[Federal Register Volume 70, Number 80 (Wednesday, April 27, 2005)]
[Proposed Rules]
[Pages 21689-21691]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-8403]



[[Page 21689]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-21028; Directorate Identifier 2004-NM-238-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-600, -700, -700C, -
800, and -900 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 737-600, -700, -700C, -800, and -900 series 
airplanes. This proposed AD would require replacing brackets that hold 
the P5 panel to the airplane structure, the standby compass bracket 
assembly, the generator drive and standby power module, and the air 
conditioning module. This proposed AD also would require, among other 
actions, inspecting for wire length and for damage of the connectors 
and the wire bundles, and doing applicable corrective actions if 
necessary. This proposed AD is prompted by an electrical burning smell 
in the flight compartment. We are proposing this AD to prevent wire 
bundles from contacting the overhead dripshield panel and modules in 
the P5 overhead panel, which could result in electrical arcing and 
shorting of the electrical connector and consequent loss of several 
critical systems essential for safe flight.

DATES: We must receive comments on this proposed AD by June 13, 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-2005-21028; the directorate identifier for this 
docket is 2004-NM-238-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-2005-21028; 
Directorate Identifier 2004-NM-238-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 reports of an electrical burning smell in the 
flight compartment. An inspection of the P5 overhead panel found chafed 
and burned wires. The chafed wires were caused by wire bundle contact 
with the overhead dripshield panel and modules in the P5 overhead 
panel, which resulted in electrical arcing and shorting of the 
electrical connector.
    In addition, an investigation at Boeing found that some of the 
earliest produced Boeing Model 737-600, -700, -700C, -800, and -900 
series airplanes delivered from Boeing may have unwanted wire length in 
the P5 overhead panels. Boeing has made several changes in production 
to eliminate this condition.
    Wire bundle contact with the overhead dripshield panel and modules 
in the P5 overhead panel, if not corrected, could result in electrical 
arcing and shorting of the electrical connector and consequent loss of 
several critical systems essential for safe flight.

Relevant Service Information

    We have reviewed Boeing Service Bulletin 737-24A1141, Revision 1, 
dated December 23, 2004. The service bulletin describes the following 
procedures:
     Replacing the five brackets that hold the P5 panel to the 
airplane structure with new brackets, which includes measuring 
resistance, and applying bonding agent;
     Doing a general visual inspection for wire length and for 
damage of the connectors and the wire bundles; and applicable 
corrective actions, which includes retying or reterminating the damaged 
wire bundle and wires that have insufficient length, repairing wire 
damage, and replacing damaged connectors with new connectors;
     Installing Teflon/lacing tape and a nylon shield;
     Making wiring changes;
     Replacing the standby compass bracket assembly with a new 
assembly; and
     Replacing the stud assemblies with new assemblies.
    We also have reviewed Boeing Component Service Bulletin 233A3205-
24-01, dated July 26, 2001. For certain airplanes, this service 
bulletin describes procedures for modifying the generator drive and 
standby power module

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assembly, which involves replacing the rear cover and four standoffs 
with new parts. In addition, we have reviewed Boeing Component Service 
Bulletin 69-37319-21-02, Revision 1, dated August 30, 2001. For certain 
other airplanes, this service bulletin describes procedures for 
modifying the air conditioning module assembly, which involves 
replacing three plate assemblies, a cover, and two standoffs with new 
parts. The actions specified in the applicable component service 
bulletin must be done before or concurrent with the actions specified 
in Boeing Service Bulletin 737-24A1141 described previously.
    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.

Costs of Compliance

    There are about 740 airplanes of the affected design in the 
worldwide fleet and 333 airplanes on the U.S. register.
    For all airplanes, the proposed replacements and inspections would 
take about 16 or 18 work hours per airplane (depending on airplane 
configuration), at an average labor rate of $65 per work hour. Required 
parts would cost about $10,231 or $11,139 per airplane (depending on 
kit). Based on these figures, the estimated cost of the replacements 
and inspections proposed by this AD is between $3,753,243 and 
$4,098,897, or between $11,271 and $12,309 per airplane.
    For certain airplanes, the modification of the generator drive and 
standby power module assembly would take about 2 work hours per 
airplane, at an average labor rate of $65 per work hour. Required parts 
would be provided by the airplane manufacturer at no cost to the 
operators. Based on these figures, the estimated cost of this 
modification proposed by this AD is $130 per airplane.
    For certain other airplanes, the modification of the air 
conditioning module assembly would take about 1 work hour per airplane, 
at an average labor rate of $65 per work hour. Required parts would be 
provided by the airplane manufacturer at no cost to the operators. 
Based on these figures, the estimated cost of this modification 
proposed by this AD is $65 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-2005-21028; Directorate Identifier 2004-NM-
238-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this AD action by June 13, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 737-600, -700, -700C, -800, 
and -900 series airplanes, certificated in any category; as 
identified in Boeing Alert Service Bulletin 737-24A1141, Revision 1, 
dated December 23, 2004.

Unsafe Condition

    (d) This AD was prompted by an electrical burning smell in the 
flight compartment. We are issuing this AD to prevent wire bundles 
from contacting the overhead dripshield panel and modules in the P5 
overhead panel, which could result in electrical arcing and shorting 
of the electrical connector and consequent loss of several critical 
systems essential for safe flight.

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.

Inspection/Replacement/Wiring Changes/Corrective Actions

    (f) Within 24 months after the effective date of this AD, do the 
actions in paragraphs (f)(1) through (f)(5) of this AD by 
accomplishing all the applicable actions specified in the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
24A1141, Revision 1, dated December 23, 2004. Any applicable 
corrective actions must be done before further flight.
    (1) Replace the five brackets that hold the P5 panel to the 
airplane structure with new brackets;
    (2) Do a general visual inspection for wire length and damage of 
the connectors and the wire bundles, and applicable corrective 
actions;
    (3) Make wiring changes;
    (4) Replace the standby compass bracket assembly with a new 
assembly; and
    (5) Replace the stud assemblies with new assemblies.

    Note 1: For the purposes of this AD, a general visual inspection 
is: ``A visual examination of an interior or exterior area, 
installation, or assembly to detect obvious damage, failure, or 
irregularity. This level of

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inspection is made from within touching distance unless otherwise 
specified. A mirror may be necessary to ensure visual access to all 
surfaces in the inspection area. This level of inspection is made 
under normally available lighting conditions such as daylight, 
hangar lighting, flashlight, or droplight and may require removal or 
opening of access panels or doors. Stands, ladders, or platforms may 
be required to gain proximity to the area being checked.''

Concurrent Requirements

    (g) Before or concurrently with the requirements of paragraph 
(f) of this AD, do the applicable action specified in Table 1 of 
this AD.

                    Table 1.--Concurrent Requirements
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   For airplanes identified in Boeing
      component service bulletin--                   Action--
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(1) 233A3205-24-01, dated July 26, 2001  Modify the generator drive and
                                          standby power module assembly
                                          in accordance with the
                                          Accomplishment Instructions of
                                          the service bulletin.
(2) 69-37319-21-02, Revision 1, dated    Modify the air conditioning
 August 30, 2001.                         module assembly in accordance
                                          with the Accomplishment
                                          Instructions of the service
                                          bulletin.
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Alternative Methods of Compliance (AMOCs)

    (h) 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 April 18, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-8403 Filed 4-26-05; 8:45 am]
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