# Boeing Alert Requirements Bulletin 737-53A1385 RB: No revision named

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- Title as filed: 737-53A1385-00-- RB - BOEING
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### Page 1

Commercial 
Airplanes
737
Requirements Bulletin
ALERT
Number: 737-53A1385 RB
Original Issue: August 16, 2019
ATA System: 5311
SUBJECT: FUSELAGE - Frames and Bulkheads - Missing Shim at STA 727 Inner Chord to Stringer
S-18A Web - Inspection
Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15
CFR 300-774). An export license may be required before it is used for development, production or use by foreign
persons from specific countries. The controller of this data has the individual responsibility to abide by all export
laws.
9E991ECCN:
Copyright © 2019 Boeing.
Unpublished Work. All Rights Reserved.
Treatment of this document and its content is governed by contract with Boeing. Rights to use this document
are licensed on a per aircraft basis and such rights may not be transferable. For more information, contact The
Boeing Company.
Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner,
BBJ, DC-8, DC-9, DC-10, KC-10, KC-46, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8, Poseidon and
Boeing liveries are all trademarks owned by The Boeing Company; and no trademark license is granted in
connection with this document unless provided in writing by Boeing.
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3.0

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Table of Contents
1 . E F F E C T I V I T Y  ................................................ 5
A. Airplanes ................................................ 5
B . S p a r e s  A f f e c t e d  ............................................ 6
2. CONCURRENT REQUIREMENTS ..................................... 6
3 . C O M P L I A N C E  ................................................ 6
4. APPROVAL ................................................ 1 0
5. ACCOMPLISHMENT INSTRUCTIONS .................................. 1 1
A. General Information ......................................... 1 1
B. Work Instructions ........................................... 1 2
FIGURE 1: GENERAL VISUAL INSPECTION AT STA 727 FRAME INNER CHORD  AT S-18A LEFT SIDE
.................................................. 1 7
FIGURE 2: GENERAL VISUAL INSPECTION AT STA 727 FRAME INNER CHORD  AT S-18A RIGHT SIDE
.................................................. 2 1
FIGURE 3: DETAILED INSPECTION FOR UNSHIMMED GAP AT STA 727 FRAME  INNER CHORD AT
S - 1 8 A  L E F T  S I D E....................................... 2 5
FIGURE 4: DETAILED INSPECTION FOR UNSHIMMED GAP AT STA 727 FRAME  INNER CHORD AT
S - 1 8 A  R I G H T  S I D E...................................... 3 0
FIGURE 5: HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTIONS OF THE STA 727 FRAME
I N N E R  C H O R D  A T  S - 1 8 A  L E F T  S I D E ............................ 3 5
FIGURE 6: HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTIONS OF THE STA 727 FRAME
I N N E R  C H O R D  A T  S - 1 8 A  R I G H T  S I D E ........................... 3 9
FIGURE 7: SHIM INSTALLATION FOR THE STA 727 FRAME INNER CHORD AT  S-18A LEFT SIDE . 43
FIGURE 8: SHIM INSTALLATION FOR THE STA 727 FRAME INNER CHORD AT  S-18A RIGHT SIDE
.................................................. 4 7
FIGURE 9: HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION OF THE S TA 727 FRAME INNER
C H O R D  A T  S - 1 8 A  L E F T  S I D E................................ 5 1
FIGURE 10: HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION OF THE STA 727 FRAME INNER
C H O R D  A T  S - 1 8 A  R I G H T  S I D E ................................ 5 4
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Commercial 
Airplanes
737
Requirements Bulletin
ALERT
Number: 737-53A1385 RB
Original Issue: August 16, 2019
ATA System: 5311
SUBJECT: FUSELAGE - Frames and Bulkheads - Missing Shim at STA 727 Inner Chord to Stringer
S-18A Web - Inspection
THIS DOCUMENT IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN
PARAGRAPH 1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS DOCUMENT
TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS DOCUMENT TO THE
NEW OWNER. THIS IS AN ENHANCED REQUIRED FOR COMPLIANCE DOCUMENT. THE BOEING
PROCESSES USED TO CREATE THE SERVICE BULLETIN (SB) AND THE REQUIREMENTS BULLETIN
(RB) ENSURE THAT THE INFORMATION BETWEEN "RC START" AND "RC END" IN THE SB ARE IDENTICAL
TO THE INFORMATION IN THE SAME SECTIONS (COMPLIANCE, WORK INSTRUCTIONS…) OF THE RB
WHICH THE SB REFERS TO AS THE RELATED DOCUMENT.
1. Effectivity
A. Airplanes
This bulletin is applicable to 737-700, 737-800, 737-900ER Airplane(s), line number(s) 6071-6073,
6075, 6077-6103, 6105-6113, 6115-6131, 6133-6153, 6155-6159, 6161-6187, 6190-6215,
6217-6221, 6223-6229, 6231-6243, 6245-6249, 6251-6269, 6271, 6274, 6276-6289, 6291-6292,
6294-6299, 6301, 6303, 6305-6307, 6309-6314, 6316-6318, 6320-6322, 6324-6325, 6327, 6329
in 1 Group(s). Where the effectivity is presented with hyphens between line numbers, the airplane
applicability means "through" and "inclusive", e.g. line numbers 1-9 means line numbers 1 through
9 inclusive.
DESCRIPTIONCONFIGURATIONGROUP
737-700, 737-800 and 737-900ER Airplanes.-1
Airplane Models:
737-700, 737-800, 737-900ER
GroupVariable Number
1YH684
1YH866 - YH875
1YN758
1YQ363 - YQ365
GroupVariable Number
1YR050
1YR210 - YR211
1YS370
1YS378
GroupVariable Number
1YS464 - YS465
1YS517
1YS897
1YS945 - YS947
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GroupVariable Number
1YS953 - YS955
1YS973 - YS974
1YT120 - YT121
1YT133
1YT184 - YT185
1YT290 - YT299
1YT347 - YT354
1YT371
1YT477
1YT565
1YT575 - YT576
1YT781
1YT938 - YT960
1YU055 - YU060
1YU215
1YU302 - YU306
1YV004
1YV012
1YV021 - YV023
GroupVariable Number
1YV030 - YV031
1YV052
1YV098
1YV129 - YV138
1YV251
1YV256
1YV307 - YV312
1YV363
1YV386 - YV388
1YV391 - YV393
1YV411
1YV441
1YV503
1YV579
1YV657 - YV659
1YV730 - YV731
1YV751 - YV754
1YV784
1YV804 - YV807
GroupVariable Number
1YV904 - YV907
1YV973 - YV976
1YW050 - YW079
1YW081 - YW083
1YW234 - YW236
1YW245
1YW267 - YW271
1YW273 - YW274
1YW283
1YW357 - YW358
1YW372 - YW384
1YW451 - YW452
1YW471 - YW472
1YW891 - YW893
1YW907
1YW916 - YW918
1YW971 - YW973
--
--
B. Spares Affected
None.
2. CONCURRENT REQUIREMENTS
None.
3. COMPLIANCE
The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to
Requirements Bulletin 737-53A1385 RB. The Airworthiness Directive will make the compliance tasks and
times given in Requirements Bulletin 737-53A1385 RB mandatory.
When more than one OPTION is given for a CONDITION, do only one of the OPTION numbers. When
more than one ACTION is given for a CONDITION or an OPTION, do all of the ACTION numbers for that
CONDITION or OPTION.
Accomplish the required action(s), based on the applicable condition(s) in Table(s) 1 and 2, in accordance
with the Accomplishment Instructions.
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Table 1: Inspections of the STA 727 Frame Inner Chord at S-18A: Left Side
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Within 7,000
flight cycles af-
ter the original
issue date of the
Requirements
Bulletin 737-
53A1385 RB.
Before 22,500
total flight cy-
cles.
Do a General Visual In-
spection for any repair of
STA 727 frame inner
chord at S-18A.
ALL AIRPLANES
-Before further flight.Contact The Boeing
Company for alternative
inspection(s) to Require-
ments Bulletin 737-
53A1385 RB, do the alter-
native inspection(s), and
do applicable on-condi-
tion action(s).
CONDITION 1:
ANY REPAIR FOUND
-Before further flight.Do a Detailed Inspection
of the STA 727 frame in-
ner chord at S-18A for
any unshimmed gap.
CONDITION 2:
NO REPAIR FOUND
-Before further flight.Do the High Frequency
Eddy Current (HFEC) in-
spections of the STA 727
frame inner chord at S-
18A for any crack.
CONDITION 2.1:
ANY UNSHIMMED GAP
FOUND
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 2.1.1:
ANY CRACK FOUND
-Before further flight.CONDITION 2.1.2 (AC-
TION 1):
CONDITION 2.1.2:
NO CRACK FOUND
Do the shim installation
between the STA 727
frame inner chord and S-
18A.
-Within 30,000 flight cycles after
the shim installation.
CONDITION 2.1.2 (AC-
TION 2):
Do a High Frequency Ed-
dy Current (HFEC) inspec-
tion of the STA 727 frame
inner chord at S-18A for
any crack. (a)
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Table 1: Inspections of the STA 727 Frame Inner Chord at S-18A: Left Side
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 2.1.2.1:
ANY CRACK FOUND
30,000 flight cycles-Repeat the High Frequen-
cy Eddy Current (HFEC)
inspection of the STA 727
frame inner chord at S-
18A for any crack. (a)
CONDITION 2.1.2.2:
NO CRACK FOUND
--No further action is re-
quired.
CONDITION 2.2: NO UN-
SHIMMED GAP FOUND
(a) It is not required to do the High Frequency Eddy Current (HFEC) inspections of the STA 727 frame inner
chord at S-18A in areas where a repair covers the affected inspection zone provided:
1. The repair is the corrective action to the crack condition identified in Requirements Bulletin 737-53A1385
RB and installed after the original issue date of Requirements Bulletin 737-53A1385 RB, AND
2. The installed repair was approved by the Boeing Company Organization Designation Authorization
(ODA) via a FAA Form 8100-9.
Table 2: Inspections of the STA 727 Frame Inner Chord at S-18A: Right Side
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Within 7,000
flight cycles af-
ter the original
issue date of the
Requirements
Bulletin 737-
53A1385 RB.
Before 22,500
total flight cy-
cles.
Do a General Visual In-
spection for any repair of
STA 727 frame inner
chord at S-18A.
ALL AIRPLANES
-Before further flight.Contact The Boeing
Company for alternative
inspection(s) to Require-
ments Bulletin 737-
53A1385 RB, do the alter-
native inspection(s), and
do applicable on-condi-
tion action(s).
CONDITION 3:
ANY REPAIR FOUND
-Before further flight.Do a Detailed Inspection
of the STA 727 frame in-
ner chord at S-18A for
any unshimmed gap.
CONDITION 4:
NO REPAIR FOUND
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Table 2: Inspections of the STA 727 Frame Inner Chord at S-18A: Right Side
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Before further flight.Do the High Frequency
Eddy Current (HFEC) in-
spections of the STA 727
frame inner chord at S-
18A for any crack.
CONDITION 4.1:
ANY UNSHIMMED GAP
FOUND
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 4.1.1:
ANY CRACK FOUND
-Before further flight.CONDITION 4.1.2 (AC-
TION 1):
CONDITION 4.1.2:
NO CRACK FOUND
Do the shim installation
between the STA 727
frame inner chord and S-
18A.
-Within 30,000 flight cycles after
the shim installation.
CONDITION 4.1.2 (AC-
TION 2):
Do a High Frequency Ed-
dy Current (HFEC) inspec-
tion of the STA 727 frame
inner chord at S-18A for
any crack. (a)
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 4.1.2.1:
ANY CRACK FOUND
30,000 flight cycles-Repeat the High Frequen-
cy Eddy Current (HFEC)
inspection of the STA 727
frame inner chord at S-
18A for any crack. (a)
CONDITION 4.1.2.2:
NO CRACK FOUND
--No further action is re-
quired.
CONDITION 4.2: NO UN-
SHIMMED GAP FOUND
(a) It is not required to do the High Frequency Eddy Current (HFEC) inspections of the STA 727 frame inner
chord at S-18A in areas where a repair covers the affected inspection zone provided:
1. The repair is the corrective action to the crack condition identified in Requirements Bulletin 737-53A1385
RB and installed after the original issue date of Requirements Bulletin 737-53A1385 RB, AND
2. The installed repair was approved by the Boeing Company Organization Designation Authorization
(ODA) via a FAA Form 8100-9.
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4. APPROVAL
This Requirements Bulletin was examined by the Federal Aviation Administration (FAA). The changes
specified in this document comply with the applicable regulations and are FAA approved, as well as European
Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved
airplanes listed in the service bulletin effectivity. This document and its approval were based on the airplane
in its original Boeing delivery configuration or as modified by other Boeing changes.
If an airplane has a non-Boeing modification or repair that affects a component or system also affected by
this Requirements Bulletin, the operator is responsible for obtaining appropriate regulatory agency approval
before incorporating this Requirements Bulletin.
This Requirements Bulletin is also approved for airplanes having FAA Aviation Partners Boeing (APB)
Supplemental Type Certificate (STC) number ST00830SE installed (not including any areas affected by
the split scimitar winglet configuration).
This Requirements Bulletin is also approved for airplanes converted into 737-800BCF under project number
TS14-0042 that have incorporated Boeing drawing 800A0003 specified in the Type Certification Data Sheet
A16WE.
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5.    ACCOMPLISHMENT INSTRUCTIONS
A. GENERAL INFORMATION
NOTE: 1. This is an Enhanced Required for Compliance document. There w ill be a separate
Service Bulletin (SB) and a separate Requirements Bulletin (RB). If an RB is mandated
by an Airworthiness Directive (AD), then all applicable requirements specified in the
RB must be done. For the related SB, some locations are marked RC Start and RC
End to identify the requirements that are restated from the RB. For the related SB,
the areas between RC Start and RC End, including sub-steps and any figures
identified between RC Start and RC End, must be done to comply with the AD.
Therefore, an Alternative Method of Compliance (AMOC) is required for any deviations
to steps between RC Start and RC End, including substeps and identified figures.
For the related SB, the steps not between RC Start and RC End may be deviated
from using accepted methods in accordance with the operator's maintenance or
inspection program without obtaining approval of an AMOC; this is provided that the
steps between RC Start and RC End, including sub-steps and identified figures, can
still be done as specified, and the airplane can be put back in an airworthy condition.
Figures not required for compliance are omitted from the RB.
2. This is an Enhanced Required for Compliance document. The Boe ing processes
used to create the Service Bulletin (SB) and the Requirements Bulletin (RB) ensure
that the information between "RC Start" and "RC End" in the SB are identical to the
information in the same sections (Compliance, Work Instructions...) of the RB which
the SB refers to as the related document.
3. The compliance times for the actions in WORK INSTRUCTIONS are  in Compliance.
4. Boeing Service Letter 737-SL-51-042 Damage Reporting and Repa ir Plan/Design
Guidelines, is an acceptable procedure to request information from Boeing for
additional structural repair instructions. The Service Letter describes what information
must be provided to Boeing before a structural repair can be provided.
5. Unless shown differently, these dimensions and tolerances are  used:
– Linear dimensions are in inches
– Tolerance on linear dimensions, other than rivet and bolt edge  margins, is plus
or minus 0.03 inch
– Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch
– Angular tolerance is plus or minus 2 degrees
– Hole dimensions for standard solid rivets and fasteners are in  Structural Repair
Manual (SRM) Chapter 51
– Torque Values:
— Values for structural fasteners are given in 737 Structural Repair Manual,
Chapter 51.
— Values for airframe maintenance tasks are included in Chapter 20 of 737
Aircraft Maintenance Manual (AMM).
— Values for electrical maintenance tasks are included in Chapter 20 of
Standard Wiring Practices Manual (SWPM).
— Values for engine maintenance tasks are included in Chapter 70 of 737
Aircraft Maintenance Manual (AMM).
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### Page 12

— Non-standard torque values for maintenance tasks are included in the
applicable installation step.
6. These work instructions refer to procedures included in other  Boeing documents.
When the words "refer to" are used and the operator has an accepted alternative
procedure, the accepted alternative procedure can be used. When the words "in
accordance with" are included in the instruction, the procedure in the Boeing document
must be used.
7. If it is necessary to remove more parts for access, you can r emove those parts. If
you can get access without removing identified parts, it is not necessary to remove
all of the identified parts. Jacking and shoring limitations must be observed.
8. Use the approved fastener, process and material substitutions  in accordance with
SRM Chapter 51.
9. A Detailed Inspection is defined as: An intensive examination  of a specific item,
installation or assembly to detect damage, failure or irregularity. This could include
tactile assessment in which a component or assembly can be checked for
tightness/security. Available lighting is normally supplemented with a direct source
of good lighting at an intensity deemed appropriate. Inspection aids such as mirrors
and magnifying lenses may be necessary. Surface cleaning and elaborate access
procedures may be required.
10. A General Visual Inspection is defined as: A visual examinat ion of an interior or
exterior area, installation or assembly to detect obvious damage, failure or irregularity.
This level of inspection is made from within touching distance, unless otherwise
specified. A mirror may be necessary to enhance visual access to all exposed surfaces
in the inspection area. This level of inspection is made under normally available
lighting conditions such as daylight, hangar lighting, flashlight or drop-light and may
require removal or opening of access panels or doors. Stands, ladders or platforms
may be required to gain proximity to the area being checked. Basic cleaning may be
required to ensure appropriate visibility.
11. When more than one OPTION is given for a CONDITION, do only one of the OPTION
numbers. When more than one ACTION is given for a CONDITION or an OPTION,
do all of the ACTION numbers for that CONDITION or OPTION.
12. If the length of any fastener specified in this service bull etin does not meet installation
standards given in SRM Chapter 51, then a fastener of the same specification, or
an approved substitute, with a length which meets the installation standards given
in SRM Chapter 51 may be used. In addition, washers may be installed for fastener
grip length in accordance with SRM Chapter 51. Refer to SOPM 20-50-01 for alternate
full threaded fasteners (screws) needed for installation in this service bulletin.
B. WORK INSTRUCTIONS
1. Requirements
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Table 1: Inspections of the STA 727 Frame Inner Chord at S-18A: Left Side
Refer to the listed
procedures in
SB737-53A1385
Original Issue or
later approved re-
visions as an ac-
cepted proce-
dure:
Method of ComplianceActionCondition
PART 1: OPEN
ACCESS
FIGURE 1Do a General Visual In-
spection for any repair of
STA 727 frame inner
chord at S-18A.
ALL AIRPLANES
PART 2: CLOSE
ACCESS
-Contact The Boeing
Company for alternative
inspection(s) to Require-
ments Bulletin 737-
53A1385 RB, do the alter-
native inspection(s), and
do applicable on-condi-
tion actions.
CONDITION 1: ANY RE-
PAIR FOUND
-FIGURE 3Do a Detailed Inspection
of the STA 727 frame in-
ner chord at S-18A for
any unshimmed gap.
CONDITION 2: NO RE-
PAIR FOUND
-FIGURE 5Do the High Frequency
Eddy Current (HFEC) in-
spections of the STA 727
frame inner chord at S-
18A for any crack.
CONDITION 2.1: ANY UN-
SHIMMED GAP FOUND
PART 2: CLOSE
ACCESS
-Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 2.1.1: ANY
CRACK FOUND
PART 2: CLOSE
ACCESS
FIGURE 7CONDITION 2.1.2 (AC-
TION 1):
CONDITION 2.1.2: NO
CRACK FOUND
Do the shim installation
between the STA 727
frame inner chord and S-
18A.
PART 1: OPEN
ACCESS
FIGURE 9CONDITION 2.1.2 (AC-
TION 2):
ANDDo a High Frequency Ed-
dy Current (HFEC) inspec-
tion of the STA 727 frame
inner chord at S-18A for
any crack. (a)
PART 2: CLOSE
ACCESS
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### Page 14

Table 1: Inspections of the STA 727 Frame Inner Chord at S-18A: Left Side
Refer to the listed
procedures in
SB737-53A1385
Original Issue or
later approved re-
visions as an ac-
cepted proce-
dure:
Method of ComplianceActionCondition
PART 2: CLOSE
ACCESS
-Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 2.1.2.1:
ANY CRACK FOUND
PART 1: OPEN
ACCESS
FIGURE 9Repeat the High Frequen-
cy Eddy Current (HFEC)
inspection of the STA 727
frame inner chord at S-
18A for any crack. (a)
CONDITION 2.1.2.2
NO CRACK FOUND
AND
PART 2: CLOSE
ACCESS
PART 2: CLOSE
ACCESS
-No further action is re-
quired.
CONDITION 2.2: NO UN-
SHIMMED GAP FOUND
(a) It is not required to do the High Frequency Eddy Current (HFEC) inspections of the STA 727 frame inner
chord at S-18A in areas where a repair covers the affected inspection zone provided:
1. The repair is the corrective action to the crack condition identified in Requirements Bulletin 737-53A1385
RB and installed after the original issue date of Requirements Bulletin 737-53A1385 RB, AND
2. The installed repair was approved by the Boeing Company Organization Designation Authorization
(ODA) via a FAA Form 8100-9.
Table 2: Inspections of the STA 727 Frame Inner Chord at S-18A: Right Side
Refer to the listed
procedures in
SB737-53A1385
Original Issue or
later approved re-
visions as an ac-
cepted proce-
dure:
Method of ComplianceActionCondition
PART 1: OPEN
ACCESS
FIGURE 2Do a General Visual In-
spection for any repair of
STA 727 frame inner
chord at S-18A.
ALL AIRPLANES
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REQUIREMENTS BULLETIN 737-53A1385
ALERTALERT

### Page 15

Table 2: Inspections of the STA 727 Frame Inner Chord at S-18A: Right Side
Refer to the listed
procedures in
SB737-53A1385
Original Issue or
later approved re-
visions as an ac-
cepted proce-
dure:
Method of ComplianceActionCondition
PART 2: CLOSE
ACCESS
-Contact The Boeing
Company for alternative
inspection(s) to Require-
ments Bulletin 737-
53A1385 RB, do the alter-
native inspection(s), and
do applicable on-condi-
tion actions.
CONDITION 3: ANY RE-
PAIR FOUND
-FIGURE 4Do a Detailed Inspection
of the STA 727 frame in-
ner chord at S-18A for
any unshimmed gap.
CONDITION 4: NO RE-
PAIR FOUND
-FIGURE 6Do the High Frequency
Eddy Current (HFEC) in-
spections of the STA 727
frame inner chord at S-
18A for any crack.
CONDITION 4.1: ANY UN-
SHIMMED GAP FOUND
--Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 4.1.1: ANY
CRACK FOUND
PART 2: CLOSE
ACCESS
FIGURE 8CONDITION 4.1.2 (AC-
TION 1):
CONDITION 4.1.2: NO
CRACK FOUND
Do the shim installation
between the STA 727
frame inner chord and S-
18A.
PART 1: OPEN
ACCESS
FIGURE 10CONDITION 4.1.2 (AC-
TION 2):
ANDDo a High Frequency Ed-
dy Current (HFEC) inspec-
tion of the STA 727 frame
inner chord at S-18A for
any crack. (a)
PART 2: CLOSE
ACCESS
PART 2: CLOSE
ACCESS
-Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 4.1.2.1:
ANY CRACK FOUND
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REQUIREMENTS BULLETIN 737-53A1385
ALERTALERT

### Page 16

Table 2: Inspections of the STA 727 Frame Inner Chord at S-18A: Right Side
Refer to the listed
procedures in
SB737-53A1385
Original Issue or
later approved re-
visions as an ac-
cepted proce-
dure:
Method of ComplianceActionCondition
PART 1: OPEN
ACCESS
FIGURE 10Repeat the High Frequen-
cy Eddy Current (HFEC)
inspection of the STA 727
frame inner chord at S-
18A for any crack. (a)
CONDITION 4.1.2.2:
NO CRACK FOUND
AND
PART 2: CLOSE
ACCESS
PART 2: CLOSE
ACCESS
-No further action is re-
quired.
CONDITION 4.2: NO UN-
SHIMMED GAP FOUND
(a) It is not required to do the High Frequency Eddy Current (HFEC) inspections of the STA 727 frame inner
chord at S-18A in areas where a repair covers the affected inspection zone provided:
1. The repair is the corrective action to the crack condition identified in Requirements Bulletin 737-53A1385
RB and installed after the original issue date of Requirements Bulletin 737-53A1385 RB, AND
2. The installed repair was approved by the Boeing Company Organization Designation Authorization
(ODA) via a FAA Form 8100-9.
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REQUIREMENTS BULLETIN 737-53A1385
ALERTALERT

### Page 17 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
STA
727
STA
727
S-18A
2865862
FIGURE 1: GENERAL VISUAL INSPECTION AT STA 727 FRAME INNER CHORD AT S-18A LEFT SIDE
(SHEET 1 OF 4)
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### Page 18 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
INNER CHORD
FRAME
S-18A
S-18A
WEB
2865863
FIGURE 1: GENERAL VISUAL INSPECTION AT STA 727 FRAME INNER CHORD AT S-18A LEFT SIDE
(SHEET 2 OF 4)
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### Page 19 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
INNER CHORD
FITTING-AFT, UPPER
S-18A
WEB
INSPECTION AREA
2865867
FIGURE 1: GENERAL VISUAL INSPECTION AT STA 727 FRAME INNER CHORD AT S-18A LEFT SIDE
(SHEET 3 OF 4)
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### Page 20

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for this figure.
More DataQtyIdentificationNameTaskStep
(a)1--Inspect1
(a) Do a General Visual Inspection for any repair in the area of STA 727 frame inner chord at S-18A.
FIGURE 1: GENERAL VISUAL INSPECTION AT STA 727 FRAME INNER CHORD AT S-18A LEFT SIDE
(SHEET 4 OF 4)
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REQUIREMENTS BULLETIN 737-53A1385
ALERTALERT

### Page 21 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
STA
STA  727
727
S-18A
2866121
FIGURE 2: GENERAL VISUAL INSPECTION AT STA 727 FRAME INNER CHORD AT S-18A RIGHT SIDE
(SHEET 1 OF 4)
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### Page 22 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
STA
727
INNER CHORD
FRAME
S-18A
S-18A
WEB
2866122
FIGURE 2: GENERAL VISUAL INSPECTION AT STA 727 FRAME INNER CHORD AT S-18A RIGHT SIDE
(SHEET 2 OF 4)
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### Page 23 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
INNER CHORD
FITTING-AFT, UPPER
S-18A
WEB
INSPECTION AREA
2866124
FIGURE 2: GENERAL VISUAL INSPECTION AT STA 727 FRAME INNER CHORD AT S-18A RIGHT SIDE
(SHEET 3 OF 4)
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### Page 24

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for this figure.
More DataQtyIdentificationNameTaskStep
(a)1--Inspect1
(a) Do a General Visual Inspection for any repair in the area of STA 727 frame inner chord at S-18A.
FIGURE 2: GENERAL VISUAL INSPECTION AT STA 727 FRAME INNER CHORD AT S-18A RIGHT SIDE
(SHEET 4 OF 4)
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REQUIREMENTS BULLETIN 737-53A1385
ALERTALERT

### Page 25 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
STA
727
STA
727
S-18A
2865873
FIGURE 3: DETAILED INSPECTION FOR UNSHIMMED GAP AT STA 727 FRAME INNER CHORD AT S-18A
LEFT SIDE
(SHEET 1 OF 5)
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### Page 26 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
STA
727
INNER CHORD
FRAME
S-18A
S-18A
WEB
2865874
FIGURE 3: DETAILED INSPECTION FOR UNSHIMMED GAP AT STA 727 FRAME INNER CHORD AT S-18A
LEFT SIDE
(SHEET 2 OF 5)
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### Page 27 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
INNER CHORD
FITTING-AFT, UPPER
S-184
WEE
2865875
FIGURE 3: DETAILED INSPECTION FOR UNSHIMMED GAP AT STA 727 FRAME INNER CHORD AT S-18A
LEFT SIDE
(SHEET 3 OF 5)
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### Page 28 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
FEELER GAUGE -
• UNSHIMMED GAP
INSPECTION AREA  2874729
FIGURE 3: DETAILED INSPECTION FOR UNSHIMMED GAP AT STA 727 FRAME INNER CHORD AT S-18A
LEFT SIDE
(SHEET 4 OF 5)
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### Page 29

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for this figure.
More DataQtyIdentificationNameTaskStep
(a)(b)1144A2619-17Inner ChordInspect1
(a) Do a Detailed Inspection of the STA 727 frame inner chord common to stringer S-18A web mating surface
using a 0.002 inch feeler gauge or equivalent to determine if there is an unshimmed gap. An unshimmed
gap exists if the feeler gauge can be inserted and makes contact with either fastener.
(b) If sealant squeeze-out inhibits inserting the feeler gauge between the mating surfaces remove the sealant
squeeze-out. Refer to 737-700 SRM 51-00-10, 737-800 SRM 51-00-10 or 737-900ER SRM 51-00-10 as
accepted procedures.
FIGURE 3: DETAILED INSPECTION FOR UNSHIMMED GAP AT STA 727 FRAME INNER CHORD AT S-18A
LEFT SIDE
(SHEET 5 OF 5)
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REQUIREMENTS BULLETIN 737-53A1385
ALERTALERT

### Page 30 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
STA
STA  727
727
S-18A
2866125
FIGURE 4: DETAILED INSPECTION FOR UNSHIMMED GAP AT STA 727 FRAME INNER CHORD AT S-18A
RIGHT SIDE
(SHEET 1 OF 5)
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### Page 31 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
INNER CHORD
FRAME
S-18A
S-18A
WEB
2866126
FIGURE 4: DETAILED INSPECTION FOR UNSHIMMED GAP AT STA 727 FRAME INNER CHORD AT S-18A
RIGHT SIDE
(SHEET 2 OF 5)
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### Page 32 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
INNER CHORD
FITTING-AFT, UPPER
S-18A
WEB
2866127
FIGURE 4: DETAILED INSPECTION FOR UNSHIMMED GAP AT STA 727 FRAME INNER CHORD AT S-18A
RIGHT SIDE
(SHEET 3 OF 5)
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### Page 33 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
FEELER GAUGE
1 UNSHIMMED GAP
INSPECTION AREA  2874731
FIGURE 4: DETAILED INSPECTION FOR UNSHIMMED GAP AT STA 727 FRAME INNER CHORD AT S-18A
RIGHT SIDE
(SHEET 4 OF 5)
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### Page 34

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for this figure.
More DataQtyIdentificationNameTaskStep
(a)(b)1144A2619-18Inner ChordInspect1
(a) Do a Detailed Inspection of the STA 727 frame inner chord common to stringer S-18A web mating surface
using a 0.002 inch feeler gauge or equivalent to determine if there is an unshimmed gap. An unshimmed
gap exists if the feeler gauge can be inserted and makes contact with either fastener.
(b) If sealant squeeze-out inhibits inserting the feeler gauge between the mating surfaces remove the sealant
squeeze-out. Refer to 737-700 SRM 51-00-10, 737-800 SRM 51-00-10 or 737-900ER SRM 51-00-10 as
accepted procedures.
FIGURE 4: DETAILED INSPECTION FOR UNSHIMMED GAP AT STA 727 FRAME INNER CHORD AT S-18A
RIGHT SIDE
(SHEET 5 OF 5)
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REQUIREMENTS BULLETIN 737-53A1385
ALERTALERT

### Page 35 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
STA
727
STA
727
S-18A
2865876
FIGURE 5: HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTIONS OF THE STA 727 FRAME INNER
CHORD AT S-18A LEFT SIDE
(SHEET 1 OF 4)
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### Page 36 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
INNER CHORD
FRAME
S-18A
S-18A
WEB
2865877
FIGURE 5: HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTIONS OF THE STA 727 FRAME INNER
CHORD AT S-18A LEFT SIDE
(SHEET 2 OF 4)
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### Page 37 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
INNER CHORD
FITTING-AFT, UPPER
2 INCHES
(2 LOCATIONS)
S-18A
WEB
HFEC SURFACE
INSPECTION AREA
OPEN HOLE HFEC
INSPECTION AREA  2865878
FIGURE 5: HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTIONS OF THE STA 727 FRAME INNER
CHORD AT S-18A LEFT SIDE
(SHEET 3 OF 4)
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### Page 38

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for this figure.
More DataQtyIdentificationNameTaskStep
(a)2BACB30NX8KBoltsRemove1
(a)2BACN11E4NutsRemove
(b)---Inspect2
(c)1144A2619-17Inner ChordInspect3
(a) Remove fasteners from the structure. Refer to 737-700 SRM 51-40-02, 737-800 SRM 51-40-02, 737-
900ER SRM 51-40-02 as accepted procedures.
(b) Do an open hole HFEC inspection of the fastener holes for any crack in accordance with 737 NDT Man-
ual Part 6, 51-00-00 Procedure 16.
(c) Do a High Frequency Eddy Current (HFEC) Surface Inspection at the radius of the inner chord where
common to the unshimmed gap area for any crack in accordance with 737 NDT Manual Part 6, 51-00-00
Procedure 4 or Procedure 23.
FIGURE 5: HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTIONS OF THE STA 727 FRAME INNER
CHORD AT S-18A LEFT SIDE
(SHEET 4 OF 4)
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REQUIREMENTS BULLETIN 737-53A1385
ALERTALERT

### Page 39 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
STA
STA  727
727
S-18A
2866120
FIGURE 6: HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTIONS OF THE STA 727 FRAME INNER
CHORD AT S-18A RIGHT SIDE
(SHEET 1 OF 4)
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### Page 40 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
STA
INNER CHORD  727
FRAME
S-18A
S-18A
WEB
2866130
FIGURE 6: HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTIONS OF THE STA 727 FRAME INNER
CHORD AT S-18A RIGHT SIDE
(SHEET 2 OF 4)
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### Page 41 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
INNER CHORD
FITTING-AFT, UPPER
2 INCHES
(2 LOCATIONS)
S-18A
WEB
HFEC SURFACE
INSPECTION AREA
OPEN HOLE HFEC  INSPECTION AREA  2866131
FIGURE 6: HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTIONS OF THE STA 727 FRAME INNER
CHORD AT S-18A RIGHT SIDE
(SHEET 3 OF 4)
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### Page 42

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for this figure.
More DataQtyIdentificationNameTaskStep
(a)2BACB30NX8KBoltsRemove1
(a)2BACN11E4NutsRemove
(b)---Inspect2
(c)1144A2619-18Inner ChordInspect3
(a) Remove fasteners from the structure. Refer to 737-700 SRM 51-40-02, 737-800 SRM 51-40-02, 737-
900ER SRM 51-40-02 as accepted procedures.
(b) Do an open hole HFEC inspection of the fastener holes for any crack in accordance with 737 NDT Man-
ual Part 6, 51-00-00 Procedure 16.
(c) Do a High Frequency Eddy Current (HFEC) Surface Inspection at the radius of the inner chord where
common to the unshimmed gap area for any crack in accordance with 737 NDT Manual Part 6, 51-00-00
Procedure 4 or Procedure 23.
FIGURE 6: HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTIONS OF THE STA 727 FRAME INNER
CHORD AT S-18A RIGHT SIDE
(SHEET 4 OF 4)
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REQUIREMENTS BULLETIN 737-53A1385
ALERTALERT

### Page 43 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
STA
727
STA
727
S-18A
2866113
FIGURE 7: SHIM INSTALLATION FOR THE STA 727 FRAME INNER CHORD AT S-18A LEFT SIDE
(SHEET 1 OF 4)
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### Page 44 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
STA
727
INNER CHORD
FRAME
S-18A
S-18A
WEB
2866114
FIGURE 7: SHIM INSTALLATION FOR THE STA 727 FRAME INNER CHORD AT S-18A LEFT SIDE
(SHEET 2 OF 4)
Original Issue: August 16, 2019
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Copyright © Unpublished
Work - See page 1 for details.

### Page 45 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
INNER CHORD
FITTING-AFT, UPPER
S-18A
WEB
2866117
FIGURE 7: SHIM INSTALLATION FOR THE STA 727 FRAME INNER CHORD AT S-18A LEFT SIDE
(SHEET 3 OF 4)
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### Page 46

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for this figure.
More DataQtyIdentificationNameTaskStep
(a)(b)(c)(d)1BACS40R010C034FShimInstall (New)1
(d)(e)(f)2BACB30NX8K10BoltsInstall (New)2
(d)(e)(f)2BACN11E4NutsInstall (New)
(a) Remove any existing sealant and measure the unshimmed gap between the inner chord and stringer S-
18A. Refer to 737-700 SRM 51-00-10, 737-800 SRM 51-00-10 or 737-900ER SRM 51-00-10 for removal
of sealant as an accepted procedure.
(b) Make, match drill and prefit shim to fill the gap, maintaining a maximum 0.006 inch after shimming and
prior to fastener pulldown. Refer to SOPM 20-50-20 as an accepted procedure.
(c) Fay surface seal both sides of shim using BMS5-95 Class B or Class C sealant. Refer to SOPM 20-50-
19 as an accepted procedure.
(d) Install new shim, fasteners and nuts. The fastener heads should be installed near side. Refer to 737-700
SRM 51-40-02, 737-800 SRM 51-40-02, 737-900ER SRM 51-40-02, SOPM 20-50-20 as accepted proce-
dures.
(e) Install 1/64 oversize fasteners up to 1/32 oversize as required. Refer to 737-700 SRM 51-40-02, 737-800
SRM 51-40-02, 737-900ER SRM 51-40-02 as accepted procedures.
The starting hole diameters for 737-700 and 737-900ER are 0.247-0.250. The starting hole diameter for
737-800 is 0.250-0.254.
For 1/64 oversize use: BACB30NX8K10X + BACN11E4
For 1/32 oversize use: BACB30NX8K10Y + BACN11E4
(f) Wet installation of fasteners, use BMS5-95 Class B or Class C sealant.
FIGURE 7: SHIM INSTALLATION FOR THE STA 727 FRAME INNER CHORD AT S-18A LEFT SIDE
(SHEET 4 OF 4)
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REQUIREMENTS BULLETIN 737-53A1385
ALERTALERT

### Page 47 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
STA
STA  727
727
S-18A
2866132
FIGURE 8: SHIM INSTALLATION FOR THE STA 727 FRAME INNER CHORD AT S-18A RIGHT SIDE
(SHEET 1 OF 4)
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### Page 48 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
STA
727
INNER CHORD
FRAME
S-18A
S-18A
WEB
2866133
FIGURE 8: SHIM INSTALLATION FOR THE STA 727 FRAME INNER CHORD AT S-18A RIGHT SIDE
(SHEET 2 OF 4)
Original Issue: August 16, 2019
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### Page 49 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
INNER CHORD
FITTING-AFT, UPPER
SHIN
S-18A
WEB
2866134
FIGURE 8: SHIM INSTALLATION FOR THE STA 727 FRAME INNER CHORD AT S-18A RIGHT SIDE
(SHEET 3 OF 4)
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### Page 50

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for this figure.
More DataQtyIdentificationNameTaskStep
(a)(b)(c)(d)1BACS40R010C034FShimInstall (New)1
(d)(e)(f)2BACB30NX8K10BoltsInstall (New)2
(d)(e)(f)2BACN11E4NutsInstall (New)
(a) Remove any existing sealant and measure the unshimmed gap between the inner chord and stringer S-
18A. Refer to 737-700 SRM 51-00-10, 737-800 SRM 51-00-10 or 737-900ER SRM 51-00-10 for removal
of sealant as an accepted procedure.
(b) Make, match drill and prefit shim to fill the gap, maintaining a maximum 0.006 inch after shimming and
prior to fastener pulldown. Refer to SOPM 20-50-20 as an accepted procedure.
(c) Fay surface seal both sides of shim using BMS5-95 Class B or Class C sealant. Refer to SOPM 20-50-
19 as an accepted procedure.
(d) Install new shim, fasteners and nuts. The fastener heads should be installed near side. Refer to 737-700
SRM 51-40-02, 737-800 SRM 51-40-02, 737-900ER SRM 51-40-02, SOPM 20-50-20 as an accepted
procedure.
(e) Install 1/64 oversize fasteners up to 1/32 oversize as required. Refer to 737-700 SRM 51-40-02, 737-800
SRM 51-40-02, 737-900ER SRM 51-40-02 as an accepted procedure.
The starting hole diameters for 737-700 and 737-900ER are 0.247-0.250. The starting hole diameter for
737-800 is 0.250-0.254.
For 1/64 oversize use: BACB30NX8K10X + BACN11E4
For 1/32 oversize use: BACB30NX8K10Y + BACN11E4
(f) Wet installation of fasteners, use BMS5-95 Class B or Class C sealant.
FIGURE 8: SHIM INSTALLATION FOR THE STA 727 FRAME INNER CHORD AT S-18A RIGHT SIDE
(SHEET 4 OF 4)
Export Controlled ECCN: 9E991
Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 16, 2019
737-53A1385 RB
50 of 56
REQUIREMENTS BULLETIN 737-53A1385
ALERTALERT

### Page 51 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
STA
727
STA
727
S-18A
2866118
FIGURE 9: HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION OF THE STA 727 FRAME INNER
CHORD AT S-18A LEFT SIDE
(SHEET 1 OF 3)
Original Issue: August 16, 2019
Export Controlled ECCN: 9E991  737-53A1385 RB
Copyright © Unpublished
Work - See page 1 for details.  51 of 56

### Page 52 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
STA
727
INNER CHORD
FRAME
S-18A
WEB  S-18A
S-18A
WEB
-INNER CHORD
HFEC SURFACE  INSPECTION AREA  2866119
A-A
FIGURE 9: HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION OF THE STA 727 FRAME INNER
CHORD AT S-18A LEFT SIDE
(SHEET 2 OF 3)
Original Issue: August 16, 2019
Export Controlled ECCN: 9E991  737-53A1385 RB
Copyright © Unpublished
Work - See page 1 for details.  52 of 56

### Page 53

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for this figure.
More DataQtyIdentificationNameTaskStep
(a)1144A2619-17Inner ChordInspect1
(a) Do the High Frequency Eddy Current (HFEC) Inspection around the fastener heads for any crack in ac-
cordance with 737 NDT Manual Part 6, 51-00-00 Procedure 4 or Procedure 23.
FIGURE 9: HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION OF THE STA 727 FRAME INNER
CHORD AT S-18A LEFT SIDE
(SHEET 3 OF 3)
Export Controlled ECCN: 9E991
Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 16, 2019
737-53A1385 RB
53 of 56
REQUIREMENTS BULLETIN 737-53A1385
ALERTALERT

### Page 54 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
STA
STA  727
727
S-18A
2866135
FIGURE 10: HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION OF THE STA 727 FRAME INNER
CHORD AT S-18A RIGHT SIDE
(SHEET 1 OF 3)
Original Issue: August 16, 2019
Export Controlled ECCN: 9E991  737-53A1385 RB
Copyright © Unpublished
Work - See page 1 for details.  54 of 56

### Page 55 (OCR)

REQUIREMENTS BULLETIN 737-53A1385
ALERT  ALERT
STA
727
INNER CHORD
FRAME
S-18A
WEB
S-18A
S-18A
WEB
INNER CHORD•
HFEC SURFACE  2866136
INSPECTION AREA  A-A
FIGURE 10: HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION OF THE STA 727 FRAME INNER
CHORD AT S-18A RIGHT SIDE
(SHEET 2 OF 3)
Original Issue: August 16, 2019
Export Controlled ECCN: 9E991  Work - See page 1 for details.  Copyright © Unpublished  737-53A1385 RB  55 of 56

### Page 56

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for this figure.
More DataQtyIdentificationNameTaskStep
(a)1144A2619-18Inner ChordInspect1
(a) Do the High Frequency Eddy Current (HFEC) Inspection around the fastener heads for any crack in ac-
cordance with 737 NDT Manual Part 6, 51-00-00 Procedure 4 or Procedure 23.
FIGURE 10: HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION OF THE STA 727 FRAME INNER
CHORD AT S-18A RIGHT SIDE
(SHEET 3 OF 3)
Export Controlled ECCN: 9E991
Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 16, 2019
737-53A1385 RB
56 of 56
REQUIREMENTS BULLETIN 737-53A1385
ALERTALERT

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