AD 99-06-10

This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A300 and A300-600 series airplanes, that requires replacement of the rivets that attach the pressurized floor panel to gantries 4 and 5 with new titanium alloy bolts. This amendment also requires, for certain airplanes, repetitive inspections to detect discrepancies of the rivets; and corrective actions, if necessary. This amendment is prompted by the issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent failure of the rivets that attach the pressurized floor panel to gantries 4 and 5, which could result in the loss of the floor panel and consequent rapid decompression of the airplane.

Final rule.

99-06-10 AIRBUS INDUSTRIE: Amendment 39-11074. Docket 98-NM-106-AD.
Applicability: Model A300 and A300-600 series airplanes on which Airbus Modification 11523 (reference Airbus Service Bulletins A300-53-0331 and A300-53-6107, both dated March 18, 1997) has not been accomplished, or on which Airbus Modification 11522 has not been installed in 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 prevent failure of the rivets that attach the pressurized floor panel to gantries 4 and 5, which could result in the loss of the floor panel and consequent rapid decompression of the airplane, accomplish the following:

(a) Accomplish paragraph (a)(1), or paragraphs (a)(2) and (a)(3), of this AD at the times specified in those paragraphs in accordance with Airbus Service Bulletin A300-53-0331, Revision 01 (for Airbus Model A300 series airplanes); or A300-53-6107, Revision 01 (for Airbus Model A300-600 series airplanes), both dated November 5, 1998; as applicable.

(1) Replace the rivets that attach the pressurized floor panel to gantries 4 and 5 with new titanium alloy bolts, at the applicable time specified in paragraph (a)(1)(i), (a)(1)(ii), (a)(1)(iii), or (a)(1)(iv) of this AD.

(i) For Airbus Model A300-600 series airplanes, replace the rivets prior to the accumulation of 7,150 total flight cycles.

(ii) For Airbus Model A300 B4-203 series airplanes, replace the rivets prior to the accumulation of 10,000 total flight cycles.

(iii) For Airbus Model A300 B4-2C and B4-103 series airplanes, replace the rivets prior to the accumulation of 12,300 total flight cycles.

(iv) For Airbus Model A300 B2-1C, B2-203, and B2K-3C series airplanes, replace the rivets prior to the accumulation of 14,600 total flight cycles.

(2) Perform a detailed visual inspection to detect any broken or discrepant rivets that attach the pressurized floor panel to gantries 4 and 5, at the applicable time specified in paragraph (a)(2)(i), (a)(2)(ii), (a)(2)(iii), or (a)(2)(iv) of this AD. Repeat the inspection thereafter at intervals not to exceed 350 flight cycles until accomplishment of the action required by paragraph (a)(3) of this AD.

(i) For Airbus Model A300-600 series airplanes, inspect the rivets prior to the accumulation of 7,500 total flight cycles, or within 350 flight cycles after the effective date of this AD, whichever occurs later.

(ii) For Airbus Model A300 B4-203 series airplanes, inspect the rivets prior to the accumulation of 10,350 total flight cycles, or within 350 flight cycles after the effective date of this AD, whichever occurs later.

(iii) For Airbus Model A300 B4-2C and B4-103 series airplanes, inspect the rivets prior to the accumulation of 12,650 total flight cycles, or within 350 flight cycles after the effective date of this AD, whichever occurs later.

(iv) For Airbus Model A300 B2-1C, B2-203, and B2K-3C series airplanes, inspect the rivets prior to the accumulation of 14,950 total flight cycles, or within 350 flight cycles after the effective date of this AD, whichever occurs later.

(3) Within 3,000 flight cycles after the effective date of this AD, replace the rivets that attach thepressurized floor panel to gantries 4 and 5 with new titanium alloy bolts in accordance with the applicable service bulletin. Accomplishment of this replacement constitutes terminating action for the repetitive inspections.

(b) If any discrepant or broken rivet is detected during any inspection specified in paragraph (a)(2) of this AD, prior to further flight, accomplish either paragraph (b)(1) or (b)(2) of this AD, as applicable, in accordance with Airbus Service Bulletin A300-53-0331, Revision 01 (for Airbus Model A300 series airplanes); or A300-53-6107, Revision 01 (for Airbus Model A300-600 series airplanes), both dated November 5, 1998; as applicable.

(1) If less than 15 discrepant or broken rivets are detected, prior to further flight, replace the discrepant or broken rivets with serviceable rivets and continue the repetitive inspections, in accordance with the applicable service bulletin, until accomplishment of the action required by paragraph (a)(3) of this AD.

(2) If 15 or more discrepant or broken rivets are detected, prior to further flight, replace all the rivets that attach the pressurized floor panel to gantries 4 and 5 with new titanium alloy bolts, in accordance with the applicable service bulletin. Accomplishment of this replacement constitutes terminating action for the repetitive inspections required by this AD.

NOTE 2: Accomplishment of the actions required by paragraphs (a) and (b) of this AD in accordance with Airbus Service Bulletin A300-53-0331, dated March 18, 1997 (for Airbus Model A300 series airplanes); or Airbus Service Bulletin A300-53-6107, dated March 18, 1997 (for Airbus Model A300-600 series airplanes), prior to the effective date of this AD, is acceptable for compliance with those paragraphs.

(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, International Branch, ANM-116, 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, International Branch, ANM-116.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.

(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 actions shall be done in accordance with Airbus Service Bulletin A300-53-0331, Revision 01, dated November 5, 1998, or Airbus Service Bulletin A300-53-6107, Revision 01, dated November 5, 1998. 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.

NOTE 4: The subject of this AD is addressed in French airworthiness directive 97-176-229(B), dated August 13, 1997.

(f) This amendment becomes effective on April 16, 1999.

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 and A300-600 series airplanes was published in the Federal Register on December 9, 1998 (63 FR 67813). That action proposed to require replacement of the rivets that attach the pressurized floor panel to gantries 4 and 5 with new titanium alloy bolts. That action also proposed to require, for certain airplanes, repetitive inspections to detect discrepancies of the rivets; and corrective actions, if necessary.

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

Request to Limit Applicability
One commenter, the manufacturer, requests that the applicability of the proposed AD be revised to exclude airplanes on which Airbus Modification 11522 has been accomplished. The commenter states that, following development of the retrofit solution defined as Airbus Modification 11523 (reference Airbus Service Bulletins A300-53-0331 and A300-53-6107, both dated March 18, 1997), a similar production solution defined as Modification 11522 was developed, and has been installed on airplanes in production since mid-1996. The FAA concurs that airplanes on which Airbus Modification 11522 has been installed in production are not subject to the requirements of this AD, and has revised the final rule accordingly.

Service Bulletin Revisions
Since issuance of the proposed AD, the manufacturer has issued Airbus Service Bulletins A300-53-0331, Revision 01, and A300-53-6107, Revision 01, both dated November 5, 1998. The FAA has reviewed these revisions and has determined that, in addition to certain nonsubstantive changes, references to certain nuts were corrected, and a cleaning agent material was revised. Since these changes do not add any additional burden to operators, paragraphs (a) and (b) of the final rule have been revised to cite Revision 01 of these service bulletins as the appropriate source of service information. For operators that may have previously accomplished the required actions in accordance with the original service bulletins, a "NOTE" has been added to the final rule to give credit for those actions.

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 with the changes described previously. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Cost Impact
The FAA estimates that 24 Airbus Model A300 series airplanes of U.S. registry will be affected by this AD. It will take approximately 26 work hours per airplane to accomplish the required replacement, at an average labor rate of $60 per work hour. Required parts will cost between $3,160 and $3,520 per airplane, depending on the service kit purchased. Based on these figures, the cost impact of the replacement required by this AD on U.S. operators is estimated to be as low as $4,720 per airplane or as high as $5,080 per airplane.

The FAA estimates that 61 Airbus Model A300-600 series airplanes of U.S. registry will be affected by this AD. It will take approximately 26 work hours per airplane to accomplish the required replacement, at an average labor rate of $60 per work hour. Required parts will cost between $3,530 and $3,550 per airplane, depending on the service kit purchased. Based on these figures, the cost impact of the replacement required by this AD on U.S. operators is estimated to be as low as $5,090 per airplane or as high as $5,110 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 wouldaccomplish those actions in the future if this AD were not adopted.

Should an operator be required to accomplish the inspection required by this AD, it will take approximately 1 work hour to accomplish, at an average labor rate of $60 per work hour. Based on this figure, the cost impact of the inspection required by this AD on U.S. operators is estimated to be $60 per airplane, per inspection cycle.

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 ExecutiveOrder 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: