Airworthiness directives: Airbus,

[Federal Register: July 20, 1999 (Volume 64, Number 138)]

[Proposed Rules]

[Page 38848-38850]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr20jy99-21]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-08-AD]

RIN 2120-AA64

Airworthiness Directives; Airbus Model A310-300 and A300-600R 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 A310-300 and A300-600R series airplanes. This proposal would require installation of a new cover assembly, associated new drain and vent pipework, and a new electrical harness on the trimmable horizontal stabilizer for the fuel tank water scavenge motive pump. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to prevent fuel leakage from the seal of the water scavenge pumps, which, if not corrected, could result in leakage of fuel into fuselage areas not designed for fuel, and consequent potential for fuel to be in contact with a fuel ignition source.

DATES: Comments must be received by August 19, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-08-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.

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: Norman B. Martenson, Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149.

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 notice may be changed in light of the comments received.

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 filedin 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 99-NM-08-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. 99-NM-08-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

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 A310-300 and A300-600R series airplanes. The DGAC advises that it has received reports of excessive water and ice build-up in the fuel tanks, particularily in the trim tank and inner tanks. This was occurring increasingly during extended twin engine operations (ETOPS), when turn around times were short, and water drainage was ineffective due to frozen drain valves.

In an attempt to reduce the need for manual sumping of the tanks, a water scavenge system was developed. The scavenge system is powered by a dedicated pump installed inside the tank, without canister type outside access. The pumps are located on the rear spar of the wing and on the horizontal stabilizer front spar in the trim tank. These pumps provide the motive force for new jet pumps installed in the tanks. The jet pumps will continually pick up water from the low points in the tanks, and therefore, prevent any ice build-up.

It was found that the trim tank scavenge pump installations did not have a double seal between the tank and fuselage section 19. If the seal on this optionally installed pump does not perform its function, the possibility exists that without a second, normally redundant seal, leakage could occur into the fuselage section 19. This condition, if not corrected, could result in leakage of fuel into fuselage areas not designed for fuel, and consequent potential for fuel to be in contact with a fuel ignition source.

[[Page 38849]]

Explanation of Relevant Service Information

Airbus has issued Service Bulletin A300-28-6035, Revision 2, dated March 17, 1993 (for Model A300-600R series airplanes), and Service Bulletin A310-28-2058, Revision 2, dated February 22, 1995 (for Model A310-300 series airplanes), which describe procedures for installation of a new cover assembly, associated new drain and vent pipework, and a new electrical harness on the trimmable horizontal stabilizer for the fuel tank water scavenge motive pump. The DGAC classified these service bulletins as mandatory and issued French airworthiness directive 98- 354-256(B), dated September 9, 1998, in order to assure 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 bulletins described previously.

Cost Impact

The FAA estimates that 102 Model A310-300 and A300-600R series airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 20 work hours per airplane to accomplish the proposed actions, and that the average labor rate is $60 per work hour. Required parts would cost approximately $5,710. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $704,820, or $6,910 per airplane.

The cost impact figure discussed above is 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.

Regulatory Impact

The regulations proposed herein would not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

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.

   Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

   Airbus Industrie: Docket 99-NM-08-AD.

   Applicability: Model A310-300 and A300-600R series airplanes, except those airplanes on which Airbus Modification 10003 (reference Airbus Service Bulletin A310-28-2058, Revision 2, dated February 22, 1995, or A300-28-6035, Revision 2, dated March 17, 1993) has been accomplished; certificated in any category.

   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 (e) 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 fuel leakage from the seal of the water scavenge pumps, which, if not corrected, could result in leakage of fuel into fuselage areas not designed for fuel, and consequent potential for fuel to be in contact with a fuel ignition source, accomplish the following:

   Model A310-300 Series Airplanes: Modification

   (a) For Model A310-300 series airplanes on which a water scavenge pump has been installed prior to the effective date of this AD, in accordance with Airbus Modification 8679 (reference Airbus Service Bulletin A310-28-2049, dated February 6, 1992; Revision 1, dated June 17, 1992; Revision 2, dated June 3, 1994; or Revision 3, dated April 5, 1996): Within 18 months after the effective date of this AD, install a new cover assembly, associated new drain and vent pipework, and a new electrical harness, in accordance with Airbus Service Bulletin A310-28-2058, Revision 2, dated February 22, 1995.

   (b) For Model A310-300 series airplanes on which a water scavenge pump is installed after the effective date of this AD, in accordance with Airbus Modification 8679 (reference Airbus Service Bulletin A310-28-2049, dated February 6, 1992; Revision 1, dated June 17, 1992; Revision 2, dated June 3, 1994; or Revision 3, dated April 5, 1996): The actions required by paragraph (a) of this AD must be accomplished simultaneously with Airbus Modification 8679.

   Model A300-600R Series Airplanes: Modification

   (c) For Model A300-600R series airplanes on which a water scavenge pump has been installed prior to the effective date of this AD, in accordance with Airbus Modification 8679 (reference Airbus Service Bulletin A300-28-6028, dated February 6, 1992; Revision 1, dated June 5, 1992; Revision 2, dated October 14, 1993; Revision 3, dated April 5, 1996; or Revision 4, dated April 3, 1997): Within 18 months after the effective date of this AD, install a new cover assembly, associated new drain and vent pipework, and a new electrical harness, in accordance with Airbus Service A300-28-6035, Revision 2, dated March 17, 1993.

   Note 2: Installation of a new cover assembly, associated new drain and vent pipework, and a new electrical harness in accordance with Airbus Service Bulletin

   [[Page 38850]]

   A300-28-6035, Revision 1, dated December 4, 1992, is considered acceptable for compliance with the requirements specified in paragraph (c) of this AD.

   (d) For Model A300-600R series airplanes on which a water scavenge pump is installed after the effective date of this AD, in accordance with Airbus Modification 8679 (reference Airbus Service Bulletin A300-28-6028, dated February 6, 1992; Revision 1, dated June 5, 1992; Revision 2, dated October 14, 1993; Revision 3, dated April 5, 1996; or Revision 4, dated April 3, 1997): The actions required by paragraph (c) of this AD must be accomplished simultaneously with Airbus Modification 8679.

   Alternative Methods of Compliance

   (e) 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, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it 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

   (f) 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 98-354-256(B), dated September 9, 1998.

   Issued in Renton, Washington, on July 14, 1999. D.L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

   [FR Doc. 99-18411Filed7-19-99; 8:45 am]

   BILLING CODE 4910-13-P