# Boeing Alert Service Bulletin 727-53A0233: No revision named - Rights: © The Boeing Company. Filed by the FAA in regulations.gov docket FAA-2010-0677; AD 2011-02-05 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Boeing Alert Service Bulletin 727-53A0233](https://openairdocs.org/service-documents/boeing/727-53a0233.md) - Title as filed: U.S. DOT/FAA - Service Bulletin - Pages: 192 - PDF: https://openairdocs.org/files/sha256/dc/72/dc72239cefef0c6d7ae48c290c5f0e39e93b72833373a553acc9efff0f68d57a - Page: https://openairdocs.org/service-documents/boeing/727-53a0233/file/dc72239cefef ## Text Some pages are OCR from a scan. OCR can misread letters and numbers. Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 1 Commercial Airplanes 727 Service Bulletin ALERT Number: 727-53A0233 Original Issue: February 19, 2010 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 730-774). 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all export laws. 9E991ECCN: BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2010 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter. Boeing also claims copyright in this document as a compilation and/or collective work. This document includes proprietary information owned by The Boeing Company and/or one or more third parties. Treatment of the document and the information it contains is governed by contract with Boeing. For more information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124. 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, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8A, Poseidon and the Boeing livery 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. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 1 of 192 2.0 ### Page 2 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 2 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT BLANK PAGE ### Page 3 Table of Contents Summary ...................................................... 5 1. PLANNING INFORMATION ........................................ 9 A. Effectivity ................................................ 9 1. Airplanes ............................................. 9 2. Spares Affected ........................................ 1 4 B. Concurrent Requirements ...................................... 1 4 C. Reason ................................................ 1 4 D. Description .............................................. 1 4 E. Compliance .............................................. 1 6 F. Approval ............................................... 4 8 G. Manpower .............................................. 4 8 H. Weight and Balance Changes .................................... 5 1 I. Electrical Load Data ......................................... 5 1 J. References .............................................. 5 1 1. Existing Data: ......................................... 5 1 2. Data supplied with this Service Bulletin: ........................... 5 1 3. Installation Drawings Used in the Preparation of this Service Bulletin: ........... 5 2 K. Publications Affected ........................................ 5 2 L. Interchangeability and Intermixability of Parts ........................... 5 2 2. MATERIAL INFORMATION ........................................ 5 3 A. Material - Price and Availability ................................... 5 3 B. Industry Support Information .................................... 5 3 C. Parts Necessary For Each Airplane ................................. 5 3 1. Kits/Parts: ........................................... 5 3 2. Parts and Materials Supplied by the Operator: ........................ 5 3 3. Parts Modified and Reidentified: ............................... 5 3 4. Parts Removed and Not Replaced: .............................. 5 3 D. Parts Necessary to Change Spares ................................. 5 4 E. Special Tooling - Price and Availability ............................... 5 4 F. Special Tooling Necessary to do this Service Bulletin ....................... 5 4 3. ACCOMPLISHMENT INSTRUCTIONS .................................. 5 5 A. GENERAL INFORMATION ..................................... 5 5 B. WORK INSTRUCTIONS ....................................... 5 7 FIGURE 1: FUSELAGE - SKIN LAP JOINTS - ZONE 1 INSPECTION [Group 1] ............ 8 6 FIGURE 2: FUSELAGE - SKIN LAP JOINTS - ZONE 1 INSPECTION [Group 2] ............ 8 9 FIGURE 3: FUSELAGE - SKIN LAP JOINTS - ZONE 1 INSPECTION [Group 3] ............ 9 2 FIGURE 4: FUSELAGE - SKIN LAP AND SKIN BUTT JOINTS - ZONE 1 INSPECTION [Group 4] . . 97 FIGURE 5: FUSELAGE - SKIN LAP JOINTS - ZONE 2 INSPECTION [Group 1] ........... 1 0 1 FIGURE 6: FUSELAGE - SKIN LAP JOINTS - ZONE 2 INSPECTION [Group 2] ........... 1 0 4 FIGURE 7: FUSELAGE - SKIN LAP AND SKIN BUTT JOINTS - ZONE 2 INSPECTION [Group 3] . 107 FIGURE 8: FUSELAGE - SKIN LAP AND SKIN BUTT JOINTS - ZONE 2 INSPECTION [Group 4] . 112 FIGURE 9: FUSELAGE - SKIN LAP AND SKIN BUTT JOINTS - ZONE 3 INSPECTION [Group 1] . 116 FIGURE 10: FUSELAGE - SKIN LAP JOINTS - ZONE 3 INSPECTION [Group 2] ........... 1 1 9 FIGURE 11: FUSELAGE - SKIN LAP JOINTS - ZONE 3 INSPECTION [Group 3] ........... 1 2 2 FIGURE 12: FUSELAGE - SKIN LAP AND SKIN BUTT JOINTS - ZONE 3 INSPECTION [Group 4] . 126 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 3 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 4 FIGURE 13: FUSELAGE - EXTERNAL APPROVED REPAIRS - ZONE 1 INSPECTION [Group 1] . . 129 FIGURE 14: FUSELAGE - EXTERNAL APPROVED REPAIRS - ZONE 1 INSPECTION [Group 2] . . 132 FIGURE 15: FUSELAGE - EXTERNAL APPROVED REPAIRS - ZONE 1 INSPECTION [Group 3] . . 135 FIGURE 16: FUSELAGE - EXTERNAL APPROVED REPAIRS - ZONE 1 INSPECTION [Group 4] . . 139 FIGURE 17: FUSELAGE - EXTERNAL FEATURES - ZONE 1 INSPECTION [Group 1] ........ 1 4 2 FIGURE 18: FUSELAGE - EXTERNAL FEATURES - ZONE 1 INSPECTION [Group 2] ........ 1 4 5 FIGURE 19: FUSELAGE - EXTERNAL FEATURES - ZONE 1 INSPECTION [Group 3] ........ 1 4 8 FIGURE 20: FUSELAGE - EXTERNAL FEATURES - ZONE 1 INSPECTION [Group 4] ........ 1 5 3 FIGURE 21: FUSELAGE - DECALS AND FAIRINGS - ZONE 1 INSPECTION [Group 3] ........ 1 5 6 FIGURE 22: FUSELAGE - DECALS AND FAIRINGS - ZONE 1 INSPECTION [Group 4] ........ 1 5 9 FIGURE 23: FUSELAGE - DECALS AND FAIRINGS - ZONE 2 INSPECTION [Group 1] ........ 1 6 1 FIGURE 24: FUSELAGE - DECALS AND FAIRINGS - ZONE 2 INSPECTION [Group 2] ........ 1 6 3 FIGURE 25: FUSELAGE - DECALS AND FAIRINGS - ZONE 2 INSPECTION [Group 3] ........ 1 6 5 FIGURE 26: FUSELAGE - DECALS AND FAIRINGS - ZONE 2 INSPECTION [Group 4] ........ 1 6 8 FIGURE 27: FUSELAGE - DECALS AND FAIRINGS - ZONE 3 INSPECTION [Group 1] ........ 1 7 0 FIGURE 28: FUSELAGE - DECALS AND FAIRINGS - ZONE 3 INSPECTION [Group 2] ........ 1 7 2 FIGURE 29: FUSELAGE - DECALS AND FAIRINGS - ZONE 3 INSPECTION [Group 3] ........ 1 7 4 FIGURE 30: FUSELAGE - DECALS AND FAIRINGS - ZONE 3 INSPECTION [Group 4] ........ 1 7 7 Appendix A: SEALANT REMOVAL PROCEDURE FOR EXTERIOR PRESSURIZED FUSELAGE SKIN. 179 Appendix B: REPORTING TEMPLATE - AIRPLANES WITH SCRIBE LINES .............. 1 8 7 Appendix C: AIRPLANE FUSELAGE SCRIBE LINE MARK SUMMARY TABLES ............ 1 8 9 Appendix D: SCRIBE LINE SAMPLE .................................... 1 9 1 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 4 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 5 Commercial Airplanes 727 Service Bulletin ALERT SummaryNumber: 727-53A0233Original Issue: February 19, 2010 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 at lap joints, external approved repairs, decals, fairings, and external features such as antennas. Instructions are also given to inspect the splice plate at certain butt joints. Fatigue cracks can develop at scribe line locations. Any crack that remains undetected could grow large and cause a rapid decompression of the airplane. 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 (lap joints and 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 the decal's outline. This type of decal trimming has also left scribe lines on the fuselage skin. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 5 of 192 ### Page 6 The above maintenance operations can each lead to the same type of scribe line damage and subsequent premature fatigue cracks. Boeing Service Related Problem (SRP) 727-SRP-53-0248 is related to this service bulletin. ACTION At or before the scribe line inspection thresholds shown in this service bulletin, remove paint and sealant at the applicable locations. Do a detailed inspection of the fuselage skin at applicable lap joints, external approved repairs, decals, fairings, and external features for any scribe line or any crack. Also, do a detailed inspection of splice plate at certain butt joints for any scribe line or any crack. If any crack is found, contact Boeing for repair instructions and do the repair. When scribe lines are found, they shall be repaired before further flight. 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 extent of 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 to provide less critical areas with appropriately reduced compliance requirements. Criticality of location determines the inspection thresholds for each location. This service bulletin uses figures and compliance times to address all of the critical locations and ranges of 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. EFFECTIVITY 727, 727-100, 727-100C, 727-200, 727-200F, 727C 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. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 6 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 7 MANPOWER Elapsed HoursTotal Task HoursAirplanes 62.0300.0727, 727-100, 727C, and 727-100C 72.0320.0727-200 and 727-200F MATERIAL INFORMATION Operator Supplied Parts/Materials. Refer to Paragraph 2.A., Material - Price and Availability. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 7 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 8 (OCR) BOEING SERVICE BULLETIN 727-53A0233 ALERT ALERT ... D DO A DETAILED INSPECTION FOR ANY SCRIBE LINE ALONG SKIN LAP JOINTS, SKIN BUTT JOINTS EXTERNAL FEATURES, EXTERNAL APPROVED REPAIRS, DECALS, AND FAIRINGS. IF A SCRIBE LINE IS FOUND DO A NON-DESTRUCTIVE TESTING INSPECTION FOR ANY CRACK. 1895741 Original Issue: February 19, 2010 727-53A0233 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 8 of 192 ### Page 9 Commercial Airplanes 727 Service Bulletin ALERT Number: 727-53A0233 Original Issue: February 19, 2010 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 D6-9825 Part 3 for Airplane Variable Number, Line Number, and Serial Number data. This service bulletin is for the airplanes shown below. DESCRIPTIONCONFIGURATIONGROUP 727 and 727-100 Airplanes-1 727C and 727-100C Airplanes-2 727-200 Airplanes-3 727-200F Airplanes-4 Airplane Models: 727, 727-100, 727-100C, 727-200, 727-200F, 727C GroupVariable Number 1E0001 - E0042 1E0101 - E0140 1E0201 - E0216 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 9 of 192 ### Page 10 GroupVariable Number 1E0301 - E0351 1E0401 - E0423 1E3001 - E3006 1E3011 - E3014 1E3021 - E3040 1E3059 1E3061 - E3077 1E3101 - E3103 1E3111 - E3118 1E3141 - E3152 1E3171 - E3177 1E3201 - E3206 1E3221 - E3224 1E3241 - E3290 1E3341 - E3350 1E3401 - E3421 1E3451 - E3452 1E3471 - E3474 1E3501 - E3513 1E3516 - E3523 1E3551 - E3553 1E3571 - E3578 1E3601 - E3604 1E3621 - E3622 1E3651 - E3655 1E3677 1E3681 - E3684 1E3701 - E3704 1E3751 - E3755 1E3781 - E3784 2E5001 - E5011 2E5031 - E5068 2E5101 - E5116 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 10 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 11 GroupVariable Number 2E5141 - E5143 2E5161 - E5164 2E5201 - E5203 2E5221 - E5245 2E5251 - E5252 2E5271 - E5281 2E5301 - E5306 2E5351 - E5353 2E5381 - E5382 2E5401 - E5424 2E5426 - E5429 2E5433 2E5435 2E5451 - E5455 2E5481 - E5483 2E5501 1E5502 3QA001 - QA046 3QA051 - QA099 3QA101 - QA199 3QA201 - QA225 3QA301 - QA349 3QA351 - QA376 3QA378 3QA401 - QA499 3QA501 - QA537 3QA551 - QA579 3QA581 - QA585 3QA601 - QA688 3QA701 - QA753 3QA801 - QA805 3QA851 - QA899 3QA901 - QA946 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 11 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 12 GroupVariable Number 3QA949 3QB001 - QB002 3QB031 - QB049 3QB051 - QB068 3QB101 - QB110 3QB114 - QB119 3QB121 - QB149 3QB151 - QB158 3QB201 - QB220 3QB301 - QB316 3QB351 - QB352 3QB401 - QB407 3QB451 - QB458 3QB501 - QB575 3QB601 - QB629 3QB651 3QB701 - QB705 3QB801 - QB810 3QB901 - QB904 3QD001 - QD012 3QD031 - QD046 3QD085 - QD088 3QD101 - QD105 3QD121 - QD127 3QD141 - QD149 3QD161 - QD164 3QD191 - QD192 3QD201 - QD239 3QD281 - QD284 3QD301 - QD305 3QD321 - QD330 3QD351 3QD401 - QD403 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 12 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 13 GroupVariable Number 3QD407 3QD410 3QD421 - QD427 3QD441 - QD453 3QD471 - QD475 3QD501 - QD518 3QD551 - QD558 3QD571 - QD572 3QD581 - QD583 3QD601 - QD607 3QD621 - QD624 3QD641 3QD661 - QD663 3QD681 - QD685 3QD691 - QD692 3QD701 - QD702 3QD711 - QD717 3QD741 3QD761 - QD769 3QD781 - QD782 3QD791 3QD801 - QD804 3QD821 - QD828 3QD901 - QD910 3QD931 - QD932 3QD951 - QD954 3QD971 - QD973 3QD991 - QD992 3QE001 - QE002 3QL001 - QL008 3QL031 - QL032 3QL081 4QL501 - QL515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 13 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 14 2. Spares Affected None. B. Concurrent Requirements None. C. Reason This service bulletin gives instructions to inspect for scribe lines in the fuselage skin at lap joints, external approved repairs, decals, fairings, and external features such as antennas. Instructions are also given to inspect the splice plate at certain butt joints. Fatigue cracks can develop at scribe line locations. Any crack that remains undetected could grow large and cause a rapid decompression of the airplane. 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 (lap joints and 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 the decal's outline. This type of decal trimming has also left scribe lines on the fuselage skin. The above maintenance operations can each lead to the same type of scribe line damage and subsequent premature fatigue cracks. Boeing Service Related Problem (SRP) 727-SRP-53-0248 is related to this service bulletin. D. Description At or before the scribe line inspection thresholds shown in this service bulletin, remove paint and sealant at the applicable locations. Do a detailed inspection of the fuselage skin at applicable lap joints, external approved repairs, decals, fairings, and external features for any scribe line or any crack. Also, do a detailed inspection of splice plate at certain butt joints for any scribe line or any crack. If any crack is found, contact Boeing for repair instructions and do the repair. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 14 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 15 When scribe lines are found, they shall be repaired before further flight. 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 extent of 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 to provide less critical areas with appropriately reduced compliance requirements. Criticality of location determines the inspection thresholds for each location. This service bulletin uses figures and compliance times to address all of the critical locations and ranges of 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. 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, 1-31, 1-32, 1- 33, 1-34, 1-35, 1-36, 2-21, 2-22, 2-23, 2-24 727, 727-100 Group 2: Affected Maintenance Zones ZoneModel 1-11, 1-12, 1-13, 1-14, 1-15, 1-16, 1-31, 1-32, 1- 33, 1-34, 1-35, 1-36, 2-21, 2-22, 2-23, 2-24 727-100C, 727C Group 3: Affected Maintenance Zones ZoneModel 1-11, 1-12, 1-13, 1-14, 1-15, 1-16, 1-31, 1-32, 1- 33, 1-34, 1-35, 1-36, 2-21, 2-22, 2-23, 2-24 727-200 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 15 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 16 Group 4: Affected Maintenance Zones ZoneModel 1-11, 1-12, 1-13, 1-14, 1-15, 1-16, 1-31, 1-32, 1- 33, 1-34, 1-35, 1-36, 2-21, 2-22, 2-23, 2-24 727-200F 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: 1. If operator’s records show that the airplane has never been stripped or repainted since delivery from Boeing and correct sealant removal procedures have been and continue to be implemented for all future work, then the skin lap joint, skin butt joint, external approved repairs, external features, and fairing scribe line inspections are not required, except as noted below. 2. If the operator’s records show that the airplane has never been stripped or repainted under the wing-to-body fairings since delivery from Boeing and correct sealant removal procedure is implemented for all future work, then the inspections in the areas under the wing-to-body fairing are not required. 3. 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, skin butt joint, external approved repairs, external features, and fairing inspection must still be done for the affected area at the threshold in accordance with this service bulletin. 4. Decal inspections are not required if the operator's records show the airplane has never had decals installed in the area of inspection since delivery. 5. 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. 6. Skin Butt Joints: Inspections are not required in skin butt joint areas where an existing external repair doubler covers a potential scribe line (i.e., along an affected butt joint location), provided the doubler includes a minimum of three fastener rows forward and three fastener rows aft of the potential scribe line location (perpendicular to the direction of the scribe line). External repairs that do not meet this requirement must be removed to allow skin butt joint inspection. Inspection zone thresholds are based upon analysis of fuselage geometry and loads. Zone 1 has the lowest inspection threshold and Zone 3 has the highest inspection threshold. This service bulletin has five (5) areas for scribe line inspections. The areas are as follows: BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 16 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 17 — Skin Lap Joints — Skin Butt Joints — External Approved Repairs — External Features — Decals and Fairings Boeing recommends that operators do inspections for scribe lines at the times given in the Compliance tables. The Compliance tables are broken down into three main sections as follows: 1. Tables 1 through 3 show the initial scribe line inspection for the five (5) areas to be inspected. 2. Tables 4 through 15 show the LRTS repeat inspection intervals for the five (5) areas to be inspected. 3. Table 16 shows how to disposition known existing scribe line damage outside of Zones 1, 2, and 3. NOTE: Refer to Accomplishment Instructions Paragraph 3.B for identification of a typical scribe line. 1. 2. Refer to Appendix A of this service bulletin as an accepted sealant removal procedure. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 17 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 18 Table 1 - Initial Scribe Line Inspections - Zone 1 Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) ActionCondition -Within 6 months after the original is- sue date on this service bulletin. -Do detailed inspections of the applicable skin lap joints, skin butt joints, external approved repairs, external features, de- cals, and fairings in Zone 1 for any scribe line using the tables in accordance with Accomplish- ment Instructions Paragraph 3.B.4 - Part 2. Airplanes with more than 60,000 total flight cycles as of the original issue date on this service bul- letin. -Within 12 months after the original is- sue date on this service bulletin. -Airplanes with more than 45,000 total flight cycles, but no more than 60,000 total flight cycles, as of the original issue date on this service bulletin. -Within 24 months after the original is- sue date on this service bulletin. Before 30,000 total flight cy- cles Airplanes with 45,000 total flight cycles or less as of the original issue date on this service bul- letin. ---No further inspections are re- quired provided the correct sealant removal procedure is implemented for all future work in accordance with Accomplish- ment Instructions Paragraph 3.B.5 - Part 3. No scribe line is found. --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. ---No repair or further inspections are required provided the cor- rect sealant removal procedure is implemented for all future work. Do surface finish restora- tion in accordance with Accom- plishment Instructions Para- graph 3.B.9 - Part 7. Scribe line is found less than 0.001 inch deep. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 18 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 19 Table 1 - Initial Scribe Line Inspections - Zone 1 Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) ActionCondition --Before further flight. Do Low or High Frequency Ed- dy Current (LFEC or HFEC) and/or Ultrasonic (UT) inspec- tions for any crack in accor- dance with Accomplishment In- structions Paragraph 3.B.7 - Part 5. Scribe line is found with- in the limits of a typical scribe line and more than or equal to 0.001 inch deep and less than or equal to 0.006 inch deep. Or --Before further flight. Contact Boeing for repair instruc- tions and do the repair. --Before further flight. Do Low or High Frequency Ed- dy Current (LFEC or HFEC) and/or Ultrasonic (UT) inspec- tions for any crack in accor- dance with Accomplishment In- structions Paragraph 3.B.7 - Part 5. Scribe line is found with- in the limits of a typical scribe line and is greater than 0.006 inch deep. And --Before further flight. Contact Boeing for repair instruc- tions and do the repair. Refer to the LRTS Tables 4 to 15 for repeat intervals. -Before LRTS repeat intervals in Tables 4 to 15. Do the LRTS repeat inspections in accordance with Accomplish- ment 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. (a) (a)(a) Or --Before further flight. Contact Boeing for repair instruc- tions and do the repair. --Before further flight. Contact Boeing for repair instruc- tions and do the repair. If any crack is found. And --Before further flight. Do detailed inspections of the applicable skin lap joints, skin butt joints, external approved repairs, external features, de- cals, and fairings in Zone 2 for any scribe line in accordance with Table 2 of Compliance Paragraph 1.E. (a) LRTS is not an option for airplanes with more than 60,000 total flight cycles. Operators must contact Boeing for additional inspections or repair after 60,000 total flight cycles. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 19 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 20 Table 2 - Initial Scribe Line Inspections - Zone 2 Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) ActionCondition -Before further flight.Do detailed inspections of the applicable skin lap joints, skin butt joints, external approved repairs, external features, de- cals, and fairings in Zone 2 for any scribe line using the tables in accordance with Accomplish- ment Instructions Paragraph 3.B.4 - Part 2. Any airplane with a crack found at a scribe line in Zone 1. -Within 12 months after the original is- sue date on this service bulletin. -Airplanes with more than 60,000 total flight cycles as of the original issue date on this service bul- letin. -Within 24 months after the original is- sue date on this service bulletin. -Airplanes with more than 45,000 total flight cycles, but no more than 60,000 total flight cycles, as of the original issue date on this service bulletin. -Within 36 months after the original is- sue date on this service bulletin. Before 45,000 total flight cy- cles Airplanes with 45,000 or less total flight cycles as of the original issue date on this service bulletin. ---No further inspections are re- quired provided the correct sealant removal procedure is implemented for all future work in accordance with Accomplish- ment Instructions Paragraph 3.B.5 - Part 3. No scribe line is found. --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. ---No repair or further inspections are required provided the cor- rect sealant removal procedure is implemented for all future work. Do surface finish restora- tion in accordance with Accom- plishment Instructions Para- graph 3.B.9 - Part 7. Scribe line is found less than 0.001 inch deep. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 20 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 21 Table 2 - Initial Scribe Line Inspections - Zone 2 Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) ActionCondition --Before further flight. Do Low or High Frequency Ed- dy Current (LFEC or HFEC) and/or Ultrasonic (UT) inspec- tions for any crack in accor- dance with Accomplishment In- structions Paragraph 3.B.7 - Part 5. Scribe line is found with- in the limits of a typical scribe line and more than or equal to 0.001 inch deep and less than or equal to 0.006 inch deep. Or --Before further flight. Contact Boeing for repair instruc- tions and do the repair. --Before further flight. Do Low or High Frequency Ed- dy Current (LFEC or HFEC) and/or Ultrasonic (UT) inspec- tions for any crack in accor- dance with Accomplishment In- structions Paragraph 3.B.7 - Part 5. Scribe line is found with- in the limits of a typical scribe line and is greater than 0.006 inch deep. And --Before further flight. Contact Boeing for repair instruc- tions and do the repair. Refer to the LRTS Tables 4 to 15 for repeat intervals. -Before LRTS repeat intervals in Tables 4 to 15. Do the LRTS repeat inspections in accordance with Accomplish- ment 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. (a) (a)(a) Or --Before further flight. Contact Boeing for repair instruc- tions and do the repair. --Before further flight. Contact Boeing for repair instruc- tions and do the repair. If any crack is found. And --Before further flight. Do detailed inspections of the applicable skin lap joints, skin butt joints, external approved repairs, external features, de- cals, and fairings in Zone 3 for any scribe line in accordance with Table 3 of Compliance Paragraph 1.E. (a) LRTS is not an option for airplanes with more than 60,000 total flight cycles. Operators must contact Boeing for additional inspections or repair after 60,000 total flight cycles. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 21 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 22 Table 3 - Initial Scribe Line Inspections - Zone 3 Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) ActionCondition -Before further flight.Do detailed inspections of the applicable skin lap joints, skin butt joints, external approved repairs, external features, de- cals, and fairings in Zone 3 for any scribe line using the tables in accordance with Accomplish- ment Instructions Paragraph 3.B.4 - Part 2. Any airplane with a crack found at a scribe line in Zone 2. -Within 24 months after the original is- sue date on this service bulletin. -Airplanes with more than 60,000 total flight cycles as of the original issue date on this service bul- letin. -Within 36 months after the original is- sue date on this service bulletin. Before 60,000 total flight cy- cles Airplanes with 60,000 or less total flight cycles as of the original issue date on this service bulletin. ---No further inspections are re- quired provided the correct sealant removal procedure is implemented for all future work in accordance with Accomplish- ment Instructions Paragraph 3.B.5 - Part 3. No scribe line is found. --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. ---No repair or further inspections are required provided the cor- rect sealant removal procedure is implemented for all future work. Do surface finish restora- tion in accordance with Accom- plishment Instructions Para- graph 3.B.9 - Part 7. Scribe line is found less than 0.001 inch deep. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 22 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 23 Table 3 - Initial Scribe Line Inspections - Zone 3 Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) ActionCondition --Before further flight. Do Low or High Frequency Ed- dy Current (LFEC or HFEC) and/or Ultrasonic (UT) inspec- tions for any crack in accor- dance with Accomplishment In- structions Paragraph 3.B.7 - Part 5. Scribe line is found with- in the limits of a typical scribe line and more than or equal to 0.001 inch deep and less than or equal to 0.006 inch deep. Or --Before further flight. Contact Boeing for repair instruc- tions and do the repair. --Before further flight. Do Low or High Frequency Ed- dy Current (LFEC or HFEC) and/or Ultrasonic (UT) inspec- tions for any crack in accor- dance with Accomplishment In- structions Paragraph 3.B.7 - Part 5. Scribe line is found with- in the limits of a typical scribe line and is greater than 0.006 inch deep. And --Before further flight. Contact Boeing for repair instruc- tions and do the repair. Refer to the LRTS Tables 4 to 15 for repeat intervals. -Before LRTS repeat intervals in Tables 4 to 15. Do the LRTS repeat inspections in accordance with Accomplish- ment 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. (a) (a)(a) Or --Before further flight. Contact Boeing for repair instruc- tions and do the repair. --Before further flight. Contact Boeing for additional inspections and repair instruc- tions. Do the inspections and repair. If any crack is found. (a) LRTS is not an option for airplanes with more than 60,000 total flight cycles. Operators must contact Boeing for additional inspections or repair after 60,000 total flight cycles. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 23 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 24 Group 1: Table 4 - Skin Lap Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition Flight Cycles Do a detailed inspection, High Frequency Eddy Current (HFEC) and/or Ultrasonic (UT) inspections for any crack in accordance with the Accomplishment Instructions Paragraph 3.B.8 - Part 6 for the skin lap joint areas that follow: All Airplanes with scribe lines using a Limited Re- turn To Service (LRTS) Program Skin Lap Joints Station LocationStringer From - ToLocation 1,200-STA 460 - 500S-26R 1,200-STA 600 - 681 2,400-STA 178 - 259.5S-24R 2,400-STA 294.5 - 328 2,400-STA 970 - 1030S-20R 1,200-STA 1130 - 1148 2,400-STA 178 - 259.5S-19R 800-STA 259.5 - 294.5 800-STA 312 - 500 4,000-STA 681 - 740 2,400-STA 259.5 - 360S-14R 1,200-STA 360 - 520 2,400-STA 520 - 580 1,600-STA 700 - 740 1,200-STA 990 - 1183 1,600-STA 259.5 - 360S-10R 2,000-STA 259.5 - 328S-4R 1,600-STA 328 - 360 1,200-STA 360 - 740 2,400-STA 740 - 783.95 1,600-STA 910 - 1030 1,200-STA 1030 - 1130 800-STA 1130 - 1148 2,400-STA 178 - 196.5RBL 5.7 - Nose 2,400-STA 178 - 196.5LBL 5.7 - Nose BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 24 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 25 Group 1: Table 4 - Skin Lap Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition S-4L 2,400 -STA 259.5 - 294.5 1,200-STA 360 - 740 2,400-STA 740 - 783.95 1,600-STA 910 - 1030 1,200-STA 1030 - 1130 800-STA 1130 - 1148 1,600-STA 259.5 - 294.5S-10L 2,800-STA 259.5 - 277S-14L 1,200-STA 360 - 441 800-STA 441 - 481 1,200-STA 481 - 740 1,200-STA 990 - 1183 2,400-STA 178 - 259.5S-19L 800-STA 259.5 - 294.5 800-STA 360 - 441 1,600-STA 441 - 740 2,800-STA 990 - 1070S-20L 2,000-STA 1070 - 1130 1,200-STA 1130 - 1148 2,400-STA 178 - 259.5S-24L 4,800-STA 259.5 - 277 1,200-STA 460 - 681S-26L 3,200-STA 1050 - 1070 2,000-STA 1090 - 1130 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 25 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 26 Group 1: Table 4 - Skin Lap Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before further flight. Contact Boeing for repair instructions and do the repair. If any crack is found. And -Before further flight. Do detailed inspections of the skin lap joints, skin butt joints, external approved repairs, external features, decals, and fairings in the next higher Zone, up to Zone 3, for any scribe line using the tables in accordance with Accomplishment Instructions 3.B.4 - Part 2. If crack is in Zone 3, contact Boeing for additional inspections and do the inspec- tions. -Before 60,000 to- tal flight cycles or within 6 months after the original issue date on this service bulletin, whichever occurs later. Contact Boeing for additional inspections or repair. Do the inspections or repair. All Airplanes with scribe lines using a LRTS Pro- gram Inspection. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 26 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 27 Group 2: Table 5 - Skin Lap Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition Flight Cycles Do a detailed inspection, High Frequency Eddy Current (HFEC) and/or Ultrasonic (UT) inspections for any crack in accordance with the Accomplishment Instructions Paragraph 3.B.8 - Part 6 for the skin lap joint areas that follow: All Airplanes with scribe lines using a Limited Re- turn To Service (LRTS) Program Skin Lap Joints Station LocationStringer From - ToLocation 1,200-STA 460 - 500S-26R 1,200-STA 600 - 681 2,400-STA 178 - 259.5S-24R 2,400-STA 294.5 - 328 1,200-STA 970 - 1030S-20R 1,200-STA 1130 - 1148 2,400-STA 178 - 259.5S-19R 800-STA 259.5 - 294.5 800-STA 312 - 500 4,000-STA 681 - 740 2,400-STA 259.5 - 360S-14R 1,200-STA 360 - 520 2,400-STA 520 - 580 1,600-STA 600 - 620 1,600-STA 700 - 740 1,200-STA 990 - 1183 1,600-STA 259.5 - 360S-10R 2,000-STA 259.5 - 328S-4R 1,600-STA 328 - 360 1,200-STA 360 - 520 800-STA 520 - 740 2,800-STA 740 - 783.95 1,600-STA 910 - 1030 1,200-STA 1030 - 1130 800-STA 1130 - 1148 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 27 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 28 Group 2: Table 5 - Skin Lap Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition RBL 5.7 - Nose 2,400 -STA 178 - 196.5 2,400-STA 178 - 196.5LBL 5.7 - Nose 2,400-STA 259.5 - 294.5S-4L 1,200-STA 360 - 420 800-STA 420 - 441 2,800-STA 740 - 783.95 1,600-STA 910 - 1030 1,200-STA 1030 - 1130 800-STA 1130 - 1148 1,200-STA 681 - 740S-6L 1,600-STA 259.5 - 294.5S-10L 2,800-STA 259.5 - 277S-14L 1,200-STA 360 - 441 3,200-STA 441 - 481 2,000-STA 681 - 740 1,200-STA 990 - 1183 2,400-STA 178 - 259.5S-19L 800-STA 259.5 - 294.5 800-STA 360 - 441 1,600-STA 681 - 740 2,800-STA 990 - 1070S-20L 2,000-STA 1070 - 1130 1,200-STA 1130 - 1148 2,400-STA 178 - 259.5S-24L 4,800-STA 259.5 - 277 1,200-STA 460 - 620S-26L 800-STA 620 - 681 3,200-STA 1050 - 1070 2,000-STA 1090 - 1130 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 28 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 29 Group 2: Table 5 - Skin Lap Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before further flight. Contact Boeing for repair instructions and do the repair. If any crack is found. And -Before further flight. Do detailed inspections of the skin lap joints, skin butt joints, external approved repairs, external features, decals, and fairings in the next higher Zone, up to Zone 3, for any scribe line using the tables in accordance with Accomplishment Instructions 3.B.4 - Part 2. If crack is in Zone 3, contact Boeing for additional inspections and do the inspec- tions. -Before 60,000 to- tal flight cycles or within 6 months after the original issue date on this service bulletin, whichever occurs later. Contact Boeing for additional inspections or repair. Do the inspections or repair. All Airplanes with scribe lines using a LRTS Pro- gram Inspection. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 29 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 30 Group 3: Table 6 - Skin Lap Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition Flight Cycles Do a detailed inspection, High Frequency Eddy Current (HFEC) and/or Ultrasonic (UT) inspections for any crack in accordance with the Accomplishment Instructions Paragraph 3.B.8 - Part 6 for the skin lap joint areas that follow: All Airplanes with scribe lines using a Limited Re- turn To Service (LRTS) Program Skin Lap Joints Station LocationStringer From - ToLocation 800-STA 400 - 560S-26R 800-STA 660 - 720B 1,600-STA 1030 - 1070 2,400-STA 178 - 259.5S-24R 1,200-STA 294.5 - 360 1,200-STA 1009 - 1070S-20R 2,400-STA 178 - 259.5S-19R 1,200-STA 259.5 - 294.5 800-STA 312 - 540 1,600-STA 640 - 720C 2,400-STA 277 - 360S-14R 800-STA 441 - 520 2,400-STA 520 - 660 800-STA 660 - 720B 2,000-STA 720B - 720E 2,000-STA 1090 - 1148 1,600-STA 259.5 - 360S-10R 2,000-STA 259.5 - 328S-4R 1,600-STA 328 - 360 1,200-STA 360 - 720A 1,600-STA 720A - 740 2,800-STA 740 - 804.5 1,600-STA 910 - 950D 800-STA 950D - 1148 2,400-STA 178 - 196.5RBL 5.7 - Nose BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 30 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 31 Group 3: Table 6 - Skin Lap Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition LBL 5.7 - Nose 2,400 -STA 178 - 196.5 2,400-STA 259.5 - 294.5S-4L 1,200-STA 360 - 720A 1,600-STA 720A - 740 2,800-STA 740 - 804.5 1,600-STA 910 - 950D 800-STA 950D - 1148 2,000-STA 259.5 - 294.5S-10L 2,000-STA 360 - 441S-14L 800-STA 441 - 720B 1,600-STA 720B - 740 2,000-STA 950D - 1009 800-STA 1009 - 1030 1,200-STA 1070 - 1148 2,400-STA 178 - 259.5S-19L 1,200-STA 259.5 - 294.5 800-STA 360 - 441 2,000-STA 441 - 681 1,600-STA 681 - 720C 2,800-STA 950F - 1009S-20L 2,800-STA 1009 - 1110 800-STA 1110 - 1148 2,400-STA 178 - 259.5S-24L 4,800-STA 259.5 - 277 800-STA 400 - 420S-26L 1,200-STA 481 - 681 800-STA 681 - 720 2,400-STA 720 - 720B 1,200-STA 1030 - 1130 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 31 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 32 Group 3: Table 6 - Skin Lap Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before further flight. Contact Boeing for repair instructions and do the repair. If any crack is found. And -Before further flight. Do detailed inspections of the skin lap joints, skin butt joints, external approved repairs, external features, decals, and fairings in the next higher Zone, up to Zone 3, for any scribe line using the tables in accordance with Accomplishment Instructions 3.B.4 - Part 2. If crack is in Zone 3, contact Boeing for additional inspections and do the inspec- tions. -Before 60,000 to- tal flight cycles or within 6 months after the original issue date on this service bulletin, whichever occurs later. Contact Boeing for additional inspections or repair. Do the inspections or repair. All Airplanes with scribe lines using a LRTS Pro- gram Inspection. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 32 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 33 Group 4: Table 7 - Skin Lap Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition Flight Cycles Do a detailed inspection, High Frequency Eddy Current (HFEC) and/or Ultrasonic (UT) inspections for any crack in accordance with the Accomplishment Instructions Paragraph 3.B.8 - Part 6 for the skin lap joint areas that follow: All Airplanes with scribe lines using a Limited Re- turn To Service (LRTS) Program Skin Lap Joints Station LocationStringer From - ToLocation 800-STA 460 - 520S-26R 1,600-STA 660 - 720A 1,600-STA 1030 - 1130 2,400-STA 178 - 259.5S-24R 1,200-STA 294.5 - 360 2,800-STA 1009 - 1030S-20R 1,600-STA 1110 - 1148 2,400-STA 178 - 259.5S-19R 1,200-STA 259.5 - 294.5 1,200-STA 312 - 540 1,200-STA 640 - 720C 2,400-STA 277 - 360S-14R 1,200-STA 360 - 520 1,200-STA 660 - 720B 2,000-STA 720C - 720E 1,200-STA 1009 - 1183 1,600-STA 259.5 - 360S-10R 2,800-STA 1050- 1148 2,000-STA 259.5 - 328S-4R 1,600-STA 328 - 441 800-STA 441 - 681 1,200-STA 681 - 720A 1,600-STA 720A - 740 2,800-STA 740 - 804.5 1,600-STA 910 - 950D BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 33 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 34 Group 4: Table 7 - Skin Lap Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition 800-STA 950D - 1148 2,400-STA 178 - 196.5RBL 5.7 - Nose 2,400-STA 178 - 196.5LBL 5.7 - Nose 2,400-STA 259.5 - 294.5S-4L 1,200-STA 360 - 441 1,200-STA 681 - 720A 1,600-STA 720A - 740 2,800-STA 740 - 804.5 1,600-STA 910 - 950D 800-STA 950D - 1148 2,000-STA 259.5 - 294.5S-10L 2,800-STA 1050 - 1148 2,400-STA 360 - 441S-14L 1,200-STA 681 - 720B 2,000-STA 720C - 720E 2,000-STA 950D - 1009 1,200-STA 1009 - 1183 2,400-STA 178 - 259.5S-19L 1,200-STA 259.5 - 294.5 2,800-STA 360 - 441 1,600-STA 681 - 720C 1,600-STA 1070 - 1148S-20L 2,400-STA 178 - 259.5S-24L 4,800-STA 259.5 - 277 1,200-STA 460 - 620S-26L 800-STA 620 - 640 1,600-STA 640 - 720A 1,200-STA 1009 - 1130 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 34 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 35 Group 4: Table 7 - Skin Lap Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before further flight. Contact Boeing for repair instructions and do the repair. If any crack is found. And -Before further flight. Do detailed inspections of the skin lap joints, skin butt joints, external approved repairs, external features, decals, and fairings in the next higher Zone, up to Zone 3, for any scribe line using the tables in accordance with Accomplishment Instructions 3.B.4 - Part 2. If crack is in Zone 3, contact Boeing for additional inspections and do the inspec- tions. -Before 60,000 to- tal flight cycles or within 6 months after the original issue date on this service bulletin, whichever occurs later. Contact Boeing for additional inspections or repair. Do the inspections or repair. All Airplanes with scribe lines using a LRTS Pro- gram Inspection. Group 1, 3: Table 8 - Skin Butt Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition Flight Cycles Do a detailed inspection and Low or High Frequency Eddy Current (LFEC or HFEC) inspections for any crack in accordance with the Accomplishment Instructions Paragraph 3.B.8 - Part 6 for the skin butt joint area that follows: All Airplanes with scribe lines using a Limited Re- turn To Service (LRTS) Program Skin Butt Joints Stringer LocationStation From - ToLocation 9,000-S-4R To S-4LSTA 481 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 35 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 36 Group 1, 3: Table 8 - Skin Butt Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before further flight. Contact Boeing for repair instructions and do the repair. If any crack is found. And -Before further flight. Do detailed inspections of the skin lap joints, skin butt joints, external approved repairs, external features, decals, and fairings in the next higher Zone, up to Zone 3, for any scribe line using the tables in accordance with Accomplishment Instructions 3.B.4 - Part 2. If crack is in Zone 3, contact Boeing for additional inspections and do the inspec- tions. -Before 60,000 to- tal flight cycles or within 6 months after the original issue date on this service bulletin, whichever occurs later. Contact Boeing for additional inspections or repair. Do the inspections or repair. All Airplanes with scribe lines using a LRTS Pro- gram Inspection. Group 4: Table 9 - Skin Butt Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition Flight Cycles Do a detailed inspection and Low or High Frequency Eddy Current (LFEC or HFEC) inspections for any crack in accordance with the Accomplishment Instructions Paragraph 3.B.8 - Part 6 for the skin butt joint areas that follow: All Airplanes with scribe lines using a Limited Re- turn To Service (LRTS) Program Skin Butt Joints Stringer LocationStation From - ToLocation 7,500-S-4R To S-10LSTA 441 9,000-S-10R To S-4RSTA 481 6,000-S-4R To S-3LSTA 520 3,000-S-4R To S-10LSTA 681 3,000-S-10R To S-4RSTA 740 3,000-S-4L To S-10LSTA 740 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 36 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 37 Group 4: Table 9 - Skin Butt Joints - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before further flight. Contact Boeing for repair instructions and do the repair. If any crack is found. And -Before further flight. Do detailed inspections of the skin lap joints, skin butt joints, external approved repairs, external features, decals, and fairings in the next higher Zone, up to Zone 3, for any scribe line using the tables in accordance with Accomplishment Instructions 3.B.4 - Part 2. If crack is in Zone 3, contact Boeing for additional inspections and do the inspec- tions. -Before 60,000 to- tal flight cycles or within 6 months after the original issue date on this service bulletin, whichever occurs later. Contact Boeing for additional inspections or repair. Do the inspections or repair. All Airplanes with scribe lines using a LRTS Pro- gram Inspection. Group 1-4: Table 10 - External Approved Repairs - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition 1,000 flight cycles-Do a detailed inspection, High Frequency Eddy Current (HFEC), and/or Ultrasonic (UT) inspections for any crack in accor- dance with Accomplishment Instructions Paragraph 3.B.8 - Part 6. All Airplanes with scribe lines using a Limited Re- turn To Service (LRTS) Program External Approved Re- pairs - 20 inches or longer on any side. 1,500 flight cycles-Do a detailed inspection, HFEC and/or UT inspections for any crack in accordance with Accomplishment Instructions Para- graph 3.B.8 - Part 6. All Airplanes with scribe lines using a LRTS Pro- gram External Approved Re- pairs - Less than 20 inches on all sides. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 37 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 38 Group 1-4: Table 10 - External Approved Repairs - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before further flight. Contact Boeing for repair instructions and do the repair. If any crack is found. And -Before further flight. Do detailed inspections of the skin lap joints, skin butt joints, external approved repairs, external features, decals, and fairings in the next higher Zone, up to Zone 3, for any scribe line using the tables in accordance with Accomplishment In- structions 3.B.4 - Part 2. If crack is in Zone 3, contact Boeing for additional inspec- tions and do the inspections. -Before 60,000 to- tal flight cycles or within 6 months after the original issue date on this service bulletin, whichever occurs later. Contact Boeing for additional inspections or repair. Do the inspections or repair. All airplanes with scribe lines using a LRTS pro- gram inspection. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 38 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 39 Group 1: Table 11 - External Features - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance Time ActionCondition Do a detailed inspection, High Frequency Eddy Current (HFEC) and/or Ultrasonic (UT) inspections for any crack in accordance with Accomplishment Instructions Paragraph 3.B.8 - Part 6 for the Exter- nal Features that follow: All Airplanes with scribe lines using a Limited Return To Service (LRTS) Pro- gram External Features Flight CyclesExternal FeatureStation Location Stringer Location 1,000-Wing Scanning Light590S-15L To S- 16L 1,000-Wing Scanning Light590S-15R To S- 16R 1,000-Rotating Beacon590S-1 To S-2L 1,000-Pitot Tube, Left Side215S-20L To S- 21L 1,000-Pitot Tubes, Right Side215S-20R To S- 21R 1,000-Traffic Collision and Avoidance (TCAS) An- tenna, lower 412 (a)C/L, bottom 1,000-TCAS Antenna, upper427 (a)S-1 To S-2L 1,000-Air Traffic Control (ATC) Antenna, lower 470 (a)C/L, bottom 1,000-ATC Antenna, upper470 (a)S-1 To S-2R 1,000-Very High Frequency (VHF) Antenna 630S-1 1,000-Rain Gutter, Passenger Door 303-340S-5L 1,000-Rain Gutter, Galley Door 640-680S-5R BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 39 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 40 Group 1: Table 11 - External Features - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance Time ActionCondition -Before further flight. Contact Boeing for repair instructions and do the repair. If any crack is found. And -Before further flight. Do detailed inspections of the skin lap joints, skin butt joints, external approved repairs, external features, decals, and fairings in the next higher Zone, up to Zone 3, for any scribe line using the tables in accordance with Accomplishment Instruc- tions 3.B.4 - Part 2. If crack is in Zone 3, contact Boeing for additional inspections and do the inspec- tions. Before 60,000 total flight cy- cles or within 6 months after the original is- sue date on this service bulletin, whichever oc- curs later. Contact Boeing for additional inspections or repair. Do the inspections or repair. All airplanes with scribe lines using a LRTS program in- spection. (a) Location may vary depending on operator. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 40 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 41 Group 2: Table 12 - External Features - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance Time ActionCondition Do a detailed inspection, High Frequency Eddy Current (HFEC) and/or Ultrasonic (UT) inspections for any crack in accordance with Accomplishment Instructions Paragraph 3.B.8 - Part 6 for the External Features that follow: All Airplanes with scribe lines using a Limited Return To Service (LRTS) Pro- gram External Features Flight CyclesExternal FeatureStation Location Stringer Loca- tion 1,000-Wing Scanning Light670S-15L To S- 16L 1,000-Wing Scanning Light590S-15R To S- 16R 1,000-Rotating Beacon590S-1 To S-2L 1,000-Pitot Tube, Left Side215S-20L To S- 21L 1,000-Pitot Tubes, Right Side215S-20R To S- 21R 1,000-Traffic Collision and Avoidance (TCAS) An- tenna, lower 412 (a)C/L, bottom 1,000-TCAS Antenna, upper427 (a)S-1To S-2L 1,000-Air Traffic Control (ATC) Antenna, lower 470 (a)C/L, bottom 1,000-ATC Antenna, upper470 (a)S-1 To S-2R 1,000-Very High Frequency (VHF) Antenna 710S-1 1,000-Rain Gutter, Passenger Door 303-340S-5L 1,000-Rain Gutter, Galley Door 640-680S-5R 1,000-Hinge, Main Cargo Door 481-620S-3L BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 41 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 42 Group 2: Table 12 - External Features - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance Time ActionCondition -Before further flight. Contact Boeing for repair instructions and do the repair. If any crack is found. And -Before further flight. Do detailed inspections of the skin lap joints, skin butt joints, external approved repairs, external fea- tures, decals, and fairings in the next higher Zone, up to Zone 3, for any scribe line using the tables in accordance with Accomplishment Instructions 3.B.4 - Part 2. If crack is in Zone 3, contact Boeing for additional inspections and do the inspections. Before 60,000 total flight cy- cles or within 6 months after the original is- sue date on this service bulletin, whichever oc- curs later. Contact Boeing for additional inspections or repair. Do the inspections or repair. All airplanes with scribe lines using a LRTS program in- spection. (a) Location may vary depending on operator. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 42 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 43 Group 3: Table 13 - External Features - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance Time ActionCondition Do a detailed inspection, High Frequency Eddy Current (HFEC) and/or Ultrasonic (UT) inspection in accordance with Accomplishment Instructions Paragraph 3.B.8 - Part 6 for the External Features that follow: All Airplanes with scribe lines using a Limited Return To Service (LRTS) Pro- gram External Features Flight CyclesExternal FeatureStation Location Stringer Loca- tion 1,000-Wing Scanning Light720B- 720C S-15L To S- 16L 1,000-Wing Scanning Light720B- 720C S-15R To S- 16R 1,000-Rotating Beacon590S-1 To S-2L 1,000-Pitot Tube, Left Side215S-20L To S- 21L 1,000-Pitot Tubes, Right Side215S-20R To S- 21R 1,000-Traffic Collision and Avoidance (TCAS) An- tenna, lower 412 (a)C/L, bottom 1,000-TCAS Antenna, upper427 (a)S-1 To S-2L 1,000-Air Traffic Control (ATC) Antenna, lower 470 (a)C/L, bottom 1,000-ATC Antenna, upper470 (a)S-1 To S-2R 1,000-Very High Frequency (VHF) Antenna 710S-1 1,000-Rain Gutter, Passenger Door 303-340S-5L 1,000-Rain Gutter, Galley Door 380-420S-8R 1,000-Rain Gutter, Service Door 1030- 1070 S-9L 1,000-Rain Gutter, Service Door 1030- 1070 S-9R BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 43 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 44 Group 3: Table 13 - External Features - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance Time ActionCondition -Before further flight. Contact Boeing for repair instructions and do the repair. If any crack is found. And -Before further flight. Do detailed inspections of the skin lap joints, skin butt joints, external approved repairs, external fea- tures, decals, and fairings in the next higher Zone, up to Zone 3, for any scribe line using the tables in accordance with Accomplishment Instructions 3.B.4 - Part 2. If crack is in Zone 3, contact Boeing for additional inspections and do the inspections. Before 60,000 total flight cy- cles or within 6 months after the original is- sue date on this service bulletin, whichever oc- curs later. Contact Boeing for additional inspections or repair. Do the inspections or repair. All airplanes with scribe lines using a LRTS program in- spection. (a) Location may vary depending on operator. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 44 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 45 Group 4: Table 14 - External Features - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance Time ActionCondition Do a detailed inspection, High Frequency Eddy Current (HFEC) and/or Ultrasonic (UT) inspections for any crack in accordance with Accomplishment Instructions Paragraph 3.B.8 - Part 6 for the Exter- nal Features that follow: All Airplanes with scribe lines using a Limited Return To Service (LRTS) Pro- gram External Features Flight CyclesExternal FeatureStation Location Stringer Location 1,000-Wing Scanning Light720B- 720C S-15L To S- 16L 1,000-Wing Scanning Light720B- 720C S-15R To S- 16R 1,000-Rotating Beacon590S-1 To S-2L 1,000-Pitot Tube, Left Side215S-20L To S- 21L 1,000-Pitot Tubes, Right Side215S-20R To S- 21R 1,000-Traffic Collision and Avoidance (TCAS) An- tenna, lower 412 (a)C/L, bottom 1,000-TCAS Antenna, upper427 (a)S-1 To S-2L 1,000-Air Traffic Control (ATC) Antenna, lower 470 (a)C/L, bottom 1,000-ATC Antenna, upper470 (a)S-1 To S-2R 1,000-Very High Frequency (VHF) Antenna 710S-1 1,000-Rain Gutter, Passenger Door 303-340S-5L 1,000-Hinge, Main Cargo Door 481-620S-3L BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 45 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 46 Group 4: Table 14 - External Features - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance Time ActionCondition -Before further flight. Contact Boeing for repair instructions and do the repair. If any crack is found. And -Before further flight. Do detailed inspections of the skin lap joints, skin butt joints, external approved repairs, external features, decals, and fairings in the next higher Zone, up to Zone 3, for any scribe line using the tables in accordance with Accomplishment Instruc- tions 3.B.4 - Part 2. If crack is in Zone 3, contact Boeing for additional inspections and do the inspec- tions. -Before 60,000 total flight cy- cles or within 6 months after the original is- sue date on this service bulletin, whichever oc- curs later. Contact Boeing for additional inspections or repair. Do the inspections or repair. All airplanes with scribe lines using a LRTS program in- spection. (a) Location may vary depending on operator. Table 15 - Decals and Fairings - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition 1,500 flight cy- cles Do a detailed inspection and High Frequen- cy Eddy Current (HFEC) inspection for any crack in accordance with Accomplishment Instructions Paragraph 3.B.8 - Part 6. All Airplanes with scribe lines using a Limited Re- turn To Service (LRTS) Program Decals and Fairings BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 46 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 47 Table 15 - Decals and Fairings - Limited Return To Service Repeat Inspection Intervals Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before further flight. Contact Boeing for repair instructions and do the repair. If any crack is found. And -Before further flight Do detailed inspections of the skin lap joints, skin butt joints, external approved repairs, external features, decals, and fairings in the next higher Zone, up to Zone 3, for any scribe line using the tables in accordance with Accomplishment Instructions 3.B.4 - Part 2. If crack is in Zone 3, contact Boeing for additional inspections and do the inspec- tions. -Before 60,000 to- tal flight cycles or within 6 months after the original issue date on this service bulletin, whichever occurs later. Contact Boeing for additional inspections or repair. Do the inspections or repair. All airplanes with scribe lines using a LRTS pro- gram inspection. Table 16 - Known Existing Scribe Line Damage - Outside of Zones 1, 2, and 3 Compliance TimeActionCondition Before 60,000 to- tal flight cycles. Measure the scribe line depth in accordance with Accom- plishment Instructions Paragraph 3.B.10 - Part 8 for the fuselage areas that follow. All Airplanes with known existing scribe line dam- age outside Zones 1, 2, and 3 Skin Lap Joints Skin Butt Joints External Approved Repairs External Features Decals and Fairings -No repair or further inspections are required provided the correct sealant removal procedure is implemented for all future work. Scribe line is less than 0.001 inch deep. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 47 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 48 Table 16 - Known Existing Scribe Line Damage - Outside of Zones 1, 2, and 3 Compliance TimeActionCondition Before further flight. Do a Low or High Frequency Eddy Current (LFEC or HFEC) and/or Ultrasonic (UT) inspections for any crack in accordance with Accomplishment Instructions Para- graph 3.B.10 - Part 8. Scribe line is greater than or equal to 0.001 inch deep. Or Before further flight. Contact Boeing for repair instructions and do the repair. -No repair or further inspections are required provided the correct sealant removal procedure is implemented for all future work. 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. Before 60,000 to- tal flight cycles. Contact Boeing for additional inspections or repair. Do the additional inspections 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. Before further flight. Contact Boeing for repair instructions and do the repair.If no crack is found and the damage is greater than 0.006 inch deep. Before further flight. Contact Boeing for additional inspections and repair in- structions. Do the additional inspections and repair. If any crack is found. F. Approval This service bulletin was examined by the Federal Aviation Administration (FAA). The changes specified in this service bulletin comply with the applicable regulations and are FAA approved, as well as European Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved airplanes listed in the service bulletin effectivity. This service bulletin and its approval were based on the airplane in its original Boeing delivery configuration or as modified by other approved Boeing changes. 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: BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 48 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 49 — 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. Group 1: Scribe Line Inspection Elapsed HoursTask HoursNumber of PersonsTask 8.080.010Figure 1 8.080.010Figure 5 6.060.010Figure 9 10.020.02Figure 13 10.020.02Figure 17 10.020.02Figure 23 10.020.02Figure 27 62.0 *300.0 *TOTAL FOR EACH AIRPLANE * Total Task Hours and Elapsed Hours dependent upon total number of fuselage areas and zones 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 8.080.010Figure 2 8.080.010Figure 6 6.060.010Figure 10 10.020.02Figure 14 10.020.02Figure 18 10.020.02Figure 24 10.020.02Figure 28 62.0 *300.0 *TOTAL FOR EACH AIRPLANE * Total Task Hours and Elapsed Hours dependent upon total number of fuselage areas and zones being inspected. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 49 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 50 Group 2: 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 repair doublers. Group 3: Scribe Line Inspection Elapsed HoursTask HoursNumber of PersonsTask 8.080.010Figure 3 8.080.010Figure 7 6.060.010Figure 11 10.020.02Figure 15 10.020.02Figure 19 10.020.02Figure 21 10.020.02Figure 25 10.020.02Figure 29 72.0 *320.0 *TOTAL FOR EACH AIRPLANE * Total Task Hours and Elapsed Hours dependent upon total number of fuselage areas and zones 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 4: Scribe Line Inspection Elapsed HoursTask HoursNumber of PersonsTask 8.080.010Figure 4 8.080.010Figure 8 6.060.010Figure 12 10.020.02Figure 16 10.020.02Figure 20 10.020.02Figure 22 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 50 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 51 Group 4: Scribe Line Inspection Elapsed HoursTask HoursNumber of PersonsTask 10.020.02Figure 26 10.020.02Figure 30 72.0 *320.0 *TOTAL FOR EACH AIRPLANE * Total Task Hours and Elapsed Hours dependent upon total number of fuselage areas and zones 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. I. Electrical Load Data Not changed. J. References 1. Existing Data: a. Boeing Service Related Problem (SRP) 727-SRP-53-0248 b. Standard Overhaul Practices Manual (SOPM) 20-30-03, 20-43-03 c. 727 Aircraft Maintenance Manual (AMM) 51-20-35, 51-31-00 d. 727 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, 51-30-25, Part 6, 53-30-21, Part 6, 53-30-22, Part 6, 53-30-24, Part 6, 53-30-25, Part 6, 53-30-26 e. 727 Structural Repair Manual (SRM) 51-20 f. Boeing Drawing 65-88700 g. Boeing Parts Standards Document D-590 h. Service Bulletin Index Document D6-9825 Part 3 2. Data supplied with this Service Bulletin: None. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 51 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 52 3. Installation Drawings Used in the Preparation of this Service Bulletin: None. K. Publications Affected 1. Publications None. 2. Damage Tolerance Based Structural Inspections: Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the Maintenance Program. This service bulletin affects FCS but no new DTIs are necessary. L. Interchangeability and Intermixability of Parts Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 52 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 53 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 or 727 SRM 51-20 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 727 AMM 51-20-35 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. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 53 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 54 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 Contact Boeing for the latest vendor information.(d) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 54 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 55 3. ACCOMPLISHMENT INSTRUCTIONS A. GENERAL INFORMATION CAUTION: KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL, METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR OTHER ELECTRICAL DAMAGE. NOTE: 1. The instructions identified in Paragraph 3.B., Work Instructions, and the Figure(s) give the recommended sequence of steps. The sequence of steps to do this service bulletin can be changed. 2. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 3. Obey all of the warnings and cautions given in the specified manual sections. 4. 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 5. These work instructions refer to procedures included in other Boeing documents. When the words "refer to" are used and the operator has an accepted alternative procedure, the accepted alternative procedure can be used. When the words "in accordance with" are included in the instruction, the procedure in the Boeing document must be used. 6. 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. 7. 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. 8. 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: BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 55 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 56 – 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 – 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. 9. 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. 10. An external approved repair is identified as any SRM repair, repair provided and approved by Boeing for specific cases that were requested by the operator, or an operator developed repair that has a Boeing approved Damage Tolerance Analysis. 11. If a scribe line is found outside of Zones 1, 2, and 3, do inspections in accordance with Work Instructions, Paragraph 3.B.10 - Part 8. 12. If any scribe line is detected at a non-approved repair, provide details of repair and scribe line to Boeing for evaluation. 13. 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. 14. 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. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 56 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 57 15. 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. 16. Inspection exemptions: Certain inspections are not required under these conditions: — If operator’s records show that the airplane has never been stripped or repainted since delivery from Boeing and correct sealant removal procedures have been and continue to be implemented for all future work, then the skin lap joint, skin butt joint, external approved repairs, external features, and fairing scribe line inspections are not required, except as noted below. — If the operator’s records show that the airplane has never been stripped or repainted under the wing-to-body fairings since delivery from Boeing and correct sealant removal procedure is implemented for all future work, then the inspections in the areas under the wing-to-body fairing are not required. — 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, skin butt joint, external approved repairs, external features, and fairing inspection must still be done for the affected area at the threshold in accordance with this service bulletin. — Decal inspections are not required if the operator's records show the airplane has never had decals installed in the area of inspection since delivery. — 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. — Skin Butt Joints: Inspections are not required in skin butt joint areas where an existing external repair doubler covers a potential scribe line (i.e., along an affected butt joint location), provided the doubler includes a minimum of three fastener rows forward and three fastener rows aft of the potential scribe line location (perpendicular to the direction of the scribe line). External repairs that do not meet this requirement must be removed to allow skin butt joint inspection. 17. Do not blend scribe lines. Blending a scribe line may hinder inspection techniques necessary to determine the presence or absence of fatigue cracks. 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. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 57 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 58 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. 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 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 58 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 59 (1) Remove the sealant as required from the lower edge of all affected lap joints. (2) Remove the paint as required 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 as required from within the gap of the affected butt joints. NOTE: 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 as required 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. (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. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 59 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT ### Page 60 4. PART 2 - DETAILED INSPECTION FOR SCRIBE LINES a. From the tables that follow, which correspond to airplane group numbers, determine the applicable figures for the inspection areas for each zone to be inspected. b. Do Part 1 - Surface Preparation - Scribe Line Inspections as necessary for each scribe line inspection area. c. Do a detailed inspection of the fuselage skin and splice plates for scribe lines. Use a minimum 10X magnifying lens to aid the inspection. d. If no scribe line is found, do Part 3 - No Scribe Line Found. e. If any scribe line is found, do Part 4 - Scribe Line Found. Group 1: Table 1 - Scribe Line Inspections Zone 3Zone 2Zone 1Area Figure 9Figure 5Figure 1Skin Lap Joints Figure 9(a)(a)Skin Butt Joints (a)(a)Figure 13External Approved Repairs (a)(a)Figure 17External Features Figure 27Figure 23(a)Decals and Fairings (a) No inspection is required for this area and zone at this inspection threshold. Group 2: Table 2 - Scribe Line Inspections Zone 3Zone 2Zone 1Area Figure 10Figure 6Figure 2Skin Lap Joints (a)(a)(a)Skin Butt Joints (a)(a)Figure 14External Approved Repairs (a)(a)Figure 18External Features Figure 28Figure 24(a)Decals and Fairings (a) No inspection is required for this area and zone at this inspection threshold. Group 3: Table 3 - Scribe Line Inspections Zone 3Zone 2Zone 1Area Figure 11Figure 7Figure 3Skin Lap Joints (a)Figure 7(a)Skin Butt Joints BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 19, 2010 727-53A0233 60 of 192 BOEING SERVICE BULLETIN 727-53A0233 ALERTALERT The text continues at https://openairdocs.org/service-documents/boeing/727-53a0233/file/dc72239cefef.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.