Airworthiness Directive

ID: 2017-19-23
Issue date: 2017-09-27
Effective date: 2017-11-01
Subject: Flight controls
Source: FAA
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Airbus Airplanes

[Federal Register Volume 82, Number 186 (Wednesday, September 27, 2017)]
[Rules and Regulations]
[Pages 44903-44907]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-20567]

––––––––––––––––––––––––––––––––––

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0498; Product Identifier 2016-NM-175-AD; Amendment 39-19053; AD
2017-19-23]

RIN 2120-AA64

Airworthiness Directives; Airbus Airplanes

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

ACTION: Final rule.

––––––––––––––––––––––––––––––––––

Summary:
We are superseding Airworthiness Directive (AD) 2015-15-10, which applied to all
Airbus Model A318, A319, A320, and A321 series airplanes. AD 2015-15-10 required repetitive
inspections of the trimmable horizontal stabilizer actuator (THSA) for damage, and replacement if
necessary; and replacement of the THSA after reaching a certain life limit. This AD requires
repetitive detailed inspections of certain THSAs, and related investigative and corrective actions if
necessary. This AD was prompted by the establishment of an additional life limit for the THSA,
based on flight cycles. In addition, the THSA manufacturer has issued service information which,
when accomplished, increases the life limit of the THSA. We are issuing this AD to address the
unsafe condition on these products.

Dates:
This AD is effective November 1, 2017.
The Director of the Federal Register approved the incorporation by reference of a certain
publication listed in this AD as of November 1, 2017.

Addresses:
For service information identified in this final rule, contact Airbus, Airworthiness
Office–EIAS, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93
36 96; fax +33 5 61 93 44 51; email account.airworth-eas@airbus.com; Internet
http://www.airbus.com.
You may view this referenced service information at the FAA, Transport Standards Branch,
1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA,
call 425-227-1221. It is also available on the Internet at http://www.regulations.gov by searching for
and locating Docket No. FAA-2017-0498.




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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-2017-0498; 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 AD,
the regulatory evaluation, any comments received, and other information. The address for the Docket
Office (telephone 800-647-5527) is Docket Management Facility, U.S. Department of
Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Sanjay Ralhan, Aerospace Engineer, International
Section, Transport Standards Branch, FAA, 1601 Lind Avenue SW., Renton, WA 98057-3356;
telephone 425-227-1405; fax 425-227-1149.

SUPPLEMENTARY INFORMATION:
Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD
2015-15-10, Amendment 39-18219 (80 FR 43928, July 24, 2015) (“AD 2015-15-10”). AD 2015-15-
10 applied to all Airbus Model A318, A319, A320, and A321 series airplanes. The NPRM published
in the Federal Register on June 2, 2017 (82 FR 25542). The NPRM was prompted by the
establishment of an additional life limit for the THSA, based on flight cycles. The NPRM proposed to
require repetitive detailed inspections of certain THSAs, and related investigative and corrective
actions if necessary. We are issuing this AD to detect and correct wear of the THSA, which could
reduce the remaining life of the THSA, possibly resulting in premature failure and consequent
reduced controllability of the airplane.
The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member
States of the European Union, has issued EASA Airworthiness Directive 2016-0184, dated
September 13, 2016 (referred to after this as the Mandatory Continuing Airworthiness Information, or
“the MCAI”), to correct an unsafe condition for all Airbus Model A318 and A319 series airplanes;
Model A320-211, -212, -214, -231, -232, and -233 airplanes; and Model A321-111, -112, -131, -211,
-212, -213, -231, and -232 airplanes. The MCAI states:

In the frame of the A320 Extended Service Goal (ESG) project and the study on the
Trimmable Horizontal Stabilizer Actuator (THSA), a sampling programme of in-
service units was performed and several cases of wear at different THSA levels were
reported.

This condition, if not detected and corrected, would reduce the remaining life of the
THSA, possibly resulting in premature failure and consequent reduced control of the
aeroplane.

Prompted by these findings, Airbus issued Service Bulletin (SB) A320-27-1227 to
provide THSA inspection instructions. Consequently, EASA issued AD 2014-0011
(later revised) [which corresponds to AD 2015-15-10] to require repetitive inspections
of the THSA [and related investigative and corrective actions] and to introduce a life
limit for the THSA, based on flight hours (FH).

Since EASA AD 2014-0011R1 was issued, an additional life limitation has been
established, based on flight cycles (FC). Furthermore, United Technologies
Corporation Aerospace Systems (UTAS), the THSA manufacturer, issued an SB
which, after accomplishment on THSA, increases the life limit of the THSA.

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For the reasons described above, this [EASA] AD retains the requirements of EASA
AD 2014-0011R1, which is superseded, and introduces an additional FC life limit for
the affected THSA. This [EASA] AD also provides a revised life limit for the THSA
after UTAS SB accomplishment on that THSA.

You may examine the MCAI in the AD docket on the Internet at http://www.regulations.gov by
searching for and locating Docket No. FAA-2017-0498.

Comments

We gave the public the opportunity to participate in developing this AD. We considered the
comments received. Air Line Pilots Association, International (ALPA) and United Airlines expressed
their support for the NPRM.

Changes Made to This AD

The NPRM specified that a THSA that had been repaired in-shop as specified in UTAS
Component Maintenance Manual 27-44-51 would be an equivalent method of compliance for the
initial inspection required by paragraph (h) of this AD. We have revised paragraph (m) of this AD to
specify that a THSA that has been repaired in-shop using a method approved by the Manager,
International Section, Transport Standards Branch, FAA; or the EASA; or Airbus's EASA Design
Organization Approval (DOA), is acceptable for compliance with the initial inspection required by
paragraph (h) of this AD. We have also added Note 1 to paragraph (m) of this AD to reference UTAS
Component Maintenance Manual 27-44-51 as an additional source of guidance for the in-shop repair
of the THSA.

Conclusion

We reviewed the relevant data, considered the comments received, and determined that air safety
and the public interest require adopting this AD with the changes described previously and minor
editorial changes. We have determined that these minor changes:
• Are consistent with the intent that was proposed in the NPRM for correcting the unsafe
condition; and
• Do not add any additional burden upon the public than was already proposed in the NPRM.
We also determined that these changes will not increase the economic burden on any operator or
increase the scope of this AD.

Related Service Information Under 1 CFR Part 51

Airbus has issued Service Bulletin A320-27-1227, Revision 03, dated April 29, 2016. This
service information describes procedures for repetitive special detailed inspections for wear of the
THSA, and related investigative and corrective actions.
This 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.

Costs of Compliance

We estimate that this AD affects 1,182 airplanes of U.S. registry.
We estimate the following costs to comply with this AD:



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Estimated Costs
Action Labor cost Parts Cost per product Cost on U.S.
cost operators
Inspections 6 work-hours × $85 per hour = $0 $510 per $602,820 per
$510 per inspection cycle inspection cycle inspection cycle.

We have received no definitive data that would enable us to provide cost estimates for the
spectrometric analysis of the oil drained from the THSA gearbox. We estimate the following costs to
do any necessary replacements or overhauls that would be required based on the results of the
inspection. We have no way of determining the number of aircraft that might need these replacements
or overhauls:

On-Condition Costs
Action Labor cost Parts Cost per
cost product
Replacement of THSA (retained from 11 work-hours × $85 per $240,000 $240,935
AD 2015-15-10) hour = $935
Overhaul of THSA (new action) 66 work-hours × $85 per 115,000 120,610
hour = $5,610

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 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 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. 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

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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.

Adoption of 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 removing Airworthiness Directive (AD) 2015-15-10, Amendment
39-18219 (80 FR 43928, July 24, 2015), and adding the following new AD:




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AIRWORTHINESS
FAA DIRECTIVE
Aviation Safety
www.faa.gov/aircraft/safety/alerts/
www.gpoaccess.gov/fr/advanced.html


2017-19-23 Airbus: Amendment 39-19053; Docket No. FAA-2017-0498; Product Identifier 2016-
NM-175-AD.

(a) Effective Date

This AD is effective November 1, 2017.

(b) Affected ADs

This AD replaces AD 2015-15-10, Amendment 39-18219 (80 FR 43928, July 24, 2015) (“AD
2015-15-10”).

(c) Applicability

This AD applies to the airplanes identified in paragraphs (c)(1) through (c)(4) of this AD,
certificated in any category, all manufacturer serial numbers.
(1) Airbus Model A318-111, -112, -121, and -122 airplanes.
(2) Airbus Model A319-111, -112, -113, -114, -115, -131, -132, and -133 airplanes.
(3) Airbus Model A320-211, -212, -214, -231, -232, and -233 airplanes.
(4) Airbus Model A321-111, -112, -131, -211, -212, -213, -231, and -232 airplanes.

(d) Subject

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

(e) Reason

This AD was prompted by reports of wear at different levels in the trimmable horizontal
stabilizer actuator (THSA). We are issuing this AD to detect and correct wear of the THSA, which
could reduce the remaining life of the THSA, possibly resulting in premature failure and consequent
reduced controllability of the airplane.

(f) Compliance

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

(g) Serviceable THSA Definition

For the purposes of this AD, a serviceable THSA is a THSA that does not exceed the life limits
as identified in table 1 to paragraphs (g) and (j) of this AD.




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• Table 1 to Paragraphs (g) and (j) of This AD–THSA Life Limits
Configuration, based on service Compliance time (whichever occurs first)
bulletin (SB) embodiment
THSA on which United Before exceeding 67,500 flight hours (FH) since first installation
Technologies Corporation on an airplane, or before exceeding 48,000 flight cycles (FC)
Aerospace Systems (UTAS) SB since first installation on an airplane.
47145-27-19 has not been
embodied
THSA on which UTAS SB Before exceeding 52,500 FH after embodiment of UTAS SB
47145-27-19 has been embodied 47145-27-19 on an airplane, without exceeding 120,000 FH
since first installation on an airplane; or before exceeding 27,000
FC after embodiment of UTAS SB 47145-27-19 on an airplane,
without exceeding 75,000 FC since first installation on an
airplane.

(h) Repetitive Inspection and Related Investigative Actions

For any airplane on which UTAS Service Bulletin 47145-27-19 has not been embodied: Before
the THSA exceeds 48,000 flight hours or 30,000 flight cycles, whichever occurs first since first
installation on an airplane, do a special detailed inspection of the THSA and do all applicable related
investigative actions, in accordance with the Accomplishment Instructions of Airbus Service Bulletin
A320-27-1227, Revision 03, dated April 29, 2016. Do all applicable related investigative actions at
the applicable times specified in paragraph 1.E., “Compliance” of Airbus Service Bulletin A320-27-
1227, Revision 03, dated April 29, 2016. Repeat the inspections thereafter at intervals not to exceed
24 months.

(i) Corrective Action

If, during any inspection required by paragraph (h) of this AD, any finding as described in the
Accomplishment Instructions of Airbus Service Bulletin A320-27-1227, Revision 03, dated April 29,
2016, is identified: At the applicable time (depending on the applicable finding) specified in
paragraph 1.E., “Compliance,” of Airbus Service Bulletin A320-27-1227, Revision 03, dated April
29, 2016, replace the THSA with a serviceable THSA, as specified in paragraph (g) of this AD, in
accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-27-1227,
Revision 03, dated April 29, 2016.

(j) THSA Replacement

Within the applicable compliance time specified in table 1 to paragraphs (g) and (j) of this AD,
replace each THSA with a serviceable THSA, as specified in paragraph (g) of this AD, in accordance
with the Accomplishment Instructions of Airbus Service Bulletin A320-27-1227, Revision 03, dated
April 29, 2016.

(k) Replacement of a THSA: Not Terminating Action

Replacement of a THSA on an airplane, as required by paragraph (i) or (j) of this AD, does not
constitute terminating action for the repetitive inspections required by paragraph (h) of this AD for
that airplane, unless the THSA has been overhauled as specified in UTAS Service Bulletin 47145-27-
19 (i.e., post-service bulletin).


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(l) Optional Terminating Action: Overhaul of THSA

Accomplishment of a modification of an airplane by installing a THSA that has been overhauled
as specified in UTAS Service Bulletin 47145-27-19 constitutes terminating action for the repetitive
inspections required by paragraph (h) of this AD, provided that, following modification, no THSA is
reinstalled on the airplane unless it has been overhauled as specified in UTAS Service Bulletin
47145-27-19.

(m) Replacement THSA Equivalency

As of the effective date of this AD: A THSA that has been repaired in-shop is acceptable for
compliance with the initial inspection required by paragraph (h) of this AD, provided that repair was
done 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).
Note 1 to paragraph (m) of this AD: Guidance for THSA repair in-shop can be found in UTAS
Component Maintenance Manual 27-44-51.

(n) Parts Installation Limitation

As of the effective date of this AD: Do not install on any airplane a THSA unless it is a
serviceable THSA as specified in paragraph (g) of this AD.

(o) Credit for Previous Actions

This paragraph provides credit for the actions required by paragraphs (h) and (i) of this AD, if
those actions were performed before the effective date of this AD using any of the service
information specified in paragraphs (o)(1), (o)(2), or (o)(3) of this AD.
(1) Airbus Service Bulletin A320-27-1227, dated July 1, 2013, which is not incorporated by
reference in this AD.
(2) Airbus Service Bulletin A320-27-1227, Revision 01, dated October 7, 2013, which was
incorporated by reference in AD 2015-15-10.
(3) Airbus Service Bulletin A320-27-1227, Revision 02, dated February 2, 2015, which is not
incorporated by reference in this AD.

(p) 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 (q)(2) of this AD. Information may be emailed to: 9-ANM-116-AMOC-
REQUESTS@faa.gov. 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 EASA; or Airbus's EASA DOA. If
approved by the DOA, the approval must include the DOA-authorized signature.


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(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.

(q) Related Information

(1) Refer to Mandatory Continuing Airworthiness Information (MCAI) EASA Airworthiness
Directive 2016-0184, dated September 13, 3016, 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-2017-0498.
(2) For more information about this AD, contact Sanjay Ralhan, Aerospace Engineer,
International Section, Transport Standards Branch, FAA, 1601 Lind Avenue SW., Renton, WA
98057-3356; telephone 425-227-1405; fax 425-227-1149.
(3) Service information identified in this AD that is not incorporated by reference is available at
the addresses specified in paragraphs (r)(3) and (r)(4) of this AD.

(r) 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) Airbus Service Bulletin A320-27-1227, Revision 03, dated April 29, 2016.
(ii) Reserved.
(3) For Airbus service information identified in this AD, contact Airbus, Airworthiness Office–
EIAS, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96;
fax +33 5 61 93 44 51; email account.airworth-eas@airbus.com; Internet http://www.airbus.com.
(4) You may view this service information at the FAA, Transport Standards Branch, 1601 Lind
Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call 425-
227-1221.
(5) 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, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

Issued in Renton, Washington, on September 14, 2017.
Jeffrey E. Duven,
Director, System Oversight Division,
Aircraft Certification Service.




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