AD 99-21-19

This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A319-131, A320-232 and -233, and A321-131 and -231 series airplanes, that requires replacement of all titanium thrust links with steel thrust links. 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 titanium thrust links due to the life limit of the thrust links, which in combination with other failures, could result in the separation of an engine from the airplane.

Final rule.

99-21-19 AIRBUS INDUSTRIE: Amendment 39-11364. Docket 99-NM-96-AD.

Applicability: Model A319-131, A320-232 and -233, and A321-131 and -231 series airplanes; except those airplanes on which Airbus Modification 26506 (reference Airbus Service Bulletin A320-71-1020, dated May 25, 1998) has been accomplished 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 (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 been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent failure of the titanium thrust links due to the life limit of the thrust links, which in combination with other failures, could result in the separation of an engine from the airplane, accomplish the following:

(a) Replace all titanium thrust links with steel thrust links in accordance with Airbus Service Bulletin A320-71-1020, dated May 25, 1998; at the later of the times specified in paragraphs (a)(1) and (a)(2) of this AD.

(1) Prior to the accumulation of the total flight cycles specified for each particular model in the tables of paragraph B.(5), "Accomplishment Timescale," of the service bulletin.

(2) Within 15 months after the effective date of this AD, or at the next engine removal, whichever occurs first.

Alternative Methods of Compliance
(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 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.

Special Flight Permits
(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.

Incorporation by Reference
(d) The replacement shall be done in accordance with Airbus Service Bulletin A320-71-1020, dated May 25, 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 3: The subject of this AD is addressed in French airworthiness directive 1999-050-126(B), dated February 10, 1999.

(e) This amendment becomes effective on November 17, 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 A319-131, A320-232 and -233, and A321-131 and -231 series airplanes was published in the Federal Register on August 4, 1999 (64 FR 42293). That action proposed to require replacement of all titanium thrust links with steel thrust links.

Comments
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
One commenter supports the proposal. Two commenters state that they are not affected by the proposed AD.

Request To Revise Certain Wording of the Compliance Section
One commenter requests that paragraph (a) of the proposed rule be revised to read, "Replace all titanium thrust links with steel thrust links in accordance with Airbus Service Bulletin A320-71-1020, dated May 25, 1998; at the earlier of the times specified in paragraphs (a)(1) and (a)(2) of this AD." The commenter states that the term "later" could allow the titanium thrust links to remain in service up to 15 months regardless of cycle times. The commenter further states that, since the cycle times are the critical parameter, "earlier" would control the use of the titanium thrust links to the critical parameter.

The FAA does not concur. Revising the AD as suggested by the commenter would result in replacement of all titanium thrust links "within 15 months or at the next engine removal", even for airplanes having very few accumulated flight cycles. Since this AD is intended to correct an unsafe condition related to the fatigue life limits of the thrust links, the FAA has determined that the compliance time for replacement of the thrust links should be correlated to the total flight cycles on each airplane. This compliance time is also in consonance with that recommended by the Direction G n rale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, in the parallel French airworthiness directive. Additionally, for airplanes with thrust links over the threshold of accumulated flight cycles, paragraph (a)(2) of the AD includes a grace period of 15 months, which corresponds with a typical "C-check" interval. The "C-check" interval is recommended in the Airbus service bulletin for accomplishment of the replacements.

The FAA has determined that the compliance threshold and grace period as proposed are adequate to accomplish timely replacement of the thrust links, while still providing operators sufficient time to perform these actions on thrust links already over the allotted number of accumulated flight cycles. No change is made to the final rule.

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 as proposed.

Cost Impact
The FAA estimates that 65 airplanes of U.S. registry will be affected by this AD, that it would take approximately 3 work hours per airplane to accomplish the required replacement, and that the average labor rate is $60 per work hour. Required parts will be supplied by the engine manufacturer at no cost to the operators. Based on these figures, the cost impact of the required AD on U.S. operators is estimated to be $11,700, or $180 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: