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 repetitive inspections to detect fatigue cracking of the lower surface panel on the wing center box; and repair if necessary. That AD also requires modification of the lower surface panel on the wing center box, which constitutes terminating action for the repetitive inspections. This action would reduce the compliance times for the inspections required by the existing AD. The actions specified by the proposed AD are intended to prevent fatigue cracking of the lower surface panel on the wing center box, which could result in reduced structural integrity of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by March 8, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-177-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 (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2002-NM-177-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 Industrie, 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 (425) 227-2125; fax (425) 227-1149.

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 2002-NM-177-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. 2002-NM-177-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On August 19, 1998, the FAA issued AD 98-22-05, amendment 39-10851 (63 FR 56542, October 22, 1998), applicable to certain Airbus Model A320 series airplanes, to require repetitive inspections to detect fatigue cracking of the lower surface panel on the wing center box; and repair if necessary. That AD also requires modification of the lower surface panel on the wing center box, which constitutes terminating action for the repetitive inspections. That action was prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The requirements of that AD are intended to prevent fatigue cracking of the lower surface panel on the wing center box, which could result in reduced structural integrity of the airplane.

Actions Since Issuance of Previous Rule

Since the issuance of AD 98-22-05, the Direction Générale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, notified the FAA that an unsafe condition may exist on certain Airbus Model A320 series airplanes. The DGAC advises that a full-scale fatigue survey on the Model A320 fleet revealed that the weight of fuel at landing and the average flight duration are higher than those defined for the analysis of fatigue-related tasks. This has led to an adjustment of the fatigue mission for the A320 fleet, in that the DGAC has required compliance thresholds and repetitive intervals for accomplishment of the inspections for fatigue cracking shorter than those required by AD 98-22-05. Fatigue-related cracking of the lower surface panel on the wing center box could result in reduced structural integrity of the airplane.

Explanation of Relevant Service Information

Airbus has issued Service Bulletin A320-57-1082, Revision 03, dated April 30, 2002. The procedures specified in Revision 03 are essentially the same as those in Revision 01 of the service bulletin, which was referenced in the existing AD for accomplishment of the inspections and corrective action. However, Revision 03 has a change that recommends a reduction in the compliance thresholds and repetitive intervals specified in Revision 01.

Airbus also has issued Service Bulletin A320-57-1043, Revision 05, dated April 30, 2002. The procedures in Revision 05 are essentially the same as those in Revision 02 of the service bulletin, which was referenced in the existing AD for accomplishment of the modification. Revision 05 recommends a reduction in the compliance thresholds specified in Revision 03, and contains editorial changes.

The DGAC classified these service bulletins as mandatory and issued French airworthiness directive 2002-342(B), dated June 26, 2002, 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 section 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 us informed of the situation described above. We have 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 AD

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 98-22-05 to continue to require repetitive inspections to detect fatigue cracking of the lower surface panel on the wing center box; and repair if necessary. The proposed AD also would continue to require modification of the lower surface panel on the wing center box, which constitutes terminating action for the repetitive inspections. This new action would reduce both the threshold and repetitive intervals for the inspections for fatigue cracking of the same area. The actions would be required to be accomplished in accordance with the service bulletins described previously, except as discussed below.

Differences Between Proposed AD and Service Information

Although Airbus Service Bulletin A320-57-1082, Revision 03, specifies that the manufacturer may be contacted for disposition of certain repair conditions, this proposed AD would require the repair of those conditions to be accomplished in accordance with a method approved by either us or the DGAC (or its delegated agent). In light of the type of repair that would be required to address the identified unsafe condition, and in consonance with existing bilateral airworthiness agreements, we have determined that a repair approved by either us or the DGAC (or its delegated agent) would be acceptable for compliance with this proposed AD.

Unlike the procedures described in Service Bulletin A320-57-1082, this proposed AD would not permit further flight if fatigue cracks are detected on the lower surface panel of the wing center box. We have determined that, because of the safety implications and consequences associated with such fatigue cracking, any subject lower surface panel that is found to be cracked must be repaired prior to further flight in accordance with a method approved by either us or the DGAC (or its delegated agent).

Service Bulletin A320-57-1082 describes procedures for completing and submitting a sheet recording compliance with the service bulletin. This proposed AD would not require those actions; we do not need this information from operators.

Work Hour Rate Increase

We have reviewed the figures we have used over the past several years to calculate AD costs to operators. To account for various inflationary costs in the airline industry, we find it necessary to increase the labor rate used in these calculations from $60 per work hour to $65 per work hour. The cost impact information, below, reflects this increase in the specified hourly labor rate.

Cost Impact

There are approximately 60 airplanes of U.S. registry that would be affected by this proposed AD. This proposed AD would reduce the compliance time for the inspections required by AD 98-22-05, and consequently adds no additional costs or work. The current costs associated with that AD are repeated as follows for the convenience of affected operators:

The inspections that are currently required by AD 98-22-05, and retained in this proposed AD, take approximately 2 work hours per airplane to accomplish, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the currently required inspections is estimated to be $130 per airplane, per inspection cycle.

The modification that is currently required by AD 98-22-05, and retained in this proposed AD, would take approximately 2 work hours per airplane to accomplish, at an average labor rate of $65 per work hours. There are no parts necessary to accomplish the modification. Based on these figures, the cost impact of the modification currently required is estimated to be $130 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of 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.