[Federal Register Volume 87, Number 242 (Monday, December 19, 2022)]
[Rules and Regulations]
[Pages 77497-77500]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-27399]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0833; Project Identifier MCAI-2021-00245-T; 
Amendment 39-22258; AD 2022-25-02]
RIN 2120-AA64


Airworthiness Directives; Airbus SAS Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2020-18-
04, which applied to Airbus SAS Model A350-941 and -1041 airplanes. AD 
2020-18-04 required a one-time health check of the slat power control 
unit (PCU) torque sensing unit (TSU) for discrepancies, and corrective 
actions if necessary; a detailed inspection of the left-hand (LH) and 
right-hand (RH) slat transmission systems for discrepancies, and 
corrective actions if necessary; and LH and RH track 12 slat gear 
rotary actuator (SGRA) water drainage and vent plug cleaning (which 
includes an inspection for moisture). This AD was prompted by a 
determination that requiring modification of the PCU by replacing each 
affected slat PCU with a serviceable PCU (one having a different part 
number) is necessary. This AD continues to require the actions required 
by AD 2020-18-04, and also requires modification (replacement of each 
affected slat PCU with a slat PCU having a different part number), and 
revising the limitations on the installation of affected parts; 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 January 23, 2023.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of January 23, 
2023.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2021-0833; 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 EASA material incorporated by reference in this AD, 
contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone 
+49 221 8999 000; email [email protected]; 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-2021-0833.

FOR FURTHER INFORMATION CONTACT: Dat Le, Aerospace Engineer, Large 
Aircraft Section, FAA, International Validation Branch, 2200 South 
216th St., Des Moines, WA 98198; telephone 516-228-7317; email 
[email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to supersede AD 2020-18-04, Amendment 39-21225 (85 FR 
54896, September 3, 2020) (AD 2020-18-04). AD 2020-18-04 applied to all 
Airbus SAS Model A350-941 and -1041 airplanes. AD 2020-18-04 required a 
one-time health check of the slat PCU TSU for discrepancies, and 
corrective actions if necessary; a detailed inspection of the LH and RH 
slat transmission systems for discrepancies, and corrective actions if 
necessary; and LH and RH track 12 SGRA water drainage and vent plug 
cleaning (which includes an inspection for moisture). The FAA issued AD 
2020-18-04 to address a slat system jam during landing phase which 
could lead to a double shaft disconnection or rupture, potentially 
causing one or more slat surfaces to be no longer connected to either 
the slat wing tip brake or the slat PCU, possibly resulting in reduced 
control of the airplane.
    The NPRM published in the Federal Register on September 30, 2021 
(86 FR 54136). The NPRM was prompted by AD 2021-0053R1, dated April 19, 
2021, issued by European Union Aviation Safety Agency (referred to 
after this as the MCAI). The MCAI states that since EASA AD 2020-
0163R1, dated August 7, 2020 (which corresponds to FAA AD 2020-18-04), 
was issued, EASA received information that prompted it to add a 
requirement for repetitive TSU health checks, introduce a definition of 
serviceable part to clarify actions that have to be accomplished on 
affected parts, and remove a requirement for a water drainage and vent 
plug cleaning of the LH and RH track 12 SGRA.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2021-0833.
    In the NPRM, the FAA proposed to remove a requirement for water 
drainage and vent plug cleaning of the SGRA, require repetitive health 
checks of the slat PCU TSU, a detailed visual inspection of the slat 
transmission systems, and corrective actions if necessary, as specified 
in EASA AD 2020-0163R1.
    The FAA issued a supplemental notice of proposed rulemaking (SNPRM) 
to amend 14 CFR part 39 to supersede AD 2020-18-04. The SNPRM published 
in the Federal Register on June 1, 2022 (87 FR 33076) (the SNPRM). The 
SNPRM was prompted by EASA issuance of AD 2021-0275, dated December 10, 
2021, (EASA AD 2021-0275), which determined that requiring modification 
of the PCU by replacing each affected slat PCU with a serviceable PCU 
(one having a different part number) is necessary, and clarified the 
limitations related to when an affected slat PCU may be installed on an 
airplane. In the SNPRM, the FAA proposed to require modification 
(replacement of each affected slat PCU with a slat PCU having a 
different part number), requiring an inspection report, and revising 
the limitations on the installation of affected parts. The FAA is 
issuing this AD to address a slat system jam during landing, which 
could lead to a double shaft disconnection/rupture, potentially causing 
one or more

[[Page 77498]]

slat surfaces to be no longer connected to either the slat wing tip 
brake or the slat PCU, possibly resulting in reduced control of the 
airplane.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from Delta Air Lines (Delta). The 
following presents the comments received on the SNPRM and the FAA's 
response to each comment.

Request for Removing the Initial Health Check Requirement

    Delta requested that the terminating action (modification of the 
PCU) specified in paragraph (6) of EASA AD 2021-0275 for the repetitive 
health checks in paragraph (4) of EASA AD 2021-0275 be extended to the 
initial health check specified in paragraph (2) of EASA AD 2021-0275 
too. Delta noted that it seems that the health checks are intended only 
for those slats that have not been modified. Delta stated that for a 
modified PCU, a detailed inspection (as specified in paragraph (1) of 
EASA AD 2021-0275) is required and that an initial health check would 
not reveal further information or instruction. Delta added that the 
detailed inspection and initial health check have the same compliance 
time. Delta recommended revising paragraph (h) of the proposed AD (in 
the SNPRM) to permit the terminating action to be used for the initial 
health check too.
    The FAA agrees to the request for the reasons that Delta provided. 
The FAA has revised paragraph (h) of this AD to provide terminating 
action for the initial health check.

Request for Removal of the Reporting Requirement

    Delta requested removing the requirement to send inspection reports 
to Airbus. Delta pointed out that Airbus provided a modification that 
terminates inspection requirements. Delta noted also that if there are 
findings that require a request for repair instruction, the operator 
would need to provide details of the discrepancies before receiving 
repair instructions. Delta recommended revising paragraph (h) of 
proposed AD (in the SNPRM) to remove the reporting requirement and 
state that reporting is not required.
    The FAA agrees with the request for the reasons stated. The FAA has 
revised paragraph (h) of this AD and the Cost of Compliance and Related 
Service Information Under 1 CFR part 51 sections of this AD 
accordingly; and added paragraph (i) to this AD to state that 
inspection reports are not required.

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 
comments 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, and any other changes described previously, this AD is adopted 
as proposed in the SNPRM. None of the changes will increase the 
economic burden on any operator.

Related Service Information Under 1 CFR Part 51

    EASA AD 2021-0275 specifies procedures for repetitive health checks 
of the slat PCU TSU for discrepancies, and corrective actions 
(replacement) if necessary; a detailed visual inspection of the LH and 
RH slat transmission systems for discrepancies, and corrective actions 
(repair) if necessary; and a modification of the PCU (replacement of 
each slat PCU having part number (P/N) 4785A0000-04 or 4785A0000-05 
with a slat PCU having P/N 4785A0000-06), which terminates the health 
checks. EASA AD 2021-0275 also specifies limitations for installing 
affected slat PCUs. 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.

Interim Action

    The preamble to AD 2020-18-04 explains that the FAA considers those 
requirements ``interim action'' and that the manufacturer is developing 
a final action to address the unsafe condition. That AD explains that 
the FAA might consider further rulemaking if a final action is 
identified. The same explanation was in the preamble of the NPRM. Since 
the FAA issued AD 2020-18-04 and the NPRM, the manufacturer has 
developed a modification to the PCU, and the FAA has determined that 
further rulemaking is indeed necessary; this AD follows from that 
determination.

Costs of Compliance

    The FAA estimates that this AD affects 15 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:

                                      Estimated Costs for Required Actions
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               Labor cost                   Parts cost         Cost per product         Cost on U.S. operators
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Up to 40 work-hours x $85 per hour = Up         $275,300  Up to $278,700............  Up to $4,180,500.
 to $3,400.
----------------------------------------------------------------------------------------------------------------

    The FAA has received no definitive data on which to base the cost 
estimates for the on-condition repairs specified in this AD.
    According to the manufacturer, some or all of the costs of this AD 
may be covered under warranty, thereby reducing the cost impact on 
affected operators. The FAA does not control warranty coverage for 
affected operators. 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.

[[Page 77499]]

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

0
1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by:
0
a. Removing Airworthiness Directive 2020-18-04, Amendment 39-21225 (85 
FR 54896, September 3, 2020); and
0
b. Adding the following new airworthiness directive:

2022-25-02 Airbus SAS: Amendment 39-22258; Docket No. FAA-2021-0833; 
Project Identifier MCAI-2021-00245-T.

(a) Effective Date

    This airworthiness directive (AD) is effective January 23, 2023.

(b) Affected ADs

    This AD replaces AD 2020-18-04, Amendment 39-21225 (85 FR 54896, 
September 3, 2020) (AD 2020-18-04).

(c) Applicability

    This AD applies to all Airbus SAS Model A350-941 and -1041 
airplanes, certificated in any category.

(d) Subject

    Air Transport Association (ATA) of America Code 27, Flight 
Controls.

(e) Reason

    This AD was prompted by a report of a slat system jam during 
landing, the determination that health checks must be repetitive to 
monitor torque sensor unit (TSU) wear, and the development of a 
modification that terminates the health checks. The FAA is issuing 
this AD to address a slat system jam during landing, which could 
lead to a double shaft disconnection/rupture, potentially causing 
one or more slat surfaces to be no longer connected to either the 
slat wing tip brake or the slat power control unit (PCU), possibly 
resulting in reduced control of the airplane.

(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) AD 
2021-0275, dated December 10, 2021 (EASA AD 2021-0275).

(h) Exceptions to EASA AD 2021-0275

    (1) Where EASA AD 2021-0275 refers to March 11, 2021 (the 
effective date of EASA AD 2021-0053, dated February 25, 2021), this 
AD requires using the effective date of this AD.
    (2) Where paragraph (2) of EASA AD 2021-0275 specifies 
compliance times for accomplishment of certain actions, replace the 
text ``but not exceeding the compliance time for the repeat health 
check as determined in accordance with the instructions of AOT 
[Alert Operators Transmission] A27P015-20, or AOT A27P016-20,'' with 
``but within the applicable compliance time specified in paragraph 
4.2.3.1 of AOT A27P015-20; or 4.2.2.2.2 or 4.2.2.3.2 of AOT A27P016-
20; as applicable.''
    (3) Where paragraph (4) of EASA AD 2021-0275 specifies 
``Appendix 5 of the AOT,'' use ``the Appendix labeled TSU Condition 
Check Flowchart of the AOT.''
    (4) Where note 2 of EASA AD 2021-0275 states that the 
certificate of release accompanying a replacement part ``will 
clarify,'' use ``may be used to clarify.''
    (5) The ``Remarks'' section of EASA AD 2021-0275 does not apply 
to this AD.
    (6) Where EASA AD 2021-0275 refers to its effective date, this 
AD requires using the effective date of this AD.
    (7) Where paragraph (7) of EASA AD 2021-0275 states that the 
modification specified in paragraph (6) of EASA AD 2021-0275 is 
terminating action for paragraph (4) of EASA AD 2021-0275, this AD 
considers accomplishing the modification specified in paragraph (6) 
of EASA AD 2021-0275 to also be terminating action for the initial 
health check specified in paragraph (2) of EASA AD 2021-0275.

(i) No Reporting Requirement

    Although the service information referenced in EASA AD 2021-0275 
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, 
Large Aircraft Section, 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 Large Aircraft Section, International Validation Branch, send it 
to the attention of the person identified in paragraph (k) of this 
AD. Information may be emailed to: [email protected]. 
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, Large Aircraft 
Section, 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 referenced 
in EASA AD 2021-0275 contains paragraphs that are labeled as RC, the 
instructions in RC paragraphs, including subparagraphs under an RC 
paragraph, must be done to comply with this AD; any paragraphs, 
including subparagraphs under those paragraphs, that are not 
identified as RC are recommended. The instructions in paragraphs, 
including subparagraphs under those paragraphs, 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 instructions identified as RC can 
be done and the airplane can be put back in an airworthy condition. 
Any substitutions or changes to instructions identified as RC 
require approval of an AMOC.

(k) Additional Information

    For more information about this AD, contact Dat Le, Aerospace 
Engineer, Large Aircraft Section, FAA, International Validation 
Branch, 2200 South 216th St., Des Moines, WA 98198; telephone 516-
228-7317; email [email protected].

(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 
January 23, 2023.
    (i) European Union Aviation Safety Agency (EASA) AD 2021-0275, 
dated December 10, 2021.

[[Page 77500]]

    (ii) [Reserved]
    (4) For EASA AD 2021-0275, contact EASA, Konrad-Adenauer-Ufer 3, 
50668 Cologne, Germany; telephone +49 221 8999 000; email 
[email protected]; website easa.europa.eu. You may find this EASA 
AD on the EASA website at ad.easa.europa.eu.
    (5) 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.
    (6) You may view this material that is incorporated by reference 
at the National Archives and Records Administration (NARA). For 
information on the availability of this material at NARA, email 
[email protected], or go to: www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on November 28, 2022.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2022-27399 Filed 12-16-22; 8:45 am]
BILLING CODE 4910-13-P