[Federal Register Volume 62, Number 202 (Monday, October 20, 1997)]
[Rules and Regulations]
[Pages 54375-54376]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-27576]



[[Page 54375]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-05-AD; Amendment 39-10168; AD 97-21-15]
RIN 2120-AA64


Airworthiness Directives; British Aerospace Model Avro 146-RJ 
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 all British Aerospace Model Avro 146-RJ series airplanes, 
that requires a modification of the electrical system in the equipment 
bay area by replacing certain cables, clamps, and fairleads with new 
components. This amendment is prompted by a report indicating that the 
incorrect size of electrical cables were used in the generator feeder 
circuit to certain busbars from the generator contactors. As a result, 
the electrical cables are not compatible with generator rating 
requirements and can overheat. The actions specified by this AD are 
intended to prevent possible overheating of electrical generator feeder 
cables and consequent damage, which could lead to possible fire or the 
loss of essential electrical systems.

DATES: Effective November 24, 1997.
    The incorporation by reference of certain publications, as listed 
in the regulations, is approved by the Director of the Federal Register 
as of November 4, 1997.

ADDRESSES: The service information referenced in this AD may be 
obtained from AI(R) American Support, Inc., 13850 Mclearen Road, 
Herndon, Virginia 20171. 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: Tim H. Backman, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2797; 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 all British Aerospace Model Avro 
146-RJ series airplanes was published in the Federal Register on 
February 28, 1997 (62 FR 9111). That action proposed to require 
modifying the electrical system in the equipment bay area by replacing 
certain cables, clamps, and fairleads with new components.

Consideration of Comment Received

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

Request to Revise the Summary Section of the Preamble of the 
Proposed AD

    The commenter requests that the description of what prompted the 
NPRM that appeared in the Summary section of the preamble to the NPRM 
be revised to read, ``* * * the generator feeder circuit to certain 
busbars from the generator contactors. As a result, the cables are not 
compatible * * *.'' The commenter suggests that this statement is more 
accurate. The FAA acknowledges that the commenter's wording is more 
accurate and has revised the final rule to reflect the suggested 
changes. In addition, the FAA has included the word ``electrical'' to 
identify which type of cables are not compatible.

Request to Revise Other Sections of the Preamble of the Proposed AD

    The commenter also requests that the description of what the CAA 
advises that appeared in the Discussion section of the preamble to the 
NPRM be revised to read, ``* * * generator feeder circuit to busbars 
AC1 and AC2.''
    In addition, the commenter requests that a description of the 
procedures referenced in the service bulletin that appeared in the 
Explanation of Relevant Service Information section of the preamble to 
the NPRM be revised to read ``* * * existing 6ANC generator feeder 
cables installed to the AC1 and AC2 busbars from the generator 
contactors * * *.''
    The commenter states that these statements will improve the 
technical accuracy of the proposal. The FAA recognizes that the 
suggested changes to these sections provide improved technical 
accuracy. However, since neither the Discussion nor the Explanation of 
Relevant Service Information sections of the preamble to the NPRM are 
restated in the final rule, no change to the final rule is necessary.

Explanation of Changes Made to the Proposal

    For clarification purposes, the FAA has revised the description of 
the unsafe condition that appeared throughout the NPRM to read, ``* * * 
possible overheating of the electrical generator feeder cables and 
consequent damage, which could lead to a possible fire or the loss of 
essential electrical systems.''
    The FAA also has revised the final rule to reflect the corporate 
name change of British Aerospace Regional Aircraft Limited, Avro 
International Aerospace Division to British Aerospace Regional 
Aircraft. In addition, the address for obtaining service information 
has been revised to AI(R) American Support, Inc., 13850 Mclearen Road, 
Herndon, Virginia 20171.
    Furthermore, the FAA has revised the area code from (206) to (425) 
of the telephone numbers in the For Further Information Contact section 
of the final rule.

Conclusion

    After careful review of the available data, including the comment 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. 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 10 British Aerospace Model Avro 146-RJ 
series airplanes of U.S. registry will be affected by this AD. 
Modification of the electrical system will take approximately 4 work 
hours per airplane to accomplish, at an average labor rate of $60 per 
work hour. Required parts will cost approximately $300 per airplane. 
Based on these figures, the cost impact of the AD on U.S. operators is 
estimated to be $5,400, or $540 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 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,

[[Page 54376]]

it is determined that this final rule does not have sufficient 
federalism implications to warrant the preparation of a Federalism 
Assessment.
    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:

97-21-15 British Aerospace Regional Aircraft (Formerly British 
Aerospace Regional Aircraft Limited, Avro International Aerospace 
Division; British Aerospace, PLC; British Aerospace Commercial 
Aircraft Limited): Amendment 39-10168. Docket 97-NM-05-AD.

    Applicability: All Model Avro 146-RJ series airplanes, 
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 (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 possible overheating of the electrical generator 
feeder cables and consequent damage, which could lead to possible 
fire or loss of essential electrical systems, accomplish the 
following:
    (a) Prior to the accumulation of 500 flight cycles after the 
effective date of this AD, modify the electrical system in the 
electrical equipment bay in accordance with British Aerospace 
Service Bulletin SB.24-113-01532A, dated March 12, 1996, or British 
Aerospace Service Bulletin SB.24-113-01532A, Revision 1, dated June 
18, 1996.
    (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, Standardization Branch, ANM-113, 
FAA, Transport Airplane Directorate. Operators shall submit their 
requests to through an appropriate FAA Principal Maintenance 
Inspector, who may add comments and then send it to the Manager, 
Standardization Branch, ANM-113.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (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.
    (d) The modification shall be done in accordance with British 
Aerospace Service Bulletin SB.24-113-01532A, dated March 12, 1996; 
or British Aerospace Service Bulletin SB.24-113-01532A, Revision 1, 
dated June 18, 1996, which contains the following list of effective 
pages:

------------------------------------------------------------------------
                                    Revision level                      
            Page No.                 shown on page    Date shown on page
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1, 2............................  1.................  June 18, 1996.    
3-15............................  Original..........  March 12, 1996.   
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    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 AI(R) American Support, Inc., 
13850 Mclearen Road, Herndon, Virginia 20171. 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 3: The subject of this AD is addressed in British 
airworthiness directive 006-03-96, dated March 12, 1996.

    (e) This amendment becomes effective on November 24, 1997.

    Issued in Renton, Washington, on October 10, 1997.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-27576 Filed 10-17-97; 8:45 am]
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