[Federal Register Volume 82, Number 189 (Monday, October 2, 2017)]
[Proposed Rules]
[Pages 45743-45747]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-20560]


========================================================================
Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of 
the proposed issuance of rules and regulations. The purpose of these 
notices is to give interested persons an opportunity to participate in 
the rule making prior to the adoption of the final rules.

========================================================================


Federal Register / Vol. 82, No. 189 / Monday, October 2, 2017 / 
Proposed Rules

[[Page 45743]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0814; Product Identifier 2017-NM-066-AD]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain The Boeing Company Model 737-600, -700, -700C, -800, -900, and 
-900ER series airplanes. This proposed AD was prompted by significant 
changes made to the airworthiness limitations (AWL) related to fuel 
tank ignition prevention and the nitrogen generation system. This 
proposed AD would require revision of the maintenance or inspection 
program, as applicable, to include the latest revision of the AWLs. We 
are proposing this AD to address the unsafe condition on these 
products.

DATES: We must receive comments on this proposed AD by November 16, 
2017.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
    <bullet> Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
    <bullet> Fax: 202-493-2251.
    <bullet> 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.
    <bullet> 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 NPRM, contact Boeing 
Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 
2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600; 
telephone 562-797-1717; Internet https://www.myboeingfleet.com. You may 
view this service information at the FAA, Transport Standards Branch, 
1601 Lind Avenue SW., Renton, WA. 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 by searching for and locating Docket No. FAA-2017-
0814; 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 NPRM, 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: Tak Kobayashi, Aerospace Engineer, 
Propulsion Section, FAA, Seattle ACO Branch, 1601 Lind Avenue SW., 
Renton, WA 98057-3356; phone: 425-917-6499; fax: 425-917-6590; email: 
<a href="/cdn-cgi/l/email-protection#4632272d272e2f3527682d2924273f27352e2f0620272768212930"><span class="__cf_email__" data-cfemail="582c39333930312b397633373a3921392b3031183e3939763f372e">[email protected]</span></a>.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2017-0814; 
Product Identifier 2017-NM-066-AD'' at the beginning of your comments. 
We specifically invite comments on the overall regulatory, economic, 
environmental, and energy aspects of this NPRM. We will consider all 
comments received by the closing date and may amend this NPRM 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 NPRM.

Discussion

    The FAA has examined the underlying safety issues involved in fuel 
tank explosions on several large transport airplanes, including the 
adequacy of existing regulations, the service history of airplanes 
subject to those regulations, and existing maintenance practices for 
fuel tank systems. As a result of those findings, we issued a final 
rule titled ``Transport Airplane Fuel Tank System Design Review, 
Flammability Reduction and Maintenance and Inspection Requirements'' 
(66 FR 23086, May 7, 2001). In addition to new airworthiness standards 
for transport airplanes and new maintenance requirements, that rule 
included Amendment 21-78, which established Special Federal Aviation 
Regulation No. 88 (``SFAR 88'') at 14 CFR part 21. Subsequently, SFAR 
88 was amended by: Amendment 21-82 (67 FR 57490, September 10, 2002; 
corrected at 67 FR 70809, November 26, 2002) and Amendment 21-83 (67 FR 
72830, December 9, 2002; corrected at 68 FR 37735, June 25, 2003, to 
change ``21-82'' to ``21-83'').
    Among other actions, SFAR 88 requires certain type design (i.e., 
type certificate (TC) and supplemental type certificate (STC)) holders 
to substantiate that their fuel tank systems can prevent ignition 
sources in the fuel tanks. This requirement applies to type design 
holders for large turbine-powered transport airplanes and for 
subsequent modifications to those airplanes. It requires them to 
perform design reviews and to develop design changes and maintenance 
procedures if their designs do not meet the new fuel tank safety 
standards. As explained in the preamble to the final rule published on 
May 7, 2001, we intended to adopt airworthiness directives to mandate 
any changes found necessary to address unsafe conditions identified as 
a result of these reviews.
    In evaluating these design reviews, we have established four 
criteria intended to define the unsafe conditions associated with fuel 
tank systems that require corrective actions. The percentage of 
operating time during which fuel tanks are exposed to flammable 
conditions is one of these criteria. The other three criteria address 
the failure types under evaluation: Single failures, single failures in 
combination with another latent

[[Page 45744]]

condition(s), and in-service failure experience. For all four criteria, 
the evaluations included consideration of previous actions taken that 
may mitigate the need for further action.
    We issued AD 2008-10-10 R1, Amendment 39-16164 (75 FR 1529, January 
12, 2010) (``AD 2008-10-10 R1''), which applies to certain The Boeing 
Company Model 737-600, -700, -700C, -800, and -900 series airplanes. AD 
2008-10-10 R1 requires incorporation of fuel system AWLs and also 
requires an initial inspection to phase in certain repetitive 
inspections, and repair if necessary. The fuel system AWLs were 
developed to satisfy SFAR 88 requirements and included in the 
Airworthiness Limitations Section (ALS) of the manufacturer's 
Instructions for Continued Airworthiness. Since we issued AD 2008-10-10 
R1, the ALS has been significantly revised by the manufacturer to 
correct technical and editorial errors and also to add new 
requirements. Those changes affect the fuel system and nitrogen 
generation system AWLs. We have determined that the specific revisions 
of the ALS mandated by AD 2008-10-10 R1, and the revisions of the ALS 
that have been delivered with airplanes as part of the type design and 
airworthiness certificate, on or after March 31, 2006 (see paragraph 
(c), ``Applicability,'' of AD 2008-10-10 R1, which applied to airplanes 
with an original standard airworthiness certificate or original export 
certificate of airworthiness issued before March 31, 2006), are 
inadequate to provide information necessary to maintain critical design 
features and perform inspections.
    We propose to adopt this new AD to require revising the maintenance 
or inspection program, as applicable, to incorporate the AWLs provided 
in Boeing 737-600/700/700C/800/900/900ER Special Compliance Items/
Airworthiness Limitations, dated January 2017 (the latest revision of 
the ALS). We are proposing this AD to prevent the potential for 
ignition sources inside the fuel tanks and also to prevent increasing 
the flammability exposure of the center fuel tank caused by latent 
failures, alterations, repairs, or maintenance actions, which could 
result in a fuel tank explosion and consequent loss of an airplane.
    We have determined that accomplishing the revision required by 
paragraph (g) of this proposed AD would terminate the following 
requirements for that airplane:
    <bullet> All requirements of AD 2008-10-10 R1.
    <bullet> The revision required by paragraphs (h) and (h)(1) of AD 
2008-06-03, Amendment 39-15415 (73 FR 13081, March 12, 2008).
    <bullet> The revision required by paragraph (g) of AD 2008-17-15, 
Amendment 39-15653 (73 FR 50714, August 28, 2008).
    <bullet> The revision required by paragraph (k) of AD 2011-18-03, 
Amendment 39-16785 (76 FR 53317, August 26, 2011).
    <bullet> All requirements of AD 2013-15-17, Amendment 39-17533 (78 
FR 52838, August 27, 2013).

Airworthiness Limitations Based on Type Design

    The FAA recently became aware of an issue related to the 
applicability of ADs that require incorporation of the Airworthiness 
Limitations section (ALS) of the Instructions for Continued 
Airworthiness (ICA) into an operator's maintenance or inspection 
program.
    U.S. operators must operate their airplanes in an airworthy 
condition, in accordance with 14 CFR 91.7(a). Included in this 
obligation is the requirement to perform any maintenance or inspections 
specified in the ALS, and in accordance with the ALS as specified in 14 
CFR 43.16 and 91.403(c), unless an alternative has been approved by the 
FAA.
    When a type certificate is issued for a type design, the specific 
ALS, including its revision level, is part of that type design, as 
specified in 14 CFR 21.31(c).
    The sum effect of these operational and maintenance requirements is 
an obligation to comply with the ALS revision defined in the type 
design referenced in the manufacturer's conformity statement. This 
obligation may introduce a conflict with an AD if the AD requires a 
specific ALS revision for new airplanes that are delivered with a later 
ALS revision as part of their type design.
    The FAA has approved alternative methods of compliance (AMOCs) that 
allow operators to incorporate the most recent ALS revision into their 
maintenance/inspection programs, in lieu of the ALS revision required 
by the AD. This enables the operator to comply with both the AD and the 
type design.
    However, compliance with AMOCs is normally optional, and we 
recently became aware that some operators choose to retain the AD-
mandated ALS revision in their fleet-wide maintenance/inspection 
programs, including those for new airplanes delivered with later ALS 
revisions, to help standardize the maintenance of the fleet. To ensure 
that operators comply with the applicable ALS revision for newly 
delivered airplanes containing a later revision than that specified in 
an AD, we plan to mandate the latest ALS revision as of the effective 
date of an AD, if we are to mandate a specific ALS revision, and limit 
the applicability to those airplanes delivered on or before the 
effective date of that AD.
    This proposed AD therefore mandates the latest ALS revision as of 
the effective date of the AD for Model 737-600, -700, -700C, -800, -
900, and -900ER series airplanes with an original certificate of 
airworthiness or original export certificate of airworthiness that was 
issued on or before the effective date of the AD. Operators of 
airplanes with an original certificate of airworthiness or original 
export certificate of airworthiness issued after that date must comply 
with the airworthiness limitations specified as part of the approved 
type design.

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing 737-600/700/700C/800/900/900ER Special 
Compliance Items/Airworthiness Limitations, D626A001-9-04, dated 
January 2017. This service information describes AWLs that include 
airworthiness limitation instructions (ALI) and critical design 
configuration control limitations (CDCCL) tasks related to fuel tank 
ignition prevention and the nitrogen generation system. This service 
information is reasonably available because the interested parties have 
access to it through their normal course of business or by the means 
identified in the ADDRESSES section.

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 require revisions to certain operator 
maintenance documents to include new actions (e.g., inspections) and 
CDCCLs. Compliance with these actions and CDCCLs is required by 14 CFR 
91.403(c). For airplanes that have been previously modified, altered, 
or repaired in the areas addressed by this proposed AD, the operator 
may not be able to accomplish the actions described in the revisions. 
In this situation, to comply with 14 CFR 91.403(c), the operator must 
request approval for an alternative method of compliance according to 
paragraph (k) of this proposed AD. The request should include a 
description of changes to the required inspections that will ensure the 
continued operational safety of the airplane.

[[Page 45745]]

    Notwithstanding any other maintenance or operational requirements, 
components that have been identified as airworthy or installed on the 
affected airplanes before accomplishing the revision of the airplane 
maintenance or inspection program specified in this proposed AD do not 
need to be reworked in accordance with the latest revision of the 
CDCCLs specified by this proposed AD for incorporation. However, once 
the airplane maintenance or inspection program has been revised as 
required by this proposed AD, future maintenance actions on these 
components must be done in accordance with the CDCCLs specified by this 
proposed AD.

Differences With the Service Information

    The ``description'' column of AWL No. 28-AWL-20 identifies certain 
operational tests. However, airplanes on which the actions specified in 
paragraph (g)(2)(ii) of AD 2011-20-07 have been done are not required 
to do the operational test for left center tank fuel boost pump relay 
R54 and right center tank fuel boost pump relay R55.
    Paragraph (g) of this proposed AD would require operators to revise 
their maintenance or inspection program by incorporating, in part, AWL 
No. 28-AWL-05, ``Wire Separation Requirements for New Wiring Installed 
in Proximity to Wiring That Goes Into the Fuel Tanks'' in Boeing 737-
600/700/700C/800/900/900ER Special Compliance Items/Airworthiness 
Limitations, D626A001-9-04, dated January 2017. Paragraph (h) of this 
proposed AD would allow certain changes to be made to the requirements 
specified in AWL No. 28-AWL-05 as an option.

Clarification of the Service Information

    The ``applicability'' column of AWL No. 28-AWL-19 identifies 
affected airplanes. For airplanes on which the actions specified in 
paragraph (s) of AD 2011-18-03 have been done, incorporation of Boeing 
Service Bulletin 737-28A1206 is not required. Therefore, those 
airplanes are not affected by AWL No. 28-AWL-19 and are not required to 
do the functional test.
    The ``applicability'' column of AWL No. 28-AWL-23 identifies 
affected airplanes. For airplanes on which the actions specified in 
paragraph (s) of AD 2011-18-03 have been done, incorporation of Boeing 
Service Bulletin 737-28A1248 is not required. Therefore, those 
airplanes are not affected by AWL No. 28-AWL-23 and are not required to 
do the functional test.

Alternative Methods of Compliance (AMOC) Previously Approved for 
Compliance With AD 2008-10-10 R1

    The FAA has previously issued AMOC approvals for compliance with 
paragraph (g)(3) of AD 2008-10-10 R1 to allow operators to incorporate 
alternative versions of AWL No. 28-AWL-05. AWL No. 28-AWL-05 includes 
the requirements for new wiring introduced by any alterations or 
changes to the type design, including STC modifications, in proximity 
to wiring that penetrates the fuel tank wall. Certain STCs that 
introduced new wiring near the fuel quantity indicating system (FQIS) 
wiring utilized design features that were different from the critical 
design features for fuel tank ignition prevention specified in the AD-
mandated version of AWL No. 28-AWL-05. For those STCs, we have approved 
alternative versions of AWL No. 28-AWL-05 that specified critical 
design features associated with STC modifications. We have determined 
that certain critical design features specified in the AMOC-approved 
versions of AWL No. 28-AWL-05 are not acceptable to meet the intent of 
this AWL. Therefore, this proposed AD does not allow credit for AMOCs 
previously approved under AD 2008-10-10 R1. However, based on our 
assessment of critical design features, we have provided an optional 
action under paragraph (h) of this proposed AD to allow certain changes 
to be made to the requirements specified in AWL No. 28-AWL-05. Under 
this optional action, certain critical design features we have 
previously approved and consider to be acceptable can be specified in 
AWL No. 28-AWL-05.
    The requirements for new wiring versus existing wiring are 
specified in AWL No. 28-AWL-05. Based on these requirements, any STC 
modifications that are installed after the incorporation of AWL No. 28-
AWL-05 (version required by paragraph (g) of this AD) must comply with 
AWL No. 28-AWL-05, including any mandatory rework, or the operator must 
request approval of an AMOC according to paragraph (k) of this proposed 
AD. Any STC modifications that are installed prior to the incorporation 
of AWL No. 28-AWL-05 (version required by paragraph (g) of this AD) are 
not required to be reworked for compliance with the new wiring 
requirements of AWL No. 28-AWL-05, except that future repair and 
replacement of existing wiring must follow AWL No. 28-AWL-05.

Costs of Compliance

    We estimate that this proposed AD affects 1,417 airplanes of U.S. 
registry. We estimate the following costs to comply with this proposed 
AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Revising the maintenance or inspection  1 work-hour x $85 per                 $0             $85        $120,445
 program.                                hour = $85.
----------------------------------------------------------------------------------------------------------------

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.
    This proposed AD is issued in accordance with authority delegated 
by the Executive Director, Aircraft Certification Service, as 
authorized by FAA Order 8000.51C. In accordance with that order, 
issuance of ADs is normally a function of the Compliance and 
Airworthiness Division, but during this transition period, the 
Executive Director has delegated the authority to

[[Page 45746]]

issue ADs applicable to transport category airplanes to the Director of 
the System Oversight Division.

Regulatory Findings

    We 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 this 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

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):

The Boeing Company: Docket No. FAA-2017-0814; Product Identifier 
2017-NM-066-AD.

(a) Comments Due Date

    We must receive comments by November 16, 2017.

(b) Affected ADs

    This AD affects the ADs specified in paragraphs (b)(1) through 
(b)(5) of this AD.
    (1) AD 2008-06-03, Amendment 39-15415 (73 FR 13081, March 12, 
2008) (``AD 2008-06-03'').
    (2) AD 2008-10-10 R1, Amendment 39-16164 (75 FR 1529, January 
12, 2010) (``AD 2008-10-10 R1'').
    (3) AD 2008-17-15, Amendment 39-15653 (73 FR 50714, August 28, 
2008) (``AD 2008-17-15'').
    (4) AD 2011-18-03, Amendment 39-16785 (76 FR 53317, August 26, 
2011) (``AD 2011-18-03'').
    (5) AD 2013-15-17, Amendment 39-17533 (78 FR 52838, August 27, 
2013) (``AD 2013-15-17'').

(c) Applicability

    This AD applies to The Boeing Company Model 737-600, -700, -
700C, -800, -900, and -900ER series airplanes, certificated in any 
category, with an original standard airworthiness certificate or 
original export certificate of airworthiness issued on or before the 
effective date of this AD.

(d) Subject

    Air Transport Association (ATA) of America Code 28, Fuel.

(e) Unsafe Condition

    This AD was prompted by significant changes made to 
airworthiness limitations (AWL) related to fuel tank ignition 
prevention and the nitrogen generation system. We are issuing this 
AD to prevent the development of an ignition source inside the fuel 
tanks and also to prevent increasing the flammability exposure of 
the center fuel tank, which could lead to fuel tank explosion and 
consequent loss of the airplane.

(f) Compliance

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

 (g) Revision of Maintenance or Inspection Program

    Within 60 days after the effective date of this AD, revise the 
maintenance or inspection program, as applicable, to incorporate the 
information in Section A, including Subsections A.1, A.2, and A.3, 
of Boeing 737-600/700/700C/800/900/900ER Special Compliance Items/
Airworthiness Limitations, D626A001-9-04, dated January 2017; except 
as provided by paragraph (h) of this AD. The initial compliance 
times for the airworthiness limitation instructions (ALI) tasks are 
within the applicable compliance times specified in paragraphs 
(g)(1) through (g)(11) of this AD:
    (1) For AWL No. 28-AWL-01, ``External Wires Over Center Fuel 
Tank'': Within 120 months after the date of issuance of the original 
standard airworthiness certificate or the date of issuance of the 
original export certificate of airworthiness, or within 120 months 
after the most recent inspection was performed as specified in AWL 
No. 28-AWL-01, whichever is later.
    (2) For AWL No. 28-AWL-03, ``Fuel Quantity Indicating System 
(FQIS)--Out Tank Wiring Lightning Shield to Ground Termination'': 
Within 120 months after the date of issuance of the original 
standard airworthiness certificate or the date of issuance of the 
original export certificate of airworthiness, or within 120 months 
after the most recent inspection was performed as specified in AWL 
No. 28-AWL-03, whichever is later.
    (3) For AWL No. 28-AWL-19, ``Center Tank Fuel Boost Pump 
Automatic Shutoff System'': Within 12 months after the date of 
issuance of the original standard airworthiness certificate or the 
date of issuance of the original export certificate of 
airworthiness, within 12 months after accomplishment of the actions 
specified in Boeing Service Bulletin 737-28A1206, or within 12 
months after the most recent inspection was performed as specified 
in AWL No. 28-AWL-19, whichever is latest. This AWL does not apply 
to airplanes that have complied with paragraph (s) of AD 2011-18-03.
    (4) For AWL No. 28-AWL-20, ``Over-Current and Arcing Protection 
Electrical Design Features Operation--Boost Pump Ground Fault 
Interrupter (GFI)'': Within 12 months after the date of issuance of 
the original standard airworthiness certificate or the date of 
issuance of the original export certificate of airworthiness, within 
12 months after accomplishment of the actions specified in Boeing 
Service Bulletin 737-28A1201, or within 12 months after the most 
recent inspection was performed as specified in AWL No. 28-AWL-20, 
whichever is latest. For airplanes that have complied with paragraph 
(g)(2)(ii) of AD 2011-20-07, the operational test for left center 
tank fuel boost pump relay R54 and right center tank fuel boost pump 
relay R55 does not apply.
    (5) For AWL No. 28-AWL-23, ``Center Tank Fuel Boost Pump Power 
Failed On Protection System'': Within 12 months after the date of 
issuance of the original standard airworthiness certificate or the 
date of issuance of the original export certificate of 
airworthiness, within 12 months after accomplishment of the actions 
specified in Boeing Service Bulletin 737-28A1248, or within 12 
months after the most recent inspection was performed as specified 
in AWL No. 28-AWL-23, whichever is latest. This AWL does not apply 
to airplanes that have complied with paragraph (s) of AD 2011-18-03.
    (6) For AWL No. 28-AWL-24, ``Spar Valve Motor Operated Valve 
(MOV) Actuator--Lightning and Fault Current Protection Electrical 
Bond'': Within 72 months after accomplishment of the actions 
specified in Boeing Service Bulletin 737-28A1207, or within 72 
months after the most recent inspection was performed as specified 
in AWL No. 28-AWL-24, whichever is later.
    (7) For AWL No. 28-AWL-29, ``Full Cushion Clamps and Teflon 
Sleeving (If Installed) Installed on Out-of-Tank Wire Bundles 
Installed on Brackets that are Mounted Directly on the Fuel Tanks'': 
For airplanes having line numbers (L/N) 1 through 1754 inclusive, 
within 120 months after accomplishment of the actions specified in 
Boeing Service Bulletin 737-57A1279. For airplanes having L/N 1755 
and on, within 120 months after the date of issuance of the original 
standard airworthiness certificate or the date of issuance of the 
original export certificate of airworthiness, or within 24 months 
after the effective date of this AD, whichever is later.
    (8) For AWL No. 47-AWL-04, ``Nitrogen Generation System--Thermal 
Switch'': Within 22,500 flight hours after the date of

[[Page 45747]]

issuance of the original standard airworthiness certificate or the 
date of issuance of the original export certificate of 
airworthiness, within 22,500 flight hours after accomplishment of 
the actions specified in Boeing Service Bulletin 737-47-1003, or 
within 22,500 flight hours after the most recent inspection was 
performed as specified in AWL No. 47-AWL-04, whichever is latest.
    (9) For AWL No. 47-AWL-06, ``Nitrogen Generation System (NGS)--
Cross Vent Check Valve'': Within 13,000 flight hours after the date 
of issuance of the original standard airworthiness certificate or 
the date of issuance of the original export certificate of 
airworthiness, within 13,000 flight hours after accomplishment of 
the actions specified in Boeing Service Bulletin 737-47-1003, or 
within 13,000 flight hours after the most recent inspection was 
performed as specified in AWL No. 47-AWL-06, whichever is latest.
    (10) For AWL No. 47-AWL-07, ``Nitrogen Generation System (NGS)--
Nitrogen Enriched Air (NEA) Distribution Ducting Integrity'': Within 
6,500 flight hours after the date of issuance of the original 
standard airworthiness certificate or the date of issuance of the 
original export certificate of airworthiness, within 6,500 flight 
hours after accomplishment of the actions specified in Boeing 
Service Bulletin 737-47-1003, or within 6,500 flight hours after the 
most recent inspection was performed as specified in AWL No. 47-AWL-
07, whichever is latest.
    (11) For AWL No. 28-AWL-101, ``Engine Fuel Suction Feed 
Operational Test'': Within 7,500 flight hours or 36 months, 
whichever occurs first, after the date of issuance of the original 
airworthiness certificate or the date of issuance of the original 
export certificate of airworthiness; or within 7,500 flight hours or 
36 months, whichever occurs first, after the most recent inspection 
was performed as specified in AWL No. 28-AWL-101; whichever is 
later.

(h) Exceptions to Service Information

    As an option, when accomplishing the actions required by 
paragraph (g) of this AD, the changes specified in paragraphs (h)(1) 
and (h)(2) of this AD can be made to AWL No. 28-AWL-05.
    (1) Where AWL No. 28-AWL-05 identifies wire types BMS 13-48, BMS 
13-58, and BMS 13-60, add the following acceptable wire types: MIL-
W-22759/16, MIL-W-22759/32, MIL-W-22759/34, MIL-W-22759/41, MIL-W-
22759/86, MIL-W-22759/87, and MIL-W-22759/92; and MIL-C-27500 cables 
constructed from these wire types.
    (2) Where AWL No. 28-AWL-05 identifies TFE-2X Standard wall for 
wire sleeving, add the following acceptable sleeving materials: 
Roundit 2000NX and Varglas Type HO, HP, or HM.

(i) No Alternative Actions, Intervals, and Critical Design 
Configuration Control Limitations (CDCCLs)

    After the maintenance or inspection program, as applicable, has 
been revised as required by paragraph (g) of this AD, no alternative 
actions (e.g., inspections), intervals, and CDCCLs may be used 
unless the actions, intervals, and CDCCLs are approved as an 
alternative method of compliance (AMOC) in accordance with the 
procedures specified in paragraph (k) of this AD.

(j) Terminating Actions

    Accomplishment of the revision required by paragraph (g) of this 
AD terminates the requirements specified in paragraphs (j)(1) 
through (j)(5) of this AD for that airplane:
    (1) The revision required by paragraphs (h) and (h)(1) of AD 
2008-06-03.
    (2) All requirements of AD 2008-10-10 R1.
    (3) The revision required by paragraph (g) of AD 2008-17-15.
    (4) The revision required by paragraph (k) of AD 2011-18-03; and
    (5) All requirements of AD 2013-15-17.

(k) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle ACO Branch, 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 certification office, send it to the attention of the 
person identified in paragraph (l)(1) of this AD. Information may be 
emailed to: <a href="/cdn-cgi/l/email-protection#d3eafe929d9efe80b6b2a7a7bfb6fe92909cfe929e9c90fe81b6a2a6b6a0a7a093b5b2b2fdb4bca5"><span class="__cf_email__" data-cfemail="192034585754344a7c786d6d757c34585a56345854565a344b7c686c7c6a6d6a597f7878377e766f">[email protected]</span></a>.
    (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.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair, modification, or alteration required by this AD 
if it is approved by the Boeing Commercial Airplanes Organization 
Designation Authorization (ODA) that has been authorized by the 
Manager, Seattle ACO Branch, to make those findings. To be approved, 
the repair method, modification deviation, or alteration deviation 
must meet the certification basis of the airplane, and the approval 
must specifically refer to this AD.

(l) Related Information

    (1) For more information about this AD, contact Tak Kobayashi, 
Aerospace Engineer, Propulsion Section, FAA, Seattle ACO Branch, 
1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-6499; 
fax: 425-917-6590; email: <a href="/cdn-cgi/l/email-protection#89fde8e2e8e1e0fae8a7e2e6ebe8f0e8fae1e0c9efe8e8a7eee6ff"><span class="__cf_email__" data-cfemail="cebaafa5afa6a7bdafe0a5a1acafb7afbda6a78ea8afafe0a9a1b8">[email protected]</span></a>.
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Contractual & Data Services 
(C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-
5600; telephone 562-797-1717; Internet https://www.myboeingfleet.com. You may view this referenced service 
information at the FAA, Transport Standards Branch, 1601 Lind Avenue 
SW., Renton, WA. For information on the availability of this 
material at the FAA, call 425-227-1221.

    Issued in Renton, Washington, on September 14, 2017.
Jeffrey E. Duven,
Director, System Oversight Division, Aircraft Certification Service.
[FR Doc. 2017-20560 Filed 9-29-17; 8:45 am]
 BILLING CODE 4910-13-P


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