03-28606. Airworthiness Directives; Airbus Model A320-111, -211, -212, and -231 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Airbus Model A320-111, -211, -212, and -231 series airplanes. This proposal would require repetitive inspections for fatigue cracking around the fasteners attaching the pressure panel to the flexible bracket at frame 36, adjacent to the longitudinal beams on the left and right sides of the airplane; and repair as necessary. This proposal would also provide an optional terminating action for the repetitive inspections. This action is necessary to detect and correct fatigue cracking around the fasteners attaching the pressure panel to the flexible bracket at the frame 36 adjacent to the longitudinal beams, which could result in reduced structural integrity and possible rapid decompression of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by December 17, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-107-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-107-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:

Tim Dulin, 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-107-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-107-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

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 A320-111, -211, -212, and -231 series airplanes. The DGAC advises that during fatigue tests, cracking was detected around the fasteners attaching the pressure panel to the flexible bracket at frame 36, adjacent to the longitudinal beams on the left and right sides of the airplane. Investigation revealed that the damage was caused by high loads in this area. Such cracking, if not corrected, could result in reduced structural integrity and possible rapid decompression of the airplane.

Explanation of Relevant Service Information

Airbus has issued Service Bulletin A320-53-1030, Revision 01, dated May 21, 2002. This service bulletin describes procedures for repetitive inspections for fatigue cracking around the fasteners attaching the pressure panel to the flexible bracket at frame 36, adjacent to the longitudinal beams on the left and right sides of the airplane; and repair if necessary. This service bulletin permits flight with cracks of specific lengths.

Airbus Service Bulletin A320-53-1030, Revision 01, includes procedures for the following actions:

• Repetitive rotating probe inspections on airplanes with a center fuel tank, or repetitive detailed inspections on airplanes without a center fuel tank, for cracking of the fastener holes that attach the pressure panel to the flexible bracket at frame 36, adjacent to the longitudinal beams.
• For certain airplanes on which cracking of specific lengths is found, installation of the applicable repair/modification kit (including modification of the pressure panel and longitudinal beams by removing material, inspection of bolt holes for cracking, repair of cracked areas, cold expansion of the bolt holes, and installation of a doubler).

Airbus Service Bulletin A320-53-1029, Revision 01, includes procedures for modifying the pressure panels located at frame 36 (including drilling and reaming fastener holes to the oversize start diameter, performing rotating probe inspections to detect cracking around fasteners holes, repairing cracked areas, and cold expanding the fastener holes). Accomplishment of this service bulletin on airplanes on which no cracking is detected eliminates the need for the repetitive inspections specified in Airbus Service Bulletin A320-53-1030, Revision 01. Installation of any repair/modification kit in accordance with the Accomplishment Instructions of either service bulletin eliminates the need for the repetitive inspections of the repaired/modified area specified in Airbus Service Bulletin A300-53-1030, Revision 01.

Accomplishment of the actions specified in Airbus Service Bulletin A300-53-1030, Revision 01, is intended to adequately address the identified unsafe condition. The DGAC classified this service bulletin as mandatory and issued French airworthiness directive 2000-531-155(B), dated December 27, 2000, 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 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 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 require accomplishment of the actions specified in Airbus Service Bulletin A300-53-1030, Revision 01, described previously, except as discussed below. This proposed AD also would provide for optional terminating action for the repetitive inspections.

Consistent with the findings of the DGAC, the proposed AD would allow repetitive inspections to continue in lieu of the terminating action, provided no cracking is found during any inspection. In making this determination, we considered that long-term continued operational safety in this case will be adequately ensured by repetitive inspections to detect cracking before it represents a hazard to the airplane.

Differences Between the Service Information and the Proposed AD

Although the service bulletins specify that operators may contact the manufacturer for disposition of certain repair conditions, this proposal would require operators to repair those conditions per a method approved by either the FAA or the DGAC (or its delegated agent). In light of the type of repair that would be required to address the unsafe condition, and consistent with existing bilateral airworthiness agreements, we have determined that, for this proposed AD, a repair approved by either the FAA or the DGAC would be acceptable for compliance with this proposed AD.

No Flight With Cracks

Unlike Airbus Service Bulletin A300-53-1030, Revision 01, this proposed AD would not permit further flight if any cracking is detected, regardless of crack length, around the fasteners that attach the pressure panel to the flexible bracket at frame 36, adjacent to the longitudinal beams on the left and right sides of the airplane. We have determined that, because of the safety implications and consequences associated with such cracking, any cracking must be repaired before further flight.

Cost Impact

The FAA estimates that 24 airplanes of U.S. registry would be affected by this proposed AD.

For airplanes without a center fuel tank, it would take approximately 1 work hour per airplane to accomplish the proposed detailed inspection, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the proposed detailed inspection is estimated to be $65 per airplane, per inspection cycle.

For airplanes with a center fuel tank, it would take approximately 2 work hours per airplane to accomplish the proposed rotating probe inspection at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the proposed inspection is estimated to $130 per airplane, per inspection cycle.

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.

Should an operator elect to perform the optional terminating action, it would take approximately 12 work hours per airplane to accomplish the proposed cold work modification, at an average labor rate of $65 per work hour. The cost of required parts is $650. Based on these figures, the cost impact of the optional terminating action is estimated to be $1,430 per airplane.

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 adding the following new airworthiness directive:

Airbus: Docket 2001-NM-107-AD.

Applicability: Model A320-111, -211, -212, and -231 series airplanes having manufacturer serial numbers 0002 through 0107 inclusive; certificated in any category; except those airplanes on which Airbus Modification 21202/K1432 has been incorporated in production, or Airbus Service Bulletin A320-53-1029, Revision 01, dated April 29, 2002, has been incorporated in service.

Compliance: Required as indicated, unless accomplished previously.

To detect and correct fatigue cracking around the fasteners connecting the pressure panel to the flexible bracket at frame 36, adjacent to the longitudinal beams on the left and right sides of the airplane, which could result in reduced structural integrity and possible rapid decompression of the airplane, accomplish the following:

Inspection and Follow-On Actions

(a) Prior to the accumulation of 30,000 total flight cycles, do a rotating probe inspection on airplanes with a center fuel tank, or a detailed inspection on airplanes without a center fuel tank, to detect cracking around the fasteners that attach the pressure panel to the flexible bracket at frame 36, adjacent to the longitudinal beams on the left and right sides of the airplane, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-53-1030, Revision 01, dated May 21, 2002.

Note 1:

For the purposes of this AD, a detailed inspection is defined as: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.”

(b) If no cracks are detected by the inspection required by paragraph (a) of this AD, repeat the applicable inspection thereafter at intervals not to exceed 6,000 flight cycles for airplanes without a center fuel tank, and at intervals not to exceed 18,000 flight cycles for airplanes with a center fuel tank.

Corrective Actions

(c) If any cracking is detected during any inspection required by paragraph (a) of this AD, before further flight, repair the affected structure by accomplishing all applicable actions in accordance with paragraphs 3.B. through 3.E. of the Accomplishment Instructions of Airbus Service Bulletin A320-53-1030, Revision 01, dated May 21, 2002. Repeat the applicable inspection thereafter at intervals not to exceed 6,000 flight cycles for airplanes without a center fuel tank, and at intervals not to exceed 18,000 flight cycles for airplanes with a center fuel tank. For any area where cracking is repaired, the repair constitutes terminating action for the repetitive inspection of that area.

Note 2:

Airbus Service Bulletin A320-53-1030 references Airbus Service Bulletin A320-53-1029, Revision 01, dated April 29, 2002, as an additional source of service information for certain repairs.

(d) If any service bulletin specifies to contact the manufacturer for appropriate action: Before further flight, repair in accordance with a method approved by the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate or the Direction Gale de l'Aviation Civile (or its delegated agent).

Optional Terminating Action

(e) Modification of the structure around the fasteners that attach the pressure panel to the flexible bracket at frame 36, adjacent to the longitudinal beams on the left and right sides of the airplane, by accomplishing all applicable actions in accordance with paragraphs 3.A. through 3.E of the Accomplishment Instructions of Airbus Service Bulletin A320-53-1029, Revision 01, dated April 29, 2002, constitutes terminating action for this AD.

Credit for Actions Done per Previous Issue of Service Bulletins

(f) Accomplishment of the required actions before the effective date of this AD in accordance with Airbus Service Bulletin A320-53-1030, dated January 5, 2000; or Airbus Service Bulletin A320-53-1029, dated January 5, 2000; is considered acceptable for compliance with the applicable requirements of paragraphs (a), (b), and (c) of this AD.

Alternative Methods of Compliance

(g) In accordance with 14 CFR 39.19, the Manager, International Branch, ANM-116, 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 2000-531-155(B), dated December 27, 2000.

Issued in Renton, Washington, on November 10, 2003.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.