
[Federal Register Volume 75, Number 35 (Tuesday, February 23, 2010)]
[Proposed Rules]
[Pages 8003-8005]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-3442]


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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]
RIN 2120-AA64


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

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 the 
products listed above. This proposed 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.
    The proposed AD would require actions that are intended to address 
the unsafe condition described in the MCAI.

DATES: We must receive comments on this proposed AD by April 9, 2010.

ADDRESSES: You may send comments 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: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-40, 1200 New 
Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday 
through Friday, except Federal holidays.
    For service information identified in this proposed 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. You may review copies of the referenced 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 or 425-227-1152.

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 this proposed AD, 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: 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:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2010-0129; 
Directorate Identifier 2009-NM-245-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD based on those comments.
    We have lengthened the 30-day comment period for proposed ADs that 
address MCAI originated by aviation authorities of other countries to 
provide adequate time for interested parties to submit comments. The 
comment period for these proposed ADs is now typically 45 days, which 
is consistent with the comment period for domestic transport ADs.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any

[[Page 8004]]

personal information you provide. We will also post a report 
summarizing each substantive verbal contact we receive about this 
proposed AD.

Discussion

    The European Aviation Safety Agency (EASA), which is the Technical 
Agent for the Member States of the European Community, has issued EASA 
Airworthiness Directive 2009-0235, dated October 29, 2009 (referred to 
after this as ``the MCAI''), 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.

Relevant Service Information

    Airbus has issued Service Bulletin A320-24-1120, Revision 03, dated 
July 10, 2009. The actions described in this service information are 
intended to correct the unsafe condition identified in the MCAI.

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 design.

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 proposed different actions in this AD from those 
in the MCAI in order to follow FAA policies. Any such differences are 
highlighted in a Note within the proposed AD.

Costs of Compliance

    Based on the service information, we estimate that this proposed AD 
would affect about 633 products of U.S. registry. We also estimate that 
it would take about 46 work-hours per product to comply with the basic 
requirements of this proposed AD. The average labor rate is $85 per 
work-hour. Required parts would 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 
costs. 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 the proposed AD on 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 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); 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 proposed AD and placed it in the AD docket.

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

    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]

    2. The FAA amends Sec.  39.13 by adding the following new AD:

Airbus: Docket No. FAA-2010-0129; Directorate Identifier 2009-NM-
245-AD.

[[Page 8005]]

Comments Due Date

    (a) We must receive comments by April 9, 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 a service bulletin identified in Table 1 of this 
AD, are considered acceptable for compliance with the corresponding 
actions specified in this AD.

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

    Issued in Renton, Washington, on February 16, 2010.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2010-3442 Filed 2-22-10; 8:45 am]
BILLING CODE 4910-13-P


