
[Federal Register: July 8, 2009 (Volume 74, Number 129)]
[Rules and Regulations]               
[Page 32423-32426]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08jy09-11]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-1116; Directorate Identifier 2007-NM-231-AD; 
Amendment 39-15954; AD 2009-14-04]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 737-100, -200, -200C, -
300, -400, and -500 Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
Boeing Model 737-100, -200, -200C, -300, -400, and -500 series 
airplanes. For certain airplanes, this AD requires deactivating or 
modifying the wiring to the outboard landing lights, until the wire 
bundles and electrical connectors have been replaced. For all 
airplanes, this AD also requires inspecting for any broken, damaged, or 
missing fairleads, grommets, and wires in the four electrical junction 
boxes of the main wheel well, and corrective actions if necessary. For 
certain airplanes, this AD also requires replacing certain wire bundles 
for the landing lights and fuel shutoff valves, and related 
investigative, other specified, and corrective actions if necessary. 
For certain airplanes, this AD also requires replacing of certain 
electrical connectors and backshell clamps. This AD results from 
reports of uncommanded engine shutdowns and burned and damaged wire 
bundles associated with the outboard landing lights and engine fuel 
shutoff valves. This AD also results from reports of damaged and 
missing grommets and broken and damaged fairleads in the electrical 
junction boxes of the main wheel well. We are issuing this AD to 
prevent a hot short between the outboard landing light and fuel shutoff 
valve circuits, which could result in an uncommanded engine shutdown. 
We are also issuing this AD to prevent corrosion of the electrical 
connectors of the wing rear spars, which could result in short circuits 
and consequent incorrect functioning of airplane systems needed for 
safe flight and landing.

DATES: This AD is effective August 12, 2009.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the AD as of August 12, 
2009.

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: Stephen Oshiro, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone (425) 917-6480; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an airworthiness directive (AD) that would apply to 
certain Boeing Model 737-100, -200, -200C, -300, -400, and -500 series 
airplanes. That NPRM was published in the Federal Register on October 
22, 2008 (73 FR 62937). That NPRM proposed to require deactivating or 
modifying of the wiring to the outboard landing lights, until the wire 
bundles and electrical connectors have been replaced. For all 
airplanes, that NPRM proposed to require inspecting for any broken, 
damaged, or missing fairleads, grommets, and wires in the four 
electrical junction boxes of the main wheel well, and corrective 
actions if necessary. For certain airplanes, that NPRM also proposed to 
require replacing of certain wire bundles for the landing lights and 
fuel shutoff valves, and related investigative, other specified, and 
corrective actions if necessary. For certain airplanes, that NPRM also 
proposed to require replacing certain electrical connectors and 
backshell clamps.

[[Page 32424]]

Comments

    We gave the public the opportunity to participate in developing 
this AD. We considered the comments received from the two commenters.

Support for the NPRM

    Boeing concurs with the contents of the NPRM.

Request for Work Instructions Correction

    Southwest Airlines states that there appears to be an error in the 
work instructions of Boeing Alert Service Bulletin 737-33A1140, dated 
May 22, 2006. Figure 2 (left wing) gives instructions to route new 
wires, and Figure 4 (right wing) has no work instructions for wire 
termination in either figure.
    We infer that Southwest Airlines requests that we revise the final 
rule to account for these apparent service bulletin errors and that 
clarification is necessary. Instructions for terminating the new wires 
are provided by the work instructions associated with Figure 1 (left 
wing) and Figure 3 (right wing) in Boeing Alert Service Bulletin 737-
33A1140, dated May 22, 2006. We have not changed the final rule 
regarding this issue.

Request Alternative to Corrective Action

    Southwest Airlines proposes that we revise the NPRM to require the 
use of detailed inspections of the referenced wire bundles of the 
landing lights and fuel shutoff valves, as well as performing 
operational checks of these items at 180-day intervals from the 
effective date of this AD, as a substitute for the corrective actions 
described by paragraph (f) of the proposed AD. The commenter states 
that the deactivation of the outboard landing lights per paragraph 
(f)(1) of the NPRM would be considered a temporary solution and would 
not provide a positive operational situation.
    We disagree. The alternative corrective action proposed by the 
commenter will not effectively address the potential unsafe condition 
for the following reasons:
    1. The short circuiting of the wires for the landing lights and 
engine fuel shutoff valves occurs within the wire bundle, which is 
covered by a protective overbraid. It is not possible to visually 
inspect the affected wires without partially removing the overbraid and 
disturbing the wires, which could cause the wires to be damaged.
    2. Operational testing of the outboard landing lights and the 
engine fuel shutoff valves at 180-day intervals will not be effective 
in detecting the failures since the short circuits occur suddenly and 
are not preceded by symptoms that indicate the onset of the failure.
    3. The corrective actions described by paragraph (f) of this AD are 
intended to be a temporary solution to the potential unsafe condition 
until sufficient replacement wire bundles can be manufactured to allow 
incorporating the final corrective action into the affected airplanes. 
The final corrective action is described by paragraph (g) of this AD. 
The compliance time for doing the final corrective action required by 
paragraph (g) of this AD is within 60 months. Mandating the final 
corrective action without the corrective action of paragraph (f) is not 
considered acceptable because this would expose the airplanes of the 
affected fleet to the potential unsafe condition for an excessive 
amount of time.
    We have not changed the final rule regarding this issue. However, 
operators may request approval of an alternative method of compliance 
in accordance with paragraph (j) of this AD.

Explanation of Changes to Costs of Compliance

    We have revised the Costs of Compliance to specify only the per 
product cost for deactivating and modifying the wiring to the outboard 
landing lights. We are not specifying the total cost for all affected 
airplanes for those two actions because operators may accomplish either 
action.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
the AD as proposed.

Costs of Compliance

    We estimate that the actions specified in Boeing Alert Service 
Bulletin 737-33A1140 affect about 511 Model 737-300, -400, and -500 
series airplanes of U.S. registry. Operators may accomplish either the 
deactivation or modification.
    We estimate that it takes about 1 work-hour per product to comply 
with the deactivation specified in this AD. The average labor rate is 
$80 per work-hour. Based on these figures, we estimate the cost of the 
deactivation, if done, to the U.S. operators to be $80 per product.
    We estimate that it takes about 31 work-hours per product to comply 
with the modification specified in this AD. The average labor rate is 
$80 per work-hour. Required parts for the modification cost about $573 
per product. Based on these figures, we estimate the cost of 
modification, if done, to the U.S. operators to be $3,053 per product.
    We estimate that the actions specified in Boeing Service Bulletin 
737-28-1241, Revision 1, dated August 31, 2007, affect up to 891 Model 
737-100, -200, -200C, -300, -400, and -500 series airplanes of U.S. 
registry. The following table provides the estimated costs, at an 
average labor rate of $80 per work-hour, for U.S. operators to comply 
with the actions specified in that service bulletin.

                                                                     Estimated Costs
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                                                                                                                          Number of U.S.-
               Action                            Work-hours                           Parts                  Cost per       registered      Fleet cost
                                                                                                             airplane        airplanes
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Part 1--Replacement of wire bundles.  Up to 91........................  Up to $18,439...................         $25,719             511     $13,142,409
Part 2--Inspection of junction boxes  1...............................  0...............................              80             891          71,280
Part 3--Replacement of electrical     2...............................  298.............................             458             400         183,200
 connectors.
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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

[[Page 32425]]

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

    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.
    You can find our regulatory evaluation and the estimated costs of 
compliance in the AD Docket.

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 FAA amends Sec.  39.13 by adding the following new AD:

2009-14-04 Boeing: Amendment 39-15954. Docket No. FAA-2008-1116; 
Directorate Identifier 2007-NM-231-AD.

Effective Date

    (a) This airworthiness directive (AD) is effective August 12, 
2009.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 737-100, -200, -200C, -300, 
-400, and -500 series airplanes, certificated in any category; as 
identified in Boeing Service Bulletin 737-28-1241, Revision 1, dated 
August 31, 2007.

Unsafe Condition

    (d) This AD results from reports of uncommanded engine shutdowns 
and burned and damaged wire bundles associated with the outboard 
landing lights and engine fuel shutoff valves. This AD also results 
from reports of damaged and missing grommets and broken and damaged 
fairleads in the electrical junction boxes of the main wheel well. 
We are issuing this AD to prevent a hot short between the outboard 
landing light and fuel shutoff valve circuits, which could result in 
an uncommanded engine shutdown. We are also issuing this AD to 
prevent corrosion of the electrical connectors of the wing rear 
spars, which could result in short circuits and consequent incorrect 
functioning of airplane systems needed for safe flight and landing.

Compliance

    (e) Comply with this AD within the compliance times specified, 
unless already done.

Deactivating or Modifying the Outboard Landing Lights

    (f) For Model 737-300, -400, and -500 series airplanes 
identified in Boeing Alert Service Bulletin 737-33A1140, dated May 
22, 2006: Within 180 days after the effective date of this AD, 
accomplish the actions specified in either paragraph (f)(1) or 
(f)(2) of this AD. Accomplishing the applicable actions required by 
paragraph (g) of this AD terminates the requirements of this 
paragraph.
    (1) Deactivate the outboard landing lights by accomplishing all 
of the actions specified in Part 1 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-33A1140, dated May 
22, 2006.

    Note 1:  The Master Minimum Equipment List (MMEL) prohibits 
dispatching an airplane for night operations with deactivated 
outboard landing lights in the event that either of the inboard 
landing lights fail. Operators should note that, if the outboard 
landing lights are deactivated in accordance with Part 1 of Boeing 
Alert Service Bulletin 737-33A1140, dated May 22, 2006, there is no 
MMEL relief allowing for this configuration for night operations 
should any inboard landing light fail.

    (2) Modify the wiring to the outboard landing lights by 
accomplishing all of the actions specified in Part 2 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
33A1140, dated May 22, 2006.

Inspection and Replacements

    (g) For all airplanes: Within 60 months after the effective date 
of this AD, do the applicable actions specified in paragraphs 
(g)(1), (g)(2), and (g)(3) of this AD, by accomplishing all of the 
applicable actions specified in the Accomplishment Instructions of 
Boeing Service Bulletin 737-28-1241, Revision 1, dated August 31, 
2007. For Model 737-300, -400, and -500 series airplanes identified 
in Boeing Alert Service Bulletin 737-33A1140, dated May 22, 2006, 
accomplishing the applicable actions required by this paragraph 
terminates the requirements of paragraph (f) of this AD.
    (1) Replace the wire bundles for the landing lights and fuel 
shutoff valves with new, redesigned wire bundles, and do the related 
investigative, other specified, and corrective actions, as 
applicable. The related investigative, other specified, and 
corrective actions must be done before further flight after the 
replacement.
    (2) Do a detailed inspection for any broken, damaged, or missing 
fairleads, any damaged or missing grommets, and any chafed or 
damaged wires or wire bundles in the four electrical junction boxes 
of the main wheel well, and do the applicable corrective actions. 
The corrective actions must be done before further flight after the 
inspection.
    (3) Replace the electrical connectors and backshell clamps with 
new, improved electrical connectors and backshell clamps, as 
applicable.

Credit for Actions Done According to Previous Issue of Service Bulletin

    (h) For airplanes identified as Groups 1 and 2 in Boeing Service 
Bulletin 737-28-1241, Revision 1, dated August 31, 2007: Actions 
done before the effective date of this AD in accordance with Boeing 
Service Bulletin 737-28-1241, dated April 7, 2006, are acceptable 
for compliance with the requirements of paragraph (g) of this AD.
    (i) For all airplanes: Actions done before the effective date of 
this AD in accordance with Part 2 of the Accomplishment Instructions 
of Boeing Service Bulletin 737-28-1241, dated April 7, 2006, are 
acceptable for compliance with the requirements of paragraph (g)(2) 
of this AD.

Alternative Methods of Compliance (AMOCs)

    (j)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, ATTN: Stephen Oshiro, Aerospace Engineer, Systems and Equipment 
Branch, ANM-130S, FAA, Seattle ACO, 1601 Lind Avenue, SW., Renton, 
Washington 98057-3356; telephone (425) 917-6480; fax (425) 917-6590; 
has the authority to approve AMOCs for this AD, if requested using 
the procedures found in 14 CFR 39.19.
    (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 appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.

Material Incorporated by Reference

    (k) You must use Boeing Service Bulletin 737-28-1241, Revision 
1, dated August 31, 2007; and Boeing Alert Service Bulletin 737-
33A1140, dated May 22, 2006; as applicable; to do the actions 
required by this AD, unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this AD, contact 
Boeing Commercial

[[Page 32426]]

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.
    (3) 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.
    (4) 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, WA, on June 11, 2009.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-15405 Filed 7-7-09; 8:45 am]

BILLING CODE 4910-13-P
