The Direction G n rale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, recently notified the FAA that an unsafe condition may exist on certain Airbus Model A300 and all Model A300-600 and A310 series airplanes. The DGAC advises that an Airbus Model A300-600 series airplane flew with autopilot 1 (AP 1), pitch trim 1 (PT 1), and pitch trim 2 (PT 2) engaged. When the flight crew engaged the vertical speed mode and selected a new vertical speed in order to change the flight level, the vertical speed of the airplane changed but did not remain at the speed that had been selected by the flight crew.
After landing, the maintenance team performed a test with the autopilot engaged in vertical speed mode. When the team selected a vertical speed, the flight director pitch bars and control columns moved, but the pitch trim wheels did not move. An open circuit was found in the connection between flight control computer 1 (FCC 1)and flight augmentation computer 1 (FAC 1). That connection is necessary to generate the autotrim function.
With the autopilot engaged in command (CMD), the FCC command (COM) and monitor (MON) lanes send signals to the FAC in order to ensure the autotrim function. When the FAC does not receive the FCC COM signal or the FCC MON signal, the autotrim function is inhibited, which results in an out-of-trim condition. If an autopilot disconnect occurs when the airplane is in an out-of-trim condition, this condition, if not corrected, could result in a sudden change in pitch and consequent reduced controllability of the airplane.
Explanation of Relevant Service Information
Airbus has issued All Operators Telexes (AOT) A300-22A0115 (for Model A300 series airplanes), A300-600-22A6042 (for Model A300-600 series airplanes), and A310-22A2053 (for Model A310 series airplanes), all dated December 23, 1999, which describe procedures for a pitch trim system test to detect any continuity defect, and follow-on corrective actions, if necessary. Corrective actions include repairing any discrepant wiring found in the pitch trim system. (The AOT s reference Aircraft Schematic Manual 22-27-00 as an additional source of service information for accomplishment of the repair.) The DGAC has classified these AOT s as mandatory and issued French airworthiness directive T2000-007-301(B), dated January 4, 2000, in order to assure the continued airworthiness of these airplanes in France.
FAA's Conclusions
These airplane models are manufactured in France 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. Pursuant to this bilateral airworthiness agreement, the DGAC has kept the FAA informed of the situation described above. The FAA has examined the findings of the DGAC, reviewed all available information, and determined that AD action is necessary for products of 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 a sudden change in pitch due to an out-of-trim condition combined with an autopilot disconnect, which could result in reduced controllability of the airplane. This AD requires performing a pitch trim system test to detect any continuity defect in the autotrim function, and follow-on corrective actions, if necessary. The actions are required to be accomplished in accordance with the AOT s described previously.
Interim Action
This is considered to be interim action. The manufacturer has advised that it currently is developing additional actions that will positively address the unsafe condition addressed by this AD. Once these actions are developed, approved, and available, the FAA may consider additional rulemaking.
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 datefor 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 2000-NM-09-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 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: