[Federal Register Volume 86, Number 57 (Friday, March 26, 2021)]
[Proposed Rules]
[Pages 16117-16121]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-05948]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0193; Project Identifier MCAI-2020-01612-T]
RIN 2120-AA64


Airworthiness Directives; Airbus SAS Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Airbus SAS Model A350-941 and -1041 airplanes. This 
proposed AD was prompted by a determination that new or more 
restrictive airworthiness limitations are necessary. This proposed AD 
would 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), which is proposed for incorporation by reference. This proposed 
AD would also require, for certain airplanes, an update of the 
hydraulic monitoring system to include additional redundancy. 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 May 10, 
2021.

[[Page 16118]]


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 https://www.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.
    For EASA material that will be incorporated by reference (IBR) in 
this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; 
telephone +49 221 8999 000; email ADs@easa.europa.eu; internet 
www.easa.europa.eu. You may find this IBR material on the EASA website 
at https://ad.easa.europa.eu. For Airbus SAS service information 
identified in this proposed AD, contact Airbus SAS, Airworthiness 
Office--EAL, Rond-Point Emile Dewoitine No: 2, 31700 Blagnac Cedex, 
France; telephone +33 5 61 93 36 96; fax +33 5 61 93 45 80; email 
continued-airworthiness.a350@airbus.com; internet http://www.airbus.com. You may view this IBR 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 on the internet at https://www.regulations.gov by searching for 
and locating Docket No. FAA-2021-0193.

Examining the AD Docket

    You may examine the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-
0193; 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, any comments received, and other information. The street 
address for Docket Operations is listed above.

FOR FURTHER INFORMATION CONTACT: Kathleen Arrigotti, Aerospace 
Engineer, Large Aircraft Section, International Validation Branch, FAA, 
2200 South 216th St., Des Moines, WA 98198; telephone and fax 206-231-
3218; Kathleen.Arrigotti@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-2021-0193; Project Identifier 
MCAI-2020-01612-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 
the 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 
https://www.regulations.gov, including any personal information you 
provide. The agency will also post a report summarizing each 
substantive verbal contact received about this proposed AD.

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 
Kathleen Arrigotti, Aerospace Engineer, Large Aircraft Section, 
International Validation Branch, FAA, 2200 South 216th St., Des Moines, 
WA 98198; telephone and fax 206-231-3218; Kathleen.Arrigotti@faa.gov. 
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 EASA, which is the Technical Agent for the Member States of the 
European Union, has issued EASA AD 2020-0268, dated December 4, 2020 
(EASA AD 2020-0268) (also referred to after this as the Mandatory 
Continuing Airworthiness Information, or the MCAI), to correct an 
unsafe condition for all Airbus SAS Model A350-941 and -1041 airplanes. 
EASA AD 2020-0268 refers to Airbus A350 Airworthiness Limitations 
Section (ALS), Part 5, ``Fuel Airworthiness Limitations (FAL),'' 
Revision 04, dated May 29, 2020, and Airbus A350 ALS Part 5, ``Fuel 
Airworthiness Limitations (FAL),'' Variation 4.1, dated September 15, 
2020. Airplanes with an original airworthiness certificate or original 
export certificate of airworthiness issued after September 15, 2020, 
must comply with the airworthiness limitations specified as part of the 
approved type design and referenced on the type certificate data sheet; 
this AD therefore does not include those airplanes in the 
applicability. You may examine the MCAI in the AD docket on the 
internet at https://www.regulations.gov by searching for and locating 
Docket No. FAA-2021-0193.
    This proposed AD was prompted by a determination that new or more 
restrictive airworthiness limitations are necessary. The FAA is 
proposing this AD to address the overheat failure mode of the hydraulic 
engine-driven pump (EDP), which may cause a fast temperature rise of 
the hydraulic fluid, and, if combined with an inoperative fuel tank 
inerting system, could lead to an uncontrolled overheat of the 
hydraulic fluid, possibly resulting in ignition of the fuel-air mixture 
of the affected fuel tank. See the MCAI for additional background 
information.

Related Service Information Under 1 CFR Part 51

    EASA AD 2020-0268 describes new or more restrictive airworthiness 
limitations related to fuel tank ignition prevention and fuel tank 
flammability reduction.
    This proposed AD would also require accomplishing a certain 
airworthiness limitation using the following service information. These 
documents are distinct since they apply to different airplane models.
     Airbus Service Bulletin A350-29-P025, dated August 10, 
2020.
     Airbus Service Bulletin A350-29-P027, dated November 24, 
2020.
     Airbus Service Bulletin A350-29-P029, dated December 16, 
2020.
    The service information describes procedures for an update of the 
hydraulic monitoring system to include additional redundancy (i.e., 
modifying the case-drain filter manifolds by installing new dual 
temperature sensors on the hydraulic EDP). This service information is 
reasonably available because the interested parties have

[[Page 16119]]

access to it through their normal course of business or by the means 
identified in the ADDRESSES section.

FAA's Determination and Requirements of This Proposed AD

    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 the State of Design Authority, 
the FAA has been notified of the unsafe condition described in the MCAI 
and service information referenced above. The FAA is proposing this AD 
because the FAA has evaluated all pertinent information and determined 
an unsafe condition exists and is likely to exist or develop on other 
products of the same type design.

Proposed Requirements of This NPRM

    This proposed AD would require revising the existing maintenance or 
inspection program, as applicable, to incorporate new or more 
restrictive airworthiness limitations, which are specified in EASA AD 
2020-0268 described previously, as incorporated by reference. Any 
differences with EASA AD 2020-0268 are identified as exceptions in the 
regulatory text of this AD. This proposed AD would require 
accomplishing a certain airworthiness limitation using the Airbus 
service information described previously.
    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 and CDCCLs 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 according to paragraph 
(j)(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 initially worked with Airbus and EASA to develop a 
process to use certain EASA ADs as the primary source of information 
for compliance with requirements for corresponding FAA ADs. The FAA has 
since coordinated with other manufacturers and civil aviation 
authorities (CAAs) to use this process. As a result, EASA AD 2020-0268 
will be incorporated by reference in the FAA final rule. This proposed 
AD would, therefore, require compliance with EASA AD 2020-0268 in its 
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 the EASA AD 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 the EASA AD.
    Service information specified in EASA AD 2020-0268 that is required 
for compliance with EASA AD 2020-0268 will be available on the internet 
at https://www.regulations.gov by searching for and locating Docket No. 
FAA-2021-0193 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 alternative method of 
compliance (AMOC) in accordance with the procedures specified in the 
AMOCs paragraph under ``Other FAA 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, 
interval, or CDCCL.

Costs of Compliance

    The FAA estimates that this proposed AD affects 15 airplanes of 
U.S. registry. The FAA estimates the following costs to comply with 
this proposed AD:
    The FAA has determined that revising the 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. Therefore, the 
agency estimates the average total cost per operator to be $7,650 (90 
work-hours x $85 per work-hour).

                                      Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
            Labor cost                  Parts cost         Cost per product         Cost on U.S. operators
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Up to 510 work-hours x $85 per     Up to $29,320.......  Up to $72,670......  Up to $1,090,050.
 hour = Up to $43,350.
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    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 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,

[[Page 16120]]

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

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 adding the following new airworthiness 
directive:

Airbus SAS: Docket No. FAA-2021-0193; Project Identifier MCAI-2020-
01612-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) action by May 10, 2021.

(b) Affected ADs

    None.

 (c) Applicability

    This AD applies to Airbus SAS Model A350-941 and -1041 
airplanes, certificated in any category; with an original 
airworthiness certificate or original export certificate of 
airworthiness issued after September 15, 2020.

(d) Subject

    Air Transport Association (ATA) of America Code 05, Time Limits/
Maintenance Checks; 29, Hydraulic power.

(e) Reason

    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 overheat failure mode of the 
hydraulic engine-driven pump, which may cause a fast temperature 
rise of the hydraulic fluid, and, if combined with an inoperative 
fuel tank inerting system, could lead to an uncontrolled overheat of 
the hydraulic fluid, possibly resulting in ignition of the fuel-air 
mixture of the affected fuel tank.

(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 
2020-0268, dated December 4, 2020 (EASA AD 2020-0268).

(h) Exceptions to EASA AD 2020-0268

    (1) Where Section 6 of the service information referenced in 
EASA AD 2020-0268 specifies to update the hydraulic monitoring 
system ``to include additional redundancy to be installed (MOD 
114073 and MOD 114075 OR 114531 and MOD 114075 OR MOD 114533 and MOD 
114075 OR MOD 114535 and MOD 114075),'' this AD requires that the 
update of the hydraulic monitoring system be accomplished using the 
method of compliance specified in paragraphs (h)(1)(i) through (iv) 
of this AD, as applicable.
    (i) For Model A350-941 airplanes identified in Airbus Service 
Bulletin A350-29-P025 (MOD 114531 and MOD 114075): The modification 
must be done in accordance with paragraphs 3.C., 3.D., and 3.E., of 
the Accomplishment Instructions of Airbus Service Bulletin A350-29-
P025, dated August 10, 2020.
    (ii) For Model A350-941 airplanes identified in Airbus Service 
Bulletin A350-29-P027 (MOD 114533 and MOD 114075): The modification 
must be done in accordance with paragraphs 3.C., 3.D., and 3.E., of 
the Accomplishment Instructions of Airbus Service Bulletin A350-29-
P027, dated November 24, 2020.
    (iii) For Model A350-941 airplanes identified in Airbus Service 
Bulletin A350-29-P029 (MOD 114535 and MOD 114075): The modification 
must be done in accordance with paragraphs 3.C., 3.D., and 3.E., of 
the Accomplishment Instructions of Airbus Service Bulletin A350-29-
P029, dated December 16, 2020.
    (iv) For Model A350-941 airplanes not identified in paragraphs 
(h)(1)(i) through (iii) of this AD, and without MOD 114073 and 
114075 installed in production: The modification must be done 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.
    (2) Where EASA AD 2020-0268 refers to its effective date, this 
AD requires using the effective date of this AD.
    (3) The requirements specified in paragraphs (1) and (2) of EASA 
AD 2020-0268 do not apply to this AD.
    (4) Paragraph (3) of EASA AD 2020-0268 specifies revising ``the 
approved AMP'' within 12 months after its effective date, but this 
AD requires revising the existing maintenance or inspection program, 
as applicable, within 90 days after the effective date of this AD.
    (5) The initial compliance time for doing the tasks specified in 
paragraph (3) of EASA AD 2020-0268 is at the applicable 
``thresholds'' as incorporated by the requirements of paragraph (3) 
of EASA AD 2020-0268, or within 90 days after the effective date of 
this AD, whichever occurs later.
    (6) The provisions specified in paragraphs (4) and (5) of EASA 
AD 2020-0268 do not apply to this AD.
    (7) The ``Remarks'' section of EASA AD 2020-0268 does not apply 
to this AD.

(i) Provisions for Alternative Actions, Intervals, and Critical Design 
Configuration Control Limitations (CDCCLs)

    After the existing maintenance or inspection program has been 
revised as required by paragraph (g) 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 2020-0268.

(j) Other FAA 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 local Flight 
Standards District 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)(2) of this AD. Information may be emailed to: 9-AVS-AIR-730-AMOC@faa.gov. Before using any

[[Page 16121]]

approved AMOC, notify your appropriate principal inspector, or 
lacking a principal inspector, the manager of the local flight 
standards district office/certificate holding district 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 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) Related Information

    (1) For information about EASA AD 2020-0268, contact EASA, 
Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone +49 221 
8999 000; email ADs@easa.europa.eu; internet www.easa.europa.eu. You 
may find this EASA AD on the EASA website at https://ad.easa.europa.eu. For Airbus SAS service information identified in 
this proposed AD, contact Airbus SAS, Airworthiness Office--EAL, 
Rond-Point Emile Dewoitine No: 2, 31700 Blagnac Cedex, France; 
telephone +33 5 61 93 36 96; fax +33 5 61 93 45 80; email continued-airworthiness.a350@airbus.com; internet http://www.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. This material may be found in the AD docket on the 
internet at https://www.regulations.gov by searching for and 
locating Docket No. FAA-2021-0193.
    (2) For more information about this AD, contact Kathleen 
Arrigotti, Aerospace Engineer, Large Aircraft Section, International 
Validation Branch, FAA, 2200 South 216th St., Des Moines, WA 98198; 
telephone and fax 206-231-3218; Kathleen.Arrigotti@faa.gov.

    Issued on March 18, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-05948 Filed 3-25-21; 8:45 am]
BILLING CODE 4910-13-P


