[Federal Register Volume 63, Number 107 (Thursday, June 4, 1998)]
[Proposed Rules]
[Pages 30425-30427]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-14791]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-118-AD]
RIN 2120-AA64


Airworthiness Directives; Aerospatiale Model ATR72 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 ATR72 
series airplanes. This proposal would require a one-time inspection of 
certain anchor nuts located on the upper surface of the wings to detect 
damage, and replacement of the anchor nuts with new or serviceable 
nuts, if necessary. 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 failure of anchor nuts on the upper surface of the wings, which 
could result in reduced structural integrity of the airplane.

DATES: Comments must be received by July 6, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-118-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:

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-118-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-118-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 ATR72 series 
airplanes. The DGAC advises that certain anchor nuts located on the 
upper skin panel of the wings were found to have failed. This failure 
has been attributed to quality defects during manufacture of a batch of 
the anchor nuts, which may cause the nuts to rupture after the 
tightening of corresponding screws. Such failures, if not corrected, 
could result in reduced structural integrity of the airplane.

Explanation of Relevant Service Information

    The manufacturer has issued Avions de Transport Regional Service 
Bulletin ATR72-57-1019, dated July 7, 1997, which describes procedures 
for a one-time inspection of certain anchor nuts located on the upper 
surface of the

[[Page 30426]]

wings to detect damage, and replacement of any damaged nuts with new or 
serviceable nuts. Accomplishment of the action 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 97-264-034(B), dated September 
24, 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 
Sec. 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 would be acceptable for 
compliance with this proposed AD.

Cost Impact

    The FAA estimates that 39 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 inspection, at an average 
labor rate of $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 $18,720, 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 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-118-AD.

    Applicability: Model ATR72-102, -201, -202, and -212 series 
airplanes, as listed in Avions de Transport Regional Service 
Bulletin ATR72-57-1019, dated July 7, 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 (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 failure of anchor nuts on the upper surface of the 
wings, which could result in reduced structural integrity of the 
airplane, accomplish the following:
    (a) Within 6 months after the effective date of this AD, inspect 
the anchor nuts having part number (P/N) NAS1473A5 located on the 
upper surface of the wing to detect damage, in accordance with 
Avions de Transport Regional Service Bulletin ATR72-57-1019, dated 
July 7, 1997.
    (1) If no damage is detected, no further action is required by 
this AD.
    (2) If any damage is detected, and the damage is within the 
allowable limits specified in the Accomplishment Instructions of the 
service bulletin, prior to the accumulation of an additional 4,000 
flight cycles following the inspection, replace the damaged nut 
having P/N NAS1473A5 with a new or serviceable nut, in accordance 
with the Accomplishment Instructions of the service bulletin.
    (3) If any damage is detected, and the damage is outside the 
allowable limits specified in the Accomplishment Instructions of the 
service bulletin, 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).
    (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

[[Page 30427]]

compliance with this AD, if any, may be obtained from the 
International Branch, ANM-116.

    (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 97-264-034(B), dated September 24, 1997.

    Issued in Renton, Washington, on May 28, 1998.
John J. Hickey,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-14791 Filed 6-3-98; 8:45 am]
BILLING CODE 4910-13-U