AD 97-11-01

This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A320 series airplanes, that requires an initial inspection of fastener holes on certain outer frames of the fuselage to detect fatigue cracking, and modification of this area by cold expanding these holes and installing oversized fasteners. This amendment is prompted by a report from the manufacturer indicating that, during full-scale fatigue testing of the test article, fatigue cracking was detected in the area where the center fuselage joins the wing. The actions specified by this AD are intended to prevent fatigue cracking and consequent reduced structural integrity of this area, which could lead to rapid depressurization of the fuselage.

Final rule.

97-11-01 AIRBUS INDUSTRIE: Amendment 39-10030. Docket 96-NM-106-AD.

Applicability: Model A320 series airplanes as listed in Airbus Service Bulletin A320-53-1026, dated August 5, 1994; on which modifications 21281P1495 and 21680P1818 have not been installed; 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 (e) 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 prevent fatigue cracking in the area where the center fuselage joins the wing, which could reduce the structural integrity of this area and consequently result in rapid decompression of the fuselage, accomplish the following:

(a) Prior to the accumulation of 16,000 total landings, or within 6 months after the effective date of this AD, whichever occurs later, perform an eddy current rotating probe inspection to detect fatigue cracking in the fastener holes of the outer frame flanges of left and right fuselage frames 37 through 41, adjacent to Stringer 23, in accordance with Airbus Service Bulletin A320-53-1026, dated August 5, 1994.

NOTE 2: Prior to the effective date of this AD, accomplishment of any modification in accordance with Airbus Service Bulletin A320-53-1025, dated August 5, 1994, is considered acceptable for compliance with the modification requirements of paragraphs (b), (c)(1)(i), (c)(2) and (d) of this AD.

(b) If the inspection required by paragraph (a) of this AD detects no cracking in any hole: Prior to the accumulation of 6,000 landings after this inspection, modify each hole in accordance with Paragraph 2.B.(5) of Airbus Service Bulletin A320-53-1025, Revision 1, dated November 24, 1994. Thereafter, no further action is required by this AD.

(c) If the inspection required by paragraph (a) of this AD detects any cracking in no more than one hole per frame cap, accomplish the requirements of paragraphs (c) (1) and (c)(2) of this AD:

(1) Prior to further flight, repair this cracked hole and conduct another rotating probe inspection of this hole to detect cracking, in accordance with Paragraph 2.B.(6) of Airbus Service Bulletin A320-53-1025, Revision 1, dated November 24, 1994.

(i) If no cracking of this repaired hole is detected: Prior to further flight, modify this hole in accordance with Paragraph 2.B.(6)(c) of this service bulletin. Thereafter, no further action with regard to this hole is required by this AD.

(ii) If any cracking of this repaired hole is detected: Prior to further flight, repair this hole in a manner approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate. Thereafter, no further action with regard to this hole is required by this AD.

(2) Prior to the accumulation of 6,000 landings after the inspection required by paragraph (a) of this AD; modify all other holes in accordance with Paragraph 2.B.(5) of Airbus Service Bulletin A320-53-1025, Revision 1, dated November 24, 1994. Thereafter, no further action is required by this AD with respect to these holes.

(d) If the inspection required by paragraph (a) of this AD detects any cracking in more than one hole per frame cap, or if this inspection detects any cracking in any frame: Prior to further flight, repair the discrepant area in a manner approved by the Manager, Standardization Branch, ANM-113; and modify all other holes in accordance with Paragraph 2.B.(5) of Airbus Service Bulletin A320-53-1025, Revision 1, dated November 24, 1994. Thereafter, no further action is required by this AD.

(e) 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. 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.

(f) 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.

(g) The actions shall be done in accordance with Airbus Service Bulletin A320-53- 1026, dated August 5, 1994; and Airbus Service Bulletin A320-53-1025, Revision 1, dated November 24, 1994. Airbus Service Bulletin A320-53-1025, Revision 1, dated November 24, 1994, contains the following list of effective pages:

Page Number
Revision Level
Shown on Page
Date
Shown on Page
1-12, 17
1
November 24, 1994
13-16, 18, 19
Original
August 5, 1994

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.

(h) This amendment becomes effective on June 27, 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 A320 series airplanes was published in the Federal Register on February 20, 1997 (62 FR 7727). That action proposed to require an initial eddy current rotation probe inspection to detect fatigue cracking in certain fastener holes in the area where the center fuselage joins the wing, and a modification to improve the resistance of this area to fatigue cracking.

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

Both commenters support the proposed rule.

Conclusion
After careful review of the available data, including the comments 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 24 Airbus Model A320 series airplanes of U.S. registry will be affected by this AD.

It will take approximately 25 work hours per airplane to accomplish the required actions, at an average labor rate of $60 per work hour. Required parts will cost approximately $557 per airplane. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $49,368, or $2,057 per airplane.

The cost impact figure discussed above is 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 Regulatory Flexibility 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: