AD 96-18-06

This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A320-111, -211, and -231 series airplanes, that requires visual inspections to detect cracks of the fittings of the pressurized floor at frame 36, and renewal of the zone protective finish or replacement of fittings with new fittings, if necessary. This amendment is prompted by a report of fatigue cracking found on the pressurized floor fitting at frame 36 under the lower surface panel. The actions specified by this AD are intended to prevent such fatigue cracking, which could result in failure of a floor fitting and subsequent depressurization of the fuselage.

Final rule.

96-18-06 AIRBUS INDUSTRIE: Amendment 39-9730. Docket 95-NM-249-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 104 inclusive; on which Airbus Modification 21282P01497 (reference Airbus Service Bulletin A320-57-1029) has 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 (c) of this AD. The request should include an assessment of the effect of the modification, alteration, orrepair 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 on the pressurized floor fitting at frame 36 under the lower surface panel, which could result in failure of a fitting and subsequent depressurization of the fuselage, accomplish the following:

NOTE 2: Inspections and replacement(s) that were performed prior to the effective date of this AD in accordance with Airbus Service Bulletin A320-57-1028, dated April 12, 1991, are considered acceptable for compliance with this AD.

(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 a visual inspection to detect cracks of the 6 fittings of the pressurized floor at frame 36 under the lower surface panel, in accordance withAirbus Service Bulletin A320-57-1028, Revision 1, dated April 19, 1996.

(1) If no cracking is found, prior to further flight, renew the zone protective finish in accordance with the service bulletin. Repeat the visual inspection thereafter at intervals not to exceed 12,000 landings.

(2) If only 1 of the 6 fittings is found to be cracked and that crack is less than or equal to 0.59 inch (15 mm) in length, prior to further flight, replace the cracked fitting with a new fitting in accordance with the service bulletin. Thereafter, prior to the accumulation of 500 landings following accomplishment of this replacement, replace the remaining 5 fittings with new fittings in accordance with the service bulletin.

(3) If only 1 of the 6 fittings is found to be cracked and that crack is greater than 0.59 inch (15 mm) in length, prior to further flight, replace all six fittings with new fittings in accordance with the service bulletin.

(4) If 2 or more fittings are found to be cracked, prior to further flight, replace all 6 fittings with new fittings in accordance with the service bulletin.

(b) Replacement of all 6 fittings with new fittings in accordance with Airbus Service Bulletin A320-57-1028, Revision 1, dated April 19, 1996, constitutes terminating action for the inspection requirements 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, 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) The actions shall be done in accordance with Airbus ServiceBulletin A320-57-1028, Revision 1, dated April 19, 1996, which contains the following list of effective pages:

Page Number
Revision Level
Shown on Page
Date
Shown on Page
1-3
1
April 19, 1996
4-15
Original
August 12, 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 October 10, 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 April 19, 1996 (61 FR 17257). That action proposed to require visual inspection(s) to detect cracks of the six fittings of the pressurized floor at frame 36 under the lower surface panel, and renewing the zone protective finish or replacement of the fittings with new fittings, if necessary.

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.

New Service Information
Airbus has issued Revision 1 of Service Bulletin A320-57-1028, dated April 19, 1996. This revision is essentially identical in its technical content as the original version, which wascited in the proposal as the appropriate source of service information. The Direction G n rale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, has classified this revised service bulletin as mandatory. Accordingly, this final rule has been revised to reference Revision 1 of the service bulletin. It has also been revised to note that any of the required actions that were performed in accordance with the originally issued service bulletin prior to the effective date of the final rule are considered acceptable for compliance with this AD.

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 with 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 22 Airbus Model A320-111, -211, and -231 series airplanes of U.S. registry will be affected by this AD, that it will take approximately 3 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 AD on U.S. operators is estimated to be $3,960, or $180 per airplane, per inspection cycle.

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: