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[Federal Register: May 17, 2010 (Volume 75, Number 94)]
[Rules and Regulations]
[Page 27414-27416]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr17my10-7]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0129; Directorate Identifier 2009-NM-245-AD;
Amendment 39-16287; AD 2010-10-08]
RIN 2120-AA64

Airworthiness Directives; Airbus A318, A319, A320, 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:

    Several occurrences of loss of the AC [alternating current] BUS
1 have been reported which led in some instances to the loss of the
AC ESS [essential] BUS and DC [direct current] ESS BUS and connected
systems. The affected systems include multiple flight deck Display
Units (Primary Flight Display, Navigation Display and Upper
Electronic Centralised Aircraft Monitoring display).
* * * * *
    The loss of multiple display units, if not corrected expediently
during a high workload period, potentially affects the capability of
the flight crew and could contribute to a loss of situational
awareness and consequent control of the aeroplane, which would
constitute an unsafe condition.
* * * * *
We are issuing this AD to require actions to correct the unsafe
condition on these products.

DATES: This AD becomes effective June 21, 2010.
    The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of June 21,
2010.

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 February 23, 2010
(75 FR 8003). That NPRM proposed to correct an unsafe condition for the
specified products. The MCAI states:

    Several occurrences of loss of the AC [alternating current] BUS
1 have been reported which led in some instances to the loss of the
AC ESS [essential] BUS and DC [direct current] ESS BUS and connected
systems. The affected systems include multiple flight deck Display
Units (Primary Flight Display, Navigation Display and Upper
Electronic Centralised Aircraft Monitoring display).
    The reasons for these events have been investigated but have not
been fully established for all cases.
    Due to the range of system losses some crews reported difficulty
in establishing the failure cause during the events and,
consequently, the appropriate actions to be taken may not be
completed in a timely manner.
    The loss of multiple display units, if not corrected expediently
during a high workload period, potentially affects the capability of
the flight crew and could contribute to a loss of situational
awareness and consequent control of the aeroplane, which would
constitute an unsafe condition.
    This AD therefore mandates the modification of the electrical
network configuration management logic consisting in adding an
automatic switching of the AC and DC ESS BUS power supply such that
upon the loss of the AC BUS 1, the AC BUS 2 will automatically take
over the power supply. On pre-MOD aeroplanes, this power supply
switching can only be accomplished manually from the cockpit and is
covered by an Electronic Centralized Aircraft Monitoring (ECAM)
procedure.

The modification of the electrical power distribution system includes,
depending on the configuration, adding a new circuit breaker and new
relay to the AC/DC ESS BUS circuit, and adding a diode between a
certain relay and terminal block. 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.

Support and Request to Reduce Compliance Time

    The Airline Pilots Association, International (ALPA) supports this
AD, and asks that the 48-month compliance time proposed in the NPRM be
reduced to 24 months. ALPA states that, given the potentially serious
consequences of the flightcrew experiencing a very high workload during
a critical phase of flight, the compliance time should be reduced based
on the number of events and the safety risk associated with BUS
failures.
    We do not agree that the compliance time should be reduced. In
developing the compliance time for this AD action, we considered not
only the safety implications of the identified unsafe condition, but
the average utilization rate of the affected fleet, the practical
aspects of modifying the fleet during the compliance time, and the
availability of required parts. In addition, we have coordinated with
the European Aviation Safety Agency (EASA), which is the Technical
Agent for the Member States of the European Community. We have
determined that the 48-month compliance time to do the modification
addresses the identified unsafe condition and ensures an adequate level
of safety for the affected fleet. We have made no change to 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.

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.

[[Page 27415]]

Costs of Compliance

    We estimate that this AD will affect 633 products of U.S. registry.
We also estimate that it will take about 46 work-hours per product to
comply with the basic requirements of this AD. The average labor rate
is $85 per work-hour. Required parts will cost about $2,200 per
product. Where the service information lists required parts costs that
are covered under warranty, we have assumed that there will be no
charge for these parts. As we do not control warranty coverage for
affected parties, some parties may incur costs higher than estimated
here. Based on these figures, we estimate the cost of this AD to the
U.S. operators to be $3,867,630, or $6,110 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:

2010-10-08 Airbus: Amendment 39-16287. Docket No. FAA-2010-0129;
Directorate Identifier 2009-NM-245-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective June 21,
2010.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Airbus Model A318-111, -112, -121, and -
122 airplanes; Model A319-111, -112, -113, -114, -115, -131, -132,
and -133 airplanes; Model A320-111, -211, -212, -214, -231, -232,
and -233 airplanes; and Model A321-111, -112, -131, -211, -212, -
213, -231, and -232 airplanes; certificated in any category; all
manufacturer serial numbers; except airplanes that have received
Airbus modification 37317 in production.

Subject

    (d) Air Transport Association (ATA) of America Code 24:
Electrical power.

Reason

    (e) The mandatory continuing airworthiness information (MCAI)
states:
    Several occurrences of loss of the AC [alternating current] BUS
1 have been reported which led in some instances to the loss of the
AC ESS [essential] BUS and DC [direct current] ESS BUS and connected
systems. The affected systems include multiple flight deck Display
Units (Primary Flight Display, Navigation Display and Upper
Electronic Centralised Aircraft Monitoring display).
    The reasons for these events have been investigated but have not
been fully established for all cases.
    Due to the range of system losses some crews reported difficulty
in establishing the failure cause during the events and,
consequently, the appropriate actions to be taken may not be
completed in a timely manner.
    The loss of multiple display units, if not corrected expediently
during a high workload period, potentially affects the capability of
the flight crew and could contribute to a loss of situational
awareness and consequent control of the aeroplane, which would
constitute an unsafe condition.
    This AD therefore mandates the modification of the electrical
network configuration management logic consisting in adding an
automatic switching of the AC and DC ESS BUS power supply such that
upon the loss of the AC BUS 1, the AC BUS 2 will automatically take
over the power supply. On pre-MOD aeroplanes, this power supply
switching can only be accomplished manually from the cockpit and is
covered by an Electronic Centralized Aircraft Monitoring (ECAM)
procedure.

The modification of the electrical power distribution system
includes, depending on the configuration, adding a new circuit
breaker and new relay to the AC/DC ESS BUS circuit, and adding a
diode between a certain relay and terminal block.

Compliance

    (f) You are responsible for having the actions required by this
AD performed within the compliance times specified, unless the
actions have already been done.

Actions

    (g) Within 48 months after the effective date of this AD, modify
the electrical power distribution system, in accordance with the
Accomplishment Instructions of Airbus Service Bulletin A320-24-1120,
Revision 03, dated July 10, 2009.
    (h) Actions accomplished before the effective date of this AD,
in accordance with any service bulletin identified in Table 1 of
this AD, are considered acceptable for compliance with the
corresponding actions specified in this AD.

[[Page 27416]]

                                       Table 1--Credit service information
----------------------------------------------------------------------------------------------------------------
       Airbus Service Bulletin--                     Revision--                            Dated--
----------------------------------------------------------------------------------------------------------------
A320-24-1120..........................  Original...........................  May 31, 2007.
A320-24-1120..........................  01.................................  December 19, 2007.
A320-24-1120..........................  02.................................  July 8, 2008.
----------------------------------------------------------------------------------------------------------------

FAA AD Differences

    Note 1: This AD differs from the MCAI and/or service information
as follows:
    No differences.

Other FAA AD Provisions

    (i) 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 principal maintenance inspector (PMI) or principal
avionics inspector (PAI), as appropriate, or lacking a principal
inspector, your local Flight Standards District Office. The AMOC
approval letter must specifically reference this AD.
    (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 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 (44
U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has
approved the information collection requirements and has assigned
OMB Control Number 2120-0056.

Related Information

    (j) Refer to MCAI European Aviation Safety Agency (EASA)
Airworthiness Directive 2009-0235, dated October 29, 2009; and
Airbus Service Bulletin A320-24-1120, Revision 03, dated July 10,
2009; for related information.

Material Incorporated by Reference

    (k) You must use Airbus Service Bulletin A320-24-1120, Revision
03, dated July 10, 2009, 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, Airworthiness Office--EAS, 1 Rond Point Maurice Bellonte,
31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5
61 93 44 51; e-mail: account.airworth-eas@airbus.com; Internet
http://www.airbus.com.
    (3) You may review copies of the service information at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington. For information on the availability of this material at
the FAA, call 425-227-1221.
    (4) You may also review copies of the 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/code_of_federal_regulations/ibr_locations.html.

    Issued in Renton, Washington, on April 27, 2010.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2010-10722 Filed 5-14-10; 8:45 am]
BILLING CODE 4910-13-P
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