AD 97-10-01

This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A310 series airplanes, that requires repetitive inspections to detect discrepancies or damage of the steady bearing assemblies of the flap transmission system, and replacement of any discrepant or damaged assembly with a new, like assembly. This amendment also requires eventual replacement of all the steady bearing assemblies with new, improved assemblies, which terminates the repetitive inspection requirements. This amendment is prompted by reports of cracking of the hardened steel inner race, and broken or missing inner races of the steady bearing assemblies. The actions specified by this AD are intended to prevent such discrepancies and damage of the shafts of the steady bearing assemblies, which could cause the shafts to fail; failure of the steady bearing shafts during a subsequent asymmetric stop could result in an uncommanded asymmetric retraction of the flap, and subsequentreduced controllability of the airplane.

Final rule.

97-10-01 AIRBUS INDUSTRIE: Amendment 39-10013. Docket 96-NM-60-AD.

Applicability: Model A310 series airplanes, on which Airbus Modification 10962 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 flap transmission shaft due to damaged steady bearing assemblies, which could cause an uncommanded asymmetric retraction of the flap, and result in reduced controllability of the airplane, accomplish the following:

(a) Prior to the accumulation of 2,000 total landings or within 500 flight hours after the effective date of this AD, whichever occurs later: Perform a visual inspection to detect damage or any discrepancy of the steady bearing assemblies of the flap transmission system, in accordance with Airbus Service Bulletin A310-27-2067, Revision 1, dated January 5, 1995.

(1) If no damage or discrepancy is detected: Repeat the inspection thereafter at intervals not to exceed 2,000 landings, until the requirements of paragraph (b) of this AD are accomplished.

(2) If any damage or discrepancy is detected and the groove depth of the shaft is less than 1 mm (.04 inch): Prior to the accumulation of 50 landingsafter detection of this discrepancy, replace the steady bearing assembly with a new, like assembly in accordance with Airbus Service Bulletin A310-27-2067, Revision 1, dated January 5, 1995.

(3) If any damage or discrepancy is detected and the groove depth on the shaft is 1 mm or more: Prior to further flight, replace the steady bearing assembly with a new, like assembly, in accordance with Airbus Service Bulletin A310-27-2067, Revision 1, dated January 5, 1995.

(b) Within 5 years after the effective date of this AD, replace all steady bearing assemblies of the flap transmission system with new, improved assemblies, in accordance with Airbus A310-27-2074, dated November 18, 1994. Accomplishment of the replacement constitutes terminating action for the requirements of this AD.

NOTE 2: Airbus Service Bulletin A310-27-2074 references Lucas Liebherr Service Bulletin 551A-27-M551-03 as an additional source of service information for replacement of the steady bearing assemblies with the new, improved assemblies.

(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 inspection and certain replacements shall be done in accordance with Airbus Service Bulletin A310-27-2067,Revision 1, dated January 5, 1995. Certain other replacements shall be done in accordance with Airbus Service Bulletin A310-27-2074, dated November 18, 1994. 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 June 10, 1997.

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 January 14, 1997 (62 FR 1859). That action proposed to require repetitive visual inspections to detect any discrepancy or damage to the steady bearing assemblies of the flap transmission system, and replacement of any damaged or discrepant assembly with a new, like assembly. That action also proposed to require eventual replacement of all steady bearing assemblies with the new, improved assemblies, which terminates the repetitive inspection requirement.

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

The commenter supports the proposed rule.
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 as proposed.

Cost Impact
The FAA estimates that 26 Airbus Model A310 series airplanes of U.S. registry will be affected by this AD, that it will take approximately 15 work hours per airplane to accomplish the required inspections, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the inspections required by this AD on U.S. operators is estimated to be $23,400, or $900 per airplane, per inspection cycle.

It will take approximately 8 work hours per airplane to accomplish the required replacement, at an average labor rate of $60 per work hour. Required parts will cost approximately $16,872 per airplane. Based on these figures, the cost impact of the required replacement on U.S. operators is estimated to be $451,152, or $17,352 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 adding the following new airworthiness directive: