[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]


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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).

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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