On December 2, 1998, the FAA issued telegraphic AD T98-25-51, which is applicable to certain Airbus Model A310 and A300-600 series airplanes equipped with Pratt & Whitney JT9D-7R4 or PW4000 series engines.
The Direction G n rale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, notified the FAA that it received a report indicating that the thrust reverser of engine number 1 on an Airbus Model A300-600 series airplane deployed during climb. At the time of the deployment, the engine was at climb power and the indicated air speed was at approximately 240 knots. The corresponding engine was set to idle power automatically. The auto restow function was activated automatically by the aircraft system logic leading to the thrust reverser being stowed away. Investigation revealed that the pressure regulator shut-off valve was defective. However, a defective pressure regulator shut-off valve is not enough to cause deployment ofthe thrust reverser, unless another failure occurs at the same time. Airbus is continuing further analysis and investigation to determine the cause of the thrust reverser deployment.
Inflight deployment of a thrust reverser, if not prevented, could result in reduced controllability of the airplane.
Explanation of Relevant Service Information
Airbus has issued All Operators Telex (AOT) 78-08, dated November 30, 1998, which describes procedures for deactivation of both thrust reversers. The DGAC classified that AOT as mandatory and issued French airworthiness directive T98-477-273(B), dated November 30, 1998, in order to assure the continued airworthiness of these airplanes in France.
That French airworthiness directive also contains a note recommending certain operational performance penalties be applied as specified in Airbus Flight Operations Telex (FOT) 999.0124/98, dated November 30, 1998, for airplanes on which the thrust reversers are deactivated.
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 the Requirements of the Rule
Since the unsafe condition described is likely to exist or develop on other airplanes of the same type design registered in the United States, the FAA issued telegraphic AD T98-25-51 to prevent inflight deployment of a thrust reverser, which could result in reduced controllability of the airplane. The AD requires deactivation of both thrust reversers,in accordance with the AOT described previously.
Additionally, the AD requires a revision of the FAA-approved airplane flight manual (AFM), in order to ensure that safe and appropriate performance is achieved during certain takeoff conditions for airplanes on which both thrust reversers have been deactivated. This AD requires a revision of the AFM to require performance penalties for those certain takeoff conditions.
Interim Action
The requirements of this AD are considered to be interim action until final action is identified, at which time the FAA may consider further rulemaking.
Since it was found that immediate corrective action was required, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual telegrams issued on December 2, 1998, to all known U.S. owners and operators of certain Airbus Model A310 and A300-600 series airplanes equipped with Pratt & Whitney JT9D-7R4 or PW4000 series engines. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it effective as to all persons.
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 suggestionsis 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-358-AD." The postcard will be date 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 obtainedfrom 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: