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Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 1 Commercial Airplanes 707 Service Bulletin ALERT Number: A3539 Original Issue: April 26, 2013 ATA System: 5330 SUBJECT: FUSELAGE - Fuselage Skin - Inspection of the Fuselage Skin for Scribe Lines 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 © 2013 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 Unpublished Work.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Issue: April 26, 2013 A3539 1 of 110 3.0 ### Page 2 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 2 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT BLANK PAGE ### Page 3 Table of Contents Summary ...................................................... 5 1. PLANNING INFORMATION ........................................ 9 A. Effectivity ................................................ 9 1. Airplanes ............................................. 9 2. Spares Affected ........................................ 1 3 B. Concurrent Requirements ...................................... 1 3 C. Reason ................................................ 1 3 D. Description .............................................. 1 4 E. Compliance .............................................. 1 6 F. Approval ............................................... 3 6 G. Manpower .............................................. 3 6 H. Weight and Balance Changes .................................... 3 8 I. Electrical Load Data ......................................... 3 9 J. References .............................................. 3 9 1. Existing Data: ......................................... 3 9 2. Data Supplied with this Service Bulletin: ........................... 3 9 3. Installation Drawings Used in the Preparation of this Service Bulletin: ........... 3 9 K. Publications Affected ........................................ 3 9 L. Interchangeability and Intermixability of Parts ........................... 3 9 M. Software Accomplishment Summary ................................ 3 9 2. MATERIAL INFORMATION ........................................ 4 1 A. Material - Price and Availability ................................... 4 1 B. Industry Support Information .................................... 4 1 C. Parts Necessary for Each Airplane ................................. 4 1 1. Kits/Parts: ........................................... 4 1 2. Parts and Materials Supplied by the Operator: ........................ 4 1 3. Parts Modified and Reidentified: ............................... 4 1 4. Parts Removed and Not Replaced: .............................. 4 1 D. Parts Necessary to Change Spares ................................. 4 2 E. Special Tooling - Price and Availability ............................... 4 2 F. Special Tooling Necessary to do this Service Bulletin ....................... 4 2 3. ACCOMPLISHMENT INSTRUCTIONS .................................. 4 3 A. GENERAL INFORMATION ..................................... 4 3 B. WORK INSTRUCTIONS ....................................... 4 5 FIGURE 1: FUSELAGE - SKIN LAP JOINTS - INSPECTION [Group 1] ................. 5 8 FIGURE 2: FUSELAGE - SKIN LAP JOINTS - INSPECTION [Group 2] ................. 6 2 FIGURE 3: FUSELAGE - SKIN LAP JOINTS - INSPECTION [Group 3] ................. 6 6 FIGURE 4: FUSELAGE - SKIN LAP JOINTS - INSPECTION [Group 4] ................. 7 0 FIGURE 5: FUSELAGE - EXTERNAL APPROVED REPAIRS - INSPECTION [Group 1] ........ 7 4 FIGURE 6: FUSELAGE - EXTERNAL APPROVED REPAIRS - INSPECTION [Group 2] ........ 7 7 FIGURE 7: FUSELAGE - EXTERNAL APPROVED REPAIRS - INSPECTION [Group 3] ........ 8 0 FIGURE 8: FUSELAGE - EXTERNAL APPROVED REPAIRS - INSPECTION [Group 4] ........ 8 3 FIGURE 9: FUSELAGE - EXTERNAL FEATURES - INSPECTION [Group 1-4] ............. 8 6 FIGURE 10: FUSELAGE - SKIN LAP JOINTS, EXTERNAL APPROVED REPAIRS, AND EXTERNAL FEATURES - NON-DESTRUCTIVE TESTING INSPECTIONS [Group 1-4] ........ 8 9 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 3 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 4 FIGURE 11: FUSELAGE - SKIN LAP JOINTS, EXTERNAL APPROVED REPAIRS, EXTERNAL FEATURES, SKIN BUTT JOINTS AND DECALS - INSPECTION [Group 5] ............... 9 1 Appendix A: SEALANT REMOVAL PROCEDURE FOR EXTERIOR PRESSURIZED FUSELAGE SKIN . 97 Appendix B: REPORTING TEMPLATE - AIRPLANES WITH SCRIBE LINES .............. 1 0 5 Appendix C: AIRPLANE FUSELAGE SCRIBE LINE MARK SUMMARY TABLES ............ 1 0 7 Appendix D: SCRIBE LINE SAMPLE .................................... 1 0 9 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 4 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 5 Commercial Airplanes 707 Service Bulletin ALERT SummaryNumber: A3539Original Issue: April 26, 2013 ATA System: 5330 SUBJECT: FUSELAGE - Fuselage Skin - Inspection of the Fuselage Skin for Scribe Lines THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH 1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OWNER. CONCURRENT REQUIREMENTS None. BACKGROUND This service bulletin gives instructions to inspect for scribe lines in the fuselage skin. Fatigue cracks can develop at scribe line locations. If this service bulletin is not done, any crack that remains undetected could grow large and cause a rapid decompression of the airplane. Although Boeing has not received reports of scribe line related cracks on 707 series airplanes, Boeing has received reports of scribe line related cracks on two 727 airplanes. One report was on a 727-100 airplane with 44,171 cycles. The crack was near a repair and caused rapid decompression of the airplane. Another report was on a 727-100 airplane with 51,195 cycles. The crack was at station 1090-1110, stringer 4L lap joint. This also resulted in rapid decompression of the airplane. A scribe line is a narrow, shallow, distinct line of damage (typically up to 0.006 inch deep), usually associated with the removal of a fillet or gap seal (skin lap joints and skin butt joints, respectively). A more detailed definition of a scribe line is included in Accomplishment Instructions Paragraph 3.B. - Identification of a "Typical" Scribe Line. A review of fleet activity yields two separate scenarios that are suspected to have caused scribe lines to the fuselage skin. The first scenario involves the paint stripping and repainting of airplanes. In the process of stripping and preparing the airplane for paint, tools were used to remove sealant and paint buildup at lap joints, at certain external approved repair doublers or door scuff plates, or around external features. Tools like scrapers (steel, wood, hard plastic, etc.), knives, or utility knives can damage the skin. Fatigue cracks can develop at scribe line locations. The second scenario is decal application on/or removal from the fuselage. To install the decals across lap joint steps or repairs, investigation into maintenance practices has shown that decals have been cut in place, using some form of knife, to allow the decal to lie flush to the skin at these stepped locations. This operation results in scribe lines at the decal cut location. Based on service reports, sharp tools have also been used for close trimming of decal outlines. This type of decal trimming also has left scribe lines on the fuselage skin. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 5 of 110 ### Page 6 Each of the above maintenance operations can lead to the same type of scribe line damage and subsequent premature fatigue cracks. Boeing Service Related Problem (SRP) 707-SRP-53-0247 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 Paragraph 1.I., Electrical Load DataNoElectrical Load Changed Paragraph 1.K., Publications AffectedYesPublications 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 YesOperator Supplied Parts/Material Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin YesSpecial Tooling Required ACTION Group 1-4: Prepare surface for inspection by removing paint and sealant at the applicable locations. Do a detailed inspection of the fuselage skin at skin lap joints, external approved repairs, and external features for any scribe line. If no scribe lines are found, no further inspections are required. If any scribe line is found, measure the depth of the scribe line. For scribe lines less than 0.001 inch deep, no repair or further inspections are required. For scribe lines greater than or equal to 0.001 inch deep, Non-Destructive Testing (NDT) inspections are required to check for cracks. If any crack is found, contact Boeing for repair instructions and do the repair. As an alternative to immediate repair, for a scribe line that qualifies, the provided Limited Return To Service (LRTS) program may be used to allow airplanes to return to revenue flight for a limited period before scribe lines are repaired. This service bulletin contains a LRTS program. NOTE: Further Boeing approval is not required to begin a LRTS program. The LRTS program consists of repeat inspections to detect any crack where scribe lines were found. Total airplane flight cycles, location, and the extent of the scribe line must meet specific criteria in order for a scribe line to qualify for a LRTS program. Inspections at each affected structural location within a LRTS program will be terminated with a repair. Since a scribe line can occur at any time during the service life of an airplane and at many locations, this program uses both total flight cycles and structural criticality of location to determine the inspection requirements. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 6 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 7 Criticality of location allows this service bulletin to address the most critical areas first and determines the inspection thresholds for each location. This service bulletin uses figures and compliance times to address all of the critical locations and their corresponding inspection thresholds. Each critical piece of structure susceptible to a scribe line is assigned to a figure. The affected structure for each group of airplanes is identified in individual figures in this service bulletin. Group 5: Prepare surface for inspection by removing paint and sealant at the applicable locations. Do a detailed inspection of the fuselage skin at all skin lap joints, external approved repairs, external features, skin butt joints, and decals for any scribe line. If no scribe lines are found, no further inspections are required. If any scribe line is found, measure the depth of the scribe line. For scribe lines less than 0.001 inch deep, no repair or further inspections are required. For scribe lines greater than or equal to 0.001 inch deep, contact Boeing for repair instructions and do the repair. NOTE: There is no LRTS program for Group 5 airplanes. EFFECTIVITY 707-100, 707-100B, 707-200, 707-300, 707-300B, 707-300C, 707-400, 720, 720B 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. INDUSTRY SUPPORT INFORMATION Boeing warranty remedies are not available for the inspections or repair procedures given in this service bulletin. MANPOWER Refer to Paragraph 1.G., Manpower. MATERIAL INFORMATION Operator Supplied Parts/Materials. Refer to Paragraph 2.A., Material - Price and Availability. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 7 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 8 (OCR) BOEING SERVICE BULLETIN A3539 ALERT ALERT GROUPS 1 THROUGH 4: DO A DETAILED INSPECTION OF THE FUSELAGE SKIN FOR SCRIBE LINES AT SKIN LAP JOINTS, EXTERNAL APPROVED REPAIRS, AND EXTERNAL FEATURES. IF A SCRIBE LINE GREATER THAN 0.001 INCH DEEP IS FOUND, DO A NON-DESTRUCTIVE TESTING (NDT) INSPECTION FOR ANY CRACK. GROUP 5: DO A DETAILED INSPECTION OF THE FUSELAGE SKIN FOR SCRIBE LINES AT SKIN LAP JOINTS, EXTERNAL APPROVED REPAIRS, EXTERNAL FEATURES, SKIN BUTT JOINTS, AND DECALS. IF A SCRIBE LINE GREATER THAN 0.001 INCH DEEP IS FOUND, CONTACT BOEING FOR REPAIR INSTRUCTIONS AND DO THE REPAIR. 2198859 Original Issue: April 26, 2013 PROPRIETARY - Copyright © Unpublished Export Controlled ECCN: 9E991 - BOEING A3539 Work - See page 1 for details. 8 of 110 ### Page 9 Commercial Airplanes 707 Service Bulletin ALERT Number: A3539 Original Issue: April 26, 2013 ATA System: 5330 SUBJECT: FUSELAGE - Fuselage Skin - Inspection of the Fuselage Skin for Scribe Lines THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH 1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OWNER. 1. PLANNING INFORMATION A. Effectivity 1. Airplanes Refer to Service Bulletin Index Document D6-1647 Part 3 for Airplane Variable Number, Line Number, and Serial Number data. This service bulletin is for the airplanes shown below. DESCRIPTIONCONFIGURATIONGROUP 707-100B Airplanes-1 707-300 Airplanes-2 707-300B Airplanes-3 707-300C Airplanes-4 707-100, 707-200, 707-400, 720, 720B Airplanes-5 Airplane Models: 707-100, 707-100B, 707-200, 707-300, 707-300B, 707-300C, 707-400, 720, 720B GroupVariable Number 5B0001 - B0029 5B0101 - B0125 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 9 of 110 ### Page 10 GroupVariable Number 5B0201 - B0203 5B0301 - B0306 5B0401 - B0402 5B0501 - B0515 5B2001 - B2008 5B2091 - B2092 5B2101 - B2116 5B2191 - B2194 5B2199 5B2201 - B2227 5B2401 - B2403 5B2501 - B2502 5B2551 - B2553 5B2601 - B2608 500001 - 00004 100005 - 00006 100101 - 00156 500201 - 00205 500301 - 00305 500401 - 00415 100416 - 00451 100471 - 00475 100501 - 00513 500601 - 00602 100701 - 00703 202001 - 02020 202101 - 02121 202201 - 02207 202301 - 02303 202401 - 02418 504001 - 04005 504020 - 04022 504101 - 04106 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 10 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 11 GroupVariable Number 504201 - 04218 504271 - 04272 504301 - 04303 305001 - 05060 305101 - 05138 305201 - 05208 305301 - 05312 305401 305601 - 05605 305631 - 05635 305701 - 05703 305801 - 05802 305821 - 05827 305831 - 05833 305851 - 05854 305891 - 05892 305921 - 05923 305941 - 05942 305961 - 05970 306001 - 06002 306101 306401 - 06404 306451 306461 407001 - 07017 407041 - 07059 407071 - 07081 407101 - 07109 407181 407191 407201 - 07215 407251 - 07271 407401 - 07407 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 11 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 12 GroupVariable Number 407451 - 07458 407501 - 07504 407601 - 07626 407661 - 07662 407681 - 07684 407701 - 07702 407801 - 07821 407901 - 07907 408001 - 08008 408021 408051 - 08056 408071 - 08077 408101 - 08104 408121 - 08129 408141 - 08144 408151 - 08153 408171 - 08173 408191 - 08192 408201 - 08210 408221 - 08224 408241 - 08244 408251 408261 408271 408301 - 08320 408324 - 08330 408333 408401 - 08410 408451 - 08452 408471 - 08475 408501 - 08502 408551 - 08553 408581 - 08582 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 12 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 13 GroupVariable Number 409001 - 09006 409101 - 09107 409161 - 09167 409201 - 09204 409221 - 09223 409227 409231 - 09232 409251 409271 409281 409286 - 09290 409411 409421 409438 409441 2. Spares Affected None. B. Concurrent Requirements None. C. Reason This service bulletin gives instructions to inspect for scribe lines in the fuselage skin. Fatigue cracks can develop at scribe line locations. If this service bulletin is not done, any crack that remains undetected could grow large and cause a rapid decompression of the airplane. Although Boeing has not received reports of scribe line related cracks on 707 series airplanes, Boeing has received reports of scribe line related cracks on two 727 airplanes. One report was on a 727-100 airplane with 44,171 cycles. The crack was near a repair and caused rapid decompression of the airplane. Another report was on a 727-100 airplane with 51,195 cycles. The crack was at station 1090-1110, stringer 4L lap joint. This also resulted in rapid decompression of the airplane. A scribe line is a narrow, shallow, distinct line of damage (typically up to 0.006 inch deep), usually associated with the removal of a fillet or gap seal (skin lap joints and skin butt joints, respectively). A more detailed definition of a scribe line is included in Accomplishment Instructions Paragraph 3.B. - Identification of a "Typical" Scribe Line. A review of fleet activity yields two separate scenarios that are suspected to have caused scribe lines to the fuselage skin. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 13 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 14 The first scenario involves the paint stripping and repainting of airplanes. In the process of stripping and preparing the airplane for paint, tools were used to remove sealant and paint buildup at lap joints, at certain external approved repair doublers or door scuff plates, or around external features. Tools like scrapers (steel, wood, hard plastic, etc.), knives, or utility knives can damage the skin. Fatigue cracks can develop at scribe line locations. The second scenario is decal application on/or removal from the fuselage. To install the decals across lap joint steps or repairs, investigation into maintenance practices has shown that decals have been cut in place, using some form of knife, to allow the decal to lie flush to the skin at these stepped locations. This operation results in scribe lines at the decal cut location. Based on service reports, sharp tools have also been used for close trimming of decal outlines. This type of decal trimming also has left scribe lines on the fuselage skin. Each of the above maintenance operations can lead to the same type of scribe line damage and subsequent premature fatigue cracks. Boeing Service Related Problem (SRP) 707-SRP-53-0247 is related to this service bulletin. D. Description Group 1-4: Prepare surface for inspection by removing paint and sealant at the applicable locations. Do a detailed inspection of the fuselage skin at skin lap joints, external approved repairs, and external features for any scribe line. If no scribe lines are found, no further inspections are required. If any scribe line is found, measure the depth of the scribe line. For scribe lines less than 0.001 inch deep, no repair or further inspections are required. For scribe lines greater than or equal to 0.001 inch deep, Non-Destructive Testing (NDT) inspections are required to check for cracks. If any crack is found, contact Boeing for repair instructions and do the repair. As an alternative to immediate repair, for a scribe line that qualifies, the provided Limited Return To Service (LRTS) program may be used to allow airplanes to return to revenue flight for a limited period before scribe lines are repaired. This service bulletin contains a LRTS program. NOTE: Further Boeing approval is not required to begin a LRTS program. The LRTS program consists of repeat inspections to detect any crack where scribe lines were found. Total airplane flight cycles, location, and the extent of the scribe line must meet specific criteria in order for a scribe line to qualify for a LRTS program. Inspections at each affected structural location within a LRTS program will be terminated with a repair. Since a scribe line can occur at any time during the service life of an airplane and at many locations, this program uses both total flight cycles and structural criticality of location to determine the inspection requirements. Criticality of location allows this service bulletin to address the most critical areas first and determines the inspection thresholds for each location. This service bulletin uses figures and compliance times to address all of the critical locations and their corresponding inspection thresholds. Each critical piece of structure susceptible to a scribe line is assigned to a figure. The affected structure for each group of airplanes is identified in individual figures in this service bulletin. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 14 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 15 Group 5: Prepare surface for inspection by removing paint and sealant at the applicable locations. Do a detailed inspection of the fuselage skin at all skin lap joints, external approved repairs, external features, skin butt joints, and decals for any scribe line. If no scribe lines are found, no further inspections are required. If any scribe line is found, measure the depth of the scribe line. For scribe lines less than 0.001 inch deep, no repair or further inspections are required. For scribe lines greater than or equal to 0.001 inch deep, contact Boeing for repair instructions and do the repair. NOTE: There is no LRTS program for Group 5 airplanes. The work in this service bulletin is done in the maintenance zone(s) given below. Group 1: Affected Maintenance Zones ZoneModel 1-11, 1-12, 1-13, 1-14, 1-15, 1-16, 2-26707-100B Group 2: Affected Maintenance Zones ZoneModel 1-11, 1-12, 1-13, 1-14, 1-15, 1-16, 2-26707-300 Group 3: Affected Maintenance Zones ZoneModel 1-11, 1-12, 1-13, 1-14, 1-15, 1-16, 2-26707-300B Group 4: Affected Maintenance Zones ZoneModel 1-11, 1-12, 1-13, 1-14, 1-15, 1-16, 2-26707-300C Group 5: Affected Maintenance Zones ZoneModel 1-11, 1-12, 1-13, 1-14, 1-15, 1-16, 2-26707-100, 707-200, 707-400, 720, 720B Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 15 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 16 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. Inspection Exemptions: Certain inspections are not required under these conditions: – Skin Lap Joints: Inspections are not required in skin lap joint areas where an existing external approved repair covers a potential scribe line, provided the repair spans a minimum of three fastener rows above and three fastener rows below the potential scribe line location. External repairs that do not meet this requirement must be removed to allow skin lap joint inspection. – If operator's records show that the airplane has never been stripped or repainted since delivery from Boeing, then the skin lap joint and external approved repair scribe line inspections are not required, except as noted below: – If a decal is installed, or was previously installed, across an area that requires inspection, the inspection exemption does not apply. The skin lap joint and external approved repair inspection must still be done for the affected area at the compliance time in accordance with this service bulletin. Group 1-4: The inspection compliance time is based upon analysis of fuselage geometry and loads. Group 1-4 airplanes have three (3) areas for scribe line inspections. The areas are as follows: — Skin Lap Joints — External Approved Repairs — External Features Boeing recommends that operators do inspections for scribe lines at the times given in the Compliance tables. The Compliance tables are broken down as follows: 1. Table 1 shows the initial scribe line inspection for the three (3) areas to be inspected. 2. Tables 2 through 7 show the Limited Return To Service (LRTS) repeat inspection intervals for the three (3) areas to be inspected. LRTS inspections are not an option for airplanes with more than 20,000 total flight cycles. 3. Table 8 shows how to disposition known existing scribe line damage outside of the service bulletin inspection areas. Group 5: Group 5 airplanes have five (5) areas for scribe line inspections. The areas are as follows: — Skin Lap Joints — External Approved Repairs — External Features — Skin Butt Joints — Decals Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 16 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 17 Boeing recommends that operators do inspections for scribe lines at the times given in the Compliance table. The Compliance table is broken down as follows: 1. Table 9 shows the initial scribe line inspection for the five (5) areas to be inspected. NOTE: There is no LRTS program for Group 5 airplanes. Group 1-4: Table 1 : Scribe Line Inspection on Fuselage Skin at Skin Lap Joints, External Approved Repairs, and External Features - Initial Inspection Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Within 12 months after the origi- nal issue date of this service bulletin. Do surface preparations for scribe line inspections in accor- dance with Accomplishment In- structions Paragraph 3.B.3 - Part 1. Airplanes with more than 15,000 total flight cycles as of the original issue date of this service bul- letin. And Do detailed inspections of the applicable skin lap joints, exter- nal approved repairs, and exter- nal features for any scribe line using the tables in accordance with Accomplishment Instruc- tions Paragraph 3.B.4 - Part 2. -Before 15,000 total flight cycles or within 24 months after the original issue date of this ser- vice bulletin, whichever occurs later. Do surface preparations for scribe line inspections in accor- dance with Accomplishment In- structions Paragraph 3.B.3 - Part 1. Airplanes with 15,000 total flight cycles or less as of the original issue date of this service bul- letin. And Do detailed inspections of the applicable skin lap joints, exter- nal approved repairs, and exter- nal features for any scribe line using the tables in accordance with Accomplishment Instruc- tions Paragraph 3.B.4 - Part 2. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 17 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 18 Group 1-4: Table 1 : Scribe Line Inspection on Fuselage Skin at Skin Lap Joints, External Approved Repairs, and External Features - Initial Inspection Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before further flight.No further inspections are re- quired in accordance with Ac- complishment Instructions Paragraph 3.B.5 - Part 3. No scribe line is found. And Do surface finish restoration in accordance with Accomplish- ment Instructions Paragraph 3.B.9 - Part 7. -Before further flight.Measure the scribe line depth in accordance with Accomplish- ment Instructions Paragraph 3.B.6 - Part 4. Any scribe line is found. -Before further flight.No repair or further inspections are required in accordance with Accomplishment Instructions Paragraph 3.B.6 - Part 4. Scribe line is found less than 0.001 inch deep. And Do surface finish restoration in accordance with Accomplish- ment Instructions Paragraph 3.B.9 - Part 7. -Before further flight.Do the applicable Non-Destruc- tive Testing (NDT) inspection for any crack in accordance with Accomplishment Instructions Paragraph 3.B.7 - Part 5. Scribe line is greater than or equal to 0.001 inch deep And Do surface finish restoration in accordance with Accomplish- ment Instructions Paragraph 3.B.9 - Part 7. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 18 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 19 Group 1-4: Table 1 : Scribe Line Inspection on Fuselage Skin at Skin Lap Joints, External Approved Repairs, and External Features - Initial Inspection Repeat Interval (Not to Exceed) Compliance TimeActionCondition Refer to the LRTS Tables 2 to 7 for repeat intervals. Before LRTS repeat intervals in Tables 2 to 7. Do the LRTS repeat inspection program in accordance with Ac- complishment Instructions Paragraph 3.B.8 - Part 6. If no crack is found and the scribe line is greater than or equal to 0.001 inch deep and less than or equal to 0.006 inch deep. And -Before further flight.Do surface finish restoration in accordance with Accomplish- ment Instructions Paragraph 3.B.9 - Part 7. Or -Before further flight.Document and propose a repair to Boeing in accordance with Accomplishment Instructions Paragraph 3.B.7 - Part 5. Do the repair. And Do surface finish restoration in accordance with Accomplish- ment Instructions Paragraph 3.B.9 - Part 7. -Before further flight.Document and propose a repair to Boeing in accordance with Accomplishment Instructions Paragraph 3.B.7 - Part 5. Do the repair. If no crack is found and the scribe line is greater than 0.006 inch deep. And Do surface finish restoration in accordance with Accomplish- ment Instructions Paragraph 3.B.9 - Part 7. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 19 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 20 Group 1-4: Table 1 : Scribe Line Inspection on Fuselage Skin at Skin Lap Joints, External Approved Repairs, and External Features - Initial Inspection Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before further flight.Document and propose a repair to Boeing in accordance with Accomplishment Instructions Paragraph 3.B.7 - Part 5. Do the repair. If any crack is found. And Do surface finish restoration in accordance with Accomplish- ment Instructions Paragraph 3.B.9 - Part 7. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 20 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 21 Group 1: Table 2 - Scribe Line Inspections on Fuselage Skin at Skin Lap Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition Do Part 1 - Surface Preparation, Part 2 - Detailed Inspection, and the applicable Non- Destructive Testing (NDT) inspection in ac- cordance with Accomplishment Instructions Paragraph 3.B.8 - Part 6 for the skin lap joint areas that follow: Airplanes with scribe lines using a Limited Re- turn To Service (LRTS) Program Skin Lap Joints LRTS inspections are not an option for airplanes with more than 20,000 total flight cycles. Flight CyclesStation Location From - To Stringer Location 1,100-STA NLG - 481S-30R 800-STA 960 - 1124.10S-29R 1,400-STA 1124.10 - 1265.20 1,700-STA 312 - 360S-25R 2,100-STA 360 - 481 2,200-STA 1364.10- 1440S-24R 1,400-STA 259.50 - 360S-20R 1,400-STA 360 - Door Cutout 1,400-STA 580 - 600K 1,200-STA 960 - Door Cutout 1,200-Door Cutout - STA 1164.10 2,900-STA 1164.10 - Door Cutout 2,900-Door Cutout - STA 1265.20 2,000-STA 360 - Door CutoutS-14R 2,000-Door Cutout - STA 481 3,000-STA 1124.10 - 1164.10 2,000-STA 1241 - Door Cutout 2,400-Door Cutout - STA 1364.10 1,800-STA 1241 - 1384.10S-10R 1,900-STA 441 - 580S-6R 3,000-STA 441 - 481S-6L 2,000-STA 360 - 481S-14L 2,000-STA 1220 - Door Cutout 1,400-STA 259.50 - 360S-20L Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 21 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 22 Group 1: Table 2 - Scribe Line Inspections on Fuselage Skin at Skin Lap Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition STA 360 - 600 1,400 - 1,300-STA 960 - 1164.10 2,900-STA 1164.10 - 1265.20 1,700-STA 312 - 360S-25L 2,000-STA 441 - 481 800-STA 960 - 1124.10S-29L 1,400-STA 1124.10- 1265.20 -Before further flight. Document and propose a repair to Boeing in accordance with Accomplishment Instruc- tions Paragraph 3.B.8 - Part 6. Do the repair. If no crack is found. And -Before further flight. Do surface finish restoration in accordance with Accomplishment Instructions Paragraph 3.B.9 - Part 7. Or Repeat at inter- vals defined above in this ta- ble. -Repeat the LRTS program in accordance with this service bulletin. And -Before further flight. Do surface finish restoration in accordance with Accomplishment Instructions Paragraph 3.B.9 - Part 7. -Before further flight. Document and propose a repair to Boeing in accordance with Accomplishment Instruc- tions Paragraph 3.B.8 - Part 6. Do the repair. If any crack is found. And -Before further flight. Do surface finish restoration in accordance with Accomplishment Instructions Paragraph 3.B.9 - Part 7. -Before 20,000 to- tal flight cycles. Contact Boeing for additional inspections or repair in accordance with Accomplishment Instructions Paragraph 3.B.8 - Part 6. Do the additional inspections or repair. Airplanes with scribe lines using a LRTS Pro- gram Inspection. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 22 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 23 Group 2: Table 3 - Scribe Line Inspections on Fuselage Skin at Skin Lap Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition Do Part 1 - Surface Preparation, Part 2 - Detailed Inspection, and the applicable Non- Destructive Testing (NDT) inspection in ac- cordance with Accomplishment Instructions Paragraph 3.B.8 - Part 6 for the skin lap joint areas that follow: Airplanes with scribe lines using a Limited Re- turn To Service (LRTS) Program Skin Lap Joints LRTS inspections are not an option for airplanes with more than 20,000 total flight cycles. Flight CyclesStation Location From - To Stringer Location 1,100-STA NLG - 481S-30R 800-STA 960 - 1124.10S-29R 1,400-STA 1124.10 - 1265.20 1,700-STA 312 - 360S-25R 2,100-STA 360 - 481 2,200-STA 1364.10 - 1440S-24R 1,400-STA 259.50 - 360S-20R 1,400-STA 360 - Door Cutout 1,400-STA 580 - 600K 1,200-STA 960 - Door Cutout 1,200-Door Cutout - STA 1164.10 2,900-STA 1164.10 - Door Cutout 2,900-Door Cutout - STA 1265.20 2,000-STA 360 - Door CutoutS-14R 2,000-Door Cutout - STA 481 3,000-STA 1124.10 - 1164.10 2,000-STA 1241 - Door Cutout 2,400-Door Cutout - STA 1364.10 1,800-STA 1241 - 1384.10S-10R 1,900-STA 441 - 580S-6R 3,000-STA 441 - 481S-6L 2,000-STA 360 - 481S-14L 2,000-STA 1220 - Door Cutout 1,400-STA 259.50 - 360S-20L Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 23 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 24 Group 2: Table 3 - Scribe Line Inspections on Fuselage Skin at Skin Lap Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition STA 360 - 441 1,400 - 2,000-STA 441 - 600H 1,300-STA 960 - 1164.10 2,900-STA 1164.10 - 1265.20 1,700-STA 312 - 360S-25L 2,000-STA 441 - 481 800-STA 960 - 1124.10S-29L 1,400-STA 1124.10- 1265.20 -Before further flight. Document and propose a repair to Boeing in accordance with Accomplishment Instruc- tions Paragraph 3.B.8 - Part 6. Do the repair. If no crack is found. And -Before further flight. Do surface finish restoration in accordance with Accomplishment Instructions Paragraph 3.B.9 - Part 7. Or Repeat at inter- vals defined above in this ta- ble. -Repeat the LRTS program in accordance with this service bulletin. And -Before further flight. Do surface finish restoration in accordance with Accomplishment Instructions Paragraph 3.B.9 - Part 7. -Before further flight. Document and propose a repair to Boeing in accordance with Accomplishment Instruc- tions Paragraph 3.B.8 - Part 6. Do the repair. If any crack is found. And -Before further flight. Do surface finish restoration in accordance with Accomplishment Instructions Paragraph 3.B.9 - Part 7. -Before 20,000 to- tal flight cycles. Contact Boeing for additional inspections or repair in accordance with Accomplishment Instructions Paragraph 3.B.8 - Part 6. Do the additional inspections or repair. Airplanes with scribe lines using a LRTS Pro- gram Inspection. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 24 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 25 Group 3: Table 4 - Scribe Line Inspections on Fuselage Skin at Skin Lap Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition Do Part 1 - Surface Preparation, Part 2 - Detailed Inspection, and the applicable Non- Destructive Testing (NDT) inspection in ac- cordance with Accomplishment Instructions Paragraph 3.B.8 - Part 6 for the skin lap joint areas that follow: Airplanes with scribe lines using a Limited Re- turn To Service (LRTS) Program Skin Lap Joints LRTS inspections are not an option for airplanes with more than 20,000 total flight cycles. Flight CyclesStation Location From - To Stringer Location 1,100-STA NLG - 481S-30R 800-STA 960 - 1124.10S-29R 1,400-STA 1124.10 - 1265.20 1,700-STA 312 - 360S-25R 2,100-STA 360 - 481 2,200-STA 1364.10 - 1440S-24R 1,400-STA 259.50 - 360S-20R 1,400-STA 360 - Door Cutout 1,400-STA 580 - 600K 1,200-STA 960 - Door Cutout 1,200-Door Cutout - STA 1164.10 2,900-STA 1164.10 - Door Cutout 2,900-Door Cutout - STA 1265.20 2,000-STA 360 - Door CutoutS-14R 2,000-Door Cutout - STA 481 3,000-STA 1124.10 - 1164.10 2,000-STA 1241 - Door Cutout 2,400-Door Cutout - STA 1364.10 1,800-STA 1241 - 1384.10S-10R 1,900-STA 441 - 580S-6R 3,000-STA 441 - 481S-6L 2,000-STA 360 - 481S-14L 2,000-STA 1220 - Door Cutout 1,400-STA 259.50 - 360S-20L Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 25 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 26 Group 3: Table 4 - Scribe Line Inspections on Fuselage Skin at Skin Lap Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition STA 360 - 441 1,400 - 2,000-STA 441 - 600H 1,300-STA 960 - 1164.10 2,900-STA 1164.10 - 1265.20 1,700-STA 312 - 360S-25L 2,000-STA 441 - 481 800-STA 960 - 1124.10S-29L 1,400-STA 1124.10 - 1265.20 -Before further flight. Document and propose a repair to Boeing in accordance with Accomplishment Instruc- tions Paragraph 3.B.8 - Part 6. Do the repair. If no crack is found. And -Before further flight. Do surface finish restoration in accordance with Accomplishment Instructions Paragraph 3.B.9 - Part 7. Or Repeat at inter- vals defined above in this ta- ble. -Repeat the LRTS program in accordance with this service bulletin. And -Before further flight. Do surface finish restoration in accordance with Accomplishment Instructions Paragraph 3.B.9 - Part 7. -Before further flight. Document and propose a repair to Boeing in accordance with Accomplishment Instruc- tions Paragraph 3.B.8 - Part 6. Do the repair. If any crack is found. And -Before further flight. Do surface finish restoration in accordance with Accomplishment Instructions Paragraph 3.B.9 - Part 7. -Before 20,000 to- tal flight cycles. Contact Boeing for additional inspections or repair in accordance with Accomplishment Instructions Paragraph 3.B.8 - Part 6. Do the additional inspections or repair. Airplanes with scribe lines using a LRTS Pro- gram Inspection. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 26 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 27 Group 4: Table 5 - Scribe Line Inspections on Fuselage Skin at Skin Lap Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition Do Part 1 - Surface Preparation, Part 2 - Detailed Inspection, and the applicable Non- Destructive Testing (NDT) inspection in ac- cordance with Accomplishment Instructions Paragraph 3.B.8 - Part 6 for the skin lap joint areas that follow: Airplanes with scribe lines using a Limited Re- turn To Service (LRTS) Program Skin Lap Joints LRTS inspections are not an option for airplanes with more than 20,000 total flight cycles. Flight CyclesStation Location From - To Stringer Location 1,100-STA NLG - 481S-30R 800-STA 960 - 1124.10S-29R 1,400-STA 1124.10 - 1265.20 1,700-STA 312 - 360S-25R 2,100-STA 360 - 481 2,200-STA 1364.10 - 1440S-24R 1,400-STA 259.50 - 360S-20R 1,400-STA 360 - Door Cutout 1,400-STA 580 - 600K 1,200-STA 960 - Door Cutout 1,200-Door Cutout - STA 1164.10 2,900-STA 1164.10 - Door Cutout 2,900-Door Cutout - STA 1265.20 2,000-STA 360 - Door CutoutS-14R 2,000-Door Cutout - STA 481 3,000-STA 1124.10 - 1164.10 2,000-STA 1241 - Door Cutout 2,400-Door Cutout - STA 1364.10 1,800-STA 1241 - 1384.10S-10R 1,900-STA 441 - 580S-6R 3,000-STA 441 - Door CutoutS-6L 2,000-STA 360 - Door CutoutS-14L 2,000-STA 1220 - Door Cutout 1,400-STA 259.50 - 360S-20L Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 27 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 28 Group 4: Table 5 - Scribe Line Inspections on Fuselage Skin at Skin Lap Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition STA 360 - 441 1,400 - 2,000-STA 600E - 600H 1,300-STA 960 - 1164.10 2,900-STA 1164.10 - 1265.20 1,700-STA 312 - 360S-25L 2,000-STA 441 - 481 800-STA 960 - 1144.10S-29L 1,400-STA 1144.10 - 1265.20 -Before further flight. Document and propose a repair to Boeing in accordance with Accomplishment Instruc- tions Paragraph 3.B.8 - Part 6. Do the repair. If no crack is found. And -Before further flight. Do surface finish restoration in accordance with Accomplishment Instructions Paragraph 3.B.9 - Part 7. Or Repeat at inter- vals defined above in this ta- ble. -Repeat the LRTS program in accordance with this service bulletin. And -Before further flight. Do surface finish restoration in accordance with Accomplishment Instructions Paragraph 3.B.9 - Part 7. -Before further flight. Document and propose a repair to Boeing in accordance with Accomplishment Instruc- tions Paragraph 3.B.8 - Part 6. Do the repair. If any crack is found. And -Before further flight. Do surface finish restoration in accordance with Accomplishment Instructions Paragraph 3.B.9 - Part 7. -Before 20,000 to- tal flight cycles. Contact Boeing for additional inspections or repair in accordance with Accomplishment Instructions Paragraph 3.B.8 - Part 6. Do the additional inspections or repair. Airplanes with scribe lines using a LRTS Pro- gram Inspection. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 28 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 29 Group 1-4: Table 6 - Scribe Line Inspections on Fuselage Skin at External Approved Repairs - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition Do Part 1 - Surface Preparation, Part 2 - De- tailed Inspection, and the applicable Non- Destructive Testing (NDT) inspection in accor- dance with Accomplishment Instructions Paragraph 3.B.8 - Part 6 for the External Ap- proved Repair areas that follow: Airplanes with scribe lines using a Limited Re- turn To Service (LRTS) Program External Approved Re- pairs LRTS inspections are not an option for airplanes with more than 20,000 total flight cycles. Flight CyclesStringer Location From - To Station Location From - To 1,200-S30R - S30LSTA 259.50 - STA 1440 External Approved Re- pairs - 20 inches or longer on any side. 1,500-S30R - S30LSTA 259.50 - STA 1440 External Approved Re- pairs - Less than 20 inches on any side. -Before further flight. Document and propose a repair to Boeing in accordance with Accomplishment Instructions Paragraph 3.B.8 - Part 6. Do the repair. If no crack is found. And -Before further flight. Do surface finish restoration in accordance with Accomplishment Instructions Paragraph 3.B.9 - Part 7. Or Repeat at inter- vals defined above in this ta- ble. -Repeat the LRTS program in accordance with this service bulletin. And -Before further flight. Do surface finish restoration in accordance with Accomplishment Instructions Paragraph 3.B.9 - Part 7. -Before further flight. Document and propose a repair to Boeing in accordance with Accomplishment Instructions Paragraph 3.B.8 - Part 6. Do the repair. If any crack is found. And -Before further flight. Do surface finish restoration in accordance with Accomplishment Instructions Paragraph 3.B.9 - Part 7. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 29 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 30 Group 1-4: Table 6 - Scribe Line Inspections on Fuselage Skin at External Approved Repairs - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before 20,000 to- tal flight cycles. Contact Boeing for additional inspections or repair in accordance with Accomplishment Instructions Paragraph 3.B.8 - Part 6. Do the additional inspections or repair. Airplanes with scribe lines using a LRTS Pro- gram Inspection. Group 1-4: Table 7 - Scribe Line Inspections on Fuselage Skin at External Features - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance Time ActionCondition Do Part 1 - Surface Preparation, Part 2 - Detailed In- spection, and the applicable Non-Destructive Testing (NDT) inspection in accordance with Accomplishment Instructions Paragraph 3.B.8 - Part 6 for the External Feature areas that follow: Airplanes with scribe lines using a Limited Return To Service (LRTS) Program External Features LRTS inspections are not an option for air- planes with more than 20,000 total flight cy- cles. Flight CyclesExternal FeatureStation Loca- tion Stringer Location 2,500-Air Traffic Control/ L- Band Antenna STA 294.50 to 312.00 S-25L To S- 25R 1,750-Antenna - Low Range Radio Altime- ter STA 1010S-30L To S- 30R 1,750-Antenna - Low Range Radio Altime- ter STA 1029S-30L To S- 30R 1,750-Antenna - Low Range Radio Altime- ter STA 1050S-30L To S- 30R 1,750-Antenna - Low Range Radio Altime- ter STA 1069S-30L To S- 30R Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 30 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 31 Group 1-4: Table 7 - Scribe Line Inspections on Fuselage Skin at External Features - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance Time ActionCondition -Before further flight. Document and propose a repair to Boeing in accor- dance with Accomplishment Instructions Paragraph 3.B.8 - Part 6. Do the repair. If no crack is found. And -Before further flight. Do surface finish restoration in accordance with Accom- plishment Instructions Paragraph 3.B.9 - Part 7. Or Repeat at inter- vals defined above in this ta- ble. -Repeat the LRTS program in accordance with this service bulletin. And -Before further flight. Do surface finish restoration in accordance with Accom- plishment Instructions Paragraph 3.B.9 - Part 7. -Before further flight. Document and propose a repair to Boeing in accor- dance with Accomplishment Instructions Paragraph 3.B.8 - Part 6. Do the repair. If any crack is found. And -Before further flight. Do surface finish restoration in accordance with Accom- plishment Instructions Paragraph 3.B.9 - Part 7. -Before 20,000 total flight cycles. Contact Boeing for additional inspections or repair in accordance with Accomplishment Instructions Para- graph 3.B.8 - Part 6. Do the additional inspections or repair. Airplanes with scribe lines using a LRTS Program Inspection. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 31 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 32 Group 1-4: Table 8: Known Existing Scribe Line Damage - Inspection for Scribe Lines Outside of Service Bulletin Inspection Areas Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before 20,000 total flight cycles.Do surface preparations in ac- cordance with Accomplishment Instructions Paragraph 3.B.3 - Part 1. Airplanes with known existing scribe line dam- age outside of this Ser- vice Bulletin Inspection areas. And Measure the scribe line depth in accordance with Accomplish- ment Instructions Paragraph 3.B.10 - Part 8 for the fuselage areas that follow: Skin Lap Joints External Approved Repairs External Features (Antennas, Lights, Beacons) Skin Butt Joints Decals and Fairings -Before further flight.No repair or further inspections are required in accordance with Accomplishment Instructions Paragraph 3.B.10 - Part 8. Scribe line is found less than 0.001 inch deep. And Do surface finish restoration in accordance with Accomplish- ment Instructions Paragraph 3.B.9 - Part 7. -Before further flight.Do the applicable Non-Destruc- tive Testing (NDT) inspection for any crack in accordance with Accomplishment Instructions Paragraph 3.B.10 - Part 8. Scribe line is greater than or equal to 0.001 inch deep And Do surface finish restoration in accordance with Accomplish- ment Instructions Paragraph 3.B.9 - Part 7. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 32 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 33 Group 1-4: Table 8: Known Existing Scribe Line Damage - Inspection for Scribe Lines Outside of Service Bulletin Inspection Areas Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before further flight.No repair or further inspections are required in accordance with Accomplishment Instructions Paragraph 3.B.10 - Part 8. If no crack is found and the scribe line is greater than or equal to 0.001 inch deep and less than or equal to 0.004 inch deep. And -Before further flight.Do surface finish restoration in accordance with Accomplish- ment Instructions Paragraph 3.B.9 - Part 7. -Before 20,000 total flight cycles.Contact Boeing for additional inspections or repair in accor- dance with Accomplishment In- structions Paragraph 3.B.10 - Part 8. Do the additional inspec- tions or repair. If no crack is found and the scribe line is greater than 0.004 inch deep and less than or equal to 0.006 inch deep. And -Before further flight.Do surface finish restoration in accordance with Accomplish- ment Instructions Paragraph 3.B.9 - Part 7. -Before further flight.Document and propose a repair to Boeing in accordance with Accomplishment Instructions Paragraph 3.B.10 - Part 8. Do the repair. If no crack is found and the scribe line is greater than 0.006 inch deep. And Do surface finish restoration in accordance with Accomplish- ment Instructions Paragraph 3.B.9 - Part 7. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 33 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 34 Group 1-4: Table 8: Known Existing Scribe Line Damage - Inspection for Scribe Lines Outside of Service Bulletin Inspection Areas Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before further flight.Document and propose a repair to Boeing in accordance with Accomplishment Instructions Paragraph 3.B.10 - Part 8. Do the repair. If any crack is found. And Contact Boeing for additional inspections in accordance with Accomplishment Instructions Paragraph 3.B.10 - Part 8. Do the additional inspections. And Do surface finish restoration in accordance with Accomplish- ment Instructions Paragraph 3.B.9 - Part 7. Group 5: Table 9 : Scribe Line Inspection on Fuselage Skin at Skin Lap Joints, External Approved Repairs, External Features, Skin Butt Joints, and Decals - Initial Inspection Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Within 12 months after the origi- nal issue date of this service bulletin. Do surface preparations for scribe line inspections in accor- dance with Accomplishment In- structions Paragraph 3.B.3 - Part 1. Airplanes with more than 15,000 total flight cycles as of the original issue date of this service bul- letin. And Do detailed inspections of all skin lap joints, external ap- proved repairs, external fea- tures, skin butt joints, and de- cals for any scribe line using the table in accordance with Accom- plishment Instructions Para- graph 3.B.4 - Part 2. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 34 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 35 Group 5: Table 9 : Scribe Line Inspection on Fuselage Skin at Skin Lap Joints, External Approved Repairs, External Features, Skin Butt Joints, and Decals - Initial Inspection Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Within 24 months after the origi- nal issue date of this service bulletin or before 15,000 total flight cycles, whichever occurs later. Do surface preparations for scribe line inspections in accor- dance with Accomplishment In- structions Paragraph 3.B.3 - Part 1. Airplanes with 15,000 total flight cycles or less as of the original issue date of this service bul- letin. And Do detailed inspections of all skin lap joints, external ap- proved repairs, external fea- tures, skin butt joints, and de- cals for any scribe line using the table in accordance with Accom- plishment Instructions Para- graph 3.B.4 - Part 2. -Before further flight.No further inspections are re- quired in accordance with Ac- complishment Instructions Paragraph 3.B.5 - Part 3. No scribe line is found. And Do surface finish restoration in accordance with Accomplish- ment Instructions Paragraph 3.B.9 - Part 7. -Before further flight.Measure the scribe line depth in accordance with Accomplish- ment Instructions Paragraph 3.B.6 - Part 4. Any scribe line is found. -Before further flight.No repair or further inspections are required in accordance with Accomplishment Instructions Paragraph 3.B.6 - Part 4. Scribe line is found less than 0.001 inch deep. And Do surface finish restoration in accordance with Accomplish- ment Instructions Paragraph 3.B.9 - Part 7. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 35 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 36 Group 5: Table 9 : Scribe Line Inspection on Fuselage Skin at Skin Lap Joints, External Approved Repairs, External Features, Skin Butt Joints, and Decals - Initial Inspection Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before further flight.Contact Boeing for repair instruc- tions and do the repair in accor- dance with Accomplishment In- structions Paragraph 3.B.6 - Part 4. Scribe line is greater than or equal to 0.001 inch deep And Do surface finish restoration in accordance with Accomplish- ment Instructions Paragraph 3.B.9 - Part 7. F. Approval 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. 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 examine the work — Time to cure the materials — Time to make the parts — Time to find the tools. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 36 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 37 Group 1: Scribe Line Inspection Elapsed HoursTask HoursNumber of PersonsTask 20.080.04Figure 1 6.012.02Figure 5 2.04.02Figure 9 28.0 *96.0 *TOTAL FOR EACH AIRPLANE * Total Task Hours and Elapsed Hours dependent upon total number of fuselage areas being inspected. * Additional time is required for paint and sealant removal. * More time will be required for additional inspections and repairs if scribe lines or other damage is found. * More time may be required for inspections around large repair doublers. Group 2: Scribe Line Inspection Elapsed HoursTask HoursNumber of PersonsTask 20.080.04Figure 2 6.012.02Figure 6 2.04.02Figure 9 28.0 *96.0 *TOTAL FOR EACH AIRPLANE * Total Task Hours and Elapsed Hours dependent upon total number of fuselage areas being inspected. * Additional time is required for paint and sealant removal. * More time will be required for additional inspections and repairs if scribe lines or other damage is found. * More time may be required for inspections around large repair doublers. Group 3: Scribe Line Inspection Elapsed HoursTask HoursNumber of PersonsTask 20.080.04Figure 3 6.012.02Figure 7 2.04.02Figure 9 28.0 *96.0 *TOTAL FOR EACH AIRPLANE * Total Task Hours and Elapsed Hours dependent upon total number of fuselage areas being inspected. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 37 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 38 Group 3: Scribe Line Inspection Elapsed HoursTask HoursNumber of PersonsTask * Additional time is required for paint and sealant removal. * More time will be required for additional inspections and repairs if scribe lines or other damage is found. * More time may be required for inspections around large approved repairs. Group 4: Scribe Line Inspection Elapsed HoursTask HoursNumber of PersonsTask 20.080.04Figure 4 6.012.02Figure 8 2.04.02Figure 9 28.0 *96.0 *TOTAL FOR EACH AIRPLANE * Total Task Hours and Elapsed Hours dependent upon total number of fuselage areas being inspected. * Additional time is required for paint and sealant removal. * More time will be required for additional inspections and repairs if scribe lines or other damage is found. * More time may be required for inspections around large approved repairs. Group 5: Scribe Line Inspection Elapsed HoursTask HoursNumber of PersonsTask 24.096.04Figure 11 24.0 *96.0 *TOTAL FOR EACH AIRPLANE * Total Task Hours and Elapsed Hours dependent upon total number of fuselage areas being inspected. * Additional time is required for paint and sealant removal. * More time will be required for additional inspections and repairs if scribe lines or other damage is found. * More time may be required for inspections around large approved repairs. H. Weight and Balance Changes None. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 38 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 39 I. Electrical Load Data Not changed. J. References 1. Existing Data: a. Boeing Service Related Problem (SRP) 707-SRP-53-0247 b. Standard Overhaul Practices Manual (SOPM) 20-30-03, 20-43-03 c. 707 Non-Destructive Testing (NDT) Manual Part 10, 53-30-01; Part 4, 53-30-05; Part 4, 53-30-06; Part 6, 51-00-00, Figure 23; Part 6, 51-00-00, Figure 4; Part 6, 53-30-22; TR 06-10, Part 6, 53-30-24; TR 06-11, Part 6, 53-30-25; TR 06-12, Part 6, 53-30-26 d. 707 Aircraft Maintenance Manual (AMM) 51-2-141, 51-3-0 e. Service Bulletin Index Document D6-1647 Part 3 2. Data Supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin: None. K. Publications Affected 1. Publications Chapter-SectionPublication 51-2707 Aircraft Maintenance Manual 2. Damage Tolerance Based Structural Inspections: Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the Maintenance Program. This service bulletin affects FCS but no new DTIs are necessary. L. Interchangeability and Intermixability of Parts Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts. M. Software Accomplishment Summary Not affected. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 39 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 40 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 40 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT BLANK PAGE ### Page 41 2. MATERIAL INFORMATION A. Material - Price and Availability None. B. Industry Support Information Boeing warranty remedies are not available for the inspections or 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: NotesNameQTYPart Number / Specification (b) (c) (g)Chemical Conversion Coating10 OuncesType 2, Class A (a) (c) (g)Primer24 OuncesBMS 10-11 Type 1 (a) (c) (d) (e) (f) (g)Primer Plus Enamel24 OuncesBMS 10-72 (a) (c) (d) (e) (f) (g)Primer24 OuncesBMS 10-79, Type II (a) (c) (d) (e) (f) (g)Topcoat24 OuncesBMS 10-60, Type II (a) Refer to the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data. (b) Refer to SOPM 20-43-03 as an accepted procedure for material sources. (c) This part is only necessary if paint is removed. (d) This part is only necessary if BMS 10-79 and BMS 10-60 or the operators normal decorative paint system is not used. (e) This part is only necessary if BMS 10-72 or the operators normal decorative paint system is not used. (f) Refer to 707 AMM 51-2-141 as an accepted procedure for decorative exterior paint system application. (g) The quantity given is an approximation. The actual quantity required will vary depending on the results of the scribe line inspections. 3. Parts Modified and Reidentified: None. 4. Parts Removed and Not Replaced: None. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 41 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 42 D. Parts Necessary to Change Spares None. E. Special Tooling - Price and Availability The operator can supply the tools shown in Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin. Tool price and supply data are not given. F. Special Tooling Necessary to do this Service Bulletin No special tooling is necessary to accomplish this bulletin. However, the following standard tools may be needed to measure scribe line depth. These tools are unusual and may not be available at all shops as standard tools. Maintenance and overhaul tools in the manuals shown in Paragraph 1.J., References, can also be necessary. Examine operator tool supply to make sure all necessary tools are available. NameNumber Digital Optical Micrometer (a) (b)Model Number 8400K Optical Micrometer (a) (c)Model 966 (Part Number 125632-1) or Model 966A (Part Number 125632) Laser Measurement System (d)Inspect Cam Model SDMS These are typical optical micrometers.(a) Rene Company(b) 1005 South Mountain Avenue Monrovia, California 91016 USA Toll free: (866) 358-9955 Tel: (626) 358-9955 Fax: (626) 358-1448 Email: info@renecompany.com Taber Industries(c) 455 Bryant Street North Tonawanda, New York 14120 USA Toll-Free: (800) 333-5300 (in USA or Canada) Phone: (716) 694-4000 Fax: (716) 694-1450 Refer to 707 NDT Manual Part 10, 53-30-01 for the latest vendor information.(d) Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 42 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 43 3. ACCOMPLISHMENT INSTRUCTIONS A. GENERAL INFORMATION CAUTION: ELECTRICALLY GROUND THE AIRPLANE. THIS WILL HELP TO PREVENT DAMAGE TO THE AIRPLANE OR EQUIPMENT. CAUTION: KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL, METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR OTHER ELECTRICAL DAMAGE. NOTE: 1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 2. Obey all of the warnings and cautions given in the specified manual sections. 3. Unless shown differently, these dimensions and tolerances are used: – Linear dimensions are in inches – Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus or minus 0.03 inch 4. 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. 5. Appendix D includes information for the fabrication or purchase of a scribe line sample for use as a training aid. The use of this sample is not required when performing actions of this service bulletin. This sample is an aid in identifying what a scribe line may look and feel like but is not intended to show all damage that is considered a scribe line. When identifying scribe lines, see the definition of a typical scribe line in the Accomplishment Instructions of this service bulletin. 6. If an optical micrometer or laser measurement system cannot be used because the upper skin of the lap joint covers a scribe line, then the scribe line depth does not need to be determined at that location. These scribe lines must be considered typical and therefore all inspection and other requirements for a typical scribe line apply. 7. It is required that individuals performing ultrasonic inspections on airplanes with scribe lines to detect cracks per the relevant procedures must be recognized by the operator or repair station as qualified to perform ultrasonic inspections on their airplanes and meet at least one of the following criteria: – The individual must be qualified to at least Level 2 in the ultrasonic method in accordance with an accepted industry standard, i.e. ATA Specification 105, Mil-Std.-410, NAS-410, SNT-TC-1A, or EN-4179 or equivalent. or – The individual has received specific Boeing training with Boeing providing a certificate stating that the individual has satisfactorily completed the training in the specific techniques. or Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 43 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 44 – The individual has a Level 1 rating in the ultrasonic method in accordance with an accepted industry standard and has received specific training and a statement from the qualifying entity (employer) that the individual is qualified for this particular inspection. 8. If scribe lines are found during any of the inspections contained in this service bulletin, when determining the requirements for inspection and repair, each scribe line shall be considered individually. 9. An external approved repair is identified as any SRM repair, a repair provided and approved by Boeing for a specific case requested by the operator, or an operator developed repair that has a Boeing approved Damage Tolerance Analysis. 10. If a scribe line is found outside of the inspections areas in this service bulletin, do inspections in accordance with Work Instructions, Paragraph 3.B.10 - Part 8. 11. If any scribe line is detected at a non-approved repair, provide details of repair and scribe line to Boeing for evaluation. Do the Boeing recommended disposition. 12. A Detailed Inspection is defined as: An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirrors, magnifying lenses, etc. may be necessary. Surface cleaning and elaborate procedures may be required. 13. Boeing has developed training video VPS13290, "Preventing Scribe Damage Through Proper Sealant Removal". To get this video, operators should contact their local Boeing Field Service Representative. 14. Operators should thoroughly familiarize themselves with all Parts and Work Instructions in this service bulletin prior to starting their scribe line inspection program. In addition, it is recommended that all Non-Destructive Testing (NDT) procedures be reviewed and limitations understood prior to the use of the NDT inspection. This will aid in understanding all available options in the event a scribe line is discovered. 15. Inspection Exemptions: Certain inspections are not required under these conditions: – Skin Lap Joints: Inspections are not required in skin lap joint areas where an existing external approved repair covers a potential scribe line, provided the repair spans a minimum of three fastener rows above and three fastener rows below the potential scribe line location. External repairs that do not meet this requirement must be removed to allow skin lap joint inspection. – If operator's records show that the airplane has never been stripped or repainted since delivery from Boeing then the skin lap joint and external approved repair scribe line inspections are not required, except as noted below: – If a decal is installed, or was previously installed, across an area that requires inspection, the inspection exemption does not apply. The skin lap joint and external approved repair inspection must still be done for the affected area at the compliance time in accordance with this service bulletin. 16. Do not blend scribe lines. Blending a scribe line may hinder inspection techniques necessary to determine the presence or absence of fatigue cracks. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 44 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 45 B. WORK INSTRUCTIONS 1. IDENTIFICATION OF A "TYPICAL" SCRIBE LINE Determine if the Scribe Line is "typical". A scribe line is defined as a narrow, shallow, distinct line of damage (typically up to 0.006 inch deep), usually associated with the removal of a fillet or gap seal (lap joints and butt joints, respectively). Scribe lines can be both tactile and non-tactile. Discoloration of the aluminum clad layer or small surface imperfections do not qualify as a scribe line. A lightning strike at a lap joint or butt joint does not qualify as a scribe line. In certain cases, the scribe lines have been associated with the trimming of fuselage skin decals. Scribe lines that create a potential safety concern are generally long continuous scribe lines or several adjacent scribe lines in a critical orientation at specific locations with relatively high stresses. If an optical micrometer or laser measurement system cannot be used because the upper skin of the lap joint covers a scribe line, then the scribe line depth does not need to be determined at that location. These scribe lines must be considered typical and therefore all inspection and other requirements for a typical scribe line apply. Grinding, gouging, or other "non-typical" damage, which is more significant (deeper or locally more extensive) than the typical scribe line must be repaired. Localized scratches, nicks and dents that might be induced in other areas of the fuselage skin during either manufacture or maintenance operations are not considered scribe lines. This type of damage should be addressed via the acceptable maintenance practices detailed in the Structural Repair Manual. 2. LOCATIONS OF "TYPICAL" SCRIBE LINES a. Skin Lap Joints In areas near skin lap joints, scribe lines normally run parallel to the lap joint in the lower skin along the edge of the upper skin. These scribe lines are typically within 0.25 inch of the lower edge of the upper skin. In some cases, portions of the scribe lines may be directly adjacent to or slightly under the lower edge of the upper skin resulting in hidden lines that cannot be viewed without disassembly. The ends of these scribe lines sometimes may also turn slightly away from the lap joint. b. Skin Butt Joints In butt joint areas, scribe lines are normally found on the splice plate in the gap between the forward and aft skin edges and run along the butt joint. c. External Approved Repairs In areas around external approved repairs, scribe lines normally follow the periphery of the external approved repairs. d. External Features In areas around external features, scribe lines normally follow the periphery of the external feature. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 45 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 46 e. Decals and Fairings In areas around decals and fairings, scribe lines normally follow the periphery of the decal or fairing. Scribe lines may be located anywhere on a skin panel where decals or fairings are currently installed or were previously were installed. 3. PART 1 - SURFACE PREPARATION - SCRIBE LINE INSPECTIONS NOTE: Refer to Appendix A of this service bulletin for an accepted procedure for sealant removal during surface preparation. a. Skin Lap Joint Surface Preparation (1) Remove the sealant from the lower edge of all affected lap joints. (2) Remove the paint from below the lower edge of all affected lap joints. The bared area should be at least one (1.0) inch wide, as measured from the lower edge of the upper skin. (3) If any section of the affected lap joints is under the wing-to-body fairing, remove the appropriate fairing panel(s) for access. b. Skin Butt Joint Surface Preparation Remove the sealant from within the gap of the affected butt joints. It is recommended that the primer and paint, if present, not be removed from the butt joint splice plate. If the primer is removed, do not use chemical stripper. c. External Approved Repair Surface Preparation Remove paint and sealant from the area of the skin around the periphery of the external approved repair. The bared area should be at least one (1.0) inch wide, around the periphery of the external approved repair. d. External Feature Surface Preparation Remove paint and sealant from the area of the skin around the periphery of the external feature. The bared area should be at least one (1.0) inch wide, around the periphery of the external feature. e. Decal and Fairing Surface Preparation Remove the paint from the applicable area of the skin around the edges of the decal or fairing as follows: (1) If decals were previously installed, and it can be determined where the edges of the decals previously were, remove the paint from the area of the skin around the edges of the decal. The bared area should be at least one half (0.5) inch wide on both sides of the edge of the decal. (2) If decals were previously installed, but it cannot be determined where the edges of the decal were, remove the paint from all of the affected decal locations. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 46 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 47 (3) For fairings, remove paint and sealant from the area of the skin around the periphery of the fairing. The bared area should be at least one (1.0) inch wide, around the periphery of the fairing. 4. PART 2 - DETAILED INSPECTION FOR SCRIBE LINES a. Do a detailed inspection of the fuselage skin for scribe lines. Use a minimum 10X magnifying lens to aid the inspection. b. From the tables that follow, which correspond to airplane group numbers, determine the applicable figures for the inspection areas to be inspected. c. If no scribe line is found, do Part 3 - No Scribe Line Found. d. If any scribe line is found, do Part 4 - Scribe Line Found. e. Scribe Line Inspections: Group 1: Table 1 - Scribe Line Inspections Area Figure 1Skin Lap Joints Figure 5External Approved Repairs Figure 9External Features Group 2: Table 2 - Scribe Line Inspections Area Figure 2Skin Lap Joints Figure 6External Approved Repairs Figure 9External Features Group 3: Table 3 - Scribe Line Inspections Area Figure 3Skin Lap Joints Figure 7External Approved Repairs Figure 9External Features Group 4: Table 4 - Scribe Line Inspections Area Figure 4Skin Lap Joints Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 47 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 48 Group 4: Table 4 - Scribe Line Inspections Area Figure 8External Approved Repairs Figure 9External Features Group 5: Table 5 - Scribe Line Inspections Area Figure 11Skin Lap Joints Figure 11External Approved Repairs Figure 11External Features Figure 11Skin Butt Joints Figure 11Decals 5. PART 3 - NO SCRIBE LINE IS FOUND a. If no scribe lines are found, no further inspections are required. b. Do Part 7 - Surface Finish Restoration. 6. PART 4 - ANY SCRIBE LINE IS FOUND NOTE: DO NOT BLEND ANY SCRIBE LINE. BLENDING A SCRIBE LINE MAY HINDER INSPECTION TECHNIQUES NECESSARY TO DETERMINE THE PRESENCE OR ABSENCE OF FATIGUE CRACKS. a. Measure and document the location and depth of all scribe lines that are found. It is recommended that you use the format outlined in Appendix C to document the scribe line. b. Do a laser measurement inspection or the optical micrometer inspection to measure the maximum depth of the scribe line. NOTE: Only the laser measurement inspection in accordance with 707 NDT Manual Part 10, 53-30-01 can be used to confirm scribe line depth less than 0.001 inch. c. If the scribe line depth is less than 0.001 inch: (1) No repair or further inspections are required at that location. (2) Do Part 7 - Surface Finish Restoration of this Service Bulletin. d. Group 1-4: If the scribe line depth is greater than or equal to 0.001 inch: (1) Do Part 5 - Non-Destructive Testing (NDT) Inspections - Scribe Lines to detect any crack. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 48 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 49 NOTE: The applicable NDT inspection(s) of the scribe line must be accomplished prior to a repair proposal to verify that no crack exists in or around the scribe line. (2) Do Part 7 - Surface Finish Restoration of this Service Bulletin. e. Group 5: If the scribe line depth is greater than or equal to 0.001 inch: (1) Contact Boeing for repair instructions and do the repair. (2) Do Part 7 - Surface Finish Restoration of this Service Bulletin. 7. Group 1-4: PART 5 - NON-DESTRUCTIVE TESTING (NDT) INSPECTIONS - SCRIBE LINES If the scribe line depth is greater than or equal to 0.001 inch, do what follows: a. Scribe Line at Skin Lap Joint: (1) Do the applicable NDT inspection in accordance with FIGURE 10. NOTE: The skin thickness must be known when conducting the Ultrasonic (UT) inspections so that the correct reference standard is used in calibration. The 707 NDT Manual Part 4, 53-30-05 (Ultrasonic Single Element) has application limitations based upon skin thickness. Use the applicable Boeing drawing to determine skin thickness if skin thickness is not known. (2) If no crack is found and the scribe line depth is greater than or equal to 0.001 inch and less than or equal to 0.006 inch, do one of the options that follows: (a) Do the Limited Return To Service (LRTS) repeat inspection program in accordance with Part 6 of this service bulletin. or (b) Document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the scribe line damage and repair proposal. NOTE: A repair is not required until the repair compliance time is reached, provided the operator chooses to do the LRTS repeat inspection program in accordance with Part 6 of this service bulletin. A repair proposal is only required if the operator has chosen not to do the LRTS repeat inspection program. (3) If no crack is found and the scribe line depth is greater than 0.006 inch, document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the scribe line damage and repair proposal. NOTE: The LRTS repeat inspection program is not an option for scribe lines greater than 0.006 inch deep. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 49 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 50 (4) If any crack is found, document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the crack and repair proposal. (5) Do Part 7 - Surface Finish Restoration of this service bulletin. b. Scribe Line at External Approved Repair: (1) Do the applicable NDT inspection in accordance with FIGURE 10. NOTE: The skin thickness must be known when conducting the Ultrasonic (UT) inspections so that the correct reference standard is used in calibration. The 707 NDT Manual Part 4, 53-30-05 (Ultrasonic Single Element) has application limitations based upon skin thickness. Use the applicable Boeing drawing to determine skin thickness if skin thickness is not known. (2) If no crack is found and the scribe line depth is greater than or equal to 0.001 inch and less than or equal to 0.006 inch, do one of the options that follows: (a) Do the Limited Return To Service (LRTS) repeat inspection program in accordance with Part 6 of this service bulletin. or (b) Document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the scribe line damage and repair proposal. NOTE: A repair is not required until the repair compliance time is reached, provided the operator chooses to do the LRTS repeat inspection program in accordance with Part 6 of this service bulletin. A repair proposal is only required if the operator has chosen not to do the LRTS repeat inspection program. (3) If no crack is found and the scribe line depth is greater than 0.006 inch, document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the scribe line damage and repair proposal. NOTE: The LRTS repeat inspection program is not an option for scribe lines greater than 0.006 inch deep. (4) If any crack is found, document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the crack and repair proposal. (5) Do Part 7 - Surface Finish Restoration of this service bulletin. c. Scribe Line at External Feature: (1) Do the applicable NDT inspection in accordance with FIGURE 10. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 50 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 51 NOTE: The skin thickness must be known when conducting the Ultrasonic (UT) inspections so that the correct reference standard is used in calibration. The 707 NDT Manual Part 4, 53-30-05 (Ultrasonic Single Element) has application limitations based upon skin thickness. Use the applicable Boeing drawing to determine skin thickness if skin thickness is not known. (2) If no crack is found and the scribe line depth is greater than or equal to 0.001 inch and less than or equal to 0.006 inch, do one of the options that follows: (a) Do the Limited Return To Service (LRTS) repeat inspection program in accordance with Part 6 of this service bulletin. or (b) Document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the scribe line damage and repair proposal. NOTE: A repair is not required until the repair compliance time is reached, provided the operator chooses to do the LRTS repeat inspection program in accordance with Part 6 of this service bulletin. A repair proposal is only required if the operator has chosen not to do the LRTS repeat inspection program. (3) If no crack is found and the scribe line depth is greater than 0.006 inch, document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the scribe line damage and repair proposal. NOTE: The LRTS repeat inspection program is not an option for scribe lines greater than 0.006 inch deep. (4) If any crack is found, document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the crack and repair proposal. (5) Do Part 7 - Surface Finish Restoration of this service bulletin. 8. Group 1-4: PART 6 - LIMITED RETURN TO SERVICE (LRTS) PROGRAM a. Skin Lap Joints - Repeat Inspection: (1) Determine which areas of the skin lap joints require repeat inspection based upon previous inspection results. (2) Do Part 1 - Surface Preparation - Scribe Line Inspection, in areas that require repeat inspection. (3) Do Part 2 - Detailed Inspection for Scribe Lines, in areas that require repeat inspection. (4) Do the applicable NDT inspection in accordance with FIGURE 10. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 51 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 52 NOTE: The skin thickness must be known when conducting the Ultrasonic (UT) inspections so that the correct reference standard is used in calibration. The 707 NDT Manual Part 4, 53-30-05 (Ultrasonic Single Element) has application limitations based upon skin thickness. Use the applicable Boeing drawing to determine skin thickness if skin thickness is not known. (5) If no crack is found, do one of the options that follows: (a) Document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the scribe line damage and repair proposal. or (b) Repeat the LRTS program in accordance with this service bulletin. Contact Boeing before the compliance time listed in Paragraph 1.E for additional inspections or repair. Do the additional inspections or repair. (6) If any crack is found, document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the crack and repair proposal. (7) Do Part 7 - Surface Finish Restoration of this service bulletin. b. External Approved Repair - Repeat Inspection: (1) Determine which areas of the external approved repairs require repeat inspection based upon previous inspection results. (2) Do Part 1 - Surface Preparation - Scribe Line Inspection, in areas that require repeat inspection. (3) Do Part 2 - Detailed Inspection for Scribe Lines, in areas that require repeat inspection. (4) Do the applicable NDT inspection in accordance with FIGURE 10. NOTE: The skin thickness must be known when conducting the Ultrasonic (UT) inspections so that the correct reference standard is used in calibration. The 707 NDT Manual Part 4, 53-30-05 (Ultrasonic Single Element) has application limitations based upon skin thickness. Use the applicable Boeing drawing to determine skin thickness if skin thickness is not known. (5) If no crack is found, do one of the options that follows: (a) Document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the scribe line damage and repair proposal. or Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 52 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 53 (b) Repeat the LRTS program in accordance with this service bulletin. Contact Boeing before the compliance time listed in Paragraph 1.E for additional inspections or repair. Do the additional inspections or repair. (6) If any crack is found, document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the crack and repair proposal. (7) Do Part 7 - Surface Finish Restoration of this service bulletin. c. External Features - Repeat Inspection: (1) Determine which areas of the external features require repeat inspection based upon previous inspection results. (2) Do Part 1 - Surface Preparation - Scribe Line Inspection, in areas that require repeat inspection. (3) Do Part 2 - Detailed Inspection for Scribe Lines, in areas that require repeat inspection. (4) Do the applicable NDT inspection in accordance with FIGURE 10. NOTE: The skin thickness must be known when conducting the Ultrasonic (UT) inspections so that the correct reference standard is used in calibration. The 707 NDT Manual Part 4, 53-30-05 (Ultrasonic Single Element) has application limitations based upon skin thickness. Use the applicable Boeing drawing to determine skin thickness if skin thickness is not known. (5) If no crack is found, do one of the options that follows: (a) Document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the scribe line damage and repair proposal. or (b) Repeat the LRTS program in accordance with this service bulletin. Contact Boeing before the compliance time listed in Paragraph 1.E for additional inspections or repair. Do the additional inspections or repair. (6) If any crack is found, document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the crack and repair proposal. (7) Do Part 7 - Surface Finish Restoration of this service bulletin. 9. PART 7 - SURFACE FINISH RESTORATION NOTE: To reduce the possibility of future scribing, Boeing recommends that the BMS 5-95 fillet seal not be reapplied except as follows: 1. In the gap at butt joints. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 53 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 54 2. The leading edge of the external approved repair for repairs that will be inspected under the LRTS program. 3. Around external features as referred to in the applicable Aircraft Maintenance Manual (AMM) section. a. Refinish the external surface finish as follows: (1) Apply Type 2, Class A chemical conversion coating. Refer to SOPM 20-43-03 as an accepted procedure. (2) Apply BMS 10-72 paint system (primer plus enamel), or BMS 10-79 Type II (primer) plus BMS 10-60 Type II (topcoat), or the operator's normal decorative paint system. Refer to 707 Aircraft Maintenance Manual 51-2-141 as an accepted procedure. b. Refinish the internal surface finish as follows: (1) Apply Type 2, Class A chemical conversion coating. Refer to SOPM 20-43-03 as an accepted procedure. (2) Apply BMS 10-11 Type 1 primer. Refer to 707 Aircraft Maintenance Manual Subject 51-2-141 as an accepted procedure. c. For external approved repairs that will be inspected under the LRTS program, apply a fillet seal of BMS 5-95 sealant at the leading edge of the external approved repair. Refer to 707 Aircraft Maintenance Manual Subject 51-3-0 as an accepted procedure. d. For external approved repairs around which no scribe lines were found, apply a fillet seal of BMS 5-95 sealant around the periphery of the external approved repair. Refer to 707 Aircraft Maintenance Manual Subject 51-3-0 as an accepted procedure. e. Put the airplane back to a serviceable condition. 10. Group 1-4: PART 8 - KNOWN EXISTING SCRIBE LINE DAMAGE - OUTSIDE OF SERVICE BULLETIN INSPECTION AREAS If scribe lines are found outside of service bulletin inspection areas, do what follows: a. Do Part 1 - Surface Preparation - Scribe Line Inspections of this service bulletin. b. Measure and document the location and depth of all scribe lines that are found. It is recommended that you use the format outlined in Appendix C to document the scribe line. c. Do a laser measurement inspection or the optical micrometer inspection to measure the maximum depth of the scribe line. NOTE: Only the laser measurement inspection in accordance with 707 NDT Manual Part 10, 53-30-01 can be used to confirm scribe line depth less than 0.001 inch. d. If the scribe line depth is less than 0.001 inch: (1) No repair or further inspections are required. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 54 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 55 (2) Do Part 7 - Surface Finish Restoration of this Service Bulletin. e. If the scribe line depth is greater than or equal to 0.001 inch, do what follows: (1) Scribe Line at Skin Lap Joint - NDT Inspection (a) Do the applicable NDT inspection in accordance with FIGURE 10. NOTE: The skin thickness must be known when conducting the Ultrasonic (UT) inspections so that the correct reference standard is used in calibration. The 707 NDT Manual Part 4, 53-30-05 (Ultrasonic Single Element) has application limitations based upon skin thickness. Use the applicable Boeing drawing to determine skin thickness if skin thickness is not known. (b) If no crack is found and the scribe line depth is greater than or equal to 0.001 inch and less than or equal to 0.004 inch, no repair or further inspections are required. (c) If no crack is found and the scribe line depth is greater than 0.004 inch and less than or equal to 0.006 inch, contact Boeing for additional inspections or repair. Do the additional inspections or repair. (d) If no crack is found and the scribe line depth is greater than 0.006 inch, document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the scribe line damage and repair proposal. (e) If any crack is found, document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the crack and repair proposal. Contact Boeing for additional inspections. Do the additional inspections. (f) Do Part 7 - Surface Finish Restoration of this Service Bulletin. (2) Scribe Line at External Approved Repair - NDT Inspection (a) Do the applicable NDT inspection in accordance with FIGURE 10. NOTE: The skin thickness must be known when conducting the Ultrasonic (UT) inspections so that the correct reference standard is used in calibration. The 707 NDT Manual Part 4, 53-30-05 (Ultrasonic Single Element) has application limitations based upon skin thickness. Use the applicable Boeing drawing to determine skin thickness if skin thickness is not known. (b) If no crack is found and the scribe line depth is greater than or equal to 0.001 inch and less than or equal to 0.004 inch, no repair or further inspections are required. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 55 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 56 (c) If no crack is found and the scribe line depth is greater than 0.004 inch and less than or equal to 0.006 inch, contact Boeing for additional inspections or repair. Do the additional inspections or repair. (d) If no crack is found and the scribe line depth is greater than 0.006 inch, document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the scribe line damage and repair proposal. (e) If any crack is found, document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the crack and repair proposal. Contact Boeing for additional inspections. Do the additional inspections. (f) Do Part 7 - Surface Finish Restoration of this Service Bulletin. (3) Scribe Line at External Feature - NDT Inspection (a) Do the applicable NDT inspection in accordance with FIGURE 10. NOTE: The skin thickness must be known when conducting the Ultrasonic (UT) inspections so that the correct reference standard is used in calibration. The 707 NDT Manual Part 4, 53-30-05 (Ultrasonic Single Element) has application limitations based upon skin thickness. Use the applicable Boeing drawing to determine skin thickness if skin thickness is not known. (b) If no crack is found and the scribe line depth is greater than or equal to 0.001 inch and less than or equal to 0.004 inch, no repair or further inspections are required. (c) If no crack is found and the scribe line depth is greater than 0.004 inch and less than or equal to 0.006 inch, contact Boeing for additional inspections or repair. Do the additional inspections or repair. (d) If no crack is found and the scribe line depth is greater than 0.006 inch, document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the scribe line damage and repair proposal. (e) If any crack is found, document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the crack and repair proposal. Contact Boeing for additional inspections. Do the additional inspections. (f) Do Part 7 - Surface Finish Restoration of this Service Bulletin. (4) Scribe Line at Skin Butt Joint - NDT Inspection (a) Based upon scribe line location, do the applicable NDT inspection in accordance with what follows: 1) Low Frequency Eddy Current (LFEC) in accordance with 707 NDT Manual TR 06-10, Part 6, 53-30-24. or Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 56 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 57 2) High Frequency Eddy Current (HFEC) in accordance with 707 NDT Manual TR 06-11, Part 6, 53-30-25. (b) If no crack is found and the scribe line depth is greater than or equal to 0.001 inch and less than or equal to 0.004 inch, no repair or further inspections are required. (c) If no crack is found and the scribe line depth is greater than 0.004 inch and less than or equal to 0.006 inch, contact Boeing for additional inspections or repair. Do the additional inspections or repair. (d) If no crack is found and the scribe line depth is greater than 0.006 inch, document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the scribe line damage and repair proposal. (e) If any crack is found, document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the crack and repair proposal. Contact Boeing for additional inspections. Do the additional inspections. (f) Do Part 7 - Surface Finish Restoration of this Service Bulletin. (5) Scribe Line at Decals and Fairings - NDT Inspection (a) Do a High Frequency Eddy Current (HFEC) inspection in accordance with 707 NDT Manual Part 6, 51-00-00, Figure 4 or 707 NDT Manual Part 6, 51-00-00, Figure 23 to detect any crack at any affected decals and fairings. (b) If no crack is found and the scribe line depth is greater than or equal to 0.001 inch and less than or equal to 0.004 inch, no repair or further inspections are required. (c) If no crack is found and the scribe line depth is greater than 0.004 inch and less than or equal to 0.006 inch, contact Boeing for additional inspections or repair. Do the additional inspections or repair. (d) If no crack is found and the scribe line depth is greater than 0.006 inch, document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the scribe line damage and repair proposal. (e) If any crack is found, document and propose a repair to Boeing. Do the repair. This will assist Boeing in the analysis of the crack and repair proposal. Contact Boeing for additional inspections. Do the additional inspections. (f) Do Part 7 - Surface Finish Restoration of this Service Bulletin. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 57 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT ### Page 58 (OCR) BOEING SERVICE BULLETIN A3539 ALERT ALERT This Figure applies only to: Group 1. STA S-24R S-24L STA 1384.10 STA STA 089971 0111 STA S-25R 1241 STA 1080 S-23R 100000000000000000 0000000000000000• STA 1220 1064.10 S-25L STA STA 1265.20 1124.10 STA STA 1303.70 1164.10 STA 1000 STA 960 S-20L S-29L 707-100B STA 820 S-20R S-18AR LANDING GEAR DOOR oco o00 LANDING GEAR DOOR S-18AL INSPECTION AREA EXISTING BUTT JOINT •SECTION 43 S-30R 00000000000000 000 STA 600K STA 600 STA 530 STA SIA STA STA 460 SECTION 41 2198830 FIGURE 1: FUSELAGE - SKIN LAP JOINTS - INSPECTION (SHEET 1 OF 4) Original Issue: April 26, 2013 PROPRIETARY - Copyright © Unpublished Export Controlled ECCN: 9E991 - BOEING A3539 Work - See page 1 for details. 58 of 110 ### Page 59 (OCR) BOEING SERVICE BULLETIN A3539 ALERT ALERT FRAME UPPER SKIN STRINGER® LOWER SKIN 1) TYPICAL SKI • SCRIBE LIN TYPICAL SKIN LAP JOINT 2198842 FIGURE 1: FUSELAGE - SKIN LAP JOINTS - INSPECTION (SHEET 2 OF 4) Original Issue: April 26, 2013 PROPRIETARY - Copyright © Unpublished Export Controlled ECCN: 9E991 - BOEING A3539 Work - See page 1 for details. 59 of 110 ### Page 60 The step numbers shown below agree with the numbers shown in the circle symbols in the figure. CAUTION: DO NOT BLEND SCRIBE LINES. BLENDING A SCRIBE LINE MAY HINDER INSPECTION TECHNIQUES NECESSARY TO DETERMINE THE PRESENCE OR ABSENCE OF FATIGUE CRACKS. MORE DATAQTYIDENTIFICATIONNAMETASKSTEP (a) (b)-S-30R, STA NLG To STA 481SkinInspect1 S-29R, STA 960 To STA 1124.10 S-29R, STA 1124.10 To STA 1265.20 S-25R, STA 312 To STA 360 S-25R, STA 360 To STA 481 S-24R, STA 1364.10 To STA 1440 S-20R, STA 259.50 To STA 360 S-20R, STA 360 To Door Cutout S-20R, STA 580 To STA 600K S-20R, STA 960 To Door Cutout S-20R, Door Cutout To STA 1164.10 S-20R, STA 1164.10 To Door Cutout S-20R, Door Cutout To STA 1265.20 S-14R, STA 360 To Door Cutout S-14R, STA Door Cutout To STA 481 S-14R, STA 1124.10 To STA 1164.10 S-14R, STA 1241 To Door Cutout S-14R, Door Cutout To STA 1364.10 S-10R, STA 1241 To STA 1384.10 S-6R, STA 441 To STA 580 S-6L, STA 441 To STA 481 S-14L, STA 360 To STA 481 S-14L, STA 1220 To Door Cutout S-20L, STA 259.50 To STA 360 S-20L, STA 360 To STA 600 FIGURE 1: FUSELAGE - SKIN LAP JOINTS - INSPECTION (SHEET 3 OF 4) Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2013 A3539 60 of 110 BOEING SERVICE BULLETIN A3539 ALERTALERT The text continues at https://openairdocs.org/service-documents/boeing/a3539/file/6a0ac8f59b88.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.