AD 96-15-09

This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A320-111, -211, and -231 series airplanes, that requires repetitive high frequency eddy current inspections to detect cracks around the fasteners of the lower forward corners of the sliding window frames, and repair, if necessary. This amendment also requires the installation of a modification for each affected fastener hole, which terminates the repetitive inspections. This amendment is prompted by the results of full-scale fatigue tests which indicated that fatigue cracking occurred on the lower forward corner of the sliding window frames at frame 4. The actions specified by this AD are intended to prevent such fatigue cracking, which could result in rapid depressurization of the airplane.

Final rule.

96-15-09 AIRBUS INDUSTRIE: Amendment 39-9699. Docket 95-NM-208-AD.

Applicability: Model A320-111, -211, and -231 series airplanes; manufacturer's serial numbers 002 through 008 inclusive, 010 through 014 inclusive, 016 through 078 inclusive, and 080 through 098 inclusive; certificated in any category.

NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been 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 shouldinclude specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent fatigue cracking on the lower forward corner of the sliding window frames at frame 4, which could result in rapid depressurization of the airplane, accomplish the following:

(a) Prior to the accumulation of 15,000 total landings, or within 3 months after the effective date of this AD, whichever occurs later, perform a high frequency eddy current inspection to detect cracks around the 5 fasteners of the lower forward corners of the sliding window frames at frame 4, in accordance with the procedures of Airbus Service Bulletin A320- 53-1082, Revision 1, dated November 9, 1994.

(1) If no cracks are detected, repeat the inspection thereafter at intervals not to exceed 15,000 landings.

(2) If any crack is detected, prior to further flight, repair it in accordance with a method approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate.

(b) Prior to the accumulation of 30,000 total landings, or within 5 years after the effective date of this AD, whichever occurs later, accomplish Airbus Modification 23685P3199 for each fastener hole, in accordance with Airbus Service Bulletin A320-53-1044, dated February 8, 1994. Accomplishment of the modification constitutes terminating action for the repetitive inspection requirements of paragraph (a) of this AD.

(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. 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 2: 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 inspection shall be done in accordance with Airbus Service Bulletin A320- 53-1082, Revision 1, dated November 9, 1994, which contains the following list of effective pages:

Page Number
Revision Level
Shown on Page
Date
Shown on Page
1, 3
1
November 9, 1994
2, 4-19
Original
February 8, 1994

The modification shall be done in accordance with Airbus Service Bulletin A320-53-1044, dated February 8, 1994. The incorporation by reference of these documents 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 September 3, 1996.

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 A320-111, -211, and -231 series airplanes was published in the Federal Register on March 28, 1996 (61 FR 13789). That action proposed to require repetitive high frequency eddy current inspections to detect cracks around the fasteners of the lower forward corners of the sliding window frames, and repair, if necessary. That action also proposed to require the installation of a modification for each affected fastener hole, which would terminate the repetitive inspections.

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

Support for the Proposal
One commenter supports the proposal.

Request to Revise Proposed Compliance Time
One commenter requests that the compliance time forthe inspection specified in proposed paragraph (a) be revised. The commenter points out that the proposal specifies that the initial inspection is to be accomplished prior to the accumulation of 15,000 total landings, or within 3 months after the effective date of the final rule, "whichever occurs first." The commenter requests that this compliance time be changed to ". . . whichever occurs later." Since the threshold for the proposed action is at 15,000 total flight cycles, the 3-month "grace period" should follow rather than precede the threshold.

The FAA concurs. The compliance language that appeared in the proposal was in error; it should have contained the phrase ". . . whichever occurs later," rather than ". . . whichever occurs first." The FAA has revised the final rule accordingly.

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 rulewith the change previously described. The FAA has determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD.

Cost Impact
The FAA estimates that 21 airplanes of U.S. registry will be affected by this AD, that it will take approximately 5 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the inspection requirements of this AD on U.S. operators is estimated to be $6,300, or $300 per airplane, per inspection cycle.

The modification will take approximately 10 work hours to accomplish, at an average labor rate of $60 per work hour. Required parts will cost approximately $311 per airplane. Based on these figures, the cost impact of the modification requirements of this AD on U.S. operators is estimated to be $19,131, or $911 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 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: