[Federal Register Volume 75, Number 94 (Monday, May 17, 2010)]
[Rules and Regulations]
[Pages 27414-27416]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-10722]


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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: <a href="/cdn-cgi/l/email-protection#b4d5d7d7dbc1dac09ad5ddc6c3dbc6c0dc99d1d5c7f4d5ddc6d6c1c79ad7dbd9"><span class="__cf_email__" data-cfemail="305153535f455e441e515942475f4244581d555143705159425245431e535f5d">[email protected]</span></a>; 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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