[Federal Register Volume 63, Number 194 (Wednesday, October 7, 1998)]
[Rules and Regulations]
[Pages 53798-53800]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-26660]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-266-AD; Amendment 39-10818; AD 98-21-10]
RIN 2120-AA64


Airworthiness Directives; Aerospatiale Model ATR42-200 and -300 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Aerospatiale Model ATR42-200 and -300 series 
airplanes, that requires repetitive inspections for cracking of the 
lower skin panels of the outer wings; and repair, if necessary. This 
amendment also requires modification of the panels and a follow-on 
inspection to detect cracking of the modified areas, which constitute 
terminating action for the repetitive inspections. This amendment is 
prompted by the issuance of mandatory continuing airworthiness 
information by a foreign civil airworthiness authority. The actions 
specified by this 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: Effective November 12, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of November 12, 1998.

ADDRESSES: The service information referenced in this AD may be 
obtained from Aerospatiale, 316 Route de Bayonne, 31060 Toulouse, Cedex 
03, France. This information may be examined at the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, Rules Docket, 
1601 Lind Avenue, SW., Renton, Washington; or at the Office of the 
Federal Register, 800 North Capitol Street, NW., suite 700, Washington, 
DC.

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: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Aerospatiale Model ATR42-
200 and -300 series airplanes was published in the Federal Register on 
February 10, 1998 (63 FR 6683). That action proposed to require 
repetitive inspections for cracking of the lower skin panels of the 
outer wings; repair, if necessary; 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.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Support for the Proposal

    One commenter supports the proposed AD.

Request to Revise Applicability of the Proposal

    One commenter, the manufacturer, requests that the applicability of 
the proposed AD be revised to exclude airplanes on which ATR 
Modification 2805 has been accomplished. The commenter states that this 
modification was developed to address cracking that was detected during 
full-scale fatigue testing and has been accomplished on certain 
airplanes during production. The commenter also points out that French 
airworthiness directive 93-190-051(B), which was referenced in the 
proposal as the parallel French airworthiness directive, excludes 
airplanes on which ATR Modification 2805 has been accomplished.
    The FAA concurs with the commenter's request and has revised the 
applicability of the final rule to exclude airplanes on which ATR 
Modification 2805 has been accomplished.

Request To Revise Compliance Time

    This same commenter expresses concern regarding the planned 
compliance time for the actions specified in the proposed AD. The 
commenter states that, for certain airplanes, the proposal allows a 
delay of

[[Page 53799]]

500 landings before the actions must be accomplished, and that such a 
delay could allow those airplanes to exceed the thresholds specified in 
the French airworthiness directive. The commenter points out that those 
thresholds were defined according to a specific fatigue and damage 
tolerance analysis.
    Although no specific request to change the final rule is made by 
the commenter in this regard, the FAA infers that the commenter is 
requesting that the FAA reduce or eliminate the grace period in the 
final rule. The FAA does not concur with the commenter's request and 
notes that the compliance times, as stated in the proposal, do indeed 
follow those specified by the French airworthiness directive. 
Specifically, the French airworthiness directive calls for 
accomplishment of the initial inspection prior to the accumulation of 
26,000 total flights. Paragraph (a) of this final rule specifies that 
the initial inspection is to be accomplished prior to the accumulation 
of 25,500 total landings, or within 500 landings after the effective 
date of the AD, whichever occurs later.
    Similarly, the French airworthiness directive calls for 
accomplishment of the modification prior to the accumulation of 33,000 
total flights. Paragraph (b) of the final rule specifies that the 
modification is to be accomplished prior to the accumulation of 32,500 
total landings, or within 500 landings after the effective date of this 
AD, whichever occurs later. The FAA considers that the grace period of 
500 landings allows operators whose airplanes have exceeded the 
thresholds of 25,500 and 32,500 total landings adequate time to 
accomplish the inspections and modification, respectively, while 
adhering as closely as possible to the compliance times specified in 
the French airworthiness directive. No change to the final rule is 
necessary in this regard.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the change described 
previously. The FAA has determined that this change will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    The FAA estimates that 101 airplanes of U.S. registry will be 
affected by this AD.
    It will take approximately 4 work hours per airplane to accomplish 
the required ultrasonic inspection, at an average labor rate of $60 per 
work hour. Based on these figures, the cost impact of the ultrasonic 
inspection required by this AD on U.S. operators is estimated to be 
$24,240, or $240 per airplane, per inspection cycle.
    It will take approximately 280 work hours per airplane to 
accomplish the required modification, at an average labor rate of $60 
per work hour. The cost of required parts will range from $1,576 to 
$6,373 per airplane. Based on these figures, the cost impact of the 
modification required 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 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 adopted herein will 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 final rule does not have sufficient federalism 
implications to warrant the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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:

98-21-10  Aerospatiale: Amendment 39-10818. Docket 97-NM-266-AD.

    Applicability: Model ATR42-200 and -300 series airplanes on 
which Avions de Transport Regional Service Bulletins ATR42-57-0040, 
dated April 21, 1994, and ATR42-57-0038, Revision 2, dated December 
18, 1997, have not been accomplished; except for those airplanes on 
which ATR Modification 2805 has 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 Avions de 
Transport Regional 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 Avions de 
Transport Regional Service Bulletin ATR42-57-0038, Revision 2, dated 
December 18, 1997. If any crack is detected, prior to further 
flight,

[[Page 53800]]

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.
    (e) Except for the repairs provided for in paragraphs (a) and 
(b) of this AD, the actions shall be done in accordance with the 
following Avions de Transport Regional Service Bulletins, which 
contain the specified list of effective pages:

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Service bulletin referenced and    Page number shown on     Revision level shown on
              date                         page                      page                 Date shown on page
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ATR42-57-0040, April 21, 1994..  1-15...................  Original..................  April 21, 1994.
ATR42-57-0038, Revision 2,       1-11, 21, 31-36 53, 55.  2.........................  December 18, 1997.
 December 18, 1997.
                                 18, 22, 27, 28, 37, 38,  1.........................  December 20, 1995.
                                  51, 52, 56, 57.
                                 12-17, 19, 20, 23-26,    Original..................  December 19, 1994.
                                  29, 30, 39-50, 54.
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This incorporation by reference was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51. Copies may be obtained from Aerospatiale, 316 Route de Bayonne, 
31060 Toulouse, Cedex 03, France. Copies may be inspected at the 
FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.

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

    (f) This amendment becomes effective on November 12, 1998.

    Issued in Renton, Washington, on September 29, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-26660 Filed 10-6-98; 8:45 am]
BILLING CODE 4910-13-U