The Direction Generale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, notified the FAA that an unsafe condition may exist on certain Airbus Model A300 B4-600, B4-600R, C4-605R Variant F, and F4-600R (collectively called A300-600) series airplanes; and Model A310 series airplanes. The DGAC advises that an operator found structural damage on the forward pyramid arm of an engine pylon during a scheduled maintenance check. Investigation revealed that the damage was caused by chafing of the integrated drive generator (IDG) electrical harness against the structure of the pyramid arm. This condition, if not corrected, could result in loss of the relevant alternating current (AC) bus bar, reduced structural integrity of the engine pylon, and consequent loss of control of the airplane.
Explanation of Relevant Service Information
Airbus has issued All Operators Telex (AOT) A300-54A6037, dated February 19, 2004 (for Model A300-600series airplanes); and AOT A310-54A2038, dated February 19, 2004 (for Model A310 series airplanes). These AOTs describe procedures for inspecting for damage of the IDG harness and pyramid arm, and related investigative and corrective actions if necessary.
The inspection involves:
Determining if the IDG electrical harness bracket on the pylon forward pyramid arm is attached, and if the retaining fasteners are in place and secured.
Determining if there is contact between the IDG electrical harness and the pyramid arms.
Determining if there is damage (chafing marks) on the pylon forward pyramid arms; and/or damage (chafing or fretting) to the IDG electrical harness, especially at the junction between the 4 convoluted conduits that protect each feeder cable, and at the large conduit that protects the 4 cables together.
The related investigative and corrective actions depend on the results of the inspection and include the following:
If there is no damage found, no further action is specified by the AOT.
If the bracket on the pylon forward pyramid arm is not attached and/or the fasteners are not in place and secured, the corrective action is to repair the bracket and/or fasteners.
If there is fretting at the convoluted conduits (with or without contact between the IDG electrical harness and the pyramid arms), the related investigative and corrective actions are to inspect the feeder cables for damage, repair the cables if necessary per the limits defined in the Airbus electrical standard practices manual, and apply self-adhesive protective tape to the IDG electrical harness at possible contact points.
If there is any contact between the IDG electrical harness and the pyramid arms, without damage to the harness or the arms, and without fretting at the convoluted conduits, the related corrective action is to apply self-adhesive protective tape to the harness at possible contact points.
If there is any damage to the pyramid arms found during any inspection, the AOTs recommend contacting Airbus before further flight for disposition of repairs.
The DGAC classified these AOTs as mandatory and issued French airworthiness directive F-2004-039, dated March 17, 2004, 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 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 hasbeen 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 loss of the relevant AC bus bar, reduced structural integrity of the engine pylon, and consequent loss of control of the airplane. This AD requires a one-time inspection for damage of the IDG electrical harness and pyramid arm, and repair if necessary. The actions are required to be accomplished in accordance with the AOTs described previously, except as discussed below.
Differences Among the French Airworthiness Directive, the AOTs, and This AD
The French airworthiness directive and the AOTs do not define the type of inspection for the IDG electrical harness and pyramid arm. This AD calls the inspection a "detailed inspection." Note 1 of this AD defines this inspection.
Although the French airworthiness directive and the AOTs specify to report inspection results to the manufacturer, this AD does not include sucha requirement.
Where the French airworthiness directive and the AOTs specify to contact Airbus for disposition of repairs if there is any damage to the pyramid arms, this AD requires operators to repair per a method approved by either the FAA or the DGAC (or its delegated agent). In light of the type of repair that would be required to address the unsafe condition, and consistent with existing bilateral airworthiness agreements, we have determined that, for this AD, a repair approved by either the FAA or the DCAG would be acceptable for compliance with this AD.
Interim Action
We consider this AD interim action. If final action is identified later, we may consider further rulemaking then.
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.
Submit comments using the following format:
Organize comments issue-by-issue. For example, discussa request to change the compliance time and a request to change the service bulletin reference as two separate issues.
For each issue, state what specific change to the AD is being requested.
Include justification (e.g., reasons or data) for each request.
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 2004-NM-57-AD." The postcard will be date stamped and returned tothe 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 RulesDocket. 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: