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Published 2019-12-16 · Federal Register document 2019-26963

Airworthiness Directives; The Boeing Company Airplanes

Publication summary

The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. This AD was prompted by significant changes made to the airworthiness limitations (AWLs) related to fuel tank ignition prevention and the nitrogen generation system. This AD requires revising the existing maintenance or inspection program, as applicable, to include new or revised AWLs. The FAA is issuing this AD to address the unsafe condition on these products.

Why this record is shown

Source: Federal Register annual FAA metadata. Acquired 2026-09-03T22:24:01.312311+00:00. The title, summary and date are source facts.

Source revision
federal_register_ad_metadata_2019-66422190cf4fa9dc
Source row
results[280]
Raw source SHA-256
66422190cf4fa9dc96bac02b1afe14648e349a1393bef6cf5fbf55644fa2ce43

Final-rule publication

Recorded publication clauses

AD identifier printed in this edition
2019-23-14
Effective date printed in this edition
2020-01-21
Read 13 complete recorded clauses
Effective Date
(a) Effective Date

    This AD is effective January 21, 2020.

Exact source excerpt. Text positions 11385–11449, end exclusive, in the original decoded publication. SHA-256: 5a3a9abb54548280c495c2419883bb4e9ea62b310d07e29cb78f5d26043e6e0b

Affected ADs
(b) Affected ADs

    This AD affects the ADs specified in paragraphs (b)(1) through 
(7) of this AD.
    (1) AD 2008-10-09 R1, Amendment 39-16148 (74 FR 69264, December 
31, 2009) (``AD 2008-10-09 R1'').
    (2) AD 2011-12-09, Amendment 39-16716 (76 FR 33988, June 10, 
2011) (``AD 2011-12-09'').
    (3) AD 2013-13-15, Amendment 39-17503 (78 FR 42415, July 16, 
2013) (``AD 2013-13-15'').
    (4) AD 2013-25-05, Amendment 39-17701 (78 FR 78701, December 27, 
2013) (``AD 2013-25-05'').
    (5) AD 2016-18-16, Amendment 39-18647 (81 FR 65864, September 
26, 2016) (``AD 2016-18-16'').
    (6) AD 2017-17-09, Amendment 39-18999 (82 FR 40477, August 25, 
2017) (``AD 2017-17-09'').
    (7) AD 2018-04-12, Amendment 39-19208 (83 FR 9178, March 5, 
2018) (``AD 2018-04-12'').

Exact source excerpt. Text positions 11449–12223, end exclusive, in the original decoded publication. SHA-256: 2594723fecdbbbe7072a14b7cc131590a6edc02b378e41566cc3058d2f11c8ec

Applicability wording · Applicability
(c) Applicability

    This AD applies to all The Boeing Company Model 737-100, -200, -
200C, -300, -400, and -500 series airplanes, certificated in any 
category.

Exact source excerpt. Text positions 12223–12388, end exclusive, in the original decoded publication. SHA-256: 3144cb36983e737245fa6a2c8cc7e518635c3c641e27f405ccee5fc5f4e3169a

Subject
(d) Subject

    Air Transport Association (ATA) of America Code 28, Fuel; 47, 
Nitrogen Generation System.

Exact source excerpt. Text positions 12388–12497, end exclusive, in the original decoded publication. SHA-256: cd5bd7fa1bf880acdb3d436ccfe2ac201f30fdd6fb49d3f9847696778bc036b5

Unsafe Condition
(e) Unsafe Condition

    This AD was prompted by a determination that new or revised 
airworthiness limitations (AWLs) are necessary related to fuel tank 
ignition prevention and the nitrogen generation system. The FAA is 
issuing this AD to address the potential of ignition sources inside 
fuel tanks, which, in combination with flammable fuel vapors, could 
result in fuel tank explosions and consequent loss of the airplane.

Exact source excerpt. Text positions 12497–12928, end exclusive, in the original decoded publication. SHA-256: cdfd19aa6d85da0eec730bc7f24a8117c4b7158ac63c0bac8e8a3677746b4dd4

Compliance
(f) Compliance

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

Exact source excerpt. Text positions 12928–13030, end exclusive, in the original decoded publication. SHA-256: 00fbfa31932483f627d0ce0a11cbd2e35e15d9231842b91ac85623ce533912d3

Maintenance or Inspection Program Revision
(g) Maintenance or Inspection Program Revision

    (1) For The Boeing Company Model 737-100, -200, and -200C series 
airplanes: Within 60 days after the effective date of this AD, 
revise the existing maintenance or inspection program, as 
applicable, to incorporate the information specified in Section C, 
including Subsections C.1, C.2, and C.3 of Boeing 737-100/200/200C/
300/400/500 Airworthiness Limitations (AWLs) and Certification 
Maintenance Requirements (CMRs), D6-38278-CMR, dated March 2019, 
except as provided in paragraph (h) of this AD. The initial 
compliance time for the ALI tasks are within the applicable 
compliance times specified in paragraphs (g)(1)(i) through (x) of 
this AD.
    (i) For AWL No. 28-AWL-01, ``External Wires Over Center Fuel 
Tank'': Within 120 months after the most recent inspection was 
performed as specified in AWL No. 28-AWL-01, or within 12 months 
after the effective date of this AD if no initial inspection has 
been performed.
    (ii) For AWL No. 28-AWL-03, ``Fuel Quantity Indicating System 
(FQIS)--Out Tank Wiring Lightning Shield to Ground Termination'': 
Within 120 months after accomplishment of the actions specified in 
Boeing Service Bulletin 737-28A1178, or within 120 months after the 
most recent inspection was performed as specified in AWL No. 28-AWL-
03, whichever is later.
    (iii) For AWL No. 28-AWL-21, ``Center Tank Fuel Boost Pump 
Automatic Shutoff System'': Within 12 months after accomplishment of 
the actions specified in Boeing Service Bulletin 737-28A1228, or 
within 12 months after the most recent inspection was performed as 
specified in AWL No. 28-AWL-21, whichever is later.
    (iv) For AWL No. 28-AWL-22, ``Auxiliary Tank Fuel Boost Pump 
Automatic Shutoff System'': Within 12 months after accomplishment of 
the actions specified in Boeing Service Bulletin 737-28A1228, or 
within 12 months after the most recent inspection was performed as 
specified in AWL No. 28-AWL-22, whichever is later.
    (v) For AWL No. 28-AWL-23, ``Over-Current and Arcing Protection 
Electrical Design Features Operation--Boost Pump Ground Fault 
Interrupter (GFI)'': Within 12 months after accomplishment of the 
actions specified in Boeing Service Bulletin 737-28A1212, or within 
12 months after the most recent inspection was performed as 
specified in AWL No. 28-AWL-23, whichever is later.
    (vi) For AWL No. 28-AWL-24, ``Center Tank Fuel Boost Pump Power 
Failed On Protection System'': Within 12 months after accomplishment 
of the actions specified in Boeing Service Bulletin 737-28A1227, or 
within 12 months after the most recent inspection was performed as 
specified in AWL No. 28-AWL-24, whichever is later.
    (vii) For AWL No. 28-AWL-25, ``Auxiliary Fuel Tank Boost Pump 
Power Failed On Protection System'': Within 12 months after 
accomplishment of the actions specified in Boeing Service Bulletin 
737-28A1227, or within 12 months after the most recent inspection 
was performed as specified in AWL No. 28-AWL-25, whichever is later.
    (viii) For AWL No. 28-AWL-29, ``AC Fuel Boost Pump 
Installation'': Within 72 months after the most recent inspection 
was performed as specified in AWL No. 28-AWL-29, or within 12 months 
after the effective date of this AD if no inspection has been 
performed in the last 72 months.
    (ix) For AWL No. 47-AWL-04, ``Nitrogen Generation System (NGS)--
Thermal Switch'': Within 22,500 flight hours after accomplishment of 
the actions specified in Boeing Service Bulletin 737-47-1005; within 
22,500 flight hours after accomplishment of the actions specified in 
Boeing Service Bulletin 737-47-1008; or within 22,500 flight hours 
after the most recent inspection was performed as specified in AWL 
No. 47-AWL-04; whichever is latest.
    (x) For AWL No. 47-AWL-05, ``Nitrogen Generation System (NGS)--
Nitrogen Enriched Air (NEA) Distribution Ducting Integrity'': Within 
14,500 flight hours after accomplishment of the actions specified in 
Boeing Service Bulletin 737-47-1005; within

[[Page 68329]]

14,500 flight hours after accomplishment of the actions specified in 
Boeing Service Bulletin 737-47-1008; or within 14,500 flight hours 
after the most recent inspection was performed as specified in AWL 
No. 47-AWL-05; whichever is latest.
    (2) For The Boeing Company Model 737-300, -400, and -500 series 
airplanes: Within 60 days after the effective date of this AD, 
revise the existing maintenance or inspection program, as 
applicable, to incorporate the information specified in Section C, 
including Subsections C.1, C.2, and C.3 of Boeing 737-100/200/200C/
300/400/500 Airworthiness Limitations (AWLs) and Certification 
Maintenance Requirements (CMRs), D6-38278-CMR, dated March 2019; 
except as provided in paragraph (h) of this AD. The initial 
compliance time for the ALI tasks are within the applicable 
compliance times specified in paragraphs (g)(2)(i) through (xi) of 
this AD.
    (i) For AWL No. 28-AWL-01, ``External Wires Over Center Fuel 
Tank'': Within 120 months after the most recent inspection was 
performed as specified in AWL No. 28-AWL-01, or within 12 months 
after the effective date of this AD if no initial inspection has 
been performed.
    (ii) For AWL No. 28-AWL-03, ``Fuel Quantity Indicating System 
(FQIS)--Out Tank Wiring Lightning Shield to Ground Termination'': 
Within 120 months after accomplishment of the actions specified in 
Boeing Service Bulletin 737-28A1175; within 120 months after 
accomplishment of the actions specified in Boeing Service Bulletin 
737-28A1183; within 120 months after accomplishment of the actions 
specified in Boeing Service Bulletin 737-28A1186; or within 120 
months after the most recent inspection was performed as specified 
in AWL No. 28-AWL-03; whichever is latest.
    (iii) For AWL No. 28-AWL-20, ``Center Tank Fuel Boost Pump 
Automatic Shutoff System'': Within 12 months after accomplishment of 
the actions specified in Boeing Service Bulletin 737-28A1216, or 
within 12 months after the most recent inspection was performed as 
specified in AWL No. 28-AWL-20, whichever is later.
    (iv) For AWL No. 28-AWL-21, ``Auxiliary Tank Fuel Boost Pump 
Automatic Shutoff System'': Within 12 months after accomplishment of 
the actions specified in Boeing Service Bulletin 737-28A1216, or 
within 12 months after the most recent inspection was performed as 
specified in AWL No. 28-AWL-21, whichever is later.
    (v) For AWL No. 28-AWL-22, ``Over-Current and Arcing Protection 
Electrical Design Features Operation--Boost Pump Ground Fault 
Interrupter (GFI)'': Within 12 months after accomplishment of the 
actions specified in Boeing Service Bulletin 737-28A1212, or within 
12 months after the most recent inspection was performed as 
specified in AWL No. 28-AWL-22, whichever is later.
    (vi) For AWL No. 28-AWL-23, ``Center Tank Fuel Boost Pump Power 
Failed On Protection System'': Within 12 months after accomplishment 
of the actions specified in Boeing Service Bulletin 737-28A1227, or 
within 12 months after the most recent inspection was performed as 
specified in AWL No. 28-AWL-23, whichever is later.
    (vii) For AWL No. 28-AWL-24, ``Auxiliary Fuel Tank Boost Pump 
Power Failed On Protection System'': Within 12 months after 
accomplishment of the actions specified in Boeing Service Bulletin 
737-28A1227, or within 12 months after the most recent inspection 
was performed as specified in AWL No. 28-AWL-24, whichever is later.
    (viii) For AWL No. 28-AWL-27, ``AC Fuel Boost Pump 
Installation'': Within 72 months after the most recent inspection 
was performed as specified in AWL No. 28-AWL-27, or within 12 months 
after the effective date of this AD if no inspection has been 
performed in the last 72 months.
    (ix) For AWL No. 28-AWL-31, ``Cushion Clamps and Teflon Sleeving 
Installed on Out-of-Tank Wire Bundles Installed on Brackets that are 
Mounted Directly on the Fuel Tanks'': Within 144 months after 
accomplishment of the actions specified in Boeing Service Bulletin 
737-28A1228.
    (x) For AWL No. 47-AWL-04, ``Nitrogen Generation System (NGS)--
Thermal Switch'': Within 22,500 flight hours after accomplishment of 
the actions specified in Boeing Service Bulletin 737-47-1005; within 
22,500 flight hours after accomplishment of the actions specified in 
Boeing Service Bulletin 737-47-1008; or within 22,500 flight hours 
after the most recent inspection was performed as specified in AWL 
No. 47-AWL-04; whichever is latest.
    (xi) For AWL No. 47-AWL-05, ``Nitrogen Generation System (NGS)--
Nitrogen Enriched Air (NEA) Distribution Ducting Integrity'': Within 
14,500 flight hours after accomplishment of the actions specified in 
Boeing Service Bulletin 737-47-1005; within 14,500 flight hours 
after accomplishment of the actions specified in Boeing Service 
Bulletin 737-47-1008; or within 14,500 flight hours after the most 
recent inspection was performed as specified in AWL No. 47-AWL-05; 
whichever is latest.

Exact source excerpt. Text positions 13030–22025, end exclusive, in the original decoded publication. SHA-256: 58879a878486e0f5352e52d2b1f509f665341a21b9890bb13c3e718b4376ada0

Additional Acceptable Wire Types and Sleeving
(h) Additional Acceptable Wire Types and Sleeving

    As an option to accomplishing the actions required by paragraph 
(g) of this AD, the changes specified in paragraphs (h)(1) and (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.

Exact source excerpt. Text positions 22025–22995, end exclusive, in the original decoded publication. SHA-256: 5b5393f43fb13c6363ce2b330a0de7db7ad1fbb4d0403834047e811cf6425c93

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

    After the existing maintenance or inspection program has been 
revised as required by paragraph (g) of this AD, no alternative 
actions (e.g., inspections), intervals, or 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.

Exact source excerpt. Text positions 22995–23470, end exclusive, in the original decoded publication. SHA-256: aae643338ef492e312876b7baa8715910e6275a874985087284dc223052a9865

Terminating Actions for Certain AD Requirements
(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 (7) of this AD for that airplane:
    (1) All requirements of AD 2008-10-09 R1.
    (2) The revision required by paragraph (l) of AD 2011-12-09.
    (3) The revision required by paragraph (h) of AD 2013-13-15.
    (4) The revision required by paragraph (j) of AD 2013-25-05.
    (5) The revisions required by paragraphs (l) and (n) of AD 2016-
18-16.
    (6) The revision required by paragraph (h) of AD 2017-17-09.
    (7) The revision required by paragraph (h) of AD 2018-04-12.

Exact source excerpt. Text positions 23470–24146, end exclusive, in the original decoded publication. SHA-256: 4be43ee8cc07c79b8226865b3e30aa898130e8331fc43ae50b6779eb4eb65e3f

Alternative Methods of Compliance (AMOCs)
(k) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Los Angeles 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: [email protected].
    (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 Company Organization Designation 
Authorization (ODA) that has been authorized by the Manager, Los 
Angeles ACO Branch, FAA, 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.
    (4) AMOCs that were previously approved for the ADs specified in 
paragraph (j) of this AD are not approved as AMOCs for this AD.

Exact source excerpt. Text positions 24146–25559, end exclusive, in the original decoded publication. SHA-256: cb2dd9febce22a323447d80a36efae7f44099816e5e32b69723f58df78b535e8

Related Information
(l) Related Information

    For more information about this AD, contact Serj Harutunian, 
Aerospace Engineer, Propulsion Section, FAA, Los Angeles ACO Branch, 
3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-
5254; fax: 562-627-5210; email: [email protected].

[[Page 68330]]

Exact source excerpt. Text positions 25559–25855, end exclusive, in the original decoded publication. SHA-256: e62145fda5b2fe08313c59914a1f9b9092ad1f277837968d8f82e5015fcc549b

Material Incorporated by Reference
(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 737-100/200/200C/300/400/500 Airworthiness 
Limitations (AWLs) and Certification Maintenance Requirements 
(CMRs), D6-38278-CMR, dated March 2019.
    (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; phone: 562-797-1717; internet: https://www.myboeingfleet.com.
    (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, email [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

Exact source excerpt. Text positions 25855–27184, end exclusive, in the original decoded publication. SHA-256: 58d3c702894d9295d7c3e2636cbc21de2512199ac725ca128d190169f667f9a0

No replacement link has been established from this edition. The complete historical rule chain and current legal effect remain unknown.

Find all recorded historical references to AD 2019-23-14 · 0 printed reference observations in this pinned collection.

These are observations from one dated publication. Current legal status is unknown; aircraft applicability, installed configuration, compliance and burden require separate evidence. Missing or unparsed conditions remain unknown.

Why these observations are shown

They were extracted offline from the same immutable official HTML source as the complete recorded text. The dated source wording, original text coordinates and exact quote digests are retained. PDF/text agreement and current regulatory effect have not been qualified.

Observation revision: whole-ad-publication-clause-observations-1.0.1. Text SHA-256: 3470546a012f50b89bbfcac3fb2a8bb60f4c3ecd96b294544a391f76d0ba4626. Source manifest: fe6fb6b6347c3862e06206759416eafcd9c23d183817e5c4b778557b533357d6.

Official source · 2019-12-16

Publication text

This is the complete recorded text of this dated publication.

Current legal effect is unknown. Aircraft applicability, installed configuration and compliance require separate evidence. PDF/text agreement has not been evaluated.

Read the complete official publication text
[Federal Register Volume 84, Number 241 (Monday, December 16, 2019)]
[Rules and Regulations]
[Pages 68326-68330]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-26963]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0326; Product Identifier 2018-NM-166-AD; Amendment 
39-19808; AD 2019-23-14]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 
series airplanes. This AD was prompted by significant changes made to 
the airworthiness limitations (AWLs) related to fuel tank ignition 
prevention and the nitrogen generation system. This AD requires 
revising the existing maintenance or inspection program, as applicable, 
to include new or revised AWLs. The FAA is issuing this AD to address 
the unsafe condition on these products.

DATES: This AD is effective January 21, 2020.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of January 21, 
2020.

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; phone: 562-797-1717; internet: https://www.myboeingfleet.com. 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 https://www.regulations.gov by searching for and locating Docket No. FAA-2019-
0326.

Examining the AD Docket

    You may examine the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2019-
0326; 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

[[Page 68327]]

Operations is 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: Serj Harutunian, Aerospace Engineer, 
Propulsion Section, FAA, Los Angeles ACO Branch, 3960 Paramount 
Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5254; fax: 562-627-
5210; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to all The Boeing Company 
Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. The 
NPRM published in the Federal Register on June 10, 2019 (84 FR 26778). 
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 revising the existing maintenance or 
inspection program, as applicable, to include new or revised AWLs.
    The FAA is issuing this AD to address the potential of ignition 
sources inside fuel tanks, which, in combination with flammable fuel 
vapors, could result in fuel tank explosions and consequent loss of the 
airplane.

Comments

    The FAA 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

    Air Line Pilots Association, International (ALPA) agreed with the 
intent of the NPRM.

Effect of Winglets on Accomplishment of the Proposed Actions

    Aviation Partners Boeing stated that the installation of winglets 
per Supplemental Type Certificate (STC) ST01219SE does not affect the 
accomplishment of the manufacturer's service instructions.
    The FAA agrees with the commenter that STC ST01219SE does not 
affect the accomplishment of the manufacturer's service instructions. 
Therefore, the installation of STC ST01219SE does not affect the 
ability to accomplish the actions required by this AD. The FAA has not 
changed this AD in this regard.

Request for Additional Affected AD

    Boeing requested that the FAA include AD 2018-04-12, Amendment 39-
19208 (83 FR 9178, March 5, 2018) (``AD 2018-04-12''), as an affected 
AD in the proposed AD. Boeing pointed out that AD 2018-04-12 requires 
operators to incorporate certain AWLs included in certain previous 
revisions of Boeing 737-100/200/200C/300/400/500 Airworthiness 
Limitations (AWLs) and Certification Maintenance Requirements (CMRs), 
D6-38278-CMR. Boeing explained that the specific AWLs referenced by AD 
2018-04-12 are still present in the latest revision mandated by this 
AD, but are at a later revision, and as such, should be considered 
terminating action for the requirements of paragraph (h) of AD 2018-04-
12. Boeing noted that AD 2013-13-15, Amendment 39-17503 (78 FR 42415, 
July 16, 2013) (``AD 2013-13-15''), has similar requirements to those 
in AD 2018-04-12, and that those similar requirements in AD 2013-13-15 
are terminated as specified in paragraph (j)(3) of the proposed AD.
    The FAA agrees with the commenter's request for the reasons 
provided. The FAA has added paragraph (b)(7) to this AD to specify that 
AD 2018-04-12 is affected by this AD, and paragraph (j)(7) to this AD 
to specify that the requirements of paragraph (h) of AD 2018-04-12 are 
terminated by the revision required by paragraph (g) of this AD.

Clarification That Previous Alternative Methods of Compliance (AMOCs) 
Are Not Approved For This AD

    The regulatory text of the NPRM did not include a paragraph 
specifying that AMOCs previously approved for the ADs specified in 
paragraph (j) of this AD are approved for the corresponding 
requirements of this AD. For clarity, the FAA has added paragraph 
(k)(4) to this AD to specify that AMOCs that were previously approved 
for the ADs specified in paragraph (j) of this AD are not approved as 
AMOCs for this AD.

Conclusion

    The FAA 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. The FAA has 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.
    The FAA 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

    The FAA reviewed Boeing 737-100/200/200C/300/400/500 Airworthiness 
Limitations (AWLs) and Certification Maintenance Requirements (CMRs), 
D6-38278-CMR, dated March 2019. 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

    The FAA estimates that this AD affects 381 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:
    The FAA has determined that revising the existing maintenance or 
inspection program takes an average of 90 work-hours per operator, 
although the FAA recognizes that this number may vary from operator to 
operator. In the past, the FAA has estimated that this action takes 1 
work-hour per airplane. Since operators incorporate maintenance or 
inspection program changes for their affected fleet(s), the FAA has 
determined that a per-operator estimate is more accurate than a per-
airplane estimate. Therefore, the FAA estimates 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.
    The FAA is 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

[[Page 68328]]

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) Will not affect intrastate aviation in Alaska, and
    (3) Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.

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):

2019-23-14 The Boeing Company: Amendment 39-19808; Docket No. FAA-
2019-0326; Product Identifier 2018-NM-166-AD.

(a) Effective Date

    This AD is effective January 21, 2020.

(b) Affected ADs

    This AD affects the ADs specified in paragraphs (b)(1) through 
(7) of this AD.
    (1) AD 2008-10-09 R1, Amendment 39-16148 (74 FR 69264, December 
31, 2009) (``AD 2008-10-09 R1'').
    (2) AD 2011-12-09, Amendment 39-16716 (76 FR 33988, June 10, 
2011) (``AD 2011-12-09'').
    (3) AD 2013-13-15, Amendment 39-17503 (78 FR 42415, July 16, 
2013) (``AD 2013-13-15'').
    (4) AD 2013-25-05, Amendment 39-17701 (78 FR 78701, December 27, 
2013) (``AD 2013-25-05'').
    (5) AD 2016-18-16, Amendment 39-18647 (81 FR 65864, September 
26, 2016) (``AD 2016-18-16'').
    (6) AD 2017-17-09, Amendment 39-18999 (82 FR 40477, August 25, 
2017) (``AD 2017-17-09'').
    (7) AD 2018-04-12, Amendment 39-19208 (83 FR 9178, March 5, 
2018) (``AD 2018-04-12'').

(c) Applicability

    This AD applies to all The Boeing Company Model 737-100, -200, -
200C, -300, -400, and -500 series airplanes, certificated in any 
category.

(d) Subject

    Air Transport Association (ATA) of America Code 28, Fuel; 47, 
Nitrogen Generation System.

(e) Unsafe Condition

    This AD was prompted by a determination that new or revised 
airworthiness limitations (AWLs) are necessary related to fuel tank 
ignition prevention and the nitrogen generation system. The FAA is 
issuing this AD to address the potential of ignition sources inside 
fuel tanks, which, in combination with flammable fuel vapors, could 
result in fuel tank explosions and consequent loss of the airplane.

(f) Compliance

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

(g) Maintenance or Inspection Program Revision

    (1) For The Boeing Company Model 737-100, -200, and -200C series 
airplanes: Within 60 days after the effective date of this AD, 
revise the existing maintenance or inspection program, as 
applicable, to incorporate the information specified in Section C, 
including Subsections C.1, C.2, and C.3 of Boeing 737-100/200/200C/
300/400/500 Airworthiness Limitations (AWLs) and Certification 
Maintenance Requirements (CMRs), D6-38278-CMR, dated March 2019, 
except as provided in paragraph (h) of this AD. The initial 
compliance time for the ALI tasks are within the applicable 
compliance times specified in paragraphs (g)(1)(i) through (x) of 
this AD.
    (i) For AWL No. 28-AWL-01, ``External Wires Over Center Fuel 
Tank'': Within 120 months after the most recent inspection was 
performed as specified in AWL No. 28-AWL-01, or within 12 months 
after the effective date of this AD if no initial inspection has 
been performed.
    (ii) For AWL No. 28-AWL-03, ``Fuel Quantity Indicating System 
(FQIS)--Out Tank Wiring Lightning Shield to Ground Termination'': 
Within 120 months after accomplishment of the actions specified in 
Boeing Service Bulletin 737-28A1178, or within 120 months after the 
most recent inspection was performed as specified in AWL No. 28-AWL-
03, whichever is later.
    (iii) For AWL No. 28-AWL-21, ``Center Tank Fuel Boost Pump 
Automatic Shutoff System'': Within 12 months after accomplishment of 
the actions specified in Boeing Service Bulletin 737-28A1228, or 
within 12 months after the most recent inspection was performed as 
specified in AWL No. 28-AWL-21, whichever is later.
    (iv) For AWL No. 28-AWL-22, ``Auxiliary Tank Fuel Boost Pump 
Automatic Shutoff System'': Within 12 months after accomplishment of 
the actions specified in Boeing Service Bulletin 737-28A1228, or 
within 12 months after the most recent inspection was performed as 
specified in AWL No. 28-AWL-22, whichever is later.
    (v) For AWL No. 28-AWL-23, ``Over-Current and Arcing Protection 
Electrical Design Features Operation--Boost Pump Ground Fault 
Interrupter (GFI)'': Within 12 months after accomplishment of the 
actions specified in Boeing Service Bulletin 737-28A1212, or within 
12 months after the most recent inspection was performed as 
specified in AWL No. 28-AWL-23, whichever is later.
    (vi) For AWL No. 28-AWL-24, ``Center Tank Fuel Boost Pump Power 
Failed On Protection System'': Within 12 months after accomplishment 
of the actions specified in Boeing Service Bulletin 737-28A1227, or 
within 12 months after the most recent inspection was performed as 
specified in AWL No. 28-AWL-24, whichever is later.
    (vii) For AWL No. 28-AWL-25, ``Auxiliary Fuel Tank Boost Pump 
Power Failed On Protection System'': Within 12 months after 
accomplishment of the actions specified in Boeing Service Bulletin 
737-28A1227, or within 12 months after the most recent inspection 
was performed as specified in AWL No. 28-AWL-25, whichever is later.
    (viii) For AWL No. 28-AWL-29, ``AC Fuel Boost Pump 
Installation'': Within 72 months after the most recent inspection 
was performed as specified in AWL No. 28-AWL-29, or within 12 months 
after the effective date of this AD if no inspection has been 
performed in the last 72 months.
    (ix) For AWL No. 47-AWL-04, ``Nitrogen Generation System (NGS)--
Thermal Switch'': Within 22,500 flight hours after accomplishment of 
the actions specified in Boeing Service Bulletin 737-47-1005; within 
22,500 flight hours after accomplishment of the actions specified in 
Boeing Service Bulletin 737-47-1008; or within 22,500 flight hours 
after the most recent inspection was performed as specified in AWL 
No. 47-AWL-04; whichever is latest.
    (x) For AWL No. 47-AWL-05, ``Nitrogen Generation System (NGS)--
Nitrogen Enriched Air (NEA) Distribution Ducting Integrity'': Within 
14,500 flight hours after accomplishment of the actions specified in 
Boeing Service Bulletin 737-47-1005; within

[[Page 68329]]

14,500 flight hours after accomplishment of the actions specified in 
Boeing Service Bulletin 737-47-1008; or within 14,500 flight hours 
after the most recent inspection was performed as specified in AWL 
No. 47-AWL-05; whichever is latest.
    (2) For The Boeing Company Model 737-300, -400, and -500 series 
airplanes: Within 60 days after the effective date of this AD, 
revise the existing maintenance or inspection program, as 
applicable, to incorporate the information specified in Section C, 
including Subsections C.1, C.2, and C.3 of Boeing 737-100/200/200C/
300/400/500 Airworthiness Limitations (AWLs) and Certification 
Maintenance Requirements (CMRs), D6-38278-CMR, dated March 2019; 
except as provided in paragraph (h) of this AD. The initial 
compliance time for the ALI tasks are within the applicable 
compliance times specified in paragraphs (g)(2)(i) through (xi) of 
this AD.
    (i) For AWL No. 28-AWL-01, ``External Wires Over Center Fuel 
Tank'': Within 120 months after the most recent inspection was 
performed as specified in AWL No. 28-AWL-01, or within 12 months 
after the effective date of this AD if no initial inspection has 
been performed.
    (ii) For AWL No. 28-AWL-03, ``Fuel Quantity Indicating System 
(FQIS)--Out Tank Wiring Lightning Shield to Ground Termination'': 
Within 120 months after accomplishment of the actions specified in 
Boeing Service Bulletin 737-28A1175; within 120 months after 
accomplishment of the actions specified in Boeing Service Bulletin 
737-28A1183; within 120 months after accomplishment of the actions 
specified in Boeing Service Bulletin 737-28A1186; or within 120 
months after the most recent inspection was performed as specified 
in AWL No. 28-AWL-03; whichever is latest.
    (iii) For AWL No. 28-AWL-20, ``Center Tank Fuel Boost Pump 
Automatic Shutoff System'': Within 12 months after accomplishment of 
the actions specified in Boeing Service Bulletin 737-28A1216, or 
within 12 months after the most recent inspection was performed as 
specified in AWL No. 28-AWL-20, whichever is later.
    (iv) For AWL No. 28-AWL-21, ``Auxiliary Tank Fuel Boost Pump 
Automatic Shutoff System'': Within 12 months after accomplishment of 
the actions specified in Boeing Service Bulletin 737-28A1216, or 
within 12 months after the most recent inspection was performed as 
specified in AWL No. 28-AWL-21, whichever is later.
    (v) For AWL No. 28-AWL-22, ``Over-Current and Arcing Protection 
Electrical Design Features Operation--Boost Pump Ground Fault 
Interrupter (GFI)'': Within 12 months after accomplishment of the 
actions specified in Boeing Service Bulletin 737-28A1212, or within 
12 months after the most recent inspection was performed as 
specified in AWL No. 28-AWL-22, whichever is later.
    (vi) For AWL No. 28-AWL-23, ``Center Tank Fuel Boost Pump Power 
Failed On Protection System'': Within 12 months after accomplishment 
of the actions specified in Boeing Service Bulletin 737-28A1227, or 
within 12 months after the most recent inspection was performed as 
specified in AWL No. 28-AWL-23, whichever is later.
    (vii) For AWL No. 28-AWL-24, ``Auxiliary Fuel Tank Boost Pump 
Power Failed On Protection System'': Within 12 months after 
accomplishment of the actions specified in Boeing Service Bulletin 
737-28A1227, or within 12 months after the most recent inspection 
was performed as specified in AWL No. 28-AWL-24, whichever is later.
    (viii) For AWL No. 28-AWL-27, ``AC Fuel Boost Pump 
Installation'': Within 72 months after the most recent inspection 
was performed as specified in AWL No. 28-AWL-27, or within 12 months 
after the effective date of this AD if no inspection has been 
performed in the last 72 months.
    (ix) For AWL No. 28-AWL-31, ``Cushion Clamps and Teflon Sleeving 
Installed on Out-of-Tank Wire Bundles Installed on Brackets that are 
Mounted Directly on the Fuel Tanks'': Within 144 months after 
accomplishment of the actions specified in Boeing Service Bulletin 
737-28A1228.
    (x) For AWL No. 47-AWL-04, ``Nitrogen Generation System (NGS)--
Thermal Switch'': Within 22,500 flight hours after accomplishment of 
the actions specified in Boeing Service Bulletin 737-47-1005; within 
22,500 flight hours after accomplishment of the actions specified in 
Boeing Service Bulletin 737-47-1008; or within 22,500 flight hours 
after the most recent inspection was performed as specified in AWL 
No. 47-AWL-04; whichever is latest.
    (xi) For AWL No. 47-AWL-05, ``Nitrogen Generation System (NGS)--
Nitrogen Enriched Air (NEA) Distribution Ducting Integrity'': Within 
14,500 flight hours after accomplishment of the actions specified in 
Boeing Service Bulletin 737-47-1005; within 14,500 flight hours 
after accomplishment of the actions specified in Boeing Service 
Bulletin 737-47-1008; or within 14,500 flight hours after the most 
recent inspection was performed as specified in AWL No. 47-AWL-05; 
whichever is latest.

(h) Additional Acceptable Wire Types and Sleeving

    As an option to accomplishing the actions required by paragraph 
(g) of this AD, the changes specified in paragraphs (h)(1) and (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, or Critical Design Configuration 
Control Limitations (CDCCLs)

    After the existing maintenance or inspection program has been 
revised as required by paragraph (g) of this AD, no alternative 
actions (e.g., inspections), intervals, or 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 (7) of this AD for that airplane:
    (1) All requirements of AD 2008-10-09 R1.
    (2) The revision required by paragraph (l) of AD 2011-12-09.
    (3) The revision required by paragraph (h) of AD 2013-13-15.
    (4) The revision required by paragraph (j) of AD 2013-25-05.
    (5) The revisions required by paragraphs (l) and (n) of AD 2016-
18-16.
    (6) The revision required by paragraph (h) of AD 2017-17-09.
    (7) The revision required by paragraph (h) of AD 2018-04-12.

(k) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Los Angeles 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: [email protected].
    (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 Company Organization Designation 
Authorization (ODA) that has been authorized by the Manager, Los 
Angeles ACO Branch, FAA, 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.
    (4) AMOCs that were previously approved for the ADs specified in 
paragraph (j) of this AD are not approved as AMOCs for this AD.

(l) Related Information

    For more information about this AD, contact Serj Harutunian, 
Aerospace Engineer, Propulsion Section, FAA, Los Angeles ACO Branch, 
3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-
5254; fax: 562-627-5210; email: [email protected].

[[Page 68330]]

(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 737-100/200/200C/300/400/500 Airworthiness 
Limitations (AWLs) and Certification Maintenance Requirements 
(CMRs), D6-38278-CMR, dated March 2019.
    (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; phone: 562-797-1717; internet: https://www.myboeingfleet.com.
    (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, email [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Des Moines, Washington, on November 20, 2019.
Dorr Anderson,
Acting Director, System Oversight Division, Aircraft Certification 
Service.
[FR Doc. 2019-26963 Filed 12-13-19; 8:45 am]
 BILLING CODE 4910-13-P


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