# AGENCY:

 Federal Aviation Administration, DOT. 

# ACTION:

 Final rule. 

# SUMMARY:

 This amendment supersedes an existing airworthiness directive (AD), applicable to certain Airbus Model A300, A300-600, and A310 series airplanes, equipped with a welded auxiliary power unit (APU) fuel feedline adapter. That AD currently requires repetitive dye penetrant inspections to detect cracks, rupture, or fuel leaks of the fuel feedline adapter; and replacement of the adapter, if necessary. That AD also provides for optional terminating action for the repetitive inspections. This amendment requires accomplishment of the previously optional terminating action. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent fuel leakage in the APU compartment, which could result in a fire in the APU compartment. 

# DATES:

 Effective March 13, 2000. 

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of March 13, 2000. 

The incorporation by reference of certain other publications, as listed in the regulations, was approved previously by the Director of the Federal Register as of October 7, 1991 (56 FR 47672, September 20, 1991). 

# ADDRESSES:

                         The service information referenced in this AD may be obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. This information may be examined at the Federal Aviation                         Start Printed Page 5752                        Administration (FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.                     

# 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:

                     A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 91-20-07, amendment 39-8041 (56 FR 47672, September 20, 1991), which is applicable to certain Airbus Model A300, A300-600, and A310 series airplanes, was published in the                     **Federal Register**                     on October 6, 1999 (64 FR 54249). The action proposed to continue to require repetitive dye penetrant inspections to detect cracks, rupture, or fuel leaks of the fuel feedline adapter, and replacement of the adapter, if necessary. The action also proposed to continue to require verification of the correct torque values of the starter motor cable terminals and the generator cable terminals. The action also proposed to require accomplishment of the previously optional terminating action.                 

## Comments 

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received. 

One commenter requests clarification concerning the relationship between the adapter part number identified in the referenced French airworthiness directive and Airbus service bulletin and the adapter part number referred to in the Airbus Illustrated Parts Catalog (IPC). The commenter has already modified its auxiliary power units (APU) to incorporate the adapter [part number (P/N) A4937021700200] specified in the service bulletin. The Airbus IPC suggests an alternative P/N for the adapter, i.e., P/N A4937021700400; yet the IPC makes no reference to any supersedure, nor does it refer to a service bulletin authorizing that P/N. The commenter asks whether the installation of an adapter having either P/N is acceptable for compliance with the French airworthiness directive and this proposed AD. 

The FAA concurs that clarification is necessary. Airbus has advised the FAA that the only difference between the two referenced P/N's is that the tolerance for the B-nut thread of the adapter having P/N A4937021700400 has been modified following service experience. P/N A4937021700400 is installed on airplanes by Airbus Modification 10323 and is two-way interchangeable with P/N A4937021700200. Airbus advises that an adapter having either P/N will fully comply with the intent of the French airworthiness directive. The FAA has determined that installation of an adapter having either P/N will adequately address the unsafe condition identified in this AD. A NOTE has been added to the final rule to state that installation of an adapter having P/N A4937021700400 is also acceptable for compliance with the requirements of paragraph (b) of the AD. 

## Conclusion 

After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the change previously described. The FAA has determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD. 

## Cost Impact 

There are approximately 165 airplanes of U.S. registry that will be affected by this AD. 

The actions that are currently required by AD 91-20-07 take approximately 2 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the currently required actions on U.S. operators is estimated to be $120 per airplane. 

The new actions that are required by this new AD will take approximately 2 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts will cost approximately $274 per airplane. Based on these figures, the cost impact of the new requirements of this AD on U.S. operators is estimated to be $394 per airplane. 

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the 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 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. 

                    For the reasons discussed above, I certify that this action: (1) Is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under 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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it 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 

2. Section 39.13 is amended by removing amendment 39-8041 ( 56 FR 47672, September 20, 1991), and by adding a new airworthiness directive (AD), amendment 39-11556, to read as follows:

**2000-02-38 Airbus Industrie:**                         Amendment 39-11556. Docket 99-NM-23-AD. Supersedes AD 91-20-07, Amendment 39-8041.                     

*Applicability*: Model A300, A300-600, and A310 series airplanes; certificated in any category; equipped with an auxiliary power unit (APU) fuel feedline adapter, P/N A4937021700000 (welded configuration).                     

# Note 1:

                             This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been 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.                             Start Printed Page 5753                            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 an APU compartment fire, accomplish the following: 

## Restatement of Requirements of AD 91-20-07, Amendment 39-8041 

## Repetitive Inspections 

(a) Within 100 hours time-in-service after October 7, 1991 (the effective date of AD 91-20-07, amendment 39-8041), and thereafter at intervals not to exceed 400 hours time-in-service: Perform a dye penetrant inspection to detect cracks, rupture or fuel leaks at the weld of the fuel feedline adapter, in accordance with Airbus Industrie All Operators Telex (AOT) 49-01, Issue 3, dated April 25, 1991. If cracks, rupture, or fuel leaks are found, replace the adapter with an improved, non-welded one-piece-body adapter prior to the next APU operation, or placard the APU inoperative until the adapter is replaced with the improved adapter, in accordance with Airbus Industrie Service Bulletin                                                                                                                                                                                                                                                                                                                A300-49-0049, A300-49-6009, or A310-49-2012; all dated July 12, 1991; as applicable. 

(b) Within 100 hours time-in-service after October 7, 1991, verify the correct torque values of the starter motor cable terminals and the generator cable terminals in accordance with Airbus Industrie All Operators Telex (AOT) 49-01, Issue 3, dated April 25, 1991. Correct any torque value discrepancies prior to further flight, in accordance with the AOT. 

## New Requirements of This AD

## Installation 

(c) Within 15 months after the effective date of this AD, install an improved APU fuel feedline adapter in accordance with the Accomplishment Instructions of Airbus Service Bulletin A300-49-0049, Revision 1 (for Model A300 series airplanes); A300-49-6009, Revision 1 (for Model A300-600 series airplanes); or A310-49-2012, Revision 1 (for Model A310 series airplanes); all dated November 28, 1991; as applicable. Such installation constitutes terminating action for the requirements of this AD. 

# Note 2:

Although the service bulletins referenced in paragraph (b) of this AD specify installation of an APU fuel feedline adapter having part number P/N A4937021700200, installation of an adapter having P/N A4937021700400 is also acceptable for compliance with the requirements of that paragraph.

## Spares 

(d) As of the effective date of this AD, no person shall install an APU fuel feedline adapter, P/N A4937021700000 (welded configuration), on any airplane. 

## 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 §§ 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. 

## Incorporation by Reference 

(g) The actions shall be done in accordance with the following Airbus All Operators Telex (AOT) and Airbus service bulletins: 

(1) The incorporation by reference of Airbus Service Bulletin A300-49-0049, Revision 1, dated November 28, 1991; Airbus Service Bulletin A300-49-6009, Revision 1, dated November 28, 1991; and Airbus Service Bulletin A310-49-2012, Revision 1, dated November 28, 1991; is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. 

(2) The incorporation by reference of Airbus All Operators Telex (AOT) 49-01, Issue 3, dated April 25, 1991; Airbus Service Bulletin A300-49-0049, dated July 12, 1991; Airbus Service Bulletin A300-49-6009, dated July 12, 1991; and Airbus Service Bulletin A310-49-2012; dated July 12, 1991; was approved previously by the Director of the Federal Register as of October 7, 1991 (56 FR 47672, September 20, 1991). 

(3) Copies may be obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. 

# Note 4:

The subject of this AD is addressed in French airworthiness directive 98-480-269(B), dated December 2, 1998.

(h) This amendment becomes effective on March 13, 2000.

Issued in Renton, Washington, on January 31, 2000. 

Donald L. Riggin, 

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. 

[FR Doc. 00-2469 Filed 2-4-00; 8:45 am] 

BILLING CODE 4910-13-U