[Federal Register Volume 62, Number 190 (Wednesday, October 1, 1997)]
[Proposed Rules]
[Pages 51388-51389]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-25977]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-NM-140-AD]


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, -320 series airplanes. This proposal would require an 
inspection to detect corrosion of the rear spars of the wings, and 
corrective actions, 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 detect and correct possible corrosion on the rear spars of 
the wings, which could result in reduced structural integrity of the 
wings.

DATES: Comments must be received by October 27, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-140-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: Gary Lium, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-1112; 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 95-NM-140-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-103, Attention: Rules 
Docket No. 95-NM-140-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 three 
reports indicating that, during routine inspections, corrosion was 
found on the rear spar lower flange of the outer wing. This condition, 
if not detected and corrected in a timely manner, could result in 
reduced structural integrity of the wing.

Explanation of Relevant Service Information

    Aerospatiale has issued Service Bulletin ATR42-57-0044, dated May 
30, 1995, and Revision 1, dated June 28, 1995, which describe 
procedures for performing a one-time detailed visual inspection to 
detect corrosion of the rear spars of the wings. The service bulletins 
also describe procedures for repair of corrosion within certain limits, 
and application of a protective compound to certain areas. The DGAC 
classified these service bulletins as mandatory and issued French 
airworthiness directive (CN) 95-127-063(B), dated August 2, 1995, in 
order to assure the continued airworthiness of these airplanes in 
France.

FAA's Conclusions

    These airplane models are manufactured in France and are 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, the 
proposed AD would require accomplishment of the actions specified in 
the service bulletins described previously.

[[Page 51389]]

Differences Between the Proposal and the Related Service Bulletins

    The proposed rule would differ from Aerospatiale Service Bulletins 
ATR42-57-0044, dated May 30, 1995, and Revision 1, dated June 28, 1995, 
in that it would not permit further flight following removal of 
corrosion. The FAA has determined that, due to the safety implications 
and consequences associated with the removal of small amounts of metal 
from the load-carrying structural elements of the rear spars of the 
wings (a normal and unavoidable result of the process of removing 
corrosion), the subject rear spars that are found to be corroded must 
be repaired prior to further flight. The repair would be required to be 
accomplished in accordance with a method approved by the FAA.

Cost Impact

    The FAA estimates that 16 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 24 work 
hours per airplane to accomplish the proposed actions, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
total cost impact of the proposed AD on U.S. operators is estimated to 
be $23,040, or $1,440 per airplane.
    The total 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 95-NM-140-AD.

    Applicability: Model ATR42-200, -300, and -320 series airplanes, 
as listed in Aerospatiale Service Bulletin ATR42-57-0044, dated May 
30, 1995, or Revision 1, dated June 28, 1995; 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 use the authority 
provided in paragraph (b) of this AD to request approval from the 
FAA. This approval may address either no action, if the current 
configuration eliminates the unsafe condition; or different actions 
necessary to address the unsafe condition described in this AD. Such 
a request should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD.

    Compliance: Required as indicated, unless accomplished 
previously.
    To detect and correct corrosion on the rear spars of the wings, 
which could result in reduced structural integrity of the wing, 
accomplish the following:
    (a) Within 60 days after the effective date of this AD, perform 
a one-time detailed visual inspection to detect corrosion of the 
rear spars of the wings, in accordance with Aerospatiale Service 
Bulletin ATR42-57-0044, dated May 30, 1995, or Revision 1, dated 
June 28, 1995.
    (1) If no corrosion is detected, prior to further flight, apply 
a protective compound to the areas specified in the service 
bulletin, in accordance with the service bulletin.
    (2) If any corrosion is detected, prior to further flight, 
repair it in a method approved by the Manager, Standardization 
Branch, ANM-113, FAA, Transport Airplane Directorate.
    (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, Standardization Branch, ANM-113, 
FAA, Transport Airplane Directorate. Operators shall submit their 
requests through an appropriate FAA Principal Maintenance Inspector, 
who may add comments and then send it to the Manager, 
Standardization Branch, ANM-113.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    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 (CN) 95-127-063(B), dated August 2, 1995.

    Issued in Renton, Washington, on September 25, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-25977 Filed 9-30-97; 8:45 am]
BILLING CODE 4910-13-U