AD 2018-20-24

[Federal Register Volume 83, Number 199 (Monday, October 15, 2018)]
[Rules and Regulations]
[Pages 51815-51819]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2018-21971]



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                                                Federal Register
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Federal Register / Vol. 83, No. 199 / Monday, October 15, 2018 / 
Rules and Regulations

[[Page 51815]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0814; Product Identifier 2017-NM-066-AD; Amendment 
39-19458; AD 2018-20-24]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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

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

DATES: This AD is effective November 19, 2018.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of November 19, 
2018.

ADDRESSES: For service information identified in this final rule, 
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 <a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>. You may view this service information at the 
FAA, Transport Standards Branch, 2200 South 216th St., Des Moines, WA. 
For information on the availability of this material at the FAA, call 
206-231-3195. It is also available on the internet at <a href="http://www.regulations.gov">http://www.regulations.gov</a> by searching for and locating Docket No. FAA-2017-
0814.

Examining the AD Docket

    You may examine the AD docket on the internet at <a href="http://www.regulations.gov">http://www.regulations.gov</a> by searching for and locating Docket No. FAA-2017-
0814; or in person at Docket Operations between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays. The AD docket contains 
this final rule, the regulatory evaluation, any comments received, and 
other information. The address for Docket Operations (phone: 800-647-
5527) is Docket Operations, 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: Tak Kobayashi, Aerospace Engineer, 
Propulsion Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des 
Moines, WA 98198; phone and fax: 206-231-3553; email: 
<a href="/cdn-cgi/l/email-protection#394d58525851504a581752565b5840584a5150795f5858175e564f"><span class="__cf_email__" data-cfemail="cdb9aca6aca5a4beace3a6a2afacb4acbea5a48dabacace3aaa2bb">[email&#160;protected]</span></a>.

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 by adding an AD that would apply to certain The Boeing Company 
Model 737-600, -700, -700C, -800, and -900 series airplanes. The NPRM 
published in the Federal Register on October 2, 2017 (82 FR 45743). The 
NPRM was prompted by significant changes made to the AWLs related to 
fuel tank ignition prevention and the nitrogen generation system. The 
NPRM proposed to require revision of the maintenance or inspection 
program, as applicable, to include the latest revision of the AWLs.
    In the NPRM, we discussed that we would mandate the latest revision 
of the Airworthiness Limitations section (ALS) of the Instructions for 
Continued Airworthiness (ICA) 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. We also discussed that operators of airplanes with an 
original certificate of airworthiness or original export of certificate 
of airworthiness issued after the effective date of the AD must comply 
with the ALS revision specified as part of the approved type design. 
Since the issuance of the NPRM, Boeing revised the ALS a number of 
times and added new AWL tasks. In order to mandate the latest ALS 
revision available as of the effective date of the AD as we originally 
proposed, we must supplement the NPRM for public comments because new 
additional AWL tasks in the later ALS revisions expand the scope of the 
NPRM. As a result, the issuance of the AD to address the unsafe 
condition would be delayed.
    Based on those conditions, we have made the following adjustments 
in this final rule. First, instead of mandating the latest ALS 
revision, we are mandating Revision January 2017 of the ALS as 
originally proposed in the NPRM. Second, we have changed the AD 
applicability to exclude those airplanes delivered with later ALS 
revisions (later than Revision January 2017) as part of the type 
design. The change in the AD applicability is intended to avoid the 
situation discussed in the NPRM where the AD mandates a specific ALS 
revision for an airplane that was delivered with a later ALS revision 
as part of the type design. Airplanes outside the AD applicability 
should use the ALS revision later than Revision January 2017 as part of 
the type design. Those adjustments we made in the final rule do not 
expand the scope of the NPRM. We will consider further rulemaking to 
mandate a later ALS revision for all affected airplanes.
    We are issuing this AD to address the development of an ignition 
source inside the fuel tanks and the flammability exposure of the 
center fuel tank, which could lead to fuel tank explosion and 
consequent loss of the airplane. We are also issuing this AD to address 
the loss of engine fuel suction feed capability, which could result in 
dual engine flameout, inability to restart engines, and consequent 
forced landing of the airplane.

Comments

    We gave the public the opportunity to participate in developing 
this final rule. The following presents the comments received on the 
NPRM and the FAA's response to each comment.

Support for the NPRM

    Commenter Nick Gianetti supported the NPRM.

[[Page 51816]]

Request To Clarify the Provision for Exceptional Short-Term Extensions

    Southwest Airlines requested clarification regarding the provision 
for ``exceptional short-term extension'' in the service information.
    We agree that clarification is necessary. Operators may use an 
exceptional short-term extension with the concurrence of the 
appropriate authority, as described in the service information. 
Exceptional short-term extensions should be used to address 
uncontrollable or unexpected situations. For any change to the interval 
of an AWL other than an exceptional short-term extension, approval must 
be handled under the provisions of paragraph (k) of this AD. No change 
to this AD is necessary.

Request To Identify AD 2011-20-07, Amendment 39-16818 (76 FR 60710, 
September 30, 2011) (``AD 2011-20-07''), as an Affected AD

    Boeing stated that AD 2011-20-07 is affected by the proposed AD 
because it relates to an AWL in the mandated service information. They 
requested that we identify AD 2011-20-07 as an affected AD under 
paragraph (b) of the proposed AD.
    We acknowledge the commenter's rationale for including AD 2011-20-
07 in paragraph (b) of this AD. However, paragraph (b), ``Affected 
ADs,'' is intended to include other affected ADs, but not all related 
ADs. It is primarily used to reference superseded ADs and other ADs 
that are terminated, in whole or in part, by requirements in a given 
AD. Although compliance with certain requirements in AD 2011-20-07 
affects this AD, the opposite is not true (i.e., this AD does not 
affect compliance with AD 2011-20-07). Therefore, we have not changed 
this AD regarding this issue.

Request To Specify the Unsafe Condition for Engine Fuel Suction Feed

    Boeing stated that the NPRM defines the unsafe condition for fuel 
tank ignition prevention and fuel tank flammability exposure reduction, 
but not the unsafe condition related to engine fuel suction feed. 
Because the proposed AD also requires the incorporation of the AWL for 
engine fuel suction feed testing, Boeing asserted that the unsafe 
condition associated with engine fuel suction feed should also be 
specified, and they proposed wording for the unsafe condition.
    We partially agree with the commenter. We agree to specify the 
unsafe condition associated with engine fuel suction feed, but we 
disagree with the wording proposed by the commenter because this AD 
does not mandate repetitive operational tests of the engine fuel 
suction feed system. This AD requires only the incorporation of certain 
AWLs, not the repetitive operational tests or other procedures 
specified in them. We have changed paragraph (e) of this AD to include 
the unsafe condition involving engine fuel suction feed.

Request To Change Wording in the Proposed AD

    Boeing requested that we replace the word ``latest'' with ``later'' 
in certain subparagraphs of paragraph (g) of the proposed AD in which 
multiple compliance times are compared.
    We do not agree with the commenter's request because the 
subparagraphs in question compare three compliance times; therefore, 
the superlative form ``latest'' is correct. We have not changed this AD 
in this regard.

Request To Provide a Grace Period in Paragraph (g)(7) of the Proposed 
AD

    Southwest Airlines stated that some airplanes could be out of 
compliance as of the effective date of the proposed AD because the 
initial 120-month compliance time specified in paragraph (g)(7) of the 
proposed AD may already have passed for those airplanes. Southwest 
Airlines requested that we change paragraph (g)(7) of the proposed AD 
to specify a grace period.
    We agree to specify a grace period for those airplanes that could 
have passed the required compliance time specified in paragraph (g)(7) 
of this AD. Therefore, we have changed paragraph (g)(7) of this AD to 
specify a grace period of 24 months after the effective date of this 
AD.

Request To Delete Paragraph (h) of the Proposed AD

    Boeing stated that some of the wire types listed in paragraph 
(h)(1) of the proposed AD are not identified in FAA Advisory Circular 
43-13-1B for the flammability aspect. Boeing also stated that they do 
not have arc-track test data for the wires listed in paragraph (h)(1) 
and therefore cannot accept the use and installation of these wire 
types on a Boeing product without written FAA approval of the wires. In 
addition, Boeing stated that it has data for TFE-2X Standard wall, but 
not for Roundit 2000NX and Varglas Types HO, HP, or HM and can 
therefore approve or recommend approval of only the TFE-2X Standard 
wall. Boeing requested that we delete paragraph (h) of the proposed AD 
or revise it to include an FAA-issued global alternative method of 
compliance (AMOC) that identifies the material listed in paragraph (h) 
of the proposed AD. Boeing stated that if the FAA decides to keep 
paragraph (h) of the proposed AD as it is, we should state that all 
materials listed in paragraph (h) of the proposed AD are approved by 
the FAA.
    We do not agree with the commenter's request. Paragraph (h) of this 
AD allows alternative wire types and sleeving materials for certain 
wire types and sleeving materials identified in AWL No. 28-AWL-05. AWL 
No. 28-AWL-05 was originally mandated by AD 2008-10-10, Amendment 39-
15516 (73 FR 25986, May 8, 2008) (``AD 2008-10-10''), which was later 
revised to AD 2008-10-10 R1, Amendment 39-16164 (75 FR 1529, January 
12, 2010) (``AD 2008-10-10 R1''). Since the issuance of AD 2008-10-10 
R1, which will be terminated by this AD, we have received numerous 
requests for approval of AMOCs from operators and supplemental type 
certificate (STC) holders (or applicants) to allow the installation of 
alternative wire types and sleeving. We evaluated certain attributes of 
those alternative wire types and sleeving for each installation, and 
issued numerous AMOC approvals for AD 2008-10-10 R1 based on our 
determination that the installation of those wire types and sleeving 
would provide an acceptable level of safety. The alternative wire types 
and sleeving specified in paragraph (h) of this AD were previously 
approved as an AMOC for AD 2008-10-10 R1. Although paragraph (h) of 
this AD provides certain allowances, it does not provide approval of 
alternative wire types and sleeving that are installed as part of an 
aircraft design change. Each applicant for any design change is 
responsible to show that the installation of alternative wire types and 
sleeving identified in paragraphs (h)(l) and (h)(2) of this AD complies 
with all applicable regulatory requirements, including flammability 
requirements, as the commenter pointed out. We have not changed this AD 
in this regard.

Request To Specify Additional Wire Type Specifications in Paragraph 
(h)(1) of the Proposed AD

    Delta Airlines (DAL) stated that the military wire specifications 
identified in paragraph (h)(1) of the proposed AD have been superseded. 
DAL requested that we revise paragraph (h)(1) of the proposed AD to 
identify additional wire type specifications.
    We agree with the commenter and have revised paragraph (h)(l) of 
this AD

[[Page 51817]]

to identify additional acceptable SAE and military wire type 
specifications.

Request To Specify Sleeving Thickness

    Boeing stated that under AWL No. 28-AWL-05, the wall thickness 
requirement for TFE-2X sleeving is specified as ``standard wall.'' 
Boeing requested that we also specify the wall thickness requirement 
for Varglas Type HO, HP, and HM, that are allowed as alternative 
sleeving under paragraph (h)(2) of the proposed AD.
    We do not agree with the commenter's request. As we explained in an 
earlier comment response, paragraph (h)(2) of this AD provides certain 
allowances for sleeving material to comply with AWL No. 28-AWL-05, but 
it does not provide approval of alternative sleeving that is installed 
as part of an aircraft design change. Each applicant for any design 
change is responsible to show that the installation of alternative 
sleeving identified in paragraph (h)(2) of this AD complies with all 
applicable regulatory requirements. This includes substantiation to 
show that sleeve installation, including the selection of sleeve 
thickness, is adequate to protect wires from chafing for the life of 
installation. We have not changed this AD regarding this issue.

Request To Mandate a Later Revision of the Service Information

    Boeing stated that Boeing 737-600/700/700C/800/900/900ER Special 
Compliance Items/Airworthiness Limitations, D626A001-9-04, Revision 
January 2017, specified by the proposed AD, is under review and subject 
to update. Boeing requested that we mandate a later revision of the 
service information.
    We do not agree with the commenter's request. As stated in the 
Discussion section of this AD, we have determined that it is 
appropriate to require the same ALS revision (Revision January 2017) 
that was proposed in the NPRM. We have also adjusted the applicability 
of this AD to exclude those airplanes delivered with a later ALS 
revision (issued after Revision January 2017) as part of the type 
design.

Effect of Winglets on Accomplishment of the Proposed Actions

    Aviation Partners Boeing stated that accomplishing the STC 
ST00830SE does not affect the actions specified in the proposed AD.
    We concur with the commenter that STC ST00830SE does not affect the 
accomplishment of the manufacturer's service instructions. Therefore, 
the installation of STC ST00830SE does not affect the ability to 
accomplish the actions required by this AD. We have not changed this 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 
this final rule with the changes described previously and minor 
editorial changes. We have determined that these minor changes:
    <bullet> Are consistent with the intent that was proposed in the 
NPRM for addressing the unsafe condition; and
    <bullet> Do not add any additional burden upon the public than was 
already proposed in the NPRM.
    We also determined that these changes will not increase the 
economic burden on any operator or increase the scope of this final 
rule.

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, Revision 
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.

Costs of Compliance

    We estimate that this AD affects 1,850 airplanes of U.S. registry. 
We estimate the following costs to comply with this AD:
    We have determined that revising the maintenance or inspection 
program takes an average of 90 work-hours per operator, although we 
recognize that this number may vary from operator to operator. In the 
past, we have estimated that this action takes 1 work-hour per 
airplane. Since operators incorporate maintenance or inspection program 
changes for their affected fleet(s), we have determined that a per-
operator estimate is more accurate than a per-airplane estimate. 
Therefore, we estimate the total cost per operator to be $7,650 (90 
work-hours x $85 per work-hour).

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

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:

[[Page 51818]]

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):

2018-20-24 The Boeing Company: Amendment 39-19458; Docket No. FAA-
2017-0814; Product Identifier 2017-NM-066-AD.

(a) Effective Date

    This AD is effective November 19, 2018.

(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, line numbers 1 through 6899 inclusive.

(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 address the development of an ignition source inside the fuel 
tanks and the flammability exposure of the center fuel tank, which 
could lead to a fuel tank explosion and consequent loss of the 
airplane. We are also issuing this AD to address the potential loss 
of engine fuel suction feed capability, which could result in dual 
engine flameouts, inability to restart engines, and consequent 
forced landing 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, Revision January 2017; 
except as provided in 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, Amendment 39-16818 (76 FR 60710, 
September 30, 2011), 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, or within 24 months after the 
effective date of this AD, whichever is later. 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 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

[[Page 51819]]

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) Additional Acceptable Wire Types and Sleeving

    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 are acceptable.
    (1) Where AWL No. 28-AWL-05 identifies wire types BMS 13-48, BMS 
13-58, and BMS 13-60, the following wire types are acceptable: MIL-
W-22759/16, SAE AS22759/16 (M22759/16), MIL-W-22759/32, SAE AS22759/
32 (M22759/32), MIL-W-22759/34, SAE AS22759/34 (M22759/34), MIL-W-
22759/41, SAE AS22759/41 (M22759/41), MIL-W-22759/86, SAE AS22759/86 
(M22759/86), MIL-W-22759/87, SAE AS22759/87 (M22759/87), MIL-W-
22759/92, and SAE AS22759/92 (M22759/92); and MIL-C-27500 and NEMA 
WC 27500 cables constructed from these military or SAE specification 
wire types, as applicable.
    (2) Where AWL No. 28-AWL-05 identifies TFE-2X Standard wall for 
wire sleeving, the following sleeving materials are acceptable: 
Roundit 2000NX and Varglas Type HO, HP, or HM.

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

    Except as provided in paragraph (h) of this AD, 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 for Certain AD Requirements

    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.
    (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) of this AD. Information may be 
emailed to: <a href="/cdn-cgi/l/email-protection#9ea7b3dfd0d3b3cdfbffeaeaf2fbb3dfddd1b3dfd3d1ddb3ccfbefebfbedeaeddef8ffffb0f9f1e8"><span class="__cf_email__" data-cfemail="d2ebff939c9fff81b7b3a6a6beb7ff93919dff939f9d91ff80b7a3a7b7a1a6a192b4b3b3fcb5bda4">[email&#160;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

    For more information about this AD, contact Tak Kobayashi, 
Aerospace Engineer, Propulsion Section, FAA, Seattle ACO Branch, 
2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-
3553; email: <a href="/cdn-cgi/l/email-protection#483c29232920213b296623272a2931293b2021082e2929662f273e"><span class="__cf_email__" data-cfemail="8cf8ede7ede4e5ffeda2e7e3eeedf5edffe4e5cceaededa2ebe3fa">[email&#160;protected]</span></a>.

(m) 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 737-600/700/700C/800/900/900ER Special Compliance 
Items/Airworthiness Limitations, D626A001-9-04, Revision January 
2017.
    (ii) Reserved.
    (3) 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 <a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>.
    (4) You may view this service information at the FAA, Transport 
Standards Branch, 2200 South 216th St., Des Moines, WA. For 
information on the availability of this material at the FAA, call 
206-231-3195.
    (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: <a href="http://www.archives.gov/federal-register/cfr/ibr-locations.html">http://www.archives.gov/federal-register/cfr/ibr-locations.html</a>.

    Issued in Des Moines, Washington, on September 19, 2018.
John P. Piccola,
Acting Director, System Oversight Division, Aircraft Certification 
Service.
[FR Doc. 2018-21971 Filed 10-12-18; 8:45 am]
 BILLING CODE 4910-13-P