[Federal Register Volume 63, Number 113 (Friday, June 12, 1998)]
[Proposed Rules]
[Pages 32152-32154]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-15676]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-146-AD]
RIN 2120-AA64
Airworthiness Directives; Aerospatiale Model ATR42 and ATR72
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
and ATR72 series airplanes. This proposal would require one-time
inspections to verify the correct shape of the stiffeners for the upper
engine cowl and to detect wear of the aft upper fittings of the rear
engine mounts, 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 prevent wear (scratches or grooving) of
the aft upper fittings of the rear engine mount, and consequent reduced
structural integrity of the engine mounts.
DATES: Comments must be received by July 13, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-146-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
[[Page 32153]]
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 98-NM-146-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. 98-NM-146-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 and ATR72
series airplanes. The DGAC advises that it has received reports
indicating that wear (scratches or grooving) was found between the aft
upper fittings of the rear engine mount and the stiffener of the upper
engine cowl. Investigation revealed that the stiffener of the upper
engine cowl, which protects the aft upper fittings, was not shaped
properly during manufacturing, which caused interference between the
engine mount and the stiffener. Installation of these misshapen
stiffeners could result in wear of the aft upper fittings of the rear
engine mount. Such wear, if not corrected, could result in reduced
structural integrity of the engine mounts.
Explanation of Relevant Service Information
The manufacturer has issued Avions de Transport Regional Service
Bulletins ATR42-54-0019 (for Model ATR42 series airplanes) and ATR72-
54-1011 (for Model ATR72 series airplanes), both dated March 9, 1998.
These service bulletins describe procedures for a one-time visual
inspection to verify the correct shape of the stiffeners for the upper
left and right engine cowls; and a one-time detailed visual inspection
to detect wear (scratches or grooving) of the aft upper fittings of the
left- and right-hand rear engine mounts; and corrective actions, if
necessary. The corrective actions include modification of the stiffener
or replacement with a new stiffener, and repair of the aft upper
fittings. Accomplishment of the 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 directives 98-069-073(B) (for Model ATR42
series airplanes), dated February 11, 1998; and 98-071-035(B) (for
Model ATR72 series airplanes), dated February 11, 1998, as revised by
Erratum 98-071-35(B), dated February 25, 1998, 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 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 Proposed Rule and Service Bulletin
Operators should note that, although the service bulletins specify
that the manufacturer may be contacted for disposition of certain wear
conditions, this proposal would require the repair of those conditions
to be accomplished in accordance with a method approved by the FAA.
Cost Impact
The FAA estimates that 152 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 15 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
cost impact of the proposed AD on U.S. operators is estimated to be
$136,800, or $900 per airplane.
The 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 98-NM-146-AD.
Applicability: Model ATR42 and Model ATR72 series airplanes, as
listed in Avions
[[Page 32154]]
de Transport Regional Service Bulletins ATR42-54-0019 (for Model
ATR42 series airplanes) and ATR72-54-1011 (for Model ATR72 series
airplanes), both dated March 9, 1998; 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 (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 wear (scratches or grooving) of the aft upper
fittings of the rear engine mount, and consequent reduced structural
integrity of the engine mounts, accomplish the following:
(a) Within 10 months after the effective date of this AD,
perform a one-time visual inspection of the stiffeners for the upper
left and right engine cowls to ensure the stiffeners have the
correct lower edge profile, in accordance with the Accomplishment
Instructions of Avions de Transport Regional Service Bulletin ATR42-
54-0019 or ATR72-54-1011, both dated March 9, 1998, as applicable.
(1) If the lower edge profile of the stiffener meets the
specifications of the applicable service bulletin, no further action
is required by this paragraph.
(2) If the lower edge profile of the stiffener does not meet the
specifications of the applicable service bulletin, prior to further
flight, modify or replace the stiffener with a new stiffener in
accordance with the applicable service bulletin.
(b) Within 10 months after the effective date of this AD,
perform a one-time detailed visual inspection for wear (scratches or
grooving) of the aft upper fittings of the left-and right-hand rear
engine mounts, in accordance with Avions de Transport Regional
Service Bulletin ATR42-54-0019 (for Model ATR42 series airplanes) or
ATR72-54-1011 (for Model ATR72 series airplanes), both dated March
9, 1998, as applicable.
(1) If no wear is detected, no further action is required by
this paragraph.
(2) If any wear is detected that cannot be removed with a Type I
or II blend-out as described in the applicable service bulletin,
prior to further flight, repair in accordance with a method approved
by the Manager, International Branch, ANM-116, FAA, Transport
Airplane Directorate.
(3) If any wear other than that specified in paragraph (b)(2) of
this AD is detected, prior to further flight, repair in accordance
with the Accomplishment Instructions of the applicable service
bulletin.
(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, 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, 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.
Note 3: The subject of this AD is addressed in French
airworthiness directives, 8-069-073(B) (for Model ATR42 series
airplanes), dated February 11, 1998, and 98-071-035(B) (for Model
ATR72 series airplanes), dated February 11, 1998, as revised by
Erratum 98-071-35(B), dated February 25, 1998.
Issued in Renton, Washington, on June 5, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-15676 Filed 6-11-98; 8:45 am]
BILLING CODE 4910-13-U
