[Federal Register Volume 65, Number 63 (Friday, March 31, 2000)]
[Proposed Rules]
[Pages 17208-17211]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-8019]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-26-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model CL-600-1A11 (CL-600) 
and CL-600-2A12 (CL-601) Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

[[Page 17209]]


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 Bombardier Model CL-600-
1A11 (CL-600) and CL-600-2A12 (CL-601) series airplanes. This proposal 
would require modification of the main landing gear (MLG) brake units 
and inboard MLG wheels; and a revision to the Airplane Flight Manual 
(AFM) to include the increased cooling times for the modified brakes. 
This proposal also would allow, for certain cases, removal of the 
inboard and/or outboard wheel discs by installation of a placard to 
limit airplane operation on the ground and a revision to the AFM to 
include information for operating the airplane with the wheel discs 
removed. 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 water 
freezing on the brake while the airplane is in flight due to water, 
slush, or snow from the runway entering into the brake assemblies 
during takeoff, and consequently, a tire burst during landing of the 
airplane.

DATES: Comments must be received by May 1, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-26-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 Centre-ville, 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, 10 Fifth 
Street, Third Floor, Valley Stream, New York.

FOR FURTHER INFORMATION CONTACT: James E. Delisio, Aerospace Engineer, 
Airframe and Propulsion Branch, ANE-171, FAA, Engine and Propeller 
Directorate, New York Aircraft Certification Office, 10 Fifth Street, 
Third Floor, Valley Stream, New York 11581; telephone (516) 256-7521; 
fax (516) 568-2716.

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 99-NM-26-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. 99-NM-26-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    Transport Canada Civil Aviation (TCCA), which is the airworthiness 
authority for Canada, notified the FAA that an unsafe condition may 
exist on certain Bombardier Model CL-600-1A11 (CL-600) and CL-600-2A12 
(CL-601) series airplanes. TCCA advises that a tire burst occurred on a 
number of airplanes during landing. Investigation revealed that the 
existing design of the main landing gear (MLG) allows water, slush, or 
snow from the runway to enter into the brake assemblies during takeoff. 
This condition, if not corrected, could result in the water freezing on 
the brake while the airplane is in flight, and consequently, a tire 
burst during landing of the airplane.

Explanation of Relevant Service Information

    Bombardier has issued Canadair Challenger Service Bulletins 600-
0369, Revision 4, dated June 27, 1984, including Attachment 1, dated 
December 6, 1983, and Attachment 2, dated January 11, 1984 [for Model 
CL-600-1A11 (CL-600) series airplanes]; and 601-0024, Revision 3, dated 
November 27, 1984, including Attachment 1, dated June 21, 1984, 
Attachment 2, dated December 6, 1983, and Attachment 3, dated January 
11, 1984 [for Model CL-600-2A12 (CL-601) series airplanes]. These 
service bulletins describe procedures for modification of the MLG brake 
units and inboard MLG wheels; and a revision to the Normal and 
Limitation Sections of the Airplane Flight Manual (AFM) to include the 
increased cooling times for the brakes. The modification involves 
installation of a wheel disc on each inboard MLG wheel; replacement of 
screws securing the wheel disc on each outboard MLG wheel with longer 
screws; installation of a water barrier shield and water deflector to 
each MLG brake unit assembly; removal of balance weights, if fitted, 
from the main wheel assemblies; and reidentification of brake unit and 
main wheel assemblies. For certain airplanes, a sealing cap is also 
installed on each MLG trailing arm aperture.
    Bombardier also has issued Canadair Challenger Service Bulletins 
600-0662, dated November 30, 1995 [for Model CL-600-1A11 (CL-600) 
series airplanes]; and 601-0467, dated November 30, 1995 [for Model CL-
600-2A12 (CL-601) series airplanes]. These service bulletins describe 
procedures for removal of the inboard and/or outboard wheel discs by 
installation of a placard to limit airplane operation on the ground and 
a revision to the Normal Procedures Section of the AFM to include 
information for operating the airplane with the wheel discs removed.
    Accomplishment of the actions specified in the service bulletins is 
intended to adequately address the identified unsafe condition. TCCA 
classified these service bulletins as mandatory and issued Canadian 
airworthiness directive CF-84-04R2, dated July 24, 1998, in order to 
assure the continued airworthiness of these airplanes in Canada.

FAA's Conclusions

    These airplane models are manufactured in Canada and are type 
certificated for operation in the United States under the provisions of 
Sec. 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the 
applicable bilateral

[[Page 17210]]

airworthiness agreement. Pursuant to this bilateral airworthiness 
agreement, TCCA has kept the FAA informed of the situation described 
above. The FAA has examined the findings of TCCA, 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.

Cost Impact

    The FAA estimates that 131 airplanes of U.S. registry would be 
affected by this proposed AD.
    It would take approximately 33 work hours [for Model CL-600-1A11 
(CL-600) series airplanes] or 26 work hours [for Model CL-600-2A12 (CL-
601) series airplanes] per airplane to accomplish the proposed 
modification, at an average labor rate of $60 per work hour. Required 
parts would cost approximately $2,977 per airplane. Based on these 
figures, the cost impact of this action proposed by this AD on U.S. 
operators is estimated to be $649,367 or $4,957 per airplane [for Model 
CL-600-1A11 (CL-600) series airplanes], and $594,347 or $4,537 per 
airplane [for Model CL-600-2A12 (CL-601) series airplanes].
    It would take approximately 1 work hour per airplane to accomplish 
the proposed AFM revision, at an average labor rate of $60 per work 
hour. Based on these figures, the cost impact of the AFM revision 
proposed by this AD on U.S. operators is estimated to be $7,860, or $60 
per airplane.
    The cost impact figures discussed above are 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 an operator elect to accomplish the optional placard 
installation and AFM revision, it would take approximately 5 work hours 
per airplane to accomplish these actions, at an average labor rate of 
$60 per work hour. Required parts would cost approximately $75 per 
airplane. Based on these figures, the cost impact of these actions is 
estimated to be $375 per airplane, per modification cycle.

Regulatory Impact

    The regulations proposed herein would not have a substantial direct 
effect 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, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    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:
Bombardier, Inc. (Formerly Canadair): Docket 99-NM-26-AD.
    Applicability: Model CL-600-1A11 (CL-600) series airplanes, 
serial numbers 1004 through 1066 inclusive and 1068 through 1085 
inclusive; and Model CL-600-2A12 (CL-601) series airplanes, serial 
numbers 3001 through 3050 inclusive; 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 (d) 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 water freezing on the brake while the airplane is in 
flight due to water, slush, or snow from the runway entering into 
the brake assemblies during takeoff, and consequently, a tire burst 
during landing of the airplane, accomplish the following:

Modification and AFM Revision

    (a) Except as required by paragraph (b) of this AD, within 300 
flight cycles after the effective date of this AD, accomplish the 
actions required by paragraphs (a)(1) and (a)(2) of this AD in 
accordance with the Accomplishment Instructions of Canadair 
Challenger Service Bulletins 600-0369, Revision 4, dated June 27, 
1984, including Attachment 1, dated December 6, 1983, and Attachment 
2, dated January 11, 1984 [for Model CL-600-1A11 (CL-600) series 
airplanes]; or 601-0024, Revision 3, dated November 27, 1984, 
including Attachment 1, dated June 21, 1984, Attachment 2, dated 
December 6, 1983, and Attachment 3, dated January 11, 1984 [for 
Model CL-600-2A12 (CL-601) series airplanes]; as applicable.
    (1) Modify the main landing gear (MLG) brake units and inboard 
MLG wheels.

    Note 2: Part A of the Accomplishment Instructions of Canadair 
Challenger Service Bulletin 600-0369, Revision 4, dated June 27, 
1984, including Attachment 1, dated December 6, 1983, and Attachment 
2, dated January 11, 1984; has been accomplished on airplane serial 
number 1072 in production.


    (2) Revise the Normal Procedures Section of the FAA-approved 
Airplane Flight Manual (AFM) to include the brake cooling times for 
the modification specified in paragraph (a)(1) of this AD. This AFM 
revision may be accomplished by inserting the applicable AFM 
revision listed in the applicable service bulletin listed in 
paragraph (a) of this AD. Subsequent AFM revisions may be inserted 
in the AFM provided that the brake cooling information is identical 
to the applicable AFM revision listed in the applicable service 
bulletin listed in paragraph (a) of this AD.

[[Page 17211]]

    (b) Operation of the airplane from contaminated runways (i.e., 
wet, snow covered, or slush covered surfaces) is prohibited until 
the actions required by paragraph (a) of this AD are accomplished.

Optional Placard Installation and AFM Revision

    (c) For airplanes that do not operate from a wet runway where 
the ambient temperature is below 10 degrees Celsius: It is 
permissible to remove the inboard and/or outboard wheel discs upon 
accomplishment of the actions specified in paragraphs (c)(1) and 
(c)(2) of this AD, in accordance with Canadair Challenger Service 
Bulletins 600-0662, dated November 30, 1995 [for Model CL-600-1A11 
(CL-600) series airplanes]; or 601-0467, dated November 30, 1995 
[for Model CL-600-2A12 (CL-601) series airplanes]; as applicable. 
The placard and AFM revision required by paragraphs (c)(1) and 
(c)(2) of this AD may be removed upon reinstallation of the inboard 
and outboard wheel discs.
    (1) Install a placard on the instrument panel that states the 
following: ``WHEEL DISCS ARE REMOVED--REFER TO AFM FOR LIMITATIONS''
    (2) Revise the Limitations Section of the AFM to include 
information for operating the airplane with the wheel discs removed. 
This AFM revision may be accomplished by inserting the applicable 
AFM revision specified in the applicable service bulletin listed in 
paragraph (a) of this AD. Subsequent AFM revisions may be inserted 
in the AFM provided that the information for operating the airplane 
with the wheel discs removed is identical to the applicable AFM 
revision specified in the applicable service bulletin listed in 
paragraph (a) of this AD.

Alternative Methods of Compliance

    (d) 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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the New York ACO.

Special Flight Permits

    (e) Special flight permits may be issued in accordance with 
Secs. 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 4: The subject of this AD is addressed in Canadian 
airworthiness directive CF-84-CF-84-04R2, dated July 24, 1998.


    Issued in Renton, Washington, on March 24, 2000.
Donald L. Riggin,
Acting Manager Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-8019 Filed 3-30-00; 8:45 am]
BILLING CODE 4910-13-P