[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]
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Rules and Regulations
Federal Register
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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
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The Code of Federal Regulations is sold by the Superintendent of Documents.
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Federal Register / Vol. 62, No. 135 / Tuesday, July 15, 1997 / Rules
and Regulations
[[Page 37707]]
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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.
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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:
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Service bulletin referenced and Revision level shown on
date Page number page Date shown on page
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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.
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[[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
