AD 2005-24-04

final rule

Airworthiness Directives; Boeing Model 767-300 Series Airplanes

AD Number
2005-24-04
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. FAA-2005-20629
FR Citation
70 FR 70711
Technical illustration of an aircraft electrical generator and wiring assembly
Problem area Electrical system

Applicability

TypeManufacturerModelDetails
aircraft The Boeing Company 767-300 Series Airworthiness Directives; Boeing Model 767-300 Series Airplanes

Unsafe Condition

A hard short circuit condition between the output of certain frequency converters and their downstream circuit breakers will produce a continuous output current that could cause the undersized output wiring to overheat when the frequency converters fail to shut off.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Replace the frequency converters used to supply power for medical and galley utility outlets with modified frequency converters. Alternatively, operators may deactivate the affected frequency converters, but reactivation requires modifying them in accordance with Boeing Service Bulletin 767-25-0334, Revision 1.

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Compliance Time

Before further flight

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Affected Aircraft

Boeing Model 767-300 series airplanes, certificated in any category, as identified in Boeing Service Bulletin 767-25-0334, Revision 1, dated June 19, 2003.

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Federal Register Abstract

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 767-300 series airplanes. This AD requires replacing the frequency converters used to supply power for medical and galley utility outlets with modified frequency converters, and related actions. This AD results from a report indicating that a hard short circuit condition between the output of certain frequency converters and their downstream circuit breakers will produce a continuous output current that could cause the undersized output wiring to overheat when the frequency converters fail to shut off. We are issuing this AD to prevent overheating of the output wiring of the frequency converters, which could result in the failure of a wire bundle and consequent adverse effects on other systems sharing the affected wire bundle.

Document Text

Show stored source text (verify against official source)
[Federal Register Volume 70, Number 225 (Wednesday, November 23, 2005)]
[Rules and Regulations]
[Pages 70711-70713]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 05-23054]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-20629; Directorate Identifier 2004-NM-266-AD; 
Amendment 39-14384; AD 2005-24-04]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 767-300 Series Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Boeing Model 767-300 series airplanes. This AD requires 
replacing the frequency converters used to supply power for medical and 
galley utility outlets with modified frequency converters, and related 
actions. This AD results from a report indicating that a hard short 
circuit condition between the output of certain frequency converters 
and their downstream circuit breakers will produce a continuous output 
current that could cause the undersized output wiring to overheat when 
the frequency converters fail to shut off. We are issuing this AD to 
prevent overheating of the output wiring of the frequency converters, 
which could result in the failure of a wire bundle and consequent 
adverse effects on other systems sharing the affected wire bundle.

DATES: Effective December 28, 2005.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of December 28, 
2005.

ADDRESSES: You may examine the AD docket on the Internet at <a href="http://dms.dot.gov">http://dms.dot.gov</a> or in person at the Docket Management Facility, U.S. 
Department of Transportation, 400 Seventh Street, SW., Nassif Building, 
Room PL-401, Washington, DC.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for service information identified in this AD.

FOR FURTHER INFORMATION CONTACT: Binh Tran, Aerospace Engineer, Systems 
and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone 
(425) 917-6485; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Examining the Docket

    You may examine the AD docket on the Internet at <a href="http://dms.dot.gov">http://dms.dot.gov</a> 
or in person at the Docket Management Facility office between 9 a.m. 
and 5 p.m., Monday through Friday, except Federal holidays. The Docket 
Management Facility office (telephone (800) 647-5227) is located on the 
plaza level of the Nassif Building at the street address stated in the 
ADDRESSES section.

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to include an AD that would apply to certain Boeing Model 
767-300 series airplanes. That NPRM was published in the Federal 
Register on March 17, 2005 (70 FR 12986). That NPRM proposed to require 
replacing the frequency converters used to supply power for medical 
outlets with modified frequency converters, and related actions.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments that have been 
received on the NPRM.

Request To Revise Date of Referenced Service Bulletin

    One commenter, the manufacturer, requests that we revise the 
release date of the service bulletin referenced in the NPRM. The 
commenter states that the correct reference is Boeing Service Bulletin 
767-25-0334, Revision 1, dated June 19, 2003.
    We agree. We inadvertently referenced the incorrect release date of 
Boeing Service Bulletin 767-25-0334, Revision 1. Therefore, we have 
revised paragraphs (c) and (f) of this AD to include the correct 
release date.

Request To Clarify Use of Frequency Converters

    The same commenter requests that we revise the ``Summary'' and 
``Relevant Service Information'' sections of the NPRM to specify that 
the affected frequency converters are also used for supplying power to 
galley utility outlets.
    We agree. We have revised the ``Summary'' section and paragraph (f) 
of this AD to clarify that the affected frequency converters are used 
to supply power to ``* * * medical and galley utility outlets * * *.'' 
However, since the ``Relevant Service Information'' section of the 
preamble does not reappear in the final rule, we have not made that 
change.

Request To Use Alternative Method of Compliance (AMOC)

    A second commenter, an operator, requests that we include an option 
to remove and deactivate the affected frequency converters and wiring, 
instead of replacing the affected frequency converters. The commenter 
states that it is not currently using the medical outlets and has 
removed the affected frequency converters from its

[[Page 70712]]

airplanes. The commenter also states that, if the medical outlets are 
later reactivated, the NPRM should require installing modified 
frequency converters.
    We agree that removing and deactivating the affected frequency 
converters is adequate for addressing the unsafe condition of this AD. 
We have moved the proposed requirement to replace the affected 
frequency converters to new paragraph (f)(1) of this supplemental NPRM 
and have added new paragraph (f)(2) to this supplemental NPRM, which 
gives operators the option of deactivating the affected frequency 
converters. Before a deactivated frequency convert can be re-installed 
on an airplane, paragraph (f)(2) also would require modifying the 
affected frequency converters in accordance with Boeing Service 
Bulletin 767-25-0334, Revision 1, dated June 19, 2003.

Request To Reference Parts Manufacturer Approval (PMA) Parts

    A third commenter requests that we identify the model and part 
number of the affected frequency converters in the NPRM. The commenter 
states that the parts manufacturer of the affected frequency converters 
produces parts both as an original equipment manufacturer (OEM) 
supplier and as a direct seller under a PMA. The commenter asserts 
that, since parts manufacturers are encouraged to use different part 
numbers for PMA and OEM parts, a PMA part identical to the OEM part, 
but having a different part number, might be installed on an airplane. 
The commenter requests that the NPRM account for any PMA parts that 
might contain the same deficiencies as an OEM part and be installed in 
its place.
    We do not concur with the commenter's request. Our available 
information indicates that any existing PMA frequency converter 
installed on any affected airplane retains the OEM original part number 
and, therefore, would be required to be removed in accordance with the 
Boeing service bulletin referenced in this AD as the appropriate source 
of service information. Once the existing parts are removed, the 
operator must replace it with the part numbers specified in the service 
bulletin in order to be in compliance with this AD. No change to the 
final rule is necessary in this regard.
    Regarding the commenter's request to address PMA part numbers in 
ADs, in general, the Transport Airplane Directorate currently is in the 
process of reviewing this issue as it applies to transport category 
airplanes. Once we have thoroughly examined all aspects of this issue 
and have made a final determination, we will consider whether our 
policy regarding addressing PMA parts in ADs needs to be revised. We 
consider that to delay this AD action would be inappropriate, since we 
have determined that an unsafe condition exists and that replacement of 
certain parts must be accomplished to ensure continued safety. 
Therefore, no change has been made to the final rule in this regard.

Conclusion

    We have carefully reviewed the available data, including the 
comments that have been received, and determined that air safety and 
the public interest require adopting the AD with the changes described 
previously. We have determined that these changes will neither increase 
the economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

    There are about 55 airplanes of the affected design in the 
worldwide fleet. This AD affects about 54 airplanes of U.S. registry. 
The actions in this AD take about 1 work hour per frequency converter, 
at an average labor rate of $65 per work hour. There are about 2 
frequency converters per airplane. Based on these figures, the 
estimated cost of the AD for U.S. operators is $7,020, or $130 per 
airplane.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
subtitle VII, part A, subpart III, section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this AD will not have federalism 
implications under Executive Order 13132. This AD 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.
    For the reasons discussed above, I certify that this AD:
    (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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this AD and placed it in the AD docket. See the ADDRESSES 
section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

2005-24-04 Boeing: Amendment 39-14384. Docket No. FAA-2005-20629; 
Directorate Identifier 2004-NM-266-AD.

Effective Date

    (a) This AD becomes effective December 28, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 767-300 series airplanes, 
certificated in any category; as identified in Boeing Service 
Bulletin 767-25-0334, Revision 1, dated June 19, 2003.

Unsafe Condition

    (d) This AD was prompted by a report indicating that a hard 
short circuit condition between the output of certain frequency 
converters and their downstream circuit breakers will produce a 
continuous output current that could cause the undersized output 
wiring to overheat when the

[[Page 70713]]

frequency converters fail to shut off. We are issuing this AD to 
prevent overheating of the output wiring of the frequency 
converters, which could result in the failure of a wire bundle and 
consequent adverse effects on other systems sharing the affected 
wire bundle.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Replace Frequency Converters

    (f) Within 18 months after the effective date of this AD, do the 
actions specified in either paragraph (f)(1) or (f)(2) of this AD.
    (1) Replace the frequency converters used to supply power for 
medical and galley utility outlets with modified frequency 
converters, and do any related actions, by doing all of the actions 
specified in the Accomplishment Instructions of Boeing Service 
Bulletin 767-25-0334, Revision 1, dated June 19, 2003.
    (2) Remove and deactivate the frequency converters used to 
supply power for medical and galley utility outlets, and cap and 
stow the frequency converter wire bundles, in accordance with B.1. 
through B.6. of the Accomplishment Instructions of Boeing Service 
Bulletin 767-25-0334, Revision 1, dated June 19, 2003. As of the 
effective date of this AD, no person may install a frequency 
converter that has been removed and deactivated in accordance with 
this paragraph, unless it is modified in accordance with the 
Accomplishment Instructions of the service bulletin.

Credit for Previous Service Bulletin

    (g) Actions done before the effective date of this AD in 
accordance with Boeing Service Bulletin 767-25-0334, dated November 
7, 2002, are acceptable for compliance with the requirements of 
paragraph (f) of this AD.

Alternative Methods of Compliance (AMOCs)

    (h) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.

Material Incorporated by Reference

    (i) You must use Boeing Service Bulletin 767-25-0334, Revision 
1, dated June 19, 2003, to perform the actions that are required by 
this AD, unless the AD specifies otherwise. The Director of the 
Federal Register approved the incorporation by reference of this 
document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. 
Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for a copy of this service information. You 
may review copies at the Docket Management Facility, U.S. Department 
of Transportation, 400 Seventh Street, SW., Room PL-401, Nassif 
Building, Washington, DC; on the Internet at <a href="http://dms.dot.gov">http://dms.dot.gov</a>; or 
at the National Archives and Records Administration (NARA). For 
information on the availability of this material at the NARA, call 
(202) 741-6030, or go to <a href="http://www.archives.gov/federal-register/cfr/ibr-locations.html">http://www.archives.gov/federal-register/cfr/ibr-locations.html</a>.

    Issued in Renton, Washington, on November 10, 2005.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-23054 Filed 11-22-05; 8:45 am]
BILLING CODE 4910-13-P

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