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), CL-600-2A12 (CL-601), CL-600-2B16 (CL-601-3A, CL-601-3R, and CL-604) series airplanes. TCCA advises that angle of attack (AOA) transducers having a certain part number may have potentiometers that wear prematurely. The problem is dormant and can only be identified on in-service airplanes by a linearity test of each AOA transducer. Prematurely worn potentiometers in the AOA transducers, if not corrected, could result in a delay in the stall computer commands for stall warning, stick shaker, and stick pusher operation, which may cause the airplane to enter a stall condition, and result in loss of control of the airplane.
Relevant Service Information
Bombardier has issued the following temporary revisions (TR) to the applicable Canadair Challenger airplane flight manual (AFM).
Bombardier Temporary Revisions
Model
Temporary revision
Product support publication
Dated
CL-600-1A11 (CL-600) series airplanes
600/20-2
600-1/15-2
600 (not stated in document)
600-1 (not stated in document)
October 15, 2004
October 15, 2004
CL-600-2A12 (CL-601) series airplanes
601/12-2
601/13-2
601/17-2
601/25-2
601-1B-1
601-1A-1
601-1B
601-1A-18 (not stated in docu-
October 15, 2004
October 15, 2004
October 15, 2004
October 15, 2004
CL-600-2B16 (CL-601-3A and -3R) series airplanes.
601/22-2
601/23-2
601A-1-1
601A-1
October 15, 2004
October 15, 2004
CL-600-2B16 (CL-604) series airplanes
604/9-6
604-1
October 15, 2004
Among other things, the TRs describe procedures for revising the Limitations, Performance, and Normal Procedures Sections of the applicable Canadair Challenger AFM, to provide the flightcrew with procedures and limitationsfor operating an airplane with any out-of- tolerance AOA transducer.
Bombardier has also issued the following alert service bulletins:
For model-
Bombardier alert service bulletin
Dated
CL-600-1A11 (CL-600) series airplanes
A600-0729
October 14, 2004
CL-600-2A12 (CL-601) series airplanes and CL-600-2B16 (CL-601-3A and -3R) series airplanes
A601-0571
October 14, 2004
CL-600-2B16 (CL-604) series airplanes
A604-27-026
October 14, 2004
The alert service bulletins describe procedures for doing repetitive linearity checks (tests) for each AOA transducer, and corrective action if necessary. The corrective action includes replacing any AOA transducer that does not meet the specified linearity requirements with a serviceable AOA transducer.
TCCA mandated the temporary revisions and alert service bulletins and issued Canadian airworthiness directive CF-2004-22, dated October 22, 2004, to ensure the continued airworthiness of these airplanes in Canada.
FAA's Determination and Requirements of This AD
These airplane models are manufactured in Canada and are type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. According to this bilateral airworthiness agreement, TCCA has kept us informed of the situation described above. We have examined the TCCA's findings, evaluated all pertinent information, and determined that we need to issue an AD for products of this type design that are certificated for operation in the United States.
Therefore, we are issuing this AD to require revising the airplane flight manual to provide the flightcrew with procedures and limitations for operating an airplane with out-of-tolerance AOA transducers. This AD also requires repetitive linearity tests of the AOA transducers, and corrective action if necessary. This AD requires accomplishing the actions specified in the service information described previously, except as described in "Differences Between This AD and Referenced Alert Service Bulletins.''
Difference Between Proposed AD and Referenced Alert Service Bulletins
Operators should note that, although the Accomplishment Instructions of the referenced alert service bulletins describe procedures for submitting service bulletin incorporation notices to the manufacturer, this AD does not require those actions.
Clarification of Terminology
In this AD, the linearity "checks'' of the AOA transducers specified in the Canadian airworthiness directive and the Bombardier alert service bulletins are referred to as "tests.''
Interim Action
This is considered to be interim action until final action is identified, at which time we may consider further rulemaking.
FAA's Determination of the Effective Date
An unsafe condition exists that requires the immediate adoption of this AD; therefore, providing notice and opportunity for public comment before the AD is issued is impracticable, and good cause exists to make this AD effective in less than 30 days.
Comments Invited
This AD is a final rule that involves requirements that affect flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any relevant written data, views, or arguments regarding this AD. Send your comments to an address listed under ADDRESSES. Include "Docket No. FAA-2004-19862; Directorate Identifier 2004-NM-228-AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD. We will consider all comments received by the closing date and may amend the AD in light of those comments.
We will post all comments we receive, without change, to http://dms.dot.gov , including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this AD. Using the search function of our docket Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You can review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you can visit http://dms.dot.gov.
We are reviewing the writing style we currently use in regulatory documents. We are interested in your comments on whether the style of this document is clear, and your suggestions to improve the clarity of our communications with you. You can get more information about plain language at http://www/faa.gov/language and http://www.plainlanguage.gov.
Regulatory Findings
We have determined that this AD will not have federalism implications under Executive Order 13132. This AD will 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.
For the reasons discussed above, I certify that the 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. 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.
We prepared a regulatory evaluation of the estimated costs to comply with this AD. See the ADDRESSES section for a location to examine the regulatory evaluation.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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. The FAA amends 39.13 by adding the following new airworthiness directive (AD):