04-6681. Airworthiness Directives; Airbus Model A330, A340-200, and A340-300 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Airbus Model A330, A340-200, and A340-300 series airplanes. This proposal would require repetitive inspections for evidence of corrosion and sheared attachment bolts of the sensor struts at flap track 4 on the left and right sides of the airplane; related investigative and corrective actions as necessary; and a terminating action for the repetitive inspections, by requiring the eventual replacement of all sensor struts with new, improved sensor struts that are less sensitive to corrosion. This action is necessary to prevent loss of the sensor strut function, resulting in the inability to detect flap drive disconnection at flap track stations 4 and 5, which could lead to separation of the outboard flap from the airplane, and consequent reduced controllability of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by April 26, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-246-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2002-NM-246-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 or 2000 or ASCII text.

The service information referenced in the proposed rule may be obtained from Airbus, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Tim Backman, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed 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 above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a 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 proposed 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 proposed 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 summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2002-NM-246-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-246-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The Direction Générale 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 A330, A340-200, and A340-300 series airplanes. The DGAC advises that it has received several reports of corroded sensor struts and sheared attachment bolts at flap track 4 on Model A330 series airplanes. Investigation revealed that corrosion of the sensor struts was due to wear of the protective surface. Further investigation revealed that the corroded sensor struts created friction with the piston rod, resulting in increased axial loads. The increased loads caused the shearing of the attachment bolts due to fatigue rupture. This condition, if not corrected, could result in loss of the sensor strut function, resulting in the inability to detect flap drive disconnection at flap track stations 4 and 5, which could lead to separation of the outboard flap from the airplane, and consequent reduced controllability of the airplane.

The sensor strut system on Model A340-200 and -300 series airplanes is identical to that on the affected Model A330 series airplanes. Therefore, those Model A340-200 and -300 series airplanes may be subject to the same unsafe condition revealed on the Model A330 series airplanes.

Explanation of Relevant Service Information

Airbus has issued Service Bulletins A330-27-3091, Revision 03 (for Model A330 series airplanes); and A340-27-4097, Revision 03 (for Model A340-200 and -300 series airplanes); both dated January 16, 2004. These service bulletins describe procedures for:

• Repetitively inspecting (by applying hand force to the piston of the sensor struts) the sensor struts at flap track 4, on the left and right sides of the airplane, for evidence of corrosion and sheared attachment bolts.
• For certain airplanes, removing affected sensor struts and measuring the axial force, cleaning sensor strut assemblies, re-installing the sensors, and inspecting (checking) the adjacent structure and attachment elements for cracking and/or deformation.
• Contacting Airbus for repair information if cracking and/or deformation are found.
• Replacing affected sensor struts with a part number as listed in Paragraph 2.C of the applicable service bulletin, including part numbers listed in the “Old Part No.” column.
• Doing an operational test of the flap system after installation of any new sensor strut.

Accomplishment of the actions specified in the applicable service bulletins is intended to adequately address the identified unsafe condition. The DGAC classified these service bulletins as mandatory and issued French airworthiness directives F-2003-425 and F-2003-426, both dated December 10, 2003, to ensure the continued airworthiness of these airplanes in France.

Airbus has also issued Service Bulletins A330-27-3092 (for Model A330 series airplanes); and A340-27-4098 (for Model A340-200 and -300 series airplanes); both dated February 14, 2003. These service bulletins describe procedures for replacing the existing sensor struts at flap track 4 on the left and right sides of the airplane with new, improved sensor struts having part number F5757492600000, that are less sensitive to corrosion; and testing the flap system after installation of new sensor struts.

Accomplishment of these service bulletins eliminates the need for the repetitive inspections specified in Airbus Service Bulletins A330-27-3091, Revision 03, and A340-27-4097, Revision 03.

Airbus Service Bulletin A330-27-3092 recommends prior or concurrent accomplishment of Airbus Service Bulletin A330-27-3091. Airbus Service Bulletin A340-27-4098 recommends prior or concurrent accomplishment of Airbus Service Bulletin A340-27-4097.

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 Proposed AD

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, the proposed AD would require accomplishment of the actions specified in the applicable service bulletins described previously, except as discussed below. This proposed AD also would provide for terminating action for the repetitive inspections.

Differences Among the Service Bulletins, French Airworthiness Directive, and the Proposed AD

Although Airbus Service Bulletins A330-27-3091, Revision 03, and A340-27-4097, Revision 03, specify to report inspection results to Airbus, this proposed AD does not require that action. We do not need this information from operators.

These service bulletins also specify that operators may contact the manufacturer for disposition of certain repair conditions. This proposed AD would require operators to repair those conditions per a method approved by either us 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 proposed AD, a repair approved by either us or the DGAC would be acceptable for compliance with this proposed AD.

Cost Impact

We estimate that 9 Airbus Model A330 airplanes of U.S. registry would be affected by this proposed AD.

It would take approximately 1 work hour per airplane to accomplish the proposed repetitive inspections, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the proposed inspections on U.S. operators is estimated to be $585, or $65 per airplane, per inspection cycle.

If required, replacement of discrepant sensor struts and attachment bolts would take approximately 3 work hours, at an average labor rate of $65 per work hour. The cost for required parts would be nominal. Based on these figures, the cost impact of the proposed replacement of sensor struts is $195 per airplane.

It would take approximately 2 work hours accomplish the installation of the new, improved sensor struts, at an average labor rate of $65 per work hour. The cost of required parts would be $8,400. Based on these figures, the cost impact of the proposed installation on U.S. operators is estimated to be $76,770, or $8,530 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions. The manufacturer may cover the cost of replacement parts associated with this proposed AD, subject to warranty conditions.

Currently, there are no Airbus Model A340 series airplanes on the U.S. Register. However, should an affected airplane be imported and placed on the U.S. Register in the future, it would take approximately work hour per airplane to accomplish the proposed inspection, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the AD for Model A340 operators would be $65 per airplane.

Should an Airbus Model A340 series airplane be imported and placed on the U.S. Register in the future and replace affected sensor struts and attachment bolts, it would take approximately 3 work hours, at an average labor rate of $65 per work hour. The cost for required parts would be nominal. Based on these figures, the cost impact of the proposed replacement of sensor struts is $195 per airplane.

It would take approximately 2 work hours accomplish the installation of the new, improved sensor struts, at an average labor rate of $65 per work hour. The cost of required parts would be $8,400. Based on these figures, the cost impact of the proposed installation is estimated to be $8,530 per airplane.

Regulatory Impact

The regulations proposed herein would 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 proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this proposed regulation (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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:

Airbus: Docket 2002-NM-246-AD.

Applicability: Model A330 series airplanes; and Model A340-200 and A340-300 series airplanes; certificated in any category; except those airplanes on which one of the following has been incorporated: Airbus Modification 48579 in production; Airbus Service Bulletin A330-27-3092, dated February 14, 2003, in-service; or Airbus Service Bulletin A340-27-4098, dated February 14, 2003, in-service.

Compliance: Required as indicated, unless accomplished previously.

To prevent loss of the sensor strut function, resulting in the inability to detect flap drive disconnection at flap track stations 4 and 5, which could lead to separation of the outboard flap from the airplane, and consequent reduced controllability of the airplane, accomplish the following:

Inspection

(a) Within 2,800 flight hours or 18 months after the effective date of this AD, whichever occurs later: Do an inspection by applying hand force to the piston of the sensor struts and moving the sensor struts longitudinally, for evidence of corrosion in the sensor struts at flap track 4, on the left and right sides of the airplane, by doing all the applicable actions specified in the Accomplishment Instructions of Airbus Service Bulletin A330-27-3091, Revision 03 (for Model A330 series airplanes); or Service Bulletin A340-27-4097, Revision 03 (for Model A340-200 and -300 series airplanes); both dated January 16, 2004; as applicable. If the longitudinal travel range is 60.0mm (2.36 inches) or more: Repeat the inspection thereafter at intervals not to exceed 18 months, until the requirements of paragraph (d) of this AD are accomplished.

Related Investigative and Corrective Actions

(b) If the result of the inspection required by paragraph (a) of this AD is a longitudinal travel range of less than 60.0mm (2.36 inches): Before further flight, remove all affected sensor struts, and measure the axial force of any affected sensor struts, by doing all of the applicable actions per the Accomplishment Instructions of Airbus Service Bulletin A330-27-3091, Revision 03 (for Model A330 series airplanes); or Service Bulletin A340-27-4097, Revision 03 (for Model A340-200 and -300 series airplanes); both dated January 16, 2004; as applicable.

(1) If the axial force F is less than or equal to 50 daN (112.41 lbf.): Clean and re-install the sensor struts per the Accomplishment Instructions of the applicable service bulletin. Repeat the inspection required by paragraph (a) of this AD thereafter at intervals not to exceed 18 months, until the requirements of paragraph (d) of this AD are accomplished.

(2) If the axial force F is more than 50 daN (112.41 lbf.): Before further flight, do a detailed inspection for cracking and/or deformation of the adjacent structure and attachment parts per the Accomplishment Instructions of the applicable service bulletin

(i) If no cracking and/or deformation is found: Within 25 flight cycles after the inspection required by paragraph (b) of this AD, replace the sensor struts and attachment bolts per the Accomplishment Instructions of the applicable service bulletin. Repeat the inspection required by paragraph (a) of this AD thereafter at intervals not to exceed 18 months, until the requirements of paragraph (d) of this AD are accomplished.

(ii) If any cracking and/or deformation is found: Before further flight, repair per a method approved by either the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate; or the Direction Générale de l'Aviation Civile (or its delegated agent); and replace the sensor struts and attachment bolts per the Accomplishment Instructions of the applicable service bulletin. Repeat the inspection required by paragraph (a) of this AD thereafter at intervals not to exceed 18 months, until the requirements of paragraph (d) of this AD are accomplished.

Note 1:

For the purposes of this AD, a detailed inspection is defined as: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.”

Concurrent Requirements

(c) The actions required by paragraphs (a) and (b) of this AD must be done before or concurrently with the requirements of paragraph (d) of this AD. Replacement of any sensor strut with a sensor strut having part number (P/N) F5757492600000, during accomplishment of paragraph (b) of this AD, is acceptable for compliance with paragraph (d) of this AD, for that strut.

Terminating Action

(d) Within 42 months after the effective date of this AD: Replace all existing sensor struts with new, improved sensor struts having P/N F5757492600000 per the Accomplishment Instructions of Airbus Service Bulletins A330-27-3092 (for Model A330 series airplanes); or A340-27-4098 (for Model A340-200 and -300 series airplanes); both dated February 14, 2003; as applicable. Accomplishment of this replacement constitutes terminating action for the repetitive inspections required by paragraphs (a) and (b) of this AD.

Credit for Actions Done per Previous Issue of Service Bulletins

(e) Accomplishment of the specified actions before the effective date of this AD per Airbus Service Bulletin A330-27-3091, dated February 2, 2002; Revision 01, dated May 17, 2002; or Revision 02, dated September 5, 2002; or A340-27-4097, dated February 6, 2002; Revision 01, dated May 17, 2002; or Revision 02, dated September 5, 2002; as applicable; is considered acceptable for compliance with the applicable requirements of paragraphs (a) and (b) of this AD.

Submission of Information Not Required

(f) Although the service bulletins specify to send inspection results to the manufacturer, those actions are not required by this AD.

Alternative Methods of Compliance

(g) In accordance with 14 CFR 39.19, the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, is authorized to approve alternative methods of compliance for this AD.

Note 2:

The subject of this AD is addressed in French airworthiness directives F-2003-425 and F-2003-426, both dated December 10, 2003.

Issued in Renton, Washington, on March 19, 2004.

Kevin M. Mullin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.