Airworthiness directives: Airbus,

[Federal Register: November 23, 1998 (Volume 63, Number 225)]

[Proposed Rules]

[Page 64661-64664]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr23no98-32]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-249-AD]

RIN 2120-AA64

Airworthiness Directives; Airbus Model A300 and A300-600 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

[[Page 64662]]

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Airbus Model A300 and A300-600 series airplanes, that currently requires inspections to detect cracks in Gear Rib 5 of the main landing gear (MLG) attachment fittings at the lower flange, and repair, if necessary. This action would establish repetitive inspection intervals for certain inspections required by the existing AD. This action also would add a requirement to modify Gear Rib 5 of the MLG attachment fittings, which constitutes terminating action for the repetitive inspections. 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 prevent fatigue cracking of the MLG attachment fittings, which could result in reduced structural integrity of the airplane.

DATES: Comments must be received by December 23, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-249-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 filedin 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-249-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-249-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On January 23, 1998, the FAA issued AD 98-03-06, amendment 39-10298 (63 FR 5224, February 2, 1998), applicable to certain Airbus Model A300 and A300-600 series airplanes, to require inspections to detect cracks in Gear Rib 5 of the main landing gear (MLG) attachment fittings at the lower flange, and repair, if necessary. 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 detect and correct fatigue cracking of the MLG attachment fittings, which could result in reduced structural integrity of the airplane.

Explanation of Relevant Service Information

Since the issuance of AD 98-03-06, the manufacturer has issued Airbus Service Bulletins A300-57-0234, Revision 01 (for Model A300 series airplanes), and A300-57-6087, Revision 01 (for Model A300-600 series airplanes), both dated March 11, 1998. Airbus Service Bulletin A300-57-0234, Revision 01, limits the effectivity of the existing AD, however, these service bulletins add no additional airplanes to the effectivity. These service bulletins recommend repetitive intervals for accomplishing detailed visual and high frequency eddy current inspections to detect cracks in Gear Rib 5 of the main landing gear (MLG) attachment fittings at the lower flange. The Direction Generale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, classified these service bulletins as mandatory and issued French airworthiness directive 98-151-247(B), dated April 8, 1998, in order to assure the continued airworthiness of these airplanes in France.

The manufacturer also has issued Airbus Service Bulletins A300-57- 0235 (for Model A300 series airplanes), and A300-57-6088 (for Model A300-600 series airplanes), both dated August 5, 1998. These service bulletins describe procedures for modification of Gear Rib 5 of the MLG attachment fittings at the lower flange by increasing the depth, diameter, and corner radius of the spotface of specified fastener holes. Accomplishment of this modification would eliminate the need for the repetitive inspections described previously. The DGAC approved these service bulletins.

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 supersede AD 98-03-06 to continue to require inspections to detect cracks in Gear Rib 5 of MLG attachment fittings at the lower flange, and repair, if necessary. The proposed AD also would establish repetitive inspection intervals for certain inspections. In addition, the proposal would require modification of Gear Rib 5 of the MLG attachment fittings, which constitutes terminating action for the repetitive inspections. The actions would be required to be accomplished in accordance with the

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service bulletins described previously, except as discussed below.

Differences Between the Proposed AD and the Related Service Bulletins

Operators should note that, although the service bulletins described previously specify that appropriate corrective action may be obtained by contacting the manufacturer for disposition of certain repair conditions, this proposal would require that any such repairs be accomplished in accordance with a method approved by either the FAA or the Direction Generale de l'Aviation Civile (or its delegated agent).

Operators also should note that this AD proposes to mandate, prior to the accumulation of 21,000 total flight cycles or within 2 years after the effective date of the AD, whichever occurs later, the modification of Gear Rib 5 of the MLG attachment fittings as described in Airbus Service Bulletins A300-57-6088 and A300-57-0235. Accomplishment of this modification would constitute terminating action for the repetitive inspections.

The FAA has determined that long-term continued operational safety will be better assured by modifications or design changes to remove the source of the problem, rather than by repetitive inspections. Long-term inspections may not be providing the degree of safety assurance necessary for the transport airplane fleet. This, coupled with a better understanding of the human factors associated with numerous repetitive inspections, has led the FAA to consider placing less emphasis on special procedures and more emphasis on design improvements. The proposed modification requirement is in consonance with these considerations.

Cost Impact

There are approximately 164 airplanes of U.S. registry that would be affected by this proposed AD.

The inspection currently required by AD 98-03-06, and retained in this proposed AD, takes approximately 6 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the currently required inspection on U.S. operators is estimated to be $59,040, or $360 per airplane, per inspection cycle.

The modification that is proposed in this AD action would take approximately 62 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts would cost approximately $10,270 per airplane. Based on these figures, the cost impact of the new actions proposed by this AD on U.S. operators is estimated to be $2,294,360, or $13,990 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the current or 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, 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 removing amendment 39-10298 (63 FR 5224, February 2, 1998), and by adding a new airworthiness directive (AD), to read as follows:

   Airbus Industrie: Docket 98-NM-249-AD. Supersedes AD 98-03-06, Amendment 39-10298.

   Applicability: Model A300 series airplanes, as listed in Airbus Service Bulletin A300-57-0234, Revision 01, dated March 11, 1998; and Model A300-600 series airplanes, as listed in Airbus Service Bulletin A300-57-6087, Revision 01, dated March 11, 1998; 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 (e) 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 prevent fatigue cracking of the main landing gear (MLG) attachment fittings, which could result in reduced structural integrity of the airplane, accomplish the following:

   (a) For Model A300 series airplanes that have accumulated more than 27,000 flight cycles as of March 9, 1998 (the effective date of AD 98-03-06, amendment 39-10298): Except as provided by paragraph (b) of this AD, within 40 flight cycles after March 9, 1998, perform a detailed visual inspection to detect cracks in Gear Rib 5 of the MLG attachment fittings at the lower flange, in accordance with Airbus Service Bulletin A300-57-0234, Revision 01, dated March 11, 1998. Thereafter, repeat the inspection at intervals not to exceed 40 flight cycles, until the initial inspections required by paragraph (b) are accomplished.

   (b) For all airplanes: Perform a detailed visual and a high frequency eddy current (HFEC) inspection to detect cracks in Gear Rib 5 of the MLG attachment fittings at the lower flange, in accordance with Airbus Service Bulletin A300-57-6087, Revision 01, dated March 11, 1998 (for Model A300-600 series airplanes); or A300- 57-0234, Revision 01, dated March 11, 1998 (for Model A300 series airplanes); as applicable; at the time specified in paragraph (b)(1) or (b)(2) of this AD, as applicable. Repeat the inspections thereafter at intervals not to exceed 1,500 flight cycles. Accomplishment of the inspections required by this paragraph terminates the inspections required by paragraph (a) of this AD.

   (1) For airplanes that have accumulated 20,000 or more total flight cycles as of March 9, 1998: Inspect within 500 flight cycles after March 9, 1998.

   (2) For airplanes that have accumulated less than 20,000 total flight cycles as of March 9, 1998: Inspect prior to the

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   accumulation of 18,000 total flight cycles, or within 1,500 flight cycles after March 9, 1998, whichever occurs later.

   Note 2: Accomplishment of the initial detailed visual and HFEC inspections in accordance with Airbus Service Bulletin A300-57A0234 or A300-57A6057, both dated August 5, 1997, as applicable, is considered acceptable for compliance with the initial inspections required by paragraph (a) or (b) of this AD.

   (c) If any crack is detected during any inspection required by this AD, prior to further flight, repair in accordance with a method approved by the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, or the Direction Generale de l'Aviation Civile (or its delegated agent).

   (d) Prior to the accumulation of 21,000 total flight cycles, or within 2 years after the effective date of this AD, whichever occurs later: Modify Gear Rib 5 of the MLG attachment fittings at the lower flange in accordance with Airbus Service Bulletin A300-57-6088 (for Model A300-600 series airplanes), or A300-57-0235 (for Model A300 series airplanes), both dated August 5, 1998, as applicable. Accomplishment of this modification constitutes terminating action for the repetitive inspection requirements of this AD.

   (e) 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. 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 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.

   (f) 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 4: The subject of this AD is addressed in French airworthiness directive 98-151-247 (B), dated April 8, 1998.

   Issued in Renton, Washington, on November 16, 1998. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

   [FR Doc. 98-31173Filed11-20-98; 8:45 am]

   BILLING CODE 4910-13-U