### Commercial **Airplanes** 

# 747 Service Bulletin **ALERT Number: 747-52A2294**  Original Issue: July 08, 2010 Revision 1: August 16, 2011 ATA System: 5232 **SUBJECT:** DOORS - Side Cargo Doors - Main Deck Side Cargo Door Latch Pin and Latch Pin Retention Bolt Inspection and Modification 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.9E991 ECCN: 

## BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2010 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter.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BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 1 of 97 5.0BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 2 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**

BLANK PAGE**Table of Contents** Revision Transmittal Sheet............................................ 5 Summary...................................................... 9 1. PLANNING INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 A. Effectivity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 1. Airplanes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2. Spares Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 B. Concurrent Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 C. Reason. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 D. Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 F. Approval. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 G. Manpower. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 I. Electrical Load Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 J. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 1. Existing Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 2. Data supplied with this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 3. Installation Drawings Used in the Preparation of this Service Bulletin. . . . . . . . . . . . 31 K. Publications Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 L. Interchangeability and Intermixability of Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . 32 2. MATERIAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 B. Industry Support Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 C. Parts Necessary For Each Airplane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 1. Kits/Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 2. Parts and Materials Supplied by the Operator. . . . . . . . . . . . . . . . . . . . . . . . 35 3. Parts Modified and Reidentified. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 4. Parts Removed and Not Replaced. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 37 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 A. GENERAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 FIGURE 1: DETAILED INSPECTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 FIGURE 2: TORQUE CHECK. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 FIGURE 3: LATCH PIN POSITION CHECK. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 FIGURE 4: PART REPLACEMENT AT LATCH PIN FITTING POSITIONS #1, #3, #7, #8, #9 AND #10 . 54 FIGURE 5: PART REPLACEMENT AT LATCH PIN FITTING POSITION #2 [Group 1-2, Configuration 2] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 FIGURE 6: PART REPLACEMENT AT LATCH PIN FITTING POSITION #2 [Group 1-2, Configuration 1; Group 3]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 FIGURE 7: PART REPLACEMENT AT LATCH PIN FITTING POSITION #4. . . . . . . . . . . . . . 63 FIGURE 8: PART REPLACEMENT AT LATCH PIN FITTING POSITION #5. . . . . . . . . . . . . . 66 FIGURE 9: PART REPLACEMENT AT LATCH PIN FITTING POSITION #6. . . . . . . . . . . . . . 69

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 3 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**FIGURE 10: MODIFICATION AT LATCH PIN FITTING POSITION #1, #3, #7, #8, #9 AND #10. . . . 72 FIGURE 11: MODIFICATION AT LATCH PIN FITTING POSITION #4. . . . . . . . . . . . . . . . . . 76 FIGURE 12: MODIFICATION AT LATCH PIN FITTING POSITION #5. . . . . . . . . . . . . . . . . . 80 FIGURE 13: MODIFICATION AT LATCH PIN FITTING POSITION #6. . . . . . . . . . . . . . . . . . 84 FIGURE 14: MODIFICATION AT LATCH PIN FITTING POSITION #2 [Group 1-2, Configuration 2] . . 88 FIGURE 15: MODIFICATION AT LATCH PIN FITTING POSITION #2 [Group 1-2, Configuration 1; Group 3] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 FIGURE 16: LATCH PIN REWORK. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 4 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**

### Commercial **Airplanes** 

# 747 Service Bulletin **ALERT Revision Transmittal Sheet**  **Number: 747-52A2294** Original Issue: July 08, 2010 Revision 1: August 16, 2011 ATA System: 5232 **SUBJECT:** DOORS - Side Cargo Doors - Main Deck Side Cargo Door Latch Pin and Latch Pin Retention Bolt Inspection and Modification This revision includes all pages of the service bulletin. **COMPLIANCE INFORMATION RELATED TO THIS REVISION** More work is necessary on the airplane(s) inspected in accordance with the original issue of this service bulletin. Repeat the latch pin retention bolt inspections at the time given in this service bulletin. In addition, at the time given in this service bulletin, Boeing recommends that the 3/16 inch diameter latch pin retention bolts be replaced with 5/16 inch diameter pin retention hardware in accordance with Revision 1. No airplanes were added to the service bulletin effectivity. **REASON FOR REVISION** This revision is sent to change the one-time inspection given in the original issue of this service bulletin into repeat inspections. Also, instructions for replacement of the 3/16 inch diameter latch pin retention bolts with 5/16 inch diameter pin retention hardware has been added. This replacement includes modification of the latch pin fittings and installation of new latch pins. New Figures 10 through 15 have been added. In addition, this revision identifies another possible configuration for Group 1 and Group 2 airplanes. If the modification given in Boeing Service Bulletin 747-52-2224 was installed, the configuration of the latch pin installation at pin fitting position #4 will be different, and similar to position #4 on Group 3 airplanes. The data given in Information Notice 747-52A2294 IN 01 is included in this revision. IN 01 was sent to clarify that in Figures 4, 5, 7, 8 and 9 it is acceptable to install an additional washer under the nut if necessary for fastener grip length adjustment. These sections have changed:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 5 of 971. On the Summary page, the "Action" section was changed to show that the detailed inspections should be repeated, and to include the retention bolt modification. 2. The illustration on the Summary page was changed to include the retention bolt modification. 3. The Group/Configuration table in Paragraph 1.A.1., Airplanes, was changed to include Configurations 1 and 2 for Groups 1 and 2. These configurations are dependent whether the modification given in Boeing Service Bulletin 747-52-2224, "Doors - Cargo Doors - Door Warning - Forward and Aft Lower Lobe and Main Deck Side Cargo Door Warning System Revision" has been installed. The modification changes the latch pin and retention bolt configuration at latch pin fitting #2. 4. Paragraph 1.B., Concurrent Requirements was changed to include Boeing Service Bulletin 747-52-2258. 5. Paragraph 1.D., Description was changed to show that the detailed inspections should be repeated, and to include the retention bolt modification. 6. In Paragraph 1.E., Compliance, Table 1 was changed to include repeat inspections, and to include the retention bolt modification as an alternative to inspection. Table 2 was added to give Compliance information for the retention bolt modification. Table 3 was added to include the repeated inspections necessary after the retention bolt modification has been accomplished. 7. In Paragraph 1.G., Manpower, a title was added to the original man-hour table. Tables 2 and 3 were added for the retention bolt modification and the after-modification inspections. 8. Items were added to Paragraph 1.J.1., Existing Data. 9. Tool Drawing MIT140U8005 was added to Paragraph 1.J.2., Data supplied with this Service Bulletin. 10. In Paragraph 1.K.2., Damage Tolerance Based Structural Inspections:, the paragraph was changed to indicate that DTIs are included in Paragraph 1.E., Compliance. 11. Paragraph 2.A., Material - Price and Availability and Paragraph 2.C., Parts Necessary for Each Airplane were changed to include Modification Top Kit 015U1916-1. 12. Paragraph 2.C.3., Parts Modified and Reidentified, was changed to include latch pins that can be reworked. 13. Paragraph 2.E., Special Tooling - Price and Availability and Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin were changed to include the MIT140U8005-1 tool kit necessary for the retention bolt modification. 14. In Paragraph 3.A., General Information, additional general notes have been included. 15. In Paragraph 3.B., Work Instructions, PART 4 was changed to describe the proper figure for latch pin fitting position #2 for the different Configurations of Group 1 and Group 2. PART 5 was changed to specify repeat inspections. PART 6, describing the retention bolt modification was added. PART 7, describing the after-modification inspections, was added. 16. Figures 10 - 15 have been added to show details of the latch pin retention bolt modification. Figure 16 was added to show an optional rework for certain latch pin part numbers. Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity, to show the location of important changes.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 6 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**Pages with no vertical lines have no important changes. **REVISION HISTORY** July 08, 2010 Original Issue: August 16, 2011 Revision 1:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 7 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 8 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 747 Service Bulletin **ALERT Summary**  **Number: 747-52A2294** Original Issue: July 08, 2010 Revision 1: August 16, 2011 ATA System: 5232 **SUBJECT:** DOORS - Side Cargo Doors - Main Deck Side Cargo Door Latch Pin and Latch Pin Retention Bolt Inspection and Modification 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** Refer to Paragraph 1.B., Concurrent Requirements. **BACKGROUND** Accomplishment of the inspections in this service bulletin will ensure that the latch pin retention bolts in the Main Deck Side Cargo Door lower sill latch pin fittings are not loose, broken or missing. A loose, broken or missing retention bolt can result in a migrated latch pin, which can become disengaged from the cargo door latch cams, and lead to increased loads in the adjacent latch pin fittings and latch cams. Increased loads can cause damage to the cargo door latch mechanism and/or the lower sill structure. The migration of two or more latch pins and subsequent failure of the latch mechanism or lower sill structure can result in the inability of the cargo door to carry limit loads, which could lead to the loss of the cargo door and depressurization of the airplane. The Main Deck Side Cargo Door has a series of ten latch pin fittings which are attached to the lower sill of the door cutout and numbered 1 through 10 forward to aft. Latch pins are installed in each latch pin fitting, and each is secured with a retention bolt. The latch pins and latch pin fittings carry structural and pressurization loads during flight. Six operators have reported that broken latch pin retention bolts were found on eight airplanes. On one airplane, with 101,609 flight-hours and 12,862 flight-cycles, the retention bolts on both the #9 and #10 latch pin fittings were found to be broken. Latch pin #10 was found to have migrated aft and was not engaging the latch cam. On another airplane, with 33,983 flight-hours and 4,723 flight-cycles, the retention bolt on the #10 latch pin fitting was found to be broken and the #9 latch pin was found to be damaged. On another airplane with 67,188 flight-hours and 14,440 flight-cycles, the retention bolt for the #10 latch pin fitting was found to be completely sheared, which allowed the latch pin to migrate aft until it no longer engaged the door latch cam. On four airplanes, only the retention bolt on the #10 latch pin fitting was found to be broken. On one airplane the retention bolt on the #10 latch pin fitting was found to be damaged. Boeing Service Related Problem (SRP) 747-SRP-52-0093 is related to this service bulletin. Boeing Fleet Team Digest article 747-FTD-52-09002 is related to this service bulletin.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 9 of 97**ACTION (PRR 85901-112RS)** Get access to the lower sill of the Main Deck Side Cargo Door (MDSCD) cutout. Do a Detailed Inspection of all ten latch pin fittings for loose, broken or missing retention bolts and nuts. Measure the latch pins to make sure they are within allowable limits. At any latch pin fitting that does not have a loose, broken or missing retention bolt and nut, and the latch pin is not damaged beyond the limits given in this service bulletin, remove sealant and do a torque check in accordance with this service bulletin. If the retention bolt passes the torque check, replace the retention bolt sealant. If the retention bolt fails the torque check, consider the bolt to be broken. At any latch pin location where the retention bolt and nut was not found to be broken, loose, damaged or missing, but the latch pin is damaged beyond the limits given in this service bulletin, replace the latch pin, the retention bolt, and related parts in accordance with this service bulletin. At any latch pin fitting with a loose, broken or missing retention bolt or nut, do a check for latch pin migration in accordance with this service bulletin. If the latch pin has not migrated, replace parts at the affected latch pin fitting location in accordance with this service bulletin. If the latch pin has migrated, do additional Detailed Inspections of adjacent door and door cutout structure and latch cams within 42 inches of the affected fitting for damage in accordance with this service bulletin. Repair any damage that is found. Replace parts at the affected latch pin fitting location and any adjacent latch pin fitting location in accordance with this service bulletin. The inspection is complete when the retention bolts at all ten latch pin fitting locations have either passed the torque check or been replaced in accordance with this service bulletin or other Boeing instructions, and all ten MDSCD latch pins are within the damage limits given in this service bulletin. Do the inspections again at the times given in this service bulletin. At the time given in this service bulletin, Boeing recommends that the 3/16 inch diameter latch pin retention bolts be replaced with 5/16 inch diameter latch pin retention hardware. As part of this replacement, the retention bolt holes in the latch pin fittings must be made larger, and new latch pins with larger diameter retention bolt holes must be installed. **EFFECTIVITY** 747-100, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400F, and 747SR Airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes. **COMPLIANCE** The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. Refer to Paragraph 1.E., Compliance. **INDUSTRY SUPPORT INFORMATION** Boeing warranty remedies are not available for the inspections and configuration changes given in this service bulletin. **MANPOWER** Refer to Paragraph 1.G., Manpower.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 10 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT MATERIAL INFORMATION**  Boeing Supplied Kits/Parts. Refer to Paragraph 2.A., Material - Price and Availability.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 11 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 12 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 747 Service Bulletin **ALERT Number: 747-52A2294**  Original Issue: July 08, 2010 Revision 1: August 16, 2011 ATA System: 5232 **SUBJECT:** DOORS - Side Cargo Doors - Main Deck Side Cargo Door Latch Pin and Latch Pin Retention Bolt Inspection and Modification 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.
**DESCRIPTION CONFIGURATION**  **GROUP** All 747-100, 747-200B, 747-200C, 747-200F, 747SR, 747-300, 747-400, and 747-400F airplanes with a Main Deck Side Cargo Door (MDSCD) installed in production or by a Boeing-approved modification, except Group 2 and Group 3 airplanes. - 1

Previously modified in accordance with Boeing Service Bulletin 747-52-2224. 1
Not previously modified in accordance with Boeing Service Bulletin 747-52-2224, or not in the effectivity of Boeing Service Bulletin 747-52-2224. 2

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 13 of 97**DESCRIPTION CONFIGURATION**  **GROUP** All 747 airplanes that are listed in the effectivity of Boeing Service Bulletin 747-52-2142. - 2
Previously modified in accordance with Boeing Service Bulletin 747-52-2224. 1
Not previously modified in accordance with Boeing Service Bulletin 747-52-2224. 2
747-200F airplanes R6156 and R6157.

- 3

Airplane Models: 747-100, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400F, 747SR **Group Variable Number** 1 RA002 1 RA006 1 RA011 1 RA015 2 RA026 1 RA028 2 RA029 1 RA030 2 RA033 2 RA101 - RA103 1 RA111 2 RA112 2 RA161 - RA163 1 RA401 - RA405 2 RA524 1 RA631 2 RA632 1 RA633 2 RA634 - RA635 2 RA749 1 RA750

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 14 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT Group**  **Variable Number**1 RA784 2 RA901 - RA902 1 RA910 2 RA911 - RA913 1 RA914 2 RA915 - RA916 2 RB041 2 RB043 2 RB101 - RB102 1 RB411 - RB413 1 RB421 1 RB604 - RB605 1 RB607 1 RB696 1 RD041 - RD044 1 RD055 1 RD082 - RD083 1 RD142 1 RD144 1 RD201 - RD204 1 RD225 1 RD227 1 RD233 - RD235 1 RD301 - RD302 1 RD358 1 RD361 - RD366 1 RD411 - RD412 1 RD433 - RD434 1 RD441 - RD442 1 RD461 1 RD531 - RD533 1 RD551 1 RD561

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 15 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT Group**  **Variable Number**1 RD571 1 RD581 - RD583 1 RD591 - RD593 2 RD601 - RD602 1 RD603 - RD607 2 RD621 - RD623 2 RD641 - RD642 1 RD643 - RD649 2 RD651 1 RD652 - RD659 1 RD661 1 RD671 2 RD681 - RD682 2 RD691 - RD692 1 RD701 - RD702 1 RD721 - RD722 1 RD741 - RD742 1 RD751 - RD755 1 RD761 1 RD771 - RD775 1 RD781 - RD783 1 RD791 - RD792 2 RJ301 - RJ302 1 RJ303 1 RJ321 - RJ322 1 RJ331 - RJ333 1 RL401 - RL403 1 RL411 - RL436 1 RL451 - RL456 1 RL461 - RL462 1 RL471 - RL481 1 RL491 - RL492 1 RL501 - RL502

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 16 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT Group**  **Variable Number**1 RL511 - RL516 1 RL521 - RL522 1 RL531 - RL534 1 RL551 1 RL561 - RL568 1 RL571 - RL572 1 RL576 - RL577 1 RL579 1 RL581 - RL586 1 RL651 - RL655 1 RL671 - RL675 1 RL681 - RL684 1 RL751 - RL752 1 RM128 1 RM801 - RM803 1 RM811 - RM813 1 RM851 - RM859 1 RM861 - RM863 1 RM871 - RM899 1 RM901 - RM906 1 RM911 1 RR005 1 RR021 - RR025 1 RR031 1 RR202 - RR206 2 RR221 - RR222 1 RR223 - RR226 2 RR261 1 RR263 - RR267 2 RR301 - RR302 1 RR303 - RR309 3 RR310 1 RR331 - RR332

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 17 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT Group**  **Variable Number**1 RR336 2 RR341 - RR344 1 RR345 1 RR361 - RR362 1 RR421 - RR422 1 RR431 - RR432 1 RR441 - RR442 1 RR451 1 RR501 - RR504 1 RR521 - RR522 1 RR526 1 RR531 1 RR551 - RR555 3 RR556 1 RR561 1 RR566 1 RR701 1 RR721 - RR724 1 RR746 - RR748 1 RR851 - RR856 1 RR861 - RR862 1 RR951 - RR952 1 RS701 - RS703 1 RS711 - RS713 1 RS721 - RS722 1 RS731 - RS732 1 RS741 - RS743 1 RS751 - RS752 1 RS761 - RS762 1 RS771 1 RS781 - RS782 1 RS786 1 RT001 - RT014

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 18 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT Group**  **Variable Number**1 RT021 - RT022 1 RT031 - RT035 1 RT041 - RT047 1 RT061 1 RT071 - RT075 1 RT101 - RT103 1 RT121 1 RT131 - RT137 1 RT151 - RT152 1 RT161 - RT168 1 RT456 1 RT461 1 RT501 1 RT506 - RT510 1 RT513 1 RT516 1 RT518 - RT520 1 RT524 1 RT528 1 RT572 - RT576 1 RT642 1 RT655 - RT657 1 RT751 - RT752 1 RT781 - RT782 1 RT837 1 RT953 - RT954 1 RT967 2. Spares Affected None. **B. Concurrent Requirements** The service bulletin listed below must be done before or at the same time as the modification given in this service bulletin:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 19 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT Description**  **Service Bulletin Company**  Inspection for interchanged cargo door latch pins and installation of pin stop brackets. 747-52-2142, Original issue, Dated May 6, 1977 Boeing Cargo door latch pin direction inspection. 747-52A2258, Original issue, Dated June 1, 1995 Boeing

**C. Reason** Accomplishment of the inspections in this service bulletin will ensure that the latch pin retention bolts in the Main Deck Side Cargo Door lower sill latch pin fittings are not loose, broken or missing. A loose, broken or missing retention bolt can result in a migrated latch pin, which can become disengaged from the cargo door latch cams, and lead to increased loads in the adjacent latch pin fittings and latch cams. Increased loads can cause damage to the cargo door latch mechanism and/or the lower sill structure. The migration of two or more latch pins and subsequent failure of the latch mechanism or lower sill structure can result in the inability of the cargo door to carry limit loads, which could lead to the loss of the cargo door and depressurization of the airplane. The Main Deck Side Cargo Door has a series of ten latch pin fittings which are attached to the lower sill of the door cutout and numbered 1 through 10 forward to aft. Latch pins are installed in each latch pin fitting, and each is secured with a retention bolt. The latch pins and latch pin fittings carry structural and pressurization loads during flight. Six operators have reported that broken latch pin retention bolts were found on eight airplanes. On one airplane, with 101,609 flight-hours and 12,862 flight-cycles, the retention bolts on both the #9 and #10 latch pin fittings were found to be broken. Latch pin #10 was found to have migrated aft and was not engaging the latch cam. On another airplane, with 33,983 flight-hours and 4,723 flight-cycles, the retention bolt on the #10 latch pin fitting was found to be broken and the #9 latch pin was found to be damaged. On another airplane with 67,188 flight-hours and 14,440 flight-cycles, the retention bolt for the #10 latch pin fitting was found to be completely sheared, which allowed the latch pin to migrate aft until it no longer engaged the door latch cam. On four airplanes, only the retention bolt on the #10 latch pin fitting was found to be broken. On one airplane the retention bolt on the #10 latch pin fitting was found to be damaged. Revision 1 is sent to change the one-time inspection given in the original issue of this service bulletin into repeat inspections. Also, instructions for replacement of the 3/16 inch diameter latch pin retention bolts with 5/16 inch diameter pin retention hardware has been added. This replacement includes modification of the latch pin fittings and installation of new latch pins. New Figures 10 through 15 have been added. In addition, Revision 1 identifies another possible configuration for Group 1 and Group 2 airplanes. If the modification given in 747-52-2224 was installed, the configuration of the latch pin installation at pin fitting position #4 will be different, and similar to position #4 on Group 3 airplanes. The data given in Information Notice 747-52A2294 IN 01 is included in Revision 1. IN 01 was sent to clarify that in Figures 4, 5, 7, 8 and 9 it is acceptable to install an additional washer under the nut if necessary for fastener grip length adjustment. Boeing Service Related Problem (SRP) 747-SRP-52-0093 is related to this service bulletin. Boeing Fleet Team Digest article 747-FTD-52-09002 is related to this service bulletin.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 20 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT D. Description**  Get access to the lower sill of the Main Deck Side Cargo Door (MDSCD) cutout. Do a Detailed Inspection of all ten latch pin fittings for loose, broken or missing retention bolts and nuts. Measure the latch pins to make sure they are within allowable limits. At any latch pin fitting that does not have a loose, broken or missing retention bolt and nut, and the latch pin is not damaged beyond the limits given in this service bulletin, remove sealant and do a torque check in accordance with this service bulletin. If the retention bolt passes the torque check, replace the retention bolt sealant. If the retention bolt fails the torque check, consider the bolt to be broken. At any latch pin location where the retention bolt and nut was not found to be broken, loose, damaged or missing, but the latch pin is damaged beyond the limits given in this service bulletin, replace the latch pin, the retention bolt, and related parts in accordance with this service bulletin. At any latch pin fitting with a loose, broken or missing retention bolt or nut, do a check for latch pin migration in accordance with this service bulletin. If the latch pin has not migrated, replace parts at the affected latch pin fitting location in accordance with this service bulletin. If the latch pin has migrated, do additional Detailed Inspections of adjacent door and door cutout structure and latch cams within 42 inches of the affected fitting for damage in accordance with this service bulletin. Repair any damage that is found. Replace parts at the affected latch pin fitting location and any adjacent latch pin fitting location in accordance with this service bulletin. The inspection is complete when the retention bolts at all ten latch pin fitting locations have either passed the torque check or been replaced in accordance with this service bulletin or other Boeing instructions, and all ten MDSCD latch pins are within the damage limits given in this service bulletin. Do the inspections again at the times given in this service bulletin. At the time given in this service bulletin, Boeing recommends that the 3/16 inch diameter latch pin retention bolts be replaced with 5/16 inch diameter pin retention hardware. As part of this replacement, the retention bolt holes in the latch pin fittings must be made larger, and new latch pins with larger diameter retention bolt holes must be installed. Revision 1 - More work is necessary on airplane(s) inspected in accordance with the original issue of this service bulletin. Repeat the latch pin retention bolt inspections at the time given in this service bulletin. In addition, at the time given in this service bulletin, Boeing recommends that the 3/16 inch diameter latch pin retention bolts be replaced with 5/16 inch diameter pin retention hardware in accordance with Revision 1. The work in this service bulletin is done in the maintenance zone(s) given below. **Group 1:**
**Affected Maintenance Zones Zone**  **Model** 261, 262 747-100, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400F, 747SR

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 21 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT Group 2:** 
**Affected Maintenance Zones Zone**  **Model** 261, 262 747-100, 747-200B, 747-200C, 747-200F **Group 3:**
**Affected Maintenance Zones Zone**  **Model** 261, 262 747-200F **E. Compliance** The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. For airplanes that have not yet been modified in accordance with this service bulletin, Boeing recommends that the inspections in Table 1 and the modifications in Table 2 be done at the times given in the tables. The inspections in Table 1 are no longer necessary after the modifications in Table 2 have been completed. After the modifications in Table 2 have been completed, do inspections in accordance with Table 3 at the times given in Table 3. **Table 1: LATCH PIN FITTING INSPECTIONS Repeat Interval**  **(Not to Exceed) Compliance Time**  **Action Condition** 

- Within 6 monthsafter the original issue date of this service bulletin. Do a Detailed Inspection of the ten Main Deck Side Cargo Door (MDSCD) latch pin retention bolts and nuts, and measurethe latch pins in accordance with Paragraph 3.A., General Information and Paragraph 3.B., Work Instructions, PART 1. All affected airplanes

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 22 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT Table 1: LATCH PIN FITTING INSPECTIONS**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- Before further flight. Do a torque check of theretention bolt in accordance with Paragraph 3.A., General Information and Paragraph 3.B., Work Instructions, PART 2. At any latch pin location where the retention bolt and nut was not found to be loose, broken, damaged or missing, and the latch pin is not damaged beyondthe limits given in Paragraph 3.B., Work Instructions , PART 1.

- - No more work is neces-sary at that location during this inspection interval. At any latch pin location where the retention bolt torque check passed andthe latch pin is not damaged beyond the limits given in Paragraph 3.B., Work Instructions , PART 1.

- Before further flight. Consider the bolt to be broken. Check the latchpin for migration in accordance with Paragraph 3.A., General Information and Paragraph 3.B., Work Instructions, PART 3. At any latch pin location where the retention bolt torque check failed.

- Before further flight. Replace the latch pin, the retention bolt, and related parts in accordance with Paragraph 3.A., GeneralInformation and Paragraph 3.B., Work Instructions, PART 4. At any latch pin location where the retention bolt and nut was not found to be broken, loose, damaged or missing, but the latch pin is damaged beyond the limits given in Paragraph 3.B., Work Instructions , PART 1.

- Before further flight. Check the latch pin for migration in accordance with Paragraph 3.A., General Information andParagraph 3.B., Work Instructions, PART 3. At any latch pin location where the retention bolt ornut was found to be broken, loose, damaged or missing.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 23 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT Table 1: LATCH PIN FITTING INSPECTIONS**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- Before further flight.Do additional Detailed Inspections of adjacent door and door cutout structure and latch cams within 42 inches of theaffected fitting for damage in accordance with Paragraph 3.A., GeneralInformation and Paragraph 3.B., Work Instructions, PART 3.At any location with a broken, loose, damaged or missing retention bolt or nut, where the latch pin is found to be migrated.

- Before further flight.Repair damage in accordance with Boeing maintenance documents(Structural Repair Manual, Component Maintenance Manual), or ask Boeing for repair dataand install the repair. Replace the latch pin, the retention bolt, and related parts at the affected latchpin fitting and any adjacent latch pin fitting in accordance with Paragraph 3.A., General Information and Paragraph 3.B., Work Instructions, PART 3 and PART 4. Damage found during theDetailed Inspections of adjacent door and door cutout structure and latch cams, done in accordance withParagraph 3.B., Work Instructions, PART 3 and PART 4.

- Before further flight. Replace the latch pin, the retention bolt, and related parts at the affected latchpin fitting and any adjacent latch pin fitting location in accordance with Paragraph 3.A., GeneralInformation and Paragraph 3.B., Work Instructions, PART 3 and PART 4. No damage found during the Detailed Inspections of adjacent door and door cutout structure and latch cams, done in accordance with Paragraph 3.B., Work Instructions, PART 3 and PART 4.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 24 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT Table 1: LATCH PIN FITTING INSPECTIONS**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- Before further flight. Replace the latch pin, the retention bolt, and related parts in accordance with Paragraph 3.A., GeneralInformation and Paragraph 3.B., Work Instructions, PART 4.At any location with a broken, loose, damaged or missing retention bolt or nut, where the latch pin is not found to be migrated.

6 months. Within 6 months ofthe previous inspection done in accordance with this service bulletin.Repeat the Detailed Inspection of the ten Main Deck Side Cargo Door(MDSCD) latch pin retention bolts and nuts, and measure the latch pins inaccordance with Paragraph 3.A., General Information and Paragraph 3.B., Work Instructions , PART 1. All ten MDSCD latch pin fitting retention bolts have either passed the torque check or been replaced in accordance with Paragraph 3.B., Work Instructions,PART 4, and all ten MDSCD latch pins are within the damage limit given inParagraph 3.B., Work Instructions , PART 1.
**Table 2: LATCH PIN FITTING MODIFICATION AND PIN REPLACEMENT Repeat Interval**  **(Not to Exceed) Compliance Time**  **Action Condition** 

- Within 48 months after the date on Revision 1 of this service bulletin. Modify the MDSCD latch pin fittings and replace the latch pins and latch pin retention fasteners inaccordance with Paragraph 3.A., General Information and Paragraph 3.B., Work Instructions, PART 6. All affected airplanes

- - Inspect in accordance with Table 3.Airplanes with the modification in accordance withParagraph 3.B., Work Instructions, PART 6 accomplished.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 25 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT Table 3: AFTER-MODIFICATION INSPECTIONS**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- Within 2 years after the modification in accordance with Paragraph 3.B., Work Instructions,PART 6 was accomplished. Do an Detailed Inspection of the ten Main Deck Side Cargo Door (MDSCD) latch pin retention bolts and nuts, and measurethe latch pins in accordance with Paragraph 3.A., General Information and Paragraph 3.B., Work Instructions, PART 7. (a) All affected airplanes withthe modification in accordance with Paragraph 3.B., Work Instructions, PART 6 accomplished.

2 years. (a)

- Repeat the Detailed In- spection of the latch pin retention bolts and nuts, and measure the latch pins in accordance with Paragraph 3.A., GeneralInformation and Paragraph 3.B., Work Instructions, PART 7. At any latch pin location where the retention bolt and nut was not found to be broken, loose, damaged or missing, and the latch pin is not damaged beyondthe limits given in Paragraph 3.B., Work Instructions, PART 7.

- Before further flight. Replace the latch pin, the retention bolt, and related parts in accordance with Paragraph 3.A., GeneralInformation and Paragraph 3.B., Work Instructions, PART 7. At any latch pin location where the retention bolt and nut was not found to be broken, loose, damaged or missing, but the latch pin is damaged beyond the limits given in Paragraph 3.B., Work Instructions, PART 7.

- Before further flight. Check the latch pin for migration in accordance with Paragraph 3.A., General Information andParagraph 3.B., Work Instructions, PART 7. At any latch pin location where the retention bolt ornut was found to be broken, loose, damaged or missing.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 26 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT Table 3: AFTER-MODIFICATION INSPECTIONS**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- Before further flight.Do additional Detailed Inspections of adjacent door and door cutout structure and latch cams within 42 inches of theaffected fitting for damage in accordance with Paragraph 3.A., GeneralInformation and Paragraph 3.B., Work Instructions, PART 7.At any location with a broken, loose, damaged or missing retention bolt or nut, where the latch pin is found to be migrated.

- Before further flight.Repair the damage in accordance with Boeing maintenance documents(Structural Repair Manual, Component Maintenance Manual) or ask Boeing for repair dataand install the repair. Replace the latch pin, the retention bolt, and related parts at the affected latchpin fitting and any adjacent latch pin fitting in accordance with Paragraph 3.A., General Information and Paragraph 3.B., Work Instructions, PART 7. Damage found during theDetailed Inspections of adjacent door and door cutout structure and latch cams, done in accordance withParagraph 3.B., Work Instructions, PART 7.

- Before further flight. Replace the latch pin, the retention bolt, and related parts at the affected latchpin fitting and any adjacent latch pin fitting location in accordance with Paragraph 3.A., GeneralInformation and Paragraph 3.B., Work Instructions, PART 7. No damage found during the Detailed Inspections of adjacent door and door cutout structure and latch cams, done in accordance with Paragraph 3.B., Work Instructions, PART 7.

- Before further flight. Replace the latch pin, the retention bolt, and related parts in accordance with Paragraph 3.A., GeneralInformation and Paragraph 3.B., Work Instructions, PART 7.At any location with a broken, loose, damaged or missing retention bolt or nut, where the latch pin is not found to be migrated.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 27 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT Table 3: AFTER-MODIFICATION INSPECTIONS**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition** 2 years.
- Repeat the Detailed In- spection of the latch pin retention bolts and nuts, measure the latch pins, and check for latch pin migration in accordance with Paragraph 3.A., General Information andParagraph 3.B., Work Instructions, PART 7. At any latch pin locationwhere the latch pin, the retention bolt, or related partswere replaced in accordance with Paragraph 3.B., Work Instructions, PART 7.

(a) This is expected to create an additional task card to be added to the operator's maintenance program. **F. Approval** This service bulletin was examined by the Federal Aviation Administration (FAA). The changes specified in this service bulletin comply with the applicable regulations and are FAA approved, as well as European Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved airplanes listed in the service bulletin effectivity. This service bulletin and its approval were based on the airplane in its original Boeing delivery configuration or as modified by other approved Boeing changes. If an airplane has a non-Boeing modification or repair that affects a component or system also affected by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval before incorporating this service bulletin. **G. Manpower** The table below shows an estimate of the task hours necessary to do this inspection for each airplane. This estimate is for direct labor only, done by an experienced crew. Adjust the estimate with operator task hour data if necessary. The estimate does not include lost time. These are some examples of lost time: • Time to adjust to the workplace • Time to schedule the work • Time to inspect the work • Time to cure the materials • Time to make the parts • Time to find the tools. **Table 1 - Inspection Elapsed Hours**  **Task Hours Number of Persons**  **Task** 0.10 0.10 1 Open Access

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 28 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT Table 1 - Inspection**  **Elapsed Hours Task Hours**  **Number of Persons Task**  1.00 1.00 1 Detailed Inspection (Figure 1) 2.00 2.00 1 Torque Check (Fig- ure 2) 0.10 0.10 1 Close Access 3.20 3.20 TOTAL FOR EACH AIRPLANE
**NOTE:**More time will be necessary for additional inspections and part replacement if damage is found. **Table 2 - Modification Elapsed Hours**  **Task Hours Number of Persons**  **Task** 0.10 0.10 1 Open Access 1.00 1.00 1 Modification (Latch Fitting #1 - Figure 10) 1.25 1.25 1 Modification (Latch Fitting #2 - Figure 14 or 15) 1.00 1.00 1 Modification (Latch Fitting #3 - Figure 10) 0.75 0.75 1 Modification (Latch Fitting #4 - Figure 11) 0.75 0.75 1 Modification (Latch Fitting #5 - Figure 12) 1.00 1.00 1 Modification (Latch Fitting #6 - Figure 13) 1.00 1.00 1 Modification (Latch Fitting #7 - Figure 10) 1.00 1.00 1 Modification (Latch Fitting #8 - Figure 10) 1.00 1.00 1 Modification (Latch Fitting #9 - Figure 10)

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 29 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT Table 2 - Modification**  **Elapsed Hours Task Hours**  **Number of Persons Task**  1.00 1.00 1 Modification (Latch Fitting #10 - Figure 10) 0.10 0.10 1 Close Access 0.75 0.75 1 Test 10.70 10.70 TOTAL FOR EACH AIRPLANE
**NOTE:**More time will be necessary for additional inspections and part replacement if damage is found. **Table 3 - After-Modification Inspection Elapsed Hours**  **Task Hours Number of Persons**  **Task** 0.10 0.10 1 Open Access 1.00 1.00 1 Detailed Inspection (Figure 1) 0.10 0.10 1 Close Access 1.20 1.20 TOTAL FOR EACH AIRPLANE
**NOTE:**More time will be necessary for additional inspections and part replacement if damage is found. **H. Weight and Balance Changes** None. **I. Electrical Load Data** Not changed. **J. References** 1. Existing Data a. Boeing Service Letter 747-SL-51-048 b. Boeing Service Related Problem (SRP) 747-SRP-52-0093 c. 747-100/200/300 Aircraft Maintenance Manual (AMM) 52-32-00 d. 747-400 Aircraft Maintenance Manual (AMM) 52-32-00

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 30 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**e. Boeing Service Bulletins 747-52-2105 , "Cargo Door Latch and Lock System Revision," 747-52-2142, "Main Deck and Lower Lobe Cargo Door Latch Pin Inspection and Fitting Modification," 747-52-2224 , "Doors - Cargo Doors - Door Warning - Forward and Aft Lower Lobe and Main Deck Side Cargo Door Warning System Revision" and 747-52A2258 , "Doors - Cargo Doors - Latch Pin Direction Inspection" f. Engineering Change Memo PRR 85901-112RS g. Standard Overhaul Practices Manual (SOPM) 20-10-01, 20-10-02, 20-50-10 h. 747-100/200/300 Structural Repair Manual (SRM) 51, 52, 53, 53-40-01 i. 747-400 Structural Repair Manual (SRM) 51, 52, 53, 53-00-90 j. 747-400F Structural Repair Manual (SRM) 51, 52, 53, 53-00-90 k. 747-400SF Structural Repair Manual (SRM) 51, 52, 53, 53-00-90 l. Overhaul Manual (OHM) 52-36-75, 52-36-76 2. Data supplied with this Service Bulletin a. Drawings:
**ADCN DCN/REV**  **Sheet Title**  **Drawing No**

- - 1 Misc Tool Cargo Door Latch Pin Fitting Re- work Tool MIT140U8005

- - 2 3. Installation Drawings Used in the Preparation of this Service Bulletin
**Title Drawing Number**  Sill Instl - Lower, Main Deck Cargo Door 65B17670 This drawing was used to prepare this service bulletin. This drawing is not necessary to make the specified changes, and is not supplied with this service bulletin. This drawing may not be applicable to all airplane configurations or operators. **K. Publications Affected** 1. Publications: **Chapter-Section Publication**  53-12 747 Illustrated Parts Catalog 53-12 747-400 Illustrated Parts Catalog 2. Damage Tolerance Based Structural Inspections:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 31 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the Maintenance Program. This service bulletin affects FCS. DTI requirements for the structure affected are contained in Paragraph 1.E., Compliance of this service bulletin. **L. Interchangeability and Intermixability of Parts** Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 32 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT 2. MATERIAL INFORMATION**  **A. Material - Price and Availability** Boeing can supply the kits 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 **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)**  **QTY Date**  **Name Kit Number** 

$11,478 382 9 May 12, 2010 Top Kit - Inspection 015U1899-1 15 July 14, 2010 $12,254 382 1 May 13, 2010 Top Kit - Inspection 015U1899-2 $5,530 431 1 July 21, 2011 Top Kit - Modification 015U1916-1 14 August 4, 2011 **B. Industry Support Information** Boeing warranty remedies are not available for the inspections and configuration changes given in this service bulletin. **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, include the parts that may be necessary for each airplane, if damage is found.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 33 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT Kit 015U1899**  **Notes Existing Part**  **Number Name**  **QTY New Part Number**  **-2 -1** 

- - Top Kit - Inspection - Group 1 and Group 2 . - 015U1899-1

- - Top Kit - Inspection - Group 3 - . 015U1899-2 (a) (b) 146U6107-1 SWITCH STRIKER 1

. 146U6107-1 (a) 69B15457-7 PIN 9 9 69B15457-7 (a) 69B15457-8 PIN 1 1 69B15457-8 (a) (b) 69B18044-1 BRACKET 1 1 69B18044-1 (a) (b) 69B18044-2 BRACKET 7 7 69B18044-2 (c)

- BOLT 9 10 BACB30LM3-27 (c)

- BOLT, HEX HEAD 1

. BACB30NM3K34

- - NUT 9 10 BACN10JC3CD

- - NUT 1

. BACN10YR3CD

- - WASHER 1

. BACW10BP3DP

- - WASHER, PLAIN 10 10 NAS1149E0332P (a) This part is used for Production (b) You can use the existing part to replace the new or changed part (c) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer than indicated. Also, if any fasteners part numbers listed are not available or have been superseded, substitute fasteners may be supplied in kits. Boeing Document D-590 and Boeing Drawing 012W6100 are used to determine the part numbers used as substitutes.
**Kit 015U1916 Notes**  **Existing Part Number**  **Name QTY**  **New Part Number -1** 

- - Top Kit - Modifica- tion - 015U1916-1 (a) (b) (c) 69B15457-7 PIN-LATCH 9 146U8355-1 (a) (b) (c) 69B15457-8 PIN-LATCH 1 146U8355-2 (a) (b) (c) 69B18044-2 PIN STOP BRACKET 7 146U8356-1

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 34 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT Kit 015U1916**  **Notes Existing Part**  **Number Name**  **QTY New Part Number** **-1** (a) (b) (c) 69B18044-1 PIN STOP BRACKET 1 146U8356-2 (d)

- BOLT, HEX HEAD 10 BACB30LJ5K28 (d)

- BOLT, HEX HEAD 1 BACB30LJ5K34

- - NUT 10 BACN10YR5CD (d)

- WASHER-PLAIN 22 BACW10BP5DP (a) Keep the existing part if there are other uses for it. (b) This part is used for Production (c) You cannot use the existing part to replace the new or changed part (d) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer than indicated. Also, if any fasteners 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. 2. Parts and Materials Supplied by the Operator
**Notes Name**  **QTY Part Number /**  **Specification** (a) (b) Sealant 8 ounces BMS 5-95 For Group 3 only. Refer to FIGURE 6. Washer 2 BACW10BP3DP (a) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data.(b) The number in the QTY column assumes that parts replacement is required at all ten affected latch pin fitting locations. The actual quantity necessary will depend upon inspection results.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 35 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**3. Parts Modified and Reidentified
**Notes New Part Number**  **(b) (c) Name**  **QTY Existing Part**  **Number** Optional to 69B15457-5 or 69B15457-7. (a) 146U8355-1 Latch Pin 1 69B15457-3

Optional to 69B15457-3 or 69B15457-7. (a) 69B15457-5

Optional to 69B15457-3 or 69B15457-5. (a) 69B15457-7

Optional to 69B15457-4 or 69B15457-6. (a) 146U8355-2 Latch Pin 1 69B15457-2

Optional to 69B15457-2 or 69B15457-6. (a) 69B15457-4

Optional to 69B15457-2 or 69B15457-4. (a) 69B15457-6

(a) Make the change in accordance with FIGURE 16 of this service bulletin. (b) This is the part number after the change is done in accordance with this service bulletin. (c) This part is used in production.
None. 4. Parts Removed and Not Replaced None. **D. Parts Necessary to Change Spares** None. **E. Special Tooling - Price and Availability** Boeing can supply the tool shown in Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin. Operators are encouraged to share schedule requirements with Boeing for incorporation of the service bulletin by e-mail to ServiceBulletinRentalLoanTools@boeing.com. The tool is subject to the terms and conditions of the Boeing standard purchase order acknowledgement. Prices are in United States dollars. Terms: Net 30 days. Reference this service bulletin and submit your purchase order by one of these methods:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 36 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**1. Order on-line via ATA Spec 2000 or Boeing Part Page 2. Fax to (425) 965-8237 **Rental Data: Daily Price as of**  **the Revision 1 date of this ser**  **vice bulletin (US Dollars)**  **Name Tool Kit Number** 

(a) Cargo Door Latch Pin Fitting Rework Tool MIT140U8005-1 (a) Pricing data was not available at the time of release of this service bulletin. Refer to the Boeing PART page on MyBoeingFleet.com orcontact First Responder at fr@boeing.com for the latest price information. **F. Special Tooling Necessary to do this Service Bulletin** To get the tools shown below, refer to Paragraph 2.E., Special Tooling - Price and Availability. Maintenance and overhaul tools in the manuals shown in Paragraph 1.J., References, can also be necessary. Examine operator tool supply to make sure all necessary tools are available.
**Name Tool Kit Number**  Cargo Door Latch Pin Fitting Rework Tool MIT140U8005-1

**NOTE:**Reamer Kit MIT140U8005-14, which is a component of Tool Kit MIT140U8005-1, can be ordered if additional reamers are needed.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 37 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 38 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**

BLANK PAGE**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 – Hole dimensions for standard solid rivets and fasteners are in Structural Repair Manual (SRM) Chapter 51 – Torque limits to tighten nuts and bolts are in SRM Chapter 51 4. Use the approved fastener and process material substitutions in accordance with SRM Chapter 51. 5. If the length of any fastener specified in this service bulletin does not meet installation standards given in SRM Chapter 51, then a fastener of the same specification, or an approved substitute, with a length which meets the installation standards given in SRM Chapter 51 may be used. In addition, washers may be installed for fastener grip length in accordance with SRM Chapter 51. 6. Boeing Service Letter 747-SL-51-048, Damage Reporting and Repair Plan/Design Guidelines, is an acceptable procedure to request information from Boeing for additional structural repair instructions. The Service Letter describes what information must be provided to Boeing before a structural repair can be provided. 7. 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. 8. A Detailed Inspection is defined as: An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirrors, magnifying lenses, etc. may be necessary. Surface cleaning and elaborate procedures may be required.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 39 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**9. The instructions in Paragraph 3.B., Work Instructions and the figures can include operation of tools or test equipment. Boeing Engineering Tool Drawings, the Illustrated Tool and Equipment Manual, and the Special Tool and Ground Handling Drawing Index contain data on versions of the tools or test equipment that you can use. It is permitted to use replaced tools. It is not permitted to use superseded tools. 10. If it is necessary to remove more parts for access, you can remove those parts. If you can get access without removing identified parts, it is not necessary to remove all of the identified parts. Jacking and shoring limitations must be observed. 11. 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. 12. Some Boeing parts are supplied in a temporary configuration. Those parts are identified with a 'U', 'W', or 'Y' in place of the '-' (dash) in the part number. It is permitted to install parts identified with a 'U', 'W', or 'Y' as an alternative to the '-' (dash) part number. Boeing Drawing 005W0900 contains more data. **B. WORK INSTRUCTIONS PART 1 - Latch Pin Retention Bolt and Latch Pin Inspection**  1. Open the Main Deck Side Cargo Door (MDSCD) as necessary to get access to the latch pin fittings (10 locations) on the lower sill of the door cutout. Refer to 747-100/200/300 AMM 52-32-00 or 747-400 AMM 52-32-00 as accepted procedures. 2. Do a Detailed Inspection of the MDSCD latch pin retention nuts and bolts and measure the latch pins in accordance with FIGURE 1. 3. At any MDSCD latch pin fitting location where the retention bolt and nut was not found to be loose, broken, damaged or missing, and the latch pin is not damaged beyond the limits given in FIGURE 1, do a torque check of the retention bolt in accordance with PART 2. 4. At any MDSCD latch pin fitting location where the retention bolt and nut was not found to be loose, broken, damaged or missing, but the latch pin is damaged beyond the limits given in FIGURE 1, replace the latch pin, retention bolt, and related parts in accordance with PART 4. 5. At any MDSCD latch pin fitting location where the retention bolt or nut was found to be broken, loose, damaged or missing, check the latch pin for migration in accordance with PART 3.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 40 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT PART 2 - Torque Check**  1. Do a torque check on the MDSCD latch pin retention bolt on the latch pin fitting in accordance with FIGURE 2. 2. At any latch pin location where the retention bolt fails the torque check (the bolt or nut cannot resist the applied torque), consider the bolt to be broken. Check the latch pin for migration in accordance with PART 3. 3. At any latch pin location where the retention bolt passes the torque check (the bolt or nut resists the applied torque), reapply BMS 5-95 sealant to the retention bolt head (or nut, as applicable). 4. Continue to PART 5. **PART 3 - Inspection for Latch Pin Migration** 1. At any latch pin fitting location where the torque check failed or the retention bolt or nut was found to be broken, loose, damaged or missing:
a. If any parts were found to be missing, to prevent foreign object damage do a search for the missing parts in the vicinity of the affected latch pin fitting on the lower sill and on the ground below. b. Check the position of the latch pin in accordance with FIGURE 3 to determine if the latch pin has migrated from its nominal installed position. c. If the latch pin has migrated, do the steps that follow: (1) Do Detailed Inspections of the latch pin fitting and the adjacent (forward and aft) latch pin fittings, the door cutout structure within 42 inches of the affected latch pin fitting, the affected latch cam and the adjacent (forward and aft) latch cams on the door, and the door structure within 42 inches of the affected latch cam for damage. Remove linings and cargo handling equipment as necessary for access. **NOTE:**The Detailed Inspections are intended to find distressed fasteners, deformation in structure, cracks, and other damage. (2) Repair any damage that is found as listed below. As an alternative to repair, replace damaged parts or ask Boeing for repair data and install the repair.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 41 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**(a) Repair fuselage structure in accordance with SRM Chapter 53. Repair door structure in accordance with SRM Chapter 52 (b) Repair latch pin fittings 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, or 747-400SF SRM 53-00-90 Repair 1. (c) Components of the Main Deck Side Cargo Door mechanisms can be repaired in accordance with OHM 52-36-75 or OHM 52-36-76 (3) Disassemble and replace the latch pin, retention bolt, and related parts in accordance with PART 4. If not already replaced during this inspection, also disassemble and replace the latch pin, retention bolt, and related parts at any latch pin fitting location adjacent to (one fitting position forward and aft of) the migrated latch pin location in accordance with PART 4. d. If the latch pin has not migrated, disassemble and replace the latch pin, retention bolt, and related parts in accordance with PART 4. 2. Continue to PART 5. **PART 4 - Disassembly and Replacement** 1. At any latch pin fitting location where the retention bolt or nut was found to be broken or loose, or where a retention bolt failed the torque check, or where the latch pin is damaged beyond the limits given in FIGURE 1, disassemble, inspect and install new parts in accordance with: a. All Groups: FIGURE 4, for latch pin fitting positions #1, #3, #7, #8, #9 and #10. FIGURE 7, for latch pin fitting position #4. FIGURE 8, for latch pin fitting position #5. FIGURE 9, for latch pin fitting position #6. b.**Group 1-2, Configuration 2:** FIGURE 5, for latch pin fitting position #2.

c.**Group 1-2, Configuration 1; Group 3:** FIGURE 6, for latch pin fitting position #2. Repair any damage that is found as listed below. As an alternative to repair, replace damaged parts or ask Boeing for repair data and install the repair.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 42 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**a. Repair fuselage structure in accordance with SRM Chapter 53. Repair door structure in accordance with SRM Chapter 52 b. Repair latch pin fittings 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, or 747-400SF SRM 53-00-90 Repair 1. c. Components of the Main Deck Side Cargo Door mechanisms can be repaired. Refer to OHM 52-36-75 and OHM 52-36-76 as accepted procedures. 2. Continue to PART 5 **PART 5 - Restoration** 1. If any latch pin fitting was removed from the airplane, adjust the MDSCD. Refer to the task "Adjustment - Side Cargo Door System" in 747-100/200/300 AMM 52-32-00 or "Adjustment - Side Cargo Door" in 747-400 AMM 52-32-00 as accepted procedures. 2. After all ten MDSCD latch pin fitting retention bolts have either passed the torque check in accordance with PART 2 or been replaced in accordance with PART 4, and all ten MDSCD latch pins are within the damage limit given in FIGURE 1 , close the MDSCD electrically. Refer to 747-100/200/300 AMM 52-32-00 or 747-400 AMM 52-32-00 as accepted procedures. Make sure that the latch cams turn freely and engage and disengage the latch pins during normal operation. 3. Put the airplane back to a serviceable condition. Do the inspection again at the time given in Paragraph 1.E., Compliance , Table 1. Modify the latch pin installations in accordance with PART 6 at the time given in Paragraph 1.E., Compliance , Table 2. **PART 6 - Modification** 1. Open the Main Deck Side Cargo Door (MDSCD) as necessary to get access to the latch pin fittings (10 locations) on the lower sill of the door cutout. Refer to 747-100/200/300 AMM 52-32-00 or 747-400 AMM 52-32-00 as accepted procedures. **NOTE:**If not previously accomplished, Boeing recommends that the MDSCD modification in Boeing Service Bulletin 747-52-2224 be installed prior to or at the same time as the modification in this service bulletin. Service Bulletin 747-52-2224 changes the configuration at latch pin fitting position #2. 2. Disassemble, inspect, and modify the latch pin fitting, and install new parts in accordance with:
a. All Groups: FIGURE 10, for latch pin fitting positions #1, #3, #7, #8, #9 and #10. FIGURE 11, for latch pin fitting position #4. FIGURE 12, for latch pin fitting position #5.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 43 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**FIGURE 13, for latch pin fitting position #6. b.**Group 1-2, Configuration 2:** FIGURE 14, for latch pin fitting position #2.

c.**Group 1-2, Configuration 1; Group 3:** FIGURE 15, for latch pin fitting position #2. **NOTE:**Existing 69B15457-3, -4, -5, -6, -7, and -8 latch pins can be reworked in accordance with FIGURE 16. Existing 69B15457-1 and -2 latch pins must first be reworked into 69B15457-3 and -4 latch pins in accordance with Boeing Service Bulletin 747-52-2105, "Cargo Door Latch and Lock System Revision". 3. If any latch pin fitting was removed from the airplane, adjust the MDSCD. Refer to the task "Adjustment - Side Cargo Door System" in 747-100/200/300 AMM 52-32-00 or "Adjustment - Side Cargo Door" in 747-400 AMM 52-32-00 as accepted procedures. 4. Close the MDSCD electrically. Refer to 747-100/200/300 AMM 52-32-00 or 747-400 AMM 52-32-00 as accepted procedures. Make sure that the latch cams turn freely and engage and disengage the latch pins during normal operation. 5. Put the airplane back to a serviceable condition. After modification of all 10 latch pin fittings, start to do inspections in accordance with PART 7 at the times given in Paragraph 1.E., Compliance, Table 3. **PART 7 - After-Modification Inspection** 1. Open the Main Deck Side Cargo Door (MDSCD) as necessary to get access to the latch pin fittings (10 locations) on the lower sill of the door cutout. Refer to 747-100/200/300 AMM 52-32-00 or 747-400 AMM 52-32-00 as accepted procedures. 2. Do a Detailed Inspection of the MDSCD latch pin retention nuts and bolts, inspect for damage or corrosion, and measure the latch pins in accordance with FIGURE 1. 3. At any MDSCD latch pin fitting location where the retention bolt and nut was not found to be loose, broken or missing, but the latch pin is damaged beyond the limits given in FIGURE 1, replace the latch pin, retention bolt, and related parts in accordance with PART 6. **NOTE:**PART 6 includes instructions to modify the latch pin fittings by making the retention bolt holes in the latch pin fittings larger. This latch pin fitting modification is only necessary the first time PART 6 is accomplished. 4. At any MDSCD latch pin fitting location where the retention bolt or nut was found to be broken, loose, damaged or missing, check the latch pin for migration in accordance with the steps that follow:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 44 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**a. If any parts were found to be missing, to prevent foreign object damage do a search for the missing parts in the vicinity of the affected latch pin fitting on the lower sill and on the ground below. b. Check the position of the latch pin in accordance with FIGURE 3 to determine if the latch pin has migrated from its nominal installed position. c. If the latch pin has migrated, do the steps that follow: (1) Do Detailed Inspections of the latch pin fitting and the adjacent (forward and aft) latch pin fittings, the door cutout structure within 42 inches of the affected latch pin fitting, the affected latch cam and the adjacent (forward and aft) latch cams on the door, and the door structure within 42 inches of the affected latch cam for damage. Remove linings and cargo handling equipment as necessary for access. **NOTE:**The Detailed Inspections are intended to find distressed fasteners, deformation in structure, cracks, and other damage. (2) Repair any damage that is found as listed below. As an alternative to repair, replace damaged parts or ask Boeing for repair data and install the repair. (a) Repair fuselage structure in accordance with SRM Chapter 53. Repair door structure in accordance with SRM Chapter 52 (b) Repair latch pin fittings 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, or 747-400SF SRM 53-00-90 Repair 1. (c) Components of the Main Deck Side Cargo Door mechanisms can be repaired. Refer to OHM 52-36-75 and OHM 52-36-76 as accepted procedures. (3) Disassemble and replace the latch pin, retention bolt, and related parts in accordance with PART 6. If not already replaced, also disassemble and replace the latch pin, retention bolt, and related parts at any latch pin fitting location adjacent to (one fitting position forward and aft of) the migrated latch pin location in accordance with PART 6. **NOTE:**PART 6 includes instructions to modify the latch pin fittings by making the retention bolt holes in the latch pin fittings larger. This latch pin fitting modification is only necessary the first time PART 6 is accomplished. d. If the latch pin has not migrated, disassemble and replace the latch pin, retention bolt, and related parts in accordance with PART 6. **NOTE:**PART 6 includes instructions to modify the latch pin fittings by making the retention bolt holes in the latch pin fittings larger. This latch pin fitting modification is only necessary the first time PART 6 is accomplished.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 45 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**5. If any latch pin fitting was removed from the airplane, adjust the MDSCD. Refer to the task "Adjustment - Side Cargo Door System" in 747-100/200/300 AMM 52-32-00 or "Adjustment - Side Cargo Door" in 747-400 AMM 52-32-00 as accepted procedures. 6. Close the MDSCD electrically. Refer to 747-100/200/300 AMM 52-32-00 or 747-400 AMM 52-32-00 as accepted procedures. Make sure that the latch cams turn freely and engage and disengage the latch pins during normal operation. 7. Put the airplane back to a serviceable condition. Continue to do inspections in accordance with PART 7 at the times given in Paragraph 1.E., Compliance, Table 3.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1: August 16, 2011 46 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT FIGURE 1: DETAILED INSPECTION**  **(SHEET 1 OF 2)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 47 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**The step number shown below agrees with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one latch pin fitting location.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  Measure the diameter of the exposed portion of the latch pin. Diameter should not be less than 1.324 inches. 1
- Latch Pin Measure 1

Do a detailed inspection of the latch pin for damage. It is not necessary to remove the latch pin for this inspection. 1
- Latch Pin Inspect

Do a Detailed Inspection to make sure that the bolt is not loose, broken or missing. 1
- Bolt Inspect 2

Do a Detailed Inspection to make sure that the nut is not loose, broken or missing. 1
- Nut Inspect

**FIGURE 1: DETAILED INSPECTION (SHEET 2 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 48 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT FIGURE 2: TORQUE CHECK**  **(SHEET 1 OF 2)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 49 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one latch pin fitting location.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  From bolt head. Optional: Remove sealant from the nut. - BMS 5-95 Sealant Remove 1

Apply 13 - 15 inchpounds of torque tothe bolt head. Optional: Apply 13 - 15 inch-pounds of torque to the nut. - - Bolt Torque 2

**FIGURE 2: TORQUE CHECK (SHEET 2 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 50 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT FIGURE 3: LATCH PIN POSITION CHECK**  **(SHEET 1 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 51 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT FIGURE 3: LATCH PIN POSITION CHECK**  **(SHEET 2 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 52 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one latch pin fitting location.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  (a) 1
- Nut Remove 1 (a) 1
- Washer Remove (a) 1
- Bolt Remove If installed.

- - Bracket Remove Check if the latch pin has migrated awayfrom the nominal installed position. (b) 1
- Latch Pin Inspect 2

(a) Unless the parts are found to be missing. If the retention bolt is fractured, use care to remove the sections of the bolt from the latch pin fitting. If both ends of the bolt have been sheared, the shank of the bolt may be trapped in the latch pin. (b) If the retention bolt hole in the latch pin is not aligned with the retention bolt hole in the latch pin fitting, consider the pin to have migrated. If the operator wishes to measure and record the distance (forward or aft) that the latch pin has migrated, this is one method that can be used: 1. Look into the retention bolt hole in the latch pin fitting. If the hole in the latch pin is not aligned with the hole in the fitting, make a markon the protruding end of the latch pin at the edge of the latch pin fitting lug. 2. Move the latch pin as necessary to align the hole in the latch pin with the hole in the fitting, and make another mark on the protruding end of the latch pin at the edge of the latch pin fitting lug. 3. Remove the latch pin and measure the distance between the two marks. The distance measured is the distance the pin has migrated.

**FIGURE 3: LATCH PIN POSITION CHECK (SHEET 3 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 53 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT FIGURE 4: PART REPLACEMENT AT LATCH PIN FITTING POSITIONS #1, #3, #7, #8, #9 AND #10**  **(SHEET 1 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 54 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one latch pin fitting location.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  If not previously removed to check for latch pin migration. 1
- Nut Remove 1

If not previously removed to check for latch pin migration. 1
- Washer Remove

If not previously removed to check for latch pin migration. 1
- Bolt Remove

If installed, and if not previously removed to check for latch pin migration. 1 69B18044-2 BRACKET Remove

- 1
- Latch Pin Remove 2 (a) (b)

- - Latch Pin Fitting Inspect 3 Not shown (a)

- - Door Latch Cams Inspect Remove old sealant from the bore. - - Latch Pin Fitting Clean
To the outer diameter of the pin and tothe bore of the fitting. - BMS 5-95 Sealant Apply 4

Install the pin while the sealant is stillwet. Line up the retention bolt holes in the latch pin with the holes in the latch pin fitting. 1 69B15457-7 PIN Install (New)

Between the latch pin fitting and theflanges of the bracket. - BMS 5-95 Sealant Apply 5

(e) 1 69B18044-2 BRACKET Install (New)

**FIGURE 4: PART REPLACEMENT AT LATCH PIN FITTING POSITIONS #1, #3, #7, #8, #9 AND #10 (SHEET 2 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 55 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** Wet with BMS 5-95 sealant. 1 BACB30LM3-27 BOLT Install (New) 6
Install 1 or 2 washers, as necessary. 2 NAS1149E0332P WASHER, PLAIN Install (New) Apply 33 - 37 inchpounds of torque tothe nut (optional: apply torque to the bolt head.) 1 BACN10JC3CD NUT Install (New)

(c) (d)

- BMS 5-95 Sealant Apply 7 (a) Do a Detailed Inspection of the affected fitting and the corresponding door latch cams for evidence of impact damage. If damage is found, contact Boeing for repair instructions and do the repair. Restore damaged finishes as necessary. (b) Do a Detailed Inspection of the retention bolt holes in the fitting for cracks or other damage. If damage is found, contact Boeing for repair instructions and do the repair. (c) Encapsulate bolt head, nut, washer, and bolt threads. Fillet seal the periphery of the bolt inside the pin. (d) Apply a fillet seal of BMS 5-95 sealant all around the latch pin at the space between the latch pin and the fitting. Use care to keep the tapered end of the pin, which will be engaged by the door latch cams, free of sealant. It is not necessary to fillet seal the end of the fitting covered by the bracket. (e) It is acceptable to reinstall the bracket that was previously removed, if it is in serviceable condition.

**FIGURE 4: PART REPLACEMENT AT LATCH PIN FITTING POSITIONS #1, #3, #7, #8, #9 AND #10 (SHEET 3 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 56 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT This Figure applies only to: Group 1-2, Configuration 2.** 

**FIGURE 5: PART REPLACEMENT AT LATCH PIN FITTING POSITION #2 (SHEET 1 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 57 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one latch pin fitting location.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  If not previously removed to check for latch pin migration. 1
- Nut Remove 1

If not previously removed to check for latch pin migration. 1
- Washer Remove

If not previously removed to check for latch pin migration. 1
- Bolt Remove

If installed, and if not previously removed to check for latch pin migration. 1 69B18044-2 BRACKET Remove

- 1
- Latch Pin Remove 2 (a) (b)

- - Latch Pin Fitting Inspect 3 Not shown (a)

- - Door Latch Cams Inspect Remove old sealant from the bore. - - Latch Pin Fitting Clean
To the outer diameter of the pin and tothe bore of the fitting. - BMS 5-95 Sealant Apply 4

Install the pin while the sealant is stillwet. Line up the retention bolt holes in the latch pin with the holes in the latch pin fitting. 1 69B15457-7 Latch Pin Install (New)

between the latch pin fitting and theflanges of the bracket. - BMS 5-95 Sealant Apply 5

(e) 1 69B18044-2 BRACKET Install (New)

**FIGURE 5: PART REPLACEMENT AT LATCH PIN FITTING POSITION #2 (SHEET 2 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 58 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** wet with BMS 5-95 sealant. 1 BACB30LM3-27 BOLT Install (New) 6
Install 1 or 2 washers, as necessary. 2 NAS1149E0332P WASHER, PLAIN Install (New) Apply 33 - 37 inchpounds of torque tothe nut (optional: apply torque to the bolt head.) 1 BACN10JC3CD NUT Install (New)

(c) (d)

- BMS 5-95 Sealant Apply 7 (a) Do a Detailed Inspection of the affected fitting and the corresponding door latch cams for evidence of impact damage. If damage is found, contact Boeing for repair instructions and do the repair. Restore damaged finishes as necessary. (b) Do a Detailed Inspection of the retention bolt holes in the fitting for cracks or other damage. If damage is found, contact Boeing for repair instructions and do the repair. (c) Encapsulate bolt head, nut, washer, and bolt threads. Fillet seal the periphery of the bolt inside the pin. (d) Apply a fillet seal of BMS 5-95 sealant all around the latch pin at the space between the latch pin and the fitting. Use care to keep the tapered end of the pin, which will be engaged by the door latch cams, free of sealant. It is not necessary to fillet seal the end of the fitting covered by the bracket. (e) It is acceptable to reinstall the bracket that was previously removed, if it is in serviceable condition.

**FIGURE 5: PART REPLACEMENT AT LATCH PIN FITTING POSITION #2 (SHEET 3 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 59 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT This Figure applies only to: Group 1-2, Configuration 1; Group 3.** 

**FIGURE 6: PART REPLACEMENT AT LATCH PIN FITTING POSITION #2 (SHEET 1 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 60 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one latch pin fitting location.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  If not previously removed to check for latch pin migration. 1
- Nut Remove 1

If not previously removed to check for latch pin migration. 3
- Washer Remove

If not previously removed to check for latch pin migration. 1
- Bolt Remove

If installed, and if not previously removed to check for latch pin migration. 1 69B18044-2 BRACKET Remove

If installed, and if not previously removed to check for latch pin migration. 1 146U6107-1 Switch Striker Remove

- 1
- Latch Pin Remove 2 (a) (b)

- - Latch Pin Fitting Inspect 3 Not shown (a)

- - Door Latch Cams Inspect Remove old sealant from the bore. - - Latch Pin Fitting Clean
To the outer diameter of the pin and tothe bore of the fitting. - BMS 5-95 Sealant Apply 4

Install the pin while the sealant is stillwet. Line up the retention bolt holes in the latch pin with the holes in the latch pin fitting. 1 69B15457-7 Latch Pin Install (New)

Between the latch pin fitting and theflanges of the bracket. - BMS 5-95 Sealant Apply 5

(e) 1 69B18044-2 BRACKET Install (New)

**FIGURE 6: PART REPLACEMENT AT LATCH PIN FITTING POSITION #2 (SHEET 2 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 61 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** Between the switch striker and theflanges of the bracket. - BMS 5-95 Sealant Apply 6

(e) 1 146U6107-1 SWITCH STRIKER Install (New) wet with BMS 5-95 sealant. 1 BACB30NM3K34 BOLT, HEX HEAD Install (New) 7
Between the switch striker and the bracket. 2 BACW10BP3DP WASHER Install (New)

Under the nut. 1 BACW10BP3DP WASHER Install (New) Apply 33 - 37 inchpounds of torque tothe nut (optional: apply torque to the bolt head.) 1 BACN10JC3CD NUT Install (New)

(c) (d)

- BMS 5-95 Sealant Apply 8 (a) Do a Detailed Inspection of the affected fitting and the corresponding door latch cams for evidence of impact damage. If damage is found, contact Boeing for repair instructions and do the repair. Restore damaged finishes as necessary. (b) Do a Detailed Inspection of the retention bolt holes in the fitting for cracks or other damage. If damage is found, contact Boeing for repair instructions and do the repair. (c) Encapsulate bolt head, nut, washer, and bolt threads. Fillet seal the periphery of the bolt inside the pin. (d) Apply a fillet seal of BMS 5-95 sealant all around the latch pin at the space between the latch pin and the fitting. Use care to keep the tapered end of the pin, which will be engaged by the door latch cams, free of sealant. It is not necessary to fillet seal the end of the fitting covered by the bracket.(e) It is acceptable to reinstall the bracket and switch striker that was previously removed, if they are in serviceable condition.

**FIGURE 6: PART REPLACEMENT AT LATCH PIN FITTING POSITION #2 (SHEET 3 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 62 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT FIGURE 7: PART REPLACEMENT AT LATCH PIN FITTING POSITION #4**  **(SHEET 1 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 63 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one latch pin fitting location.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  If not previously removed to check for latch pin migration. 1
- Nut Remove 1

If not previously removed to check for latch pin migration. 1
- Washer Remove

If not previously removed to check for latch pin migration. 1
- Bolt Remove

- 1
- Latch Pin Remove 2 (a) (b)

- - Latch Pin Fitting Inspect 3 Not shown (a)

- - Door Latch Cams Inspect Remove old sealant from the bore. - - Latch Pin Fitting Clean
To the outer diameter of the pin and tothe bore of the fitting. - BMS 5-95 Sealant Apply 4

Install the pin while the sealant is stillwet. Line up the retention bolt holes in the latch pin with the holes in the latch pin fitting. 1 69B15457-8 PIN Install (New)

wet with BMS 5-95 sealant. 1 BACB30LM3-27 BOLT Install (New) 5
Install 1 or 2 washers, as necessary. 2 NAS1149E0332P WASHER, PLAIN Install (New) Apply 33 - 37 inchpounds of torque tothe nut (optional: apply torque to the bolt head.) 1 BACN10JC3CD NUT Install (New)

(c) (d)

- BMS 5-95 Sealant Apply 6 (a) Do a Detailed Inspection of the affected fitting and the corresponding door latch cams for evidence of impact damage. If damage is found, contact Boeing for repair instructions and do the repair. Restore damaged finishes as necessary.

**FIGURE 7: PART REPLACEMENT AT LATCH PIN FITTING POSITION #4 (SHEET 2 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 64 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** (b) Do a Detailed Inspection of the retention bolt holes in the fitting for cracks or other damage. If damage is found, contact Boeing for repair instructions and do the repair. (c) Encapsulate bolt head, nut, washer, and bolt threads. Fillet seal the periphery of the bolt inside the pin. (d) Apply a fillet seal of BMS 5-95 sealant all around the latch pin at the space between the latch pin and the fitting on both the forward and aft ends of the fitting. Use care to keep the tapered end of the pin, which will be engaged by the door latch cams, free of sealant.

**FIGURE 7: PART REPLACEMENT AT LATCH PIN FITTING POSITION #4 (SHEET 3 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 65 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT FIGURE 8: PART REPLACEMENT AT LATCH PIN FITTING POSITION #5**  **(SHEET 1 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 66 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one latch pin fitting location.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  If not previously removed to check for latch pin migration. 1
- Nut Remove 1

If not previously removed to check for latch pin migration. 1
- Washer Remove

If not previously removed to check for latch pin migration. 1
- Bolt Remove

- 1
- Latch Pin Remove 2 (a) (b)

- - Latch Pin Fitting Inspect 3 Not shown (a)

- - Door Latch Cams Inspect Remove old sealant from the bore. - - Latch Pin Fitting Clean
To the outer diameter of the pin and tothe bore of the fitting. - BMS 5-95 Sealant Apply 4

Install the pin while the sealant is stillwet. Line up the retention bolt holes in the latch pin with the holes in the latch pin fitting. 1 69B15457-7 PIN Install (New)

wet with BMS 5-95 sealant. 1 BACB30LM3-27 BOLT Install (New) 5
Install 1 or 2 washers, as necessary. 2 NAS1149E0332P WASHER, PLAIN Install (New) Apply 33 - 37 inchpounds of torque tothe nut (optional: apply torque to the bolt head.) 1 BACN10JC3CD NUT Install (New)

(c) (d)

- BMS 5-95 Sealant Apply 6 (a) Do a Detailed Inspection of the affected fitting and the corresponding door latch cams for evidence of impact damage. If damage is found, contact Boeing for repair instructions and do the repair. Restore damaged finishes as necessary.

**FIGURE 8: PART REPLACEMENT AT LATCH PIN FITTING POSITION #5 (SHEET 2 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 67 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** (b) Do a Detailed Inspection of the retention bolt holes in the fitting for cracks or other damage. If damage is found, contact Boeing for repair instructions and do the repair. (c) Encapsulate bolt head, nut, washer, and bolt threads. Fillet seal the periphery of the bolt inside the pin. (d) Apply a fillet seal of BMS 5-95 sealant all around the latch pin at the space between the latch pin and the fitting on both the forward and aft ends of the fitting. Use care to keep the tapered end of the pin, which will be engaged by the door latch cams, free of sealant.

**FIGURE 8: PART REPLACEMENT AT LATCH PIN FITTING POSITION #5 (SHEET 3 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 68 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT FIGURE 9: PART REPLACEMENT AT LATCH PIN FITTING POSITION #6**  **(SHEET 1 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 69 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one latch pin fitting location.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  If not previously removed to check for latch pin migration. 1
- Nut Remove 1

If not previously removed to check for latch pin migration. 1
- Washer Remove

If not previously removed to check for latch pin migration. 1
- Bolt Remove

If installed, and if not previously removed to check for latch pin migration. 1 69B18044-1 BRACKET Remove

- 1
- Latch Pin Remove 2 (a) (b)

- - Latch Pin Fitting Inspect 3 Not shown (a)

- - Door Latch Cams Inspect Remove old sealant from the bore. - - Latch Pin Fitting Clean
To the outer diameter of the pin and tothe bore of the fitting. - BMS 5-95 Sealant Apply 4

Install the pin while the sealant is stillwet. Line up the retention bolt holes in the latch pin with the holes in the latch pin fitting. 1 69B15457-7 Latch Pin Install (New)

between the latch pin fitting and theflanges of the bracket. - BMS 5-95 Sealant Apply 5

(e) 1 69B18044-1 BRACKET Install (New)

**FIGURE 9: PART REPLACEMENT AT LATCH PIN FITTING POSITION #6 (SHEET 2 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 70 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** wet with BMS 5-95 sealant. 1 BACB30LM3-27 BOLT Install (New) 6
Install 1 or 2 washers, as necessary. 2 NAS1149E0332P WASHER, PLAIN Install (New) Apply 33 - 37 inchpounds of torque tothe nut (optional: apply torque to the bolt head.) 1 BACN10JC3CD NUT Install (New)

(c) (d)

- BMS 5-95 Sealant Apply 7 (a) Do a Detailed Inspection of the affected fitting and the corresponding door latch cams for evidence of impact damage. If damage is found, contact Boeing for repair instructions and do the repair. Restore damaged finishes as necessary. (b) Do a Detailed Inspection of the retention bolt holes in the fitting for cracks or other damage. If damage is found, contact Boeing for repair instructions and do the repair. (c) Encapsulate bolt head, nut, washer, and bolt threads. Fillet seal the periphery of the bolt inside the pin. (d) Apply a fillet seal of BMS 5-95 sealant all around the latch pin at the space between the latch pin and the fitting. Use care to keep the tapered end of the pin, which will be engaged by the door latch cams, free of sealant. It is not necessary to fillet seal the end of the fitting covered by the bracket. (e) It is acceptable to reinstall the bracket that was previously removed, if it is in serviceable condition.

**FIGURE 9: PART REPLACEMENT AT LATCH PIN FITTING POSITION #6 (SHEET 3 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 71 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT FIGURE 10: MODIFICATION AT LATCH PIN FITTING POSITION #1, #3, #7, #8, #9 AND #10**  **(SHEET 1 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 72 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one latch pin fitting location. **NOTE:** The procedure given below assumes that each affected latch pin fitting will be reworked while installed on the airplane. As an alternative, the latch pin fittings can be removed from the airplane and reworked. The retention bolt hole in latch pin fittings that are removed from the airplane can be made larger using standard machine tools rather than with the special tool described below. Refer to SOPM 20-10-01 and SOPM 20-10-02 for requirements when machining high strength steel. 1.

2. If any latch pin fitting is removed from the airplane, it will be necessary to adjust the MDSCD as described in Paragraph 3.B., Work Instructions, PART 6. 3. On commonly affected airplanes, installation of a pin stop bracket in accordance with this figure supersedes the pin stop bracket installation shown in Boeing Service Bulletin 747-52-2142 for the affected latch pin fitting position.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP** 

- 1
- Nut Remove 1

- 1
- Washer Remove

- 1
- Bolt Remove If installed. 1
- Bracket Remove

- 1
- Latch Pin Remove 2 Remove old sealant from the bore. - - Latch Pin Fitting Clean 3 (a) (b) (e)

- - Latch Pin Fitting Inspect 4 Not shown (a)

- - Door Latch Cams Inspect

**FIGURE 10: MODIFICATION AT LATCH PIN FITTING POSITION #1, #3, #7, #8, #9 AND #10 (SHEET 2 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 73 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** Increase hole diameter to 0.3140 - 0.3180 inch. Refer to Boeing Tool Kit MIT140U8005-1 foran accepted procedure. (f) 1
- Retention Bolt Hole Drill / Ream 5

Break sharp edges.

- - Latch Pin Fitting Clean/Deburr Apply one coat of primer to any bare metal surface on the outside of the fitting. After the first coat is dry, apply a second coat of primer. - BMS 10-11, TYPE I Primer Apply

Mark "modified by SB 747-52A2294"on the fitting to identify that this service bulletin has been done. Refer to SOPM 20-50-10 (method: rubberstamp with a protective overcoat) as an accepted procedure. - - Latch Pin Fitting Identify

To the outer diameter of the pin and tothe bore of the fitting. - BMS 5-95 Sealant Apply 6

Install the pin while the sealant is stillwet. Line up the retention bolt holes in the latch pin with the holes in the latch pin fitting. 1 146U8355-1 PIN-LATCH Install (New)

Between the latch pin fitting and theflanges of the bracket. - BMS 5-95 Sealant Apply 7

- 1 146U8356-1 PIN STOP BRACKET Install (New)

**FIGURE 10: MODIFICATION AT LATCH PIN FITTING POSITION #1, #3, #7, #8, #9 AND #10 (SHEET 3 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 74 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** Wet with BMS 5-95 sealant. 1 BACB30LJ5K28 BOLT, HEX HEAD Install (New) 8
Install 1 or 2 washers, as necessary. 2 BACW10BP5DP WASHER-PLAIN Install (New) Apply 120 - 130 inch-pounds of torque to the nut (optional: apply torque to the bolt head.) 1 BACN10YR5CD NUT Install (New)

(c) (d)

- BMS 5-95 Sealant Apply 9 (a) Do a Detailed Inspection of the affected fitting and the corresponding door latch cams for evidence of impact damage. If damage is found, contact Boeing for repair instructions and do the repair. Restore damaged finishes as necessary. (b) Do a Detailed Inspection of the retention bolt holes in the fitting for cracks or other damage. If damage is found, contact Boeing for repair instructions and do the repair. (c) Encapsulate bolt head, nut, washer, and bolt threads. Fillet seal the periphery of the bolt inside the pin. (d) Apply a fillet seal of BMS 5-95 sealant all around the latch pin at the space between the latch pin and the fitting. Use care to keep the tapered end of the pin, which will be engaged by the door latch cams, free of sealant. It is not necessary to fillet seal the end of the fitting covered by the bracket. (e) Do a Detailed Inspection of the pin bore and the retention bolt hole of the latch pin fitting for corrosion. If corrosion is found, repair 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, or 747-400SF SRM 53-00-90 Repair 1. (f) This procedure can be used on fittings that have been repaired 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, or 747-400SF SRM 53- 00-90 Repair 1.

**FIGURE 10: MODIFICATION AT LATCH PIN FITTING POSITION #1, #3, #7, #8, #9 AND #10 (SHEET 4 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 75 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT FIGURE 11: MODIFICATION AT LATCH PIN FITTING POSITION #4**  **(SHEET 1 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 76 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one latch pin fitting location. **NOTE:** The procedure given below assumes that each affected latch pin fitting will be reworked while installed on the airplane. As an alternative, the latch pin fittings can be removed from the airplane and reworked. The retention bolt hole in latch pin fittings that are removed from the airplane can be made larger using standard machine tools rather than with the special tool described below. Refer to SOPM 20-10-01 and SOPM 20-10-02 for requirements when machining high strength steel. 1.

2. If any latch pin fitting is removed from the airplane, it will be necessary to adjust the MDSCD as described in Paragraph 3.B., Work Instructions, PART 6.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP** 

- 1
- Nut Remove 1

- 1
- Washer Remove

- 1
- Bolt Remove

- 1
- Latch Pin Remove 2 Remove old sealant from the bore. - - Latch Pin Fitting Clean 3 (a) (b) (e)

- - Latch Pin Fitting Inspect 4 Not shown (a)

- - Door Latch Cams Inspect

**FIGURE 11: MODIFICATION AT LATCH PIN FITTING POSITION #4 (SHEET 2 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 77 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** Increase hole diameter to 0.3140 - 0.3180 inch. Refer to Boeing Tool Kit MIT140U8005-1 foran accepted procedure. (f) 1
- Retention Bolt Hole Drill / Ream 5

Break sharp edges.

- - Latch Pin Fitting Clean/Deburr Apply one coat of primer to any bare metal surface on the outside of the fitting. After the first coat is dry, apply a second coat of primer. - BMS 10-11, TYPE I Primer Apply

Mark "modified by SB 747-52A2294"on the fitting to identify that this service bulletin has been done. Refer to SOPM 20-50-10 (method: rubberstamp with a protective overcoat) as an accepted procedure. - - Latch Pin Fitting Identify

To the outer diameter of the pin and tothe bore of the fitting. - BMS 5-95 Sealant Apply 6

Install the pin while the sealant is stillwet. Line up the retention bolt holes in the latch pin with the holes in the latch pin fitting. 1 146U8355-2 PIN-LATCH Install (New)

**FIGURE 11: MODIFICATION AT LATCH PIN FITTING POSITION #4 (SHEET 3 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 78 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** wet with BMS 5-95 sealant. 1 BACB30LJ5K28 BOLT, HEX HEAD Install (New) 7
Install 1 or 2 washers, as necessary. 2 BACW10BP5DP WASHER-PLAIN Install (New) Apply 120 - 130 inch-pounds of torque to the nut (optional: apply torque to the bolt head.) 1 BACN10YR5CD NUT Install (New)

(c) (d)

- BMS 5-95 Sealant Apply 8 (a) Do a Detailed Inspection of the affected fitting and the corresponding door latch cams for evidence of impact damage. If damage is found, contact Boeing for repair instructions and do the repair. Restore damaged finishes as necessary. (b) Do a Detailed Inspection of the retention bolt holes in the fitting for cracks or other damage. If damage is found, contact Boeing for repair instructions and do the repair. (c) Encapsulate bolt head, nut, washer, and bolt threads. Fillet seal the periphery of the bolt inside the pin. (d) Apply a fillet seal of BMS 5-95 sealant all around the latch pin at the space between the latch pin and the fitting on both the forward and aft ends of the fitting. Use care to keep the tapered end of the pin, which will be engaged by the door latch cams, free of sealant. (e) Do a Detailed Inspection of the pin bore and the retention bolt hole of the latch pin fitting for corrosion. If corrosion is found, repair 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, or 747-400SF SRM 53-00-90 Repair 1. (f) This procedure can be used on fittings that have been repaired 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, or 747-400SF SRM 53- 00-90 Repair 1.

**FIGURE 11: MODIFICATION AT LATCH PIN FITTING POSITION #4 (SHEET 4 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 79 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT FIGURE 12: MODIFICATION AT LATCH PIN FITTING POSITION #5**  **(SHEET 1 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 80 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one latch pin fitting location. **NOTE:** The procedure given below assumes that each affected latch pin fitting will be reworked while installed on the airplane. As an alternative, the latch pin fittings can be removed from the airplane and reworked. The retention bolt hole in latch pin fittings that are removed from the airplane can be made larger using standard machine tools rather than with the special tool described below. Refer to SOPM 20-10-01 and SOPM 20-10-02 for requirements when machining high strength steel. 1.

2. If any latch pin fitting is removed from the airplane, it will be necessary to adjust the MDSCD as described in Paragraph 3.B., Work Instructions, PART 6.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP** 

-. 1
- Nut Remove 1

- 1
- Washer Remove

- 1
- Bolt Remove

- 1
- Latch Pin Remove 2 Remove old sealant from the bore. - - Latch Pin Fitting Clean 3 (a) (b) (e)

- - Latch Pin Fitting Inspect 4 Not shown (a)

- - Door Latch Cams Inspect

**FIGURE 12: MODIFICATION AT LATCH PIN FITTING POSITION #5 (SHEET 2 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 81 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** Increase hole diameter to 0.3140 - 0.3180 inch. Refer to Boeing Tool Kit MIT140U8005-1 foran accepted procedure. (f) 1
- Retention Bolt Hole Drill / Ream 5

Break sharp edges.

- - Latch Pin Fitting Clean/Deburr Apply one coat of primer to any bare metal surface on the outside of the fitting. After the first coat is dry, apply a second coat of primer. - BMS 10-11, TYPE I Primer Apply

Mark "modified by SB 747-52A2294"on the fitting to identify that this service bulletin has been done. Refer to SOPM 20-50-10 (method: rubberstamp with a protective overcoat) as an accepted procedure. - - Latch Pin Fitting Identify

To the outer diameter of the pin and tothe bore of the fitting. - BMS 5-95 Sealant Apply 6

Install the pin while the sealant is stillwet. Line up the retention bolt holes in the latch pin with the holes in the latch pin fitting. 1 146U8355-1 PIN-LATCH Install (New)

**FIGURE 12: MODIFICATION AT LATCH PIN FITTING POSITION #5 (SHEET 3 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 82 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** wet with BMS 5-95 sealant. 1 BACB30LJ5K28 BOLT, HEX HEAD Install (New) 7
Install 1 or 2 washers, as necessary. 2 BACW10BP5DP WASHER-PLAIN Install (New) Apply 120 - 130 inch-pounds of torque to the nut (optional: apply torque to the bolt head.) 1 BACN10YR5CD NUT Install (New)

(c) (d)

- BMS 5-95 Sealant Apply 8 (a) Do a Detailed Inspection of the affected fitting and the corresponding door latch cams for evidence of impact damage. If damage is found, contact Boeing for repair instructions and do the repair. Restore damaged finishes as necessary. (b) Do a Detailed Inspection of the retention bolt holes in the fitting for cracks or other damage. If damage is found, contact Boeing for repair instructions and do the repair. (c) Encapsulate bolt head, nut, washer, and bolt threads. Fillet seal the periphery of the bolt inside the pin. (d) Apply a fillet seal of BMS 5-95 sealant all around the latch pin at the space between the latch pin and the fitting on both the forward and aft ends of the fitting. Use care to keep the tapered end of the pin, which will be engaged by the door latch cams, free of sealant. (e) Do a Detailed Inspection of the pin bore and the retention bolt hole of the latch pin fitting for corrosion. If corrosion is found, repair 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, or 747-400SF SRM 53-00-90 Repair 1. (f) This procedure can be used on fittings that have been repaired 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, or 747-400SF SRM 53- 00-90 Repair 1.

**FIGURE 12: MODIFICATION AT LATCH PIN FITTING POSITION #5 (SHEET 4 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 83 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT FIGURE 13: MODIFICATION AT LATCH PIN FITTING POSITION #6**  **(SHEET 1 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 84 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one latch pin fitting location. **NOTE:** The procedure given below assumes that each affected latch pin fitting will be reworked while installed on the airplane. As an alternative, the latch pin fittings can be removed from the airplane and reworked. The retention bolt hole in latch pin fittings that are removed from the airplane can be made larger using standard machine tools rather than with the special tool described below. Refer to SOPM 20-10-01 and SOPM 20-10-02 for requirements when machining high strength steel. 1.

2. If any latch pin fitting is removed from the airplane, it will be necessary to adjust the MDSCD as described in Paragraph 3.B., Work Instructions, PART 6. 3. On commonly affected airplanes, installation of a pin stop bracket in accordance with this figure supersedes the pin stop bracket installation shown in Boeing Service Bulletin 747-52-2142 for the affected latch pin fitting position.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP** 

- 1
- Nut Remove 1

- 1
- Washer Remove

- 1
- Bolt Remove If installed. 1
- Bracket Remove

- 1
- Latch Pin Remove 2 Remove old sealant from the bore. - - Latch Pin Fitting Clean 3 (a) (b) (e)

- - Latch Pin Fitting Inspect 4 Not shown (a)

- - Door Latch Cams Inspect

**FIGURE 13: MODIFICATION AT LATCH PIN FITTING POSITION #6 (SHEET 2 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 85 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** Increase hole diameter to 0.3140 - 0.3180 inch. Refer to Boeing Tool Kit MIT140U8005-1 foran accepted procedure. (f) 1
- Retention Bolt Hole Drill / Ream 5

Break sharp edges.

- - Latch Pin Fitting Clean/Deburr Apply one coat of primer to any bare metal surface on the outside of the fitting. After the first coat is dry, apply a second coat of primer. - BMS 10-11, TYPE I Primer Apply

Mark "modified by SB 747-52A2294"on the fitting to identify that this service bulletin has been done. Refer to SOPM 20-50-10 (method: rubberstamp with a protective overcoat) as an accepted procedure. - - Latch Pin Fitting Identify

To the outer diameter of the pin and tothe bore of the fitting. - BMS 5-95 Sealant Apply 6

Install the pin while the sealant is stillwet. Line up the retention bolt holes in the latch pin with the holes in the latch pin fitting. 1 146U8355-1 PIN-LATCH Install (New)

between the latch pin fitting and the flanges of the pin stop bracket. - BMS 5-95 Sealant Apply 7

- 1 146U8356-2 PIN STOP BRACKET Install (New)

**FIGURE 13: MODIFICATION AT LATCH PIN FITTING POSITION #6 (SHEET 3 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 86 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** wet with BMS 5-95 sealant. 1 BACB30LJ5K28 BOLT, HEX HEAD Install (New) 8
Install 1 or 2 washers, as necessary. 2 BACW10BP5DP WASHER-PLAIN Install (New) Apply 120 - 130 inch-pounds of torque to the nut (optional: apply torque to the bolt head.) 1 BACN10YR5CD NUT Install (New)

(c) (d)

- BMS 5-95 Sealant Apply 9 (a) Do a Detailed Inspection of the affected fitting and the corresponding door latch cams for evidence of impact damage. If damage is found, contact Boeing for repair instructions and do the repair. Restore damaged finishes as necessary. (b) Do a Detailed Inspection of the retention bolt holes in the fitting for cracks or other damage. If damage is found, contact Boeing for repair instructions and do the repair. (c) Encapsulate bolt head, nut, washer, and bolt threads. Fillet seal the periphery of the bolt inside the pin. (d) Apply a fillet seal of BMS 5-95 sealant all around the latch pin at the space between the latch pin and the fitting. Use care to keep the tapered end of the pin, which will be engaged by the door latch cams, free of sealant. It is not necessary to fillet seal the end of the fitting covered by the bracket. (e) Do a Detailed Inspection of the pin bore and the retention bolt hole of the latch pin fitting for corrosion. If corrosion is found, repair 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, or 747-400SF SRM 53-00-90 Repair 1. (f) This procedure can be used on fittings that have been repaired 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, or 747-400SF SRM 53- 00-90 Repair 1.

**FIGURE 13: MODIFICATION AT LATCH PIN FITTING POSITION #6 (SHEET 4 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 87 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT This Figure applies only to: Group 1-2, Configuration 2.** 

**FIGURE 14: MODIFICATION AT LATCH PIN FITTING POSITION #2 (SHEET 1 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 88 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one latch pin fitting location. **NOTE:** The procedure given below assumes that each affected latch pin fitting will be reworked while installed on the airplane. As an alternative, the latch pin fittings can be removed from the airplane and reworked. The retention bolt hole in latch pin fittings that are removed from the airplane can be made larger using standard machine tools rather than with the special tool described below. Refer to SOPM 20-10-01 and SOPM 20-10-02 for requirements when machining high strength steel. 1.

2. If any latch pin fitting is removed from the airplane, it will be necessary to adjust the MDSCD as described in Paragraph 3.B., Work Instructions, PART 6. 3. On commonly affected airplanes, installation of a pin stop bracket in accordance with this figure supersedes the pin stop bracket installation shown in Boeing Service Bulletin 747-52-2142 for the affected latch pin fitting position.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP** 

- 1
- Nut Remove 1

- 1
- Washer Remove

- 1
- Bolt Remove If installed. 1
- Bracket Remove

- 1
- Latch Pin Remove 2 Remove old sealant from the bore. - - Latch Pin Fitting Clean 3 (a) (b) (e)

- - Latch Pin Fitting Inspect 4 Not shown (a)

- - Door Latch Cams Inspect

**FIGURE 14: MODIFICATION AT LATCH PIN FITTING POSITION #2 (SHEET 2 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 89 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** Increase hole diameter to 0.3140 - 0.3180 inch. Refer to Boeing Tool Kit MIT140U8005-1 foran accepted procedure. (f) 1
- Retention Bolt Hole Drill / Ream 5

Break sharp edges.

- - Latch Pin Fitting Clean/Deburr Apply one coat of primer to any bare metal surface on the outside of the fitting. After the first coat is dry, apply a second coat of primer. - BMS 10-11, TYPE I Primer Apply

Mark "modified by SB 747-52A2294"on the fitting to identify that this service bulletin has been done. Refer to SOPM 20-50-10 (method: rubberstamp with a protective overcoat) as an accepted procedure. - - Latch Pin Fitting Identify

To the outer diameter of the pin and tothe bore of the fitting. - BMS 5-95 Sealant Apply 6

Install the pin while the sealant is stillwet. Line up the retention bolt holes in the latch pin with the holes in the latch pin fitting. 1 146U8355-1 PIN-LATCH Install (New)

between the latch pin fitting and theflanges of the bracket. - BMS 5-95 Sealant Apply 7

- 1 146U8356-1 PIN STOP BRACKET Install (New)

**FIGURE 14: MODIFICATION AT LATCH PIN FITTING POSITION #2 (SHEET 3 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 90 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** wet with BMS 5-95 sealant. 1 BACB30LJ5K28 BOLT, HEX HEAD Install (New) 8
Install 1 or 2 washers, as necessary. 2 BACW10BP5DP WASHER-PLAIN Install (New) Apply 120 - 130 inch-pounds of torque to the nut (optional: apply torque to the bolt head.) 1 BACN10YR5CD NUT Install (New)

(c) (d)

- BMS 5-95 Sealant Apply 9 (a) Do a Detailed Inspection of the affected fitting and the corresponding door latch cams for evidence of impact damage. If damage is found, contact Boeing for repair instructions and do the repair. Restore damaged finishes as necessary. (b) Do a Detailed Inspection of the retention bolt holes in the fitting for cracks or other damage. If damage is found, contact Boeing for repair instructions and do the repair. (c) Encapsulate bolt head, nut, washer, and bolt threads. Fillet seal the periphery of the bolt inside the pin. (d) Apply a fillet seal of BMS 5-95 sealant all around the latch pin at the space between the latch pin and the fitting. Use care to keep the tapered end of the pin, which will be engaged by the door latch cams, free of sealant. It is not necessary to fillet seal the end of the fitting covered by the bracket. (e) Do a Detailed Inspection of the pin bore and the retention bolt hole of the latch pin fitting for corrosion. If corrosion is found, repair 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, or 747-400SF SRM 53-00-90 Repair 1. (f) This procedure can be used on fittings that have been repaired 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, or 747-400SF SRM 53- 00-90 Repair 1.

**FIGURE 14: MODIFICATION AT LATCH PIN FITTING POSITION #2 (SHEET 4 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 91 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT This Figure applies only to: Group 1-2, Configuration 1; Group 3.** 

**FIGURE 15: MODIFICATION AT LATCH PIN FITTING POSITION #2 (SHEET 1 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 92 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one latch pin fitting location. **NOTE:** The procedure given below assumes that each affected latch pin fitting will be reworked while installed on the airplane. As an alternative, the latch pin fittings can be removed from the airplane and reworked. The retention bolt hole in latch pin fittings that are removed from the airplane can be made larger using standard machine tools rather than with the special tool described below. Refer to SOPM 20-10-01 and SOPM 20-10-02 for requirements when machining high strength steel. 1.

2. If any latch pin fitting is removed from the airplane, it will be necessary to adjust the MDSCD as described in Paragraph 3.B., Work Instructions, PART 6. 3. On commonly affected airplanes, installation of a pin stop bracket in accordance with this figure supersedes the pin stop bracket installation shown in Boeing Service Bulletin 747-52-2142 for the affected latch pin fitting position.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP** 

-. 1
- Nut Remove 1

- 3
- Washer Remove

- 1
- Bolt Remove If installed. 1
- Bracket Remove

- 1 146U6107-1 Switch Striker Remove / Keep (e) 2 146U6107-1 Switch Striker Drill / Ream 2

- 1
- Latch Pin Remove 3 Remove old sealant from the bore. - - Latch Pin Fitting Clean 4 (a) (b) (f)

- - Latch Pin Fitting Inspect 5 Not shown (a)

- - Door Latch Cams Inspect

**FIGURE 15: MODIFICATION AT LATCH PIN FITTING POSITION #2 (SHEET 2 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 93 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** Increase hole diameter to 0.3140 - 0.3180 inch. Refer to Boeing Tool Kit MIT140U8005-1 foran accepted procedure. (g) 1
- Retention Bolt Hole Drill / Ream 6

Break sharp edges.

- - Latch Pin Fitting Clean/Deburr Apply one coat of primer to any bare metal surface on the outside of the fitting. After the first coat is dry, apply a second coat of primer. - BMS 10-11, TYPE I Primer Apply

Mark "modified by SB 747-52A2294"on the fitting to identify that this service bulletin has been done. Refer to SOPM 20-50-10 (method: rubberstamp with a protective overcoat) as an accepted procedure. - - Latch Pin Fitting Identify

To the outer diameter of the pin and tothe bore of the fitting. - BMS 5-95 Sealant Apply 7

Install the pin while the sealant is stillwet. Line up the retention bolt holes in the latch pin with the holes in the latch pin fitting. 1 146U8355-1 PIN-LATCH Install (New)

Between the latch pin fitting and theflanges of the bracket. - BMS 5-95 Sealant Apply 8

- 1 146U8356-1 PIN STOP BRACKET Install (New)

**FIGURE 15: MODIFICATION AT LATCH PIN FITTING POSITION #2 (SHEET 3 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 94 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** Between the switch striker and theflanges of the bracket. - BMS 5-95 Sealant Apply 9

- 1 146U6107-1 Switch Striker Install (Kept) wet with BMS 5-95 sealant. 1 BACB30LJ5K34 BOLT, HEX HEAD Install (New) 10
Between the switch striker and the bracket. 2 BACW10BP5DP WASHER-PLAIN Install (New)

Under the nut. 1 BACW10BP5DP WASHER-PLAIN Install (New) Apply 120 - 130 inch-pounds of torque to the nut (optional: apply torque to the bolt head.) 1 BACN10YR5CD NUT Install (New)

(c) (d)

- BMS 5-95 Sealant Apply 11 (a) Do a Detailed Inspection of the affected fitting and the corresponding door latch cams for evidence of impact damage. If damage is found, contact Boeing for repair instructions and do the repair. Restore damaged finishes as necessary. (b) Do a Detailed Inspection of the retention bolt holes in the fitting for cracks or other damage. If damage is found, contact Boeing for repair instructions and do the repair. (c) Encapsulate bolt head, nut, washer, and bolt threads. Fillet seal the periphery of the bolt inside the pin. (d) Apply a fillet seal of BMS 5-95 sealant all around the latch pin at the space between the latch pin and the fitting. Use care to keep the tapered end of the pin, which will be engaged by the door latch cams, free of sealant. It is not necessary to fillet seal the end of the fitting covered by the bracket. (e) Make the retention bolt holes in the switch striker larger, to 0.342 - 0.354 inch diameter. After rework, apply one coat of BMS 10-11 Type I primer to any bare metal areas of the part. After the first primer coat dries, apply a second coat of BMS 10-11 Type I primer and one coat of BMS-10-11, Type II enamel. (f) Do a Detailed Inspection of the pin bore and the retention bolt hole of the latch pin fitting for corrosion. If corrosion is found, repair 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, or 747-400SF SRM 53-00-90 Repair 1. (g) This procedure can be used on fittings that have been repaired 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, or 747-400SF SRM 53- 00-90 Repair 1.

**FIGURE 15: MODIFICATION AT LATCH PIN FITTING POSITION #2 (SHEET 4 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 95 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one latch pin.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  (a) Increase hole diameter to 0.3140 - 0.3180 inch. Refer to SOPM 20-10-01 and SOPM 20-10-02 for requirements when machining high strength steel. 1
- Latch Pin Drill / Ream 1

Break sharp edges.Maintain a 63 microinch finish on the outer surface of the latch pin. Maintain a 125 inch microinch finish on all other surfaces. 1
- Latch Pin Clean/Deburr 2

Apply one coat of primer to any bare metal surface on the outside of the pin. After the first coat is dry, apply a second coat of primer. - BMS 10-11, TYPE I Primer Apply 3

**FIGURE 16: LATCH PIN REWORK (SHEET 1 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 96 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** (b) (c) Rubber stamp new part number on pin. Refer to SOPM20-50-10 as an accepted procedure. - - Latch Pin Identify 4

(a) Applicable to 69B15457-3, -4, -5, -6, -7 or -8 latch pins. Existing 69B15457-1 and -2 latch pins must first be reworked into 69B15457-3 and -4 latch pins in accordance with Boeing Service Bulletin 747-52-2105, "Cargo Door Latch and Lock System Revision". (b) Identify modified 69B15457-3, -5 or -7 latch pins as 146U8355-1. (c) Identify modified 69B15457-4, -6 or -8 latch pins as 146U8355-2.

**FIGURE 16: LATCH PIN REWORK (SHEET 2 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 08, 2010 747-52A2294 Revision 1 August 16, 2011 97 of 97 **BOEING SERVICE BULLETIN 747-52A2294 ALERT**  **ALERT**