The FAA recently received reports of four separate incidents of partial to full jamming of the aileron control circuit during flight of Cessna Model 750 airplanes. In each instance, control of the airplane was maintained by reversion to the backup manual control of the flight controls, yaw input, or by application of secondary roll control input. In the reported occurrences, the affected airplanes were exposed to precipitation on the ground prior to flight, or had encountered precipitation while in flight. Investigation revealed that water contamination and subsequent accretion of ice on the center aileron roll feel and centering assembly can prevent free movement of the bungee shaft, which may cause jamming of the aileron control circuit. This condition, if not corrected, could result in reduced controllability of the airplane.
Explanation of Relevant Service Information
Cessna has issued Citation Alert Service Letter ASL750-12-02, dated September29, 1997, which describes procedures for repetitive lubrication of the aileron feel cartridge assembly shaft.
The FAA has reviewed and approved Cessna Citation Service Bulletin 750-27-10, dated January 16, 1998, which includes Supplemental Data to Service Bulletin 750-27-10, dated January 16, 1998, which describes procedures for replacement of the roll feel and centering bungee assembly with an improved assembly that would prevent ice accumulation on the aileron feel cartridge assembly shaft. Accomplishment of this replacement eliminates the need for the repetitive lubrications of the aileron feel cartridge assembly shaft.
Explanation of the Requirements of the Rule
Since an unsafe condition has been identified that is likely to exist or develop on airplanes of the same type design, this AD is being issued to prevent the possibility of accumulation of ice on the aileron feel cartridge assembly shaft, which could result in jamming of the aileron control circuit, and consequentreduced controllability of the airplane. This AD requires accomplishment of the actions specified in the alert service letter and the service bulletin described previously, except as discussed below.
Differences Between the AD and the Relevant Service Bulletin
Operators should note that, although the service bulletin recommends accomplishing the replacement within 90 days after the release of the service bulletin, the FAA has determined that an interval of 90 days would not address the identified unsafe condition in a timely manner. In developing an appropriate compliance time for this AD, the FAA 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 replacement. In light of all of these factors, the FAA finds 60 days to be an appropriate compliance time for initiating the required actions in that it representsthe maximum interval of time allowable for affected airplanes to continue to operate without compromising safety.
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.
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 98-NM-38-AD." The postcard will bedate stamped and returned to the commenter.
Regulatory Impact
The regulations adopted herein will not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.
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 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.
39.13 [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: