[Federal Register: September 25, 2002 (Volume 67, Number 186)]
[Proposed Rules]               
[Page 60187-60189]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr25se02-17]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-93-AD]
RIN 2120-AA64

 
Airworthiness Directives; Bombardier Model CL-600-2C10 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 all Bombardier CL-600-2C10 series 
airplanes. This proposal would require revising the Airworthiness 
Limitations Section of the Instructions for Continued Airworthiness to 
incorporate functional and operational checks of the active and standby 
actuators of the rudder travel limiter (RTL) system. This action is 
necessary to prevent a significant latent failure in the RTL, which 
could lead to a critical loss of RTL function under certain conditions, 
and consequent loss of controllability of the airplane or structural 
damage. This action is intended to address the identified unsafe 
condition.

DATES: Comments must be received by October 21, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-93-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. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must 
contain ``Docket No. 2002-NM-93-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    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, Atlanta 
Aircraft Certification Office, One Crown Center, 1895 Phoenix 
Boulevard, suite 450, Atlanta, Georgia.

FOR FURTHER INFORMATION CONTACT: Dan Parrillo, Aerospace Engineer, 
Systems and Flight Test Branch, ANE-172, FAA, New York Aircraft 
Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New 
York 11581; telephone (516) 256-7505; 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 action may be changed in 
light of the comments received.
    Submit comments using the following format:
    [sbull] Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] Include justification (e.g., reasons or data) for each 
request.
    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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2002-NM-93-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. 2002-NM-93-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 all Bombardier Model CL-600-2C10 series airplanes. TCCA 
advises that a significant latent failure may exist in the rudder 
travel limiter (RTL) system. A failure of the active actuator lane 
(actuator 1 and spoiler stabilizer command module (SSCM) 
channel 1A) may lead to a critical loss of function of the RTL under 
either of the following two conditions:
    1. A dormant failure of the RTL on SSCM channel 1B, 2A, or 2B, or 
an undetected mechanical jam may be present in the RTL (standby) 
actuator 2; or
    2. An undetected mechanical jam may be present in the RTL active 
actuator in the range of 4 to 8 degrees.

[[Page 60188]]

    Under either of these two conditions, this latent failure in the 
RTL could lead to a critical loss of RTL function, which, if not 
corrected, could result in loss of controllability of the airplane or 
structural damage.

Explanation of Relevant Service Information

    The manufacturer has issued the following temporary revisions:

                       Table--Temporary Revisions
------------------------------------------------------------------------
CRJ 700 Regional jet temporary
           revision                Task number        Task description
------------------------------------------------------------------------
MRM2-41, dated September 28,         27-20-00-108  RTL standby actuator
 2001.                                              (with SSCU part
                                                    number (P/N)
                                                    C13045BA01):
                                                    Operational check of
                                                    the RTL standby
                                                    actuator.
MRM2-42, dated September 28,         27-20-00-107  RTL active and
 2001.                                              standby actuators
                                                    (with SSCU P/N
                                                    C13045BA02):
                                                    Functional check of
                                                    the RTL active and
                                                    standby actuators.
MRM2-43, dated September 28,         27-20-00-102  RTL active and
 2001.                                              standby actuators
                                                    (with SSCU P/N
                                                    C13045BA02):
                                                    Operational check of
                                                    the RTL active and
                                                    standby actuators.
------------------------------------------------------------------------

Accomplishment of the actions specified in the temporary revisions is 
intended to adequately address the identified unsafe condition. TCCA 
classified these temporary revisions as mandatory and issued Canadian 
airworthiness directive CF-2002-06, dated January 21, 2002, in order to 
assure the continued airworthiness of these airplanes in Canada.

FAA's Conclusions

    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 (14 CFR 21.29) and the 
applicable bilateral 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 revising the 
Airworthiness Limitations Section of the Instructions for Continued 
Airworthiness to incorporate functional and operational checks of the 
active and standby actuators of the RTL system. The actions would be 
required to be accomplished in accordance with the temporary revisions 
described previously.

Cost Impact

    The FAA estimates that 15 Model CL-600-2C10 series 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 
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 $900, or $60 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. The cost impact figures 
discussed in AD rulemaking actions represent only the time necessary to 
perform the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.

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 2002-NM-93-AD.

    Applicability: All Model CL-600-2C10 series airplanes, 
certificated in any category.

    Note 1: This AD requires revisions to certain operator 
maintenance documents to include new inspections. Compliance with 
these inspections is required by 14 CFR Part 91.403(c). For 
airplanes that have been previously modified, altered, or repaired 
in the areas addressed by these inspections, the operator may not be 
able to accomplish the inspections described in the revisions. In 
this situation, to comply with 14 CFR part 91.403(c), the operator 
must request approval for an alternative method of compliance in 
accordance with paragraph (c) of this AD. The request should include 
a description of changes to the required inspections that will 
ensure the continued damage tolerance of the affected structure. The 
FAA has provided guidance for this determination in Advisory 
Circular (AC) 25-1529.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent a significant latent failure in the rudder travel 
limiter (RTL), which could lead to a critical loss of RTL function 
under certain conditions, and consequent loss of controllability of 
the airplane or structural damage, accomplish the following:

[[Page 60189]]

Revise Airworthiness Limitations Section

    (a) Within 30 days of the effective date of this AD, revise the 
Airworthiness Limitations Section of the Instructions for Continued 
Airworthiness by incorporating the tasks of the Temporary Revisions 
of Part 2 of the Maintenance Requirements Manual (MRM), Section 1, 
Appendix A, Certification Maintenance Requirements; as listed in the 
following table; into the Airworthiness Limitations Section:

                       Table--Temporary Revisions
------------------------------------------------------------------------
CRJ 700 Regional jet temporary
           revision                Task number        Task description
------------------------------------------------------------------------
MRM2-41, dated September 28,         27-20-00-108  RTL standby actuator
 2001.                                              (with SSCU part
                                                    number (P/N)
                                                    C13045BA01):
                                                    Operational check of
                                                    the RTL standby
                                                    actuator.
MRM2-42, dated September 28,         27-20-00-107  RTL active and
 2001.                                              standby actuators
                                                    (with SSCU P/N
                                                    C13045BA02):
                                                    Functional check of
                                                    the RTL active and
                                                    standby actuators.
MRM2-43, dated September 28,         27-20-00-102  RTL active and
 2001.                                              standby actuators
                                                    (with SSCU P/N
                                                    C13045BA02):
                                                    Operational check of
                                                    the RTL active and
                                                    standby actuators.
------------------------------------------------------------------------

    (b) Thereafter, except as provided by paragraph (c) of this AD, 
no alternative operational and functional checks or check intervals 
may be approved for the task numbers specified in the temporary 
revisions listed in paragraph (a) of this AD.

Alternative Methods of Compliance

    (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, Atlanta Aircraft Certification 
Office (ACO), FAA. Operators shall submit their requests through an 
appropriate FAA Principal Maintenance Inspector, who may add 
comments and then send it to the Manager, Atlanta ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Atlanta ACO.

Special Flight Permits

    (d) Special flight permits may be issued in accordance with 
Sec. Sec.  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 Canadian 
airworthiness directive CF-2002-06, dated January 21, 2002.


    Issued in Renton, Washington, on September 16, 2002.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-24282 Filed 9-24-02; 8:45 am]
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