AD 94-03-04

Active

Rivet Heads

Key Information
94-03-04
Active
March 14, 1994
Not specified
93-NM-36-AD
39-8811
Applicability
["Aircraft"]
["Large Airplane"]
Airbus
A320-111 A320-211 A320-212 A320-214 A320-231 A320-232 A320-233
Summary

This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A320 series airplanes, that requires repetitive inspections to detect breakage of the rivet heads at a certain skin-to-frame junction of the fuselage and replacement of discrepant rivets. This amendment also requires eventual replacement of the currently installed rivets with high-strength bolts; when accomplished, this replacement terminates the need for the repetitive inspections. This amendment is prompted by test reports of fatigue-related damage found on the rivet heads at a certain skin-to-frame junction of the fuselage. The actions specified by this AD are intended to prevent loss of fuselage skin and rapid decompression of the airplane.

Action Required

Final rule.

Regulatory Text

94-03-04 AIRBUS INDUSTRIE: Amendment 39-8811. Docket 93-NM-36-AD.

Applicability: Model A320 series airplanes; serial numbers 005 through 008 inclusive, and 010 through 030 inclusive; on which Modification 20925, as described in Airbus Industrie Service Bulletin A320-53-1010, Revision 3, dated July 30, 1992, has not been accomplished; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent structural loss of fuselage skin and rapid decompression of the airplane, accomplish the following:

(a) Prior to the accumulation of 10,000 total landings, or within the next 60 days after the effective date of this AD, whichever occurs later; and thereafter at intervals not to exceed 6,000 landings; perform an external detailed visual inspection to detect breakage of the rivet heads at the junction between frames 13 and 14, and at the skin on the left and right side, between stringers 1 and 7, in accordance with Airbus Industrie Service Bulletin A320-53-1036, dated October 5, 1989.

(1) If breakage is detected on fewer than 8 rivet heads on each side: Within the next 100 landings after discovery of breakage, replace all of the currently installed rivets with new or serviceable high-strength titanium Hilite bolts in accordance with Airbus Industrie Service Bulletin A320-53-1010, Revision 3, dated July 30, 1992. No further action is required by this AD.

(2) If breakage is detected on 8 or more rivet heads on either side: Prior to further flight, replace all of the currently installed rivets with new or serviceable high-strength titanium Hilite bolts in accordance with Airbus Industrie Service Bulletin A320-53-1010, Revision 3, dated July 30, 1992. No further action is required by this AD.

(3) If no breakage is detected on any rivet head: Prior to the accumulation of 22,000 total landings, replace all of the currently installed rivets with new or serviceable high- strength titanium Hilite bolts in accordance with Airbus Industrie Service Bulletin A320-53-1010, Revision 3, dated July 30, 1992. Replacement of the rivets constitutes terminating action for the repetitive inspection requirements of this AD.

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

(c) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.(d) The inspection shall be done in accordance with Airbus Industrie Service Bulletin A320-53-1036, dated October 5, 1989. The replacement shall be done in accordance with Airbus Industrie Service Bulletin A320-53-1010, Revision 3, dated July 30, 1992, which contains the following list of effective pages:

Page Number
Revision Level
Shown on Page
Date
Shown on Page
1, 3, 18
3
July 30, 1992
2, 4
1
October 19, 1989
5-14, 17, 19
Original
February 16, 1989
15-16
2
May 10, 1991

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.

(e) This amendment becomes effective on March 14, 1994.

Supplementary Information

A proposal to amend part 39 of the Federal Aviation Regulations to include an airworthiness directive (AD) that is applicable to certain Airbus Model A320 series airplanes was published in the Federal Register on May 27, 1993 (58 FR 30721). That action proposed to require repetitive external detailed visual inspections to detect breakage of the rivet heads at the junction between frames 13 and 14, and at the skin on the left and right side, between stringers 1 and 7, and replacement of discrepant rivets. That action also proposed to require eventual replacement of the currently installed rivets with high-strength titanium Hilite bolts; when accomplished, this replacement would terminate the need for the proposed 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.

Two commenters support the proposed rule.

One commenter requests removal of the proposed requirement to replace the currently installed rivets with new or serviceable high-strength titanium Hilite bolts, as described in Airbus Industrie Service Bulletin A320-53-1010, Revision 3, dated July 30, 1992. The commenter maintains that the Direction G n rale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, considers that repetitive external detailed visual inspections alone are adequate to ensure the continued structural airworthiness of the affected airplanes; therefore, the FAA should do likewise. The FAA does not concur. The FAA has determined that long term continued operational safety will be better assured by design changes to remove the source of the problem, rather than by repetitive inspections or special operating procedures. Long term repetitive inspections may not be providing the degree of safety assurance necessary for the transport airplane fleet. This, coupled with a better understanding of thehuman factors associated with numerous continual repetitive inspections has led the FAA to consider placing less emphasis on inspections and more emphasis on design improvements. The replacement requirement of this final rule is in consonance with these considerations.

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.

Currently, there are no affected Model A320 series airplanes on the U.S. Register. However, should an affected airplane be imported and placed on the U.S. Register in the future, it would require approximately 73 work hours to accomplish the required actions, at an average labor charge of $55 per work hour. The cost of required parts would be $3,626. Based on these figures, the total cost impact of this AD would be $7,641 per airplane.

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 in14 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 14 CFR part 39 of the Federal Aviation Regulations as follows:

PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89.

39.13 - [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive:

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Contact Information

Stephen Slotte, Aerospace Engineer, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 227-2797; fax (206) 227-1320.

References
This information is not available.
--- - Part 39 [59 FR 6537 NO. 29 02/11/94]
FAA Documents