Document ID: FAA-2008-1143-0007
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Boeing Model 737-600, -700, -700C, -800, and -900 Series Airplanes
Posted Date: 2009-08-18T04:00Z

[Federal Register: August 18, 2009 (Volume 74, Number 158)]
[Rules and Regulations]
[Page 41607-41611]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr18au09-5]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-1143; Directorate Identifier 2008-NM-136-AD;
Amendment 39-15990; AD 2009-16-07]
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.

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SUMMARY: The FAA is superseding an existing airworthiness directive
(AD), which applies to certain Boeing Model 737-600, -700, -700C, -800,
and -900 series airplanes. That AD currently 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, as applicable. The existing AD also
currently 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 new AD requires an additional
operational test of the P5-14 panel. This AD results from a report of
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;
and to ensure proper operation of the passenger oxygen system. If an
improperly functioning passenger oxygen system goes undetected, the
passenger oxygen mask could fail to deploy and result in possible
incapacitation of passengers during a depressurization event.

DATES: This AD becomes effective September 22, 2009.
    The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in the AD as of September 22,
2009.
    On June 22, 2006 (71 FR 28766, May 18, 2006), the Director of the
Federal Register approved the incorporation by reference of certain
other publications listed in the AD.

ADDRESSES: For service information identified in this AD, contact
Boeing Commercial Airplanes, Attention: Data & Services Management,
P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-
544-5000, extension 1; fax 206-766-5680; e-mail me.boecom@boeing.com;
Internet https://www.myboeingfleet.com.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Management Facility
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The AD docket contains this AD, the regulatory evaluation,
any comments received, and other information. The address for the
Docket Office (telephone 800-647-5527) is the Document Management
Facility, U.S. Department of Transportation, Docket Operations, M-30,
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE.,
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Binh Tran, Systems and Equipment
Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind
Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6485;
fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to include an AD that supersedes AD 2006-10-17, amendment
39-14601 (71 FR 28766, May 18, 2006). The existing AD applies to
certain Boeing Model 737-600, -700, -700C, -800, and -900 series
airplanes. That NPRM was published in the Federal Register on October
31, 2008 (73 FR 64894). That NPRM proposed to continue to require
replacing brackets that hold the P5 panel to the airplane structure,
the standby compass bracket assembly, the generator drive and

[[Page 41608]]

standby power module, and the air conditioning module. That NPRM also
proposed to continue 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. That NPRM also
proposed to require an additional operational test of the P5-14 panel.

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 Align AD Action With Related Service Bulletin

    One commenter, Boeing, requests that the NPRM wording for paragraph
(f)(4) be revised to align with Boeing Service Bulletin 737-24A1141,
Revision 3, dated February 20, 2008. Boeing states that the current
wording in the NPRM indicates that the standby compass bracket assembly
must be replaced with a new assembly. Boeing states that Boeing Service
Bulletin 737-24A1141, Revision 3, dated February 20, 2008, states that
the standby compass bracket assembly need not be replaced for all
groups of airplanes. Boeing Service Bulletin 737-24A1141, Revision 3,
dated February 20, 2008, also states to replace the standby compass
bracket if necessary.
    We agree that clarification may be necessary. Paragraph (f)(4) is a
restatement of actions required by AD 2006-10-17, and is retained in
this supersedure. Paragraph (f) of this AD states that the corrective
actions (including replacing the standby compass bracket assembly as
required by paragraph (f)(4) of this AD) must be done, as applicable.
In addition, we note that a new requirement of this AD, paragraph (i)
of this AD, requires that after the effective date of this AD, only
Revision 3 of Boeing Service Bulletin 737-24A1141, dated February 20,
2008, be used to do all applicable actions. We have not made any
changes to the AD in this regard.

Request To Clarify Terminology

    One commenter, the Air Transport Association (ATA), on behalf of
its member Delta Airlines, requests that the terminology in Boeing
Service Bulletin 737-24A1141 be clarified. In its comment, Delta states
that it believes that Boeing Service Bulletin 737-24A1141 contains
material that is vague in nature, which would leave information subject
to interpretation.
    Delta states that Boeing Service Bulletin 737-24A1141 includes
figures that contain statements such as, ``Some airplanes may have
different wires, panels or connectors'' (e.g., in Figures 6-11 and 94
of the service bulletin). Delta is concerned that statements such as
these, when dealing with compliance situations in which many different
individuals are left to determine the intent and method prescribed by
such instructions, can lead to problems determining the state of
compliance of aircraft that have had work accomplished per the required
accomplishment instructions. In the past, this has led to the grounding
of airplanes at significant expense to the airlines, while confusion
over the interpretation of said instructions is determined and
resolved. Therefore, Delta believes that either Boeing Service Bulletin
737-24A1141 should be revised to clarify the meaning of vague terms
(e.g., ``typical''), or the AD should include notes to accomplish the
same intent.
    Delta states that failure to clarify the vague terms will likely
lead to the same compliance issues that operators previously
experienced with the B737 Rudder System Enhancement Program (AD 2007-
03-07, Amendment 39-14918, 72 FR 4625, February 1, 2007) and MD88
auxiliary hydraulic pump feeder wire inspection/modification (AD 2006-
15-15, Amendment 39-14696, 71 FR 43035, July 31, 2006).
    We find that clarification of certain material contained in Boeing
Service Bulletin 737-24A1141, Revision 3, dated February 20, 2008, is
necessary. We discussed the material referenced by the commenter as
``vague'' with Boeing to clarify the intended meaning.
    Boeing noted that Boeing Service Bulletin 737-24A1141, Revision 3,
dated February 20, 2008, was initially released in January 2004, and
since then has been revised three times (December 2004, December 2005,
and February 2008) to update and correct information. As specified in
Boeing Service Bulletin 737-24A1141, Revision 3, dated February 20,
2008, required actions include: replacing brackets to lower the P5
overhead panel to increase the space between the wire bundles and the
dripshield panel and modules; inspecting to determine if unwanted wire
length or damage exists; retying the wire bundle or reterminating the
wire bundle into the connector to eliminate the unwanted wire; and
repairing damaged wire and using teflon tape, nylon sheet, and lacing
tape to give greater protection to the wire bundles. Also, depending on
airplane configuration, the service bulletin specifies replacing the
standby compass bracket assembly with a new assembly, and replacing the
stud assemblies with new assemblies.
    Boeing clarified that the P5 overhead panel varies from customer to
customer, as indicated in the 98 figures contained in Boeing Service
Bulletin 737-24A1141, Revision 3, dated February 20, 2008. Boeing
explains that the phrase questioned by the commenter--i.e., ``Some
airplanes may have different wires, panels or connectors''--was used in
the illustrations in the figures to indicate that the configuration on
any given customer's airplane may be different from that shown in the
illustrations. The illustrations simply provide examples of various
configurations an operator might find; therefore, the information
provided in the illustrations of the figures is for reference. Boeing
explained further that the word ``typical'' is intended to represent a
configuration that is in more than one location within an illustration.
Additionally, while accomplishment of the steps specified in the tables
of the figures is required, the illustrations are simply examples of
the wiring configuration.
    In addition, we find that the word ``unwanted'' requires
clarification. That term is used in various locations in the service
bulletin in conjunction with wire length conditions--e.g., paragraph
3.B.9. of the Accomplishment Instructions states to ``Inspect the
connectors and the wire bundles in the rear, P5 aft panel to determine
if unwanted wire length exists in Group 1-22 airplanes. See Figure 6.''
We clarify that the General Information section of the Accomplishment
Instructions of Boeing Service Bulletin 737-24A1141, Revision 3, dated
February 20, 2008, references Boeing Standard Wiring Practices Manual
(SWPM) 20-10-11 for wire installation procedures, including defining
the amount of slack and making sure that all wire slack is securely
tied into the parent harness or clamped. Additionally, it should be
noted that tables found in certain figures of Boeing Service Bulletin
737-24A1141, Revision 3, dated February 20, 2008 (Figure 6, for
example), refer operators to the SWPM for general conditions for wire
installation.
    We have revised this final rule to include new Note 2 and Note 3 to
clarify the meaning of the terminology discussed previously.

[[Page 41609]]

Updated Contact Information for Alternative Methods of Compliance
(AMOCs)

    We have updated the contact information for paragraph (k) of this
final rule.

Conclusion

    We reviewed the relevant data, considered the comments received,
and determined that air safety and the public interest require adopting
the AD with the change described previously. We also determined that
this change will not increase the economic burden on any operator or
increase the scope of the AD.

Costs of Compliance

    There are about 740 airplanes of the affected design in the
worldwide fleet. This AD affects about 333 airplanes of U.S. registry.
    For all airplanes, the required inspection, replacements, and
wiring change that are required by AD 2006-10-17 and retained in this
AD take about 16 or 18 work hours per airplane (depending on airplane
configuration), at an average labor rate of $80 per work hour. Required
parts 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
$3,833,163 and $4,188,807, or between $11,511 and $12,579 per airplane.
    For certain airplanes, the modification of the generator drive and
standby power module assembly that is required by AD 2006-10-17 and
retained in this AD takes about 2 work hours per airplane, at an
average labor rate of $80 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 $160 per airplane.
    For certain other airplanes, the modification of the air
conditioning module assembly that is required by AD 2006-10-17 and
retained in this AD takes about 1 work hour per airplane, at an average
labor rate of $80 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
$80 per airplane.
    For certain airplanes, the new action takes about 21 or 23 work
hours per airplane depending on the airplane configuration, at an
average labor rate of $80 per work hour. Based on these figures, the
estimated cost of the new actions required by this AD for U.S.
operators is $1,680 or $1,840 per airplane, depending on the airplane
configuration.

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
removing amendment 39-14601 (71 FR 28766, May 18, 2006) and by adding
the following new airworthiness directive (AD):

2009-16-07 Boeing: Amendment 39-15990. Docket No. FAA-2008-1143;
Directorate Identifier 2008-NM-136-AD.

Effective Date

    (a) This AD becomes effective September 22, 2009.

Affected ADs

    (b) This AD supersedes AD 2006-10-17.

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 3, dated
February 20, 2008.

Unsafe Condition

    (d) This AD results from a report of 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; and to ensure proper
operation of the passenger oxygen system. If an improperly
functioning passenger oxygen system goes undetected, the passenger
oxygen mask could fail to deploy and result in possible
incapacitation of passengers during a depressurization event.

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.

Requirements of AD 2006-10-17

Inspection/Replacements/Wiring Changes/Corrective Actions

    (f) Within 36 months after June 22, 2006 (the effective date of
AD 2006-10-17), do the applicable 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,
except as provided by paragraph (i) of this AD. 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;

[[Page 41610]]

    (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 June 22, 2006, 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.

                    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
                                Boeing Component Service Bulletin
                                233A3205-24-01, dated July 26, 2001.
(2) 69-37319-21-02, Revision   Modify the air conditioning module
 1, dated August 30, 2001.      assembly in accordance with the
                                Accomplishment Instructions of Boeing
                                Component Service Bulletin 69[dash]37319-
                                21-02, Revision 1, dated August 30,
                                2001.
------------------------------------------------------------------------

New Actions Required by This AD

New Service Bulletin Revision

    (i) As of the effective date of this AD, use only the
Accomplishment Instructions of Boeing Service Bulletin 737-24A1141,
Revision 3, dated February 20, 2008, to do all the applicable
actions required by paragraph (f) of this AD.

    Note 2: Accomplishment of the steps specified in the tables of
the figures of Boeing Service Bulletin 737-24A1141, Revision 3,
dated February 20, 2008, is required. Due to the variability of
airplane configurations, the illustrations in the figures are
provided as examples.

    Note 3:  Boeing Service Bulletin 737-24A1141, Revision 3, dated
February 20, 2008, refers to ``unwanted'' wire length. ``Unwanted''
wire length is any wire length that does not meet the wire length
requirements specified in the Standard Wiring Practices Manual
(SWPM).

Additional Operational Test

    (j) For airplanes on which the actions required by paragraph (f)
of this AD have been done in accordance with Boeing Service Bulletin
737-24A1141, Revision 2, dated December 1, 2005, before the
effective date of this AD: Within 12 months after the effective date
of this AD, do an operational test of the P5-14 panel in accordance
with paragraphs 3.B.92. and 3.B.93., as applicable, of the
Accomplishment Instructions of Boeing Service Bulletin 737-24A1141,
Revision 3, dated February 20, 2008.

Alternative Methods of Compliance (AMOCs)

    (k)(1) The Manager, Seattle Aircraft Certification Office, FAA,
has the authority to approve AMOCs for this AD, if requested using
the procedures found in 14 CFR 39.19. Send information to Attn: Binh
Tran, Aerospace Engineer, Systems and Equipment Branch, ANM-130S,
FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW.,
Renton, Washington 98057-3356; telephone (425) 917-6485; fax (425)
917-6590. Or, e-mail information to 9-ANM-Seattle-ACO-AMOC-
Requests@faa.gov.
    (2) To request a different method of compliance or a different
compliance time for this AD, follow the procedures in 14 CFR 39.19.
Before using any approved AMOC on any airplane to which the AMOC
applies, notify your principal maintenance inspector (PMI) or
principal avionics inspector (PAI), as appropriate, or lacking a
principal inspector, your local Flight Standards District Office.
The AMOC approval letter must specifically reference this AD.
    (3) AMOCs approved previously in accordance with AD 2006-10-17
are approved as AMOCs for the corresponding provisions of this AD.

Material Incorporated by Reference

    (l) You must use the service information contained in Table 2 of
this AD to do the actions required by this AD, unless the AD
specifies otherwise.

                                 Table 2--All Material Incorporated by Reference
----------------------------------------------------------------------------------------------------------------
                 Document                         Revision level                           Date
----------------------------------------------------------------------------------------------------------------
Boeing Component Service Bulletin          Original....................  July 26, 2001.
 233A3205-24-01.
Boeing Component Service Bulletin 69-      1...........................  August 30, 2001.
 37319-21-02.
Boeing Service Bulletin 737-24A1141......  3...........................  February 20, 2008.
----------------------------------------------------------------------------------------------------------------

     (1) The Director of the Federal Register approved the
incorporation by reference of the service information contained in
Table 3 of this AD under 5 U.S.C. 552(a) and 1 CFR part 51.

                                 Table 3--New Material Incorporated by Reference
----------------------------------------------------------------------------------------------------------------
                 Document                         Revision level                           Date
----------------------------------------------------------------------------------------------------------------
Boeing Service Bulletin 737-24A1141......  3...........................  February 20, 2008.
----------------------------------------------------------------------------------------------------------------

[[Page 41611]]

     (2) The Director of the Federal Register previously approved
the incorporation by reference of the service information contained
in Table 4 of this AD on June 22, 2006 (71 FR 28766, May 18, 2006).

                             Table 4--Material Previously Incorporated by Reference
----------------------------------------------------------------------------------------------------------------
                 Document                         Revision level                           Date
----------------------------------------------------------------------------------------------------------------
Boeing Component Service Bulletin          Original....................  July 26, 2001.
 233A3205-24-01.
Boeing Component Service Bulletin 69-      1...........................  August 30, 2001.
 37319-21-02.
----------------------------------------------------------------------------------------------------------------

    (3) For service information identified in this AD, contact
Boeing Commercial Airplanes, Attention: Data & Services Management,
P. O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone
206-544-5000, extension 1; fax 206-766-5680; e-mail
me.boecom@boeing.com; Internet https://www.myboeingfleet.com.
    (4) You may review copies of the service information at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington. For information on the availability of this material at
the FAA, call 425-227-1221 or 425-227-1152.
    (5) You may also review copies of the service information that
is incorporated by reference at the National Archives and Records
Administration (NARA). For information on the availability of this
material at NARA, call 202-741-6030, or go to: http://
www.archives.gov/federal_register/code_of_federal_regulations/
ibr_locations.html.

    Issued in Renton, Washington, on August 7, 2009.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E9-19180 Filed 8-17-09; 8:45 am]

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