Discussion
Transport Canada Civil Aviation (TCCA), which is the airworthiness authority for Canada, notified us that an unsafe condition may exist on Bombardier Model CL-215-6B11 (CL-215T variant) and CL-215-6B11 (CL-415 variant) airplanes. TCCA advises that during a routine inspection, an operator reported corrosion on the rudder lower torque tube upper bearing, part number DAT48-64A, on two airplanes. These bearings had been installed in accordance with Bombardier Service Bulletin 215-4328, Revision 3, dated May 20, 2008, as part of the torque tube replacement. Corroded lower torque tube upper bearings can lead to hinge deformation, which could result in a rudder jam and consequent reduced controllability of the airplane.
Relevant Service Information
Bombardier has issued Bombardier Service Bulletin 215-3151, dated May 5, 2008 (for 215T variant airplanes); and Bombardier Service Bulletin 215-4394, dated May 5, 2008 (for 415 variant airplanes). These service bulletins describe procedures for repetitive detailed inspections for signs of contamination, including corrosion/rust particles in the flange and housing of the rudder lower torque tube upper bearing. These service bulletins also describe procedures for bearing wear checks, and grease applications of the rudder lower torque tube upper bearing, and a rudder upper hinge gap check; and related investigative and corrective actions if necessary. Related investigative actions include inspecting old grease for signs of contamination, measuring the distance from the top of the bearing housing to the top of the lower bearing flange shoulder at multiple locations around the bearing, and doing a visual inspection to determine the cause of the excessive wear. Corrective actions include replacing the bearing(s) and adjusting the hinge gap. TCCA mandated the service information and issued Canadian airworthiness directive CF- 2008-29, dated August 20, 2008 (referred to after thisas "the MCAI''), to ensure the continued airworthiness of these airplanes in Canada.
FAA's Determination and Requirements of This AD
This product has been approved by the aviation authority of another country, and is approved for operation in the United States. Pursuant to our bilateral agreement with the State of Design Authority, we have been notified of the unsafe condition described in the MCAI and service information referenced above. We are issuing this AD because we evaluated all pertinent information and determined an unsafe condition exists and is likely to exist or develop on other products of the same type design.
Therefore, we are issuing this AD to detect and correct corroded bearings which can lead to hinge deformation, and result in a rudder jam and consequent reduced controllability of the airplane. This AD requires accomplishing the actions specified in the service information described previously, except as discussed under "Differences Between This AD andthe Canadian Airworthiness Directive.''
Differences Between This AD and the Canadian Airworthiness Directive
Bombardier Service Bulletin 215-3151, dated May 5, 2008 (for 215T variant airplanes); and Bombardier Service Bulletin 215-4394, dated May 5, 2008 (for 415 variant airplanes) recommend accomplishing the required actions "before and after every fire season,'' but we find this interval to be imprecise and vague. In developing appropriate compliance times for this AD, we considered not only the manufacturer's recommendation, but the degree of urgency associated with addressing the subject unsafe condition, the average utilization of the affected fleet, and the time necessary to perform the required actions. In light of all of these factors, we find that a 6-month repetitive interval for the required actions is an appropriate interval of time for affected airplanes to continue to operate without compromising safety. This difference has been coordinated with TCCA.
InterimAction
We consider this proposed AD interim action. If final action is later identified, we might consider further rulemaking then.
Costs of Compliance
None of the airplanes affected by this action are on the U.S. Register. All airplanes affected by this AD are currently operated by non-U.S. operators under foreign registry; therefore, they are not directly affected by this AD action. However, we consider this AD necessary to ensure that the unsafe condition is addressed if any affected airplane is imported and placed on the U.S. Register in the future.
The following table provides the estimated costs to comply with this AD for any affected airplane that might be imported and placed on the U.S. Register in the future.
Estimated Costs
Action
Work hours
Average labor rate per hour
Parts cost
Cost per airplane
Inspection
4
$80
None
$320 per inspection cycle
FAA's Determination of the Effective Date
No airplane affected by this AD is currently on the U.S. Register. Therefore, providing notice and opportunity for public comment is unnecessary before this AD is issued, and this AD may be made effective in less than 30 days after it is published in the Federal Register.
Comments Invited
This AD is a final rule that involves requirements affecting flight safety, and we did not provide you with notice and an opportunity to provide your comments before it becomes effective. However, we invite you to send any written data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include "Docket No. FAA-2009-0159; Directorate Identifier 2008-NM-175-AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments.
We will post all comments we receive, without change, to http:// www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this AD.
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.
We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, "General requirements.'' Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.
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 and placed it in the AD docket. 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.
Sec. 39.13 [Amended]
2. The Federal Aviation Administration (FAA) amends Sec. 39.13 by adding the following new airworthiness directive (AD):