
[Federal Register Volume 78, Number 45 (Thursday, March 7, 2013)]
[Rules and Regulations]
[Pages 14644-14647]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-04633]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0860; Directorate Identifier 2012-NM-123-AD; 
Amendment 39-17369; AD 2013-04-11]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company 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 
The Boeing Company Model 737-600, -700, -800, and -900ER series 
airplanes. This AD was prompted by incorrect wire support clamps 
installed within the left environmental control systems (ECS) bay, 
which could allow wiring to come in contact with the exposed metal of 
the improper clamp. This AD requires inspections to identify the part 
number of the wire support clamp, related investigative actions, and 
corrective actions if necessary. We are issuing this AD to prevent 
electrical arcing and a potential ignition source within the ECS bay, 
which in combination with flammable fuel vapors, could result in a 
center wing fuel tank explosion, and consequent loss of the airplane.

DATES: This AD is effective April 11, 2013.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of April 11, 
2013.

ADDRESSES: For service information identified in this AD, contact 
Boeing

[[Page 14645]]

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; Internet https://www.myboeingfleet.com. 
You may review copies of the referenced 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.

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 (phone: 800-647-5527) is 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: Georgios Roussos, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-3356; 
phone: 425-917-6482; fax: 425-917-6590; email: 
georgios.roussos@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an AD that would apply to the specified products. 
That NPRM published in the Federal Register on August 27, 2012 (77 FR 
51720). That NPRM proposed to require inspections to identify the part 
number (P/N) of the wire support clamp, related investigative actions, 
and corrective actions if necessary.

Comments

    We gave the public the opportunity to participate in developing 
this AD. The following presents the comments received on the proposal 
(77 FR 51720, August 27, 2012) and the FAA's response to each comment.

Statement To Address Effects of NPRM (77 FR 51720, August 27, 2012) on 
Winglets

    Aviation Partners Boeing stated that the installation of winglets 
per Supplemental Type Certificate (STC) ST00830SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/408E012E008616A7862578880060456C?OpenDocument&Highlight=st00830se) does 
not affect the actions specified by the NPRM (77 FR 51720, August 27, 
2012).

Requests To Remove or Change the ``Parts Installation Prohibition'' 
Section

    Boeing requested the ``Parts Installation Prohibition,'' paragraph 
(h) of the NPRM (77 FR 51720, August 27, 2012), be removed because 
there are other types of clamps installed within the ECS bay that are 
not included in either Boeing Special Attention Service Bulletin 737-
28-1303, dated April 26, 2012, or the NPRM (77 FR 51720, August 27, 
2012). Boeing also requested that we include P/Ns TA0930034-10P, 
TA0930034-11, and TA0930034-12P wire support clamps because they are 
interchangeable with P/N TA0930034-10. Alaska Airlines requested that 
the ``Parts Installation Prohibition'' paragraph be changed to clarify 
affected airplanes, and pointed out that AD 2010-24-11, Amendment 39-
16530 (75 FR 74616, December 1, 2010), also addresses clamps installed 
in the left ECS bay, but allows installation of clamp P/N TA0930034-11 
at the same clamp position. Delta Air Lines (Delta) requested that we 
ensure that paragraph (h) of the NPRM, only applies to those airplanes 
subject to the NPRM. Japan Airlines requested that we specify, in 
paragraph (h) of the NPRM, the locations within the left ECS bay that 
P/N TA0930034-10P clamps may be installed.
    We agree to revise paragraph (i) of this AD (referred to as 
paragraph (h) in the NPRM (77 FR 51720, August 27, 2012)). We agree to 
allow installation of wire support clamps P/Ns TA0930034-10P, 
TA0930034-11, and TA0930034-12P, in addition to P/N TA0930034-10, and 
to limit the prohibition to the locations specified in Figures 1 
through 4 of Boeing Special Attention Service Bulletin 737-28-1303, 
dated April 26, 2012. We have revised paragraph (i) of this AD 
accordingly.
    In addition, we agree to clarify the phrase ``on any airplane'' 
used in paragraph (i) of this AD. The applicability statement in all AD 
actions lists all airplanes affected by that AD. All of the 
requirements stated in an AD are applicable only to the airplanes 
listed in the applicability of that AD. We have not changed the final 
rule regarding this issue.

Requests To Allow Use of Certain Other Wire Support Clamps

    Boeing and Japan Airlines requested that the NPRM (77 FR 51720, 
August 27, 2012) allow use of certain other wire support clamps in 
addition to P/N TA0930034-10, as specified by Boeing Special Attention 
Service Bulletin 737-28-1303, dated April 26, 2012. Japan Airlines 
requested that we allow the use of clamp P/N TA0930034-10P, and 
referred to discussions with Boeing that support use of this part 
number clamp, that is also fully cushioned. Boeing requested the 
corrective actions statement in the ``Relevant Service Information'' 
section of the preamble of the NPRM (77 FR 51720, August 27, 2012) be 
revised to read, ``Corrective actions include replacing the discrepant 
clamp with a new or serviceable TA0930034-10, TA0930034-10P, TA0930034-
11, or TA0930034-12P wire support clamp if the part number is 
incorrect, and repairing or replacing chafed wiring.'' Boeing stated 
that P/Ns TA0930034-10P, TA0930034-11, and TA0930034-12P are 
interchangeable with P/N TA0930034-10.
    We agree to allow installation of P/Ns TA0930034-10P, TA0930034-11, 
and TA0930034-12P wire support clamps. We have added new paragraph (h) 
in this final rule to provide an exception to Boeing Special Attention 
Service Bulletin 737-28-1303, dated April 26, 2012, allow use of P/Ns 
TA0930034-10P, TA0930034-11, and TA0930034-12P wire support clamps. We 
have re-identified subsequent paragraphs accordingly.
    We partially agree with the intent of Boeing's request to revise 
the ``Relevant Service Information'' section of the NPRM (77 FR 51720, 
August 27, 2012). Boeing's request included removing the phrase ``or if 
the flange cushions do not completely surround the two metal strap 
sections of the wire support clamp.'' This phrase is based on the 
procedures specified in Step 1 of Figures 1 and 2 of Boeing Special 
Attention Service Bulletin 737-28-1303, dated April 26, 2012, and is 
part of the inspection required by this AD. Therefore, we do not agree 
that this phrase should be removed from the description of the 
inspection. As stated previously, we do agree that installing P/Ns 
TA0930034-10P, TA0930034-11, and TA0930034-12P wire support clamps is 
acceptable for accomplishing the corrective action. However, the 
``Relevant Service Information'' section of the NPRM is not restated in 
this AD, so we have not revised this AD in this regard.

[[Page 14646]]

Request To Clarify Impacted Fuel Tank

    Boeing requested that the ``Summary'' and ``Discussion'' sections 
in the NPRM (77 FR 51720, August 27, 2012) be revised to add the text, 
``in the center wing tank,'' and to read, ``We are proposing this AD to 
prevent electrical arcing and a potential ignition source in the center 
wing tank, which in combination with flammable fuel vapors could result 
in a fuel tank explosion, and consequent loss of the airplane,'' to 
clarify the area that might be potentially impacted by the unsafe 
condition identified in the NPRM.
    We partially agree. We agree with Boeing's request to identify the 
center wing tank as the impacted tank, because the center wing tank 
located above the ECS bay is the fuel tank potentially affected by the 
unsafe condition identified in this AD. We disagree to state that this 
AD will prevent electrical arcing and a potential ignition source in 
the center wing tank, because the potential ignition source has been 
identified to be within the ECS bay, which is a flammable leakage fluid 
zone. A potential ignition within the ECS bay could lead to a fire in 
the area and potentially result in a center wing tank explosion. 
Therefore, we agree to identify the center wing tank as the affected 
fuel tank without including the misleading statement that this AD will 
prevent electrical arcing within the fuel tank. We further recognize 
that the same issue applies to paragraph (e), ``Unsafe Condition,'' of 
this AD and note that the ``Discussion'' section that appeared in the 
NPRM (77 FR 51720, August 27, 2012) is not restated in the final rule. 
We have revised the Summary and paragraph (e) of this AD to specify 
that we are issuing this AD ``to prevent electrical arcing and a 
potential ignition source within the ECS bay, which in combination with 
flammable fuel vapors, could result in a center wing fuel tank 
explosion, and consequent loss of the airplane.''

Request To Clarify Airplane Maintenance Data

    Delta pointed to inconsistencies between the type design data and 
the aircraft illustrated parts catalog (AIPC) used for maintaining 
airplanes. Delta stated that the AIPC does not accurately identify all 
clamp locations that are needed for AD compliance, and pointed out that 
discrepancies within type design data and maintenance data could result 
in a re-occurrence of clamp installation discrepancies, which occurred 
in production and resulted in the airworthiness directive.
    We acknowledge that if operators refer to and use an inaccurate 
AIPC, it could result in non-compliance with AD requirements. However, 
it is the responsibility of the operators to ensure that they are in 
compliance with AD requirements. In addition, the AIPC is not an FAA 
approved or controlled document. We have not changed the AD in this 
regard.

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 changes described previously-- and minor editorial 
changes. We have determined that these minor changes:
     Are consistent with the intent that was proposed in the 
NPRM (77 FR 51720, August 27, 2012) for correcting the unsafe 
condition; and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM (77 FR 51720, August 27, 2012).
    We also determined that these changes will not increase the 
economic burden on any operator or increase the scope of the AD.

Costs of Compliance

    We estimate that this AD affects 297 airplanes of U.S. registry.
    We estimate the following costs to comply with this AD:

                                                 Estimated costs
----------------------------------------------------------------------------------------------------------------
                                                                     Cost per        Number of     Cost on U.S.
            Action                 Labor cost       Parts cost        product        airplanes       operators
----------------------------------------------------------------------------------------------------------------
Inspection Group 1 airplanes..  10 work-hours x               $0            $850             185        $157,250
                                 $85 per hour =
                                 $850.
Inspection Group 2 airplanes..  2 work-hours x                 0             170             112          19,040
                                 $85 per hour =
                                 $170.
----------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do any necessary replacements 
that would be required based on the results of the required inspection. 
We have no way of determining the number of aircraft that might need 
these replacements.

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replacement of wire support clamp............  1 work-hour x $85 per hour =                 $3              $88
                                                $85.
----------------------------------------------------------------------------------------------------------------

    According to the manufacturer, some of the costs of this AD may be 
covered under warranty, thereby reducing the cost impact on affected 
individuals. We do not control warranty coverage for affected 
individuals. As a result, we have included all costs in our cost 
estimate.
    We have received no definitive data that would enable us to provide 
cost estimates for the on-condition repair of chafed or damaged wiring 
specified in this AD.

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

[[Page 14647]]

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),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    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 airworthiness 
directive (AD):

2013-04-11 The Boeing Company: Amendment 39-17369; Docket No. FAA-
2012-0860; Directorate Identifier 2012-NM-123-AD.

(a) Effective Date

    This AD is effective April 11, 2013.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 737-600, -700, -800, 
and -900ER series airplanes, certificated in any category, 
identified in Boeing Special Attention Service Bulletin 737-28-1303, 
dated April 26, 2012.

(d) Subject

    Joint Aircraft System Component (JASC)/Air Transport Association 
(ATA) of America Code 28, Fuel System.

(e) Unsafe Condition

    This AD was prompted by incorrect wire support clamps installed 
within the left environmental control systems (ECS) bay, which could 
allow wiring to come in contact with the exposed metal of the 
improper clamp. We are issuing this AD to prevent electrical arcing 
and a potential ignition source within the ESC bay, which in 
combination with flammable fuel vapors, could result in a center 
wing fuel tank explosion, and consequent loss of the airplane.

(f) Compliance

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

(g) Inspection and Corrective Actions

    Within 60 months after the effective date of this AD, do a 
detailed inspection for part number (P/N) TA0930034-10 wire support 
clamp at the locations specified in Figures 1 through 4 of Boeing 
Special Attention Service Bulletin 737-28-1303, dated April 26, 
2012, and do all applicable related investigative and corrective 
actions, in accordance with the Accomplishment Instructions of 
Boeing Special Attention Service Bulletin 737-28-1303, dated April 
26, 2012, except as provided by paragraph (h) of this AD. Do all 
applicable related investigative and corrective actions before 
further flight.

(h) Exception to Service Information

    Where Boeing Special Attention Service Bulletin 737-28-1303, 
dated April 26, 2012, specifies to install P/N TA0930034-10 wire 
support clamp, this AD also allows installation of P/Ns TA0930034-
10P, TA0930034-11, and TA0930034-12P wire support clamps.

(i) Parts Installation Prohibition

    As of the effective date of this AD, no person may install a 
wire support clamp at the locations specified in Figures 1 through 4 
of Boeing Special Attention Service Bulletin 737-28-1303, dated 
April 26, 2012, on any airplane, unless the wire support clamp is P/
N TA0930034-10, TA0930034-10P, TA0930034-11, or TA0930034-12P.

(j) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19. In accordance with 14 
CFR 39.19, send your request to your principal inspector or local 
Flight Standards District Office, as appropriate. If sending 
information directly to the manager of the ACO, send it to the 
attention of the person identified in the Related Information 
section of this AD. Information may be emailed to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(k) Related Information

    For more information about this AD, contact Georgios Roussos, 
Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, 
Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, 
WA 98057-3356; phone: 425-917-6482; fax: 425-917-6590; email: 
georgios.roussos@faa.gov.

(l) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Boeing Special Attention Service Bulletin 737-28-1303, dated 
April 26, 2012.
    (ii) Reserved.
    (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; Internet https://www.myboeingfleet.com.
    (4) You may view this service information at 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.
    (5) You may view this 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/cfr/ibr-locations.html.

    Issued in Renton, Washington, on February 20, 2013.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-04633 Filed 3-6-13; 8:45 am]
BILLING CODE 4910-13-P


