AD 2010-25-03

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 accordance with design regulation, the THSA [trimmable horizontal stabilizer actuator] has a failsafe design. Its upper attachment to the aeroplane has two load paths, a Primary Load Path (PLP) and a Secondary Load Path (SLP), which is only engaged in case of PLP failure. Following the design intent, engagement of the SLP leads to jam the THSA, indicating the failure of the PLP.

Tests carried out under the loads-measured during representative flights have demonstrated that, when the SLP is engaged, it does not systematically jam the THSA. In addition, laboratory tests have confirmed that the SLP will only withstand the loads for a limited periodof time.

This condition of PLP failure during an extended period of time, if not detected and corrected, would lead to the rupture of the THSA upper attachment and consequent THSA loss of command, resulting in reduced control of the aeroplane.

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We are issuing this AD to require actions to correct the unsafe condition on these products.

Final rule.

2010-25-03 Airbus: Amendment 39-16536. Docket No. FAA-2010-0850; Directorate Identifier 2010-NM-076-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective January 11, 2011.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Airbus Model A300 B2-1A, B2-1C, B4-2C, B2K-3C, B4-103, B2-203, and B4-203 airplanes, certificated in any category, all serial numbers.

Subject

(d) Air Transport Association (ATA) of America Code 27: Flight Controls.

Reason

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

In accordance with design regulation, the THSA [trimmable horizontal stabilizer actuator] has a failsafe design. Its upper attachment to the aeroplane has two load paths, a Primary Load Path (PLP) and a Secondary Load Path (SLP), which is only engaged in case of PLP failure. Following the design intent, engagement of the SLP leads to jam the THSA, indicating the failure of the PLP.

Tests carried out under the loads-measured during representative flights have demonstrated that, when the SLP is engaged, it does not systematically jam the THSA. In addition, laboratory tests have confirmed that the SLP will only withstand the loads for a limited period of time.

This condition of PLP failure during an extended period of time, if not detected and corrected, would lead to the rupture of the THSA upper attachment and consequent THSA loss of command, resulting in reduced control of the aeroplane.

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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 2,500 flight hours after the effective date of this AD, do a detailed visual inspection for metallic particles, cracks, scratches, and missing materials of the THSA upper attachment and screw shaft, in accordance with the Accomplishment Instructions of Airbus Mandatory Service Bulletin A300-27-0203, dated June 8, 2009. Repeat the inspection thereafter at intervals not to exceed 2,500 flight hours.

(h) If during any inspection required by paragraph (g) of this AD, any metallic particle, crack, scratch, or missing material is found, before further flight, contact Airbus to obtain approved corrective action instructions, and accomplish those instructions accordingly.

(i) Doing the corrective actions specified in paragraph (h) of this AD is not a terminating action for the repetitive inspections required by paragraph (g) of this AD.

FAA AD Differences

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

Other FAA AD Provisions

(j) 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 proceduresfound in 14 CFR 39.19. Send information to ATTN: Dan Rodina, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 227-2125; 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

(k) Refer to MCAI European Aviation Safety Agency Airworthiness Directive 2010-0019, dated February 5, 2010; and Airbus Mandatory Service Bulletin A300-27-0203, dated June 8, 2009; for related information.

Material Incorporated by Reference

(l) You must use Airbus Mandatory Service Bulletin A300-27-0203, excluding Appendix 01, dated June 8, 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 SAS-EAW (Airworthiness Office), 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.

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 August 27, 2010 (75 FR 52652). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:

In accordance with design regulation, the THSA [trimmable horizontal stabilizer actuator] has a failsafe design. Its upper attachment to the aeroplane has two load paths, a Primary Load Path (PLP) and a Secondary Load Path (SLP), which is only engaged in case of PLP failure. Following the design intent, engagement of the SLP leads to jam the THSA, indicating the failure of the PLP.

Tests carried out under the loads-measured during representative flights have demonstrated that, when the SLP is engaged, it does not systematically jam the THSA. In addition, laboratory tests have confirmed that the SLP will only withstand the loads for a limited period of time.

This condition of PLP failure during an extended period of time, if not detected and corrected, would lead to the rupture of the THSA upper attachment and consequent THSA loss of command, resulting in reduced control of the aeroplane.

For the reasons stated above, this [EASA] AD requires repetitive [detailed] inspections to detect if damage exists to the THSA upper attachment and if the SLP has been engaged and corrective actions, depending on findings.

The corrective actions include contacting Airbus for instructions and doing those instructions. 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 received no comments on the NPRM or on the determination of the cost to the public.

Conclusion

We reviewed the available data 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.

Costs of Compliance

We estimate that this AD will affect 5 products of U.S. registry. We also estimate that it will take about 2 work-hours per product to comply with the basic requirements of this AD. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of this AD to the U.S. operators to be $850, or $170per 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 Order13132. 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: