AD 97-20-07

This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A300-600 series airplanes, that requires repetitive inspections to detect fatigue cracking in the left and right wings in the area where the top skin attaches to the center spar; and repair or modification of this area, if necessary. This amendment is prompted by a report from the manufacturer indicating that, during full-scale fatigue testing of the airframe, fatigue cracking was detected in this area. The actions specified by this AD are intended to detect and correct this cracking, which could reduce the residual strength of the top skin of the wings, and consequently affect the structural integrity of the airframe.

Final rule.

97-20-07 AIRBUS: Amendment 39-10145. Docket 96-NM-170-AD.

Applicability: Model A300-600 series airplanes on which Airbus Modification 10160 has not been installed during production; certificated in any category.

NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To detect and correct fatigue cracking in the left and right wings in the area where the top skin attaches to the center spar, which could reduce the residual strength of this skin, and consequently affect the structural integrity of the airframe, accomplish the following:

(a) For airplanes on which Airbus Modification 10089 has not been installed: Prior to the accumulation of 18,000 total landings, or within 1,500 landings after the effective date of this AD, whichever occurs later, conduct either a detailed visual inspection or a high frequency eddy current (HFEC) inspection to detect fatigue cracking in the left and right wings in the area where the top skin attaches to the center spar between ribs 1 and 7, in accordance with Airbus Service Bulletin A300-57-6044, Revision 2, dated September 6, 1995, including Appendix 1.

(1) If no cracking is detected, conduct repetitive inspections thereafter at the following intervals:

(i)If the immediately preceding inspection was conducted using detailed visual techniques, conduct the next inspection within 5,000 landings.

(ii) If the immediately preceding inspection was conducted using HFEC techniques, conduct the next inspection within 9,500 landings.

(2) If any cracking is detected or suspected during any detailed visual inspection required by paragraph (a), (a)(1), or (a)(3)(i) of this AD, prior to further flight, confirm this finding and the length of this cracking by conducting a HFEC inspection, in accordance with the service bulletin. If no cracking is confirmed during the HFEC inspection, accomplish the repetitive inspection required by paragraph (a)(1)(ii) of this AD at the time specified in that paragraph.

(3) If any cracking is detected or confirmed during any HFEC inspection required by paragraph (a), (a)(1), or (a)(2) of this AD:

(i) If the cracking is 75 mm or less per rib bay, prior to further flight, repair in accordance with the service bulletin. Thereafter, conduct repetitive detailed visual inspections of the repaired area at intervals not to exceed 50 landings, in accordance with the service bulletin.

(ii) If the cracking exceeds 75 mm per rib bay, prior to further flight, install Airbus Modification 10089, in accordance with the service bulletin. Thereafter, conduct a low frequency eddy current inspection in accordance with the requirements of paragraph (b) of this AD.

NOTE 2: The Airbus service bulletin references Airbus Service Bulletin A300-57-6041, Revision 4, dated November 16, 1995, as an additional source of service information for installing Airbus Modification 10089.

(b) For airplanes on which Airbus Modification 10089 has been installed: Prior to the accumulation of 22,000 total landings after this modification has been installed, or within 1,500 landings after the effective date of this AD, whichever occurs later, conduct a low frequency eddy current inspection to detect fatigue cracking in the inboard and rear edges of the top skin reinforcing plates, in accordance with Airbus Service Bulletin A300-57-6044, Revision 2, dated September 6, 1995, including Appendix 1.

(1) If no cracking is detected, repeat this inspection thereafter at intervals not to exceed 11,000 landings.

(2) If any cracking is detected, prior to further flight, repair in accordance with a method approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate. Thereafter, repeat this inspection at intervals not to exceed 11,000 landings.

(c) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Standardization Branch, ANM-113.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.

(d) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

(e) The inspections and installation shall be done in accordance with Airbus Service Bulletin A300-57-6044, Revision 2, dated September 6, 1995, including Appendix 1, which contains the specified effective pages:

Page Number
Shown on Page
Revision Level
Shown on Page
Date
Shown on Page
1-8
2
September 6, 1995
9, 10
Original
March 1, 1993

Appendix 1

1
1
November 25, 1994
2-6
Original
March 1, 1993

This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(f) This amendment becomes effective on October 30, 1997.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain Airbus Model A300-600 series airplanes was published in the Federal Register on May 1, 1997 (62 FR 23697). That action proposed to require repetitive inspections to detect fatigue cracking in the left and right wings in the area where the top skin attaches to the center spar between ribs 1 and 7; and repair or modification of this area, if necessary.

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the single comment received.

The commenter supports the proposed rule.

Conclusion
After careful review of the available data, including the comment noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

Cost Impact

The FAA estimates that 35Airbus Model A300-600 series airplanes of U.S. registry will be affected by this AD.

For airplanes on which Airbus Modification 10089 has not been installed, it will take approximately 2 work hours to accomplish each detailed visual inspection or 3 work hours to accomplish each high frequency eddy current (HFEC) inspection. The average labor rate is $60 per work hour. Based on these figures, the cost impact of each inspection on U.S. operators is estimated to be either $120 or $180 per airplane, depending on the type of inspection conducted.

For airplanes on which Airbus Modification 10089 has been installed, it will take approximately 3 work hours to accomplish each low frequency eddy current inspection. The average labor rate is $60 per work hour. Based on these figures, the cost impact of the each inspection on U.S. operators is estimated to be $180 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

Regulatory Impact
The regulations adopted herein will not have substantial direct effects 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. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under 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 RegulatoryFlexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."

List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (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.
39.13 [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: