02-24282. Airworthiness Directives; Bombardier Model CL-600-2C10 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 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 [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. 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 [phone]; fax [phone].

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:

• 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.
• For each issue, state what specific change to the proposed AD is being requested.
• 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.

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, 2001	27-20-00-108	RTL standby actuator (with SSCU part number (P/N) C13045BA01): Operational check of the RTL standby actuator.
MRM2-42, dated September 28, 2001	27-20-00-107	RTL active and standby actuators (with SSCU P/N C13045BA02): Functional check of the RTL active and standby actuators.
MRM2-43, dated September 28, 2001	27-20-00-102	RTL active and 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 § 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.

§ 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:

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, 2001	27-20-00-108	RTL standby actuator (with SSCU part number (P/N) C13045BA01): Operational check of the RTL standby actuator.
MRM2-42, dated September 28, 2001	27-20-00-107	RTL active and standby actuators (with SSCU P/N C13045BA02): Functional check of the RTL active and standby actuators.
MRM2-43, dated September 28, 2001	27-20-00-102	RTL active and 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 §§ 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.