Airworthiness directives: Aerospatiale,

[Federal Register: June 23, 1999 (Volume 64, Number 120)]

[Proposed Rules]

[Page 33441-33443]

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

[DOCID:fr23jn99-29]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-201-AD]

RIN 2120-AA64

Airworthiness Directives; Aerospatiale Model ATR42-300 and ATR42- 320 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 Aerospatiale Model ATR42- 300 and ATR42-320 series airplanes. This proposal would require a one- time inspection for cracking of a fastener hole located on the lower surface of the outer wing, and repair, if necessary; and cold working of the hole and installation of a new fastener in the hole. 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 damage on the outer wing and consequent reduced structural integrity of the wing.

DATES: Comments must be received by July 23, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-201-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 Aerospatiale, 316 Route de Bayonne, 31060 Toulouse, Cedex 03, 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:

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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-201-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-201-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 Aerospatiale Model ATR42-300 and ATR42- 320 series airplanes. Fatigue testing conducted by the manufacturer on the test airframe revealed damage to several fastener holes located on the lower surface of the outer wing. A service bulletin previously issued by the manufacturer contained procedures for cold working of certain fastener holes where such fatigue damage could occur. However, the service bulletin inadvertently omitted identification of one fastener hole located on the lower surface of the outer wing near the spar/rib 15 junction for cold working. Failure to accomplish cold working of the hole could allow fatigue damage to develop on the lower surface panel of the outer wing. This condition, if not corrected, could result in reduced structural integrity of the wing.

Other Relevant Rulemaking

The FAA has previously issued AD 89-25-12, amendment 39-6414 (54 FR 50343, December 6, 1989), which requires operators to perform cold working of certain fastener holes located on the lower surface of the outer wing, in accordance with Avions de Transport Regional Service Bulletin ATR42-57-0010, Revision 1, dated May 20, 1989.

This proposed AD will not affect the requirements of AD 89-25-12.

Explanation of Relevant Service Information

Aerospatiale has issued Avions de Transport Regional Service Bulletin ATR42-57-0050, dated April 17, 1998, which describes procedures for a one-time high frequency eddy current inspection to detect cracking of a fastener hole located on the lower surface of the outer wing near the spar/rib 15 junction. The service bulletin also describes procedures for cold working of the hole and installation of a new fastener in the hole. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition. The DGAC classified this service bulletin as mandatory and issued French airworthiness directive 98-147-075(B), dated April 8, 1998, 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 the service bulletin described previously, except as discussed below.

Differences Between Proposed Rule and Service Bulletin

Operators should note that, although the service bulletin specifies that the manufacturer may be contacted for disposition of certain repair conditions, this proposal would require the repair of those conditions to be accomplished in accordance with 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 identified unsafe condition, and in consonance with existing bilateral airworthiness agreements, the FAA has determined that, for this proposed AD, a repair approved by either the FAA or the DGAC (or its delegated agent) would be acceptable for compliance with this proposed AD.

Cost Impact

The FAA estimates that 14 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 8 work hours per airplane to accomplish the proposed actions, and that the average labor rate is $60 per work hour. Required parts would be provided by the manufacturer at no cost to the operator. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $6,720, or $480 per airplane.

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.

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

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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:

   Aerospatiale: Docket 98-NM-201-AD.

   Applicability: Model ATR42-300 and ATR42-320 series airplanes, serial numbers 3 through 59 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 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 prevent fatigue damage on the outer wing and consequent reduced structural integrity of the wing, accomplish the following:

   Corrective Action

   (a) Prior to the accumulation of 33,000 total landings, or within 2,000 landings after the effective date of this AD, whichever occurs later, accomplish paragraphs (a)(1) and (a)(2) of this AD in accordance with Avions de Transport Regional Service Bulletin ATR42- 57-0050, dated April 17, 1998.

   (1) Perform a high frequency eddy current inspection to detect cracking of the fastener hole located on the lower surface of the outer wing near the spar/rib 15 junction. If any cracking is found, prior to further flight, repair the cracking in accordance with a method approved by either the Manager, International Branch, ANM- 116, FAA, Transport Airplane Directorate, or the Direction Generale de l'Aviation Civile (or its delegated agent).

   (2) Perform cold working of the fastener hole located on the lower surface of the outer wing near the spar/rib 15 junction, and install a new fastener in the hole.

   Alternative Methods of Compliance

   (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. 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.

   Special Flight Permits

   (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 98-147-075(B), dated April 8, 1998.

   Issued in Renton, Washington, on June 17, 1999. Vi L. Lipski, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

   [FR Doc. 99-15929Filed6-22-99; 8:45 am]

   BILLING CODE 4910-13-U