### Commercial **Airplanes** 

# 757 Service Bulletin **ALERT Number: 757-52A0091**  Original Issue: March 09, 2010 Revision 1: December 19, 2014 ATA System: 5232
**SUBJECT:** DOORS - Main Cargo Door - Cam Latch and Latch Pin Inspection and Modification Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15 CFR 300-774). An export license may be required before it is used for development, production or use by foreign persons from specific countries. The controller of this data has the individual responsibility to abide by all export laws. 9E991 ECCN: 

## BOEING PROPRIETARY, CONFIDENTIAL AND/OR TRADE SECRET Copyright © 2010 Boeing. Unpublished Work. All Rights Reserved. Treatment of this document and its content is governed by contract with Boeing. Rights to use this document are licensed on a per aircraft basis and such rights may not be transferable. For more information, contact The Boeing Company. Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner, BBJ, DC-8, DC-9, DC-10, KC-10, KC-46, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8, Poseidon and Boeing liveries are all trademarks owned by The Boeing Company; and no trademark license is granted in connection with this document unless provided in writing by Boeing.

Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 1 of 62 3.0Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 2 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT**

BLANK PAGE**Table of Contents** Revision Transmittal Sheet............................................ 5 Summary...................................................... 7 1. PLANNING INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 A. Effectivity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 1. Airplanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 B. Concurrent Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 C. Reason. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 I. Electrical Load Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 J. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 2. Data Supplied with this Service Bulletin:. . . . . . . . . . . . . . . . . . . . . . . . . . . 26 3. Installation Drawings Used in the Preparation of this Service Bulletin:. . . . . . . . . . . 26 K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 L. Interchangeability and Intermixability of Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . 27 M. Software Accomplishment Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 2. MATERIAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 C. Parts Necessary for Each Airplane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 1. Kits/Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 2. Parts and Materials Supplied by the Operator. . . . . . . . . . . . . . . . . . . . . . . . 29 3. Parts Modified and Reidentified. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 4. Parts Removed and Not Replaced. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 30 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 FIGURE 1: MAIN CARGO DOOR - CAM LATCHES AND LATCH PINS INSPECTION. . . . . . . . . 37 FIGURE 2: MAIN CARGO DOOR - LATCH PIN CROSS BOLT TORQUE. . . . . . . . . . . . . . . . 40 FIGURE 3: MAIN CARGO DOOR - LATCH PIN EXTENSION MEASUREMENT. . . . . . . . . . . . 42 FIGURE 4: MAIN CARGO DOOR - CAM LATCH 1 AND CAM LATCH 2 INSPECTION. . . . . . . . 44 FIGURE 5: MAIN CARGO DOOR - LATCH PIN CROSS BOLT REPLACEMENT. . . . . . . . . . . 46 FIGURE 6: MAIN CARGO DOOR - CAM LATCH REPLACEMENT. . . . . . . . . . . . . . . . . . . 48 FIGURE 7: MAIN CARGO DOOR - LATCH PIN REPLACEMENT. . . . . . . . . . . . . . . . . . . . 51 FIGURE 8: MAIN CARGO DOOR - CAM LATCH REMOVAL AND INSPECTION. . . . . . . . . . . 53 FIGURE 9: MAIN CARGO DOOR - CAM LATCHES, LATCH PINS AND LATCH PIN CROSS BOLTS INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 3 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT**FIGURE 10: MAIN CARGO DOOR - CAM LATCH AND LATCH PIN RIGGING. . . . . . . . . . . . . 58 FIGURE 11: MAIN CARGO DOOR - MAIN CARGO DOOR EDGE FLUSHNESS MEASUREMENT . . 61

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 4 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT**

### Commercial **Airplanes** 

# 757 Service Bulletin **ALERT Revision Transmittal Sheet**  **Number: 757-52A0091** Original Issue: March 09, 2010 Revision 1: December 19, 2014 ATA System: 5232
**SUBJECT:** DOORS - Main Cargo Door - Cam Latch and Latch Pin Inspection and Modification This revision includes all pages of the service bulletin.
**COMPLIANCE INFORMATION RELATED TO THIS REVISION** Federal Aviation Administration (FAA) Notice of Proposed Rule Making NPRM 2011-NM-163-AD, is related to this service bulletin. No more work is necessary on the airplane(s) changed or inspected in accordance with the original issue of this service bulletin.
**REASON FOR REVISION** This revision is sent to clarify the requirements of the compliance tables. These sections were changed: 1. Summary a. Background: (1) Background statement revised and new service history information was added. (2) Summary Evaluation Table added. b. Action - Changed to agree with work instructions. c. Compliance - NPRM statement added. 2. Planning Information
a. Reason - Added the reason for Revision 1 is sent to statement. b. Description - Changed to agree with work instructions. c. Compliance: (1) NPRM statement added.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 5 of 62(2) Compliance Tables 1 and 2 revised to clarify inspections, conditions and actions. 3. Accomplishment Instructions a. General Information - Notes numbering has been changed and new notes added.
b. Work Instructions - Revised for clarification. Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity and format changes, to show the location of all content changes. Pages with no vertical lines have no changes.
**REVISION HISTORY**
March 09, 2010 Original Issue: December 19, 2014 Revision 1:

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 6 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT**

### Commercial **Airplanes** 

# 757 Service Bulletin **ALERT Summary**  **Number: 757-52A0091** Original Issue: March 09, 2010 Revision 1: December 19, 2014 ATA System: 5232
**SUBJECT:** DOORS - Main Cargo Door - Cam Latch and Latch Pin 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**
None.
**BACKGROUND** Accomplishment of the inspections in this service bulletin will make sure the Main Cargo Door (MCD) cam latches are inspected for damage and the latch pins are inspected for damage and migration. The inspections are necessary in order to find and replace damaged cam latches, latch pins and latch pin cross bolts. If not replaced, damaged cam latches, latch pins and latch pin cross bolts could lead to a failure of the cam latches and may result in a possible rapid decompression and potential separation of the cargo door from the airplane. Boeing has received one report from one operator that the MCD forward most cam latch on the forward center cam latch pair (cam latch number 3) broke during flight. The airplane that reported the broken cam latch had 20,000 flight hours and 9,500 flight cycles when the cam latch broke. The crew heard a loud noise coming from the MCD shortly after cruise. Upon landing, an inspection was performed and a cam latch was found broken. The broken cam latch mating latch pin was also found to have significant wear as evidenced by the loss of the plating on the surface that is normally in contact with the cam. The latch pin was also deformed approximately 0.05 inch in the area of the wear surface. The cause of the broken cam latch has been determined to be from a poorly rigged MCD. Although rigged per the original Aircraft Maintenance Manual (AMM) procedures, significant variation was allowed in the rigging dimensions. This variation can cause some of the latch pin/cam latch locations to have a significant preload placed on them during engagement and rotation of the cam latches during latching and unlatching operations. This preload is believed to have imparted a torque on the latch pin from the cam latch rotation during latching and unlatching operations. The torque transmitted to the latch pin is then believed to have caused the latch pin cross bolt to fail in shear.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 7 of 62If the latch pin cross bolt fails, the latch pin could migrate either towards the cam latch or away from the cam latch. Latch pin migration towards the cam latch can cause significant interference with the mating cam latch leading to cam latch damage. In this case, the latch pin migrated into the cam latch and caused damage to the cam latch. The crack initiated at the damage site caused by the latch pin and then led to the cam latch breaking. Latch pin migration away from the cam latch could cause disengagement from the cam latch, resulting in no load transfer between the cam latch and the mating latch pin and may not be noticed before critical conditions are exceeded in adjacent cam latches or latch pins. Accomplishment of the work given in this service bulletin will make sure the cam latches, latch pins and latch pin cross bolt are inspected and repaired or replaced as required. The MCD rig will be verified to the Service Bulletin requirements and if necessary, the MCD will be re-rigged to the updated AMM requirements. Since the original report, there have been two additional reports of sheared latch pin cross bolts. Boeing Service Related Problem (SRP) 757-SRP-52-0088 is related to this service bulletin. This table is provided to operators for planning purposes only. Refer to the applicable sections for more information.
**Reference Affected**  **Planning Data** Paragraph 1.A.2., Spares Affected No Spares Affected Paragraph 1.E., Compliance and Paragraph 1.F., Approval Yes AD Related
Paragraph 1.H., Weight and Balance Changes No Weight and Balance Change Paragraph 1.I., Electrical Load Data No Electrical Load Changed Paragraph 1.K., Publications Affected Yes Publications Affected Paragraph 1.K., Publications Affected No Airplane Flight Operations Affected (Flight CrewOperations Manual and/or FAA Approved Airplane Flight Manual) Paragraph 2.C.1., Kits/Parts No Kits/Parts Required Paragraph 2.C.2., Parts and Materials Supplied by the Operator No Operator Supplied Parts/Material
Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin No Special Tooling Required

**ACTION** Get access to the MCD. Do a general visual inspection of the cam latches, latch pins and latch pin cross bolt. Torque the cross bolts in the latch pins. Measure the extension of the latch pins. Replace all alloy steel cross bolts through the latch pins with Corrosion Resistant Steel (CRES) cross bolts. Check for lip deformation on all cam latches. Do a High Frequency Eddy Current (HFEC) or magnetic particle inspection of cam latch 1 and cam latch 2 for cracks. Replace any cracked or broken parts. Check the rig of the MCD to the requirements of the Service Bulletin and if necessary, the MCD will be re-rigged to the latest AMM requirements. Do repetitive general visual and detailed inspections of the cam latches and latch pins after the rig is verified or adjusted. Do repetitive HFEC or magnetic particle inspections of cam latch 1 and cam latch 2 for cracks after the rig is verified or adjusted.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 8 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT EFFECTIVITY**  757-200CB, 757-200PF and 757-200 Special Freighter delivered under a Boeing Supplemental Type Certificate (STC) Airplanes. Refer to Paragraph 1.A.1., Airplanes for the list of affected airplanes.
**COMPLIANCE** Federal Aviation Administration (FAA) Notice of Proposed Rule Making NPRM 2011-NM-163-AD, is related to this service bulletin. Refer to Paragraph 1.E., Compliance.
**INDUSTRY SUPPORT INFORMATION** Boeing warranty remedies are not available for the inspections and modifications given in this service bulletin.
**MANPOWER** Refer to Paragraph 1.G., Manpower.
**MATERIAL INFORMATION** Operator Supplied Parts/Materials. Refer to Paragraph 2.A., Material - Price and Availability

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 9 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 10 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT**

### Commercial **Airplanes** 

# 757 Service Bulletin **ALERT Number: 757-52A0091**  Original Issue: March 09, 2010 Revision 1: December 19, 2014 ATA System: 5232
**SUBJECT:** DOORS - Main Cargo Door - Cam Latch and Latch Pin 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 D624N001 Part 3 for Airplane Variable Number, Line Number, and Serial Number data. This service bulletin is for the airplanes shown below.
**DESCRIPTION CONFIGURATION**  **GROUP** 757-200PF, 757-200CB and 757-200 Special Freighter delivered under a Boeing Supplemental Type Certificate (STC) Airplanes - 1

Airplane Models: 757-200, 757-200CB, 757-200PF **Group Variable Number**  1 NA201 - NA204 1 NA206 - NA213 1 NA215 - NA236 1 NC901 - NC951 1 NC971 1 NC973 - NC974

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 11 of 62**Group Variable Number**  1 ND895 1 NS601 - NS616 1 NT001 - NT009 2. Spares Affected
None. **B. Concurrent Requirements**
None.
**C. Reason** Accomplishment of the inspections in this service bulletin will make sure the Main Cargo Door (MCD) cam latches are inspected for damage and the latch pins are inspected for damage and migration. The inspections are necessary in order to find and replace damaged cam latches, latch pins and latch pin cross bolts. If not replaced, damaged cam latches, latch pins and latch pin cross bolts could lead to a failure of the cam latches and may result in a possible rapid decompression and potential separation of the cargo door from the airplane. Boeing has received one report from one operator that the MCD forward most cam latch on the forward center cam latch pair (cam latch number 3) broke during flight. The airplane that reported the broken cam latch had 20,000 flight hours and 9,500 flight cycles when the cam latch broke. The crew heard a loud noise coming from the MCD shortly after cruise. Upon landing, an inspection was performed and a cam latch was found broken. The broken cam latch mating latch pin was also found to have significant wear as evidenced by the loss of the plating on the surface that is normally in contact with the cam. The latch pin was also deformed approximately 0.05 inch in the area of the wear surface. The cause of the broken cam latch has been determined to be from a poorly rigged MCD. Although rigged per the original Aircraft Maintenance Manual (AMM) procedures, significant variation was allowed in the rigging dimensions. This variation can cause some of the latch pin/cam latch locations to have a significant preload placed on them during engagement and rotation of the cam latches during latching and unlatching operations. This preload is believed to have imparted a torque on the latch pin from the cam latch rotation during latching and unlatching operations. The torque transmitted to the latch pin is then believed to have caused the latch pin cross bolt to fail in shear. If the latch pin cross bolt fails, the latch pin could migrate either towards the cam latch or away from the cam latch. Latch pin migration towards the cam latch can cause significant interference with the mating cam latch leading to cam latch damage. In this case, the latch pin migrated into the cam latch and caused damage to the cam latch. The crack initiated at the damage site caused by the latch pin and then led to the cam latch breaking. Latch pin migration away from the cam latch could cause disengagement from the cam latch, resulting in no load transfer between the cam latch and the mating latch pin and may not be noticed before critical conditions are exceeded in adjacent cam latches or latch pins.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 12 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT**Accomplishment of the work given in this service bulletin will make sure the cam latches, latch pins and latch pin cross bolts are inspected and repaired or replaced as required. The MCD rig will be verified to the Service Bulletin requirements and if necessary, the MCD will be re-rigged to the latest AMM requirements. Since the original report, there have been two additional reports of a sheared latch pin cross bolts. Boeing Service Related Problem (SRP) 757-SRP-52-0088 is related to this service bulletin. Revision 1 is sent to clarify the requirements of the compliance tables. **D. Description** Get access to the MCD. Do a general visual inspection of the cam latches, latch pins and latch pin cross bolts. Torque the cross bolts in the latch pins. Measure the extension of the latch pins. Replace all alloy steel cross bolts through the latch pins with CRES cross bolts. Check for lip deformation on all cam latches. Do a HFEC or magnetic particle inspection of cam latch 1 and cam latch 2 for cracks. Replace any cracked or broken parts. The MCD rig will be verified to the Service Bulletin requirements and if necessary, the MCD will be re-rigged to the updated AMM requirements. Do repetitive general visual and detailed inspections of the cam latches and latch pins after the rig is verified or adjusted. Do repetitive HFEC or magnetic particle inspections of cam latch 1 and cam latch 2 for cracks after the rig is verified or adjusted. Effects of this Issue on airplanes on which Original Issue was previously done:
None The work in this service bulletin is done in the maintenance zone(s) given below.
**Affected Maintenance Zones Zone**  **Model** 838 757-200, 757-200CB, 757- 200PF **E. Compliance** Federal Aviation Administration (FAA) Notice of Proposed Rule Making NPRM 2011-NM-163-AD, is related to this service bulletin. If all Table 1 requirements, including rigging of the main cargo door, have been accomplished in accordance with the original issue of this service bulletin, continue repetitive inspections in accordance with Table 2. If Table 1 requirements have not been accomplished in accordance with the original issue of this service bulletin, then all Table 1 requirements, including rigging of the main cargo door, must be accomplished before starting Table 2 requirements.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 13 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT Table 1: Initial and Repetitive Inspections of the Cam Latches, Latch Pins and Latch Pin Cross Bolts for**  **the Main Cargo Door (Pre-Rig Check) Repeat Interval (Not to**  **Exceed) Compliance Time (Whichever**  **Occurs First) Action**  **Condition**

- Within 150 daysafter the original issue date of this service bulletin. Within 330 flight cycles after the original issuedate of this service bulletin. Do the following for all MCD cam latches and latch pins:Do a general visual inspection for any broken cam latches, latch pins and latch pin cross bolts, and for any missing cam latches, latch pins and latch pin cross bolts inaccordance with Paragraph 3.B., Work Instructions Step 1.b. All airplanes

AND Torque the cross bolts inthe latch pins in accordance with Paragraph 3.B., Work Instructions Step 1.c. AND Measure the extensionof the latch pins in accordance with Paragraph 3.B., Work Instructions Step 1.d. ANDDo a general visual inspection of all camlatches for lip deformation in accordance with Paragraph 3.B., Work Instructions Step 1.e.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 14 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT Table 1: Initial and Repetitive Inspections of the Cam Latches, Latch Pins and Latch Pin Cross Bolts for**  **the Main Cargo Door (Pre-Rig Check) Repeat Interval (Not to**  **Exceed) Compliance Time (Whichever**  **Occurs First) Action**  **Condition**

- Before further flight Replace all broken and missing cam latches, latch pins and latch pincross bolts in accordance with Paragraph 3.B., Work Instructions Step 2.a. Condition 1: One or more of the following is found: 1. Broken or missing cam latch(es).
2. Broken or missing latch pin(s).
3. Broken or missing latch pin cross bolt(s). AND Do a detailed inspectionof mating part(s) and immediately adjacent cam latch(es) and latch pin(s) for any cracks, or any gouges in critical areas in accordance with Paragraph 3.B., Work Instructions Step 2.b. AND Unless replaced with new or reworked parts, do a HFEC or magnetic particle inspection of cam latch 1 and cam latch 2 for any cracks inaccordance with Paragraph 3.B., Work Instructions Step 2.c. (b) AND Check the rig of the MCD in accordance with Paragraph 3.B., Work Instructions Step 2.d. AND Replace all alloy steel cross bolts through the latch pins with CREScross bolts in accordance with Paragraph 3.B., Work Instructions Step 2.d.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 15 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT Table 1: Initial and Repetitive Inspections of the Cam Latches, Latch Pins and Latch Pin Cross Bolts for**  **the Main Cargo Door (Pre-Rig Check) Repeat Interval (Not to**  **Exceed) Compliance Time (Whichever**  **Occurs First) Action**  **Condition**

- Within 150 days after the latch pin extension was measured. Within 330 flight cycles after thelatch pin extension was measured. Replace the discrepant latch pin in accordance with Paragraph 3.B., Work Instructions Step 3.a. Condition 2: The latch pin extension is less than 0.89 inches or greater than 0.91 inches.
AND Do a detailed inspection of the mating cam latch for any cracks, or gouges in critical areas in accordance with Paragraph 3.B., Work Instructions Step 3.b. 330 flight cycles or 150 days, whichever occurs first. (a) Within 150 days after the initial inspection. Within 330 flight cycles after theinitial inspection. Do the following for all MCD cam latches and latch pins:Do a general visual inspection for any broken cam latches, latch pins and latch pin cross bolts, and for any missing cam latches, latch pins and latch pin cross bolts inaccordance with Paragraph 3.B., Work Instructions Step 3.c. AND

- Within 24 months afterthe original issue date of this service bulletin. Within 3,000flight cycles after the original issue date ofthis service bulletin. Do a detailed inspection of all cam latches and mating latch pins for anycracks, or gouges in critical areas in accordance with Paragraph 3.B., Work Instructions Step 3.d.

- Within 24 months afterthe original issue date of this service bulletin. Within 3,000flight cycles after the original issue date ofthis service bulletin. Unless replaced with new or reworked parts, do a HFEC or magnetic particle inspection of cam latch 1 and cam latch 2 for any cracks inaccordance with Paragraph 3.B., Work Instructions Step 3.e.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 16 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT Table 1: Initial and Repetitive Inspections of the Cam Latches, Latch Pins and Latch Pin Cross Bolts for**  **the Main Cargo Door (Pre-Rig Check) Repeat Interval (Not to**  **Exceed) Compliance Time (Whichever**  **Occurs First) Action**  **Condition**
(b) AND Check the rig of the MCD in accordance with Paragraph 3.B., Work Instructions Step 3.f. AND Replace all alloy steel cross bolts through the latch pins with CREScross bolts in accordance with Paragraph 3.B., Work Instructions Step 3.f.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 17 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT Table 1: Initial and Repetitive Inspections of the Cam Latches, Latch Pins and Latch Pin Cross Bolts for**  **the Main Cargo Door (Pre-Rig Check) Repeat Interval (Not to**  **Exceed) Compliance Time (Whichever**  **Occurs First) Action**  **Condition**
330 flight cycles or 150 days, whichever occurs first. Within 150 days after the initial inspection. Within 330 flight cycles after theinitial inspection. Do a detailed inspection of the discrepant cam latch and mating latch pin for any cracks, or gouges in critical areas in accordance with Paragraph 3.B., Work Instructions Step 4.a. Condition 3: If a cam latch is found with lip deformation. (a)

AND 330 flight cycles or 150 days, whichever occurs first. Within 150 days after the initial inspection. Within 330 flight cycles after theinitial inspection. Do the following for all MCD cam latches and latch pins:Do a general visual inspection for any broken cam latches, latch pins and latch pin cross bolts, and for any missing cam latches, latch pins and latch pin cross bolts inaccordance with Paragraph 3.B., Work Instructions Step 4.b. (a)

AND

- Within 24 months afterthe original issue date of the service bulletin. Within 3,000flight cycles after the original issue date ofthe service bulletin. Do a detailed inspection of all cam latches and mating latch pins for anycracks, or gouges in critical areas in accordance with Paragraph 3.B., Work Instructions Step 4.c. AND

- Within 24 months afterthe original issue date of the service bulletin. Within 3,000flight cycles after the original issue date ofthe service bulletin. Unless replaced with new or reworked parts, do a HFEC or magnetic particle inspection of cam latch 1 and cam latch 2 for any cracks inaccordance with Paragraph 3.B., Work Instructions Step 4.d. (b) AND

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 18 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT Table 1: Initial and Repetitive Inspections of the Cam Latches, Latch Pins and Latch Pin Cross Bolts for**  **the Main Cargo Door (Pre-Rig Check) Repeat Interval (Not to**  **Exceed) Compliance Time (Whichever**  **Occurs First) Action**  **Condition**
Check the rig of the MCD in accordance with Paragraph 3.B., Work Instructions Step 4.e. AND Replace all alloy steel cross bolts through the latch pins with CREScross bolts in accordance with Paragraph 3.B., Work Instructions Step 4.e.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 19 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT Table 1: Initial and Repetitive Inspections of the Cam Latches, Latch Pins and Latch Pin Cross Bolts for**  **the Main Cargo Door (Pre-Rig Check) Repeat Interval (Not to**  **Exceed) Compliance Time (Whichever**  **Occurs First) Action**  **Condition**
330 flight cycles or 150 days, whichever occurs first. Within 150 days after the initial inspection. Within 330 flight cycles after theinitial inspection.Do a general visual inspection for any brokenand missing cam latches, latch pins and latchpin cross bolts in accordance with Paragraph 3.B., Work Instructions Step 5.a.Condition 4: No discrepancies found (c) (a)

3,000 flight cycles or 24months, whichever occurs first. Within 24 months afterthe initial inspection. Within 3,000flight cycles after the initial inspection. Do a detailed inspection of the cam latches and latch pins for any cracks, or any gouges in critical areas in accordance with Paragraph 3.B., Work Instructions Step 5.b. (a)

AND Unless replaced with new or reworked parts, do a HFEC or magnetic particle inspection of cam latch 1 and cam latch 2 for any cracks inaccordance with Paragraph 3.B., Work Instructions Step 5.c. (b)

- Within 48 months afterthe original issue date of this service bulletin. Within 6,000flight cycles after the original issue date ofthis service bulletin. Check the rig of the MCD in accordance with Paragraph 3.B., Work Instructions Step 5.d. AND Replace all alloy steel cross bolts through the latch pins with CREScross bolts in accordance with Paragraph 3.B., Work Instructions Step 5.d.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 20 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT Table 1: Initial and Repetitive Inspections of the Cam Latches, Latch Pins and Latch Pin Cross Bolts for**  **the Main Cargo Door (Pre-Rig Check) Repeat Interval (Not to**  **Exceed) Compliance Time (Whichever**  **Occurs First) Action**  **Condition**

- Before further flight. Replace cracked or gouged cam latch(es)and latch pin(s) in accordance with Paragraph 3.B., Work Instructions Step 6.a.Condition 5: If the detailed, HFEC or magnetic particle inspections inConditions 1 thru 4 reveal any of the following: 1. Cracked or gouged camlatch(es) in critical areas.
2. Cracked or gouged latch pin(s) in critical areas. AND Do a detailed inspectionof mating part(s) and immediately adjacent cam latch(es) and latch pin(s) for any cracks, or any gouges in critical areas in accordance with Paragraph 3.B., Work Instructions Step 6.b. AND Unless replaced with new or reworked parts, do a HFEC or magnetic particle inspection of cam latch 1 and cam latch 2 for any cracks inaccordance with Paragraph 3.B., Work Instructions Step 6.c. (b) AND Check the rig of the MCD in accordance with Paragraph 3.B., Work Instructions Step 6.d. AND Replace all alloy steel cross bolts through the latch pins with CREScross bolts in accordance with Paragraph 3.B., Work Instructions Step 5.e. (a) All Table 1 repeat inspections are terminated when the rig of the MCD has been checked in accordance Paragraph 3.B., Work Instructions. Refer to Table 2 for post-rig check inspection requirements. (b) A reworked cam latch is defined as a cam latch that has been reworked within limits of CMM 52-32-03and/or a Boeing ODA approved repair via FAA Form 8100-9 and has been HFEC or magnetic particle inspected, and has no crack(s) or gouge(s) in critical area(s).

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 21 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT Table 1: Initial and Repetitive Inspections of the Cam Latches, Latch Pins and Latch Pin Cross Bolts for**  **the Main Cargo Door (Pre-Rig Check) Repeat Interval (Not to**  **Exceed) Compliance Time (Whichever**  **Occurs First) Action**  **Condition**
(c) Discrepancy is defined as: Any broken, cracked, missing or gouged cam latches or latch pins, broken or missing latch pin cross bolts, latch pin extension less than 0.89 inches or greater than 0.91 inches, or cam latch lip deformation.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 22 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT Table 2: Repetitive Inspection Requirements for Airplanes that have accomplished All Table 1 Require**  **ments, Including Rigging of the Main Cargo Door in accordance with the Original Issue or Revision 1 of this service bulletin.**  **Repeat Inter val (Not to**  **Exceed) Compliance Time (Whichever Occurs**  **Later) Action**  **Condition**

375 flight cycles. Within 375 flight cycles after the rig of the MCD was checked.Do a general visual inspection for any broken or missing cam latches, latch pins and latch pin cross bolts in accordance with Paragraph 3.B., Work Instructions Step 7.a.1. Condition 6: Airplanes that have accomplished all Table 1 requirements, including rigging of themain cargo door in accordance with the original issue or revision 1 of this service bulletin and no rigging adjustment of any latch pin or any latch pin fitting was required. 3,000 flight cycles. If latch pin flight cycles are known: Before 40,000 total latch pin flight cycles. Do a detailed inspection of the latch pins for any cracks, or any gouges incritical areas in accordance with Paragraph 3.B., Work Instructions Step 7.a.2. 3,000 flight cycles. If latch pin flight cycles are unknown: Within 3,000 flight cycles after the rig of the MCD was checked. AND During previous pre-rigcheck inspection no discrepancy was found. (b) 3,000 flight cycles. If cam latch flight cycles are known and cam latch is not a reworked part: Do a detailed inspection of the cam latches for any cracks, or any gouges in critical areasin accordance with Paragraph 3.B., Work Instructions Step 7.a.2. (a) Before 40,000 total cam latch flight cycles. 3,000 flight cycles. If cam latch flight cycles are unknown or if cam latch is a reworked part: (a) Within 3,000 flight cycles after the rig of the MCD was checked. 6,000 flight cycles. If cam latch flight cycles are known and cam latch is not a reworked part: Do a HFEC or magnetic particle inspection of cam latch 1 and cam latch 2for any cracks in accordance with Paragraph 3.B., Work Instructions Step 7.a.3. (a) Before 40,000 total cam latch flight cycles. 6,000 flight cycles. If cam latch flight cycles are unknown or if cam latch is a reworked part: (a) Within 6,000 flight cycles after the rig of the MCD was checked.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 23 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT Table 2: Repetitive Inspection Requirements for Airplanes that have accomplished All Table 1 Require**  **ments, Including Rigging of the Main Cargo Door in accordance with the Original Issue or Revision 1 of this service bulletin.**  **Repeat Inter val (Not to**  **Exceed) Compliance Time (Whichever Occurs**  **Later) Action**  **Condition**

375 flight cycles. Within 375 flight cycles after the rig of the MCD was checked.Do a general visual inspection for any broken or missing cam latch(es), latch pin(s) and latch pincross bolt(s) in accordance with Paragraph 3.B., Work Instructions Step 8.a.1 Condition 7: Airplanes that have accomplished all Table 1 requirements, including rigging of themain cargo door in accordance with the original issue or revision 1 of thisservice bulletin and rigging adjustment of any latch pin or any latch pin fitting was required. 3,000 flight cycles. Within 3,000 flight cycles after the rig of the MCD was checked. Do a detailed inspection of the cam latches and latch pins for any cracks, or any gouges in critical areas in accordance withParagraph 3.B., Work Instructions Step 8.a.2 OR During previous pre-rig check inspection, any discrepancy was found. (b) 6,000 flight cycles. Within 6,000 flight cycles after the rig of the MCD was checked. Do a HFEC or magnetic particle inspection of cam latch 1 and cam latch 2for any cracks in accordance with Paragraph 3.B., Work Instructions Step 8.a.3

- Before further flight. Contact The BoeingCompany for repair instructions and do the repair. Any discrepancy found during Condition 6 or Condition 7 inspections.
(a) A reworked cam latch is defined as a cam latch that has been reworked within limits of CMM 52-32-03and/or a Boeing ODA approved repair via FAA Form 8100-9 and has been HFEC or magnetic particle inspected, and has no crack(s) or gouge(s) in critical area(s). (b) Discrepancy is defined as: Any broken, cracked, missing or gouged cam latches or latch pins, broken or missing latch pin cross bolts, latch pin extension less than 0.89 inches or greater than 0.91 inches, or cam latch lip deformation. **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.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 24 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT**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 the inspections and modifications 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. **Elapsed Hours Task Hours**  **Number of Per- sons**  **Task**

0.25 0.25 1 Open Access 1.60 1.60 1 FIGURE 1 0.50 0.50 1 FIGURE 2 0.50 0.50 1 FIGURE 3 1.00(h) 1.00(h) 1 FIGURE 4 1.00 1.00 1 FIGURE 5 0.50(a) (f) (i) 0.50(a) (f) (i) 1(i) FIGURE 6 0.10(b) (g) 0.10(b) (g) 1 FIGURE 7 0.60(c) 0.60(c) 1 FIGURE 8 0.10(d) 0.10(d) 1 FIGURE 9 20.0 48.0 2-3 FIGURE 10 - FIG- URE 11 0.25 0.25 1 Close Access (e) (e) TOTAL FOR EACH AIRPLANE (a) Estimate is per cam latch requiring replacement. (b) Estimate is per latch pin requiring replacement. (c) Estimate is per cam latch requiring inspection. (d) Estimate is per cam latch.(e) Total time required may vary depending upon conditions found during inspections. (f) Does not include time to match drill cam shaft.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 25 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT Elapsed Hours**  **Task Hours Number of Per-**  **sons Task** 
(g) Does not include time to match drill latch pin (h) Does not include NDI inspection time (i) Cam latch 4 will require 2 hours and a second person to remove. **H. Weight and Balance Changes Change in Moment**  **(Pound-Inches) Change in Weight**  **(Pounds) Airplane**  Negligible Negligible 757-200CB Negligible Negligible 757-200PF Negligible Negligible 757-200 Special Freighter
**I. Electrical Load Data** Not changed.
**J. References** 1. Existing Data: a. Boeing Service Related Problem (SRP) 757-SRP-52-0088 b. Component Maintenance Manual (CMM) 52-32-03, Repair 7-2. c. Federal Aviation Administration (FAA) Notice of Proposed Rule Making (NPRM) 2011-NM-163-AD d. Standard Overhaul Practices Manual (SOPM) 20-20-01 e. 757 Aircraft Maintenance Manual (AMM) 52-32-00 f. 757 Non-Destructive Testing (NDT) Manual Part 6, 51-00-12 or 51-00-21 2. Data Supplied with this Service Bulletin:
None. 3. Installation Drawings Used in the Preparation of this Service Bulletin:
**Title Drawing Number**  DOOR INSTALLATION - MAIN CARGO 65-25326 LATCH MECHANISM INSTALLATION - MAIN CARGO DOOR 65-25339 SILL INSTL - LOWER, MAIN CARGO DOOR 143N8750

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 26 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT Title**  **Drawing Number** LATCH PIN FITTING - ASSY 65-67872 CAM - LATCH MECHANISM CARGO DOOR 69-23438 These drawings were used to prepare this service bulletin. These drawings are not necessary to make the specified changes, and are not supplied with this service bulletin. These drawings may not be applicable to all airplane configurations or operators.
**K. Publications Affected**
1. Publications: **Chapter-Section Publication**  52-32, 52-33 757 Illustrated Parts Catalog 52-32 757 Component Maintenance Manual 52-32 757 Aircraft Maintenance Manual 2. Damage Tolerance Based Structural Inspections: Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the Maintenance Program. This service bulletin affects FCS. DTI requirements for the structure affected are contained in Paragraph 1.E., Compliance of this service bulletin. Repairs accomplished on cam latch(es) in accordance with CMM 52-32-03 are structurally acceptable as Category A repairs as defined in 757-200 SRM 51-00-06, 757-200CB SRM 51-00-06 and 757-200PF SRM 51-00-06, therefore no supplemental inspections to the mandated damage tolerance inspections contained in Paragraph 1.E., Compliance, Table 2, of this service bulletin, are required. **L. Interchangeability and Intermixability of Parts** Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts. **M. Software Accomplishment Summary**
Not affected.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 27 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 28 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT**

BLANK PAGE**2. MATERIAL INFORMATION A. Material - Price and Availability**  The operator can supply the parts and materials shown in Paragraph 2.C., Parts Necessary for Each Airplane. As an alternative, operators can purchase the parts from Boeing Spares. This service bulletin does not show the Boeing price and supply data. **B. Industry Support Information** Boeing warranty remedies are not available for the inspections and modifications given in this service bulletin. **C. Parts Necessary for Each Airplane**
1. Kits/Parts
None. 2. Parts and Materials Supplied by the Operator
**Notes Existing Part Number**  **Name QTY**  **Part Number / Specification**  (a) (b) NAS6603-24 BOLT, HEX HEAD, 160 KSI MIN TENSILE, LONG THREAD, A286, NONLOCKING 8 BACB30LM3-24 OR BACB30LM3-22 OR BACB30NF3-22 (c) 69-23438-2 Cam Latch 1 1 69-23438-2 (c) 143N8060-1 Cam Latch 2 1 143N8060-1 (c) 143N8027-2 Cam Latch 3 1 143N8027-2 (c) 69-23439-3 Cam Latch 4 1 69-23439-3 (c) 69-23439-4 Cam Latch 5 1 69-23439-4 (c) 143N8027-1 Cam Latch 6 1 143N8027-1 (c) 143N8060-2 Cam Latch 7 1 143N8060-2 (c) 69-23438-1 Cam Latch 8 1 69-23438-1 (c) 6-83137-2 Latch Pin 8 6-83137-2 (a) Refer to 757 Structural Repair Manual Chapter 51 for alternate fasteners. (b) BACB30LM3-24 and NAS6603-24 used if 143N8157-2 Clip Assembly is installed. (c) Part numbers and quantities necessary are based on inspection findings.
**NOTE:** Rubber Quicksetting Putty (G50673) is needed if the door rigging procedure per 757 AMM 52-32-00 20Sep2008 Revision or later is used.
3. Parts Modified and Reidentified
None.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 29 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT**4. Parts Removed and Not Replaced
None. **D. Parts Necessary to Change Spares**
None. **E. Special Tooling - Price and Availability**
None. **F. Special Tooling Necessary to do this Service Bulletin** No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 30 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT 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 Values: — Values for structural fasteners are given in 757 Structural Repair Manual, Chapter 51. — Values for airframe maintenance tasks are included in Chapter 20 of 757 Airplane Maintenance Manual (AMM). — Non-standard torque values for maintenance tasks are included in the applicable installation step.

4. Use the approved fastener, process and 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. Clearance between fasteners and surrounding structures or mechanisms may be minimal by design at some locations. Use caution when adjusting grip length of fasteners and make sure no interference conditions exist after installation. Interference between moving parts may be difficult to detect. Complete full cycle of mechanisms to ensure no interference conditions exist. 7. 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.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 31 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT**8. A General Visual Inspection is defined as: A visual examination of an interior or exterior area, installation or assembly to detect obvious damage, failure or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight or drop-light and may require removal or opening of access panels or doors. Stands, ladders or platforms may be required to gain proximity to the area being checked. 9. 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. 10. 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. 11. 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. 12. Where the work instructions include installation of a kept part, a new or reworked part with the same part number can be installed as an alternative to the kept part. 13. Damage found on cam latch(es) within the reworkable limits of CMM 52-32-03 can be reworked in accordance with CMM 52-32-03.
14. A reworked cam latch is defined as a cam latch that has been reworked within the limits of CMM 52-32-03 and/or a Boeing ODA approved repair via FAA Form 8100-9 and has been HFEC or magnetic particle inspected, and has no crack(s) or gouge(s) in critical area(s). 15. Discrepancy is defined as: Any broken, cracked, missing or gouged cam latches or latch pins, broken or missing latch pin cross bolts, latch pin extension less than 0.89 inches or greater than 0.91 inches, or cam latch lip deformation.
**B. WORK INSTRUCTIONS** 1. Initial (Pre-Rig Check) Inspections a. Get access to the Main Cargo Door (MCD). b. Do a general visual inspection for any broken cam latches, latch pins and latch pin cross bolts and for any missing cam latches, latch pins and latch pin cross bolts in accordance with FIGURE 9 . c. Torque the cross bolts in the latch pins in accordance with FIGURE 2. d. Measure the extension of the latch pins in accordance with FIGURE 3.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 32 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT**e. Do a general visual inspection of all cam latches for lip deformation in accordance with FIGURE 1.
2. Condition 1: One or more of the following is found: – Broken or missing cam latch(es) – Broken or missing latch pin(s) – Broken or missing latch pin cross bolt(s) a. Replace broken or missing cam latch(es) in accordance with FIGURE 6, replace broken and missing latch pin(s) in accordance with FIGURE 7 and replace broken and missing latch pin cross bolt(s) in accordance with FIGURE 5. b. Do a detailed inspection of mating part(s) and immediately adjacent cam latches and latch pins for any cracks, or any gouges in critical areas in accordance with FIGURE 8. Do all applicable corrective actions as described in Condition 5. c. Unless replaced with new or reworked parts, do a HFEC or magnetic particle inspection of cam latch 1 and cam latch 2 for of cracks in critical areas in accordance with FIGURE 4. Do all applicable corrective actions as described in Condition 5. d. Check the rig of the Main Cargo Door in accordance with FIGURE 10 and FIGURE 11, and replace all alloy steel cross bolts through the latch pins with CRES cross bolts in accordance with FIGURE 5. If MCD is out of rig and cannot be adjusted in accordance with FIGURE 10 and FIGURE 11, rig the MCD. Refer to 757 AMM 52-32-00 Rev 20Sep2008 or later as an accepted procedure for MCD rigging.
3. Condition 2: The latch pin extension is less than 0.89 inches or greater than 0.91 inches: a. Replace the discrepant latch pin in accordance with FIGURE 7. b. Do a detailed inspection of the mating cam latch for any cracks, or gouges in critical areas in accordance with FIGURE 8. Do all applicable corrective actions as described in Condition 5. c. Do a general visual inspection for any broken cam latches, latch pins and latch pin cross bolts and for any missing cam latches, latch pins and latch pin cross bolts in accordance with FIGURE 9 . Do all applicable corrective actions as described in Condition 1. d. Do a detailed inspection of the latch pin(s) and mating cam latch(es) for any cracks, or any gouges in critical areas in accordance with FIGURE 1. Do all applicable corrective actions as described in Condition 5. e. Unless replaced with new or reworked parts, do a HFEC or magnetic particle inspection of cam latch 1 and cam latch 2 for any cracks in critical areas in accordance with FIGURE 4. Do all applicable corrective actions as described in Condition 5.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 33 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT**f. Check the rig of the Main Cargo Door in accordance with FIGURE 10 and FIGURE 11, and replace all alloy steel cross bolts through the latch pins with CRES cross bolts in accordance with FIGURE 5. If MCD is out of rig and cannot be adjusted in accordance with FIGURE 10 and FIGURE 11, rig the MCD. Refer to 757 AMM 52-32-00 Rev 20Sep2008 or later as an accepted procedure for MCD rigging.
**NOTE:** Rigging for the latch pin will require it to be installed properly with an extension of 0.90 +/- 0.01 inches. A latch pin with an original extension between 0.84 to 0.94 inches, with no cracks or gouges in critical areas and no other discrepancies may be re-used by clocking the latch pin 90 degrees +/- 10 degrees from original position and match drilling a new cross bolt hole that provides the correct latch pin extension. Fill old cross bolt hole in pin with BMS 5-95 sealant and install pin with BMS 3-27 corrosion inhibiting compound.
4. Condition 3: If a cam latch is found with lip deformation. a. Do a detailed inspection of the discrepant cam latch and mating latch pin for any cracks, or gouges in critical areas in accordance with FIGURE 1. Do all applicable corrective actions as described in Condition 5. b. Do a general visual inspection for any broken cam latches, latch pins and latch pin cross bolts and for any missing cam latches, latch pins and latch pin cross bolts in accordance with FIGURE 9. Do all applicable corrective actions as described in Condition 1. c. Do a detailed inspection of the latch pin(s) and mating cam latch(es) for any cracks, or any gouges in critical areas in accordance with FIGURE 1. Do all applicable corrective actions as described in Condition 5. d. Unless replaced with new or reworked parts, do a HFEC or magnetic particle inspection of cam latch 1 and cam latch 2 for any cracks in critical areas in accordance with FIGURE 4. Do all applicable corrective actions as described in Condition 5. e. Check the rig of the Main Cargo Door in accordance with FIGURE 10 and FIGURE 11, and replace all alloy steel cross bolts through the latch pins with CRES cross bolts in accordance with FIGURE 5. If MCD is out of rig and cannot be adjusted in accordance with FIGURE 10 and FIGURE 11, rig the MCD. Refer to 757 AMM 52-32-00 Rev 20Sep2008 or later as an accepted procedure for MCD rigging.
5. Condition 4: No discrepancies found: a. Do a general visual inspection for any broken and missing cam latches, latch pins and latch pin cross bolts in accordance with FIGURE 9. Do all applicable corrective actions as described in Condition 1. b. Do a detailed inspection of the cam latches and latch pins for any cracks, or any gouges in critical areas in accordance with FIGURE 1. Do all applicable corrective actions as described in Condition 5.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 34 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT**c. Unless replaced with new or reworked parts, do a HFEC or magnetic particle inspection of cam latch 1 and cam latch 2 for any cracks in critical areas in accordance with FIGURE 4. Do all applicable corrective actions as described in Condition 5. d. Check the rig of the Main Cargo Door in accordance with FIGURE 10 and FIGURE 11, and replace all alloy steel cross bolts through the latch pins with CRES cross bolts in accordance with FIGURE 5. If MCD is out of rig and cannot be adjusted in accordance with FIGURE 10 and FIGURE 11, rig the MCD. Refer to 757 AMM 52-32-00 Rev 20Sep2008 or later as an accepted procedure for MCD rigging.
6. Condition 5: If the detailed, HFEC or magnetic particle inspections in Conditions 1 thru 4 reveal any of the following: – Cracked or gouged cam latch(es) in critical areas. – Cracked or gouged latch pin(s) in critical areas. a. Replace cracked or gouged cam latch(es) in accordance with FIGURE 6, replace cracked or gouged latch pin(s) in accordance with FIGURE 7. b. Do a detailed inspection of mating part(s) and immediately adjacent cam latches and latch pins for any cracks or any gouges in critical areas in accordance with FIGURE 8. Do all applicable corrective actions as described in Condition 5. c. Unless replaced with new or reworked parts, do a HFEC or magnetic particle inspection of cam latch 1 and cam latch 2 for any cracks in critical areas in accordance with FIGURE 4. Do all applicable corrective actions as described in Condition 5. d. Check the rig of the MCD in accordance with FIGURE 10 and FIGURE 11 and replace all alloy steel cross bolts with CRES cross bolts in accordance with FIGURE 5. If MCD is out of rig and cannot be adjusted in accordance with FIGURE 10 and FIGURE 11, rig the MCD. Refer to 757 AMM 52-32-00 Rev 20Sep2008 or later as an accepted procedure for MCD rigging. 7. Post Rig Check Repetitive Inspections.
a. Condition 6: Airplanes that have accomplished all Table 1 requirements identified in Paragraph 1.E., Compliance, including rigging of the main cargo door in accordance with the original issue or revision 1 of this service bulletin and no rigging adjustment of any latch pin or any latch pin fitting was required, and during previous pre-rig check inspections there were no discrepancies found: (1) Do a general visual inspection for any broken or missing cam latches, latch pins and latch pin Cross Bolt in accordance with FIGURE 9. (2) Do a detailed inspection of the cam latches and latch pins for any cracks or any gouges in critical areas in accordance with FIGURE 1. (3) Do a HFEC or magnetic particle inspection of cam latch 1 and cam latch 2 for any cracks in critical areas in accordance with FIGURE 4.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 35 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT**(4) If any discrepancy is found during the Condition 6 inspections, contact The Boeing Company for repair instructions and do the repair. 8. Post Rig Check Repetitive Inspections.
a. Condition 7: Airplanes that have accomplished all Table 1 requirements identified in Paragraph 1.E., Compliance, including rigging of the main cargo door in accordance with the original issue or revision 1 of this service bulletin and rigging adjustment of any latch pin or any latch pin fitting was required, or during previous pre-rig check inspections there were any discrepancies found. (1) Do a general visual inspection for any broken or missing cam latches, latch pins and latch pin cross bolts in accordance with FIGURE 9. (2) Do a detailed inspection of the cam latches and latch pins for any cracks or any gouges in critical areas in accordance with FIGURE 1. (3) Do a HFEC or magnetic particle inspection of cam latch 1 and cam latch 2 for any cracks in critical areas in accordance with FIGURE 4. (4) If any discrepancy is found during the Condition 7 inspections, contact The Boeing Company for repair instructions and do the repair. 9. Put the airplane back to a serviceable condition.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1: December 19, 2014 36 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT FIGURE 1: MAIN CARGO DOOR - CAM LATCHES AND LATCH PINS INSPECTION**  **(SHEET 1 OF 3)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 37 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT FIGURE 1: MAIN CARGO DOOR - CAM LATCHES AND LATCH PINS INSPECTION**  **(SHEET 2 OF 3)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 38 of 62 **BOEING SERVICE BULLETIN 757-52A0091 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 this figure.
**More Data Qty**  **Identification Name**  **Task Step**  Detailed inspection of the cam latch.(a) (b) 1 69-23438-2 Cam Latch 1 Inspect 1

Detailed inspection of the cam latch.(a) (b) 1 143N8060-1 Cam Latch 2 Inspect 2

Detailed inspection of the cam latch.(a) (b) 1 143N8027-2 Cam Latch 3 Inspect 3

Detailed inspection of the cam latch.(a) (b) 1 69-23439-3 Cam Latch 4 Inspect 4

Detailed inspection of the cam latch.(a) (b) 1 69-23439-4 Cam Latch 5 Inspect 5

Detailed inspection of the cam latch.(a) (b) 1 143N8027-1 Cam Latch 6 Inspect 6

Detailed inspection of the cam latch.(a) (b) 1 143N8060-2 Cam Latch 7 Inspect 7

Detailed inspection of the cam latch.(a) (b) 1 69-23438-1 Cam Latch 8 Inspect 8

Detailed inspection of the latch pin.(a) 8 6-83137-2 Latch Pin Inspect 9
(a) Look for cracks or gouges in critical areas. (b) Do a general visual inspection for lip deformation.

**FIGURE 1: MAIN CARGO DOOR - CAM LATCHES AND LATCH PINS INSPECTION (SHEET 3 OF 3)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 39 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT FIGURE 2: MAIN CARGO DOOR - LATCH PIN CROSS BOLT TORQUE**  **(SHEET 1 OF 2)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 40 of 62 **BOEING SERVICE BULLETIN 757-52A0091 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 this figure.
**More Data Qty**  **Identification Name**  **Task Step**  (a) 8

- Cross Bolt Torque 1 (a) Make sure the latch pin cross bolt is capable of reaching a 15 pound-inch, +/- 1 pound-inch, torque from the head side of the bolt and also the nut side if no nutplate is used. The 15 pound-inch, +/- 1 pound-inch, torque value is approximately one-half of the installation torque and is used to give an indication of a broken cross bolt.

**FIGURE 2: MAIN CARGO DOOR - LATCH PIN CROSS BOLT TORQUE (SHEET 2 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 41 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT FIGURE 3: MAIN CARGO DOOR - LATCH PIN EXTENSION MEASUREMENT**  **(SHEET 1 OF 2)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 42 of 62 **BOEING SERVICE BULLETIN 757-52A0091 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 this figure.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  Make sure the latch pin extends out 0.90 inch +/- 0.01 inch from the wear plate. 8 6-83137-2 Latch Pin Measure 1

**FIGURE 3: MAIN CARGO DOOR - LATCH PIN EXTENSION MEASUREMENT (SHEET 2 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 43 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT FIGURE 4: MAIN CARGO DOOR - CAM LATCH 1 AND CAM LATCH 2 INSPECTION**  **(SHEET 1 OF 2)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 44 of 62 **BOEING SERVICE BULLETIN 757-52A0091 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 this figure.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  1 69-23438-2 Cam Latch 1 Remove / Keep 1 1 143N8060-1 Cam Latch 2 Remove / Keep 2 Do a HFEC inspection of cam latch 1 for cracks in accordance with 757 NDT Part 6, 51-00-12 or 51-00-21.(a) (b) (c) 1 69-23438-2 Cam Latch 1 Inspect 3

Do a HFEC inspection of cam latch 2 for cracks in accordance with 757 NDT Part 6, 51-00-12 or 51-00-21.(a) (b) (c) 1 143N8060-1 Cam Latch 2 Inspect

1 69-23438-2 Cam Latch 1 Install (Kept) 4 1 143N8060-1 Cam Latch 2 Install (Kept) 5 (a) Use a 0.080 inch diameter or smaller HFEC probe. Set the HFEC instrument to operate between 50 KHzand 75 KHz. If HFEC method indicates a crack, confirm the crack indication using magnetic particle inspection. Refer to SOPM 20-20-01 as an accepted procedure. (b) An optional magnetic particle inspection can be used. Refer to SOPM 20-20-01 as an accepted procedure. (c) HFEC crack indications can be confirmed using the magnetic particle inspection. If crack indications are found with HFEC and could not be confirmed with magnetic particle inspection, the HFEC crack indication is a non relevant indication due to chrome cracking.

**FIGURE 4: MAIN CARGO DOOR - CAM LATCH 1 AND CAM LATCH 2 INSPECTION (SHEET 2 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 45 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT FIGURE 5: MAIN CARGO DOOR - LATCH PIN CROSS BOLT REPLACEMENT**  **(SHEET 1 OF 2)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 46 of 62 **BOEING SERVICE BULLETIN 757-52A0091 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 this figure.
**More Data Qty**  **Identification Name**  **Task Step** 

- 8 NAS6603-24(BACB30NF3-22 optional) Latch Pin Cross Bolt Remove 1

Install with BMS 3-27 corrosion inhibiting material 8 BACB30LM3-24(BACB30LM3-22 optional) Latch Pin Cross Bolt Install (New) 2

**FIGURE 5: MAIN CARGO DOOR - LATCH PIN CROSS BOLT REPLACEMENT (SHEET 2 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 47 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT FIGURE 6: MAIN CARGO DOOR - CAM LATCH REPLACEMENT**  **(SHEET 1 OF 3)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 48 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT FIGURE 6: MAIN CARGO DOOR - CAM LATCH REPLACEMENT**  **(SHEET 2 OF 3)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 49 of 62 **BOEING SERVICE BULLETIN 757-52A0091 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 this figure.
**More Data Qty**  **Identification Name**  **Task Step**  (a) 1 69-23438-2 Cam Latch 1 Remove 1 (a) 1 143N8060-1 Cam Latch 2 Remove (a) 1 143N8027-2 Cam Latch 3 Remove (a) Gusset must beremoved to allow removal of cam latch number 4. 1 69-23439-3 Cam Latch 4 Remove

(a) 1 69-23439-4 Cam Latch 5 Remove (a) 1 143N8027-1 Cam Latch 6 Remove (a) 1 143N8060-2 Cam Latch 7 Remove (a) 1 69-23438-1 Cam Latch 8 Remove (a) (b) (d) 1 69-23438-2 Cam Latch 1 Install (New) 2 (a) (b) (c) (d) 1 143N8060-1 Cam Latch 2 Install (New) (a) (b) (d) 1 143N8027-2 Cam Latch 3 Install (New) (a) (b) (d) Gusset must be removed to allow installation of cam latch number 4. 1 69-23439-3 Cam Latch 4 Install (New)

(a) (b) (d) 1 69-23439-4 Cam Latch 5 Install (New) (a) (b) (d) 1 143N8027-1 Cam Latch 6 Install (New) (a) (b) (c) (d) 1 143N8060-2 Cam Latch 7 Install (New) (a) (b) (d) 1 69-23438-1 Cam Latch 8 Install (New) (a) Part numbers and quantities necessary are based on inspection findings.(b) Use the original removed cam latch as a pattern/template to locate new cross bolt holes. Match hole angularity from existing cam latch. (c) Cam latch number 2 and cam latch number 7 only have two cross bolt holes. (d) It is acceptable to install a reworked Cam Latch with the same part number instead of a new part.

**FIGURE 6: MAIN CARGO DOOR - CAM LATCH REPLACEMENT (SHEET 3 OF 3)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 50 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT FIGURE 7: MAIN CARGO DOOR - LATCH PIN REPLACEMENT**  **(SHEET 1 OF 2)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 51 of 62 **BOEING SERVICE BULLETIN 757-52A0091 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 this figure.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP** 

- - 6-83137-2 Latch Pin Remove 1 Install latch pin wet with BMS 3-27 corrosion inhibiting material on faying surfaces. Make sure the latch pin extends out 0.90 inch +/- 0.01 inch from the wear plate. - 6-83137-2 Latch Pin Install (New) 2

**FIGURE 7: MAIN CARGO DOOR - LATCH PIN REPLACEMENT (SHEET 2 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 52 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT FIGURE 8: MAIN CARGO DOOR - CAM LATCH REMOVAL AND INSPECTION**  **(SHEET 1 OF 3)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 53 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT FIGURE 8: MAIN CARGO DOOR - CAM LATCH REMOVAL AND INSPECTION**  **(SHEET 2 OF 3)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 54 of 62 **BOEING SERVICE BULLETIN 757-52A0091 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 this figure.
**More Data Qty**  **Identification Name**  **Task Step**  (a) (b) 1 69-23438-2 Cam Latch 1 Remove / Keep 1 (a) (b) 1 143N8060-1 Cam Latch 2 Remove / Keep (a) (b) 1 143N8027-2 Cam Latch 3 Remove / Keep (a) (b) (c) 1 69-23439-3 Cam Latch 4 Remove / Keep (a) (b) 1 69-23439-4 Cam Latch 5 Remove / Keep (a) (b) 1 143N8027-1 Cam Latch 6 Remove / Keep (a) (b) 1 143N8060-2 Cam Latch 7 Remove / Keep (a) (b) 1 69-23438-1 Cam Latch 8 Remove / Keep Detailed inspection of the cam latch for cracks or gouges in critical areas. (d) - - Cam Latch Inspect 2

(a) (b) (e) 1 69-23438-2 Cam Latch 1 Install (Kept) 3 (a) (b) (e) 1 143N8060-1 Cam Latch 2 Install (Kept) (a) (b) (e) 1 143N8027-2 Cam Latch 3 Install (Kept) (a) (b) (e) 1 69-23439-3 Cam Latch 4 Install (Kept) (a) (b) (e) 1 69-23439-4 Cam Latch 5 Install (Kept) (a) (b) (e) 1 143N8027-1 Cam Latch 6 Install (Kept) (a) (b) (e) 1 143N8060-2 Cam Latch 7 Install (Kept) (a) (b) (e) 1 69-23438-1 Cam Latch 8 Install (Kept) Detailed inspection of the latch pin for cracks or gouges in critical areas. 8 6-83137-2 Latch Pin Inspect 4

(a) It is important to identify the Cam Latch part locations to ensure the parts are re-installed in correct locations. Cam latches installed incorrectly may seriously compromise proper door operation. (b) Part numbers and quantities necessary are based on inspection findings. (c) Gusset must be removed to allow removal of cam latch number 4. (d) Only inspect removed cam latch(es). (e) Do not install kept cam latch if cracked or gouged in critical areas.

**FIGURE 8: MAIN CARGO DOOR - CAM LATCH REMOVAL AND INSPECTION (SHEET 3 OF 3)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 55 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT FIGURE 9: MAIN CARGO DOOR - CAM LATCHES, LATCH PINS AND LATCH PIN CROSS BOLTS**  **INSPECTION (SHEET 1 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 56 of 62 **BOEING SERVICE BULLETIN 757-52A0091 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 this figure.
**More Data Qty**  **Identification Name**  **Task Step**  General visual inspection of the cam latch.(a) 1 69-23438-2 Cam Latch 1 Inspect 1

General visual inspection of the cam latch.(a) 1 143N8060-1 Cam Latch 2 Inspect

General visual inspection of the cam latch.(a) 1 143N8027-2 Cam Latch 3 Inspect

General visual inspection of the cam latch.(a) 1 69-23439-3 Cam Latch 4 Inspect

General visual inspection of the cam latch.(a) 1 69-23439-4 Cam Latch 5 Inspect

General visual inspection of the cam latch.(a) 1 143N8027-1 Cam Latch 6 Inspect

General visual inspection of the cam latch.(a) 1 143N8060-2 Cam Latch 7 Inspect

General visual inspection of the cam latch.(a) 1 69-23438-1 Cam Latch 8 Inspect

General visual inspection of the latch pins.(a) 8 6-83137-2 Latch Pin Inspect 2

General visual inspection of the latch pin cross bolts.(a) 8

- Cross Bolt Inspect 3

(a) Inspect for broken parts. Also inspect for missing parts.

**FIGURE 9: MAIN CARGO DOOR - CAM LATCHES, LATCH PINS AND LATCH PIN CROSS BOLTS INSPECTION**  **(SHEET 2 OF 2)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 57 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT FIGURE 10: MAIN CARGO DOOR - CAM LATCH AND LATCH PIN RIGGING**  **(SHEET 1 OF 3)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 58 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT FIGURE 10: MAIN CARGO DOOR - CAM LATCH AND LATCH PIN RIGGING**  **(SHEET 2 OF 3)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 59 of 62 **BOEING SERVICE BULLETIN 757-52A0091 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 this figure.
**More Data Qty**  **Identification Name**  **Task Step**  (a) (b) 8

- Cam Latch Measure 1 (a) (b) 8 6-83137-2 Latch Pin Measure (c) 8

- Latch Pin Fitting Measure (a) During rigging procedure the latch pin is not to contact the cam latch in any direction. (b) Wrap a single layer of 0.002 inch thick shim stock around latch pins 1 and 8. Use thin tape to keep shim in place. With latch pins 1 and 8 engaging their respective cam latches, and with latch pins 2 through 7 not contacting their respective cam latches in any direction, adjust if required, latch pin fittings 2 through 7 such that latch pins 2 through 7 axial centerlines and their respective cam latch axial centerlines are within the tolerance shown. (c) Adjust latch pin fittings by moving fitting on serrations and by adjusting shim thickness. On the two forward and two aft cam latches the Latch Pin Fitting/Cam Latch gap is 0.14 +/- 0.01 inch. On the four center cam latches the Latch Pin Fitting/Cam Latch gap is 0.08 +/- 0.01 inch. Make sure the maximum allowed shim thickness of 0.20 inch is not exceeded.

**FIGURE 10: MAIN CARGO DOOR - CAM LATCH AND LATCH PIN RIGGING (SHEET 3 OF 3)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 60 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT FIGURE 11: MAIN CARGO DOOR - MAIN CARGO DOOR EDGE FLUSHNESS MEASUREMENT**  **(SHEET 1 OF 2)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 61 of 62 **BOEING SERVICE BULLETIN 757-52A0091 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 this figure.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  Hold scale 90 degrees to door edge. Make sure the MCD lower edge and lower corner flushness are within the tolerance shown. - - Main Cargo Door Measure 1

**FIGURE 11: MAIN CARGO DOOR - MAIN CARGO DOOR EDGE FLUSHNESS MEASUREMENT (SHEET 2 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 09, 2010 757-52A0091 Revision 1 December 19, 2014 62 of 62 **BOEING SERVICE BULLETIN 757-52A0091 ALERT**  **ALERT**