AD 2009-15-07

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:

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].
* * * * *

The unsafe condition is an uncommanded steering condition during takeoff or landing, which could result indeparture of the airplane from the runway. We are issuing this AD to require actions to correct the unsafe condition on these products.

Final rule.

2009-15-07 Airbus: Amendment 39-15970. Docket No. FAA-2008-1365; Directorate Identifier 2008-NM-076-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective August 25, 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 paragraph (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.

The unsafe condition is an uncommanded steering condition during takeoff or landing, which could result in departure of the airplane from the runway. The corrective action also includes replacement of certain DUNLOP tires that are not compatible with BSCU standard 10.

Actions and Compliance

(f) Unless already done, do the following actions.
(1) Within 18 months after the effective date ofthis 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 1: ThisAD 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 (425) 227-1149. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in theFAA 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.

Material Incorporated by Reference(i) You must use Airbus Mandatory Service Bulletin A320-32-1336, Revision 01, dated January 10, 2008, 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 or 425-227-1152.
(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.

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 January 7, 2009 (74 FR 664). That NPRM proposed 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.

The unsafe condition is an uncommanded steering condition during takeoff or landing, which could result in departure of the airplane from the runway. The corrective action also includes replacement of certain DUNLOP tires that are not compatible with BSCU standard 10. 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 comments received.

Support for the AD

JetBlue Airways Corporation supports the actions specified in the NPRM.

Request To Relocate Certain Language

Airbus suggests that we relocate the following sentence in the Reason section: "An uncommanded steering condition during takeoff or landing could result in departure of the airplane from the runway.'' Airbus states that relocating that sentence away from the previous sentence, which addresses replacing tires, would avoid misinterpretation by association.
We acknowledge the Airbus comment and we have relocated the subject sentence and clarified that it is the statement of the unsafe condition in both the Discussion and Reason sections of this AD.

Conclusion

We reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the AD with the change described previously. We determined that this change will not increase the economic burden on any operator or increase the scope of the AD.

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 591 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 perwork-hour. Required parts will 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 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 $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 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

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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: