[Federal Register Volume 59, Number 139 (Thursday, July 21, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-17763]
[[Page Unknown]]
[Federal Register: July 21, 1994]
VOL. 59, NO. 139
Thursday, July 21, 1994
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 94-NM-84-AD]
Airworthiness Directives; Aerospatiale Model ATR42-300 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
series airplanes. This proposal would require an inspection to
determine the model and orientation of certain flight control rods, and
replacement with modified rods, if necessary. This proposal is prompted
by reports of corrosion found on the pitch trim and rudder trim rods.
The actions specified by the proposed AD are intended to prevent
problems associated with corrosion of the flight control rods, which
could compromise the required strength of these items.
DATES: Comments must be received by September 19, 1994.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 94-NM-84-AD, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056. Comments may be inspected at this location
between 9 a.m. and 3 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: Sam Grober, Aerospace Engineer,
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206)
227-1187; fax (206) 227-1100.
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 94-NM-84-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. 94-NM-84-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, recently notified the FAA that an
unsafe condition may exist on certain Aerospatiale Model ATR42 series
airplanes. The DGAC advises that corrosion has been detected on the
pitch and rudder trim fail-safe rods installed on these airplanes.
(This corrosion was found during inspections that were conducted as a
part of a sampling program carried out by the manufacturer.) In some
cases, corrosion apparently was caused by water accumulating in the
lower part of the rods and freezing; the rods in these cases were
installed with their open end oriented upwards (rather than downwards),
which allowed water to accumulate between the internal and external
tubes of the rod. Some cracking was associated with corrosion in these
cases. Such corrosion could compromise the required strength of these
flight control rods.
Aerospatiale has issued the following service bulletins which
address the identified problems:
a. Service Bulletin ATR42-27-0071, dated February 23, 1994,
describes procedures for inspecting the elevator trim rod and rudder
trim rod to determine the orientation of the open rod end. It also
describes procedures for replacing rods having open ends that are
oriented upwards with rods on which the open end of the rod is oriented
downwards. A downward-oriented rod end will prevent the accumulation of
water between the internal and external tubes of the rod. The DGAC
classified the material contained in this service bulletin as mandatory
and issued French Airworthiness Directive 94-003-053(B), dated January
5, 1994, in order to assure the continued airworthiness of these
airplanes in France.
b. Service Bulletin ATR42-27-0048, Revision 2, dated May 16, 1991,
describes procedures for reversing the installation of the ends of the
elevator tab and rudder tab control rods so that the open end of the
rod is oriented downwards. The DGAC has classified this service
bulletin as ``recommended.''
c. Service Bulletin ATR42-27-0049, Revision 2, dated May 16, 1991,
describes procedures for replacing the elevator tab and rudder tab
control rods with new rods that have been modified by the addition of a
drain hole in the non-open end of the rod and the application of a
protective treatment. The DGAC has classified this service bulletin as
``recommended.''
This airplane model is manufactured in France and is 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.
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 an inspection to
determine the orientation of the end of rudder trim and elevator trim
fail-safe rods, and replacement of those rods having downwards-oriented
ends. The actions would be required to be accomplished in accordance
with the service bulletins described previously.
Airplanes on which Aerospatiale Modification 02723 has been
installed are not affected by the requirements of this proposed AD. The
subject flight control rods on those airplanes have been modified prior
to airplane delivery.
The FAA estimates that 128 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 4 work
hour per airplane to accomplish the proposed inspection action, and
that the average labor rate is $55 per work hour. Based on these
figures, the total cost impact of the proposed AD on U.S. operators is
estimated to be $28,160, or $220 per airplane. This total cost impact
figure 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.
Should replacement of any of the flight control rods be necessary,
the number of work hours and the cost of required parts would vary
according to the type of replacement accomplished. In a ``worst case
scenario'' (both subject rods needing replacement), the cost of parts
would be approximately $6,000 per airplane. Labor necessary to
accomplish replacement of a rod(s) would vary from 54 work hours to 87
work hours, at an average labor rate of $55 per work hour.
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. App. 1354(a), 1421 and 1423; 49 U.S.C.
106(g); and 14 CFR 11.89.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
Aerospatiale: Docket 94-NM-84-AD.
Applicability: Model ATR42-300 and -320 series airplanes on
which Aerospatiale Modification 02723 has not been installed,
certificated in any category.
Compliance: Required as indicated, unless accomplished
previously.
To prevent problems associated with corrosion of the flight
control rods, which could compromise the required strength of these
items, accomplish the following:
(a) Within 18 months after the effective date of this AD,
visually inspect the elevator trim and rudder trim fail-safe rods to
determine the model and the orientation of the open end of the rod,
in accordance with Aerospatiale Service Bulletin ATR42-27-0071,
dated February 23, 1994.
(1) If a SARMA-type rod is installed at either of these
locations, prior to further flight, replace that rod with a modified
rod, in accordance with Aerospatiale Service Bulletin ATR42-27-0049,
Revision 2, dated May 16, 1991.
(2) If a TAC-type rod is installed at either of these locations,
and if the open end of the rod is oriented in any direction other
than downwards, prior to further flight, accomplish the reverse
installation procedures specified in Aerospatiale Service Bulletin
ATR42-27-0048, Revision 2, dated May 16, 1994.
(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.
(c) 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.
Issued in Renton, Washington, on July 15, 1994.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 94-17763 Filed 7-20-94; 8:45 am]
BILLING CODE 4910-13-U
