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Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 1 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. 9E991ECCN: 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 Unpublished Work.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April 01, 2014 747-53A2861 1 of 77 4.0 ### Page 2 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details.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 ALERTALERT BLANK PAGE ### Page 3 Table of Contents Summary ...................................................... 5 1. PLANNING INFORMATION ........................................ 9 A. Effectivity ................................................ 9 1. Airplanes ............................................. 9 2. Spares Affected ........................................ 1 7 B. Concurrent Requirements ...................................... 1 7 C. Reason ................................................ 1 7 D. Description .............................................. 1 7 E. Compliance .............................................. 1 8 F. Approval ............................................... 4 2 G. Manpower .............................................. 4 2 H. Weight and Balance Changes .................................... 4 3 I. Electrical Load Data ......................................... 4 3 J. References .............................................. 4 3 1. Existing Data: ......................................... 4 3 2. Data Supplied with this Service Bulletin: ........................... 4 3 3. Installation Drawings Used in the Preparation of this Service Bulletin: ........... 4 3 K. Publications Affected ........................................ 4 4 L. Interchangeability and Intermixability of Parts ........................... 4 4 M. Software Accomplishment Summary ................................ 4 4 2. MATERIAL INFORMATION ........................................ 4 5 A. Material - Price and Availability ................................... 4 5 B. Industry Support Information .................................... 4 5 C. Parts Necessary for Each Airplane ................................. 4 5 1. Kits/Parts ............................................ 4 5 2. Parts and Materials Supplied by the Operator ........................ 4 5 3. Parts Modified and Reidentified ................................ 4 5 4. Parts Removed and Not Replaced .............................. 4 5 D. Parts Necessary to Change Spares ................................. 4 5 E. Special Tooling - Price and Availability ............................... 4 5 F. Special Tooling Necessary to do this Service Bulletin ....................... 4 5 3. ACCOMPLISHMENT INSTRUCTIONS .................................. 4 7 A. GENERAL INFORMATION ..................................... 4 7 B. WORK INSTRUCTIONS ....................................... 4 9 FIGURE 1: INSPECTION AREA 1 (STA 741) [Group 1] ......................... 5 4 FIGURE 2: INSPECTION AREA 2 (STA 1741) [Group 1] ......................... 5 6 FIGURE 3: INSPECTION AREA 3 (STA 1961) [Group 1] ......................... 5 8 FIGURE 4: INSPECTION AREA 4 (STA 2181) [Group 1] ......................... 6 0 FIGURE 5: INSPECTION AREA 2 (STA 1741) [Group 2] ......................... 6 2 FIGURE 6: INSPECTION AREA 3 (STA 1961) [Group 2] ......................... 6 4 FIGURE 7: WING TO BODY FAIRING PANEL REMOVAL [Group 2] .................. 6 6 FIGURE 8: WING TO BODY FAIRING PANEL INSTALLATION [Group 2] ............... 6 8 APPENDIX A: LOGIC DIAGRAM - GROUP 1 ................................. 7 0 APPENDIX B: LOGIC DIAGRAM - GROUP 2 ................................. 7 2 APPENDIX C: GROUP 1 SKIN PANEL DATA [Group 1] ........................... 7 5 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 ALERTALERT ### Page 4 APPENDIX D: GROUP 2 (747SP) SKIN PANEL DATA [Group 2] ...................... 7 7 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 ALERTALERT ### Page 5 Commercial Airplanes 747 Service Bulletin ALERT SummaryNumber: 747-53A2861Original 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. ReferenceAffectedPlanning Data Paragraph 1.A.2., Spares AffectedNoSpares Affected Paragraph 1.E., Compliance and Paragraph 1.F., Approval YesAD Related Paragraph 1.H., Weight and Balance ChangesNoWeight 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 ### Page 6 ReferenceAffectedPlanning Data Paragraph 1.I., Electrical Load DataNoElectrical Load Changed Paragraph 1.K., Publications AffectedNoPublications Affected Paragraph 1.K., Publications AffectedNoAirplane Flight Operations Affected (Flight Crew Operations Manual and/or FAA Approved Air- plane Flight Manual) Paragraph 2.C.1., Kits/PartsNoKits/Parts Required Paragraph 2.C.2., Parts and Materials Supplied by the Operator NoOperator Supplied Parts/Material Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin NoSpecial 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 ALERTALERT ### Page 7 INDUSTRY SUPPORT INFORMATION Boeing warranty remedies are not available for the inspection and repair procedures given in this service bulletin. MANPOWER Elapsed HoursTotal Task HoursAirplanes 32.75121.25Group 1 22.5085.50Group 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 ALERTALERT ### Page 8 (OCR) BOEING SERVICE BULLETIN 747-53A2861 ALERT ALERT STA 741 STA 1741 STA STA 1961 2181 GROUP 1 DO EXTERNAL SURFACE LOW FREQUENCY EDDY CURRENT INSPECTIONS FOR CORROSION, AND SURFACE HIGH FREQUENCY EDDY CURRENT INSPECTIONS FOR CRACKS AT CERTAIN LOWER LOBE SKIN SPLICE LOCATIONS STA STA 1961 1741 GROUP 2 2258288 Original Issue: April 01, 2014 PROPRIETARY - Copyright © Unpublished Export Controlled ECCN: 9E991 - BOEING 747-53A2861 Work - See page 1 for details. 8 of 77 ### Page 9 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. DESCRIPTIONCONFIGURATIONGROUP 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 GroupVariable Number 1RA544 - RA548 1RA726 - 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 ### Page 10 GroupVariable Number 1RA750 1RA784 1RB411 - RB413 1RB421 1RB681 - RB697 1RB711 1RB721 - RB723 1RB741 - RB748 1RD047 - RD059 1RD081 - RD083 1RD091 - RD092 1RD122 - RD127 1RD134 - RD144 1RD166 - RD167 1RD171 - RD172 1RD181 - RD183 1RD201 - RD204 1RD221 - RD227 1RD231 - RD235 1RD241 - RD243 1RD251 - RD262 1RD271 - RD272 1RD291 - RD292 1RD301 - RD302 1RD311 1RD351 - RD358 1RD361 - RD366 1RD381 - RD383 1RD411 - RD414 1RD421 - RD426 1RD431 - RD435 1RD441 - RD442 1RD451 - 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 ALERTALERT ### Page 11 GroupVariable Number 1RD461 1RD471 - RD475 1RD513 - RD519 1RD531 - RD533 1RD551 1RD561 1RD571 1RD581 - RD583 1RD591 - RD593 1RD603 - RD607 1RD643 - RD649 1RD652 - RD659 1RD661 1RD671 1RD701 - RD702 1RD721 - RD722 1RD741 - RD742 1RD751 - RD755 1RD761 1RD771 - RD775 1RD781 - RD783 1RD791 - RD792 1RE001 1RF001 - RF006 2RG006 - RG009 2RG095 2RG104 2RG161 - RG164 2RG172 - RG174 2RG191 - RG193 2RG211 - RG213 2RG221 - RG222 2RH101 - 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 ALERTALERT ### Page 12 GroupVariable Number 2RH111 - RH112 2RH121 - RH122 1RJ152 1RJ303 1RJ321 - RJ322 1RJ331 - RJ333 1RL401 - RL403 1RL411 - RL436 1RL451 - RL456 1RL461 - RL462 1RL471 - RL481 1RL491 - RL492 1RL501 - RL502 1RL511 - RL516 1RL521 - RL522 1RL531 - RL534 1RL551 1RL561 - RL568 1RL571 - RL572 1RL576 - RL577 1RL579 1RL581 - RL586 1RL651 - RL655 1RL671 - RL675 1RL681 - RL684 1RL751 - RL752 1RM001 - RM007 1RM010 - RM013 1RM021 - RM024 1RM026 - RM030 1RM036 - RM045 1RM051 - RM053 1RM071 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 ALERTALERT ### Page 13 GroupVariable Number 1RM081 - RM084 1RM091 1RM096 - RM097 1RM116 - RM117 1RM126 - RM132 1RM136 - RM147 1RM156 - RM158 1RM166 - RM177 1RM191 - RM192 1RM231 - RM233 1RM241 - RM246 1RM261 - RM264 1RM316 - RM318 1RM331 - RM333 1RM341 1RM351 - RM355 1RM366 - RM367 1RM401 - RM403 1RM426 1RM431 1RM441 - RM443 1RM445 1RM801 - RM803 1RM811 - RM813 1RM851 - RM859 1RM861 - RM863 1RM871 - RM899 1RM901 - RM906 1RM911 1RR001 - RR005 1RR021 - RR025 1RR031 1RR202 - 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 ALERTALERT ### Page 14 GroupVariable Number 1RR223 - RR226 1RR262 - RR267 1RR303 - RR310 1RR331 - RR332 1RR336 1RR345 1RR361 - RR362 1RR421 - RR422 1RR431 - RR432 1RR441 - RR442 1RR451 1RR501 - RR504 1RR521 - RR522 1RR526 1RR531 1RR551 - RR556 1RR561 1RR566 1RR701 1RR721 - RR724 1RR746 - RR748 1RR851 - RR856 1RR861 - RR862 1RR951 - RR952 1RS001 - RS002 1RS201 1RS211 - RS212 1RS221 - RS222 1RS231 - RS241 1RS251 - RS259 1RS263 1RS265 - RS268 1RS271 - 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 ALERTALERT ### Page 15 GroupVariable Number 1RS291 - RS292 1RS301 - RS306 1RS311 - RS320 1RS331 - RS333 1RS341 - RS342 1RS699 1RS701 - RS703 1RS711 - RS713 1RS721 - RS722 1RS731 - RS732 1RS741 - RS743 1RS751 - RS752 1RS761 - RS762 1RS771 1RS781 - RS782 1RS786 1RT001 - RT014 1RT021 - RT022 1RT031 - RT035 1RT041 - RT047 1RT061 1RT071 - RT075 1RT101 - RT103 1RT121 1RT131 - RT137 1RT151 - RT152 1RT161 - RT168 1RT401 - RT412 1RT431 - RT447 1RT451 - RT469 1RT471 - RT499 1RT501 - RT535 1RT551 - 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 ALERTALERT ### Page 16 GroupVariable Number 1RT571 - RT591 1RT601 - RT630 1RT633 - RT657 1RT671 - RT673 1RT681 - RT682 1RT691 - RT699 1RT701 - RT704 1RT711 - RT717 1RT741 - RT742 1RT744 - RT757 1RT776 - RT777 1RT781 - RT784 1RT801 - RT803 1RT811 - RT814 1RT831 - RT837 1RT861 - RT864 1RT877 - RT880 1RT931 - RT932 1RT945 - RT949 1RT951 - RT955 1RT966 - RT967 1RU001 - RU006 1RU016 - RU017 1RU031 - RU032 1RU051 - RU052 1RU059 - RU062 1RU081 - RU083 1RU101 - RU102 1RU121 - RU132 1RU801 - RU809 1RU831 - 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 ALERTALERT ### Page 17 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 ALERTALERT ### Page 18 The work in this service bulletin is done in the maintenance zone(s) given below. Group 1: Affected Maintenance Zones ZoneModel 125, 126, 143, 144, 147, 148747-100B, 747-100B SUD, 747- 200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR Group 2: Affected Maintenance Zones ZoneModel 143, 144747SP 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) ActionCondition -Within 3,000 flight cycles or 24 months after the original is- sue date of this service bulletin, whichever oc- curs first. Before 10,000 total flight cy- cles, or within 10 years from the date of is- suance of the original certifi- cate of airworthi- ness or the origi- nal export certifi- cate of airworthi- ness, 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 ALERTALERT ### Page 19 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) ActionCondition -Before further flight.Do PART 2: EXTERNAL LOW- ER LOBE EXTERNAL DOU- BLER SURFACE LFEC INSPEC- TION 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 IN THE AFFECTED AR- EAS -Before further flight.Do PART 3: EXTERNAL LOW- ER LOBE SKIN SURFACE LFEC INSPECTION FOR COR- ROSION in affected areas. CONDITION 2: AF- FECTED AREAS WITH NO EXISTING EXTER- NAL DOUBLER FOUND 800 flight cycles or 24 months, whichever oc- curs earlier. If the doubler ends on a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS in the area of the dou- bler. CONDITION 3: NO SKIN CRACK FOUND UNDER EXTERNAL DOUBLER 3,000 flight cy- cles or 24 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. --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 ALERTALERT ### Page 20 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) ActionCondition -Before further flight.(ACTION 1) Do PART 5: RE- PAIR. CONDITION 4: ANY SKIN CRACK FOUND UNDER EXTERNAL DOUBLER 800 flight cyclesor 24 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. 3,000 flight cy- cles or 24 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. --(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 ALERTALERT ### Page 21 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) ActionCondition -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 SUR- FACE 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 oc- curs 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 SKIN CRACKS in the area of the dou- bler. 3,000 flight cy- cles or 24 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. --(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 cy- cles or 24 months, whichever oc- curs earlier. -Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPECTION FOR COR- ROSION and PART 4: EXTER- NAL LOWER LOBE SKIN SUR- FACE HFEC INSPECTION FOR CRACKS at all affected unre- paired 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 ALERTALERT ### Page 22 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) ActionCondition -Before further flight.(ACTION 1) Do PART 5: RE- PAIR. CONDITION 8: ANY CRACK FOUND 800 flight cycles or 24 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. 3,000 flight cy- cles or 24 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. --(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 cy- cles or 24 months, whichever oc- curs earlier. -(ACTION 3) Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPEC- TION 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 ALERTALERT ### Page 23 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) ActionCondition -Within 3,000 flight cycles or 24 months after the original is- sue date of this service bulletin, whichever oc- curs first. Before 10,000 total flight cy- cles, or within 10 years from the date of is- suance of the original certifi- cate of airworthi- ness or the origi- nal export certifi- cate of airworthi- ness, 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 SKIN CRACKS in the area of the dou- bler. Determine if the doubler ends on a row of fasteners common to a stringer. CONDITION 1: ANY EXISTING EXTERNAL DOUBLER FOUND IN THE AFFECTED AR- EAS -Before further flight.Do PART 3: EXTERNAL LOW- ER LOBE SKIN SURFACE LFEC INSPECTION FOR COR- ROSION in affected areas. CONDITION 2: AF- FECTED AREAS WITH NO EXISTING EXTER- NAL 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 ALERTALERT ### Page 24 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) ActionCondition 1,500 flight cy- cles or 48 months, whichever oc- curs earlier. If the doubler ends on a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS in the area of the dou- bler. CONDITION 3: NO SKIN CRACK FOUND UNDER EXTERNAL DOUBLER 6,000 flight cy- cles or 48 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. --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 cy-cles or 48 months, whichever oc- curs earlier. -(ACTION 2) If the doubler ends on a stringer fastener row: Re- peat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS in the area of the doubler. 6,000 flight cy- cles or 48 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. --(ACTION 2) If the doubler ends three or more fastener rows be- yond 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 ALERTALERT ### Page 25 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) ActionCondition -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 SUR- FACE HFEC INSPECTION FOR CRACKS in affected areas where no corrosion was found or where corrosion was removed by blending. 1,500 flight cy- cles or 48 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. 6,000 flight cy- cles or 48 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. --(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 ALERTALERT ### Page 26 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) ActionCondition 6,000 flight cy- cles or 48 months, whichever oc- curs earlier. -Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPECTION FOR COR- ROSION and PART 4: EXTER- NAL LOWER LOBE SKIN SUR- FACE HFEC INSPECTION FOR CRACKS at all affected unre- paired 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 ALERTALERT ### Page 27 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) ActionCondition -Before further flight.(ACTION 1) Do PART 5: RE- PAIR. CONDITION 8: ANY CRACK FOUND 1,500 flight cy- cles or 48 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. 6,000 flight cy- cles or 48 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. --(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 cy- cles or 48 months, whichever oc- curs earlier. -(ACTION 3) Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPEC- TION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR SKIN CRACKS at all affected unre- paired 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 ALERTALERT ### Page 28 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) ActionCondition -Within 3,000 flight cycles or 24 months after the original is- sue date of this service bulletin, whichever oc- curs first. Before 10,000 total flight cy- cles, or within 10 years from the date of is- suance of the original certifi- cate of airworthi- ness or the origi- nal export certifi- cate of airworthi- ness, 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 SKIN CRACKS in the area of the dou- bler. Determine if the doubler ends on a row of fasteners common to a stringer. CONDITION 1: ANY EXISTING EXTERNAL DOUBLER FOUND IN THE AFFECTED AR- EAS -Before further flight.Do PART 3: EXTERNAL LOW- ER LOBE SKIN SURFACE LFEC INSPECTION FOR COR- ROSION in affected areas. CONDITION 2: AF- FECTED AREAS WITH NO EXISTING EXTER- NAL 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 ALERTALERT ### Page 29 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) ActionCondition 800 flight cycles or 24 months, whichever oc- curs earlier. If the doubler ends on a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS in the area of the dou- bler. CONDITION 3: NO SKIN CRACK FOUND UNDER EXTERNAL DOUBLER 6,000 flight cy- cles or 48 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. --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 cyclesor 24 months, whichever oc- curs earlier. -(ACTION 2) If the doubler ends on a stringer fastener row: Re- peat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS in the area of the doubler. 6,000 flight cy- cles or 48 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. --(ACTION 2) If the doubler ends three or more fastener rows be- yond 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 ALERTALERT ### Page 30 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) ActionCondition -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 SUR- FACE 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 oc- curs 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 SKIN CRACKS in the area of the dou- bler. 6,000 flight cy- cles or 48 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. --(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 ALERTALERT ### Page 31 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) ActionCondition 6,000 flight cy- cles or 48 months, whichever oc- curs earlier. -Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPECTION FOR COR- ROSION and PART 4: EXTER- NAL LOWER LOBE SKIN SUR- FACE HFEC INSPECTION FOR CRACKS at all affected unre- paired 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 ALERTALERT ### Page 32 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) ActionCondition -Before further flight.(ACTION 1) Do PART 5: RE- PAIR. CONDITION 8: ANY CRACK FOUND 800 flight cycles or 24 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. 6,000 flight cy- cles or 48 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. --(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 cy- cles or 48 months, whichever oc- curs earlier. -(ACTION 3) Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPEC- TION 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 ALERTALERT ### Page 33 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) ActionCondition -Within 3,000 flight cycles or 24 months after the original is- sue date of this service bulletin, whichever oc- curs first. Before 10,000 total flight cy- cles, or within 10 years from the date of is- suance of the original certifi- cate of airworthi- ness or the origi- nal export certifi- cate of airworthi- ness, 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 SKIN CRACKS in the area of the dou- bler. Determine if the doubler ends on a row of fasteners common to a stringer. CONDITION 1: ANY EXISTING EXTERNAL DOUBLER FOUND IN THE AFFECTED AR- EAS -Before further flight.Do PART 3: EXTERNAL LOW- ER LOBE SKIN SURFACE LFEC INSPECTION FOR COR- ROSION in affected areas. CONDITION 2: AF- FECTED AREAS WITH NO EXISTING EXTER- NAL 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 ALERTALERT ### Page 34 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) ActionCondition 800 flight cycles or 24 months, whichever oc- curs earlier. If the doubler ends on a stringer fastener row: Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS in the area of the dou- bler. CONDITION 3: NO SKIN CRACK FOUND UNDER EXTERNAL DOUBLER 6,000 flight cy- cles or 48 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. --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 cyclesor 24 months, whichever oc- curs earlier. -(ACTION 2) If the doubler ends on a stringer fastener row: Re- peat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS in the area of the doubler. 6,000 flight cy- cles or 48 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. --(ACTION 2) If the doubler ends three or more fastener rows be- yond 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 ALERTALERT ### Page 35 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) ActionCondition -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 SUR- FACE 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 oc- curs 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 SKIN CRACKS in the area of the dou- bler. 6,000 flight cy- cles or 48 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. --(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 ALERTALERT ### Page 36 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) ActionCondition 3,000 flight cy- cles or 24 months, whichever oc- curs earlier. -Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPECTION FOR COR- ROSION and PART 4: EXTER- NAL LOWER LOBE SKIN SUR- FACE HFEC INSPECTION FOR CRACKS at all affected unre- paired 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 ALERTALERT ### Page 37 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) ActionCondition -Before further flight.(ACTION 1) Do PART 5: RE- PAIR. CONDITION 8: ANY CRACK FOUND 800 flight cycles or 24 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. 6,000 flight cy- cles or 48 months, whichever oc- curs 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 SKIN CRACKS in the area of the dou- bler. --(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 cy- cles or 24 months, whichever oc- curs earlier. -(ACTION 3) Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPEC- TION 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 ALERTALERT ### Page 38 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) ActionCondition -Within 3,000 flight cycles or 24 months after the original is- sue date of this service bulletin, whichever oc- curs first. Before 10,000 total flight cy- cles, or within 10 years from the date of is- suance of the original certifi- cate of airworthi- ness or the origi- nal export certifi- cate of airworthi- ness, 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 inspection requirements and do the inspec- tions. CONDITION 9: ANY EXISTING REPAIR DOUBLER FOUND IN THE AFFECTED AR- EAS -Before further flight.In Area 2A, do PART 3: EXTER- NAL LOWER LOBE SKIN SUR- FACE LFEC INSPECTION FOR CORROSION. CONDITION 10: AF- FECTED 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 DE- TAILED INSPECTION FOR CRACKS 3,000 flight cy- cles or 24 months, whichever oc- curs 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 cy-cles or 24 months, whichever oc- curs earlier. -Repeat PART 2: EXTERNAL LOWER LOBE DOUBLER SURFACE LFEC INSPECTION FOR SKIN CRACKS in unre- paired 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 ALERTALERT ### Page 39 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) ActionCondition -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 SUR- FACE HFEC INSPECTION FOR CRACKS in affected areas where no corrosion was found or where corrosion was removed by blending. 6,000 flight cy- cles or 48 months, whichever oc- curs earlier. -Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPECTION FOR COR- ROSION and PART 4: EXTER- NAL LOWER LOBE SKIN SUR- FACE 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 cy- cles or 48 months, whichever oc- curs earlier. -(ACTION 2) Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPEC- TION FOR CORROSION and PART 4: EXTERNAL LOWER LOBE SKIN SURFACE HFEC INSPECTION FOR CRACKS in unrepaired areas of Area 2A. (b) 1,500 flight cy- cles or 24 months, whichever oc- curs 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 ALERTALERT ### Page 40 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) ActionCondition -Before further flight.(ACTION 1) Do PART 5: RE- PAIR. CONDITION 12: ANY CRACK FOUND In Area 2C 1,500 flight cy- cles or 24 months, whichever oc- curs earlier. -(ACTION 2) Repeat PART 6: EXTERNAL LOWER LOBE SKIN DETAILED INSPECTION FOR CRACKS in unrepaired ar- eas 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) ActionCondition -Within 3,000 flight cycles or 24 months after the original is- sue date of this service bulletin, whichever oc- curs first. Before 10,000 total flight cy- cles, or within 10 years from the date of is- suance of the original certifi- cate of airworthi- ness or the origi- nal export certifi- cate of airworthi- ness, 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 inspection requirements and do the inspec- tions. CONDITION 9: ANY EXISTING REPAIR DOUBLER FOUND IN THE AFFECTED AR- EAS -Before further flight.Do PART 3: EXTERNAL LOW- ER LOBE SKIN SURFACE LFEC INSPECTION FOR COR- ROSION in affected areas. CONDITION 10: AF- FECTED 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 ALERTALERT ### Page 41 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) ActionCondition -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 SUR- FACE HFEC INSPECTION FOR CRACKS in affected areas where no corrosion was found or where corrosion was removed by blending. 6,000 flight cy- cles or 48 months, whichever oc- curs earlier. -Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPECTION FOR COR- ROSION and PART 4: EXTER- NAL LOWER LOBE SKIN SUR- FACE HFEC INSPECTION FOR CRACKS at all affected unre- paired 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 cy- cles or 48 months, whichever oc- curs earlier. -(ACTION 2) Repeat PART 3: EXTERNAL LOWER LOBE SKIN SURFACE LFEC INSPEC- TION 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 ALERTALERT ### Page 42 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 HoursTask HoursNumber of PersonsTask 3.253.251External inspection for doublers 14.7559.004External inspection for corrosion 14.7559.004External inspection for cracks 32.75121.25TOTAL 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 HoursTask HoursNumber of PersonsTask 1.501.501External 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 ALERTALERT ### Page 43 Group 2: Table 2 - Inspection Elapsed HoursTask HoursNumber of PersonsTask 10.5042.004External inspection for corrosion 10.5042.004External inspection for cracks 22.5085.50TOTAL 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 ALERTALERT ### Page 44 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 ALERTALERT ### Page 45 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 ALERTALERT ### Page 46 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 ALERTALERT BLANK PAGE ### Page 47 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 ALERTALERT ### Page 48 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 ALERTALERT ### Page 49 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 ALERTALERT ### Page 50 {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 ALERTALERT ### Page 51 (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 ALERTALERT ### Page 52 (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 ALERTALERT ### Page 53 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 ALERTALERT ### Page 54 (OCR) BOEING SERVICE BULLETIN 747-53A2861 ALERT ALERT This Figure applies only to: Group 1. STA STA 520 1000 S-19L - S-23L - S-34L — S-39L - S-45L J S-44L • BL-0 - STA INSPECTION AREA 760 ENTRY DOOR AND WINDOWS NOT INSTALLED ON ALL AFFECTED AIRPLANES FIGURE 1: INSPECTION AREA 1 (STA 741) (SHEET 1 OF 2) Original Issue: April 01, 2014 Export Controlled ECCN: 9E991 - BOEING 747-53A2861 PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 54 of 77 ### Page 55 (OCR) BOEING SERVICE BULLETIN 747-53A2861 ALERT ALERT STA SIA 741 STA 1000 520 S-19R S-23R — S-34R - S-39R TS45R • S-44R - BL-O STA STA • INSPECTION AREA 760 720 FWD ENTRY DOOR AND WINDOWS NOT INSTALLED ON ALL AFFECTED AIRPLANES 2255876 FIGURE 1: INSPECTION AREA 1 (STA 741) (SHEET 2 OF 2) Original Issue: April 01, 2014 Export Controlled ECCN: 9E991 - BOEING 747-53A2861 PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 55 of 77 ### Page 56 (OCR) BOEING SERVICE BULLETIN 747-53A2861 ALERT ALERT This Figure applies only to: Group 1. STA 1480 STA 1961 STA STA 1961 1480 7700 000 G00 • S-19L - S-23L 030000 CeCI • S-34L • S-40L • S-42L ~S-45L - S-46L 388 BLO - - BL O • INSPECTION AREA FWD STA STA 1720 1760 ENTRY DOOR AND WINDOWS NOT INSTALLED ON ALL AFFECTED AIRPLANES 2255902 FIGURE 2: INSPECTION AREA 2 (STA 1741) (SHEET 1 OF 2) Original Issue: April 01, 2014 Export Controlled ECCN: 9E991 - BOEING 747-53A2861 PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 56 of 77/ ### Page 57 (OCR) BOEING SERVICE BULLETIN 747-53A2861 ALERT ALERT STA STA STA 1961 1741 1480 S-19R - S-23R - 0000 S-34R S-40R S-42R 88 S-45R S-46R - 38% BL 0 - INSPECTION AREA STA STA 1760 1720 FWD ENTRY DOOR AND WINDOWS NOT INSTALLED ON ALL AFFECTED AIRPLANES FIGURE 2: INSPECTION AREA 2 (STA 1741) (SHEET 2 OF 2) Original Issue: April 01, 2014 Export Controlled ECCN: 9E991 - BOEING 747-53A2861 PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 57 of 77 ### Page 58 (OCR) BOEING SERVICE BULLETIN 747-53A2861 ALERT ALERT This Figure applies only to: Group 1. SIA 1741 SIA STA STA STA 1961 2181 2360 1741 0000 0000 S-19L - S-23L - 00000 000 000000 S-34L - S-40L - S-46L S-47L5 BL-0 - INSPECTION AREA STA FWD 1980 ENTRY DOORS, CARGO DOOR AND WINDOWS NOT INSTALLED ON ALL AFFECTED AIRPLANES FIGURE 3: INSPECTION AREA 3 (STA 1961) (SHEET 1 OF 2) Original Issue: April 01, 2014 Export Controlled ECCN: 9E991 - BOEING 747-53A2861 PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 58 of 77 ### Page 59 (OCR) BOEING SERVICE BULLETIN 747-53A2861 ALERT ALERT STA STA STA STA 2360 2181 1961 1741 000000 taken 00000 - S-34R — S-40R - S-46R \S-47R INSPECTION AREA - BLO STA 1980 FWD ENTRY DOORS AND WINDOWS NOT INSTALLED ON ALL AFFECTED AIRPLANES FIGURE 3: INSPECTION AREA 3 (STA 1961) (SHEET 2 OF 2) Original Issue: April 01, 2014 Export Controlled ECCN: 9E991 - BOEING 747-53A2861 PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 59 of 77 ### Page 60 (OCR) BOEING SERVICE BULLETIN 747-53A2861 ALERT ALERT This Figure applies only to: Group 1. STA 1961 B STA 2360 STA STA STA 1961 2181 2360 | 25 S-19L - S-23L - S-34L - S-401 T S-4/L • INSPECTION AREA BL-0 - STA 2200 STA 2160 FWD WINDOWS NOT INSTALLED ON ALL AFFECTED AIRPLANES FIGURE 4: INSPECTION AREA 4 (STA 2181) (SHEET 1 OF 2) Original Issue: April 01, 2014 Export Controlled ECCN: 9E991 - BOEING 747-53A2861 PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 60 of 77 The text continues at https://openairdocs.org/service-documents/boeing/747-53a2861/file/d8533779837c.md?from=61 --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain, except the copies of manufacturers’ service documents, which belong to their rights holders.