01-12177. Airworthiness Directives; Airbus Model A319, A320, and A321 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 A319, A320, and A321 series airplanes. This proposal would require modifications of route segregation between the low voltage wire bundles of the fuel quantity indicating system and the high voltage wire bundles of the ground power control unit. This action is necessary to prevent injection of 115 volt alternating current (VAC) into 28 volt direct current (VDC) wire bundles, which could result in high voltage conditions within the fuel tank and the potential for damage to equipment, electrical arcing, and fuel vapor ignition on the ground. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by June 14, 2001.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2000-NM-383-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 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. 2000-NM-383-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 for Windows or ASCII text.

The service information referenced in the proposed rule may be obtained from Airbus Industrie, 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 Dulin, 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 notice must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2000-NM-383-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. 2000-NM-383-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 A319, A320, and A321 series airplanes. The DGAC advises that, in response to industry concerns, a review of the routing of wires that terminate/enter the fuel tank was performed on production aircraft. The review identified an unsafe condition in a 700-millimeter span of wiring at the back of shelf 92VU in the forward avionics compartment. Along that 700-millimeter span there is no permanent segregation between the electrical wire bundle connected to the fuel quantity indicating system (FQIS) and the bundle connected to the ground power control unit (GPCU). In the event that both bundles had wires damaged down to the core, and an electrical path, such as fluid or metallic contamination, occurred between the two wire bundles, conditions would exist that could result in the injection of 115 volts, alternating current (VAC), from the GPCU wires into the 28 volts, direct current (VDC), FQIS wires down to the fuel tanks. Such a high voltage injection into low voltage wiring could result in the potential for damage to equipment, electrical arcing, and fuel vapor ignition on the ground. This result could not occur in flight because the GPCU is powered only on the ground.

Explanation of Relevant Service Information

Airbus has issued Revision 02 of Service Bulletin A320-92-1007, dated August 4, 2000, which describes procedures for installing an additional protective conduit for each wiring route and a dual branch tubular ramp to ensure physical separation of the wiring routes. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition. The DGAC classified this service bulletin as mandatory and issued French airworthiness directive 2000-407-150(B), dated September 20, 2000, 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 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 Rule

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 service bulletin described previously.

Cost Impact

The FAA estimates that 291 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 24 to 42 work hours per airplane to accomplish the proposed modifications, depending on the wiring configuration of the airplane, and that the average labor rate is $60 per work hour. Required parts would cost approximately $1,300 per airplane. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be between $797,340 and $1,111,620 or between $2,740 and $3,820 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 proposed AD were not adopted.

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 Industrie: Docket 2000-NM-383-AD.

Applicability: Model A319, A320, and A321 series airplanes, certificated in any category, except those on which Airbus Industrie Modification 28289 has been installed.

Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent injection of 115 volt alternating current (VAC) into 28 volt direct current (VDC) wire bundles, which could result in high voltage conditions within the fuel tank and the potential for damage to equipment, electrical arcing, and fuel vapor ignition on the ground, accomplish the following:

Modification

(a) Within 4 years after the effective date of this AD, install additional protective conduits and new supports to ensure physical route segregation between the low voltage wire bundles of the fuel quantity indicating system (FQIS) and the high voltage wire bundles of the ground power control unit (GPCU), in accordance with Airbus Service Bulletin A320-92-1007, Revision 02, dated August 4, 2000.

Note 2:

Modifications accomplished prior to the effective date of this AD in accordance with Airbus Service Bulletin A320-92-1007, dated January 12, 2000, or Airbus Service Bulletin A320-92-1007, Revision 01, dated June 29, 2000, are considered acceptable for compliance with the applicable actions specified in this amendment.

Alternative Methods of Compliance

(b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send them to the Manager, International Branch, ANM-116.

Note 3:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.

Special Flight Permits

(c) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Note 4:

The subject of this AD is addressed in French airworthiness directive 2000-407-150(B), dated September 20, 2000.

Issued in Renton, Washington, on May 9, 2001.

Donald L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.