AD 2008-22-20

This AD becomes effective December 17, 2008.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of December 17, 2008.

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.

Vladimir Ulyanov, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 227-1138; fax (425) 227-1149.

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 June 24, 2008 (73 FR 35603). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:

During fatigue tests (EF3) on the A340-600, damages were found in longitudinal doubler at VTP [vertical tail plane] attachment cutout between Frame (FR) 80 and FR86. This damage occurred between 58341 and 72891 simulated Flight Cycles (FC).

Due to the higher Design Service Goal and different design (e.g., doubler thickness) [of the] A330-200/-300 and A340-300 aircraft series, the damage assessment concluded [there was] potential impact on [the airplanes specified in the] applicability.

[T]o allow early detection of cracks, which could [prevent] possible crack propagation and consequently to maintain the structural integrity of the upper shell structure between FR80 and FR86, this Airworthiness Directive (AD) mandates an inspection program [for cracking] of this area using a high frequency eddy current (HFEC) method, and a modification to improve the upper shell structure.

The unsafe condition is crack propagation in the VTP attachment cutout, which could reduce airplane structural integrity in the tail section. Corrective actions include doing eddy current inspections for cracking of certain fastener rows, and contacting Airbus for repair instructions and repairing. You may obtain further information by examining the MCAI in the AD docket.

We gave the public the opportunity to participate in developing this AD. We considered the comment received.

Northwest Airlines (NWA) requests that we reconsider eliminating the provision for flight with certain cracks. NWA states that the MCAI and Airbus service bulletins (that were referenced in the NPRM as appropriate sources of service information) provide for flight with certain cracks if follow-on inspections are accomplished in accordance with the service bulletin.

We do not concur. Our policy specifies the requirement to repair known cracks before further flight (though we may make exceptions to this policy in certain cases of unusual need, as discussed below). This policy is based on the fact that such damaged airplanes do not conform to the FAA-certificated type design and, therefore, are not airworthy until a properly approved repair is made. While recognizing that repair deferrals might be necessary at times, our policy is intended to minimize adverse human factors relating to the lack of reliability of long-term repetitive inspections, which might reduce the safety of the type-certificated design if such repair deferrals are practiced routinely.

As noted above, we may make an exception to this policy in certain cases, if there is an unusual need for a temporary deferral. Unusual needs include such circumstances as legitimate difficulty in acquiring parts to accomplish repairs. Under such conditions, we may allow a temporary deferral of the repair, subject to a stringent inspection program acceptable to the FAA. We acknowledge that the manufacturer has specified inspection intervals that are intended to allow continued operation with known cracks, and to prevent the need for extensive repairs. However, since we are not aware of any unusual need for repair deferral in regard to this AD, we have not evaluated these inspection intervals.

Under the provisions of paragraph (g)(1) of this AD, we will consider requests for approval of an AMOC if sufficient data are submitted to substantiate that temporary deferral of repair with follow-on inspections would provide an acceptable level of safety. We have not changed the AD in this regard.

Airbus has issued revisions to two service bulletins referenced in the NPRM as appropriate sources of service information. Airbus Mandatory Service Bulletins A330-53-3168 and A340-53-4174, both Revision 01, both dated February 15, 2008, are essentially the same as the original versions of those service bulletins except for clarifications, and no additional work is required for airplanes modified per the original issue. We have changed the references in paragraphs (f)(1), (f)(2)(i), and (h) of this AD to include Revision 01 of those service bulletins, and added paragraph (f)(4) to this AD to give credit for actions performed according to the original issues.

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

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.

We estimate that this AD will affect about 26 products of U.S. registry. We also estimate that it will take about 202 work-hours per product to comply with the basic requirements of this AD. The average labor rate is $80 per work-hour. Required parts will cost about $19,020 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 $914,680, or $35,180 per product.

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.

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.

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.

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

1. The authority citation for part 39 continues to read as follows:

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