[Federal Register Volume 63, Number 33 (Thursday, February 19, 1998)]
[Proposed Rules]
[Pages 8373-8374]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 98-4110]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-303-AD]
RIN 2120-AA64


Airworthiness Directives; Aerospatiale Model ATR42-200, -300, and 
-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-
200, -300, and -320 series airplanes. This proposal would require an 
inspection to detect fatigue cracking of the windshield frame 
structure, and modification of the windshield frame structure. 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 
reduced structural integrity of the airplane resulting from fatigue 
cracking of the windshield frame structure.

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

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 97-NM-303-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 97-NM-303-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-303-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 ATR42-200, -300, and 
-320 series airplanes. The DGAC advises that it has received reports of 
fatigue cracking on in-service airplanes. The cracking began at the 
lower end of the center post of the windshield frame structure. 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 Bulletins ATR42-53-0093, Revision 
1, and ATR42-53-0094, Revision 2, both dated February 19, 1996. These 
service bulletins describe procedures for an inspection to detect 
fatigue cracking of the windshield frame structure, and modification of 
the windshield frame structure. Accomplishment of the modification 
involves installation of new supports and nut plates. Accomplishment of 
these actions specified in the service bulletins is intended to 
adequately address the identified unsafe condition. The DGAC classified 
these service bulletins as mandatory and issued French airworthiness 
directive 95-126-061(B), dated June 21, 1995, 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 bulletins described previously, 
except as discussed below.

Differences Between the Proposed Rule and the Service Information

    Whereas Aerospatiale Service Bulletin ATR42-53-0094 requires that 
operators contact the manufacturer for repair instructions for any 
crack exceeding a specified length, this proposed AD would require that 
repair of such cracking be accomplished in accordance with a method 
approved by the FAA.

Cost Impact

    The FAA estimates that 106 airplanes of U.S. registry would be 
affected by this proposed AD.
    It would take approximately 19 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 $120,840, or 
$1,140 per airplane.
    It would take approximately 191 work hours per airplane to 
accomplish the proposed modification specified in

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Aerospatiale Service Bulletin ATR42-53-0093, Revision 1, dated February 
19, 1996, at an average labor rate of $60 per work hour. Required parts 
would be provided by the manufacturer at no cost to the operators. 
Based on these figures, the cost impact of this proposed modification 
on U.S. operators is estimated to be $11,460 per airplane.
    It would take approximately 281 work hours per airplane to 
accomplish the proposed modification specified in Aerospatiale Service 
Bulletin ATR42-53-0094, Revision 2, dated February 19, 1996, at an 
average labor rate of $60 per work hour. Required parts would be 
provided by the manufacturer at no cost to the operators. Based on 
these figures, the cost impact of this proposed modification on U.S. 
operators is estimated to be $16,860 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 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-303-AD.

    Applicability: Model ATR42-200, -300, and -320 series airplanes, 
on which Aerospatiale Modification 01392 has not been installed, 
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 (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 reduced structural integrity of the airplane 
resulting from fatigue cracking of the windshield frame structure, 
accomplish the following:
    (a) Prior to the accumulation of 24,000 total flight cycles, or 
within 60 days after the effective date of this AD, whichever occurs 
later: Inspect to detect cracking of the windshield frame structure 
in accordance with Operation Description (B--Inspection) of the 
Accomplishment Instructions of Aerospatiale Service Bulletin ATR42-
53-0093, Revision 1, or ATR42-53-0094, Revision 2, both dated 
February 19, 1996.
    (1) If the inspection reveals no crack, or reveals cracking that 
does not exceed the specifications listed in Figure 6, Sheet 1, of 
Service Bulletin ATR42-53-0093, Revision 1, dated February 19, 1996: 
Prior to further flight, modify the windshield frame structure in 
accordance with either service bulletin.
    (2) If the inspection reveals any crack that exceeds the 
specifications in Figure 6, Sheet 1, of Service Bulletin ATR42-53-
0093, Revision 1, dated February 19, 1996, but does not exceed the 
cut-out areas specified in Figure 7, Sheet 1, of Service Bulletin 
ATR42-53-0094, Revision 2, dated February 19, 1996: Prior to further 
flight, modify the windshield frame structure in accordance with 
Service Bulletin 42-53-0094, Revision 2, dated February 19, 1996.
    (3) If the inspection reveals any crack that exceeds the cut-out 
areas specified in Figure 7, Sheet 1, of Service Bulletin ATR42-53-
0094, Revision 2, dated February 19, 1996: Prior to further flight, 
modify the windshield frame structure in accordance with a method 
approved by the Manager, International Branch, ANM-116, FAA, 
Transport Airplane Directorate.

    Note 2: Accomplishment of the modifications specified in ATR 
Service Bulletin ATR42-53-0093, Revision 1, or ATR42-53-0094, 
Revision 2, both dated February 19, 1996, is not equivalent to 
accomplishment of Aerospatiale Modification 01392. Therefore the 
ATR42 Time Limits Document inspection items with ``PRE MOD 1392'' 
effectivity are still applicable for airplanes modified by either of 
the previously described service bulletins.

    (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 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.

    (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 4: The subject of this AD is addressed in French 
airworthiness directive 95-126-061(B), dated June 21, 1995.

    Issued in Renton, Washington, on February 11, 1998.
Gilbert L. Thompson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-4110 Filed 2-18-98; 8:45 am]
BILLING CODE 4910-13-U