[Federal Register Volume 63, Number 27 (Tuesday, February 10, 1998)]
[Proposed Rules]
[Pages 6683-6685]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-3233]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-266-AD]
RIN 2120-AA64


Airworthiness Directives; Aerospatiale Model ATR42-200 and -300 
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-
200 and -300 series airplanes. This proposal would require repetitive 
inspections for cracking of the lower skin panels of the outer wings; 
and repair, if necessary. This proposal also would require modification 
of the panels and a follow-on inspection to detect cracking of the 
modified areas, which would constitute terminating action for the 
repetitive inspections. This proposal is prompted by the 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 lower skin panels of the 
outer wings, and consequent reduced structural integrity of the 
airplane.

DATES: Comments must be received by March 12, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 97-NM-266-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.


[[Page 6684]]


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 97-NM-266-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. 97-NM-266-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 ATR 42-200 and -300 
series airplanes. The DGAC advises that full-scale fatigue testing by 
the manufacturer has revealed damage of the lower skin panels of the 
outer wings at several rib junction attachments. 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

    Aerospatiale has issued Service Bulletin ATR42-57-0040, dated April 
21, 1994, which describes procedures for repetitive ultrasonic 
inspections for cracking of the lower skin panels of the outer wings at 
rib 14. Aerospatiale also has issued Service Bulletin ATR42-57-0038, 
Revision 2, dated December 18, 1997, which describes procedures for 
modification of the lower skin panels of the outer wings at ribs 13 and 
14, and a follow-on high frequency eddy current (HFEC) inspection to 
detect cracking of the modified area. The modification involves 
expansion of some holes located between ribs 13 and 18 (left and right 
sides) to increase resistance of corresponding areas. Accomplishment of 
the modification and the HFEC inspection would eliminate the need for 
the repetitive ultrasonic inspections. The DGAC classified these 
service bulletins as mandatory. Additionally, the DGAC previously 
issued a French airworthiness directive [93-190-051(B), dated October 
27, 1993] 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 described below.

Differences Between the Proposed AD and the Related Service 
Information

    The proposed AD would differ from Aerospatiale Service Bulletins 
ATR42-57-0038 and ATR42-57-0040, described previously, in that the 
service bulletins recommend that any crack detected during an 
inspection be repaired in accordance with instructions requested from 
the manufacturer. However, the FAA has determined that the repair of 
any crack would be required to be accomplished in accordance with a 
method approved by the FAA.

Cost Impact

    The FAA estimates that 101 airplanes of U.S. registry would be 
affected by this proposed AD.
    It would take approximately 4 work hours per airplane to accomplish 
the proposed ultrasonic inspection, at an average labor rate of $60 per 
work hour. Based on these figures, the cost impact of the ultrasonic 
inspection proposed by this AD on U.S. operators is estimated to be 
$24,240, or $240 per airplane, per inspection cycle.
    It would take approximately 280 work hours per airplane to 
accomplish the proposed modification, at an average labor rate of $60 
per work hour. The cost of required parts could range from $1,576 to 
$6,373 per airplane. Based on these figures, the cost impact of the 
modification proposed by this AD on U.S. operators is estimated to be 
between $1,855,976 ($18,376 per airplane) and $2,340,473 ($23,173 per 
airplane).
    The cost impact figures discussed above are 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

[[Page 6685]]

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 97-NM-266-AD.

    Applicability: Model ATR42-200 and -300 series airplanes on 
which Aerospatiale Service Bulletins ATR42-57-0040, dated April 21, 
1994, and ATR42-57-0038, Revision 2, dated December 18, 1997, have 
not been accomplished; certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise 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 prevent fatigue cracking of the lower skin panels of the 
outer wings between ribs 13 and 18, and consequent reduced 
structural integrity of the airplane, accomplish the following:
    (a) Prior to the accumulation of 25,500 total landings, or 
within 500 landings after the effective date of this AD, whichever 
occurs later, perform an ultrasonic inspection for cracking of the 
lower skin panels of the outer wings, in accordance with 
Aerospatiale Service Bulletin ATR42-57-0040, dated April 21, 1994. 
If any crack is detected, prior to further flight, repair it in 
accordance with a method approved by the Manager, International 
Branch, ANM-116, FAA, Transport Airplane Directorate. Thereafter, 
repeat the inspection at intervals not to exceed 9,000 landings.
    (b) Prior to the accumulation of 32,500 total landings, or 
within 500 landings after the effective date of this AD, whichever 
occurs later, modify the lower skin panels of the outer wings, and 
perform a follow-on high frequency eddy current (HFEC) inspection 
for cracking of the modified areas, in accordance with Aerospatiale 
Service Bulletin ATR42-57-0038, Revision 2, dated December 18, 1997. 
If any crack is detected, prior to further flight, repair it in 
accordance with a method approved by the Manager, International 
Branch, ANM-116. Accomplishment of the modification and follow-on 
HFEC inspection constitutes terminating action for the repetitive 
ultrasonic inspection requirements of paragraph (a) of this AD.
    (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. 
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.

    Note 3: The subject of this AD is addressed in French 
airworthiness directive 93-190-051(B), dated October 27, 1993.

    Issued in Renton, Washington, on February 3, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-3233 Filed 2-9-98; 8:45 am]
BILLING CODE 4910-13-U