[Federal Register: January 7, 2009 (Volume 74, Number 4)]
[Proposed Rules]
[Page 664-666]
[DOCID:fr07ja09-11]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-1365; Directorate Identifier 2008-NM-076-AD]
RIN 2120-AA64

Airworthiness Directives; Airbus Model A319, A320, and 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: In 2005 a lateral runway excursion occurred on an A320
aircraft. Such excursions are classified as hazardous, with a large
reduction in safety margins. Investigation has shown that the aircraft
landed with the nose wheels rotated nearly 20 degrees from center.
During subsequent tests on the removed BSCU [Braking and Steering
Control Unit], a BSCU hardware failure was found, affecting the
monitoring function, including the system reconfiguration management,
and leading to a runaway of [the] Nose Wheel Steering [uncommanded
steering]. An uncommanded steering condition during takeoff or landing
could result in departure of the airplane from the runway. 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 February 6,
2009.

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:<PHONE_NUMBER>.
     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.

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<PHONE_NUMBER>) 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<PHONE_NUMBER>.

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-2008-1365;
Directorate Identifier 2008-NM-076-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 will post all comments we receive, without change, to http://
www.regulations.gov, including any 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 2008-0048, dated February 28, 2008 (referred to
after this as ``the MCAI''), to correct an unsafe condition for the
specified products. The MCAI states:

    In 2005 a lateral runway excursion occurred on an A320 aircraft.
Such excursions are classified as hazardous, with a large reduction
in safety margins. Investigation has shown that the aircraft landed
with the nose wheels rotated nearly 20 degrees from center. During
subsequent tests on the removed BSCU [Braking and Steering Control
Unit], a BSCU hardware failure was found, affecting the monitoring
function, including the system reconfiguration management, and
leading to a runaway of [the] Nose Wheel Steering [uncommanded
steering].
    DGAC [Direction G[eacute]n[eacute]rale de l'Aviation Civile]
Airworthiness Directive (AD) F-1992-117-025(B), Revision 1 [which
corresponds to FAA AD 94-24-07], mandated the BSCU upgrade in order
to improve the steering logic, but this modification has shown not
to be sufficient to address the identified failure mechanism.
    A software modification is now implemented in BSCU standard 10
which improves the system reconfiguration management when this
failure mechanism is detected.
    BSCU standard 10 also includes other improvements--as detailed
in the associated Service Bulletin.
    This AD therefore mandates the modification or replacement of
the BSCU standard 7, 9 or 9.1, by the BSCU standard 10.

This AD also requires replacement of certain DUNLOP tires that are not
compatible with BSCU standard 10. An uncommanded steering condition

during takeoff or landing could result in departure of the airplane
from the runway. You may obtain further information by examining the
MCAI in the AD docket.

Relevant Service Information

    Airbus has issued Mandatory Service Bulletin A320-32-1336, Revision
01, dated January 10, 2008. The actions described in this service
information are intended to correct the unsafe condition identified in
the MCAI.

Other Relevant Rulemaking

    On November 21, 1994, we issued AD 94-24-07, amendment 39-9080 (59
FR 62998 December 7, 1994). That AD applies to certain Airbus Model
A320 series airplanes, line numbers 001 through 813 inclusive. That AD
requires modification of the brake steering control unit (BSCU). That
AD resulted from reports that the BSCU on Model A320 airplanes allowed
a 90-degree rotation of the nose gear after landing, which resulted in
significant damage to the wheels. The actions specified by that AD are
intended to prevent failure of the nose gear tires and wheels and the
loss of directional control of the airplane while it is on the ground.
The actions required by this proposed AD terminate the modification
required by AD 94-24-07.

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 591 products of U.S. registry. We also estimate that
it would take about 3 work hours per product to comply with the basic
requirements of this proposed AD. The average labor rate is $80 per
work-hour. Required parts would cost about $0 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 $141,840, 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 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-2008-1365; Directorate Identifier 2008-NM-
076-AD.

Comments Due Date

    (a) We must receive comments by February 6, 2009.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Airbus Model A319-111, -112, -113, -114,
-115, -131, -132, and -133; A320-111, -211, -212, -214, -231, -232,
and -233; and A321-111, -112, -131, -211, -212, -213, -231, and -232
series airplanes; certificated in any category; equipped with one
conventional pre-Enhanced Manufacture and Maintainability (pre-EMM)
Braking and Steering Control Unit (BSCU), having the part numbers
specified in paragraphs (c)(1), (c)(2), or (c)(3) of this AD.
    (1) C20216332292C (standard 7) installed by Airbus Modification
24449 in production, or by Airbus Service Bulletin A320-32-1124 in
service.
    (2) C202163372D32 (standard 9) installed by Airbus Modification
31106 in production, or by Airbus Service Bulletin A320-32-1227 or
A320-32-1232 in service.
    (3) C202163382D32 (standard 9.1) installed by Airbus
Modification 32500 in production, or by Airbus Service Bulletin
A320-32-1254 in service.

Subject

    (d) Air Transport Association (ATA) of America Code 32: Landing
gear.

Reason

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

    In 2005 a lateral runway excursion occurred on an A320 aircraft.
Such excursions are classified as hazardous, with a large reduction
in safety margins. Investigation has shown that the aircraft landed
with the nose wheels rotated nearly 20 degrees from center. During
subsequent tests on the removed BSCU [Braking and Steering Control
Unit], a BSCU hardware failure was found, affecting the monitoring
function, including the system reconfiguration management, and
leading to a runaway of [the] Nose Wheel Steering [uncommanded
steering].
    DGAC [Direction G[eacute]n[eacute]rale de l'Aviation Civile]
Airworthiness Directive (AD) F-1992-117-025(B), Revision 1 [which
corresponds to FAA AD 94-24-07], mandated the BSCU upgrade in order
to improve the steering logic, but this modification has shown not
to be sufficient to address the identified failure mechanism.
    A software modification is now implemented in BSCU standard 10
which improves the system reconfiguration management when this
failure mechanism is detected.
    BSCU standard 10 also includes other improvements--as detailed
in the associated Service Bulletin.
    This AD therefore mandates the modification or replacement of
the BSCU standard 7, 9 or 9.1, by the BSCU standard 10.

    This AD also requires replacement of certain DUNLOP tires that
are not compatible with BSCU standard 10. An uncommanded steering
condition during takeoff or landing could result in departure of the
airplane from the runway.

Actions and Compliance

    (f) Unless already done, do the following actions.
    (1) Within 18 months after the effective date of this AD: Modify
or replace the BSCU in accordance with the Accomplishment
Instructions of Airbus Mandatory Service Bulletin A320-32-1336,
Revision 01, dated January 10, 2008; and inspect the airplane to
determine if DUNLOP tires 46x16-20 having part number (P/N) 11659 T
or 11661 T are installed. If those tires are installed, before
further flight, replace with acceptable tires using a method
approved by either the Manager, International Branch, ANM-116,
Transport Airplane Directorate, FAA; or the European Aviation Safety
Agency (EASA) (or its delegated agent). Accomplishment of the
applicable requirements in this paragraph terminates the
requirements of AD 94-24-07, amendment 39-9080.
    (2) Previous accomplishment of the modification or replacement
of the BSCU before the effective date of this AD in accordance with
Airbus Mandatory Service Bulletin A320-32-1336, dated September 19,
2007, meets the requirements of paragraph (f)(1) of this AD.

FAA AD Differences

    Note: This AD differs from the MCAI and/or service information
as follows: Although the MCAI and service information do not provide
procedures for replacing the tires as specified in paragraph (f)(1)
of this AD, this AD requires that you replace the tires using a
method approved by either the Manager, International Branch, ANM-
116, FAA, or the EASA (or its delegated agent).

Other FAA AD Provisions

    (g) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager,
International Branch, 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<PHONE_NUMBER>. 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 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 MCAI EASA Airworthiness Directive 2008-0048, dated
February 28, 2008, and Airbus Mandatory Service Bulletin A320-32-
1336, Revision 01, dated January 10, 2008, for related information.

    Issued in Renton, Washington, on December 18, 2008.
Stephen P. Boyd,
Assistant Manager, Transport Airplane Directorate, Aircraft
Certification Service.
 [FR Doc. E9-30 Filed 1-6-09; 8:45 am]

BILLING CODE 4910-13-P