AD 96-17-06

This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A310 series airplanes, that requires repetitive inspections to detect discrepancies of the slat universal joint and steady bearing assemblies, and replacement of any discrepant assembly with a new, like assembly. This amendment also requires replacement of all slat universal joint and steady bearing assemblies with improved assemblies, which would terminate the repetitive inspections. This amendment is prompted by reports of broken or missing inner races on the slat universal joint and steady bearing assemblies of the slat transmission system. The actions specified by this AD are intended to prevent cracking of the inner race, which could cause it to break off and, consequently, allow the slat universal joint and steady bearing assemblies to become worn; this situation could result in failure of the shaft of the slat transmission system, and subsequent uncommanded movement of the associated slat.

Final rule.

96-17-06 AIRBUS INDUSTRIE: Amendment 39-9715. Docket 95-NM-241-AD.

Applicability: Model A310 series airplanes, on which Airbus Modification 6022 or 6485 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, 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 shaft of the slat transmission system, and subsequent uncommanded movement of the associated slat, accomplish the following:

(a) Prior to the accumulation of 2,000 landings or 500 flight hours after the effective date of this AD, whichever occurs later, perform a visual inspection to detect discrepancies of the slat universal joint and steady bearing assemblies, in accordance with Airbus Service Bulletin A310-27-2040, Revision 2, dated January 5, 1995.

NOTE 2: Airbus Service Bulletin A310-27-2040 inadvertently references LUCAS/LIEBHERR Service Bulletin 551A-27-6010 as the appropriate source for accomplishing the inspection. LUCAS/LIEBHERR Service Bulletin 551A-27-610 is the appropriate source of information.

(1) If no discrepancy is found, repeat the inspection thereafter at intervals not to exceed 2,000 landings.

(2) If any discrepancy is detected and the groove depth on the shaft is greater than or equal to 1 mm (0.04 in.), prior to further flight, replace the discrepant bearing assembly with a new, like assembly, in accordance with the service bulletin. After replacement, repeat the visual inspection thereafter at intervals not to exceed 2,000 landings.

(3) If any discrepancy is detected and the groove depth on the shaft is less than 1 mm (0.04 in.), prior to 50 landings after accomplishing the initial inspection, replace the discrepant bearing assembly with a new, like assembly, in accordance with the service bulletin. After the replacement, repeat the visual inspection thereafter at intervals not to exceed 2,000 landings.

(b) Within 5 years after the effective date of this AD, replace the slat universal joint and steady bearing assemblies with new assemblies, in accordance with LUCAS/LIEBHERR Service Bulletin 523-27-M523-1, dated April 25, 1986. Accomplishment of the replacement constitutes terminating action for the repetitive inspection requirements of paragraph (a)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) 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 A310-27-2040, Revision 2, dated January 5, 1995, and LUCAS/LIEBHERR Service Bulletin 523-27-M523-1, dated April 25, 1986. 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.

(f) This amendment becomes effective on September 23, 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 A310 series airplanes was published in the Federal Register on May 8, 1996 (61 FR 20762). That action proposed to require repetitive visual inspections to detect discrepancies of the slat universal joint and steady bearing assemblies, and replacement of any discrepant assembly with a new, like assembly. That action also proposed to require replacement of all slat universal joint and steady bearing assemblies with new assemblies, which would constitute terminating action for the repetitive inspection requirements.

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.

Conclusion
After careful review of the available data, includingthe 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 26 Airbus Model A310 series airplanes of U.S. registry will be affected by this AD.

It will take approximately 5 work hours per airplane to accomplish the required inspection, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the required inspection on U.S. operators is estimated to be $7,800, or $300 per airplane, per inspection.

It will take approximately 9 work hours per airplane to accomplish the required replacement, at an average labor rate of $60 per work hour. Required parts will cost approximately $48,108 per airplane. Based on these figures, the cost impact of the required replacement on U.S. operators is estimated to be $1,264,848, or $48,648 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 theRegulatory 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: