AD 99-02-04

This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A320 and A321 series airplanes. This amendment requires modification of the slat and flap control computer (SFCC) in the aft electronics rack. This amendment is prompted by 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 SFCC caused by computer software anomalies or contamination by conductive dust. This condition, if not corrected, could result in uncommanded slat retraction during takeoff and consequent insufficient wing lift available to complete a successful takeoff.

Final rule.

99-02-04 AIRBUS INDUSTRIE: Amendment 39-10993. Docket 98-NM-67-AD.

Applicability: Model A320 series airplanes, as listed in Airbus Service Bulletin A320-27-1096, Revision 01, dated January 14, 1998; and Model A321 series airplanes, as listed in Airbus Service Bulletin A320-27-1103, dated June 14, 1996; 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 (b) 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 beeneliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent failure of the slat and flap control computer (SFCC), which could result in uncommanded slat retraction during takeoff and consequent insufficient wing lift available to complete a successful takeoff, accomplish the following:

(a) Within 24 months after the effective date of this AD, modify the SFCC 1 and SFCC 2 in the aft electronics rack, in accordance with Airbus Service Bulletin A320-27-1096, dated March 14, 1996, or Revision 01, dated January 14, 1998 (for Model A320 series airplanes); or Airbus Service Bulletin A320-27-1103, dated June 14, 1996, or Revision 01, dated January 26, 1998 (for Model A321 series airplanes); as applicable.

NOTE 2: After accomplishment of the modification required by paragraph (a) of this AD, Temporary Revision No. 4.02.00/02 may be removed from the Airbus Model A320 and A321 Airplane Flight Manuals.

(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, 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.

(c) 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.

(d) The modification shall be done in accordance with Airbus Service Bulletin A320-27-1096, dated March 14, 1996; Airbus Service BulletinA320-27-1096, Revision 01, dated January 14, 1998; Airbus Service Bulletin A320-27-1103, dated June 14, 1996; or Airbus Service Bulletin A320-27-1103, Revision 01, dated January 26, 1998; as applicable. 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 97-085-099(B), dated March 12, 1997.

(e) This amendment becomes effective on February 19, 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 A320 and A321 series airplanes was published in the Federal Register on April 6, 1998 (63 FR 16709). That action proposed to require modification of the slat and flap control computer (SFCC) in the aft electronics rack.

Comments Received
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
Two commenters support the proposed rule.

Request to Reference Additional Service Bulletin Revisions
One commenter, an operator, states that it has already started accomplishment of Airbus Service Bulletin A320-27-1096, dated March 14, 1996, for its Airbus Model A320 series airplanes. Therefore, the operator requests that the proposed rule be revised to reference the original issue of that service bulletin, as well as Revision 01.

The FAA does not concur that the final rule should be revised. Airbus Service Bulletin A320-27-1096, dated March 14, 1996, and Revision 01, dated January 14, 1998, were both referenced in paragraph (a) of the proposal as appropriate sources of service information and are retained as such in the final rule. Therefore, no change to the final rule is necessary.

Additional Service Bulletin Reference
The FAA has reviewed Airbus Service Bulletin A320-27-1103, Revision 01, dated January 26, 1998 (for Airbus Model A321 series airplanes). The FAA has determined that the technical procedures described in that revision are equivalent to the technical procedures described in Airbus Service Bulletin A320-27-1103, dated June 14, 1996 (the appropriate service information for Airbus Model A321 series airplanes referenced in the proposed rule). Therefore, the FAA has revised paragraph (a) of this AD to include Revision01 of that service bulletin as an additional source of service information.

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 described previously. 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 118 airplanes of U.S. registry will be affected by this AD, that it will take approximately 1 work hour per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will be supplied by the manufacturer at no cost to operators. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $7,080, or $60 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: