04-3207. Airworthiness Directives; Airbus Model A320 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Airbus Model A320 series airplanes, that currently requires modification of the rear spar web of the wing, 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), repetitive inspections for fatigue cracking in certain areas of the rear spar of the wing, and corrective action if necessary. That AD also provides for optional terminating action for the requirements of the AD. This proposed AD would revise the threshold and repetitive intervals for the inspection. The actions specified by the proposed AD are intended to detect and correct fatigue cracking, which may lead to reduced structural integrity of the wing and the MLG. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by March 15, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-254-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2001-NM-254-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 or 2000 or ASCII text.

The service information referenced in the proposed rule may be obtained from Airbus, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Dan Rodina, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the proposed AD is being requested.
• Include justification (e.g., reasons or data) for each request.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2001-NM-254-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-254-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On May 16, 2000, the FAA issued AD 2000-10-15, amendment 39-11739 (65 FR 34069, May 26, 2000), applicable to certain Airbus Model A320 series airplanes, to require modification of the rear spar web of the wing, 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), repetitive inspections for fatigue cracking of certain areas of the rear spar of the wing, and corrective action if necessary. That AD also provides for optional terminating action for the requirements of the AD. That action was prompted by the results of fatigue testing conducted by the manufacturer.

The requirements of AD 2000-10-15 are intended 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 MLG.

Actions Since Issuance of Previous Rule

Since we issued AD 2000-10-15, the manufacturer discovered the potential for additional cracking on an airplane that had been modified in accordance with that AD. This finding has led to an adjustment of the related “reference fatigue mission” for Model A320 series airplanes, and resulted in revised inspection thresholds and repetitive intervals expressed in both flight cycles and flight hours.

Explanation of Relevant Service Information

AD 2000-10-15 cites Airbus Service Bulletins A320-57-1088, Revision 02, and A320-57-1089, Revision 02 and earlier, as the appropriate sources of service information for the inspections and optional modification, respectively. Airbus has since issued Service Bulletins A320-57-1088, Revision 04, dated August 16, 2001; and A320-57-1089, Revision 03, dated February 9, 2001. Service Bulletin A320-57-1088 revised the compliance times to incorporate flight hours in addition to flight cycles; otherwise the new revisions describe essentially the same procedures as those described in the earlier versions. The Direction Générale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, mandated Service Bulletin A310-57-1088 and approved Service Bulletin A320-57-1089. The DGAC issued French airworthiness directive 2001-249(B), dated June 27, 2001, to ensure the continued airworthiness of these airplanes in France.

FAA's Conclusions

This airplane model is manufactured in France and is type certificated for operation in the United States under the provisions of § 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the DGAC has kept the FAA informed of the situation described above. The FAA has examined the findings of the DGAC, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would supersede AD 2000-10-15 to continue to require modification of the rear spar web of the wing, cold expansion of certain attachment holes for the forward pintle fitting and certain holes at the actuating cylinder anchorage of the MLG, repetitive inspections for fatigue cracking in certain areas of the rear spar of the wing, and corrective action if necessary. The proposed AD would also continue to provide for optional terminating action. This proposed AD would revise the thresholds and repetitive intervals for the inspection. The proposed compliance times for the initial inspection range from 12,000 to 17,300 total flight cycles; or from 22,400 to 37,300 total flight hours. The actions would be required to be accomplished in accordance with the service information described previously.

Cost Impact

This proposed AD would affect about 126 airplanes of U.S. registry. The following table provides the cost estimates of the actions currently required by AD 2000-10-15:

Cost Estimates

Action	Work hours	Hourly labor rate	Parts cost	Cost per airplane
Modification	60	$65	$0	$3,900.
Cold expansion	600	65	$0	$39,000.
Inspection	24	65	$0	$1,560, per inspection cycle.
Optional terminating action	750	65	$27,036-$32,727 (depending on action airplane configuration)	$75,786-$81,477.

This proposed AD would not add any new actions and therefore would not increase the economic burden on operators—except for the additional cost associated with a potentially shortened inspection interval.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations proposed herein would 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 proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this proposed regulation (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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 copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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 39-11739 (65 FR 34069, May 26, 2000), and by adding a new airworthiness directive (AD), to read as follows:

Airbus: Docket 2001-NM-254-AD. Supersedes AD 2000-10-15, Amendment 39-11739.

Applicability: Model A320 series airplanes, certificated in any category, except those modified in accordance with 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; or Revision 03, dated February 9, 2001).

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 Certain Requirements of AD 2000-10-15

Modification

(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.

(b) For airplanes having MSNs 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 1:

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 Requirements of This AD

Ultrasonic Inspection

(c) Do an ultrasonic inspection for cracking of the rear spar of the wing, in accordance with Airbus Service Bulletin A320-57-1088, Revision 04, dated August 6, 2001. Inspect at the applicable time specified in paragraph 1.E. of the service bulletin, except as required by paragraphs (c)(1) and (c)(2) of this AD.

Note 2:

An inspection done before the effective date of this AD in accordance with Airbus Service Bulletin A320-57-1088, Revision 02, dated July 29, 1999; or Revision 03, dated February 9, 2001; is acceptable for compliance with the requirements of the initial inspection required by paragraph (c) of this AD.

(1) For any airplane that has not been inspected but has exceeded the applicable specified compliance time as of the effective date of this AD: Inspect within 60 days after the effective date of this AD.

(2) For any airplane that has been inspected before the effective date of this AD: Repeat the inspection within 3,600 flight cycles after the most recent inspection.

Repetitive Inspections

(d) Repeat the inspection required by paragraph (c) of this AD at intervals not to exceed 3,600 flight cycles or 6,700 flight hours, whichever occurs first, until the requirements of paragraph (f) have been done.

Corrective Action

(e) If any crack is found during any inspection required by paragraph (c) or (d) of this AD: Before further flight, repair in accordance with a method approved by either the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate; or the Direction Generale de l'Aviation Civile (or its delegated agent).

Optional Terminating Action

(f) Modification of all specified fastener holes in the rear spar of the wing terminates the initial and repetitive inspections required by paragraphs (c) and (d) of this AD, if the modification is done in accordance with Airbus Service Bulletin A320-57-1089, dated December 22, 1996; Revision 01, dated April 17, 1997; Revision 02, dated November 6, 1998; or Revision 03, dated February 9, 2001. If done before the airplane accumulates 12,000 total flight cycles, the modification also terminates the actions required by paragraphs (a) and (b) of this AD.

Alternative Methods of Compliance

(g) In accordance with 14 CFR 39.19, the Manager, International Branch, FAA, is authorized to approve alternative methods of compliance for this AD.

Note 3:

The subject of this AD is addressed in French airworthiness directive 2001-249(B), dated June 27, 2001.

Issued in Renton, Washington, on February 5, 2004.

Kevin M. Mullin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.