### Commercial **Airplanes** 

# 737

Service Bulletin **ALERT Number:**  **737-53A1352** Original Issue: October 02, 2015 ATA System: 5331 **SUBJECT:** FUSELAGE - Skin - S-14 Lap Splice Lower Fastener Row 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 Unpublished Work.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Original Issue: October 02, 2015 737-53A1352 1of49 3.0Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 2of49 **BOEING SERVICE BULLETIN 737-53A1352 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

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 D. Description

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

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 F. Approval

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 G. Manpower

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 H. Weight and Balance Changes

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 I. Electrical Load Data

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 J. References

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 1. Existing Data:

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

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

. . . . . . . . . . . 32 K. Publications Affected

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

. . . . . . . . . . . . . . . . . . . . . . . . . . . 33 M. Software Accomplishment Summary

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 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: LFEC INSPECTION OF S-14 LAP SPLICE LOWER FASTENER ROW[Group 1]

. . . . . 40 FIGURE 2: LFEC INSPECTION OF S-14 LAP SPLICE LOWER FASTENER ROW[Group 2]

. . . . . 43 APPENDIX A: LOGIC DIAGRAM FOR PARAGRAPH 1.E. COMPLIANCE: TABLE 1: INSPECTION FOR ANY

CRACK AT S-14 LAP SPLICE

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 APPENDIX B: LOGIC DIAGRAM FOR PARAGRAPH 1.E. COMPLIANCE: TABLE 2: INSPECTION FOR ANY

CRACK AT S-14 LAP SPLICE

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

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 3of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 4of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT**

BLANK PAGE

### Commercial **Airplanes** 

# 737

Service Bulletin **ALERT Summary**  **Number: 737-53A1352**  Original Issue: October 02, 2015 ATA System: 5331 **SUBJECT:** FUSELAGE - Skin - S-14 Lap Splice Lower Fastener Row 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** Widespread Fatigue Damage (WFD) analysis of the 737NG, as required by 14 CFR 26.21(b), has resulted in the conclusion that the existing737-600/700/800/900 MPD Section 9, Airworthiness Limitation Instruction (ALI) inspection program is not sufficient to preclude the occurrence of WFD in the S-14L and S-14R lap splice, lower fastener rows between STA 360-540 and STA 727-887 as the airplane ages. These lap splices have multiple adjacent identical details which have the potential for Multi-Site Damage (MSD) 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). Boeing has not received any in-service fleet reports of cracks in these lap splices. Accomplishment of the inspections described in this service bulletin will enable detection and repair of cracks if they should occur, at these lap splices. 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. This Service Bulletin provides more frequent external inspection of the S-14 lap splices in order to prevent WFD out to the LOV. The fuselage skin S-14L and S-14R lap splice lower fastener row between STA 360 to STA 540 and STA 727 to STA 887 has been determined to be structure that is susceptible to WFD. Boeing Fleet Team Digest737NG FTD 53-14001is related to this service bulletin. Boeing Service Related Problem (SRP)737NG-SRP-53-00471is 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: October 02, 2015 737-53A1352 5of49**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 Group 1:**  1. Do PART 1: Low Frequency Eddy Current (LFEC) Inspection for any crack on the S-14L and S-14R lap splice, lower fastener row, between STA 360 to STA 540 and STA 727 to STA 887. If no crack is found, repeat PART 1: LFEC INSPECTION at the repeat interval inParagraph 1.E., Compliance. If any crack is found, contact The Boeing Company to get instructions for S-14 lap splice crack repair and do the repair. **Group 2:** 1. Do PART 1: Low Frequency Eddy Current (LFEC) Inspection for any crack on S-14L lap splice, lower fastener row, between STA 500 to STA 540 and STA 727 to STA 887 and S-14R lap splice, lower fastener row, between STA 360 to STA 540 and STA 727 to STA 887. If no crack is found, repeat PART 1: LFEC INSPECTION at the repeat interval inParagraph 1.E., Compliance. If any crack is found, contact The Boeing Company for repair instructions and do the repair. **EFFECTIVITY** All 737-600/-700/-700C/-800/-900/-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.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 6of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT**This service bulletin affects Principle Structural Element (PSE) 53-30-04-6, 53-30-04-6a, 53-60-04-6 and

53-60-04-6a of Subsection B, Airworthiness Limitations-Structural Inspections of737-600/700/800/900 MPD Section 9, which is mandated byAD 2013-19-23

. Refer toParagraph 1.E., Compliance

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

. **MATERIAL INFORMATION** None.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 7of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 8of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT**

### Commercial **Airplanes** 

# 737

Service Bulletin **ALERT Number:**  **737-53A1352** Original Issue: October 02, 2015 ATA System: 5331 **SUBJECT:** FUSELAGE - Skin - S-14 Lap Splice Lower Fastener Row 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 all 737-600/-700/-700C/-800/-900/-900ER Airplanes, line numbers 1-99999 in 2 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/-800/-900/-900ER Passenger airplane.

- 1 737-700C Convertible airplane.

- 2

Airplane Models: 737-600, 737-700, 737-700C, 737-800, 737-900, 737-900ER **Group Variable Number**  1 YA001 - YA099 1 YA101 - YA199

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 9of49**Group Variable Number**  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 1 YA751 - YA756 1 YA801 - YA803 1 YA809

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 10of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Group**  **Variable Number** 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 1 YB901 - YB903 1 YB911 1 YB961 - YB975

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 11of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Group**  **Variable Number** 1 YB981 1 YB986 - YB998 1 YC001 - YC030 1 YC051 - YC084 1 YC091 - YC095 1 YC101 - YC104 1 YC111 - YC113 1 YC121 1 YC126 - YC127 1 YC136 - YC141 1 YC146 - YC147 1 YC151 - YC156 1 YC166 - YC171 1 YC176 - YC179 1 YC186 - YC190 1 YC201 - YC203 1 YC206 - YC207 1 YC301 - YC305 1 YC321 - YC387 1 YC391 - YC394 1 YC396 1 YC401 - YC417 1 YC421 - YC422 1 YC426 - YC428 1 YC436 - YC439 1 YC441 - YC448 1 YC451 - YC455 1 YC459 1 YC461 - YC467 1 YC471 - YC499 1 YC501 - YC526 1 YC571 - YC583 1 YC587 - YC589

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 12of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Group**  **Variable Number** 1 YC591 - YC593 1 YC601 - YC655 1 YC681 - YC696 1 YC701 - YC715 1 YC720 - YC725 1 YC727 - YC752 1 YC761 - YC770 1 YC781 - YC793 1 YC801 - YC892 1 YC901 - YC907 1 YC921 - YC922 1 YC931 - YC932 1 YC941 - YC951 1 YC971 - YC978 1 YC981 - YC983 1 YD001 - YD007 1 YD021 - YD025 1 YD041 - YD057 1 YD081 - YD084 1 YD101 - YD117 1 YD121 - YD126 1 YD151 - YD159 1 YD171 - YD172 1 YD201 - YD203 1 YD206 - YD209 1 YD216 - YD219 1 YD251 - YD254 1 YD256 - YD257 1 YD261 1 YD301 - YD334 1 YD391 1 YD401 - YD410 1 YD412 - YD422

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 13of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Group**  **Variable Number** 1 YD481 - YD485 1 YD491 - YD499 1 YD501 - YD512 1 YD531 - YD535 1 YD541 - YD547 1 YD561 - YD564 1 YD571 - YD572 1 YD591 - YD595 1 YD601 - YD612 1 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 1 YF001 - YF011 1 YF021 - YF049 1 YF051 - YF080 1 YF086 - YF087 1 YF106 - YF107 1 YF111 - YF114 1 YF116 - YF119 1 YF121 - YF132 1 YF176 - YF178 1 YF191 - YF192 1 YF201 - YF276 1 YF401 - YF402 1 YF431 - YF432 1 YF436 - YF437

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 14of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Group**  **Variable Number** 1 YF441 - YF442 1 YF451 - YF460 1 YF501 - YF599 1 YF601 - YF682 1 YF701 - YF707 1 YF801 - YF805 1 YF831 - YF832 1 YF836 - YF838 1 YF871 - YF872 1 YF901 - YF905 1 YF921 - YF928 1 YF951 - YF954 1 YG001 - YG044 1 YG061 - YG064 1 YG066 - YG089 1 YG091 - YG099 1 YG101 - YG104 1 YG111 - YG114 1 YG116 - YG143 1 YG146 1 YG201 - YG205 1 YG211 - YG214 1 YG221 - YG224 1 YG251 - YG252 2 YG501 - YG513 2 YG515 2 YG601 - YG602 2 YG701 2 YG711 2 YG721 - YG722 1 YH001 - YH012 1 YH031 - YH055 1 YH071 - YH080

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 15of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Group**  **Variable Number** 1 YH101 - YH132 1 YH201 - YH202 1 YH206 - YH207 1 YH301 - YH306 1 YH321 - YH322 1 YH501 - YH542 1 YH551 - YH594 1 YH601 - YH606 1 YH611 - YH620 1 YH631 - YH632 1 YH636 - YH637 1 YH641 1 YH681 - YH683 1 YH701 - YH732 1 YH735 - YH742 1 YH751 - YH754 1 YH801 - YH843 1 YH851 - YH858 1 YH901 - YH908 1 YH911 - YH915 1 YH951 - YH952 1 YJ001 - YJ013 1 YJ021 1 YJ471 - YJ480 1 YJ501 - YJ517 1 YJ531 - YJ579 1 YJ591 - YJ599 1 YJ631 - YJ632 1 YJ671 - YJ694 1 YJ801 - YJ867 1 YJ871 - YJ880 1 YJ901 - YJ904 1 YJ908 - YJ929

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 16of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Group**  **Variable Number** 1 YJ931 - YJ937 1 YJ941 - YJ956 1 YJ961 1 YJ976 - YJ977 1 YK001 - YK007 1 YK101 - YK104 1 YK111 - YK112 1 YK121 - YK122 1 YK131 - YK133 1 YK136 - YK139 1 YK141 - YK142 1 YK146 - YK148 1 YK151 - YK154 1 YK161 - YK167 1 YK171 1 YK176 - YK177 1 YK186 1 YK191 1 YK196 1 YK201 - YK202 1 YK301 - YK314 1 YK321 - YK340 1 YK361 - YK378 1 YK401 - YK406 1 YK426 - YK427 1 YK431 - YK450 1 YK456 - YK467 1 YK471 - YK473 1 YK476 1 YK480 - YK487 1 YK491 - YK493 1 YK495 - YK499 1 YK511 - YK516

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 17of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Group**  **Variable Number** 1 YK521 - YK530 1 YK551 - YK571 1 YK576 - YK577 1 YK580 - YK585 1 YK601 - YK602 1 YK606 - YK607 1 YK611 - YK616 1 YK621 - YK634 1 YK641 - YK644 1 YK651 - YK665 1 YK671 - YK672 1 YK676 - YK677 1 YK681 - YK686 1 YK691 1 YK695 - YK699 1 YK701 - YK713 1 YK716 - YK719 1 YK721 - YK741 1 YK751 - YK770 1 YK776 - YK778 1 YK781 - YK785 1 YK791 - YK792 1 YK796 - YK797 1 YK801 - YK899 1 YK901 - YK912 1 YK918 - YK919 1 YK921 - YK929 1 YK941 - YK999 1 YL001 - YL005 1 YL011 - YL016 1 YL021 - YL024 1 YL051 - YL052 1 YL056 - YL057

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 18of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Group**  **Variable Number** 1 YL061 1 YL066 - YL069 1 YL076 - YL077 1 YL101 - YL137 1 YL201 - YL237 1 YL241 - YL242 1 YL271 - YL272 1 YL281 - YL284 1 YL301 - YL303 1 YL311 - YL314 1 YL316 - YL321 1 YL351 - YL353 1 YL371 - YL374 1 YL401 1 YL421 - YL429 1 YL431 - YL444 1 YL461 - YL478 1 YL501 - YL509 1 YL531 - YL534 1 YL541 - YL551 1 YL561 - YL579 1 YL591 - YL598 1 YL601 - YL606 1 YL611 - YL612 1 YL616 - YL617 1 YL621 1 YL626 1 YL631 - YL634 1 YL636 - YL637 1 YL661 - YL664 1 YL676 - YL691 1 YL696 - YL697 1 YL701 - YL707

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 19of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Group**  **Variable Number** 1 YL731 1 YL751 - YL752 1 YL756 - YL757 1 YL761 - YL780 1 YL796 - YL797 1 YL801 - YL815 1 YL901 - YL910 1 YL921 - YL940 1 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 1 YN061

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 20of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Group**  **Variable Number** 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 - YN564 1 YN581 - YN585 1 YN591 - YN592 1 YN601 - YN606 1 YN651 - YN653 1 YN701 - YN702 1 YN741 - YN746 1 YN756 1 YQ001 - YQ003 1 YQ011 - YQ021 1 YQ026 - YQ029 1 YQ036 - YQ045 1 YQ201 - YQ207 1 YQ231 1 YQ241 - YQ251 1 YQ281 - YQ284 1 YQ291 - YQ296 1 YQ301 - YQ302 1 YQ321 - YQ324 1 YQ331 - YQ334 1 YQ346 - YQ347 1 YQ351

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 21of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Group**  **Variable Number** 1 YQ354 - YQ355 1 YQ362 1 YQ371 1 YQ401 - YQ403 1 YQ451 - YQ454 1 YQ456 1 YQ461 1 YQ471 1 YQ501 - YQ520 1 YR001 - YR043 1 YR045 1 YR051 - YR087 1 YR090 - YR098 1 YR101 - YR105 1 YR111 - YR124 1 YR126 - YR144 1 YR166 - YR182 1 YR186 - YR198 1 YR201 - YR205 1 YR231 - YR294 1 YR296 - YR297 1 YR301 - YR334 1 YR338 - YR341 1 YR361 - YR366 1 YR371 - YR373 1 YR376 1 YR381 - YR382 1 YR386 - YR388 1 YR391 1 YR396 - YR398 1 YR401 - YR405 1 YR411 - YR413 1 YR416 - YR418

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 22of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Group**  **Variable Number** 1 YR421 - YR424 1 YR426 - YR455 1 YR457 - YR499 1 YR501 - YR506 1 YR511 - YR520 1 YR526 - YR544 1 YR546 - YR551 1 YR556 - YR562 1 YR571 - YR582 1 YR591 - YR592 1 YR601 - YR605 1 YR616 - YR658 1 YR661 - YR663 1 YR671 - YR672 1 YR676 - YR678 1 YR681 - YR682 1 YR701 - YR769 1 YR771 - YR799 1 YR801 - YR816 1 YR831 - YR838 1 YR841 - YR898 1 YR901 - YR903 1 YR931 - YR934 1 YR938 - YR944 1 YR951 - YR979 1 YR981 - YR996 1 YS001 - YS002 1 YS006 - YS009 1 YS031 - YS032 1 YS051 - YS073 1 YS101 - YS120 1 YS126 - YS138 1 YS149 - YS160

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 23of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Group**  **Variable Number** 1 YS166 - YS194 1 YS196 - YS197 1 YS201 - YS209 1 YS221 - YS225 1 YS231 - YS236 1 YS271 - YS287 1 YS301 - YS334 1 YS343 - YS347 1 YS351 - YS365 1 YS369 1 YS371 - YS374 1 YS377 1 YS381 - YS383 1 YS401 1 YS451 1 YS456 - YS457 1 YS462 1 YS467 1 YS501 - YS502 1 YS506 1 YS511 - YS513 1 YS515 - YS516 1 YS531 1 YS538 1 YS541 1 YS551 - YS553 1 YS556 1 YS561 - YS578 1 YS581 - YS595 1 YS601 - YS690 1 YS701 - YS708 1 YS721 - YS759 1 YS761 - YS762

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 24of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Group**  **Variable Number** 1 YS771 - YS780 1 YS806 - YS810 1 YS816 - YS818 1 YS823 - YS825 1 YS851 - YS860 1 YS876 1 YS881 - YS883 1 YS901 - YS909 1 YS911 - YS928 1 YS938 - YS939 1 YS951 1 YS956 - YS957 1 YS961 - YS965 1 YS981 - YS983 1 YS991 - YS998 1 YT001 - YT004 1 YT006 1 YT026 - YT027 1 YT031 - YT032 1 YT036 - YT038 1 YT061 - YT068 1 YT101 - YT112 1 YT115 - YT117 1 YT126 - YT130 1 YT136 - YT138 1 YT176 - YT181 1 YT191 1 YT196 - YT199 1 YT201 1 YT206 - YT207 1 YT211 - YT213 1 YT251 - YT271 1 YT278 - YT287

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 25of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Group**  **Variable Number** 1 YT301 - YT304 1 YT306 - YT307 1 YT311 - YT312 1 YT321 - YT328 1 YT340 - YT342 1 YT381 1 YT391 1 YT395 1 YT401 - YT403 1 YT411 - YT415 1 YT427 1 YT461 - YT471 1 YT475 1 YT491 - YT492 1 YT501 - YT504 1 YT516 - YT521 1 YT551 1 YT556 1 YT558 - YT561 1 YT563 1 YT571 - YT572 1 YT601 - YT606 1 YT701 - YT702 1 YT705 - YT706 1 YT761 - YT780 1 YT791 1 YT796 1 YT801 - YT804 1 YT811 - YT813 1 YT831 1 YT852 1 YT856 - YT862 1 YT891 - YT894

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 26of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Group**  **Variable Number** 1 YT901 - YT908 1 YT915 - YT925 1 YU001 - YU046 1 YU053 - YU054 1 YU201 - YU212 1 YV001 1 YV045 1 YV081 1 YV083 1 YV101 - YV106 1 YV115 - YV121 1 YV351 - YV353 1 YV356 - YV358 1 YV381 1 YV383 1 YV501 1 YV521 1 YV571 1 YV575 1 YV651 - YV654 1 YV695 1 YV741 - YV743 1 YV781 1 YV801 - YV802 1 YW011 - YW040 1 YW261
2. Spares Affected None. **B. Concurrent Requirements**  None.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 27of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT C.**  **Reason**

Widespread Fatigue Damage (WFD) analysis of the 737NG, as required by 14 CFR 26.21(b), has resulted in the conclusion that the existing737-600/700/800/900 MPD Section 9, Airworthiness Limitation Instruction (ALI) inspection program is not sufficient to preclude the occurrence of WFD in the S-14L and S-14R lap splice, lower fastener rows between STA 360-540 and STA 727-887 as the airplane ages. These lap splices have multiple adjacent identical details which have the potential for Multi-Site Damage (MSD) 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). Boeing has not received any in-service fleet reports of cracks in these lap splices. Accomplishment of the inspections described in this service bulletin will enable detection and repair of cracks if they should occur, at these lap splices. 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. This Service Bulletin gives a more frequent inspection for the S-14 lap splices to prevent WFD out to the LOV. The fuselage skin S-14L and S-14R lap splice lower fastener row between STA 360 to STA 540 and STA 727 to STA 887 has been determined to be structure that is susceptible to WFD. Boeing Fleet Team Digest737NG FTD 53-14001is related to this service bulletin. Boeing Service Related Problem737NG-SRP-53-00471is related to this service bulletin. **D. Description**  **Group 1:** 1. Do PART 1: Low Frequency Eddy Current (LFEC) Inspection for any crack on the S-14L and S-14R lap splice, lower fastener row, between STA 360 to STA 540 and STA 727 to STA 887. If no crack is found, repeat PART 1: LFEC INSPECTION at the repeat interval inParagraph 1.E., Compliance. If any crack is found, contact The Boeing Company for repair instructions and do the repair. **Group 2:** 1. Do PART 1: Low Frequency Eddy Current (LFEC) Inspection for any crack on the S-14L lap splice, lower fastener row, between STA 500 to STA 540 and STA 727 to STA 887 and S-14R lap splice, lower fastener row, between STA 360 to STA 540 and STA 727 to STA 887. If no crack is found, repeat PART 1: LFEC INSPECTION at the repeat interval inParagraph 1.E., Compliance. If any crack is found, contact The Boeing Company for repair instructions and do the repair. 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, 737-800, 737-900, 737-900ER

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 28of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Group 2:** 
**Affected Maintenance Zones Zone**  **Model** 231, 232, 241, 242 737-700C
**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. For airplanes which have not incorporated Boeing Business Jet Lower Cabin Altitude (LCA) Supplemental Type Certificate ST01697SE (6,500 feet maximum cabin altitude in lieu of 8,000 feet) as referenced in Boeing Service Bulletin737-21-1149. This service bulletin affects Principle Structural Element (PSE) 53-30-04-6, 53-30-04-6a, 53-60-04-6, and 53-60-04-6a of Subsection B, Airworthiness Limitations-Structural Inspections of737-600/700/800/900 MPD Section 9C626A001-CMR Table 9-2, which is mandated byAD 2013-19-23

. For airplanes which have incorporated Boeing Business Jet Lower Cabin Altitude (LCA) Supplemental Type Certificate ST01697SE (6,500 feet maximum cabin altitude in lieu of 8,000 feet) as referenced in Boeing Service Bulletin737-21-1149. This service bulletin affects Principle Structural Element (PSE) 53-30-04-6 and 53-60-04-6 of Subsection B, Airworthiness Limitations-Structural Inspections of 737-600/700/800/900 MPD Section 9626A001-CMR Table 9-3, which is mandated byAD 2013-19-23

. Do the required actions in accordance with Paragraph 3. Accomplishment Instructions. A logic diagram showing compliance tasks and compliance times is included as an aid inAPPENDIX AandAPPENDIX B

. **Table 1: Inspection For Any Crack at S-14 Lap Splice Repeat Interval**  **(Not to Exceed) Compliance Time**  **Action Condition** 

- Before 54,000 To- tal Flight Cycles.Do PART 1: LFEC INSPECTION for any crack.Airplanes that have not accomplished Boeing Service Bulletin737-21-1149

.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 29of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Table 1: Inspection For Any Crack at S-14 Lap Splice**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- Before further flight. ACTION 1: Contact The BoeingCompany for repair instructions and do the repair. CONDITION 1: ANY CRACK FOUND

12,000 Flight Cycles. - ACTION 2: Repeat PART 1: LFEC INSPECTION for any crack at the unrepaired areas. 12,000 Flight Cycles. - Repeat PART 1: LFEC INSPECTION for any crack. CONDITION 2: NO CRACK FOUND

**Table 2: Inspection For Any Crack at S-14 Lap Splice Repeat Interval**  **(Not to Exceed) Compliance Time**  **Action Condition** 

- Before 41,000 To- tal Flight Cycles.Do PART 1: LFEC INSPECTION for any crack.Airplanes that have accomplished Boeing Service Bulletin737-21-1149

.

- Before further flight. ACTION 1: Contact The BoeingCompany for repair instructions and do the repair. CONDITION 1: ANY CRACK FOUND

8,800 Flight Cycles. - ACTION 2: Repeat PART 1: LFEC INSPECTION for any crack at the unrepaired areas. 8,800 Flight Cycles. - Repeat PART 1: LFEC INSPECTION for any crack. CONDITION 3: NO CRACK FOUND

**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.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 30of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT**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. In addition, for airplanes which have incorporated Boeing Business Jet Lower Cabin Altitude (LCA) 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 Manager of the FAA Seattle Aircraft Certification Office (SACO) approves the accomplishment of the inspections defined in this Service Bulletin (SB) along with the corresponding compliance times specified in Paragraph 1.E., Compliance, of this SB, Original Issue as an Alternative Method of Compliance (AMOC) to the inspections, defined in D626A001-DTR for PSEs 53-30-04-6 and 53-60-04-6, and737-600/700/800/900 MPD Section 9, D626A001-CMR Table 9-3, required by paragraph (g) and (h) of Airworthiness Directive (AD)AD 2013-19-23. This AMOC is only applicable after accomplishment of the initial inspections specified in Paragraph 1.E., Complianceof this service bulletin. All provisions ofAD 2013-19-23that are not specifically referenced in this paragraph remain fully applicable and must be complied with accordingly. In addition, for airplanes which have not incorporated Boeing Business Jet Lower Cabin Altitude (LCA) 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 Manager of the FAA Seattle Aircraft Certification Office (SACO) approves the accomplishment of the inspections defined in this Service Bulletin (SB) along with the corresponding compliance times specified in Paragraph 1.E., Compliance, of this SB, Original Issue as an Alternative Method of Compliance (AMOC) to the inspections, defined in D626A001-DTR for PSEs 53-30-04-6, 53-30-04-6a, 53-60-04-6, and 53-60-04-6a, and 737-600/700/800/900 MPD Section 9D626A001-CMR Table 9-2, required by paragraph (g) and (h) of Airworthiness Directive (AD)AD 2013-19-23. This AMOC is only applicable after accomplishment of the initial inspections specified inParagraph 1.E., Complianceof this service bulletin. All provisions ofAD 2013-19-23that are not specifically referenced in this paragraph remain fully applicable and must be complied with accordingly. **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. **Group 1: Elapsed Hours**  **Task Hours Number of Persons**  **Task** 42.00 84.00 2 Figure 1

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 31of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Group 1:**  **Elapsed Hours Task Hours**  **Number of Persons Task**  42.00 84.00 TOTAL FOR EACH AIRPLANE **Group 2: Elapsed Hours**  **Task Hours Number of Persons**  **Task** 32.50 65.00 2 Figure 2 32.50 65.00 TOTAL FOR EACH AIRPLANE
**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 Letter737-SL-51-042

c. Boeing Service Related Problem (SRP)737NG-SRP-53-00471 d. Federal Aviation Administration (FAA) Airworthiness Directive (AD)2013-19-23

e. Service Bulletin IndexD6-19567 f. Standard Overhaul Practices Manual (SOPM)20-50-01 g. 737 Non-Destructive Testing (NDT) ManualPart 6, 53-30-50 h. 737-600/700/800/900 Maintenance Planning Data (MPD)Section 9 i. 737NG Fleet Team Digest (FTD)53-14001 2. Data Supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin:
**Title Drawing Number**  Skin Installation - STA 259.5 to STA 540, S-24L to S-4R 142A3000

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 32of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT Title**  **Drawing Number** Skin Installation - S-10 to S-14, STA 360 to 540 143A3150 Skin Installation - STA 360 to 540, S-14L to S-24L 143A3210 Skin Installation - STA 360 to 540, S-14R to S-24R 143A3250 Skin Installation, S-10 to S-14, Station 727-888 146A3150 Skin Installation, S-14L to S-23L, Station 727-888 146A3200 Skin Installation, S-14R to S-23R, Station 727-888 146A3250 The table above lists applicable drawings used to prepare this service bulletin. The drawings are not necessary to make the specified changes, and are not supplied with this service bulletin. The drawings may not be applicable to all airplane configurations or operators. **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.

**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: October 02, 2015 737-53A1352 33of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 34of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT**

BLANK PAGE**2. MATERIAL INFORMATION A.**  **Material - Price and Availability** None. **B. Industry Support Information**  Boeing warranty remedies are not available for the inspection procedures 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 the change in this service bulletin. But maintenance and overhaul tools in the manuals given inParagraph 1.J., References, can also 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: October 02, 2015 737-53A1352 35of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 36of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT**

BLANK PAGE**3. ACCOMPLISHMENT INSTRUCTIONS A.**  **GENERAL INFORMATION 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.

— Values for airframe maintenance tasks are included in Chapter 20 of 737 Aircraft Maintenance Manual (AMM).

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

SRM Chapter 51. 5. If the length of any fastener specified in this service bulletin does not meet installation standards given in SRM Chapter 51, then a fastener of the same specification, or an approved substitute, with a length which meets the installation standards given in SRM Chapter 51 may be used. In addition, washers may be installed for fastener grip length in accordance with SRM Chapter 51. Refer toSOPM 20-50-01for alternate full threaded fasteners (screws) needed for installation in this service bulletin. 6. 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.
7. 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. 8. Boeing Service Letter737-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.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 37of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT**9. Refer toAPPENDIX AandAPPENDIX Bfor logic diagram. 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. 10. 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. 11. 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. 12. Use of colors in Figures is based on guidance from the ATA e-Business Program (ATA) iSpec 2200. 13. The compliance times for the actions in Paragraph 3.B., WORK INSTRUCTIONS are inParagraph 1.E., Compliance

. 14. The CONDITIONS, ACTIONS and OPTIONS shown apply to each S-14 Lap Splice independently. 15. 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. Airplanes that have not accomplished Boeing Service Bulletin737-21-1149, Boeing Business Jet Lower Cabin Altitude (LCA) Supplemental Type Certificate ST01697SE (6,500 feet maximum cabin altitude in lieu of 8,000 feet).

a. Do PART 1: LFEC INSPECTION for any crack. (1) CONDITION 1: ANY CRACK FOUND. (a) ACTION 1: Contact The Boeing Company for repair instructions and do the repair. (b) ACTION 2: Repeat PART 1: LFEC INSPECTION for any crack at the unrepaired areas at the repeat interval inParagraph 1.E., Compliance

. (2) CONDITION 2: NO CRACK FOUND.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 38of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT**(a) Repeat PART 1: LFEC INSPECTION for any crack at the repeat interval inParagraph 1.E., Compliance

. 2. Airplanes that have accomplished Boeing Service Bulletin737-21-1149, Boeing Business Jet Lower Cabin Altitude (LCA) Supplemental Type Certificate ST01697SE (6,500 feet maximum cabin altitude in lieu of 8,000 feet).

a. Do PART 1: LFEC INSPECTION for any crack. (1) CONDITION 1: ANY CRACK FOUND. (a) ACTION 1:Contact The Boeing Company for repair instructions and do the repair. (b) ACTION 2: Repeat PART 1: LFEC INSPECTION for any crack at the unrepaired areas at the repeat interval inParagraph 1.E., Compliance

. (2) CONDITION 3: NO CRACK FOUND. (a) Repeat PART 1: LFEC INSPECTION for any crack at the repeat interval inParagraph 1.E., Compliance

. 3. Put the airplane back to a serviceable condition. **PART 1: LFEC INSPECTION** 1. RC - Do Low Frequency Eddy Current (LFEC) inspection for any crack at S-14L and S-14R lap splice for any crack at lower fastener row in accordance with737 NDT Manual Part 6, 53-30-50 and the table below: **Figure Group**  FIGURE 1 1 FIGURE 2 2

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 39of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT This Figure applies only to: Group 1.** 

**FIGURE 1: LFEC INSPECTION OF S-14 LAP SPLICE LOWER FASTENER ROW**  **(SHEET 1 OF 3)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 40of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT FIGURE 1:** **LFEC INSPECTION OF S-14 LAP SPLICE LOWER FASTENER ROW (SHEET 2 OF 3)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 41of49 **BOEING SERVICE BULLETIN 737-53A1352 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 by location identification provided.
**More Data**  **Location Name**  **Task Step**  (a) Between STA 360 to STA 540 S-14L Lap Splice Inspect 1 (a) Between STA 360 to STA 540 S-14R Lap Splice Inspect (a) Between STA 727 to STA 887 S-14L Lap Splice Inspect 2 (a) Between STA 727 to STA 887 S-14R Lap Splice Inspect (a) In accordance with737 NDT Manual Part 6, 53-30-50

.

**FIGURE 1: LFEC INSPECTION OF S-14 LAP SPLICE LOWER FASTENER ROW**  **(SHEET 3 OF 3)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 42of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT This Figure applies only to: Group 2.** 

**FIGURE 2: LFEC INSPECTION OF S-14 LAP SPLICE LOWER FASTENER ROW**  **(SHEET 1 OF 3)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 43of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT FIGURE 2:** **LFEC INSPECTION OF S-14 LAP SPLICE LOWER FASTENER ROW (SHEET 2 OF 3)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 44of49 **BOEING SERVICE BULLETIN 737-53A1352 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 by location identification provided.
**More Data**  **Location Name**  **Task Step**  (a) Between STA 500 and STA 540 S-14L Lap Splice Inspect 1 (a) Between STA 360 and STA 540 S-14R Lap Splice Inspect (a) Between STA 727 and STA 887 S-14L Lap Splice Inspect 2 (a) Between STA 727 and STA 887 S-14R Lap Splice Inspect (a) In accordance with737 NDT Manual Part 6, 53-30-50

.

**FIGURE 2: LFEC INSPECTION OF S-14 LAP SPLICE LOWER FASTENER ROW**  **(SHEET 3 OF 3)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 45of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT**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. 1. The table below gives the description for the parts and conditions called out in the logic diagrams. **Description Title**  LFEC INSPECTION for any crack. PART 1: ANY CRACK FOUND CONDITION 1: Contact The Boeing Company for repair instructions and do the repair. ACTION 1: Repeat PART 1: LFEC INSPECTION for any crack at the unrepaired areas. ACTION 2: NO CRACK FOUND CONDITION 2:

**APPENDIX A: LOGIC DIAGRAM FOR PARAGRAPH 1.E. COMPLIANCE: TABLE 1: INSPECTION FOR ANY**  **CRACK AT S-14 LAP SPLICE (SHEET 1 OF 2)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 46of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT APPENDIX A:** **LOGIC DIAGRAM FOR PARAGRAPH 1.E. COMPLIANCE: TABLE 1: INSPECTION FOR ANY CRACK AT S-14 LAP SPLICE**  **(SHEET 2 OF 2)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 47of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT**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. 1. The table below gives the description for the parts and conditions called out in the logic diagrams. **Description Title**  LFEC INSPECTION for any crack. PART 1: ANY CRACK FOUND CONDITION 1: Contact The Boeing Company for repair instructions and do the repair. ACTION 1: Repeat PART 1: LFEC INSPECTION for any crack at the unrepaired areas. ACTION 2: NO CRACK FOUND CONDITION 3:

**APPENDIX B: LOGIC DIAGRAM FOR PARAGRAPH 1.E. COMPLIANCE: TABLE 2: INSPECTION FOR ANY**  **CRACK AT S-14 LAP SPLICE (SHEET 1 OF 2)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 48of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT APPENDIX B:** **LOGIC DIAGRAM FOR PARAGRAPH 1.E. COMPLIANCE: TABLE 2: INSPECTION FOR ANY CRACK AT S-14 LAP SPLICE**  **(SHEET 2 OF 2)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 02, 2015 737-53A1352 49of49 **BOEING SERVICE BULLETIN 737-53A1352 ALERT**  **ALERT**