and compliance times specified in, 

and in accordance with, European Union 

Aviation Safety Agency (EASA) AD 2023– 

0014, dated January 18, 2023 (EASA AD 

2023–0014). Thereafter, before the 

accumulation of 39,400 total flight cycles on 


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Federal Register / Vol. 89, No. 2 / Wednesday, January 3, 2024 / Rules and Regulations 235 

any motoreductor, part number 4255417, 

4394656, or 4339747, replace it with a 

serviceable part as defined in EASA AD 

2023–0014. 

(h) Exceptions to EASA AD 2023–0014 

(1) Where EASA AD 2023–0014 refers to its 

effective date, this AD requires using the 

effective date of this AD. 

(2) This AD does not adopt the ‘‘Remarks’’ 

section of EASA AD 2023–0014. 

(i) No Reporting Requirement 

Although the service information 

referenced in EASA AD 2023–0014 specifies 

to submit certain information to the 

manufacturer, this AD does not include that 

requirement. 

(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: 9-AVS-AIR-730-AMOC@faa.gov. 

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 (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 Tim Dowling, Aviation Safety 

Engineer, FAA, 1600 Stewart Avenue, Suite 

410, Westbury, NY 11590; telephone 206– 

231–3667; email timothy.p.dowling@faa.gov. 

(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. 

(i) European Union Aviation Safety Agency 

(EASA) AD 2023–0014, dated January 18, 

2023 (EASA AD 2023–0014). 

(ii) [Reserved] 

(3) For EASA AD 2023–0014, 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 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/ 

ibrlocations.html, or email fr.inspection@

nara.gov. 

Issued on December 14, 2023. 

Victor Wicklund, 

Deputy Director, Compliance & Airworthiness 

Division, Aircraft Certification Service. 

[FR Doc. 2023–28847 Filed 1–2–24; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2023–1887; Project 

Identifier MCAI–2023–00543–T; Amendment 

39–22642; AD 2023–25–15] 

RIN 2120–AA64 

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 +49 221 

8999 000; email ADs@easa.europa.eu; 

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 (516) 228–7317; 

email dat.v.le@faa.gov. 

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 


ddrumheller on DSK120RN23PROD with RULES1