[Federal Register: March 17, 2005 (Volume 70, Number 51)]
[Proposed Rules]
[Page 12986-12988]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr17mr05-10]
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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]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 767-300 Series Airplanes
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for certain Boeing Model 767-300 series airplanes. This proposed AD
would require replacing the frequency converters used to supply power
for medical outlets with modified frequency converters, and related
actions. This proposed AD is 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 frequency converters fail to shut off. We are
proposing 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: We must receive comments on this proposed AD by May 2, 2005.
ADDRESSES: Use one of the following addresses to submit comments on
this proposed AD.
DOT Docket Web site: Go to http://dms.dot.gov and follow
the instructions for sending your comments electronically.
Government-wide rulemaking Web site: Go to http://www.regulations.gov
and follow the instructions for sending your
comments electronically.
Mail: Docket Management Facility, U.S. Department of
Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401,
Washington, DC 20590.
By fax: (202) 493-2251.
Hand Delivery: Room PL-401 on the plaza level of the
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
For service information identified in this proposed AD, contact
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.
You can examine the contents of this AD docket on the Internet at
http://dms.dot.gov, or in person at the Docket Management Facility,
U.S. Department of Transportation, 400 Seventh Street, SW., room PL-
401, on the plaza level of the Nassif Building, Washington, DC. This
docket number is FAA-2005-20629; the directorate identifier for this
docket is 2004-NM-266-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:
Comments Invited
We invite you to submit any relevant written data, views, or
arguments regarding this proposed AD. Send your comments to an address
listed under ADDRESSES. Include ``Docket No. FAA-2005-20629;
Directorate Identifier 2004-NM-266-AD'' in the subject line of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of the proposed AD. We will
consider all comments submitted by the closing date and may amend the
proposed AD in light of those comments.
We will post all comments we receive, without change, to http://dms.dot.gov
, including any personal information you provide. We will
also post a report summarizing each substantive verbal contact with FAA
personnel concerning this proposed AD. Using the search function of
that Web site, anyone can find and read the comments in any of our
dockets, including the name of the individual who sent the comment (or
signed the comment on behalf of an association, business, labor union,
etc.). You can review DOT's complete Privacy Act Statement in the
Federal Register published on April 11, 2000 (65 FR 19477-78), or you
can visit http://dms.dot.gov.
Examining the Docket
You can examine the AD docket on the Internet at http://dms.dot.gov
, 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 DOT
street address stated in the ADDRESSES section. Comments will be
available in the AD docket shortly after the DMS receives them.
Discussion
We have received a report indicating that analysis by the airplane
manufacturer has shown that a hard short circuit condition between the
output of certain frequency converters and their downstream, load
circuit breakers will produce a continuous output current of 170--200
percent of nominal, on certain Boeing Model 747-200F and -400 series
airplanes; Model 767-300 and -400ER series airplanes; and Model 777
series airplanes. The continuous current could cause the undersized
output wiring to exceed its wire temperature rating of 150 degrees
Celsius and consequently overheat when the frequency converters fail to
shut off in response to a short circuit or overload. Overheating of the
output wiring, if not corrected, could result in the failure of a wire
bundle and consequent adverse effects on other systems sharing the
affected wire bundle.
Other Related Rulemaking
On September 1, 2004, we proposed to amend 14 CFR part 39 with an
AD for certain Boeing Model 747-200F and -400 series airplanes; Model
767-400ER series airplanes; and Model 777 series airplanes. That
action, published in the Federal Register on September 13, 2004 (69 FR
55120), proposed to require replacing the frequency converter(s) used
to supply electrical power for utility outlets (for the galley, medical
equipment, or personal computers) with modified frequency converter(s).
That action also proposed to require any specified action and related
concurrent actions, as necessary. That proposed AD was prompted by a
report that a hard short condition between the frequency
[[Page 12987]]
converter's output and its downstream circuit breakers will produce a
continuous circuit that could cause the undersized output wiring to
overheat. The actions required by that proposed AD are intended to
prevent the overheating of the frequency converter's undersized output
wiring, which could lead to the failure of a wire bundle, and
consequent adverse effects on other systems sharing the affected wire
bundle.
Since issuance of that proposed AD, we have determined that the
same unsafe condition addressed in that proposed AD also exists on
certain Model 767-300 series airplanes. We have been advised that 54
Model 767-300 series airplanes were delivered with outlet installations
using frequency converters affected by that proposed AD. Therefore,
these additional airplanes are also subject to the same unsafe
condition addressed in that proposed AD.
Relevant Service Information
We have reviewed Boeing Service Bulletin 767-25-0334, Revision 1,
dated June 19, 2002. The service bulletin describes procedures for
replacing the frequency converters used to supply power for medical
outlets with modified frequency converters, and related actions.
Replacement includes removing and sending the frequency converters to
the vendor (Avionic Instruments, Inc.) for rework, and installing the
reworked frequency converters. The other related actions include the
following:
Collaring and labeling the circuit breaker(s) of the
frequency converter input as ``INOP'' and removing the label(s) after
installation of the modified frequency converters;
Capping and stowing the wire bundles of the frequency
converters and reinstalling/connecting the wire bundles after
installation of the modified frequency converters;
Installing a ``DEACTIVATED'' label on the frequency
converter outlets and removing the labels after installation of the
modified frequency converters;
Contacting the vendor for coordination of the rework; and
Doing a functional test of the replaced frequency
converters.
Accomplishing the actions specified in the service information is
intended to adequately address the unsafe condition.
FAA's Determination and Requirements of the Proposed AD
We have evaluated all pertinent information and identified an
unsafe condition that is likely to exist or develop on other airplanes
of this same type design. Therefore, we are proposing this AD, which
would require accomplishing the actions specified in the service
information described previously.
We have considered a number of factors in determining whether to
issue a separate proposed AD or a supplemental notice of proposed
rulemaking (NPRM) to the ``related'' NPRM (69 FR 55120, September 13,
2004). Although the 54 additional airplanes included in the
applicability of this proposed AD were inadvertently omitted from the
``related'' NPRM, issuing a supplemental NPRM would require reopening
the comment period of the ``related'' NPRM. However, to delay that
action would be inappropriate, since we have determined that an unsafe
condition exists and that modifications need to be made to ensure
continued safety. We also have considered the entire fleet size that
would be affected by issuing a supplemental NPRM and the fact that no
new work would be required for airplanes affected by the ``related''
NPRM. In light of this, we have determined that a less burdensome
approach is to propose a separate AD applicable only to the additional
airplanes. This proposed AD would not reopen the comment period of the
``related'' NPRM; airplanes listed in the applicability of the
``related'' NPRM would be required to comply with the requirements of
that proposed AD. This proposed AD is a separate AD action that is
applicable only to certain Boeing Model 767-300 series airplanes,
certificated in any category.
Costs of Compliance
There are about 55 airplanes of the affected design in the
worldwide fleet. This proposed AD would affect about 54 airplanes of
U.S. registry. The proposed actions would 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 proposed 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 proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 the 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. 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 proposed AD. 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, Safety.
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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. The FAA amends Sec. 39.13 by adding the following new
airworthiness directive (AD):
Boeing: Docket No. FAA-2005-20629; Directorate Identifier 2004-NM-
266-AD.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive
comments on this AD action by May 2, 2005.
[[Page 12988]]
Affected ADs
(b) None.
Applicability
(c) This AD applies to certain Boeing Model 767-300 series
airplanes, certificated in any category; as listed in Boeing Service
Bulletin 767-25-0334, Revision 1, dated June 19, 2002.
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 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,
replace the frequency converters used to supply power for medical
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, 2002.
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.
Issued in Renton, Washington, on March 8, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 05-5289 Filed 3-16-05; 8:45 am]
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