AD 2006-10-17

final rule

Airworthiness Directives; Boeing Model 737-600, -700, -700C, -800, and -900 Series Airplanes

AD Number
2006-10-17
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. FAA-2005-21028
FR Citation
71 FR 28766
Technical illustration of an aircraft electrical generator and wiring assembly
Problem area Electrical system

Applicability

TypeManufacturerModelDetails
aircraft Boeing 737-600 Airworthiness Directives; Boeing Model 737-600, -700, -700C, -800, and -900 Series Airplanes

Unsafe Condition

Wire bundles 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.

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

Required Actions

Replace 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. Inspect for wire length and damage of the connectors and wire bundles, and perform applicable corrective actions if necessary.

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

Compliance Time

Within 36 months of the effective date.

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

Affected Aircraft

Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes, as determined by Boeing Service Bulletin 737-24A1141, Revision 2.

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

Federal Register Abstract

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes. This AD requires 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 AD also requires, 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 AD results from 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.

Document Text

Show stored source text (verify against official source)
[Federal Register Volume 71, Number 96 (Thursday, May 18, 2006)]
[Rules and Regulations]
[Pages 28766-28769]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 06-4595]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-21028; Directorate Identifier 2004-NM-238-AD; 
Amendment 39-14601; AD 2006-10-17]
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: Final rule.

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

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Boeing Model 737-600, -700, -700C, -800, and -900 series 
airplanes. This AD requires 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 AD also requires, 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 AD results from 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.

DATES: This AD becomes effective June 22, 2006.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the AD as of June 22, 2006.

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 airworthiness directive (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 
737-600, -700, -700C, -800, and -900 series airplanes. That NPRM was 
published in the Federal Register on April 27, 2005 (70 FR 21689). That 
NPRM proposed to 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. That NPRM also proposed to 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.

New Relevant Service Information

    Since the issuance of the NPRM, we have reviewed Revision 2 of 
Boeing Service Bulletin 737-24A1141, dated December 1, 2005 (Revision 1 
of the service bulletin was referenced in the NPRM as the appropriate 
source of service information for doing certain proposed actions). 
Revision 2 updates multiple figures to correct typographical errors in 
the graphics or in the task or flag note tables. Revision 2 also moves 
a certain group of airplanes from one figure to another. The procedures 
in Revision 2 are essentially identical to those in Revision 1. No more 
work is necessary on airplanes changed as shown in Revision 1 of the 
service bulletin. Therefore, we have revised paragraph (f) of this AD 
to refer to Revision 2 as the appropriate source of service information 
for doing the required inspection, replacements, wiring changes, and 
corrective actions if necessary. We also have revised the applicability 
to refer to Revision 2 as the appropriate source of service information 
for determining the affected airplanes. In addition, we have added a 
new paragraph (g) to the AD (and redesignated subsequent paragraphs) to 
give operators credit for doing the actions required by paragraph (f) 
before

[[Page 28767]]

the effective date of this AD in accordance with Revision 1.

Comments

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

Support for NPRM

    AirTran Airways and The Boeing Company support the NRPM.

Requests To Extend Compliance Time

    The Air Transport Association (ATA) of America, Inc., on behalf of 
one of its members (American Airlines), and Continental Airlines 
request that the compliance time specified in paragraph (f) of the NPRM 
be extended. Continental Airlines states that a compliance time of 36 
months is necessary, because of the large number of work hours 
specified in Boeing Alert Service Bulletin 737-24A1141, Revision 1, for 
doing the examination, change, and retermination if necessary. American 
Airlines states that a compliance time of 48 months is necessary to 
align with heavy maintenance schedules and to avoid an unnecessary 
financial burden.
    We agree that the compliance time in paragraph (f) of this AD can 
be extended somewhat. We intended to require the inspection, 
replacements, wiring change, and retermination if necessary at 
intervals that would coincide with regularly scheduled maintenance 
visits for the majority of the affected fleet, when the airplanes would 
be located at a base where special equipment and trained personnel 
would be readily available, if necessary. Based on the information 
supplied by the operators, we have determined that 36 months 
corresponds more closely to the interval representative of most of the 
affected operators' heavy maintenance schedules. We have revised 
paragraph (f) of the AD accordingly. We do not consider that this 
extension will adversely affect safety.

Request for an Alternative Method of Compliance (AMOC)

    The ATA of America, Inc., on behalf of one of its members (Delta 
Air Lines), states that there are a number of errors in Boeing Alert 
Service Bulletin 737-24A1141, Revision 1, and requests that we approve 
corrections made to the service bulletin as an AMOC for the 
corresponding proposed actions in the NPRM. Delta Air Lines states that 
other errors have been identified in Boeing Information Notice 69-
37319-21-02 IN 02.
    We partially agree. We agree with the ATA of America, Inc., and 
Delta Air Lines that there are several errors in Boeing Alert Service 
Bulletin 737-24A1141, Revision 1, but do not agree to revise the AD as 
suggested by them. As discussed previously in ``New Relevant Service 
Information,'' we have reviewed Boeing Service Bulletin 737-24A1141, 
Revision 2, and have revised this AD to refer to that revision as an 
appropriate source of service information for the actions required by 
paragraph (f) of this AD.

Request To Refer to Original Issue of Service Bulletin

    The ATA of America, Inc., on behalf of one of its members (Delta 
Air Lines), requests that we refer to the original release of Boeing 
Component Service Bulletin 69-37319-21-02, dated March 15, 2001, in 
paragraph (g)(2) of the NPRM (redesignated as paragraph (h)(2) in this 
AD) as an acceptable means of compliance with the proposed 
modification, if the modification specified in the original release was 
done before the effective date of the AD. Delta Air Lines notes that 
Revision 1 of the component service bulletin, which is cited in 
paragraph (g)(2) as the appropriate source of service information, 
states, ``No more work is necessary on components changed as shown on 
the initial release of this service bulletin.''
    We do not agree. We have confirmed with The Boeing Company that the 
statement above in Revision 1 of the component service bulletin is 
incorrect. More work is necessary on components changed as shown in the 
original issue of the component service bulletin. The Boeing Company 
has issued Information Notice 69-37319-21-02 IN 03 to inform operators 
of this error. Therefore, we have made no change to the AD in this 
regard.

Request To Verify Parts Availability

    Alaska Airlines finds the proposed actions and the 24-month 
compliance time acceptable provided that the kits for parts for the 
modification are readily available during that period of time.
    From this comment, we infer that Alaska Airlines is requesting that 
we verify whether parts will be available for doing the modifications 
within the proposed compliance time. The Boeing Company has informed us 
that there are sufficient parts available for doing the required 
modification within the compliance time.

Request To Revise Work Hour Estimate

    Continental Airlines requests that the work hour estimates for the 
replacements, inspections, and modifications in ``Costs of Compliance'' 
of the NPRM be aligned with the total task hours specified in Boeing 
Alert Service Bulletin 737-24A1141, Revision 1. Continental Airlines 
also points out that the cure time (eight hours) and the time for 
retermination of connectors are not included in the total task hours in 
the service bulletin.
    We do not agree. The ``Costs of Compliance'' describes only the 
direct costs of the actions required by this AD. Based on the best data 
available, The Boeing Company provided 16 or 18 work hours (depending 
on airplane configuration) for doing the required inspection, 
replacements, and wiring changes; provided 2 work hours for doing the 
required modification of the generator drive and standby power module 
assembly; and provided 1 work hour for doing the required modification 
of the air conditioning module assembly. These numbers represent the 
time necessary to perform only the actions actually required by this 
AD. We recognize that, in doing the actions required by an AD, 
operators may incur incidental costs in addition to the direct costs. 
The cost analysis in AD rulemaking actions, however, typically does not 
include incidental costs such as the time required to gain access and 
close up, time necessary for planning, or time necessitated by other 
administrative actions. Those incidental costs, which may vary 
significantly among operators, are almost impossible to calculate.
    In addition, the economic analysis of an AD is limited to the cost 
of actions that are actually required. The economic analysis does not 
consider the costs of conditional actions, such as repairing damaged 
wire bundles detected during a required inspection. Such conditional 
repairs would be required--regardless of AD direction--to correct an 
unsafe condition identified in an airplane and to ensure that the 
airplane is operated in an airworthy condition, as required by the 
Federal Aviation Regulations. Therefore, we have made no change to this 
AD in this regard.

Clarification of Alternative Method of Compliance (AMOC) Paragraph

    We have revised this action to clarify the appropriate procedure 
for notifying the principal inspector before using any approved AMOC on 
any airplane to which the AMOC applies.

Conclusion

    We have carefully reviewed the available data, including the 
comments received, and determined that air safety and the public 
interest require adopting

[[Page 28768]]

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 740 airplanes of the affected design in the 
worldwide fleet and 333 affected airplanes on the U.S. register.
    For all airplanes, the required inspection, replacements, and 
wiring change will 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 will cost about $10,231 or $11,139 per 
airplane (depending on the kit). Based on these figures, the estimated 
cost of the replacements and inspections required by this AD for U.S. 
operators 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 will take about 2 work hours per 
airplane, at an average labor rate of $65 per work hour. The airplane 
manufacturer states that it will supply required parts to operators at 
no cost. Based on these figures, the estimated cost of this 
modification required by this AD is $130 per airplane.
    For certain other airplanes, the modification of the air 
conditioning module assembly will take about 1 work hour per airplane, 
at an average labor rate of $65 per work hour. The airplane 
manufacturer states that it will supply required parts to operators at 
no cost. Based on these figures, the estimated cost of this 
modification required 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 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):

2006-10-17 Boeing: Amendment 39-14601. Docket No. FAA-2005-21028; 
Directorate Identifier 2004-NM-238-AD.

Effective Date

    (a) This AD becomes effective June 22, 2006.

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 Service Bulletin 737-24A1141, Revision 2, dated 
December 1, 2005.

Unsafe Condition

    (d) This AD results from 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/Replacements/Wiring Changes/Corrective Actions

    (f) Within 36 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 Service Bulletin 737-24A1141, 
Revision 2, dated December 1, 2005. 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 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.''

    (g) Actions done before the effective date of this AD in 
accordance with Boeing Alert Service Bulletin 737-24A1141, Revision 
1, dated December 23, 2004, are acceptable for compliance with the 
requirements of paragraph (f) of this AD.

Concurrent Requirements

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

[[Page 28769]]



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

Alternative Methods of Compliance (AMOCs)

    (i)(1) 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.
    (2) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.

Material Incorporated by Reference

    (j) You must use the applicable service information identified 
in Table 2 of this AD 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 these 
documents 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/code_of_federal_regulations/ibr_locations.html">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html</a>.

                                  Table 2.--Material Incorporated by Reference
----------------------------------------------------------------------------------------------------------------
           Service bulletin                       Revision level                            Date
----------------------------------------------------------------------------------------------------------------
(1) Boeing Component Service Bulletin   Original Issue...................  July 26, 2001.
 233A3205-24-01.
----------------------------------------------------------------------------------------------------------------
(2) Boeing Component Service Bulletin   1................................  August 30, 2001.
 69-37319-21-02.
----------------------------------------------------------------------------------------------------------------
(3) Boeing Service Bulletin 737-        2................................  December 1, 2005.
 24A1141.
----------------------------------------------------------------------------------------------------------------


    Issued in Renton, Washington, on May 8, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 06-4595 Filed 5-17-06; 8:45 am]
BILLING CODE 4910-13-P

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