### Commercial **Airplanes** 

# 747 Service Bulletin **ALERT Number: 747-53A2861**  Original Issue: April 01, 2014 ATA System: 5331 **SUBJECT:** FUSELAGE - Skin - Lower Lobe Skin Inspection for Corrosion at Circumferential Splice Locations 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 © 2014 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 Unpublished Work.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Original Issue: April 01, 2014 747-53A2861 1 of 77 4.0Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 2 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT**

BLANK PAGE**Table of Contents** Summary...................................................... 5 1. PLANNING INFORMATION........................................ 9 A. Effectivity................................................ 9 1. Airplanes............................................. 9 2. Spares Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 B. Concurrent Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 C. Reason. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 D. Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 F. Approval. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 G. Manpower. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 I. Electrical Load Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 J. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 1. Existing Data:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 2. Data Supplied with this Service Bulletin:. . . . . . . . . . . . . . . . . . . . . . . . . . . 43 3. Installation Drawings Used in the Preparation of this Service Bulletin:. . . . . . . . . . . 43 K. Publications Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 L. Interchangeability and Intermixability of Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . 44 M. Software Accomplishment Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 2. MATERIAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 B. Industry Support Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 C. Parts Necessary for Each Airplane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 1. Kits/Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 2. Parts and Materials Supplied by the Operator. . . . . . . . . . . . . . . . . . . . . . . . 45 3. Parts Modified and Reidentified. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 4. Parts Removed and Not Replaced. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 45 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 A. GENERAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 FIGURE 1: INSPECTION AREA 1 (STA 741) [Group 1]. . . . . . . . . . . . . . . . . . . . . . . . . 54 FIGURE 2: INSPECTION AREA 2 (STA 1741) [Group 1]. . . . . . . . . . . . . . . . . . . . . . . . . 56 FIGURE 3: INSPECTION AREA 3 (STA 1961) [Group 1]. . . . . . . . . . . . . . . . . . . . . . . . . 58 FIGURE 4: INSPECTION AREA 4 (STA 2181) [Group 1]. . . . . . . . . . . . . . . . . . . . . . . . . 60 FIGURE 5: INSPECTION AREA 2 (STA 1741) [Group 2]. . . . . . . . . . . . . . . . . . . . . . . . . 62 FIGURE 6: INSPECTION AREA 3 (STA 1961) [Group 2]. . . . . . . . . . . . . . . . . . . . . . . . . 64 FIGURE 7: WING TO BODY FAIRING PANEL REMOVAL [Group 2]. . . . . . . . . . . . . . . . . . 66 FIGURE 8: WING TO BODY FAIRING PANEL INSTALLATION [Group 2]. . . . . . . . . . . . . . . 68 APPENDIX A: LOGIC DIAGRAM - GROUP 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 APPENDIX B: LOGIC DIAGRAM - GROUP 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 APPENDIX C: GROUP 1 SKIN PANEL DATA [Group 1]. . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 3 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT**APPENDIX D: GROUP 2 (747SP) SKIN PANEL DATA [Group 2]. . . . . . . . . . . . . . . . . . . . . . 77

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 4 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT**

### Commercial **Airplanes** 

# 747 Service Bulletin **ALERT Summary**  **Number: 747-53A2861** Original Issue: April 01, 2014 ATA System: 5331 **SUBJECT:** FUSELAGE - Skin - Lower Lobe Skin Inspection for Corrosion at Circumferential Splice Locations 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 do external inspections of the skin in the lower lobe at certain circumferential splice locations for corrosion and cracks. Skin corrosion that is not found and repaired can result in cracks, which can become large and adversely affect the structural integrity of the airplane. Several operators have reported that corrosion was found on the mating surfaces between the skin and stringers in Section 42 and Section 46 at the circumferential skin splices. There were no visual indications of corrosion apparent during both internal and external inspections of the affected areas. Review of the applicable drawings shows that the stringers in these circumferential splice locations were not installed with faying surface sealant. Fillet seals were applied on both the upper and lower sides of the stringer, so if a fillet seal is compromised, moisture can enter the area and result in corrosion in the area between the skin and the stringer. Accomplishment of the inspections in this service bulletin will help ensure the structural integrity of the fuselage skin at the affected circumferential splice locations. Boeing Service Related Problem (SRP) 747-SRP-53-0392 is 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 Paragraph 1.E., Compliance and Paragraph 1.F., Approval Yes AD Related Paragraph 1.H., Weight and Balance Changes No Weight and Balance Change

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 5 of 77**Reference Affected**  **Planning Data** 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 external General Visual Inspections (GVI) of the fuselage skin at the lower circumferential splices at STA 741 (Group 1 only), STA 1741, STA 1961 and STA 2181 (Group 1 only) for the presence of existing external skin repair doublers or production doublers. If existing repair doublers or production doublers that cover the skin common to the stringers are found, do surface Low Frequency Eddy Current (LFEC) inspections of the doublers for cracks in the skin in the areas common to the stringers that are covered by the repair doublers or production doublers. If cracks are found, repair in accordance with this service bulletin. If no existing external repair doublers or production doublers are found, and in affected areas not covered by existing repair doublers or production doublers, do external surface LFEC inspections of the fuselage skin in the affected areas for corrosion that may exist between the skin inner surface and the stringers. If corrosion is found, repair in accordance with this service bulletin. In areas where no corrosion was found, do external surface High Frequency Eddy Current (HFEC) inspections of the skin at the fastener locations common to the skin and stringers for cracks. Repair any crack found in accordance with this service bulletin. If no corrosion is found, do external surface HFEC inspections of the skin at the fastener locations common to the skin and stringers for cracks. Repair any crack found in accordance with this service bulletin. Repeat the inspections in this service bulletin at the times given in Paragraph 1.E., Compliance. **EFFECTIVITY** 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR and 747SP 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. Refer to Paragraph 1.E., Compliance.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 6 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT INDUSTRY SUPPORT INFORMATION**  Boeing warranty remedies are not available for the inspection and repair procedures given in this service bulletin. **MANPOWER Elapsed Hours**  **Total Task Hours Airplanes**  32.75 121.25 Group 1 22.50 85.50 Group 2 Refer to Paragraph 1.G., Manpower. **MATERIAL INFORMATION** None.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 7 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 8 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT**

### Commercial **Airplanes** 

# 747 Service Bulletin **ALERT Number: 747-53A2861**  Original Issue: April 01, 2014 ATA System: 5331 **SUBJECT:** FUSELAGE - Skin - Lower Lobe Skin Inspection for Corrosion at Circumferential Splice Locations THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH 1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OWNER. **1. PLANNING INFORMATION A. Effectivity**  1. Airplanes Refer to Service Bulletin Index D6-30300 Part 3 for Airplane Variable Number, Line Number, and Serial Number data. This service bulletin is applicable to 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR and 747SP airplanes line number 310 through 1419, except 747 Large Cargo Freighter (LCF) airplanes, in two Groups. The Variable Numbers and Group Information for the applicable airplanes is given below.
**DESCRIPTION CONFIGURATION**  **GROUP** 747 airplanes line number 310 through 1419, except 747 Large Cargo Freighter (LCF) airplanes and 747SP airplanes. - 1

747SP airplanes line number 310 through 1419.

- 2

Airplane Models: 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SP, 747SR **Group Variable Number**  1 RA544 - RA548 1 RA726 - RA731

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 9 of 77**Group Variable Number**  1 RA750 1 RA784 1 RB411 - RB413 1 RB421 1 RB681 - RB697 1 RB711 1 RB721 - RB723 1 RB741 - RB748 1 RD047 - RD059 1 RD081 - RD083 1 RD091 - RD092 1 RD122 - RD127 1 RD134 - RD144 1 RD166 - RD167 1 RD171 - RD172 1 RD181 - RD183 1 RD201 - RD204 1 RD221 - RD227 1 RD231 - RD235 1 RD241 - RD243 1 RD251 - RD262 1 RD271 - RD272 1 RD291 - RD292 1 RD301 - RD302 1 RD311 1 RD351 - RD358 1 RD361 - RD366 1 RD381 - RD383 1 RD411 - RD414 1 RD421 - RD426 1 RD431 - RD435 1 RD441 - RD442 1 RD451 - RD456

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 10 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group**  **Variable Number** 1 RD461 1 RD471 - RD475 1 RD513 - RD519 1 RD531 - RD533 1 RD551 1 RD561 1 RD571 1 RD581 - RD583 1 RD591 - RD593 1 RD603 - RD607 1 RD643 - RD649 1 RD652 - RD659 1 RD661 1 RD671 1 RD701 - RD702 1 RD721 - RD722 1 RD741 - RD742 1 RD751 - RD755 1 RD761 1 RD771 - RD775 1 RD781 - RD783 1 RD791 - RD792 1 RE001 1 RF001 - RF006 2 RG006 - RG009 2 RG095 2 RG104 2 RG161 - RG164 2 RG172 - RG174 2 RG191 - RG193 2 RG211 - RG213 2 RG221 - RG222 2 RH101 - RH102

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 11 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group**  **Variable Number** 2 RH111 - RH112 2 RH121 - RH122 1 RJ152 1 RJ303 1 RJ321 - RJ322 1 RJ331 - RJ333 1 RL401 - RL403 1 RL411 - RL436 1 RL451 - RL456 1 RL461 - RL462 1 RL471 - RL481 1 RL491 - RL492 1 RL501 - RL502 1 RL511 - RL516 1 RL521 - RL522 1 RL531 - RL534 1 RL551 1 RL561 - RL568 1 RL571 - RL572 1 RL576 - RL577 1 RL579 1 RL581 - RL586 1 RL651 - RL655 1 RL671 - RL675 1 RL681 - RL684 1 RL751 - RL752 1 RM001 - RM007 1 RM010 - RM013 1 RM021 - RM024 1 RM026 - RM030 1 RM036 - RM045 1 RM051 - RM053 1 RM071

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 12 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group**  **Variable Number** 1 RM081 - RM084 1 RM091 1 RM096 - RM097 1 RM116 - RM117 1 RM126 - RM132 1 RM136 - RM147 1 RM156 - RM158 1 RM166 - RM177 1 RM191 - RM192 1 RM231 - RM233 1 RM241 - RM246 1 RM261 - RM264 1 RM316 - RM318 1 RM331 - RM333 1 RM341 1 RM351 - RM355 1 RM366 - RM367 1 RM401 - RM403 1 RM426 1 RM431 1 RM441 - RM443 1 RM445 1 RM801 - RM803 1 RM811 - RM813 1 RM851 - RM859 1 RM861 - RM863 1 RM871 - RM899 1 RM901 - RM906 1 RM911 1 RR001 - RR005 1 RR021 - RR025 1 RR031 1 RR202 - RR206

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 13 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group**  **Variable Number** 1 RR223 - RR226 1 RR262 - RR267 1 RR303 - RR310 1 RR331 - RR332 1 RR336 1 RR345 1 RR361 - RR362 1 RR421 - RR422 1 RR431 - RR432 1 RR441 - RR442 1 RR451 1 RR501 - RR504 1 RR521 - RR522 1 RR526 1 RR531 1 RR551 - RR556 1 RR561 1 RR566 1 RR701 1 RR721 - RR724 1 RR746 - RR748 1 RR851 - RR856 1 RR861 - RR862 1 RR951 - RR952 1 RS001 - RS002 1 RS201 1 RS211 - RS212 1 RS221 - RS222 1 RS231 - RS241 1 RS251 - RS259 1 RS263 1 RS265 - RS268 1 RS271 - RS276

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 14 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group**  **Variable Number** 1 RS291 - RS292 1 RS301 - RS306 1 RS311 - RS320 1 RS331 - RS333 1 RS341 - RS342 1 RS699 1 RS701 - RS703 1 RS711 - RS713 1 RS721 - RS722 1 RS731 - RS732 1 RS741 - RS743 1 RS751 - RS752 1 RS761 - RS762 1 RS771 1 RS781 - RS782 1 RS786 1 RT001 - RT014 1 RT021 - RT022 1 RT031 - RT035 1 RT041 - RT047 1 RT061 1 RT071 - RT075 1 RT101 - RT103 1 RT121 1 RT131 - RT137 1 RT151 - RT152 1 RT161 - RT168 1 RT401 - RT412 1 RT431 - RT447 1 RT451 - RT469 1 RT471 - RT499 1 RT501 - RT535 1 RT551 - RT568

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 15 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group**  **Variable Number** 1 RT571 - RT591 1 RT601 - RT630 1 RT633 - RT657 1 RT671 - RT673 1 RT681 - RT682 1 RT691 - RT699 1 RT701 - RT704 1 RT711 - RT717 1 RT741 - RT742 1 RT744 - RT757 1 RT776 - RT777 1 RT781 - RT784 1 RT801 - RT803 1 RT811 - RT814 1 RT831 - RT837 1 RT861 - RT864 1 RT877 - RT880 1 RT931 - RT932 1 RT945 - RT949 1 RT951 - RT955 1 RT966 - RT967 1 RU001 - RU006 1 RU016 - RU017 1 RU031 - RU032 1 RU051 - RU052 1 RU059 - RU062 1 RU081 - RU083 1 RU101 - RU102 1 RU121 - RU132 1 RU801 - RU809 1 RU831 - RU841

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 16 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT**2. Spares Affected None. **B. Concurrent Requirements** None. **C. Reason** This service bulletin gives instructions to do external inspections of the skin in the lower lobe at certain circumferential splice locations for corrosion and cracks. Skin corrosion that is not found and repaired can result in cracks, which can become large and adversely affect the structural integrity of the airplane. Several operators have reported that corrosion was found on the mating surfaces between the skin and stringers in Section 42 and Section 46 at the circumferential skin splices. There were no visual indications of corrosion apparent during both internal and external inspections of the affected areas. Review of the applicable drawings shows that the stringers in these circumferential splice locations were not installed with faying surface sealant. Fillet seals were applied on both the upper and lower sides of the stringer, so if a fillet seal is compromised, moisture can enter the area and result in corrosion in the area between the skin and the stringer. Accomplishment of the inspections in this service bulletin will help ensure the structural integrity of the fuselage skin at the affected circumferential splice locations. Boeing Service Related Problem (SRP) 747-SRP-53-0392 is related to this service bulletin. **D. Description** Do external General Visual Inspections (GVI) of the fuselage skin at the lower circumferential splices at STA 741 (Group 1 only), STA 1741, STA 1961 and STA 2181 (Group 1 only) for the presence of existing external skin repair doublers or production doublers. If existing repair doublers or production doublers that cover the skin common to the stringers are found, do surface Low Frequency Eddy Current (LFEC) inspections of the doublers for cracks in the skin in the areas common to the stringers that are covered by the repair doublers or production doublers. If cracks are found, repair in accordance with this service bulletin. If no existing external repair doublers or production doublers are found, and in affected areas not covered by existing repair doublers or production doublers, do external surface LFEC inspections of the fuselage skin in the affected areas for corrosion that may exist between the skin inner surface and the stringers. If corrosion is found, repair in accordance with this service bulletin. In areas where no corrosion was found, do external surface High Frequency Eddy Current (HFEC) inspections of the skin at the fastener locations common to the skin and stringers for cracks. Repair any crack found in accordance with this service bulletin. If no corrosion is found, do external surface HFEC inspections of the skin at the fastener locations common to the skin and stringers for cracks. Repair any crack found in accordance with this service bulletin. Repeat the inspections in this service bulletin at the times given in Paragraph 1.E., Compliance.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 17 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT**The work in this service bulletin is done in the maintenance zone(s) given below. **Group 1:**
**Affected Maintenance Zones Zone**  **Model** 125, 126, 143, 144, 147, 148 747-100B, 747-100B SUD, 747- 200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR **Group 2:**
**Affected Maintenance Zones Zone**  **Model** 143, 144 747SP **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. Do the required actions in accordance with Paragraph 3. Accomplishment Instructions. When more than one OPTION is given for a CONDITION, do only one of the OPTION numbers. When more than one ACTION is given for a CONDITION number or an OPTION number, do all of the ACTION numbers for that CONDITION number or OPTION number. **Group 1: Table 1: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 741 (Area 1)**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- Within 3,000 flight cycles or 24 months afterthe original issue date of this service bulletin,whichever occurs first. Before 10,000total flight cycles, or within 10 years fromthe date of issuance of theoriginal certificate of airworthiness or the original export certificate of airworthiness, whichever occurs first. Do external GVI of the fuselage skin in Area 1 as shown in PART 1: INSPECTION AREAS for the presence of external doublers. All airplanes

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 18 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 1:**  **Table 1: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 741 (Area 1) Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition**

- Before further flight. Do PART 2: EXTERNAL LOW-ER LOBE EXTERNAL DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS in the area of any doubler. Determine if the doubler ends on a row of fasteners common to a stringer. CONDITION 1: ANY EXISTING EXTERNAL DOUBLER FOUND INTHE AFFECTED AREAS

- Before further flight. Do PART 3: EXTERNAL LOW- ER LOBE SKIN SURFACELFEC INSPECTION FOR CORROSION in affected areas.CONDITION 2: AFFECTED AREAS WITHNO EXISTING EXTERNAL DOUBLER FOUND 800 flight cycles or 24 months,whichever occurs earlier. If the doubler ends on a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler. CONDITION 3: NO SKIN CRACK FOUND UNDER EXTERNAL DOUBLER

3,000 flight cycles or 24 months,whichever occurs earlier. - If the doubler ends one or two fastener rows beyond a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler.

- - If the doubler ends three or more fastener rows beyond a stringer fastener row: No more work is necessary in the area of the doubler.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 19 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 1:**  **Table 1: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 741 (Area 1) Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition**

- Before further flight. (ACTION 1) Do PART 5: RE- PAIR. CONDITION 4: ANY SKIN CRACK FOUND UNDER EXTERNAL DOUBLER 800 flight cycles or 24 months,whichever occurs earlier. - (ACTION 2) If the repair doubler installed in accordance with PART 5: REPAIR ends on a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler. 3,000 flight cycles or 24 months,whichever occurs earlier. - (ACTION 2) If the repair doubler installed in accordance with PART 5: REPAIR ends one or two fastener rows beyond a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler.

- - (ACTION 2) If the repair doubler installed in accordance with PART 5: REPAIR ends three or more fastener rows beyond a stringer fastener row: No more work is necessary in the area of the repair.

- Before further flight. Do PART 4: EXTERNAL LOW- ER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS in affected areas. CONDITION 5: NO CORROSION FOUND

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 20 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 1:**  **Table 1: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 741 (Area 1) Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition**

- Before further flight. (ACTION 1) Do PART 5: RE- PAIR in areas where corrosion was found. CONDITION 6: ANY CORROSION FOUND

- Before further flight. (ACTION 2) Do PART 4: EXTER-NAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS in affected areas where no corrosion was found or where corrosion was removed by blending. 800 flight cycles or 24 months,whichever occurs earlier. - (ACTION 3) If a repair doubler installed in accordance with PART 5: REPAIR ends on a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler. 3,000 flight cycles or 24 months,whichever occurs earlier. - (ACTION 3) If a repair doubler installed in accordance with PART 5: REPAIR ends one or two fastener rows beyond a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler.

- - (ACTION 3) If a repair doubler installed in accordance with PART 5: REPAIR ends three or more fastener rows beyond a stringer fastener row: No more work is necessary in the area of the repair. 3,000 flight cycles or 24 months,whichever occurs earlier. - Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACELFEC INSPECTION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FORCRACKS at all affected unrepaired areas. (a) CONDITION 7: NO CRACK FOUND

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 21 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 1:**  **Table 1: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 741 (Area 1) Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition**

- Before further flight. (ACTION 1) Do PART 5: RE- PAIR. CONDITION 8: ANY CRACK FOUND 800 flight cycles or 24 months,whichever occurs earlier. - (ACTION 2) If a repair doubler installed in accordance with PART 5: REPAIR ends on a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler. 3,000 flight cycles or 24 months,whichever occurs earlier. - (ACTION 2) If a repair doubler installed in accordance with PART 5: REPAIR ends one or two fastener rows beyond a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler.

- - (ACTION 2) If a repair doubler installed in accordance with PART 5: REPAIR ends three or more fastener rows beyond a stringer fastener row: No more work is necessary in the area of the repair. 3,000 flight cycles or 24 months,whichever occurs earlier. - (ACTION 3) Repeat PART 3: EXTERNAL LOWER LOBESKIN SURFACE LFEC INSPECTION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS at all affected unrepaired areas. (a) (a) For the purposes of these inspections, "unrepaired areas" are defined as affected areas where the skin is not covered with a doubler. Areas repaired with only blends or oversized fasteners should be treated as unrepaired.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 22 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 1:**  **Table 2: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 1741 (Area 2)**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- Within 3,000 flight cycles or 24 months afterthe original issue date of this service bulletin,whichever occurs first. Before 10,000total flight cycles, or within 10 years fromthe date of issuance of theoriginal certificate of airworthiness or the original export certificate of airworthiness, whichever occurs first. Do external GVI of the fuselage skin in Area 2 as shown in PART 1: INSPECTION AREAS for the presence of external doublers. All airplanes

- Before further flight. Do PART 2: EXTERNAL LOW- ER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler. Determine if the doubler ends on a row of fasteners common to a stringer. CONDITION 1: ANY EXISTING EXTERNAL DOUBLER FOUND INTHE AFFECTED AREAS

- Before further flight. Do PART 3: EXTERNAL LOW- ER LOBE SKIN SURFACELFEC INSPECTION FOR CORROSION in affected areas.CONDITION 2: AFFECTED AREAS WITHNO EXISTING EXTERNAL DOUBLER FOUND

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 23 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 1:**  **Table 2: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 1741 (Area 2)**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition**  1,500 flight cycles or 48 months,whichever occurs earlier. If the doubler ends on a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler. CONDITION 3: NO SKIN CRACK FOUND UNDER EXTERNAL DOUBLER

6,000 flight cycles or 48 months,whichever occurs earlier. - If the doubler ends one or two fastener rows beyond a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler.

- - If the doubler ends three or more fastener rows beyond a stringer fastener row: No more work is necessary in the area of the doubler.

- Before further flight. (ACTION 1) Do PART 5: RE- PAIR. CONDITION 4: ANY SKIN CRACK FOUND UNDER EXTERNAL DOUBLER 1,500 flight cycles or 48 months,whichever occurs earlier. - (ACTION 2) If the doubler endson a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS in the area of the doubler. 6,000 flight cycles or 48 months,whichever occurs earlier. - (ACTION 2) If the doubler ends one or two fastener rows beyond a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler.

- - (ACTION 2) If the doubler endsthree or more fastener rows beyond a stringer fastener row: No more work is necessary in the area of the doubler.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 24 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 1:**  **Table 2: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 1741 (Area 2)**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- Before further flight. Do PART 4: EXTERNAL LOW- ER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS in affected areas. CONDITION 5: NO CORROSION FOUND

- Before further flight. (ACTION 1) Do PART 5: RE- PAIR in areas where corrosion was found. CONDITION 6: ANY CORROSION FOUND

- Before further flight. (ACTION 2) Do PART 4: EXTER-NAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS in affected areas where no corrosion was found or where corrosion was removed by blending. 1,500 flight cycles or 48 months,whichever occurs earlier. - (ACTION 3) If a repair doubler installed in accordance with PART 5: REPAIR ends on a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler. 6,000 flight cycles or 48 months,whichever occurs earlier. - (ACTION 3) If a repair doubler installed in accordance with PART 5: REPAIR ends one or two fastener rows beyond a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler.

- - (ACTION 3) If a repair doubler installed in accordance with PART 5: REPAIR ends three or more fastener rows beyond a stringer fastener row: No more work is necessary in the area of the repair.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 25 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 1:**  **Table 2: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 1741 (Area 2)**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition**  6,000 flight cycles or 48 months,whichever occurs earlier. - Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACELFEC INSPECTION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FORCRACKS at all affected unrepaired areas. (a) CONDITION 7: NO CRACK FOUND

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 26 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 1:**  **Table 2: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 1741 (Area 2)**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- Before further flight. (ACTION 1) Do PART 5: RE- PAIR. CONDITION 8: ANY CRACK FOUND 1,500 flight cycles or 48 months,whichever occurs earlier. - (ACTION 2) If a repair doubler installed in accordance with PART 5: REPAIR ends on a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler. 6,000 flight cycles or 48 months,whichever occurs earlier. - (ACTION 2) If a repair doubler installed in accordance with PART 5: REPAIR ends one or two fastener rows beyond a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler.

- - (ACTION 2) If a repair doubler installed in accordance with PART 5: REPAIR ends three or more fastener rows beyond a stringer fastener row: No more work is necessary in the area of the repair. 6,000 flight cycles or 48 months,whichever occurs earlier. - (ACTION 3) Repeat PART 3: EXTERNAL LOWER LOBESKIN SURFACE LFEC INSPECTION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR SKINCRACKS at all affected unrepaired areas. (a) (a) For the purposes of these inspections, "unrepaired areas" are defined as affected areas where the skin is not covered with a doubler. Areas repaired with only blends or oversized fasteners should be treated as unrepaired.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 27 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 1:**  **Table 3: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 1961 (Area 3)**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- Within 3,000 flight cycles or 24 months afterthe original issue date of this service bulletin,whichever occurs first. Before 10,000total flight cycles, or within 10 years fromthe date of issuance of theoriginal certificate of airworthiness or the original export certificate of airworthiness, whichever occurs first. Do external GVI of the fuselage skin in Area 3 as shown in PART 1: INSPECTION AREAS for the presence of external doublers. All airplanes

- Before further flight. Do PART 2: EXTERNAL LOW- ER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler. Determine if the doubler ends on a row of fasteners common to a stringer. CONDITION 1: ANY EXISTING EXTERNAL DOUBLER FOUND INTHE AFFECTED AREAS

- Before further flight. Do PART 3: EXTERNAL LOW- ER LOBE SKIN SURFACELFEC INSPECTION FOR CORROSION in affected areas.CONDITION 2: AFFECTED AREAS WITHNO EXISTING EXTERNAL DOUBLER FOUND

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 28 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 1:**  **Table 3: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 1961 (Area 3)**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition**  800 flight cycles or 24 months,whichever occurs earlier. If the doubler ends on a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler. CONDITION 3: NO SKIN CRACK FOUND UNDER EXTERNAL DOUBLER

6,000 flight cycles or 48 months,whichever occurs earlier. - If the doubler ends one or two fastener rows beyond a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler.

- - If the doubler ends three or more fastener rows beyond a stringer fastener row: No more work is necessary in the area of the doubler.

- Before further flight. (ACTION 1) Do PART 5: RE- PAIR. CONDITION 4: ANY SKIN CRACK FOUND UNDER EXTERNAL DOUBLER 800 flight cycles or 24 months,whichever occurs earlier. - (ACTION 2) If the doubler endson a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS in the area of the doubler. 6,000 flight cycles or 48 months,whichever occurs earlier. - (ACTION 2) If the doubler ends one or two fastener rows beyond a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler.

- - (ACTION 2) If the doubler endsthree or more fastener rows beyond a stringer fastener row: No more work is necessary in the area of the doubler.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 29 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 1:**  **Table 3: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 1961 (Area 3)**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- Before further flight. Do PART 4: EXTERNAL LOW- ER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS in affected areas. CONDITION 5: NO CORROSION FOUND

- Before further flight. (ACTION 1) Do PART 5: RE- PAIR in areas where corrosion was found. CONDITION 6: ANY CORROSION FOUND

- Before further flight. (ACTION 2) Do PART 4: EXTER-NAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS in affected areas where no corrosion was found or where corrosion was removed by blending. 800 flight cycles or 24 months,whichever occurs earlier. - (ACTION 3) If a repair doubler installed in accordance with PART 5: REPAIR ends on a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler. 6,000 flight cycles or 48 months,whichever occurs earlier. - (ACTION 3) If a repair doubler installed in accordance with PART 5: REPAIR ends one or two fastener rows beyond a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler.

- - (ACTION 3) If a repair doubler installed in accordance with PART 5: REPAIR ends three or more fastener rows beyond a stringer fastener row: No more work is necessary in the area of the repair.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 30 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 1:**  **Table 3: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 1961 (Area 3)**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition**  6,000 flight cycles or 48 months,whichever occurs earlier. - Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACELFEC INSPECTION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FORCRACKS at all affected unrepaired areas. (a) CONDITION 7: NO CRACK FOUND

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 31 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 1:**  **Table 3: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 1961 (Area 3)**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- Before further flight. (ACTION 1) Do PART 5: RE- PAIR. CONDITION 8: ANY CRACK FOUND 800 flight cycles or 24 months,whichever occurs earlier. - (ACTION 2) If a repair doubler installed in accordance with PART 5: REPAIR ends on a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler. 6,000 flight cycles or 48 months,whichever occurs earlier. - (ACTION 2) If a repair doubler installed in accordance with PART 5: REPAIR ends one or two fastener rows beyond a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler.

- - (ACTION 2) If a repair doubler installed in accordance with PART 5: REPAIR ends three or more fastener rows beyond a stringer fastener row: No more work is necessary in the area of the repair. 6,000 flight cycles or 48 months,whichever occurs earlier. - (ACTION 3) Repeat PART 3: EXTERNAL LOWER LOBESKIN SURFACE LFEC INSPECTION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS at all affected unrepaired areas. (a) (a) For the purposes of these inspections, "unrepaired areas" are defined as affected areas where the skin is not covered with a doubler. Areas repaired with only blends or oversized fasteners should be treated as unrepaired.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 32 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 1:**  **Table 4: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 2181 (Area 4)**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- Within 3,000 flight cycles or 24 months afterthe original issue date of this service bulletin,whichever occurs first. Before 10,000total flight cycles, or within 10 years fromthe date of issuance of theoriginal certificate of airworthiness or the original export certificate of airworthiness, whichever occurs first. Do external GVI of the fuselage skin in Area 4 as shown in PART 1: INSPECTION AREAS for the presence of external doublers. All airplanes

- Before further flight. Do PART 2: EXTERNAL LOW- ER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler. Determine if the doubler ends on a row of fasteners common to a stringer. CONDITION 1: ANY EXISTING EXTERNAL DOUBLER FOUND INTHE AFFECTED AREAS

- Before further flight. Do PART 3: EXTERNAL LOW- ER LOBE SKIN SURFACELFEC INSPECTION FOR CORROSION in affected areas.CONDITION 2: AFFECTED AREAS WITHNO EXISTING EXTERNAL DOUBLER FOUND

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 33 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 1:**  **Table 4: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 2181 (Area 4)**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition**  800 flight cycles or 24 months,whichever occurs earlier. If the doubler ends on a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler. CONDITION 3: NO SKIN CRACK FOUND UNDER EXTERNAL DOUBLER

6,000 flight cycles or 48 months,whichever occurs earlier. - If the doubler ends one or two fastener rows beyond a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler.

- - If the doubler ends three or more fastener rows beyond a stringer fastener row: No more work is necessary in the area of the doubler.

- Before further flight. (ACTION 1) Do PART 5: RE- PAIR. CONDITION 4: ANY SKIN CRACK FOUND UNDER EXTERNAL DOUBLER 800 flight cycles or 24 months,whichever occurs earlier. - (ACTION 2) If the doubler endson a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS in the area of the doubler. 6,000 flight cycles or 48 months,whichever occurs earlier. - (ACTION 2) If the doubler ends one or two fastener rows beyond a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler.

- - (ACTION 2) If the doubler endsthree or more fastener rows beyond a stringer fastener row: No more work is necessary in the area of the doubler.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 34 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 1:**  **Table 4: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 2181 (Area 4)**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- Before further flight. Do PART 4: EXTERNAL LOW- ER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS in affected areas. CONDITION 5: NO CORROSION FOUND

- Before further flight. (ACTION 1) Do PART 5: RE- PAIR in areas where corrosion was found. CONDITION 6: ANY CORROSION FOUND

- Before further flight. (ACTION 2) Do PART 4: EXTER-NAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS in affected areas where no corrosion was found or where corrosion was removed by blending. 800 flight cycles or 24 months,whichever occurs earlier. - (ACTION 3) If a repair doubler installed in accordance with PART 5: REPAIR ends on a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler. 6,000 flight cycles or 48 months,whichever occurs earlier. - (ACTION 3) If a repair doubler installed in accordance with PART 5: REPAIR ends one or two fastener rows beyond a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler.

- - (ACTION 3) If a repair doubler installed in accordance with PART 5: REPAIR ends three or more fastener rows beyond a stringer fastener row: No more work is necessary in the area of the repair.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 35 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 1:**  **Table 4: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 2181 (Area 4)**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition**  3,000 flight cycles or 24 months,whichever occurs earlier. - Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACELFEC INSPECTION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FORCRACKS at all affected unrepaired areas. (a) CONDITION 7: NO CRACK FOUND

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 36 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 1:**  **Table 4: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 2181 (Area 4)**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- Before further flight. (ACTION 1) Do PART 5: RE- PAIR. CONDITION 8: ANY CRACK FOUND 800 flight cycles or 24 months,whichever occurs earlier. - (ACTION 2) If a repair doubler installed in accordance with PART 5: REPAIR ends on a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler. 6,000 flight cycles or 48 months,whichever occurs earlier. - (ACTION 2) If a repair doubler installed in accordance with PART 5: REPAIR ends one or two fastener rows beyond a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKINCRACKS in the area of the doubler.

- - (ACTION 2) If a repair doubler installed in accordance with PART 5: REPAIR ends three or more fastener rows beyond a stringer fastener row: No more work is necessary in the area of the repair. 3,000 flight cycles or 24 months,whichever occurs earlier. - (ACTION 3) Repeat PART 3: EXTERNAL LOWER LOBESKIN SURFACE LFEC INSPECTION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS at all affected unrepaired areas. (a) (a) For the purposes of these inspections, "unrepaired areas" are defined as affected areas where the skin is not covered with a doubler. Areas repaired with only blends or oversized fasteners should be treated as unrepaired.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 37 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 2:**  **Table 5: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 1741 (Area 2)**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- Within 3,000 flight cycles or 24 months afterthe original issue date of this service bulletin,whichever occurs first. Before 10,000total flight cycles, or within 10 years fromthe date of issuance of theoriginal certificate of airworthiness or the original export certificate of airworthiness, whichever occurs first. Do external GVI of the fuselage skin in Area 2 as shown in PART 1: INSPECTION AREAS for the presence of repair doublers. (a) All airplanes

- Before further flight. Contact Boeing for inspectionrequirements and do the inspections. CONDITION 9: ANY EXISTING REPAIR DOUBLER FOUND INTHE AFFECTED AREAS

- Before further flight. In Area 2A, do PART 3: EXTER-NAL LOWER LOBE SKIN SURFACE LFEC INSPECTION FOR CORROSION.CONDITION 10: AFFECTED AREAS WITH NO EXISTING REPAIR DOUBLER FOUND

- Before further flight. In Area 2B, do PART 2: EXTER- NAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS (a)

- Before further flight. In Area 2C, do PART 6: EXTER-NAL LOWER LOBE SKIN DETAILED INSPECTION FOR CRACKS 3,000 flight cycles or 24 months,whichever occurs earlier. - Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS (a) CONDITION 3: NO SKIN CRACK FOUND UNDER EXTERNAL DOUBLER In Area 2B

- Before further flight. (ACTION 1) Do PART 5: RE- PAIR. CONDITION 4: ANY SKIN CRACK FOUND UNDER EXTERNAL DOUBLER In Area 2B 3,000 flight cycles or 24 months,whichever occurs earlier. - Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTIONFOR SKIN CRACKS in unrepaired areas. (b)

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 38 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 2:**  **Table 5: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 1741 (Area 2)**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- Before further flight. Do PART 4: EXTERNAL LOW- ER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS CONDITION 5: NO CORROSION FOUND In Area 2A

- Before further flight. (ACTION 1) Do PART 5: RE- PAIR in areas where corrosion was found. CONDITION 6: ANY CORROSION FOUND In Area 2A

- Before further flight. (ACTION 2) Do PART 4: EXTER-NAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS in affected areas where no corrosion was found or where corrosion was removed by blending. 6,000 flight cycles or 48 months,whichever occurs earlier. - Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACELFEC INSPECTION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS in unrepaired areas of Area 2A. (b) CONDITION 7: NO CRACK FOUND In Area 2A

- Before further flight. (ACTION 1) Do PART 5: RE- PAIR. CONDITION 8: ANY CRACK FOUND In Area 2A 6,000 flight cycles or 48 months,whichever occurs earlier. - (ACTION 2) Repeat PART 3: EXTERNAL LOWER LOBESKIN SURFACE LFEC INSPECTION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS in unrepaired areas of Area 2A. (b) 1,500 flight cycles or 24 months,whichever occurs earlier. - Repeat PART 6: EXTERNAL LOWER LOBE SKIN DETAILED INSPECTION FOR CRACKS in unrepaired areas of Area 2C. (b) CONDITION 11: NO CRACK FOUND In Area 2C

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 39 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 2:**  **Table 5: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 1741 (Area 2)**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- Before further flight. (ACTION 1) Do PART 5: RE- PAIR. CONDITION 12: ANY CRACK FOUND In Area 2C 1,500 flight cycles or 24 months,whichever occurs earlier. - (ACTION 2) Repeat PART 6: EXTERNAL LOWER LOBE SKIN DETAILED INSPECTIONFOR CRACKS in unrepaired areas of Area 2C. (b) (a) An existing doubler installed during production covers all of the affected fuselage skin in Area 2B and should not be considered a repair doubler. (b) For the purposes of these inspections, "unrepaired areas" are defined as affected areas where the skin is not covered with a repair doubler. Areas repaired with only blends or oversized fasteners should be treated as unrepaired. **Group 2: Table 6: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 1961 (Area**  **3) Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition**

- Within 3,000 flight cycles or 24 months afterthe original issue date of this service bulletin,whichever occurs first. Before 10,000total flight cycles, or within 10 years fromthe date of issuance of theoriginal certificate of airworthiness or the original export certificate of airworthiness, whichever occurs first. Do external GVI of the fuselage skin in Area 3 as shown in PART 1: INSPECTION AREAS for the presence of external doublers. All airplanes

- Before further flight. Contact Boeing for inspectionrequirements and do the inspections. CONDITION 9: ANY EXISTING REPAIR DOUBLER FOUND INTHE AFFECTED AREAS

- Before further flight. Do PART 3: EXTERNAL LOW- ER LOBE SKIN SURFACELFEC INSPECTION FOR CORROSION in affected areas.CONDITION 10: AFFECTED AREAS WITH NO EXISTING REPAIR DOUBLER FOUND

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 40 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 2:**  **Table 6: Inspection and Repair of the Skin at the Lower Lobe Circumferential Splice at STA 1961 (Area 3)**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- Before further flight. Do PART 4: EXTERNAL LOW- ER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS in affected areas. CONDITION 5: NO CORROSION FOUND

- Before further flight. (ACTION 1) Do PART 5: RE- PAIR in areas where corrosion was found. CONDITION 6: ANY CORROSION FOUND

- Before further flight. (ACTION 2) Do PART 4: EXTER-NAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS in affected areas where no corrosion was found or where corrosion was removed by blending. 6,000 flight cycles or 48 months,whichever occurs earlier. - Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACELFEC INSPECTION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FORCRACKS at all affected unrepaired areas. (a) CONDITION 7: NO CRACK FOUND

- Before further flight. (ACTION 1) Do PART 5: RE- PAIR. CONDITION 8: ANY CRACK FOUND 6,000 flight cycles or 48 months,whichever occurs earlier. - (ACTION 2) Repeat PART 3: EXTERNAL LOWER LOBESKIN SURFACE LFEC INSPECTION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS at all affected unrepaired areas. (a) (a) For the purposes of these inspections, "unrepaired areas" are defined as affected areas where the skin is not covered with a doubler. Areas repaired with only blends or oversized fasteners should be treated as unrepaired.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 41 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT F. Approval**  This service bulletin was examined by the Federal Aviation Administration (FAA). The changes specified in this service bulletin comply with the applicable regulations and are FAA approved, as well as European Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved airplanes listed in the service bulletin effectivity. This service bulletin and its approval were based on the airplane in its original Boeing delivery configuration or as modified by other approved Boeing changes. If an airplane has a non-Boeing modification or repair that affects a component or system also affected by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval before incorporating this service bulletin. **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: Table 1 - Inspection**  **Elapsed Hours Task Hours**  **Number of Persons Task**  3.25 3.25 1 External inspection for doublers 14.75 59.00 4 External inspection for corrosion 14.75 59.00 4 External inspection for cracks 32.75 121.25 TOTAL FOR EACH AIRPLANE

**NOTE:**More time will be necessary for additional inspections if existing doublers are found. More time will also be required for repairs if corrosion or cracks are found. **Group 2: Table 2 - Inspection**  **Elapsed Hours Task Hours**  **Number of Persons Task**  1.50 1.50 1 External inspection for doublers

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 42 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Group 2:**  **Table 2 - Inspection Elapsed Hours**  **Task Hours Number of Persons**  **Task** 10.50 42.00 4 External inspection for corrosion 10.50 42.00 4 External inspection for cracks 22.50 85.50 TOTAL FOR EACH AIRPLANE

**NOTE:**More time will be necessary for additional inspections if existing doublers are found. More time will also be required for repairs if corrosion or cracks are found. **H. Weight and Balance Changes** None. **I. Electrical Load Data** Not changed. **J. References** 1. Existing Data: a. Boeing Service Related Problem (SRP) 747-SRP-53-0392 b. Service Bulletin Index D6-30300 c. 747 Non-Destructive Testing (NDT) Manual Part 6, 51-00-00, Part 6, 53-30-03 d. 747-100/200/300 Structural Repair Manual (SRM) 53-30-03 e. 747-400 Structural Repair Manual (SRM) 53-00-01 f. 747-400F Structural Repair Manual (SRM) 53-00-01 g. 747-400SF Structural Repair Manual (SRM) 53-00-01 h. 747-SP Structural Repair Manual (SRM) 53-39-01 2. Data Supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin: None.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 43 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT 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. DTI requirements for the structure affected are contained in Paragraph 1.E., Compliance of this service bulletin. **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: April 01, 2014 747-53A2861 44 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT 2. MATERIAL INFORMATION**  **A. Material - Price and Availability** None. **B. Industry Support Information** Boeing warranty remedies are not available for the inspection and repair 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 do the change in this service bulletin. But, maintenance and overhaul tools in the manuals given in Paragraph 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: April 01, 2014 747-53A2861 45 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 46 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT**

BLANK PAGE**3. ACCOMPLISHMENT INSTRUCTIONS A. GENERAL INFORMATION**  **NOTE:** 1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 2. Obey all of the warnings and cautions given in the specified manual sections. 3. Unless shown differently, these dimensions and tolerances are used: – Linear dimensions are in inches – Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus or minus 0.03 inch – Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch – Angular tolerance is plus or minus 2 degrees – Hole dimensions for standard solid rivets and fasteners are in Structural Repair Manual (SRM) Chapter 51 – Torque Values: — Values for structural fasteners are given in 747 Structural Repair Manual, Chapter 51. — Values for airframe maintenance tasks are included in Chapter 20 of 747 Airplane Maintenance Manual (AMM). — Values for electrical maintenance tasks are included in Chapter 20 of Standard Wiring Practices Manual (SWPM). — Values for engine maintenance tasks are included in Chapter 70 of 747 Airplane Maintenance Manual (AMM). — Non-standard torque values for maintenance tasks are included in the applicable installation step.

4. Use the approved fastener and process 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 747-SL-51-048, 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. 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.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 47 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT**8. 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. 9. Where the work instructions include installation of a kept part, a new or serviceable part with the same part number can be installed as an alternative to the kept part. 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. When more than one OPTION is given for a CONDITION, do only one of the OPTION numbers. When more than one ACTION is given for a CONDITION number or an OPTION number, do all of the ACTION numbers for that CONDITION number or OPTION number. 12. The compliance times for the actions in Paragraph 3.B., WORK INSTRUCTIONS are in Paragraph 1.E., Compliance. 13. The CONDITIONS, ACTIONS and OPTIONS shown apply to each affected skin joint independently. 14. Refer to APPENDIX A and APPENDIX B 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. 15. Refer to APPENDIX C and APPENDIX D for data about the affected skin panels. This information may be helpful in accomplishing the necessary inspections. 16. Some steps in the Work Instructions are identified as Required for Compliance (RC). If this service bulletin is mandated by an Airworthiness Directive (AD), then the steps identified as RC must be done to comply with the AD. Alternative procedures for steps not identified with RC can be used if the RC steps can still be done as specified, and the airplane can be put back in a serviceable condition. An Alternative Method of Compliance (AMOC) is not necessary for deviations to steps that are not identified as RC. 17. Paragraph 3.B., Work Instructions, PART 1, shows the applicable general areas to be inspected. In any given inspection area, do the described inspections only along the rows of fasteners common to the skin, doubler (if installed), and stringers. 18. A General Visual Inspection is defined as: A visual examination of an interior or exterior area, installation or assembly to detect obvious damage, failure or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight or drop-light and may require removal or opening of access panels or doors. Stands, ladders or platforms may be required to gain proximity to the area being checked.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 48 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT B. WORK INSTRUCTIONS**  **Group 1:** 1. Do external General Visual Inspections of the fuselage skin in the affected areas shown in PART 1: INSPECTION AREAS for the presence of external repair doublers. a. CONDITION 1: ANY EXISTING EXTERNAL DOUBLER FOUND IN THE AFFECTED AREAS (1) Do PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS in the area of the doubler. Determine if the doubler ends on a row of fasteners common to a stringer. **NOTE:**Refer to CONDITION 2 for actions in affected areas that are not covered by a doubler. (a) CONDITION 3: NO SKIN CRACK FOUND UNDER EXTERNAL DOUBLER 1) Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS in the area of the doubler. (b) CONDITION 4: ANY SKIN CRACK FOUND UNDER EXTERNAL DOUBLER 1) (ACTION 1) Do PART 5: REPAIR. 2) (ACTION 2) Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS in the area of the doubler. **NOTE:** If any doubler ends three or more fastener rows beyond a row of fasteners common to a stringer, no more inspections of that doubler are necessary. b. CONDITION 2: AFFECTED AREAS WITH NO EXISTING EXTERNAL DOUBLER FOUND (1) Do PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPECTION FOR CORROSION in affected areas. (a) CONDITION 5: NO CORROSION FOUND 1) Do PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS in affected areas. a) CONDITION 7: NO CRACK FOUND {1} Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPECTION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS in affected unrepaired areas. b) CONDITION 8: ANY CRACK FOUND {1} (ACTION 1) Do PART 5: REPAIR.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 49 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT**{2} (ACTION 2) Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPECTION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS at all affected unrepaired areas. (b) CONDITION 6: ANY CORROSION FOUND 1) (ACTION 1) Do PART 5: REPAIR in areas where corrosion was found. 2) (ACTION 2) Do PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS in affected areas where no corrosion was found or where corrosion was removed by blending. a) CONDITION 7: NO CRACK FOUND {1} Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPECTION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS at all affected unrepaired areas. b) CONDITION 8: ANY CRACK FOUND {1} (ACTION 1) Do PART 5: REPAIR. {2} (ACTION 2) If a repair doubler was installed in accordance with PART 5: REPAIR, repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS in the area of the doubler. {3} (ACTION 3) Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPECTION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS at all affected unrepaired areas. 3) (ACTION 3) If a repair doubler was installed in accordance with PART 5: REPAIR, repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS in the area of the doubler. 2. Put the airplane back to a serviceable condition. **Group 2:** 1. Remove wing-to-body fairing panels for access to the lower body skin near STA 1741. Refer to FIGURE 7 as an accepted procedure. 2. Do external General Visual Inspections of the fuselage skin in the affected areas shown in PART 1: INSPECTION AREAS for the presence of external repair doublers. **NOTE:**An existing doubler installed during production covers all of the affected fuselage skin in Area 2B. a. CONDITION 9: ANY EXISTING REPAIR DOUBLER FOUND IN THE AFFECTED AREAS

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 50 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT**(1) Contact Boeing for inspection requirements, and do the inspections. b. CONDITION 10: AFFECTED AREAS WITH NO EXISTING REPAIR DOUBLER FOUND (1) Do the inspections that follow: (a) In Area 2A and Area 3, do PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPECTION FOR CORROSION. (b) In Area 2B, do PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS. (c) In Area 2C, do PART 6: EXTERNAL LOWER LOBE SKIN DETAILED INSPECTION FOR CRACKS. c. CONDITION 3: NO SKIN CRACK FOUND UNDER EXTERNAL DOUBLER (1) In Area 2B, repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS in the area of the doubler. d. CONDITION 4: ANY SKIN CRACK FOUND UNDER EXTERNAL DOUBLER (1) (ACTION 1) In Area 2B, do PART 5: REPAIR. (2) (ACTION 2) In Area 2B, repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS in the area of the doubler. e. CONDITION 5: NO CORROSION FOUND (1) In Area 2A and Area 3, do PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS in affected areas. (a) CONDITION 7: NO CRACK FOUND 1) In Area 2A and Area 3, repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPECTION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS in affected unrepaired areas. (b) CONDITION 8: ANY CRACK FOUND 1) (ACTION 1) In Area 2A and Area 3, do PART 5: REPAIR. 2) (ACTION 2) In Area 2A and Area 3, repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPECTION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS at all affected unrepaired areas. f. CONDITION 6: ANY CORROSION FOUND (1) (ACTION 1) In Area 2A and Area 3, do PART 5: REPAIR in areas where corrosion was found.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 51 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT**(2) (ACTION 2) In Area 2A and Area 3, do PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS in affected areas where no corrosion was found or where corrosion was removed by blending. (a) CONDITION 7: NO CRACK FOUND 1) In Area 2A and Area 3, repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPECTION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS at all affected unrepaired areas. (b) CONDITION 8: ANY CRACK FOUND 1) (ACTION 1) In Area 2A and Area 3, do PART 5: REPAIR. 2) (ACTION 2) In Area 2A and Area 3, repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPECTION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS at all affected unrepaired areas. g. CONDITION 11: NO CRACK FOUND (1) In Area 2C, repeat PART 6: EXTERNAL LOWER LOBE SKIN DETAILED INSPECTION FOR CRACKS. h. CONDITION 12: ANY CRACK FOUND (1) (ACTION 1) In Area 2C, do PART 5: REPAIR. (2) (ACTION 2) In Area 2C, repeat PART 6: EXTERNAL LOWER LOBE SKIN DETAILED INSPECTION FOR CRACKS at all affected unrepaired areas. 3. Install wing-to-body fairing panels that were removed for access to the lower body skin near STA 1741. Refer to FIGURE 8 as an accepted procedure. 4. Put the airplane back to a serviceable condition. **PART 1: INSPECTION AREAS**
1. **Group 1:** a. STA 741 (Area 1) is shown in FIGURE 1. Area 1 extends from STA 720 to STA 760, along stringers S-45, S-46 and S-47. b. STA 1741 (Area 2) is shown in FIGURE 2. Area 2 extends from STA 1720 to STA 1760, along stringers S-42, S-43, S-44 and S-45. c. STA 1961 (Area 3) is shown in FIGURE 3. Area 3 extends from STA 1961 to STA 1980, along stringers S-47, S-48, S-49, S-50 and S-51. d. STA 2181 (Area 4) is shown in FIGURE 4. Area 4 extends from STA 2160 to STA 2200, along stringers S-47, S-48, S-49, S-50 and S-51.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 52 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT**2. **Group 2:** a. STA 1741 (Area 2) is shown in FIGURE 5. – Area 2A extends from STA 1720 to STA 1741, along stringers S-42, S-43, S-44 and S-45. – Area 2B extends from STA 1741 to STA 1760, along stringers S-42, S-43, S-44 and S-45. – Area 2C extends from STA 1720 to STA 1741, along stringers S-47, S-48, S-49, S-50 and S-51. b. STA 1961 (Area 3) is shown in FIGURE 6. Area 3 extends from STA 1961 to STA 1980, along stringers S-47, S-48, S-49, S-50 and S-51. **PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS** 1. RC - Do external surface LFEC inspections of the fuselage skin under repairs in affected areas for cracks, in accordance with 747 NDT Manual Part 6, 51-00-00, Procedure 8. **PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPECTION FOR CORROSION** 1. RC - Do external surface LFEC inspections of the skin in affected areas for corrosion that may exist between the skin inner surface and the stringer, in accordance with 747 NDT Manual Part 6, 51-00-00, Procedure 5 or Procedure 12. **PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS** 1. RC - Do external surface HFEC inspections of the skin in affected areas (at fastener locations common to the skin and stringers) for cracks, in accordance with 747 NDT Manual Part 6, 53-30-03 or 747 NDT Manual Part 6, 51-00-00, Procedure 4 or Procedure 23. **PART 5: REPAIR** 1. RC - Repair any damage found in accordance with 747-100/200/300 SRM 53-30-03, 747-400 SRM 53-00-01, 747-400F SRM 53-00-01, 747-400SF SRM 53-00-01, or 747-SP SRM 53-39-01. If the damage exceeds the limits given in the Structural Repair Manual, contact Boeing for repair data and do the repair. **PART 6: EXTERNAL LOWER LOBE SKIN DETAILED INSPECTION FOR CRACKS** 1. RC - Do external detailed inspections of the skin in affected areas (at fastener locations common to the skin and stringers) for cracks.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 53 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT This Figure applies only to: Group 1.** 

**FIGURE 1: INSPECTION AREA 1 (STA 741) (SHEET 1 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 54 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT FIGURE 1: INSPECTION AREA 1 (STA 741)**  **(SHEET 2 OF 2)**
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**FIGURE 2: INSPECTION AREA 2 (STA 1741) (SHEET 1 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 56 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT FIGURE 2: INSPECTION AREA 2 (STA 1741)**  **(SHEET 2 OF 2)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 57 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT This Figure applies only to: Group 1.** 

**FIGURE 3: INSPECTION AREA 3 (STA 1961) (SHEET 1 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 58 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT FIGURE 3: INSPECTION AREA 3 (STA 1961)**  **(SHEET 2 OF 2)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 59 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT This Figure applies only to: Group 1.** 

**FIGURE 4: INSPECTION AREA 4 (STA 2181) (SHEET 1 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 60 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT FIGURE 4: INSPECTION AREA 4 (STA 2181)**  **(SHEET 2 OF 2)**
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**FIGURE 5: INSPECTION AREA 2 (STA 1741) (SHEET 1 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 62 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT FIGURE 5: INSPECTION AREA 2 (STA 1741)**  **(SHEET 2 OF 2)**
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**FIGURE 6: INSPECTION AREA 3 (STA 1961) (SHEET 1 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 64 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT FIGURE 6: INSPECTION AREA 3 (STA 1961)**  **(SHEET 2 OF 2)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 65 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT This Figure applies only to: Group 2.** 

**FIGURE 7: WING TO BODY FAIRING PANEL REMOVAL (SHEET 1 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 66 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for each airplane.

**More Data Qty**  **Identification Name**  **Task Step**  (a) (b) 8

- Wing-to-Body Fairing Panel Remove / Keep 1 (a) 193C, 193D, 293D and 293E on the left side. (b) 194C, 194D, 294D and 294E on the right side.

**FIGURE 7: WING TO BODY FAIRING PANEL REMOVAL (SHEET 2 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 67 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT This Figure applies only to: Group 2.** 

**FIGURE 8: WING TO BODY FAIRING PANEL INSTALLATION (SHEET 1 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 68 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for each airplane.

**More Data Qty**  **Identification Name**  **Task Step**  (a) (b) 8

- Wing-to-Body Fairing Panel Install (Kept) 1 (a) 193C, 193D, 293D and 293E on the left side. (b) 194C, 194D, 294D and 294E on the right side.

**FIGURE 8: WING TO BODY FAIRING PANEL INSTALLATION (SHEET 2 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 69 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT APPENDIX A: LOGIC DIAGRAM - GROUP 1**  **(SHEET 1 OF 2)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 70 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT APPENDIX A: LOGIC DIAGRAM - GROUP 1**  **(SHEET 2 OF 2)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 71 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT APPENDIX B: LOGIC DIAGRAM - GROUP 2**  **(SHEET 1 OF 3)**
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Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 73 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT APPENDIX B: LOGIC DIAGRAM - GROUP 2**  **(SHEET 3 OF 3)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 74 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT This Appendix applies only to: Group 1.** 

**Table 1 - Area 1 Skin Panel Data Effectivity**  **Skin Panel Type Thickness**  **(inches) Part Number**  **Location**
R0351-R0381, R1073-R1261, R1262- R1267, R1513-R1519, R1544-R1620, R1621-R1629, R4009-R4009, R4103- R4107, R4108-R4108, R6009-R6016, R6103-R6143, R6144-R6153, R6154- R6157 Solid with no taper 0.062 65B04107-2 STA 720-741, S-45L - S-45R

R2001-R2005, R2006-R2015, R2016- R2027, R2028-R2055, R2401-R2414, R2415-R2425, R2426-R2478, R2479- R2533, R2534-R2721, R2901-R2902, R2903-R2920 0.063 65B04107-26

R2722-R2726, R6601-R6654, R6655- R6715, R7001-R7002, R7003-R7006, R7201-R7206 142U3280-1/-11

R6501-R6518 Machined with no taper 142U3013-1 R7101-R7110, R7111-R7134, R7135- R7199, R7251-R7299 142U3281-1/-11 All affected airplanes 65B04313-2, 142U3282-1/-2 /- 11/-12/-13/-14 /- 15 STA 741-760, S-45L - S-45R

**Table 2 - Area 2 Skin Panel Data Effectivity**  **Skin Panel Type Thickness**  **(inches) Part Number**  **Location** All affected airplanes Machined with taper (refer to drawing) Taper from 0.071 to 0.17 65B04488-7/-8 /- 9/-10/-21/-22 /- 23/-24/-29/-30 /- 31/-32 STA 1720- 1741, S-42L/R - S-45L/R All affected airplanes Solid with no taper 0.063 65B04141-2/-5, 146U3275-1/-2, 146U3271-3 STA 1741- 1760, S-42L - S-45L

**APPENDIX C: GROUP 1 SKIN PANEL DATA (SHEET 1 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 75 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT Table 2 - Area 2 Skin Panel Data**  **Effectivity Skin Panel Type**  **Thickness (inches)**  **Part Number Location**  All affected airplanes Bonded with 0.04 inter- nal doubler 0.08 65B07002-8, 65B23792-1/-2 /- 5/-6/-17/-19/-20 STA 1741- 1760, S-42R - S-43R Chem Milled STA 1741- 1760, S-44R - S-45R
**Table 3 - Area 3 Skin Panel Data Effectivity**  **Skin Panel Type Thickness**  **(inches) Part Number**  **Location** All affected airplanes chem milled with no ta- per 0.10 146U3292-2/-4/- 7, 146U3293-2, 65B20264-1/-2 STA 1961-1980, S-47L - S-47R

**Table 4 - Area 4 Skin Panel Data Effectivity**  **Skin Panel Type Thickness**  **(inches) Part Number**  **Location** All affected airplanes chem milled with no ta- per 0.10 65B20264-1/-2, 146U3292-2/-4/- 7, 146U3293-2 STA 2160-2181, S-47L - S-47R All affected airplanes Machined with no taper 0.103 65B06801-1/-4, 146U3282-5/-6/- 7 STA 2181-2200, S-47L - S-47R

**APPENDIX C: GROUP 1 SKIN PANEL DATA (SHEET 2 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 76 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT This Appendix applies only to: Group 2.**  **Effectivity Skin Panel Type**  **Thickness (inches)**  **Part Number Inspection Area**  All affected airplanes Solid with no taper 0.09 65B18643-1/-2 2A All affected airplanes Solid; no taper; 0.032 inch external Doubler 0.062 65B04141-326 2B (S-42L - S-45L)
R3019-R3021, R3301- R3301 Solid; no taper 0.08 65B07002-8 2B (S-42R - S-43R) Solid; no taper; 0.04 inch internal Doubler 0.12 65B07002-8 2B (S-44R - S-45R)
R3022-R3035, R3302- R3310 Chem-milled, no taper 0.16 65B23792-1 2B (S-42R - S-45R) All affected airplanes Machined with taper (re- fer to drawing) Taper from 0.11 to 0.183 65B19098-1 2C All affected airplanes Chem-milled 0.09 65B19633-1 3

**APPENDIX D: GROUP 2 (747SP) SKIN PANEL DATA (SHEET 1 OF 1)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 01, 2014 747-53A2861 77 of 77 **BOEING SERVICE BULLETIN 747-53A2861 ALERT**  **ALERT**