AD 98-9751

[Federal Register Volume 63, Number 71 (Tuesday, April 14, 1998)] [Proposed Rules] [Pages 18153-18155] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 98-9751]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-20-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 to detect missing or cracked bolts and fittings of the frame-to-pressure-floor connection; and corrective actions, if necessary. This proposal also provides for optional terminating action for the repetitive inspections of the affected fittings. This proposal is prompted by 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 bolts and fittings of the frame-to-pressure-floor connection, which could result in reduced structural integrity of the airplane.

DATES: Comments must be received by May 14, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-20-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 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: Norman B. Martenson, Manager, 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 98-NM-20-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. 98-NM-20-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 structural fatigue test, the inboard aft bolt at the right side of frame 43 sheared off after 76,055 simulated flights. In addition, a crack developed in the frame fitting at the right side of frame 43 after 81,551 simulated flights. Such fatigue cracking, if not detected and corrected in a timely manner, could result in reduced structural integrity of the airplane.

Explanation of Relevant Service Information

Airbus has issued Service Bulletin A320-53-1083, Revision 2, dated August 28, 1997, which describes procedures for repetitive detailed visual inspections to detect cracking of the bolts and fittings of the frame-to-pressure-floor connection at frames (FR) 43 and 44 and to determine if any bolt is missing. The service bulletin also describes procedures for replacement of cracked or missing bolts and fittings with new or serviceable parts. The service bulletin references Airbus Service Bulletin A320-53- 1015, Revision 02, dated July 17, 1997, as an additional source of service information for accomplishment of the replacement. Airbus Service Bulletin A320-53-1015 also describes procedures for reinforcement of the frame segments and frame fittings at FR 43 and FR 44 between left and right stringers 18 and 23. Such reinforcement, if accomplished, eliminates the need for the repetitive inspections for the affected fitting. The DGAC classified Airbus Service Bulletin A320-53-1083 as mandatory and issued French airworthiness directive 97-316-110(B), dated October 22, 1997, in order to assure 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 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 Airbus Service Bulletins A320-53-

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1083 and A320-53-1015 (for certain corrective actions), described previously, except as discussed in the ``Differences Between Proposed Rule and Service Bulletins'' paragraph below. The proposed AD also would provide for optional terminating action for the repetitive inspections of the affected fittings. Operators should note that, in consonance with the findings of the DGAC, the FAA has determined that the repetitive inspections proposed by this AD can be allowed to continue in lieu of accomplishment of a terminating action. In making this determination, the FAA considers that, in this case, long-term continued operational safety will be adequately assured by accomplishing the repetitive inspections to detect cracking before it represents a hazard to the airplane.

Differences Between Proposed Rule and Service Bulletins

Operators also should note that, unlike the procedures described in Airbus Service Bulletins A320-53-1083 and A320-53-1015, this proposed AD would not permit further flight if cracks are detected in the bolts and fittings of the frame-to-pressure-floor connection at frames 43 and 44. The FAA has determined that, because of the safety implications and consequences associated with such cracking, corrective actions for any fitting or bolt of the frame-to-pressure-floor connection at frames 43 and 44 that is found to be cracked must be accomplished prior to further flight.

Cost Impact

The FAA estimates that 5 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 9 work hours per airplane to accomplish the proposed inspection, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the inspection proposed by this AD on U.S. operators is estimated to be $2,700, or $540 per airplane, per inspection cycle. The cost impact figure discussed above is 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. Should an operator elect to accomplish the optional terminating action that would be provided by this AD action, it would take approximately 119 work hours to accomplish it, at an average labor rate of $60 per work hour. The cost of required parts would be approximately $12,920 per airplane. Based on these figures, the cost impact of the optional terminating action would be $20,060 per airplane.

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, 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 98-NM-20-AD. Applicability: Model A320-111, -211, and -231 series airplanes; as listed in Airbus Service Bulletin A320-53-1083, Revision 2, dated August 28, 1997; certificated in any category.

Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been 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 (c) 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 the bolts and fittings of the frame-to-pressure-floor connection, which could result in reduced structural integrity of the airplane, accomplish the following: (a) Prior to the accumulation of 20,000 total flight cycles, or within 60 days after the effective date of this AD, whichever occurs later, perform a detailed visual inspection to detect cracked or missing bolts and fittings of the frame-to-pressure-floor connection at frames 43 and 44, in accordance with Airbus Service Bulletin A320-53-1083, Revision 2, dated August 28, 1997. If no crack is detected, repeat the detailed visual inspection thereafter at intervals not to exceed 5,100 flight cycles. (1) If any bolt is found to be cracked or missing during any inspection required by paragraph (a) of this AD, prior to further flight, replace the bolt with a new bolt in accordance with the service bulletin. Repeat the detailed visual inspection thereafter at intervals not to exceed 5,100 flight cycles. (2) If any fitting is found to be cracked during any inspection required by paragraph (a) of this AD, prior to further flight, accomplish the actions specified in paragraph (b) of this AD for the cracked fitting and its corresponding bolts and fuselage frame, in accordance with Airbus Service Bulletin A320-53-1015, Revision 02, dated July 17, 1997. (b) Reinforcement of the fitting in accordance with Airbus Service Bulletin A320-53-1015, Revision 02, dated July 17, 1997, constitutes terminating action for the requirements of this AD for the affected fitting. (c) 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 International Branch, ANM-116.

(d) 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.

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Note 3: The subject of this AD is addressed in French airworthiness directive 97-316-110(B), dated October 22, 1997.

Issued in Renton, Washington on April 7, 1998. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 98-9751 Filed 4-13-98; 8:45 am] BILLING CODE 4910-13-U