AD 2000-10-15

This amendment supersedes two existing airworthiness directives (AD), applicable to certain Airbus Model A320 series airplanes, that currently require modification of the rear spar web of the wing and cold expansion of certain attachment holes for the forward pintle fitting and certain holes at the actuating cylinder anchorage of the main landing gear (MLG). This amendment adds a requirement for repetitive inspections to detect fatigue cracking in certain areas of the rear spar of the wing, and corrective action, if necessary. This amendment also provides for optional terminating action for the requirements of this AD. 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 detect and correct fatigue cracking, which may lead to reduced structural integrity of the wing and the MLG.

Final rule.

2000-10-15 AIRBUS INDUSTRIE: Amendment 39-11739. Docket 98-NM-99-AD. Supersedes AD 93-08-15, Amendment 39-8563; and AD 93-25-13, Amendment 39-8777.

Applicability: Model A320 series airplanes, certificated in any category, except those on which Airbus Modification 24591 (Airbus Service Bulletin A320-57-1089, dated December 22, 1996; Revision 01, dated April 17, 1997; or Revision 02, dated November 6, 1998) has been accomplished.

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 (f)(1) 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 detect and correct fatigue cracking in certain areas of the rear spar of the wing, which may lead to reduced structural integrity of the wing and the main landing gear (MLG), accomplish the following:

RESTATEMENT OF ACTIONS REQUIRED BY AD 93-08-15:

(a) For airplanes having manufacturer's serial numbers (MSN) 003 through 008 inclusive, and 010 through 021 inclusive: Prior to the accumulation of 12,000 total flight cycles, or within 500 flight cycles after June 11, 1993 (the effective date of AD 93-08-15, amendment 39-8563), whichever occurs later, modify the inner rear spar web of the wing in accordance with Airbus Service Bulletin A320-57-1004, Revision 1, dated September 24, 1992, or Revision 2, dated June 14, 1993.

RESTATEMENT OF ACTIONS REQUIRED BY AD 93-25-13:

(b) For airplanes having MSN's 002 through 051 inclusive: Prior to the accumulation of 12,000 total flight cycles, or within 2,000 flight cycles after February 14, 1994 (the effective date of AD 93-25-13, amendment 39-8777), whichever occurs later, accomplish the requirements of paragraphs (b)(1) and (b)(2) of this AD in accordance with Airbus Service Bulletin A320-57-1060, dated December 8, 1992; or Revision 2, dated December 16, 1994.

(1) Perform a cold expansion of all the attachment holes for the forward pintle fitting of the MLG, except for the holes that are for taper-lok bolts.

(2) Perform a cold expansion of the holes at the actuating cylinder anchorage of the MLG.

NOTE 2: Accomplishment of the cold expansion in accordance with Airbus Service Bulletin A320-57-1060, Revision 1, dated April 26, 1993, is also acceptable for compliance with the requirements of paragraph (b) of this AD.

NEW ACTIONS REQUIRED BY THIS AD:

Ultrasonic Inspections and Corrective Action

(c) For all airplanes: Perform an ultrasonic inspection to detect cracking of the rear spar of the wing, in accordance with Airbus Service Bulletin A320-57-1088, Revision 02, dated July 29, 1999; at the applicable time specified by paragraph (c)(1) or (c)(2) of this AD. Repeat the inspection thereafter at intervals not to exceed 3,600 flight cycles.

(1) For airplanes on which the actions specified by Airbus Service Bulletin A320-57-1004, Revision 2, dated June 14, 1993, or earlier version; and Airbus Service Bulletin A320-57-1060, Revision 02, dated December 16, 1994, or earlier version; have been accomplished: Perform the inspection of all applicable fastener holes within 12,000 flight cycles after accomplishment of the service bulletins, or within 750 flight cycles after the effective date of this AD, whichever occurs later.

(2) For airplanes on which the actions specified by Airbus Production Modification 20740 and Airbus Service Bulletin A320-57-1060, Revision 2, dated December 16, 1994, or earlier version, have been accomplished; or on which Airbus Production Modifications 20740, 20741, and 20796 have been accomplished: Perform the inspections at the locations and applicable times specified by paragraphs (c)(2)(i) and (c)(2)(ii) of this AD.

(i) Perform the inspection of left and right fastener holes 52 to 55, 82, 83, 87, and 88; located in the rear spar of the wing; prior to the accumulation of 17,300 total flight cycles, or within 750 flight cycles after the effective date of this AD, whichever occurs later. If any cracking is found, prior to further flight, accomplish the requirements of paragraph (c)(2)(ii) of this AD.

(ii) Except as required by paragraph (c)(2)(i) of this AD: Perform the inspection of all fastener holes located in the rear spar of the wing that are not identified in paragraph (c)(2)(i) of this AD prior to the accumulation of 20,000 total flight cycles, or within 200 flight cycles after the effective date of this AD, whichever occurs later.

NOTE 3: Accomplishment of the actions specified by Airbus Service Bulletin A320-57-1088, dated September 30, 1996, or Revision 01, dated September 17, 1997, prior to the effective date of this AD is acceptable for compliance with the requirements of the initial inspection required by paragraph (c) of this AD.

(d) If any crack is found during any inspection required by paragraph (c) of this AD: Prior to further flight, repair in accordance with a method approved by either the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate; or the Direction G n rale de l'Aviation Civile (DGAC) (or its delegated agent). For a repair method to be approved by the Manager, International Branch, ANM-116, as required by this paragraph, the Manager's approval letter must specifically reference this AD.

Optional Terminating Action

(e) Modification ofall specified fastener holes in the rear spar of the wing in accordance with Airbus Service Bulletin A320-57-1089, dated December 22, 1996; Revision 01, dated April 17, 1997; or Revision 02, dated November 6, 1998; constitutes terminating action for the ultrasonic inspections required by paragraph (c) of this AD. Such modification, if accomplished prior to the accumulation of 12,000 total flight cycles, also constitutes terminating action for the actions required by paragraphs (a) and (b) of this AD.

Alternative Methods of Compliance

(f) (1) 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. 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.

(2) Alternative methods of compliance, approved previously in accordance with AD 93-25-13; amendment 39-8777, are approved as alternative methods of compliance with this AD.

NOTE 4: 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

(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.

Incorporation by Reference

(h) Except as required by paragraph (d) of the AD, the actions shall be done in accordance with Airbus Service Bulletin A320-57-1004, Revision 1, dated September 24, 1992; Airbus Service Bulletin A320-57-1004, Revision 2, dated June 14, 1993; Airbus Service Bulletin A320-57-1060, dated December 8, 1992; Airbus Service Bulletin A320-57-1060, Revision 2, dated December 16, 1994; or Airbus Service Bulletin A320-57-1088, Revision 02, including Appendix 01, dated July 29, 1999; as applicable. Airbus Service Bulletin A320-57-1004, Revision 2, dated June 14, 1993, contains the following list of effective pages:

Page Number
Revision Level Shown on Page
Date Shown on Page
1, 4, 12, 14, 17-20, 22, 23,
28, 292
June 14, 1993
15
1
September 24, 1992
2, 3, 5-11, 13, 16, 21, 24-27, 30
Original
July 9, 1991

(1) The incorporation by reference of Airbus Service Bulletin A320-57-1004, Revision 2, dated June 14, 1993; Airbus Service Bulletin A320-57-1060, Revision 2, dated December 16, 1994; and Airbus Service Bulletin A320-57-1088, Revision 02, including Appendix 01, dated July 29, 1999; is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.

(2) The incorporation by reference of Airbus Service Bulletin A320-57-1004, Revision 1, dated September 24, 1992, was approved previously by the Director of the Federal Registeras of June 11, 1993 (58 FR 27923, May 12, 1993).

(3) The incorporation by reference of Airbus Service Bulletin A320-57-1060, dated December 8, 1992, was approved previously by the Director of the Federal Register as of February 14, 1994 (59 FR 1903, January 13, 1994).

(4) 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 5: The subject of this AD is addressed in French airworthiness directive 1999-264-135(B), dated June 30, 1999.

(i) This amendment becomes effective on June 30, 2000.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 93-08-15, amendment 39-8563 (58 FR 27923, May 12, 1993), and AD 93-25-13, amendment 39-8777 (59 FR 1903, January 13, 1994), which are both applicable to certain Airbus Model A320 series airplanes, was published in the Federal Register on February 10, 2000 (65 FR 6566). The action proposed to continue to require modification of the wing rear spar web and cold expansion of certain attachment holes for the forward pintle fitting and certain holes at the actuating cylinder anchorage of the MLG. The AD proposed to add a requirement for repetitive ultrasonic inspections to detect fatigue cracking in certain areas of the wing rear spar, and repair of cracking. The AD also proposed to provide for optional terminating action for the inspections proposed by this AD.

Comments Received
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 concurs with the proposed AD. Another commenter states that Airbus Production Modification 24591 is installed on its airplanes; therefore, it is not affected by the proposed AD.

Inspection Threshold for Certain Airplanes
One commenter requests that the proposed AD be revised to allow "Group 2" airplanes to accomplish the initial inspection of the wing rear spar within 12,000 flight cycles after accomplishment of Airbus Service Bulletin A320-57-1060. The commenter defines "Group 1" airplanes as manufacturer's serial numbers (MSN) 002 through 021, on which Airbus Service Bulletins A320-57-1004 and A320-57-1060 are accomplished as retrofit. "Group 2" airplanes are defined as MSN's 022 through 051, on which Airbus Modification 20740 (equivalent to A320-57-1004) has been accomplished in production, and Airbus Service Bulletin A320-57-1060 as retrofit.
The commenter notes that "Group 1" airplanes are granted 12,000 flight cycles after accomplishment of A320-57-1060, yet "Group 2" airplanes are required to undergo inspection prior to accumulation of 17,300 total flight cycles, regardless of when modification per A320-57-1060 was accomplished.

The commenter states that "Group 1" and "Group 2" airplanes are in the same configuration and will have a similar fatigue life; therefore, both should have the same inspection threshold.

The FAA does not concur. Although the FAA acknowledges that "Group 1" and "Group 2" airplanes may be in a similar modification configuration, the design configuration of these airplanes is different. "Group 1" airplanes are composed of Model A320-100 series airplanes, and "Group 2" airplanes are composed of Model A320-200 series airplanes. Model A320-200 series airplanes are equipped with a center fuel tank (not installed on Model A320-100 series airplanes) that increases the airplanes' weight. For thisreason, it is necessary that "Group 2" airplanes be inspected for cracking prior to accumulation of 17,300 total flight cycles, regardless of when Service Bulletin A320-57-1060 is accomplished. No change is made to the final rule.

Terminating Modification for Certain Airplanes
One commenter requests that modification in accordance with Airbus Service Bulletin A320-57-1089 be considered as terminating action to all inspection requirements if accomplished prior to the initial inspection interval, or to repetitive inspections if accomplished after the initial inspection interval. The commenter states that terminating action credit is allowed under paragraph (e) of the proposed AD only if accomplished prior to 12,000 total flight cycles. The commenter states that accomplishment of the terminating modification includes a non-destructive test inspection of the inner rear spar at each hole location. Since this inspection during the modification will ensure that the inner rear sparis free of defects, terminating action to the follow-on inspection requirements should also be provided.

The FAA notes that terminating modification to the inspection requirements of the AD is already provided for in paragraph (e) of the proposed AD, and considers that clarification of the provisions for terminating modification is necessary. As stated in the second sentence of paragraph (e) of the AD, the threshold of 12,000 total flight cycles is required only if modification per Service Bulletin A320-57-1089 is chosen in lieu of accomplishing the modifications required by paragraphs (a) and (b) of the AD. However, the modification also constitutes acceptable terminating action for the ultrasonic inspection requirements of the AD, as stated in the first sentence of paragraph (e) of the AD. Paragraph (e) has been revised to more clearly specify the terminating action provisions of the AD.

Cost Estimate for Terminating Modification
Two commenters request that the proposed AD be revised to provide correct cost estimates for the optional modification described in Airbus Service Bulletin A320-57-1089. The commenters state that the service bulletin lists the labor cost as 980 work hours, yet the proposed AD provides an estimate of 750 work hours.

The FAA acknowledges that the service bulletin estimate specifies additional work hours (for access and close) that are not included in the proposed AD. However, the cost impact information in an AD typically describes only the "direct" costs of specific actions, and does not include incidental costs, such as the time required to gain access and close up; planning time; or time necessitated by other administrative actions. Because incidental costs may vary significantly from operator to operator, they are almost impossible to calculate. Additionally, since this is an optional modification, operators may choose not to incur such costs, or may minimize costs by accomplishing the modification during scheduled maintenance. No change is made to the final rule.

Additional Changes to the AD
To clarify actions for airplanes on which modifications have been installed in production and those on which service bulletins have been accomplished as retrofit, the FAA has revised paragraph (c)(2) of the AD to refer to certain modifications as "Airbus Production Modification . . . ." Additionally, a heading has been included to specify the actions required by paragraphs (c) and (d) of the AD.

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 with the changes previously described. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Cost Impact
There are approximately 126 airplanes of U.S. registry that will be affected by this AD.

It takes approximately 60 work hoursper airplane to accomplish the modification of the rear spar web of the wing, as required by AD 93-08-15 and retained in this AD, at an average labor rate of $60 per work hour. Based on these figures, the total cost impact of the modification on U.S. operators is estimated to be $3,600 per airplane.

It takes approximately 600 work hours per airplane to accomplish the cold expansion of certain holes associated with the MLG, as required by AD 93-25-13 and retained in this AD, at an average labor rate of $60 per work hour. Required parts are provided by the manufacturer at no cost to the operators. Based on these figures, the total cost impact of the cold expansion on U.S. operators is estimated to be $36,000 per airplane.

The new inspection that is required by this new AD will take approximately 24 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 requirements of this AD on U.S. operators is estimated to be $181,440, or $1,440 per airplane, per inspection cycle.

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.

Should an operator elect to accomplish the optional terminating action specified in this AD, it would take approximately 750 work hours, at an average labor rate of $60 per work hour.

The required parts would cost $27,036; $30,595; or $32,727; depending on the airplane configuration. Based on these figures, the cost per airplane of the optional terminating action provided by this AD is estimated to be $72,036; $75,595; or $77,727.

Regulatory Impact
The regulations adopted herein will not have a substantial direct effect 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, it is determined that this final rule does not have federalism implications under Executive Order 13132.

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 amendments 39-8563 (58 FR 27923, May 12, 1993) and 39-8777 (59 FR 1903, January 13, 1994), and by adding a new airworthiness directive (AD), amendment 39-11739, to read as follows: