[Federal Register Volume 64, Number 120 (Wednesday, June 23, 1999)]
[Proposed Rules]
[Pages 33441-33443]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-15929]


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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).

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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:

[[Page 33442]]

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-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

[[Page 33443]]

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. 99-15929 Filed 6-22-99; 8:45 am]
BILLING CODE 4910-13-U