[Federal Register: September 29, 2004 (Volume 69, Number 188)]
[Proposed Rules]
[Page 58109-58111]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr29se04-25]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2004-19203; Directorate Identifier 2004-NM-109-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 757-200 Series Airplanes
AGENCY: Federal Aviation Administration (FAA), 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 757-200 series airplanes. This proposed AD
would require modifying the frequency converters located in the closet
assembly in the passenger compartment, and making various wiring
changes in and between the closet assembly and forward purser work
station. This proposed AD also would require modifying the in-flight
entertainment system prior to or concurrently with the modification of
the frequency converters. This proposed AD is prompted by a
certification review that revealed a frequency converter failure mode
not identified in the original system design. We are proposing this AD
to prevent a short circuit between the frequency converter output and
the distribution circuit breakers, which could result in overheating
and failure of adjacent wiring and consequent degraded operation of
airplane systems.
DATES: We must receive comments on this proposed AD by November 15,
2004.
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 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-2004-19203; the directorate identifier for this docket is
2004-NM-109-AD.
FOR FURTHER INFORMATION CONTACT: Technical information: 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.
Plain language information: Marcia Walters, marcia.walters@faa.gov.
SUPPLEMENTARY INFORMATION:
Docket Management System (DMS)
The FAA has implemented new procedures for maintaining AD dockets
electronically. As of May 17, 2004, new AD actions are posted on DMS
and assigned a docket number. We track each action and assign a
corresponding directorate identifier. The DMS AD docket number is in
the form ``Docket No. FAA-2004-99999.'' The Transport Airplane
Directorate identifier is in the form ``Directorate Identifier 2004-NM-
999-AD.'' Each DMS AD docket also lists the directorate identifier
(``Old Docket Number'') as a cross-reference for searching purposes.
Comments Invited
We invite you to submit any written relevant data, views, or
arguments regarding this proposed AD. Send your comments to an address
listed under ADDRESSES. Include ``Docket No. FAA-2004-19203;
Directorate Identifier 2004-NM-109-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
[[Page 58110]]
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.
We are reviewing the writing style we currently use in regulatory
documents. We are interested in your comments on whether the style of
this document is clear, and your suggestions to improve the clarity of
our communications that affect you. You can get more information about
plain language at http://www.faa.gov/language and http://www.plainlanguage.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
During a certification review of a Boeing Model 737-700C series
airplane, a frequency converter failure mode that was not identified in
the original system design was found. This failure mode could cause a
wiring short circuit between the frequency converter output and the
distribution circuit breakers. The current is only limited by the
maximum current capacity of the frequency converter. The frequency
converter reacts to a short circuit condition by increasing the output
current to approximately 54 amps, and significantly reducing the
voltage. Investigation revealed that the wiring between the converter
and the wiring fault was inadequate in size to handle the frequency
converters increased output current. These conditions, if not
corrected, could result in a short circuit between the frequency
converter output and the distribution circuit breakers, which could
result in overheating and failure of adjacent wiring and consequent
degraded operation of airplane systems.
The frequency converters on certain Model 757-200 series airplanes
are identical to those on the affected Model 737-700C series airplane
(the unsafe condition has been corrected on Model 737-700C series
airplanes). Therefore, all of these models may be subject to the same
unsafe condition.
Relevant Service Information
We have reviewed Boeing Service Bulletin 757-25-0255, dated
December 11, 2003. The service bulletin describes procedures for
modifying the frequency converters located in the closet assembly in
the passenger compartment. The modification involves installing new,
improved frequency converters, relay assemblies, thermal switches, and
related components, and making various wiring changes in and between
the closet assembly and forward purser work station.
Affected airplanes are separated into Groups 1 and 2, and the
Accomplishment Instructions of the service bulletin provide
modification procedures for each group, as follows: The procedures for
Groups 1 and 2 include replacing three frequency converters in closet
assembly S3 in the passenger compartment; installing three relay
assemblies; and changing wire bundles in the P37 panel and forward
purser work station, including at and above closet assembly S3.
Additional procedures for Group 2 include changing wire bundle W3910 in
the ceiling between closet assembly S3 and the forward purser work
station. The procedures for Groups 1 and 2 also specify doing an
operational test of the new/changed frequency converters and related
circuit changes.
Service Bulletin 757-25-0255 recommends prior or concurrent
accomplishment of Boeing Service Bulletin 757-24-0093, dated August 14,
2003. Service Bulletin 757-24-0093 describes procedures for modifying
the in-flight entertainment system (circuit breaker, relays, and
wiring). The modification procedures include installing a relay and
changing the wiring in the main electronics compartment at the P37
panel assembly; and installing a relay and changing the wiring in the
P36 panel assembly. The procedures also specify doing a continuity
test. The modification procedures are for airplanes listed in Group 1
of Service Bulletin 757-24-0093.
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 modifying the frequency converters located in the closet
assembly in the passenger compartment, and making various wiring
changes in and between the closet assembly and forward purser work
station. This proposed AD also would require accomplishment of various
other actions prior to or concurrently with the modification of the
frequency converters. The proposed AD would require you to use the
service information described previously to perform these actions.
Costs of Compliance
This proposed AD would affect about 4 airplanes of U.S. registry
and 4 airplanes worldwide.
For airplanes listed in Group 1 of Service Bulletin 757-25-0255:
The proposed modification would take about 97 work hours (including
access, close-up, and test), at an average labor rate of $65 per work
hour. Required parts would cost about $10,710 per airplane. Based on
these figures, the estimated cost of the proposed modification for U.S.
operators is $17,015 per airplane.
For airplanes listed in Group 2 of Service Bulletin 757-25-0255:
The proposed modification would take about 105 work hours (including
access, close-up, and test), at an average labor rate of $65 per work
hour. Required parts would cost about $10,956 per airplane. Based on
these figures, the estimated cost of the proposed modification for U.S.
operators is $17,781 per airplane.
For airplanes listed in Group 1 of Service Bulletin 757-24-0093:
The proposed concurrent modification, if not previously done, would
take about 49 work hours, at an average labor rate of $65 per work
hour. Required parts would cost about $5,315 per airplane. Based on
these figures, the estimated cost of the proposed modification for U.S.
operators is $8,500 per airplane.
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
[[Page 58111]]
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-2004-19203; Directorate Identifier 2004-NM-
109-AD.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive
comments on this AD action by November 15, 2004.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Model 757-200 series airplanes,
certificated in any category, as listed in Boeing Service Bulletin
757-25-0255, dated December 11, 2003.
Unsafe Condition
(d) This AD was prompted by a certification review that revealed
a frequency converter failure mode not identified in the original
system design. We are issuing this AD to prevent a short circuit
between the frequency converter output and the distribution circuit
breakers, which could result in overheating and failure of adjacent
wiring and consequent degraded operation of airplane systems.
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.
Modification
(f) For all airplanes: Within 18 months after the effective date
of this AD: Modify the frequency converters located in the closet
assembly in the passenger compartment by doing all the applicable
actions in accordance with the Accomplishment Instructions of Boeing
Service Bulletin 757-25-0255, dated December 11, 2003.
Prior or Concurrent Modification
(g) For Group 1 airplanes listed in Boeing Service Bulletin 757-
24-0093, dated August 14, 2003: Before or concurrent with
accomplishment of paragraph (f) of this AD, Modify the in-flight
entertainment system by doing all the applicable actions in
accordance with Boeing Service Bulletin 757-24-0093, dated August
14, 2003.
Part Installation
(h) As of the effective date of this AD, no person may install a
frequency converter having part number 1-002-0102-0730 on any
airplane unless it has been modified as required by paragraph (f) of
this AD.
Alternative Methods of Compliance (AMOCs)
(i) The Manager, Seattle Aircraft Certification Office, 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 September 21, 2004.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 04-21818 Filed 9-28-04; 8:45 am]
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