AD 96-02-03

This amendment supersedes an existing airworthiness directive (AD), applicable to all Airbus Model A310 series airplanes, that currently requires inspections to detect cracks in the area of the shock absorber attachment at the top of the barrel at the main landing gear (MLG), a measurement of the gap between the barrel and the shock absorber attachment; and corrective action, if necessary. That AD was prompted by a report of the rupture of the aft hinge arm of the left MLG barrel. This amendment requires a measurement of the gap between the washer and barrel of the MLG, eddy current inspections to detect cracking of the MLG barrel, correction of any discrepancy, and accomplishment of certain other follow-on actions. Terminating actions are also provided by this AD. The actions specified by this AD are intended to prevent collapse of the MLG.

Final rule.

96-02-03 AIRBUS INDUSTRIE: Amendment 39-9488. Docket 95-NM-66-AD. Supersedes AD 91-22-52, Amendment 39-8119.

Applicability: Model A310 series airplanes on which Airbus Modification 1033 (reference Airbus Service Bulletin A310-32-2066, Revision 1, dated January 30, 1992) 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 use the authority provided in paragraph (e) of this AD to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition; or different actions necessary to address the unsafe condition described in this AD. Sucha request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any airplane from the applicability of this AD.

Compliance: Required as indicated, unless accomplished previously.

To prevent collapse of the main landing gear (MLG), accomplish the following:

(a) Perform a measurement of the gap between the washer and barrel at the times specified in paragraph (a)(1) or (a)(2) of this AD, as applicable, in accordance with Messier Bugatti Airbus A310 Service Bulletin 470-32-726, Revision 2, dated February 8, 1994.

(1) For airplanes equipped with MLG barrels applicable to Table No. 1 of the service bulletin: Perform the measurement within 8 days after the effective date of this AD.

(2) For airplanes equipped with MLG barrels applicable to Table No. 2 of the service bulletin: Perform the measurement within 3 months after theeffective date of this AD.

(b) If the gap measurement is less than 1 mm (0.04 in.): Accomplish either paragraph (b)(1) or (b)(2) of this AD, as applicable.

(1) For airplanes equipped with MLG barrels applicable to Table No. 1 of the service bulletin: No further action is required by this paragraph for those airplanes.

(2) For airplanes equipped with MLG barrels applicable to Table No. 2 of the service bulletin: Prior to further flight, coat the MLG barrel and shock absorber connecting rod nut with a rubber sealant in accordance with Messier Bugatti Airbus A310 Service Bulletin 470-32-726, Revision 2, dated February 8, 1994.

(c) If the gap is equal to or greater than 1 mm (0.04 in.): Accomplish paragraphs (c)(1), (c)(2), and (c)(3) of this AD, as applicable, in accordance with Messier Bugatti Airbus A310 Service Bulletin 470-32-726, Revision 2, dated February 8, 1994.

(1) For all airplanes: Within 15 days after accomplishing the measurement required by paragraph (a) of this AD, perform a gap recovery procedure in accordance with paragraph 2.B.(5) of the Accomplishment Instructions of the service bulletin.

(2) For airplanes equipped with MLG barrels applicable to Table No. 2 of the service bulletin: Prior to further flight after accomplishing the gap recovery procedure required by paragraph (c)(1) of this AD, coat the MLG barrel and connecting rod nut with a rubber sealant in accordance with the service bulletin.

(3) For all airplanes: Within 15 days after accomplishing the measurement required by paragraph (a) of this AD, perform a visual inspection to detect cracks of the MLG barrel, in accordance with paragraph 2.B.1 of the Accomplishment Instructions of the service bulletin.

(i) If no crack is detected: Repeat the visual inspection thereafter at intervals not to exceed 7 days until the eddy current inspection required by paragraph (d) of this AD is accomplished.

(ii) If any crack is detected: Prior to further flight, replace the MLG barrel with a barrel that has been modified in accordance with Messier Bugatti Service Bulletin 470-32-640, dated July 11, 1988, and Messier Bugatti Service Bulletin 470-32-763, dated February 28, 1994. Accomplishment of this replacement shall be done in accordance with Messier Bugatti Airbus A310 Service Bulletin 470-32-726, Revision 2, dated February 8, 1994. After accomplishment of this replacement, no further action is required by this AD.

(d) Except as provided by paragraph (c)(3)(ii) of this AD (MLG barrel replacement): Following accomplishment of either paragraph (b) or (c) of this AD, and at the applicable times specified in Table No. 1 and Table No. 2 of Messier Bugatti Airbus A310 Service Bulletin 470- 32-726, Revision 2, dated February 8, 1994, remove the rubber sealant and perform an eddy current inspection to detect cracks of the MLG barrel in accordance with Table No. 3 of that service bulletin.

(1) If no crack is detected: At the times specified in Table No. 3 of the service bulletin, perform the various follow-on actions in accordance with the service bulletin. (The follow-on actions include repetitive gap measurements, repetitive eddy current and visual inspections, installation of a new bushing, and replacement of the bronze washer with a stainless steel washer.)

(i) However, in lieu of installing a new bushing on crack-free barrels having no oxidation of the cadmium plating at the next overhaul, as specified in the service bulletin, operators must either repeat the gap measurement and eddy current inspection at intervals not to exceed 2 years, or install a new bushing and replace the bronze washer at the upper part of the MLG barrel with a stainless steel washer, in accordance with the service bulletin.

(ii) After accomplishment of the installation of a new bushing (reference Messier Bugatti Service Bulletin 470-32-640) and the replacement of the bronze washer (reference Messier Bugatti Service Bulletin 470-32-763), no further action is required by this AD.

(2) If any crack is detected: Prior to further flight, replace the barrel with a barrel that has been modified in accordance with Messier Bugatti Service Bulletin 470-32-640, dated July 11, 1988, and Messier Bugatti Service Bulletin 470-32-763, dated February 28, 1994. Accomplishment of this replacement shall be done in accordance with the Messier Bugatti Airbus A310 Service Bulletin 470-32-726, Revision 2, dated February 8, 1994. After accomplishment of this replacement, no further action is required by this AD.

(e) 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 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.

(f) 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.

(g) The actions shall be done in accordance with Messier Bugatti Airbus A310 Service Bulletin 470-32-726, Revision 2, dated February 8, 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 Messier Services, 45635 Willow Pond Plaza, Sterling, Virginia 20164. 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.

(h) This amendment becomes effective on February 26, 1996.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 91-22-52, amendment 39-8119 (57 FR 5372, February 14, 1992), which is applicable to all Airbus Model A310 series airplanes, was published in the Federal Register on November 8, 1995 (60 FR 56271). That action proposed to require a measurement of the gap between the washer and barrel of the main landing gear (MLG), eddy current inspections to detect cracking of the MLG barrel, correction of any discrepancy, and accomplishment of certain other follow-on actions.

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.

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.The FAA estimates that 18 airplanes of U.S. registry will be affected by this proposed AD.

To accomplish the gap measurements, visual inspections, and other follow-on actions will require approximately 5 work hours per airplane, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of these required actions on U.S. operators is estimated to be $5,400, or $300 per airplane, per cycle.

To accomplish the eddy current inspections will require approximately 8 work hours per airplane, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of these required inspections on U.S. operators is estimated to be $8,640, or $480 per airplane, per inspection cycle.

Based on the figures discussed above, the cost impact of this AD on U.S. operators is estimated to be $14,040, or $780 per airplane. The cost impact figures 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.

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 preparedfor 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 USC 106(g), 40113, 44701.
39.13 - [Amended]
2. Section 39.13 is amended by removing amendment 39-8119 (57 FR 5372, February 14, 1992), and by adding a new airworthiness directive (AD), amendment 39-9488, to read as follows: