AD 99-02-10

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Airbus Model A320 series airplanes, that currently requires modification of the trimmable horizontal stabilizer (THS). This amendment adds a requirement for a one-time inspection of the flexible hoses of the elevator return lines on the THS to detect installation of incorrect clamps, or missing clamps or bonding leads; and for replacement of the clamps or bonding leads with new parts, if necessary. 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 leakage from hydraulic pipe fittings in the THS, which could result in failure of the THS and consequent reduced controllability of the airplane.

Final rule.

99-02-10 AIRBUS INDUSTRIE: Amendment 39-11001. Docket 98-NM-215-AD. Supersedes AD 95-17-12, Amendment 39-9342.

Applicability: Model A320 series airplanes; serial numbers 002 through 008 inclusive, 010 through 014 inclusive, 016 through 078 inclusive, 080 through 104 inclusive, 106 through 363 inclusive, 365 through 384 inclusive, 386 through 411 inclusive, 413 through 433 inclusive, 435 through 457 inclusive, 459 through 467 inclusive, and 469 through 472 inclusive; except for airplanes on which Airbus Service Bulletin A320-29-1058, Revision 1, dated November 28, 1994, has been accomplished; 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, theowner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) 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 leakage from hydraulic pipe fittings in the trimmable horizontal stabilizer (THS), which could result in failure of the THS and consequent reduced controllability of the airplane, accomplish the following:

(a) For airplanes on which Airbus Modification 22621 and Airbus Modification 23556 have not been installed: Within 3,500 flight hours after September 21, 1995 (the effective date of AD 95-17-12), modify the THS in accordance with Airbus Service Bulletin A320-29- 1058, dated July 16, 1993, or Revision 1, datedNovember 28, 1994, and Airbus Service Bulletin A320-27-1041, Revision 2, dated April 20, 1994. After the effective date of this AD, only Revision 1 of Airbus Service Bulletin A320-29-1058 shall be used.

(b) For airplanes other than those identified in paragraph (a) of this AD: Within 3,500 flight hours after the effective date of this AD, modify the THS in accordance with Airbus Service Bulletin A320-29-1058, Revision 1, dated November 28, 1994, and Airbus Service Bulletin A320-27-1041, Revision 2, dated April 20, 1994.

(c) Within 500 flight hours after the effective date of this AD, perform a one-time inspection of the flexible hoses of the elevator return lines on the THS to detect installation of incorrect clamps, or missing clamps or bonding leads, in accordance with Airbus All Operator Telex (AOT) 29-10, Revision 02, dated February 13, 1995.

(1) If the correct clamps are installed, and there are no missing clamps or bonding leads, no further action is required by paragraph (b) of this AD.

(2) If any incorrect clamp is installed, prior to further flight, replace the incorrect clamp with the correct clamp; and, if any bonding lead is missing, prior to further flight, install a new bonding lead, in accordance with the AOT.

(3) If any clamp or bonding lead is missing, prior to further flight, install new parts in accordance with the AOT.

(d) 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 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.

(e) 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.

(f) The inspection shall be done in accordance with Airbus All Operator Telex (AOT) 29-10, Revision 02, dated February 13, 1995. The modification shall be done in accordance with Airbus Service Bulletin A320-29-1058, dated July 16, 1993; Airbus Service Bulletin A320-29-1058, Revision 1, dated November 28, 1994; and Airbus Service Bulletin A320-27-1041, Revision 2, dated April 20, 1994; as applicable.

(1) The incorporation by reference of Airbus Service Bulletin A320-29-1058, Revision 1, dated November 28, 1994, and Airbus All Operator Telex (AOT) 29- 10, Revision 02, dated February 13, 1995, is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.

(2) The incorporation by reference of AirbusService Bulletin A320-29-1058, dated July 16, 1993, and Airbus Service Bulletin A320-27-1041, Revision 2, dated April 20, 1994, was approved previously by the Director of the Federal Register as of September 21, 1995 (60 FR 43519, August 22, 1995).

(3) 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 3: The subject of this AD is addressed in French airworthiness directive 93-123-046(B)R1, dated May 10, 1995.

(g) This amendment becomes effective on February 23, 1999.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 95-17-12, amendment 39-9342 (60 FR 43519, August 22, 1995), which is applicable to certain Airbus Model A320 series airplanes, was published in the Federal Register on October 15, 1998 (63 FR 55352). The action proposed to continue to require modification of the trimmable horizontal stabilizer (THS). In addition, the action proposed to add requirements for a one-time inspection of the flexible hoses of the elevator return lines on the THS to detect installation of incorrect clamps, or missing clamps or bonding leads; and for replacement of the clamps or bonding leads with new parts, if necessary.

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.

Two commenters indicate that they are not affected by the proposed rule.Request to Revise Applicability of the AD
Two commenters request that the applicability of the proposed AD be revised to exclude airplanes on which Airbus Service Bulletin A320-29-1058, Revision 1, dated November 28, 1994, has been accomplished. One commenter, an operator, notes that it has already modified its fleet in accordance with Revision 1 of the service bulletin, which provides for installation of clamps having the correct part numbers. Therefore, the operator states that the additional one-time inspection to detect installation of incorrect clamps, as proposed in the AD, should not be required for its fleet.

Another commenter, the manufacturer, suggests a revision to paragraph (a) of the proposed AD to delete references to Airbus Modifications 22621 and 23556, and a revision to paragraph (c) of the proposed AD to narrow its applicability to those airplanes on which Airbus Modification 23556 has been installed in production, or on which Airbus Service Bulletin A320-29-1058, dated July 16, 1993, has been accomplished. The manufacturer states that these changes would correctly exclude airplanes on which Revision 1 of service bulletin A320-29-1058 has been accomplished.

The FAA concurs that airplanes on which Revision 1 of the referenced service bulletin has been accomplished are not affected by the new requirements of the AD. The applicability in the proposed AD correctly specifies effectivity based on manufacturer serial numbers, as did the effectivity of the parallel French airworthiness directive. However, the FAA has determined that the applicability may be narrowed to exclude airplanes on which Revision 1 of service bulletin A320-29-1058 has been accomplished, and has revised the final rule accordingly. Although the changes suggested by the manufacturer have not been incorporated verbatim, the FAA has determined that the final rule, as revised, will meet the intent of the changes proposed by these commenters.

Conclusion
After carefulreview 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
There are approximately 126 airplanes of U.S. registry that will be affected by this AD.

The modification that is currently required by AD 95-17-12, takes approximately 13 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts are provided by the manufacturer at no cost to the operators. Based on these figures, the cost impact of the currently required actions on U.S. operators is estimated to be $98,280, or $780 per airplane.

The inspection that is required by this new AD will take approximately 5 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the required inspection of this AD on U.S. operators is estimated to be $37,800, or $300 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 removing amendment 39-9342 (60 FR 43519, August 22, 1995), and by adding a new airworthiness directive (AD), amendment 39-11001, to read as follows: