# Boeing Alert Service Bulletin 737-57A1344: No revision named

- Rights: © The Boeing Company. Filed by the FAA in regulations.gov docket FAA-2019-0487, the docket of AD 2019-23-16. Not covered by OpenAirDocs’ CC0 dedication.
- Document: [Boeing Alert Service Bulletin 737-57A1344](https://openairdocs.org/service-documents/boeing/737-57a1344.md)
- Title as filed: 737-57A1344-00 Feb 2019--RB
- Pages: 15
- PDF: https://openairdocs.org/files/sha256/06/dc/06dc176d486bf0134693d15324968ea21c7e9dc08d4b470a26695a0f8ba77b9e
- Page: https://openairdocs.org/service-documents/boeing/737-57a1344/file/06dc176d486b

## Text

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### Page 1

Commercial 
Airplanes
737
Requirements Bulletin
ALERT
Number: 737-57A1344 RB
Original Issue: February 18, 2019
ATA System: 5730
SUBJECT: WINGS - Plates/Skin - Inspection of Upper Skin at Wing Buttock Line 157 Between
Stringer 4 and 5
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Unpublished Work.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.
Original Issue: February 18, 2019
737-57A1344 RB
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2.0

### Page 2

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### Page 3

Table of Contents
1. EFFECTIVITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
A. Airplanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
B. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2. CONCURRENT REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. COMPLIANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4. APPROVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
A. General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
B. Work Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
FIGURE 1: LEFT UPPER WING SKIN - SURFACE HIGH FREQUENCY EDDY CURRENT (HFEC) AND
GENERAL VISUAL INSPECTION [Group 2-3] . . . . . . . . . . . . . . . . . . . . . . . . 12
FIGURE 2: RIGHT UPPER WING SKIN - SURFACE HIGH FREQUENCY EDDY CURRENT (HFEC) AND
GENERAL VISUAL INSPECTION [Group 2-3] . . . . . . . . . . . . . . . . . . . . . . . . 14
Export Controlled ECCN: 9E991
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Export Controlled ECCN: 9E991
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Commercial 
Airplanes
737
Requirements Bulletin
ALERT
Number: 737-57A1344 RB
Original Issue: February 18, 2019
ATA System: 5730
SUBJECT: WINGS - Plates/Skin - Inspection of Upper Skin at Wing Buttock Line 157 Between
Stringer 4 and 5
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 737-100, 737-200, 737-200C, 737-300, 737-400, 737-500 Airplane(s), line
number(s) 1-3132 in 3 Group(s).
DESCRIPTIONCONFIGURATIONGROUP
737-100, 737-200, 737-200C, Airplane with line numbers 1-291.-1
737-200, 737-200C, Airplane with line numbers 292-1585.-2
737-300, 737-400, 737-500, Airplane with line numbers 1001-3132.-3
B. Spares Affected
None.
2. CONCURRENT REQUIREMENTS
None.
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### Page 6

3. COMPLIANCE
The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to
Requirements Bulletin 737-57A1344 RB. The Airworthiness Directive will make the compliance tasks and
times given in Requirements Bulletin 737-57A1344 RB mandatory.
Accomplish the required actions, based on the applicable conditions in Tables 1 and 2 in accordance with
the Accomplishment Instructions.
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.
Group 1:
Boeing endorses the FAA rules related to Limit of Validity (LOV) and recommends immediate and permanent
removal from service of any airplanes upon reaching the LOV, whether or not it is operated under FAA
jurisdiction. As such, Boeing no longer provides maintenance instructions for airplanes that have accumulated
flight cycles beyond the LOV. Airplanes in Group 1 (line numbers 1-291) have accumulated flight cycles
beyond the LOV of the maintenance program. 14 CFR 121.1115 and 129.115 prohibit operation of an
airplane beyond its LOV.
Group 2:
Table 1: Surface High Frequency Eddy Current (HFEC) and general visual inspection of the upper wing
skin.
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Within 2,000
flight cycles af-
ter the original
issue date of
Requirements
Bulletin 737-
57A1344 RB.
Before 30,000
total flight cy-
cles.
Do a surface HFEC inspection
of the upper wing skin at WBL
157, between stringer 4 and
stringer 5, and a general visu-
al inspection of the upper wing
skin in the adjacent rib bay
areas for any crack.
All Airplanes
-Before further flight.ACTION 1: Contact The Boe-
ing Company for repair instruc-
tions and do the repair.
CONDITION 1: ANY
CRACK FOUND
2,000 flight cycles.-ACTION 2: Repeat the surface
HFEC inspection of the upper
wing skin at WBL 157, be-
tween stringer 4 and stringer
5, and general visual inspec-
tion of the upper wing skin in
the adjacent rib bay areas for
any crack in the unrepaired
area.
Export Controlled ECCN: 9E991
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REQUIREMENTS BULLETIN 737-57A1344
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### Page 7

Group 2:
Table 1: Surface High Frequency Eddy Current (HFEC) and general visual inspection of the upper wing
skin.
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
2,000 flight cycles.-Repeat the surface HFEC in-
spection of the upper wing
skin at WBL 157, between
stringer 4 and stringer 5, and
general visual inspection of
the upper wing skin in the ad-
jacent rib bay areas for any
crack.
CONDITION 2: NO
CRACK FOUND
Group 3:
Table 2: Surface High Frequency Eddy Current (HFEC) and general visual inspection of the upper wing
skin.
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Within 4,500
flight cycles af-
ter the original
issue date of
Requirements
Bulletin 737-
57A1344 RB.
Before 30,000
total flight cy-
cles.
Do a surface HFEC inspection
of the upper wing skin at WBL
157, between stringer 4 and
stringer 5, and a general visu-
al inspection of the upper wing
skin in the adjacent rib bay
areas for any crack.
All Airplanes
-Before further flight.ACTION 1: Contact The Boe-
ing Company for repair instruc-
tions and do the repair.
CONDITION 1: ANY
CRACK FOUND
4,500 flight cycles.-ACTION 2: Repeat the surface
HFEC inspection of the upper
wing skin at WBL 157, be-
tween stringer 4 and stringer
5, and general visual inspec-
tion of the upper wing skin in
the adjacent rib bay areas for
any crack in the unrepaired
area.
4,500 flight cycles.-Repeat the surface HFEC in-
spection of the upper wing
skin at WBL 157, between
stringer 4 and stringer 5, and
general visual inspection of
the upper wing skin in the ad-
jacent rib bay areas for any
crack.
CONDITION 2: NO
CRACK FOUND
Export Controlled ECCN: 9E991
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Original Issue: February 18, 2019
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REQUIREMENTS BULLETIN 737-57A1344
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### Page 8

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.
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### Page 9

5.    ACCOMPLISHMENT INSTRUCTIONS
A. GENERAL INFORMATION
NOTE: 1. This is an Enhanced Required for Compliance document. There will 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 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.
3. The compliance times for the actions in WORK INSTRUCTIONS are in Compliance.
4. Boeing Service Letter 737-SL-51-042, Damage Reporting and Repair 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 10

— 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 remove 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. A General Visual Inspection is defined as: A visual examination 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.
9. 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.
B. WORK INSTRUCTIONS
Actions Required for Compliance
1. Requirements
Group 1:
Boeing endorses the FAA rules related to Limit of Validity (LOV) and recommends immediate and
permanent removal from service of any airplanes upon reaching the LOV, whether or not it is
operated under FAA jurisdiction. As such, Boeing no longer provides maintenance instructions for
airplanes that have accumulated flight cycles beyond the LOV. Airplanes in Group 1 (line numbers
1-291) have accumulated flight cycles beyond the LOV of the maintenance program. 14 CFR
121.1115 and 129.115 prohibit operation of an airplane beyond its LOV.
Export Controlled ECCN: 9E991
Copyright © Unpublished
Work - See page 1 for details.
Original Issue: February 18, 2019
737-57A1344 RB
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REQUIREMENTS BULLETIN 737-57A1344
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### Page 11

Group 2-3:
Table 1: Surface High Frequency Eddy Current (HFEC) and general visual inspection of the upper wing
skin.
Refer to the listed procedures
in SB 737-57A1344 Original Is-
sue or later approved revisions
as an accepted procedure.
Method of
Compliance
ActionCondition
-FIGURE 1Do a surface HFEC inspection of
the upper wing skin at WBL 157,
between stringer 4 and stringer 5,
and a general visual inspection of
the upper wing skin in the adja-
cent rib bay areas for any crack.
All Airplanes
FIGURE 2
--ACTION 1: Contact The Boeing
Company for repair instructions
and do the repair.
CONDITION 1: ANY
CRACK FOUND
-FIGURE 1ACTION 2: Repeat the surface
HFEC inspection of the upper
wing skin at WBL 157, between
stringer 4 and stringer 5, and
general visual inspection of the
upper wing skin in the adjacent rib
bay areas for any crack in the un-
repaired area.
FIGURE 2
-FIGURE 1Repeat the surface HFEC inspec-
tion of the upper wing skin at WBL
157, between stringer 4 and
stringer 5, and general visual in-
spection of the upper wing skin in
the adjacent rib bay areas for any
crack.
CONDITION 2: NO
CRACK FOUND FIGURE 2
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### Page 12 (OCR)

REQUIREMENTS BULLETIN 737-57A1344
ALERT  ALERT
This Figure applies only to: Group 2-3.
WBL
135.50
_S-6
WBL  _S-5
157.00
DRY  . S-4
BAY
WBL  . S-3
183.40
777 3 1 30 13)  + 39 39
REAR SPAR
17
IBD
GENERAL VISUAL
INSPECTION AREA
HFEC INSPECTION AREA  A-A  2849641
FIGURE 1: LEFT UPPER WING SKIN - SURFACE HIGH FREQUENCY EDDY CURRENT (HFEC) AND
GENERAL VISUAL INSPECTION
(SHEET 1 OF 2)
Original Issue: February 18, 2019
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Work - See page 1 for details.  12 of 15

### Page 13

More DataQtyIdentificationNameTaskStep
(a)(c)--UPPER WING SKINInspect1
(b)(c)--UPPER WING SKINInspect2
(a) Do a surface HFEC inspection of the upper wing skin around fasteners for any crack in accordance with
737 NDT Manual PART 6, 51-00-00, Procedures 4 or 23.
(b) Do a general visual inspection of the upper wing skin in the specified adjacent rib bay areas for any crack.
(c) An inspection area covered by an existing repair with Boeing Organization Designation Authorization
(ODA) FAA 8100-9 Form do not need to be inspected in accordance with this figure.
FIGURE 1: LEFT UPPER WING SKIN - SURFACE HIGH FREQUENCY EDDY CURRENT (HFEC) AND
GENERAL VISUAL INSPECTION
(SHEET 2 OF 2)
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REQUIREMENTS BULLETIN 737-57A1344
ALERTALERT

### Page 14 (OCR)

REQUIREMENTS BULLETIN 737-57A1344
ALERT  ALERT
This Figure applies only to: Group 2-3.
WBL
135.50
S-6
S-5  WBL
157.00
S-4.  DRY
BAY
S-3  WBL
183.40
+ CEL CE
• CE +
REAR SPAR
GENERAL VISUAL
INSPECTION AREA  INBD
HFEC INSPECTION AREA
A-A
FIGURE 2: RIGHT UPPER WING SKIN - SURFACE HIGH FREQUENCY EDDY CURRENT (HFEC) AND
GENERAL VISUAL INSPECTION
(SHEET 1 OF 2)
Original Issue: February 18, 2019
Export Controlled ECCN: 9E991  737-57A1344 RB
Copyright © Unpublished
Work - See page 1 for details.  14 of 15

### Page 15

More DataQtyIdentificationNameTaskStep
(a)(c)--UPPER WING SKINInspect1
(b)(c)--UPPER WING SKINInspect2
(a) Do a surface HFEC inspection of the upper wing skin around fasteners for any crack in accordance with
737 NDT Manual PART 6, 51-00-00, Procedures 4 or 23.
(b) Do a general visual inspection of the upper wing skin in the specified adjacent rib bay areas for any crack.
(c) An inspection area covered by an existing repair with Boeing Organization Designation Authorization
(ODA) FAA 8100-9 Form do not need to be inspected in accordance with this figure.
FIGURE 2: RIGHT UPPER WING SKIN - SURFACE HIGH FREQUENCY EDDY CURRENT (HFEC) AND
GENERAL VISUAL INSPECTION
(SHEET 2 OF 2)
Export Controlled ECCN: 9E991
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REQUIREMENTS BULLETIN 737-57A1344
ALERTALERT

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