# Boeing Alert Service Bulletin 747-53A2835: Revision 1 - Rights: © The Boeing Company. Filed by the FAA in regulations.gov docket FAA-2011-0915; AD 2012-07-07 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Boeing Alert Service Bulletin 747-53A2835](https://openairdocs.org/service-documents/boeing/747-53a2835.md) - Title as filed: U.S. DOT/FAA - Service Bulletin - Pages: 324 - PDF: https://openairdocs.org/files/sha256/50/a0/50a0cdbcb0980d1f37e43c422c7c8a94b58dceb31273b585c752f836e1a27e5e - Page: https://openairdocs.org/service-documents/boeing/747-53a2835/file/50a0cdbcb098 ## 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 747 Service Bulletin ALERT Number: 747-53A2835 Original Issue: October 28, 2010 Revision 1: December 08, 2011 ATA System: 5312 SUBJECT: FUSELAGE - Center Section: Station 520 To Station 2360 - Forward and Aft Lower Lobe Cargo Door Lower Sills - Latch Pin Inspection and Replacement 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all export laws. 9E991ECCN: BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2010 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter.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 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details.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: October 28, 2010 747-53A2835Revision 1: December 08, 2011 1 of 324 4.0 ### Page 2 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 2 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT BLANK PAGE ### Page 3 Table of Contents Revision Transmittal Sheet ............................................ 5 Summary ...................................................... 7 1. PLANNING INFORMATION ........................................ 1 1 A. Effectivity ............................................... 1 1 1. Airplanes ............................................ 1 1 2. Spares Affected ........................................ 2 4 B. Concurrent Requirements ...................................... 2 4 C. Reason ................................................ 2 5 D. Description .............................................. 2 5 E. Compliance .............................................. 2 7 F. Approval ............................................... 3 3 G. Manpower .............................................. 3 4 H. Weight and Balance Changes .................................... 4 0 I. Electrical Load Data ......................................... 4 0 J. References .............................................. 4 0 1. Existing Data .......................................... 4 0 2. Data supplied with this Service Bulletin ............................ 4 1 3. Installation Drawings Used in the Preparation of this Service Bulletin ............ 4 1 K. Publications Affected ........................................ 4 1 L. Interchangeability and Intermixability of Parts ........................... 4 1 2. MATERIAL INFORMATION ........................................ 4 3 A. Material - Price and Availability ................................... 4 3 B. Industry Support Information .................................... 4 4 C. Parts Necessary For Each Airplane ................................. 4 5 1. Kits/Parts ............................................ 4 5 2. Parts and Materials Supplied by the Operator ........................ 4 6 3. Parts Modified and Reidentified ................................ 4 7 4. Parts Removed and Not Replaced .............................. 4 7 D. Parts Necessary to Change Spares ................................. 4 7 E. Special Tooling - Price and Availability ............................... 4 7 F. Special Tooling Necessary to do this Service Bulletin ....................... 4 7 3. ACCOMPLISHMENT INSTRUCTIONS .................................. 4 9 A. GENERAL INFORMATION ..................................... 4 9 B. WORK INSTRUCTIONS ....................................... 5 0 FIGURE 1: LOWER LOBE FORWARD AND AFT CARGO DOORS - LATCH PIN INSPECTIONS . . 58 FIGURE 2: LOWER LOBE FORWARD AND AFT CARGO DOORS - LATCH PIN REPLACEMENT [Group 1, Configuration 1, 5; Group 2, Configuration 1, 3; Group 3; Group 4-5, Configuration 1] . 61 FIGURE 3: LOWER LOBE FORWARD AND AFT CARGO DOORS - LATCH PIN REPLACEMENT [Group 1, Configuration 2, 6; Group 2, Configuration 2, 4; Group 4-5, Configuration 2] ....... 6 6 FIGURE 4: LOWER LOBE FORWARD AND AFT CARGO DOORS - LATCH PIN REPLACEMENT [Group 1, Configuration 3, 7] ...................................... 7 1 FIGURE 5: LOWER LOBE FORWARD AND AFT CARGO DOORS - LATCH PIN REPLACEMENT [Group 1, Configuration 4, 8] ...................................... 7 6 FIGURE 6: LOWER LOBE FORWARD AND AFT CARGO DOORS - LATCH PIN AND BEARING PLATE MODIFICATION OR REPLACEMENT [Group 1, Configuration 3, 7] ............ 8 1 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 3 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 4 FIGURE 7: LOWER LOBE FORWARD AND AFT CARGO DOORS - LATCH PIN AND BEARING PLATE MODIFICATION OR REPLACEMENT [Group 1, Configuration 4, 8] ............ 9 2 FIGURE 8: LOWER LOBE FORWARD CARGO DOORS - LATCH PIN MODIFICATION [Group 1-2, Configuration 1; Group 3; Group 4, Configuration 1] .................... 1 0 3 FIGURE 9: LOWER LOBE AFT CARGO DOORS - LATCH PIN MODIFICATION [Group 1-2, Configuration 1; Group 3; Group 4, Configuration 1] ............................ 1 1 2 FIGURE 10: LOWER LOBE FORWARD CARGO DOORS - LATCH PIN MODIFICATION [Group 1-2, 4, Configuration 2] ........................................ 1 2 1 FIGURE 11: LOWER LOBE AFT CARGO DOORS - LATCH PIN MODIFICATION [Group 1-2, 4, Configuration 2 ] ................................................ 1 3 0 FIGURE 12: LOWER LOBE FORWARD CARGO DOORS - LATCH PIN MODIFICATION [Group 1, Configuration 3] ........................................ 1 3 9 FIGURE 13: LOWER LOBE AFT CARGO DOORS - LATCH PIN MODIFICATION [Group 1, Configuration 3 ] ................................................ 1 5 4 FIGURE 14: LOWER LOBE FORWARD CARGO DOORS - LATCH PIN MODIFICATION [Group 1, Configuration 4] ........................................ 1 6 9 FIGURE 15: LOWER LOBE AFT CARGO DOORS - LATCH PIN MODIFICATION [Group 1, Configuration 4 ] ................................................ 1 8 4 FIGURE 16: LOWER LOBE FORWARD CARGO DOORS - LATCH PIN MODIFICATION [Group 1, Configuration 5; Group 2, Configuration 3; Group 5, Configuration 1] ........... 1 9 9 FIGURE 17: LOWER LOBE AFT CARGO DOORS - LATCH PIN MODIFICATION [Group 1, Configuration 5; Group 2, Configuration 3; Group 5, Configuration 1] ................... 2 0 8 FIGURE 18: LOWER LOBE FORWARD CARGO DOORS - LATCH PIN MODIFICATION [Group 1, Configuration 6; Group 2, Configuration 4; Group 5, Configuration 2] ........... 2 1 7 FIGURE 19: LOWER LOBE AFT CARGO DOORS - LATCH PIN MODIFICATION [Group 1, Configuration 6; Group 2, Configuration 4; Group 5, Configuration 2] ................... 2 2 6 FIGURE 20: LOWER LOBE FORWARD CARGO DOORS - LATCH PIN MODIFICATION [Group 1, Configuration 7] ........................................ 2 3 5 FIGURE 21: LOWER LOBE AFT CARGO DOORS - LATCH PIN MODIFICATION [Group 1, Configuration 7 ] ................................................ 2 5 0 FIGURE 22: LOWER LOBE FORWARD CARGO DOORS - LATCH PIN MODIFICATION [Group 1, Configuration 8] ........................................ 2 6 5 FIGURE 23: LOWER LOBE AFT CARGO DOORS - LATCH PIN MODIFICATION [Group 1, Configuration 8 ] ................................................ 2 8 0 FIGURE 24: LOWER LOBE FORWARD CARGO DOORS - POST-MODIFICATION INSPECTION . . 295 FIGURE 25: LOWER LOBE AFT CARGO DOORS - POST-MODIFICATION INSPECTION ...... 2 9 8 FIGURE 26: LOWER LOBE FORWARD CARGO DOORS - POST-MODIFICATION LATCH PIN REPLACEMENT [Group 1, Configuration 1-4; Group 2, Configuration 1-2; Group 3-4] . . 301 FIGURE 27: LOWER LOBE AFT CARGO DOORS - POST-MODIFICATION LATCH PIN REPLACEMENT [Group 1, Configuration 1-4; Group 2, Configuration 1-2; Group 3-4] ........... 3 0 7 FIGURE 28: LOWER LOBE FORWARD CARGO DOORS - POST-MODIFICATION LATCH PIN REPLACEMENT [Group 1, Configuration 5-8; Group 2, Configuration 3-4; Group 5] . . . 313 FIGURE 29: LOWER LOBE AFT CARGO DOORS - POST-MODIFICATION LATCH PIN REPLACEMENT [Group 1, Configuration 5-8; Group 2, Configuration 3-4; Group 5] ............. 3 1 9 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 4 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 5 Commercial Airplanes 747 Service Bulletin ALERT Revision Transmittal SheetNumber: 747-53A2835Original Issue: October 28, 2010 Revision 1: December 08, 2011 ATA System: 5312 SUBJECT: FUSELAGE - Center Section: Station 520 To Station 2360 - Forward and Aft Lower Lobe Cargo Door Lower Sills - Latch Pin Inspection and Replacement This revision includes all pages of the service bulletin. COMPLIANCE INFORMATION RELATED TO THIS REVISION Federal Aviation Administration (FAA) Airworthiness Directive AD 2000-02-37 is related to this service bulletin. More work is necessary on the airplanes changed in accordance with the original issue of this service bulletin. The compliance time has been reduced for airplanes that have had all existing latch pins at all latch fitting locations replaced in the same maintenance visit. Also do the latch pin modification, which installs new and improved latch pins, and do the post-modification inspection at the times given in this service bulletin. No airplanes were added to this service bulletin effectivity. However, certain airplanes in Group 2 were moved to Group 4 and 5, which were added in this service bulletin. REASON FOR REVISION This revision is sent to give instructions for latch pin modification and post-modification inspections to improve the effectiveness in finding damage before breaking of the latch pins. The original latch pins were made from 17-4PH CRES. The latch pin modification installs new and improved latch pins that are made from 15-5PH CRES, which is more fatigue durable and corrosion resistant, and with increased wall thickness for added strength. Also, the compliance time has been changed for airplanes that have had all existing latch pins at all latch fitting locations replaced in the same maintenance visit; the effectivity was updated to move certain airplanes from Group 2 to new Group 4 and 5; and added additional configurations in the group/configuration table. These sections were changed: 1. In Summary, Background, added latch pin modification information for this revision and changed overhaul manual (OHM) references to component maintenance manual (CMM). 2. In Summary, Action, updated the group/configuration applicability and added an action statement for the latch pin modification. 3. In Summary, Compliance, added a Federal Aviation Administration (FAA) Airworthiness Directive (AD) reference. 4. In Summary, Material Information, added a reference to Boeing supplied Kits/Parts. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 5 of 324 ### Page 6 5. In Summary, Figure, updated to give a description of latch pin modification. 6. In Paragraph 1.A.1., Airplanes, updated group/configuration information; and added Group 4 and 5 airplanes. 7. In Paragraph 1.C., Reason, added a revision description and changed OHM references to CMM. 8. In Paragraph 1.D., Description, updated the group/configuration applicability and added an action statement for the latch pin modification. Also, updated the Affected Maintenance Zones tables. 9. In Paragraph 1.E., Compliance, added an FAA AD reference, Tables 1 through 4, updated the group/configuration applicability, added references to the corresponding "Part" of the work instructions in the action column of the tables, changed one compliance time, and added footnotes. Also added Tables 5 and 6 for the latch pin modification and post-modification inspection, respectively. 10. In Paragraph 1.G., Manpower, updated the group/configuration applicability and titles. Also added manpower information for the latch pin modification and post-modification inspection. 11. In Paragraph 1.J.1., Existing Data, updated the reference list. 12. In Paragraph 1.K., Publications Affected, updated the publications table. 13. In Paragraph 2.A., Material - Price and Availability, added top kit information for the latch pin modification. 14. In Paragraph 2.C.1., Kits/Parts, added top kit information for the latch pin modification. 15. In Paragraph 2.C.2., Parts and Materials Supplied by the Operator, updated the group/configuration applicability and added an operator supplied part. 16. In Paragraph 3.B., Work Instructions, added "Part 1" heading for the previous inspection and replacement instructions in the original issue. Added a note to reference the latch pin modification as an alternative action in Part 1. Updated the group/configuration applicability and changed the OHM references to CMM in Part 1. Also, added Part 2 and Part 3 for the latch pin modification and post-modification inspection, respectively. 17. In Figures 2 through 7, updated the group/configuration applicability. 18. Added Figures 8 through 29 for the latch pin modification and post-modification inspection. Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity, to show the location of important changes. Pages with no vertical lines have no important changes. REVISION HISTORY October 28, 2010Original Issue: December 08, 2011Revision 1: BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 6 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 7 Commercial Airplanes 747 Service Bulletin ALERT SummaryNumber: 747-53A2835Original Issue: October 28, 2010 Revision 1: December 08, 2011 ATA System: 5312 SUBJECT: FUSELAGE - Center Section: Station 520 To Station 2360 - Forward and Aft Lower Lobe Cargo Door Lower Sills - Latch Pin Inspection and Replacement 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 A latch pin, from the number 8 (most aft) latch position on aft lower lobe cargo door lower sill, has fractured in service. Investigation revealed the crack initiated by fatigue and propagated by a combination of fatigue and stress corrosion. If the latch pins on the forward and aft cargo door lower sill are not regularly inspected and broken latch pins are not replaced, the forward and/or aft cargo doors could open unexpectedly during service, causing rapid decompression and possible loss of the cargo door. One operator has reported a fractured latch pin from the lower sill of the aft lower lobe cargo door. Part of the pin was found on the ground during an airplane walk around. The airplane had completed 75,495 flight hours and 9,393 flight cycles. A dye penetrant inspection of the remaining seven latch pins in the aft cargo door was done with no defects found. The number 8 latch pin was assumed to be original. The number 8 latch cam was a reworked/overhauled part. The latch pin fracture initiated on the pin internal diameter. This service bulletin provides inspections for broken or cracked latch pins on the forward and aft lower lobe cargo door lower sills. Replacing broken or cracked latch pins will mitigate the possibility that a cargo door could open unexpectedly during service. In addition, Boeing has conducted analysis of broken, as well as intact, latch pins of the current design. The analysis showed a potential for large variations in the modes of crack initiation and propagation in the existing latch pins. The analysis also showed that these variations could result in the existing inspections not finding pin damage before breaking of the pin. Boeing has designed new and improved latch pins that minimize the variations in the mode of crack initiation and propagation. The original latch pins were made from 17-4 CRES. The new and improved latch pins are made from 15-5PH CRES, which is more fatigue durable and corrosion resistant, and with increased wall thickness for added strength. This service bulletin gives instructions for latch pin modification, which installs new and improved latch pins, and instructions for post-modification inspections. The latch pin modification with the post-modification inspections improve the effectiveness in finding damage before breaking of the latch pins. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 7 of 324 ### Page 8 The inspections for broken or cracked latch pins provided by this service bulletin do not replace inspections for latch pin wear. CMM 52-34-11 and CMM 52-35-11 give wear limits for the latch pins. Boeing Service Related Problem (SRP) 747-SRP-53-0351 is related to this service bulletin. ACTION (PRR 85901-105RS) Group 1, Configuration 1-2, 5-6; Group 2-5: Open the lower lobe forward and aft cargo doors to get access to the latch pins on the lower sill. Do a general visual inspection for broken or missing latch pins and a detailed inspection of the latch pins for cracking. For each latch fitting location where a latch pin is broken, replace the latch pin and replace the latch pin(s) at the adjacent latch fitting location(s). For each latch pin where any crack is found, replace the latch pin. Put the airplane back to a serviceable condition. Repeat the inspections. Group 1, Configuration 3-4, 7-8: Open the lower lobe forward and aft cargo doors to get access to the latch pins on the lower sill. Do a general visual inspection for broken or missing latch pins and a detailed inspection of the latch pins for cracking. Option 1: For each latch fitting location where a latch pin is broken, replace the latch pin and replace the latch pin(s) at the adjacent latch fitting location(s). For each latch pin where any crack is found, replace the latch pin. Option 2: Modify or replace the latch pins and modify the bearing plates at all latch fitting locations. Put the airplane back to a serviceable condition. Repeat the inspections. For all airplanes, do the latch pin modification at the time given in this service bulletin. The latch pin modification installs new and improved latch pins. Put the airplane back to a serviceable condition. After the latch pin modification, do the post-modification inspection at the time given in this service bulletin. EFFECTIVITY All 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SP, 747SR airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes. COMPLIANCE Federal Aviation Administration (FAA) Airworthiness Directive AD 2000-02-37 is related to this service bulletin. 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 configuration changes, inspection and/or repair procedures given in this service bulletin. MANPOWER Refer to Paragraph 1.G., Manpower. MATERIAL INFORMATION Boeing Supplied Kits/Parts. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 8 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 9 (OCR) BOEING SERVICE BULLETIN 747-53A2835 ALERT ALERT Operator Supplied Parts/Materials. Refer to Paragraph 2.A., Material - Price and Availability DOORWAY LOWER SILL NOTE: NUMBERS ADJACENT TO LATCH FITTINGS DENOTE LATCH FITTING LOCATIONS 6 2 LOCATIONS SOME STRUCTURE NOT SHOWN FOR CLARITY INSPECT FOR BROKEN OR CRACKED LATCH PIN. IF LATCH PIN IS CRACKED, REPLACE THE LATCH PIN. IF LATCH PIN IS BROKEN OR MISSING, REPLACE THE LATCH PIN AND REPLACE THE LATCH PIN(S) AT ADJACENT LATCH FITTING LOCATION(S) AT THE SPECIFIED TIME DO THE LATCH PIN MODIFICATION IN TYPICAL ACCORDANCE WITH THIS 16 LOCATIONS TOTAL SERVICE BULLETIN ODD NUMBERED LATCH FITTING LOCATION SHOWN EVEN NUMBERED LATCH FITTING LOCATION OPPOSITE B 2085503 Original Issue: October 28, 2010 Revision 1: December 08, 2011 747-53A2835 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 9 of 324 ### Page 10 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 10 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT BLANK PAGE ### Page 11 Commercial Airplanes 747 Service Bulletin ALERT Number: 747-53A2835 Original Issue: October 28, 2010 Revision 1: December 08, 2011 ATA System: 5312 SUBJECT: FUSELAGE - Center Section: Station 520 To Station 2360 - Forward and Aft Lower Lobe Cargo Door Lower Sills - Latch Pin Inspection and Replacement 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 D6-30300 Part 3 for Airplane Variable Number, Line Number, and Serial Number data. This service bulletin is for the airplanes shown below. An equivalent change is on subsequent production airplanes. Refer to PRR 85901-105RS for data about this change. The group/configuration descriptions give changes that are affected by the following service bulletins: – Boeing Service Bulletin 747-52-2105 rewords the latch pins and latch fitting bearing plates on the forward and aft lower lobe cargo doors to reduce latch operating friction and improve the engagement on the latch cams. – Boeing Service Bulletin 747-52-2260 modifies the latch fittings to install bracket assemblies on the forward and aft lower lobe cargo doors to prevent backward installation of latch pins. – Boeing Service Bulletin 747-52-2224 modifies the door warning system to install new switches on the forward and aft lower lobe and main deck side cargo doors. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 11 of 324 ### Page 12 DESCRIPTIONCONFIGURATIONGROUP 747-100, 747-200B, 747-200C, 747-200F, 747SP, and 747SR airplanes line numbers 1 through 263 and 265. -1 Airplanes that have modified or replaced latch pins and latch fitting bearing plates in accordance with Boeing Service Bulletin 747-52-2105 Original Issue, Revision 1 or Revision 2 on the lower lobe forward and aft cargo doors, or in accordance with Figure 6 or Figure 7 of this service bulletin, AND have done Boeing Service Bulletin 747-52-2260 Original Issue or Revision 1, AND have not installed auxiliary door-closed switches with brackets on the forward and aft lower lobe cargo doors as shown in Boeing Service Bulletin 747-52-2224 or have not done Boeing Service Bulletin 747-52-2224. 1 Airplanes that have modified or replaced latch pins and latch fitting bearing plates in accordance with Boeing Service Bulletin 747-52-2105 Original Issue, Revision 1 or Revision 2 on the lower lobe forward and aft cargo doors, or in accordance with Figure 6 or Figure 7 of this service bulletin, AND have not done Boeing Service Bulletin 747-52-2260 Original Issue or Revision 1, AND have not installed auxiliary door-closed switches with brackets on the forward and aft lower lobe cargo doors as shown in Boeing Service Bulletin 747-52-2224 or have not done Boeing Service Bulletin 747-52-2224. 2 Airplanes that have not modified or replaced latch pins and latch fitting bearing plates in accordance with Boeing Service Bulletin 747-52-2105 Original Issue, Revision 1 or Revision 2 on the lower lobe forward and aft cargo doors, or in accordance with Figure 6 or Figure 7 of this service bulletin, AND have done Boeing Service Bulletin 747-52-2260 Original Issue or Revision 1, AND have not installed auxiliary door-closed switches with brackets on the forward and aft lower lobe cargo doors as shown in Boeing Service Bulletin 747-52-2224 or have not done Boeing Service Bulletin 747-52-2224. 3 Airplanes that have not modified or replaced latch pins and latch fitting bearing plates in accordance with Boeing Service Bulletin 747-52-2105 Original Issue, Revision 1 or Revision 2 on the lower lobe forward and aft cargo doors, or in accordance with Figure 6 or Figure 7 of this service bulletin, AND have not done Boeing Service Bulletin 747-52-2260 Original Issue or Revision 1, AND have not installed auxiliary door-closed switches with brackets on the forward and aft lower lobe cargo doors as shown in Boeing Service Bulletin 747-52-2224 or have not done Boeing Service Bulletin 747-52-2224. 4 5 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 12 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 13 DESCRIPTIONCONFIGURATIONGROUP Airplanes that have modified or replaced latch pins and latch fitting bearing plates in accordance with Boeing Service Bulletin 747-52-2105 Original Issue, Revision 1 or Revision 2 on the lower lobe forward and aft cargo doors, or in accordance with Figure 6 or Figure 7 of this service bulletin, AND have done Boeing Service Bulletin 747-52-2260 Original Issue or Revision 1, AND have installed auxiliary door-closed switches with brackets on the forward and aft lower lobe cargo doors as shown in Boeing Service Bulletin 747-52-2224 or have done Boeing Service Bulletin 747-52-2224. Airplanes that have modified or replaced latch pins and latch fitting bearing plates in accordance with Boeing Service Bulletin 747-52-2105 Original Issue, Revision 1 or Revision 2 on the lower lobe forward and aft cargo doors, or in accordance with Figure 6 or Figure 7 of this service bulletin, AND have not done Boeing Service Bulletin 747-52-2260 Original Issue or Revision 1, AND have installed auxiliary door-closed switches with brackets on the forward and aft lower lobe cargo doors as shown in Boeing Service Bulletin 747-52-2224 or have done Boeing Service Bulletin 747-52-2224. 6 Airplanes that have not modified or replaced latch pins and latch fitting bearing plates in accordance with Boeing Service Bulletin 747-52-2105 Original Issue, Revision 1 or Revision 2 on the lower lobe forward and aft cargo doors, or in accordance with Figure 6 or Figure 7 of this service bulletin, AND have done Boeing Service Bulletin 747-52-2260 Original Issue or Revision 1, AND have installed auxiliary door-closed switches with brackets on the forward and aft lower lobe cargo doors as shown in Boeing Service Bulletin 747-52-2224 or have done Boeing Service Bulletin 747-52-2224. 7 Airplanes that have not modified or replaced latch pins and latch fitting bearing plates in accordance with Boeing Service Bulletin 747-52-2105 Original Issue, Revision 1 or Revision 2 on the lower lobe forward and aft cargo doors, or in accordance with Figure 6 or Figure 7 of this service bulletin, AND have not done Boeing Service Bulletin 747-52-2260 Original Issue or Revision 1, AND have installed auxiliary door-closed switches with brackets on the forward and aft lower lobe cargo doors as shown in Boeing Service Bulletin 747-52-2224 or have done Boeing Service Bulletin 747-52-2224. 8 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 13 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 14 DESCRIPTIONCONFIGURATIONGROUP 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SP, and 747SR airplanes line numbers 264 and 266 through 822. -2 Airplanes that have accomplished Boeing Service Bulletin 747-52-2260 Original Issue or Revision 1, AND have not installed auxiliary door-closed switches with brackets on the forward and aft lower lobe cargo doors as shown in Boeing Service Bulletin 747-52-2224 or have not done Boeing Service Bulletin 747-52-2224. 1 Airplanes that have not accomplished Boeing Service Bulletin 747-52-2260 Original Issue or Revision 1 AND have not installed auxiliary door-closed switches with brackets on the forward and aft lower lobe cargo doors as shown in Boeing Service Bulletin 747-52-2224 or have not done Boeing Service Bulletin 747-52-2224. 2 Airplanes that have accomplished Boeing Service Bulletin 747-52-2260 Original Issue or Revision 1, AND have installed auxiliary door-closed switches with brackets on the forward and aft lower lobe cargo doors as shown in Boeing Service Bulletin 747-52-2224 or have done Boeing Service Bulletin 747-52-2224. 3 Airplanes that have not accomplished Boeing Service Bulletin 747-52-2260 Original Issue or Revision 1, AND have installed auxiliary door-closed switches with brackets on the forward and aft lower lobe cargo doors as shown in Boeing Service Bulletin 747-52-2224 or have done Boeing Service Bulletin 747-52-2224. 4 747-400 and 747-400F airplanes line numbers 1079 through 1419.-3 747-400, 747-400D, and 747-400F airplanes line numbers 696 through 1078. -4 Airplanes that have accomplished Boeing Service Bulletin 747-52-2260 Original Issue or Revision 1. 1 Airplanes that have not accomplished Boeing Service Bulletin 747-52-2260 Original Issue or Revision 1. 2 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 14 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 15 DESCRIPTIONCONFIGURATIONGROUP 747-200F airplanes line number 878 and 886. These airplanes have auxiliary door-closed switches with brackets installed in production on the forward and aft lower lobe cargo doors, which is the same as Boeing Service Bulletin 747-52-2224. -5 Airplanes that have accomplished Boeing Service Bulletin 747-52-2260 Original Issue or Revision 1. 1 Airplanes that have not accomplished Boeing Service Bulletin 747-52-2260 Original Issue or Revision 1. 2 Airplane Models: 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SP, 747SR GroupVariable Number 1RA001 - RA034 1RA101 - RA115 1RA161 - RA164 1RA201 - RA203 1RA216 - RA217 1RA245 - RA246 1RA251 - RA265 2RA266 1RA301 - RA317 2RA318 1RA351 - RA360 1RA369 - RA373 1RA401 - RA418 1RA501 - RA502 1RA521 - RA528 1RA532 - RA543 2RA544 - RA548 1RA551 - RA552 1RA559 - RA561 1RA581 - RA582 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 15 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 16 GroupVariable Number 1RA585 1RA601 - RA602 1RA631 - RA635 1RA651 - RA652 1RA671 - RA677 1RA701 - RA702 1RA721 - RA724 2RA725 - RA731 1RA741 - RA745 1RA749 2RA750 1RA761 - RA762 1RA781 - RA783 2RA784 1RA901 - RA916 1RB001 - RB010 2RB011 - RB012 1RB013 - RB016 1RB041 - RB044 1RB071 - RB075 1RB101 - RB102 2RB411 - RB413 2RB421 1RB601 - RB607 2RB681 - RB697 2RB711 2RB721 - RB723 2RB741 - RB748 1RD001 - RD004 1RD021 - RD022 1RD041 - RD044 2RD045 - RD059 1RD071 - RD072 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 16 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 17 GroupVariable Number 2RD081 - RD083 2RD091 - RD092 1RD101 - RD104 2RD121 - RD127 2RD131 - RD144 2RD166 - RD167 2RD171 - RD172 2RD181 - RD183 2RD201 - RD204 2RD221 - RD227 2RD231 - RD235 2RD241 - RD243 2RD251 - RD262 2RD271 - RD272 2RD291 - RD292 2RD301 - RD302 2RD311 2RD351 - RD358 2RD361 - RD366 2RD381 - RD383 2RD411 - RD414 2RD421 - RD426 2RD431 - RD435 2RD441 - RD442 2RD451 - RD456 2RD461 2RD471 - RD475 2RD513 - RD519 2RD531 - RD533 2RD551 2RD561 2RD571 2RD581 - RD583 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 17 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 18 GroupVariable Number 2RD591 - RD593 2RD601 - RD607 1RD621 - RD622 2RD623 2RD641 - RD649 2RD651 - RD659 2RD661 2RD671 2RD681 - RD682 2RD691 - RD692 2RD701 - RD702 2RD721 - RD722 2RD741 - RD742 2RD751 - RD755 2RD761 2RD771 - RD775 2RD781 - RD783 2RD791 - RD792 2RE001 3RF001 - RF006 1RG001 2RG002 - RG009 2RG091 2RG095 2RG101 - RG104 2RG121 - RG126 2RG141 - RG142 2RG161 - RG164 2RG171 - RG174 2RG191 - RG193 2RG211 - RG213 2RG221 - RG222 2RH101 - RH102 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 18 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 19 GroupVariable Number 2RH111 - RH112 2RH121 - RH122 1RJ131 - RJ133 2RJ151 - RJ152 2RJ301 - RJ303 2RJ321 - RJ322 2RJ331 - RJ333 3RL401 - RL403 3RL411 - RL436 3RL451 - RL456 3RL461 - RL462 3RL471 - RL481 3RL491 - RL492 3RL501 - RL502 3RL511 - RL516 3RL521 - RL522 3RL531 - RL534 3RL551 3RL561 - RL568 3RL571 - RL572 3RL576 - RL577 3RL579 3RL581 - RL586 3RL651 - RL655 3RL671 - RL675 3RL681 - RL684 3RL751 - RL752 3RM001 - RM007 3RM010 - RM013 3RM021 - RM024 3RM026 - RM030 3RM036 - RM045 3RM051 - RM053 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 19 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 20 GroupVariable Number 3RM071 3RM081 - RM084 3RM091 3RM096 - RM097 3RM116 - RM117 3RM126 - RM132 3RM136 - RM147 3RM156 - RM158 3RM166 - RM177 3RM191 - RM192 3RM231 - RM233 3RM241 - RM246 3RM261 - RM264 3RM316 - RM318 3RM331 - RM333 3RM341 3RM351 - RM355 3RM366 - RM367 3RM401 - RM403 3RM426 3RM431 3RM441 - RM443 3RM445 3RM801 - RM803 3RM811 - RM813 3RM851 - RM859 3RM861 - RM863 3RM871 - RM899 3RM901 - RM906 3RM911 2RR001 - RR005 2RR021 - RR025 2RR031 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 20 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 21 GroupVariable Number 1RR201 2RR202 - RR206 1RR221 2RR222 - RR226 1RR261 2RR262 - RR267 1RR301 2RR302 - RR309 5RR310 2RR331 - RR332 2RR336 1RR341 - RR342 2RR343 - RR345 2RR361 - RR362 2RR421 - RR422 2RR431 - RR432 2RR441 - RR442 2RR451 2RR501 - RR504 2RR521 - RR522 2RR526 2RR531 2RR551 - RR555 5RR556 2RR561 2RR566 4RR701 4RR721 - RR722 3RR723 - RR724 4RR746 - RR747 3RR748 4RR851 - RR854 3RR855 - RR856 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 21 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 22 GroupVariable Number 3RR861 - RR862 4RR951 - RR952 2RS001 - RS002 2RS201 2RS211 - RS212 2RS221 - RS222 2RS231 - RS241 2RS251 - RS259 2RS263 2RS265 - RS268 2RS271 - RS276 2RS291 - RS292 2RS301 - RS306 2RS311 - RS320 2RS331 - RS333 2RS341 - RS342 2RS699 2RS701 - RS703 2RS711 - RS713 2RS721 - RS722 2RS731 - RS732 2RS741 - RS743 2RS751 - RS752 2RS761 - RS762 2RS771 2RS781 - RS782 2RS786 4RT001 - RT011 3RT012 - RT014 4RT021 - RT022 4RT031 - RT033 3RT034 - RT035 4RT041 - RT047 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 22 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 23 GroupVariable Number 4RT061 4RT071 - RT075 4RT101 - RT103 4RT121 4RT131 - RT134 3RT135 - RT137 4RT151 - RT152 4RT161 - RT168 4RT401 - RT412 4RT431 - RT441 3RT442 - RT447 4RT451 - RT469 4RT471 - RT499 4RT501 - RT535 4RT551 - RT568 4RT571 - RT588 3RT589 - RT590 4RT591 4RT601 - RT622 3RT623 - RT630 4RT631 - RT636 3RT637 - RT640 4RT641 - RT657 4RT671 - RT673 4RT681 - RT682 4RT691 - RT699 4RT701 - RT704 4RT711 - RT717 4RT741 - RT755 3RT756 - RT757 4RT776 - RT777 4RT781 - RT784 3RT801 - RT803 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 23 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 24 GroupVariable Number 3RT811 - RT814 4RT831 - RT833 3RT834 - RT837 4RT861 - RT864 4RT876 - RT880 4RT931 - RT932 4RT945 - RT946 3RT947 - RT949 4RT951 - RT954 3RT955 4RT966 - RT967 4RU001 - RU004 3RU005 - RU006 3RU016 - RU017 4RU031 - RU032 4RU051 - RU052 4RU059 - RU062 4RU081 - RU083 3RU101 - RU102 4RU121 - RU124 3RU125 - RU132 4RU801 - RU809 4RU831 - RU841 2. Spares Affected Examine your spares supply for the parts or components identified in Paragraph 2.C., Parts Necessary for Each Airplane. If any parts or components are found, refer to Paragraph 2.C. for the recommended use. B. Concurrent Requirements None. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 24 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 25 C. Reason A latch pin, from the number 8 (most aft) latch position on aft lower lobe cargo door lower sill, has fractured in service. Investigation revealed the crack initiated by fatigue and propagated by a combination of fatigue and stress corrosion. If the latch pins on the forward and aft cargo door lower sill are not regularly inspected and broken latch pins are not replaced, the forward and/or aft cargo doors could open unexpectedly during service, causing rapid decompression and possible loss of the cargo door. One operator has reported a fractured latch pin from the lower sill of the aft lower lobe cargo door. Part of the pin was found on the ground during an airplane walk around. The airplane had completed 75,495 flight hours and 9,393 flight cycles. A dye penetrant inspection of the remaining seven latch pins in the aft cargo door was done with no defects found. The number 8 latch pin was assumed to be original. The number 8 latch cam was a reworked/overhauled part. The latch pin fracture initiated on the pin internal diameter. This service bulletin provides inspections for broken or cracked latch pins on the forward and aft lower lobe cargo door lower sills. Replacing broken or cracked latch pins will mitigate the possibility that a cargo door could open unexpectedly during service. In addition, Boeing has conducted analysis of broken, as well as intact, latch pins of the current design. The analysis showed a potential for large variations in the modes of crack initiation and propagation in the existing latch pins. The analysis also showed that these variations could result in the existing inspections not finding pin damage before breaking of the pin. Boeing has designed new and improved latch pins that minimize the variations in the mode of crack initiation and propagation. The original latch pins were made from 17-4 CRES. The new and improved latch pins are made from 15-5PH CRES, which is more fatigue durable and corrosion resistant, and with increased wall thickness for added strength. This service bulletin gives instructions for latch pin modification, which installs new and improved latch pins, and instructions for post-modification inspections. The latch pin modification with the post-modification inspections improve the effectiveness in finding damage before breaking of the latch pins. The inspections for broken or cracked latch pins provided by this service bulletin do not replace inspections for latch pin wear. CMM 52-34-11 and CMM 52-35-11 give wear limits for the latch pins. Revision 1 is sent to give instructions for latch pin modification and post-modification instructions. Also, the compliance time has been changed for airplanes that have had all existing latch pins at all latch fitting locations replaced in the same maintenance visit; the effectivity was updated to move certain airplanes from Group 2 to new Group 4 and 5; and added additional configurations in the group/configuration table. Boeing Service Related Problem (SRP) 747-SRP-53-0351 is related to this service bulletin. D. Description Group 1, Configuration 1-2, 5-6; Group 2-5: Open the lower lobe forward and aft cargo doors to get access to the latch pins on the lower sill. Do a general visual inspection for broken or missing latch pins and a detailed inspection of the latch pins for cracking. For each latch fitting location where a latch pin is broken or missing, replace the latch pin and replace the latch pin(s) at the adjacent latch fitting location(s). For each latch pin where any crack is found, replace the latch pin. Put the airplane back to a serviceable condition. Repeat the inspections. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 25 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 26 Group 1, Configuration 3-4, 7-8: Open the lower lobe forward and aft cargo doors to get access to the latch pins on the lower sill. Do a general visual inspection for broken or missing latch pins and a detailed inspection of the latch pins for cracking. Option 1: For each latch fitting location where a latch pin is broken or missing, replace the latch pin and replace the latch pin(s) at the adjacent latch fitting location(s). For each latch pin where any crack is found, replace the latch pin. Option 2: Modify or replace the latch pins and modify the bearing plates at all latch fitting locations. Put the airplane back to a serviceable condition. Repeat the inspections. For all airplanes, do the latch pin modification at the time given in this service bulletin. The latch pin modification installs new and improved latch pins. Put the airplane back to a serviceable condition. After the latch pin modification, do the post-modification inspection at the time given in this service bulletin. Revision 1 - More work is necessary on the airplanes changed in accordance with the original issue of this service bulletin. The compliance time has been reduced for airplanes that have had all existing latch pins at all latch fitting locations replaced in the same maintenance visit. Also do the latch pin modification, which installs new and improved latch pins, and do the post-modification inspection at the times given 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 122, 142747-100, 747-200B, 747-200C, 747-200F, 747SP, 747SR Group 2: Affected Maintenance Zones ZoneModel 122, 142747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SP, 747SR Group 3: Affected Maintenance Zones ZoneModel 122, 142747-400, 747-400F BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 26 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 27 Group 4: Affected Maintenance Zones ZoneModel 122, 142747-400, 747-400D, 747-400F Group 5: Affected Maintenance Zones ZoneModel 122, 142747-200F E. Compliance Federal Aviation Administration (FAA) Airworthiness Directive AD 2000-02-37 is related to this service bulletin. 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. Group 1, Configuration 1, 5; Group 2, Configuration 1, 3; Group 3; Group 4-5, Configuration 1: Table 1: Forward and Aft Lower Lobe Cargo Door - Latch Pin Inspection and Replacement Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) Action (c)Condition -Within 1,000 flight cycles af- ter the original issue date of this service bulletin. Before 6,000 total flight cy- cles. Do a general visual inspection for broken or missing latch pins and a detailed inspection of the latch pins for cracking in accor- dance with Paragraph 3.B., Work Instructions, Part 1, Step 2. All airplanes. -Before further flight.Replace each broken or missing latch pin and replace the latch pin(s) adjacent to each broken or missing latch pin in accor- dance with Paragraph 3.B., Work Instructions, Part 1, Step 2.a. If a latch pin is broken into two or more pieces. -Before further flight.Replace each cracked latch pin in accordance with Paragraph 3.B., Work Instructions, Part 1, Step 2.b. If any crack is found in a latch pin. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 27 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 28 Group 1, Configuration 1, 5; Group 2, Configuration 1, 3; Group 3; Group 4-5, Configuration 1: Table 1: Forward and Aft Lower Lobe Cargo Door - Latch Pin Inspection and Replacement Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) Action (c)Condition 1,600 flight cycles (a) (b) Within 2,400 flight cycles after replacement of latch pins. For each door: Repeat the general visual in- spection for broken or missing latch pins and the detailed in- spection of the latch pins for cracking in accordance with Paragraph 3.B., Work Instruc- tions, Part 1, Step 2. Doors with all latch pins replaced with new latch pins at all latch fitting locations and at the same maintenance visit in accordance with this service bulletin. 1,600 flight cycles (a) (b) Within 1,600 flight cycles after the previous inspection of all latch pins. For each door: Repeat the general visual in- spection for broken or missing latch pins and the detailed in- spection of the latch pins for cracking in accordance with Paragraph 3.B., Work Instruc- tions, Part 1, Step 2. Doors without all latch pins replaced with new latch pins at all latch fit- ting locations and at the same maintenance visit in accordance with this service bulletin. (a) Replacement of a latch pin is not terminating action for the inspections of that latch pin. (b) Continue to do the repeat inspections until the latch pin modification in accordance with Paragraph 3.B., Work Instructions, Part 2, is accomplished at all latch fitting locations. (c) Do the latch pin modification in accordance with Paragraph 3.B., Work Instructions, Part 2, at the time given in Table 5. Group 1, Configuration 2, 6; Group 2, Configuration 2, 4; Group 4-5, Configuration 2: Table 2: Forward and Aft Lower Lobe Cargo Door - Latch Pin Inspection and Replacement Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) Action (c)Condition -Within 1,000 flight cycles af- ter the original issue date of this service bulletin. Before 6,000 total flight cy- cles. Do a general visual inspection for broken or missing latch pins and a detailed inspection of the latch pins for cracking in accor- dance with Paragraph 3.B., Work Instructions, Part 1, Step 3. All airplanes. -Before further flight.Replace each broken or missing latch pin and replace the latch pin(s) adjacent to each broken or missing latch pin in accor- dance with Paragraph 3.B., Work Instructions, Part 1, Step 3.a. If a latch pin is broken into two or more pieces. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 28 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 29 Group 1, Configuration 2, 6; Group 2, Configuration 2, 4; Group 4-5, Configuration 2: Table 2: Forward and Aft Lower Lobe Cargo Door - Latch Pin Inspection and Replacement Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) Action (c)Condition -Before further flight.Replace each cracked latch pin in accordance with Paragraph 3.B., Work Instructions, Part 1,Step 3.b. If any crack is found in a latch pin. 1,600 flight cycles (a) (b) Within 2,400 flight cycles after replacement of latch pins. For each door: Repeat the general visual in- spection for broken or missing latch pins and the detailed in- spection of the latch pins for cracking in accordance with Paragraph 3.B., Work Instruc- tions, Part 1, Step 3. Doors with all latch pins replaced with new latch pins at all latch fitting locations and at the same maintenance visit in accordance with this service bulletin. 1,600 flight cycles (a) (b) Within 1,600 flight cycles after the previous inspection of all latch pins. For each door: Repeat the general visual in- spection for broken or missing latch pins and the detailed in- spection of the latch pins for cracking in accordance with Paragraph 3.B., Work Instruc- tions, Part 1, Step 3. Doors without all latch pins replaced with new latch pins at all latch fit- ting locations and at the same maintenance visit in accordance with this service bulletin. (a) Replacement of a latch pin is not terminating action for the inspections of that latch pin. (b) Continue to do the repeat inspections until the latch pin modification in accordance with Paragraph 3.B., Work Instructions, Part 2, is accomplished at all latch fitting locations. (c) Do the latch pin modification in accordance with Paragraph 3.B., Work Instructions, Part 2, at the time given in Table 5. Group 1, Configuration 3, 7: Table 3: Forward and Aft Lower Lobe Cargo Door - Latch Pin Inspection and Replacement Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) Action (c)Condition -Within 1,000 flight cycles af- ter the original issue date of this service bulletin. Before 6,000 total flight cy- cles. Do a general visual inspection for broken or missing latch pins and a detailed inspection of the latch pins for cracking in accor- dance with Paragraph 3.B., Work Instructions, Part 1, Step 4. All airplanes. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 29 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 30 Group 1, Configuration 3, 7: Table 3: Forward and Aft Lower Lobe Cargo Door - Latch Pin Inspection and Replacement Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) Action (c)Condition -Before further flight.Replace each broken or missing latch pin and replace the latch pin(s) adjacent to each broken or missing latch pin in accor- dance with Paragraph 3.B., Work Instructions, Part 1, Step 4.a. OPTION 1 or OPTION 2. If a latch pin is broken into two or more pieces. -Before further flight.Replace each cracked latch pin in accordance with Paragraph 3.B., Work Instructions, Part 1, Step 4.a. OPTION 1 or OPTION 2. If any crack is found in a latch pin. 1,600 flight cycles (a) (b) Within 2,400 flight cycles after replacement of latch pins. For each door: Repeat the general visual in- spection for broken or missing latch pins and the detailed in- spection of the latch pins for cracking in accordance with Paragraph 3.B., Work Instruc- tions, Part 1, Step 4. Doors with all latch pins replaced with new latch pins at all latch fitting locations and at the same maintenance visit in accordance with this service bulletin. 1,600 flight cycles (a) (b) Within 1,600 flight cycles after the previous inspection of all latch pins. For each door: Repeat the general visual in- spection for broken or missing latch pins and the detailed in- spection of the latch pins for cracking in accordance with Paragraph 3.B., Work Instruc- tions, Part 1, Step 4. Doors without all latch pins replaced with new latch pins at all latch fit- ting locations and at the same maintenance visit in accordance with this service bulletin. (a) Replacement of a latch pin is not terminating action for the inspections of that latch pin. (b) Continue to do the repeat inspections until the latch pin modification in accordance with Paragraph 3.B., Work Instructions, Part 2, is accomplished at all latch fitting locations. (c) Do the latch pin modification in accordance with Paragraph 3.B., Work Instructions, Part 2, at the time given in Table 5. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 30 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 31 Group 1, Configuration 4, 8: Table 4: Forward and Aft Lower Lobe Cargo Door - Latch Pin Inspection and Replacement Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) Action (c)Condition -Within 1,000 flight cycles af- ter the original issue date of this service bulletin. Before 6,000 total flight cy- cles. Do a general visual inspection for broken or missing latch pins and a detailed inspection of the latch pins for cracking in accor- dance with Paragraph 3.B., Work Instructions, Part 1, Step 5. All airplanes. -Before further flight.Replace each broken or missing latch pin and replace the latch pin(s) adjacent to each broken or missing latch pin in accor- dance with Paragraph 3.B., Work Instructions, Part 1, Step 5.a. OPTION 1 or OPTION 2. If a latch pin is broken into two or more pieces. -Before further flight.Replace each cracked latch pin in accordance with Paragraph 3.B., Work Instructions, Part 1, Step 5.a. OPTION 1 or OPTION 2. If any crack is found in a latch pin. 1,600 flight cycles (a) (b) Within 2,400 flight cycles after replacement of latch pins. For each door: Repeat the general visual in- spection for broken or missing latch pins and the detailed in- spection of the latch pins for cracking in accordance with Paragraph 3.B., Work Instruc- tions, Part 1, Step 5. Doors with all latch pins replaced with new latch pins at all latch fitting locations and at the same maintenance visit in accordance with this service bulletin. 1,600 flight cycles (a) (b) Within 1,600 flight cycles after the previous inspection of all latch pins. For each door: Repeat the general visual in- spection for broken or missing latch pins and the detailed in- spection of the latch pins for cracking in accordance with Paragraph 3.B., Work Instruc- tions, Part 1, Step 5. Doors without all latch pins replaced with new latch pins at all latch fit- ting locations and at the same maintenance visit in accordance with this service bulletin. (a) Replacement of a latch pin is not terminating action for the inspections of that latch pin. (b) Continue to do the repeat inspections until the latch pin modification in accordance with Paragraph 3.B., Work Instructions, Part 2, is accomplished at all latch fitting locations. (c) Do the latch pin modification in accordance with Paragraph 3.B., Work Instructions, Part 2, at the time given in Table 5. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 31 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 32 Table 5: Forward and Aft Lower Lobe Cargo Door - Latch Pin Modification Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Within 6,000 flight cycles or 6 years after the Revision 1 date of this service bulletin, whichever occurs first. Do the latch pin modifica- tion in accordance with Paragraph 3.B., Work In- structions, Part 2. All airplanes. --Refer to Table 6.Doors with latch pin modifi- cation accomplished at all latch fitting locations in ac- cordance with Paragraph 3.B., Work Instructions, Part 2. Table 6: Forward and Aft Lower Lobe Cargo Door - Post-Modification Inspection Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Within 2,400 flight cycles or 24 months after the latch pin modifi- cation, whichever occurs first. For each door: Do a detailed inspection of the latch fittings for any impact damage (which includes nicks, gouges, and scratches), corrosion, and cracks; a general vi- sual inspection for broken or missing latch pins; and a detailed inspection of the latch pins for any cracks in accordance with Paragraph 3.B., Work In- structions, Part 3. Doors with latch pin modifi- cation accomplished at all latch fitting locations in ac- cordance with Paragraph 3.B., Work Instructions, Part 2. 2,400 flight cycles or 24 months, whichever occurs first. Within 2,400 flight cycles or 24 months after the previous inspec- tion, whichever occurs first. For each door: Do a detailed inspection of the latch fittings for any nicks, gouges, scratches, corrosion, and cracks; a general visual inspection for broken or missing latch pins; and a detailed inspection of the latch pins for any cracks in ac- cordance with Paragraph 3.B., Work Instructions, Part 3. Doors with no nicks, gouges, scratches, corro- sion, and cracks found in the latch fittings; and with no broken, missing, and cracked latch pins found. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 32 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 33 Table 6: Forward and Aft Lower Lobe Cargo Door - Post-Modification Inspection Repeat Interval (Not to Exceed) Compliance TimeActionCondition Before further flight.Do the SRM repair or re- place the latch fitting in accordance with Para- graph 3.B., Work Instruc- tions, Part 3. If any nicks, gouges, scratches, corrosion, or cracks are found in a latch fitting. -Before further flight.Replace each broken or missing latch pin and re- place the latch pin(s) ad- jacent to each broken or missing latch pin in accor- dance with Paragraph 3.B., Work Instructions, Part 3. If a latch pin is broken into two or more pieces. -Before further flightReplace each cracked latch pin in accordance with Paragraph 3.B., Work Instructions, Part 3. If any crack is found in a latch pin. 2,400 flight cycles or 24 months, whichever occurs first. Within 2,400 flight cycles or 24 months after the previous inspec- tion, whichever occurs first. For each door: Do a detailed inspection of the latch fittings for any impact damage (nicks, gouges, and scratches), corrosion, and cracks; a general visual inspection for broken or missing latch pins; and a detailed inspection of the latch pins for any cracks in ac- cordance with Paragraph 3.B., Work Instructions, Part 3. Doors with any repairs or replacement of the latch fittings and/or with latch pins replaced. 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. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 33 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 34 The Manager of the FAA Seattle Aircraft Certification Office (ACO) approves the modification with the corresponding time specified in Table 5, under Paragraph 1.E., "Compliance," of Service Bulletin 747-53A2835, Revision 1 as an alternative method of compliance (AMOC) to the modification required by paragraph (c) of AD 2000-02-37. All provisions of AD 2000-02-37 that are not specifically referenced in this paragraph remain fully applicable and must be complied with. G. Manpower The tables below show an estimate of the task hours necessary to do this inspection, replacement, and modification for each airplane. This estimate is for direct labor only, done by an experienced crew. Adjust the estimate with operator task hour data if necessary. The estimate does not include lost time. These are some examples of lost time:  Time to adjust to the workplace  Time to schedule the work  Time to inspect the work  Time to cure the materials  Time to make the parts  Time to find the tools. Group 1, Configuration 1, 5; Group 2, Configuration 1, 3; Group 3; Group 4-5, Configuration 1: Table 1: Part 1 - Latch Pin Inspection and Replacement Elapsed HoursTask HoursNumber of PersonsTask 0.250.251Open Access 1.001.001FIGURE 1 4.008.002FIGURE 2 (a) 0.250.251Close Access 5.509.50TOTAL FOR EACH AIRPLANE (a) (a) This estimate includes replacement of all 16 latch pins. It may not be necessary to replace all 16 latch pins. Group 1, Configuration 2, 6; Group 2, Configuration 2, 4; Group 4-5, Configuration 2: Table 2: Part 1 - Latch Pin Inspection and Replacement Elapsed HoursTask HoursNumber of PersonsTask 0.250.251Open Access 1.001.001FIGURE 1 4.008.002FIGURE 3 (a) 0.250.251Close Access 5.509.50TOTAL FOR EACH AIRPLANE (a) (a) This estimate includes replacement of all 16 latch pins. It may not be necessary to replace all 16 latch pins. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 34 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 35 Group 1, Configuration 3, 7: Table 3: Part 1 - Latch Pin Inspection and Replacement; OPTION 1: DO NOT MODIFY THE LATCH FITTINGS Elapsed HoursTask HoursNumber of PersonsTask 0.250.251Open Access 1.001.001FIGURE 1 4.008.002FIGURE 4 (a) 0.250.251Close Access 5.509.50TOTAL FOR EACH AIRPLANE (a) (a) This estimate includes replacement of all 16 latch pins. It may not be necessary to replace all 16 latch pins. Group 1, Configuration 3, 7: Table 4: Part 1 - Latch Pin Inspection and Replacement; OPTION 2: MODIFY THE LATCH FITTINGS Elapsed HoursTask HoursNumber of PersonsTask 0.250.251Open Access 1.001.001FIGURE 1 18.0036.002FIGURE 6 (a) 0.250.251Close Access 19.5037.50TOTAL FOR EACH AIRPLANE (a) (a) This estimate includes modification of all latch pins and latch fitting bearing plates. It is acceptable to replace latch pins and bearing plates with new parts. Group 1, Configuration 4, 8: Table 5: Part 1 - Latch Pin Inspection and Replacement; OPTION 1: DO NOT MODIFY THE LATCH FITTINGS Elapsed HoursTask HoursNumber of PersonsTask 0.250.251Open Access 1.001.001FIGURE 1 4.008.002FIGURE 5 (a) 0.250.251Close Access 5.509.50TOTAL FOR EACH AIRPLANE (a) (a) This estimate includes replacement of all 16 latch pins. It may not be necessary to replace all 16 latch pins. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 35 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 36 Group 1, Configuration 4, 8: Table 6: Part 1 - Latch Pin Inspection and Replacement; OPTION 2: MODIFY THE LATCH FITTINGS Elapsed HoursTask HoursNumber of PersonsTask 0.250.251Open Access 1.001.001FIGURE 1 18.0036.002FIGURE 7 (a) 0.250.251Close Access 19.5037.50TOTAL FOR EACH AIRPLANE (a) (a) This estimate includes modification of all latch pins and latch fitting bearing plates. It is acceptable to replace latch pins and bearing plates with new parts. Group 1-2, Configuration 1; Group 3; Group 4, Configuration 1: Table 7: Part 2 - Latch Pin Modification Elapsed HoursTask HoursNumber of PersonsTask 0.250.251Open Access 2.254.502FIGURE 8 2.254.502FIGURE 9 0.250.251Close Access(a) 5.009.50TOTAL FOR EACH AIRPLANE(a) (a) This estimate does not include the adjustment of the lower lobe cargo door. Additional time is necessary for the adjustment of the lower lobe cargo door if any latch fitting is removed. Group 1-2, 4, Configuration 2: Table 8: Part 2 - Latch Pin Modification Elapsed HoursTask HoursNumber of PersonsTask 0.250.251Open Access 2.254.502FIGURE 10 2.254.502FIGURE 11 0.250.251Close Access(a) 5.009.50TOTAL FOR EACH AIRPLANE(a) (a) This estimate does not include the adjustment of the lower lobe cargo door. Additional time is necessary for the adjustment of the lower lobe cargo door if any latch fitting is removed. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 36 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 37 Group 1, Configuration 3: Table 9: Part 2 - Latch Pin Modification Elapsed HoursTask HoursNumber of PersonsTask 0.250.251Open Access 9.0018.002FIGURE 12 (a) 9.0018.002FIGURE 13 (a) 0.250.251Close Access(b) 18.5036.50TOTAL FOR EACH AIRPLANE(a) (b) (a) This estimate includes modification of all latch fitting bearing plates. It is ac- ceptable to replace bearing plates with new parts. (b) This estimate does not include the adjustment of the lower lobe cargo door. Additional time is necessary for the adjustment of the lower lobe cargo door if any latch fitting is removed. Group 1, Configuration 4: Table 10: Part 2 - Latch Pin Modification Elapsed HoursTask HoursNumber of PersonsTask 0.250.251Open Access 9.0018.002FIGURE 14 (a) 9.0018.002FIGURE 15 (a) 0.250.251Close Access(b) 18.5036.50TOTAL FOR EACH AIRPLANE(a) (b) (a) This estimate includes modification of all latch fitting bearing plates. It is ac- ceptable to replace bearing plates with new parts. (b) This estimate does not include the adjustment of the lower lobe cargo door. Additional time is necessary for the adjustment of the lower lobe cargo door if any latch fitting is removed. Group 1, Configuration 5; Group 2, Configuration 3; Group 5, Configuration 1: Table 11: Part 2 - Latch Pin Modification Elapsed HoursTask HoursNumber of PersonsTask 0.250.251Open Access 2.254.502FIGURE 16 2.254.502FIGURE 17 0.250.251Close Access(a) 5.009.50TOTAL FOR EACH AIRPLANE(a) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 37 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 38 Group 1, Configuration 5; Group 2, Configuration 3; Group 5, Configuration 1: Table 11: Part 2 - Latch Pin Modification Elapsed HoursTask HoursNumber of PersonsTask (a) This estimate does not include the adjustment of the lower lobe cargo door. Additional time is necessary for the adjustment of the lower lobe cargo door if any latch fitting is removed. Group 1, Configuration 6; Group 2, Configuration 4; Group 5, Configuration 2: Table 12: Part 2 - Latch Pin Modification Elapsed HoursTask HoursNumber of PersonsTask 0.250.251Open Access 2.254.502FIGURE 18 2.254.502FIGURE 19 0.250.251Close Access(a) 5.009.50TOTAL FOR EACH AIRPLANE(a) (a) This estimate does not include the adjustment of the lower lobe cargo door. Additional time is necessary for the adjustment of the lower lobe cargo door if any latch fitting is removed. Group 1, Configuration 7: Table 13: Part 2 - Latch Pin Modification Elapsed HoursTask HoursNumber of PersonsTask 0.250.251Open Access 9.0018.002FIGURE 20 (a) 9.0018.002FIGURE 21 (a) 0.250.251Close Access(b) 18.5036.50TOTAL FOR EACH AIRPLANE(a) (b) (a) This estimate includes modification of all latch fitting bearing plates. It is ac- ceptable to replace bearing plates with new parts. (b) This estimate does not include the adjustment of the lower lobe cargo door. Additional time is necessary for the adjustment of the lower lobe cargo door if any latch fitting is removed. Group 1, Configuration 8: Table 14: Part 2 - Latch Pin Modification Elapsed HoursTask HoursNumber of PersonsTask 0.250.251Open Access 9.0018.002FIGURE 22 (a) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 38 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 39 Group 1, Configuration 8: Table 14: Part 2 - Latch Pin Modification Elapsed HoursTask HoursNumber of PersonsTask 9.0018.002FIGURE 23 (a) 0.250.251Close Access(b) 18.5036.50TOTAL FOR EACH AIRPLANE(a) (b) (a) This estimate includes modification of all latch fitting bearing plates. It is ac- ceptable to replace bearing plates with new parts. (b) This estimate does not include the adjustment of the lower lobe cargo door. Additional time is necessary for the adjustment of the lower lobe cargo door if any latch fitting is removed. Group 1, Configuration 1-4; Group 2, Configuration 1-2; Group 3-4: Table 15: Part 3 - Post-Modification Inspection Elapsed HoursTask HoursNumber of PersonsTask 0.250.251Open Access 1.251.251FIGURE 24 1.251.251FIGURE 25 2.004.002FIGURE 26 (a) 2.004.002FIGURE 27 (a) 0.250.251Close Access(b) 7.0011.00TOTAL FOR EACH AIRPLANE(a) (b) (a) This estimate includes replacement of all latch pins. It may not be necessary to replace all latch pins. (b) This estimate does not include the adjustment of the lower lobe cargo door. Additional time is necessary for the adjustment of the lower lobe cargo door if any latch fitting is removed. Group 1, Configuration 5-8; Group 2, Configuration 3-4; Group 5: Table 16: Part 3 - Post-Modification Inspection Elapsed HoursTask HoursNumber of PersonsTask 0.250.251Open Access 1.251.251FIGURE 24 1.251.251FIGURE 25 2.004.002FIGURE 28 (a) 2.004.002FIGURE 29 (a) 0.250.251Close Access(b) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 39 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 40 Group 1, Configuration 5-8; Group 2, Configuration 3-4; Group 5: Table 16: Part 3 - Post-Modification Inspection Elapsed HoursTask HoursNumber of PersonsTask 7.0011.00TOTAL FOR EACH AIRPLANE(a) (b) (a) This estimate includes replacement of all latch pins. It may not be necessary to replace all latch pins. (b) This estimate does not include the adjustment of the lower lobe cargo door. Additional time is necessary for the adjustment of the lower lobe cargo door if any latch fitting is removed. H. Weight and Balance Changes None. I. Electrical Load Data Not changed. J. References 1. Existing Data a. Engineering Change Memo PRR 85901-105RS b. Boeing Service Bulletin 747-52-2105, 747-52-2224, 747-52-2260 c. Boeing Service Related Problem (SRP) 747-SRP-53-0351 d. Component Maintenance Manual (CMM) 52-34-11, 52-35-11 e. Federal Aviation Administration (FAA) Airworthiness Directive (AD) 2000-02-37 f. Standard Overhaul Practices Manual (SOPM) 20-10-02, 20-10-03, 20-20-01, 20-30-02, 20-41-02, 20-42-03, 20-42-05, 20-50-08, 20-50-10, 20-50-19 g. 747-100/200/300 Aircraft Maintenance Manual (AMM) 52-34-00 h. 747-100/200/300 Structural Repair Manual (SRM) 53-40-01 i. 747-400 Aircraft Maintenance Manual (AMM) 52-34-00 j. 747-400 Structural Repair Manual (SRM) 53-00-90 Repair 1 k. 747-400F Structural Repair Manual (SRM) 53-00-90 Repair 1 l. 747-400LCF Structural Repair Manual (SRM) 53-00-90 Repair 1 m. 747-400SF Structural Repair Manual (SRM) 53-00-90 Repair 1 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 40 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 41 n. 747-SP Structural Repair Manual (SRM) 53-40-01 2. Data supplied with this Service Bulletin None. 3. Installation Drawings Used in the Preparation of this Service Bulletin TitleDrawing Number SILL INSTL - LOWER MAIN, FWD CARGO DOOR65B04216 SILL INSTALLATION - LOWER MAIN, AFT CARGO DOOR65B04642 The table above lists applicable drawings used to prepare this service bulletin. The drawings are not necessary to make the specified changes, and are not supplied with this service bulletin. The drawings may not be applicable to all airplane configurations or operators. K. Publications Affected 1. Publications: Chapter-SectionPublication 53-12747 Illustrated Parts Catalog 2. Damage Tolerance Based Structural Inspections: Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the Maintenance Program. This service bulletin affects FCS. DTI requirements for the structure affected are contained in Paragraph 1.E., Compliance of this service bulletin. L. Interchangeability and Intermixability of Parts Refer to Paragraph 2.C., Parts Necessary for Each Airplane, for interchangeability and intermixability information. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 41 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 42 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 42 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT BLANK PAGE ### Page 43 2. MATERIAL INFORMATION A. Material - Price and Availability Boeing can supply the kits parts shown in Paragraph 2.C., Parts Necessary for Each Airplane. Operators are encouraged to share schedule requirements with Boeing for incorporation of the service bulletin. The kits are subject to the terms and conditions of the Boeing standard purchase order acknowledgment. Prices are in United States Dollars. Terms: Net 30 days. Reference this service bulletin and submit your purchase order by one of these methods: 1. Order on-line via ATA Spec 2000 or The Boeing PART Page 2. Fax to (206) 662-7145 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 43 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 44 Group 1, Configuration 1-4; Group 2, Configuration 1-2; Group 3-4: REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION Unit Price as of the Revision 1 date of this Ser- vice Bulletin (US Dollars) ROLT as of the Revision 1 date of this Service Bul- letin (Calendar Days) QTYDateNameKit Number $8,177.00280801/25/2012TOP KIT - FORWARD AND AFT LOWER LOBE CARGO DOOR LATCH PINS 015U1908-1 802/10/2012 803/09/2012 804/06/2012 805/04/2012 806/04/2012 707/02/2012 1507/31/2012 1508/28/2012 1509/26/2012 Group 1, Configuration 5-8; Group 2, Configuration 3-4; Group 5: Unit Price as of the Revision 1 date of this Ser- vice Bulletin (US Dollars) ROLT as of the Revision 1 date of this Service Bul- letin (Calendar Days) QTYDateNameKit Number $7,809.00280701/25/2012TOP KIT - FORWARD AND AFT LOWER LOBE CARGO DOOR LATCH PINS 015U1908-2 702/10/2012 703/09/2012 704/06/2012 705/04/2012 706/04/2012 807/02/2012 B. Industry Support Information Boeing warranty remedies are not available for the configuration changes, inspection and/or repair procedures given in this service bulletin. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 44 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 45 C. Parts Necessary For Each Airplane 1. Kits/Parts To get the kits/parts shown below, refer to Paragraph 2.A., Material - Price and Availability. NOTE: One top kit and the items shown in Paragraph 2.C.2., Parts and Materials Supplied by the Operator, are necessary for each airplane. Kit 015U1908 NotesExisting Part Number NameQTYNew Part Number -2-1 --Top Kit - Forward and Aft Lower Lobe Cargo Door Latch Pins .-015U1908-1 --Top Kit - Forward and Aft Lower Lobe Cargo Door Latch Pins -.015U1908-2 Discard the exist- ing part. 69B02005-( )PIN-LATCH, CAR- GO DOOR 1616675U0003-1 Discard the exist- ing bracket assem- bly if in- stalled. -PIN STOP BRACKET 1214675U0003-2 (a)-BOLT1616BACB30LM3K28 --NUT1616BACN10YR3CD --WASHER1616BACW10BP3CD --WASHER1616BACW10BP3DP (a) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer than indicated. Also, if any fastener part numbers listed are not available or have been superseded, substitute fasteners may be supplied in kits. Boeing Document D-590 and Boeing Drawing 65B88700 are used to determine the part numbers used as substitutes. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 45 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 46 2. Parts and Materials Supplied by the Operator Group 1, Configuration 1-2, 5-6; Group 2-5: NotesExisting Part Number NameQTYPart Number / Specification (a) (b)69B02005-4 ORPIN, LATCH1669B02005-6 (69B02005-4 or 69B02005-5 optional) 69B02005-5 OR 69B02005-6 (c)-PRESSURE AND ENVIRON- MENTAL SEALANT-CHRO- MATE TYPE 8 OzBMS5-95 TYPE I, CLASS B (c)-PRIMER8 OzBMS10-11 TYPE I (a) One new latch pin is required for each latch pin location where the existing latch pin is broken or missing. There are 16 latch pins on each airplane. (b) Discard existing latch pins that are broken or cracked and discard existing latch pins adjacent to broken latch pins. (c) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data. Group 1, Configuration 3-4, 7-8: NotesExisting Part Number NameQTYPart Number / Specification (a)65B04299-1 OR 65B04299-5 BEARING PLATE865B04299-15 (65B04299-7 or 65B04299-13 optional) (a)65B04299-2 OR 65B04299-6 BEARING PLATE865B04299-16 (65B04299-8 or 65B04299-14 optional) (b) (c) (d)69B02005-3LATCH PIN1669B02005-6 (69B02005-3, 69B02005-4 or 69B02005-5 op- tional) (e)-SOLID FILM LUBRICANT, LIQUID DISPERSED 8 OzBMS3-8 TYPE I (e)-PRESSURE AND ENVIRON- MENTAL SEALANT-CHRO- MATE TYPE 8 OzBMS5-95 TYPE I, CLASS B (e)-PRESSURE AND ENVIRON- MENTAL SEALANT-CHRO- MATE TYPE 8 OzBMS5-95 TYPE I, CLASS C (e)-PRIMER8 OzBMS10-11 TYPE I (a) New bearing plates are required if Option 2, 'Modify the latch fittings', is selected. Alternatively, the existing bearing plates can be modified. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 46 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 47 Group 1, Configuration 3-4, 7-8: NotesExisting Part Number NameQTYPart Number / Specification (b) One new latch pin is required for each latch pin location where the existing latch pin is broken or missing. There are 16 latch pins on each airplane. (c) Discard existing latch pins that are broken or cracked and discard existing latch pins adjacent to broken latch pins. (d) If a 69B02005-3 latch pin is removed, it is necessary to rework the latch fitting before installing a 69B02005-4, 69B02005-5 or 69B02005-6 latch pin. (e) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data. 3. Parts Modified and Reidentified None. 4. Parts Removed and Not Replaced None. D. Parts Necessary to Change Spares None. E. Special Tooling - Price and Availability None. F. Special Tooling Necessary to do this Service Bulletin No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 47 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 48 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 48 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT BLANK PAGE ### Page 49 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. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 2. Obey all of the warnings and cautions given in the specified manual sections. 3. Unless shown differently, these dimensions and tolerances are used: – Linear dimensions are in inches – Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus or minus 0.03 inch – Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch – Angular tolerance is plus or minus 2 degrees – Torque limits to tighten nuts and bolts are in 747 SRM 51. 4. Use the approved fastener and process material substitutions in accordance with 747 SRM 51. 5. If the length of any fastener specified in this service bulletin does not meet the installation standards in 747 SRM 51, then a fastener of the same specification, or an approved substitute, with a length which meets the installation standards in 747 SRM 51 may be used. 6. A Detailed Inspection is defined as: An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirrors, magnifying lenses, etc. may be necessary. Surface cleaning and elaborate access procedures may be required. 7. A General Visual Inspection is defined as: A visual examination of an interior or exterior area, installation or assembly to detect obvious damage, failure or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight or drop-light and may require removal or opening of access panels or doors. Stands, ladders or platforms may be required to gain proximity to the area being checked. 8. 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. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 49 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 50 9. Where the work instructions include installation of a kept part, a new or serviceable part with the same part number can be installed as an alternative to the kept part. The removed part can be discarded if a new or serviceable part is installed. B. WORK INSTRUCTIONS Part 1 - Latch Pin Inspection and Replacement 1. Open the lower lobe forward and aft cargo doors to get access to the latch pins on the lower sill. Refer to 747-100/200/300 AMM 52-34-00 or 747-400 AMM 52-34-00 as an accepted procedure. NOTE: Do the latch pin modification in accordance with Part 2 at the time given in Paragraph 1.E., Compliance. 2. Group 1, Configuration 1, 5; Group 2, Configuration 1, 3; Group 3; Group 4-5, Configuration 1: Do a general visual inspection for broken or missing latch pins and a detailed inspection of the latch pins for cracking in accordance with FIGURE 1. NOTE: It is optional to replace all latch pins with new latch pins at all latch fitting locations in accordance with FIGURE 2. Refer to Paragraph 1.E., Compliance. a. If a latch pin is broken into two or more pieces or is missing, replace the latch pin and replace the latch pin(s) at the adjacent latch fitting location(s) in accordance with FIGURE 2. b. If any crack is found in a latch pin, replace the cracked latch pin in accordance with FIGURE 2. c. Repeat the inspections at the time given in Paragraph 1.E., Compliance. NOTE: The inspections for broken or cracked latch pins provided by this service bulletin do not replace inspections for latch pin wear. CMM 52-34-11 and CMM 52-35-11 give wear limits for the latch pins. 3. Group 1, Configuration 2, 6; Group 2, Configuration 2, 4; Group 4-5, Configuration 2: Do a general visual inspection for broken latch pins and a detailed inspection of the latch pins for cracking in accordance with FIGURE 1. NOTE: It is optional to replace all latch pins with new latch pins at all latch fitting locations in accordance with FIGURE 3. Refer to Paragraph 1.E., Compliance. a. If a latch pin is broken into two or more pieces or is missing, replace the latch pin and replace the latch pin(s) at the adjacent latch fitting location(s) in accordance with FIGURE 3. b. If any crack is found in a latch pin, replace the cracked latch pin in accordance with FIGURE 3. c. Repeat the inspections at the time given in Paragraph 1.E., Compliance. NOTE: The inspections for broken or cracked latch pins provided by this service bulletin do not replace inspections for latch pin wear. CMM 52-34-11 and CMM 52-35-11 give wear limits for the latch pins. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 50 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 51 4. Group 1, Configuration 3, 7: Do a general visual inspection for broken or missing latch pins and a detailed inspection of the latch pins for cracking in accordance with FIGURE 1. NOTE: It is optional to replace all latch pins with new latch pins at all latch fitting locations in accordance with FIGURE 4 or FIGURE 6. Refer to Paragraph 1.E., Compliance. a. If a latch pin is broken or missing or if any crack is found in a latch pin, do one of the following: (1) OPTION 1 - DO NOT MODIFY THE LATCH FITTINGS NOTE: This option requires that 69B02005-3 latch pins are installed. 69B02005-3 latch pins are not available from Boeing Spares. (a) If a latch pin is broken into two or more pieces or is missing, replace the latch pin and replace the latch pin(s) at the adjacent latch fitting location(s) in accordance with FIGURE 4. (b) If any crack is found in a latch pin, replace the cracked latch pin in accordance with FIGURE 4. (2) OPTION 2 - MODIFY THE LATCH FITTINGS NOTE: Accomplishment of this option is equivalent to the change given in Boeing Service Bulletin 747-52-2105 and changes the configuration of the airplane. Refer to Paragraph 1.A., Effectivity, for the correct configuration. (a) Modify or replace the latch pins and bearing plates at all latch fitting locations in accordance with FIGURE 6. 1) If a latch pin is broken into two or more pieces or is missing, replace the latch pin and replace the latch pin(s) at the adjacent latch fitting location(s). Do not modify these latch pins. 2) If any crack is found in a latch pin, replace the cracked latch pin. Do not modify the latch pin. b. Repeat the inspections at the time given in Paragraph 1.E., Compliance. NOTE: The inspections for broken or cracked latch pins provided by this service bulletin do not replace inspections for latch pin wear. CMM 52-34-11 and CMM 52-35-11 give wear limits for the latch pins. 5. Group 1, Configuration 4, 8: Do a general visual inspection for broken or missing latch pins and a detailed inspection of the latch pins for cracking in accordance with FIGURE 1. NOTE: It is optional to replace all latch pins with new latch pins at all latch fitting locations in accordance with FIGURE 5 or FIGURE 7. Refer to Paragraph 1.E., Compliance. a. If a latch pin is broken or missing or if any crack is found in a latch pin, do one of the following: (1) OPTION 1 - DO NOT MODIFY THE LATCH FITTINGS BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 51 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 52 NOTE: This option requires that 69B02005-3 latch pins are installed. 69B02005-3 latch pins are not available from Boeing Spares. (a) If a latch pin is broken into two or more pieces or is missing, replace the latch pin and replace the latch pin(s) at the adjacent latch fitting location(s) in accordance with FIGURE 5. (b) If any crack is found in a latch pin, replace the cracked latch pin in accordance with FIGURE 5. (2) OPTION 2 - MODIFY THE LATCH FITTINGS NOTE: Accomplishment of this option is equivalent to the change given in Boeing Service Bulletin 747-52-2105 and changes the configuration of the airplane. Refer to Paragraph 1.A., Effectivity, for the correct configuration. (a) Modify or replace the latch pins and modify the bearing plates at all latch fitting locations in accordance with FIGURE 7. 1) If a latch pin is broken into two or more pieces or is missing, replace the latch pin and replace the latch pin(s) at the adjacent latch fitting location(s). Do not modify these latch pins. 2) If any crack is found in a latch pin, replace the cracked latch pin. Do not modify the latch pin. b. Repeat the inspections at the time given in Paragraph 1.E., Compliance. NOTE: The inspections for broken or cracked latch pins provided by this service bulletin do not replace inspections for latch pin wear. CMM 52-34-11 and CMM 52-35-11 give wear limits for the latch pins. 6. Put the airplane back to a serviceable condition. Refer to 747-100/200/300 AMM 52-34-00 or 747-400 AMM 52-34-00 as an accepted procedure for closing the lower lobe forward and aft cargo doors. Part 2 - Latch Pin Modification 1. Open the lower lobe forward and aft cargo doors as necessary to get access to the latch pins on the lower sill. Refer to 747-100/200/300 AMM 52-34-00 or 747-400 AMM 52-34-00 as an accepted procedure. 2. Group 1-2, Configuration 1; Group 3; Group 4, Configuration 1: Do the latch pin modification on the lower lobe forward door in accordance with FIGURE 8. Do the latch pin modification on the lower lobe aft door in accordance with FIGURE 9. 3. Group 1-2, 4, Configuration 2: Do the latch pin modification on the lower lobe forward door in accordance with FIGURE 10. Do the latch pin modification on the lower lobe aft door in accordance with FIGURE 11. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 52 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 53 4. Group 1, Configuration 3: Do the latch pin modification on the lower lobe forward door in accordance with FIGURE 12. Do the latch pin modification on the lower lobe aft door in accordance with FIGURE 13. NOTE: Accomplishment of FIGURE 12 and FIGURE 13 include the bearing plate modification, which is equivalent to the bearing plate modification given in Boeing Service Bulletin 747-52-2105. 5. Group 1, Configuration 4: Do the latch pin modification on the lower lobe forward door in accordance with FIGURE 14. Do the latch pin modification on the lower lobe aft door in accordance with FIGURE 15. NOTE: Accomplishment of FIGURE 14 and FIGURE 15 include the bearing plate modification, which is equivalent to the bearing plate modification given in Boeing Service Bulletin 747-52-2105. 6. Group 1, Configuration 5; Group 2, Configuration 3; Group 5, Configuration 1: Do the latch pin modification on the lower lobe forward door in accordance with FIGURE 16. Do the latch pin modification on the lower lobe aft door in accordance with FIGURE 17. 7. Group 1, Configuration 6; Group 2, Configuration 4; Group 5, Configuration 2: Do the latch pin modification on the lower lobe forward door in accordance with FIGURE 18. Do the latch pin modification on the lower lobe aft door in accordance with FIGURE 19. 8. Group 1, Configuration 7: Do the latch pin modification on the lower lobe forward door in accordance with FIGURE 20. Do the latch pin modification on the lower lobe aft door in accordance with FIGURE 21. NOTE: Accomplishment of FIGURE 20 and FIGURE 21 include the bearing plate modification, which is equivalent to the bearing plate modification given in Boeing Service Bulletin 747-52-2105. 9. Group 1, Configuration 8: Do the latch pin modification on the lower lobe forward door in accordance with FIGURE 22. Do the latch pin modification on the lower lobe aft door in accordance with FIGURE 23. NOTE: Accomplishment of FIGURE 22 and FIGURE 23 include the bearing plate modification, which is equivalent to the bearing plate modification given in Boeing Service Bulletin 747-52-2105. 10. If any latch fitting is removed from the airplane, adjust the affected lower lobe cargo door. Refer to the task "Forward/Aft Cargo Doors Adjustment" in 747-100/200/300 AMM 52-34-00 or "Forward/Aft Cargo Doors - Adjustment" in 747-400 AMM 52-34-00 as an accepted procedure. Adjustment of the lower lobe cargo door is necessary only if any latch fitting is removed. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 53 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 54 11. Put the airplane back to a serviceable condition. Refer to 747-100/200/300 AMM 52-34-00 or 747-400 AMM 52-34-00 as an accepted procedure for closing the lower lobe forward and aft cargo doors. After the latch pin modification, do the post-modification inspections in Part 3 at the time given in Paragraph 1.E., Compliance. Part 3 - Post-Modification Inspection 1. Open the lower lobe forward and aft cargo doors as necessary to get access to the latch pins on the lower sill. Refer to 747-100/200/300 AMM 52-34-00 or 747-400 AMM 52-34-00 as an accepted procedure. 2. Group 1, Configuration 1-4; Group 2, Configuration 1-2; Group 3-4: Do the post-modification inspection as follows: a. For the lower lobe forward cargo door: Do a detailed inspection of the latch fittings for any impact damage (which includes nicks, gouges, and scratches) corrosion, and cracks; a general visual inspection for broken or missing latch pins; and a detailed inspection of the latch pins for cracking in accordance with FIGURE 24. (1) Doors with no nicks, gouges, scratches, corrosion, and cracks found in the latch fittings; and with no broken, missing, and cracked latch pins found; repeat the inspections at the time given in Paragraph 1.E., Compliance. NOTE: The inspections for broken or cracked latch pins provided by this service bulletin do not replace inspections for latch pin wear. CMM 52-34-11 and CMM 52-35-11 give wear limits for the latch pins. (2) If any nicks, gouges, scratches, corrosion, or cracks are found in the latch fittings, repair the latch fitting in accordance with 747-100/200/300 SRM 53-40-01, 747-400 SRM 53-00-90 Repair 1, 747-400F SRM 53-00-90 Repair 1, 747-SP SRM 53-40-01, 747-400SF SRM 53-00-90 Repair 1, or 747-400LCF SRM 53-00-90 Repair 1. (3) If a latch pin is broken into two or more pieces or is missing, replace the latch pin and replace the latch pin(s) at the adjacent latch fitting location(s) in accordance with FIGURE 26. (4) If any crack is found in a latch pin, replace the cracked latch pin in accordance with FIGURE 26. (5) Doors with any repairs or replacement of the latch fittings and/or with replacement of latch pins, repeat the inspections at the time given in Paragraph 1.E., Compliance. NOTE: The inspections for broken or cracked latch pins provided by this service bulletin do not replace inspections for latch pin wear. CMM 52-34-11 and CMM 52-35-11 give wear limits for the latch pins. b. For the lower lobe aft cargo door: BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 54 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 55 Do a detailed inspection of the latch fittings for any impact damage (which includes nicks, gouges, and scratches) corrosion, and cracks; a general visual inspection for broken or missing latch pins; and a detailed inspection of the latch pins for cracking in accordance with FIGURE 25. (1) Doors with no nicks, gouges, scratches, corrosion, and cracks found in the latch fittings; and with no broken, missing, and cracked latch pins found; repeat the inspections at the time given in Paragraph 1.E., Compliance. NOTE: The inspections for broken or cracked latch pins provided by this service bulletin do not replace inspections for latch pin wear. CMM 52-34-11 and CMM 52-35-11 give wear limits for the latch pins. (2) If any nicks, gouges, scratches, corrosion, or cracks are found in the latch fittings, repair the latch fitting in accordance with 747-100/200/300 SRM 53-40-01, 747-400 SRM 53-00-90 Repair 1, 747-400F SRM 53-00-90 Repair 1, 747-SP SRM 53-40-01, 747-400SF SRM 53-00-90 Repair 1, or 747-400LCF SRM 53-00-90 Repair 1. (3) If a latch pin is broken into two or more pieces or is missing, replace the latch pin and replace the latch pin(s) at the adjacent latch fitting location(s) in accordance with FIGURE 27. (4) If any crack is found in a latch pin, replace the cracked latch pin in accordance with FIGURE 27. (5) Doors with any repairs or replacement of the latch fittings and/or with replacement of latch pins, repeat the inspections at the time given in Paragraph 1.E., Compliance. NOTE: The inspections for broken or cracked latch pins provided by this service bulletin do not replace inspections for latch pin wear. CMM 52-34-11 and CMM 52-35-11 give wear limits for the latch pins. 3. Group 1, Configuration 5-8; Group 2, Configuration 3-4; Group 5: Do the post-modification inspection as follows: a. For the lower lobe forward cargo door: Do a detailed inspection of the latch fittings for any impact damage (which includes nicks, gouges, and scratches) corrosion, and cracks; a general visual inspection for broken or missing latch pins; and a detailed inspection of the latch pins for cracking in accordance with FIGURE 24. (1) Doors with no nicks, gouges, scratches, corrosion, and cracks found in the latch fittings; and with no broken, missing, and cracked latch pins found; repeat the inspections at the time given in Paragraph 1.E., Compliance. NOTE: The inspections for broken or cracked latch pins provided by this service bulletin do not replace inspections for latch pin wear. CMM 52-34-11 and CMM 52-35-11 give wear limits for the latch pins. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 55 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 56 (2) If any nicks, gouges, scratches, corrosion, or cracks are found in the latch fittings, repair the latch fitting in accordance with 747-100/200/300 SRM 53-40-01, 747-400 SRM 53-00-90 Repair 1, 747-400F SRM 53-00-90 Repair 1, 747-SP SRM 53-40-01, 747-400SF SRM 53-00-90 Repair 1, or 747-400LCF SRM 53-00-90 Repair 1. (3) If a latch pin is broken into two or more pieces or is missing, replace the latch pin and replace the latch pin(s) at the adjacent latch fitting location(s) in accordance with FIGURE 28. (4) If any crack is found in a latch pin, replace the cracked latch pin in accordance with FIGURE 28. (5) Doors with any repairs or replacement of the latch fittings and/or with replacement of latch pins, repeat the inspections at the time given in Paragraph 1.E., Compliance. NOTE: The inspections for broken or cracked latch pins provided by this service bulletin do not replace inspections for latch pin wear. CMM 52-34-11 and CMM 52-35-11 give wear limits for the latch pins. b. For the lower lobe aft cargo door: Do a detailed inspection of the latch fittings for any impact damage (which includes nicks, gouges, and scratches) corrosion, and cracks; a general visual inspection for broken or missing latch pins; and a detailed inspection of the latch pins for cracking in accordance with FIGURE 25. (1) Doors with no nicks, gouges, scratches, corrosion, and cracks found in the latch fittings; and with no broken, missing, and cracked latch pins found; repeat the inspections at the time given in Paragraph 1.E., Compliance. NOTE: The inspections for broken or cracked latch pins provided by this service bulletin do not replace inspections for latch pin wear. CMM 52-34-11 and CMM 52-35-11 give wear limits for the latch pins. (2) If any nicks, gouges, scratches, corrosion, or cracks are found in the latch fittings, repair the latch fitting in accordance with 747-100/200/300 SRM 53-40-01, 747-400 SRM 53-00-90 Repair 1, 747-400F SRM 53-00-90 Repair 1, 747-SP SRM 53-40-01, 747-400SF SRM 53-00-90 Repair 1, or 747-400LCF SRM 53-00-90 Repair 1. (3) If a latch pin is broken into two or more pieces or is missing, replace the latch pin and replace the latch pin(s) at the adjacent latch fitting location(s) in accordance with FIGURE 29. (4) If any crack is found in a latch pin, replace the cracked latch pin in accordance with FIGURE 29. (5) Doors with any repairs or replacement of the latch fittings and/or with replacement of latch pins, repeat the inspections at the time given in Paragraph 1.E., Compliance. NOTE: The inspections for broken or cracked latch pins provided by this service bulletin do not replace inspections for latch pin wear. CMM 52-34-11 and CMM 52-35-11 give wear limits for the latch pins. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 56 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 57 4. If any latch fitting is removed from the airplane, adjust the affected lower lobe cargo door. Refer to the task "Forward/Aft Cargo Doors Adjustment" in 747-100/200/300 AMM 52-34-00 or "Forward/Aft Cargo Doors - Adjustment" in 747-400 AMM 52-34-00 as an accepted procedure. Adjustment of the lower lobe cargo door is necessary only if any latch fitting is removed. 5. Put the airplane back to a serviceable condition. Refer to 747-100/200/300 AMM 52-34-00 or 747-400 AMM 52-34-00 as an accepted procedure for closing the lower lobe forward and aft cargo doors. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1: December 08, 2011 57 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT ### Page 58 (OCR) BOEING SERVICE BULLETIN 747-53A2835 ALERT ALERT NOTE: NUMBERS ADJACENT TO LATCH FITTINGS DENOTE LATCH FITTING LOCATIONS DOORWAY LOWER SILL • LOCATION OME STRUCTURE NOT SHOWN FOR CLARIT' 2085486 FIGURE 1: LOWER LOBE FORWARD AND AFT CARGO DOORS - LATCH PIN INSPECTIONS (SHEET 1 OF 3) Original Issue: October 28, 2010 Revision 1 December 08, 2011 BOEING PROPRIETARY - 747-53A2835 Copyright © Unpublished Work - See page 1 for details. 58 of 324 ### Page 59 (OCR) BOEING SERVICE BULLETIN 747-53A2835 ALERT ALERT BEARING PLATE TYPICAL CRACK LOCATIONS TYPICAL LATCH FITTING LOCATIONS 1, 3, 5 AND 7 BEARING PLATE TYPICAL CRACK LOCATIONS TYPICAL LATCH FITTING LOCATIONS 2,4,6 AND 8 1980876 FIGURE 1: LOWER LOBE FORWARD AND AFT CARGO DOORS - LATCH PIN INSPECTIONS (SHEET 2 OF 3) Original Issue: October 28, 2010 Revision 1 December 08, 2011 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. ### Page 60 The step numbers shown below agree with the numbers shown in the circle symbols in the figure. MORE DATAQTYIDENTIFICATIONNAMETASKSTEP (a)869B02005-( )LATCH PINInspect1 (b)869B02005-( )LATCH PINInspect2 (a) Do a general visual inspection of the latch pin to find if the pin is broken into two or more pieces or is missing. (b) Do a detailed inspection of the visible external surfaces of the latch pin for cracking. Removal of the bearing plate is not required. This step is not necessary if the latch pin is broken. FIGURE 1: LOWER LOBE FORWARD AND AFT CARGO DOORS - LATCH PIN INSPECTIONS (SHEET 3 OF 3) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 28, 2010 747-53A2835Revision 1 December 08, 2011 60 of 324 BOEING SERVICE BULLETIN 747-53A2835 ALERTALERT The text continues at https://openairdocs.org/service-documents/boeing/747-53a2835/file/50a0cdbcb098.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.