A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to Bombardier Model CL-600-2C10 (Regional Jet Series 700, & 701) series airplanes was published in the Federal Register on May 19, 2004 (69 FR 28865). That action proposed to require an inspection of the thrust reverser cascades for correct installation; removing and reinstalling the cascade in the correct location, if necessary; and reworking the thrust reverser cascades to add locating spigots (metal protrusions) to each cascade; as applicable.
Comments
Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.
Request To Clarify Intent of Paragraph (b) of the Proposed AD
The commenter requests clarification on the inspection of the cascades upon the reinstallation of a cascade. The commenter wonders: "In the event only one cascade is removed and reinstalled, does this paragraph require performance of the entire service bulletin ([Bombardier Alert Service Bulletin] A670BA-78-001) meaning both [engine] nacelles, on the corresponding nacelle, or for the individual cascade?'
We agree that clarification may be needed. We intended only for the corresponding nacelle or for the individual cascade to be inspected for correct installation when a cascade is removed and reinstalled. We have not changed the AD in this regard.
Request To Change the Applicability of Paragraph (b)
The commenter requests that the applicability of paragraph (b) of the proposed AD be changed since the applicability of paragraph (a) is limited to airplanes with serial numbers (S/N) 10005 through 10040. The commenter suggests revising paragraph (b) to be applicable only to cascades that have been removed and reinstalled.
We agree that the reasoning for the applicability of paragraph (b) of this ADneeds to be clarified. However, we disagree that paragraph (b) needs to be revised. Airplanes with S/N 10005 through 10040 inclusive may have been delivered to customers with incorrectly installed cascades (before awareness of the incorrect cascade installation occurred). Airplanes with S/N 10003, 10004, and 10041 through 10116 were subject to a pre-delivery inspection to ensure that the airplanes were delivered with correctly configured cascades. However, those airplanes were delivered with cascades that could be mis-installed during maintenance actions. Airplanes with S/N 10117 and subsequent were delivered with cascades that were modified to help prevent mis-installation of the cascades. We have not changed the AD in this regard.
Request To Revise Cost Impact Statement
The commenter states that the cost impact statements do not reflect those in the referenced service bulletins. We infer that the commenter requests that the cost estimates be revised.
We partially agreeto revise the cost impact statement. We erroneously stated the per nacelle cost to perform the modification as the per airplane cost. We have revised the statement to state the correct per airplane cost for the modification. However, we do not agree to revise the cost estimate for the inspection. We only include costs directly related to the required action. While the service bulletin includes an estimate on the cost to access and close-up the inspection area and other actions not directly a part of the inspection, we do not include those costs in our estimate. Those actions can be used in combination with other ADs, service bulletins, or maintenance actions that use the same access points.
Request To Delete Paragraph (e) of This AD
The commenter states that due to the amount of work hours involved in modifying the cascades, the applicability of paragraph (e) of the proposed AD should be modified to be limited only to cascades that have been removed and reinstalled or replacedper the inspection criteria in paragraph (b) of the proposed AD.
We do not agree to eliminate or modify paragraph (e) of this AD. The actions of paragraphs (b) and (e) of this AD are intended to differentiate between installation and reinstallation situations. For instance, a situation where an operator removes a cascade to gain access to an engine component may be considered a "reinstallation" situation, and the operator would be required to inspect the cascade installation to ensure that the removed cascade was reinstalled correctly. In that case, paragraph (b) would apply and the operator would not need to modify the cascade per paragraph (e). In contrast, if an operator was removing a cascade to do an action on it or to replace the cascade with another cascade, then the operator would be required to ensure that the cascade being installed has been modified in accordance with paragraph (e) and would not be permitted to only inspect for proper installation. The modification inparagraph (e) is intended as a terminating action for the inspections required by this AD. We have not changed the AD in this regard.
Parts Availability
The commenter also states that spares are not readily available. The commenter adds that the lead time (order to delivery) for kits to modify the thrust reverser cascades is 10 to 12 weeks. We infer that the commenter wants the compliance time for the modified parts required in paragraph (e) of this AD to be extended.
We agree to extend the compliance time of paragraph (e) of this AD and have modified paragraph (e) to have a compliance time of 90 days after the effective date of this AD. We have evaluated the level of risk and have determined that extending the compliance time for paragraph (e) of this AD will not adversely affect safety. Should it be necessary, paragraph (g) of this AD provides operators the opportunity to request an additional extension of the compliance time if data (such as proof that parts have beenordered) are presented to justify such an extension.
Request To Revise Reference in Note 2
The commenter notes that the Bombardier service bulletin reference in Note 2 is missing a "B" from the service bulletin number.
We agree. We have changed the reference in Note 2 to correctly reference the Bombardier service bulletin.
Explanation of Change to Applicability
We have revised the applicability of the existing AD to identify model designations as published in the most recent type certificate data sheet for the affected models.
Clarification of Alternative Method of Compliance (AMOC) Paragraph
We have revised this action to clarify the appropriate procedure for notifying the principal inspector before using any approved AMOC on any airplane to which the AMOC applies.
Clarification of Previous Difference With the Canadian Airworthiness Directive
In the NPRM, we differed from the Canadian airworthiness directive available at that time (CF-2002-30,dated May 22, 2002) and proposed requiring the modification actions in paragraph (d) of this AD. We also noted that Transport Canada Civil Aviation (TCCA) was considering superseding their airworthiness directive to mandate the same actions we specified in paragraph (d). On June 22, 2004, the TCCA issued a revised Canadian airworthiness directive (CF-2002-30R1) that added a requirement for the modification that is the same as the actions of paragraph (d). We no longer differ from the Canadian airworthiness directive. We have revised Note 3 of this AD to refer to the revised Canadian airworthiness directive.
Conclusion
After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes described previously. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.
Cost ImpactThe FAA estimates that 102 airplanes of U.S. registry will be affected by this AD. The average labor rate is $65 per work hour.
It will take approximately 1 work hour per airplane to accomplish the inspection. Based on these figures, the cost impact of the inspection on U.S. operators is estimated to be $6,630, or $65 per airplane, per inspection cycle.
It will take approximately 6 work hours per airplane to accomplish the modification. Based on these figures, the cost impact of the rework on U.S. operators is estimated to be $39,780, or $390 per airplane.
The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the 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.
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 inthis rulemaking action.
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.
For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under 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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at 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: