[Federal Register Volume 83, Number 112 (Monday, June 11, 2018)]
[Proposed Rules]
[Pages 26882-26884]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-12229]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0506; Product Identifier 2018-NM-045-AD]
RIN 2120-AA64


Airworthiness Directives; Airbus

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain Airbus Model A350-941 airplanes. This proposed AD was prompted 
by the discovery of inadequate corrosion protection in certain areas of 
the horizontal stabilizer and the rear fuselage cone structure. This 
proposed AD would require application of sealant and protective 
treatment on the affected areas of the horizontal stabilizer and the 
rear fuselage cone structure and, for certain airplanes, modification 
of the trimmable horizontal stabilizer (THS) torsion box and re-
identification of the elevator. We are proposing this AD to address the 
unsafe condition on these products.

DATES: We must receive comments on this proposed AD by July 26, 2018.

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 http://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 service information identified in this NPRM, contact Airbus 
SAS, Airworthiness Office--EAL, 1 Rond Point Maurice Bellonte, 31707 
Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5 61 93 45 
80; email [email protected]; internet http://www.airbus.com. You may view this service information at the FAA, 
Transport Standards Branch, 2200 South 216th St., Des Moines, WA. For 
information on the availability of this material at the FAA, call 206-
231-3195.

Examining the AD Docket

    You may examine the AD docket on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2018-
0506; or in person at the Docket Management Facility between 9 a.m. and 
5 p.m., Monday through Friday, except Federal holidays. The AD docket 
contains this NPRM, the regulatory evaluation, any comments received, 
and other information. The street address for the Docket Operations 
office (telephone 800-647-5527) is in the ADDRESSES section. Comments 
will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Kathleen Arrigotti, Aerospace 
Engineer, International Section, Transport Standards Branch, FAA, 2200 
South 216th St., Des Moines, WA 98198; telephone and fax 206-231-3218.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2018-0506; 
Product Identifier 2018-NM-045-AD'' at the beginning of your comments. 
We specifically invite comments on the overall regulatory, economic, 
environmental, and energy aspects of this NPRM. We will consider all 
comments received by the closing date and may amend this NPRM based on 
those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this NPRM.

Discussion

    The European Aviation Safety Agency (EASA), which is the Technical 
Agent for the Member States of the European Union, has issued EASA AD 
2018-0036, dated February 7, 2018 (referred to after this as the 
Mandatory Continuing

[[Page 26883]]

Airworthiness Information, or ``the MCAI''), to correct an unsafe 
condition for certain Airbus Model A350-941 airplanes. The MCAI states:

    In some areas of the Horizontal Tail Plane (HTP) [horizontal 
stabilizer] and fuselage Section (S) 19 [rear fuselage cone 
structure], the interfay sealant for multimaterial joints (hybrid 
joints) was only applied on the surface in direct contact with 
aluminium parts and not between all surfaces of the joint parts. 
This situation does not ensure full barrier properties. To avoid any 
risk of water ingress in multi-material-stacks involving aluminium, 
it is necessary to apply interfay sealant between all assembled 
parts, even between parts made of corrosion resistant material. This 
ensures a double barrier in the joint and prevents subsequent 
potential galvanic corrosion on the aluminum holes on top of the 
single barrier already applied in aluminium parts.
    This condition, if not corrected, could reduce the structural 
integrity of the HTP and fuselage at S19.
    To address this unsafe condition, Airbus developed production 
mod [Modification] 106695 for fuselage at S19 and mod 107824 for HTP 
to improve protection against corrosion, and issued [Airbus] SB 
[Service Bulletin] A350-53-P029 (Airbus mod 110281) and [Airbus] SB 
A350-55-P003 (Airbus mod 107877 and mod 108494) to provide 
modification instructions for in-service pre-mod aeroplanes.
    For the reasons described above, this [EASA] AD requires 
application of sealant and protective treatment on the affected 
areas of the HTP and fuselage at S19 and, for certain aeroplanes, 
modification of the trimmable horizontal stabilizer (THS) torsion 
box [and re-identification of the elevator].

Related Service Information Under 1 CFR Part 51

    Airbus has issued Service Bulletin A350-53-P029, dated November 17, 
2017. This service information describes procedures to apply sealant 
and protective treatment on the affected areas of the rear fuselage 
cone structure.
    Airbus has issued Service Bulletin A350-55-P003, dated November 6, 
2017. This service information describes procedures to apply sealant 
and protective treatment on the affected areas of the horizontal 
stabilizer, modify the THS torsion box in zone 330 and 340, and re-
identify the elevator in zone 335 and 345.
    The service information 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 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 our bilateral agreement with the State of Design Authority, we have 
been notified of the unsafe condition described in the MCAI and service 
information referenced above. We are proposing this AD because we 
evaluated all pertinent information and determined an unsafe condition 
exists and is likely to exist or develop on other products of the same 
type designs.

Costs of Compliance

    We estimate that this proposed AD affects 6 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed 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 57 work-hours x $85 per hour =   Unavailable............  Up to $4,845...........  Up to $29,070.
 $4,845.
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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 individuals. We do not control warranty coverage for 
affected individuals. As a result, we have included all known costs in 
our 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.
    We are 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.
    This proposed AD is issued in accordance with authority delegated 
by the Executive Director, Aircraft Certification Service, as 
authorized by FAA Order 8000.51C. In accordance with that order, 
issuance of ADs is normally a function of the Compliance and 
Airworthiness Division, but during this transition period, the 
Executive Director has delegated the authority to issue ADs applicable 
to transport category airplanes to the Director of the System Oversight 
Division.

Regulatory Findings

    We 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. Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979);
    3. Will not affect intrastate aviation in Alaska; and
    4. 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 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.

[[Page 26884]]

Sec.  39.13   [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

Airbus: Docket No. FAA-2018-0506; Product Identifier 2018-NM-045-AD.

(a) Comments Due Date

    We must receive comments by July 26, 2018.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Airbus Model A350-941 airplanes certificated 
in any category, all manufacturer serial numbers, except those on 
which Airbus Modification 106695 (or retrofit Modification 110281) 
and Modification 107824 (or retrofit Modification 107877 and 
retrofit Modification 108494) have been embodied in production.

(d) Subject

    Air Transport Association (ATA) of America Code 53, Fuselage; 
55, Stabilizers.

(e) Reason

    This AD was prompted by the discovery of inadequate corrosion 
protection in certain areas of the horizontal stabilizer and the 
rear fuselage cone structure. We are issuing this AD to prevent 
reduced structural integrity of the horizontal stabilizer and the 
rear fuselage cone structure.

(f) Compliance

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

(g) Definitions

    (1) For the purpose of this AD, Group 1 airplanes are those with 
manufacturer serial numbers (MSNs) listed in Section 1.A., 
``Applicability'' of Airbus Service Bulletin A350-53-P029, dated 
November 17, 2017.
    (2) For the purpose of this AD, Group 2 airplanes are those with 
MSNs listed in Section 1.A., ``Applicability'' of Airbus Service 
Bulletin A350-55-P003, dated November 6, 2017.

(h) Modification

    (1) For Group 1 airplanes: Before exceeding 36 months since the 
date of issuance of the original standard airworthiness certificate 
or date of issuance of the original export certificate of 
airworthiness, or within 90 days after the effective date of this 
AD, whichever occurs later, apply sealant and protective treatment 
on the affected areas of the rear fuselage cone structure, as 
defined in, and in accordance with the Accomplishment Instructions 
of Airbus Service Bulletin A350-53-P029, dated November 17, 2017.
    (2) For Group 2 airplanes: Before exceeding 36 months since the 
date of issuance of the original standard airworthiness certificate 
or date of issuance of the original export certificate of 
airworthiness, or within 90 days after the effective date of this 
AD, whichever occurs later, accomplish concurrently the actions 
specified in paragraphs (h)(2)(i) and (h)(2)(ii) of this AD, in 
accordance with the Accomplishment Instructions of Airbus Service 
Bulletin A350-55-P003, dated November 6, 2017.
    (i) Apply sealant and protective treatment on the affected areas 
of the horizontal stabilizer, as defined in Airbus Service Bulletin 
A350-55-P003, dated November 6, 2017.
    (ii) Modify the trimmable horizontal stabilizer (THS) torsion 
box in zone 330 and 340, and re-identify the elevator in zone 335 
and 345.

(i) Other FAA AD Provisions

    The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, 
International Section, Transport Standards 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 International Section, send it to the attention of 
the person identified in paragraph (j)(2) 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 local flight 
standards district office/certificate holding district office.
    (2) Contacting the Manufacturer: For any requirement in this AD 
to obtain corrective actions from a manufacturer, the action must be 
accomplished using a method approved by the Manager, International 
Section, Transport Standards Branch, FAA; or the European Aviation 
Safety Agency (EASA); or Airbus's EASA Design Organization Approval 
(DOA). If approved by the DOA, the approval must include the DOA-
authorized signature.
    (3) Required for Compliance (RC): 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.

(j) Related Information

    (1) Refer to Mandatory Continuing Airworthiness Information 
(MCAI) EASA AD 2018-0036, dated February 7, 2018, for related 
information. This MCAI may be found in the AD docket on the internet 
at http://www.regulations.gov by searching for and locating Docket 
No. FAA-2018-0506.
    (2) For more information about this AD, contact Kathleen 
Arrigotti, Aerospace Engineer, International Section, Transport 
Standards Branch, FAA, 2200 South 216th St., Des Moines, WA 98198; 
telephone and fax 206-231-3218.
    (3) For service information identified in this AD, contact 
Airbus SAS, Airworthiness Office--EAL, 1 Rond Point Maurice 
Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96; 
fax +33 5 61 93 45 80; email [email protected]; internet http://www.airbus.com. You 
may view this service information at the FAA, Transport Standards 
Branch, 2200 South 216th St., Des Moines, WA. For information on the 
availability of this material at the FAA, call 206-231-3195.

    Issued in Des Moines, Washington, on May 25, 2018.
Jeffrey E. Duven,
Director, System Oversight Division, Aircraft Certification Service.
[FR Doc. 2018-12229 Filed 6-8-18; 8:45 am]
 BILLING CODE 4910-13-P