AD 98-06-20

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Airbus Model A320 series airplanes, that currently requires inspections to detect cracking of certain floor beams and side box-beams, and repair of cracks; and modification of the pressure floor. That AD was prompted by results of a full-scale fatigue test. This amendment adds a one-time inspection to verify proper clearance between the fasteners of the reinforcement bracket and the bellcrank of the free-fall extension system of the main landing gear (MLG) and its associated tie rod attachment nut. This amendment also adds a requirement for a new improved modification of the pressure floor. The actions specified by this AD are intended to prevent reduced structural integrity of the fuselage, restricted operation of the MLG free-fall system and, consequently, reduced ability to use the MLG during an emergency.

Final rule.

98-06-20 AIRBUS INDUSTRIE: Amendment 39-10398. Docket 95-NM-216-AD. Supersedes AD 93-14-04, Amendment 39-8628.

Applicability: Model A320 series airplanes, manufacturer's serial numbers 002 through 008 inclusive, 010 through 078 inclusive, and 080 through 107 inclusive; certificated in any category.

NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been 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 (f) 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 shouldinclude specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent reduced structural integrity of the fuselage, restricted operation of the main landing gear (MLG) free-fall system, and, consequently, reduced ability to use the MLG during an emergency, accomplish the following:

(a) Prior to the accumulation of 12,000 total landings, or within 6 months after August 23, 1993 (the effective date of AD 93-14-04, amendment 39-8628), whichever occurs later, accomplish the requirements of paragraphs (a)(1) and (a)(2) of this AD, in accordance with Airbus Service Bulletin A320-53-1024, dated September 23, 1992, or Revision 1, dated March 31, 1994. As of the effective date of this new AD, only Revision 1 of this service bulletin shall be used.

(1) Conduct an eddy current inspection to detect cracking around the fastener/bolt holes at the top horizontal flange of the floor beams and side box-beams, at the two sides of the pressure floor, and at the vertical integral stiffener of the side box-beams; and

(2) Conduct a detailed visual inspection to detect cracking around the fastener/bolt holes at the fillet radius and riveted area of the top outboard flange of the side box- beam, and at the flange-corner radius of the slanted inboard flange of the side box-beam and fittings.

(b) If any crack is detected during the inspections required by paragraph (a) of this AD, prior to further flight, repair the crack in accordance with a method approved by the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate.

(c) For airplanes on which the modification specified in Airbus Service Bulletin A320-53-1023, dated September 23, 1992, as amended by Service Bulletin Change Notice 0A, dated January 20, 1993; Revision 1, dated March 23, 1993; Revision 2, dated October 22, 1993; Revision 3, dated March 18, 1994; Revision 4, dated September 30, 1994; Revision 5, dated February28, 1995; or Revision 6, dated September 4, 1995; has been accomplished: Accomplish paragraphs (c)(1) and (c)(2) of this AD.

(1) Prior to the accumulation of 1,000 landings after the effective date of this AD, perform a one-time inspection to verify proper clearance between the fasteners of the reinforcement bracket and the bellcrank of the free-fall extension system of the MLG and its associated tie rod attachment nut, in accordance with Airbus All Operators Telex (AOT) 53-08, Revision 01, dated January 15, 1996.

(i) If the minimum clearance is greater than 3 mm (0.118 inch) and no evidence of interference is detected, within 60 months following accomplishment of the inspection required by paragraph (c)(1) of this AD, reinstall the reinforcement bracket fasteners in accordance with Airbus Service Bulletin A320-53-1023, Revision 7, dated November 3, 1995.

(ii) If the minimum clearance is 3 mm (0.118 inch) or less, and no evidence of interference is detected, within18 months following accomplishment of the inspection required by paragraph (c)(1) of this AD, accomplish either paragraph (c)(1)(ii)(A) or (c)(1)(ii)(B) of this AD.

(A) Reinstall the reinforcement bracket fasteners in accordance with Airbus Service Bulletin A320-53-1023, Revision 7, dated November 3, 1995; or

(B) Rework the bellcrank lever and fasteners in accordance with Airbus AOT 53-08, Revision 01, dated January 15, 1996. Within 60 months following accomplishment of the rework, reinstall the reinforcement bracket fasteners in accordance with Airbus Service Bulletin A320-53-1023, Revision 7, dated November 3, 1995.

(iii) If any interference is detected, prior to further flight, accomplish either paragraph (c)(1)(iii)(A) or (c)(1)(iii)(B) of this AD.

(A) Reinstall the reinforcement bracket fasteners in accordance with Airbus Service Bulletin A320-53-1023, Revision 7, dated November 3, 1995; or

(B) Rework the bellcrank lever and fasteners in accordance with Airbus AOT 53-08, Revision 01, dated January 15, 1996. Within 60 months following accomplishment of the rework, reinstall the reinforcement bracket fasteners in accordance with Airbus Service Bulletin A320-53-1023, Revision 7, dated November 3, 1995.

(2) Prior to the accumulation of 24,000 total landings, or within 6 months after the effective date of this AD, whichever occurs later, modify the pressure floor at section 15 of the fuselage in accordance with Airbus Service Bulletin A320-53-1023, Revision 7, dated November 3, 1995. Accomplishment of the modification terminates the requirements of this AD.

(d) For airplanes on which the modification specified in Airbus Service Bulletin A320-53-1023, dated September 23, 1992, as amended by Service Bulletin Change Notice 0A, dated January 20, 1993; Revision 1, dated March 23, 1993; Revision 2, dated October 22, 1993; Revision 3, dated March 18, 1994; Revision 4, dated September 30, 1994; Revision 5, dated February28, 1995; or Revision 6, dated September 4, 1995; has not been accomplished: Prior to the accumulation of 18,000 total landings, or within 6 months after the effective date of this AD, whichever occurs later, modify the pressure floor at section 15 of the fuselage in accordance with Airbus Service Bulletin A320-53-1023, Revision 7, dated November 3, 1995. Accomplishment of the modification terminates the requirements of this AD.

(e) Accomplishment of the modification of the pressure floor at section 15 of the fuselage in accordance with Airbus Service Bulletin A320-53-1023, Revision 7, dated November 3, 1995, constitutes terminating action for the requirements of this AD.

(f) 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.

(g) 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.

(h) The actions shall be done in accordance with Airbus Service Bulletin A320-53- 1024, dated September 23, 1992; Airbus Service Bulletin A320-53-1024, Revision 1, dated March 31, 1994; Airbus All Operators Telex (AOT) 53-08, Revision 01, dated January 15, 1996; and Airbus Service Bulletin A320-53-1023, Revision 7, dated November 3, 1995; as applicable. Revision 7 of Airbus Service Bulletin A320-53-1023 contains the following list of effective pages:

Page Number
Revision Level
Shown on Page
Date
Shown on Page
1, 15-55
7
November 3, 1995
2-14
6
September 4, 1995

The incorporation by reference of Airbus Industrie Service Bulletin A320-53-1024, dated September 23, 1992, as listed in the regulations, was approved previously by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51 as of August 23, 1993 (58 FR 39440, July 23, 1993). The incorporation by reference of the remainder of the service documents listed above is 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 directives (CN's) 92-205-033(B)R1, dated June 22, 1994, and 96-053-077(B)R1, dated June 5, 1996.

(i) This amendment becomes effective on April 24, 1998.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 93-14-04, amendment 39-8628 (58 FR 39440, July 23, 1993), which is applicable to certain Airbus Model A320 series airplanes, was published as a supplemental notice of proposed rulemaking (NPRM) in the Federal Register on March 12, 1997 (62 FR 11388). The action proposed to continue to require inspections to detect cracking of the floor beams and the side box-beams, and repair of cracks. The action also proposed to add a one-time inspection to verify proper clearance between the fasteners of the reinforcement bracket and the bellcrank of the free-fall extension system of the main landing gear (MLG) and its associated tie rod attachment nut. In addition, the action proposed to add a requirement for a new improved modification of the pressure floor.

Comments
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 requests that paragraph (c)(1)(ii) of the supplemental NPRM be revised to include an option to rework the bellcrank just like paragraph (c)(1)(iii)(B) of the supplemental NPRM. The commenter points out that the Direction G n rale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, has included this rework option in its revised French airworthiness directive (CN) 96-053-77(B)R1, dated June 5, 1996.

The FAA concurs. The FAA has reviewed the subject French airworthiness directive, and has revised paragraph (c)(1)(ii) of this final rule to include an option to rework the bellcrank lever and fasteners, and reinstall the reinforcement bracket fasteners, which is identical to the requirements of paragraph (c)(1)(iii)(B) of the AD.

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 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 24 Airbus Model A320 series airplanes of U.S. registry that will be affected by this AD.

The inspections that are currently required by AD 93-14-04 take approximately 37 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 currently required inspections on U.S. operators is estimated to be $53,280, or $2,220 per airplane.

The new inspection that is required by this AD action will take approximately 11 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 new inspection required by this AD on U.S. operators is estimated to be $15,840, or $660 per airplane

The new modification that is required by this AD action will take approximately 142 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts will be supplied by the manufacturer at no cost to the operators. Based on these figures, the cost impact of the modification required by this AD on U.S. operators is estimated to be $204,480, or $8,520 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 39-8628 (58 FR 39440, July 23, 1993), and by adding a new airworthiness directive (AD), amendment 39-10398, to read as follows: