[Federal Register Volume 59, Number 49 (Monday, March 14, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-5851]
[[Page Unknown]]
[Federal Register: March 14, 1994]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 93-NM-222-AD]
Airworthiness Directives; Canadair Model CL-600-2B16 (CL-601-3A)
Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of Proposed Rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to certain Canadair Model CL-600-2B16
series airplanes. This proposal would require inspection to detect
chafing of the wiring harness of the air driven generator (ADG),
modification of the wiring harness, and repair of any chafed harness.
This proposal is prompted by a report that the wiring harness on
certain airplanes were produced in a configuration that is subject to
chafing and electrical shorting. The actions specified by the proposed
AD are intended to prevent loss of ADG power to the essential bus when
the ADG is deployed during an emergency situation.
DATES: Comments must be received by May, 9, 1994.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 93-NM-222-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 Bombardier, Inc., Canadair, Aerospace Group, P.O. Box
6087, Station A, Montreal, Quebec, H3C 3G9 Canada. This information may
be examined at the FAA, Transport Airplane Directorate, 1601 Lind
Avenue, SW., Renton, Washington; or at the FAA Engine and Propeller
Directorate, New York Aircraft Certification Office, 181 South Franklin
Avenue, room 202, Valley Stream, New York.
FOR FURTHER INFORMATION CONTACT: Michele Maurer, Aerospace Engineer,
Systems and Equipment Branch, ANE-173, FAA Engine and Propeller
Directorate, New York Aircraft Certification Office, 181 South Franklin
Avenue, room 202, Valley Stream, New York 11581; telephone (516) 791-
6427; fax (516) 791-9024.
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 93-NM-222-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. 93-NM-222-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
On August 23, 1991, the FAA issued AD 91-19-01, Amendment 39-8026
(56 FR 45893, September 9, 1991), applicable to certain Canadair Model
CL-600-1A11, CL-600-2A12, and CL-600-2B16 series airplanes. That AD
requires inspection to detect chafing and modification of the wiring
harness of the air driven generator (ADG), and repair of any chafed
harness. That action was prompted by reports of chafing of the ADG
electrical output harness against the backshell of the connector on the
turbine generator assembly. Although the chafing occurred while the ADG
was in the stowed position, when the ADG was deployed, the chafed wires
shorted to the airplane structure and prevented the ADG from powering
the essential bus. This essential bus provides electrical power to the
hydraulic flight control system and to the essential flight control
equipment. In these instances, the shorting also damaged the ADG output
harness and its support structure.
This condition, if not corrected, could result in loss of emergency
power to the essential bus when the ADG is deployed.
Since issuance of AD 91-19-01, Transport Canada Aviation, which is
the airworthiness authority for Canada, notified the FAA that the same
unsafe condition addressed in AD 91-19-01 may exist on certain
additional Model CL-600-2B16 series airplanes. Transport Canada
Aviation advises that, during production of Model CL-600-2B16 series
airplanes having serial numbers 5099 through 5131, inclusive, the
wiring harnesses of the ADG's were not modified to preclude chafing
against the backshell of the connector on the turbine generator
assembly. (AD 91-19-01 is applicable only to airplanes having serial
numbers 5001 through 5098, inclusive.) Therefore, these airplanes are
also subject to losing ADG power to the essential bus when the ADG is
deployed during an emergency situation.
Canadair has issued Alert Service Bulletin A601-0370, Revision 1,
dated April 15, 1993, that describes procedures for a one-time
inspection to detect chafing and modification of the ADG wiring
harness, and repair of any chafed harness. This modification entails
replacing two existing harness support brackets with redesigned
brackets that would preclude chafing of the harness. The effectivity of
this service bulletin includes Model CL-600-2B16 series airplanes
having serial numbers 5099 through 5131 only. Transport Canada Aviation
classified this alert service bulletin as mandatory and issued Canadian
Airworthiness Directive CF-91-21R1, dated May 6, 1993, in order to
assure the continued airworthiness of these airplanes in Canada.
This airplane model is manufactured in Canada and is type
certificated for operation in the United States under the provisions of
Sec. 21.29 of the Federal Aviation Regulations and the applicable
bilateral airworthiness agreement. Pursuant to this bilateral
airworthiness agreement, Transport Canada Aviation has kept the FAA
informed of the situation described above. The FAA has examined the
findings of Transport Canada Aviation, 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 inspection to
detect chafing and modification of the wiring harness of the ADG, and
repair of any chafed harness. The actions would be required to be
accomplished in accordance with the alert service bulletin described
previously. This proposed AD would apply only to airplanes having
serial numbers 5099 through 5131, inclusive.
Note: The FAA's normal policy is that when an AD requires a
substantive change, such as a change in its applicability, the
``old'' AD is superseded by removing it from the system and a new AD
is added. In the case of this AD action, the FAA normally would have
proposed superseding AD 91-19-01 to expand its applicability to
include the additional affected airplanes. However, in
reconsideration of the entire fleet size that would be affected by a
supersedure action, and the consequent workload associated with
revising maintenance record entries, the FAA has determined that a
less burdensome approach is to issue a separate AD applicable only
to these additional airplanes. This AD does not supersede AD 91-19-
01; airplanes listed in the applicability of AD 91-19-01 are
required to continue to comply with the requirements of that AD.
This proposed AD is a separate AD action, and is applicable only to
airplanes having serial numbers 5099 through 5131, inclusive.)
The FAA estimates that 25 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 1 work
hour per airplane to accomplish the proposed inspection, and that the
average labor rate is $55 per work hour. Based on these figures, the
total cost impact of the proposed inspection on U.S. operators is
estimated to be $1,375, or $55 per airplane.
The FAA estimates that it would take approximately 9 work hours per
airplane to accomplish the proposed modification and the average labor
rate is $55 per work hour. Required parts would cost approximately $199
per airplane. Based on these figures, the total cost impact of the
proposed modification on U.S. operators is estimated to be $17,350 or
$694 per airplane.
Based on the figures, above, the total (inspection plus
modification) cost impact of the proposed AD on U.S. operators is
estimated to be $18,725 or $749 per airplane.
The total 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.
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 14
CFR part 39 of the Federal Aviation Regulations 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:
Canadair: Docket 93-NM-222-AD.
Applicability: Model CL-600-2B16 series airplanes having serial
numbers 5099 through 5131, inclusive; certificated in any category.
Note 1: Airplanes having serial numbers 5001 through 5098,
inclusive, are subject to the requirements of AD 91-19-01, Amendment
39-8026.
Compliance: Required as indicated, unless accomplished
previously.
To prevent loss of emergency power to the essential bus when the
air driven generator (ADG) is deployed, accomplish the following:
(a) Within 25 hours time-in-service after the effective date of this
AD, inspect to detect chafing of the wiring harness of the ADG in
accordance with Canadair Alert Service Bulletin A601-0370, Revision
1, dated April 15, 1993. If chafing is found, prior to further
flight, repair in accordance with the service bulletin.
(b) Within 60 days after the effective date of this AD, modify
the harness installation of the ADG in accordance with Canadair
Alert Service Bulletin A601-0370, Revision 1, dated April 15, 1993.
(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, New York Aircraft Certification
Office (ACO), FAA, Engine and Propeller Directorate. Operators shall
submit their requests through an appropriate FAA Principal
Maintenance Inspector, who may add comments and then send it to the
Manager, New York ACO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the New York ACO.
(d) Special flight permits may be issued in accordance with
Federal Aviation Regulations (FAR) 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 March 8, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 94-5851 Filed 3-11-94; 8:45 am]
BILLING CODE 4910-13-U