AD 97-30330

[Federal Register Volume 62, Number 223 (Wednesday, November 19, 1997)] [Proposed Rules] [Pages 61704-61706] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 97-30330]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-184-AD] RIN 2120-AA64

Airworthiness Directives; Airbus Model A320-111, -211, and -231 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Airbus Model A320-111, - 211, and -231 series airplanes. This proposal would require repetitive inspections for cracking in the transition and pick-up angles in the lower part of the center fuselage area, and corrective action, if necessary. This proposal would also provide for an optional terminating modification for the repetitive inspection requirements. This proposal is prompted by the issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to detect and correct fatigue cracking in the transition and pick-up angles of the lower part of the center fuselage, which could result in reduced structural integrity of the wing-fuselage support and fuselage pressure vessel.

DATES: Comments must be received by December 19, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 96-NM-184-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays. The service information referenced in the proposed rule may be obtained from Airbus Industrie, 1 Rond Point Maurice

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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: International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue SW, Renton, Washington 98055-4056; telephone (425) 227-2110; 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 notice may be changed in light of the comments received. 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 notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 96-NM-184-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-103, Attention: Rules Docket No. 96-NM-184-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The Direction Generale 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, and -231 series airplanes. The DGAC advises that, during a full-scale fatigue test on a Model A320 test article, cracking was found on the transition and pick-up angles between frames 35 and 36. Such cracking is attributed to fatigue-related stress as a result of fastener movement during vibration and loading. Fatigue-related cracking in the pick-up and transition angles in the lower part of the center fuselage, if not detected and corrected in a timely manner, could result in reduced structural integrity of the wing-fuselage support and fuselage pressure vessel.

Explanation of Relevant Service Information

Airbus has issued Service Bulletin A320-53-1028, dated March 1, 1994, which describes procedures for performing repetitive visual inspections of the transition angle between frames 35 and 36, just below left- and right-hand stringer 30; and repetitive rotating probe inspections of the fastener holes of the left- and right-hand pick-up angles. For structure that is free of cracking, Airbus has also issued Service Bulletin A320-53-1027, dated March 1, 1994; Revision 1, dated September 5, 1994; and Revision 2, dated June 8, 1995. The service bulletin describes procedures for modification of the center fuselage. The modification involves the installation of additional washers between the transition angle and fasteners, and the cold-expansion of the most fatigue-sensitive fastener holes. Accomplishment of this modification would eliminate the need for the repetitive inspections for structure that was free of cracking. The DGAC classified Airbus Service Bulletin A300-53-1028 as mandatory and issued French airworthiness directive 95-097-065(B), dated May 24, 1995, in order to assure the continued airworthiness of these airplanes in France. The DGAC also approved Airbus Service Bulletin A320-53-1027, Revision 2, dated June 8, 1995.

FAA's Conclusions

These airplane models are manufactured in France and are 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 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 require accomplishment of the actions specified in the service bulletins described previously; except where cracking is detected and it is 1.9 mm or greater in length, in which case the repair would be required to be accomplished in accordance with a method approved by the FAA.

Differences Between the Proposal and the Related French AD

The proposed AD would differ from the parallel French airworthiness directive in that the proposed AD would not permit further flight with cracking detected in the transition or pick-up angles of the wing- fuselage support. The FAA has determined that, due to safety implications and consequences associated with such cracking, the subject transition and pick-up angles that are found to be cracked must be repaired prior to further flight.

Cost Impact

The FAA estimates that 24 airplanes of U.S. registry would be affected by this proposed AD. It would take approximately 9 work hours per airplane to accomplish the proposed inspections at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the inspections proposed by this AD on U.S. operators is estimated to be $12,960, or $540 per airplane, per inspection cycle. It would take approximately 10 work hours per airplane to accomplish the proposed modification, at an average labor rate of $60 per work hour. Required parts would cost approximately $2,895 per airplane. Based on these figures, the cost impact of the modification proposed by this AD on U.S. operators is estimated to be $83,880, or $3,495 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.

Regulatory Impact

The regulations proposed herein would 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,

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in accordance with Executive Order 12612, it is determined that this proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. 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.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

Airbus Industrie: Docket 96-NM-184-AD.

Applicability: Model A320-111, -211, and -231 series airplanes, manufacturer's serial numbers 002 through 008 inclusive, 010 through 014 inclusive, 016 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 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 (b) 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 reduced structural integrity of the wing- fuselage support and fuselage pressure vessel resulting from structural fatigue cracking in the transition and pick-up angles, accomplish the following: (a) Prior to the accumulation of 16,000 total landings, or within 6 months after the effective date of this AD, whichever occurs later, accomplish paragraphs (a)(1) and (a)(2) of this AD, in accordance with Airbus Service Bulletin A320-53-1028, dated March 1, 1994. (1) Perform a visual inspection to detect cracks of the transition angle, in accordance with the service bulletin. (i) If no crack is detected during the visual inspection required by paragraph (a)(1) of this AD, accomplish either paragraph (a)(1)(i)(A) or paragraph (a)(1)(i)(B) of this AD. (A) Repeat the visual inspection thereafter at intervals not to exceed 12,000 landings. Or (B) Prior to further flight, modify the center fuselage in accordance with Airbus Service Bulletin A320-53-1027, dated March 1, 1994; Revision 1, dated September 5, 1994; or Revision 2, dated June 8, 1995. Accomplishment of the modification constitutes terminating action for the repetitive inspection requirements of paragraph (a)(1)(i)(A) of this AD. (ii) If any crack is detected during the visual inspection required by paragraph (a)(1) of this AD, prior to further flight, replace the transition angle with a new transition angle, in accordance with Airbus Service Bulletin A320-53-1027, dated March 1, 1994; Revision 1, dated September 5, 1994; or Revision 2, dated June 8, 1995. (2) Perform a rotating probe inspection to detect cracks of the pick-up angle, in accordance with the service bulletin. (i) If no crack is detected during the rotating probe inspection required by paragraph (a)(2) of this AD, accomplish either paragraph (a)(2)(i)(A) or (a)(2)(i)(B) of this AD. (A) Repeat the visual and rotating probe inspections thereafter at intervals not to exceed 12,000 landings. Or (B) Prior to further flight, modify the center fuselage in accordance with Airbus Service Bulletin A320-53-1027, dated March 1, 1994; Revision 1, dated September 5, 1994; or Revision 2, dated June 8, 1995. Accomplishment of the modification constitutes terminating action for the repetitive inspection requirements of paragraph (a)(2)(i)(A) of this AD. (ii) If any crack is detected and it is less than 1.9 mm in length, prior to further flight, accomplish the applicable corrective actions specified in the service bulletin. For holes that have not been modified in accordance with the service bulletin, repeat the rotating probe inspection thereafter at intervals not to exceed 12,000 landings. (iii) If any crack is detected and it is 1.9 mm or greater in length, prior to further flight, repair it in accordance with the method approved by the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate. (b) 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 Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate.

(c) 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.

Note 3: The subject of this AD is addressed in French airworthiness directive 95-097-065(B), dated May 24, 1995.

Issued in Renton, Washington, on November 13, 1997. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 97-30330 Filed 11-18-97; 8:45 am] BILLING CODE 4910-13-P