Airworthiness Directives; Airbus Model A310 Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Final rule.

SUMMARY:

We are superseding an existing 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:

During routine visual inspection, a crack has been found in the wing MLG (main landing gear) rib 5 forward attachment lug on two A310 in-service aircraft. Laboratory examination of one of the cracked ribs confirmed that the crack is due to the presence of pitting corrosion in the forward lug holes. Also on both aircraft medium to heavy corrosion was found in the forward lugs on the opposite wing after removal of the bushes. This situation if not detected, could affect the structural integrity of the MLG attachment. * * *

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

DATES:

This AD becomes effective September 17, 2008.

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

The Director of the Federal Register previously approved the incorporation by reference of Airbus Service Bulletin A310-57A2088, excluding Appendix 01, dated November 6, 2006, listed in this AD, as of February 6, 2007 (72 FR 2612, January 22, 2007).

ADDRESSES:

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.

FOR FURTHER INFORMATION CONTACT:

Tom Stafford, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 227-1622; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:

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 April 7, 2008 (73 FR 18722). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:

During routine visual inspection, a crack has been found in the wing MLG (main landing gear) rib 5 forward attachment lug on two A310 in-service aircraft. Laboratory examination of one of the cracked ribs confirmed that the crack is due to the presence of pitting corrosion in the forward lug holes. Also on both aircraft medium to heavy corrosion was found in the forward lugs on the opposite wing after removal of the bushes. This situation if not detected, could affect the structural integrity of the MLG attachment. As an interim measure, Airbus published Alert Service Bulletin (ASB) A310-57A2088 to introduce a repetitive detailed visual inspection (DVI) of the forward attachment lug of MLG Rib 5. EASA issued Emergency Airworthiness Directive (EAD) 2006-0335-E [which corresponds to FAA AD 2007-02-09] to require the accomplishment of this repetitive DVI.

In order to ensure the detection of any crack at an early stage in the forward lug of the RH (right-hand) and LH (left-hand) MLG Rib 5 aft bearing attachment, the Type Certificate holder has developed a new inspection by means of ultrasonic method. For the reasons described above, this new inspection program is rendered mandatory by this AD, which cancels and replaces the requirement of EAD 2006-0335-E.

The corrective action includes repairing or replacing MLG Rib 5, as applicable. 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.

Clarification of Certain Requirements

Airbus asks that we revise paragraph (g)(2) of the NPRM to clarify the intent of Airbus Service Bulletin A310-57-2090, Revision 01, dated December 19, 2007. Airbus states that paragraph (g)(2) of the NPRM refers to that service bulletin for replacement of the MLG Rib 5. However, Airbus clarifies that the intent of Service Bulletin A310-57-2090 is not to provide instructions for the MLG Rib 5 replacement, but to introduce new bushes with increased interference fit into the aft bearing forward lug of MLG Rib 5. Airbus asks that paragraph (g)(2) of the NPRM be changed as follows, for clarification: “Replacement of the MLG Rib 5 bushes with high interference fit in accordance with the instructions defined in Airbus Service Bulletin A310-57-2090. * * *”

We agree that paragraph (g)(2) of this AD should be further clarified to address the commenter's suggestion; therefore, we have changed that paragraph accordingly.

Airbus also asks that the last sentence of paragraphs (g)(3) and (g)(4)(ii) of the NPRM be changed to remove the reference to Airbus Service Bulletin A310-57-2090, Revision 01, dated December 19, 2007, when the MLG Rib 5 replacement is in question. Airbus asks that paragraphs (g)(3) and (g)(4)(ii) of the NPRM be changed as follows, for clarification: “After MLG Rib 5 replacement, whether Airbus Service Bulletin A310-57-2090, Revision 01, dated December 19, 2007 is not accomplished: * * *”

We agree that paragraphs (g)(3) and (g)(4)(ii) of this AD should be further clarified to capture the commenter's intent; therefore, we have changed those paragraphs accordingly.

Conclusion

We reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We also determined that these changes 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 68 products of U.S. registry. We also estimate that it will take about 5 work-hours per product to comply with the basic requirements of this AD. The average labor rate is $80 per work-hour. Based on these figures, we estimate the cost of this AD to the U.S. operators to be $27,200, or $400 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.

2. The FAA amends § 39.13 by removing Amendment 39-14896 ( 72 FR 2612, January 22, 2007) and adding the following new AD:

2008-17-02 Airbus: Amendment 39-15640. Docket No. FAA-2008-0406; Directorate Identifier 2007-NM-196-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective September 17, 2008.

Affected ADs

(b) The AD supersedes AD 2007-02-09, Amendment 39-14896.

Applicability

(c) This AD applies to Airbus Model A310 airplanes, certificated in any category, all certified models, all serial numbers; except for those where LH (left-hand) and RH (right-hand) wing MLG (main landing gear) rib 5 forward lugs have been repaired by installation of oversized interference fit bushes as per Airbus A310 Repair Instruction R572-49121, or which have had Airbus Service Bulletin A310-57-2090 (Airbus modification 13329) embodied in service.

Subject

(d) Air Transport Association (ATA) of America Code 57: Wings.

Reason

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

During routine visual inspection, a crack has been found in the wing MLG (main landing gear) rib 5 forward attachment lug on two A310 in-service aircraft. Laboratory examination of one of the cracked ribs confirmed that the crack is due to the presence of pitting corrosion in the forward lug holes. Also on both aircraft medium to heavy corrosion was found in the forward lugs on the opposite wing after removal of the bushes. This situation if not detected, could affect the structural integrity of the MLG attachment. As an interim measure, Airbus published Alert Service Bulletin (ASB) A310-57A2088 to introduce a repetitive detailed visual inspection (DVI) of the forward attachment lug of MLG Rib 5. EASA issued Emergency Airworthiness Directive (EAD) 2006-0335-E [which corresponds to FAA AD 2007-02-09] to require the accomplishment of this repetitive DVI.

In order to ensure the detection of any crack at an early stage in the forward lug of the RH (right-hand) and LH (left-hand) MLG Rib 5 aft bearing attachment, the Type Certificate holder has developed a new inspection by means of ultrasonic method. For the reasons described above, this new inspection program is rendered mandatory by this AD, which cancels and replaces the requirement of EAD 2006-0335-E.

The corrective action includes repairing or replacing MLG Rib 5, as applicable.

Restatement of Requirements of AD 2007-02-09

(f) Unless already done, do the following actions specified in paragraphs (f)(1), (f)(2), and (f)(3) of this AD in accordance with the instructions defined in Airbus Service Bulletin A310-57A2088, dated November 6, 2006.

(1) Before the accumulation of 12,000 total flight cycles, or within 14 days after February 6, 2007 (the effective date of AD 2007-02-09), whichever occurs later: Perform a detailed visual inspection of the LH and RH wing MLG Rib 5 aft bearing forward lugs.

(2) If any crack is detected at LH and/or RH aft bearing forward lug, contact Airbus and proceed with the replacement before next flight.

(3) Repeat the inspection at intervals not exceeding 100 flight cycles.

New Requirements of This AD: Actions and Compliance

(g) Unless already done, before the accumulation of 12,000 total flight cycles or before the accumulation of 12,000 flight cycles on MLG Rib 5, or within 14 days after the effective date of this AD, whichever occurs latest: Perform either a detailed visual inspection (DVI) or an ultrasonic inspection of the LH and RH MLG Rib 5 aft bearing forward lug for cracks, in accordance with the instructions defined in Airbus Service Bulletin A310-57-2091, excluding Appendix 01, dated May 22, 2007. If a MLG Rib 5 has been replaced on one side only, then the RH and LH must be considered separately. Doing this inspection ends the requirements of paragraph (f) for that MLG Rib 5 only.

Note 1:

The ultrasonic inspection will detect any crack at an early stage and will limit the risk of extensive repairs. This earlier crack detection is not possible with the DVI.

(1) If no crack is detected during any inspection required by paragraph (g) of this AD: Repeat the applicable inspection at the time specified in paragraph (g)(1)(i) or (g)(1)(ii) of this AD.

(i) Repeat the DVI thereafter at intervals not to exceed 100 flight cycles.

(ii) Repeat the ultrasonic inspection thereafter at intervals not to exceed 825 flight cycles.

(2) Replacement of the MLG Rib 5 bushes with new bushes with high interference fit in the aft bearing forward lugs of MLG Rib 5, in accordance with the instructions defined in Airbus Service Bulletin A310-57-2090, Revision 01, dated December 19, 2007, ends the repetitive inspections required by paragraph (g)(1) of this AD for that MLG Rib 5 only.

(3) If any crack is detected during the DVI required by paragraph (g) of this AD: Before further flight, contact Airbus for replacement instructions and replace the MLG Rib 5 bushes before further flight. Repeat the applicable inspection in paragraph (g) of this AD at the time specified in paragraph (g)(1)(i) or (g)(1)(ii) of this AD. Accomplishing the replacement of the MLG Rib 5 bushes with new bushes with high interference fit in the aft bearing forward lugs of MLG Rib 5, in accordance with the instructions defined in Airbus Service Bulletin A310-57-2090, Revision 01, dated December 19, 2007, ends the repetitive inspections required by paragraph (g)(1) of this AD for that MLG Rib 5 only.

(4) If any crack is detected during the ultrasonic inspection required by paragraph (g) of this AD, before further flight, accomplish the actions specified in paragraph (g)(4)(i) or (g)(4)(ii) of this AD, as applicable.

(i) If any crack is not visible on MLG Rib 5: Before further flight, repair MLG Rib 5 using Airbus A310 Repair Instruction R572-49121, Issue C, dated May 2007. After embodiment of the repair instruction, no further actions are necessary as required by this AD and specified in Airbus Service Bulletin A310-57-2091, excluding Appendix 01, dated May 22, 2007, for that MLG Rib 5 only.

(ii) If any crack is visible on MLG Rib 5: Before further flight, contact Airbus for rib replacement instructions, and replace before further flight. Repeat the applicable inspection in paragraph (g) of this AD at the time specified in paragraph (g)(1)(i) or (g)(1)(ii) of this AD. Accomplishing the replacement of the MLG Rib 5 bushes with new bushes with high interference fit in the aft bearing forward lugs of MLG Rib 5, in accordance with the instructions defined in Airbus Service Bulletin A310-57-2090, Revision 01, dated December 19, 2007, ends the repetitive inspections required by paragraph (g) of this AD for that MLG Rib 5 only.

FAA AD Differences

Note 2:

This AD differs from the MCAI and/or service information as follows:

(1) Although the MCAI or service information allows flight with cracks on aft bearing forward lugs for a certain period of time, this AD requires replacing MLG Rib 5 before further flight if any crack is found.

(2) Although the MCAI or service information specifies submitting an inspection report sheet to Airbus, this AD would not require that action.

Other FAA AD Provisions

(h) 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: Tom Stafford, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 227-1622; fax (425) 227-1149. 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

(i) Refer to MCAI European Aviation Safety Agency Airworthiness Directive 2007-0195, dated July 19, 2007; and Airbus Service Bulletins A310-57-2090, Revision 01, dated December 19, 2007; and A310-57-2091, including Appendix 01, dated May 22, 2007; for related information.

Material Incorporated by Reference

(j) You must use the applicable service information specified in Table 1 of this AD 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 the service information specified in Table 2 of this AD under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) The Director of the Federal Register previously approved the incorporation by reference of Airbus Service Bulletin A310-57A2088, excluding Appendix 01, dated November 6, 2006, on February 6, 2007 (72 FR 2612, January 22, 2007).

(3) For service information identified in this AD, contact Airbus, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France.

(4) You may review copies at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or 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/cfr/ibr-locations.html .