June 30, 1994

Revision 2: May 25, 2006 737-53A1166

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 1 of 198

ALERT ALERT

Commercial

Airplane

Group 737

ALERT ALERT

Service Bulletin

Number: 737-53A1166

Date: June 30, 1994

Revision 2 May 25, 2006

ATA System: 5311

SUBJECT: FUSELAGE - Frames - Body Station 727 Outboard Chord at Stringer 18A, Inspection 

and Preventive Modification

BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET

Copyright © 1994 The Boeing Company

Unpublished Work - All Rights Reserved

Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable 

subject matter. Boeing also claims copyright in this document as a compilation and/or collective work.

This document includes proprietary information owned by The Boeing Company and/or one or more third 

parties. Treatment of the document and the information it contains is governed by contract with Boeing. For 

more information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124.

Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, BBJ, DC-8, DC-9, 

DC-10, MD-10, MD-11, MD-80, MD-88, MD-90, and the red-white-and-blue Boeing livery 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.
 BLANK PAGE

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ALERT ALERT

BLANK PAGE
 Table of Contents

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

Table of Contents

Revision Transmittal Sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1. PLANNING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

A. Effectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

1. Airplanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

2. Data supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . 76

3. Installation Drawings Used in the Preparation of this Service Bulletin: . . . . . . . . . . 78

K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . 78

2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

C. Parts Necessary For Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

1. Kits/Parts: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

2. Parts and Materials Supplied by the Operator: . . . . . . . . . . . . . . . . . . . . . . 105

3. Parts Modified and Reidentified: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

4. Parts Removed and Not Replaced: . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . 108

3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

FIGURE 1: THIS FIGURE WAS DELETED AT REVISION 2 . . . . . . . . . . . . . . . . . . . . . . 127

FIGURE 2: THIS FIGURE WAS DELETED AT REVISION 2 . . . . . . . . . . . . . . . . . . . . . . 128

FIGURE 3: THIS FIGURE WAS DELETED AT REVISION 2 . . . . . . . . . . . . . . . . . . . . . . 129

FIGURE 4: THIS FIGURE WAS DELETED AT REVISION 2 . . . . . . . . . . . . . . . . . . . . . . 130

FIGURE 5: THIS FIGURE WAS DELETED AT REVISION 2 . . . . . . . . . . . . . . . . . . . . . . 131

FIGURE 6: THIS FIGURE WAS DELETED AT REVISION 2 . . . . . . . . . . . . . . . . . . . . . . 132

FIGURE 7: EXTERNAL ULTRASONIC INSPECTION OF THE STA 727 FRAME OUTBOARD CHORD

FORWARD FLANGE - GROUPS 1 THROUGH 11, CONFIGURATIONS 1 AND 4. . . . 133

FIGURE 8: EDDY CURRENT INSPECTION - GROUPS 1 THROUGH 11, CONFIGURATION 1. . . . 136

FIGURE 9: SURFACE HFEC INSPECTION - GROUPS 1 THROUGH 11, CONFIGURATION 4. . . . 138

FIGURE 10: OPEN HOLE HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION OF THE STA 727
 Table of Contents

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ALERT ALERT

OUTBOARD CHORD FORWARD FLANGE. . . . . . . . . . . . . . . . . . . . . . . 140

FIGURE 11: AUXILIARY CHORD INSPECTION - GROUPS 1 THROUGH 3, CONFIGURATION 3. . 143

FIGURE 12: AUXILIARY CHORD INSPECTION - GROUPS 1 THROUGH 3, CONFIGURATION 4. . 145

FIGURE 13: EXTERNAL DETAILED INSPECTION AND SURFACE HIGH FREQUENCY EDDY

CURRENT (HFEC) INSPECTION OF THE S-18A OUTBOARD CHORD - GROUP 1 . 147

FIGURE 14: EXTERNAL DETAILED INSPECTION AND SURFACE HIGH FREQUENCY EDDY

CURRENT (HFEC) INSPECTION OF THE S-18A OUTBOARD CHORD - GROUPS 2, 3, 4,

5, 6, 9 AND 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150

FIGURE 15: PREPARATION FOR THE STA 727 FRAME OUTBOARD CHORD TIME-LIMITED REPAIR

153

FIGURE 16: TIME-LIMITED REPAIR - SURFACE HIGH FREQUENCY EDDY CURRENT (HFEC)

INSPECTION FOR CRACK TIP LOCATION . . . . . . . . . . . . . . . . . . . . . . 160

FIGURE 17: MAKE THE TIME-LIMITED REPAIR PARTS . . . . . . . . . . . . . . . . . . . . . . . 163

FIGURE 18: INSTALL THE TIME-LIMITED REPAIR. . . . . . . . . . . . . . . . . . . . . . . . . . 168

FIGURE 19: TIME-LIMITED REPAIR - REMOVAL. . . . . . . . . . . . . . . . . . . . . . . . . . . 176

FIGURE 20: MAKE THE REPLACEMENT PARTS TO REPLACE THE TIME-LIMITED REPAIR WITH A

NEW FRAME CHORD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181

FIGURE 21: STRINGER S-18A OUTBOARD CHORD AFT FASTENERS - INSPECTION - GROUP 1, 2,

3, 4, 5, 6 AND 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183

FIGURE 22: STA 727 OUTBOARD CHORD FORWARD FLANGE AT STRINGER 18A - EVALUATION. 

185

FIGURE 23: INSTALL THE SHEAR BEAM REPAIR . . . . . . . . . . . . . . . . . . . . . . . . . . 187

FIGURE 24: AUXILIARY CHORD INSPECTION - GROUPS 1 THROUGH 3, CONFIGURATION 1;

GROUPS 4 THROUGH 11, CONFIGURATION 1 AND 4 . . . . . . . . . . . . . . . . 193

APPENDIX A: ADDENDUM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
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ALERT ALERT

Commercial

Airplane

Group 737

ALERT ALERT

Service Bulletin

Number: 737-53A1166 Revision Transmittal Sheet

Date: June 30, 1994

Revision 2: May 25, 2006

ATA System: 5311

SUBJECT: FUSELAGE - Frames - Body Station 727 Outboard Chord at Stringer 18A, Inspection 

and Preventive Modification

This revision includes all pages of the service bulletin.

COMPLIANCE INFORMATION RELATED TO THIS REVISION

Federal Aviation Administration (FAA) Airworthiness Directive 95-12-17, Amendment 39-9268, is related to this 

service bulletin.

Airplane line numbers 1000 through 3132 were added to this service bulletin effectivity.

More work is necessary on airplanes changed as shown in the previous releases of this service bulletin. Further 

inspections as shown in this service bulletin will need to be accomplished.

REASON FOR REVISION

This revision is sent to revise inspections, repairs, modifications and parts fabrication and to expand the airplane 

effectivity to cover all 737-100/200/300/400/500 series airplanes. Additional inspections are added to address 

new cracks found in the STA 727 outboard chord frame, STA 727 frame auxiliary chord and the stringer S-18A 

outboard chord. Instructions are added to modify the STA 727 frame time-limited repair into a permanent repair. 

Instructions are added to install a preventive modification for the S-18A outboard chord.

Changes to this revision include:

— Planning Information - The service history information relating to the new cracks is updated. All references 

are updated to reflect the inclusion of 737-300/400/500 series airplanes into the effectivity.

— Material Information - New top kits are added to this service bulletin revision.

— Accomplishment Instructions - Instructions are added to do new inspections, repairs and modifications.

— Figures 1, 2, 3, 4, 5 and 6 are deleted.

— Figures 7, 8, 9, 10, 11, 12, 13, 14, 16, 21, 22 and 24 are added to show new inspections.

— Figure 15 is added to show access for the Time-limited repair.

— Figure 17 is added to show the fabrication of parts for the Time-limited repair.

— Figure 18 is added to show the installation of the Time-limited repair.

— Figure 19 is added to show the removal of the Time-limited repair.

— Figures 20 is added to show fabrication of the Time-limited repair replacement parts.

— Figures 23 is added to show installation of the Shear Beam Repair.

— Appendix A is revised to show the new compliance data.
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The data given in Notice of Status Change 737-53A1166 NSC 1 is included in this revision. Notice of Status 

Change 737-53A1166 NSC 1 advised operators of a revision to drawing 65C37277, sheet PL, as shown in 

ADCN 3, supplied with this service bulletin.

Paragraph I.A., Effectivity, shows changes of airplane operators. Each operator should examine the Effectivity 

paragraph for changes.

Vertical lines are put on the left edge of each page, except in Paragraph I.A., Effectivity, to show the location of 

important changes.

Pages with a revision number and date, but no vertical lines, have no important changes.

REVISION HISTORY

Initial Release: June 30, 1994

Revision 1: May 25, 1995

Revision 2: May 25, 2006
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ALERT ALERT

Commercial

Airplane

Group 737

ALERT ALERT

Service Bulletin

Number: 737-53A1166 Summary

Date: June 30, 1994

Revision 2 May 25, 2006

ATA System: 5311

SUBJECT: FUSELAGE - Frames - Body Station 727 Outboard Chord at Stringer 18A, Inspection 

and Preventive Modification

THIS BULLETIN 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 SERVICE 

BULLETIN TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE 

BULLETIN TO THE NEW OWNER.

CONCURRENT REQUIREMENTS

None.

BACKGROUND

The changes shown in this service bulletin will decrease the probability of cracks in the frame at Station (STA) 

727 where Stringer (S)-18A is attached. This area is a primary structural element. Operation with cracks in the 

frame will decrease the structural integrity of this area. Unscheduled downtime can be necessary to replace a 

frame that has a crack. Cracks in the S-18A chord are not a safety concern.

Several operators have reported numerous cracks on multiple airplanes in the STA 727 frame outboard chord, 

where the S-18A outboard chord is attached. The cracks ranged from 0.016 inches, to a severed chord. Cracks 

initiate common to the 3 fastener holes or close vicinity to the fastener holes and on the forward edge of the 

frame outboard chords. For the fastener holes susceptible to cracking, several elongated holes were also found. 

Airplanes have accumulated between 20,000 - 85,000 flight-cycles and 27,000 - 74,000 flight hours. Previous 

revisions of this service bulletin inspected for cracks on airplanes with 7075-T6 frame outboard chords (Line 

Number 1-999) only. Since the release of Rev 1, seven operators have reported cracks in 7075-T73 chords with 

20,000 - 52,000 flight-cycles. As a result of these new findings, this revision of the service bulletin expands the 

effectivity to include airplanes with 7075-T73 frame outboard chords. The cracks were caused by fatigue; for 

line number 1-999 airplanes (7075-T6 frame outboard chord), fretting of adjacent parts contributed to the 

initiation of the fatigue damage.

Three operators have reported four cracks in the radius of the 65-46547-9 Auxiliary Chord on three airplanes. 

1.00 inch cracks were reported. Airplanes have accumulated between 46,000 - 85,000 flight-cycles and 41,000 

- 64,000 flight hours.
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Several operators have reported numerous cracks on multiple aircraft in the S-18A outboard chord common to 

the fastener locations just aft of STA 727. Airplanes have accumulated between 30,000 - 76,000 flight-cycles 

and 32,000 - 65,000 flight hours. One operator found one crack on one airplane in the S-18A chord, forward of 

STA 727 in the lower fastener row. The aircraft had 68,000 flight-cycles and 71,000 flight hours. Cracks have 

been found in S-18A chord sections of thickness at STA 727 of 0.33 inches or less. The cracks were caused by 

fatigue.

Four operators have reported four cracks on three aircraft with a "T" profile S-18A outboard chord. The vertical 

flange of the chord has cracked at the base, at the vertical flange run-out, near STA 727. These cracks can grow 

along the base of the vertical flange in the radius. These cracks have been associated with S-18A outboard 

chord installation pre-loads.

As part of a service bulletin validation program, the inspection, frame chord replacement, and preventive 

modification was completed on airplane PG576 before the initial release of this service bulletin.

Boeing Service Related Problem (SRP) 737-SRP-53-0162 is related to this service bulletin.

Federal Aviation Administration (FAA) Airworthiness Directive AD 95-12-17, is related to this service bulletin. 

The FAA is considering additional rule making that will make the compliance tasks and times given in Revision 

2 of this Service Bulletin mandatory.

Boeing Structural Item Interim Advisory (SIIA) 737-131 is related to this service bulletin.

ACTION

Do inspections of the outboard chord of the frame at STA 727 where S-18A is attached. Look for cracks. Do the 

inspections at the times given in the Compliance section.

If cracks are found in the outboard chord of the frame at STA 727, install the time-limited repair or replace the 

chord and, optionally, install the preventive modification. If no cracks are found, install the preventive 

modification or do the repeat inspections. Do the inspections at the times given in the Compliance section until 

the STA 727 frame preventive modification is installed. If the STA 727 frame outboard chord preventive 

modification is installed with an edge margin greater than or equal to 1.7D, there are no further inspection 

requirements per this bulletin for the STA 727 frame outboard chord.

Do an inspection of the STA 727 frame auxiliary chord for cracks. Do the inspection at the times given in the 

Compliance section. If cracks are found, repair before further flight. Contact Boeing for repair data. If no cracks 

are found, but a permanent frame chord modification has not been installed, continue inspections at the times 

given in the Compliance section. If no cracks are found and STA 727 frame outboard chord modification strap 

has been installed, and the frame chord is 7075-T73, there are no further inspection or modification 

requirements for the STA 727 frame auxiliary chord.

Do inspections of the outboard chord of S-18A at STA 727. If cracks are found in the outboard chord of S-18A, 

do the S-18A repair. If no cracks are found in the outboard chord of S-18A, install the S-18A Preventive 

Modification. If the S-18A modification or repair is installed, there are no further inspection requirements per this 

bulletin for the S-18A outboard chord.

More work is necessary for operators that have replaced the outboard chord of the frame at STA 727 as shown 

in Service Bulletin 737-53-1088 and who have not installed a permanent modification. Refer to the Compliance 

section.
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EFFECTIVITY

All 737-100/200/200C/300/400/500 series airplanes. See paragraph 1.A., Effectivity.

COMPLIANCE

See Service Bulletin Paragraph 1.E. for compliance information.

INDUSTRY SUPPORT INFORMATION

Boeing warranty remedies are not available for the inspection and/or repair procedures given in this service 

bulletin.

MANPOWER

Refer to Paragraph I.G. Manpower.

MATERIAL INFORMATION

Boeing Supplied Kits

Refer to Paragraph 2.A., Material - Price and Availability.
 

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ALERT ALERT

STRINGER 18A

FOR CRACKS IN

INSPECT AREA

INSPECTIONS

727 FRAME

FOR STA

AFT SKIN

FWD SKIN

CRACKS

FLANGE FOR

FORWARD

727 FRAME

INSPECT STA

FLANGE

EDGE OF

FORWARD

INSPECT

INSPECTION

CHORD

AUXILIARY

FOR

FOR CRACKS

CHORD RADIUS

AUXILIARY

INSPECT

CHORD

AUXILIARY

CRACK

TYPICAL

B

CHORD

AUXILIARY

CHORD

FRAME AFT SKIN

WEB

BULKHEAD

UP

FWD

VIEW FROM INSIDE CARGO BAY

SEE A

A

SEE B

D41500

NOT SHOWN

STRUCTURE

SUPPORT

FAIRING

PLATE)

CHORD OF STRINGER 18A IS A FLAT

(ON MOST AIRPLANES THE OUTBOARD

STRINGER 18A

CRACKS

TYPICAL

LEFT SIDE SHOWN

RIGHT SIDE OPPOSITE

(WING-TO-BODY FAIRING NOT SHOWN)

STA

727

WEB

BULKHEAD

STA 727

CRACK

TYPICAL

CHORD ONLY)

S-18A OUTBOARD

A 'T' PROFILE

(AIRPLANES WITH

TYPICAL CRACK
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ALERT ALERT

Commercial

Airplane

Group 737

ALERT ALERT

Service Bulletin

Number: 737-53A1166

Date: June 30, 1994

Revision 2: May 25, 2006

ATA System: 5311

SUBJECT: FUSELAGE - Frames - Body Station 727 Outboard Chord at Stringer 18A, Inspection 

and Preventive Modification

THIS BULLETIN 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 SERVICE 

BULLETIN TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE 

BULLETIN TO THE NEW OWNER.

1. PLANNING INFORMATION

A. Effectivity

1. Airplanes

Refer to Service Bulletin Index Document D6-19567 Part 3 for Airplane Variable Number, Line 

Number, and Serial Number data.

This service bulletin is for the airplanes shown below. Refer to PRR 35005-244RS for data about 

this change.

NOTE:As the group configurations are described below, a single airplane may meet the 

description for two separate configurations. The left side configuration may be different

 than the right side configuration.
 

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ALERT ALERT

GROUP CONFIGURATION DESCRIPTION

1 - 737-100/200/200C Series airplanes, line 

numbers 1-310. These airplanes have a "T" 

profile S-18A Outboard Chord with a thickness 

of 0.20 inch at STA 727.

1 Airplanes with a replaced Station (STA) 727 

Frame Outboard Chord and without the STA 

727 Frame Outboard Chord Preventive 

Modification installed as shown in previous 

revisions of this bulletin.

2 Airplanes with the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

3 Airplanes without the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

4 Airplanes without the STA 727 Frame Outboard 

Chord replaced and without the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.
 

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

2 - 737-200/200C Series airplanes, line numbers 

311-972. These airplanes have a Flat Strap S18A Outboard Chord with a thickness of 0.20 

inch at STA 727.

1 Airplanes with a replaced Station (STA) 727 

Frame Outboard Chord and without the STA 

727 Frame Outboard Chord Preventive 

Modification installed as shown in previous 

revisions of this bulletin.

2 Airplanes with the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

3 Airplanes without the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

4 Airplanes without the STA 727 Frame Outboard 

Chord replaced and without the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

GROUP CONFIGURATION DESCRIPTION
 

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ALERT ALERT

3 - 737-200/200C Series airplanes, line numbers 

973-999 that have a Flat Strap S-18A Outboard 

Chord with a thickness of 0.33 inch at STA 727, 

early skin panels and early fairing support 

structure.

1 Airplanes with a replaced STA 727 Frame 

Outboard Chord and without the STA 727 

Frame Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

2 Airplanes with the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

3 Airplanes without the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

4 Airplanes without the STA 727 Frame Outboard 

Chord replaced and without the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

GROUP CONFIGURATION DESCRIPTION
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4 - 737-200/200C Series airplanes, line numbers 

1000-1585 that have a Flat Strap S-18A 

Outboard Chord with a thickness of 0.33 inch at 

STA 727, early skin panels and early fairing 

support structure.

1 Airplanes with a replaced STA 727 Frame 

Outboard Chord and without the STA 727 

Frame Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

2 Airplanes with the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

3 Airplanes without the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

4 Airplanes without the STA 727 Frame Outboard 

Chord replaced and without the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

GROUP CONFIGURATION DESCRIPTION
 

June 30, 1994

Revision 2: May 25, 2006 737-53A1166

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

5 - 737-300/500 Series airplanes, line numbers 

1001-2664 that have a Flat Strap S-18A 

Outboard Chord with a thickness of 0.33 inch at 

STA 727, early skin panels and later fairing 

support structure.

1 Airplanes with a replaced STA 727 Frame 

Outboard Chord and without the STA 727 

Frame Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

2 Airplanes with the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

3 Airplanes without the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

4 Airplanes without the STA 727 Frame Outboard 

Chord replaced and without the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

GROUP CONFIGURATION DESCRIPTION
 

June 30, 1994

Revision 2: May 25, 2006 737-53A1166

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

6 - 737-300/500 Series airplanes, line numbers 

2667-3130 that have a Flat Strap S-18A 

Outboard Chord with a thickness of 0.33 inch at 

STA 727, later skin panels and later fairing 

support structure.

1 Airplanes with a replaced STA 727 Frame 

Outboard Chord and without the STA 727 

Frame Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

2 Airplanes with the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

3 Airplanes without the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

4 Airplanes without the STA 727 Frame Outboard 

Chord replaced and without the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

GROUP CONFIGURATION DESCRIPTION
 

June 30, 1994

Revision 2: May 25, 2006 737-53A1166

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 18 of 198

BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

7 - 737-400 Series airplanes, line numbers 1487-

2657 that have a Flat Strap S-18A Outboard 

Chord with a thickness of 0.40 or 0.45 inch at 

STA 727, later skin panels and early fairing 

support structure.

1 Airplanes with a replaced STA 727 Frame 

Outboard Chord and without the STA 727 

Frame Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

2 Airplanes with the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

3 Airplanes without the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

4 Airplanes without the STA 727 Frame Outboard 

Chord replaced and without the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

GROUP CONFIGURATION DESCRIPTION
 

June 30, 1994

Revision 2: May 25, 2006 737-53A1166

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

8 - 737-300/400/500 Series airplanes, line numbers 

2665-3132 that have a Flat Strap S-18A 

Outboard Chord with a thickness of 0.40 or 0.45 

inch at STA 727, later skin panels and later 

fairing support structure.

1 Airplanes with a replaced STA 727 Frame 

Outboard Chord and without the STA 727 

Frame Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

2 Airplanes with the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

3 Airplanes without the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

4 Airplanes without the STA 727 Frame Outboard 

Chord replaced and without the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

GROUP CONFIGURATION DESCRIPTION
 

June 30, 1994

Revision 2: May 25, 2006 737-53A1166

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

9 - 737-300/500 Series airplanes, line numbers 

2938-2942 that have a Flat Strap S-18A 

Outboard Chord with a thickness of 0.33 inch on 

one side and 0.40 or 0.45 inch on the opposite 

side at STA 727, with later skin panels and later 

fairing support structure.

1 Airplanes with a replaced STA 727 Frame 

Outboard Chord and without the STA 727 

Frame Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

2 Airplanes with the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

3 Airplanes without the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

4 Airplanes without the STA 727 Frame Outboard 

Chord replaced and without the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

GROUP CONFIGURATION DESCRIPTION
 

June 30, 1994

Revision 2: May 25, 2006 737-53A1166

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

10 - 737-300/500 Series airplanes, line numbers 

1842-1896 that have a Flat Strap S-18A 

Outboard Chord with a thickness of 0.33 inch at 

STA 727, early skin panels, later fairing support 

structure and short edge margin repair installed 

per 65C36009 Detail 7.

1 Airplanes with a replaced STA 727 Frame 

Outboard Chord and without the STA 727 

Frame Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

2 Airplanes with the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

3 Airplanes without the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

4 Airplanes without the STA 727 Frame Outboard 

Chord replaced and without the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

GROUP CONFIGURATION DESCRIPTION
 

June 30, 1994

Revision 2: May 25, 2006 737-53A1166

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

Airplane models:

737-100 737-200 737-200C 737-300

737-400 737-500

IDENTIFICATION BY CUSTOMER, CUSTOMER CODE, GROUP AND VARIABLE NUMBER

ADAM AIR (DAM)

5 PP508 PP840

6 PU301

7 PM556 PW009 PW119

ADC AIRLINES (ADN)

2 PJ118–PJ119

3 PN033–PN034

AEGEAN AIRLINES S.A. (CRM)

5 PM392 PS608

6 PR028 PR030 PS961

7 PW002 PW046 PW053 PW157

PW261 PW502 PW564

8 PV287 PW276 PW289

11 - 737-400 Series airplanes, line numbers 1844-

1908 that have a Flat Strap S-18A Outboard 

Chord with a thickness of 0.40 or 0.45 inch at 

STA 727, later skin panels, early fairing support 

structure and short edge margin repair installed 

per 65C36009 Detail 7.

1 Airplanes with a replaced STA 727 Frame 

Outboard Chord and without the STA 727 

Frame Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

2 Airplanes with the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

3 Airplanes without the STA 727 Frame Outboard 

Chord replaced and with the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

4 Airplanes without the STA 727 Frame Outboard 

Chord replaced and without the STA 727 Frame 

Outboard Chord Preventive Modification 

installed as shown in previous revisions of this 

bulletin.

GROUP CONFIGURATION DESCRIPTION
 

June 30, 1994

Revision 2: May 25, 2006 737-53A1166

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

AER LINGUS (ARL)

5 PT167–PT168

AERGO CAPITAL LIMITED (CLJ)

1 PY031

2 PK462 PK468 PK772 PK820

4 PK528 PN405

AERO CONTRACTORS OF NIGERIA (NCC)

5 PQ194 PQ196

AERO CONTROLS (AEO)

1 PG312 PG629

AEROCONDOR (EDR)

2 PL401

4 PN491

AEROGAL/GALAPAGOS AIRLINES (ERG)

2 PK715 PK827

3 PN030

4 PL624–PL625

AEROLINEAS ARGENTINAS (ARG)

1 PG584–PG585 PH705–PH708 PH741–PH742 PY007

2 PH743 PK102–PK103 PK735–PK737 PK739–PK740

PK747 PN112

4 PK750–PK751 PK755 PK757 PK760–PK765

PN113

5 PP948 PT042 PT303–PT306 PT309

PT509–PT510

AEROLINEAS AUSTRAL CHILE S.A. (LUT)

2 PL405 PM141–PM142

AEROSERVICE (SRI)

1 PL742

2 PL743

AEROSUCRE (SUS)

1 PY341

2 PY201 PY451

AEROSUR (REO)

2 PK594

AEROSVIT (UKA)

2 PK564

5 PP924 PQ284 PT614–PT615

7 PW265 PW591–PW592 PW595–PW596

AEROVISTA GULF EXPRESS (GXP)

2 PL556
 

June 30, 1994

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ALERT ALERT

AIGLE AZUR (AZU)

5 PP962

AIR ALGERIE (ALG)

2 PK633–PK634 PL722 PL724 PY051

PY053

AIR ATLANTA ICELANDIC (AID)

5 PP352 PP913 PQ222

7 PW011 PW094

AIR AUSTRAL (AUX)

5 PT215

6 PS621

AIR BERLIN (BER)

8 PJ811 PW524 PW528–PW530

AIR CANADA (ACN)

2 PK679–PK680

AIR CANADA JAZZ (ANI)

2 PK310

AIR CHINA (BEJ)

5 PP521–PP522 PQ361–PQ364

6 PQ345–PQ346 PQ373 PQ438 PQ447

PQ971 PQ975 PS957

AIR CHINA INNER MONGOLIAN (IML)

5 PQ365–PQ366 PQ370 PS614–PS617

6 PQ372 PQ988 PQ990

AIR CHINA SOUTHWEST BRANCH (XIN)

5 PP631–PP634 PQ401–PQ406 PQ408–PQ410

6 PS811

AIR CHINA TIANJIN BRANCH (TJA)

5 PQ367–PQ369 PQ371

AIR CORRIDOR (KRD)

2 PK749

AIR EUROPA (ARE)

7 PW266

AIR FRANCE (AFA)

5 PT214 PT501–PT508 PT511–PT514

AIR GABON (GBN)

2 PY191
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

AIR GUINEE (GNE)

2 PY651

4 PN456

AIR HORIZONS (AHZ)

1 PY004

5 PP965 PP967

7 PW065

AIR MADAGASCAR (MAD)

1 PG375

2 PL793

5 PP852 PQ297 PQ299

AIR MALAWI (AML)

5 PS602

AIR MALTA (MLT)

5 PQ791 PQ793

6 PS873–PS874

AIR MEDITERRANEE (AMV)

1 PG028–PG029 PY301

AIR NAMIBIA (NAM)

2 PK355 PK731

4 PN492

AIR NAURU (NAU)

7 PW556

AIR NEW ZEALAND (ANZ)

5 PS651

6 PQ997 PR041 PR062–PR066 PR077–PR080

PR101 PS866–PS868

AIR NIPPON (ANK)

5 PT053 PT060 PT063–PT064

6 PT126 PT128–PT131 PT871–PT886

7 PW026

8 PJ817

AIR NORTH YUKON'S AIRLINE (AND)

2 PK596 PK599
 

June 30, 1994

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ALERT ALERT

AIR ONE (ADH)

2 PK432

4 PK933 PK938

5 PM410–PM411 PQ228–PQ229

6 PQ347–PQ348

7 PV231–PV234 PV236–PV237 PW041 PW043

PW052 PW054 PW106 PW111–PW112

PW115 PW267 PW288 PW302

PW317 PW526

8 PW831 PW851

AIR PHILIPPINES (PHP)

1 PG001 PG039 PG061–PG062 PG066

2 PK099 PK541–PK542 PN021–PN022 PN025

3 PN029 PN031 PN038

AIR PLUS COMET (PLD)

5 PP904 PP912

AIR SAHARA (SAQ)

5 PQ306

6 PR012 PR021–PR022

7 PW061 PW064 PW066

8 PW264 PW273

AIR SENEGAL INTERNATIONAL (SNG)

5 PT023

AIR SLOVAKIA (SLO)

4 PK936

AIR TANZANIA (TNZ)

2 PY611

AIR VANUATU (VAN)

6 PQ454

AIR ZIMBABWE (ZMB)

4 PN431–PN433

AIRASIA BERHAD (ASW)

10 PM391

5 PM385 PM388 PM390 PM397–PM398

PP002 PP021 PP023 PP234

PP406–PP409 PP411–PP412 PP419 PP421

PP471 PP473 PP504 PP509

PP516–PP517 PP676–PP677 PP684 PP686–PP687

PP848 PP920 PQ184 PQ332

PS657

6 PQ448
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

AIRBALTIC CORPORATION (BCB)

5 PT005 PT161–PT163

6 PU311 PU313

AIRCRAFT 23383, LLC. (LSG)

5 PP028

AIRCRAFT MAINTENANCE CORP. (AMF)

2 PK254

AIRFAST INDONESIA (PTF)

1 PY343

2 PK562

4 PN481

AIRTRAN AIRWAYS (CQT)

2 PK697

AIRWORK NZ (ANX)

2 PY741

5 PQ026

AIRZENA (GEI)

5 PP044 PT611

7 PW262

ALASKA AIRLINES (ASA)

2 PY112 PY134 PY270 PY461–PY462

4 PY463 PY593–PY594

7 PJ301–PJ302 PW116 PW231–PW249

8 PJ601–PJ615 PW250–PW252

ALBARKA AIR SERVICES (ABF)

2 PL111

ALOHA AIRLINES (ALO)

2 PK905 PK926 PY231

3 PN085

4 PK934–PK935 PL626 PM251 PM253

PN473 PY592 PY595 PY721

ALTER BAIL AVIATION (ABH)

2 PK215 PK359

AMERICA WEST AIRLINES (AMW)

2 PL081 PL559–PL560

5 PP022 PP029 PP183–PP187 PP189

PP194–PP195 PP197–PP199 PP383 PP472

PP474–PP475 PP831 PP833–PP834 PP846

PP891 PP893 PP895 PP898–PP899

PP901 PP931–PP934 PP936 PS666–PS669

6 PR067
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

AMERICAN FALCON AIR (FAK)

2 PK464 PL026

AMERISTAR AIR CARGO (CGG)

1 PY345–PY346

2 PK221 PK560 PM051

APOLLO AVIATION CAPITAL, LLC. (APV)

1 PL761

ARAL (RII)

7 PW031

ARKIA ISRAELI AIRLINES (ARK)

2 PK822 PL402 PL404 PL414

ASIA AIRLINES (YDO)

1 PY005

2 PY135

ASIANA AIRLINES (AAR)

5 PT851

6 PT852–PT853

7 PW283 PW286

8 PV204–PV206 PV208 PV226–PV229

ASTRAEUS, LTD. (AUA)

5 PP845 PP929 PP935 PS605

6 PQ994

ATA AIRLINES, INC. (AAT)

5 PQ188 PQ190

ATA ATLANTICO TRANSPORTE AEREO (AUI)

1 PY003 PY321–PY322 PY361

ATLANTIC AIRLINES (LNL)

2 PL008 PL010 PL622–PL623

ATLAS BLUE (ABT)

11 PW632

7 PW631 PW633–PW636

AURELA (URE)

5 PQ307

AUSTRAL - CIELOS DEL SUR (ALA)

2 PN103–PN104 PN110–PN111

4 PN114–PN115 PN117

AUTOMATIC 9W (TMW)

10 PQ191

5 PQ193 PQ195
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

AUTOMATIC LLC (AUM)

2 PJ114–PJ115 PK502 PK504 PK801–PK804

PK821 PK824 PK901 PK974

AVENSA (AVN)

2 PK042

AVIACSA AEROEXO (AEJ)

2 PK289 PK598 PK625–PK626 PM101–PM102

PM106–PM107 PM115–PM117

4 PK216–PK220 PM181 PN454

AVIATION CAPITAL GROUP (CGP)

2 PK286

AVIATION CONSULTANTS (ACT)

1 PG037 PY001

2 PK546

AVIOGENEX (AVG)

4 PN501

AVIOR (AWD)

2 PK549 PK591

AVOLAR (AOL)

5 PT001

AXIS AIRWAYS (AXY)

5 PP947 PQ301 PQ341

7 PW033

BAHAMASAIR (BAH)

2 PK672–PK673 PL501 PL506

BALI AIR (ZBL)

2 PL504

BASIC CAPITAL MANAGEMENT (BCM)

4 PN455

BATAVIA AIR (BTV)

2 PJ107 PJ112 PK252 PK283–PK284

PK305 PK360 PK514 PK563

PK617 PK622 PK635 PK711

PK825

4 PK515

5 PS631

7 PW005 PW015 PW032 PW575

BAYU INDONESIA AIR (BAY)

2 PK561
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

BELAVIA (ITU)

6 PT722 PT971

BELLVIEW AIRLINES (BEB)

2 PK203 PK612 PK872 PL028

BLUE AIR (BTR)

10 PT211

5 PS618

BLUE DART AVIATION (BDA)

2 PK231–PK232 PL451

4 PM281 PN521

BLUE PANORAMA AIRLINES (BPA)

11 PW518

7 PW284 PW519 PW741–PW742

BLUEBIRD CARGO (BLS)

5 PM383 PQ242 PQ342–PQ344

BMI BRITISH MIDLAND (BMA)

5 PQ291–PQ292 PQ431 PT186–PT188 PT701–PT703

6 PP520 PQ433–PQ435 PQ974 PQ992

PQ996 PS625 PS861

BOEING (TBC)

1 PG051 PG215

BOURAQ AIRLINES (PTB)

2 PK255 PK302–PK303 PK307–PK309 PK501

PK913 PK918–PK920 PK931 PL409–PL410

PM021

BRA TRANSPORTES AEREOS (BRW)

5 PP907 PP946 PP984 PQ226

PQ243 PQ260–PQ261

7 PW020–PW021 PW504

BRITISH AIRWAYS (BAB)

10 PT295

5 PM399 PP841–PP842 PQ283 PQ305

PT009 PT021 PT183 PT185

PT307–PT308

6 PT515–PT516

7 PW101 PW301 PW305–PW308 PW312

PW314–PW315 PW318–PW327

BULGARIA AIR (BLD)

5 PQ224–PQ225 PQ262 PT170 PT427

PT437

6 PR025–PR026
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

BURAQ AIR (BQA)

2 PL723 PL725

C.I.T. LEASING CORPORATION (TCI)

5 PP836 PP964

7 PW562

CANADIAN NORTH (ANP)

2 PL415 PY152–PY154 PY422 PY441

CANJET (CNJ)

5 PT424–PT426 PT428–PT429 PT434–PT435 PT438

PT616

CAYMAN AIRWAYS (CAY)

2 PJ009 PY244

4 PK753

5 PQ293 PQ481

CHANCHANGI AIRLINES (CGI)

2 PL412 PL416–PL417

CHANNEL EXPRESS (AIR SERVICES) (CEX)

5 PP908–PP909 PP914 PQ027 PQ030–PQ039

PQ051–PQ052 PQ054–PQ055 PQ058–PQ059

CHARTER AIR (FIH)

6 PS630 PS871

CHILEAN AIR FORCE (CHF)

5 PQ053

6 PT996

CHINA EASTERN AIRLINES (CEA)

6 PQ977 PQ979 PQ981 PR141–PR143

CHINA EASTERN AIRLINES WUHAN (WUH)

5 PQ472 PQ491–PQ492

6 PR081–PR082 PR131

CHINA EASTERN YUNNAN AIRLINES (YUN)

5 PP651–PP652 PQ263 PQ411–PQ412

6 PQ414–PQ415 PQ417–PQ418 PS622–PS623 PS628

8 PQ416

CHINA SOUTHERN AIRLINES (GUN)

5 PM408–PM409 PM412 PM541–PM544 PM547

PM549 PQ252–PQ255 PQ407 PQ479–PQ480

PS836–PS837 PS841–PS844 PT041 PT043–PT049

PT052 PT061–PT062

6 PR121–PR122 PS845–PS846
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

CHINA UNITED AIRLINES (CUL)

5 PP728–PP729 PQ288–PQ289 PS609–PS610

6 PS896–PS897

CHINA XINHUA AIRLINES (XIH)

5 PM546 PQ264 PQ804–PQ805 PS856

6 PR001

8 PW852–PW854

CHINA XINJIANG AIRLINES (XIJ)

5 PM545 PM548

CIRRUS AIRLINES (CSG)

5 PT146

CIS AIR HOLDINGS (CIS)

1 PG217

COMAIR LIMITED (CML)

2 PK734 PK738 PK744 PK748

PK904 PK907

4 PK754 PK758

5 PQ001 PQ003–PQ006 PQ008 PQ010

7 PW303 PW310–PW311

CONOCOPHILLIPS ALASKA, INC. (ATR)

2 PK610

4 PN452–PN453

CONTINENTAL AIRLINES (CAL)

5 PP671–PP675 PP678 PP680–PP683 PP685

PP688–PP699 PP701 PP703–PP710 PP712–PP726

PP730 PP732–PP733 PT801–PT818 PT826–PT828

6 PT819–PT825 PT829–PT834 PT901–PT905 PT907–PT930

CONVIASA S.A. (VSS)

5 PQ117 PS604

CORENDON AIRLINES (HVA)

5 PQ286

6 PQ451

CORSAIR (COR)

7 PW661–PW662

CSA (CSA)

5 PT184 PT301–PT302 PT617–PT621

6 PT136 PT138 PT981–PT985

7 PW039 PW102 PW268 PW304

PW309 PW517

8 PJ816 PV302 PW431–PW435
 

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ALERT ALERT

CSC TRANSPORT (CTC)

7 PW007

DASAB AIR (DSB)

2 PN024

3 PN036

DBA (DBA)

5 PP507 PP511 PP515 PP838

PP961 PQ119 PQ152 PS655

6 PR015–PR017

DELTA AIR LINES (DAL)

3 PN131–PN135

4 PN136–PN163 PN401–PN404 PN407–PN420

5 PP231–PP233 PP235–PP243 PP506 PQ086

PQ231–PQ232

DODSON AVIATION (DOO)

1 PJ032

DOLPHIN AIR (FDN)

2 PL151 PY241

EARTH AIRLINES (ETL)

1 PG352

EAS AIRLINES NIG (EAV)

2 PL453

3 PN032

4 PK681

EAST AFRICAN AIRLINES (EAB)

2 PL023

EASYJET (EZY)

5 PP510 PP518–PP519 PS652

6 PR003–PR004 PR167–PR172 PS971 PS974–PS978

EG&G TECHNICAL SERVICES (EGN)

2 PJ205 PJ207–PJ210 PJ218 PL763

EGYPTAIR (EGP)

1 PG026

5 PT561 PT563–PT565

ESTAFETA (EST)

2 PY131 PY275

3 PY056–PY057

5 PP825–PP826
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

ESTONIAN AIR (ENA)

5 PT010

6 PT137 PT716–PT717 PU312

ETHIOPIAN AIRLINES (ETH)

4 PN512

EUROATLANTIC AIRWAYS (MAE)

5 PP985

EUROPE AIRPOST (EUE)

5 PP392 PP832 PP925 PP951–PP952

PQ421 PQ771–PQ772 PS607 PS641–PS644

6 PR096

EUROPEAN AVIATION AIR CHARTER (EUL)

2 PK044–PK046 PK048–PK050 PK053 PN001

PY273

EXECUTIVE JET AIRCRAFT COMPANY (EXF)

2 PL441

EXPORT RESTRICTED AIRPLANES (YWV)

1 PA002 PG021 PG041 PG074

PG218–PG219 PG224 PG305 PG307–PG308

PG310–PG311 PG574 PH731 PJ002

PJ102 PY021

2 PJ003 PK391 PL758 PY022

PY141–PY142

EXTRA AIRWAYS (CIN)

1 PG279

11 PW503

2 PN083

3 PN084 PN086

7 PW117 PW761

FAA (FAA)

2 PL768

FACTS AIR (FAD)

1 PX701

FALCON AIR (FLK)

5 PS636–PS638

FALCON AIR EXPRESS (FAX)

5 PP897

FALCONBRIDGE (NAD)

2 PY612
 

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ALERT ALERT

FASCO AIRWAYS (EAO)

1 PG228

FEDERATIVE REPUBLIC OF BRAZIL (BRZ)

2 PK068–PK069

FINOVA (GRB)

4 PK759

FIRST AIR (BRS)

2 PK358 PL407 PY133 PY281

PY421

FISCHER AIR POLAND (FSP)

6 PS973

FLY AIR (FHA)

5 PQ281

FLYGLOBESPAN.COM (FGS)

6 PS962–PS963

FLYING CARPET (FYC)

4 PM064

FLYME (FMA)

5 PP393 PP902 PP910–PP911

FREEDOM AIR INTERNATIONAL (SPT)

6 PR045

FRONTIER AIRLINES (FRO)

2 PK495

FUTURA (FUA)

5 PP430 PP892 PQ197

7 PW034–PW035 PW047–PW048 PW114 PW501

PW527 PW561

GARUDA INDONESIA (GIA)

5 PM393–PM394 PM404 PQ285 PQ487

PS606

6 PQ986–PQ987 PR061 PR068–PR072 PR091–PR092

PS956 PT681–PT682 PT684–PT685

7 PV271–PV272 PW022 PW028 PW067

PW461–PW467

8 PV301 PW272 PW441–PW450 PW525

9 PT683

GARY 737 LLC (BHA)

2 PL745
 

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ALERT ALERT

GE AVIATION MATERIALS (GML)

5 PP001

GE CAPITAL CORPORATION (GEF)

1 PG220–PG221 PG651–PG652

2 PK026–PK027 PK256 PK465–PK467

5 PM407

7 PW051

GENERIC CUSTOMER/SUPPLIER (XXX)

2 PK274

GERMANIA (GER)

5 PP503 PQ087 PQ230 PQ233–PQ237

GLOBAL AIR (YCH)

2 PK548 PL013

GOL AIRLINES (GOT)

5 PQ056 PQ123–PQ124 PQ144–PQ145 PQ159–PQ160

PQ162–PQ163

HAINAN AIRLINES (HNA)

5 PQ088–PQ091 PQ156–PQ157 PQ473–PQ474 PS611

PS613

6 PQ475 PR005 PR010

7 PV203 PW093

8 PV356–PV357 PW086–PW088

HAMRA AIR (HMA)

5 PP420

HAPAG LLOYD EXPRESS (HLX)

5 PT104

HAPAG-LLOYD FLUG (HAP)

10 PT101

5 PT102–PT103 PT105

HEMUS AIR (HEU)

7 PM554

HEWA BORA AIRWAYS (EXD)

1 PG274

HOLA AIRLINES (HLB)

10 PQ304

5 PP894

ICARO (IKA)

2 PK742
 

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ALERT ALERT

INDIAN AIR FORCE (IDF)

1 PH712–PH713

3 PM016–PM017

INDIAN AIRLINES (IND)

2 PK237–PK240 PM001–PM006 PY631

INTAL AIR (IRT)

2 PY242 PY274

INTER AIR (ITI)

1 PY046–PY047

INTERLEASE AVIATION (ILA)

1 PG210

INTERNATIONAL AIR LEASES (IAL)

1 PL803

INTERNATIONAL AIR PARTS (IAO)

1 PG580

INTERNATIONAL TRANSPORT (YIT)

1 PG304

INT'L AVIATION SERVICES GROUP (ISG)

2 PK318

ISRAEL AIRCRAFT INDUSTRIES (IAI)

1 PG575

2 PK692

JAL INTERNATIONAL (JAL)

8 PW411–PW418

JANCO AIRCRAFT AND ENGINES (JNC)

4 PM282–PM283

JAPAN TRANSOCEAN AIR (SWL)

7 PW401 PW515–PW516 PW520 PW681–PW683

8 PW402–PW408 PW521

JAT YUGOSLAV AIRLINES (JAT)

5 PP771–PP779 PQ241

7 PV023–PV024 PW092

JATAYU AIR (JAJ)

1 PG068

2 PJ117 PK257 PK511

4 PK937

JERRY CONWAY (JCW)

2 PK552
 

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ALERT ALERT

JET AIRWAYS (JPL)

7 PW215–PW216

8 PV207 PV209 PW421–PW424

JET FREIGHT (JFO)

5 PQ158 PQ161

JET MIDWEST (JMI)

2 PK558

JETALLIANCE (JFB)

6 PS862

JETCONNECT LIMITED (JCL)

5 PQ002 PQ007 PQ009 PQ011–PQ015

7 PW537–PW539

JETRAN INTERNATIONAL, LTD. (JTI)

1 PC005

2 PK306 PK592–PK593 PK601 PK605

PK607 PL552 PL557 PM103–PM105

3 PM118–PM119 PN035

5 PP009–PP010 PP013

7 PV041–PV043

JETSCAPE LEASING (IAN)

7 PW091

JETSTAR AIRCRAFT SALES (JTS)

1 PG306

JORDAN AVIATION (JOR)

4 PY410

5 PP896 PQ187

K.A.B. (KBH)

2 PK315

KALININGRADAVIA (JSK)

5 PP305 PP801 PP843–PP844 PP916

PQ302

KARTHAGO AIRLINES (KAG)

5 PP926 PP928 PP930

6 PQ432 PR029

KENYA AIRWAYS (KEN)

2 PK641–PK642 PY272

6 PR031–PR034

KITTY HAWK AIR CARGO (KHC)

5 PM382 PM396 PM405 PP847

PP862 PQ221 PQ223
 

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ALERT ALERT

KLM - ROYAL DUTCH AIRLINES (KLM)

5 PP861 PP863–PP866 PP868–PP869 PP871–PP875

6 PP876–PP877

7 PW014 PW017 PW611–PW622

KRASAIR (ZXD)

5 PQ792

LAB (LAB)

6 PQ951

LAC (CQC)

2 PY113

LAM (LAM)

4 PL455–PL456 PN451

LAN AIRLINES (LAN)

1 PJ104

2 PJ006 PJ105–PJ106 PJ109 PK212

PK431 PK433 PK524–PK525 PK745

PK775 PK902–PK903 PK908–PK912 PK914–PK916

PK921–PK923 PK927 PL025

LAPA ARGENTINA (LAZ)

2 PK051

LIBYAN AIRLINES (LAA)

2 PK361

LINA CONGO (LNA)

2 PY411

LINEAS AEREAS AZTECA (AZX)

5 PP802 PP915 PP923 PP983

PP986 PQ116

LION AIR (MLI)

7 PW016 PW023 PW025 PW027

PW037–PW038 PW042

LITHUANIAN AIRLINES (LIJ)

2 PK632 PL611

5 PT169

6 PT721 PT723 PT972–PT973

LOCALEASE (LLA)

2 PK282

LOCKHEED MARTIN (LMA)

5 PQ057
 

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ALERT ALERT

LOGISTIC AIR, INC. (LGA)

1 PY303–PY304

LOT POLISH AIRLINES (LOT)

5 PT651–PT656

6 PQ978 PQ980

7 PV281–PV284

8 PV285–PV286

LUFTHANSA GERMAN AIRLINES (DLH)

5 PQ060–PQ085 PQ092 PS701–PS703 PT331–PT360

6 PS704–PS706

LUXAIR (LUX)

5 PT671–PT672

MACEDONIAN AIRLINES, MACEDONIA (MCC)

5 PP043

MAERSK AIR (MRS)

6 PT135

MAGIC CARPET AVIATION (MCI)

5 PP991

MAGNICHARTERS (MAM)

2 PJ004 PK143 PK145 PK595

PL454 PL554 PL558

5 PQ028 PQ168

MALAYSIA AIRLINES (MAS)

7 PJ551–PJ556 PW201–PW214 PW217–PW230

8 PJ557–PJ561

MANDALA AIRLINES (MND)

2 PK354 PK463 PK614 PK636–PK637

PK874 PK925 PL027 PL061

PL421 PN002

7 PW004 PW010

MARANATHA LEASING CORPORATION (MNT)

1 PG436

2 PK201–PK202 PL011 PM062

MERPATI NUSANTARA AIRLINES (PNM)

2 PK615 PK623–PK624 PK819 PK917

PK929–PK930

MEXICAN AIR FORCE (MXA)

4 PN041

MEXICO'S PRESIDENTIAL AIRCRAFT (MXG)

5 PP919 PQ155
 

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ALERT ALERT

MNG AIRLINES (MHK)

7 PW282 PW285 PW512 PW514

PW593

NAT AVIATION U.S.A. (NTV)

2 PK258 PK551 PK557 PK732

NATIONWIDE AIRLINES (NWR)

2 PJ007–PJ008 PK357 PK741 PK871

PK906 PK928 PK932 PL631–PL632

PN107 PN109

5 PT612–PT613

NEWJET (NES)

2 PL172 PL562

NIGERIA AIRWAYS (NIA)

2 PL785 PL788

NORTHROP GRUMMAN CORPORATION (GRU)

1 PG208

NORTHSTAR PRESIDIO MANAGEMENT (INH)

2 PK094–PK095

NORWEGIAN AIR SHUTTLE AS (NSB)

10 PP807

5 PM381 PM389 PM401–PM402 PP805–PP806

PP808 PP918 PS654

6 PQ983 PQ985 PR002

NOVA AIR (PDM)

2 PL007 PL406

OLYMPIC AIRLINES (OLY)

11 PW063

2 PM022

5 PQ298

7 PW044 PW062 PW068 PW072

PW296 PW711–PW717 PW771

ORENBURG AIRLINES (ORG)

7 PW036

OZJET AIRLINES (OZJ)

2 PK041 PK052
 

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ALERT ALERT

PACE AIRLINES (PIE)

1 PG075 PG203

11 PW563

2 PL001 PL502–PL503 PN102 PN105

PN108

4 PN116

5 PP181–PP182 PP196 PP835 PP837

PP867 PP870

PAKISTAN INT'L AIRLINES (PIA)

5 PP281–PP286 PS612

PEGASUS AIRLINES (PGS)

11 PW030

8 PW263

PEGASUS AVIATION, INC. (PSS)

1 PL712

2 PK043 PK233 PK235 PL403

PL413

4 PK752 PK756

PEMCO WORLD AIR SERVICES (PEF)

5 PQ154

PERUVIAN AIR FORCE (PRF)

1 PG251 PG253 PG351

6 PT517

PHILIPPINE AIRLINES (PAL)

5 PM384 PM395 PQ803 PS601

7 PM561 PW029 PW156

PHOENIX AVIATION (PHX)

1 PG578–PG579

2 PK213–PK214 PK222 PK671 PK823

PK826 PK830

4 PM252

PHUKET AIRLINES (PHK)

1 PG581–PG582

3 PN037

4 PN039

PLM INTERNATIONAL (PLI)

2 PK675

PLUNA (PLU)

2 PL201–PL203

5 PQ287

PREMIER AIRLINES (PMN)

4 PN493
 

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ALERT ALERT

PULKOVO AIRLINES (STG)

5 PT164–PT166

Q AVIATION (QAV)

10 PQ189

2 PK288 PK603–PK604 PK883

5 PQ192 PT397

QANTAS (QAN)

5 PQ016

7 PW531–PW536 PW540–PW547 PW557

8 PW548–PW550

QWEST AIR PARTS (QWE)

1 PG438

REPEX AIRLINES (REX)

1 PY344

2 PY102–PY103

REPUBLIC FINANCIAL CORPORATION (RFC)

1 PA011 PG199 PG225 PG433

PG502–PG503 PG622 PG704

REPUBLIC OF INDONESIA (IDO)

2 PL601–PL602

3 PL603

REPUBLIC OF KOREA AIR FORCE (KAF)

5 PP221

REPUBLIC OF NIGER (NIR)

2 PY166

REPUBLIC OF VENEZUELA (VNZ)

2 PK070

REPUBLICAIR (RPB)

2 PL553 PL555

RICO (RLA)

2 PK119–PK120

ROYAL AIR MAROC (RAM)

2 PK271–PK272 PY671

3 PY672

5 PT581–PT584

6 PT585–PT586

ROYAL THAI AIR FORCE (TAF)

3 PK519

8 PV296
 

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ALERT ALERT

RUTACA AIRLINES (ZRU)

2 PK281 PK611 PK613

RYAN INTERNATIONAL AIRLINES (RYN)

2 PK097 PK543 PK602 PK606

PK608 PN106

RYANAIR (RYR)

2 PK503

RYM AIRLINES (RYM)

2 PL017–PL019

SAFAIR (SFA)

1 PY002

2 PK733 PK743 PK746 PK771

PL110

SAMCO AVIATION (SMO)

2 PL581

SAS BRAATHENS (BRT)

10 PT022

11 PW573

5 PT002–PT004 PT006–PT008 PT011–PT012 PT024–PT025

6 PT013–PT015

7 PW574 PW576

8 PV351

SAT AIRLINES (SKH)

2 PL221

SAUDI ARABIAN AIRLINES (SVA)

1 PL727–PL728 PY036

2 PK312 PK316–PK317 PL729–PL733 PL735

SEB MANAGEMENT CORPORATION (YNS)

5 PT219

SHAHEEN INTERNATIONAL (SHK)

2 PL003 PL551 PL561

SHANDONG AIRLINES (SHG)

5 PM413–PM414

6 PQ391–PQ395 PR007–PR009 PR013–PR014 PR161

9 PR006

SHANTOU AIRLINES (SHT)

5 PM415–PM417

SHEIKH MUSTAFA EDREES (SME)

2 PL505
 

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ALERT ALERT

SHENZHEN AIRLINES (SHZ)

5 PQ486 PS691–PS692 PS851–PS852

6 PQ972 PQ976 PQ995 PS629

SIBERIA AIRLINES (SBR)

5 PT381 PT388–PT389 PT396 PT401

PT420–PT421 PT430–PT431 PT433

SIERRA PACIFIC AIRLINES (SRP)

2 PK627 PL621

SILVER AIR (SARI) (SVT)

1 PL726

2 PK313–PK314 PL734

SKY AIRLINES (SYC)

7 PV235 PW001 PW278 PW281

PW293

SKY KING (SKN)

1 PG059

2 PK351–PK353 PK696 PL002 PL006

SKY SERVICE (SSV)

1 PL736 PL740

2 PK628–PK629 PK881 PK884 PK971

PK973

4 PK526–PK527

SKYEUROPE (SKP)

5 PT050–PT051 PT054 PT056–PT057 PT147–PT148

6 PR162–PR166

SKYNET ASIA AIRWAYS (SNU)

7 PM555

8 PW274 PW855–PW856

SLOK AIR (SRO)

2 PM108–PM113

SLOVAK AIRLINES (SLV)

5 PP851 PP903

SOUTH AFRICAN AIRWAYS (SAA)

2 PK774 PK776 PL102 PL104–PL109

PL112–PL113

SOUTHERN AIRCRAFT SERVICES (HUZ)

2 PL471

SOUTHERN WINDS (SOW)

2 PJ005 PK029 PK047 PK116

PK146 PK253 PK616
 

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ALERT ALERT

SOUTHWEST AIRLINES (SWA)

5 PP101–PP169 PP188 PP190–PP193 PP202–PP205

PP301–PP304 PP351 PP353 PP376–PP382

PP402–PP403 PP501–PP502 PP727 PP731

PP803–PP804 PP821–PP824 PP827 PS751–PS778

PU001–PU025

6 PS779–PS799 PS901–PS941

SPACE WORLD AIRLINE/SWA (WIN)

2 PL021–PL022

SRIWIJAYA AIR (SJA)

2 PK304 PN023 PN026–PN027

4 PL746 PM254

STA SUPPLIES PTE. LTD. (SSP)

5 PQ040–PQ041

STAR AIR (SRH)

2 PK777 PL744

4 PN040 PN042–PN043

STAR UP S.A. (SRU)

2 PY101

STERLING EUROPEAN AIRLINES (STR)

5 PT121 PT125

6 PT127 PT132–PT134

SUNDOWNER OKLAHOMA CITY LLC (SDO)

5 PP514 PS653

7 PW313 PW316

TAAG (ANGOLA AIRLINES) (ANG)

2 PK661 PK664 PY162

4 PK665–PK666

TACA INTERNATIONAL AIRLINES (TAC)

1 PL737

TAF AEREAS LINHAS (TFL)

1 PY323 PY342

2 PK118

TANS (TAX)

2 PK113 PL101 PL103 PN082

TAROM - ROMANIAN AIR TRANSPORT (TRM)

5 PQ931–PQ934

6 PQ935

TEEBAH AIRLINES (EBH)

2 PN028
 

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ALERT ALERT

THAI AIRWAYS INTERNATIONAL (TII)

7 PW161–PW162 PW164–PW167 PW594

8 PW168–PW171

THE PEGASUS AVIATION COMPANY (PEG)

2 PK285

THOMSONFLY (BRI)

5 PT123–PT124 PT181–PT182

6 PQ436–PQ437 PR011 PR024

9 PR023

TITAN AIRWAYS (TIU)

5 PM387 PP505 PS620

TNT AIRWAYS (TNB)

5 PP384 PP391 PP414 PP416

PP702 PP711

TRANS AIR CONGO (TSC)

2 PY243

TRANSAERO AIRLINES (TRX)

2 PK451–PK452 PK773 PK779

5 PP963 PP966

7 PW024 PW040 PW113 PW120

TRANSMILE AIR SERVICES (TML)

1 PY381

2 PY151

4 PN472 PN474

TRAVEL SERVICE (TSF)

5 PT432 PT436

7 PW006

TRITON AVIATION SERVICES (TIA)

1 PJ101 PJ103

2 PK674 PK677–PK678 PL408 PL411

PL770 PN101

TUI AIRLINES BELGIUM (TLB)

7 PW511 PW513

8 PW522

TUNISAIR (TUN)

2 PK861–PK863 PY621

5 PT641–PT643

6 PT644
 

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ALERT ALERT

TURKISH AIRLINES (THY)

7 PM552–PM553 PM557 PM559–PM560 PM562–PM564

PW012 PW018–PW019 PW045 PW049–PW050

PW287

8 PW290–PW291

TURKMENISTAN AIRLINES (TUE)

5 PQ265 PQ801–PQ802

UKRAINE INTERNATIONAL AIRLINES (UKR)

5 PQ251 PT055 PT059

6 PQ991 PR042 PR181

7 PM551 PW701–PW702

UNICAPITAL AIR GROUP (UAG)

2 PK695

UNITED AIRLINES (UAL)

1 PG024 PG052 PG054–PG055 PG057

PG067 PG069–PG071

2 PL004–PL005 PL009 PL012 PL014–PL016

PL020

5 PQ101–PQ115 PQ118 PQ120–PQ122 PQ125–PQ143

PQ146–PQ151 PQ164–PQ167 PQ169–PQ183 PQ185–PQ186

PQ198–PQ199 PQ201–PQ202 PT382–PT387 PT390–PT395

PT398–PT399 PT402–PT419 PT422–PT423

UNIVERSAL ASSET MANAGEMENT (UAM)

2 PM054 PM056–PM061

US AIR FORCE (USF)

2 PJ202 PJ206 PJ211 PJ213–PJ217

PJ219

US AIRWAYS (USA)

11 PV032 PV038

2 PK597 PK609 PM114

5 PP003–PP008 PP012 PP014–PP020 PP024–PP027

PP030–PP032 PP034–PP042 PP045–PP054 PP401

PP404–PP405 PP410 PP413 PP415

PP417–PP418 PP422–PP429 PP431–PP440

7 PV001–PV010 PV012–PV022 PV025–PV031 PV033–PV037

PV039–PV040 PV044–PV055

UT FINANCE CORPORATION (ZZJ)

5 PQ153
 

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ALERT ALERT

VARIG AIRLINES (VAR)

10 PQ331

2 PK111–PK112 PK114 PK144 PK211

5 PP839 PP905–PP906 PP917 PP921–PP922

PP927 PP981–PP982 PP987–PP990 PQ227

PQ256–PQ259 PQ266–PQ267 PQ290 PQ303

PS619 PT058 PT212–PT213 PT216–PT218

PT220

6 PR043–PR044 PR132 PS624 PS627

PS872 PT724–PT725 PT854

7 PV201–PV202 PW008 PW118

VASP AIRLINES (VSP)

1 PG472

2 PK581

VIRGIN EXPRESS AIRLINES (EBA)

5 PS656

6 PQ984 PQ989 PQ993 PS972

7 PW013 PW571–PW572

8 PW271 PW275

VIRGIN NIGERIA (VNA)

6 PQ982

VISION AIR (VEG)

6 PS626

WEBJET LINHAS AEREAS LTDA. (WJL)

5 PP679 PS603

WELLS FARGO (FSB)

1 PL741

2 PJ110–PJ111

WESTAIR CARGO AIRLINES (WCO)

1 PY037

WESTJET (WJI)

2 PJ108 PJ113 PK241 PK713–PK714

PK716 PL171

4 PK565

XIAMEN AIRLINES (XIA)

5 PQ295–PQ296 PQ471 PQ493 PT026–PT029

6 PT030–PT031
 

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ALERT ALERT

IDENTIFICATION BY VARIABLE NUMBER

Variable Group

PA001–PA022 1

PA099 1

PA231–PA232 1

PC001–PC005 1

PG001–PG075 1

PG199 1

PG201–PG230 1

PG251–PG255 1

PG271–PG279 1

PG301–PG314 1

PG331–PG332 1

PG351–PG356 1

PG375 1

PG401–PG403 1

PG431–PG442 1

PG471–PG475 1

PG501–PG505 1

PG571–PG586 1

PG621–PG630 1

PG651–PG652 1

PG701–PG705 1

PH001 2

PH011–PH013 2

PH021–PH024 2

PH701–PH715 1

PH731–PH732 1

PH741–PH742 1

PH743 2

PJ001–PJ002 1

PJ003–PJ009 2

PJ031–PJ032 1

PJ071–PJ072 1

PJ101–PJ104 1

PJ105–PJ119 2

PJ201–PJ219 2

PJ301–PJ302 7

PJ551–PJ556 7
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PJ557–PJ561 8

PJ601–PJ615 8

PJ811 8

PJ816–PJ817 8

PK026–PK029 2

PK041–PK053 2

PK061–PK070 2

PK081–PK082 2

PK091–PK099 2

PK101–PK103 2

PK111–PK120 2

PK141–PK146 2

PK201–PK204 2

PK211–PK215 2

PK216–PK220 4

PK221–PK223 2

PK231–PK241 2

PK251–PK258 2

PK271–PK274 2

PK281–PK289 2

PK291 2

PK301–PK318 2

PK341 2

PK351–PK361 2

PK391 2

PK431–PK433 2

PK451–PK452 2

PK461–PK469 2

PK495 2

PK501–PK504 2

PK511–PK514 2

PK515 4

PK519 3

PK521–PK525 2

PK526–PK528 4

PK541–PK564 2

PK565 4

PK581 2

PK591–PK599 2

Variable Group
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PK601–PK617 2

PK621–PK637 2

PK641–PK642 2

PK661–PK664 2

PK665–PK666 4

PK671–PK680 2

PK681 4

PK691–PK697 2

PK711–PK716 2

PK731–PK749 2

PK750–PK765 4

PK771–PK779 2

PK801–PK804 2

PK819–PK827 2

PK830 2

PK861–PK863 2

PK871–PK874 2

PK881–PK884 2

PK901–PK932 2

PK933–PK938 4

PK971–PK974 2

PL001–PL028 2

PL061 2

PL081 2

PL101–PL113 2

PL151 2

PL171–PL172 2

PL201–PL203 2

PL221 2

PL401–PL417 2

PL421 2

PL441 2

PL451–PL454 2

PL455–PL456 4

PL471 2

PL491 2

PL501–PL506 2

PL551–PL562 2

PL581 2

Variable Group
 

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

PL601–PL602 2

PL603 3

PL611 2

PL621–PL623 2

PL624–PL626 4

PL631–PL632 2

PL711–PL712 1

PL716 1

PL717–PL725 2

PL726–PL728 1

PL729–PL735 2

PL736–PL742 1

PL743–PL745 2

PL746–PL747 4

PL756 1

PL758 2

PL761 1

PL762–PL770 2

PL781–PL788 2

PL793 2

PL801–PL803 1

PM001–PM006 2

PM016–PM017 3

PM021–PM023 2

PM051–PM062 2

PM063–PM066 4

PM101–PM117 2

PM118–PM119 3

PM141–PM142 2

PM171 4

PM181 4

PM251–PM255 4

PM281–PM283 4

PM381–PM390 5

PM391 10

PM392–PM399 5

PM401–PM417 5

PM541–PM550 5

PM551–PM564 7

Variable Group
June 30, 1994

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PN001–PN002 2

PN021–PN028 2

PN029–PN038 3

PN039–PN043 4

PN081–PN083 2

PN084–PN086 3

PN101–PN112 2

PN113–PN117 4

PN131–PN135 3

PN136–PN163 4

PN401–PN420 4

PN431–PN433 4

PN451–PN456 4

PN471–PN474 4

PN481 4

PN491–PN493 4

PN501–PN502 4

PN511–PN512 4

PN521 4

PP001–PP054 5

PP101–PP169 5

PP181–PP199 5

PP201–PP205 5

PP221 5

PP231–PP243 5

PP281–PP286 5

PP301–PP305 5

PP351–PP353 5

PP376–PP384 5

PP391–PP393 5

PP401–PP440 5

PP471–PP475 5

PP501–PP519 5

PP520 6

PP521–PP522 5

PP631–PP634 5

PP651–PP652 5

PP671–PP699 5

PP701–PP733 5

Variable Group
June 30, 1994

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PP771–PP779 5

PP801–PP806 5

PP807 10

PP808 5

PP821–PP827 5

PP831–PP848 5

PP851–PP852 5

PP861–PP875 5

PP876–PP877 6

PP891–PP899 5

PP901–PP936 5

PP946–PP948 5

PP951–PP952 5

PP961–PP967 5

PP981–PP991 5

PP993 5

PQ001–PQ016 5

PQ026–PQ041 5

PQ051–PQ092 5

PQ101–PQ188 5

PQ189 10

PQ190 5

PQ191 10

PQ192–PQ199 5

PQ201–PQ202 5

PQ221–PQ237 5

PQ241–PQ243 5

PQ251–PQ267 5

PQ281–PQ299 5

PQ301–PQ303 5

PQ304 10

PQ305–PQ307 5

PQ331 10

PQ332 5

PQ341–PQ344 5

PQ345–PQ348 6

PQ361–PQ371 5

PQ372–PQ373 6

PQ391–PQ395 6

Variable Group
 

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

PQ401–PQ413 5

PQ414–PQ415 6

PQ416 8

PQ417–PQ418 6

PQ421 5

PQ431 5

PQ432–PQ438 6

PQ447–PQ448 6

PQ451 6

PQ454 6

PQ471–PQ474 5

PQ475 6

PQ479–PQ481 5

PQ486–PQ487 5

PQ491–PQ493 5

PQ771–PQ772 5

PQ791–PQ793 5

PQ801–PQ805 5

PQ931–PQ934 5

PQ935 6

PQ951 6

PQ971–PQ997 6

PR001–PR005 6

PR006 9

PR007–PR017 6

PR021–PR022 6

PR023 9

PR024–PR034 6

PR041–PR045 6

PR061–PR072 6

PR077–PR082 6

PR091–PR092 6

PR096 6

PR101 6

PR121–PR122 6

PR131–PR132 6

PR141–PR143 6

PR161–PR172 6

PR181 6

Variable Group
 

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

PS601–PS620 5

PS621–PS630 6

PS631 5

PS636–PS638 5

PS641–PS644 5

PS651–PS657 5

PS666–PS669 5

PS691–PS692 5

PS701–PS703 5

PS704–PS706 6

PS751–PS778 5

PS779–PS799 6

PS811 6

PS836–PS837 5

PS841–PS844 5

PS845–PS846 6

PS851–PS852 5

PS856 5

PS861–PS863 6

PS866–PS868 6

PS871–PS874 6

PS896–PS897 6

PS901–PS941 6

PS956–PS957 6

PS961–PS963 6

PS971–PS978 6

PT001–PT012 5

PT013–PT015 6

PT021 5

PT022 10

PT023–PT029 5

PT030–PT031 6

PT041–PT064 5

PT101 10

PT102–PT105 5

PT121–PT125 5

PT126–PT138 6

PT146–PT148 5

PT161–PT170 5

Variable Group
 

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

PT181–PT188 5

PT211 10

PT212–PT220 5

PT295 10

PT301–PT309 5

PT331–PT360 5

PT381–PT399 5

PT401–PT438 5

PT501–PT514 5

PT515–PT517 6

PT561–PT565 5

PT581–PT584 5

PT585–PT586 6

PT611–PT621 5

PT641–PT643 5

PT644 6

PT651–PT656 5

PT671–PT672 5

PT681–PT682 6

PT683 9

PT684–PT685 6

PT701–PT703 5

PT716–PT717 6

PT721–PT725 6

PT801–PT818 5

PT819–PT825 6

PT826–PT828 5

PT829–PT834 6

PT851 5

PT852–PT854 6

PT871–PT886 6

PT901–PT930 6

PT971–PT973 6

PT981–PT985 6

PT996 6

PU001–PU025 5

PU301 6

PU311–PU313 6

PV001–PV031 7

Variable Group
 

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

PV032 11

PV033–PV037 7

PV038 11

PV039–PV055 7

PV201–PV203 7

PV204–PV209 8

PV226–PV229 8

PV231–PV237 7

PV271–PV272 7

PV281–PV284 7

PV285–PV287 8

PV296 8

PV301–PV302 8

PV351 8

PV356–PV357 8

PW001–PW029 7

PW030 11

PW031–PW054 7

PW061–PW062 7

PW063 11

PW064–PW068 7

PW072 7

PW086–PW088 8

PW091–PW094 7

PW101–PW102 7

PW106 7

PW111–PW120 7

PW156–PW157 7

PW161–PW167 7

PW168–PW171 8

PW201–PW249 7

PW250–PW252 8

PW261–PW262 7

PW263–PW264 8

PW265–PW268 7

PW271–PW276 8

PW278 7

PW281–PW288 7

PW289–PW292 8

Variable Group
 

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

PW293 7

PW296 7

PW301–PW327 7

PW401 7

PW402–PW408 8

PW411–PW418 8

PW421–PW424 8

PW431–PW435 8

PW441–PW450 8

PW461–PW467 7

PW501–PW502 7

PW503 11

PW504 7

PW511–PW517 7

PW518 11

PW519–PW520 7

PW521–PW522 8

PW524–PW525 8

PW526–PW527 7

PW528–PW530 8

PW531–PW547 7

PW548–PW550 8

PW556–PW557 7

PW561–PW562 7

PW563 11

PW564 7

PW571–PW572 7

PW573 11

PW574–PW576 7

PW591–PW596 7

PW611–PW622 7

PW631 7

PW632 11

PW633–PW636 7

PW637 8

PW661–PW662 7

PW681–PW683 7

PW701–PW702 7

PW711–PW717 7

Variable Group
 

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

PW741–PW742 7

PW761 7

PW771 7

PW831 8

PW851–PW856 8

PX071 1

PX701 1

PY001–PY008 1

PY021 1

PY022 2

PY031 1

PY036–PY037 1

PY046–PY047 1

PY048 2

PY051–PY053 2

PY056–PY057 3

PY101–PY103 2

PY111–PY113 2

PY131–PY135 2

PY141–PY143 2

PY151–PY154 2

PY156–PY157 2

PY161–PY162 2

PY166 2

PY191 2

PY201 2

PY221–PY222 2

PY231 2

PY241–PY244 2

PY270–PY275 2

PY281 2

PY286 2

PY301–PY304 1

PY321–PY323 1

PY341–PY346 1

PY361–PY362 1

PY381 1

PY401 2

PY409–PY410 4

Variable Group
 

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

2. Spares Affected

None.

B. Concurrent Requirements

None.

C. Reason

The changes shown in this service bulletin will decrease the probability of cracks in the frame at STA 

727 where Stringer (S)-18A is attached. This area is a primary structural element. Operation with 

cracks in the frame will decrease the structural integrity of this area. Unscheduled downtime can be 

necessary to replace a frame that has a crack. Cracks in the S-18A chord are not a safety concern.

Several operators have reported numerous cracks on multiple airplanes in the STA 727 frame 

outboard chord, where the S-18A outboard chord is attached. The cracks ranged from 0.016 inches, 

to a severed chord. Cracks initiate common to the 3 fastener holes or close vicinity to the fastener 

holes and on the forward edge of the frame outboard chords. For the fastener holes susceptible to 

cracking, several elongated holes were also found. Airplanes have accumulated between 20,000 - 

85,000 flight-cycles and 27,000 - 74,000 flight hours. Previous revisions of this service bulletin 

inspected for cracks on airplanes with 7075-T6 frame outboard chords (Line Number 1-999) only. 

Since the release of Rev 1, seven operators have reported cracks in 7075-T73 chords with 20,000 - 

52,000 flight-cycles. As a result of these new findings, this revision of the service bulletin expands the 

effectivity to include airplanes with 7075-T73 frame outboard chords. The cracks were caused by 

fatigue; for line number 1-999 airplanes (7075-T6 frame outboard chord), fretting of adjacent parts 

contributed to the initiation of the fatigue damage.

Three operators have reported four cracks in the radius of the 65-46547-9 Auxiliary Chord on three 

airplanes. 1.00 inch cracks were reported. Airplanes have accumulated between 46,000 - 85,000 

flight-cycles and 41,000 - 64,000 flight hours.

PY411 2

PY421–PY422 2

PY441 2

PY451 2

PY461–PY462 2

PY463 4

PY591–PY595 4

PY611–PY612 2

PY621 2

PY631 2

PY651 2

PY671 2

PY672 3

PY721 4

PY741 2

Variable Group
 

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

Several operators have reported numerous cracks on multiple aircraft in the S-18A outboard chord 

common to the fastener locations just aft of STA 727. Airplanes have accumulated between 30,000 - 

76,000 flight-cycles and 32,000 - 65,000 flight hours. One operator found one crack on one airplane 

in the S-18A chord, forward of STA 727 in the lower fastener row. The aircraft had 68,000 flight-cycles 

and 71,000 flight hours. Cracks have been found in S-18A chord sections at STA 727 of a thickness 

of 0.33 inches or less. The cracks were caused by fatigue.

Four operators have reported four cracks on three aircraft with a "T" profile S-18A outboard chord. The 

vertical flange of the chord has cracked at the base, at the vertical flange run-out, near STA 727. 

These cracks can grow along the base of the vertical flange in the radius. These cracks have been 

associated with S-18A outboard chord installation pre-loads.

Boeing Service Related Problem (SRP) 737-SRP-53-0162 is related to this service bulletin.

Boeing Supplemental Structural Inspection Document D6-37089, Section 8.2, SSI Number F.29, is 

related to this service bulletin.

Boeing Structural Item Interim Advisory (SIIA) 737-131 is related to this service bulletin.

Boeing Structural Item Interim Advisory (SIIA) 737-44, 737-60, 737-74, 737-194, 737-274 impact the 

area of this bulletin but are not related.

Federal Aviation Administration (FAA) Airworthiness Directive AD 95-12-17, is related to this service 

bulletin. The FAA is considering additional rule making that will make the compliance tasks and times 

given in Revision 2 of this Service Bulletin mandatory.

Revision 1 was sent to add a S-18A outer chord repair. In addition, instructions were added, to trim 

the "Time Limited Repair" parts, to eliminate interference with fasteners.

Revision 2 is sent to revise inspections, repairs, modifications and parts fabrication and to expand the 

airplane effectivity to cover all 737-100/200/300/400/500 series airplanes. Additional inspections are 

added to address new cracks found in the STA 727 outboard chord frame, STA 727 frame auxiliary 

chord and the stringer S-18A outboard chord. Instructions are added to modify the STA 727 frame 

time-limited repair into a permanent repair. Instructions are added to install a preventive modification 

for the S-18A outboard chord.

Changes to this revision include:

— Planning Information - The service history information relating to the new cracks is updated. All 

references are updated to reflect the inclusion of 737-300/400/500 series airplanes into the 

effectivity.

— Material Information - New top kits are added to this service bulletin revision.

— Accomplishment Instructions - Instructions are added to do new inspections, repairs and 

modifications.

— Figures 1, 2, 3, 4, 5 and 6 are deleted.

— Figures 7, 8, 9, 10, 11, 12, 13, 14, 16, 21, 22 and 24 are added to show new inspections.

— Figure 15 is added to show access for the Time-limited repair.

— Figure 17 is added to show the fabrication of parts for the Time-limited repair.

— Figure 18 is added to show the installation of the Time-limited repair.

— Figure 19 is added to show the removal of the Time-limited repair.

— Figures 20 is added to show fabrication of the Time-limited repair replacement parts.

— Figures 23 is added to show installation of the Shear Beam Repair.

— Appendix A is revised to show the new compliance data.
 

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

As part of a service bulletin validation program, the inspection, frame chord replacement, and 

preventive modification was completed on airplane PG576 before the initial release of this bulletin.

D. Description

The airplane effectivity is divided in 11 groups because of differences in airplane configuration. Do the 

inspections that follow at the times given in the Compliance section.

Do an external (wheel well) ultrasonic inspection of the STA 727 frame outboard chord at S-18A. Do 

an external (wheel well) HFEC inspection of the STA 727 frame outboard chord at S-18A. Do a 

detailed inspection for loose fasteners common to the four holes of the STA 727 frame outboard chord, 

forward flange at S-18A. Do an open hole eddy current inspection for cracks and a detailed inspection 

for hole elongation in stringer S-18A. Do these inspections as shown in PART 1 of the 

Accomplishment Instructions at the times given in the Compliance section.

As part of the accomplishment of this Service Bulletin, a frame chord replacement may be required. 

Boeing Service Bulletin 737-53-1088 Revision 1, dated May 25, 2006 in conjunction with this service 

bulletin provides instructions on the STA 727 frame outboard chord replacement. Boeing Service 

Bulletin 737-53-1088 Revision 1, dated May 25, 2006 replaces the STA 727 frame outboard chord in 

two parts, an upper and lower outboard chord segment. Only the upper STA 727 frame outboard chord 

segment replacement is required to satisfy the requirements of this service bulletin. 

NOTE:Boeing recommends that the STA 727 frame outboard chord preventive modification be 

installed with the replaced STA 727 frame outboard chord. Operators may install the STA 727 

frame outboard chord modification at a later time, however inspections may be required and 

increased installation costs will be incurred. Boeing also recommends replacing both chord 

segments at the same time. Replacing both chord segments at the same time will reduce 

inspection requirements and task hours required to perform the STA 727 frame outboard chord 

replacement.

If cracks are found in the STA 727 frame outboard chord, replace the frame outboard chord and 

optionally add the preventive modification, or install the time-limited frame chord repair as shown in 

this service bulletin before any more flights or ask Boeing for repair data.

If the preventive modification is installed on a new or crack free existing STA 727 frame outboard 

chord where the final edge margins are equal to or greater than 1.7D, then the modification is 

permanent and inspection requirements are terminated.

If the preventive modification is installed on a new or crack free existing STA 727 frame outboard 

chord where the final edge margins are equal to or greater than 1.5D but less than 1.7D, then do a 

one-time HFEC hole inspection as shown in PART 8 of the Accomplishment Instructions at the times 

given in the Compliance section.

If a new or crack free existing STA 727 frame outboard chord is installed without the preventive 

modification then perform inspections as shown in PART 1 of the Accomplishment Instructions at the 

times given in the Compliance section.

As an option to the STA 727 frame outboard chord replacement, a time-limited repair can be fabricated 

and installed. A time-limited repair can be used to repair cracks that extend from the forward edge of 

the STA 727 frame outboard chord, or from the forward fastener hole, but do not extend past the 

second fastener hole aft on the forward flange. The time-limited repair angle replaces the forward 

splice angle of the STA 727 frame outboard chord if a chord replacement kit has been previously 

installed per Boeing Service Bulletin 737-53-1088.
 

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

NOTE:The time-limited repair is intended to provide an option if a replacement chord is not available 

in a timely manner. Boeing recommends that a replacement chord be used whenever possible. 

The time-limited repair will result in additional work and future chord replacement.

Within 4500 flight cycles after the time-limited repair was installed, remove the repair and perform a 

STA 727 frame outboard chord replacement using additional instructions provided in the 

accomplishment instructions and optionally add the preventive modification as previously described, 

including an evaluation of the chord’s condition.

If no cracks are found in the STA 727 frame outboard chord, then continue inspections as shown in 

the accomplishment instructions or optionally add the preventive modification as shown in this service 

bulletin. 

NOTE:Boeing recommends that the stringer S-18A outboard chord preventive modification be 

installed when the STA 727 frame outboard chord preventive modification is installed. 

To convert a modification with inspection requirements to a permanent modification, ask Boeing for 

repair instructions.

NOTE:This conversion will likely use a STA 727 frame outboard chord replacement with the 

installation of a modification strap.

Do an internal (cargo hold) detailed and eddy current inspection of the STA 727 frame auxiliary chord 

for cracks in the radius, between stringer S-17 and S-23 (end of chord) per PART 1 of the 

Accomplishment Instructions at times given in the compliance section.

If cracks are found, repair before further flight. Contact Boeing for repair data.

NOTE:A local repair will be provided to address the STA 727 frame auxiliary chord cracks.

Report airplane flight-cycles, crack length, location and growth direction to Boeing for any size cracks 

in the STA 727 frame auxiliary chord. Provide photographs if possible.

If no cracks are found, and a permanent frame chord modification has not been installed, continue 

inspections as shown in PART 1 of the Accomplishment Instructions at times given in the Compliance 

section. If no cracks are found, repeat auxiliary chord inspections until the frame chord is replaced with 

7075-T73 and modified per PART 6 of the Accomplishment Instructions.

Do an external detailed inspection of the S-18A outboard chord at STA 727 for cracks. Do an external 

surface HFEC inspection of the S-18A outboard chord at STA 727 for cracks.

Do a surface eddy current inspection on airplanes that have a "T" profile on the stringer outboard 

chord. Inspect the run-out of the vertical flange across the run-out face and the radii on both sides of 

the flange from the run-out to two inches forward.

Perform these inspections per PART 2 of the Accomplishment Instructions at times given in the 

Compliance section.

If cracks are found in the S-18A outboard chord, install the S-18A outboard chord permanent repair 

as shown in this service bulletin before further flight or ask Boeing for repair instructions. Inspection 

requirements for S-18A outboard chord are terminated once the S-18A chord is repaired.
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

If no cracks are found, continue inspections as shown in PART 2 Accomplishment Instructions. 

Optionally install the S-18A outboard chord preventive modification. The S-18A outboard chord 

preventive modification is permanent and inspection requirements for the S-18A outboard chord are 

terminated.

NOTE:Boeing recommends that the S-18A outboard chord preventive modification be installed when 

the STA 727 frame outboard chord preventive modification is installed.

More work is necessary for operators that have replaced the chord as shown in the initial release of 

Service Bulletin 737-53-1088. Refer to Paragraph 1.E., Compliance of this service bulletin.

Airplanes modified or repaired per a previous issue require additional inspections.

NOTE:

1. The changes given in Boeing Service Bulletin 737-53A1039, "Fuselage - Skin Lap Joint 

Inspection and Repair" can be made on applicable airplanes before or during the changes 

given in this service bulletin.

2. The changes given in Boeing Service Bulletin 737-53-1066, "Fuselage - Stringer 18A 

Shear Beam Inspection, Repair and Modification", can be made on applicable airplanes 

before or during the changes given in this service bulletin.

3. The changes given in Boeing Service Bulletin 737-53-1076, "Fuselage - Circumferential 

Butt Splices and Bonded Doublers Inspection, Repair and Modification", can be made on 

applicable airplanes before or during the changes given in this service bulletin.

4. The changes given in Boeing Service Bulletin 737-53-1077, "Fuselage - Skin Inspection, 

Repair, and Modification Aft of Body Station 727 Between Stringer S-18 and S-21", can be 

made on applicable airplanes before or during the changes given in this service bulletin.

5. The changes given in Boeing Service Bulletin 737-53-1089, "Fuselage - Skin Cracks at 

Stringer 17 Inspection and Preventive Modification", can be made on applicable airplanes 

before or during the changes given in this service bulletin.

6. The changes given in Boeing Service Bulletin 737-53-1124, "Fuselage - Bonded Doublers 

(Tear Straps) - Inspection and Repair - For Delamination above Stringer 26 Between 

Stations 259 and 1016", can be made on applicable airplanes before or during the 

changes given in this service bulletin.

PLEASE SEND A REPORT OF YOUR INSPECTION PROGRAM. ALSO, SEND THE INSPECTION 

RESULTS WHEN EACH INSPECTION IS COMPLETE. REFER TO THE FLIGHT SAFETY SECTION 

IN THE ADDENDUM.
 

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

E. Compliance

This bulletin has a Flight Safety Inspection Program that is the minimum necessary to keep the 

structural integrity of the STA 727 frame outboard chord. 

Table 1 inspection of the S-18A outboard chord is recommended as an economic inspection to find 

cracks prior to causing extensive damage needing a costly repair.

Table 2 through 5 inspections of the STA 727 frame and auxiliary chord are required inspections to 

maintain safety of flight.

Group 1-6, 9 and 10: Table 1 - Inspection for cracks in S-18A Outboard Chord with a thickness of 0.33 inches

or less (Recommended Economic Inspection)

Condition Action

Threshold (which ever occurs 

later) Repeat Interval 

(Not to Exceed 

Flight Cycles)

Terminating 

action for 

Repeat 

Inspection

Total Airplane 

Flight Cycles

Airplane Flight 

Cycles

No 

previous 

inspections

Detailed Inspection 

as shown in 

Accomplishment 

Instructions, 

Paragraph 3.B., 

PART 2 - Economic 

Inspection Program

27,000 5,000 after the 

date of this 

Service Bulletin 

Revision 2

5,000 Repair or 

modification of the 

S-18A Outboard 

Chord as shown 

in 

Accomplishment 

Instructions, 

Paragraph 3.B., 

PART 5 - S-18A 

Outboard Chord 

Repair or 

Paragraph 3.B., 

PART 7 - S-18A 

Outboard Chord 

Preventive 

Modification

Eddy Current 

Inspection as 

shown in 

Accomplishment 

Instructions, 

Paragraph 3.B., 

PART 2 - Economic 

Inspection Program

42,000 20,000 after the 

date of this 

Service Bulletin 

Revision 2

15,000

Inspected 

as given in 

a previous 

release of 

this Service 

Bulletin

Detailed Inspection 

as shown in 

Accomplishment 

Instructions, 

Paragraph 3.B., 

PART 2 - Economic 

Inspection Program

- At next repeat 

interval as given in 

this service 

bulletin, Revision 

1 or original issue, 

or within 5,000 

after Revision 2 

release, whichever 

is sooner.

5,000 Repair or 

modification of the 

S-18A Outboard 

Chord as shown 

in 

Accomplishment 

Instructions, 

Paragraph 3.B., 

PART 5 - S-18A 

Outboard Chord 

Repair or 

Paragraph 3.B., 

PART 7 - S-18A 

Outboard Chord 

Preventive 

Modification

Eddy Current 

Inspection as 

shown in 

Accomplishment 

Instructions, 

Paragraph 3.B., 

PART 2 - Economic 

Inspection Program

- At next repeat 

interval as given in 

this service 

bulletin, Revision 

1 or original issue, 

or within 20,000 

after Revision 2 

release, whichever 

is sooner.

15,000
June 30, 1994

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Groups 1-11 Configuration 4: Table 2 - Inspection for cracks in STA 727 Frame Outboard Chord for airplanes

with original production frame chord and without the STA 727 Frame Modification Installed (Required minimum

for safety)

Condition Action

Threshold (which ever occurs 

later) Repeat Interval 

(Not to Exceed 

Flight Cycles)

Terminating 

action for 

Repeat 

Inspection

Total Airplane 

Flight Cycles

Airplane Flight 

Cycles

No 

previous 

inspections

Ultrasonic and 

surface HFEC 

Inspections as 

shown in 

Accomplishment 

Instructions, 

Paragraph 3.B., 

PART 1 - Flight 

Safety Inspection 

Program

27,000 5,000 after the 

date of this 

Service Bulletin 

Revision 2

5,000 Modification of the 

STA 727 

Outboard Chord 

as shown in 

Accomplishment 

Instructions, 

Paragraph 3.B., 

PART 6 - STA 727 

Frame Outboard 

Chord Preventive 

Modification Open hole Eddy 

Current Inspection 

as shown in 

Accomplishment 

Instructions, 

Paragraph 3.B., 

PART 1 - Flight 

Safety Inspection 

Program

27,000 10,000 after the 

date of this 

Service Bulletin 

Revision 2

15,000

Inspected 

as given in 

a previous 

release of 

this Service 

Bulletin

Ultrasonic and 

surface HFEC 

Inspections as 

shown in 

Accomplishment 

Instructions, 

Paragraph 3.B., 

PART 1 - Flight 

Safety Inspection 

Program

- At next repeat 

interval as given 

in this service 

bulletin, Revision 

1 or original 

issue, or within 

5,000 after 

Revision 2 

release, 

whichever is 

sooner.

5,000 Modification of the 

STA 727 

Outboard Chord 

as shown in 

Accomplishment 

Instructions, 

Paragraph 3.B., 

PART 6 - STA 727 

Frame Outboard 

Chord Preventive 

Modification

Open hole Eddy 

Current Inspection 

as shown in 

Accomplishment 

Instructions, 

Paragraph 3.B., 

PART 1 - Flight 

Safety Inspection 

Program

- At next repeat 

interval as given 

in this service 

bulletin, Revision 

1 or original 

issue, or within 

10,000 after 

Revision 2 

release, 

whichever is 

sooner.

15,000
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

Groups 1-11 Configuration 1: Table 3 - Inspection for cracks in the STA 727 Frame Outboard Chord for

airplanes with the Outboard Chord replaced without the Modification of the STA 727 Frame Outboard Chord

accomplished. (Required minimum for safety)

Condition Action

Threshold (which ever occurs 

later)

Repeat Interval 

(Not to Exceed 

Flight Cycles)

Terminating 

action for Repeat 

Inspection

Total Airplane 

Flight Cycles 

After Chord 

Replacement 

Airplane Flight 

Cycles

No previous 

inspections

Ultrasonic, LFEC 

and edge HFEC 

Inspections as 

shown in 

Accomplishment 

Instructions, 

Paragraph 3.B., 

PART 1 - Flight 

Safety Inspection 

Program

27,000 5,000 after the 

date of this 

Service Bulletin 

Revision 2

5,000 Modification of the 

STA 727 Outboard 

Chord as shown in 

Accomplishment 

Instructions, 

Paragraph 3.B., 

PART 6 - STA 727 

Frame Outboard 

Chord Preventive 

Modification

Open hole Eddy 

Current 

Inspection as 

shown in 

Accomplishment 

Instructions, 

Paragraph 3.B., 

PART 1 - Flight 

Safety Inspection 

Program

27,000 10,000 after the 

date of this 

Service Bulletin 

Revision 2

15,000

Inspected as 

given in a 

previous 

release of 

this Service 

Bulletin

Ultrasonic, LFEC 

and edge HFEC 

Inspections as 

shown in 

Accomplishment 

Instructions, 

Paragraph 3.B., 

PART 1 - Flight 

Safety Inspection 

Program

- At next repeat 

interval as given 

in this service 

bulletin, 

Revision 1 or 

original issue, or 

within 5,000 

after Revision 2 

release, 

whichever is 

sooner.

5,000 Modification of the 

STA 727 Outboard 

Chord as shown in 

Accomplishment 

Instructions, 

Paragraph 3.B., 

PART 6 - STA 727 

Frame Outboard 

Chord Preventive 

Modification

Open hole Eddy 

Current 

Inspection as 

shown in 

Accomplishment 

Instructions, 

Paragraph 3.B., 

PART 1 - Flight 

Safety Inspection 

Program

- At next repeat 

interval as given 

in this service 

bulletin, 

Revision 1 or 

original issue, or 

within 10,000 

after Revision 2 

release, 

whichever is 

sooner.

15,000
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

Table 4 - "One-Time" Follow On Inspection for cracks in STA 727 Frame Outboard Chord at S-18A for airplanes

with the Outboard Chord Interim modification accomplished (Edge Margin less than 1.7D but equal to or greater

than 1.5). (Required minimum for Safety).

Condition Action

Threshold

Repeat Interval 

(Not to Exceed 

Flight Cycles)

Lowest Airplane 

Flight Cycles after 

the STA 727 frame 

outboard chord 

modification was 

accomplished

Highest Airplane 

Flight Cycles after 

the STA 727 frame 

outboard chord 

modification was 

accomplished

Each location 

where the fastener 

edge margin in the 

STA 727 Frame 

Outboard Chord 

forward flange is 

equal to or greater 

than 1.5D and less 

than 1.7D

Open Hole Eddy Current 

as shown in 

Accomplishment 

Instructions, Paragraph 

3.B., PART 8 - One Time 

Inspection of STA 727 

Frame Outboard Chord 

Interim Modification.

50,000 60,000 None

Groups 1-3, Configurations 1, 3 and 4; Group 4-11, Configurations 1 and 4: Table 5 - Inspection for cracks in

STA 727 Auxiliary Chord on Airplanes without the STA 727 outboard chord modification accomplished or with

7075-T6 Frames. (Required minimum for Safety)

Action

Threshold (whichever occurs later)

Repeat Interval 

(Not to Exceed 

Flight Cycles)

Terminating action for 

Repeat Inspection

(a) Total 

Airplane 

Flight Cycles

Airplane Flight 

Cycles after the 

date of this Service 

Bulletin Revision 2

Detailed Inspection as 

shown in 

Accomplishment 

Instructions, 

Paragraph 3.B., PART 

1 - Flight Safety 

Inspection Program

27,000 5,000 15,000 Modification of the STA 

727 Outboard Chord as 

shown in Accomplishment 

Instructions, Paragraph 

3.B., PART 6 - STA 727 

Frame Outboard Chord 

Preventive Modification 

and complete chord 

replacement as shown in 

Accomplishment 

Instructions Paragraph 

3.B., Part 3 - STA 727 

Frame Outboard Chord 

Repair. (b)

Eddy Current 

Inspection as shown 

in Accomplishment 

Instructions, 

Paragraph 3.B., PART 

1 - Flight Safety 

Inspection Program

27,000 5,000 15,000

(a) Groups 1-11, Configuration 1 - Airplane Flight Cycles After Frame Chord Replacement

(b) Accomplishment of the terminating actions does not prevent cracks in the auxiliary chord but mitigates the 

safety concern related to the STA 727 frame outboard chord. Inspections of the auxiliary chord after 

completion of the terminating actions are optional.
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

Federal Aviation Administration (FAA) Airworthiness Directive AD 95-12-17, is related to this service 

bulletin. The FAA is considering additional rule making that will make the compliance tasks and times 

given in Revision 2 of this Service Bulletin mandatory.

F. Approval

This service bulletin was examined by the Federal Aviation Administration (FAA). The changes 

specified in this service bulletin 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 service bulletin and its approval 

were based on the airplane in its original Boeing delivery configuration or as modified by other 

approved Boeing changes.

If an airplane has a non-Boeing modification or repair that affects a component or system also affected 

by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency 

approval before incorporating this service bulletin.

This service bulletin has been approved by the FAA. In addition, the Manager of the FAA Seattle 

Aircraft Certification Office approves the compliance and accomplishment instructions (i.e. 

compliance times, inspection or modification) defined in this service bulletin as an alternative method 

of compliance (AMOC) to the requirements of paragraph (a), (b), (c), (d), (e), (f) and (g) of AD 

95-12-17. All provisions of AD 95-12-17 that are not specifically referenced in the above statement 

remain fully applicable and must be complied with. As part of this latest revision, inspections of the 

outboard chord of stringer S-18A are no longer required. The FAA is considering further rule making 

that would mandate the recommendations included in Revision 2 of this Service Bulletin.

The compliance information provided in Appendix A, Table 1, of this service bulletin, Revision 2, are 

approved as an alternative method of compliance to paragraph (b) and (c) of Airworthiness Directive 

(AD) 98-11-04 R1 for the inspections of Structurally Significant Item F-29 of Supplemental Structural 

Inspection Document, D6-37089. This AMOC only applies to the areas inspected per this service 

bulletin, Revision 2, and to those airplanes identified in this service bulletin, Revision 2. All provisions 

of 98-11-04 R1 that are not specifically referenced in the above statements remain fully applicable and 

must be complied with. If operators choose this AMOC, then they must revise their FAA approved 

maintenance or inspection program with these alternative inspections.

Table 6: STA 727 Frame Outboard Chord Time-Limited Repair

Condition Action

Compliance Time

(Not to Exceed Flight 

Cycles from the Time of 

Installation of the Repair)

STA 727 Frame Outboard 

Chord Time-Limited 

Repair installed

Replace the Time-Limited 

Repair as shown in 

Accomplishment Instructions, 

Paragraph 3.B., Part 9 - 

Replacement of the TimeLimited Repair

4,500
June 30, 1994

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G. Manpower

The data below shows an estimate of the man-hours necessary to do the inspection, repair, and 

preventive modification for each airplane. This estimate is for direct labor only, done by an 

experienced crew. Adjust the estimate with operator man-hour data if necessary. The estimate does 

not include lost time. These are some examples of lost time:

— Time to adjust to the workplace

— Time to schedule the work

— Time to examine the work

— Time to make the parts

— Time to find the tools.

PART 1 - Flight Safety Inspection Program

Task

Number of 

Persons Task-Hours Elapsed Hours

Access 2 2 1

Figure 7 2 2.10 1.05

Figure 8 1 1 1

Figure 9 1 0.75 0.75

Figure 11 2 1.75 0.87

Figure 12 2 1.75 0.87

Figure 24 2 1.75 0.87

Close Access 2 2 1

TOTAL FOR EACH AIRPLANE 13.10 7.41

Group 1, 2, 3, 4, 5, 6, 9 and 10

PART 2 - Economic Inspection Program

Task

Number of 

Persons Task-Hours Elapsed Hours

Access 2 2 1

Figure 13 2 1.50 0.75

Figure 14 2 1.50 0.75

Close Access 2 2 1

TOTAL FOR EACH AIRPLANE 7 3.5

PART 3 - STA 727 Frame Outboard Chord Repair

Task

Number of 

Persons Task-Hours Elapsed Hours

Access 5 5 1

TOTAL FOR EACH AIRPLANE 5 1
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

PART 4 - STA 727 Frame Outboard Chord Time-Limited Repair

Task

Number of 

Persons Task-Hours Elapsed Hours

Access 5 11.50 2.30

Inspection 2 1 0.50

Figure 15 2 8 4

Figure 16 1 1 1

Figure 17 (a) - - -

Figure 18 4 30 7.50

Close Access 5 11.50 2.30

TOTAL FOR EACH AIRPLANE 63 17.60

(a) Time to make parts not included.

Group 1, 2, 3, 4, 5, 6, and 9

PART 5 - S-18A Outboard Chord Repair

Task

Number of 

Persons Task-Hours Elapsed Hours

Access 5 11.50 2.30

Figure 21 4 26 6.50

Close Access 5 11.50 2.30

TOTAL FOR EACH AIRPLANE 49 11.10

PART 6 - STA 727 Frame Outboard Chord Preventive Modification

Task

Number of 

Persons Task-Hours Elapsed Hours

Access 5 11.50 2.30

Inspection 2 2 1

Figure 7 2 2.10 1.05

Figure 8 1 1 1

Figure 9 1 0.75 0.75

Figure 10 2 5 2.50

Figure 22 1 0.25 0.25

Close Access 5 11.50 2.30

TOTAL FOR EACH AIRPLANE 34.10 11.15

Group 1, 2, 3, 4, 5, 6, and 9

PART 7 - S-18A Outboard Chord Preventive Modification

Task

Number of 

Persons Task-Hours Elapsed Hours

Access 2 2 1

Close Access 2 2 1

TOTAL FOR EACH AIRPLANE 4 2
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

H. Weight and Balance Changes

I. Electrical Load Data

Not applicable

PART 8 - One-Time Inspection of the STA 727 Frame Outboard Chord Interim 

Modification

Task

Number of 

Persons Task-Hours Elapsed Hours

Access 2 2 1

Figure 10 2 5 2.50

Close Access 2 2 1

TOTAL FOR EACH AIRPLANE 9 4.50

PART 9 - Replacement of the Time-Limited Repair

Task

Number of 

Persons Task-Hours Elapsed Hours

Access 2 6.50 3.25

Figure 19 4 10 2

Figure 20 (a) - - -

Figure 23 4 30 7.50

Close Access 2 6.50 3.25

TOTAL FOR EACH AIRPLANE 53 16

(a) Time to make parts not included.

Task Change in Weight 

(Pounds)

Change in Moment 

(Pound-Inches)

STA 727 Frame Preventive Modification Kit:

65C37277-1, -2, -3, -4, -5, -6, -7, -8.

+8 +5,800

STA 727 Frame Time Limited Repair +6 +4,360

Time Limited Repair Modification 

(Shear Beam Repair)

None None

S-18A Preventive Modification

Kit: 65C38491-1, -2.

+4 +2,900

STA 727 Frame and S-18A Preventive 

Modification Combination Kit: 65C37277-17, -18, -19,

-20, -21, -22.

+10 +7,270

STA 727 Frame and S-18A Preventive Modification

Combination Kit: 65C37277-23, -24, -25, -26.

+7.8 +5,670

S-18A Chord Repair: Repair Kit 65C37565-5, -6, -7, -8 +6.4 +4,650

S-18A Chord Repair: Repair Kit 65C38642-1, -2, -3, -4,

-5, -6

+13.4 +9,740

S-18A Chord Repair: Repair Kit 65C38642-7, -8, -9, -10 +10 +7,270
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

J. References

1. Existing Data:

a. 737-100/200 Maintenance Manual (AMM) Subjects 25-52-51, 25-52-123, 25-52-131, 

25-52-141, 26-21-11, 27-51-141, 27-51-261, 53-23-1, 53-51-21

b. 737-300/400/500 Maintenance Manual (AMM) Subject 25-52-51, 25-52-73, 25-52-81, 

25-52-91, 26-21-11, 27-51-32, 27-51-67, 53-23-12, 53-51-21

c. 737-100/200 Structural Repair Manual (SRM) Subjects 51-10-6, 51-20-1, 51-50-1

d. 737-300 Structural Repair Manual (SRM) Subject 51-10-02, 51-30-01, 51-50-02

e. 737-400 Structural Repair Manual (SRM) Subject 51-10-02, 51-30-01, 51-50-02

f. 737-500 Structural Repair Manual (SRM) Subject 51-10-02, 51-30-01, 51-50-02

g. 737 Nondestructive Test (NDT) Manual D6-37239, Part 4, Subject 51-40-00, Figure 1 

h. 737 Nondestructive Test (NDT) Manual D6-37239, Part 4, Subject 53-10-01

i. 737 Nondestructive Test (NDT) Manual D6-37239, Part 6, Subject 51-00-00, Figures 4, 16 

and 23

j. 737 Nondestructive Test (NDT) Manual D6-37239, Part 6, Subject 53-30-00, Figure 5

k. Boeing Standard Overhaul Practices Manual (SOPM) Subject 20-41-02, 20-43-03

l. Service Related Problem (SRP) 737-SRP-53-0162

m. 737 Structural Item Interim Advisory (SIIA) 737-131, 737-44, 737-60, 737-74, 737-194, 

737-274

n. 737 Supplemental Structural Inspection Document (SSID) D6-37089, Section 8.2, SSI 

Number F.29

o. Boeing Service Bulletin 737-53-1088, “Fuselage - Station Number 727 Bulkhead - Outboard 

Chord Inspection and Replacement”

p. Boeing Service Bulletin 737-53A1039, "Fuselage - Skin Lap Joint Inspection and Repair"

q. Boeing Service Bulletin 737-53-1066, "Fuselage - Stringer 18A Shear Beam Inspection, 

Repair and Modification"

r. Boeing Service Bulletin 737-53-1076, "Fuselage - Circumferential Butt Splices and Bonded 

Doublers Inspection, Repair and Modification"

s. Boeing Service Bulletin 737-53-1077, "Fuselage - Skin Inspection, Repair, and Modification 

Aft of Body Station 727 Between Stringer S-18 and S-21"

t. Boeing Service Bulletin 737-53-1089, "Fuselage - Skin Cracks at Stringer 17 Inspection and 

Preventive Modification"
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

u. Boeing Service Bulletin 737-53-1124, "Fuselage - Bonded Doublers (Tear Straps) - 

Inspection and Repair - For Delamination above Stringer 26 Between Stations 259 and 

1016"

v. Boeing Service Bulletin 737-53-1170, "Fuselage - Stringer 18A Web at BS 727- Inspection, 

Repair and Preventive Change"

w. Boeing Service Bulletin 737-53-1179, "Fuselage - Bonded Skin Doublers (Tear Straps) - 

Delamination Inspection and Repair"

x. FAA Airworthiness Directive 03-14-06, Amendment 39-13225

y. FAA Airworthiness Directive 95-12-17, Amendment 39-9268

z. FAA Airworthiness Directive 88-22-11, Amendment 39-6432

aa. FAA Airworthiness Directive 89-09-03, Amendment 39-6184

ab. FAA Airworthiness Directive 91-08-12, Amendment 39-6967

ac. FAA Airworthiness Directive 92-25-09, Amendment 39-8424

ad. FAA Airworthiness Directive 98-11-04, Amendment 39-10984

ae. Boeing Drawing 65C36009

2. Data supplied with this Service Bulletin:

a. Drawings:

Drawing Number Title Sheet DCN ADCN

65C38491-1 (a) S-18A Preventive Modification KPL A -

65C38491-2 (a) KPL A -

65C38491 (a) 1 - -
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

65C37277-17 (a) Strap Installation - Station 727 

Bulkhead, S-18 to S-20, Preventive 

Modification (Top Kit)

KPL A -

65C37277-18 (a) KPL A -

65C37277-19 (a) KPL A -

65C37277-20 (a) KPL A -

65C37277-21 (a) KPL A -

65C37277-22 (a) KPL A -

65C37277-23 (a) KPL A -

65C37277-24 (a) KPL A -

65C37277-25 (a) KPL A -

65C37277-26 (a) KPL A -

65C37277 PL - 3 (a)

1- -

2 (a) - -

3 (a) - -

4 (a) - -

5 (a) - -

6 (a) - -

65C38642-1 (a) Strap Installation - S-18A Outboard 

Chord Repair - Station 727

KPL A -

65C38642-2 (a) KPL A -

65C38642-3 (a) KPL A -

65C38642-4 (a) KPL A -

65C38642-5 (a) KPL A -

65C38642-6 (a) KPL A -

65C38642-7 (a) KPL A -

65C38642-8 (a) KPL A -

65C38642-9 (a) KPL A -

65C38642-10 (a) KPL A -

65C38642 (a) 1 - -

2- -

3- -

4- -

5- -

65C37565 (b) Strap Installation - S-18A Outboard 

Chord Repair - Station 727

PL - -

1- -

(a) Sent with Revision 2. 

(b) Sent with Revision 1. 

Drawing Number Title Sheet DCN ADCN
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

3. Installation Drawings Used in the Preparation of this Service Bulletin:

These drawings were used to prepare this service bulletin. These drawings are not necessary to 

make the specified changes, and are not supplied with this service bulletin. These drawings may 

not be applicable to all airplane configurations or operators.

K. Publications Affected

L. Interchangeability and Intermixability of Parts

Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts.

Drawing Number Title

65-45771 Skin Panel Installation - S-10 to S-18A, STA 540 to STA 727

65-45774 Skin Panel Installation - S-14L to S-25L, STA 727 to STA 908

65-45775 Skin Panel Installation - S-14R to S-25R, STA 727 to STA 908

65-45776 Skin Panel Installation - S-25L to S-25R, STA 727 to STA 1016

65-46547 Bulkhead installation - STA 727

65-46877 Strap and Beam Installation - Stringer 18A, STA 639 to STA 747

65-48654 Frame Installation - Aft Wing/Body Fairing, STA 729.38

Publication Chapter-Section

737 Non-Destructive Test Manual Part 4 and Part 6

737-100/200 Structural Repair Manual 53-10-2

737-300 Structural Repair Manual 53-10-00

737-400 Structural Repair Manual 53-10-00

737-500 Structural Repair Manual 53-10-00
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

2. MATERIAL INFORMATION

A. Material - Price and Availability

Boeing can supply the kits/parts shown in Paragraph 2.C., Parts Necessary For Each Airplane as 

shown below. If there is a limit to the quantity (QTY) of available kits/parts, a supply sequence is given 

by Spares. More kits/parts become available as shown in the Reorder Lead Time (ROLT). ROLT is 

calculated from the date Boeing gets the purchase order.

Kit/Part

Number Name Date QTY ROLT (weeks)

Unit Price thru 

Jan 31/06

65C37277-1 Top Kit, Left Side - - 48 $6,836.00

65C37277-2 Top Kit, Right Side - - 48 $6,836.00

65C37277-3 Top Kit, Left Side - - 48 $6,567.00

65C37277-4 Top Kit, Right Side - - 48 $6,567.00

65C37277-5 Top Kit, Left Side - - 48 $6,583.00

65C37277-6 Top Kit, Right Side - - 48 $6,583.00

65C37277-7 Top Kit, Left Side Inactive for procurement

65C37277-8 Top Kit, Right Side Inactive for procurement

65C37565-1 Top Kit, Left Side Inactive for procurement

65C37565-2 Top Kit, Right Side Inactive for procurement

65C37565-3 Top Kit, Left Side Inactive for procurement

65C37565-4 Top Kit, Right Side Inactive for procurement

65C37565-5 Top Kit, Left Side - - 48 $5,357.00

65C37565-6 Top Kit, Right Side - - 48 $5,357.00

65C37565-7 Top Kit, Left Side - - 48 $4,937.00

65C37565-8 Top Kit, Right Side - - 48 $4,937.00

65C37277-17 Top Kit, Left Side March/21/06 5 48 $6,642.00

65C37277-18 Top Kit, Right Side March/21/06 5 48 $6,642.00

65C37277-19 Top Kit, Left Side March/21/06 10 48 $6,393.00

March/24/06 10

March/29/06 5

65C37277-20 Top Kit, Right Side March/21/06 10 48 $6,393.00

March/24/06 10

March/29/06 5

65C37277-21 Top Kit, Left Side March/21/06 1 48 $6,405.00

65C37277-22 Top Kit, Right Side March/21/06 1 48 $6,405.00

65C37277-23 Top Kit, Left Side March/21/06 1 48 $6,198.00

65C37277-24 Top Kit, Right Side March/21/06 1 48 $6,198.00

65C37277-25 Top Kit, Left Side March/21/06 1 48 $6,257.00

65C37277-26 Top Kit, Right Side March/21/06 1 48 $6,257.00

65C38491-1 Top Kit, Left Side - - 48 $3,545.00
 

June 30, 1994

Revision 2: May 25, 2006 737-53A1166

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

The kits are subject to the terms and conditions of the Boeing standard purchase order 

acknowledgment. After the Unit Price date, new price (and ROLT) data is applicable. Prices are in 

United States Dollars. Terms: Net 30 days.

Send purchase orders and letters about the supply data to the Director of Spares and refer to this 

service bulletin number.

B. Industry Support Information

Boeing warranty remedies are not available for the inspection and /or repair procedures given in this 

service bulletin.

65C38491-2 Top Kit, Right Side - - 48 $3,545.00

65C38642-1 Top Kit, Left Side - - 48 $8,279.00

65C38642-2 Top Kit, Right Side - - 48 $8,279.00

65C38642-3 Top Kit, Left Side - - 48 $8,256.00

65C38642-4 Top Kit, Right Side - - 48 $8,256.00

65C38642-5 Top Kit, Left Side - - 48 $8,206.00

65C38642-6 Top Kit, Right Side - - 48 $8,308.00

65C38642-7 Top Kit, Left Side - - 48 $8,932.00

65C38642-8 Top Kit, Right Side - - 48 $8,932.00

65C38642-9 Top Kit, Left Side - - 48 $8,493.00

65C38642-10 Top Kit, Right Side - - 48 $8,493.00

65C38643-1 Shear Beam Web, Left

Side

- - 48 $519.00

65C38643-2 Shear Beam Web,

Right Side

- - 48 $519.00

69-78347-1 Shear Beam Web, Left

Side

- - 48 $519.00

69-78347-2 Shear Beam Web,

Right Side

- - 48 $519.00

Kit/Part

Number Name Date QTY ROLT (weeks)

Unit Price thru 

Jan 31/06
 

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

C. Parts Necessary For Each Airplane

1. Kits/Parts:

Usage Kit Number Effectivity Kit Action Remarks

STA 727 

Frame 

Preventive 

Modification 

(without S-18A 

Preventive 

Modification)

65C37277-1 (Left Side) Group 1 (a) Install 

external 

strap for 

Frame 

Preventive 

Modification

(1) Concurrent incorporation of 

65C38491-1/-2 (add 

S-18A Preventive Modification) 

recommended. 

(2) If S-18A Chord Repair is needed, 

see 65C38642. (Note 65C37565 

repair kits are also satisfactory for 

usage, however they are not 

compatible with 65C33722 Frame 

replacement kit). S-18A Chord is 0.20 

inch thick with early frames.

65C37277-2 (Right Side)

65C37277-3 (Left Side) Group 1 (b)

65C37277-4 (Right Side)

65C37277-5 (Left Side) Group 2

65C37277-6 (Right Side)

S-18A Chord 

Preventive 

Modification

65C38491-1 (Left Side) Group 1 

and 2

Install 

external 

strap for 

S-18A 

Chord 

Preventive 

Modification 

(1) For use with Frame Preventive 

Modification 65C37277-1 through -6.

(2) For airplanes that have 

incorporated 65C37277-( ), see flag 

notes on 65C38491-( ) for fastener 

information. S-18A Chord is 0.20 inch 

thick. 

65C38491-2 (Right Side)

STA 727 

Frame and 

S-18A Chord 

Preventive 

Modification 

Combination

65C37277-17 (Left Side) Group 3 

and 4

Install 

external 

straps for 

Frame 

Preventive 

Modification 

and S-18A 

Chord 

Preventive 

Modification 

Kit includes both Frame and S-18A 

Preventive Modification Strap. S-18A 

Chord is 0.33 thick, early skin panels 

and early fairing panels. 

65C37277-18 (Right Side)

65C37277-19 (Left Side) Group 5 

and 10

Kit includes both Frame and S-18A 

Preventive Modification Strap. S-18A 

Chord is 0.33 inch thick, later skin 

panels and early fairing panels.

65C37277-20 (Right Side)

65C37277-21 (Left Side) Group 6 

and 9 (c)

Kit includes both Frame and S-18A 

Preventive Modification Strap. S-18A 

Chord is 0.33 inch thick, later skin 

panels and later fairing panels.

65C37277-22 (Right Side)

STA 727 

Frame 

Preventive 

Modification

65C37277-23 (Left Side) Group 7 

and 11

Install 

external 

straps for 

Frame 

Preventive 

Modification 

Kit includes Frame Preventive 

Modification only. S-18A Chord is 

0.40 or 0.45 inch thick, later skin 

panels and early fairing panels. 

65C37277-24 (Right Side)

65C37277-25 (Left Side) Group 8 

and 9 (d)

Kit includes Frame Preventive 

Modification only. S-18A Chord is 

0.40 or 0.45 inch thick, later skin 

panels and later fairing panels.

65C37277-26 (Right Side)
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

S-18A Chord 

Repair

65C37565-5 (Left Side) Group 1 (b) Install 

external 

strap for 

S-18A 

Chord 

repair 

Not compatible with 65C33722 Frame 

replacement. See 65C38642-7/-8 or -

9/-10. 65C37565-1 through -4 are 

used without 65C37277-1 through -6 

installed (obsolete). Superseded by 

65C38642-7/-8 or-9/-10. 65C37565-5 

through -8 are used with 65C37277-1 

through -6 installed. S-18A Chord is 

0.20 inch thick. 

65C37565-6 (Right Side)

65C37565-7 (Left Side) Group 2

65C37565-8 (Right Side)

S-18A Chord 

Repair

65C38642-7 (Left Side) Group 1 (b) Install 

external 

strap for 

Frame 

Modification 

and 

S-18A 

Chord 

Repair.

Kit includes S-18A Chord Repair and 

Frame Preventive Modification straps 

(Tee S-18A Chord). S-18A Chord is 

0.20 inch thick.

65C38642-8 (Right Side)

S-18A Chord 

Repair

65C38642-9 (Left Side) Group 2 Install 

external 

strap for 

Frame 

Modification 

and 

S-18A 

Chord 

Repair.

Kit includes S-18A Chord Repair and 

Frame Preventive Modification straps 

(Flat S-18A Chord). S-18A Chord is 

0.20 inch thick.

65C38642-10 (Right Side)

S-18A Chord 

Repair

65C38642-5 (Left Side) Group 3 

and 4

Install 

external 

strap for 

Frame 

Modification 

and 

S-18A 

Chord 

Repair. 

Kit includes S-18A Chord Repair and 

Frame Preventive Modification straps. 

S-18A Chord is 0.33 inch thick, early 

skin panels and early fairings.

65C38642-6 (Right Side)

S-18A Chord 

Repair

65C38642-1 (Left Side) Group 5 

and 10

Install 

external 

strap for 

Frame 

Modification 

and 

S-18A 

Chord 

Repair.

Kit includes S-18A Chord Repair and 

Frame Preventive Modification straps. 

S-18A Chord is 0.33 inch thick, later 

skin panels and early fairings. 

65C38642-2 (Right Side)

Usage Kit Number Effectivity Kit Action Remarks
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

To get the kits/parts shown below, refer to Paragraph 2.A., Material - Price and Availability.

S-18A Chord 

Repair

65C38642-3 (Left Side) Group 6 

and 9 (c)

Install 

external 

strap for 

Frame 

Modification 

and 

S-18A 

Chord 

Repair

Kit includes S-18A Chord Repair and 

Frame Preventive Modification straps. 

S-18A Chord is 0.33 inch thick, later 

skin panels and later fairings.

65C38642-4 (Right Side)

(a) For Group 1 Airplanes, Line Number 1-23 only.

(b) For Group 1 Airplanes, Line Number 24-310 only.

(c) This kit is only applicable to one side of Group 9 airplanes where the S-18A Chord thickness is 

0.33inches.

(d) This kit is only applicable to one side of Group 9 airplanes where the S-18A Chord thickness is 0.40 or 

0.45 inches.

Group 1and 2

Kit 65C37277 - STA 727 Frame Preventive Modification (Without S-18A Preventive Modification)

New Part Number

QTY

-6 -5 -4 -3 -2 -1 Name Notes

65C37277-1 . . . . . - PREVENTIVE MOD KIT - 

LEFT SIDE

(a)

65C37277-2 . . . . - . PREVENTIVE MOD KIT - 

RIGHT SIDE

(a)

65C37277-3 . . . - . . PREVENTIVE MOD KIT - 

LEFT SIDE

(b)

65C37277-4 . . - . . . PREVENTIVE MOD KIT - 

RIGHT SIDE

(b)

65C37277-5 . - . . . . PREVENTIVE MOD KIT - 

LEFT SIDE

(c)

65C37277-6 - . . . . . PREVENTIVE MOD KIT - 

RIGHT SIDE

(c)

65C37277-11 1 1 1 1 1 1 FILLER - TAPERED

65C37277-12 . . . . 1 1 FASTENER ASSY

65C37277-13 . . 1 1 . . FASTENER ASSY

65C37277-14 1 1 . . . . FASTENER ASSY

65-48654-10 2 2 2 2 2 2 FILLER - TAPERED

65-48654-14 1 1 1 1 1 1 FILLER - FLAT

69-78767-3 . 1 . 1 . . ATTACH ANGLE

69-78767-4 1 . 1 . . . ATTACH ANGLE

Usage Kit Number Effectivity Kit Action Remarks
 

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

69-78767-5 . . . . . 1 ATTACH ANGLE

69-78767-6 . . . . 1 . ATTACH ANGLE

69-78768-2 1 1 1 1 . . WEB

69-78768-3 . . . . 1 1 WEB

69-78769-1 . 1 1 . . STIFFENER

69-78769-2 1 . 1 . . . STIFFENER

69-78769-3 . . . . . 1 STIFFENER

69-78769-4 . . . . 1 . STIFFENER

69-78769-5 . 1 . 1 . 1 ANGLE

69-78769-6 1 . 1 . 1 . ANGLE

69-78770-1 . 1 . 1 . 1 STRAP-EXTERNAL

69-78770-2 1 . 1 . 1 . STRAP-EXTERNAL

69-78773-1 1 1 1 1 . . FILLER - FLAT

69-78773-2 . . . . 1 1 FILLER - FLAT

69-78773-3 . . . . 1 1 FILLER - TAPERED

69-78773-4 . . . . 1 1 FILLER - TAPERED

69-78773-5 . . . . 1 1 FILLER - TAPERED

69-78773-6 1 1 1 1 . . FILLER - TAPERED

69-78773-7 1 1 1 1 . . FILLER - TAPERED

69-78773-8 1 1 1 1 . . FILLER - TAPERED

69-78773-10 1 1 1 1 . . SHIM - LAMINATED

BACF3F008W011NG 1 1 1 1 1 1 FILLER - FLAT

BACF3F023L083AG . . . . 2 2 FILLER - FLAT

(a) For Group 1 airplanes, Line numbers 1 - 23 only.

(b) For Group 1 airplanes, Line numbers 24 - 310 only.

(c) For Group 2 airplanes.

Group 1and 2

Kit 65C37277 - STA 727 Frame Preventive Modification (Without S-18A Preventive Modification)

New Part Number

QTY

-6 -5 -4 -3 -2 -1 Name Notes
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

Group 3, 4, 5, 6, 9 and 10

Kit 65C37277 - STA 727 Frame and S-18A Preventive Modification Combination 

New Part Number

QTY

-22 -21 -20 -19 -18 -17 Name Notes

65C37277-17 . . . . . - STA 727 FRAME 

AND S-18A MOD KIT

(a)

65C37277-18 . . . . - . STA 727 FRAME 

AND S-18A MOD KIT

(a)

65C37277-19 . . . - . . STA 727 FRAME 

AND S-18A MOD KIT

(b)

65C37277-20 . . - . . . STA 727 FRAME 

AND S-18A MOD KIT

(b)

65C37277-21 . - . . . . STA 727 FRAME 

AND S-18A MOD KIT

(c) (d)

65C37277-22 - . . . . . STA 727 FRAME 

AND S-18A MOD KIT

(c) (d)

65-48654-82 2 2 2 2 2 2 FILLER

65-48654-84 3 3 3 3 3 3 FILLER

65C37277-11 1 1 1 1 1 1 FILLER-TAPERED

65C38496-1 1 1 1 1 1 1 STRAP S-18A 

OUTBD CHORD 

MOD, STA 727 

DETAIL.

69-78767-7 . . . 1 . 1 ATTACH ANGLE - 

AFT WING BODY 

FAIRING, STA 727 + 

2.38

69-78767-8 . . 1 . 1 . ATTACH ANGLE - 

AFT WING BODY 

FAIRING, STA 727 + 

2.38

69-78767-9 . 1 . . . . ATTACH ANGLE - 

AFT WING BODY 

FAIRING, STA 727 + 

2.38

69-78768-4 . . 1 1 1 1 WEB - AFT WING 

BODY FAIRING, STA 

727 + 2.38

69-78768-5 1 1 . . . . WEB - AFT WING 

BODY FAIRING, STA 

727 + 2.38

69-78769-5 . . . 1 . 1 ANGLE

69-78769-6 . . 1 . 1 . ANGLE

69-78769-7 . 1 . . . . DETAILS - AFT WING 

BODY FAIRING, STA 

727 + 2.38
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

69-78769-8 1 . . . . . DETAILS - AFT WING 

BODY FAIRING, STA 

727 + 2.38

69-78769-9 . . . 1 . 1 STIFFENER - AFT 

WING BODY 

FAIRING, STA 727 + 

2.38

69-78770-3 . 1 . 1 . 1 STRAP-EXTERNAL, 

STA 727

69-78770-4 1 . 1 . 1 . STRAP-EXTERNAL, 

STA 727

69-78773-1 . . . . 1 1 FILLER-FLAT

69-78773-6 1 1 1 1 . . FILLER-TAPERED

69-78773-7 . . . . 1 1 FILLER-TAPERED

69-78773-9 . . . . 1 1 FILLER

69-78767-10 1 . . . . . ATTACH ANGLE - 

AFT WING BODY 

FAIRING, STA 727 + 

2.38

69-78769-10 . . 1 . 1 . STIFFENER - AFT 

WING BODY 

FAIRING, STA 727 + 

2.38

69-78769-11 . 1 . . . . DETAILS - AFT WING 

BODY FAIRING, STA 

727 + 2.38

69-78769-12 1 . . . . . DETAILS - AFT WING 

BODY FAIRING, STA 

727 + 2.38

69-78773-10 . . . . 1 1 SHIM,LAMINATED

69-78773-11 1 1 1 1 . . FILLER-DETAILS

69-78773-12 1 1 1 1 . . FILLER DETAILS

69-78773-13 . . . . 1 1 FILLER DETAILS

69-78773-14 1 1 1 1 . . FILLER-DETAILS

69-78773-15 1 1 1 1 . . FILLER-DETAILS

69-78773-16 1 1 1 1 1 1 FILLER DETAILS

BACB30MB10A16 3 3 3 3 3 3 BOLT, PROTRUDING 

HD

(e)

BACB30MB10A17 1 1 1 1 3 3 BOLT, PROTRUDING 

HD

(e)

Group 3, 4, 5, 6, 9 and 10

Kit 65C37277 - STA 727 Frame and S-18A Preventive Modification Combination 

New Part Number

QTY

-22 -21 -20 -19 -18 -17 Name Notes
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

BACB30MB10A18 2 2 2 2 . . BOLT, PROTRUDING 

HD

(e)

BACB30MB10A19 2 2 2 2 2 2 BOLT, HEX DRIVE (e)

BACB30MY8K10Y 3 3 3 3 2 2 BOLT, PROTRUDING 

HD

(e)

BACB30MY8K11X 1 1 1 1 1 1 BOLT, PROTRUDING 

HD

(e)

BACB30MY8K11Y 1 1 1 1 1 1 BOLT, PROTRUDING 

HD

(e)

BACB30MY8K12Y 3 3 3 3 3 3 BOLT, PROTRUDING 

HD

(e)

BACB30MY8K13Y 2 2 2 2 2 2 BOLT, PROTRUDING 

HD

(e)

BACB30MY8K14X 1 1 1 1 1 1 BOLT, PROTRUDING 

HD

(e)

BACB30MY8K14Y 8 8 8 8 8 8 BOLT, PROTRUDING 

HD

(e)

BACB30MY8K15Y 7 7 7 7 7 7 BOLT, PROTRUDING 

HD

(e)

BACB30MY8K16X 1 1 1 1 1 1 BOLT, PROTRUDING 

HD

(e)

BACB30MY8K16Y 7 7 7 7 7 7 BOLT, PROTRUDING 

HD

(e)

BACB30MY8K17Y 3 3 3 3 3 3 BOLT, PROTRUDING 

HD

(e)

BACB30MY8K18Y 6 6 6 6 6 6 BOLT, PROTRUDING 

HD

(e)

BACB30MY8K20Y 1 1 1 1 1 1 BOLT, PROTRUDING 

HD

(e)

BACB30MY8K6X 1 1 1 1 1 1 BOLT, PROTRUDING 

HD

(e)

BACB30MY8K7X 1 1 1 1 1 1 BOLT, PROTRUDING 

HD

(e)

BACB30MY8K7Y 25 25 25 25 25 25 BOLT, PROTRUDING 

HD

(e)

BACB30MY8K8X 6 6 6 6 6 6 BOLT, PROTRUDING 

HD

(e)

BACB30MY8K8Y 9 9 9 9 9 9 BOLT, PROTRUDING 

HD

(e)

BACB30MY8K9Y 4 4 4 4 4 4 BOLT, PROTRUDING 

HD

(e)

Group 3, 4, 5, 6, 9 and 10

Kit 65C37277 - STA 727 Frame and S-18A Preventive Modification Combination 

New Part Number

QTY

-22 -21 -20 -19 -18 -17 Name Notes
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

BACB30NX6K3 7 7 7 7 7 7 BOLT, PROTRUDING 

HD

(e)

BACB30NX6K4 3 3 3 3 3 3 BOLT, PROTRUDING 

HD

(e)

BACB30NX6K4X 9 9 9 9 9 9 BOLT, PROTRUDING 

HD

(e)

BACB30NX6K5X 1 1 1 1 1 1 BOLT, PROTRUDING 

HD

(e)

BACB30NX8K7 5 5 5 5 5 5 BOLT, HEX DRIVE (e)

BACB30YP6K5 2 2 2 2 2 2 BOLT, 100 DEG HEX 

DR

(e)

BACB30YP8K5 1 1 1 1 1 1 BOLT, 100 DEG HEX 

DR

(e)

BACC30BH10 8 8 8 8 8 8 COLLAR

BACC30BH6 10 10 10 10 10 10 COLLAR

BACC30BH8 5 5 5 5 5 5 COLLAR

BACC30BL6 2 2 2 2 2 2 COLLAR

BACC30BL8 1 1 1 1 1 1 COLLAR

BACC30M6 10 10 10 10 10 10 COLLAR

BACC30M8 11 11 11 11 12 12 COLLAR

BACC30R8 86 86 86 86 86 86 COLLAR

BACF3F009N010NN 1 1 1 1 1 1 FILLER, FLAT.

BACF3T01E07-10 1 1 1 1 1 1 TAPERED FILLER

BACF3T03R34-10 1 1 1 1 1 1 FILLER, TAPERED

BACF3T04R26-10 1 1 1 1 1 1 FILLER, TAPERED.

BACR15BB6D6C 45 45 45 45 45 45 RIVET, UNIVERSAL 

HD

(e)

BACR15BB6D7C 7 7 7 7 7 7 RIVET, UNIVERSAL 

HD

(e)

BACS40R010B046F . . . . 1 1 SHIM, LAMINATED

BACS40R010B054F 1 1 1 1 1 1 SHIM, LAMINATED

BACS40R021B097F 1 1 1 1 . . SHIM, LAMINATED

BACW10BN31AP 10 10 10 10 10 10 WASHER, PLAIN

BACW10BN3AP 12 12 12 12 12 12 WASHER

BACW10BN41AP 10 10 10 10 10 10 WASHER, 

COUNTERSUNK, 

OVERSIZE

Group 3, 4, 5, 6, 9 and 10

Kit 65C37277 - STA 727 Frame and S-18A Preventive Modification Combination 

New Part Number

QTY

-22 -21 -20 -19 -18 -17 Name Notes
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

BACW10BN42AP 86 86 86 86 86 86 WASHER, 

COUNTERSUNK, 

OVERSIZE

BACW10BN4AP 6 6 6 6 6 6 WASHER, PLAIN

BACW10BN5AP 8 8 8 8 8 8 WASHER, 

COUNTERSUNK, 

OVERSIZE

BACW10CA104CC 39 39 39 39 39 39 WASHER, SELFALIGN

BACW10CA104CV 38 38 38 38 38 38 WASHER, SELFALIGN

BACW10CA104PV 1 1 1 1 1 1 WASHER, SELFALIGN

BACW10CA5CC 8 8 8 8 8 8 WASHER

BACW10CA5CV 8 8 8 8 8 8 WASHER

(a) For Group 3 and 4 airplanes.

(b) For Group 5 and 10 airplanes.

(c) For Group 6 and 9 airplanes.

(d) This kit is only applicable to one side of Group 9 airplanes where the S-18A Chord thickness is 

0.33inches.

(e) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length 

longer than indicated. Also, if any fasteners part numbers listed are not available or have been 

superseded, substitute fasteners may be supplied in kits. Boeing Document D-590 and Boeing 

Drawing 65-88700 are used to determine the part numbers used as substitutes.

Group 7, 8, 9 and 11

Kit 65C37277 - STA 727 Frame Preventive Modification 

New Part Number

QTY

-26 -25 -24 -23 Name Notes

65C37277-23 . . . - STA 727 FRAME PREVENTIVE MODIFICATION (a)

65C37277-24 . . - . STA 727 FRAME PREVENTIVE MODIFICATION (a)

65C37277-25 . - . . STA 727 FRAME PREVENTIVE MODIFICATION (b) (c)

65C37277-26 - . . . STA 727 FRAME PREVENTIVE MODIFICATION (b) (c)

65-48654-82 2 2 2 2 FILLER

65-48654-84 3 3 3 3 FILLER

65C37277-11 1 1 1 1 FILLER-TAPERED

69-78767-7 . . . 1 ATTACH ANGLE - AFT WING BODY FAIRING, 

STA 727 + 2.38

Group 3, 4, 5, 6, 9 and 10

Kit 65C37277 - STA 727 Frame and S-18A Preventive Modification Combination 

New Part Number

QTY

-22 -21 -20 -19 -18 -17 Name Notes
 

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

69-78767-8 . . 1 . ATTACH ANGLE - AFT WING BODY FAIRING, 

STA 727 + 2.38

69-78767-9 . 1 . . ATTACH ANGLE - AFT WING BODY FAIRING, 

STA 727 + 2.38

69-78768-4 . . 1 1 WEB - AFT WING BODY FAIRING, STA 727 + 

2.38

69-78768-5 1 1 . . WEB - AFT WING BODY FAIRING, STA 727 + 

2.38

69-78769-5 . . . 1 ANGLE

69-78769-6 . . 1 . ANGLE

69-78769-7 . 1 . . DETAILS - AFT WING BODY FAIRING, STA 727 

+ 2.38

69-78769-8 1 . . . DETAILS - AFT WING BODY FAIRING, STA 727 

+ 2.38

69-78769-9 . . . 1 STIFFENER - AFT WING BODY FAIRING, STA 

727 + 2.38

69-78770-3 . 1 . 1 STRAP-EXTERNAL, STA 727

69-78770-4 1 . 1 . STRAP-EXTERNAL, STA 727

69-78773-6 1 1 1 1 FILLER-TAPERED

69-78767-10 1 . . . ATTACH ANGLE - AFT WING BODY FAIRING, 

STA 727 + 2.38

69-78769-10 . . 1 . STIFFENER - AFT WING BODY FAIRING, STA 

727 + 2.38

69-78769-11 . 1 . . DETAILS - AFT WING BODY FAIRING, STA 727 

+ 2.38

69-78769-12 1 . . . DETAILS - AFT WING BODY FAIRING, STA 727 

+ 2.38

69-78773-11 1 1 1 1 FILLER-DETAILS

69-78773-12 1 1 1 1 FILLER DETAILS

69-78773-14 1 1 1 1 FILLER-DETAILS

69-78773-15 1 1 1 1 FILLER-DETAILS

69-78773-16 1 1 1 1 FILLER DETAILS

BACB30MB10A16 2 2 2 2 BOLT, PROTRUDING HD (d)

BACB30MB10A17 2 2 2 2 BOLT, PROTRUDING HD (d)

BACB30MB10A18 2 2 2 2 BOLT, PROTRUDING HD (d)

BACB30MB10A19 2 2 2 2 BOLT, HEX DRIVE (d)

BACB30MY8K10Y 3 3 3 3 BOLT, PROTRUDING HD (d)

BACB30MY8K11X 1 1 1 1 BOLT, PROTRUDING HD (d)

Group 7, 8, 9 and 11

Kit 65C37277 - STA 727 Frame Preventive Modification 

New Part Number

QTY

-26 -25 -24 -23 Name Notes
 

June 30, 1994

Revision 2: May 25, 2006 737-53A1166

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 91 of 198

BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

BACB30MY8K11Y 3 3 3 3 BOLT, PROTRUDING HD (d)

BACB30MY8K12Y 4 4 4 4 BOLT, PROTRUDING HD (d)

BACB30MY8K13Y 1 1 1 1 BOLT, PROTRUDING HD (d)

BACB30MY8K14X 1 1 1 1 BOLT, PROTRUDING HD (d)

BACB30MY8K14Y 6 6 6 6 BOLT, PROTRUDING HD (d)

BACB30MY8K15Y 6 6 6 6 BOLT, PROTRUDING HD (d)

BACB30MY8K16X 1 1 1 1 BOLT, PROTRUDING HD (d)

BACB30MY8K16Y 8 8 8 8 BOLT, PROTRUDING HD (d)

BACB30MY8K17Y 5 5 5 5 BOLT, PROTRUDING HD (d)

BACB30MY8K18Y 6 6 6 6 BOLT, PROTRUDING HD (d)

BACB30MY8K20Y 1 1 1 1 BOLT, PROTRUDING HD (d)

BACB30MY8K6X 1 1 1 1 BOLT, PROTRUDING HD (d)

BACB30MY8K7X 1 1 1 1 BOLT, PROTRUDING HD (d)

BACB30MY8K7Y 23 23 23 23 BOLT, PROTRUDING HD (d)

BACB30MY8K8X 6 6 6 6 BOLT, PROTRUDING HD (d)

BACB30MY8K8Y 8 8 8 8 BOLT, PROTRUDING HD (d)

BACB30MY8K9Y 4 4 4 4 BOLT, PROTRUDING HD (d)

BACB30NX6K3 7 7 7 7 BOLT, PROTRUDING HD (d)

BACB30NX6K4 3 3 3 3 BOLT, PROTRUDING HD (d)

BACB30NX6K4X 9 9 9 9 BOLT, PROTRUDING HD (d)

BACB30NX6K5X 1 1 1 1 BOLT, PROTRUDING HD (d)

BACB30NX8K7 5 5 5 5 BOLT, HEX DRIVE (d)

BACB30YP6K5 2 2 2 2 BOLT, 100 DEG HEX DR (d)

BACB30YP8K5 1 1 1 1 BOLT, 100 DEG HEX DR (d)

BACC30BH10 8 8 8 8 COLLAR

BACC30BH6 10 10 10 10 COLLAR

BACC30BH8 5 5 5 5 COLLAR

BACC30BL6 2 2 2 2 COLLAR

BACC30BL8 1 1 1 1 COLLAR

BACC30M6 10 10 10 10 COLLAR

BACC30M8 12 12 12 12 COLLAR

BACC30R8 86 86 86 86 COLLAR

BACF3F009N010NN 1 1 1 1 FILLER, FLAT.

BACF3F010G025NN 2 2 2 2 FILLER

BACF3T01E07-10 1 1 1 1 TAPERED FILLER

BACF3T03R34-10 1 1 1 1 FILLER, TAPERED

Group 7, 8, 9 and 11

Kit 65C37277 - STA 727 Frame Preventive Modification 

New Part Number

QTY

-26 -25 -24 -23 Name Notes
 

June 30, 1994

Revision 2: May 25, 2006 737-53A1166

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 92 of 198

BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

BACF3T04R26-10 1 1 1 1 FILLER, TAPERED.

BACR15BB6D6C 45 45 45 45 RIVET, UNIVERSAL HD (d)

BACR15BB6D7C 7 7 7 7 RIVET, UNIVERSAL HD (d)

BACS40R010B054F 1 1 1 1 SHIM, LAMINATED

BACS40R021B097F 1 1 1 1 SHIM, LAMINATED

BACW10BN31AP 10 10 10 10 WASHER, PLAIN

BACW10BN3AP 12 12 12 12 WASHER

BACW10BN41AP 10 10 10 10 WASHER, COUNTERSUNK, OVERSIZE

BACW10BN42AP 86 86 86 86 WASHER, COUNTERSUNK, OVERSIZE

BACW10BN4AP 6 6 6 6 WASHER, PLAIN

BACW10BN5AP 8 8 8 8 WASHER, COUNTERSUNK, OVERSIZE

BACW10CA104CC 39 39 39 39 WASHER, SELF-ALIGN

BACW10CA104CV 38 38 38 38 WASHER, SELF-ALIGN

BACW10CA104PV 1 1 1 1 WASHER, SELF-ALIGN

BACW10CA5CC 8 8 8 8 WASHER

BACW10CA5CV 8 8 8 8 WASHER

(a) For Group 7 and 11 airplanes.

(b) For Group 8 and 9 airplanes.

(c) This kit is only applicable to one side of Group 9 airplanes where the S-18A Chord thickness is 0.40 or 

0.45 inches.

(d) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer 

than indicated. Also, if any fasteners part numbers listed are not available or have been superseded, 

substitute fasteners may be supplied in kits. Boeing Document D-590 and Boeing Drawing 65-88700 are 

used to determine the part numbers used as substitutes.

Group 1 and 2

Kit 65C37565 - S-18A Chord Repair 

New Part Number

QTY

-8 -7 -6 -5 Name Notes

65C37565-5 . . . - S-18A REPAIR KIT - LEFT SIDE (a)

65C37565-6 . . - . S-18A REPAIR KIT - RIGHT SIDE (a)

65C37565-7 . - . . S-18A REPAIR KIT - LEFT SIDE (b)

65C37565-8 - . . . S-18A REPAIR KIT - RIGHT SIDE (b)

65C37565-17 1 1 1 1 FASTENER KIT

65C37566-10 1 1 1 1 FILLER

65C37566-2 1 1 1 1 STRAP

65C37566-3 1 1 1 1 STRAP

Group 7, 8, 9 and 11

Kit 65C37277 - STA 727 Frame Preventive Modification 

New Part Number

QTY

-26 -25 -24 -23 Name Notes
 

June 30, 1994

Revision 2: May 25, 2006 737-53A1166

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 93 of 198

BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

65C37566-4 1 1 1 1 STRAP

65C37566-5 . . . 1 STRAP

65C37566-6 . . 1 . STRAP

65C37566-7 . 1 . . STRAP

65C37566-8 1 . . . STRAP

65C37566-9 1 1 1 1 FILLER

69-87822-1 . 1 . 1 SPLICE ANGLE

69-87822-2 1 . 1 . SPLICE ANGLE

BACF3F008J017NN 1 1 1 1 FILLER

BACF3F016J018NN 1 1 1 1 FILLER

BACS40R023B027P 1 1 1 1 SHIM, LAMINATED

65C37565-10 1 . 1 . STIFFENER

65C37565-11 . 1 . 1 ATTACH ANGLE

65C37565-12 1 . 1 . ATTACH ANGLE

65C37565-13 . 1 . 1 ATTACH ANGLE

65C37565-14 1 . 1 . ATTACH ANGLE

65C37565-15 1 1 1 1 WEB

65C37565-9 . 1 . 1 STIFFENER

(a) For Group 1 airplanes, Line numbers 24 - 310 only.

(b) For Group 2 airplanes.

Group 1 and 2

Kit 65C38491 - S-18A Chord Preventive Modification 

New Part Number

QTY

-2 -1 Name Notes

65C38491-1 . - S-18A PREVENTIVE MOD

65C38491-2 - . S-18A PREVENTIVE MOD

65-46877-31 1 1 FILLER-TAPERED

65-48654-82 2 2 FILLER

65-48654-84 3 3 FILLER

65C38496-1 1 1 STRAP S-18A OUTBD CHORD 

MOD, STA 727 DETAIL.

69-78767-7 . 1 ATTACH ANGLE - AFT WING 

BODY FAIRING, STA 727 + 2.38

69-78767-8 1 . ATTACH ANGLE - AFT WING 

BODY FAIRING, STA 727 + 2.38

Group 1 and 2

Kit 65C37565 - S-18A Chord Repair 

New Part Number

QTY

-8 -7 -6 -5 Name Notes
 

June 30, 1994

Revision 2: May 25, 2006 737-53A1166

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 94 of 198

BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

69-78768-4 1 1 WEB - AFT WING BODY 

FAIRING, STA 727 + 2.38

69-78769-9 . 1 STIFFENER - AFT WING BODY 

FAIRING, STA 727 + 2.38

69-78769-10 1 . STIFFENER - AFT WING BODY 

FAIRING, STA 727 + 2.38

BACB30MB10A14 2 2 BOLT, PROTRUDING HD (a)

BACB30MB10A15 2 2 BOLT, PROTRUDING HD (a)

BACB30MB10A16 4 4 BOLT, PROTRUDING HD (a)

BACB30MB10A17 4 4 BOLT, PROTRUDING HD (a)

BACB30MB10A18 2 2 BOLT, PROTRUDING HD (a)

BACB30MB10A19 2 2 BOLT, HEX DRIVE (a)

BACB30MC10A14 2 2 BOLT, PROTRUDING HD (a)

BACB30MC10A15 2 2 BOLT, PROTRUDING HD (a)

BACB30MC10A16 4 4 BOLT, PROTRUDING HD (a)

BACB30MC10A17 4 4 BOLT, PROTRUDING HD (a)

BACB30MC10A18 2 2 BOLT, PROTRUDING HD (a)

BACB30MC10A19 2 2 BOLT, HEX DRIVE (a)

BACB30MY8K10X 1 1 BOLT, PROTRUDING HD (a)

BACB30MY8K10Y 2 2 BOLT, PROTRUDING HD (a)

BACB30MY8K11X 2 2 BOLT, PROTRUDING HD (a)

BACB30MY8K11Y 7 7 BOLT, PROTRUDING HD (a)

BACB30MY8K12X 1 1 BOLT, PROTRUDING HD (a)

BACB30MY8K12Y 11 11 BOLT, PROTRUDING HD (a)

BACB30MY8K13Y 7 7 BOLT, PROTRUDING HD (a)

BACB30MY8K14Y 5 5 BOLT, PROTRUDING HD (a)

BACB30MY8K15Y 5 5 BOLT, PROTRUDING HD (a)

BACB30MY8K16Y 2 2 BOLT, PROTRUDING HD (a)

BACB30MY8K17Y 2 2 BOLT, PROTRUDING HD (a)

BACB30MY8K18Y 1 1 BOLT, PROTRUDING HD (a)

BACB30MY8K7X 5 5 BOLT, PROTRUDING HD (a)

BACB30MY8K7Y 12 12 BOLT, PROTRUDING HD (a)

BACB30MY8K8X 1 1 BOLT, PROTRUDING HD (a)

BACB30MY8K8Y 1 1 BOLT, PROTRUDING HD (a)

BACB30MY8K9X 6 6 BOLT, PROTRUDING HD (a)

BACB30MY8K9Y 13 13 BOLT, PROTRUDING HD (a)

Group 1 and 2

Kit 65C38491 - S-18A Chord Preventive Modification 

New Part Number

QTY

-2 -1 Name Notes
 

June 30, 1994

Revision 2: May 25, 2006 737-53A1166

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 95 of 198

BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

BACB30NX6K3 7 7 BOLT, PROTRUDING HD (a)

BACB30NX6K4 4 4 BOLT, PROTRUDING HD (a)

BACB30NX6K4X 9 9 BOLT, PROTRUDING HD (a)

BACC30BH10 8 8 COLLAR

BACC30BH6 11 11 COLLAR

BACC30M6 9 9 COLLAR

BACC30M8 9 9 COLLAR

BACC30R8 37 37 COLLAR

BACF3F010N027NN 1 1 FILLER

BACF3T01E07-10 1 1 TAPERED FILLER

BACF3T03R34-10 1 1 FILLER, TAPERED

BACF3T04R26-10 1 1 FILLER, TAPERED.

BACR15BB6D6C 40 40 RIVET, UNIVERSAL HD (a)

BACR15BB8D5C 2 2 RIVET, UNIVERSAL HD (a)

BACS40R010B027F 1 1 SHIM, LAMINATED

BACS40R010E045F 1 1 SHIM, LAMINATED

BACS40R010E055F 1 1 SHIM, LAMINATED

BACW10BN31AP 9 9 WASHER, PLAIN

BACW10BN3AP 9 9 WASHER

BACW10BN41AP 9 9 WASHER, COUNTERSUNK, 

OVERSIZE

BACW10BN42AP 25 25 WASHER, COUNTERSUNK, 

OVERSIZE

BACW10BN5AP 8 8 WASHER, COUNTERSUNK, 

OVERSIZE

BACW10CA104CC 13 13 WASHER, SELF-ALIGN

BACW10CA104CV 13 13 WASHER, SELF-ALIGN

BACW10CA5CC 8 8 WASHER

BACW10CA5CV 8 8 WASHER

(a) If grip length shown is not available at Boeing, fasteners supplied in kits may be 

one grip length longer than indicated. Also, if any fasteners part numbers listed are 

not available or have been superseded, substitute fasteners may be supplied in kits. 

Boeing Document D-590 and Boeing Drawing 65-88700 are used to determine the 

part numbers used as substitutes.

Group 1 and 2

Kit 65C38491 - S-18A Chord Preventive Modification 

New Part Number

QTY

-2 -1 Name Notes
 

June 30, 1994

Revision 2: May 25, 2006 737-53A1166

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 96 of 198

BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

Group 3, 4, 5, 6, 9 and 10

Kit 65C38642 - S-18A Chord Repair 

New Part Number

QTY

-6 -5 -4 -3 -2 -1 Name Notes

65C38642-1 . . . . . - S-18A REPAIR (a)

65C38642-2 . . . . - . S-18A REPAIR (a)

65C38642-3 . . . - . . S-18A REPAIR (b) (c)

65C38642-4 . . - . . . S-18A REPAIR (b) (c)

65C38642-5 . - . . . . S-18A REPAIR (d)

65C38642-6 - . . . . . S-18A REPAIR (d)

65-48654-84 3 3 3 3 3 3 FILLER

65C37277-11 1 1 1 1 1 1 FILLER-TAPERED

65C37566-3 . . 1 1 1 1 STRAP

65C37566-12 1 1 1 1 1 1 STRAP S-18A 

OUTBD CHORD 

REPAIR, STA 727, 

KIT

65C37566-15 . 1 . 1 . 1 STRAP S-18A 

OUTBD CHORD 

REPAIR, STA 727, 

KIT

65C37566-16 1 . 1 . 1 . STRAP S-18A 

OUTBD CHORD 

REPAIR, STA 727, 

KIT

65C37566-17 1 1 . . . . STRAP S-18A 

OUTBD CHORD 

REPAIR, STA 727, 

KIT

65C37566-18 1 1 1 1 1 1 STRAP S-18A 

OUTBD CHORD 

REPAIR, STA 727, 

KIT

69-78768-6 1 1 . . 1 1 WEB - AFT WING 

BODY FAIRING, 

STA 727 + 2.38

69-78768-7 . . 1 1 . . WEB - AFT WING 

BODY FAIRING, 

STA 727 + 2.38

69-78769-5 . 1 . . . 1 ANGLE

69-78769-6 1 . . . 1 . ANGLE

69-78769-7 . . . 1 . . DETAILS - AFT 

WING BODY 

FAIRING, STA 727 

+ 2.38
 

June 30, 1994

Revision 2: May 25, 2006 737-53A1166

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 97 of 198

BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

69-78769-8 . . 1 . . . DETAILS - AFT 

WING BODY 

FAIRING, STA 727 

+ 2.38

69-78770-3 . 1 . 1 . 1 STRAPEXTERNAL, STA 

727

69-78770-4 1 . 1 . 1 . STRAPEXTERNAL, STA 

727

69-78773-1 1 1 . . . . FILLER-FLAT

69-78773-7 1 1 . . . . FILLER-TAPERED

69-78773-9 1 1 . . . . FILLER

69-78767-11 . 1 . 1 . 1 ATTACH ANGLE - 

AFT WING BODY 

FAIRING, STA 727 

+ 2.38

69-78767-12 1 . 1 . 1 . ATTACH ANGLE - 

AFT WING BODY 

FAIRING, STA 727 

+ 2.38

69-78769-13 . 1 . . . 1 STIFFENER - AFT 

WING BODY 

FAIRING, STA 727 

+ 2.38

69-78769-14 1 . . . 1 . STIFFENER - AFT 

WING BODY 

FAIRING, STA 727 

+ 2.38

69-78769-15 . . . 1 . . STIFFENER - AFT 

WING BODY 

FAIRING, STA 727 

+ 2.38

69-78769-16 . . 1 . . . STIFFENER - AFT 

WING BODY 

FAIRING, STA 727 

+ 2.38

69-78773-11 . . 1 1 1 1 FILLER-DETAILS

69-78773-12 . . 1 1 1 1 FILLER DETAILS

69-78773-14 . . 1 1 1 1 FILLER-DETAILS

69-78773-15 . . 1 1 1 1 FILLER-DETAILS

69-78773-16 1 1 1 1 1 1 FILLER DETAILS

Group 3, 4, 5, 6, 9 and 10

Kit 65C38642 - S-18A Chord Repair 

New Part Number

QTY

-6 -5 -4 -3 -2 -1 Name Notes
 

June 30, 1994

Revision 2: May 25, 2006 737-53A1166

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 98 of 198

BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

BACB30MB10A17 2 2 2 2 2 2 BOLT, 

PROTRUDING HD

(e)

BACB30MB10A18 4 4 4 4 4 4 BOLT, 

PROTRUDING HD

(e)

BACB30MB10A20 2 2 2 2 2 2 BOLT, 

PROTRUDING HD

(e)

BACB30MY8K10Y 3 3 3 3 3 3 BOLT, 

PROTRUDING HD

(e)

BACB30MY8K11X 1 1 1 1 1 1 BOLT, 

PROTRUDING HD

(e)

BACB30MY8K12Y 2 2 2 2 2 2 BOLT, 

PROTRUDING HD

(e)

BACB30MY8K14X 1 1 1 1 1 1 BOLT, 

PROTRUDING HD

(e)

BACB30MY8K14Y 12 12 12 12 12 12 BOLT, 

PROTRUDING HD

(e)

BACB30MY8K15Y 3 3 3 3 3 3 BOLT, 

PROTRUDING HD

(e)

BACB30MY8K16X 1 1 1 1 1 1 BOLT, 

PROTRUDING HD

(e)

BACB30MY8K16Y 11 11 11 11 11 11 BOLT, 

PROTRUDING HD

(e)

BACB30MY8K17Y 3 3 3 3 3 3 BOLT, 

PROTRUDING HD

(e)

BACB30MY8K18Y 6 6 6 6 6 6 BOLT, 

PROTRUDING HD

(e)

BACB30MY8K21Y 1 1 1 1 1 1 BOLT, 

PROTRUDING HD

(e)

BACB30MY8K5Y 3 3 3 3 3 3 BOLT, 

PROTRUDING HD

(e)

BACB30MY8K6X 1 1 1 1 1 1 BOLT, 

PROTRUDING HD

(e)

BACB30MY8K7X 1 1 3 3 1 1 BOLT, 

PROTRUDING HD

(e)

BACB30MY8K7Y 23 23 23 23 23 23 BOLT, 

PROTRUDING HD

(e)

BACB30MY8K8X 6 6 6 6 6 6 BOLT, 

PROTRUDING HD

(e)

BACB30MY8K8Y 9 9 9 9 9 9 BOLT, 

PROTRUDING HD

(e)

Group 3, 4, 5, 6, 9 and 10

Kit 65C38642 - S-18A Chord Repair 

New Part Number

QTY

-6 -5 -4 -3 -2 -1 Name Notes
 

June 30, 1994

Revision 2: May 25, 2006 737-53A1166

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 99 of 198

BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

BACB30MY8K9Y 2 2 2 2 2 2 BOLT, 

PROTRUDING HD

(e)

BACB30NX6K3 7 7 7 7 7 7 BOLT, 

PROTRUDING HD

(e)

BACB30NX6K4 3 3 3 3 3 3 BOLT, 

PROTRUDING HD

(e)

BACB30NX6K4X 9 9 9 9 9 9 BOLT, 

PROTRUDING HD

(e)

BACB30NX6K5X 1 1 1 1 1 1 BOLT, 

PROTRUDING HD

(e)

BACB30NX8K7 5 5 5 5 5 5 BOLT, HEX DRIVE (e)

BACB30YP6K5 2 2 2 2 2 2 BOLT, 100 DEG 

HEX DR

(e)

BACB30YP8K5 1 1 1 1 1 1 BOLT, 100 DEG 

HEX DR

(e)

BACC30BH10 8 8 8 8 8 8 COLLAR

BACC30BH6 10 10 10 10 10 10 COLLAR

BACC30BH8 5 5 5 5 5 5 COLLAR

BACC30BL6 2 2 2 2 2 2 COLLAR

BACC30BL8 1 1 1 1 1 1 COLLAR

BACC30M6 10 10 10 10 10 10 COLLAR

BACC30M8 11 11 11 11 11 11 COLLAR

BACC30R8 86 86 86 86 86 86 COLLAR

BACF3F009N010NN . . 1 1 1 1 FILLER, FLAT.

BACF3F009P010NN 1 1 . . . . FILLER

BACF3F010A030BN 1 1 . . . . FILLER, FLAT

BACF3F024A166BN 1 1 . . . . FILLER, FLAT

BACF3T01F08-10B 3 3 3 3 3 3 FILLER

BACF3T01T36-10 1 1 1 1 1 1 FILLER, 

TAPERED.

BACF3T01T38-10 1 1 1 1 1 1 FILLER, 

TAPERED.

BACF3T02F12-10 1 1 1 1 1 1 FILLER, TAPERED

BACR15BB6D6C 40 40 40 40 40 40 RIVET, 

UNIVERSAL HD

(e)

BACR15BB6D7C 7 7 7 7 7 7 RIVET, 

UNIVERSAL HD

(e)

BACR15BB8AD5C 2 2 2 2 2 2 RIVET, 

UNIVERSAL HD

(e)

Group 3, 4, 5, 6, 9 and 10

Kit 65C38642 - S-18A Chord Repair 

New Part Number

QTY

-6 -5 -4 -3 -2 -1 Name Notes
 

June 30, 1994

Revision 2: May 25, 2006 737-53A1166

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 100 of 198

BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

BACS40R010A025P 1 1 1 1 1 1 SHIM, LAMINATED

BACW10BN31AP 10 10 10 10 10 10 WASHER, PLAIN

BACW10BN3AP 12 12 12 12 12 12 WASHER

BACW10BN41AP 10 10 10 10 10 10 WASHER, 

COUNTERSUNK, 

OVERSIZE

BACW10BN42AP 86 86 86 86 86 86 WASHER, 

COUNTERSUNK, 

OVERSIZE

BACW10BN4AP 6 6 6 6 6 6 WASHER, PLAIN

BACW10BN5AP 8 8 8 8 8 8 WASHER, 

COUNTERSUNK, 

OVERSIZE

BACW10CA104CC 19 19 19 19 19 19 WASHER, SELFALIGN

BACW10CA104CV 18 18 18 18 18 18 WASHER, SELFALIGN

BACW10CA104PV 1 1 1 1 1 1 WASHER, SELFALIGN

BACW10CA5CC 8 8 8 8 8 8 WASHER

BACW10CA5PV 8 8 8 8 8 8 WASHER, SELFALIGN

(a) For Group 5 and 10 airplanes.

(b) For Group 6 airplanes.

(c) For Group 9 airplanes where the S-18A Chord thickness is 0.33 inches.

(d) For Group 3 and 4 airplanes.

(e) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length 

longer than indicated. Also, if any fasteners part numbers listed are not available or have been 

superseded, substitute fasteners may be supplied in kits. Boeing Document D-590 and Boeing 

Drawing 65-88700 are used to determine the part numbers used as substitutes.

Group 1 and 2

Kit 65C38642 - S-18A Chord Repair 

New Part Number

QTY

-10 -9 -8 -7 Name Notes

65C38642-7 . . . - S-18A REPAIR (a)

65C38642-8 . . - . S-18A REPAIR (a)

65C38642-9 . - . . S-18A REPAIR (b)

65C38642-10 - . . . S-18A REPAIR (b)

Group 3, 4, 5, 6, 9 and 10

Kit 65C38642 - S-18A Chord Repair 

New Part Number

QTY

-6 -5 -4 -3 -2 -1 Name Notes
 

June 30, 1994

Revision 2: May 25, 2006 737-53A1166

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 101 of 198

BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

65-48654-82 2 2 2 2 FILLER

65-48654-84 3 3 3 3 FILLER

65C37277-11 1 1 1 1 FILLER-TAPERED

65C37566-2 1 1 1 1 STRAP

65C37566-4 1 1 1 1 STRAP

65C37566-5 . . . 1 STRAP

65C37566-6 . . 1 . STRAP

65C37566-7 . 1 . . STRAP

65C37566-8 1 . . . STRAP

65C37566-17 1 1 1 1 STRAP S-18A 

OUTBD CHORD 

REPAIR, STA 727, 

KIT

69-78767-7 . 1 . 1 ATTACH ANGLE - 

AFT WING BODY 

FAIRING, STA 727 

+ 2.38

69-78767-8 1 . 1 . ATTACH ANGLE - 

AFT WING BODY 

FAIRING, STA 727 

+ 2.38

69-78768-4 1 1 1 1 WEB - AFT WING 

BODY FAIRING, 

STA 727 + 2.38

69-78769-5 . 1 . 1 ANGLE

69-78769-6 1 . 1 . ANGLE

69-78769-9 . 1 . 1 STIFFENER - AFT 

WING BODY 

FAIRING, STA 727 

+ 2.38

69-78770-3 . 1 . 1 STRAPEXTERNAL, STA 

727

69-78770-4 1 . 1 . STRAPEXTERNAL, STA 

727

69-78773-1 1 1 1 1 FILLER-FLAT

69-78773-7 1 1 1 1 FILLER-TAPERED

69-78773-9 1 1 1 1 FILLER

Group 1 and 2

Kit 65C38642 - S-18A Chord Repair 

New Part Number

QTY

-10 -9 -8 -7 Name Notes
 

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ALERT ALERT

69-78769-10 1 . 1 . STIFFENER - AFT 

WING BODY 

FAIRING, STA 727 

+ 2.38

69-78773-16 1 1 1 1 FILLER DETAILS

BACB30MB10A16 2 2 2 2 BOLT, 

PROTRUDING HD

(c)

BACB30MB10A17 4 4 4 4 BOLT, 

PROTRUDING HD

(c)

BACB30MB10A19 1 1 2 2 BOLT, HEX DRIVE (c)

BACB30MB10A20 1 1 . . BOLT, 

PROTRUDING HD

(c)

BACB30MY8K10Y . . 8 8 BOLT, 

PROTRUDING HD

(c)

BACB30MY8K11X 1 1 2 2 BOLT, 

PROTRUDING HD

(c)

BACB30MY8K11Y 1 1 4 4 BOLT, 

PROTRUDING HD

(c)

BACB30MY8K12X . . 1 1 BOLT, 

PROTRUDING HD

(c)

BACB30MY8K12Y 4 4 12 12 BOLT, 

PROTRUDING HD

(c)

BACB30MY8K13Y 4 4 8 8 BOLT, 

PROTRUDING HD

(c)

BACB30MY8K14X 1 1 . . BOLT, 

PROTRUDING HD

(c)

BACB30MY8K14Y 12 12 4 4 BOLT, 

PROTRUDING HD

(c)

BACB30MY8K15Y 5 5 2 2 BOLT, 

PROTRUDING HD

(c)

BACB30MY8K16X 1 1 . . BOLT, 

PROTRUDING HD

(c)

BACB30MY8K16Y 8 8 . . BOLT, 

PROTRUDING HD

(c)

BACB30MY8K17Y 3 3 . . BOLT, 

PROTRUDING HD

(c)

BACB30MY8K19Y 1 1 1 1 BOLT, 

PROTRUDING HD

(c)

BACB30MY8K5Y 3 3 3 3 BOLT, 

PROTRUDING HD

(c)

Group 1 and 2

Kit 65C38642 - S-18A Chord Repair 

New Part Number

QTY

-10 -9 -8 -7 Name Notes
 

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ALERT ALERT

BACB30MY8K6X 1 1 1 1 BOLT, 

PROTRUDING HD

(c)

BACB30MY8K7X 5 5 1 1 BOLT, 

PROTRUDING HD

(c)

BACB30MY8K7Y 28 28 28 28 BOLT, 

PROTRUDING HD

(c)

BACB30MY8K8X 6 6 6 6 BOLT, 

PROTRUDING HD

(c)

BACB30MY8K8Y 6 6 6 6 BOLT, 

PROTRUDING HD

(c)

BACB30MY8K9Y 4 4 3 3 BOLT, 

PROTRUDING HD

(c)

BACB30NX6K3 7 7 7 7 BOLT, 

PROTRUDING HD

(c)

BACB30NX6K4 3 3 3 3 BOLT, 

PROTRUDING HD

(c)

BACB30NX6K4X 9 9 9 9 BOLT, 

PROTRUDING HD

(c)

BACB30NX6K5X 1 1 1 1 BOLT, 

PROTRUDING HD

(c)

BACB30NX8K7 5 5 5 5 BOLT, HEX DRIVE (c)

BACB30YP6K5 2 2 2 2 BOLT, 100 DEG 

HEX DR

(c)

BACB30YP8K5 1 1 1 1 BOLT, 100 DEG 

HEX DR

(c)

BACC30BH10 8 8 8 8 COLLAR

BACC30BH6 10 10 10 10 COLLAR

BACC30BH8 5 5 5 5 COLLAR

BACC30BL6 2 2 2 2 COLLAR

BACC30BL8 1 1 1 1 COLLAR

BACC30M6 10 10 10 10 COLLAR

BACC30M8 11 11 11 11 COLLAR

BACC30R8 86 86 86 86 COLLAR

BACF3F009P010NN 1 1 1 1 FILLER

BACF3F010A030BN 1 1 1 1 FILLER, FLAT

BACF3F024A166BN 1 1 1 1 FILLER, FLAT

BACF3T01R30-10 1 1 1 1 FILLER, TAPERED.

BACF3T01R38-10 1 1 1 1 FILLER, TAPERED

BACF3T02F12-10 1 1 1 1 FILLER, TAPERED

Group 1 and 2

Kit 65C38642 - S-18A Chord Repair 

New Part Number

QTY

-10 -9 -8 -7 Name Notes
 

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ALERT ALERT

BACR15BB6D6C 40 40 40 40 RIVET, 

UNIVERSAL HD

(c)

BACR15BB6D7C 7 7 7 7 RIVET, 

UNIVERSAL HD

(c)

BACR15BB8AD5C 2 2 2 2 RIVET, 

UNIVERSAL HD

(c)

BACW10BN31AP 10 10 10 10 WASHER, PLAIN

BACW10BN3AP 12 12 12 12 WASHER

BACW10BN41AP 10 10 10 10 WASHER, 

COUNTERSUNK, 

OVERSIZE

BACW10BN42AP 86 86 86 86 WASHER, 

COUNTERSUNK, 

OVERSIZE

BACW10BN4AP 6 6 6 6 WASHER, PLAIN

BACW10BN5AP 8 8 8 8 WASHER, 

COUNTERSUNK, 

OVERSIZE

BACW10CA104CC 25 25 25 25 WASHER, SELFALIGN

BACW10CA104CV 24 24 24 24 WASHER, SELFALIGN

BACW10CA104PV 1 1 1 1 WASHER, SELFALIGN

BACW10CA5CC 8 8 8 8 WASHER

BACW10CA5PV 8 8 8 8 WASHER, SELFALIGN

(a) For Group 1 airplanes.

(b) For Group 2 airplanes.

(c) If grip length shown is not available at Boeing, fasteners supplied in kits may be one 

grip length longer than indicated. Also, if any fasteners part numbers listed are not 

available or have been superseded, substitute fasteners may be supplied in kits. 

Boeing Document D-590 and Boeing Drawing 65-88700 are used to determine the part 

numbers used as substitutes.

Group 1 and 2

Kit 65C38642 - S-18A Chord Repair 

New Part Number

QTY

-10 -9 -8 -7 Name Notes
 

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ALERT ALERT

2. Parts and Materials Supplied by the Operator:

a. Parts and Materials Supplied by the Operator for the STA 727 Frame Outboard Chord 

Time-Limited Repair:

The table that follows shows the parts necessary at each installation.

Groups 1 and 2, Configurations 1 and 4:

Part 65C38643 

New Part Number QTY Name Notes

65C38643-1 1 Shear Beam Web, Left

Side

(a) (b) 

(c)

65C38643-2 1 Shear Beam Web,

Right Side

(a) (b) 

(c)

(a) Discard the existing part.

(b) This part is not used in production.

(c) This part is required for the replacement of the STA 727 

Frame Outboard Chord Time-Limited Repair.

Groups 3 through 9, Configurations 1 and 4:

Part 69-78347 

New Part Number QTY Name Notes

69-78347-1 1 Shear Beam Web, Left

Side

(a) (b) 

(c)

69-78347-2 1 Shear Beam Web,

Right Side

(a) (b) 

(c)

(a) Discard the existing part.

(b) This part is not used in production.

(c) This part is required for the replacement of the STA 727 

Frame Outboard Chord Time-Limited Repair.

Part Number / Specification QTY Name Notes

BMS 5-95 Type I or II, Class 

B1/2 or B2.

16 Ounces Sealant (a)

BMS 10-11, Type 1 16 Ounces Primer (a)

Type 2, Class A 8 Ounces Chemical Conversion Coating (b)

AND10134-2008 x 20.8 

inches, 7075-T6 or equivalent

1 Frame Repair Angle

1.25 x 4.25 x 0.032 inch 1 Shim A (c)

1.25 x 6 x 0.18 inch 1 Repair Strap (c)

1.2 x 1.4 x 0.14 inch 1 Filler A (c) (d)

8.2 x 1.4 x 0.202 inch 1 Filler B (c) (e)

8.2 x 4.25 x 0.15 inch 1 Shear Beam Repair Angle (f)

2.1 x 11.4 x 0.18 inch 1 Shim B (c)
 

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ALERT ALERT

1.2 x 8.7 x 0.18 inch 1 Shim C (c)

6.9 x 1.9 x 0.09 inch 1 Filler (Tapered) (c)

BACB30MB8A( ) 70 Bolt (g) (h) (i) (m)

BACB30FN8A( ) 1 Bolt (g) (i) (k)

BACC30BH8 70 Collar (j) (m)

BACC30M8 1 Collar (l)

BACR15BA6D( )C 8 Rivet (g) (i)

BACR15BB6D( )C 

OR 

BACR15FT6D( )C

8 Rivet (g) (i)

BACB30ZB4-6 3 Bolt (g) (n)

BACB30ZB4-7 2 Bolt (g) (n)

BACB30ZB4-8 1 Bolt (g) (n)

NAS1149D0463H 4 Washer

NAS679A4W 4 Nut

(a) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data.

(b) Refer to Boeing Standard Overhaul Practices Manual 20-43-03 or 737 Structural Repair Manual, 

Chapter 51, for material sources.

(c) Fabricate from 7075-T6 Aluminum Alloy Sheet as shown in Figure 17.

(d) If shear beam flange thickness is 0.125 inches, make Filler A 0.125 inch thick.

(e) If shear beam thickness is 0.125 inches, make Filler B 0.217 inch thick.

(f) Fabricate from 7075-T0 Aluminum Alloy Sheet as shown in Figure 17.

(g) Refer to 737 Structural Repair Manual Chapter 51 for alternative fasteners.

(h) If 1/64 oversize is required, use BACB30MC( )A( ) bolts. If 1/32 oversize is required, use 

BACB30MD( )A( ) bolts. 

(i) Fastener length determined on installation.

(j) If a 1/32 oversize bolt is required, use BACC30AC( ) collar.

(k) If 1/64 oversize is required, use BACB30FQ( )A( ) bolts. If 1/32 oversize is required, use 

BACB30KF( )A( ) bolts. 

(l) If a 1/32 oversize bolt is required, use BACC30R( ) collar.

(m) There are more parts than are required.

(n) A total of 4 BACB30ZB4-( ) bolts are required for installation.

Part Number / Specification QTY Name Notes
 

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ALERT ALERT

b. Parts and Materials Supplied by the Operator for the replacement of the STA 727 Frame 

Outboard Chord Time-Limited Repair:

The table that follows shows the parts necessary at each installation.

Part Number / Specification QTY Name Notes

BMS 5-95 Type I or II, Class 

B1/2 or B2.

16 Ounces Sealant (a)

BMS 10-11, Type 1 16 Ounces Primer (a)

Type 2, Class A 8 Ounces Chemical Conversion Coating (b)

1.2 x 1.4 x inch 1 Filler A (c) (d)

1 x 6 x 0.15 inch 1 Filler B (c) (e)

BACB30MB8A( ) 60 Bolt (f) (g) (h) (l)

BACB30FN8A( ) 1 Bolt (f) (j) (k)

BACC30BH8 60 Collar (i) (l)

BACC30M8 1 Collar (k)

BACR15BA6D( )C 8 Rivet (f) (h)

BACR15BB6D( )C 

OR 

BACR15FT6D( )C

8 Rivet (f) (h)

BACB30ZB4-6 3 Bolt (f) (m)

BACB30ZB4-7 2 Bolt (f) (m)

BACB30ZB4-8 1 Bolt (f) (m)

NAS1149D0463H 4 Washer

NAS679A4W 4 Nut

(a) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data.

(b) Refer to Boeing Standard Overhaul Practices Manual 20-43-03 or 737 Structural Repair Manual, 

Chapter 51, for material sources.

(c) Fabricate from 7075-T6 Aluminum Alloy Sheet as shown in Figure 20.

(d) Thickness to match existing WL 190 stiffener. Target thickness is 0.156 or 0.125 inches.

(e) Part is longer than required.

(f) Refer to 737 Structural Repair Manual Chapter 51 for alternative fasteners.

(g) If 1/64 oversize is required, use BACB30MC( )A( ) bolts. If 1/32 oversize is required, use 

BACB30MD( )A( ) bolts. 

(h) Fastener length determined on installation.

(i) If a 1/32 oversize bolt is required, use BACC30AC( ) collar.

(j) If 1/64 oversize is required, use BACB30FQ( )A( ) bolts. If 1/32 oversize is required, use 

BACB30KF( )A( ) bolts. 

(k) If a 1/32 oversize bolt is required, use BACC30R( ) collar.

(l) There are more parts than are required.

(m) A total of 4 BACB30ZB4-( ) bolts are required for installation.
 

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ALERT ALERT

c. Parts and Materials Supplied by the Operator for the replacement of fasteners after open 

hole HFEC inspection (Figure 10):

The table that follows shows the parts necessary for each airplane.

3. Parts Modified and Reidentified:

None.

4. Parts Removed and Not Replaced:

None

D. Parts Necessary to Change Spares

None

E. Special Tooling - Price and Availability

None

F. Special Tooling Necessary to do this Service Bulletin

No special tools or equipment are necessary to do the change in this service bulletin. Also, 

maintenance and overhaul tools in manuals shown in Paragraph I.J., References, can be necessary. 

Examine operator tool supply to make sure all necessary tools are available.

Part Number / Specification QTY Name Notes

BMS 5-95 Type I or II, Class 

B1/2 or B2.

2 Ounces Sealant (a)

BACB30MB8A( ) (Steel) 

OR 

BACB30NX8K( ) (Titanium)

8 Bolt (b) (c) (d) (e)

BACC30BH8 8 Collar (f)

(a) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data.

(b) Refer to 737 Structural Repair Manual Chapter 51 for alternative fasteners.

(c) Steel bolts only - If 1/64 oversize is required, use BACB30MC8A( ) bolts. If 1/32 oversize is required, 

use BACB30MD8A( ) bolts. If 3/64 oversize is required, use BACB30ME8A( ) bolts.

(d) Titanium bolts only - If 1/64 oversize is required, use BACB30NX8K( )X bolts. If 1/32 oversize is 

required, use BACB30NX8K( )Y bolts.

(e) Fastener length determined on installation.

(f) If a 1/32 oversize bolt is required, use BACC30AC8 collar. If a 3/64 oversize bolt is required use 

BACC30U8 collar (for steel bolts only).
 

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

3. ACCOMPLISHMENT INSTRUCTIONS

A. GENERAL INFORMATION

CAUTION: KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL

PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED

MATERIAL, METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES

CAN CAUSE DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE

SPARKS OR OTHER ELECTRICAL DAMAGE.

NOTE:

1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for 

definition of the acronyms.

2. Obey all of the warnings and cautions given in the specified manual sections.

3. 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 are given in 737 Structural Repair Manual, 

Chapter 51

— Torque limits to tighten nuts and bolts are given in 737 Structural Repair Manual, 

Chapter 51

— Edge margins for fasteners are given in 737 Structural Repair Manual, Chapter 51

4. For approved fastener substitutions, refer to 737 Structural Repair Manual, Chapter 51 or 

refer to Boeing D-590 Supersession List for standard parts.

5. If the length of fasteners specified in this service bulletin do not meet the installation 

standards, fasteners of the same specification, or an approved substitute, one grip length 

longer or shorter may be used.

6. Fastener installation is given in 737 Structural Repair Manual Chapter 51. Hex drive bolts 

and lock bolts may be oversized by up to 1/32 inch diameter, unless stated otherwise, 

while maintaining edge margin requirements.

7. All Hex drive bolts, lock bolts and bolts unless otherwise specified shall be installed wet 

with BMS5-95. Rivets shall be installed dry. Install hex drive bolts, lock bolts and bolts in 

transition fit holes or close ream fit holes for steel parts.

8. Shim all gaps greater than 0.01 inch up to a max of 0.04 inch prior to fastener installation 

unless otherwise stated.

9. A Detailed Inspection is defined as: An intensive examination of a specific item, 

installation, or assembly to detect damage, failure, or irregularity. Available lighting is 

normally supplemented with a direct source of good lighting at an intensity deemed 

appropriate. Inspection aids such as mirrors magnifying lenses, etc. may be necessary. 

Surface cleaning and elaborate procedures may be required.
 

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ALERT ALERT

10. 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 ensure visual access to all surfaces in the inspection area. This level 

of inspection is made under normal 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.

B. WORK INSTRUCTIONS

PART 1 - FLIGHT SAFETY INSPECTION PROGRAM

1. Access

Groups 1 through 3, Configurations 1, 3 and 4; Groups 4 through 11, Configurations 1 and 4:

a. Fully extend the trailing edge flaps. Get access to the outboard side of the frame at STA 727 

through the opening in the flap fairing. At the operators option, for more access, remove the 

fairing for the inboard track of the inboard flap as given in 737-100/200 AMM 27-51-141 or 

737-300/400/500 AMM 27-51-32. Keep the fairing and all fasteners for installation.

b. Get access to the inboard side of the frame at STA 727 from inside the wheel well. On the 

left side, at the operators option for more access, disconnect the connectors for the gauge 

and the detonator on the aft fire bottle as given in 737-100/200 AMM 26-21-11 or 737-300/

400/500 AMM 26-21-11.

2. Auxiliary Chord Inspection

Groups 1 through 3, Configurations 1, 3 and 4; Groups 4 through 11, Configurations 1 and 4: Do 

the inspection that follows at the threshold specified in Paragraph 1.E., Compliance, Table 5. 

a. Groups 1 through 3, Configuration 3: Do the internal detailed inspection and eddy current 

inspection of the STA 727 auxiliary chord radius shown in Figure 11.

b. Groups 1 through 3, Configuration 4: Do the internal detailed inspection and eddy current 

inspection of the STA 727 auxiliary chord radius shown in Figure 12.

c. Groups 1 through 3, Configuration 1; Groups 4 through 11, Configurations 1 and 4: Do the 

internal detailed inspection and eddy current inspection of the STA 727 auxiliary chord 

radius shown in Figure 24.

d. If cracks are found, repair before further flight. Contact Boeing for repair data.

NOTE:A local repair will be provided to address the STA 727 frame auxiliary chord cracks.

3. STA 727 Frame Outboard Chord Inspection

Groups 1 through 11, Configurations 1 and 4: Do the inspections that follow at the thresholds 

specified in Paragraph 1.E., Compliance, Table 2 or 3 as applicable. 

a. Do the external ultrasonic inspection of the STA 727 frame outboard chord forward flange 

as shown in Figure 7.
 

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ALERT ALERT

b. Groups 1 through 11, Configuration 1: Do the external (wheel well) eddy current inspection 

of the replaced STA 727 frame outboard chord forward flange shown in Figure 8.

c. Groups 1 through 11, Configuration 4: Do the external (wheel well) surface HFEC inspection 

of the STA 727 frame outboard chord forward flange as shown in Figure 9.

CAUTION: MAKE SURE FASTENER HOLES ARE ROUND BEFORE PERFORMING THE

FIGURE 10 INSPECTIONS. 

d. Do the open hole eddy current inspection of the STA 727 frame outboard chord forward 

flange shown in Figure 10.

NOTE:The inspection provided in Figure 10 inspects for cracks in the aluminum STA 727 

frame chord. Inspection of steel parts with this inspection procedure may produce 

false positive crack indications. This service bulletin does not require the inspection 

of the steel repair doubler used for short edge margin repair for Group 10 and Group 

11 airplane.

NOTE:When performing the open hole eddy current inspections of the STA 727 frame 

outboard chord shown in Figure 10, it is recommended to minimize the growth of the 

fastener hole diameter when inspecting the hole or installing a fastener. Larger 

fastener holes may impact future inspections and the accomplishment of PART 6 - 

STA 727 Frame Outboard Chord Preventive Modification. 

CAUTION: THE PART 4 - STA 727 FRAME OUTBOARD CHORD TIME-LIMITED REPAIR IS

LIMITED TO CRACKS THAT EXTEND FROM THE FORWARD EDGE OF THE

CHORD, OR FROM THE FASTENER HOLE, BUT DO NOT EXTEND PAST THE

SECOND FASTENER HOLE AFT. CRACKS NOT MEETING THIS DESCRIPTION

MUST BE REPAIRED BY PART 3 - STA 727 FRAME OUTBOARD CHORD

REPAIR.

e. If cracks are found, repair before further flight as shown in PART 3 - STA 727 Frame 

Outboard Chord Repair or PART 4 - STA 727 Frame Outboard Chord Time-Limited Repair. 

If the repairs shown in PART 3 or PART 4 cannot be installed, contact Boeing for repair data. 

If a PART 3 repair is installed, inspections are still required per Compliance Table 3. If a 

PART 3 repair is installed along with a PART 6 modification, an inspection may be required 

per Compliance Table 4. If a PART 4 repair is installed then replacement is required per 

Compliance Table 6. Refer to Paragraph 1.E., Compliance, Table 3 or 4 or 6 as applicable.

(1) Groups 1 through 9, Configurations 1 and 4: Repair as shown in PART 3 - STA 727 

Frame Outboard Chord Repair or PART 4 - STA 727 Frame Outboard Chord 

Time-Limited Repair. If the repairs shown in PART 3 or PART 4 cannot be installed, 

contact Boeing for repair data. If a PART 3 repair is installed, inspections are still 

required per Compliance Table 3. If a PART 3 repair is installed along with a PART 6 

modification, an inspection may be required per Compliance Table 4. If a PART 4 repair 

is installed then replacement is required per Compliance Table 6. Refer to Paragraph 

1.E., Compliance, Table 3 or 4 or 6 as applicable.

(2) Groups 10 and 11, Configurations 1 and 4: Contact Boeing for repair data.
 

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ALERT ALERT

f. Groups 1 through 9, Configurations 1 and 4: If no cracks are found, put the airplane back to 

a serviceable condition or modify as shown in PART 6 - STA 727 Frame Outboard Chord 

Preventive Modification. If the modification is not installed, repeat the PART 1 inspections 

at the time specified in Paragraph 1.E., Compliance, Table 2 or 3 as applicable. If a STA 727 

frame outboard chord interim modification is installed, do the inspections in PART 8 - STA 

727 Frame Outboard Chord Interim Modification at the time specified in Paragraph 1.E., 

Compliance, Table 4. If a STA 727 frame outboard chord permanent modification is 

installed, inspections of the STA 727 frame outboard chord are terminated. 

g. Groups 10 and 11, Configurations 1 and 4: If no cracks are found, put the airplane back to 

a serviceable condition or contact Boeing for instructions to install a STA 727 Frame 

Outboard Chord Preventive Modification. If the modification is not installed, repeat the PART 

1 inspections at the time specified in Paragraph 1.E., Compliance, Table 2 or 3 as 

applicable.

4. Close Access

Groups 1 through 3, Configurations 1, 3 and 4, Groups 4 through 11, Configurations 1 and 4:

a. If disconnected in Step 1. b, install the connectors for the gauge and the detonator on the 

aft fire bottle as given in 737-100/200 AMM 26-21-11 or 737-300/400/500 AMM 26-21-11.

b. If removed in Step 1. a, install the fairing for the inboard track of the inboard flap as given in 

737-100/200 AMM 27-51-141 or 737-300/400/500 AMM 27-51-32.

c. Return the airplane to a serviceable condition.

PART 2 - ECONOMIC INSPECTION PROGRAM

1. Access

Groups 1 through 6, 9 and 10:

NOTE:This inspection program looks for cracks in the stringer (S)-18A outboard chord where the 

chord thickness is 0.20 or 0.33 inches thick at STA 727.

Group 9: This inspection program applies to one side of the airplane only where the S-18A 

Outboard Chord has a thickness of 0.33 inch at STA 727. The S-18A Outboard Chord is 

0.33 inch thick on the left side of line numbers 2938 and 2940 and on the right side of line 

number 2942. 

a. Fully extend the trailing edge flaps. Get access to the outboard side of the frame at STA 727 

through the opening in the flap fairing. At the operators option, for more access, remove the 

fairing for the inboard track of the inboard flap as given in 737-100/200 AMM 27-51-141 or 

737-300/400/500 AMM 27-51-32. Keep the fairing and all fasteners for installation. 

b. Get access to the inboard side of the frame at STA 727 from inside the wheel well. On the 

left side, at the operators option for more access, disconnect the connectors for the gauge 

and the detonator on the aft fire bottle as given in 737-100/200 AMM 26-21-11 or 737-300/

400/500 AMM 26-21-11.

2. Stringer 18A Outboard Chord Inspection
 

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Group 1 through 6, 9 and 10: Do the inspections that follow at the thresholds specified in the 

Compliance section.

a. Group 1: Do the external Detailed Inspection and the Eddy Current Inspection of the S-18A 

outboard chord as shown in Figure 13.

b. Group 2; Group 3; Group 4; Group 5; Group 6; Group 9; Group 10: Do the external Detailed 

Inspection and the Eddy Current Inspection of the S-18A outboard chord as shown in Figure 

14.

c. Group 1; Group 2; Group 3; Group 4; Group 5; Group 6; Group 9: If cracks are found, repair 

before further flight as shown in PART 5 - S-18A Outboard Chord Repair. If the repairs 

shown in PART 5 cannot be installed, contact Boeing for repair data. If a S-18A repair is 

installed, S-18A outboard chord inspections are terminated.

d. Group 10: If cracks are found, repair before further flight. Contact Boeing for repair data.

e. Group 1; Group 2; Group 3; Group 4; Group 5; Group 6; Group 9: If no cracks are found, put 

the airplane back to a serviceable condition or modify as shown in PART 7 - S-18A Outboard 

Chord Preventive Modification. If the S-18A outboard chord modification is not installed, 

repeat the PART 2 inspections at the time specified in Paragraph 1.E., Compliance, Table 

1. If a S-18A outboard chord modification is installed, inspections of the S-18A outboard 

chord are terminated. 

f. Group 10: If no cracks are found, put the airplane back to a serviceable condition or contact 

Boeing to install a S-18A Outboard Chord Preventive Modification. If the S-18A outboard 

chord modification is not installed, repeat the PART 2 inspections at the time specified in 

Paragraph 1.E., Compliance, Table 1.

3. Close Access

Groups 1 through 6, 9 and 10:

a. If disconnected in Step 1. b, install the connectors for the gauge and the detonator on the 

aft fire bottle as given in 737-100/200 AMM 26-21-11 or 737-300/400/500 AMM 26-21-11.

b. If removed in Step 1. a, install the fairing for the inboard track of the inboard flap as given in 

737-100/200 AMM 27-51-141 or 737-300/400/500 AMM 27-51-32.

c. Return the airplane to a serviceable condition.

PART 3 - STA 727 FRAME OUTBOARD CHORD REPAIR

1. Prepare Airplane For Maintenance

Groups 1-9

NOTE:STA 727 Frame Outboard Chord Repair is not available for Groups 10 and 11, contact 

Boeing for repair data.

a. Support the airplane in the jig position as given in 737-100/200 SRM 51-50-1 or 737-300 

SRM 51-50-02 or 737-400 SRM 51-50-02 or 737-500 SRM 51-50-02. If support cradles are 

used, do not install the cradle at STA 727 to allow access for repair.
 

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2. STA 727 Frame Outboard Chord Repair

a. As of the release date of Revision 2 of this service bulletin, replace the STA 727 frame 

outboard chord as given in Boeing Service Bulletin 737-53-1088 Revision 1, dated May 25, 

2006. If the frame outboard chord was replaced and modified as given in the initial release 

of Boeing Service Bulletin 737-53-1088, no more work is necessary.

NOTE:

1. When performing the PART 3 - STA 727 frame outboard chord repair, it is 

recommended to keep expansion of the fastener holes common to the S-18A 

outboard chord to a minimum. Larger diameter fastener holes may impact future 

inspections and the accomplishment of PART 6 - STA 727 Frame Outboard 

Chord Preventive Modification.

2. Boeing recommends that the PART 6 - STA 727 frame outboard chord 

preventive modification and PART 7 - S-18A outboard chord preventive 

modification be installed with the replaced STA 727 frame outboard chord. 

Operators may install the PART 6 - STA 727 frame outboard chord preventive 

modification and PART 7 - S-18A outboard chord preventive modification at a 

later time, however inspections may be required and increased installation costs 

will be incurred.

3. The PART 3 - STA 727 frame outboard chord repair can be accomplished at the 

same time on both the left and right sides of the airplane.

4. If the Part 6 - STA 727 Frame Outboard Chord Preventive Modification, or the 

Part 5 - S-18A Outboard Chord Repair or the Part 7 - S-18A Outboard Chord 

Preventive Modification is being accomplished at the same time as a STA 727 

frame outboard chord replacement using instructions from Boeing Service 

Bulletin 737-53-1088 Revision 1, dated May 25, 2006, use the fasteners as 

specified in this service bulletin at common locations. 

PART 4 - STA 727 FRAME OUTBOARD CHORD TIME-LIMITED REPAIR

1. Prepare Airplane For Maintenance

NOTE:The Time-Limited Repair is intended to provide the operator with options if a replacement 

chord is not available in a timely manner. Boeing recommends that a replacement chord 

be used whenever possible. The Time-Limited Repair will result in additional work and 

future chord replacement.

CAUTION: THE INSTALLATION OF THIS TIME-LIMITED REPAIR USES NESTED ANGLES

AND PLATES THAT MAY RESULT IN LOW EDGE MARGINS AND

INSUFFICIENT RADIUS CLEARANCE FOR FASTENER INSTALLATIONS.

CHECK EXISTING FASTENER LOCATIONS PRIOR TO PROCEEDING WITH
 

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THIS INSTALLATION. 

THE PART 4 - STA 727 FRAME OUTBOARD CHORD TIME-LIMITED REPAIR IS 

LIMITED TO CRACKS THAT EXTEND FROM THE FORWARD EDGE OF THE 

CHORD, OR FROM THE FASTENER HOLE, BUT DO NOT EXTEND PAST THE 

SECOND FASTENER HOLE AFT. THE EXTENT OF THE CRACK WILL NOT BE 

KNOWN UNTIL AFTER THE EXISTING STRUCTURE IS TRIMMED OR 

REMOVED. CRACKS NOT MEETING THIS DESCRIPTION MUST BE REPAIRED 

BY PART 3 - STA 727 FRAME OUTBOARD CHORD REPAIR.

FOR AIRPLANES WITH A SHEAR BEAM REPAIRED PER S/B 737-53-1170, THE 

FRAME CHORD MUST BE REPAIRED USING PART 3 - STA 727 FRAME 

OUTBOARD CHORD REPAIR. 

a. If a repair was previously installed per drawing 65C36009 to address short edge margins 

along S-18A and the existing repair is common to STA 727, contact Boeing for repair data.

b. Support the airplane in the jig position as given in 737-100/200 SRM 51-50-1 or 737-300 

SRM 51-50-02 or 737-400 SRM 51-50-02 or 737-500 SRM 51-50-02. If support cradles are 

used, do not install the cradle at STA 727 to allow access for repair.

c. Fully extend the trailing edge flaps. Get access to the outboard side of the frame at STA 727 

through the opening in the flap fairing. At the operators option, for more access, remove the 

fairing for the inboard track of the inboard flap as given in 737-100/200 AMM 27-51-141 or 

737-300/400/500 AMM 27-51-32. Keep the fairing and all fasteners for installation. 

d. Remove the following equipment from the wheel well and cargo compartments as 

necessary for access to the STA 727 Frame Outboard Chord.

2. Stringer 18A and STA 727 Outboard Chord Inspection

a. Do a General Visual Inspection to identify the quantity of fasteners attaching the stringer 

S-18A to the STA 727 frame outboard chord forward flange. If four fasteners are identified 

then proceed with the time-limited repair. If less than four fasteners are identified, contact 

Boeing for repair data.

b. Do a Detailed Inspection of the exposed STA 727 outboard chord forward flange for 

corrosion.

Equipment 737-100/-200 AMM Subject 737-300/-400/-500 AMM Subject

Wing-to-Body Fairing 53-51-21 53-51-21

Fire Extinguisher Bottles 26-21-11 26-21-11

Cargo Liner 25-52-123 25-52-73

Cargo Floor Panel 25-52-51 25-52-51

Cargo Bulkhead Panel 25-52-131 25-52-81

Auxiliary Fuel Tank (if installed) 53-23-1 53-23-12

Insulation Blankets 25-52-141 25-52-91

Flap Right Angle Gearbox 27-51-261 27-51-67
 

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(1) If corrosion is found, remove the corrosion as shown in 737-100/200 SRM 51-10-6 or 

737-300 SRM 51-10-02 or 737-400 SRM 51-10-02 or 737-500 SRM 51-10-02.

c. On the forward side of the bulkhead at STA 727, locate the horizontal stiffener at 

approximately Water Line (WL) 190. Trim the horizontal stiffener and S-18A shear beam 

web as shown in Figure 15 to allow for the installation of the repair angle.

NOTE:

1. Boeing Service Bulletin 737-53-1066 and 737-53-1170 provide a repair or a 

preventive modification that installs sheet aluminum components common to the 

S-18A shear beam and the horizontal stiffener at approximately WL 190.

2. This repair is limited to cracks that extend from the forward edge of the chord, or 

from the forward fastener hole, but do not extend past the second fastener hole 

aft. The extent of the crack will not be known until after existing structure is 

trimmed or removed. Cracks not meeting this description must be repaired by 

PART 3 - STA 727 Frame Outboard Chord Repair.

d. Do a High Frequency Eddy Current (HFEC) inspection of the inboard surface of the STA 

727 frame chord to determine the location of the end of the crack as shown in Figure 16. As 

an option to trimming the shear beam flange, remove the shear beam web from 

approximately STA 711 to STA 727 to provide access to the inboard surface of the STA 727 

frame outboard chord forward flange.

NOTE:The shear beam web removal option will allow inspection of the frame chord without 

trimming the shear beam. If the STA 727 frame chord outboard flange is cracked 

beyond allowable limits for the time-limited repair, this option will allow re-use of the 

shear beam web with a STA 727 frame chord replacement.

(1) If the crack extends from the forward edge of the chord, or from the forward fastener 

hole, but does not extend past the second fastener hole aft, then stop drill the crack 

using the procedure given in 737-100/200 SRM 51-10-1 or 737-300 SRM 51-10-02 or 

737-400 SRM 51-10-02 or 737-500 SRM 51-10-02. Use 737 NDT Part 6 51-00-00 

Figure 16 for open hole inspections using the 0.020 notch standard. If the crack is 

contained within a fastener hole in the STA 727 frame outboard chord, the fastener 

hole is the stop drill hole, otherwise drill a new hole in the STA 727 frame outboard 

chord only, as described in the SRM. Existing fastener holes acting as a stop drill hole 

or a new stop drill hole must be inspected and have an insurance cut as described in 

the SRM. Contact Boeing if a new stop drill hole location is less than 1.2 stop drill hole 

diameters from existing holes. For both new and existing holes do the stop drill and 

insurance cut in the STA 727 frame outboard chord only.

NOTE:Do the stop drill and insurance cut of holes in the STA 727 frame outboard chord 

from the wheel well side. Protect the structure on the exit side of the hole from 

potential drill damage.

(2) If the crack or stop drill hole extends past the second fastener hole aft of the forward 

edge of the chord, do PART 3 - STA 727 Frame Outboard Chord Repair. If the shear 

beam was optionally removed, reinstall it using the same size and type fasteners as 

removed unless stated differently in this service bulletin. Install hex drive and lock bolt 

fasteners in transition fit holes using BMS5-95.
 

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e. Make the repair parts as shown in Figure 17.

f. Install the repair parts as shown in Figure 18.

If the shear beam web was removed, reinstall the shear beam web using the same size and 

type fasteners as were removed. Install hex drive and lock bolt fasteners in transition fit 

holes with BMS5-95. Reinstall fasteners common to the repair parts as shown in Figure 18.

NOTE:

1. The repair angle replaces the forward splice angle of the STA 727 frame 

outboard chord if a chord replacement kit has been previously installed per 

Boeing Service Bulletin 737-53-1088. Use the existing fastener locations 

common to the area previously covered by the forward splice angle. Replace 

fasteners with the same size and type. Install hex drive and lock bolt fasteners 

in transition fit holes with BMS5-95. Install fasteners in new locations as shown 

in Figure 18.

2. When performing the STA 727 frame outboard chord Time-Limited repair, it is 

recommended to keep expansion of the fastener holes common to the S-18A 

outboard chord to a minimum. Larger diameter fastener holes may impact future 

inspections and the accomplishment of PART 6 - STA 727 Frame Outboard 

Chord Preventive Modification.

3. Close Access

a. Install the equipment in the wheel well and cargo hold that was removed for access.

b. At the time specified in Paragraph 1.E. Compliance Table 6, replace the STA 727 frame 

outboard chord as shown in PART 9: Replacement of the Time-limited Repair.

c. Put the airplane back to a serviceable condition.

PART 5 - STRINGER 18A OUTBOARD CHORD REPAIR

1. Prepare Airplane For Maintenance

Groups 1 through 6 and Group 9:

NOTE:Group 9: This repair only applies to one side of the airplane only where the S-18A 

Outboard Chord has a thickness of 0.33 inch at STA 727.

NOTE:S-18A repair is not available for Groups 10 and 11, contact Boeing for repair data.

a. Support the airplane in the jig position as given in 737-100/200 SRM 51-50-1 or 737-300 

SRM 51-50-02 or 737-400 SRM 51-50-02 or 737-500 SRM 51-50-02. If support cradles are 

used, do not install the cradle at STA 727 to allow access for repair.

b. Fully extend the trailing edge flaps. Get access to the outboard side of the frame at STA 727 

through the opening in the flap fairing. At the operators option, for more access, remove the 

fairing for the inboard track of the inboard flap as given in 737-100/200 AMM 27-51-141 or 

737-300/400/500 AMM 27-51-32. Keep the fairing and all fasteners for installation. 
 

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c. Remove the following equipment from the wheel well and cargo compartments as 

necessary for access to the STA 727 Frame Outboard Chord.

2. Stringer 18A Outboard Chord Inspection

a. Do the inspection as shown in Figure 21 to identify the quantity of fasteners in the aft end of 

the S-18A outboard chord aft of the STA 727 frame outboard chord aft flange. If there are 

less than 15 fasteners in a single row, contact Boeing for repair data.

b. Do the S-18A outboard chord repair as shown in drawing 65C38642.

NOTE:

1. Revision 1 and earlier versions of this service bulletin previously installed the 

S-18A outboard chord repair as shown in drawing 65C37565. Drawing 

65C37565 is now superseded by drawing 65C38642.

2. When performing the PART 5 - S-18A Outboard Chord Repair, it is 

recommended to keep expansion of the fastener holes common to STA 727 

frame outboard chord to a minimum when installing fasteners. Larger fastener 

hole diameters may impact future inspections and the accomplishment of PART 

6 - STA 727 Frame Outboard Chord Preventive Modification. 

3. Drawing 65C38642 provides repair procedures for airplanes with and without the 

PART 6 - STA 727 frame outboard chord preventive modification installed.

4. The S-18A repair parts can be purchased as a repair kit 65C38642, refer to 

Paragraph 2.A., Material - Price and Availability, or, as an option, the S-18A 

repair parts can be made by the operator. Refer to Drawing 65C38642.

5. The stringer S-18A repair installs new structure to replace most of the STA 727 

fairing support structure that was removed.

3. Close Access

a. Install the equipment that was removed for access.

b. Put the airplane back to a serviceable condition.

Equipment 737-100/-200 AMM Subject 737-300/-400/-500 AMM Subject

Wing-to-Body Fairing 53-51-21 53-51-21

Fire Extinguisher Bottles 26-21-11 26-21-11

Cargo Liner 25-52-123 25-52-73

Cargo Floor Panel 25-52-51 25-52-51

Cargo Bulkhead Panel 25-52-131 25-52-81

Auxiliary Fuel Tank (if installed) 53-23-1 53-23-12

Insulation Blankets 25-52-141 25-52-91

Flap Right Angle Gearbox 27-51-261 27-51-67
 

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PART 6 - STA 727 FRAME OUTBOARD CHORD PREVENTIVE MODIFICATION

1. Access

Group 1 through 9

NOTE:

1. STA 727 frame outboard chord preventive modification is not available for Groups 10 

and 11, contact Boeing for repair data.

2. When the Part 6 - STA 727 Frame Outboard Chord Preventive Modification, or the 

Part 5 - S-18A Outboard Chord Repair or the Part 7 - S-18A Outboard Chord 

Preventive Modification is being accomplished at the same time as a STA 727 frame 

outboard chord replacement using instructions from Boeing Service Bulletin 

737-53-1088 Revision 1, dated May 25, 2006, use the fasteners as specified in this 

service bulletin at common locations. 

3. These instructions provide a STA 727 frame outboard chord modification option to 

address specific edge margin conditions that result in follow-on inspections. 

4. Boeing recommends that the PART 7 - S-18A outboard chord preventive modification 

be installed with the PART 6 - STA 727 frame outboard chord preventive modification.

a. If a repair was previously installed per drawing 65C36009 to address short edge margins 

along S-18A and the existing repair is common to the locations to be impacted by the Part 

6 Modification, contact Boeing for repair data.

b. Support the airplane in the jig position as given in 737-100/200 SRM 51-50-1 or 737-300 

SRM 51-50-02 or 737-400 SRM 51-50-02 or 737-500 SRM 51-50-02. If support cradles are 

used, do not install the cradle at STA 727 to allow access for the modification.

c. Fully extend the trailing edge flaps. Get access to the outboard side of the frame at STA 727 

through the opening in the flap fairing. At the operators option, for more access, remove the 

fairing for the inboard track of the inboard flap as given in 737-100/200 AMM 27-51-141 or 

737-300/400/500 AMM 27-51-32. Keep the fairing and all fasteners for installation. 

d. Remove the following equipment from the wheel well and cargo compartment as necessary 

for access to the STA 727 Frame Outboard Chord and the inboard side of S-18A between 

STA 709 and STA 727.

Equipment 737-100/-200 

AMM Subject

737-300/-400/-500 

AMM Subject

Wing-to-Body Fairing 53-51-21 53-51-21

Fire Extinguisher Bottles 26-21-11 26-21-11

Cargo Liner 25-52-123 25-52-73

Cargo Floor Panel 25-52-51 25-52-51

Cargo Bulkhead Panel 25-52-131 25-52-81
 

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2. STA 727 Frame Outboard Chord Forward and Aft Flange Inspection

a. Do a General Visual Inspection to identify the quantity of fasteners attaching the S-18A 

stringer to the STA 727 frame outboard chord forward flange. If four fasteners are identified 

then proceed with the preventive modification. If less than four fasteners are identified, 

contact Boeing for repair data. 

b. Do the inspection as shown in Figure 21 to identify the quantity of fasteners in the aft end of 

the S-18A outboard chord aft of the STA 727 frame outboard chord aft flange. If there are 

less than 15 fasteners in a single row, contact Boeing for repair data.

c. Do a Detailed Inspection of the exposed STA 727 outboard chord forward flange for 

corrosion.

(1) If corrosion is found, remove the corrosion as shown in 737-100/200 SRM 51-10-6 or 

737-300 SRM 51-10-02 or 737-400 SRM 51-10-02 or 737-500 SRM 51-10-02.

NOTE:A corrosion inspection is not required when a STA 727 frame outboard chord is 

replaced and the STA 727 frame outboard chord preventive modification is 

installed at the same time.

d. Remove fasteners as required for modification.

e. Inspect for disbonding of the doublers from the skins of both the forward and aft skin panels 

using 737 NDT Manual Part 4, 51-40-00 Figure 1. Inspect the area that will be covered by 

the STA 727 frame outboard chord preventive modification strap. If disbonding is identified 

contact Boeing for repair data before further flight.

f. Evaluate the existing condition of the fastener holes in the STA 727 frame outboard chord 

at the intersection of the S-18A outboard chord as shown below.

(1) Measure the edge margin and inspect fastener holes for roundness at fastener 

locations in the STA 727 frame outboard chord forward flange common to the S-18A 

outboard chord as shown in Figure 22.

(2) Do an open hole HFEC inspection of the 4 fastener holes in the STA 727 frame 

outboard chord forward flange as shown in Figure 10 using a 0.020 notch standard. 

NOTE:The use of 0.02 inch notch standards in the open hole inspection may give false 

crack indications if holes are not clean or round. The holes can be oversized for 

clean-up within the limitations of tables 1 and 2 provided the appropriate 

insurance cut and edge margins are obtained.

(3) Do an external ultrasonic inspection of the STA 727 frame outboard chord forward 

flange as shown in Figure 7.

Auxiliary Fuel Tank (if installed) 53-23-1 53-23-11

Insulation Blankets 25-52-141 25-52-91

Flap Right Angle Gearbox 27-51-261 27-51-67

Equipment 737-100/-200 

AMM Subject

737-300/-400/-500 

AMM Subject
 

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(4) Groups 1 through 9, Configuration 4: From the wheel well, do a surface HFEC 

inspection of the STA 727 frame outboard chord forward flange as shown in Figure 9.

(5) Groups 1 through 9, Configuration 1: From the wheel well, do the eddy current 

inspections (LFEC and HFEC) of the STA 727 frame outboard chord forward flange as 

shown in Figure 8.

g. If cracks are found, repair before further flight as shown in PART 3 - STA 727 Frame 

Outboard Chord Repair or PART 4 - STA 727 Frame Outboard Chord Time-Limited Repair. 

If the repairs shown in PART 3 or PART 4 cannot be installed, contact Boeing for repair data. 

If a PART 3 or PART 4 repair is installed, inspections are still required. Refer to Paragraph 

1.E., Compliance.

h. If no cracks are found, then determine if a permanent modification, interim modification or a 

frame replacement should be accomplished. If the Edge Margin after insurance cut is 1.7 or 

greater (Table 1), then install a permanent modification. If the Edge Margin after insurance 

cut is less than 1.7 but greater than or equal to 1.5 (Table 2), then install an interim 

modification. If the edge margin is less than 1.5 then replace the 727 frame chord. 

NOTE:

1. If the interim modification is installed, then a one-time post modification 

inspection will be required in accordance with Paragraph 1.E. Compliance, 

Table 4. 

2. The chord replacement as given in this service bulletin installs a chord with extra 

edge material on the forward flange at stringer 18A.

i. Install the applicable STA 727 frame outboard chord modification. Use drawing 65C37277 

and the minimum fastener size required to meet the installation requirements specified in 

Table 1 or Table 2. Table 3 provides titanium fasteners and associated collars as equivalent 

to the steel fasteners provided in Table 1 or Table 2. 

NOTE:

1. Make sure proper insurance cuts are taken as shown in Tables 1 and 2, after the 

HFEC hole probe inspection shows no crack indications. 

2. Use repair washers as directed by drawing 65C37277 where existing 

countersink locations are covered by the modification strap.

Table 1: Permanent Modification (Edge Margin greater than 1.7D) (a)

Starting Hole 

Size (Nominal + 

Oversize)

Minimum 

Starting Edge 

Margin 

(1.7D Final)

Hole Diameter 

Range for Hole 

Probe Inspection 

(b)

Final Close 

Ream Hole Size 

For Insurance 

Cut

Fastener 

1/4 0.53 0.2495 - 0.2661 0.3120 - 0.3130 BACB30MB10A* + 

BACC30BH10

1/4 + 1/64 0.53 0.2651 - 0.2661 0.3120 - 0.3130 BACB30MB10A* + 

BACC30BH10

1/4 + 1/32 0.56 0.2807 - 0.2817 0.3276 - 0.3286 BACB30MC10A* + 

BACC30BH10
 

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1/4 + 3/64 0.58 0.2963 - 0.2973 0.3432 - 0.3442 BACB30MD10A* + 

BACC30AC10

5/16 0.61 0.312 - 0.313 0.3589 - 0.3599 BACB30ME10A* + 

BACC30U10

(a) Used on production or replaced STA 727 frame outboard chords.

(b) 737 NDT Part 6, 51-00-00 Figure 16 with 0.020 notch standard.

Table 2: Interim Modification With Follow-on Inspections (Edge Margin greater than 1.5D but less than

1.7D) (a)

Starting Hole 

Size (Nominal + 

Oversize)

Minimum 

Starting Edge 

Margin 

(1.5D Final)

Hole Diameter 

Range for Hole 

Probe Inspection 

(b)

Final Close 

Ream Hole Size 

For Insurance 

Cut

Fastener 

1/4 0.47 0.2495 - 0.2661 0.3120 - 0.3130 BACB30MB10A* + 

BACC30BH10

1/4 + 1/64 0.47 0.2651 - 0.2661 0.3120 - 0.3130 BACB30MB10A* + 

BACC30BH10

1/4 + 1/32 0.49 0.2807 - 0.2817 0.3276 - 0.3286 BACB30MC10A* + 

BACC30BH10

1/4 + 3/64 0.52 0.2963 - 0.2973 0.3432 - 0.3442 BACB30MD10A* + 

BACC30AC10

5/16 0.54 0.312 - 0.313 0.3589 - 0.3599 BACB30ME10A* + 

BACC30U10

(a) Used on production or replaced STA 727 frame outboard chords.

(b) 737 NDT Part 6, 51-00-00 Figure 16 with 0.020 notch standard.

Table 3: Titanium Equivalent Fasteners and Collars

Steel Fasteners + 

Collar 

Titanium Fasteners 

+ Collar 

BACB30MB*A* + 

BACC30BH*

BACB30NX*K* + 

BACC30BH*

BACB30MC*A* + 

BACC30BH*

BACB30NX*K*X + 

BACC30BH*

BACB30MD*A* + 

BACC30AC*

BACB30NX*K*Y + 

BACC30AC*

Table 1: Permanent Modification (Edge Margin greater than 1.7D) (a)

Starting Hole 

Size (Nominal + 

Oversize)

Minimum 

Starting Edge 

Margin 

(1.7D Final)

Hole Diameter 

Range for Hole 

Probe Inspection 

(b)

Final Close 

Ream Hole Size 

For Insurance 

Cut

Fastener 
 

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

NOTE:

1. Service Bulletin 737-53-1077 installs a repair patch at STA 727 and S-18A. If the 

repair patch is installed, then the 69-78773-10 filler is not needed. If necessary, 

install an additional filler forward of STA 727 to match the thickness of the repair 

patch. If necessary, also use a tapered filler forward of STA 727, same as the 

69-78773-7 tapered filler, but with the thickness increased to match the repair 

patch. Keep the same taper ratio.

2. The preventive modification installs new structure to replace most of the STA 

727 fairing support structure that was removed. 

3. Close Access

a. Install the equipment that was removed for access.

b. Put the airplane back to a serviceable condition.

PART 7 - STRINGER 18A OUTBOARD CHORD PREVENTIVE MODIFICATION

1. Access

Group 1; Group 2; Group 3; Group 4; Group 5; Group 6; Group 9:

NOTE:

1. S-18A outboard chord preventive modification is not available for Groups 10 and 11, 

contact Boeing for repair data.

2. Boeing recommends that the PART 7 - S-18A outboard chord preventive modification 

be installed with the PART 6 - STA 727 frame outboard chord preventive modification.

3. Group 9: The PART 7 - S-18A outboard chord preventive modification only applies to 

one side of the airplane only where the S-18A Outboard Chord has a thickness of 

0.33 inch at STA 727.

a. Fully extend the trailing edge flaps. Get access to the outboard side of the frame at STA 727 

through the opening in the flap fairing. At the operators option, for more access, remove the 

fairing for the inboard track of the inboard flap as given in 737-100/200 AMM 27-51-141 or 

737-300/400/500 AMM 27-51-32. Keep the fairing and all fasteners for installation. 

b. Remove the Wing-to-Body Fairings as necessary for access to the S-18A Outboard Chord 

as given in 737-100/200/300/400/500 AMM 53-51-21.
 

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ALERT ALERT

2. Preventive Modification

a. Do the inspection as shown in Figure 21 to identify the quantity of fasteners in the aft end of 

the S-18A outboard chord aft of the STA 727 frame outboard chord aft flange. If there are 

less than 15 fasteners in a single row, contact Boeing for repair data.

b. Group 1; Group 2: Do the S-18A outboard chord modification as specified in drawing 

65C38491-1/-2.

NOTE:

1. The stringer S-18A preventive modification installs new structure to replace most 

of the STA 727 fairing support structure that was removed.

2. When performing the PART 7 - S-18A Outboard Chord Preventive Modification, 

it is recommended to keep expansion of the fastener holes common to the STA 

727 frame outboard chord to a minimum when installing fasteners. Larger 

fastener hole diameters may impact future inspections and the accomplishment 

of PART 6 - STA 727 Frame Outboard Chord Preventive Modification. 

c. Group 3; Group 4; Group 5; Group 6; Group 9: Do the S-18A outboard chord modification 

as specified in drawing 65C37277.

NOTE:

1. The stringer S-18A preventive modification installs new structure to replace most 

of the STA 727 fairing support structure that was removed.

2. When performing the PART 7 - S-18A Outboard Chord Preventive Modification, 

it is recommended to keep expansion of the fastener holes common to the STA 

727 frame outboard chord to a minimum when installing fasteners. Larger 

fastener hole diameters may impact future inspections and the accomplishment 

of PART 6 - STA 727 Frame Outboard Chord Preventive Modification. 

3. Close Access

a. Install the equipment that was removed for access.

b. Put the airplane back to a serviceable condition.

PART 8 - ONE TIME INSPECTION OF THE STA 727 FRAME OUTBOARD CHORD INTERIM 

MODIFICATION

1. Access

a. Fully extend the trailing edge flaps. Get access to the outboard side of the frame at STA 727 

through the opening in the flap fairing. At the operators option, for more access, remove the 

fairing for the inboard track of the inboard flap as given in 737-100/200 AMM 27-51-141 or 

737-300/400/500 AMM 27-51-32. Keep the fairing and all fasteners for installation. 
 

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ALERT ALERT

b. Get access to the inboard side of the frame at STA 727 from inside the wheel well. On the 

left side, at the operators option for more access, disconnect the connectors for the gauge 

and the detonator on the aft fire bottle as given in 737-100/200 AMM 26-21-11 or 737-300/

400/500 AMM 26-21-11.

2. STA 727 Frame Outboard Chord Inspection

a. Do the inspections that follow at the thresholds specified in paragraph 1.E., Compliance, 

Table 4. 

b. At each fastener location with a frame chord edge margin greater than or equal to 1.5D and 

less than 1.7D do a one-time HFEC hole probe inspection of the STA 727 frame outboard 

chord as shown Figure 10.

c. Replace hex drive fasteners and collars with the same size and type. If necessary, use 1/64 

inch oversize. Install hex drive fasteners in a close ream fit at these locations with steel 

parts. Install wet with BMS5-95.

NOTE:Do not exceed 3/8 fastener diameter. If final edge margin with replacement fasteners 

will be less than 1.5D, contact Boeing.

3. Close Access

a. Install and reconnect the equipment in the wheel well that was removed or disconnected for 

access.

b. Put the airplane back to a serviceable condition.

PART 9 - REPLACMENT OF THE TIME-LIMITED REPAIR

1. Access

NOTE:Boeing recommends that the PART 6 - STA 727 frame outboard chord preventive 

modification and PART 7 - S-18A outboard chord preventive modification be installed at 

the same time as the PART 3 - STA 727 frame outboard chord replacement. Operators 

may do the PART 6 - STA 727 frame outboard chord preventive modification and PART 7 

- S-18A outboard chord preventive modification at a later time, however inspections may 

be required and increased installation costs will be incurred.

a. Fully extend the trailing edge flaps. Get access to the outboard side of the frame at STA 727 

through the opening in the flap fairing. At the operators option, for more access, remove the 

fairing for the inboard track of the inboard flap as given in 737-100/200 AMM 27-51-141 or 

737-300/400/500 AMM 27-51-32. Keep the fairing and all fasteners for installation. 

b. Remove the following equipment from the wheel well and cargo compartment as necessary 

for access to the STA 727 Frame Outboard Chord.

Equipment 737-100/-200 AMM Subject 737-300/-400/-500 AMM Subject

Wing-to-Body Fairing 53-51-21 53-51-21

Fire Extinguisher Bottles 26-21-11 26-21-11

Cargo Liner 25-52-123 25-52-73
 

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ALERT ALERT

2. Removal of the Time Limited Repair

a. Remove the Time-Limited Repair as shown in Figure 19.

b. Make new parts for the shear beam repair as shown in the Figure 20.

c. Install PART 3 - STA 727 Frame Outboard Chord Repair using Figure 23 to remove and 

install a new S-18A shear beam web. Remove and replace the shear beam web aft section 

from approximately STA 711 to STA 727. Use the same size and type fasteners as removed. 

Install fasteners common to both the STA 727 frame outboard chord and the shear beam 

web at frame chord installation per instructions provided in Part 3.

(1) Groups 1 and 2, Configurations 1 and 4: Replace the shear beam web using the new 

part 65C38643-1/-2.

(2) Groups 3 through 9, Configurations 1 and 4: Replace the shear beam web using the 

new part 69-78347-1/-2.

(3) For Airplane Line Number 3, contact Boeing for repair instructions.

3. Close Access

a. Install the equipment that was removed for access.

b. Put the airplane back to a serviceable condition.

Cargo Floor Panel 25-52-51 25-52-51

Cargo Bulkhead Panel 25-52-131 25-52-81

Auxiliary Fuel Tank (if installed) 53-23-1 53-23-11

Insulation Blankets 25-52-141 25-52-91

Flap Right Angle Gearbox 27-51-261 27-51-67

Equipment 737-100/-200 AMM Subject 737-300/-400/-500 AMM Subject
 FIGURE 1: THIS FIGURE WAS DELETED AT REVISION 2

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ALERT ALERT

FIGURE 1: THIS FIGURE WAS DELETED AT REVISION 2

NOTE: REVISION 2 REMOVED FIGURE 1

D39061

(SHEET 1 OF 1)
 FIGURE 2: THIS FIGURE WAS DELETED AT REVISION 2

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ALERT ALERT

FIGURE 2: THIS FIGURE WAS DELETED AT REVISION 2

NOTE: REVISION 2 REMOVED FIGURE 2

D41118

(SHEET 1 OF 1)
 FIGURE 3: THIS FIGURE WAS DELETED AT REVISION 2

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ALERT ALERT

FIGURE 3: THIS FIGURE WAS DELETED AT REVISION 2

NOTE: REVISION 2 REMOVED FIGURE 3

D39063

(SHEET 1 OF 1)
 FIGURE 4: THIS FIGURE WAS DELETED AT REVISION 2

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

FIGURE 4: THIS FIGURE WAS DELETED AT REVISION 2

NOTE: REVISION 2 REMOVED FIGURE 4

J74437

(SHEET 1 OF 1)
 FIGURE 5: THIS FIGURE WAS DELETED AT REVISION 2

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ALERT ALERT

FIGURE 5: THIS FIGURE WAS DELETED AT REVISION 2

NOTE: REVISION 2 REMOVED FIGURE 5

D39065

(SHEET 1 OF 1)
 FIGURE 6: THIS FIGURE WAS DELETED AT REVISION 2

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ALERT ALERT

FIGURE 6: THIS FIGURE WAS DELETED AT REVISION 2

NOTE: REVISION 2 REMOVED FIGURE 6

D39067

(SHEET 1 OF 1)
 FIGURE 7: EXTERNAL ULTRASONIC INSPECTION OF THE STA 727 FRAME OUTBOARD CHORD 

FORWARD FLANGE - GROUPS 1 THROUGH 11, CONFIGURATIONS 1 AND 4.

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ALERT ALERT

FIGURE 7: EXTERNAL ULTRASONIC INSPECTION OF THE STA 727 FRAME OUTBOARD CHORD 

FORWARD FLANGE - GROUPS 1 THROUGH 11, CONFIGURATIONS 1 AND 4.

(WING-TO-BODY FAIRING NOT SHOWN)

RIGHT SIDE OPPOSITE

LEFT SIDE SHOWN

SEE A

D39072

(SHEET 1 OF 3)
 FIGURE 7: EXTERNAL ULTRASONIC INSPECTION OF THE STA 727 FRAME OUTBOARD CHORD 

FORWARD FLANGE - GROUPS 1 THROUGH 11, CONFIGURATIONS 1 AND 4.

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ALERT ALERT

INBD

FWD

STA

727

STA

727

FLANGE

FORWARD

FRAME

SKIN

AFT

SKIN

FORWARD

AREA

INSPECTION

SEE B

A

B

D40369

A FLAT STRAP)

STRINGER 18A IS

THE OUTER CHORD OF

(ON MOST AIRPLANES

STRINGER 18A

CRACK

TYPICAL

VIEW LOOKING INBOARD

STRUCTURE NOT SHOWN FOR CLARITY)

(STRINGER 18A AND FAIRING SUPPORT

1

(SHEET 2 OF 3)
 FIGURE 7: EXTERNAL ULTRASONIC INSPECTION OF THE STA 727 FRAME OUTBOARD CHORD 

FORWARD FLANGE - GROUPS 1 THROUGH 11, CONFIGURATIONS 1 AND 4.

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. 

STEP TASK NAME PROCEDURE REFERENCES MORE DATA

1 Inspect Frame Chord 

Forward Flange

External Ultrasonic 737 NDT Part 4 

Subject 53-10-01

(a) (b) For cracks

(a) An External Inspection is done from outside the airplane in the wheel well area.

(b) Cracks can also be found between fasteners.

(SHEET 3 OF 3)
 FIGURE 8: EDDY CURRENT INSPECTION - GROUPS 1 THROUGH 11, CONFIGURATION 1.

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

FIGURE 8: EDDY CURRENT INSPECTION - GROUPS 1 THROUGH 11, CONFIGURATION 1.

727

STA

FWD

(LEFT SIDE SHOWN, RIGHT SIDE SIMILAR)

VIEW FROM INSIDE THE WHEEL WELL

SEE A

1

D39253

SPLICE STRAP.

OUTBOARD CHORD

STATION 727 FRAME

INSPECTION DETAIL

LOCATIONS AND EDGE

FOR POSSIBLE CRACK

FWD FLANGE

OUTBOARD CHORD

STA 727 FRAME

PANEL

FWD SKIN

CHORD

OUTBOARD

S-18A

BEAM

SHEAR

S-18A

SKIN PANEL

OF FWD

LOWER EDGE

SPLICE ANGLE

OUTBOARD CHORD

STA 727 FRAME

WEB

BULKHEAD

STA 727

INBD

AREA

INSPECTION

(SHEET 1 OF 2)
 FIGURE 8: EDDY CURRENT INSPECTION - GROUPS 1 THROUGH 11, CONFIGURATION 1.

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. 

STEP TASK NAME PROCEDURE REFERENCES MORE DATA

1 Inspect Frame Chord 

Forward Flange

External Low 

Frequency Eddy 

Current (LFEC) 

(a) 737 NDT Part 6 

Subject 53-30-00 

Figure 5

(b) (c) For cracks

2 Inspect Frame Chord 

Forward Flange 

Forward Edge

External High 

Frequency Eddy 

Current (HFEC) 

737 NDT Part 6 

Subject 51-00-00 

Figure 4 or 23

(b) For cracks

(a) Use Reference Standard ANDT1053.

(b) The Inspection is done from outside the airplane in the wheel well area.

(c) Cracks can also be found between fasteners.

727

STA

FWD

A

2

D39254

SPLICE STRAP

OUTBOARD CHORD

STA 727 FRAME

OUTBOARD CHORD

STA 727 FRAME

OUTBOARD CHORD

IN STA 727 FRAME

TYPICAL CRACK

INBD

SPLICE ANGLE

OUTBOARD CHORD

STA 727 FRAME

AREA

INSPECTION

(SHEET 2 OF 2)
 FIGURE 9: SURFACE HFEC INSPECTION - GROUPS 1 THROUGH 11, CONFIGURATION 4.

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

FIGURE 9: SURFACE HFEC INSPECTION - GROUPS 1 THROUGH 11, CONFIGURATION 4.

727

STA

FWD INBD

(LEFT SIDE SHOWN, RIGHT SIDE SIMILAR)

VIEW FROM INSIDE THE WHEEL WELL

1

D39258

FORWARD FLANGE

OUTBD CHORD

STA 727 FRAME

SKIN PANEL

FORWARD

CHORD

OUTBD

S-18A

BEAM

SHEAR

S-18A

SKIN PANEL

OF FORWARD

LOWER EDGE

UPRIGHT FLANGE

OUTBD CHORD

STA 727 FRAME

WEB

BULKHEAD

STA 727

CHORD

FRAME OUTBD

THE STA 727

LOCATION IN

POSSIBLE CRACK

AREA

INSPECTION

(SHEET 1 OF 2)
 FIGURE 9: SURFACE HFEC INSPECTION - GROUPS 1 THROUGH 11, CONFIGURATION 4.

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. 

STEP TASK NAME PROCEDURE REFERENCES MORE DATA

1 Inspect Frame Chord 

Forward Flange

HFEC 737 NDT Part 6 

Subject 51-00-00, 

Figure 4 or Figure 23 

(a) (b) For cracks

(a) An External Inspection is done from outside the airplane in the wheel well area.

(b) Cracks can also be found between fasteners.

(SHEET 2 OF 2)
 FIGURE 10: OPEN HOLE HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION OF THE STA 727 

OUTBOARD CHORD FORWARD FLANGE

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

FIGURE 10: OPEN HOLE HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION OF THE STA 727 

OUTBOARD CHORD FORWARD FLANGE

(WING-TO-BODY FAIRING NOT SHOWN)

RIGHT SIDE OPPOSITE

LEFT SIDE SHOWN

SEE A

D39073

(SHEET 1 OF 3)
 FIGURE 10: OPEN HOLE HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION OF THE STA 727 

OUTBOARD CHORD FORWARD FLANGE

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ALERT ALERT

INBD

FWD

STA

727

STA

727

FLANGE

FRAME FWD

SEE B

3

A

B

3

FWD

UP

1 2

1 2

D40617

A FLAT STRAP)

STRINGER 18A IS

THE OUTER CHORD OF

(ON MOST AIRPLANES

STRINGER 18A

TYPICAL

CRACK

FWD SKIN AFT SKIN

STRUCTURE NOT SHOWN FOR CLARITY)

(STRINGER 18A AND FAIRING SUPPORT

(SHEET 2 OF 3)
 FIGURE 10: OPEN HOLE HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION OF THE STA 727 

OUTBOARD CHORD FORWARD FLANGE

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

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 one side of the airplane.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

CAUTION: MAKE SURE THE FASTENER HOLES ARE ROUND BEFORE PERFORMING THE HFEC 

OPEN HOLE INSPECTIONS. LOOSE FASTENERS MAY INDICATE HOLES THAT ARE NOT ROUND. 

MINIMIZE THE AMOUNT OF FASTENER HOLE REAMING USED TO CLEAN-UP HOLES FOR HFEC 

OPEN HOLES INSPECTIONS. LARGER FASTENER HOLES MAY IMPACT FUTURE INSPECTIONS 

AND THE ACCOMPLISHMENT OF PART 6 - STA 727 FRAME OUTBOARD CHORD PREVENTIVE 

MODIFICATION.

1 Remove Fastener - 4

2 Inspect Fastener Holes HFEC 4 (a) (b) For cracks as given 

in 737 NDT Part 6 Subject 

51-00-00 Figure 16

3 Install Bolt - 4 (c) (d) (e) See Fastener 

Table 1 or 2. Collar - 4

(a) Use a 0.030 notch standard for inspection and repeat inspection program

(b) Use a 0.020 notch standard for modification inspection requirements

(c) Only necessary if no cracks are found and the PART 6 - STA 727 frame outboard chord preventive 

modification is not done before further flight.

(d) Grip length to be determined on installation.

(e) Use the replacement fasteners identified in Table 1 or Table 2. Select the correct fastener diameter 

that provides the smallest diameter required for a transition fit for all aluminum parts or a close ream fit 

for stack-ups that contain steel parts. Select the grip length that matches the removed fastener. Install 

wet using BMS5-95. Do not exceed 5/16 diameter

Table 1: Stainless Steel Replacement Fasteners

Bolt Collar

Nominal BACB30MB*A* BACC30BH*

1/64 OverSize BACB30MC*A* BACC30BH*

1/32 OverSize BACB30MD*A* BACC30AC*

3/64 OverSize BACB30ME*A* BACC30U*

Table 2: Alternate - Titanium Replacement Fasteners

Bolt Collar

Nominal BACB30NX*K* BACC30BH*

1/64 OverSize BACB30NX*K*X BACC30BH*

1/32 OverSize BACB30NX*K*Y BACC30AC*

3/64 OverSize - -

(SHEET 3 OF 3)
 FIGURE 11: AUXILIARY CHORD INSPECTION - GROUPS 1 THROUGH 3, CONFIGURATION 3.

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

FIGURE 11: AUXILIARY CHORD INSPECTION - GROUPS 1 THROUGH 3, CONFIGURATION 3. 

CHORD

AUXILIARY

(LEFT SIDE SHOWN, RIGHT SIDE SIMILAR)

VIEW FROM INSIDE REAR CARGO BAY

CRACK

TYPICAL

727

STA

540

STA

STA

727

1 2

STA

727

BL 0

S-25

S-20

S-18

S-17

S-19

S-21

S-22

S-23

S-24

S-26

S-27

A

SEE A

D39431

FWD

SPLICE

SKIN LAP

SKIN

AREA

INSPECTION

CHORD

AUXILIARY

CHORD

FRAME

AFT SKIN

WEB

BULKHEAD

(SHEET 1 OF 2)
 FIGURE 11: AUXILIARY CHORD INSPECTION - GROUPS 1 THROUGH 3, CONFIGURATION 3.

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. 

STEP TASK NAME PROCEDURE REFERENCES MORE DATA

1 Inspect Auxiliary Chord 

Radius

Detailed 

Inspection

- For cracks

2 Inspect Auxiliary Chord 

Radius

High Frequency 

Eddy Current 

(HFEC)

737 NDT Part 6 

Subject 51-00-00 

Figure 23

(a) For cracks

(a) 737 NDT Part 6 Subject 51-00-00 Figure 4 is an alternative procedure

(SHEET 2 OF 2)
 FIGURE 12: AUXILIARY CHORD INSPECTION - GROUPS 1 THROUGH 3, CONFIGURATION 4.

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

FIGURE 12: AUXILIARY CHORD INSPECTION - GROUPS 1 THROUGH 3, CONFIGURATION 4.

CRACK

TYPICAL (LEFT SIDE SHOWN, RIGHT SIDE SIMILAR)

VIEW FROM INSIDE REAR CARGO BAY

727

STA

540

STA

STA

727

1 2

STA

727

BL 0

S-25

S-20

S-18

S-17

S-19

S-21

S-22

S-23

S-24

S-26

S-27

A

SEE A

J23072

FWD

SPLICE

SKIN LAP

SKIN

AREA

INSPECTION

CHORD

AUXILIARY

CHORD

AUXILIARY

CHORD

FRAME

AFT SKIN

WEB

BULKHEAD

(SHEET 1 OF 2)
 FIGURE 12: AUXILIARY CHORD INSPECTION - GROUPS 1 THROUGH 3, CONFIGURATION 4.

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. 

STEP TASK NAME PROCEDURE REFERENCES MORE DATA

1 Inspect Auxiliary Chord 

Radius

Detailed 

Inspection

- For cracks

2 Inspect Auxiliary Chord 

Radius

High Frequency 

Eddy Current 

(HFEC)

737 NDT Part 6 

Subject 51-00-00 

Figure 23

(a) For cracks

(a) 737 NDT Part 6 Subject 51-00-00 Figure 4 is an alternative procedure

(SHEET 2 OF 2)
 FIGURE 13: EXTERNAL DETAILED INSPECTION AND SURFACE HIGH FREQUENCY EDDY CURRENT 

(HFEC) INSPECTION OF THE S-18A OUTBOARD CHORD - GROUP 1

June 30, 1994

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ALERT ALERT

FIGURE 13: EXTERNAL DETAILED INSPECTION AND SURFACE HIGH FREQUENCY EDDY CURRENT 

(HFEC) INSPECTION OF THE S-18A OUTBOARD CHORD - GROUP 1

(WING-TO-BODY FAIRING NOT SHOWN)

RIGHT SIDE OPPOSITE

LEFT SIDE SHOWN

SEE A

D39074

(SHEET 1 OF 3)
 FIGURE 13: EXTERNAL DETAILED INSPECTION AND SURFACE HIGH FREQUENCY EDDY CURRENT 

(HFEC) INSPECTION OF THE S-18A OUTBOARD CHORD - GROUP 1

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

INBD

FWD FWD SKIN AFT SKIN

STRUCTURE

SUPPORT

FAIRING

AREA

INSPECTION

STA

727

STA

727

SEE B

B

1 2

A

D40618

STRINGER 18A

CRACK

TYPICAL

18A

STRINGER

(SHEET 2 OF 3)
 FIGURE 13: EXTERNAL DETAILED INSPECTION AND SURFACE HIGH FREQUENCY EDDY CURRENT 

(HFEC) INSPECTION OF THE S-18A OUTBOARD CHORD - GROUP 1

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. 

STEP TASK NAME PROCEDURE REFERENCES MORE DATA

1 Inspect Stringer Chord Detailed 

Inspection

- For cracks

2 Inspect Stringer Chord HFEC 737 NDT Part 6 

Subject 51-00-00 

Figure 23

(a) For cracks

(a) 737 NDT Part 6 Subject 51-00-00 Figure 4 is an alternative procedure

(SHEET 3 OF 3)
 FIGURE 14: EXTERNAL DETAILED INSPECTION AND SURFACE HIGH FREQUENCY EDDY CURRENT 

(HFEC) INSPECTION OF THE S-18A OUTBOARD CHORD - GROUPS 2, 3, 4, 5, 6, 9 AND 10

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

FIGURE 14: EXTERNAL DETAILED INSPECTION AND SURFACE HIGH FREQUENCY EDDY CURRENT 

(HFEC) INSPECTION OF THE S-18A OUTBOARD CHORD - GROUPS 2, 3, 4, 5, 6, 9 AND 10

(WING-TO-BODY FAIRING NOT SHOWN)

RIGHT SIDE OPPOSITE

LEFT SIDE SHOWN

SEE A

D39075

(SHEET 1 OF 3)
 FIGURE 14: EXTERNAL DETAILED INSPECTION AND SURFACE HIGH FREQUENCY EDDY CURRENT 

(HFEC) INSPECTION OF THE S-18A OUTBOARD CHORD - GROUPS 2, 3, 4, 5, 6, 9 AND 10

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

INBD

FWD FWD SKIN AFT SKIN

STRUCTURE

SUPPORT

FAIRING

AREA

INSPECTION

STA

727

STA

727

SEE B

B

1 2

A

FWD

UP

D41124

STRINGER 18A

CRACK

TYPICAL

STRINGER 18A

(SHEET 2 OF 3)
 FIGURE 14: EXTERNAL DETAILED INSPECTION AND SURFACE HIGH FREQUENCY EDDY CURRENT 

(HFEC) INSPECTION OF THE S-18A OUTBOARD CHORD - GROUPS 2, 3, 4, 5, 6, 9 AND 10

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. 

STEP TASK NAME PROCEDURE REFERENCES MORE DATA

1 Inspect Stringer Chord Detailed 

Inspection

- For cracks

2 Inspect Stringer Chord HFEC 737 NDT Part 6 

Subject 51-00-00 

Figure 23

(a) For cracks

(a) 737 NDT Part 6 Subject 51-00-00 Figure 4 is an alternative procedure

(SHEET 3 OF 3)
 FIGURE 15: PREPARATION FOR THE STA 727 FRAME OUTBOARD CHORD TIME-LIMITED REPAIR

June 30, 1994

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ALERT ALERT

FIGURE 15: PREPARATION FOR THE STA 727 FRAME OUTBOARD CHORD TIME-LIMITED REPAIR

SUPPORT FITTING

FLAP TRACK

S-26

END OF CHORD

S-25

(LEFT SIDE SHOWN, RIGHT SIDE SIMILAR)

STA 727 - BULKHEAD

S-22

S-24

S-23

S-20

S-18A

S-17

0

BL

BL 0

STA 727

S-27

BEAM

SHEAR

S-18A

SEE A

FWD

D39440

INBD

(SHEET 1 OF 7)
 FIGURE 15: PREPARATION FOR THE STA 727 FRAME OUTBOARD CHORD TIME-LIMITED REPAIR

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

SHOWN RIGHT SIDE SIMILAR)

AFT SKIN NOT SHOWN (LEFT SIDE

VIEW LOOKING AFT

STA 727 BULKHEAD WEB OUTBOARD CHORD

STA 727 FRAME

CHORD

OUTBOARD

S-18A

BEAM

SHEAR

S-18A

FORWARD SKIN

S-18A

A A

B

B

MEASUREMENT

CLEARANCE

INBD

2

5

6

S-20

WL 190

A

2

D39444

(SHEET 2 OF 7)
 FIGURE 15: PREPARATION FOR THE STA 727 FRAME OUTBOARD CHORD TIME-LIMITED REPAIR

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

WEB

BULKHEAD

CHORD

OUTBOARD

FRAME

CHORD

AUXILIARY

AFT SKIN

STIFFENER

HORIZONTAL

AIRPLANES

ON SOME

ANGLE ONLY

OF JOGGLE

FWD END

FWD SKIN

FILLER

TAPERED

AREA

TRIMMED

BEAM WEB

SHEAR

MEASUREMENT

CLEARANCE

727

STA

C

C

INBD

FWD

8 9

4

10

7 9

3

D39455

A-A

(SHEET 3 OF 7)
 FIGURE 15: PREPARATION FOR THE STA 727 FRAME OUTBOARD CHORD TIME-LIMITED REPAIR

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

S-18A

1

727

STA

1

FWD

UP

7 9

(6 LOCATIONS)

AND STOP DRILL

TYPICAL CRACK

CHORD

FRAME OUTBOARD

D40213

B-B

CHORD

AUXILIARY

BULKHEAD WEB

SHEAR BEAM

STIFFENER

HORIZONTAL

CONFIGURATION

SHEAR BEAM SHOWN IN TRIMMED

HORIZONTAL STIFFENER AND

MEASUREMENT

CLEARANCE

(SHEET 4 OF 7)
 FIGURE 15: PREPARATION FOR THE STA 727 FRAME OUTBOARD CHORD TIME-LIMITED REPAIR

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

S-18A

727

STA

FWD

UP

CHORD

FRAME OUTBOARD

3 4

J66908

C-C

CHORD

AUXILIARY

BULKHEAD WEB

SHEAR BEAM

STIFFENER

HORIZONTAL

SHEAR BEAM SHOWN BEFORE TRIM

HORIZONTAL STIFFENER AND

MEASUREMENT

CLEARANCE

MEASUREMENT

CLEARANCE

(SHEET 5 OF 7)
 FIGURE 15: PREPARATION FOR THE STA 727 FRAME OUTBOARD CHORD TIME-LIMITED REPAIR

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

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 one side of the airplane.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Inspect Fastener Hole 

Distance

- - (a) (e) 

2 Inspect Fastener Hole 

Distance

- - (a) (f) 

3 Inspect Fastener Hole 

Distance

- - (a) (g) 

4 Inspect Edge Margin - - (a) (h) 

5 Remove/

Keep

Tee 65-48692-( ) 1 Remove and keep shims 

if installed.

6

Remove/

Keep

Bracket 69-39436-( ) 1 Left Side. Remove and 

keep shims if installed.

69-39437-( ) 1 Right Side. Remove and 

keep shims if installed.

7

Cut Shear Beam Web - - (b) (c) Trim the aft part of 

the outboard vertical 

side to allow for the 

installation of the frame 

chord repair angle. Trim 

the forward end of the 

joggle. Remove 

attaching fasteners.

8

Cut Horizontal 

Stiffener

- - (b) (c) Trim the outboard 

part of the vertical leg to 

allow for the installation 

of the frame chord repair 

angle. Remove attaching 

fasteners.

9

Apply Chemical 

Conversion 

Coating

Type 2, Class A - (d) As given in SOPM 

20-43-03.

Primer BMS 10-11, Type 1 - (d) 2 coats as given in 

SOPM 20-41-02.

10 Remove Tapered Filler 65-46877-( ) 1

(a) If the Time-Limited repair cannot be accomplished, replace the chord as shown in PART 3 - STA 

727 Frame Outboard Chord Repair.

(b) Maintain a 1.7D minimum edge margin and a 0.375 minimum radius.

(c) Protect the remaining structure during trimming.

(d) To all trimmed edges.

(e) Make sure the replacement fastener collars can clear the radius of the nested frame chord repair 

angle. Fastener centerline to bulkhead web distance must be more than 0.58 inches to provide 

collar clearance. 

(SHEET 6 OF 7)
 FIGURE 15: PREPARATION FOR THE STA 727 FRAME OUTBOARD CHORD TIME-LIMITED REPAIR

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

(f) Make sure replacement fastener collars can clear the nested shear beam repair angle. Fastener 

centerline to shear beam web distance must be more than 0.36 inches to provide collar clearance.

(g) Make sure replacement fastener collars can clear the repair strap. Fastener centerline to 

horizontal stiffener distance must be more than 0.39 inches to provide collar clearance. 

(h) The horizontal stiffener repair strap may reduce the available edge margin for the shear beam 

repair angle. Fastener centerline to the horizontal stiffener distance must be a minimum 0.43 inches 

to provide sufficient edge margin for installation of 1/4 inch diameter fastener into the shear beam 

repair angle. This distance must be a minimum 0.45 inches for a 1/4+1/64 oversize fastener. This 

distance must be a minimum 0.46 inches for a 1/4 + 1/32 oversize fastener.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

(SHEET 7 OF 7)
 FIGURE 16: TIME-LIMITED REPAIR - SURFACE HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION FOR CRACK TIP LOCATION

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

FIGURE 16: TIME-LIMITED REPAIR - SURFACE HIGH FREQUENCY EDDY CURRENT (HFEC) 

INSPECTION FOR CRACK TIP LOCATION

SUPPORT FITTING

FLAP TRACK

S-26

END OF CHORD

S-25

(LEFT SIDE SHOWN, RIGHT SIDE SIMILAR)

STA 727 - BULKHEAD

S-22

S-24

S-23

S-20

S-18A

S-17

0

BL

BL 0

STA 727

S-27

BEAM

SHEAR

S-18A

SEE A

FWD

D39443

INBD

(SHEET 1 OF 3)
 FIGURE 16: TIME-LIMITED REPAIR - SURFACE HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION FOR CRACK TIP LOCATION

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

RIGHT SIDE SIMILAR)

(LEFT SIDE SHOWN

AFT SKIN NOT SHOWN

VIEW LOOKING AFT

STA 727 BULKHEAD WEB

OUTBOARD CHORD

STA 727 FRAME

CHORD

OUTBOARD

S-18A

BEAM

SHEAR

S-18A

SKIN

FORWARD

S-18A

A

A

INBD

S-20

WL 190

A

D40214

(SHEET 2 OF 3)
 FIGURE 16: TIME-LIMITED REPAIR - SURFACE HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION FOR CRACK TIP LOCATION

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. 

REPAIR INSPECTION

STEP TASK NAME PROCEDURE REFERENCES MORE DATA

1 Inspect Frame Chord 

Forward Flange

HFEC 737 NDT Part 6 

Subject 51-00-00 

Figure 23

(a) Identify the 

location of the crack 

tip.

(a) 737 NDT Part 6 Subject 51-00-00 Figure 4 is an alternative procedure. 

S-18A

727

STA

FWD

UP

TYPICAL CRACK

CHORD

FRAME OUTBOARD

1

LENGTH

CRACK

MAXIMUM

D40215

A-A

CHORD

AUXILIARY

BULKHEAD WEB

SHEAR BEAM

(SHEET 3 OF 3)
 FIGURE 17: MAKE THE TIME-LIMITED REPAIR PARTS

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

FIGURE 17: MAKE THE TIME-LIMITED REPAIR PARTS

A

A

1 10 1 10

D40216

A-A

(SHEET 1 OF 5)
 FIGURE 17: MAKE THE TIME-LIMITED REPAIR PARTS

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

FLANGE, IF REQUIRED

AREA OF EXTENDED

4.25

1.25 1.25

6.0

8.2

1.4 1.4

1.2

8.2

2 10 3

5 4

6

6

10

10 10

10

10

6 10

D39079

(SHEET 2 OF 5)
 FIGURE 17: MAKE THE TIME-LIMITED REPAIR PARTS

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

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 one side of the airplane.

STEP TASK NAME MATERIAL QTY MORE DATA

1 Make Frame Repair 

Angle

AND10134-2008 or equivalent 

x 20.8 inches. 7075-T0

1 (a) (k)

Cut Frame Repair 

Angle

- 1 (p)

Bend Frame Repair 

Angle

- 1 To match frame.

Heat 

Treat

Frame Repair 

Angle

- 1 Heat Treat to T6 condition.

2 Make Shim A 7075-T6 clad sheet 1 (a) (b) (j) 0.032 inch thick.

3 Make Repair Strap 7075-T6 clad sheet 1 (a) (j) 0.18 inch thick.

4 Make Filler A 7075-T6 clad sheet 1 (a) (c) 0.14 inch thick.

5 Make Filler B 7075-T6 clad sheet 1 (a) (d) 0.202 inch thick, 

tolerance +/- 0.01inches.

6 Make Shear Beam 

Repair Angle

4.25 X 8.2 inches 

7075-T0 clad sheet

1 (a) (f) (g) (n) (q) 0.15 inch thick.

Bend Vertical Flange - 1 (e) (h)

Heat 

Treat

Shear Beam 

Repair Angle

- 1 Heat Treat to T6 condition.

7 Make Shim B 7075-T6 clad sheet 1 (a) (l) 0.18 inch thick

2.1

11.4

8.7

1.2

7

8

10

10

6.9

1.6

0.01

0.01

0.09

9 10

1.9

J77517

(SHEET 3 OF 5)
 FIGURE 17: MAKE THE TIME-LIMITED REPAIR PARTS

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

8 Make Shim C 7075-T6 clad sheet 1 (a) (m) 0.18 inch thick

9 Make Filler (Tapered) 7075-T6 clad sheet 1 (a) (o) (r) 0.09 inch thick.

10 Apply Chemical 

Conversion 

Coating

Type 2, Class A - (i) As given in SOPM 20-43-03.

Primer BMS 10-11, Type 1 - (i) 2 coats as given in SOPM 

20-41-02.

(a) Break sharp edges and remove burrs.

(b) Airplanes where the Bulkhead Attachment Angle at WL 190 is 0.125 inch thick, make shim from 7075-T6 

clad sheet, 0.063 inch thick.

(c) Airplanes where the S-18A Shear Beam flange is 0.125 inch thick, make the Filler from 7075-T6 clad 

sheet, 0.125 inch thick.

(d) Airplanes where the S-18A Shear Beam flange is 0.125 inch thick, make the shim from 7075-T6 clad 

sheet, 0.217 inch thick, tolerance +/- 0.01inches.

(e) Refer to 737-100/200 SRM 51-20-1 or 737-300/400/500 SRM 51-30-01. Minimum bend radius of 0.44.

(f) If required, extend the vertical flange aft, as illustrated on sheet 2 of this figure, to obtain a minimum 

fastener hole edge margin of 1.7D 

(g) If required, chamfer the vertical flange aft edge to 0.10 x 45 degrees to nest in the radius of the Step 1 

frame repair angle. 

(h) Bend the vertical flange to fit with the Step 5 Filler B and Step 1 Frame Repair Angle on installation. 

(i) All fabricated parts.

(j) These detailed parts have been sized to attach with five fasteners. Interference may occur with the most 

inboard fastener position. If required, these parts can be trimmed and installed using four fasteners.

(k) If required, the inboard edge of the repair angle can be trimmed to prevent interference with fasteners 

common to the bulkhead inboard of the STA 727 frame chord. Maintain a minimum fastener hole edge 

margin of 1.7D.

(l) Dimensions shown are typical. Use the Tee removed in Step 5 of Figure 15 as a template for the correct 

size and shape.

(m) Dimensions shown are typical. Use the Bracket removed in Step 6 of Figure 15 as a template for the 

correct size and shape.

(n) To provide the operator with additional edge margin in the horizontal flange and to maintain fastener 

spacing, the repair angle is fabricated 0.25 inch oversize. Trim a maximum of 0.25 inch locally as required. 

Maintain a minimum fastener hole edge margin of 1.7D.

(o) Size the filler and the taper to fit in the gap between the shear beam and the shear beam repair angle. 

STEP TASK NAME MATERIAL QTY MORE DATA

(SHEET 4 OF 5)
 FIGURE 17: MAKE THE TIME-LIMITED REPAIR PARTS

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

(p) Use the airplane to correctly size and trim the frame repair angle. Trim the upper end of the frame repair 

angle to install just below S-18. Provide a minimum 1.5D edge margin in the frame repair angle for the first 

row of fasteners below S-18 common to the skin. Trim the lower end of the frame repair angle providing a 

minimum 1.5D edge margin for the second fastener row below S-20 common to the frame inboard flange. 

Trim away the forward leg of the frame repair angle to match the STA 727 frame outboard chord trim. 

(q) For airplanes with angles installed in production in the center of the shear beam web, trim the inboard 

edge of the horizontal flange of the shear beam repair to accommodate the production angle. Maintain a 

1.5D minimum edge margin.

(r) For airplanes with angles installed in production in the center of the shear beam web, trim the inboard 

edge of the filler to accommodate the production angle. Maintain a 1.5D minimum edge margin. For 

airplanes without the angle installed in production, the filler shall be 1.9 inches wide.

STEP TASK NAME MATERIAL QTY MORE DATA

(SHEET 5 OF 5)
 FIGURE 18: INSTALL THE TIME-LIMITED REPAIR

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

FIGURE 18: INSTALL THE TIME-LIMITED REPAIR

SUPPORT FITTING

FLAP TRACK

S-26

END OF CHORD

S-25

(LEFT SIDE SHOWN, RIGHT SIDE SIMILAR)

STA 727 - BULKHEAD

S-22

S-24

S-23

S-20

S-18A

S-17

0

BL

BL 0

STA 727

S-27

BEAM

SHEAR

S-18A

SEE A

FWD

D39441

INBD

(SHEET 1 OF 8)
 FIGURE 18: INSTALL THE TIME-LIMITED REPAIR

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

REFERENCE FASTENER

FASTENER

REMOVED EXISTING

A A

B

B

INBD

RIGHT SIDE SIMILAR)

(LEFT SIDE SHOWN

AFT SKIN NOT SHOWN

VIEW LOOKING AFT

A

CHORD

OUTBOARD

S-18A

FRAME OUTBOARD CHORD

SKIN

FORWARD

BULKHEAD WEB

REPAIR ANGLE

FRAME CHORD

REPAIR ANGLE

SHEAR BEAM

REPAIR STRAP

TEE

BRACKET

D40217

4 5

WL 190

S-18A

S-20

1 2 3

1 2 3 4 6 7 4 10

1 2 3

12 13 14 15 16 17

12 13 14 15 16 17

18

19

S-18

(SHEET 2 OF 8)
 FIGURE 18: INSTALL THE TIME-LIMITED REPAIR

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

FASTENER

REMOVED EXISTING

NEW FASTENER

AUXILIARY CHORD

AFT SKIN

BULKHEAD WEB

SOME AIRPLANES

ANGLE ONLY ON

SHEAR BEAM WEB

FWD SKIN

FRAME OUTBOARD CHORD

OUTBOARD FLANGE

SHEAR BEAM

REPAIR ANGLE

FRAME CHORD

FILLER A

FILLER B

FWD

INBD

STA

727

1 2 3 4

1 2 3 4 5

1 2 3 4 8

1 2 3 4 10 1 2 3 4 9

1 2 3 4 7

6

SHIM A

REPAIR STRAP

REPAIR ANGLE

SHEAR BEAM

D40219

A-A

(SHEET 3 OF 8)
 FIGURE 18: INSTALL THE TIME-LIMITED REPAIR

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

REFERENCE FASTENER

REMOVED EXISTING FASTENER

NEW FASTENER FWD

FILLER A REPAIR ANGLE

SHEAR BEAM

FILLER B

S-20

STA

727

S-18

S-18A

S-19

1

CHORD

OUTBOARD

FWD SKIN

2 3 4 5

1 2 3 4 8 1 2 3 4 10

1 2 3 4 9

1 2 3 4 11

REPAIR ANGLE

FRAME CHORD

D40226

VIEW LOOKING OUTBOARD

B-B

CHORD

AUXILIARY

WEB

BULKHEAD

SHEAR BEAM

FILLER (TAPERED)

(SHEET 4 OF 8)
 FIGURE 18: INSTALL THE TIME-LIMITED REPAIR

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

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 a one side of the airplane.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

CAUTION: WHEN PERFORMING THE REPLACEMENT OF THE STA 727 FRAME OUTBOARD CHORD 

TIME-LIMITED REPAIR IT IS DESIRABLE TO MINIMIZE THE GROWTH OF THE FASTENER HOLE 

DIAMETERS WHEN INSTALLING FASTENERS. LARGER FASTENER HOLES MAY IMPACT FUTURE 

INSPECTIONS AND THE ACCOMPLISHMENT OF PART 6 - STA 727 FRAME OUTBOARD CHORD 

PREVENTIVE MODIFICATION

1

Align Frame Chord

Repair Angle

- 1

Shim Shim A 1

Repair Strap - 1

Filler Filler A 1

Filler Filler B 1

Shear Beam

Repair Angle

- 1

Filler Filler (Tapered) 1

2

Drill Frame Chord

Repair Angle

- 1 (a) (b) (j)

Shim Shim A 1

Repair Strap - 1

Filler Filler A 1

Filler Filler B 1

Shear Beam

Repair Angle

- 1

Filler Filler (Tapered) 1

3

Remove Frame Chord

Repair Angle

- 1

Shim Shim A 1

Repair Strap - 1

Filler Filler A 1

Filler Filler B 1

Shear Beam

Repair Angle

- 1

Filler Filler (Tapered) 1

(SHEET 5 OF 8)
 FIGURE 18: INSTALL THE TIME-LIMITED REPAIR

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ALERT ALERT

4

Deburr Frame Chord

Repair Angle

- 1

Shim Shim A 1

Repair Strap - 1

Filler Filler A 1

Filler Filler B 1

Shear Beam

Repair Angle

- 1

Filler Filler (Tapered) 1

5 Install Frame Chord

Repair Angle

- 1 (c) (d) (e) (f) (g) (h) (k)

6 Install Shim Shim A 1 (c) (d) (e) (f) (h) (k)

7 Install Repair Strap - 1 (c) (d) (e) (f) (h) (k)

8 Install Filler Filler A 1 (c) (d) (e) (f) (h) (k)

9 Install Filler Filler B 1 (c) (d) (e) (f) (h) (k)

10 Install Shear Beam

Repair Angle

- 1 (c) (d) (e) (f) (g) (h) (k)

11 Install Filler Filler (Tapered) 1 (c) (d) (e) (f) (h) (k)

12 Cut Shim Shim B 1 (i)

Shim Shim C 1 (i)

13

Apply Chemical 

Conversion 

Coating

Type 2, Class A - To the bare edges as 

given in SOPM 20-43-03.

Primer BMS 10-11, Type 1 - 2 coats as given in SOPM 

20-41-02.

14

Align (New) Shim B - 1

Shim C - 1

Align (Kept) Tee 65-48692-( ) 1

Bracket 69-39436-( ) 1 Left Side.

69-39437-( ) 1 Right Side.

15

Drill Shim B - 1

Shim C - 1

Tee 65-48692-( ) 1

Bracket 69-39436-( ) 1 Left Side.

69-39437-( ) 1 Right Side.

16

Remove Shim B - 1

Shim C - 1

Tee 65-48692-( ) 1

Bracket 69-39436-( ) 1 Left Side.

69-39437-( ) 1 Right Side.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

(SHEET 6 OF 8)
 FIGURE 18: INSTALL THE TIME-LIMITED REPAIR

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ALERT ALERT

17

Deburr Shim B - 1

Shim C - 1

Tee 65-48692-( ) 1

Bracket 69-39436-( ) 1 Left Side.

69-39437-( ) 1 Right Side.

18

Install Shim Shim B 1 (c) (d) (e) (f) (h) (k)

Install (Kept) Tee 65-48692-( ) 1 (l) (m) Removed in Step 5 

of Figure 15.

19

Install Shim Shim C 1 (c) (d) (e) (f) (h) (k)

Install (Kept) Bracket 69-39436-( ) 1 (l) (m) Left Side. 

Removed in Step 6 of 

Figure 15.

69-39437-( ) 1 (l) (m) Right Side.

Removed in Step 6 of 

Figure 15.

(a) Drill fastener holes matching the existing fastener hole nominal size, within a close ream tolerance. If 

necessary holes may be oversized by up to 3/64th, but should not exceed 0.2973 (1/4 + 3/64 oversize).

(b) Maintain a 1.7D minimum edge margin.

(c) Shim all gaps greater than 0.01 before fastener installation.

(d) Install wet with sealant (Ref. BMS 5-95).

(e) Replace protruding head hex drive or lock bolt fasteners in transition fit holes with the same size as 

removed. If necessary use up to 1/32 oversize. See Fastener Installation Table for replacement fastener and 

collar types. 

(f) Replace 100 degree countersunk hex drive or lock bolt fasteners in transition fit holes with the same size 

as removed. If necessary use up to 1/32 oversize. See Fastener Installation Table for replacement fastener 

and collar types. 

(g) For new fastener locations, install BACB30MB8A( ) and BACC30BH8 fasteners and collars.

(h) Install hex drive fasteners and bolts wet with sealant (Ref. BMS 5-95).

(i) Cut the outboard end of the shim so it will be flush with the frame chord repair angle.

(j) Adjust fastener pattern common to the Shear Beam horizontal web to adapt to existing fastener pattern. 

Maintain 1.7D minimum edge margin. For new fastener locations, maintain 3D to 6D fastener spacing, 

staggered fastener pattern is acceptable. Use the same quantity of fasteners as indicated.

(k) Replace rivets with the same size and type.

(l) Common to the STA 727 frame outboard chord, replace hexdrive, lock bolts and bolts with the same type 

and smallest size to maintain a transition fit hole. Do not exceed 5/16 inch diameter for these fasteners.

(m) Common to the STA 727 frame outboard chord, replace rivets with the same type and size rivets. Do not 

exceed 6/32 inch diameter rivet for replacement of a production 5/32 inch diameter rivet. Do not exceed 1/4 

inch diameter rivet for replacement of a production 6/32 inch diameter rivet.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

(SHEET 7 OF 8)
 FIGURE 18: INSTALL THE TIME-LIMITED REPAIR

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ALERT ALERT

Fastener Installation Table

Removed Existing 

Fastener

New Fastener and Collar

Existing Size 1/64 Oversize 1/32 Oversize 

Protruding Head BACB30MB( )A( ) 

+ 

BACC30BH( )

BACB30MC( )A( ) 

+ 

BACC30BH( )

BACB30MD( )A( ) 

+ 

BACC30AC( )

Countersunk BACB30FN( )A( ) 

+ 

BACC30M( )

BACB30FQ( )A( ) 

+ 

BACC30M( )

BACB30KF( )A( ) 

+ 

BACC30R( )

None

(New Fastener)

BACB30MB8A( ) 

+ 

BACC30BH8

- -

(SHEET 8 OF 8)
 FIGURE 19: TIME-LIMITED REPAIR - REMOVAL

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ALERT ALERT

FIGURE 19: TIME-LIMITED REPAIR - REMOVAL

SUPPORT FITTING

FLAP TRACK

S-26

END OF CHORD

S-25

(LEFT SIDE SHOWN, RIGHT SIDE SIMILAR)

STA 727 - BULKHEAD

S-22

S-24

S-23

S-20

S-18A

S-17

0

BL

BL 0

STA 727

S-27

BEAM

SHEAR

S-18A

SEE A

FWD

D40866

INBD

(SHEET 1 OF 5)
 FIGURE 19: TIME-LIMITED REPAIR - REMOVAL

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A A

B

B

INBD

A

CHORD

OUTBOARD

S-18A

FRAME OUTBOARD CHORD

SKIN

FORWARD

BULKHEAD WEB

RIGHT SIDE SIMILAR)

(LEFT SIDE SHOWN

AFT SKIN NOT SHOWN

VIEW LOOKING AFT

D40867

4

2

1

8

WL 190

S-18A

S-20

3 5

(SHEET 2 OF 5)
 FIGURE 19: TIME-LIMITED REPAIR - REMOVAL

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ALERT ALERT

AFT SKIN

BULKHEAD WEB

SOME AIRPLANES

ANGLE ONLY ON

SHEAR BEAM WEB

FWD SKIN

OUTBOARD FLANGE

SHEAR BEAM

AUXILIARY CHORD

CHORD

OUTBOARD

FRAME

FWD

INBD

3

4

STA

727

5 6

8

7

1 2 3 4 7

REPAIR STRAP

D40868

A-A

(SHEET 3 OF 5)
 FIGURE 19: TIME-LIMITED REPAIR - REMOVAL

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ALERT ALERT

FWD

6

5

7

S-20

STA

727

S-18

S-18A

S-19

8

CHORD

OUTBOARD

FWD SKIN

9

D40869

VIEW LOOKING OUTBOARD

B-B

CHORD

AUXILIARY

WEB

BULKHEAD

SHEAR BEAM

(SHEET 4 OF 5)
 FIGURE 19: TIME-LIMITED REPAIR - REMOVAL

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ALERT ALERT

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 one side of the airplane.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Remove/Keep Tee 65-48692-( ) 1

Remove Shim Shim B 1

2

Remove/Keep Bracket 69-39436-( ) 1 Left Side.

69-39437-( ) 1 Right Side.

Remove Shim Shim C 1

3 Remove/Keep Repair Strap - 1

4 Remove Shim Shim A 1

5 Remove Shear Beam 

Repair Angle

- 1

6 Remove Filler Filler B 1

7 Remove Filler Filler A 1

8 Remove Frame Chord 

Repair Angle

- 1

9 Remove Filler Filler (Tapered) 1

(SHEET 5 OF 5)
 FIGURE 20: MAKE THE REPLACEMENT PARTS TO REPLACE THE TIME-LIMITED REPAIR WITH A 

NEW FRAME CHORD

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ALERT ALERT

FIGURE 20: MAKE THE REPLACEMENT PARTS TO REPLACE THE TIME-LIMITED REPAIR WITH A NEW 

FRAME CHORD

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 one side of the airplane.

Note: Make the repair parts as shown in the table that follows. The dimensions provided are target values, use 

existing parts as guides to make sure correct fit and a minimum fastener hole edge margin of 1.7D is 

obtained.

STEP TASK NAME MATERIAL QTY MORE DATA

1 Make Filler A 7075-T6 clad sheet. 1 (a) (b) Thickness to match 

existing WL 190 

Horizontal Stiffener. 

Target thickness is 0.156 

or 0.125 inches.

2 Make Filler B 7075-T6 bare. 1 (a) (c)

3 Apply Chemical 

Conversion 

Coating

Type 2, Class A - (d) As given in SOPM 

20-43-03.

Primer BMS 10-11, Type 1 - (d) 2 coats as given in 

SOPM 20-41-02.

(a) Break sharp edges and remove burrs.

1 3

1.5

1.75

0.15

1.0

0.85

0.02

2 3

D40872

(SHEET 1 OF 2)
 FIGURE 20: MAKE THE REPLACEMENT PARTS TO REPLACE THE TIME-LIMITED REPAIR WITH A 

NEW FRAME CHORD

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ALERT ALERT

(b) Trim the outboard end to match the contour of the frame.

(c) Measure the length of the shear beam joggle gap. Size the length of the constant thickness section 

of the filler to fill the joggle gap.

(d) All fabricated parts.

STEP TASK NAME MATERIAL QTY MORE DATA

(SHEET 2 OF 2)
 FIGURE 21: STRINGER S-18A OUTBOARD CHORD AFT FASTENERS - INSPECTION - GROUP 1, 2, 3, 

4, 5, 6 AND 9

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ALERT ALERT

FIGURE 21: STRINGER S-18A OUTBOARD CHORD AFT FASTENERS - INSPECTION - GROUP 1, 2, 3, 4, 

5, 6 AND 9

LEFT SIDE SHOWN

RIGHT SIDE OPPOSITE

(WING-TO-BODY FAIRING NOT SHOWN)

S-19

S-18A

S-20

S-17

STA

716

STA

709

727A (737-200/300/400/500)

STA

747 (737-100)

STA

727

S-18

SEE A

D41498

(SHEET 1 OF 2)
 FIGURE 21: STRINGER S-18A OUTBOARD CHORD AFT FASTENERS - INSPECTION - GROUP 1, 2, 3, 

4, 5, 6 AND 9

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ALERT ALERT

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. 

STEP TASK NAME PROCEDURE REFERENCES MORE DATA

1 Inspect Fasteners General Visual 

Inspection

- (a)

(a) Record the quantity of fasteners in the S-18A outboard chord aft of the STA 727 frame.

CHORD

OUTBOARD

S-18A

SKIN ASSEMBLY

PATTERN SHOWN

TYPICAL FASTENER

A

FWD

UP

1

D40231

NOT SHOWN FOR CLARITY

FAIRING SUPPORT STRUCTURE

(737-100)

747

STA

(737-200/300/400/500)

727A

STA

S-19

727

STA

(SHEET 2 OF 2)
 FIGURE 22: STA 727 OUTBOARD CHORD FORWARD FLANGE AT STRINGER 18A - EVALUATION

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ALERT ALERT

FIGURE 22: STA 727 OUTBOARD CHORD FORWARD FLANGE AT STRINGER 18A - EVALUATION

A

A

STA

727

INBD

RIGHT SIDE SIMILAR

LEFT SIDE SHOWN

AFT SKIN NOT SHOWN

S-20

S-18A

WL 190

UP

BULKHEAD SKIN

D39442

(SHEET 1 OF 2)
 FIGURE 22: STA 727 OUTBOARD CHORD FORWARD FLANGE AT STRINGER 18A - EVALUATION

June 30, 1994

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ALERT ALERT

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 one side of the airplane.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Measure Edge Margin - 2 (a)

2 Inspect Fastener Holes - 4 (b)

(a) Measure the distance from the center of the fastener hole to the forward edge of the STA 727 frame 

outboard chord.

(b) Make sure the fastener holes are round.

S-18A

1

1

727

STA

2

FWD

UP

D39837

A-A

CHORD

AUXILIARY

BULKHEAD WEB

FORWARD EDGE

FRAME CHORD

EDGE MARGIN

(SHEET 2 OF 2)
 FIGURE 23: INSTALL THE SHEAR BEAM REPAIR

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ALERT ALERT

FIGURE 23: INSTALL THE SHEAR BEAM REPAIR

SUPPORT FITTING

FLAP TRACK

S-26

END OF CHORD

S-25

(LEFT SIDE SHOWN, RIGHT SIDE SIMILAR)

STA 727 - BULKHEAD

S-22

S-24

S-23

S-20

S-18A

S-17

0

BL

BL 0

STA 727

S-27

BEAM

SHEAR

S-18A

SEE A

FWD

D40884

INBD

(SHEET 1 OF 6)
 FIGURE 23: INSTALL THE SHEAR BEAM REPAIR

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ALERT ALERT

AND FILLER A

REPAIR STRAP

REFERENCE FASTENER

REMOVED EXISTING FASTENER

A A

B

B

INBD

RIGHT SIDE SIMILAR)

(LEFT SIDE SHOWN

AFT SKIN NOT SHOWN

VIEW LOOKING AFT

A

CHORD

OUTBOARD

S-18A

FRAME OUTBOARD CHORD

SKIN

FORWARD

BULKHEAD WEB

1 2 3 4 5 6 7

D40878

10

WL 190

S-18A

S-20

9

(SHEET 2 OF 6)
 FIGURE 23: INSTALL THE SHEAR BEAM REPAIR

June 30, 1994

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ALERT ALERT

AFT SKIN

BULKHEAD WEB

SOME AIRPLANES

ANGLE ONLY ON

FWD SKIN

OUTBOARD FLANGE

SHEAR BEAM

FRAME OUTBOARD CHORD

AUXILIARY CHORD

AIRPLANES

ON SOME

DOUBLER ONLY

REPAIR STRAP

FWD

INBD

STA

727

1 2 3 4 5 6 7

1 2 3 4 5 6 8

1 2 3 4 8

FILLER A

FILLER B

SHEAR BEAM

D40893

A-A

(SHEET 3 OF 6)
 FIGURE 23: INSTALL THE SHEAR BEAM REPAIR

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ALERT ALERT

FASTENER

REMOVED EXISTING

FWD

S-20

STA

727

S-18

S-18A

S-19

CHORD

OUTBOARD

FWD SKIN

1 2 3 4 5 6 8

1 2 3 4 8

SHEAR BEAM

FILLER B

D40911

VIEW LOOKING OUTBOARD

B-B

CHORD

AUXILIARY

WEB

BULKHEAD

(SHEET 4 OF 6)
 FIGURE 23: INSTALL THE SHEAR BEAM REPAIR

June 30, 1994

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ALERT ALERT

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 one side of the airplane.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1

Align Filler A (Refer to Step 1 of Figure 20.) 1

Repair Strap (Refer to Step 3 of Figure 19.) 1

Filler B (Refer to Step 2 of Figure 20.) 1

Shear Beam Web - 1 (a) As shown in 

drawing 65-46877.

2

Drill Filler A (Refer to Step 1 of Figure 20.) 1 (b) (c)

Repair Strap (Refer to Step 3 of Figure 19.) 1 (b) (c)

Filler B (Refer to Step 2 of Figure 20.) 1

Shear Beam Web - 1 (a) As shown in 

drawing 65-46877.

3

Remove/

Keep

Filler A (Refer to Step 1 of Figure 20.) 1

Repair Strap (Refer to Step 3 of Figure 19.) 1

Filler B (Refer to Step 2 of Figure 20.) 1

Shear Beam Web - 1 (a) As shown in 

drawing 65-46877.

4

Deburr Filler A (Refer to Step 1 of Figure 20.) 1

Repair Strap (Refer to Step 3 of Figure 19.) 1

Filler B (Refer to Step 2 of Figure 20.) 1

Shear Beam Web - 1 (a) As shown in 

drawing 65-46877.

5

Apply Chemical 

Conversion Coating

Type 2, Class A - To the bare edges 

as given in SOPM 

20-43-03.

6 Apply Primer BMS 10-11 Type 1 - 2 coats as given in 

SOPM 20-41-02.

7

Install 

(Kept)

Filler A (Refer to Step 1 of Figure 20.) 1 (d) (e) (f) (g) (h) (i) (j)

Install 

(Kept)

Repair Strap (Refer to Step 3 of Figure 19.) 1 (d) (e) (f) (g) (h) (i) (j)

8

Install 

(Kept)

Filler B (Refer to Step 2 of Figure 20.) 1 (d) (e) (f) (g) (h) (i) (j)

Install 

(New)

Shear Beam Web - 1 (a) As shown in 

drawing 65-46877.

9

Install 

(Kept)

Tee 65-48692-( ) 1 (k) (l) Install the Tee 

removed in Step 1 of 

Figure 19.

(SHEET 5 OF 6)
 FIGURE 23: INSTALL THE SHEAR BEAM REPAIR

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ALERT ALERT

10

Install 

(Kept)

Bracket 69-39436-( ) 1 (k) (l)

Left Side. Install the 

Bracket removed in 

Step 2 of Figure 19.

69-39437-( ) 1 (k) (l) Right Side. 

Install the Bracket 

removed in Step 2 of 

Figure 19.

(a) Refer to Paragraph 3.B. Accomplishment Instructions Part 9 Paragraph e. for part number of Shear 

Beam Web applicable to Airplane Group.

(b) Drill fastener holes matching the existing fastener hole nominal size, within a transition fit tolerance. If 

necessary holes may be oversized by up to 3/64th, but should not exceed 0.2973 (1/4 + 3/64 oversize).

(c) Maintain a 1.7D minimum edge margin.

(d) Shim all gaps greater than 0.01 before fastener installation.

(e) Install wet with sealant (Ref. BMS 5-95).

(f) Replace protruding head hex drive or lockbolt fasteners in transition fit holes with the same size as 

removed. If necessary use up to 1/32 oversize while maintaining a 1.7D minimum edge margin. Do not 

exceed 5/16 inch diameter. See Fastener Installation Table. 

(g) Replace 100 degree countersunk hex drive or lockbolt fasteners in transition fit holes with the same 

size as removed. If necessary use up to 1/32 oversize while maintaining a 1.7D minimum edge margin. 

Do not exceed 5/16 inch diameter. See Fastener Installation Table. 

(h) Install hex drive fasteners and bolts wet with sealant (Ref. BMS 5-95).

(i) If PART 3 or PART 6 requires different fasteners, use the fasteners given in PART 3 or PART 6.

(j) Replace rivets with the same size and type.

(k) Replace hexdrive, lock bolts and bolts with the same type and smallest size to maintain a transition fit 

hole. Do not exceed 5/16 inch diameter for these fasteners.

(l) Replace rivets with the same type and size rivets. Do not exceed 6/32 inch diameter rivet for 

replacement of a production 5/32 inch diameter rivet. Do not exceed 1/4 inch diameter rivet for 

replacement of a production 6/32 inch diameter rivet.

Fastener Installation Table

Removed Existing 

Fastener

New Fastener and Collar

Existing Size 1/64 Oversize 1/32 Oversize 

Protruding Head BACB30MB( )A( ) 

+ 

BACC30BH( )

BACB30MC( )A( ) 

+ 

BACC30BH( )

BACB30MD( )A( ) 

+ 

BACC30AC( )

Countersunk BACB30FN( )A( ) 

+ 

BACC30M( )

BACB30FQ( )A( ) 

+ 

BACC30M( )

BACB30KF( )A( ) 

+ 

BACC30R( )

STEP TASK NAME IDENTIFICATION QTY MORE DATA

(SHEET 6 OF 6)
 FIGURE 24: AUXILIARY CHORD INSPECTION - GROUPS 1 THROUGH 3, CONFIGURATION 1; 

GROUPS 4 THROUGH 11, CONFIGURATION 1 AND 4

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ALERT ALERT

FIGURE 24: AUXILIARY CHORD INSPECTION - GROUPS 1 THROUGH 3, CONFIGURATION 1; GROUPS 

4 THROUGH 11, CONFIGURATION 1 AND 4

CRACK

TYPICAL (LEFT SIDE SHOWN, RIGHT SIDE SIMILAR)

VIEW FROM INSIDE REAR CARGO BAY

727

STA

540

STA

STA

727

1 2

STA

727

BL 0

S-25

S-20

S-18

S-17

S-19

S-21

S-22

S-23

S-24

S-26

S-27

A

SEE A

U34781

FWD

SPLICE

SKIN LAP

SKIN

AREA

INSPECTION

CHORD

AUXILIARY

CHORD

AUXILIARY

CHORD

FRAME

AFT SKIN

WEB

BULKHEAD

(SHEET 1 OF 2)
 FIGURE 24: AUXILIARY CHORD INSPECTION - GROUPS 1 THROUGH 3, CONFIGURATION 1; 

GROUPS 4 THROUGH 11, CONFIGURATION 1 AND 4

June 30, 1994

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ALERT ALERT

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. 

STEP TASK NAME PROCEDURE REFERENCES MORE DATA

1 Inspect Auxiliary Chord 

Radius

Detailed 

Inspection

- For cracks

2 Inspect Auxiliary Chord 

Radius

High Frequency 

Eddy Current 

(HFEC)

737 NDT Part 6 

Subject 51-00-00 

Figure 23

(a) For cracks

(a) 737 NDT Part 6 Subject 51-00-00 Figure 4 is an alternative procedure

(SHEET 2 OF 2)
 APPENDIX A: ADDENDUM

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

APPENDIX A: ADDENDUM

FLIGHT SAFETY SECTION

INSPECTION TO ENSURE STRUCTURAL INTEGRITY OF AIRFRAME

A structural reassessment of the 737 airplane has been conducted under the requirements of Federal Aviation 

Administration (FAA) Advisory Circular 91-56 in accordance with Federal Aviation Regulation (FAR) 25.571, as 

amended in 1978, to ensure safe operation of 737 airplanes throughout their operational life.

Table 1 is a summary of the inspections specified in Paragraph 1.E Compliance that are recommended for the 

detection of cracks in the STA 727 frame outboard chord prior to their reaching critical lengths. Failure to detect 

cracks prior to their reaching critical length may result in failure of the STA 727 frame outboard chord. 

Any cracked structure should be replaced prior to further flight unless specifically approved by your cognizant 

regulatory agency.

Please report any discrepancies to Boeing Customer Support Engineering using the reporting system described 

in the addendum.

Table 1 - STA 727 Frame Outboard Chord at Stringer 18A

Airplane Condition Compliance

STA 727 Frame is in the as delivered condition. The inspection as given in 1.E., Compliance, 

Table 2 of this service bulletin replaces the local 

F-29 inspections. The F-29 inspections remain 

valid for all other areas of F-29 not inspected 

per Table 2. 

STA 727 Frame Outboard Chord replaced, but 

the STA 727 Frame Outboard Chord 

modification per this service bulletin has not 

been accomplished. 

The inspection as given in 1.E., Compliance, 

Table 3 of this service bulletin replaces the local 

F-29 inspections. The F-29 inspections remain 

valid for all other areas of F-29 not inspected 

per Table 3. 

STA 727 Frame Outboard Chord replaced and 

the STA 727 Frame Outboard Chord 

modification per this service bulletin has been 

accomplished.

Service Bulletin 737-53-1088 Revision 1, dated 

May 25, 2006 contains the alternate F-29 

inspections.

STA 727 Frame Outboard Chord is as 

delivered, but the STA 727 Frame Outboard 

Chord modification per this service bulletin has 

been accomplished.

The F-29 inspections remain effective. An 

alternate inspection is not required for this 

configuration. 
 APPENDIX A: ADDENDUM

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

Boeing requests that operators use the following Structural Significant Item (SSI) Reporting System to report 

any discrepancies that are found in accomplishing a Flight Safety Inspection.

1. Upon recognition of discrepancy, the following information should be telegraphed to Boeing:

Heading: ATTENTION - SSI DISCREPANCY - SERVICE BULLETIN RELATED 

- Service Bulletin number

- Airplane serial number on which discrepancy was found

- Identification of structural item found damaged

- Flight cycles and hours on damaged item

- Location and description of damage including direction and size

- When discovered and inspection method used

Send telegram through Boeing Field Service Representative or directly to:

737 Customer Support Engineering

2. An Operator's Follow-Up Report containing all available pertinent data, relative to the structural 

discrepancy, shall be sent to Boeing. A summary of the information that should be reported is shown in the 

DISCREPANT STRUCTURE REPORT form attached. Operators may use this form or any suitable 

alternative which contains the same information.

3. All data and reports dealing with the Flight Safety Inspection Program shall be submitted either through a 

Boeing Field Service Representative or directly to:

The Boeing Commercial Airplane Group 

P.O. Box 3707

Seattle, Washington 98124-2207, USA

Attn: 707/727/737 Service Engineering Director

Org. M-7201 Mail Stop 2H-84

4. All reports will be reviewed promptly.
 APPENDIX A: ADDENDUM

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

SCHEDULED MAINTENANCE WALK-AROUND

6.

5.

4.

3.

4A.

4B.

2. AIRCRAFT DATA

DISCREPANT STRUCTURE REPORT

1.

STATION

MODEL

REPORT DATA A.T.A. INDEX

NAME

IPC/DWG REF

COMPONENT FLIGHT CYCLES SINCE NEW 

COMPLETE THE FOLLOWING IF KNOWN AND DIFFERENT FROM SECTION 2:

S/N

REPAIR DATA PLANNED COMPLETED

ACTION

SB

MPD

STRUCTURAL SIGNIFICANT ITEM NO.

SERVICE BULLLETINS INCORPORATED IN AREA OF DISCREPANCY

INSPECTION DATA 

CORRESPONDING INSPECTION LEVELS

X 24291 ORIG. 3/84 (FRONT)

6A. WHEN DISCOVERED

OVERHAUL

UNSCHEDULED

SYMPTOM (FUEL/PRESS. LEAK . . . )

RELATED FLEET EXPERIENCE

ACCIDENT INVESTIGATION

SSID

SERIES 50

6B. INSPECTION LEVEL

GENERAL VISUAL

EXTERNAL SURVEILLANCE

DETAILED

SPECIAL

6C. DETECTION METHOD

INTERNAL SURVEILLANCE

VISUAL

MAG. VISUAL

DYE PENETRANT

ULTRASONIC

X-RAY

LOW FREQUENCY

EDDY CURRENT

HIGH FREQUENCY

EDDY CURRENT

BORESCOPE

MAGNETIC 

PARTICLE

TAP TEST

SOUND

SMELL

FEEL

FUEL LEAK

PRESS. LOSS

SIDE 1

AIRLINE/AGENCY MONTH DAY YEAR

REPORT NO.

MFG. SERIAL NO. FLIGHT HOURS

SERIES TAIL NO.

FLIGHT CYCLES

COMPONENT FLIGHT HOURS SINCE NEW

COMPONENT DATA (AS APPLICABLE AND AVAILABLE):

P/N

SRM REF

SINCE OVERHAUL

SINCE OVERHAUL

NO.

SERVICE BULLETIN 

OF SERVICE BULLETIN

APPLICABLE SECTION

INCORPORATION

DATE OF

CYCLES AT INCORPORATION

TOTAL FLIGHT HOURS AND

HOURS

HOURS

HOURS

FLIGHTS

FLIGHTS

FLIGHTS

AD

OTHER (E.G., SDR, MRR)

IPC SRM

SIIA

SERIES 50 NO.

(COMPLETE KNOWN INFO., CHECK APPROPRIATE ITEMS FOR DISCREPANT STRUCTURE):

CURRENT INSPECTION INTERVALS (FLIGHT)

SPECIAL/DIRECTED (AD, SB . . . )

REFERENCES ASSOCIATED WITH INSPECTION/REPAIR (SPECIFY NO., PAGE, FIGURE, ETC)

W76755
 APPENDIX A: ADDENDUM

June 30, 1994

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BOEING SERVICE BULLETIN 737-53A1166

ALERT ALERT

STRINGER

Attach sketch, photos and text as required to describe defect and specific location.

DISCREPANT STRUCTURE REPORT

X 2491 ORIG. 1/84 (BACK)

INSPECTED BY

ORIGINATED BY

REPAIRED BY

DATE

7. DISCREPANCY DESCRIPTION:

SIDE 2

associated discrepancies on the same airplane, related experience with this discrepancy on any airplane, and previous

modification(s) to the discrepant structure.

When applicable, give details of

7A. TYPE OF DISCREPANCY:

LEAK

DETACHED

DENTED

DELAMINATED

DEFORMED

CRACKED

CORRODED

BENT CONTAMINATED

BURNED

BUCKLED

BROKEN

CLOGGED WORN

STUCK

OUT-OF-TOLERANCE

MISSING

LOOSE

ADJUSTED

IMPROPERLY

WRINKLED

7B. SIZE OF DISCREPANCY: INCHES, OR CENTIMETERS

AREA

FINAL MEASUREMENT (IF DIFFERENT)

CRACK LENGTH INITIALLY DETECTED

DEPTH

DATE

DATE

X

7C. DISCREPANT PART:

FRAME/BULKHEAD

PRESSURE BULKHEAD

FRAME AROUND OPENING

WINDOW FORGING

KEEL BEAM

FLOOR

SPAR

RIB

FLAP TRACK

FAIRING

WING CENTER SECTION

WING DRY-BAY AREA/COMPT

LANDING GEAR BEAM

JOINT/SPLICE

LUG

WELD

BOND

OPEN HOLE

FASTENER HOLE

CUTOUT

NOTCH/GROOVE

DISCONTINUITY

BASIC MATERIAL

BUSHING

PIN

SKIN

PLATE/PANEL

CHORD

NO.

STRUT/BRACE

BEAM

LINK/ROD

LONGERON

FITTING

BRACKET/SLIP

STOP

FASTENER

ACCESS/LIGHTENING HOLE

7D. LOCATION OF DISCREPANT PART:

GENERAL LOCATION (E.G., BILGE, UNDER GALLEY)

WING STA NO.

BODY STA NO.

VERT STAB. STA

HORIZ STAB. STA

NOSE LANDING GEAR

MAIN LANDING GEAR

WING LANDING GEAR

BODY LANDING GEAR

DOOR ACCESS PANEL

RUDDER

ELEVATOR

AILERON

FLAP

SLAT

SPOILER

TAB (ALSO CHECK ABOVE)

INTERIOR

INBOARD

LEFT

FORWARD

UPPER

LEADING EDGE

MIDDLE

SPECIFIC LOCATION

EXTERIOR

OUTBOARD

RIGHT

AFT

LOWER

TRAILING EDGE

SIDE

NACELLE/PYLON

COMPARTMENT

W76756