[Federal Register Volume 65, Number 175 (Friday, September 8, 2000)]
[Rules and Regulations]
[Pages 54407-54409]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-22907]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-54-AD; Amendment 39-11892; AD 2000-18-07]
RIN 2120-AA64


Airworthiness Directives; Airbus Model A300, A300-600, and A310 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Airbus Model A300, A300-600, and A310 series 
airplanes, that requires replacement of the transformer rectifier units 
(TRU) in the avionics compartment with new, improved TRU's. 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 failure of the TRU's. 
Failure of multiple TRU's could result in loss of the thrust reversers, 
autothrottle, flaps, and various systems (wing/cockpit window anti-ice, 
trim tank pumps, and windshield wipers) on the airplane; or incorrect 
information displayed to the flight crew.

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

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 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) to include an airworthiness 
directive (AD) that is applicable to certain Airbus Model A300, A300-
600, and A310 series airplanes was published in the Federal Register on 
April 19, 2000 (65 FR 20922). That action proposed to require 
replacement of the transformer rectifier units (TRU) in the avionics 
compartment with new, improved TRU's.

Later Service Bulletin Revisions

    Airbus has issued Service Bulletins A300-24-0089, A300-24-6068, and 
A310-24-2077, all Revision 01, all dated February 10, 2000. The 
original releases of these service bulletins were cited in the proposed 
AD as the appropriate source of service information for the actions 
required by the AD. These later revisions of the service bulletins are 
essentially equivalent to the previous revisions; however, the 
interchangeability code has been updated. The AD has been revised to 
reference the later service bulletin revisions as the appropriate 
source of service information. A NOTE also has been added to give 
credit to operators that may have accomplished the actions required by 
this AD in accordance with the original version of the service 
bulletins.

Comments Received

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

Request To Extend Compliance Time

    Three commenters request that the compliance time specified in the 
proposed AD for the TRU replacements be extended to September 30, 2001, 
which is the time mandated by the related French airworthiness 
directive 1999-435-296(B), dated November 3, 1999. One commenter, the 
TRU vendor, states that the last batch of parts will not be available 
until December 2000, and the subsequent lead time for modification of 
the TRU's is 6 to 8 months. Another commenter states that more than 50 
percent of TRU's installed on U.S.-registered airplanes are at earlier 
amendment levels, and these TRU's will require significantly more parts 
and work hours to accomplish the additional modifications necessary to 
bring the TRU's to later amendment levels.
    Another commenter, the airplane manufacturer, states that there has 
been no overall decrease in TRU reliability for most operators, and 
there has been no recent increase in double TRU failures. However, a 
limited number of operators have experienced a lower mean-time-between-
failure (MTBF) rate for the TRU over the last several years. Therefore, 
the commenter advises that the Master Minimum Equipment List (MMEL) is 
being revised, to reduce the amount of time in which dispatch is 
allowed with one TRU inoperative. With the MMEL restriction in place as 
an interim measure, and given the lack of availability of parts, the 
commenter proposes extension of the compliance threshold to September 
30, 2001.
    The FAA partially concurs. The FAA has verified that the lead time 
for modifying the TRU's will exceed the proposed compliance time of 6 
months after the effective date of this AD. In light of this situation, 
and in consideration of the more restrictive MMEL requirements, the FAA 
has determined that extending the compliance time as suggested will 
accommodate the time necessary for affected operators to replace the 
TRU's, without adversely affecting safety. However, there is no direct 
analytical relationship identified between the suggested calendar date 
of September 30, 2001, and the amount of time necessary to accomplish 
the required actions. Therefore, rather than specifying a calendar 
date, the FAA has revised the compliance time to 12 months after the 
effective date of this AD. This threshold should provide operators with 
time in which to accomplish the requirements of the AD approximately 
equivalent to the suggested calendar date.

Request To Revise Cost Information

    One commenter states that, although the proposed AD provides an 
estimate of 2 work hours per airplane to accomplish the TRU 
replacements, about 12 to 16 work hours will actually be required to 
modify each TRU prior to installation on the airplane. The commenter's 
work hour estimate includes the time necessary to revise the TRU to 
later amendment levels (if not already included), prior to modifying 
the TRU for installation as required by this AD. The commenter also 
notes that the AD should clarify that the costs of modification to 
later amendment levels will be borne by the operators. Additionally, 
the commenter states that only the modification parts provided by the 
manufacturer will be at no cost to the operators if modification of the

[[Page 54408]]

TRU's is accomplished at the vendor's (AUXILEC) facilities.
    The FAA's intent with regard to the work hour estimate was to 
provide an approximation of the time required for replacement of all 
TRU's on an airplane. The estimate was not intended to include all work 
hours necessary for prior modification of certain TRU's to the required 
configuration. However, the FAA does not object to noting that 
additional work hours may be required for accomplishment of such 
modifications. The cost impact information, below, has been revised 
accordingly. Additionally, the statement regarding cost of modification 
parts has been revised to clarify that the statement applies only to 
modification parts provided by the manufacturer.

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 changes described 
previously. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    The FAA estimates that 122 airplanes of U.S. registry will be 
affected by this AD, that it will take approximately 2 work hours per 
airplane to accomplish the required actions, and that the average labor 
rate is $60 per work hour. Additional work hours may be necessary for 
prior modification of the TRU's. Required parts from the manufacturer 
will be provided by the manufacturer at no cost to the operators if 
modification of the TRU's is accomplished at the vendor's (AUXILEC) 
facilities; otherwise the required parts will cost approximately $253 
per TRU. Based on these figures, the cost impact of the AD on U.S. 
operators is estimated to be between $120 and $1,132 per airplane.
    The cost impact figure discussed above is 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.


Sec. 39.13  [Amended]

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

2000-18-07 Airbus Industrie: Amendment 39-11892. Docket 2000-NM-54-
AD.

    Applicability: Model A300, A300-600, and A310 series airplanes; 
certificated in any category; equipped with AUXILEC transformer 
rectifier units (TRU) having part number (P/N) F11QB3121.

    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 (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 failure of multiple TRU's, which could result in loss 
of the thrust reversers, autothrottle, flaps, and various systems 
(wing/cockpit window anti-ice, trim tank pumps, and windshield 
wipers) on the airplane; or incorrect information displayed to the 
flight crew; accomplish the following:

Replacement

    (a) Within 12 months after the effective date of this AD, 
replace the TRU's in the avionics compartment with new, improved 
TRU's, in accordance with Airbus Service Bulletin A300-24-0089 (for 
Model A300 series airplanes), A300-24-6068 (for Model A300-600 
series airplanes), or A310-24-2077 (for Model A310 series 
airplanes); all Revision 01, all dated February 10, 2000; as 
applicable.

    Note 2: Accomplishment of TRU replacements prior to the 
effective date of this AD in accordance with Airbus Service Bulletin 
A300-24-0089, dated March 4, 1998; A300-24-6068, dated January 28, 
1998; or A310-24-2077, dated January 21, 1998; as applicable; is 
acceptable for compliance with paragraph (a) of this AD.


    Note 3: The Airbus service bulletins reference AUXILEC Service 
Bulletin F11QB3121-24-007, dated February 2, 1998, as an additional 
source of service information for accomplishing the replacement 
required by this AD.

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, 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 4: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Manager, 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.

Incorporation by Reference

    (d) The actions shall be done in accordance with Airbus Service 
Bulletin
    A300-24-0089, Revision 01, dated February 10, 2000; Airbus 
Service Bulletin A300-24-6068, Revision 01, dated February 10, 2000; 
or Airbus Service Bulletin A310-24-2077, Revision 01, dated February 
10, 2000; as applicable. This incorporation by reference was 
approved by the Director of the Federal Register in accordance with 
5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from 
Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac 
Cedex, France. Copies may be inspected at the FAA,

[[Page 54409]]

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 5: The subject of this AD is addressed in French 
airworthiness directive 1999-435-296(B), dated November 3, 1999.

    (e) This amendment becomes effective on October 13, 2000.

    Issued in Renton, Washington, on August 31, 2000.
D.L. Riggin,
 Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-22907 Filed 9-7-00; 8:45 am]
BILLING CODE 4910-13-P