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Proposed Rule

Airworthiness Directives; Airbus Model A300 B4-620, A310-304, A310-324, and A310-325 Airplanes

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

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AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Airbus Model A300 B4-620, A310-304, A310-324, and A310-325 airplanes. This proposed AD would require installing fused adaptors between the external wiring harness and the in-tank wiring at the connectors on the fuel tank wall of the auxiliary center tank (ACT). This proposed AD is prompted by the results of fuel system reviews conducted by the manufacturer. We are proposing this AD to prevent an ignition source in the ACT, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.

DATES:

We must receive comments on this proposed AD by September 7, 2005.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD.

  • DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
  • Government-wide Rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
  • Mail: Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., Nassif Building, Room PL-401, Washington, DC 20590.
  • Fax: (202) 493-2251.
  • Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Contact Airbus, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France, for service information identified in this proposed AD.

Start Further Info

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 (425) 227-2797; fax (425) 227-1149.

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SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Include the docket number “Docket No. FAA-2005-22032; Directorate Identifier 2005-NM-049-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.Start Printed Page 45588

We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of our docket Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647-5227) is located on the plaza level of the Nassif Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them.

Discussion

The FAA has examined the underlying safety issues involved in recent fuel tank explosions on several large transport airplanes, including the adequacy of existing regulations, the service history of airplanes subject to those regulations, and existing maintenance practices for fuel tank systems. As a result of those findings, we issued a regulation titled “Transport Airplane Fuel Tank System Design Review, Flammability Reduction and Maintenance and Inspection Requirements” (67 FR 23086, May 7, 2001). In addition to new airworthiness standards for transport airplanes and new maintenance requirements, this rule included Special Federal Aviation Regulation No. 88 (“SFAR 88,” Amendment 21-78, and subsequent Amendments 21-82 and 21-83).

Among other actions, SFAR 88 requires certain type design (i.e., type certificate (TC) and supplemental type certificate (STC)) holders to substantiate that their fuel tank systems can prevent ignition sources in the fuel tanks. This requirement applies to type design holders for large turbine-powered transport airplanes and for subsequent modifications to those airplanes. It requires them to perform design reviews and to develop design changes and maintenance procedures if their designs do not meet the new fuel tank safety standards. As explained in the preamble to the rule, we intended to adopt airworthiness directives to mandate any changes found necessary to address unsafe conditions identified as a result of these reviews.

In evaluating these design reviews, we have established four criteria intended to define the unsafe conditions associated with fuel tank systems that require corrective actions. The percentage of operating time during which fuel tanks are exposed to flammable conditions is one of these criteria. The other three criteria address the failure types under evaluation: single failures, single failures in combination with another latent condition(s), and in-service failure experience. For all four criteria, the evaluations included consideration of previous actions taken that may mitigate the need for further action.

The Joint Aviation Authorities (JAA) has issued a regulation that is similar to SFAR 88. (The JAA is an associated body of the European Civil Aviation Conference (ECAC) representing the civil aviation regulatory authorities of a number of European States who have agreed to co-operate in developing and implementing common safety regulatory standards and procedures.) Under this regulation, the JAA stated that all members of the ECAC that hold type certificates for transport category airplanes are required to conduct a design review against explosion risks.

The Direction Générale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, notified us that an unsafe condition may exist on certain Airbus Model A300 B4-620, A310-304, A310-324, and A310-325 airplanes. The DGAC advises that the electrical wiring for the fuel quantity indicators (FQIs) of the auxiliary center tank (ACT) is installed in harnesses that also contain 115V wiring that supplies other systems. The DGAC further advises that, pursuant to SFAR 88 and JAA reviews, the electrical routing of the ACT FQI wiring should be improved by segregating it from the 115V wiring. Wiring that is not segregated could result in an ignition source in the ACT, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.

Relevant Service Information

Airbus has issued the service bulletins in the following table.

Airbus Service Bulletins

Service bulletinRevisionDateModel
A300-28-6073OriginalDecember 23, 2004A300 B4-620 airplanes.
A310-28-2149OriginalSeptember 29, 2004A310-304, A310-324, and A310-325 airplanes.

These service bulletins describe procedures for installing fused adaptors between the external wiring harness and the in-tank wiring at the connectors on the fuel tank wall of the ACT. Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition. The DGAC mandated the service information and issued French airworthiness directive F-2005-021, dated February 2, 2005, to ensure the continued airworthiness of these airplanes in France.

FAA's Determination and Requirements of the Proposed AD

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. We have examined the DGAC's findings, evaluated all pertinent information, and determined that we need to issue an AD for airplanes of this type design that are certificated for operation in the United States.

Therefore, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously.Start Printed Page 45589

Difference Between the French Airworthiness Directive and This Proposed AD

The applicability of French airworthiness directive F-2005-021 excludes airplanes on which Airbus Service Bulletin A300-28-6073 or Airbus Service Bulletin A310-28-2149 was accomplished in service. However, we have not excluded those airplanes in the applicability of this proposed AD; rather, this proposed AD includes a requirement to accomplish the actions specified in those service bulletins. This requirement would ensure that the actions specified in the service bulletins and required by this proposed AD are accomplished on all affected airplanes. Operators must continue to operate the airplane in the configuration required by this proposed AD unless an alternative method of compliance is approved. This difference has been coordinated with the DGAC.

Costs of Compliance

This proposed AD would affect about 2 airplanes of U.S. registry. The proposed actions would take about 52 work hours per airplane, at an average labor rate of $65 per work hour. Required parts would cost about $5,410 per ACT (up to two ACTs per airplane). Based on these figures, the estimated cost of the proposed AD for U.S. operators is $8,790 per ACT, per airplane.

Currently, there are no Model A300 B4-620 airplanes of U.S. registry with one or more ACTs. However, if an affected airplane is imported and placed on the U.S. Register in the future, the required actions would take about 52 work hours, at an average labor rate of $65 per work hour. Required parts would cost about $10,730 per ACT, per airplane. Based on these figures, we estimate the cost of this AD to be $14,110 per ACT.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in subtitle VII, part A, subpart III, section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD 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.

For the reasons discussed above, I certify that the 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. 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.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD. See the ADDRESSES section for a location to examine the regulatory evaluation.

Start List of Subjects

List of Subjects in 14 CFR Part 39

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The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

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PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Start Authority

Authority: 49 U.S.C. 106(g), 40113, 44701.

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[Amended]

2. The Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

Airbus: Docket No. FAA-2005-22032; Directorate Identifier 2005-NM-049-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by September 7, 2005.

Affected ADs

(b) None.

Applicability: (c) This AD applies to Airbus Model A300 B4-620, A310-304, A310-324, and A310-325 airplanes, certificated in any category; equipped with one or more auxiliary center tank (ACT), except those on which Airbus Modification 12471 has been accomplished in production.

Unsafe Condition

(d) This AD is prompted by the results of fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent an ignition source in the ACT, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.

Compliance: (e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Modification

(f) Within 24 months after the effective date of this AD: Install fused adaptors between the external wiring harness and the in-tank wiring at the connectors on the fuel tank wall of the ACT by doing all the actions specified in the Accomplishment Instructions of the applicable service bulletin in Table 1 of this AD.

Table 1.—Airbus Service Bulletins

Airbus service bulletinRevisionDateModel
A300-28-6073OriginalDecember 23, 2004A300 B4-620 airplanes.
A310-28-2149OriginalSeptember 29, 2004A310-304, A310-324, and A310-325 airplanes.

Alternative Methods of Compliance (AMOCs)

(g) The Manager, ANM-116, Transport Airplane Directorate, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

Related Information

(h) French airworthiness directive F-2005-021, dated February 2, 2005, also addresses the subject of this AD.

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Start Printed Page 45590

Issued in Renton, Washington, on August 2, 2005.

Kevin Mullin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

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[FR Doc. 05-15591 Filed 8-5-05; 8:45 am]

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