Transport Canada Civil Aviation (TCCA), which is the airworthiness authority for Canada, recently notified the FAA that an unsafe condition may exist on all Bombardier Model CL-600-2B19 series airplanes. TCCA advises that endurance test results indicate that Appendix B--Airworthiness Limitations, Part 2, of the Canadair Regional Jet Maintenance Requirements Manual must be revised to incorporate life limits for certain horizontal stabilizer trim actuators (HSTAs), and replacement of those HSTAs to prevent failure of key components. Such failure, if not corrected, could result in loss of horizontal trim control and consequent reduced controllability of the airplane.
Explanation of Relevant Service Information
Bombardier has issued Canadair Regional Jet Temporary Revision (TR) 2B-816, dated November 28, 2001, which describes procedures for incorporating life limits for the HSTAs, Canadair part number (P/N) 601R92305-1 (vendor P/N 8396-2), and Canadair P/N 601R92305-3 (vendor P/N 8396-3), into Appendix B--Airworthiness Limitations, Part 2, of the Canadair Regional Jet Maintenance Requirements Manual. Accomplishment of the action specified in the TR is intended to adequately address the identified unsafe condition. TCCA classified this service information as mandatory and issued Canadian airworthiness directive CF-2002-20, dated March 20, 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 productsof this type design that are certificated for operation in the United States.
Explanation of Requirements of 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, this AD is being issued to prevent failure of key components of the HSTAs, which could result in loss of horizontal trim control and consequent reduced controllability of the airplane. This AD requires revising Appendix B--Airworthiness Limitations, Part 2, of the Canadair Regional Jet Maintenance Requirements Manual to incorporate life limits for certain HSTAs, and replacing the HSTAs with new or serviceable HSTAs. The actions are required to be accomplished per the service information described previously, except as discussed below.
Difference Between This AD and Service Information
Operators should note that the previously referenced Canadair airworthiness directive and TR do not include specific procedures for the replacement action. However, this AD requires replacement of the HSTAs with new or serviceable HSTAs per a method approved by the FAA.
Explanation of Action Taken by the FAA
In accordance with airworthiness standards requiring "damage tolerance assessments" for transport category airplanes [Sec. 25.571 of the Federal Aviation Regulations (14 CFR 25.571), and the Appendices referenced in that section], all products certificated to comply with that section must have Instructions for Continued Airworthiness (or, for some products, maintenance manuals) that include an Airworthiness Limitations Section (ALS). That section must set forth:
Mandatory replacement times for structural components,
Structural inspection intervals, and
Related approved structural inspection procedures necessary to show compliance with the damage-tolerance requirements.
Compliance with the terms specified in the ALS is required by Secs. 43.16 (for persons maintaining products) and 91.403 (for operators) of the Federal Aviation Regulations (14 CFR 43.16 and 91.403).
In order to require compliance with these inspection intervals and life limits, the FAA must engage in rulemaking, namely the issuance of an AD. For products certificated to comply with the referenced part 25 requirements, it is within the authority of the FAA to issue an AD requiring a revision to the ALS that includes reduced life limits, or new or different structural inspection requirements. These revisions then are mandatory for operators under Sec. 91.403(c) of the Federal Aviation Regulations (14 CFR 91.403), which prohibits operation of an airplane for which airworthiness limitations have been issued unless the inspection intervals specified in those limitations have been complied with.
After that document is revised, as required, and the AD has been fully complied with, the life limit or structural inspection change remains enforceable as a part of the airworthiness limitations. (This is analogous to ADs that require changes to the Limitations Section of the Airplane Flight Manual.)
Requiring a revision of the airworthiness limitations, rather than requiring individual inspections, is advantageous for operators because it allows them to record AD compliance status only once--at the time they make the revision--rather than after every inspection. It also has the advantage of keeping all airworthiness limitations, whether imposed by original certification or by AD, in one place within the operator's maintenance program, thereby reducing the risk of non-compliance because of oversight or confusion.
Determination of Rule's Effective Date
Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.
Comments Invited
Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.
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 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 rule that might suggest a need to modify the 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 that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 2002-NM-135-AD." The postcard will be date stamped and returned to the commenter.
Regulatory Impact
The regulations adopted herein 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.
The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docketat the location provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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: