[Federal Register Volume 62, Number 135 (Tuesday, July 15, 1997)]
[Rules and Regulations]
[Pages 37707-37710]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-18202]



 ========================================================================
 Rules and Regulations
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains regulatory documents 
 having general applicability and legal effect, most of which are keyed 
 to and codified in the Code of Federal Regulations, which is published 
 under 50 titles pursuant to 44 U.S.C. 1510.
 
 The Code of Federal Regulations is sold by the Superintendent of Documents. 
 Prices of new books are listed in the first FEDERAL REGISTER issue of each 
 week.
 
 ========================================================================
 

  Federal Register / Vol. 62, No. 135 / Tuesday, July 15, 1997 / Rules 
and Regulations  

[[Page 37707]]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-NM-84-AD; Amendment 39-10075, AD 97-15-02]
RIN 2120-AA64


Airworthiness Directives; Aerospatiale Model ATR42 and ATR72 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to all Aerospatiale Model ATR42 and ATR72 series airplanes, 
that requires replacement of the attachment clips on the wing-to-
fuselage fairings and on the upper cowlings of the engine nacelle with 
new improved attachment clips, and adding cup washers on the wing-to-
fuselage fairing panels on certain airplanes. This amendment also 
requires a one-time inspection of certain fairings and the upper 
cowlings of the engine nacelle to detect discrepancies of the 
attachment hardware and the fairing panel; and replacement of the panel 
with a serviceable panel, if necessary. This amendment is prompted by a 
report of deformed attachment clips found on the wing-to-fuselage 
fairings and on the upper cowlings of the engine nacelle, and by a 
report of severe inflight vibration due to a loose wing/body fairing 
panel. The actions specified by this AD are intended to prevent 
deformation of the attachment clips due to insufficient strength of the 
attachment clip material. Such deformation of the attachment clips 
could result in the fairings and cowlings detaching from the airplane 
during flight and subsequently causing damage to the empennage or 
posing a hazard to persons or property on the ground.

DATES: Effective July 30, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 30, 1997.
    Comments for inclusion in the rules docket must be received on or 
before September 15, 1997.

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: 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) 227-1320.

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 all Aerospatiale Model ATR42 and 
ATR72 series airplanes was published in the Federal Register on January 
11, 1996 (61 FR 1015). That action proposed to require replacement of 
the existing attachment clips on the wing-to-fuselage fairings and on 
the engine nacelle upper cowlings with new and improved attachment 
clips for certain airplanes. That action also proposed to require 
adding cup washers under the fastener countersunk holes, as well as 
replacement of the existing attachment clips on the wing-to-fuselage 
fairings and on the engine nacelle upper cowlings with new and improved 
attachment clips for certain other airplanes.
    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 rule.

Request To Revise Work Hour Estimate

    One commenter requests that the number of work hours required to 
accomplish the proposed replacement of the attachment clips and 
addition of cup washers be increased from 20 to 80. The commenter 
states that there is an economic loss associated with the longer down 
time required to accomplish the proposed actions; however, the 
commenter does not provide specifics nor offer a proposed solution.
    The FAA agrees that 80 work hours represents a more accurate 
representation of the number of work hours necessary to accomplish the 
required actions. The FAA has revised the cost impact information, 
below, to reflect this revised work hour estimate.

Actions Since Issuance of the Proposal

    Since the issuance of the proposal, the FAA has received a report 
indicating that severe inflight vibration occurred in the rudder and 
aileron controls on a Model ATR42 series airplane. This vibration was 
caused by a loose wing/body fairing panel. During this incident, the 
flightcrew experienced difficulty controlling the airplane. During 
descent, the flightcrew could not maintain altitude, and the airplane 
descended at 1,500 feet per minute until the flaps were lowered and 
control of the airplane was regained. The flightcrew diverted the 
airplane and landed it safely. Investigation revealed that three other 
recent instances of loose fairing panels had occurred previously on the 
same airplane. In each case, resultant vibration occurred during 
descent of the airplane; the vibration occurred at relatively high 
airspeed.
    During subsequent replacement of the affected fairing panel, close 
inspection revealed cracking at the upper edge (towards the center) of 
the upper forward wing access panel 291BL. The crack extended from the 
upper leading edge rearward for approximately eight inches. The 
operator of the affected airplane stated that the crack was not visible 
with the fairing panel installed on the airplane because the panel is 
composite, and normal flexing of the panel with the airplane on the 
ground made the crack invisible. The operator suspected that the panel 
may have been damaged during a heavy maintenance check, or that the 
panel may have failed due to its age. The FAA believes that

[[Page 37708]]

flight operations with improper attachment screws and clips also may 
have contributed to the development of the crack.

Explanation of Additional Requirements of This AD

    The FAA considers that the incident described above indicates the 
unsafe condition addressed in the proposal is more severe than 
understood previously. Consequently, due to the seriousness of the 
incident, the FAA finds it prudent to require actions beyond those 
specified in the proposal to ensure an acceptable level of safety 
during the time period prior to accomplishment of the actions required 
by the original proposed AD.
    Therefore, this AD adds a requirement for a one-time detailed 
visual inspection of the wing-to-fuselage fairings and the upper 
cowlings of the engine nacelle to ensure that all attachment screws, 
clips, and other attachment hardware is secure, and that the fairing 
panel contains no visible cracks, tears, delamination, or other damage. 
If any screw, clip, or other attachment hardware is loose, bent or 
otherwise not secure, this AD requires that the panel be removed and a 
detailed visual inspection be performed to detect cracks, tears, 
delamination, or other visible signs of damage. If any discrepancy is 
found, this AD requires replacement of the panel with a serviceable 
panel.
    In making this change to the original proposal, the FAA finds that, 
with respect to requiring this inspection, since a situation exists 
that requires immediate adoption of this requirement, notice and public 
procedure hereon are impracticable, and good cause exists for making 
this amendment effective in less than 30 days.

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 changes previously 
described.

Cost Impact

    The FAA estimates that 175 airplanes of U.S. registry will be 
affected by this AD.
    It will take approximately 2 work hours per airplane to accomplish 
the required detailed inspection, at an average labor rate of $60 per 
work hour. Based on these figures, the cost impact of the required 
detailed inspection on U.S. operators is estimated to be $21,000, or 
$120 per airplane.
    Should an operator be required to accomplish the required 
replacement of attachment clips and addition of cup washers, it will 
take approximately 80 work hours per airplane to accomplish, at an 
average labor rate of $60 per work hour. The manufacturer will provide 
required parts at no cost to operators. Based on these figures, the 
cost impact of these required actions on U.S. operators (approximately 
81 airplanes) is estimated to be $388,800, or $4,800 per airplane.
    Should an operator be required to accomplish the required 
replacement of attachment clips, it will take approximately 20 work 
hours per airplane to accomplish, at an average labor rate of $60 per 
work hour. The manufacturer will provide required parts at no cost to 
operators. Based on these figures, the cost impact of this required 
action on U.S. operators (approximately 94 airplanes) is estimated to 
be $112,800, or $1,200 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.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety, and the inspection and repair 
requirements of this AD were not preceded by notice and an opportunity 
for public comment, comments are invited on this portion of the rule. 
Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the rules docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 95-NM-84-AD.'' The postcard will be date stamped and 
returned to the commenter.

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.

[[Page 37709]]

Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

97-15-02  Aerospatiale: Amendment 39-10075. Docket 95-NM-84-AD.

    Applicability: All Model ATR42 series airplanes and Model ATR72 
series airplanes, 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 (e) 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 deformation of the attachment clips on the wing-to-
fuselage fairings and on the upper cowlings of the engine nacelle, 
which could result in the fairing and cowlings detaching from the 
airplane during flight and subsequently causing damage to the 
empennage or posing a hazard to persons or property on the ground, 
accomplish the following:
    (a) Within 30 days after the effective date of this AD, perform 
a one-time detailed visual inspection of the wing-to-fuselage 
fairings and the upper cowlings of the engine nacelle to ensure that 
all attachment screws, clips, and other attachment hardware is 
secure, and that the fairing panel contains no visible cracks, 
tears, delamination, or other damage.
    (b) If no discrepancy is found during the inspection required by 
paragraph (a) of this AD, within 9 months after the effective date 
of this AD, accomplish the requirements of paragraph (b)(1), (b)(2), 
(b)(3), or (b)(4) of this AD, as applicable.
    (1) For Model ATR42 series airplanes on which Modification 2601 
(Aerospatiale Service Bulletin ATR42-53-0063) has been installed: 
Replace the existing attachment clips at the wing-to-fuselage 
fairings and the engine nacelle upper cowlings with new attachment 
clips, in accordance with Aerospatiale Service Bulletin ATR42-53-
0081, Revision 1, dated December 9, 1994.
    (2) For Model ATR42 series airplanes on which Modification 2601 
(Aerospatiale Service Bulletin ATR42-53-0063) has not been 
installed: Install cup washers (NAS1169C10) on the wing-to-fuselage 
fairing panels, and replace the existing attachment clips at the 
wing-to-fuselage fairings and the engine nacelle upper cowlings with 
new attachment clips, in accordance with Aerospatiale Service 
Bulletin ATR42-53-0082, dated June 6, 1994.
    (3) For Model ATR72 series airplanes on which Modification 2601 
(Aerospatiale Service Bulletin ATR72-53-1008) has been installed: 
Replace the existing attachment clips at the wing-to-fuselage 
fairings and the engine nacelle upper cowlings with new attachment 
clips, in accordance with Aerospatiale Service Bulletin ATR72-53-
1043, Revision 1, dated December 9, 1994.
    (4) For Model ATR72 series airplanes on which Modification 2601 
(Aerospatiale Service Bulletin ATR72-53-1008) has not been 
installed: Install cup washers (NAS1169C10) on the wing-to-fuselage 
fairing panels, and replace the existing attachment clips at the 
wing-to-fuselage fairings and the engine nacelle upper cowlings with 
new attachment clips, in accordance with Aerospatiale Service 
Bulletin ATR72-53-1044, dated June 6, 1994.
    (c) If any discrepancy is found during the inspection required 
by paragraph (a) of this AD, prior to further flight, remove the 
fairing panel, and perform a detailed visual inspection to detect 
cracks, tears, delamination, or other visible signs of damage of the 
fairing panel.
    (1) If no discrepancy is found during the detailed visual 
inspection required by paragraph (c) of this AD, prior to further 
flight, reinstall the panel and accomplish the requirements of 
paragraph (b)(1), (b)(2), (b)(3), or (b)(4) of this AD, as 
applicable. No further action is required by this AD.
    (2) If any discrepancy is found during the detailed visual 
inspection required by paragraph (c) of this AD, prior to further 
flight, replace the fairing panel with a serviceable panel, and 
install the panel on the airplane in accordance with the 
requirements of paragraph (b)(1), (b)(2), (b)(3), or (b)(4) of this 
AD, as applicable. No further action is required by this AD.
    (d) As of the effective date of this AD, no person shall install 
an attachment clip, part number S5391010000000 or part number 
S5391009400000, on any airplane.
    (e) 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.

    (f) 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.
    (g) The actions shall be done in accordance with the following 
Aerospatiale service bulletins, which contains the specified 
effective pages:

----------------------------------------------------------------------------------------------------------------
 Service bulletin referenced and                           Revision level shown on                              
               date                     Page  number                page                 Date shown on page     
----------------------------------------------------------------------------------------------------------------
ATR42-53-0081, Revision 1,         1-3..................  1.......................  December 9, 1994.           
 December 9, 1994.                                                                                              
                                   4-15.................  Original................  June 6, 1994.               
ATR42-53-0082, June 6, 1994......  1-31.................  Original................  June 6, 1994.               
ATR72-53-1043, Revision 1,         1, 2.................  1.......................  December 9, 1994.           
 December 9, 1994.                                                                                              
                                   3-15.................  Original................  June 6, 1994.               
ATR72-53-1044, June 6, 1994......  1-38.................  Original................  June 6, 1994.               
----------------------------------------------------------------------------------------------------------------


[[Page 37710]]

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.
    (h) This amendment becomes effective on July 30, 1997.

    Issued in Renton, Washington, on July 7, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-18202 Filed 7-14-97; 8:45 am]
BILLING CODE 4910-13-U