
[Federal Register: December 20, 2010 (Volume 75, Number 243)]
[Proposed Rules]               
[Page 79317-79320]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr20de10-18]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-1199; Directorate Identifier 2010-NM-225-AD]
RIN 2120-AA64

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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to supersede an existing airworthiness directive 
(AD) that applies to the products listed above. The existing AD 
currently requires replacement of the power control relays in the P91 
and P92 power distribution panels for the fuel boost and override pumps 
with new, improved relays having a ground fault interrupter (GFI) 
feature, or installation and maintenance of universal fault 
interrupters (UFIs) using a certain supplemental type certificate. 
Since we issued that AD, we have determined that we need to clarify 
which relays may be replaced by installation of UFIs. This proposed AD 
would continue to require the actions of the existing AD and also 
specify which relays may be replaced by GFIs or UFIs. We are proposing 
this AD to prevent pump housing burn-through due to electrical arcing, 
which could create a potential ignition source inside a fuel tank. This 
condition, in combination with flammable fuel vapors, could result in a 
fuel tank explosion and consequent loss of the airplane.

DATES: We must receive comments on this proposed AD by February 3, 
2011.

[[Page 79318]]


ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://
www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    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. 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 proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Office (phone: 800-647-5527) is in the ADDRESSES 
section. Comments will be available in the AD docket shortly after 
receipt.

FOR FURTHER INFORMATION CONTACT: Georgios Roussos, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone (425) 917-6482; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2010-1199; 
Directorate Identifier 2010-NM-225-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because of those comments.
    We will post all comments we receive, without change, to http://
www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    On July 27, 2010, we issued AD 2010-17-05, Amendment 39-16395 (75 
FR 50859, August 18, 2010), for certain Model 737-600, -700, -700C, -
800, and -900 series airplanes. That AD requires replacement of the 
power control relays in the P91 and P92 power distribution panels for 
the fuel boost and override pumps with new, improved relays having a 
ground fault interrupter (GFI) feature, or installation and maintenance 
of universal fault interrupters (UFIs) using a certain supplemental 
type certificate. That AD resulted from fuel system reviews conducted 
by the manufacturer. We issued that AD to prevent pump housing burn-
through due to electrical arcing, which could create a potential 
ignition source inside a fuel tank. This condition, in combination with 
flammable fuel vapors, could result in a fuel tank explosion and 
consequent loss of the airplane.

Actions Since Existing AD Was Issued

    Since we issued AD 2010-17-05, we have determined that there are 
errors in paragraph (f) of that AD. Paragraph (f)(2) of AD 2010-17-05 
contained a typographical error in the reference to the STC number; 
that AD refers to ``STC ST02079LA'' instead of the intended 
``ST02076LA.'' That paragraph also permits, in error, installation of 
the STC as an acceptable means of compliance for replacing relays R18, 
R19, R20, R21, R54, and R55. STC ST02076LA is a method of compliance 
only for relays R54 and R55.
    Since the STC number was referenced incorrectly, no operator could 
have used STC ST02076LA as a method of compliance for relays R18, R19, 
R20, or R21, unless an alternative method of compliance (AMOC) was 
approved. No AMOCs were approved for AD 2010-17-05.
    Paragraph (g)(1) of this notice of proposed rulemaking (NPRM) has 
been revised to specify that Boeing Alert Service Bulletin 737-28A1201, 
Revision 1, dated May 28, 2009, must be used to accomplish replacement 
of relays R18, R19, R20, and R21. Paragraph (g)(2) of this NPRM has 
been revised to specify that relays R54 and R55 must be replaced in 
accordance with either the service bulletin or by installing and 
maintaining UFIs using STC ST02076LA.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

Proposed AD Requirements

    This proposed AD would retain certain requirements of AD 2010-17-05 
with new compliance times. This proposed AD would also correct the 
reference to the STC and specify which relays may be replaced with UFIs 
by installing STC ST02076LA.

Change to Existing AD

    Since AD 2010-17-05 was issued, the AD format has been revised, and 
certain paragraphs have been rearranged. As a result, the corresponding 
paragraph identifiers have changed in this proposed AD, as listed in 
the following table:

                      Revised Paragraph Identifiers
------------------------------------------------------------------------
                                             Corresponding  requirement
       Requirement in AD 2010-17-05             in this  proposed AD
------------------------------------------------------------------------
Paragraph (f).............................  Paragraph (g).
Paragraph (g).............................  Paragraph (h).
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Costs of Compliance

    We estimate that this proposed AD affects 754 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

[[Page 79319]]



                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
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Installation of GFI relays (retained    8 work-hours x $85 per           $11,010         $11,690      $8,814,260
 actions from existing AD--which are     hour = $680.
 restated as a convenience for
 operators).
----------------------------------------------------------------------------------------------------------------

    The new requirements of this proposed AD add no additional economic 
burden.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
subtitle VII, part A, subpart III, section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect on the States, on the relationship 
between the national Government and the States, or on the distribution 
of power and responsibilities among the various levels of government.
    For the reasons discussed above, I certify that the proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979),
    (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.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

    2. The FAA amends Sec.  39.13 by removing airworthiness directive 
(AD) 2010-17-05, Amendment 39-16395 (75 FR 50859, August 18, 2010), and 
adding the following new AD:

The Boeing Company: Docket No. FAA-2010-1199; Directorate Identifier 
2010-NM-225-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by February 
3, 2011.

Affected ADs

    (b) This AD supersedes AD 2010-17-05, Amendment 39-16395.

Applicability

    (c) This AD applies to The Boeing Company Model 737-600, -700, -
700C, -800, and -900 series airplanes, certificated in any category; 
as identified in Boeing Alert Service Bulletin 737-28A1201, Revision 
1, dated May 28, 2009.

Subject

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

Unsafe Condition

    (e) This AD was prompted by fuel system reviews conducted by the 
manufacturer. We are issuing this AD to prevent pump housing burn-
through due to electrical arcing, which could create a potential 
ignition source inside a fuel tank. This condition, in combination 
with flammable fuel vapors, could result in a fuel tank explosion 
and consequent loss of the airplane.

Compliance

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

Replacement or Installation

    (g) Within 60 months after the effective date of this AD, do the 
actions required in paragraphs (g)(1) and (g)(2) of this AD.
    (1) Replace the power control relays that are located in the 
R18, R19, R20, and R21 positions in the P91 and P92 power 
distribution panels for the fuel boost pumps with new, improved 
relays, part number KDAG-X4F-001, having a ground fault interrupter 
(GFI) feature, in accordance with the Accomplishment Instructions of 
Boeing Alert Service Bulletin 737-28A1201, Revision 1, dated May 28, 
2009.
    (2) Replace the power control relays that are located in the R54 
and R55 positions in the P91 and P92 power distribution panels for 
the fuel override pumps, in accordance with the actions required in 
paragraph (g)(2)(i) or (g)(2)(ii) of this AD.
    (i) Replace with new, improved relays, part number KDAG-X4F-001, 
having a GFI feature, in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-28A1201, Revision 
1, dated May 28, 2009.
    (ii) Install and maintain TDG Aerospace universal fault 
interrupters (UFIs) using Supplemental Type Certificate ST02076LA, 
issued October 26, 2007.

    Note: Boeing Alert Service Bulletin 737-28A1201, Revision 1, 
dated May 28, 2009, refers to Honeywell Service Bulletin 1151932-24-
61 and Honeywell Service Bulletin 1151934-24-62, both Revision 5, 
both dated May 25, 2009, as additional sources of guidance for 
replacement of the power control relays in the P91 and P92 power 
distribution panels.

Credit for Actions Accomplished in Accordance With Previous Service 
Information

    (h) Actions done before the effective date of this AD in 
accordance with Boeing Alert Service Bulletin 737-28A1201, dated 
February 19, 2007, are acceptable for compliance with the 
requirements of paragraphs (g)(1) and (g)(2)(i) of this AD, provided 
that Revision 5 of Honeywell Service Bulletins 1151932-24-61 and 
1151934-24-62, both dated May 25, 2009, is used as an additional 
source of guidance.

Alternative Methods of Compliance (AMOCs)

    (i)(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 e-mailed to: 9-ANM-Seattle-
ACO-AMOC-Requests@faa.gov.
    (2) Before using any approved AMOC, notify your Principal 
Maintenance Inspector

[[Page 79320]]

or Principal Avionics Inspector, as appropriate, or lacking a 
principal inspector, your local Flight Standards District Office.

Related Information

    (j) 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, Washington 98057-3356; telephone (425) 917-6482; fax (425) 
917-6590.
    (k) 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. 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.

    Issued in Renton, Washington, on December 10, 2010.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2010-31828 Filed 12-17-10; 8:45 am]
BILLING CODE 4910-13-P

