
[Federal Register: May 2, 2008 (Volume 73, Number 86)]
[Rules and Regulations]               
[Page 24160-24162]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr02my08-11]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-0081; Directorate Identifier 2007-NM-186-AD; 
Amendment 39-15497; AD 2008-09-16]
RIN 2120-AA64

 
Airworthiness Directives; Airbus A318, A319, A320, and A321 
Series Airplanes

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

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for the 
products listed above. This AD results from mandatory continuing 
airworthiness information (MCAI) originated by an aviation authority of 
another country to identify and correct an unsafe condition on an 
aviation product. The MCAI describes the unsafe condition as:

    A number of occurrences of an incorrect installation of the 
trimmable horizontal stabilizer actuator (THSA) have been found and 
reported during the accomplishment of the AIRBUS Service Bulletin 
(SB) A320-27-1164 mandated by EASA AD 2006-0223.
    These issues could lead to a degradation of the integrity of the 
THSA primary load path and to secondary load path partial or full 
engagement.
* * * * *

Degradation of the THSA primary load path could result in latent 
(undetected) loading and eventual failure of the THSA secondary load 
path, with consequent uncontrolled movement of the horizontal 
stabilizer and loss of control of the airplane. We are issuing this AD 
to require actions to correct the unsafe condition on these products.

DATES: This AD becomes effective June 6, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of June 6, 
2008.

ADDRESSES: You may examine the AD docket on the Internet at http://
www.regulations.gov or in person at the U.S. Department of 
Transportation, Docket Operations, M-30, West Building, Ground Floor, 
Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC.

FOR FURTHER INFORMATION CONTACT: Tim Dulin, Aerospace Engineer, 
International Branch, ANM-116, Transport Airplane Directorate, FAA, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
227-2141; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an AD that would apply to the specified products. 
That NPRM was published in the Federal Register on October 25, 2007 (72 
FR 60591). That NPRM proposed to correct an unsafe condition for the 
specified products. The MCAI states:

A number of occurrences of an incorrect installation of the 
trimmable horizontal stabilizer actuator (THSA) have been found and 
reported during the accomplishment of the AIRBUS Service Bulletin 
(SB) A320-27-1164 mandated by EASA AD 2006-0223.
    These issues could lead to a degradation of the integrity of the 
THSA primary load path and to secondary load path partial or full 
engagement. This AD therefore mandates a one-time detailed visual 
inspection of specific parts of the THSA attachments.

Degradation of the THSA primary load path could result in latent 
(undetected) loading and eventual failure of the THSA secondary load 
path, with consequent uncontrolled movement of the horizontal 
stabilizer and loss of control of the airplane. The corrective actions 
include doing a one-time detailed visual inspection of the lower and 
the upper THSA attachments for correct installation and the presence of 
metallic particles, contacting Airbus for repair instructions if any 
installation deviations or metallic particles are found, and doing 
repairs. You may obtain further information by examining the MCAI in 
the AD docket.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We considered the comment received.

Request to Withdraw the NPRM

    The Air Transport Association (ATA), on behalf of its member 
Northwest Airlines (NWA), requests that we reconsider the need for this 
proposed AD. NWA states that the proposed rule is based on reports from 
Airbus of a number of occurrences of incorrect THSA installations that 
resulted from published procedures not being followed either during 
aircraft production or by operators after delivery of the aircraft. NWA 
agrees that an incorrectly installed THSA could be a safety concern, 
but asserts that accomplishing a one-time inspection will not prevent 
improper THSA installations in the future, and does not understand what 
corrective action is being taken (or should be taken) to prevent 
similar installation problems in the future. Furthermore, NWA feels 
that the airplane maintenance manual (AMM) is clear and concise 
regarding THSA installation procedures and states that, unless 
incorrect installations were accomplished during production or the AMM 
installation instructions were incorrect, a one-time inspection 
mandated by an AD is unwarranted. NWA asserts that it has accomplished 
AD 2007-06-02, amendment 39-14983 (72 FR 12072, March 15, 2007), on all 
its Model A319 and A320 airplanes with no findings of note. (AD 2007-
06-02, which corresponds to EASA AD 2006-0223, dated July 21, 2006, 
requires inspections of the upper and lower THSA attachments for proper 
clearances, and for the presence of cracking, damage, and metallic 
particles.) NWA concludes that incorrect installations due to operator 
error should be addressed by actions other than issuing an all-fleet 
AD.
    Although we understand NWA's concern, we do not agree with this 
request. If incorrect THSA installation was limited to only one 
operator (an isolated case of not following maintenance instructions), 
an AD would not have been an appropriate method of dealing with the 
situation. However, as THSA installation errors have been reported at 
multiple operators, and installation errors could result in the 
identified unsafe condition that is likely to exist or develop on other 
airplanes, an AD is appropriate. Further, we have determined that, 
although technically correct, the maintenance instructions were 
insufficiently clear to ensure that no confusion could occur during 
installation of the THSA. In regard to future installations, Airbus has 
informed us that the maintenance instructions have been revised and 
clarified to prevent confusion during any future installation of the 
THSA. We have not changed the AD in this regard.

Conclusion

    We reviewed the available data, including the comment received, and 
determined that air safety and the public interest require adopting the 
AD as proposed.

[[Page 24161]]

Differences Between This AD and the MCAI or Service Information

    We have reviewed the MCAI and related service information and, in 
general, agree with their substance. But we might have found it 
necessary to use different words from those in the MCAI to ensure the 
AD is clear for U.S. operators and is enforceable. In making these 
changes, we do not intend to differ substantively from the information 
provided in the MCAI and related service information.
    We might also have required different actions in this AD from those 
in the MCAI in order to follow our FAA policies. Any such differences 
are highlighted in a NOTE within the AD.

Costs of Compliance

    We estimate that this AD will affect 721 products of U.S. registry. 
We also estimate that it will take about 3 work-hours per product to 
comply with the basic requirements of this AD. The average labor rate 
is $80 per work-hour. Based on these figures, we estimate the cost of 
this AD to the U.S. operators to be $173,040, or $240 per product.

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.

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 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); 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this AD and placed it in the AD docket.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Operations office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains the 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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
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 adding the following new AD:

2008-09-16 Airbus: Amendment 39-15497. Docket No. FAA-2007-0081; 
Directorate Identifier 2007-NM-186-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective June 6, 
2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Airbus A318, A319, A320, and A321 series 
airplanes, certificated in any category, all certified models, all 
manufactured serial numbers (MSN) up to and including MSN 2860.

Subject

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

Reason

    (e) The mandatory continuing airworthiness information (MCAI) 
states:

    A number of occurrences of an incorrect installation of the 
trimmable horizontal stabilizer actuator (THSA) have been found and 
reported during the accomplishment of the AIRBUS Service Bulletin 
(SB) A320-27-1164 mandated by EASA AD 2006-0223.
    These issues could lead to a degradation of the integrity of the 
THSA primary load path and to secondary load path partial or full 
engagement.
    This AD therefore mandates a one-time detailed visual inspection 
of specific parts of the THSA attachments.

Degradation of the THSA primary load path could result in latent 
(undetected) loading and eventual failure of the THSA secondary load 
path, with consequent uncontrolled movement of the horizontal 
stabilizer and loss of control of the airplane. The corrective 
actions include doing a one-time detailed visual inspection of the 
lower and the upper THSA attachments for correct installation and 
the presence of metallic particles, contacting Airbus for repair 
instructions if any installation deviations or metallic particles 
are found, and doing repairs.

Actions and Compliance

    (f) Unless already done, do the following actions.
    (1) Within 600 flight hours or 750 flight cycles or 100 days 
after the effective date of this AD, whichever occurs first, inspect 
the lower and the upper THSA attachments for installation deviations 
and metallic particles, in accordance with Airbus Service Bulletin 
A320-27A1179, dated January 12, 2007; and, if any installation 
deviations or metallic particles are found, before further flight, 
contact Airbus for repair instructions and repair.

FAA AD Differences

    Note: This AD differs from the MCAI and/or service information 
as follows: No Difference.

Other FAA AD Provisions

    (g) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, 
International Branch, ANM-116, Transport Airplane Directorate, FAA, 
has the authority to approve AMOCs for this AD, if requested using 
the procedures found in 14 CFR 39.19. Send information to ATTN: Tim 
Dulin, Aerospace Engineer, International Branch, ANM-116, Transport 
Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 
98057-3356; telephone (425) 227-2141; fax (425) 227-1149. Before 
using any approved AMOC on any airplane to which the AMOC applies, 
notify your appropriate principal inspector (PI) in the FAA Flight 
Standards District Office (FSDO), or lacking a PI, your local FSDO.
    (2) Airworthy Product: For any requirement in this AD to obtain 
corrective actions from a manufacturer or other source, use these 
actions if they are FAA-approved. Corrective actions are considered 
FAA-approved if they

[[Page 24162]]

are approved by the State of Design Authority (or their delegated 
agent). You are required to assure the product is airworthy before 
it is returned to service.
    (3) Reporting Requirements: For any reporting requirement in 
this AD, under the provisions of the Paperwork Reduction Act, the 
Office of Management and Budget (OMB) has approved the information 
collection requirements and has assigned OMB Control Number 2120-
0056.

Related Information

    (h) Refer to European Aviation Safety Agency (EASA) 
Airworthiness Directive 2007-0178, dated June 22, 2007; and Airbus 
Service Bulletin A320-27A1179, dated January 12, 2007; for related 
information.

Material Incorporated by Reference

    (i) You must use Airbus Service Bulletin A320-27A1179, dated 
January 12, 2007, to do the actions required by this AD, unless the 
AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this AD, contact 
Airbus, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France.
    (3) You may review copies at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or 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 April 18, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-9441 Filed 5-1-08; 8:45 am]

BILLING CODE 4910-13-P
