### Commercial **Airplanes** 

# 737

Service Bulletin **ALERT Number:**  **737-53A1351** Original Issue: July 08, 2015 ATA System: 5330 **SUBJECT:** FUSELAGE - Skin - Window Corner Inspection Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15 CFR 300-774). An export license may be required before it is used for development, production or use by foreign persons from specific countries. The controller of this data has the individual responsibility to abide by all export laws. 9E991 ECCN: 

## BOEING PROPRIETARY, CONFIDENTIAL AND/OR TRADE SECRET Copyright © 2015 Boeing. Unpublished Work. All Rights Reserved. Treatment of this document and its content is governed by contract with Boeing. Rights to use this document are licensed on a per aircraft basis and such rights may not be transferable. For more information, contact The Boeing Company. Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner, BBJ, DC-8, DC-9, DC-10, KC-10, KC-46, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8, Poseidon and Boeing liveries are all trademarks owned by The Boeing Company; and no trademark license is granted in connection with this document unless provided in writing by Boeing.

Original Issue: July 08, 2015 737-53A1351 1of53 3.0Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 2of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT**

BLANK PAGE**Table of Contents**

Summary

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 5 1. PLANNING INFORMATION

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 A. Effectivity

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 9 1. Airplanes

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2. Spares Affected

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . 27 B. Concurrent Requirements

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 27 C. Reason

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . 27 D. Description

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 E. Compliance

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 F. Approval

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . 32 G. Manpower

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 H. Weight and Balance Changes

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 I. Electrical Load Data

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 33 J. References

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 1. Existing Data:

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . 33 2. Data Supplied with this Service Bulletin:

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

. . . . . .. . . . . 33 K. Publications Affected

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 L. Interchangeability and Intermixability of Parts

. . . . . . . . . . . . . . . . . . . . . .. . . . . 34 M. Software Accomplishment Summary

. . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 34 2. MATERIAL INFORMATION

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 35 A. Material - Price and Availability

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 B. Industry Support Information

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . 35 C. Parts Necessary for Each Airplane

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 1. Kits/Parts

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 2. Parts and Materials Supplied by the Operator

. . . . . . . . . . . . . . . . . . .. . . . . 35 3. Parts Modified and Reidentified

. . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 35 4. Parts Removed and Not Replaced

. . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 35 D. Parts Necessary to Change Spares

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

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

. . . . . . . . . . . . . . . . . . . . . . . 35 3. ACCOMPLISHMENT INSTRUCTIONS

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 A. GENERAL INFORMATION

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . 37 B. WORK INSTRUCTIONS

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 FIGURE 1: EXTERNAL INSPECTION OF THE UPPER FORWARD AND LOWER AFT WINDOW CORNER,

STA 360 TO STA 540 LEFT SIDE

. . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 40 FIGURE 2: EXTERNAL INSPECTION OF THE UPPER FORWARD AND LOWER AFT WINDOW CORNER,

STA 360 TO STA 540 RIGHT SIDE

. . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 42 FIGURE 3: EXTERNAL INSPECTION OF THE LOWER FORWARD AND UPPER AFT WINDOW CORNER,

STA 727 TO STA 887 LEFT SIDE

. . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 44 FIGURE 4: EXTERNAL INSPECTION OF THE LOWER FORWARD AND UPPER AFT WINDOW CORNER,

STA 727 TO STA 887 RIGHT SIDE

. . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 46 APPENDIX A: LOGIC DIAGRAM FOR PARAGRAPH 1.E., COMPLIANCE: TABLE 1: WINDOW CORNER

EXTERNAL INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887 [Group 1]

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 3of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT**APPENDIX B: LOGIC DIAGRAM FOR PARAGRAPH 1.E., COMPLIANCE: TABLE 2: WINDOW CORNER EXTERNAL INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887 [Group 2]

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 APPENDIX C: LOGIC DIAGRAM FOR PARAGRAPH 1.E., COMPLIANCE: TABLE 3: WINDOW CORNER

EXTERNAL INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887 [Group 3]

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 4of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT**

### Commercial **Airplanes** 

# 737

Service Bulletin **ALERT Summary**  **Number: 737-53A1351**  Original Issue: July 08, 2015 ATA System: 5330 **SUBJECT:** FUSELAGE - Skin - Window Corner Inspection 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** This service bulletin gives instructions to inspect for any crack in the skin around fasteners in window corners from STA 360 to STA 540 and from STA 727 to STA 887, left and right side between stringers S-10 and S-14. Widespread Fatigue Damage (WFD) analysis of the 737NG, as required by 14 CFR 26.21(b), has resulted in the conclusion that the existing MPD Section 9, Airworthiness Limitation Instruction (ALI) inspection program is not sufficient to preclude the occurrence of WFD in the window corner surround structure from STA 360 to STA 540 and from STA 727 to STA 887, left and right sides between S-10 and S-14, as the airplane ages. The window corner surround structure has multiple adjacent identical details which have the potential for Multi-Element Damage (MED) and the potential for WFD. 14 CFR 26.21 requires evaluation of such designs for the potential for WFD and implementation of the appropriate service actions to ensure that WFD is precluded out to the Limit of Validity (LOV). Accomplishment of the inspections described in this service bulletin will enable detection and repair of cracks if they should occur, at the window corner surround structure. Boeing has not received any in-service fleet reports of cracks in the window corner surround structure. If widespread fatigue cracking is not found and repaired, the cracks can rapidly link up and can result in possible rapid decompression and loss of structural integrity. The window corner surround structure from STA 360 to STA 540 and from STA 727 to STA 887, left and right sides between S-10 and S-14, has been determined to be structure that is susceptible to WFD. Boeing Fleet Team Digest 737NG FTD 53-14001 is related to this service bulletin Boeing Service Related Problem (SRP)737NG-SRP-53-0474is related to this service bulletin. This table is provided to operators for planning purposes only. Refer to the applicable sections for more information.
**Reference Affected**  **Planning Data** Paragraph 1.A.2., Spares Affected No Spares Affected

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 5of53**Reference Affected**  **Planning Data** Paragraph 1.E., ComplianceandParagraph 1.F., Approval Yes AD Related Paragraph 1.H., Weight and Balance Changes No Weight and Balance Change Paragraph 1.I., Electrical Load Data No Electrical Load Changed Paragraph 1.K., Publications Affected No Publications Affected Paragraph 1.K., Publications Affected No Airplane Flight Operations Affected (Flight CrewOperations Manual and/or FAA Approved Airplane Flight Manual) Paragraph 2.C.1., Kits/Parts No Kits/Parts Required Paragraph 2.C.2., Parts and Materials Supplied by the Operator No Operator Supplied Parts/Material Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin No Special Tooling Required

**ACTION** Do an external High Frequency Eddy Current (HFEC) inspection of the skin around fasteners in window corners from STA 360 to STA 540 and from STA 727 to STA 887. If no crack is found, do repeat inspections. If any crack is found, contact The Boeing Company for work instructions and do the work. **EFFECTIVITY** All 737-600, -700, -700C, -800, -900, and -900ER Airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes. **COMPLIANCE** The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. Federal Aviation Administration (FAA) Airworthiness DirectiveAD 2013-19-23is related to this service bulletin. The effective date ofAD 2013-19-23is November 7, 2013. This service bulletin affects Principle Structural Element (PSE) 53-30-05-1, 53-30-05-2, 53-30-05-3, 53-60-05-1, 53-60-05-2, and 53-60-05-3 of Subsection B, Airworthiness Limitations-Structural Inspections of Section 9 of the737-600/700/800/900 MPD626A001-CMR, which is mandated byAD 2013-19-23

. Refer toParagraph 1.E., Compliance

. **INDUSTRY SUPPORT INFORMATION** Boeing warranty remedies are not available for the inspection given in this service bulletin. **MANPOWER** Refer toParagraph 1.G., Manpower

.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 6of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT MATERIAL INFORMATION** 

None.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 7of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 8of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT**

BLANK PAGE

### Commercial **Airplanes** 

# 737

Service Bulletin **ALERT Number:**  **737-53A1351** Original Issue: July 08, 2015 ATA System: 5330 **SUBJECT:** FUSELAGE - Skin - Window Corner Inspection 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 toService Bulletin Index D6-19567Part 3 for Airplane Variable Number, Line Number, and Serial Number data. This service bulletin is applicable to 737-600/-700/-700C/-800/-900/-900ER Airplanes, line numbers 1-99999 in 3 Groups. The Variable Numbers and Group Information for the applicable airplanes is given below. **NOTE:** The Variable Number table below includes all affected airplanes up to Line Number 6060. Affected airplanes after Line Number 6060 will be added to the service bulletin's MyBoeingFleet.com (MBF) "get effectivity" result when they are added to the MBF Fleet Profile Page.
**DESCRIPTION CONFIGURATION**  **GROUP** 737-600/700 airplanes.

- 1 737-700C/900 airplanes.

- 2 737-800/900ER airplanes.

- 3

Airplane Models: 737-600,737-700,737-700C,737-800,737-900,737-900ER

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 9of53**Group Variable Number**  1 YA001 - YA099 1 YA101 - YA199 1 YA201 - YA211 1 YA221 1 YA231 - YA242 1 YA251 - YA256 1 YA271 - YA272 1 YA291 1 YA301 - YA302 1 YA311 - YA314 1 YA321 - YA323 1 YA336 - YA345 1 YA351 1 YA356 - YA357 1 YA366 - YA367 1 YA371 - YA377 1 YA501 - YA536 1 YA541 - YA552 1 YA571 - YA578 1 YA601 - YA615 1 YA621 - YA622 1 YA626 - YA631 1 YA635 - YA636 1 YA641 - YA642 1 YA645 - YA650 1 YA656 - YA659 1 YA666 - YA667 1 YA671 - YA672 1 YA681 - YA691 1 YA701 - YA710 1 YA721 - YA722 1 YA731 - YA734

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 10of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Group**  **Variable Number** 1 YA751 - YA756 1 YA801 - YA803 1 YA809 1 YA811 - YA814 1 YA831 - YA835 1 YA841 - YA862 1 YA881 - YA882 1 YA891 - YA892 1 YA961 - YA978 1 YB001 - YB006 1 YB101 - YB132 1 YB151 - YB153 1 YB156 - YB158 1 YB161 - YB164 1 YB171 - YB172 1 YB181 - YB184 1 YB201 - YB208 1 YB271 1 YB276 1 YB301 - YB310 1 YB371 - YB392 1 YB501 - YB502 1 YB521 - YB526 1 YB541 - YB544 1 YB551 1 YB561 - YB598 1 YB601 - YB636 1 YB651 1 YB656 1 YB671 - YB672 1 YB851 - YB863 1 YB871 - YB874 1 YB881 - YB893

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 11of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Group**  **Variable Number** 1 YB901 - YB903 1 YB911 1 YB961 - YB975 1 YB981 1 YB986 - YB998 3 YC001 - YC030 3 YC051 - YC084 3 YC091 - YC095 3 YC101 - YC104 3 YC111 - YC113 3 YC121 3 YC126 - YC127 3 YC136 - YC141 3 YC146 - YC147 3 YC151 - YC156 3 YC166 - YC171 3 YC176 - YC179 3 YC186 - YC190 3 YC201 - YC203 3 YC206 - YC207 3 YC301 - YC305 3 YC321 - YC387 3 YC391 - YC394 3 YC396 3 YC401 - YC417 3 YC421 - YC422 3 YC426 - YC428 3 YC436 - YC439 3 YC441 - YC448 3 YC451 - YC455 3 YC459 3 YC461 - YC467 3 YC471 - YC499

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 12of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Group**  **Variable Number** 3 YC501 - YC526 3 YC571 - YC583 3 YC587 - YC589 3 YC591 - YC593 3 YC601 - YC655 3 YC681 - YC696 3 YC701 - YC715 3 YC720 - YC725 3 YC727 - YC752 3 YC761 - YC770 3 YC781 - YC793 3 YC801 - YC892 3 YC901 - YC907 3 YC921 - YC922 3 YC931 - YC932 3 YC941 - YC951 3 YC971 - YC978 3 YC981 - YC983 3 YD001 - YD007 3 YD021 - YD025 3 YD041 - YD057 3 YD081 - YD084 3 YD101 - YD117 3 YD121 - YD126 3 YD151 - YD159 3 YD171 - YD172 3 YD201 - YD203 3 YD206 - YD209 3 YD216 - YD219 3 YD251 - YD254 3 YD256 - YD257 3 YD261 3 YD301 - YD334

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 13of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Group**  **Variable Number** 3 YD391 3 YD401 - YD410 3 YD412 - YD422 3 YD481 - YD485 3 YD491 - YD499 2 YD501 - YD512 2 YD531 - YD535 2 YD541 - YD547 2 YD561 - YD564 2 YD571 - YD572 2 YD591 - YD595 2 YD601 - YD612 2 YD651 - YD655 1 YE001 - YE020 1 YE051 1 YE101 - YE109 1 YE151 - YE157 1 YE171 - YE172 1 YE201 - YE206 1 YE301 - YE305 1 YE321 - YE326 1 YE371 - YE383 3 YF001 - YF011 3 YF021 - YF049 3 YF051 - YF080 3 YF086 - YF087 3 YF106 - YF107 3 YF111 - YF114 3 YF116 - YF119 3 YF121 - YF132 3 YF176 - YF178 3 YF191 - YF192 3 YF201 - YF276

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 14of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Group**  **Variable Number** 3 YF401 - YF402 3 YF431 - YF432 3 YF436 - YF437 3 YF441 - YF442 3 YF451 - YF460 3 YF501 - YF599 3 YF601 - YF685 3 YF691 - YF695 3 YF701 - YF707 3 YF801 - YF805 3 YF831 - YF832 3 YF836 - YF838 3 YF871 - YF872 3 YF901 - YF905 3 YF921 - YF928 3 YF951 - YF954 1 YG001 - YG044 1 YG061 - YG064 1 YG066 - YG089 1 YG091 - YG099 1 YG101 - YG104 1 YG111 - YG114 1 YG116 - YG146 1 YG201 - YG205 1 YG211 - YG214 1 YG221 - YG224 1 YG251 - YG252 2 YG501 - YG515 2 YG601 - YG602 2 YG701 2 YG711 2 YG721 - YG722 3 YH001 - YH012

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 15of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Group**  **Variable Number** 3 YH031 - YH055 3 YH071 - YH080 3 YH101 - YH132 3 YH201 - YH202 3 YH206 - YH207 3 YH301 - YH307 3 YH321 - YH322 3 YH501 - YH542 3 YH551 - YH594 3 YH601 - YH606 3 YH611 - YH620 3 YH631 - YH632 3 YH636 - YH637 3 YH641 3 YH681 - YH683 3 YH701 - YH740 3 YH751 - YH755 3 YH801 - YH856 3 YH901 - YH908 3 YH911 - YH915 3 YH951 - YH952 3 YJ001 - YJ013 3 YJ021 3 YJ471 - YJ480 3 YJ501 - YJ517 3 YJ531 - YJ579 3 YJ591 - YJ599 3 YJ631 - YJ632 3 YJ671 - YJ694 3 YJ801 - YJ867 3 YJ871 - YJ880 3 YJ901 - YJ904 3 YJ908 - YJ929

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 16of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Group**  **Variable Number** 3 YJ931 - YJ937 3 YJ941 - YJ956 3 YJ961 3 YJ976 - YJ977 3 YK001 - YK007 3 YK101 - YK104 3 YK111 - YK112 3 YK121 - YK122 3 YK131 - YK133 3 YK136 - YK139 3 YK141 - YK142 3 YK146 - YK148 3 YK151 - YK154 3 YK161 - YK167 3 YK171 3 YK176 - YK177 3 YK186 3 YK191 3 YK196 3 YK201 - YK202 3 YK301 - YK314 3 YK321 - YK340 3 YK361 - YK378 3 YK401 - YK406 3 YK426 - YK427 3 YK431 - YK450 3 YK456 - YK467 3 YK471 - YK473 3 YK476 3 YK478 3 YK480 - YK487 3 YK491 - YK493 3 YK495 - YK499

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 17of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Group**  **Variable Number** 3 YK511 - YK516 3 YK521 - YK530 3 YK551 - YK571 3 YK576 - YK577 3 YK580 - YK585 3 YK601 - YK602 3 YK606 - YK607 3 YK611 - YK616 3 YK621 - YK634 3 YK641 - YK644 3 YK651 - YK665 3 YK671 - YK672 3 YK676 - YK677 3 YK681 - YK686 3 YK691 3 YK695 - YK699 3 YK701 - YK713 3 YK716 - YK719 3 YK721 - YK741 3 YK751 - YK770 3 YK776 - YK778 3 YK781 - YK785 3 YK791 - YK792 3 YK796 - YK797 3 YK801 - YK899 3 YK901 - YK912 3 YK918 - YK919 3 YK921 - YK929 3 YK941 - YK999 3 YL001 - YL005 3 YL011 - YL016 3 YL021 - YL024 3 YL051 - YL052

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 18of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Group**  **Variable Number** 3 YL056 - YL057 3 YL061 3 YL066 - YL069 3 YL076 - YL077 3 YL101 - YL137 3 YL201 - YL237 3 YL241 - YL242 3 YL271 - YL272 3 YL281 - YL284 3 YL301 - YL303 3 YL311 - YL314 3 YL316 - YL321 3 YL351 - YL353 3 YL371 - YL374 3 YL401 3 YL421 - YL429 3 YL431 - YL444 3 YL461 - YL478 3 YL501 - YL509 3 YL531 - YL534 3 YL541 - YL551 3 YL561 - YL579 3 YL591 - YL598 3 YL601 - YL606 3 YL611 - YL612 3 YL616 - YL617 3 YL621 3 YL626 3 YL631 - YL634 3 YL636 - YL637 3 YL661 - YL664 3 YL676 - YL691 3 YL696 - YL697

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 19of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Group**  **Variable Number** 3 YL701 - YL707 3 YL731 3 YL751 - YL752 3 YL756 - YL757 3 YL761 - YL780 3 YL796 - YL797 3 YL801 - YL815 3 YL901 - YL910 3 YL921 - YL940 3 YL951 - YL968 1 YM101 - YM103 1 YM201 - YM244 1 YM251 - YM299 1 YM301 - YM399 1 YM401 - YM415 1 YM471 1 YM481 - YM484 1 YM501 - YM515 1 YM521 - YM522 1 YM541 1 YM551 - YM553 1 YM571 - YM572 1 YM581 - YM582 1 YM591 - YM599 1 YM631 - YM634 1 YM641 - YM652 1 YM671 - YM674 1 YM691 - YM699 1 YM701 - YM710 1 YM761 - YM765 1 YM771 - YM779 1 YN001 - YN016 1 YN021 - YN024

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 20of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Group**  **Variable Number** 1 YN061 1 YN071 - YN082 1 YN091 - YN092 1 YN101 - YN112 1 YN121 1 YN126 1 YN201 - YN202 1 YN211 - YN219 1 YN231 - YN236 1 YN261 1 YN501 1 YN531 - YN534 1 YN551 - YN566 1 YN581 - YN585 1 YN591 - YN592 1 YN601 - YN606 1 YN651 - YN653 1 YN701 - YN702 1 YN741 - YN746 1 YN756 3 YQ001 - YQ003 3 YQ011 - YQ021 3 YQ026 - YQ029 3 YQ036 - YQ045 3 YQ201 - YQ207 3 YQ231 3 YQ241 - YQ251 3 YQ281 - YQ284 3 YQ291 - YQ296 3 YQ301 - YQ302 3 YQ321 - YQ324 3 YQ331 - YQ334 3 YQ346 - YQ347

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 21of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Group**  **Variable Number** 3 YQ351 - YQ362 3 YQ371 3 YQ401 - YQ403 3 YQ451 - YQ454 3 YQ456 3 YQ461 3 YQ471 3 YQ501 - YQ520 3 YR001 - YR044 3 YR051 - YR098 3 YR101 - YR105 3 YR111 - YR124 3 YR126 - YR144 3 YR166 - YR182 3 YR186 - YR198 3 YR201 - YR204 3 YR231 - YR294 3 YR296 - YR297 3 YR301 - YR334 3 YR338 - YR341 3 YR361 - YR366 3 YR371 - YR373 3 YR376 - YR377 3 YR381 - YR382 3 YR386 - YR388 3 YR391 3 YR396 - YR398 3 YR401 - YR405 3 YR411 - YR413 3 YR416 - YR418 3 YR421 - YR424 3 YR426 - YR455 3 YR457 - YR499

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 22of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Group**  **Variable Number** 3 YR501 - YR506 3 YR511 - YR520 3 YR526 - YR544 3 YR546 - YR551 3 YR556 - YR562 3 YR571 - YR582 3 YR591 - YR592 3 YR601 - YR605 3 YR616 - YR658 3 YR661 - YR663 3 YR671 - YR672 3 YR676 - YR678 3 YR681 - YR682 3 YR701 - YR769 3 YR771 - YR799 3 YR801 - YR820 3 YR831 - YR838 3 YR841 - YR899 3 YR901 - YR903 3 YR931 - YR934 3 YR938 - YR944 3 YR951 - YR976 3 YR981 - YR996 3 YS001 - YS002 3 YS006 - YS009 3 YS031 - YS032 3 YS051 - YS073 3 YS101 - YS120 3 YS126 - YS142 3 YS146 - YS148 3 YS151 - YS160 3 YS166 - YS194 3 YS196 - YS197

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 23of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Group**  **Variable Number** 3 YS201 - YS209 3 YS221 - YS225 3 YS231 - YS236 3 YS271 - YS288 3 YS301 - YS346 3 YS351 - YS368 3 YS371 - YS377 3 YS381 - YS383 3 YS401 3 YS451 3 YS456 - YS457 3 YS462 3 YS467 3 YS501 - YS502 3 YS506 3 YS511 - YS516 3 YS531 3 YS536 - YS538 3 YS541 3 YS551 - YS556 3 YS561 - YS578 3 YS581 - YS595 3 YS601 - YS690 3 YS701 - YS708 3 YS721 - YS762 3 YS771 - YS780 3 YS806 - YS810 3 YS816 - YS818 3 YS823 - YS825 3 YS851 - YS861 3 YS876 3 YS881 - YS883 3 YS901 - YS909

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 24of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Group**  **Variable Number** 3 YS911 - YS939 3 YS951 3 YS956 - YS957 3 YS961 - YS965 3 YS981 - YS987 3 YS991 - YS998 3 YT001 - YT004 3 YT006 3 YT026 - YT027 3 YT031 - YT032 3 YT036 - YT038 3 YT061 - YT068 3 YT101 - YT117 3 YT126 - YT131 3 YT136 - YT138 3 YT176 - YT181 3 YT191 3 YT196 - YT199 3 YT201 3 YT206 - YT207 3 YT211 - YT213 3 YT251 - YT283 3 YT301 - YT307 3 YT311 - YT312 3 YT321 - YT341 3 YT381 3 YT391 - YT395 3 YT401 - YT403 3 YT411 - YT417 3 YT427 3 YT461 - YT474 3 YT491 - YT492 3 YT501 - YT520

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 25of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Group**  **Variable Number** 3 YT551 - YT552 3 YT556 - YT559 3 YT561 - YT563 3 YT571 3 YT601 - YT606 3 YT701 - YT706 3 YT761 - YT780 3 YT791 - YT793 3 YT796 - YT797 3 YT801 - YT804 3 YT811 - YT813 3 YT826 - YT827 3 YT831 - YT832 3 YT851 - YT852 3 YT856 - YT859 3 YT891 - YT895 3 YT901 - YT925 3 YU001 - YU054 3 YU201 - YU212 3 YV001 - YV002 3 YV006 - YV008 3 YV041 - YV042 3 YV045 - YV047 3 YV081 3 YV083 3 YV097 3 YV101 - YV119 3 YV301 - YV305 3 YV351 - YV356 3 YV381 - YV382 3 YV431 - YV433 3 YV501 3 YV521

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 26of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Group**  **Variable Number** 3 YV571 - YV574 3 YV601 - YV605 3 YV651 - YV654 3 YV711 3 YV741 3 YV781 3 YV801 3 YV881 - YV883 3 YW001 3 YW011 - YW032
2. Spares Affected None. **B. Concurrent Requirements**  None. **C. Reason**  This service bulletin gives instructions to inspect for any crack in the skin around fasteners in window corners from STA 360 to STA 540 and from STA 727 to STA 887, left and right side between stringers S-10 and S-14. Widespread Fatigue Damage (WFD) analysis of the 737NG, as required by 14 CFR 26.21(b), has resulted in the conclusion that the existing MPD Section 9, Airworthiness Limitation Instruction (ALI) inspection program is not sufficient to preclude the occurrence of WFD in the window corner surround structure from STA 360 to STA 540 and from STA 727 to STA 887, left and right sides between S-10 and S-14, as the airplane ages. The window corner surround structure has multiple adjacent identical details which have the potential for Multi-Element Damage (MED) and the potential for WFD. 14 CFR 26.21 requires evaluation of such designs for the potential for WFD and implementation of the appropriate service actions to ensure that WFD is precluded out to the Limit of Validity (LOV). Accomplishment of the inspections described in this service bulletin will enable detection and repair of cracks if they should occur, at the window corner surround structure. Boeing has not received any in-service fleet reports of cracks in the window corner surround structure. If widespread fatigue cracking is not found and repaired, the cracks can rapidly link up and can result in possible rapid decompression and loss of structural integrity. The window corner surround structure from STA 360 to STA 540 and from STA 727 to STA 887, left and right sides between S-10 and S-14, has been determined to be structure that is susceptible to WFD. Boeing Fleet Team Digest 737NG FTD 53-14001 is related to this service bulletin Boeing Service Related Problem (SRP)737NG-SRP-53-0474is related to this service bulletin.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 27of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT D.**  **Description**

Do an external High Frequency Eddy Current (HFEC) inspection of the skin around fasteners in window corners from STA 360 to STA 540 and from STA 727 to STA 887. If no crack is found, do repeat inspections. If any crack is found, contact The Boeing Company for work instructions and do the work. The work in this service bulletin is done in the maintenance zone(s) given below. **Group 1:**
**Affected Maintenance Zones Zone**  **Model** 231, 232, 241, 242 737-600, 737-700 **Group 2:**
**Affected Maintenance Zones Zone**  **Model** 231, 232, 241, 242 737-700C, 737-900 **Group 3:**
**Affected Maintenance Zones Zone**  **Model** 231, 232, 241, 242 737-800, 737-900ER
**E. Compliance**  The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. Federal Aviation Administration (FAA) Airworthiness DirectiveAD 2013-19-23is related to this service bulletin. The effective date ofAD 2013-19-23is November 7, 2013. Logic diagrams showing compliance times and compliance tasks are included as an aid in Appendix A, B, and C. For airplanes which have incorporated Boeing Business Jet Lower Cabin Altitude Supplemental Type Certificate ST01697SE (6,500 feet maximum cabin altitude in lieu of 8,000 feet) as referenced in Boeing Service Bulletin737-21-1149, the flight cycle related compliance times are different from those specified in this service bulletin. The initial compliance time (threshold) for 737-700 airplanes must be reduced to 46,000 total flight cycles and the repeat interval must be reduced to 3,400 flight cycles. The initial compliance time (threshold) for 737-800, -900ER airplanes must be reduced to 39,000 total flight cycles and the repeat interval must be reduced to 3,400 flight cycles.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 28of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT**For airplanes that have not incorporated Boeing Business Jet Lower Cabin Altitude Supplemental Type Certificate ST01697SE (6,500 feet maximum cabin altitude in lieu of 8,000 feet) as referenced in Boeing Service Bulletin 737-21-1149: This service bulletin affects PSE 53-30-05-2 and 53-60-05-2 of Subsection B, Airworthiness Limitations-Structural Inspections of Section 9 of the737-600/700/800/900 MPD 626A001-CMR Table 9-2, which is mandated byAD 2013-19-23. The inspections in this bulletin are for the skin surrounding the passenger window frame at two of the four corners and must be accomplished in addition to the737-600/700/800/900 MPDD626A001-CMR inspections (which apply only to the window frames), beginning at the threshold identified in section E of this bulletin. For airplanes which have incorporated Boeing Business Jet Lower Cabin Altitude Supplemental Type Certificate ST01697SE (6,500 feet maximum cabin altitude in lieu of 8,000 feet) as referenced in Boeing Service Bulletin 737-21-1149: This service bulletin affects Principle Structural Element (PSE) 53-30-05-1, 53-30-05-2, 53-30-05-3, 53-60-05-1, 53-60-05-2, and 53-60-05-3 of Subsection B, Airworthiness Limitations-Structural Inspections of Section 9 of the737-600/700/800/900 MPD626A001-CMR Table 9-3, which is mandated byAD 2013-19-23. The inspections in this bulletin are for the skin surrounding the passenger window frames at two of the four corners and must be accomplished in addition to the 737-600/700/800/900 MPDD626A001-CMR inspections beginning at the threshold identified in section E of this bulletin.737-600/700/800/900 MPDD626A001-CMR PSE number 53-30-05-3 and 53-60-05-3 inspections apply to the skin completely surrounding the passenger window frames.737-600/700/800/900 MPDD626A001-CMR PSE number 53-30-05-1, 53-60-05-1, 53-30-05-2 and 53-60-05-2 inspections apply only to the window frames. Do the required actions in accordance with Paragraph 3., Accomplishment Instructions. **Group 1: Table 1: Window Corner External Inspection From STA 360 to STA 540 and From STA 727 to STA 887**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- Before 64,000 total flight cycles. Do PART 1: WINDOW CORNER EXTERNAL HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887, LEFT AND RIGHT SIDE for any crack. All Airplanes

4,600 flight cycles.

- Repeat PART 1: WIN-DOW CORNER EXTERNAL HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887, LEFT AND RIGHT SIDE for any crack. CONDITION 1: NO CRACK FOUND

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 29of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Group 1:** 

**Table 1: Window Corner External Inspection From STA 360 to STA 540 and From STA 727 to STA 887 Repeat Interval**  **(Not to Exceed) Compliance Time**  **Action Condition** 

- Before Further Flight. ACTION 1: CONDITION 2: ANY CRACK FOUND Contact The BoeingCompany for repair instructions and do the repair. 4,600 flight cycles.

- ACTION 2:Repeat PART 1: WINDOW CORNER EXTERNAL HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887, LEFT AND RIGHT SIDE for any crack at the unrepaired areas. **Group 2: Table 2: Window Corner External Inspection From STA 360 to STA 540 and From STA 727 to STA 887**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- Before 58,000 total flight cycles. Do PART 1: WINDOW CORNER EXTERNAL HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887, LEFT AND RIGHT SIDE for any crack. All Airplanes

4,600 flight cycles.

- Repeat PART 1: WIN-DOW CORNER EXTERNAL HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887, LEFT AND RIGHT SIDE for any crack. CONDITION 1: NO CRACK FOUND

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 30of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Group 2:** 

**Table 2: Window Corner External Inspection From STA 360 to STA 540 and From STA 727 to STA 887 Repeat Interval**  **(Not to Exceed) Compliance Time**  **Action Condition** 

- Before Further Flight. ACTION 1: CONDITION 2: ANY CRACK FOUND Contact The BoeingCompany for repair instructions and do the repair. 4,600 flight cycles.

- ACTION 2:Repeat PART 1: WINDOW CORNER EXTERNAL HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887, LEFT AND RIGHT SIDE for any crack at the unrepaired areas. **Group 3: Table 3: Window Corner External Inspection From STA 360 to STA 540 and From STA 727 to STA 887**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- Before 53,000 total flight cycles. Do PART 1: WINDOW CORNER EXTERNAL HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887, LEFT AND RIGHT SIDE for any crack. All Airplanes

4,600 flight cycles.

- Repeat PART 1: WIN-DOW CORNER EXTERNAL HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887, LEFT AND RIGHT SIDE for any crack. CONDITION 1: NO CRACK FOUND

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 31of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Group 3:** 

**Table 3: Window Corner External Inspection From STA 360 to STA 540 and From STA 727 to STA 887 Repeat Interval**  **(Not to Exceed) Compliance Time**  **Action Condition** 

- Before Further Flight. ACTION 1: CONDITION 2: ANY CRACK FOUND Contact The BoeingCompany for repair instructions and do the repair. 4,600 flight cycles.

- ACTION 2:Repeat PART 1: WINDOW CORNER EXTERNAL HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887, LEFT AND RIGHT SIDE for any crack at the unrepaired areas.
**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. This service bulletin is also approved for airplanes having FAA Aviation Partners Boeing (APB) Supplemental Type Certificate (STC) number ST00830SE installed (not including any areas affected by the split scimitar winglet configuration). 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. **G. Manpower**  The table below shows an estimate of the task hours necessary to do this inspection for each airplane. This estimate is for direct labor only, done by an experienced crew. Adjust the estimate with operator task 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 inspect the work

• Time to cure the materials

• Time to make the parts

• Time to find the tools.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 32of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT Elapsed Hours**  **Task Hours Number of Persons**  **Task** 0.50 0.50 1 Inspect 0.50 0.50 TOTAL FOR EACH WINDOW(a) (a) Estimate for each window, multiply number of windows to be inspected by the estimate given to arrive at the total for each aircraft.
**H. Weight and Balance Changes**  None. **I. Electrical Load Data**  Not applicable. **J. References**  1. Existing Data:

a. Boeing Service Bulletin737-21-1149 b. Boeing Service Related Problem (SRP)737NG-SRP-53-0474

c. Federal Aviation Administration (FAA) Airworthiness Directive (AD)2013-19-23 d. Service Bulletin IndexD6-19567

e. 737 Non-Destructive Testing (NDT) ManualPart 6, 51-00-00 f. 737-600/700/800/900 Maintenance Planning Data (MPD)
2. Data Supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin: None. **K. Publications Affected**  1. Publications: None. 2. Damage Tolerance Based Structural Inspections: Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the Maintenance Program. This service bulletin affects FCS but no new DTIs are necessary.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 33of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT L.**  **Interchangeability and Intermixability of Parts**

Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts. **M. Software Accomplishment Summary**  Not affected.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 34of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT 2. MATERIAL INFORMATION**  **A. Material - Price and Availability**  None. **B. Industry Support Information**  Boeing warranty remedies are not available for the inspection given in this service bulletin. **C. Parts Necessary for Each Airplane**  1. Kits/Parts None. 2. Parts and Materials Supplied by the Operator None. 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. But, maintenance and overhaul tools in the manuals given inParagraph 1.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 35of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 36of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT**

BLANK PAGE**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 toParagraph 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 and fasteners are in Structural Repair Manual (SRM) Chapter 51

– Torque Values:

— Values for structural fasteners are given in 737 Structural Repair Manual, Chapter 51.

— Non-standard torque values for maintenance tasks are included in the applicable installation step.

4. Use the approved fastener, process and material substitutions in accordance with

SRM Chapter 51.
5. These work instructions refer to procedures included in other Boeing documents. When the words "refer to" are used and the operator has an accepted alternative procedure, the accepted alternative procedure can be used. When the words "in accordance with" are included in the instruction, the procedure in the Boeing document must be used. 6. Boeing Service Letter 737-SL-51-042, Damage Reporting and Repair Plan/Design

Guidelines, is an acceptable procedure to request information from Boeing for additional structural repair instructions. The Service Letter describes what information must be provided to Boeing before a structural repair can be provided.
7. Refer to Appendix A, B, and C for logic diagrams. Logic diagrams are provided as an aid only. Information contained in Paragraph 1.E., Compliance is the primary source for compliance times. Information in Paragraph 3.B., Work Instructions is the primary source for tasks required for compliance.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 37of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT**8. The instructions in Paragraph 3.B., Work Instructions and the figures can include operation of tools or test equipment. Boeing Engineering Tool Drawings, the Illustrated Tool and Equipment Manual, and the Special Tool and Ground Handling Drawing Index contain data on versions of the tools or test equipment that you can use. It is permitted to use replaced tools. It is not permitted to use superseded tools. 9. If it is necessary to remove more parts for access, you can remove those parts. If you can get access without removing identified parts, it is not necessary to remove all of the identified parts. Jacking and shoring limitations must be observed. 10. If shading is used, shaded areas in Figures are to separate the non-critical and non-authoritative information from the critical and authoritative information. 11. Use of colors in Figures is based on guidance from the ATA e-Business Program (ATA) iSpec 2200.
12. The compliance times for the actions in Paragraph 3.B., WORK INSTRUCTIONS are inParagraph 1.E., Compliance

. 13. The CONDITIONS, ACTIONS and OPTIONS shown apply to each inspection location independently. 14. Some steps in the Work Instructions are labeled as Required for Compliance (RC). If this service bulletin is mandated by an Airworthiness Directive (AD), then the steps labeled as RC, including sub-steps under an RC step and any figures identified in an RC step, must be done to comply with the AD. An Alternative Method of Compliance (AMOC) is required for any deviations to RC steps, including sub-steps and identified figures. Steps not labeled as RC may be deviated from using accepted methods in accordance with the operator's maintenance or inspection program without obtaining approval of an AMOC. This is provided that the RC steps, including sub-steps and identified figures, can still be done as specified, and the airplane can be put back in an airworthy condition. **B. WORK INSTRUCTIONS** 
1. RC - Do PART 1: WINDOW CORNER EXTERNAL HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887, LEFT AND RIGHT SIDE for any crack.

a. CONDITION 1: NO CRACK FOUND. (1) RC - Repeat PART 1: WINDOW CORNER EXTERNAL SURFACE HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887 for any crack at the repeat interval inParagraph 1.E., Compliance

. b. CONDITION 2: ANY CRACK FOUND. (1) RC - ACTION 1: Contact The Boeing Company for repair instructions and do the repair. (2) RC - ACTION 2: Repeat PART 1: WINDOW CORNER EXTERNAL HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887, LEFT AND RIGHT SIDE for any crack at the unrepaired areas.
2. Put the airplane back to a serviceable condition.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 38of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT PART 1: WINDOW CORNER EXTERNAL HFEC INSPECTION FROM STA 360 TO STA 540 AND**  **FROM STA 727 TO STA 887, LEFT AND RIGHT SIDE**
1. Do the following inspections: **NOTE:** If a Boeing ODA approved repair via FAA Form 8100-9 was installed to eliminate cracking that was previously found, inspections in the window corner are not required at the repaired location only. **Group 2: NOTE:**  For 737-700C airplanes, inspections are not required at the windows in the main deck cargo door located between STA 360 and STA 540.

a. Do an external High Frequency Eddy Current (HFEC) inspection for any crack in the skin at the upper forward and lower aft corners of each left side window from STA 360 to STA 540 in accordance withFIGURE 1

. b. Do an external HFEC inspection for any crack in the skin at the upper forward and lower aft corners of each right side window from STA 360 to STA 540 in accordance withFIGURE 2

.
c. Do an external HFEC inspection for any crack in the skin at the lower forward and upper aft corners of each left side window from STA 727 to STA 887 in accordance withFIGURE 3

. d. Do an external HFEC inspection for any crack in the skin at the lower forward and upper aft corners of each right side window from STA 727 to STA 887 in accordance withFIGURE 4

.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 39of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT FIGURE 1:** **EXTERNAL INSPECTION OF THE UPPER FORWARD AND LOWER AFT WINDOW CORNER, STA 360 TO STA 540 LEFT SIDE**  **(SHEET 1 OF 2)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 40of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** (a)

- - Skin Inspect 1 (a) Do an external HFEC inspection for any crack in the skin around the fasteners in window corners in accordance with737 NDT Manual Part 6, 51-00-00, Procedure 4 or 23.

**FIGURE 1: EXTERNAL INSPECTION OF THE UPPER FORWARD AND LOWER AFT WINDOW CORNER,**  **STA 360 TO STA 540 LEFT SIDE (SHEET 2 OF 2)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 41of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT FIGURE 2:** **EXTERNAL INSPECTION OF THE UPPER FORWARD AND LOWER AFT WINDOW CORNER, STA 360 TO STA 540 RIGHT SIDE**  **(SHEET 1 OF 2)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 42of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** (a)

- - Skin Inspect 1 (a) Do an external HFEC inspection for any crack in the skin around the fasteners in window corners in accordance with737 NDT Manual Part 6, 51-00-00, Procedure 4 or 23.

**FIGURE 2: EXTERNAL INSPECTION OF THE UPPER FORWARD AND LOWER AFT WINDOW CORNER,**  **STA 360 TO STA 540 RIGHT SIDE (SHEET 2 OF 2)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 43of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT FIGURE 3:** **EXTERNAL INSPECTION OF THE LOWER FORWARD AND UPPER AFT WINDOW CORNER, STA 727 TO STA 887 LEFT SIDE**  **(SHEET 1 OF 2)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 44of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** (a)

- - Skin Inspect 1 (a) Do an external HFEC inspection for any crack in the skin around the fasteners in window corners in accordance with737 NDT Manual Part 6, 51-00-00, Procedure 4 or 23.

**FIGURE 3: EXTERNAL INSPECTION OF THE LOWER FORWARD AND UPPER AFT WINDOW CORNER,**  **STA 727 TO STA 887 LEFT SIDE (SHEET 2 OF 2)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 45of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT FIGURE 4:** **EXTERNAL INSPECTION OF THE LOWER FORWARD AND UPPER AFT WINDOW CORNER, STA 727 TO STA 887 RIGHT SIDE**  **(SHEET 1 OF 2)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 46of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** (a)

- - Skin Inspect 1 (a) Do an external HFEC inspection for any crack in the skin around the fasteners in window corners in accordance with737 NDT Manual Part 6, 51-00-00, Procedure 4 or 23.

**FIGURE 4: EXTERNAL INSPECTION OF THE LOWER FORWARD AND UPPER AFT WINDOW CORNER,**  **STA 727 TO STA 887 RIGHT SIDE (SHEET 2 OF 2)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 47of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT This Appendix applies only to: Group 1.** 

Logic diagrams are provided as an aid only. Information contained inParagraph 1.E., Complianceis the primary source for compliance times. Information contained inParagraph 3.B., Work Instructionsis the primary source for tasks required for compliance.

**APPENDIX A: LOGIC DIAGRAM FOR PARAGRAPH 1.E., COMPLIANCE: TABLE 1: WINDOW CORNER**  **EXTERNAL INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887 (SHEET 1 OF 2)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 48of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT**1. The table below gives the description for the parts and conditions called out in the logic diagrams. **Description Title**  WINDOW CORNER EXTERNAL HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887, LEFT AND RIGHT SIDE PART 1
NO CRACK FOUND CONDITION 1 ANY CRACK FOUND CONDITION 2

**APPENDIX A: LOGIC DIAGRAM FOR PARAGRAPH 1.E., COMPLIANCE: TABLE 1: WINDOW CORNER**  **EXTERNAL INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887 (SHEET 2 OF 2)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 49of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT This Appendix applies only to: Group 2.** 

Logic diagrams are provided as an aid only. Information contained inParagraph 1.E., Complianceis the primary source for compliance times. Information contained inParagraph 3.B., Work Instructionsis the primary source for tasks required for compliance.

**APPENDIX B: LOGIC DIAGRAM FOR PARAGRAPH 1.E., COMPLIANCE: TABLE 2: WINDOW CORNER**  **EXTERNAL INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887 (SHEET 1 OF 2)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 50of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT**1. The table below gives the description for the parts and conditions called out in the logic diagrams. **Description Title**  WINDOW CORNER EXTERNAL HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887, LEFT AND RIGHT SIDE PART 1
NO CRACK FOUND CONDITION 1 ANY CRACK FOUND CONDITION 2

**APPENDIX B: LOGIC DIAGRAM FOR PARAGRAPH 1.E., COMPLIANCE: TABLE 2: WINDOW CORNER**  **EXTERNAL INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887 (SHEET 2 OF 2)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 51of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT This Appendix applies only to: Group 3.** 

Logic diagrams are provided as an aid only. Information contained inParagraph 1.E., Complianceis the primary source for compliance times. Information contained inParagraph 3.B., Work Instructionsis the primary source for tasks required for compliance.

**APPENDIX C: LOGIC DIAGRAM FOR PARAGRAPH 1.E., COMPLIANCE: TABLE 3: WINDOW CORNER**  **EXTERNAL INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887 (SHEET 1 OF 2)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 52of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT**1. The table below gives the description for the parts and conditions called out in the logic diagrams. **Description Title**  WINDOW CORNER EXTERNAL HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887, LEFT AND RIGHT SIDE PART 1
NO CRACK FOUND CONDITION 1 ANY CRACK FOUND CONDITION 2

**APPENDIX C: LOGIC DIAGRAM FOR PARAGRAPH 1.E., COMPLIANCE: TABLE 3: WINDOW CORNER**  **EXTERNAL INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 887 (SHEET 2 OF 2)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2015 737-53A1351 53of53 **BOEING SERVICE BULLETIN 737-53A1351 ALERT**  **ALERT**