On March 20, 2002, the FAA issued emergency AD 2002-06-53, which is applicable to Airbus Model A319, A320, A321, A330, and A340 series airplanes equipped with certain Thales Avionics DDRMIs.
The Direction Generale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, recently notified the FAA that an unsafe condition may exist on Airbus Model A319, A320, A321, A330, and A340 series airplanes, equipped with certain Thales Avionics DDRMIs.
The DGAC indicated that several operators have reported DDRMI circuit breaker tripping, followed by the loss of Very High Frequency Omni Range (VOR) and Distance Measuring Equipment (DME) sources for navigation and displays. Investigation has revealed that the DDRMI transformer short-circuited, leading to leakage of 115 volt alternating current (AC) to systems connected to DDRMI ARINC 429 input data busses.
The computers connected to the ARINC 429 bus that may be affected include VOR 1 and 2, DME 1 and 2, Automatic Direction Finder (ADF) 1 and 2, Display Management Computer (DMC) 1 and 2 and 3, Centralized Fault Display Interface Unit (CFDIU), Control and Display Unit--Air Data/Inertial Reference System (CDU-ADIRS), ADIRS 1 and 3, Fuel Quantity Indicating Computer (FQIC), Data Management Unit (DMU), Flight Augmentation Computer (FAC) 2, Flight Management and Guidance Computer (FMGC) 2, Braking and Steering Control Unit (BSCU), Spoiler and Elevator Computer (SEC) 2 and 3, Elevator and Aileron Computer (ELAC) 2, Multi Mode Receiver (MMR) 1, Centralized Maintenance Computer (CMC) 1 and 2, Flight Warning Computer (FWC) 1 and 2, and Multipurpose Control and Display Unit (MCDU) 2.
Failure of the DDRMI, if not corrected, could cause the loss of data from the affected computers to other systems and degradation or total failure of the computers, leading to reduced ability to control the airplane in adverse conditions.
Explanation of Relevant Service Information
Airbus has issued the following All Operators Telexes (AOTs) which describe procedures for deactivation of certain Thales Avionics DDRMIs:
Airbus AOT A320-34A1262, dated March 19, 2002, applicable to certain Airbus Model A319, A320, and A321 series airplanes;
Airbus AOT A330-34A3109, dated March 19, 2002, applicable to certain Airbus Model A330 series airplanes; and
Airbus AOT A340-34A4120, dated March 19, 2002, applicable to certain Airbus Model A340 series airplanes.
The DGAC classified these AOTs as mandatory and issued French airworthiness directives T2002-150(B), dated March 19, 2002, applicable to Airbus Model A319, A320, and A321 series airplanes; and T2002-151(B), dated March 19, 2002, applicable to Airbus Model A330 and A340 series airplanes; in order to ensure 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 theprovisions 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 emergency AD 2002-06-53 to prevent failure of the DDRMI, which could cause the loss of data from the affected computers to other systems and degradation or total failure of the computers, leading to reduced ability to control the airplane in adverse conditions. The AD requires deactivation of certain Thales AvionicsDDRMIs. The actions are required to be accomplished in accordance with the applicable Airbus AOT, except as described below.
Corrections to Emergency AD
The FAA has revised paragraph (b) of this AD to indicate that operators must submit requests for approval of alternative methods of compliance to the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA.
In addition, the FAA has included the date of Airbus AOT A320-34A1262 in the applicability of this AD. That date was inadvertently omitted from the applicability of the emergency AD.
Differences Between Foreign Airworthiness Directives and This AD
The French airworthiness directives apply both to airplanes on which DDRMIs with specified part numbers were installed in production since 1999, and also to other airplanes on which DDRMIs with these same part numbers have been repaired or replaced since 1999. This AD applies to airplanes equipped with Thales Avionics DDRMIs listed in the applicable Airbus AOTs, regardless of repair or replacement status. The FAA has determined that it is possible that a DDRMI could have been repaired or replaced and that the required retention period for maintaining such records may have expired. Therefore, operators may not be able to ascertain whether repair or replacement has been accomplished.
Since the FAA considers the unsafe condition resulting from failure of the DDRMI is far more critical than the operational consequences of deactivating the DDRMI, this AD mandates deactivation of all Thales Avionics DDRMIs listed in the applicable Airbus AOTs. Operators may request authorization to reactivate a particular DDRMI, if they have data to substantiate that the DDRMI is not susceptible to the failure condition identified in this AD.
In addition, the French airworthiness directives specify that dispatch with an inoperative standby compass (Master Minimum Equipment List item 34-22-02a) is limited to a "B" rectification interval. This AD does not contain this restriction because the FAA's Master Minimum Equipment List already limits an inoperative standby compass to a "B" rectification interval.
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 notices issued on March 20, 2002, to all known U.S. owners and operators of Airbus Model A319, A320, A321, A330, and A340 series airplanes equipped with certain Thales DDRMIs. 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.
Interim Action
This AD is considered to be interim action until final action is identified, at which time the FAA may consider further rulemaking.
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 therule. 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 2002-NM-80-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.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: