Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 1 of 230 ALERT ALERT 

### Commercial **Airplanes** 

# 747

**ALERT ALERT**  

# Service Bulletin

**Number: 747-53A2502** Original Issue: April 21, 2005 Revision 1: June 17, 2010 ATA System: 5300 **SUBJECT:** FUSELAGE - Non Stretched Upper Deck Tension Ties and Frames - Inspection and Repair. 

## BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2005 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter.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.**BLANK PAGE** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 2 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BLANK PAGE**Table of Contents** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 3 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT Table of Contents**  Revision Transmittal Sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1. PLANNING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 A. Effectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 1. Airplanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 2. Data supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . 38 3. Installation Drawings Used in the Preparation of this Service Bulletin: . . . . . . . . . . 39 K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . 40 2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 C. Parts Necessary For Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 1. Kits/Parts: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 2. Parts and Materials Supplied by the Operator: . . . . . . . . . . . . . . . . . . . . . . 42 3. Parts Modified and Reidentified: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 4. Parts Removed and Not Replaced: . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . 42 3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 FIGURE 1: INSPECTION - Group 1, Configuration 1 . . . . . . . . . . . . . . . . . . . . . . . . . . 64 FIGURE 2: OVERSIZED HOLE REPAIR - Group 1, Configuration 1 . . . . . . . . . . . . . . . . . . 73 FIGURE 3: INSPECTION - Group 1, Configuration 2 . . . . . . . . . . . . . . . . . . . . . . . . . . 80 FIGURE 4: OVERSIZED HOLE REPAIR - Group 1, Configuration 2 . . . . . . . . . . . . . . . . . . 90 FIGURE 5: INSPECTION - Group 1, Configuration 3 . . . . . . . . . . . . . . . . . . . . . . . . . . 99 FIGURE 6: OVERSIZED HOLE REPAIR - Group 1, Configuration 3 . . . . . . . . . . . . . . . . . . 107 FIGURE 7: INSPECTION - Group 1, Configuration 4 . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4 FIGURE 8: OVERSIZE HOLE REPAIR - Group 1, Configuration 4 . . . . . . . . . . . . . . . . . . . 122 FIGURE 9: ACCESS - Group 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 FIGURE 10: INSPECTION - Group 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 FIGURE 11: OVERSIZED HOLE REPAIR - Group 2 . . . . . . . . . . . . . . . . . . . . . . . . . . 136**Table of Contents** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 4 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** FIGURE 12: CLOSE ACCESS - Group 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 FIGURE 13: INSPECTION - Group 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 FIGURE 14: OVERSIZED HOLE REPAIR - Group 3. . . . . . . . . . . . . . . . . . . . . . . . . . 149 FIGURE 15: INSPECTION - Group 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 FIGURE 16: OVERSIZED HOLE REPAIR - Group 4. . . . . . . . . . . . . . . . . . . . . . . . . . 163 FIGURE 17: INSPECTION - Group 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 FIGURE 18: OVERSIZE HOLE REPAIR - Group 5 . . . . . . . . . . . . . . . . . . . . . . . . . . 179 FIGURE 19: INSPECTION - Group 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 FIGURE 20: OVERSIZE HOLE REPAIR - Group 6 . . . . . . . . . . . . . . . . . . . . . . . . . . 194 FIGURE 21: HFEC INSPECTION OF HOLES FOR INSULATION BLANKET STUDS . . . . . . . . 201 FIGURE 22: ONE-TIME INSPECTION FOR CORRECT CONFIGURATION - Group 2 . . . . . . . . 204 FIGURE 23: ADDITIONAL INSPECTION OF INCORRECT CONFIGURATION - Group 2 . . . . . . 218 APPENDIX A: DELETED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 APPENDIX B: TENSION TIE DISCONNECTION METHODS . . . . . . . . . . . . . . . . . . . . . 224 APPENDIX C: GENERAL ILLUSTRATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 5 of 230 ALERT ALERT 

### Commercial **Airplanes** 

# 747

**ALERT ALERT**  

# Service Bulletin

**Number: 747-53A2502** 

### Revision Transmittal Sheet Original Issue: April 21, 2005 Revision 1: June 17, 2010 ATA System: 5300 **SUBJECT:** FUSELAGE - Non Stretched Upper Deck Tension Ties and Frames - Inspection and Repair.
This Revision includes all pages of the service bulletin. **COMPLIANCE INFORMATION RELATED TO THIS REVISION** Group 2: More work is necessary on airplanes changed as shown in the original issue of this service bulletin. After additional analysis of the tension tie structure, Boeing has determined that the initial inspection of tension ties at STA 720, STA 740, and STA 760 should be done at an earlier time. The new compliance time for the initial inspection is given in paragraph 1.E., Compliance. In addition, a new one-time inspection (and corrective action, as necessary) has been added to ensure the configuration of all tension ties on Group 2 airplanes is in accordance with production engineering configuration. Group 1, 3-6: No more work is necessary on airplanes changed as shown in the original issue of this service bulletin. However, all previously released actions given in this service bulletin have been upgraded from "Special Attention" status to "Alert" status based on the current criteria for determination of airplane safety related issues. Federal Aviation Administration (FAA) Airworthiness Directive 84-19-01, is related to this service bulletin. Federal Aviation Administration (FAA) Airworthiness Directive 94-13-06, is related to this service bulletin. Federal Aviation Administration (FAA) Airworthiness Directive 2004-07-22 R1, is related to this service bulletin. Federal Aviation Administration (FAA) Airworthiness Directive 2006-01-07, is related to this service bulletin. **REASON FOR REVISION** This revision is sent to reduce the initial inspection compliance time for Group 2 airplanes at STA 720, STA 740, and STA 760 and to add an inspection to ensure the correct tension tie configurations on Group 2 airplanes. Other changes have also been made in Revision 1. Terminology has been changed in the Work Instruction to agree with the terminology defined in Paragraph 3.A., General Information - Notes. These sections were changed: — In Summary: Updated to reflect current information and requirements.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 6 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** — In paragraph 1.C., Reason: Updated to reflect current information and requirements. — In paragraph 1.D., Description: Clarified description of existing work, and added description of new requirements for Group 2 airplanes. — In paragraph 1.E., Compliance: Revised compliance information for existing inspection requirements for Group 2 airplanes. Added Table 4 for compliance information related to new inspections. Updated Airworthiness Directive references. — In paragraph 1.F., Approval: Updated approval paragraph and existing AMOC statements. Added AMOC statement for AD 2006-01-07. — In paragraph 1.G., Manpower: Revised notes in some tables. Added table for new inspection requirements. — In paragraph 1.J., References: Has been updated. — In paragraph 1.K., Publications Affected: Added Damage Tolerance Inspection statement. — In paragraph 2.A., Material - Price and Availability: Added tension tie segment and tension tie splice channel. — In paragraph 2.B., Industry Support Information: Added warranty statement for the new one-time inspection and corrective actions for 747-400F airplanes. — In paragraph 2.C., Parts Necessary For Each Airplane: Added tension tie segment and tension tie splice channel. — In paragraph 3.A., General Information: Updated, clarified, and corrected existing notes. Added notes 22, 23, and 24. — In paragraph 3.B., Work Instructions: Added one-time inspection for correct configuration (Revision 1 - more work). Updated AMM references in ACCESS and RESTORATION section. Added SRM references for tension tie repairs and frame repairs. Also, clarified and/or removed redundant steps throughout this section. Changes to this section have resulted in re-sequencing and/or re-numbering of some steps. — In Figures 1, 3, 5, 7, 10, 13, 15, 17, and 19: Clarified notes (e) and (g), corrected note (d) step number reference in some inspection figures, and corrected and/or revised some view section arrows and view callouts. Also, added inspection requirement for aluminum channel at STA 940, which was previously in the Work Instructions. — In Figures 10, 11, 13, and 14: Corrected SRM references. — Figure 22: This new figure has been added for one-time inspection for correct tension tie configuration on 747-400F airplanes (Group 2 only). — Figure 23: This new figure has been added to give additional inspection requirements if an incorrect tension tie configuration is found (Group 2 only). — Appendix A: The Appendix has been deleted. In the original issue of this service bulletin, Appendix A was a logic diagram of inspection requirements. Logic diagrams are no longer maintained to match current compliance information. — Appendix B: Deleted Method 2 and 4 for disconnecting tension ties. Method 2 and 4, that were specified in the original issue, are no longer recommended. The data given in Information Notice 747-53-2502 IN 01 is included in this revision Paragraph 1.A., Effectivity, shows changes of airplane operators. Each operator should examine the Effectivity paragraph for changes. Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity, to show the location of important changes. Pages with no vertical lines have no important changes.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 7 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT REVISION HISTORY**  Original Issue: April 21, 2005 Revision 1:Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 8 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BLANK PAGEOriginal Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 9 of 230 ALERT ALERT 

### Commercial **Airplanes** 

# 747

**ALERT ALERT**  

# Service Bulletin

**Number: 747-53A2502** 

### Summary Original Issue: April 21, 2005 Revision 1: June 17, 2010 ATA System: 5300 **SUBJECT:** FUSELAGE - Non Stretched Upper Deck Tension Ties and Frames - Inspection and Repair.

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 work given in this service bulletin will make sure the tension ties and frames aft of the upper deck floor are not cracked. Cracks in tension ties and/or frames could cause the tension ties to become severed or disconnected from the frames. Severed or disconnected tension ties and/or frames at multiple locations could result in rapid in-flight decompression. Tension ties are installed to connect the left and right hand sides of the body structure aft of the upper deck floor. During routine maintenance of a 747-200F airplane one operator reported a crack in the tension tie, at the body station (STA) 820 frame connection. The crack was found to be 1/8 inch at a fastener hole. Inspection of the 747SR fatigue test airplane showed similar cracks in both the tension ties and frames at the tension tie to frame connections. The cracks were found at STA 800, 820, and 840 at 40,000 flight cycles (20,000 operating cycles, 20,000 test cycles). Cracks in the frames were up to 1.25 inches long, and cracks in the tension ties were up to 0.20 inches long. Revision 1: Subsequent to the release of the original issue of this service bulletin, an operator reported finding a total of twelve cracks on forward and aft tension tie channels at STA 740 and STA 760 on a 747-400F airplane. After comparing the structure to the Boeing design configuration, it was determined that only seven fasteners were installed common to the frame at each end of the STA 760 tension tie. A quantity of nine fasteners should have been installed common to the frame at each end of the tension tie. Revision 1: After investigation, it has been determined that the airplane on which the discrepancy was found was manufactured and delivered by Boeing with the incorrect tension tie configuration at STA 760. Reduced load carrying capability of the STA 760 tension tie, due to cracks, subsequently lead to increased loads and premature fatigue cracks in the adjacent tension tie at STA 740.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 10 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** Revision 1: 747-200F airplanes and Boeing modified 747 Special Freighter airplanes have a unique tension tie configuration at STA 760, and only 747-400F airplanes have tension ties at STA 720 and STA 740. Therefore, only 747-400F airplanes are affected by the new inspection for correct configuration which was added in Revision 1. Revision 1: In addition, due to new analysis of the tension tie structure, Boeing has determined that stresses are higher in the STA 720, STA 740, and STA 760 tension ties on 747-400F airplanes. Therefore, even if the tension tie configurations are correct, the detailed and high frequency eddy current (HFEC) inspections given in this service bulletin should begin at an earlier time. This has resulted in a reduced flight cycle compliance time for the initial inspection threshold at STA 720, STA 740, and STA 760 tension ties on 747-400F airplanes. This service bulletin provides instructions for inspections and repair of the tension ties and frames aft of the upper deck floor. The tension ties and frames have been found to be structually significant in that it is critical to the structual integrity of the airplane. tension tie and frame cracks not found before they reach critical crack lengths can cause in-flight depressurization. If the work given in this service bulletin is not done the airplane structure may not be able to withstand current regulatory fail-safe loads. Boeing Service Related Problem (SRP) 747OP-SRP-53-0200 is related to this service bulletin. Boeing Service Related Problem (SRP) 747-SRP-53-0349 is related to this service bulletin. Boeing Fleet Team Digest (FTD) article 747-FTD-53-09008 is related to this service bulletin. Modification Service Bulletin 747-53A2605 has been released to address Widespread Fatigue Damage (WFD) in the tension ties and adjacent frame structure. Accomplishment of the modification in accordance with Service Bulletin 747-53A2605 will terminate the repeat inspection requirements of this service bulletin. **ACTION** (PRR 85901-46RS) Group 1, 3-6: Get access to all tension ties. Do detailed and HFEC inspections for cracks in all tension ties, adjacent frame structure, and adjacent structure that attaches to the tension ties. If any crack is found, repair as specified in this service bulletin, before further flight. Repeat inspections at the specified intervals. Group 2: Do detailed and HFEC inspections for cracks in the tension ties and adjacent structure. If cracks are found, do the repair given in this service bulletin before further flight. Repeat inspections at the specified intervals. In addition, do a one-time general visual inspection at each tension tie location to determine if the correct design configuration is installed. At any tension tie where the correct configuration is not installed, do detailed and open hole HFEC inspections for cracks in the tension tie channels where they attach to the side of body frames. If no crack is found, install the correct tension tie configuration. If any crack is found, repair the tension tie in accordance with this service bulletin, or contact Boeing for repair instructions. All actions specified in this section should be done at the times given in paragraph 1.E., Compliance. This service bulletin contains only a flight safety inspection program. The flight safety inspection program is the minimum inspection program to maintain the structural integrity of the affected area of the airplane. An optional economics based inspection, to be done earlier than the flight safety inspection, would usually be included in this type of bulletin. However, for this area there is no economics based inspection program. The repair necessary when a crack is found in the flight safety inspection is the same as the repair necessary if a crack is found earlier.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 11 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT EFFECTIVITY**  747-100, 747-100B, 747-200B, 747-200C, 747-200F, 747-400F, 747SP, and 747SR airplanes. Refer to paragraph 1.A.1., Airplanes, for the list of affected airplanes. **COMPLIANCE** Refer to paragraph 1.E., Compliance. Federal Aviation Administration (FAA) Airworthiness Directive AD 84-19-01 is related to this service bulletin. Federal Aviation Administration (FAA) Airworthiness Directive AD 94-13-06 is related to this service bulletin. Federal Aviation Administration (FAA) Airworthiness Directive AD 2004-07-22 R1 is related to this service bulletin. Federal Aviation Administration (FAA) Airworthiness Directive AD 2006-01-07 is related to this service bulletin. The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. **INDUSTRY SUPPORT INFORMATION** Boeing warranty remedies are not available for the inspection or repair procedures given in this service bulletin, except for the one-time inspection and corrective actions related to inspection for incorrect configurations on 747-400F airplanes. Please refer to Paragraph 2.B., Industry Support Information section of this service bulletin for more information. **MANPOWER** Refer to Paragraph 1.G., Manpower. **MATERIAL INFORMATION** Operator Supplied Parts/Materials. Refer to Paragraph 2.A., Material - Price and Availability.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 12 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

FRAME (TYPICAL)

TENSION TIE (TYPICAL)

HORIZONTAL SHEAR WEB (TYPICAL BOTH SIDES) SLOPING SHEAR WEB (TYPICAL BOTH SIDES) INSPECT TENSION TIES, FRAMES, AND ADJACENT STRUCTURE FOR FATIGUE CRACKS. ON 747-400F AIRPLANES, ALSO DO A ONETIME INSPECTION TO ENSURE CORRECT TENSION TIE CONFIGURATIONS. DO REPAIRS AND/OR INSTALL THE CORRECT CONFIGURATIONS, AS NECESSARY. FWD359685Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 13 of 230 ALERT ALERT 

### Commercial **Airplanes** 

# 747

**ALERT ALERT**  

# Service Bulletin

**Number: 747-53A2502** Original Issue: April 21, 2005 Revision 1: June 17, 2010 ATA System: 5300 **SUBJECT:** FUSELAGE - Non Stretched Upper Deck Tension Ties and Frames - Inspection and Repair.

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 This service bulletin is for the airplanes shown below. Refer to PRR 85901-46RS for data about this change.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 14 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** Refer to Service Bulletin Index Document D6-30300 Part 3 for Airplane Variable Number, Line Number, and Serial Number data.

Airplane models: 747-100 747-100B 747-200B 747-200C 747-200F 747-400F 747SP 747SR IDENTIFICATION BY CUSTOMER, CUSTOMER CODE, GROUP AND VARIABLE NUMBER 3P AIR FREIGHTERS (PFL) 5 RR307 **GROUP CONFIGURATION DESCRIPTION** 1 - All 747-100, -100B, -200B, and 747SR airplanes, except airplanes that have been modified by Boeing to Special Freighter configuration. 1 Group 1 airplanes, line numbers 1 through 203, that have not had a long steel plate installed at STA 760 in accordance with Service Bulletin 747-53-2088. 2 Group 1 airplanes, line numbers 1 through 203 that have had a long steel plate installed at STA 760 in accordance with Service Bulletin 747-53- 2088. 3 Group 1 airplanes with Extended Upper Deck (EUD) modifications, or other modifications not listed elsewhere, that replaced the tension tie at STA 760 and/or STA 780 with a floor beam. 4 Group 1 airplanes, line numbers 203 and on, that had a long steel plate installed at STA 760 during production. 2 - All 747-400F airplanes. These airplanes have tension ties from STA 720 to STA 940. 3 - All 747-SP airplanes. These airplanes have tension ties from STA 1040 to STA 1140. 4 - 747-100, -200B, and 747SR airplanes that have been modified by Boeing to Special Freighter configuration. 5 - All 747-200F airplanes. These airplanes have tension ties from STA 760 to STA 940 and a long steel plate installed at STA 780. 6 - All 747-200C (convertible) airplanes. These airplanes have tension ties from STA 800 to STA 940, and have a long steel plate installed at STA 920.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 15 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** AAR AIRCRAFT SALES & LEASING (AFD) 1 RB681–RB682 RB691 AERO CONTROLS (AEO) 1 RA722–RA723 AEROLINEAS ARGENTINAS (ARG) 1 RD122–RD127 AFRICA UNITED HOLDING CO. (UHD) 1 RB010 RD513 AFX (AXL) 1 RD201 AGES AIRCRAFT SALES & LEASING (AGJ) 1 RB004 AIR ATLANTA ICELANDIC (AID) 1 RD414 RD647–RD648 RD755 RD771 2 RM861 5 RR204 AIR CHINA (BEJ) 1 RD783 5 RR451 AIR CHINA CARGO (CGC) 2 RL501–RL502 RR853 AIR CONTRACTORS LIMITED (HCA) 5 RR561 AIR FRANCE (AFA) 2 RL671 RL673–RL675 5 RR308–RR309 AIR INDIA (AIN) 1 RA729 RA731 AIR UNIVERSAL (UVL) 1 RD291 RD649 AIRBRIDGE CARGO (ABM) 2 RL576–RL577 RL579 RL672 5 RR555–RR556 ARKIA ISRAELI AIRLINES (ARK) 1 RA253 ASIANA AIRLINES (AAR) 2 RM862–RM863 RR746–RR747Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 16 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** ATLAS AIR (TLS) 1 RD692 RD753–RD754 2 RM892–RM893 RM895 RM897–RM899 RM901–RM904 RM906 RR748 4 RD361–RD364 RD366 RD641 RD646 RD691 5 RR301 6 RJ333 AVIATION EXPOSURE MANAGEMENT (EXU) 1 RD131–RD132 RD143 BAHRAIN ROYAL FLIGHT (BHR) 3 RH102 BALTIA AIR LINES (BLT) 1 RD004 BANC OF AMERICA LEASING (SBC) 1 RD001–RD002 BIMAN BANGLADESH AIRLINES (BNG) 1 RD260 BOEING (TBC) 5 RR222–RR223 BOEING AIRCRAFT HOLDING CO. (BHC) 1 RB693 RD181 RD451–RD454 6 RJ132 BOEING WICHITA MOD CENTER (WMC) 1 RD455 BULLFINCH LTD (BFN) 1 RB411–RB413 C.A.L. CARGO AIR LINES (CRG) 6 RJ331–RJ332 C.I.T. LEASING CORPORATION (TCI) 1 RB011 RD047 CAPITAL ASSET MANAGEMENT (CPG) 1 RD053 CARGAIR (CGL) 1 RD203 CARGOLUX AIRLINES (CLX) 2 RL551 RM881–RM890 RR722–RR724Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 17 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** CATHAY PACIFIC AIRWAYS (CAT) 2 RL581–RL586 RM856–RM859 RR951–RR952 CHINA AIRLINES (CHI) 2 RL411–RL412 RL414–RL430 RL481 CHINA CARGO (CIQ) 2 RL521–RL522 CHINA SOUTHERN AIRLINES (GUN) 2 RL751–RL752 DUBAI AIR WING (DAW) 2 RM852 4 RD622 EL AL ISRAEL AIRLINES (ELA) 5 RR225–RR226 ELITE AIRLINES S.A. (ETE) 4 RB696 EUREX AIRLINES (EXY) 5 RR552 EVA AIR (EVA) 2 RL401–RL403 EVERGREEN INTERNATIONAL A/L (EVR) 1 RA028 RA631 RA633 RD042 RD772–RD774 4 RB604 RB607 RD041 RD043 5 RR206 6 RJ131 RJ133 EVERGREEN TRADE INC. (EVG) 1 RA371 RD056–RD057 RD241 RD243 RD254–RD255 RD257 EXPORT RESTRICTED AIRPLANES (YWV) 1 RB711 RD681–RD682 RD791 3 RG101–RG104 RG141–RG142 RG171 4 RA101–RA103 RA112 RA161–RA163 5 RR001–RR004 6 RJ322 FINOVA (GRB) 1 RA651 G.A. TELESIS COMPONENT REPAIR (GTG) 1 RB692 RB697Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 18 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** GE (GEC) 1 RA016 GECAS (GEF) 1 RA007 RA013 RA027 GENERIC CUSTOMER/SUPPLIER (XXX) 1 RA749–RA750 RD104 RD531 RD592 5 RR202–RR203 GLOBAL PEACE INITIATIVE (GPI) 3 RG174 GLOBAL SUPPLY SYSTEMS (GSS) 2 RM891 RM894 RM896 GRACE CATHEDRAL INC. (GCI) 3 RG193 GRAND STAR (GCG) 2 RR861 GREAT WALL AIRLINES (GWL) 2 RM853 RR855 HELLENIC IMPERIAL AIRWAYS (HLE) 1 RD231–RD232 RD292 RD775 HORTA (HOB) 3 RG163 INTERNATIONAL AIR LEASES (IAL) 1 RB006 IRAQI AIRWAYS (IRQ) 3 RG095 RG172 6 RJ301–RJ303 JADE CARGO INTERNATIONAL (JDE) 2 RL511–RL516 JAL INTERNATIONAL (JAL) 2 RL461–RL462 JET AERO HOLDINGS (JHD) 3 RG122 JETT8 (JGP) 5 RR553 JOHNSON SPACE CENTER (ZBR) 1 RA908 RB601 3 RG091Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 19 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** JUMBO JET LEASING (JJL) 1 RA526 RA532–RA534 RA539 KABO AIR (KAB) 1 RA305 RA316 RA560 RB008 RD121 RD261–RD262 KALITTA AIR (KAC) 1 RA401–RA402 RA546 RD052 RD054 RD221 RD571 RD621 4 RA524 RA635 RA913 RD083 RD225 RD623 5 RR261–RR262 RR265–RR266 RR361–RR362 RR501 KLM - ROYAL DUTCH AIRLINES (KLM) 2 RL684 KOREAN AIR (KAL) 2 RL451–RL456 RM871–RM880 RR862 KUWAIT AIRWAYS (KUW) 1 RD202 RD204 L-3 COMMUNICATIONS (LCS) 1 RD352 LOADAIR CARGO (LRC) 2 RL571–RL572 LOGISTIC AIR, INC. (LGA) 1 RA015 RA217 RA266 RB722–RB723 4 RA910 5 RR342–RR343 MALAYSIA AIRLINES (MAS) 2 RL491–RL492 4 RD142 RD144 MARTINAIR HOLLAND (MTH) 2 RL681–RL683 MIDEX AIRLINES (MIX) 5 RR310 MK AIRLINES (MKA) 1 RD781 4 RD055 RD441 5 RR022–RR023 RR224 RR264 RR336 RR421 RR504 NEA HOLDINGS, INC. (NEA) 1 RB001 RD045–RD046Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 20 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** NIPPON CARGO AIRLINES (NCA) 2 RL471–RL480 4 RD461 NORTHWEST AIRLINES (NWA) 1 RD242 RD252–RD253 RD258–RD259 4 RD301–RD302 5 RR005 RR341 RR344–RR345 RR431–RR432 RR503 RR566 OCEAN AIRLINES (OCE) 1 RD658–RD659 OMAN ROYAL FLIGHT (RFO) 3 RG161 ORIENT THAI AIRLINES (OTH) 1 RA540 RA543–RA544 PAKISTAN INT'L AIRLINES (PIA) 1 RD701 POLAR AIR CARGO (PAO) 2 RL651–RL655 RM905 4 RD752 PRATT & WHITNEY ENGINE SERVICE (PWE) 3 RG213 RG222 PRONAIR (TXI) 5 RR221 RAYYAN AIR (RYY) 6 RJ321 ROYAL AIR MAROC (RAM) 1 RD671 S583 (583) 1 RD166–RD167 SAUDI ARABIAN AIRLINE (SRF) 3 RH101 RH122 SAUDI ARABIAN AIRLINES (SVA) 1 RB741–RB746 RB748 3 RH121 5 RR526 SIACARGO (SIT) 2 RL431–RL436 RM854–RM855 RR851–RR852 RR854 RR856Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 21 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** SINGAPORE AIRLINES (SIA) 2 RM851 SOUTHERN AIR (SOF) 1 RD751 4 RD411–RD412 RD583 RD642–RD643 5 RR024–RR025 RR302–RR305 RR551 RR554 STAR AIRLINES (SRQ) 1 RB421 RD426 SUO1 (UO1) 1 RB013–RB016 TIGER AIRCRAFT TRADING INC. (TGE) 4 RD233–RD235 TIGER AIRWAYS (TGR) 1 RD657 TNT AIRWAYS (TNB) 2 RL531–RL534 TRANSAERO AIRLINES (TRX) 1 RD226 RD356 RD471–RD475 TRANSATLANTIC INTL AIRLINES (TIB) 3 RG173 TRITON AVIATION SERVICES (TIA) 1 RA726 UNI-TOP AIRLINES (UTO) 1 RD782 UNKNOWN CUSTOMER (UNZ) 1 RA784 RB005 4 RD358 UPS (UPS) 1 RD051 RD058–RD059 RD593 2 RL561–RL568 RR701 RR721 4 RA026 RA029 RA033 RA902 RA912 RA915–RA916 US AIR FORCE (USF) 2 RM911 WINGS WORLD WIDE (WWW) 3 RG221 WORLDWIDE AIRCRAFT HOLDING CO. (WAH) 3 RG008Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 22 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** YANGTZE RIVER EXPRESS (YTH) 2 RL413 YEMENIA (YEM) 3 RG162 YONA (IOP) 3 RG009 RG191 IDENTIFICATION BY VARIABLE NUMBER **Variable Group** RA001–RA025 1 RA026 4 RA027–RA028 1 RA029 4 RA030–RA032 1 RA033 4 RA034 1 RA101–RA103 4 RA104–RA110 1 RA111–RA112 4 RA113–RA115 1 RA161–RA163 4 RA164 1 RA201–RA203 1 RA216–RA217 1 RA245–RA246 1 RA251–RA266 1 RA301–RA318 1 RA351–RA360 1 RA369–RA373 1 RA401–RA418 1 RA501–RA502 1 RA521–RA523 1 RA524 4 RA525–RA528 1 RA532–RA548 1 RA551–RA552 1 RA559–RA561 1 RA581–RA582 1 RA585 1Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 23 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

RA601–RA602 1 RA631 1 RA632 4 RA633 1 RA634–RA635 4 RA651–RA652 1 RA671–RA677 1 RA701–RA702 1 RA721–RA731 1 RA741–RA745 1 RA749–RA750 1 RA761–RA762 1 RA781–RA784 1 RA901–RA902 4 RA903–RA909 1 RA910–RA916 4 RB001–RB016 1 RB041 4 RB042 1 RB043 4 RB044 1 RB071–RB075 1 RB101–RB102 1 RB411–RB413 1 RB421 1 RB601–RB603 1 RB604–RB605 4 RB606 1 RB607 4 RB681–RB695 1 RB696 4 RB697 1 RB711 1 RB721–RB723 1 RB741–RB748 1 RD001–RD004 1 RD021–RD022 1 RD041 4 RD042 1 **Variable Group**Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 24 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

RD043–RD044 4 RD045–RD054 1 RD055 4 RD056–RD059 1 RD071–RD072 1 RD081 1 RD082–RD083 4 RD091–RD092 1 RD101–RD104 1 RD121–RD127 1 RD131–RD141 1 RD142 4 RD143 1 RD144 4 RD166–RD167 1 RD171–RD172 1 RD181–RD183 1 RD201–RD204 1 RD221–RD224 1 RD225 4 RD226 1 RD227 4 RD231–RD232 1 RD233–RD235 4 RD241–RD243 1 RD251–RD262 1 RD271–RD272 1 RD291–RD292 1 RD301–RD302 4 RD311 1 RD351–RD357 1 RD358 4 RD361–RD366 4 RD411–RD412 4 RD413–RD414 1 RD421–RD426 1 RD431–RD435 1 RD441–RD442 4 RD451–RD456 1 **Variable Group**Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 25 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

RD461 4 RD471–RD475 1 RD513–RD519 1 RD531–RD533 1 RD551 4 RD561 1 RD571 1 RD581–RD583 4 RD591–RD593 1 RD621 1 RD622–RD623 4 RD641–RD643 4 RD644–RD645 1 RD646 4 RD647–RD649 1 RD651–RD659 1 RD661 1 RD671 1 RD681–RD682 1 RD691 4 RD692 1 RD701–RD702 1 RD741–RD742 1 RD751 1 RD752 4 RD753–RD755 1 RD761 1 RD771–RD775 1 RD781–RD783 1 RD791–RD792 1 RE001 1 RG001–RG009 3 RG091 3 RG095 3 RG101–RG104 3 RG121–RG126 3 RG141–RG142 3 RG161–RG164 3 RG171–RG174 3 **Variable Group**Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 26 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

RG191–RG193 3 RG211–RG213 3 RG221–RG222 3 RH101–RH102 3 RH111–RH112 3 RH121–RH122 3 RJ131–RJ133 6 RJ151–RJ152 6 RJ301–RJ303 6 RJ321–RJ322 6 RJ331–RJ333 6 RL401–RL403 2 RL411–RL436 2 RL451–RL456 2 RL461–RL462 2 RL471–RL481 2 RL491–RL492 2 RL501–RL502 2 RL511–RL516 2 RL521–RL522 2 RL531–RL534 2 RL551 2 RL561–RL568 2 RL571–RL572 2 RL576–RL577 2 RL579 2 RL581–RL586 2 RL651–RL655 2 RL671–RL675 2 RL681–RL684 2 RL751–RL752 2 RM851–RM859 2 RM861–RM863 2 RM871–RM899 2 RM901–RM906 2 RM911 2 RR001–RR005 5 RR021–RR025 5 RR031 5 **Variable Group**Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 27 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

2. Spares Affected None. **B. Concurrent Requirements** None. **C. Reason** Accomplishment of the work given in this Service Bulletin will make sure the tension ties and frames aft of the upper deck floor are not cracked. Cracks in tension ties and/or frames could cause the tension ties to become severed or disconnected from the frames. Severed or disconnected tension ties and/or frames at multiple locations could result in rapid in-flight decompression. Tension ties are installed to connect the left and right hand sides of the body structure aft of the upper deck floor. RR201–RR206 5 RR221–RR226 5 RR261–RR267 5 RR301–RR310 5 RR331–RR332 5 RR336 5 RR341–RR345 5 RR361–RR362 5 RR421–RR422 5 RR431–RR432 5 RR441–RR442 5 RR451 5 RR501–RR504 5 RR521–RR522 5 RR526 5 RR531 5 RR551–RR556 5 RR561 5 RR566 5 RR701 2 RR721–RR724 2 RR746–RR748 2 RR851–RR856 2 RR861–RR862 2 RR951–RR952 2 **Variable Group**Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 28 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

During routine maintenance of a 747-200F airplane one operator reported a crack in the tension tie, at the body station (STA) 820 frame connection. The crack was found to be 1/8 inch at a fastener hole. Inspection of the 747SR fatigue test airplane showed similar cracks in both the tension ties and frames at the tension tie to frame connections. The cracks were found at STA 800, 820, and 840 at 40,000 flight cycles (20,000 operating cycles, 20,000 test cycles). Cracks in the frames were up to 1.25 inches long, and cracks in the tension ties were up to 0.20 inches long. Revision 1: Subsequent to the release of the original issue of this service bulletin, an operator reported finding a total of twelve cracks on forward and aft tension tie channels at STA 740 and STA 760 on a 747-400F airplane. After comparing the structure to the Boeing design configuration, it was determined that only seven fasteners were installed common to the frame at each end of the STA 760 tension tie. A quantity of nine fasteners should have been installed common to the frame at each end of the tension tie. Revision 1: After investigation, it has been determined that the airplane on which the discrepancy was found was manufactured and delivered by Boeing with the incorrect tension tie configuration at STA 760. Reduced load carrying capability of the STA 760 tension tie, due to cracks, subsequently lead to increased loads and premature fatigue cracks in the adjacent tension tie at STA 740. Revision 1: 747-200F airplanes and Boeing modified 747 Special Freighter airplanes have a unique tension tie configuration at STA 760, and only 747-400F airplanes have tension ties at STA 720 and STA 740. Therefore, only 747-400F airplanes are affected by the new inspection for correct configuration which was added in Revision 1. Revision 1: In addition, due to new analysis of the tension tie structure, Boeing has determined that stresses are higher in the STA 720, STA 740, and STA 760 tension ties on 747-400F airplanes. Therefore, even if the tension tie configurations are correct, the detailed and HFEC inspections given in this service bulletin should begin at an earlier time. This has resulted in a reduced flight cycle compliance time for the initial inspection threshold at STA 720, STA 740, and STA 760 tension ties on 747-400F airplanes. This service bulletin provides instructions for inspections and repair of the tension ties and frames aft of the upper deck floor. The tension ties and frames have been found to be structually significant in that it is critical to the structual integrity of the airplane. Tension tie and frame cracks not found before they reach critical crack lengths can cause in-flight depressurization. If the work given in this service bulletin is not done the airplane structure may not be able to withstand current regulatory fail-safe loads. Boeing Service Related Problem (SRP) 747OP-SRP-53-0200 is related to this service bulletin. Boeing Service Related Problem (SRP) 747-SRP-53-0349 is related to this service bulletin. Boeing Fleet Team Digest (FTD) article 747-FTD-53-09008 is related to this service bulletin. Modification Service Bulletin 747-53A2605 has been released to address Widespread Fatigue Damage (WFD) in the tension ties and adjacent frame structure. Accomplishment of the modification in accordance with Service Bulletin 747-53A2605 will terminate the repeat inspection requirements of this service bulletin.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 29 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

Revision 1 is sent to reduce the initial inspection compliance time for Group 2 airplanes at STA 720, STA 740, and STA 760 and to add an inspection to ensure the correct tension tie configurations on Group 2 airplanes. Other changes have also been made in Revision 1. A list of Revision 1 changes can be found on the Revision Transmittal Sheet for Revision 1. **D. Description** Group 1, 3-6: Get access to all tension ties. Do detailed and HFEC inspections for cracks in all tension ties, adjacent frame structure, and adjacent structure that attaches to the tension ties. If any crack is found, repair as specified in this service bulletin, before further flight. Repeat inspections at the specified intervals. Group 2: Do detailed and HFEC inspections for cracks in the tension ties and adjacent structure. If cracks are found, do the repair given in this service bulletin before further flight. Repeat inspections at the specified intervals. In addition, do a one-time general visual inspection at each tension tie location to determine if the correct design configuration is installed. At any tension tie where the correct configuration is not installed, do detailed and open hole HFEC inspections for cracks in the tension tie channels where they attach to the side of body frames. If no crack is found, install the correct tension tie configuration. If any crack is found, repair the tension tie in accordance with this service bulletin, or contact Boeing for repair instructions. All actions specified in this section should be done at the times given in paragraph 1.E., Compliance. The basic airplanes have tension ties from STA 760 to STA 940. However, on some airplanes, some tension ties have been replaced by upper deck floor beams due to extended upper deck modifications, upper deck aft galley modification, or other modification. Operators should determine whether a floor beam or tension tie is installed at each station. **NOTE:** This service bulletin recommends inspection of tension ties that are made up of back to back channels, and the body frames that those tension ties connect to. On some airplanes, some tension ties have been replaced by upper deck floor beams due to extended upper deck modification, upper deck aft galley modification, or other modification. Due to the large number of modifications available that each operator may have incorporated, this service bulletin does not include groupings for airplanes incorporating all of these modifications. Operators should determine whether a floor beam or a tension tie is installed at each station. Refer to Appendix C, Figure B for an illustration of these configurations. **NOTE:** Tension ties made from back to back aluminum channels have a steel plate installed at each end of the tension tie at the connection to the frame. A distinction is made between "long" steel plates and "short" steel plates. Long steel plates are approximately 20 inches long and are installed at station 760 on 747-100, 747-SR, 747-200B, and 747-200 Combi airplanes (that have not been modified by an extended upper deck modification). Long steel plates are also installed at station 780 on 747-200 Freighter airplanes, and at station 920 on 747-200 convertible airplanes. Short steel plates are approximately 10 inches long and are typical at all locations where long steel plates are not installed. Refer to Appendix C, Figure C for illustrations of short and long steel plate configurations.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 30 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

**NOTE:** An Airplane with an Extended Upper Deck is not the same as a Stretched Upper Deck. In an Extended Upper Deck (EUD) Airplane, the upper deck contour extends aft to STA 1000. Typically, EUD Airplanes have the tension ties at STA 760 and STA 780 replaced by floor beams to extend the floor area of the upper deck. In a Stretched Upper Deck (SUD) Airplane, the upper deck contour extends aft to STA 1283, as installed on 747-200 SUD Modified Airplanes during production and 747-300 and 747-400 Passenger Airplanes. This service bulletin does not apply to Stretched Upper Deck (SUD) Airplanes. Refer to Appendix C, Figure A for an illustration of these configurations. **NOTE:** Some Airplanes were delivered with Extended Upper Deck Modifications that installed floor beams aft of Station 740. These Airplanes are not the same as Airplanes delivered with a Stretched Upper Deck (SUD), which includes 747-300, 747-400 Passenger Airplanes, and some 747-100 and 200 SUD Modified Airplanes. **NOTE:** On 747-200 Freighter airplanes and Boeing modified 747 Special Freighter airplanes, the tension tie at STA 760 is a built-up beam, made of an upper chord and a lower chord with a shear web in between. This tension tie looks similar to a floor beam, but is considered a tension tie, and should be inspected as specified in this service bulletin. Refer to Appendix C, Figure B for an illustration of this configuration. **NOTE:** Except for 747SP airplanes, airplanes modified from passenger to Special Freighter typically have the life raft beams removed from above main entry door number 2. Removal of the life raft beams changes the loads in the adjacent tension ties. For the purposes of this service bulletin, airplanes modified to a Special Freighter or which have had the life raft beam removed, are in airplane group 4 (This does not apply to 747SP airplanes because the tension ties are not adjacent to a door). **NOTE:** If the damaged area is more than the specified limits, write to Boeing for repair instructions. Give the size and location of the damage. When possible, send sketches and photographs. If the damage includes corrosion, send data on the length, width, and largest depth of clean up. Send to: BOEING COMMERCIAL AIRPLANES GROUP ATTENTION: MANAGER, AIRLINE SUPPORT **E. Compliance** Group 1, 3, 6: Table 1 - Compliance Times for Tension Tie Inspections.
**Condition Action Compliance Time**  **(Whichever Occurs Later) Repeat Interval**  **(Not to Exceed)** All airplanes. Do detailed and HFEC inspections of the tension ties in accordance with the INSPECTION steps of the Work Instructions. Before 20,000 total flight cycles. Within 1,000 flight cycles after the original issue date of this service bulletin. 4,000 flight cycles.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 31 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** Group 4-5: Table 2 - Compliance Times for Tension Tie Inspections.
**Condition Action Compliance Time**  **(Whichever Occurs Later) Repeat Interval**  **(Not to Exceed)** All airplanes. Do detailed and HFEC inspections of the tension ties in accordance with the INSPECTION steps of the Work Instructions. Before 17,000 total flight cycles Within 1,000 flight cycles after the original issue date of this service bulletin 3,000 flight cycles.

Group 2: Table 3 - Compliance Times for Tension Tie Inspections.
**Condition Action Compliance Time**  **(Whichever Occurs Later) Repeat Interval**  **(Not to Exceed)** All airplanes. At STA 720, 740, and 760, do detailed and HFEC inspections of the tension ties in accordance with the INSPECTION steps of the Work Instructions. Before 8,000 total flight cycles Within 1,000 flight cycles after the Revision 1 date of this service bulletin. 3,000 flight cycles.

At STA 780 through STA 940, do detailed and HFEC inspections of the tension ties in accordance with the INSPECTION steps of the Work Instructions. Before 17,000 total flight cycles Within 1,000 flight cycles after the original issue date of this service bulletin 3,000 flight cycles.

Group 2: Table 4 - Compliance Times for One-Time Inspection for Correct Configuration.
**Condition Action Compliance Time**  **(Whichever Occurs Later)** All airplanes. Do a general visual inspection of the tension ties for correct configuration in accordance with the MORE WORK - ONE TIME INSPECTION FOR CORRECT CONFIGURATION section of paragraph 3.B., Work Instructions. Before 8,000 total flight cycles Within 1,000 flight cycles after the Revision 1 date of this service bulletin. All tension ties have the correct configuration. No more work is required for the one-time inspection for correct configuration. - -Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 32 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

1. Life raft beams on passenger and convertible airplanes are installed over main entry door number 2. a. Airplanes modified from passenger to Special Freighter typically have the life raft beams removed from above main entry door number 2. b. Airplanes that do not have life raft beams over main entry door number 2 have higher loads in the adjacent tension ties than Airplanes with life raft beams installed. For the purpose of this Service Bulletin, Airplanes which do not have a life raft beam installed at main entry door number 2 (excluding group 3) should be inspected as shown for Airplane group 4. Federal Aviation Administration (FAA) Airworthiness Directive AD 84-19-01 is related to this service bulletin. Federal Aviation Administration (FAA) Airworthiness Directive AD 94-13-06 is related to this service bulletin. Federal Aviation Administration (FAA) Airworthiness Directive AD 2004-07-22 R1 is related to this service bulletin. Federal Aviation Administration (FAA) Airworthiness Directive AD 2006-01-07 is related to this service bulletin. The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. Incorrect configuration found. Do detailed and HFEC inspections for cracks at tension tie locations where the incorrect configuration was found, in accordance with the MORE WORK - ONE TIME INSPECTION FOR CORRECT CONFIGURATION section of paragraph 3.B., Work Instructions. Before further flight.

Any crack found. Do a repair, or contact Boeing for repair instructions, in accordance with the MORE WORK - ONE TIME INSPECTION FOR CORRECT CONFIGURATION section of paragraph 3.B., Work Instructions. Before further flight.

No crack found. Install the correct configuration for the tension ties at locations where the incorrect configuration was found, in accordance with the MORE WORK - ONE TIME INSPECTION FOR CORRECT CONFIGURATION section of paragraph 3.B., Work Instructions. Before further flight. Group 2: Table 4 - Compliance Times for One-Time Inspection for Correct Configuration.
**Condition Action Compliance Time**  **(Whichever Occurs Later)**Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 33 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT 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. The Manager of the FAA Seattle Aircraft Certification Office (ACO) approves the inspection and repair procedures with the corresponding compliance times specified in Service Bulletin 747-53A2502, Revision 1, as an Alternative Method of Compliance (AMOC) to the inspections and repairs required by paragraphs (h), (i), and (j) of AD 2004-07-22 R1, for the inspection of Structural Significant Item (SSI) F-19A of the Supplemental Structural Inspection Document (SSID) D6-35022, Revision G. This AMOC only applies to the areas inspected by this service bulletin. When this service bulletin specifies contacting Boeing for repair instructions, the repair instructions must be approved by the FAA in accordance with paragraph (l) of the AD. All provisions of AD 2004-07-22 R1 that are not specifically referenced in this paragraph remain fully applicable and must be complied with. The Manager of the FAA Seattle ACO approves the inspection and repair procedures with the corresponding compliance times specified in Service Bulletin 747-53A2502, Revision 1, as an AMOC to the inspections, repair and modification with the corresponding compliance times required by paragraphs A. and B. of AD 84-19-01. When this service bulletin specifies contacting Boeing for repair instructions, the repair instructions must be approved by the FAA in accordance with paragraph C. of the AD. All provisions of AD 84-19-01 that are not specifically referenced in this paragraph remain fully applicable and must be complied with. The Manager of the FAA Seattle ACO approves the inspection and repair procedures with the corresponding compliance times specified in Service Bulletin 747-53A2502, Revision 1, as an AMOC to the inspections, repair and modification with the corresponding compliance times required by paragraphs (a) and (b) of AD 94-13-06. When this service bulletin specifies contacting Boeing for repair instructions, the repair instructions must be approved by the FAA in accordance with paragraph (c) of the AD. All provisions of AD 94-13-06 that are not specifically referenced in this paragraph remain fully applicable and must be complied with. The Manager of the FAA Seattle ACO approves the inspection and repair procedures with the corresponding compliance times specified in Service Bulletin 747-53A2502, Revision 1, as an AMOC to the inspections and corrective actions with the corresponding compliance times required by paragraph (f) of AD 2006-01-07. When this service bulletin specifies contacting Boeing for repair instructions, the repair instructions must be approved by the FAA in accordance with paragraph (g) of the AD. All provisions of AD 2006-01-07 that are not specifically referenced in this paragraph remain fully applicable and must be complied with. **G. Manpower** The table below shows an estimate of the task-hours necessary to do this change 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:Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 34 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

— Time to adjust to the workplace — Time to schedule the work — Time to examine the work — Time to cure the materials — Time to make the parts — Time to find the tools. Group 1, Configuration 1: Inspection for Fatigue Cracks
**Task Number of**  **Persons Task-Hours Elapsed Hours** ACCESS 2 2.0 1.0 Figure 1 2 8.0 4.0 Figure 2 2 6.0 3.0 RESTORATION 2 2.0 1.0 TOTAL FOR EACH TENSION TIE LOCATION (a) (b) 18.0 9.0 (a) Most airplanes have ten tension tie locations. However, some airplanes could have six or eight tension tie locations. (b) It may not be necessary to do the work given in all Figures at all locations. Operators should refer to paragraph 1.E., Compliance and Appendix A - Logic Diagram, and total the number of hours required for each Figure as necessary. Group 1, Configuration 2: Inspection for Fatigue Cracks
**Task Number of**  **Persons Task-Hours Elapsed Hours** ACCESS 2 2.0 1.0 Figure 3 2 8.0 4.0 Figure 4 2 6.0 3.0 RESTORATION 2 2.0 1.0 TOTAL FOR EACH TENSION TIE LOCATION (a) (b) 18.0 9.0 (a) Most airplanes have ten tension tie locations. However, some airplanes could have six or eight tension tie locations. (b) It may not be necessary to do the work given in all Figures at all locations. Operators should refer to paragraph 1.E., Compliance and Appendix A - Logic Diagram, and total the number of hours required for each Figure as necessary. Group 1, Configuration 3: Inspection for Fatigue Cracks
**Task Number of**  **Persons Task-Hours Elapsed Hours** ACCESS 2 2.0 1.0 Figure 5 2 8.0 4.0 Figure 6 2 6.0 3.0 RESTORATION 2 2.0 1.0Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 35 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

TOTAL FOR EACH TENSION TIE LOCATION (a) (b) 18.0 9.0 (a) There are 8 tension tie locations on each airplane. (b) It may not be necessary to do the work given in all Figures at all locations. Operators should refer to paragraph 1.E., Compliance and Appendix A - Logic Diagram, and total the number of hours required for each Figure as necessary. Group 1, Configuration 4: Inspection for Fatigue Cracks
**Task Number of**  **Persons Task-Hours Elapsed Hours** ACCESS 2 2.0 1.0 Figure 7 2 8.0 4.0 Figure 8 2 6.0 3.0 RESTORATION 2 2.0 1.0 TOTAL FOR EACH TENSION TIE LOCATION (a) (b) 18.0 9.0 (a) Most airplanes have ten tension tie locations. However, some airplanes could have six or eight tension tie locations. (b) It may not be necessary to do the work given in all Figures at all locations. Operators should refer to paragraph 1.E., Compliance and Appendix A - Logic Diagram, and total the number of hours required for each Figure as necessary. Group 2: Inspection for Fatigue Cracks
**Task Number of**  **Persons Task-Hours Elapsed Hours** ACCESS 2 0.50 0.25 Figure 9 2 1.5 0.75 Figure 10 2 8.0 4.0 Figure 11 2 6.0 3.0 Figure 12 2 1.5 0.75 RESTORATION 2 0.50 0.25 TOTAL FOR EACH TENSION TIE LOCATION (a) (b) 18.0 9.0 (a) There are 12 tension tie locations on each airplane. (b) It may not be necessary to do the work given in all Figures at all locations. Operators should refer to paragraph 1.E., Compliance and Appendix A - Logic Diagram, and total the number of hours required for each Figure as necessary. Group 1, Configuration 3: Inspection for Fatigue Cracks
**Task Number of**  **Persons Task-Hours Elapsed Hours**Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 36 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

Group 3: Inspection for Fatigue Cracks
**Task Number of**  **Persons Task-Hours Elapsed Hours** ACCESS 2 2.0 1.0 Figure 13 2 8.0 4.0 Figure 14 2 6.0 3.0 RESTORATION 2 2.0 1.0 TOTAL FOR EACH TENSION TIE LOCATION (a) (b) 18.0 9.0 (a) There are 6 tension tie locations on each airplane. (b) It may not be necessary to do the work given in all Figures at all locations. Operators should refer to paragraph 1.E., Compliance and Appendix A - Logic Diagram, and total the number of hours required for each Figure as necessary. Group 4: Inspection for Fatigue Cracks
**Task Number of**  **Persons Task-Hours Elapsed Hours** ACCESS 2 2.0 1.0 Figure 15 2 8.0 4.0 Figure 16 2 6.0 3.0 RESTORATION 2 2.0 1.0 TOTAL FOR EACH TENSION TIE LOCATION (a) (b) 18.0 9.0 (a) Most airplanes have nine tension tie locations. However, some airplanes could have six or eight tension tie locations. (b) It may not be necessary to do the work given in all Figures at all locations. Operators should refer to paragraph 1.E., Compliance and Appendix A - Logic Diagram, and total the number of hours required for each Figure as necessary. Group 5: Inspection for Fatigue Cracks
**Task Number of**  **Persons Task-Hours Elapsed Hours** ACCESS 2 2.0 1.0 Figure 17 2 8.0 4.0 Figure 18 2 6.0 3.0 RESTORATION 2 2.0 1.0 TOTAL FOR EACH TENSION TIE LOCATION (a) (b) 18.0 9.0 (a) There are 9 tension tie locations on each airplane. (b) It may not be necessary to do the work given in all Figures at all locations. Operators should refer to paragraph 1.E., Compliance and Appendix A - Logic Diagram, and total the number of hours required for each Figure as necessary.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 37 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

**H. Weight and Balance Changes** None. **I. Electrical Load Data** Not applicable. **J. References** 1. Existing Data: a. Engineering Change Memo PRR 85901-46RS b. 747-100/200/300 Aircraft Maintenance Manual (AMM) 24-22-00, 25-14-02, 25-22-04, 25-25-01 c. 747-100/200/300 Structural Repair Manual (SRM) 51-30-03, 51-30-05, 51-40-03, 53-10-04, 53-10-11, 53-30-03 d. 747-400 Aircraft Maintenance Manual (AMM) 24-22-00, 25-21-04, 25-59-01 e. 747-400 Structural Repair Manual (SRM) 51-40-03 Group 6: Inspection for Fatigue Cracks
**Task Number of**  **Persons Task-Hours Elapsed Hours** ACCESS 2 2.0 1.0 Figure 19 2 8.0 4.0 Figure 20 2 6.0 3.0 RESTORATION 2 2.0 1.0 TOTAL FOR EACH TENSION TIE LOCATION (a) (b) 18.0 9.0 (a) There are 8 tension tie locations on each airplane. (b) It may not be necessary to do the work given in all Figures at all locations. Operators should refer to paragraph 1.E., Compliance and Appendix A - Logic Diagram, and total the number of hours required for each Figure as necessary. Group 2: One-Time Inspection for Correct Configuration (Revision 1 - More Work)
**Task Number of**  **Persons Task Hours Elapsed Hours** ACCESS 5 20.0 4.0 Figure 22 2 6.0 3.0 RESTORATION 5 20.0 4.0 TOTAL FOR EACH AIRPLANE (a) 46.0 11.0 (a) More time will be required if repairs are necessary, or if an incorrect configuration is found.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 38 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** f. 747-400F Structural Repair Manual (SRM) 51-40-03, 51-40-05, 51-70-11, 53-00-01, 53-20-07, 53-20-30 g. 747-SP Structural Repair Manual (SRM) 51-30-03, 51-30-05, 51-40-03, 53-19-02, 53-19-11 h. 747 Non-Destructive Testing (NDT) Manual, Part 6, Subject 51-00-00, Figure 1, 11, or 16, Part 6, Subject 51-00-00, Figure 16, Part 6, Subject 51-00-00, Figure 19, Part 6, Subject 51-00-00, Figure 4 i. Boeing Service Related Problem (SRP) 747-SRP-53-0349 j. Boeing Service Related Problem (SRP) 747OP-SRP-53-0200 k. Boeing Service Bulletin 747-53-2088, 747-53-2371, 747-53A2605 l. Federal Aviation Administration (FAA) Airworthiness Directive 2004-07-22 R1, 2006-01-07, 84-19-01, 94-13-06 m. Standard Overhaul Practices Manual (SOPM) 20-41-05, 20-50-19 2. Data supplied with this Service Bulletin: None.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 39 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

3. Installation Drawings Used in the Preparation of this Service Bulletin:

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 **Drawing Number Title** 65B09631 Tension Tie Installation - STA 760 to STA 940, STA 1040 to STA 1220. 747/100/200/SP Airplanes 142U1023 Tension Tie Installation - STA 720 to STA 940 747-400F Airplanes 65B24488 Tension Tie Installation - STA 760 to STA 940 - Mod Drawing. 65B01729 Body Station 720 Machined Fitting (400F only) 65B01730 Body Station 740 Machined Fitting (400F only) 65B01731 Body Station 760 Machined Fitting 65B01732 Body Station 780 Machined Fitting 65B01733 Body Station 800 Machined Fitting 65B01734 Body Station 820 Built Up Frame Section 65B01735 Body Station 840 Built Up Frame Section 65B01736 Body Station 860 Built Up Frame Section 65B01737 Body Station 880 Built Up Frame Section 65B01738 Body Station 900 Built Up Frame Section 65B01739 Body Station 920 Built Up Frame Section 65B01740 Body Station 940 Built Up Frame Section 65B01745 Body Station 1040 Built Up Frame Section (SP only) 65B01746 Body Station 1060 Built Up Frame Section (SP only) 65B01747 Body Station 1080 Built Up Frame Section (SP only) 65B01748 Body Station 1100 Built Up Frame Section (SP only) 65B01749 Body Station 1120 Built Up Frame Section (SP only) 65B18703 Body Station 1140 Built Up Frame Section (SP only) 65B38730 Installation of life raft beam over main entry door number 2. 65B12358 Installation of life raft beam over main entry door number 2. 65B38730 Built-up Tension Tie at STA 760 65B16291 Body Station 760 Tension Tie Beam Installation (Special Freighter) 65B16292 Body Station 780 Tension Tie Installation (Special Freighter)

**Publication Chapter-Section** 747 Structural Repair Manual 53-11 747 Illustrated Parts Catalog 53-12Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 40 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

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 and new 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.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 41 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT 2. MATERIAL INFORMATION**  **A. Material - Price and Availability** Boeing can supply the parts shown in Paragraph 2.C., Parts Necessary For Each Airplane as shown below. If there is a limit to the quantity (QTY) of available parts, a supply sequence is given by Spares. More parts become available as shown in the Reorder Lead Time (ROLT). ROLT is calculated from the date Boeing gets the purchase order.

**B. Industry Support Information** Boeing warranty remedies are not available for the inspection or repair procedures given in this service bulletin, except as specified below. Group 2: Boeing warranty remedies are available for inspection and corrective actions related to the one-time inspection for incorrect configuration on 747-400F airplanes in warranty as of September 9, 2009. For inspection task hour reimbursement for airplanes in warranty as of that date, send a warranty claim to Boeing Commercial Airplanes Group - Warranties. If the incorrect configuration condition described in this service bulletin is found during the inspection for airplanes in warranty as of that date and additional task hours and/or parts are required, send a warranty claim to Boeing Commercial Airplanes Group - Warranties. Please refer to this service bulletin number and reference the airplane variable number in your purchase order. **C. Parts Necessary For Each Airplane** 1. Kits/Parts: To get the parts shown below, refer to Paragraph 2.A., Material - Price and Availability. **Part Number Name Date QTY ROLT**  **(Weeks) Unit Price thru**  **Dec 31/10** 142U0105-4 Tension Tie Segment Jun 08/10 60 15 $580.00 142U0104-1 Tension Tie Splice Jun 04/10 60 15 $391.00

**New Part Number QTY Name Existing Part**  **Number Notes** 142U0105-4 2 Tension Tie Segment - (a) (b) 142U0104-1 2 Tension Tie Splice - (a) (b) (a) This part is needed to perform SRM at STA 720, STA 740, and STA 760 on 747-400F airplanes. A limit number of these parts are available in Boeing Spares. The quantity shown is the number of parts necessary to do SRM repair at each end of the tension tie where. As an option to purchasing these parts from Boeing, operators can fabricate their own parts in accordance with the SRM. (b) This part is identified to support the one-time inspection for correct configuration on 747- 400F airplanes.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 42 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

2. Parts and Materials Supplied by the Operator:

3. Parts Modified and Reidentified: None. 4. Parts Removed and Not Replaced: None. **D. Parts Necessary to Change Spares** None. **E. Special Tooling - Price and Availability** None. **F. Special Tooling Necessary to do this Service Bulletin** No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available. **Part Number / Specification QTY Name Notes**  BACB30NX( )K( ) 450 Hex Drive Bolt (a) (c) (d) (e) BACN10YT( )CD 450 Nut (a) (c) (d) (e) BACW10BP( )DP 450 Washer (a) (c) (d) BMS 3-23, Type II 24 ounces Corrosion Inhibiting Compound (b) (c) BMS 3-27 (BMS 3-38 optional) 12 ounces Sealant (b) (c) BMS 10-11 Type 1 12 ounces Primer (b) (c) Alodine 1200 12 ounces Chemical Conversion Coating (b) (c) (a) Refer to 747 Structural Repair Manual Chapter 51 for alternative fasteners. (b) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data. (c) Quantities are approximate. The actual quantity required will vary depend the group and configuration of the airplane, inspection results, and if any repairs are accomplished. (d) Operators should have access to standard, first and second over size 3/16 and 1/4 inch diameter fasteners, and 5/16 standard diameter fasteners in grip lengths ranging from -3 to -8. (e) To allow for easier removal during repeat inspections, it is optional to install BACB30MR( )K( ) bolts and BACW10BP( )CD washers, with BACN11Z( )CD nuts and BACW10BP( )DP washers at fastener locations common to the steel plates. However, availability of BACB30MR( )K( ) bolts is limited. Also, if fasteners are substituted, the same type of fastener should be used throughout each joint, as shown in Appendix C, Figure F.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 43 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **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: — Hole dimensions for standard solid rivets are given in 747 Structural Repair Manual, Chapter 51. — Torque limits to tighten nuts and bolts are given in 747 Structural Repair Manual, Chapter 51. 4. Use the approved fastener and process material substitutions in accordance with 747 SRM, Chapter 51. Alternate fasteners are listed in 747 SRM, Chapter 51 and Boeing Drawing 012W6100. 5. If the length of any fastener specified in this service bulletin does not meet the installation standards in SRM Chapter 51, then a fastener of the same specification, or an approved substitute, with a length which meets the installation standards in SRM Chapter 51 may be used. 6. The following Instructions apply to all tension ties that are made by fastening two aluminum channels back to back. Some of the tension ties also have an aluminum doubler sandwiched between the channels, and others have an additional aluminum channel fastened to the lower flanges of the back to back channels. Refer to Appendix C, Figure D for an illustration of these configurations.7. This Service Bulletin recommends inspection of tension ties that are made up of backto-back channels, and the body frames that those tension ties connected to. On some Airplanes, some tension ties have been replaced by upper deck floor beams due to extended upper deck modifications, or other modifications. Due to the large number of modifications available that each operator may have incorporated, this service bulletin does not include groupings for Airplanes incorporating all of these modifications. Operators should determine whether a floor beam or tension tie is installed at each station. Refer to Appendix C, Figure B for an illustration of these configurations. 8. Some airplanes in Group 4 (Boeing-Modified Special Freighter) and Group 5 (747-200 Freighter) have a built-up beam installed at STA 760 that looks similar to a floor beam, but is a tension tie. There are no floor panels attached to this built-up tension tie. For Group 4 and Group 5 airplanes that have a built-up tension tie installed at STA 760, an inspection of this tension tie is required in accordance with this service bulletin.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 44 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** 9. This service bulletin does not apply to locations where floor beams are installed instead of tension ties. For inspections of floor beams, refer to Boeing document D6-35022, Supplemental Structural Inspection Document for 747 airplanes and other applicable service documents. 10. The basic airplanes have tension ties from STA 760 to STA 940. However, on some airplanes, some tension ties have been replaced by upper deck floor beams due to extended upper deck modifications, upper deck aft galley modification, or other modification. Operators should determine whether a floor beam or tension tie is installed at each station. 11. 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. 12. In the instructions and Figures, the tension tie to frame joint configuration shown is a typical representative view. Actual configurations vary depending on location. 13. For Group 1 airplanes that have tension ties at STA 760 and STA 780, some airplanes could have been modified with a longer steel plate at STA 760 and/or STA 780 in accordance with Service Bulletin 747-53-2088. This modification would not be installed on airplanes with an extended upper deck modification. Refer to Appendix C, Figure E for an illustration of this configuration. 14. For 747 airplanes, line numbers 1 through 203, Service Bulletin 747-53-2088 and Service Bulletin 747-53-2371 inspections also apply if modifications in accordance with those service bulletins have not been accomplished. 15. In the Figures of this service bulletin, Right Buttock Line (RBL) and Left Buttock Line (LBL) are used as reference points. RBL is defined as the perpendicular distance in inches right of the fuselage vertical center line. LBL is defined as the perpendicular distance in inches left of the fuselage center line. 16. Some airplanes may have been modified with a longer steel plate at some locations, in accordance with Service Bulletin 747-53-2088. If longer steel plates are found, ensure that they conform to Service Bulletin 747-53-2088, and re-install them as necessary during accomplishment of this service bulletin. 17. Some airplanes may have been modified or repaired at some locations, in accordance with Service Bulletin 747-53-2371 or Service Bulletin 747-53-2088 optional modification, which trims the aft tension tie channel and installs a repair strap under the steel plate. If a repair strap is installed in accordance with Service Bulletin 747-53-2088 or Service Bulletin 747-53-2371, then re-install the short steel plate and repair strap. If an aft channel is being replaced by this service bulletin, it is not necessary to re-install the Service Bulletin 747-53-2088 or Service Bulletin 747-53-2371 repair strap. 18. In the following work instructions, it is acceptable to substitute fasteners in accordance with 747-100/200/300 SRM 51-30-03, or 747-400F SRM 51-40-03, or 747-SP SRM 51-30-03. However, if fasteners are substituted, the same type of fastener should be used throughout each joint in accordance with Appendix C, Figure F.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 45 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** 19. Instead of repairing tension ties, it is acceptable to replace tension ties from end to end, at operator’s discretion. 20. This note is deleted (Revision 1). 21. Appendix B shows tension tie disconnection methods. 22. These work instructions refer to procedures included on 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. 23. The instructions identified in Paragraph 3.B. Work Instructions and the Figures(s) give the recommended sequence of steps. The sequence of steps to do this service bulletin can be changed. 24. 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 ensure visual access to all surfaces in the inspection area. This level of inspection is made under normal 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. 25. Where these work instructions state that a removed part must be kept and later installed, the operator may discard the part and install a new or serviceable part, with the same part number, in lieu of the kept/removed part, unless otherwise noted in the instructions. **B. WORK INSTRUCTIONS Group 1: ACCESS**  1. Remove electrical power and ground the airplane. Refer to 747-100/200/300 AMM 24-22-00 as an accepted procedure. 2. Remove seats as necessary between STA 760 and STA 940. Refer to 747-100/200/300 AMM 25-25-01 as an accepted procedure. 3. Remove the ceiling panels as necessary to get access to the tension ties. Refer to 747-100/200/ 300 AMM 25-22-04 as an accepted procedure. 4. Remove insulation as necessary to get access to the tension ties. Refer to 747-100/200/300 AMM 25-14-02 as an accepted procedure. **Group 2: ACCESS** 1. Remove electrical power and ground the airplane. Refer to 747-400 AMM 24-22-00 as an accepted procedure. 2. Remove ceiling panels as necessary between STA 720 and STA 940. Refer to Figure 9 for an accepted procedure.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 46 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

3. Remove insulation as necessary to get access to the tension ties. Refer to 747-400 AMM 25-21-04 as an accepted procedure. **Group 3: ACCESS** 1. Remove electrical power and ground the airplane. Refer to 747-100/200/300 AMM 24-22-00 as an accepted procedure. 2. Remove seats as necessary between STA 1040 and STA 1140. Refer to 747-100/200/300 AMM 25-25-01 as an accepted procedure. 3. Remove the ceiling panels as necessary to get access to the tension ties. Refer to 747-100/200/ 300 AMM 25-22-04 as an accepted procedure. 4. Remove insulation as necessary to get access to the tension ties. Refer to 747-100/200/300 AMM 25-14-02 as an accepted procedure. **Group 4-6: ACCESS** 1. Remove electrical power and ground the airplane. Refer to 747-100/200/300 AMM 24-22-00 as an accepted procedure. 2. Remove the ceiling panels as necessary to get access to the tension ties. Refer to 747-100/200/ 300 AMM 25-22-04 as an accepted procedure. 3. Remove the insulation as necessary to get access to the tension ties. Refer to 747-100/200/300 AMM 25-14-02 as an accepted procedure. **Group 1, Configuration 1: INSPECTION CAUTION:**  DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. 1. Inspect the tension ties, frames, and associated parts for cracks in accordance with Figure 1. **NOTE:** If there are insulation blanket studs attached to the frames in the inspection area, check to see if the studs are bonded on to the frames, or if they go through holes in the frames. At locations where the studs go through holes in the frames, remove the stud and inspect the hole in accordance with Figure 21. 2. If no cracks are found, install removed parts with new fasteners in accordance with Figure 1, and repeat the INSPECTION steps at the intervals specified in paragraph 1.E., Compliance. 3. On airplanes that have a tension tie at STA 760, but do not have an extended upper deck modification or other modifications, there is a full-length aluminum doubler installed at STA 760 between the tension tie channels. If the doubler is cracked, before further flight, do one of the following steps: a. For small cracks at hole locations that can be removed by oversizing the hole to a maximum hole diameter of 0.313 inch, do the OVERSIZE HOLE REPAIR steps.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 47 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** b. If any crack is found in the doubler that cannot be removed by doing OVERSIZE HOLE REPAIR, repair in accordance with 747-100/200/300 SRM 53-10-11 Figure 2 Detail XI, or contact Boeing for repair instructions. 4. At STA 940, there is a full length aluminum reinforcing channel installed on the bottom of the tension tie. If the aluminum channel is cracked, repair it before further flight. Repair in accordance with 747-100/200/300 SRM 53-10-11 Figure 2 Detail VIII, or contact Boeing for repair instructions. 5. If any crack is found in a shear web component, contact Boeing for repair instructions. **NOTE:** Shear webs are installed at STA 820 - STA 840 or STA 840 - STA 860, depending on the airplane. 6. On built-up frames, if a shear tie is cracked at the flange common to the skin, do the following: a. Remove fasteners as required and do an open-hole HFEC inspection of the skin for cracks at all fastener locations common to the cracked shear tie. b. Repair the shear tie before further flight. Repair in accordance with 747-100/200/300 SRM 53-10-04 Figures 132 through 139, the FRAME REPAIR steps, or contact Boeing for repair instructions. 7. If a crack is found in the skin, repair the skin before further flight in accordance with 747-100/200/ 300 SRM 53-30-03, or contact Boeing for repair instructions. 8. If cracks are found in holes where insulation blanket studs go through the frames, repair in accordance with 747-100/200/300 SRM 53-10-04 Figures 132 through 139, the FRAME REPAIR steps, or contact Boeing for repair instructions and install the repair before further flight. 9. If cracks are found in fastener holes in the tension ties or frames, before further flight, do the repair as follows: a. For small cracks at hole locations that can be removed by oversizing the hole to a maximum hole diameter of 0.313 inch, do the OVERSIZE HOLE REPAIR steps. b. For any frame crack that cannot be removed by doing OVERSIZE HOLE REPAIR, do the FRAME REPAIR steps. c. For any tension tie crack that cannot be removed by doing OVERSIZE HOLE REPAIR, repair the tension tie in accordance with 747-100/200/300 SRM 53-10-11, Figure 2. 10. Assemble parts with new fasteners in accordance with Figure 1. Where fasteners are not specified in Figure 1 or in a repair, install original size and type fasteners. 11. Repeat the INSPECTION steps at the intervals specified in paragraph 1.E., Compliance. **Group 1, Configuration 2: INSPECTION CAUTION:**  DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSIONOriginal Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 48 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** TIES. 1. Inspect the tension ties, frames, and associated parts for cracks in accordance with Figure 3. **NOTE:** If there are insulation blanket studs attached to the frames in the inspection area, check to see if the studs are bonded on to the frames, or if they go through holes in the frames. At locations where the studs go through holes in the frames, remove the stud and inspect the hole in accordance with Figure 21. 2. If no cracks are found, install removed parts with new fasteners in accordance with Figure 3, and repeat the INSPECTION steps at the intervals specified in paragraph 1.E., Compliance. 3. On airplanes that have a tension tie at STA 760, but do not have an extended upper deck modification or other modifications, there is a full-length aluminum doubler installed at STA 760 between the tension tie channels. If the doubler is cracked, before further flight, do one of the following steps: a. For small cracks at hole locations that can be removed by oversizing the hole to a maximum hole diameter of 0.313 inch, do the OVERSIZE HOLE REPAIR steps. b. If any crack is found in the doubler that cannot be removed by doing OVERSIZE HOLE REPAIR, repair in accordance with 747-100/200/300 SRM 53-10-11 Figure 2, or contact Boeing for repair instructions. 4. At STA 940, there is a full length aluminum reinforcing channel installed on the bottom of the tension tie. If the aluminum channel is cracked, repair it before further flight. Repair in accordance with 747-100/200/300 SRM 53-10-11 Figure 2 Detail XI, or contact Boeing for repair instructions. 5. If any crack is found in a shear web component, contact Boeing for repair instructions. **NOTE:** Shear webs are installed at STA 820 - STA 840 or STA 840 - STA 860, depending on the Airplane. 6. On built-up frames, if the shear tie is cracked at the flange common to the skin, do the following: a. Remove fasteners as required and do an open-hole HFEC inspection of the skin for cracks at all fastener locations common to the cracked shear tie. b. Repair the shear tie before further flight. Repair in accordance with 747-100/200/300 SRM 53-10-04 Figures 132 through 139, the FRAME REPAIR steps, or contact Boeing for repair instructions. 7. If a crack is found in the skin, repair the skin before further flight in accordance with 747-100/200/ 300 SRM 53-30-03, or contact Boeing for repair instructions. 8. If cracks are found in holes where insulation blanket studs go through the frames, repair in accordance with 747-100/200/300 SRM 53-10-04 Figures 132 through 139, the FRAME REPAIR steps, or contact Boeing for repair instructions and install the repair before further flight. 9. If cracks are found in fastener holes in the tension ties or frames, before further flight, do the repair as follows:Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 49 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** a. For small cracks at hole locations that can be removed by oversizing the hole to a maximum hole diameter of 0.313 inch, do the OVERSIZE HOLE REPAIR steps. b. For any frame crack that cannot be removed by doing OVERSIZE HOLE REPAIR, do the FRAME REPAIR steps. c. For any tension tie crack that cannot be removed by doing OVERSIZE HOLE REPAIR, repair the tension tie in accordance with 747-100/200/300 SRM 53-10-11, Figure 2. 10. Assemble parts with new fasteners in accordance with Figure 3. Where fasteners are not specified in Figure 3 or in a repair, install original size and type fasteners. 11. Repeat the INSPECTION steps at the intervals specified in paragraph 1.E., Compliance. **Group 1, Configuration 3: INSPECTION CAUTION:**  DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. 1. Inspect the tension ties, frames, and associated parts for cracks in accordance with Figure 5. **NOTE:** If there are insulation blanket studs attached to the frames in the inspection area, check to see if the studs are bonded on to the frames, or if they go through holes in the frames. At locations where the studs go through holes in the frames, remove the stud and inspect the hole in accordance with Figure 21. 2. If no cracks are found, install removed parts with new fasteners in accordance with Figure 5, and repeat the INSPECTION steps at the intervals specified in paragraph 1.E., Compliance. 3. At STA 940, there is a full length aluminum reinforcing channel installed on the bottom of the tansion tie. If the aluminum channel is cracked, repair it before further flight. Repair in accordance with 747-100/200/300 SRM 53-10-11 Figure 2, or contact Boeing for repair instructions. 4. If any crack is found in a shear web component, contact Boeing for repair instructions. **NOTE:** Shear webs are installed at STA 820 - STA 840 or STA 840 - STA 860, depending on the Airplane. 5. On built-up frames, if the shear tie is cracked at the flange common to the skin, do the following: a. Remove fasteners as required and do an open-hole HFEC inspection of the skin for cracks at all fastener locations common to the cracked shear tie. b. Repair the shear tie before further flight. Repair in accordance with 747-100/200/300 SRM 53-10-04 Figures 132 through 139, the FRAME REPAIR steps, or contact Boeing for repair instructions. 6. If a crack is found in the skin, repair the skin before further flight in accordance with 747-100/200/ 300 SRM 53-30-03, or contact Boeing for repair instructions.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 50 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

7. If cracks are found in holes where insulation blanket studs go through the frames, repair in accordance with 747-100/200/300 SRM 53-10-04 Figures 132 through 139, the FRAME REPAIR steps, or contact Boeing for repair instructions and install the repair before further flight. 8. If cracks are found in fastener holes in the tension ties or frames, before further flight, do the repair as follows: a. For small cracks at hole locations that can be removed by oversizing the hole to a maximum hole diameter of 0.313 inch, do the OVERSIZE HOLE REPAIR steps. b. For any frame crack that cannot be removed by doing OVERSIZE HOLE REPAIR, do the FRAME REPAIR steps. c. For any tension tie crack that cannot be removed by doing OVERSIZE HOLE REPAIR, repair the tension tie in accordance with 747-100/200/300 SRM 53-10-11, Figure 2. 9. Assemble parts with new fasteners in accordance with Figure 5. Where fasteners are not specified in Figure 5 or in a repair, install original size and type fasteners. 10. Repeat the INSPECTION steps at the intervals specified in paragraph 1.E., Compliance. **Group 1, Configuration 4: INSPECTION CAUTION:**  DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. 1. Inspect the tension ties, frames, and associated parts for cracks in accordance with Figure 7. **NOTE:** If there are insulation blanket studs attached to the frames in the inspection area, check to see if the studs are bonded on to the frames, or if they go through holes in the frames. At locations where the studs go through holes in the frames, remove the stud and inspect the hole in accordance with Figure 21. 2. If no cracks are found, install removed parts with new fasteners in accordance with Figure 7, and repeat the INSPECTION steps at the intervals specified in paragraph 1.E., Compliance. 3. On airplanes that have a tension tie at STA 760, but do not have an extended upper deck modification or other modifications, there is a full-length aluminum doubler installed at STA 760 between the tension tie channels. If the doubler is cracked, before further flight, do one of the following steps: a. For small cracks at hole locations that can be removed by oversizing the hole to a maximum hole diameter of 0.313 inch, do the OVERSIZE HOLE REPAIR steps. b. If any crack is found in the doubler that cannot be removed by doing OVERSIZE HOLE REPAIR, repair in accordance with 747-100/200/300 SRM 53-10-11 Figure 2, or contact Boeing for repair instructions.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 51 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

4. At STA 940, there is a full length aluminum reinforcing channel installed on the bottom of the tension tie. If the aluminum channel is cracked, repair it before further flight. Repair in accordance with 747-100/200/300 SRM 53-10-11 Figure 2, or contact Boeing for repair instructions. 5. If any crack is found in a shear web component, contact Boeing for repair instructions. **NOTE:** Shear webs are installed at STA 820 - STA 840 or STA 840 - STA 860, depending on the Airplane. 6. On built-up frames, if the shear tie is cracked at the flange common to the skin, do the following: a. Remove fasteners as required and do an open-hole HFEC inspection of the skin for cracks at all fastener locations common to the cracked shear tie. b. Repair the shear tie before further flight. Repair in accordance with 747-100/200/300 SRM 53-10-04 Figures 132 through 139, the FRAME REPAIR steps, or contact Boeing for repair instructions. 7. If a crack is found in the skin, repair the skin before further flight in accordance with 747-100/200/ 300 SRM 53-30-03, or contact Boeing for repair instructions. 8. If cracks are found in holes where insulation blanket studs go through the frames, repair in accordance with 747-100/200/300 SRM 53-10-04 Figures 132 through 139, the FRAME REPAIR steps, or contact Boeing for repair instructions and install the repair before further flight. 9. If cracks are found in fastener holes in the tension ties or frames, before further flight, do the repair as follows: a. For small cracks at hole locations that can be removed by oversizing the hole to a maximum hole diameter of 0.313 inch, do the OVERSIZE HOLE REPAIR steps. b. For any frame crack that cannot be removed by doing OVERSIZE HOLE REPAIR, do the FRAME REPAIR steps. c. For any tension tie crack that cannot be removed by doing OVERSIZE HOLE REPAIR, repair the tension tie in accordance with 747-100/200/300 SRM 53-10-11, Figure 2. 10. Assemble parts with new fasteners in accordance with Figure 7. Where fasteners are not specified in Figure 7 or in a repair, install original size and type fasteners. 11. Repeat the INSPECTION steps at the intervals specified in paragraph 1.E., Compliance. **Group 2: INSPECTION CAUTION:**  DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. 1. Inspect the tension ties, frames, and associated parts for cracks in accordance with Figure 10.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 52 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT NOTE:**  If there are insulation blanket studs attached to the frames in the inspection area, check to see if the studs are bonded on to the frames, or if they go through holes in the frames. At locations where the studs go through holes in the frames, remove the stud and inspect the hole in accordance with Figure 21. 2. If no cracks are found, install removed parts with new fasteners in accordance with Figure 10, and repeat the INSPECTION steps at the intervals specified in paragraph 1.E., Compliance. 3. At STA 940, there is a full length aluminum reinforcing channel installed on the bottom of the tension tie. If the aluminum channel is cracked, repair it before further flight. Repair in accordance with 747-400F SRM 53-20-30 Repair 1, or contact Boeing for repair instructions. 4. If any crack is found in a shear web component, contact Boeing for repair instructions. **NOTE:** Shear webs are installed at STA 780 to STA 800. 5. On built-up frames, if the shear tie is cracked at the flange common to the skin, do the following: a. Remove fasteners as required and do an open-hole HFEC inspection of the skin for cracks at all fastener locations common to the cracked shear tie. b. Repair the shear tie before further flight. Repair in accordance with 747-400F SRM 53-20-07 Repairs 1 - 10, do the FRAME REPAIR steps, or contact Boeing for repair instructions. 6. If a crack is found in the skin, repair the skin before further flight in accordance with 747-400F SRM 53-00-01, or contact Boeing for repair instructions. 7. If cracks are found in holes where insulation blanket studs go through the frames, repair before further flight. Repair in accordance with 747-400F SRM 53-20-07 Repairs 1 - 10, or contact Boeing for repair instructions. 8. If cracks are found in fastener holes in the tension ties or frames, before further flight, do the repair as follows: a. For small cracks at hole locations that can be removed by oversizing the hole to a maximum hole diameter of 0.313 inch, do the OVERSIZE HOLE REPAIR steps. b. For any frame crack that cannot be removed by doing OVERSIZE HOLE REPAIR, do the FRAME REPAIR steps. c. For any tension tie crack that cannot be removed by doing OVERSIZE HOLE REPAIR, repair the tension tie in accordance with 747-400F SRM 53-20-30, Repair 1. 9. Assemble parts with new fasteners in accordance with Figure 10. Where fasteners are not specified in Figure 10 or in a repair, install original size and type fasteners. 10. Repeat the INSPECTION steps at the intervals specified in paragraph 1.E., Compliance. **Group 3: INSPECTION CAUTION:**  DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENTOriginal Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 53 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. 1. Inspect the tension ties, frames, and associated parts for cracks in accordance with Figure 13. **NOTE:** If there are insulation blanket studs attached to the frames in the inspection area, check to see if the studs are bonded on to the frames, or if they go through holes in the frames. At locations where the studs go through holes in the frames, remove the stud and inspect the hole in accordance with Figure 21. 2. If no cracks are found, install removed parts with new fasteners in accordance with Figure 13, and repeat the INSPECTION steps at the intervals specified in paragraph 1.E., Compliance. 3. At STA 1140, there is a full length aluminum reinforcing channel installed at the bottom of the tension tie. If the aluminum channel is cracked, repair it before further flight. Repair in accordance with 747-SP SRM 53-19-11 Figure 1 Detail II, or contact Boeing for repair instructions. 4. If any crack is found in a shear web component, contact Boeing for repair instructions. **NOTE:** Shear webs are installed at STA 1040 to STA 1060. 5. On built-up frames, if the shear tie is cracked at the flange common to the skin, do the following: a. Remove fasteners as required and do an open-hole HFEC inspection of the skin for cracks at all fastener locations common to the cracked shear tie. b. Repair the shear tie before further flight. Repair in accordance with 747-SP SRM 53-19-02 Figures 65 - 70, do the FRAME REPAIR steps, or contact Boeing for repair instructions. 6. If a crack is found in the skin, repair the skin before further flight. Repair in accordance with 747-SP SRM 53-19-01 Figure 1, or contact Boeing for repair instructions. 7. If cracks are found in holes where insulation blanket studs go through the frames, repair before further flight. Repair in accordance with the FRAME REPAIR steps or contact Boeing for repair instructions. 8. If cracks are found in fastener holes in the tension ties or frames, before further flight, do the repair as follows: a. For small cracks at hole locations that can be removed by oversizing the hole to a maximum hole diameter of 0.313 inch, do the OVERSIZE HOLE REPAIR steps. b. For any frame crack that cannot be removed by doing OVERSIZE HOLE REPAIR, do the FRAME REPAIR steps. c. For any tension tie crack that cannot be removed by doing OVERSIZE HOLE REPAIR, repair the tension tie in accordance with 747-SP SRM 53-19-11, Figure 1. 9. Assemble parts with new fasteners in accordance with Figure 13. Where fasteners are not specified in Figure 13 or in a repair, install original size and type fasteners.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 54 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

10. Repeat the INSPECTION steps at the intervals specified in paragraph 1.E., Compliance. **Group 4: INSPECTION CAUTION:**  DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. 1. Inspect the tension ties, frames, and associated parts for cracks in accordance with Figure 15. **NOTE:** If there are insulation blanket studs attached to the frames in the inspection area, check to see if the studs are bonded on to the frames, or if they go through holes in the frames. At locations where the studs go through holes in the frames, remove the stud and inspect the hole in accordance with Figure 21. 2. If no cracks are found, install removed parts with new fasteners in accordance with Figure 15, and repeat the INSPECTION steps at the intervals specified in paragraph 1.E., Compliance. 3. At STA 940, there is a full length aluminum reinforcing channel installed on the bottom of the tension tie. If the aluminum channel is cracked, repair it before further flight. Repair in accordance with 747-100/200/300 SRM 53-10-11 Figure 2, or contact Boeing for repair instructions. 4. On some airplanes, the tension tie at STA 760 is a built-up beam made from an upper chord, lower chord, and a shear web in between. This tension tie looks similar to a floor beam, but is considered a tension tie. Do a detailed inspection of the upper chord, lower chord, and web of the tension tie at STA 760 from end to end. If any crack is found on the built up beam, repair before further flight. If necessary, contact Boeing for Repair instructions. 5. If any crack is found in a shear web component, contact Boeing for repair instructions. **NOTE:** Shear webs are installed either between STA 820 and STA 840, or between STA 840 and STA 860, depending on the airplane. 6. On built-up frames, if the shear tie is cracked at the flange common to the skin, do the following: a. Remove fasteners as required and do an open-hole HFEC inspection of the skin for cracks at all fastener locations common to the cracked shear tie. b. Repair the shear tie before further flight. Repair in accordance with 747-100/200/300 SRM 53-10-04 Figures 132 through 139, the FRAME REPAIR steps, or contact Boeing for repair instructions. 7. If a crack is found in the skin, repair the skin before further flight in accordance with 747-100/200/ 300 SRM 53-30-03, or contact Boeing for repair instructions. 8. If cracks are found in holes where insulation blanket studs go through the frames, repair in accordance with 747-100/200/300 SRM 53-10-04 Figures 132 through 139, the FRAME REPAIR steps, or contact Boeing for repair instructions and install the repair before further flight.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 55 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

9. If cracks are found in fastener holes in the tension ties or frames, before further flight, do the repair as follows: a. For small cracks at hole locations that can be removed by oversizing the hole to a maximum hole diameter of 0.313 inch, do the OVERSIZE HOLE REPAIR steps. b. For any frame crack that cannot be removed by doing OVERSIZE HOLE REPAIR, do the FRAME REPAIR steps. c. For any tension tie crack that cannot be removed by doing OVERSIZE HOLE REPAIR, repair the tension tie in accordance with 747-100/200/300 SRM 53-10-11, Figure 2. 10. Assemble parts with new fasteners in accordance with Figure 15. Where fasteners are not specified in Figure 15 or in a repair, install original size and type fasteners. 11. Repeat the INSPECTION steps at the intervals specified in paragraph 1.E., Compliance. **Group 5: INSPECTION CAUTION:**  DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. 1. Inspect the tension ties, frames, and associated parts for cracks in accordance with Figure 17. **NOTE:** If there are insulation blanket studs attached to the frames in the inspection area, check to see if the studs are bonded on to the frames, or if they go through holes in the frames. At locations where the studs go through holes in the frames, remove the stud and inspect the hole in accordance with Figure 21. 2. If no cracks are found, install removed parts with new fasteners in accordance with Figure 17, and repeat the INSPECTION steps at the intervals specified in paragraph 1.E., Compliance. 3. At STA 940, there is a full length aluminum reinforcing channel installed on the bottom of the tension tie. If the aluminum channel is cracked, repair it before further flight. Repair in accordance with 747-100/200/300 SRM 53-10-11 Figure 2 or contact Boeing for repair instructions. 4. The tension tie at STA 760 is a built-up beam made from an upper chord, lower chord, and a shear web in between. This tension tie looks similar to a floor beam, but is considered a tension tie. Do a detailed inspection of the upper chord, lower chord, and web of the tension tie at STA 760 from end to end. If any crack is found on the built up beam, repair before further flight. If necessary, contact Boeing for Repair instructions. 5. If any crack is found in a shear web component, contact Boeing for repair instructions. **NOTE:** Shear webs are installed at STA 820 to STA 840. 6. On built-up frames, if the shear tie is cracked at the flange common to the skin, do the following:Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 56 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** a. Remove fasteners as required and do an open-hole HFEC inspection of the skin for cracks at all fastener locations common to the cracked shear tie. b. Repair the shear tie before further flight. Repair in accordance with 747-100/200/300 SRM 53-10-04 Figures 132 through 139, the FRAME REPAIR steps, or contact Boeing for repair instructions. 7. If a crack is found in the skin, repair the skin before further flight in accordance with 747-100/200/ 300 SRM 53-30-03, or contact Boeing for repair instructions. 8. If cracks are found in holes where insulation blanket studs go through the frames, repair in accordance with 747-100/200/300 SRM 53-10-04 Figures 132 through 139, the FRAME REPAIR steps, or contact Boeing for repair instructions and install the repair before further flight. 9. If cracks are found in fastener holes in the tension ties or frames, before further flight, do the repair as follows: a. For small cracks at hole locations that can be removed by oversizing the hole to a maximum hole diameter of 0.313 inch, do the OVERSIZE HOLE REPAIR steps. b. For any frame crack that cannot be removed by doing OVERSIZE HOLE REPAIR, do the FRAME REPAIR steps. c. For any tension tie crack that cannot be removed by doing OVERSIZE HOLE REPAIR, repair the tension tie in accordance with 747-100/200/300 SRM 53-10-11, Figure 2. 10. Assemble parts with new fasteners in accordance with Figure 17. Where fasteners are not specified in Figure 17 or in a repair, install original size and type fasteners. 11. Repeat the INSPECTION steps at the intervals specified in paragraph 1.E., Compliance. **Group 6: INSPECTION CAUTION:**  DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. 1. Inspect the tension ties, frames, and associated parts for cracks in accordance with Figure 19. **NOTE:** If there are insulation blanket studs attached to the frames in the inspection area, check to see if the studs are bonded on to the frames, or if they go through holes in the frames. At locations where the studs go through holes in the frames, remove the stud and inspect the hole in accordance with Figure 21. 2. If no cracks are found, install removed parts with new fasteners in accordance with Figure 19, and repeat the INSPECTION steps at the intervals specified in paragraph 1.E., Compliance. 3. At STA 940, there is a full length aluminum reinforcing channel installed on the bottom of the tension tie. If the aluminum channel is cracked, repair it before further flight. Repair in accordance with 747-100/200/300 SRM 53-10-11 Figure 2, or contact Boeing for repair instructions.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 57 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

4. If any crack is found in a shear web component, contact Boeing for repair instructions. **NOTE:** Shear webs are installed at STA 820 to STA 840. 5. On built-up frames, if the shear tie is cracked at the flange common to the skin, do the following: a. Remove fasteners as required and do an open-hole HFEC inspection of the skin for cracks at all fastener locations common to the cracked shear tie. b. Repair the shear tie before further flight. Repair in accordance with 747-100/200/300 SRM 53-10-04 Figures 132 through 139, the FRAME REPAIR steps, or contact Boeing for repair instructions. 6. If a crack is found in the skin, repair the skin before further flight in accordance with 747-100/200/ 300 SRM 53-30-03, or contact Boeing for repair instructions. 7. If cracks are found in holes where insulation blanket studs go through the frames, repair in accordance with 747-100/200/300 SRM 53-10-04 Figures 132 through 139, the FRAME REPAIR steps, or contact Boeing for repair instructions and install the repair before further flight. 8. If cracks are found in fastener holes in the tension ties or frames, before further flight, do the repair as follows: a. For small cracks at hole locations that can be removed by oversizing the hole to a maximum hole diameter of 0.313 inch, do the OVERSIZE HOLE REPAIR steps. b. For any frame crack that cannot be removed by doing OVERSIZE HOLE REPAIR, do the FRAME REPAIR steps. c. For any tension tie crack that cannot be removed by doing OVERSIZE HOLE REPAIR, repair the tension tie in accordance with 747-100/200/300 SRM 53-10-11, Figure 2. 9. Assemble parts with new fasteners in accordance with Figure 19. Where fasteners are not specified in Figure 19 or in a repair, install original size and type fasteners. 10. Repeat the INSPECTION steps at the intervals specified in paragraph 1.E., Compliance. **Group 1, Configuration 1: OVERSIZE HOLE REPAIR CAUTION:**  DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. 1. Remove small cracks at holes by oversizing the hole in accordance with Figure 2. 2. If any edge margin is less than 1.5D in the frame webs, do the FRAME REPAIR steps. 3. If any edge margin is less than 1.5D in the fail-safe chord, replace the chord. It is acceptable to splice in a new segment of fail-safe chord in accordance with 747-100/200/300 SRM 51-40-03. The dimensions of the new chord should be increased to maintain minimum edge margin of 2 times fastener diameter (2D).Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 58 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

4. If any edge margin is less than 1.5D in the tension tie or tension tie steel plate, repair the tension tie in accordance with 747-100/200/300 SRM 53-10-11 Figure 2, or contact Boeing for repair instructions. **Group 1, Configuration 2: OVERSIZE HOLE REPAIR CAUTION:**  DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. 1. Remove small cracks at holes by oversizing the hole in accordance with Figure 4. 2. If any edge margin is less than 1.5D in the frame webs, do the FRAME REPAIR steps. 3. If any edge margin is less than 1.5D in the fail-safe chord, replace the chord. It is acceptable to splice in a new segment of fail-safe chord in accordance with 747-100/200/300 SRM 51-40-03. The dimensions of the new chord should be increased to maintain minimum edge margin of 2 times fastener diameter (2D). 4. If any edge margin is less than 1.5D in the tension tie or tension tie steel plate, repair the tension tie in accordance with 747-100/200/300 SRM 53-10-11 Figure 2, or contact Boeing for repair instructions. **Group 1, Configuration 3: OVERSIZE HOLE REPAIR CAUTION:**  DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. 1. Remove cracks in holes by oversizing hole in accordance with Figure 6. 2. If any edge margin is less than 1.5D in the frame webs, do the FRAME REPAIR steps. 3. If any edge margin is less than 1.5D in the fail-safe chord, replace the chord. It is acceptable to splice in a new segment of fail-safe chord in accordance with 747-100/200/300 SRM 51-40-03. The dimensions of the new chord should be increased to maintain minimum edge margin of 2 times fastener diameter (2D). 4. If any edge margin is less than 1.5D in the tension tie or tension tie steel plate, repair the tension tie in accordance with 747-100/200/300 SRM 53-10-11 Figure 2, or contact Boeing for repair instructions. **Group 1, Configuration 4: OVERSIZE HOLE REPAIR CAUTION:**  DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSIONOriginal Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 59 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** TIES. 1. Remove cracks in holes by oversizing hole in accordance with Figure 8. 2. If any edge margin is less than 1.5D in the frame webs, do the FRAME REPAIR steps. 3. If any edge margin is less than 1.5D in the fail-safe chord, replace the chord. It is acceptable to splice in a new segment of fail-safe chord in accordance with 747-100/200/300 SRM 51-40-03. The dimensions of the new chord should be increased to maintain minimum edge margin of 2 times fastener diameter (2D). 4. If any edge margin is less than 1.5D in the tension tie or tension tie steel plate, repair the tension tie in accordance with 747-100/200/300 SRM 53-10-11 Figure 2, or contact Boeing for repair instructions. **Group 2: OVERSIZE HOLE REPAIR CAUTION:**  DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. 1. Remove small cracks at holes by oversizing holes in accordance with Figure 11. 2. If any edge margin is less than 1.5D in the frame webs, do the FRAME REPAIR steps. 3. If any edge margin is less than 1.5D in the fail-safe chord, replace the chord. It is acceptable to Splice in a new segment of fail-safe chord in accordance with 747-400F SRM 51-70-11. The dimensions of the new chord should be increased to maintain minimum edge margin of 2D. 4. If any edge margin is less than 1.5D in the tension tie or tension tie steel plate, repair the tension tie in accordance with 747-400F SRM 53-20-30 Repair 1, or contact Boeing for repair instructions. **Group 3: OVERSIZE HOLE REPAIR CAUTION:**  DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. 1. Remove small cracks at holes by oversizing hole in accordance with Figure 14. 2. If any edge margin is less than 1.5D in the frame webs, do the FRAME REPAIR steps. 3. If any edge margin is less than 1.5D in the fail-safe chord, replace the chord. It is acceptable to Splice in a new segment of fail-safe chord in accordance with 747-SP SRM 51-40-03. The dimensions of the new chord should be increased to maintain minimum edge margin of 2D. 4. If any edge margin is less than 1.5D in the tension tie or tension tie steel plate, repair the tension tie in accordance with 747-SP SRM 53-19-11 Figure 1, or contact Boeing for repair instructions.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 60 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

**Group 4: OVERSIZE HOLE REPAIR CAUTION:**  DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. 1. Remove any small cracks at holes by oversizing hole in accordance with Figure 16. 2. If any edge margin is less than 1.5D in the frame webs, do the FRAME REPAIR steps. 3. If any edge margin is less than 1.5D in the fail-safe chord, replace the chord. It is acceptable to splice in a new segment of fail-safe chord in accordance with 747-100/200/300 SRM 51-40-03. The dimensions of the new chord should be increased to maintain minimum edge margin of 2 times fastener diameter (2D). 4. If any edge margin is less than 1.5D in the tension tie or tension tie steel plate, repair the tension tie in accordance with 747-100/200/300 SRM 53-10-11 Figure 2, or contact Boeing for repair instructions. **Group 5: OVERSIZE HOLE REPAIR CAUTION:**  DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. 1. Remove small cracks at holes by oversizing hole in accordance with Figure 18. 2. If any edge margin is less than 1.5D in the frame webs, do the FRAME REPAIR steps. 3. If any edge margin is less than 1.5D in the fail-safe chord, replace the chord. It is acceptable to splice in a new segment of fail-safe chord in accordance with 747-100/200/300 SRM 51-40-03. The dimensions of the new chord should be increased to maintain minimum edge margin of 2 times fastener diameter (2D). 4. If any edge margin is less than 1.5D in the tension tie or tension tie steel plate, repair the tension tie in accordance with 747-100/200/300 SRM 53-10-11 Figure 2, or contact Boeing for repair instructions. **Group 6: OVERSIZE HOLE REPAIR CAUTION:**  DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. 1. Remove small cracks at holes by oversizing hole in accordance with Figure 20. 2. If any edge margin is less than 1.5D in the frame webs, do the FRAME REPAIR steps.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 61 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

3. If any edge margin is less than 1.5D in the fail-safe chord, replace the chord. It is acceptable to splice in a new segment of fail-safe chord in accordance with 747-100/200/300 SRM 51-40-03. The dimensions of the new chord should be increased to maintain minimum edge margin of 2 times fastener diameter (2D). 4. If any edge margin is less than 1.5D in the tension tie or tension tie steel plate, repair the tension tie in accordance with 747-100/200/300 SRM 53-10-11 Figure 2, or contact Boeing for repair instructions. **Group 1: FRAME REPAIR** 1. For frame cracks at STA 820 through STA 940 (built up frames) repair in accordance with 747-100/200/300 SRM 53-10-04 Figures 132 through 139. 2. For frame cracks at stations forward of STA 820 (machined frames), contact Boeing for repair instructions. **Group 2: FRAME REPAIR** 1. For frame cracks at STA 820 through STA 940 (built up frames) repair in accordance with 747-400F SRM 53-20-07 Repairs 1 through 10. 2. For frame cracks at stations forward of STA 820 (machined frames), contact Boeing for repair instructions. **Group 3: FRAME REPAIR** 1. Repair frame cracks in accordance with 747-SP SRM 53-19-02 Figures 65 through 70. **Group 4-6: FRAME REPAIR** 1. For frame cracks at STA 820 through STA 940 (built up frames) repair in accordance with 747-100/200/300 SRM 53-10-04 Figures 132 through 139. 2. For frame cracks at stations forward of STA 820 (machined frames), contact Boeing for repair instructions. **Group 1: RESTORATION** 1. Apply BMS 3-23, Type II, Corrosion Inhibiting Compound to all areas where fasteners were removed, and where repairs were done. Refer to SOPM 20-41-05 as an accepted procedure. 2. Install insulation. Refer to 747-100/200/300 AMM 25-14-02 as an accepted procedure. 3. Install ceiling panels. Refer to 747-100/200/300 AMM 25-22-04 as an accepted procedure. 4. Install seats between STA 760 and STA 940. Refer to 747-100/200/300 AMM 25-25-01 as an accepted procedure. 5. Return airplane to a Serviceable Condition.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 62 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

**Group 2: RESTORATION** 1. Apply BMS 3-23, Type II, Corrosion Inhibiting Compound to all areas where fasteners were removed, and where repairs were done. Refer to SOPM 20-41-05 as an accepted procedure. 2. Install insulation. Refer to 747-400 AMM 25-21-04 as an accepted procedure 3. Install ceiling panels. Refer to Figure 12 for an accepted procedure. 4. Return airplane to a serviceable condition. **Group 3: RESTORATION** 1. Apply BMS 3-23, Type II, Corrosion Inhibiting Compound to all areas where fasteners were removed, and where repairs were done. Refer to SOPM 20-41-05 as an accepted procedure. 2. Install insulation. Refer to 747-100/200/300 AMM 25-14-02 as an accepted procedure. 3. Install ceiling panels. Refer to 747-100/200/300 AMM 25-22-04 as an accepted procedure. 4. Install seats between STA 1040 and STA 1140. Refer to 747-100/200/300 AMM 25-25-01 as an accepted procedure. 5. Return airplane to a serviceable condition. **Group 4-6: RESTORATION** 1. Apply BMS 3-23, Type II, Corrosion Inhibiting Compound to all areas where fasteners were removed, and where repairs were done. Refer to SOPM 20-41-05 as an accepted procedure. 2. Install insulation. Refer to 747-100/200/300 AMM 25-14-02 as an accepted procedure. 3. Install ceiling panels. Refer to 747-100/200/300 AMM 25-22-04 as an accepted procedure. 4. Return airplane to a serviceable condition. **Group 2: MORE WORK - ONE TIME INSPECTION FOR CORRECT CONFIGURATION (Revision 1)**  1. Do a general visual inspection of the tension ties to ensure all tension ties have the correct configuration where they attach to the side of body frames. Do this inspection in accordance with Figure 22. 2. If all tension ties match the correct configurations shown in Figure 22, then no more work is required for this one time inspection. 3. If any tension tie does not match the correct configuration shown in Figure 22, do the following steps, as applicable: a. Do the detailed and open hole HFEC inspections for cracks in the tension tie and frame in accordance with Figure 23. Do these inspections at both ends of any tension tie where the configuration did not match the correct configuration shown in Figure 22.Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 63 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** b. If any crack is found in a tension tie channel, repair the cracked tension tie in accordance with 747-400F SRM 53-20-30 Repair 1, or contact Boeing for repair instructions. c. If any crack is found in a frame from STA 820 through STA 940, repair in accordance with 747-400F SRM 53-20-07 Repairs 1 through 10. d. If any crack is found in a frame forward of STA 820, contact Boeing for repair instructions. e. If no crack is found, or if cracks have been repaired, install the correct configuration for the tension ties at locations where the incorrect configuration was found. If necessary, contact Boeing for installation instructions.**FIGURE 1: INSPECTION - Group 1, Configuration 1** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 64 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 1: INSPECTION**  **- Group 1, Configuration 1**

760 STA 940 STA

760 STA

940 STA FRAME (TYPICAL)

(2 LOCATIONS) HORIZONTAL SHEAR WEB (2 LOCATIONS) SLOPING SHEAR WEB (TYPICAL) TENSION TIE

B SEE A SEE 9 10

OR SEE C OR SEE D

FWD381593

**(SHEET 1 OF 9) FIGURE 1: INSPECTION - Group 1, Configuration 1**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 65 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

REMOVED STEEL PLATE (KEEP)

SURFACE HFEC OPEN HOLE HFEC EXISTING FASTENERS (REF) BL26 STRINGERS AT ALL LOCATIONS) VERTICAL POST (NOT PRESENT

CHORD FAILSAFE



### VIEW LOOKING AFT (TYPICAL) SHEAR TIES

VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION, ACTUAL FASTENER PATTERN AND CONFIGURATION TO VERTICAL POST FITTING COMMON

747-53-2371, FIGURE 3) (TYPICAL WITHOUT REPAIR OR MODIFICATION PER SERVICE BULLETIN FRAME SKIN

A A 8

6 1 4 UP

INBD 2



### A 5

9
13 14 11

7D36589

**(SHEET 2 OF 9) FIGURE 1: INSPECTION - Group 1, Configuration 1**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 66 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

REMOVED STEEL PLATE (KEEP)

EXISTING FASTENERS SURFACE HFEC OPEN HOLE HFEC TO VERTICAL POST FITTING COMMON

SHEAR TIES SKIN

CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN AND BL26 STRINGERS

CHORD FAILSAFE FRAME ALL LOCATIONS) (NOT PRESENT AT VERTICAL POST

747-53-2371 FIGURE 3)

(TYPICAL WITHOUT REPAIR OR MODIFICATION PER SERVICE BULLETIN 

### VIEW LOOKING AFT B B 7

1 4 2 6



### B UP
OUTBD 5

9

14 13 11

8D36683

**(SHEET 3 OF 9) FIGURE 1: INSPECTION - Group 1, Configuration 1**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 67 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

REMOVED STEEL PLATE (KEEP)

EXISTING FASTENERS (REF) OPEN HOLE HFEC SURFACE HFEC SKIN REMOVED ALUMINUM REPAIR STRAP (KEEP)

BL26 STRINGERS FRAME

FAILSAFE CHORD 

### VIEW LOOKING AFT SHEAR TIES (TYPICAL)

NOTE: TYPICAL CONFIGURATION, ACTUAL FASTENER PATTERN AND CONFIGURATION VARIES DEPENDING ON LOCATION. (TYPICAL WITH REPAIR OR MODIFICATION PER SERVICE BULLETIN 747-53-2371 FIGURE 3, OR WITH OPTIONAL MODIFICATION PER SERVICE BULLETIN 747-53-2088) ALUMINUM REPAIR STRAP STEEL PLATE VERTICAL POST (ACTUAL LOCATION MAY VARY)

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL



### A-A G G A A
E E 8

6

1 4 UP

INBD 2



### C 5

9

13 11

7

12 12

3 4 3 4

2 9 14D36606

**(SHEET 4 OF 9) FIGURE 1: INSPECTION - Group 1, Configuration 1**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 68 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BL26 STRINGERS FRAME VERTICAL POST (ACTUAL LOCATION MAY VARY)

FAILSAFE CHORD 

### VIEW LOOKING AFT SHEAR TIES (TYPICAL)

NOTE: TYPICAL CONFIGURATION, ACTUAL FASTENER PATTERN AND CONFIGURATION VARIES DEPENDING ON LOCATION. (TYPICAL WITH REPAIR OR MODIFICATION PER SERVICE BULLETIN 747-53-2371 FIGURE 3, OR WITH OPTIONAL MODIFICATION PER SERVICE BULLETIN 747-53-2088) ALUMINUM REPAIR STRAP STEEL PLATE REMOVED STEEL PLATE (KEEP)

EXISTING FASTENERS (REF) OPEN HOLE HFEC SURFACE HFEC SKIN REMOVED ALUMINUM REPAIR STRAP (KEEP)

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL



### B-B G G

B B E E 8

6
1 4 UP
INBD 2



### D 5

9

13 14 11

7 3 12

2 4

9D36686

**(SHEET 5 OF 9) FIGURE 1: INSPECTION - Group 1, Configuration 1**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 69 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

FRAME

ALUMINUM CHANNEL

HORIZONTAL SHEAR WEB TENSION TIE AFT CHANNEL (TYPICAL)

STEEL PLATE

TENSION TIE FWD CHANNEL (TYPICAL) 

### C-C

E-E (STA 940 ONLY)

(AT LOCATIONS WITH A SHEAR WEB) (AT ALL OTHER

LOCATIONS) 

### D-D

D-D D-D

G-G 2 1

2 1 2 1 2 1

9

9 9 9

2 1 3 12 4 9

9 10D36690

**(SHEET 6 OF 9) FIGURE 1: INSPECTION - Group 1, Configuration 1**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 70 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** This Figure applies to Group 1, Configuration 1: The step numbers shown below agree with the numbers shown in the circle symbols in the Figure. **CAUTION:** UNLESS THE AIRPLANE IS SUPPORTED IN THE JIGGED POSITION, DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. **STEP TASK NAME Part Number NOTES** 1 Remove Fasteners - (a) 2 Remove/Keep Steel Plates 65B09631-( ) - 3 Remove/Keep Aluminum Repair Strap - (n) 4 Inspect Fastener Holes in the Frame and Frame doubler (if installed) - (b) Tension Tie channels, and all aluminum parts in the stackup. 65B09631-( ) (b) 5 Inspect Steel Plates 65B09631-( ) (c) 6 Inspect Tension Tie forward and aft channels 65B09631-( ) (d) 7 Inspect Frame Structure (e) 8 Inspect Skin (f) 9 Inspect Tension Tie forward and aft channels and associated parts attached to the Tension Tie channels 65B09631-( ) (g)

10 Inspect Tension Ties, Shear Webs, Aluminum Channel 65B09631-( ) 65B09661 (g) 11 Install (Kept) Steel Plates 65B09631-( ) (h) 12 Install (Kept) Aluminum Repair Strap - (n) 13 **CAUTION:** If fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations common to the Steel Plates. Install washers under nuts. (i) (j) (l) (m) (o) Washers BACW10BP( )DP Nuts BACN10YT( )CD 14 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations NOT common to the Steel Plates. Install washers under nuts. (i) (k) (l) (m) (p) Washers BACW10BP( )DP Nuts BACN10YT( )CD (a) Remove all fasteners common to steel plates, plus six fasteners inboard of the steel plate at each end of the tension tie. (b) Open-hole HFEC inspect all holes in aluminum parts, in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16.

**(SHEET 7 OF 9) FIGURE 1: INSPECTION - Group 1, Configuration 1**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 71 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

(c) One Steel Plate on each side of the airplane at each Tension Tie location. Open-hole HFEC inspect all holes in the steel plates in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 19. (d) Surface HFEC inspect the Tension Tie forward and aft channel vertical webs adjacent to and around all fastener heads and bucked tails between BL 26 and the outboard to three fastener rows inboard of the steel plates. Include all remaining fastener locations where fasteners have not been removed for inspection per step 4. Exclude areas around fasteners in the fittings common to the vertical posts at BL 39. Do inspections in accordance with 747 NDT Manual, Part 6, Subject 51- 00-00, Figure 4. (e) Do a detailed inspection for cracks in the Frames and associated parts from minimum (2) stringers above to a minimum (2) stringers below the Tension Ties. Pay special attention to the corners of the stringer cut outs. On built-up frames, also pay special attention to the fail-safe chords and shear ties. (f) Do this step only if cracks were found in the shear tie. If cracks were found on the shear tie, remove fasteners in the fuselage skin common to the affected shear tie and open-hole HFEC inspect the skin in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. (g) Do a detailed inspection of the Tension Tie forward and aft channels from end to end. At STA 940, do a detailed inspection of the Aluminum Channel. Pay special attention to where shear webs and other structure attach to the Tension Tie channels. Also, do a detailed inspection of the shear webs where they attach to the tension tie. (h) Only reinstall the Steel Plates if step 4 inspections reveal no cracks indications. If the Steel Plate is found cracked, before further flight, replace with new or contact Boeing for repair instructions. (i) Oversize undamaged holes up to 0.0312 inch over original as required to make holes round and to be within diameter limits for the specified hole size and fastener fit. If the holes need additional oversizing, do the OVERSIZE HOLE REPAIR steps as specified in the Work Instructions. (j) At open hole locations common to the Steel Plates, install fasteners in close ream holes in accordance with 747-100/200/300 SRM 51-30-05. Install fasteners wet with BMS 3-27 or BMS 3- 38. Refer to SOPM 20-50-19 wet fastener installation method 2. If BACB30NX hex-drive bolts are installed with BMS 3-38, they must be installed with the following torque values applied to the nut: 3/16 inch bolt = 20 to 25 pound-inches. 1/4 inch bolt = 50 to 75 pound-inches. 5/16 inch bolt = 90 to 125 pound-inches. (k) At open hole locations not common to the Steel Plates, install fasteners in transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. (l) It is acceptable to substitute fasteners in accordance with 747-100/200/300 SRM 51-30-03. However, if fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. (m) New fasteners are to be supplied by the operator. **STEP TASK NAME Part Number NOTES**

**(SHEET 8 OF 9) FIGURE 1: INSPECTION - Group 1, Configuration 1**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 72 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

(n) This part is only installed on Tension Ties that have been modified in accordance with Service Bulletin 747-53-2371, Figure 3. It is not necessary to re-install this part if the affected end of the Tension Tie aft channel is being replaced (either complete replacement of the channel, or a new segment spliced in). (o) To allow for easier removal during repeat inspections, it is optional to install BACB30MR( )K( ) bolts and BACW10BP( )CD washers, with BACN11Z( )CD nuts and BACW10BP( )DP washers at fastener locations common to the steel plates. However, availability of BACB30MR( )K( ) bolts is limited. Also, if fasteners are substituted, the same type of fastener should be used throughout each joint, as shown in Appendix C, Figure F. (p) If an aluminum repair strap was installed by Service Bulletin 747-53-2371, Figure 3, and is being re-installed, install BACB30NX( )K( ) bolts inboard of the steel plate, common to the aluminum repair strap plus three fastener rows inboard of the aluminum repair strap. **STEP TASK NAME Part Number NOTES**

**(SHEET 9 OF 9) FIGURE 2: OVERSIZED HOLE RE**  **PAIR - Group 1, Configuration 1** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 73 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 2: OVERSIZED HOLE REPAIR - Group 1, Configuration 1** 

760 STA

940 STA FRAME (TYPICAL)

(TYPICAL) TENSION TIE (2 LOCATIONS) SHEAR WEB WEB HORIZONTAL

(2 LOCATIONS) SLOPING SHEAR WEB

760 STA 940 STA

B OR SEE A OR SEE C SEE D SEE

FWD380701

**(SHEET 1 OF 7) FIGURE 2: OVERSIZED HOLE REPAIR - Group 1, Configuration 1**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 74 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

STEEL PLATE SHEAR TIE STRINGER CHORD FAILSAFE

FRAME



### VIEW LOOKING AFT 747-53-2371, FIGURE 3.) (TYPICAL WITHOUT REPAIR OR MODIFICATION PER SERVICE BULLETIN

AND CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN BL26

A A 1 2 3 4



### A UP

OUTBD 5 6D36739

**(SHEET 2 OF 7) FIGURE 2: OVERSIZED HOLE RE**  **PAIR - Group 1, Configuration 1** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 75 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

STRINGER CHORD FAILSAFE

FRAME



### VIEW LOOKING AFT STEEL PLATE SHEAR TIE

AND CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN 747-53-2371 FIGURE 3) (TYPICAL WITHOUT REPAIR OR MODIFICATION PER SERVICE BULLETIN

BL26

B B 1 2 3 4



### B UP
OUTBD 5 6381991

**(SHEET 3 OF 7) FIGURE 2: OVERSIZED HOLE REPAIR - Group 1, Configuration 1**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 76 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BL26 STRINGER CHORD FAILSAFE

FRAME

747-53-2088) 747-53-2371 FIGURE 3, OR OPTIONAL MODIFICATION PER SERVICE BULLETIN (TYPICAL WITH REPAIR OR MODIFICATION PER SERVICE BULLETIN (ACTUAL LOCATION MAY VARY) ALUMINUM REPAIR STRAP
(ACTUAL LOCATION MAY VARY) TRIM LINE IN AFT TENSION CHANNEL



### VIEW LOOKING AFT

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL SHEAR TIE PLATE STEEL

AND CONFIGURATION VARIES DEPENDING ON LOCATION NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN 

### A-A A A 1 2 3 4

UP

INBD


### C 5 6380702

**(SHEET 4 OF 7) FIGURE 2: OVERSIZED HOLE RE**  **PAIR - Group 1, Configuration 1** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 77 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BL26 STRINGER CHORD FAILSAFE

FRAME

BULLETIN 747-53-2088) 747-53-2371 FIGURE 3 OR PER OPTIONAL MODIFICATION PER SERVICE (TYPICAL WITH REPAIR OR MODIFICATION PER SERVICE BULLETIN

(ACTUAL LOCATION MAY VARY) ALUMINUM REPAIR STRAP
(ACTUAL LOCATION MAY VARY) TRIM LINE IN AFT TENSION CHANNEL



### VIEW LOOKING AFT

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL SHEAR TIE PLATE STEEL

AND CONFIGURATION VARIES DEPENDING ON LOCATION NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN 

### B-B B B 1 2 3 4

UP

INBD


### D 5 6D36708

**(SHEET 5 OF 7) FIGURE 2: OVERSIZED HOLE REPAIR - Group 1, Configuration 1**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 78 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** This Figure applies to Group 1, Configuration 1: The step numbers shown below agree with the numbers shown in the circle symbols in the Figure. **NOTE:** Only do these steps at locations where crack indications are present in the Frame and/or Tension Tie and can be cleaned up by oversizing the hole to a maximum hole size of 0.313 inch. If the crack is larger, contact Boeing for repair instructions. **CAUTION:** UNLESS THE AIRPLANE IS SUPPORTED IN THE JIGGED POSITION, DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. **STEP TASK NAME PART NUMBER NOTES** 1 Oversize Holes in Tension Tie Channels, Frame, Steel Plate, associated parts in the stackup. - (a)

2 Inspect Holes in Tension Tie Channels, Frame, and associated aluminum parts in the stack up. - (b) (c)

3 Oversize Holes Tension Tie Channels, Frame, in Plate, and associated parts in the stackup. - (d) (e)

**NOTE:** Holes can only be oversized to a maximum 0.313 inch diameter. 4 Measure Edge Margin and Spacing - (f) 5 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations common to the Steel Plates. Install washers under nuts. (g) (i) (j) Washers BACW10BP( )DP Nuts BACN10YT( )CD 6 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations NOT common to the Steel Plates. Install washers under nuts. (h) (i) Washers BACW10BP( )DP Nuts BACN10YT( )CD (a) Oversize the minimum amount required to remove the cracks, in 0.0156 inches increments, up to a maximum hole size of 0.313 inch. (b) Open-hole HFEC inspect holes in the aluminum parts in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. (c) Repeat steps 1 to 2 if crack indications are still present, until there are no more crack indications. Once there are no more crack indications, go to step 3. (d) Make the final hole diameters in the entire stackup common to the steel plates within limits for close ream holes in accordance with 747-100/200/300 SRM 51-30-05. If holes are already within SRM limits for close ream holes, do not further oversize. (e) Make the final hole diameters in the stackup NOT common to the steel plates within limits for transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. If the holes are already within SRM limits for transition fit holes, do not further oversize.

**(SHEET 6 OF 7) FIGURE 2: OVERSIZED HOLE RE**  **PAIR - Group 1, Configuration 1** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 79 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

(f) A minimum 1.5D edge margin (center of hole to edge of part) and 2.5D spacing (center of hole to center of hole) should be maintained. If edge margin and spacing cannot be maintained, contact Boeing for repair instructions. (g) At open hole locations common to the Steel Plates, install fasteners in close ream holes in accordance with 747-100/200/300 SRM 51-30-05. Install fasteners wet with BMS 3-27 or BMS 3- 38. Refer to SOPM 20-50-19 wet fastener installation method 2. If BACB30NX hex-drive bolts are installed with BMS 3-38, they must be installed with the following torque values applied to the nut: 3/16 inch bolt = 20 to 25 pound-inches. 1/4 inch bolt = 50 to 75 pound-inches. 5/16 inch bolt = 90 to 125 pound-inches. (h) At open hole locations not common to the Steel Plates, install fasteners in transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. (i) It is acceptable to substitute fasteners in accordance with 747-100/200/300 SRM 51-30-03. However, if fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. (j) To allow for easier removal during repeat inspections, it is optional to install BACB30MR( )K( ) bolts and BACW10BP( )CD washers, with BACN11Z( )CD nuts and BACW10BP( )DP washers at fastener locations common to the steel plates. However, availability of BACB30MR( )K( ) bolts is limited. Also, if fasteners are substituted, the same type of fastener should be used throughout each joint, as shown in Appendix C, Figure F. **STEP TASK NAME PART NUMBER NOTES**

**(SHEET 7 OF 7) FIGURE 3: INSPECTION - Group 1, Configuration 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 80 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 3: INSPECTION - Group 1, Configuration 2** 

760 STA FRAME (TYPICAL)

(2 LOCATIONS) SLOPING SHEAR WEB

(2 LOCATIONS) HORIZONTAL SHEAR WEB (TYPICAL) TENSION TIE

800 STA 760 STA 940 STA

940 STA FWD 9

D OR SEE B SEE
A SEE 9

8

F SEE

SEE OR SEE C E381603

**(SHEET 1 OF 10) FIGURE 3: INSPECTION - Group 1, Configuration 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 81 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BL26 VERTICAL POST

FITTING MACHINED FRAME STRINGERS REMOVED STEEL PLATE (KEEP)

AND CONFIGURATION VARIES DEPENDING ON LOCATION NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN SURFACE HFEC OPEN HOLE HFEC EXISTING FASTENERS (REF)

BULLETIN 747-53-2088 MODIFICATION LONG STEEL PLATE INSTALLED PER SERVICE (STA 760 ONLY) VIEW LOOKING AFT D A A

UP
INBD



### A 1 4 13

6 14 5 11

9 2 7 8D37308

**(SHEET 2 OF 10) FIGURE 3: INSPECTION - Group 1, Configuration 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 82 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

STRINGERS REMOVED STEEL PLATE (KEEP)

BL26 VERTICAL POST

MACHINED FRAME FITTING

NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN AND CONFIGURATION VARIES DEPENDING ON LOCATION. EXISTING FASTENERS (REF) OPEN HOLE HFEC SURFACE HFEC

VIEW LOOKING AFT (STA 760 ONLY) LONG STEEL PLATE INSTALLED PER SERVICE BULLETIN 747-53-2088 MODIFICATION C C D

E D B B E 1 4



### B 13

6 14

UP
INBD 5 11

9 2 8 7D36998

**(SHEET 3 OF 10) FIGURE 3: INSPECTION - Group 1, Configuration 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 83 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

TO VERTICAL POST FITTING COMMON

AND CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION, ACTUAL FASTENER PATTERN SKIN

SHEAR TIES REMOVED STEEL PLATE (KEEP)

SURFACE HFEC OPEN HOLE HFEC EXISTING FASTENERS (REF) BL26 STRINGERS

FRAME ALL LOCATIONS) (NOT PRESENT AT VERTICAL POST

CHORD FAILSAFE



### VIEW LOOKING AFT
MODIFICATION NOT DONE) AND SERVICE BULLETIN 747-53-2088 OPTIONAL (SERVICE BULLETIN 747-53-2371 MODIFICATION A A 8

6 1 4

UP

INBD 2



### C 5

9 7 11

13 14D30804

**(SHEET 4 OF 10) FIGURE 3: INSPECTION - Group 1, Configuration 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 84 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BL26 STRINGERS

FRAME VERTICAL POST (NOT PRESENT AT ALL LOCATIONS)



### VIEW LOOKING AFT EXISTING FASTENERS (REF) OPEN HOLE HFEC SURFACE HFEC REMOVED STEEL PLATE (KEEP)

FITTING COMMON TO VERTICAL POST SKIN

SHEAR TIES FAILSAFE CHORD

NOTE: TYPICAL CONFIGURATION, ACTUAL FASTENER PATTERN AND CONFIGURATION VARIES DEPENDING ON LOCATION. (SERVICE BULLETIN 747-53-2371 MODIFICATION AND SERVICE BULLETIN 747-53-2088 OPTIONAL MODIFICATION NOT DONE) C C

D D

E E
B B 8

6 1 4 UP

INBD 2



### D 5

9 7 11

13 14D30805

**(SHEET 5 OF 10) FIGURE 3: INSPECTION - Group 1, Configuration 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 85 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL REMOVED STEEL PLATE (KEEP)

EXISTING FASTENERS (REF) OPEN HOLE HFEC SURFACE HFEC SKIN REMOVED ALUMINUM REPAIR STRAP (KEEP)

BL26 STRINGERS

FRAME VERTICAL POST (ACTUAL LOCATION MAY VARY)

FAILSAFE CHORD 

### VIEW LOOKING AFT SHEAR TIES (TYPICAL)

NOTE: TYPICAL CONFIGURATION, ACTUAL FASTENER PATTERN AND CONFIGURATION VARIES DEPENDING ON LOCATION. (TYPICAL WITH REPAIR OR MODIFICATION PER SERVICE BULLETIN 747-53-2371 FIGURE 3 OR OPTIONAL MODIFICATION PER SERVICE BULLETIN 747-53-2088) ALUMINUM REPAIR STRAP STEEL PLATE



### A-A G G

A A E E 8

6 1 4 UP

INBD 2



### E

2 5

9

9 13 14 11

7 3 12

3 12D38465

**(SHEET 6 OF 10) FIGURE 3: INSPECTION - Group 1, Configuration 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 86 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL REMOVED STEEL PLATE (KEEP)

EXISTING FASTENERS (REF) OPEN HOLE HFEC SURFACE HFEC SKIN REMOVED ALUMINUM REPAIR STRAP (KEEP)

BL26 STRINGERS

FRAME VERTICAL POST (ACTUAL LOCATION MAY VARY)

FAILSAFE CHORD 

### VIEW LOOKING AFT SHEAR TIES (TYPICAL)

NOTE: TYPICAL CONFIGURATION, ACTUAL FASTENER PATTERN AND CONFIGURATION VARIES DEPENDING ON LOCATION. ALUMINUM REPAIR STRAP STEEL PLATE



### B-B (TYPICAL WITH REPAIR OR MODIFICATION PER SERVICE BULLETIN 747-53-2371 FIGURE 3 OR OPTIONAL MODIFICATION PER SERVICE BULLETIN 747-53-2088) B B G G

E E 8

6 1 4 UP
INBD 2



### F

2 5

9

9 13 14 11

7 3 12

3 12D38464

**(SHEET 7 OF 10) FIGURE 3: INSPECTION - Group 1, Configuration 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 87 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

ALUMINUM CHANNEL FRAME

HORIZONTAL SHEAR WEB TENSION TIE AFT CHANNEL (TYPICAL)

STEEL PLATE

TENSION TIE FWD CHANNEL (TYPICAL) 

### C-C

E-E (STA 940 ONLY)

(AT LOCATIONS WITH A SHEAR WEB) (AT ALL OTHER

LOCATIONS) 

### D-D

D-D D-D

G-G 2 1

2 1 2 1 2 1

9

9 9 9

2 1 3 9

9 4 12 10D37342

**(SHEET 8 OF 10) FIGURE 3: INSPECTION - Group 1, Configuration 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 88 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** This Figure applies to Group 1, Configuration 2: The step numbers shown below agree with the numbers shown in the circle symbols in the Figure. **CAUTION:** UNLESS THE AIRPLANE IS SUPPORTED IN THE JIGGED POSITION, DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. **STEP TASK NAME Part Number NOTES** 1 Remove Fasteners - (a) 2 Remove/Keep Steel Plates 65B09631-( ) - 3 Remove/Keep Aluminum Repair Strap - (n) 4 Inspect Fastener Holes in the Frame and Frame doubler (if installed) - (b) Tension Tie channels, and all aluminum parts in the stackup. 65B09631-( ) (b) 5 Inspect Steel Plates 65B09631-( ) (c) 6 Inspect Tension Tie forward and aft channels 65B09631-( ) (d) 7 Inspect Frame Structure - (e) 8 Inspect Skin - (f) 9 Inspect Tension Tie forward and aft channels and associated parts attached to the Tension Tie channels 65B09631-( ) (g)

10 Inspect Tension Ties, Shear Webs, Aluminum Channel 65B09631-( ) 65B09661 (g) 11 Install (Kept) Steel Plates 65B09631-( ) (h) 12 Install (Kept) Aluminum Repair Strap - (n) 13 **CAUTION:** If fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations common to the Steel Plates. Install washers under nuts. (i) (j) (l) (m) (o) Washers BACW10BP( )DP Nuts BACN10YT( )CD 14 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations NOT common to the Steel Plates. Install washers under nuts. (i) (k) (l) (m) (p) Washers BACW10BP( )DP Nuts BACN10YT( )CD (a) Remove all fasteners common to steel plates, plus six fasteners inboard of the steel plate at each end of the tension tie. (b) Open-hole HFEC inspect all holes in aluminum parts, in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16.

**(SHEET 9 OF 10) FIGURE 3: INSPECTION - Group 1, Configuration 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 89 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

(c) One Steel Plate on each side of the Airplane at each Tension Tie location. Open-hole HFEC inspect all holes in the steel plates in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 19. (d) Surface HFEC inspect the Tension Tie forward and aft channel vertical webs adjacent to and around all fastener heads and bucked tails between BL 26 and the outboard to three fastener rows inboard of the steel plates. Include all remaining fastener locations where fasteners have not been removed for inspection per step 4. Exclude areas around fasteners in the fittings common to the vertical posts at BL 39. Do inspections in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 4. (e) Do a detailed inspection for cracks in the Frames and associated parts from minimum (2) stringers above to a minimum (2) stringers below the Tension Ties. Pay special attention to the corners of the stringer cut outs. On built-up frames, also pay special attention to the fail-safe chords and shear ties. (f) Do this step only if cracks were found in the shear tie. If cracks were found on the shear tie, remove fasteners in the fuselage skin common to the affected shear tie and open-hole HFEC inspect the skin in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. (g) Do a detailed inspection of the Tension Tie forward and aft channels from end to end. At STA 940, do a detailed inspection of the Aluminum Channel. Pay special attention to where shear webs and other structure attach to the Tension Tie channels. Also, do a detailed inspection of the shear webs where they attach to the tension tie. (h) Only reinstall the Steel Plates if step 4 inspections reveal no crack indications. If the Steel Plate is found cracked, before further flight, replace with new or contact Boeing for repair instructions. (i) Oversize undamaged holes up to 0.0312 inch over original as required to make holes round and to be within diameter limits for the specified hole size and fastener fit. If the holes need additional oversizing, do the OVERSIZE HOLE REPAIR steps as specified in the Work Instructions. (j) At open hole locations common to the Steel Plates, install fasteners in close ream holes in accordance with 747-100/200/300 SRM 51-30-05. Install fasteners wet with BMS 3-27 or BMS 3- 38. Refer to SOPM 20-50-19 wet fastener installation method 2. If BACB30NX hex-drive bolts are installed with BMS 3-38, they must be installed with the following torque values applied to the nut: 3/16 inch bolt = 20 to 25 pound-inches. 1/4 inch bolt = 50 to 75 pound-inches. 5/16 inch bolt = 90 to 125 pound-inches. (k) At open hole locations not common to the Steel Plates, install fasteners in transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. (l) It is acceptable to substitute fasteners in accordance with 747-100/200/300 SRM 51-30-03. However, if fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. (m) New fasteners are to be supplied by the operator. (n) This part is only installed on Tension Ties that have been modified in accordance with Service Bulletin 747-53-2371, Figure 3. It is not necessary to re-install this part if the affected end of the Tension Tie aft channel is being replaced (either complete replacement of the channel, or a new segment spliced in). (o) To allow for easier removal during repeat inspections, it is optional to install BACB30MR( )K( ) bolts and BACW10BP( )CD washers, with BACN11Z( )CD nuts and BACW10BP( )DP washers at fastener locations common to the steel plates. However, availability of BACB30MR( )K( ) bolts is limited. Also, if fasteners are substituted, the same type of fastener should be used throughout each joint, as shown in Appendix C, Figure F.(p) If an aluminum repair strap was installed by Service Bulletin 747-53-2371, Figure 3, and is being reinstalled, install BACB30NX( )K( ) bolts inboard of the steel plate, common to the aluminum repair strap plus three fastener rows inboard of the aluminum repair strap. **STEP TASK NAME Part Number NOTES**

**(SHEET 10 OF 10) FIGURE 4: OVERSIZED HOLE REPAIR - Group 1, Configuration 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 90 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 4: OVERSIZED HOLE REPAIR - Group 1, Configuration 2** 

760 STA

940 STA FRAME (TYPICAL)

(2 LOCATIONS) SLOPING SHEAR WEB

(2 LOCATIONS) HORIZONTAL SHEAR WEB (TYPICAL) TENSION TIE

800 STA 760 STA 940 STA

FWD C OR SEE D OR SEE B SEE
A SEE

F SEE

E SEED37358

**(SHEET 1 OF 9) FIGURE 4: OVERSIZED HOLE RE**  **PAIR - Group 1, Configuration 2** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 91 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

STRINGERS BL26 VERTICAL POST

AND CONFIGURATION VARIES DEPENDING ON LOCATION NOTE: TYPICAL CONFIGURATION. ACTUAL FSTENER PATTERN FITTING MACHINED FRAME

BULLETIN 747-53-2088 MODIFICATION LONG STEEL PLATE INSTALLED PER SERVICE RR201 ONLY) (STA 760 OR STA 780 FOR AIRPLANE VIEW LOOKING AFT A A

UP
INBD


### A 1 2 3 4 5 6D37361

**(SHEET 2 OF 9) FIGURE 4: OVERSIZED HOLE REPAIR - Group 1, Configuration 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 92 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

STRINGERS BL26 VERTICAL POST

FITTING MACHINED FRAME

AND CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN BULLETIN 747-53-2088 MODIFICATION LONG STEEL PLATE INSTALLED PER SERVICE RR201 ONLY) (STA 760 OR STA 780 FOR AIRPLANE VIEW LOOKING AFT B B



### B UP
INBD 1 2 3 4 5 6D37362

**(SHEET 3 OF 9) FIGURE 4: OVERSIZED HOLE RE**  **PAIR - Group 1, Configuration 2** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 93 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

VIEW LOOKING AFT SHEAR TIE

STEEL PLATE

AND CONFIGURATION VARIES DEPENDING ON LOCATION NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN BL26 STRINGER CHORD FAILSAFE

FRAME

(SERVICE BULLETIN 747-53-2371 NOT DONE) POST VERTICAL

A A 1 2 3 4

UP

INBD



### C 5 6381607

**(SHEET 4 OF 9) FIGURE 4: OVERSIZED HOLE REPAIR - Group 1, Configuration 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 94 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

STEEL PLATE

AND CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN BL26 STRINGER CHORD FAILSAFE

FRAME

VIEW LOOKING AFT (SERVICE BULLETIN 747-53-2371 NOT DONE) SHEAR TIE POST VERTICAL

B B 1 2 3 4



### D UP
OUTBD 5 6D30808

**(SHEET 5 OF 9) FIGURE 4: OVERSIZED HOLE RE**  **PAIR - Group 1, Configuration 2** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 95 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

VIEW LOOKING AFT

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL SHEAR TIE PLATE STEEL

AND CONFIGURATION VARIES DEPENDING ON LOCATION NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN BL26 STRINGER CHORD FAILSAFE

FRAME

747-53-2088) 747-53-2371 FIGURE 3 OR OPTIONAL MODIFICATION PER SERVICE BULLETIN (TYPICAL WITH REPAIR OR MODIFICATION PER SERVICE BULLETIN (ACTUAL LOCATION MAY VARY) ALUMINUM REPAIR STRAP
(ACTUAL LOCATION MAY VARY) TRIM LINE IN AFT TENSION CHANNEL POST VERTICAL



### A-A A A 1 2 3 4

UP

INBD 5 6



### ED38458

**(SHEET 6 OF 9) FIGURE 4: OVERSIZED HOLE REPAIR - Group 1, Configuration 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 96 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

STRINGER CHORD FAILSAFE

FRAME (ACTUAL LOCATION MAY VARY) ALUMINUM REPAIR STRAP
(ACTUAL LOCATION MAY VARY) TRIM LINE IN AFT TENSION CHANNEL



### VIEW LOOKING AFT

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL SHEAR TIE PLATE STEEL BL26



### B-B POST VERTICAL

AND CONFIGURATION VARIES DEPENDING ON LOCATION NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN 747-53-2088) 747-53-2371 FIGURE 3 OR OPTIONAL MODIFICATION PER SERVICE BULLETIN (TYPICAL WITH REPAIR OR MODIFICATION PER SERVICE BULLETIN B B 1 2 3 4

UP

INBD 

### F 5 6D38459

**(SHEET 7 OF 9) FIGURE 4: OVERSIZED HOLE RE**  **PAIR - Group 1, Configuration 2** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 97 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** This Figure applies to Group 1, Configuration 2: The step numbers shown below agree with the numbers shown in the circle symbols in the Figure. **NOTE:** Only do these steps at locations where crack indications are present in the Frame and/or Tension Tie and can be cleaned up by oversizing the hole to a maximum hole size of 0.313 inch. If the crack is larger, contact Boeing for repair instructions. **CAUTION:** UNLESS THE AIRPLANE IS SUPPORTED IN THE JIGGED POSITION, DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. **STEP TASK NAME PART NUMBER NOTES** 1 Oversize Holes in Tension Tie Channels, Frame, Steel Plate, associated parts in the stackup. - (a)

2 Inspect Holes in Tension Tie Channels, Frame, and associated aluminum parts in the stack up. - (b) (c)

3 Oversize Holes Tension Tie Channels, Frame, Steel Plate, and associated parts in the stackup. - (d) (e)

**NOTE:** Holes can only be oversized to a maximum 0.313 inch diameter. 4 Measure Edge Margin and Spacing - (f) 5 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations common to the Steel Plates. Install washers under nuts. (g) (i) (j) Washers BACW10BP( )DP Nuts BACN10YT( )CD 6 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations NOT common to the Steel Plates. Install washers under nuts. (h) (i) Washers BACW10BP( )DP Nuts BACN10YT( )CD (a) Oversize the minimum amount required to remove the cracks, in 0.0156 inches increments, up to a maximum hole size of 0.313 inch. (b) Open-hole HFEC inspect holes in the aluminum parts in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. (c) Repeat steps 1 to 2 if crack indications are still present, until there are no more crack indications. Once there are no more crack indications, go to step 3. (d) Make the final hole diameters in the entire stackup common to the steel plates within limits for close ream holes in accordance with 747-100/200/300 SRM 51-30-05. If holes are already within SRM limits for close ream holes, do not further oversize. (e) Make the final hole diameters in the stackup NOT common to the steel plates within limits for transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. If the holes are already within SRM limits for transition fit holes, do not further oversize.

**(SHEET 8 OF 9) FIGURE 4: OVERSIZED HOLE REPAIR - Group 1, Configuration 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 98 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

(f) A minimum 1.5D edge margin (center of hole to edge of part) and 2.5D spacing (center of hole to center of hole) should be maintained. If edge margin and spacing cannot be maintained, contact Boeing for repair instructions. (g) At open hole locations common to the Steel Plates, install fasteners in close ream holes in accordance with 747-100/200/300 SRM 51-30-05. Install fasteners wet with BMS 3-27 or BMS 3- 38. Refer to SOPM 20-50-19 wet fastener installation method 2. If BACB30NX hex-drive bolts are installed with BMS 3-38, they must be installed with the following torque values applied to the nut: 3/16 inch bolt = 20 to 25 pound-inches. 1/4 inch bolt = 50 to 75 pound-inches. 5/16 inch bolt = 90 to 125 pound-inches. (h) At open hole locations not common to the Steel Plates, install fasteners in transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. (i) It is acceptable to substitute fasteners in accordance with 747-100/200/300 SRM 51-30-03. However, if fasteners are substituted the same type fasteners should be used throughout each joint, as shown in Appendix C, Figure F. (j) To allow for easier removal during repeat inspections, it is optional to install BACB30MR( )K( ) bolts and BACW10BP( )CD washers, with BACN11Z( )CD nuts and BACW10BP( )DP washers at fastener locations common to the steel plates. However, availability of BACB30MR( )K( ) bolts is limited. Also, if fasteners are substituted, the same type of fastener should be used throughout each joint, as shown in Appendix C, Figure F. **STEP TASK NAME PART NUMBER NOTES**

**(SHEET 9 OF 9) FIGURE 5: INSPECTION - Group 1, Configuration 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 99 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 5: INSPECTION - Group 1, Configuration 3** 

800 STA 940 STA

FRAME (TYPICAL)

(TYPICAL) TENSION TIE

(2 LOCATIONS) HORIZONTAL SHEAR WEB (2 LOCATIONS) SLOPING SHEAR WEB

800 STA

940 STA FWD B OR SEE A OR SEE 10

D SEE C SEE 10 9386272

**(SHEET 1 OF 8) FIGURE 5: INSPECTION - Group 1, Configuration 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 100 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BL26 STRINGERS

FRAME ALL LOCATIONS) (NOT PRESENT AT VERTICAL POST

CHORD FAILSAFE

VIEW LOOKING AFT (TYPICAL) SHEAR TIES

AND CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION, ACTUAL FASTENER PATTERN TO VERTICAL POST FITTING COMMON REMOVED STEEL PLATE (KEEP)

SURFACE HFEC OPEN HOLE HFEC EXISTING FASTENERS (REF) SKIN

FIGURE 3) (TYPICAL WITHOUT REPAIR OR MODIFICATION PER SERVICE BULLETIN 747-53-2371 A A 8

6 1 4

UP

INBD 2



### A 5

9

13 14 11

7386453

**(SHEET 2 OF 8) FIGURE 5: INSPECTION - Group 1, Configuration 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 101 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BL26 STRINGERS

FAILSAFE CHORD FRAME VERTICAL POST (NOT PRESENT AT ALL LOCATIONS)



### VIEW LOOKING AFT (TYPICAL WITHOUT REPAIR OR MODIFICATION PER SERVICE BULLETIN 747-53-2371 FIGURE 3) REMOVED STEEL PLATE (KEEP)

OPEN HOLE HFEC SURFACE HFEC EXISTING FASTENERS FITTING COMMON TO VERTICAL POST

SHEAR TIES SKIN

NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN AND CONFIGURATION VARIES DEPENDING ON LOCATION. C C

D D

E E

B B 7

1 4

2 6



### B UP
OUTBD 5

9 14 13 11

8386454

**(SHEET 3 OF 8) FIGURE 5: INSPECTION - Group 1, Configuration 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 102 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

REMOVED STEEL PLATE (KEEP)

EXISTING FASTENERS (REF) OPEN HOLE HFEC SURFACE HFEC SKIN REMOVED ALUMINUM REPAIR STRAP (KEEP)

STRINGERS

FRAME VERTICAL POST (ACTUAL LOCATION MAY VARY)

FAILSAFE CHORD VIEW LOOKING AFT SHEAR TIES (TYPICAL)

NOTE: TYPICAL CONFIGURATION, ACTUAL FASTENER PATTERN AND CONFIGURATION VARIES DEPENDING ON LOCATION. ALUMINUM REPAIR STRAP STEEL PLATE BL26

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL



### A-A (TYPICAL WITH REPAIR OR MODIFICATION PER SERVICE BULLETIN 747-53-2371, FIGURE 3.) (AIRPLANES LINE 1-203 ONLY) G G
A A E E 8

6
1 4 UP
INBD 2



### C 5

9

13 14 11

7 3 12

3 12 4

2 9D37133

**(SHEET 4 OF 8) FIGURE 5: INSPECTION - Group 1, Configuration 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 103 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BL26 STRINGERS

FRAME VERTICAL POST (ACTUAL LOCATION MAY VARY)

FAILSAFE CHORD VIEW LOOKING AFT SHEAR TIES (TYPICAL)

NOTE: TYPICAL CONFIGURATION, ACTUAL FASTENER PATTERN AND CONFIGURATION VARIES DEPENDING ON LOCATION. ALUMINUM REPAIR STRAP STEEL PLATE

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL REMOVED STEEL PLATE (KEEP)

EXISTING FASTENERS (REF) OPEN HOLE HFEC SURFACE HFEC SKIN REMOVED ALUMINUM REPAIR STRAP (KEEP)



### B-B (TYPICAL WITH REPAIR OR MODIFICATION PER SERVICE BULLETIN 747-53-2371, FIGURE 3.) (AIRPLANES LINE 1-203 ONLY) G G

B B E E 8

6
1 4
UP

INBD 2



### D

2 5

9

9 13 14 11

7 3

3 12 12 4D37158

**(SHEET 5 OF 8) FIGURE 5: INSPECTION - Group 1, Configuration 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 104 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

ALUMINUM CHANNEL FRAME

HORIZONTAL SHEAR WEB TENSION TIE AFT CHANNEL (TYPICAL)

STEEL PLATE

TENSION TIE FWD CHANNEL (TYPICAL) 

### C-C

E-E (STA 940 ONLY)

(AT LOCATIONS WITH A SHEAR WEB) (AT ALL OTHER

LOCATIONS) 

### D-D

D-D D-D

G-G 2 1

2 1 2 1 2 1

9

9 9 9

2 1 3 12 9

9 9 10D37159

**(SHEET 6 OF 8) FIGURE 5: INSPECTION - Group 1, Configuration 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 105 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** This Figure applies to Group 1, Configuration 3: The step numbers shown below agree with the numbers shown in the circle symbols in the Figure. **CAUTION:** UNLESS THE AIRPLANE IS SUPPORTED IN THE JIGGED POSITION, DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. **STEP TASK NAME Part Number NOTES** 1 Remove Fasteners - (a) 2 Remove/Keep Steel Plates 65B09631-( ) - 3 Remove/Keep Aluminum Repair Strap - (n) 4 Inspect Fastener Holes in the Frame and Frame doubler (if installed) - (b) Tension Tie channels, and all aluminum parts in the stackup. 65B09631-( ) (b) 5 Inspect Steel Plates 65B09631-( ) (c) 6 Inspect Tension Tie forward and aft channels 65B09631-( ) (d) 7 Inspect Frame Structure - (e) 8 Inspect Skin - (f) 9 Inspect Tension Tie forward and aft channels and associated parts attached to the Tension Tie channels 65B09631-( ) (g)

10 Inspect Tension Ties, Shear Webs, Aluminum Channel 65B09631-( ) 98B09661-( ) (g) 11 Install (Kept) Steel Plates 65B09631-( ) (h) 12 Install (Kept) Aluminum Repair Strap - (n) 13 **CAUTION:** If fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations common to the Steel Plates. Install washers under nuts. (i) (j) (l) (m) (o) Washers BACW10BP( )DP Nuts BACN10YT( )CD 14 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations NOT common to the Steel Plates. Install washers under nuts. (i) (k) (l) (m) (p) Washers BACW10BP( )DP Nuts BACN10YT( )CD (a) Remove all fasteners common to steel plates, plus six fasteners inboard of the steel plate at each end of the tension tie. (b) Open-hole HFEC inspect all holes in aluminum parts, in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16.

**(SHEET 7 OF 8) FIGURE 5: INSPECTION - Group 1, Configuration 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 106 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

(c) One Steel Plate on each side of the Airplane at each Tension Tie location. Open-hole HFEC inspect all holes in the steel plates in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 19. (d) Surface HFEC inspect the Tension Tie forward and aft channel vertical webs adjacent to and around all fastener heads and bucked tails between BL 26 and the outboard to three fastener rows inboard of the steel plates. Include all remaining fastener locations where fasteners have not been removed for inspection per step 4. Exclude areas around fasteners in the fittings common to the vertical posts at BL 39. Do inspections in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 4. (e) Do a detailed inspection for cracks in the Frames and associated parts from minimum (2) stringers above to a minimum (2) stringers below the Tension Ties. Pay special attention to the corners of the stringer cut outs. On built-up frames, also pay special attention to the fail-safe chords and shear ties. (f) Do this step only if cracks were found in the shear tie. If cracks were found on the shear tie, remove fasteners in the fuselage skin common to the affected shear tie and open-hole HFEC inspect the skin in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. (g) Do a detailed inspection of the Tension Tie forward and aft channels from end to end. At STA 940, do a detailed inspection of the Aluminum Channel. Pay special attention to where shear webs and other structure attach to the Tension Tie channels. Also, do a detailed inspection of the shear webs where they attach to the tension tie. (h) Only reinstall the Steel Plates if step 4 inspections reveal no crack indications. If the Steel Plate is found cracked, before further flight, replace with new or contact Boeing for repair instructions. (i) Oversize undamaged holes up to 0.0312 inch over original as required to make holes round and to be within diameter limits for the specified hole size and fastener fit. If the holes need additional oversizing, do the OVERSIZE HOLE REPAIR steps as specified in the Work Instructions. (j) At open hole locations common to the Steel Plates, install fasteners in close ream holes in accordance with 747-100/200/300 SRM 51-30-05. Install fasteners wet with BMS 3-27 or BMS 3- 38. Refer to SOPM 20-50-19 wet fastener installation method 2. If BACB30NX hex-drive bolts are installed with BMS 3-38, they must be installed with the following torque values applied to the nut: 3/16 inch bolt = 20 to 25 pound-inches. 1/4 inch bolt = 50 to 75 pound-inches. 5/16 inch bolt = 90 to 125 pound-inches. (k) At open hole locations not common to the Steel Plates, install fasteners in transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. (l) If necessary, it is acceptable to substitute fasteners in accordance with 747-100/200/300 SRM 51-30-03. However, if fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. (m) New fasteners are to be supplied by the operator. (n) This part is only installed on Tension Ties that have been modified in accordance with Service Bulletin 747-53-2371, Figure 3. It is not necessary to re-install this part if the affected end of the Tension Tie aft channel is being replaced (either complete replacement of the channel, or a new segment spliced in). (o) To allow for easier removal during repeat inspections, it is optional to install BACB30MR( )K( ) bolts and BACW10BP( )CD washers, with BACN11Z( )CD nuts and BACW10BP( )DP washers at fastener locations common to the steel plates. However, availability of BACB30MR( )K( ) bolts is limited. Also, if fasteners are substituted, the same type of fastener should be used throughout each joint, as shown in Appendix C, Figure F.(p) If an aluminum repair strap was installed by Service Bulletin 747-53-2371, Figure 3, and is being reinstalled, install BACB30NX( )K( ) bolts inboard of the steel plate, common to the aluminum repair strap plus three fastener rows inboard of the aluminum repair strap. **STEP TASK NAME Part Number NOTES**

**(SHEET 8 OF 8) FIGURE 6: OVERSIZED HOLE RE**  **PAIR - Group 1, Configuration 3** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 107 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 6: OVERSIZED HOLE REPAIR - Group 1, Configuration 3** 

800 STA 940 STA

800 STA

940 STA FRAME (TYPICAL)
(TYPICAL) TENSION TIE (2 LOCATIONS) HORIZONTAL SHEAR WEB

(2 LOCATIONS) SLOPING SHEAR WEB

FWD B OR SEE A OR SEE D SEE C SEED37169

**(SHEET 1 OF 7) FIGURE 6: OVERSIZED HOLE REPAIR - Group 1, Configuration 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 108 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

STEEL PLATE SHEAR TIE

AND CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN BL26 STRINGER CHORD FAILSAFE

VIEW LOOKING AFT SERVICE BULLETIN 747-53-2371, FIGURE 3.) (TYPICAL WITHOUT REPAIR OR MODIFICATION PER POST VERTICAL

A A

FRAME 1 2 3 4



### A UP

OUTBD 5 6D37175

**(SHEET 2 OF 7) FIGURE 6: OVERSIZED HOLE RE**  **PAIR - Group 1, Configuration 3** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 109 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

SERVICE BULLETIN 747-53-2371, FIGURE 3.) (TYPICAL WITHOUT REPAIR OR MODIFICATION PER B B BL26 STRINGER CHORD FAILSAFE

FRAME

VIEW LOOKING AFT 1 2 3 4



### B UP
OUTBD 5 6

STEEL PLATE SHEAR TIE

AND CONFIGURATION VARIES DEPENDING ON LOCATION NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERND37178

**(SHEET 3 OF 7) FIGURE 6: OVERSIZED HOLE REPAIR - Group 1, Configuration 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 110 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

A-A BL26 STRINGER CHORD FAILSAFE

FRAME (ACTUAL LOCATION MAY VARY) ALUMINUM REPAIR STRAP
(ACTUAL LOCATION MAY VARY) TRIM LINE IN AFT TENSION CHANNEL

VIEW LOOKING AFT

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL SHEAR TIE PLATE STEEL

AND CONFIGURATION VARIES DEPENDING ON LOCATION NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN (AIRPLANES LINE 1-203 ONLY) SERVICE BULLETIN 747-53-2371, FIGURE 3.) (TYPICAL WITH REPAIR OR MODIFICATION PER A A 1 2 3 4

UP

INBD 5 6



### CD37177

**(SHEET 4 OF 7) FIGURE 6: OVERSIZED HOLE RE**  **PAIR - Group 1, Configuration 3** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 111 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

B-B (AIRPLANES LINE 1-203 ONLY) SERVICE BULLETIN 747-53-2371, FIGURE 3.) (TYPICAL WITH REPAIR OR MODIFICATION PER B B BL26 STRINGER CHORD FAILSAFE

FRAME (ACTUAL LOCATION MAY VARY) ALUMINUM REPAIR STRAP
(ACTUAL LOCATION MAY VARY) TRIM LINE IN AFT TENSION CHANNEL 1 2 3 4

VIEW LOOKING AFT UP

INBD 

### D

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL 5 6

SHEAR TIE PLATE STEEL

AND CONFIGURATION VARIES DEPENDING ON LOCATION NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERND37181

**(SHEET 5 OF 7) FIGURE 6: OVERSIZED HOLE REPAIR - Group 1, Configuration 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 112 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** This Figure applies to Group 1, Configuration 3: The step numbers shown below agree with the numbers shown in the circle symbols in the Figure. **NOTE:** Only do these steps at locations where crack indications are present in the Frame and/or Tension Tie and can be cleaned up by oversizing the hole to a maximum hole size of 0.313 inch. If the crack is larger, contact Boeing for repair instructions. **CAUTION:** UNLESS THE AIRPLANE IS SUPPORTED IN THE JIGGED POSITION, DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. **STEP TASK NAME PART NUMBER NOTES** 1 Oversize Holes in Tension Tie Channels, Frame, Steel Plate, associated parts in the stackup. - (a)

2 Inspect Holes in Tension Tie Channels, Frame, and associated aluminum parts in the stack up. - (b) (c)

3 Oversize Holes Tension Tie Channels, Frame, Steel Plate, and associated parts in the stackup. - (d) (e)

**NOTE:** Holes can only be oversized to a maximum 0.313 inch diameter. 4 Measure Edge Margin and Spacing - (f) 5 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations common to the Steel Plates. Install washers under nuts. (g) (i) (j) Washers BACW10BP( )DP Nuts BACN10YT( )CD 6 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations NOT common to the Steel Plates. Install washers under nuts. (h) (i) Washers BACW10BP( )DP Nuts BACN10YT( )CD (a) Oversize the minimum amount required to remove the cracks, in 0.0156 inches increments, up to a maximum hole size of 0.313 inch. (b) Open-hole HFEC inspect holes in the aluminum parts in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. (c) Repeat steps 1 to 2 if crack indications are still present, until there are no more crack indications. Once there are no more crack indications, go to step 3. (d) Make the final hole diameters in the entire stackup common to the steel plates within limits for close ream holes in accordance with 747-100/200/300 SRM 51-30-05. If holes are already within SRM limits for close ream holes, do not further oversize. (e) Make the final hole diameters in the stackup NOT common to the steel plates within limits for transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. If the holes are already within SRM limits for transition fit holes, do not further oversize.

**(SHEET 6 OF 7) FIGURE 6: OVERSIZED HOLE RE**  **PAIR - Group 1, Configuration 3** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 113 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

(f) A minimum 1.5D edge margin (center of hole to edge of part) and 2.5D spacing (center of hole to center of hole) should be maintained. If edge margin and spacing cannot be maintained, contact Boeing for repair instructions. (g) At open hole locations common to the Steel Plates, install fasteners in close ream holes in accordance with 747-100/200/300 SRM 51-30-05. Install fasteners wet with BMS 3-27 or BMS 3- 38. Refer to SOPM 20-50-19 wet fastener installation method 2. If BACB30NX hex-drive bolts are installed with BMS 3-38, they must be installed with the following torque values applied to the nut: 3/16 inch bolt = 20 to 25 pound-inches. 1/4 inch bolt = 50 to 75 pound-inches. 5/16 inch bolt = 90 to 125 pound-inches. (h) At open hole locations not common to the Steel Plates, install fasteners in transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. (i) If necessary, it is acceptable to substitute fasteners in accordance with 747-100/200/300 SRM 51-30-03. However, if fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. (j) To allow for easier removal during repeat inspections, it is optional to install BACB30MR( )K( ) bolts and BACW10BP( )CD washers, with BACN11Z( )CD nuts and BACW10BP( )DP washers at fastener locations common to the steel plates. However, availability of BACB30MR( )K( ) bolts is limited. Also, if fasteners are substituted, the same type of fastener should be used throughout each joint, as shown in Appendix C, Figure F. **STEP TASK NAME PART NUMBER NOTES**

**(SHEET 7 OF 7) FIGURE 7: INSPECTION - Group 1, Configuration 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 114 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 7: INSPECTION**  **- Group 1, Configuration 4**

STA 760 STA 940

C 760 STA

940 STA FRAME (TYPICAL)

9 (2 LOCATIONS) SLOPING SHEAR WEB

(2 LOCATIONS) HORIZONTAL SHEAR WEB D SEE (TYPICAL) TENSION TIE

B SEE
800 STA A SEE 9

8

SEED38388 FWD

**(SHEET 1 OF 8) FIGURE 7: INSPECTION - Group 1, Configuration 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 115 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

A A STRINGERS

UP
INBD REMOVED STEEL PLATE (KEEP)

D BL26 VERTICAL POST



### A
(STA 760 ONLY) VIEW LOOKING AFT 1 3 11

5 12

FITTING MACHINED FRAME 4 10

8 2 6 7D38401

**(SHEET 2 OF 8) FIGURE 7: INSPECTION - Group 1, Configuration 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 116 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

C C

D D

E B B E STRINGERS REMOVED STEEL PLATE (KEEP)

1 3 BL26 VERTICAL POST



### B VIEW LOOKING AFT

(STA 760 ONLY) 11

5 12

MACHINED FRAME FITTING UP
INBD 4 10

8 2 7 6D38403

**(SHEET 3 OF 8) FIGURE 7: INSPECTION - Group 1, Configuration 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 117 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

TO VERTICAL POST FITTING COMMON

AND CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION, ACTUAL FASTENER PATTERN SKIN

SHEAR TIES A A BL26 STRINGERS

FRAME ALL LOCATIONS) (NOT PRESENT AT VERTICAL POST

CHORD FAILSAFE VIEW LOOKING AFT STA 780 TO STA 940



### A-A TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL

2 7

5 1 3

UP

INBD 2



### C 4 REMOVED STEEL PLATE (KEEP)

SURFACE HFEC OPEN HOLE HFEC 8 6 10

11 12

8D38414

**(SHEET 4 OF 8) FIGURE 7: INSPECTION - Group 1, Configuration 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 118 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

C C

D D

E E FITTING COMMON TO VERTICAL POST

NOTE: TYPICAL CONFIGURATION, ACTUAL FASTENER PATTERN AND CONFIGURATION VARIES DEPENDING ON LOCATION. SKIN

SHEAR TIES B B BL26 STRINGERS

FRAME VERTICAL POST (NOT PRESENT AT ALL LOCATIONS)

FAILSAFE CHORD 

### VIEW LOOKING AFT STA 780 TO STA 940



### B-B TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL

2 7

5 1 3 UP

INBD 2



### D 4

8 6 10

11 12 REMOVED STEEL PLATE (KEEP)

8 OPEN HOLE HFEC SURFACE HFECD38415

**(SHEET 5 OF 8) FIGURE 7: INSPECTION - Group 1, Configuration 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 119 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

This Figure applies to Group 1, Configuration 4: The step numbers shown below agree with the numbers shown in the circle symbols in the Figure. **CAUTION:** UNLESS THE AIRPLANE IS SUPPORTED IN THE JIGGED POSITION, DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. **STEP TASK NAME Part Number NOTES** 1 Remove Fasteners - (a) 2 Remove/Keep Steel Plates 65B09631-( ) - FRAME

ALUMINUM CHANNEL HORIZONTAL SHEAR WEB

TENSION TIE AFT CHANNEL (TYPICAL)

STEEL PLATE

TENSION TIE FWD CHANNEL (TYPICAL) 

### C-C

E-E (STA 940 ONLY) (AT LOCATIONS WITH A SHEAR WEB)

(AT ALL OTHER

LOCATIONS) 

### D-D D-D

D-D 2 1

2 1 2 1 2 1

8

8 8 8

8 8

8

8 9D38416

**(SHEET 6 OF 8) FIGURE 7: INSPECTION - Group 1, Configuration 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 120 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

3 Inspect Fastener Holes in the Frame and Frame doubler (if installed) - (b) Tension Tie channels, and all aluminum parts in the stackup. 65B09631-( ) (b) 4 Inspect Steel Plates 65B09631-( ) (c) 5 Inspect Tension Tie forward and aft channels 65B09631-( ) (d) 6 Inspect Frame Structure - (e) 7 Inspect Skin - (f) 8 Inspect Tension Tie forward and aft channels and associated parts attached to the Tension Tie channels 65B09631-( ) (g)

9 Inspect Tension Ties, Shear Webs, Aluminum Channel 65B09631-( ) 65B09661-( ) (g) 10 Install (Kept) Steel Plates 65B09631-( ) (h) 11 **CAUTION:** If fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations common to the Steel Plates. Install washers under nuts. (i) (j) (l) (m) (n) Washers BACW10BP( )DP Nuts BACN10YT( )CD 12 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations NOT common to the Steel Plates. Install washers under nuts. (i) (k) (l) (m) Washers BACW10BP( )DP Nuts BACN10YT( )CD (a) Remove all fasteners common to steel plates, plus six fasteners inboard of the steel plate at each end of the tension tie. (b) Open-hole HFEC inspect all holes in aluminum parts, in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. (c) One Steel Plate on each side of the Airplane at each Tension Tie location. Open-hole HFEC inspect all holes in the steel plates in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 19. (d) Surface HFEC inspect the Tension Tie forward and aft channel vertical webs adjacent to and around all fastener heads and bucked tails between BL 26 and the outboard to three fastener rows inboard of the steel plates. Include all remaining fastener locations where fasteners have not been removed for inspection per step 3. Exclude areas around fasteners in the fittings common to the vertical posts at BL 39. Do inspections in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 4. (e) Do a detailed inspection for cracks in the Frames and associated parts from minimum (2) stringers above to a minimum (2) stringers below the Tension Ties. Pay special attention to the corners of the stringer cut outs. On built-up frames, also pay special attention to the failsafe chords and shear ties. (f) Do this step only if cracks were found in the shear tie. If cracks were found on the shear tie, remove fasteners in the fuselage skin common to the affected shear tie and open-hole HFEC inspect the skin in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. **STEP TASK NAME Part Number NOTES**

**(SHEET 7 OF 8) FIGURE 7: INSPECTION - Group 1, Configuration 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 121 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

(g) Do a detailed inspection of the Tension Tie forward and aft channels from end to end. At STA 940, do a detailed inspection of the Aluminum Channel. Pay special attention to where shear webs and other structure attach to the Tension Tie channels. Also, do a detailed inspection of the shear webs where they attach to the tension tie. (h) Only reinstall the Steel Plates if step 4 inspections reveal no crack indications. If the Steel Plate is found cracked, before further flight, replace with new or contact Boeing for repair instructions. (i) Oversize undamaged holes up to 0.0312 inch over original as required to make holes round and to be within diameter limits for the specified hole size and fastener fit. If the holes need additional oversizing, do the OVERSIZE HOLE REPAIR steps as specified in the Work Instructions. (j) At open hole locations common to the Steel Plates, install fasteners in close ream holes in accordance with 747-100/200/300 SRM 51-30-05. Install fasteners wet with BMS 3-27 or BMS 3- 38. Refer to SOPM 20-50-19 wet fastener installation method 2. If BACB30NX hex-drive bolts are installed with BMS 3-38, they must be installed with the following torque values applied to the nut: 3/16 inch bolt = 20 to 25 pound-inches. 1/4 inch bolt = 50 to 75 pound-inches. 5/16 inch bolt = 90 to 125 pound-inches. (k) At open hole locations not common to the Steel Plates, install fasteners in transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. (l) If necessary, it is acceptable to substitute fasteners in accordance with 747-100/200/300 SRM 51-30-03. However, if fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. (m) New fasteners are to be supplied by the operator. (n) To allow for easier removal during repeat inspections, it is optional to install BACB30MR( )K( ) bolts and BACW10BP( )CD washers, with BACN11Z( )CD nuts and BACW10BP( )DP washers at fastener locations common to the steel plates. However, availability of BACB30MR( )K( ) bolts is limited. Also, if fasteners are substituted, the same type of fastener should be used throughout each joint, as shown in Appendix C, Figure F. **STEP TASK NAME Part Number NOTES**

**(SHEET 8 OF 8) FIGURE 8: OVERSIZE HOLE RE**  **PAIR - Group 1, Configuration 4** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 122 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 8: OVERSIZE HOLE REPAIR - Group 1, Configuration 4** 

STA 760 STA 940

C SEE 760 STA

940 STA FRAME (TYPICAL)

(2 LOCATIONS) SLOPING SHEAR WEB

(2 LOCATIONS) HORIZONTAL SHEAR WEB D SEE (TYPICAL) TENSION TIE

B SEE
800 STA A SEED38421 FWD

**(SHEET 1 OF 6) FIGURE 8: OVERSIZE HOLE RE**  **PAIR - Group 1, Configuration 4** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 123 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

A A STRINGERS

UP
INBD BL26 VERTICAL POST



### A
(STA 760 ONLY) VIEW LOOKING AFT 1 2

FITTING MACHINED FRAME 3 4 5 6D38441

B B STRINGERS BL26 VERTICAL POST



### B

FITTING MACHINED FRAME UP
INBD

(STA 760 ONLY) VIEW LOOKING AFT 1 2 3 4 5 6D38445

**(SHEET 2 OF 6) FIGURE 8: OVERSIZE HOLE RE**  **PAIR - Group 1, Configuration 4** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 124 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

A-A A A BL26 STRINGER CHORD FAILSAFE

FRAME

STA 780 TO STA 940 1 2 3 4



### VIEW LOOKING AFT UP

INBD



### C

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL 5 6

SHEAR TIE

STEEL PLATE

AND CONFIGURATION VARIES DEPENDING ON LOCATION NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERND38446

**(SHEET 3 OF 6) FIGURE 8: OVERSIZE HOLE RE**  **PAIR - Group 1, Configuration 4** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 125 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

B B BL26 STRINGER CHORD FAILSAFE

FRAME



### VIEW LOOKING AFT

STA 780 TO STA 940



### B-B 1 2 3 4



### D UP
OUTBD

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL 5 6

STEEL PLATE SHEAR TIE

AND CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERND38448

**(SHEET 4 OF 6) FIGURE 8: OVERSIZE HOLE RE**  **PAIR - Group 1, Configuration 4** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 126 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** This Figure applies to Group 1, Configuration 4: The step numbers shown below agree with the numbers shown in the circle symbols in the Figure. **NOTE:** Only do these steps at locations where crack indications are present in the Frame and/or Tension Tie and can be cleaned up by oversizing the hole to a maximum hole size of 0.313 inch. If the crack is larger, contact Boeing for repair instructions. **CAUTION:** UNLESS THE AIRPLANE IS SUPPORTED IN THE JIGGED POSITION, DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. **STEP TASK NAME PART NUMBER NOTES** 1 Oversize Holes in Tension Tie Channels, Frame, Steel Plate, associated parts in the stackup. - (a)

2 Inspect Holes in Tension Tie Channels, Frame, and associated aluminum parts in the stack up. - (b) (c)

3 Oversize Holes Tension Tie Channels, Frame, Steel Plate, and associated parts in the stackup. - (d) (e)

**NOTE:** Holes can only be oversized to a maximum 0.313 inch diameter. 4 Measure Edge Margin and Spacing - (f) 5 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations common to the Steel Plates. Install washers under nuts. (g) (i) (j) Washers BACW10BP( )DP Nuts BACN10YT( )CD 6 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations NOT common to the Steel Plates. Install washers under nuts. (h) (i) Washers BACW10BP( )DP Nuts BACN10YT( )CD (a) Oversize the minimum amount required to remove the cracks, in 0.0156 inches increments, up to a maximum hole size of 0.313 inch. (b) Open-hole HFEC inspect holes in the aluminum parts in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. (c) Repeat steps 1 to 2 if crack indications are still present, until there are no more crack indications. Once there are no more crack indications, go to step 3. (d) Make the final hole diameters in the entire stackup common to the steel plates within limits for close ream holes in accordance with 747-100/200/300 SRM 51-30-05. If holes are already within SRM limits for close ream holes, do not further oversize. (e) Make the final hole diameters in the stackup NOT common to the steel plates within limits for transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. If the holes are already within SRM limits for transition fit holes, do not further oversize.

**(SHEET 5 OF 6) FIGURE 8: OVERSIZE HOLE RE**  **PAIR - Group 1, Configuration 4** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 127 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

(f) A minimum 1.5D edge margin (center of hole to edge of part) and 2.5D spacing (center of hole to center of hole) should be maintained. If edge margin and spacing cannot be maintained, contact Boeing for repair instructions. (g) At open hole locations common to the Steel Plates, install fasteners in close ream holes in accordance with 747-100/200/300 SRM 51-30-05. Install fasteners wet with BMS 3-27 or BMS 3- 38. Refer to SOPM 20-50-19 wet fastener installation method 2. If BACB30NX hex-drive bolts are installed with BMS 3-38, they must be installed with the following torque values applied to the nut: 3/16 inch bolt = 20 to 25 pound-inches. 1/4 inch bolt = 50 to 75 pound-inches. 5/16 inch bolt = 90 to 125 pound-inches. (h) At open hole locations not common to the Steel Plates, install fasteners in transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. (i) If required, it is acceptable to substitute fasteners in accordance with 747-100/200/300 SRM 51-30-03. However, if fasteners are substituted the same type fasteners should be used throughout each joint, as shown in Appendix C, Figure F. (j) To allow for easier removal during repeat inspections, it is optional to install BACB30MR( )K( ) bolts and BACW10BP( )CD washers, with BACN11Z( )CD nuts and BACW10BP( )DP washers at fastener locations common to the steel plates. However, availability of BACB30MR( )K( ) bolts is limited. Also, if fasteners are substituted, the same type of fastener should be used throughout each joint, as shown in Appendix C, Figure F. **STEP TASK NAME PART NUMBER NOTES**

**(SHEET 6 OF 6) FIGURE 9: ACCESS - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 128 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 9: ACCESS - Group 2** 

This Figure applies to Group 2: JC 232 LC 232
NC 232 QC 232

HC 231 KC 231 MC 231

JC 231 LC 231 NC 231 PC 231

QC 231 BC 242

AC 241

BC 231 DC 242

CC 241

DC 231 720 STA 960 STA

1 10

2

3 4 5 7 13 16

17

18

14 15 11 12

6 9 8382760

**(SHEET 1 OF 2) FIGURE 9: ACCESS - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 129 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **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 each airplane. **STEP TASK NAME PANEL NUMBER QTY NOTES** 1 Remove/Keep Main Deck Ceiling Panel 232JC 1 (a) 2 Remove/Keep Main Deck Ceiling Panel 231HC 1 (a) 3 Remove/Keep Main Deck Ceiling Panel 231JC 1 (a) 4 Remove/Keep Main Deck Ceiling Panel 232LC 1 (a) 5 Remove/Keep Main Deck Ceiling Panel 231KC 1 (a) 6 Remove/Keep Main Deck Ceiling Panel 231LC 1 (a) 7 Remove/Keep Main Deck Ceiling Panel 232NC 1 (a) 8 Remove/Keep Main Deck Ceiling Panel 231MC 1 (a) 9 Remove/Keep Main Deck Ceiling Panel 231NC 1 (a) 10 Remove/Keep Main Deck Ceiling Panel 232QC 1 (a) 11 Remove/Keep Main Deck Ceiling Panel 231PC 1 (a) 12 Remove/Keep Main Deck Ceiling Panel 231QC 1 (a) 13 Remove/Keep Main Deck Ceiling Panel 242BC 1 (a) 14 Remove/Keep Main Deck Ceiling Panel 241AC 1 (a) 15 Remove/Keep Main Deck Ceiling Panel 231BC 1 (a) 16 Remove/Keep Main Deck Ceiling Panel 242DC 1 (a) 17 Remove/Keep Main Deck Ceiling Panel 241CC 1 (a) 18 Remove/Keep Main Deck Ceiling Panel 241DC 1 (a) (a) Refer to 747-400 AMM 25-59-01 as an accepted procedure.

**(SHEET 2 OF 2) FIGURE 10: INSPECTION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 130 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 10: INSPECTION - Group 2** 

720 STA

940 STA FRAME (TYPICAL)

TENSION TIE (TYPICAL)

(2 LOCATIONS) HORIZONTAL SHEAR WEB (2 LOCATIONS) SLOPING SHEAR WEB 720 STA 940 STA

B SEE A SEE 8 9

FWD383965

**(SHEET 1 OF 6) FIGURE 10: INSPECTION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 131 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

FORWARD CHANNEL TENSION TIE FRAME AFT CHANNEL TENSION TIE REMOVED STEEL PLATE (KEEP)

SURFACE HFEC OPEN HOLE HFEC EXISTING FASTENERS (REF) SKIN

BL26 STRINGERS

FRAME ALL LOCATIONS) (NOT PRESENT AT VERTICAL POST

CHORD FAILSAFE 

### VIEW LOOKING AFT (TYPICAL) SHEAR TIES

CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION, ACTUAL FASTENER PATTERN AND TO VERTICAL POST FITTING COMMON

A A



### A-A 7

5 1 3 UP

INBD 2



### A

2 4

8

8 11 12 10
6383966

**(SHEET 2 OF 6) FIGURE 10: INSPECTION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 132 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

TENSION TIE FORWARD CHANNEL FRAME REMOVED STEEL PLATE (KEEP)

OPEN HOLE HFEC SURFACE HFEC EXISTING FASTENERS FITTING COMMON TO VERTICAL POST

SHEAR TIES SKIN

NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN AND CONFIGURATION VARIES DEPENDING ON LOCATION. BL26 STRINGERS

FAILSAFE CHORD FRAME VERTICAL POST (NOT PRESENT AT ALL LOCATIONS)



### VIEW LOOKING AFT

TENSION TIE AFT CHANNEL C C

D D B B



### B-B E E 6

1 3 2 5

8 

### B UP

OUTBD

2 4

8

12 11 10

7383967

**(SHEET 3 OF 6) FIGURE 10: INSPECTION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 133 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

This Figure applies to Group 2: The step numbers shown below agree with the numbers shown in the circle symbols in the Figure. **CAUTION:** UNLESS THE AIRPLANE IS SUPPORTED IN THE JIGGED POSITION, DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. **STEP TASK NAME Part Number NOTES** 1 Remove Fasteners - (a) 2 Remove/Keep Steel Plates 65B09631-( ) - 

### C-C

E-E (STA 940 ONLY) (AT LOCATIONS WITH A SHEAR WEB)

(AT ALL OTHER

LOCATIONS) 

### D-D D-D

D-D FRAME HORIZONTAL SHEAR WEB

TENSION TIE AFT CHANNEL (TYPICAL)

STEEL PLATE

TENSION TIE FWD CHANNEL (TYPICAL) ALUMINUM CHANNEL 2 1

2 1 2 1 2 1

8

8 8 8

8 8

8

8 9383969

**(SHEET 4 OF 6) FIGURE 10: INSPECTION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 134 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

3 Inspect Fastener Holes in the Frame and Frame doubler (if installed) - (b) Tension Tie channels, and all aluminum parts in the stackup. 65B09631-( ) (b) 4 Inspect Steel Plates 65B09631-( ) (c) 5 Inspect Tension Tie forward and aft channels 65B09631-( ) (d) 6 Inspect Frame Structure - (e) 7 Inspect Skin - (f) 8 Inspect Tension Tie forward and aft channels and associated parts attached to the Tension Tie channels 65B09631-( ) (g)

9 Inspect Tension Ties, Shear Webs, Aluminum Channel 65B09631-( ) 65B09661-( ) (g) 10 Install (Kept) Steel Plates 65B09631-( ) (h) 11 **CAUTION:** If fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations common to Steel Plates. Install washers under nuts. (i) (j) (l) (m) (n) Washers BACW10BP( )DP Nuts BACN10YT( )CD 12 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations NOT common to Steel Plates. Install washers under nuts. (i) (k) (l) (m) Washers BACW10BP( )DP Nuts BACN10YT( )CD (a) Remove all fasteners common to steel plates, plus six fasteners inboard of the steel plate at each end of the tension tie. (b) Open-hole HFEC inspect all holes in aluminum parts, in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. (c) One Steel Plate on each side of the Airplane at each Tension Tie location. Open-hole HFEC inspect all holes in the steel plates in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 19. (d) Surface HFEC inspect the Tension Tie forward and aft channel vertical webs adjacent to and around all fastener heads and bucked tails between BL 26 and the outboard to three fastener rows inboard of the steel plates. Include all remaining fastener locations where fasteners have not been removed for inspection per step 3. Exclude areas around fasteners in the fittings common to the vertical posts at BL 39. Do inspections in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 4. (e) Do a detailed inspection for cracks in the Frames and associated parts from minimum (2) stringers above to a minimum (2) stringers below the Tension Ties. Pay special attention to the corners of the stringer cut outs. On built-up frames, also pay special attention to the fail-safe chords and shear ties. (f) Do this step only if cracks were found in the shear tie. If cracks were found on the shear tie, remove fasteners in the fuselage skin common to the affected shear tie and open-hole HFEC inspect the skin in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. **STEP TASK NAME Part Number NOTES**

**(SHEET 5 OF 6) FIGURE 10: INSPECTION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 135 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

(g) Do a detailed inspection of the Tension Tie forward and aft channels from end to end. At STA 940, do a detailed inspection of the Aluminum Channel. Pay special attention to where shear webs and other structure attach to the Tension Tie channels. Also, do a detailed inspection of the shear webs where they attach to the tension tie. (h) Only reinstall the Steel Plates if step 4 inspections reveal no crack indications. If the Steel Plate is found cracked, before further flight, replace with new or contact Boeing for repair instructions. (i) Oversize undamaged holes up to 0.0312 inch over original as required to make holes round and to be within diameter limits for the specified hole size and fastener fit. If the holes need additional oversizing, do the OVERSIZE HOLE REPAIR steps as specified in the Work Instructions. (j) At open hole locations common to the Steel Plates, install fasteners in close ream holes in accordance with 747-400F SRM 51-40-05. Install fasteners wet with BMS 3-27 or BMS 3-38. Refer to SOPM 20-50-19 wet fastener installation method 2. If BACB30NX hex-drive bolts are installed with BMS 3-38, they must be installed with the following torque values applied to the nut: 3/16 inch bolt = 20 to 25 pound-inches. 1/4 inch bolt = 50 to 75 pound-inches. 5/16 inch bolt = 90 to 125 pound-inches. (k) At open hole locations not common to the Steel Plates, install fasteners in transition fit holes in accordance with 747-400F SRM 51-40-05. (l) It is acceptable to substitute fasteners in accordance with 747-400F SRM 51-40-03. However, if fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. (m) New fasteners are to be supplied by the operator. (n) To allow for easier removal during repeat inspections, it is optional to install BACB30MR( )K( ) bolts and BACW10BP( )CD washers, with BACN11Z( )CD nuts and BACW10BP( )DP washers at fastener locations common to the steel plates. However, availability of BACB30MR( )K( ) bolts is limited. Also, if fasteners are substituted, the same type of fastener should be used throughout each joint, as shown in Appendix C, Figure F. **STEP TASK NAME Part Number NOTES**

**(SHEET 6 OF 6) FIGURE 11: OVERSIZED HOLE REPAIR - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 136 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 11: OVERSIZED HOLE REPAIR - Group 2** 

720 STA 940 STA FRAME (TYPICAL)

TENSION TIE (TYPICAL)

(2 LOCATIONS) HORIZONTAL SHEAR WEB (2 LOCATIONS) SLOPING SHEAR WEB

720 STA

940 STA B SEE

FWD SEE A383971

**(SHEET 1 OF 5) FIGURE 11: OVERSIZED HOLE REPAIR - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 137 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BL26 STRINGER CHORD FAILSAFE

FRAME



### VIEW LOOKING AFT

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL SHEAR TIE

STEEL PLATE

AND CONFIGURATION VARIES DEPENDING ON LOCATION NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN A A



### A-A 1 2 3 4

UP

INBD


### A 5 6383972

**(SHEET 2 OF 5) FIGURE 11: OVERSIZED HOLE REPAIR - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 138 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL STEEL PLATE SHEAR TIE

AND CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN BL26 STRINGER

FRAME



### VIEW LOOKING AFT CHORD FAILSAFE

B B



### B-B 1 2 3 4



### B UP

OUTBD 5 6383973

**(SHEET 3 OF 5) FIGURE 11: OVERSIZED HOLE REPAIR - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 139 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** This Figure applies to Group 2: The step numbers shown below agree with the numbers shown in the circle symbols in the Figure. **NOTE:** Only do these steps at locations where crack indications are present in the Frame and/or Tension Tie and can be cleaned up by oversizing the hole to a maximum hole size of 0.313 inch. If the crack is larger, contact Boeing for repair instructions. **CAUTION:** UNLESS THE AIRPLANE IS SUPPORTED IN THE JIGGED POSITION, DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. **STEP TASK NAME PART NUMBER NOTES** 1 Oversize Holes in Tension Tie Channels, Frame, Steel Plate, associated parts in the stackup. - (a)

2 Inspect Holes in Tension Tie Channels, Frame, and associated aluminum parts in the stack up. - (b) (c)

3 Oversize Holes Tension Tie Channels, Frame, Steel Plate, and associated parts in the stackup. - (d) (e)

**NOTE:** Holes can only be oversized to a maximum 0.313 inch diameter. 4 Measure Edge Margin and Spacing - (f) 5 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations common to the Steel Plates. Install washers under nuts. (g) (i) (j) Washers BACW10BP( )DP Nuts BACN10YT( )CD 6 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations NOT common to the Steel Plates. Install washers under nuts. (h) (i) Washers BACW10BP( )DP Nuts BACN10YT( )CD (a) Oversize the minimum amount required to remove the cracks, in 0.0156 inches increments, up to a maximum hole size of 0.313 inch. (b) Open-hole HFEC inspect holes in the aluminum parts in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. (c) Repeat steps 1 to 2 if crack indications are still present, until there are no more crack indications. Once there are no more crack indications, go to step 3. (d) Make the final hole diameters in the entire stackup common to the steel plates within limits for close ream holes in accordance with 747-400F SRM 51-40-05. (e) Make the final hole diameters in the stackup NOT common to the steel plates within limits for transition fit holes in accordance with 747-400F SRM 51-40-05. If the holes are already within SRM limits for transition fit holes, do not further oversize.

**(SHEET 4 OF 5) FIGURE 11: OVERSIZED HOLE REPAIR - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 140 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

(f) A minimum 1.5D edge margin (center of hole to edge of part) and 2.5D spacing (center of hole to center of hole) should be maintained. If edge margin and spacing cannot be maintained, repair contact Boeing for repair instructions. (g) At open hole locations common to the Steel Plates, install fasteners in close ream holes in accordance with 747-400F SRM 51-40-05. Install fasteners wet with BMS 3-27 or BMS 3-38. Refer to SOPM 20-50-19 wet fastener installation method 2. If BACB30NX hex-drive bolts are installed with BMS 3-38, they must be installed with the following torque values applied to the nut: 3/16 inch bolt = 20 to 25 pound-inches. 1/4 inch bolt = 50 to 75 pound-inches. 5/16 inch bolt = 90 to 125 pound-inches. (h) At open hole locations not common to the Steel Plates, install fasteners in transition fit holes in accordance with 747-400F SRM 51-40-05. (i) It is acceptable to substitute fasteners in accordance with 747-400F SRM 51-40-03. However, if fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. (j) To allow for easier removal during repeat inspections, it is optional to install BACB30MR( )K( ) bolts and BACW10BP( )CD washers, with BACN11Z( )CD nuts and BACW10BP( )DP washers at fastener locations common to the steel plates. However, availability of BACB30MR( )K( ) bolts is limited. Also, if fasteners are substituted, the same type of fastener should be used throughout each joint, as shown in Appendix C, Figure F. **STEP TASK NAME PART NUMBER NOTES**

**(SHEET 5 OF 5) FIGURE 12: CLOSE ACCESS - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 141 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 12: CLOSE ACCESS - Group 2** 

This Figure applies to Group 2: The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY JC 232 LC 232
NC 232 QC 232

HC 231 KC 231 MC 231

JC 231 LC 231 NC 231 PC 231

QC 231 BC 242

AC 241

BC 231 DC 242

CC 241

DC 231 720 STA 960 STA

1 10

2

3 4 5 7 13 16

17

18

14 15 11 12

6 9 8384081

**(SHEET 1 OF 2) FIGURE 12: CLOSE ACCESS - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 142 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** numbers shown below are the number of parts necessary for each airplane. **STEP TASK NAME PANEL NUMBER QTY NOTES** 1 Install (kept) Main Deck Ceiling Panel 232JC 1 (a) 2 Install (kept) Main Deck Ceiling Panel 231HC 1 (a) 3 Install (kept) Main Deck Ceiling Panel 231JC 1 (a) 4 Install (kept) Main Deck Ceiling Panel 232LC 1 (a) 5 Install (kept) Main Deck Ceiling Panel 231KC 1 (a) 6 Install (kept) Main Deck Ceiling Panel 231LC 1 (a) 7 Install (kept) Main Deck Ceiling Panel 232NC 1 (a) 8 Install (kept) Main Deck Ceiling Panel 231MC 1 (a) 9 Install (kept) Main Deck Ceiling Panel 231NC 1 (a) 10 Install (kept) Main Deck Ceiling Panel 232QC 1 (a) 11 Install (kept) Main Deck Ceiling Panel 231PC 1 (a) 12 Install (kept) Main Deck Ceiling Panel 231QC 1 (a) 13 Install (kept) Main Deck Ceiling Panel 242BC 1 (a) 14 Install (kept) Main Deck Ceiling Panel 241AC 1 (a) 15 Install (kept) Main Deck Ceiling Panel 231BC 1 (a) 16 Install (kept) Main Deck Ceiling Panel 242DC 1 (a) 17 Install (kept) Main Deck Ceiling Panel 241CC 1 (a) 18 Install (kept) Main Deck Ceiling Panel 241DC 1 (a) (a) Refer to 747-400 AMM 25-59-01 as an accepted procedure.

**(SHEET 2 OF 2) FIGURE 13: INSPECTION - Group 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 143 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 13: INSPECTION - Group 3** 

1040 STA

1140 STA 1040 STA 1140 STA

FRAME (TYPICAL)
(TYPICAL) TENSION TIE (2 LOCATIONS) HORIZONTAL SHEAR WEB (2 LOCATIONS) SLOPING SHEAR WEB

FWD B SEE A 9

SEE 9

9384770

**(SHEET 1 OF 6) FIGURE 13: INSPECTION - Group 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 144 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BL26 STRINGERS

FRAME ALL LOCATIONS) (NOT PRESENT AT VERTICAL POST

CHORD FAILSAFE 

### VIEW LOOKING AFT

(TYPICAL) SHEAR TIES

AND CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION, ACTUAL FASTENER PATTERN TO VERTICAL POST FITTING COMMON

FORWARD CHANNEL TENSION TIE AFT CHANNEL TENSION TIE REMOVED STEEL PLATE (KEEP)

SURFACE HFEC OPEN HOLE HFEC EXISTING FASTENERS (REF) SKIN

FRAME A

A



### A-A 7

5 1 3 UP

INBD 2



### A

2 4

8

8 11 12 10

6384779

**(SHEET 2 OF 6) FIGURE 13: INSPECTION - Group 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 145 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BL26 STRINGERS

FAILSAFE CHORD FRAME VERTICAL POST (NOT PRESENT AT ALL LOCATIONS)



### VIEW LOOKING AFT

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL REMOVED STEEL PLATE (KEEP)

OPEN HOLE HFEC SURFACE HFEC EXISTING FASTENERS FITTING COMMON TO VERTICAL POST

SHEAR TIES SKIN

NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN AND CONFIGURATION VARIES DEPENDING ON LOCATION. C C

D D B B



### B-B E E 6

1 3 2 5

8 

### B UP
OUTBD

2 4

8

12 11 10
7384780

**(SHEET 3 OF 6) FIGURE 13: INSPECTION - Group 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 146 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

This Figure applies to Group 3: The step numbers shown below agree with the numbers shown in the circle symbols in the Figure. **CAUTION:** UNLESS THE AIRPLANE IS SUPPORTED IN THE JIGGED POSITION, DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. **STEP TASK NAME Part Number NOTES** 1 Remove Fasteners - (a) 2 Remove/Keep Steel Plates 65B09631-( ) - 

### C-C

E-E (STA 1140 ONLY) (AT LOCATIONS WITH A SHEAR WEB)

(AT ALL OTHER

LOCATIONS) 

### D-D D-D

D-D FRAME HORIZONTAL SHEAR WEB

TENSION TIE AFT CHANNEL (TYPICAL)

STEEL PLATE

TENSION TIE FWD CHANNEL (TYPICAL) ALUMINUM CHANNEL 2 1

2 1 2 1 2 1

8

8 8 8

8 8

8

8 9384781

**(SHEET 4 OF 6) FIGURE 13: INSPECTION - Group 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 147 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

3 Inspect Fastener Holes in the Frame and Frame doubler (if installed) - (b) Tension Tie channels, and all aluminum parts in the stackup. 65B09631-( ) (b) 4 Inspect Steel Plates 65B09631-( ) (c) 5 Inspect Tension Tie forward and aft channels 65B09631-( ) (d) 6 Inspect Frame Structure - (e) 7 Inspect Skin - (f) 8 Inspect Tension Tie forward and aft channels and associated parts attached to the Tension Tie channels 65B09631-( ) (g)

9 Inspect Tension Ties, Shear Webs, Aluminum Channel 65B09631-( ) 65B09661-( ) (g) 10 Install (Kept) Steel Plates 65B09631-( ) (h) 11 **CAUTION:** If fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. Install (New) Hex Drive Bolts BACB30NX( )K( ) at locations common to Steel Plates. Install washers under nuts. (i) (j) (l) (m) (n) Washers BACW10BP( )DP Nuts BACN10YT( )CD 12 Install (New) Hex Drive Bolts BACB30NX( )K( ) at locations NOT common to Steel Plates. Install washers under nuts. (j) (k) (l) (m) Washers BACW10BP( )DP Nuts BACN10YT( )CD (a) Remove all fasteners common to steel plates, plus six fasteners inboard of the steel plate at each end of the tension tie. (b) Open-hole HFEC inspect all holes in aluminum parts, in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. (c) One Steel Plate on each side of the Airplane at each Tension Tie location. Open-hole HFEC inspect all holes in the steel plates in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 19. (d) Surface HFEC inspect the Tension Tie forward and aft channel vertical webs adjacent to and around all fastener heads and bucked tails between BL 26 and the outboard to three fastener rows inboard of the steel plates. Include all remaining fastener locations where fasteners have not been removed for inspection per step 3. Exclude areas around fasteners in the fittings common to the vertical posts at BL 39. Do inspections in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 4. (e) Do a detailed inspection for cracks in the Frames and associated parts from minimum (2) stringers above to a minimum (2) stringers below the Tension Ties. Pay special attention to the corners of the stringer cut outs. On built-up frames, also pay special attention to the fail-safe chords and shear ties. (f) Do this step only if cracks were found in the shear tie. If cracks were found on the shear tie, remove fasteners in the fuselage skin common to the affected shear tie and open-hole HFEC inspect the skin in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. **STEP TASK NAME Part Number NOTES**

**(SHEET 5 OF 6) FIGURE 13: INSPECTION - Group 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 148 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

(g) Do a detailed inspection of the Tension Tie forward and aft channels from end to end. At STA 940, do a detailed inspection of the Aluminum Channel. Pay special attention to where shear webs and other structure attach to the Tension Tie channels. Also, do a detailed inspection of the shear webs where they attach to the tension tie. (h) Only reinstall the Steel Plates if step 4 inspections reveal no crack indications. If the Steel Plate is found cracked, before further flight, replace with new or contact Boeing for repair instructions. (i) Oversize undamaged holes up to 0.0312 inch over original as required to make holes round and to be within diameter limits for the specified hole size and fastener fit. If the holes need additional oversizing, do the OVERSIZE HOLE REPAIR steps as specified in the Work Instructions. (j) At open hole locations common to the Steel Plates, install fasteners in close ream holes in accordance with 747-SP SRM 51-30-05. Install fasteners wet with BMS 3-27 or BMS 3-38. Refer to SOPM 20-50-19 wet fastener installation method 2. If BACB30NX hex-drive bolts are installed with BMS 3-38, they must be installed with the following torque values applied to the nut: 3/16 inch bolt = 20 to 25 pound-inches. 1/4 inch bolt = 50 to 75 pound-inches. 5/16 inch bolt = 90 to 125 pound-inches. (k) At open hole locations not common to the Steel Plates, install fasteners in transition fit holes in accordance with 747-SP SRM 51-30-05. (l) If necessary, it is acceptable to substitute fasteners in accordance with 747-SP SRM 51-30-03. However, if fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. (m) New fasteners are to be supplied by the operator. (n) To allow for easier removal during repeat inspections, it is optional to install BACB30MR( )K( ) bolts and BACW10BP( )CD washers, with BACN11Z( )CD nuts and BACW10BP( )DP washers at fastener locations common to the steel plates. However, availability of BACB30MR( )K( ) bolts is limited. Also, if fasteners are substituted, the same type of fastener should be used throughout each joint, as shown in Appendix C, Figure F. **STEP TASK NAME Part Number NOTES**

**(SHEET 6 OF 6) FIGURE 14: OVERSIZED HOLE REPAIR - Group 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 149 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 14: OVERSIZED HOLE REPAIR - Group 3** 

1040 STA

1140 STA 1040 STA 1140 STA

FRAME (TYPICAL)
(TYPICAL) TENSION TIE (2 LOCATIONS) HORIZONTAL SHEAR WEB

(2 LOCATIONS) SLOPING SHEAR WEB

B SEE A SEE

FWD384782

**(SHEET 1 OF 5) FIGURE 14: OVERSIZED HOLE REPAIR - Group 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 150 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

AND CONFIGURATION VARIES DEPENDING ON LOCATION NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN BL26 STRINGER CHORD FAILSAFE

FRAME



### VIEW LOOKING AFT

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL SHEAR TIE

STEEL PLATE A A



### A-A 1 2 3 4

UP

INBD



### A 5 6384783

**(SHEET 2 OF 5) FIGURE 14: OVERSIZED HOLE REPAIR - Group 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 151 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

STRINGER CHORD FAILSAFE

FRAME



### VIEW LOOKING AFT

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL STEEL PLATE SHEAR TIE BL26

AND CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN B B



### B-B 1 2 3 4



### B UP
OUTBD 5 6384784

**(SHEET 3 OF 5) FIGURE 14: OVERSIZED HOLE REPAIR - Group 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 152 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** This Figure applies to Group 3: The step numbers shown below agree with the numbers shown in the circle symbols in the Figure. **NOTE:** Only do these steps at locations where crack indications are present in the Frame and/or Tension Tie and can be cleaned up by oversizing the hole to a maximum hole size of 0.313 inch. If the crack is larger, contact Boeing for repair instructions. **CAUTION:** UNLESS THE AIRPLANE IS SUPPORTED IN THE JIGGED POSITION, DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. **STEP TASK NAME PART NUMBER NOTES** 1 Oversize Holes in Tension Tie Channels, Frame, Steel Plate, associated parts in the stackup. - (a)

2 Inspect Holes in Tension Tie Channels, Frame, and associated aluminum parts in the stack up. - (b) (c)

3 Oversize Holes Tension Tie Channels, Frame, Steel Plate, and associated parts in the stackup. - (d) (e)

**NOTE:** Holes can only be oversized to a maximum 0.313 inch diameter. 4 Measure Edge Margin and Spacing - (f) 5 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations common to the Steel Plates. Install washers under nuts. (g) (i) (j) Washers BACW10BP( )DP Nuts BACN10YT( )CD 6 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations NOT common to the Steel Plates. Install washers under nuts. (h) (i) Washers BACW10BP( )DP Nuts BACN10YT( )CD (a) Oversize the minimum amount required to remove the cracks, in 0.0156 inches increments, up to a maximum hole size of 0.313 inch. (b) Open-hole HFEC inspect holes in the aluminum parts in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. (c) Repeat steps 1 to 2 if crack indications are still present, until there are no more crack indications. Once there are no more crack indications, go to step 3. (d) Make the final hole diameters in the entire stackup common to the steel plates within limits for close ream holes in accordance with 747-SP SRM 51-30-05. If holes are already within SRM limits for close ream holes, do not further oversize. (e) Make the final hole diameters in the stackup NOT common to the steel plates within limits for transition fit holes in accordance with 747-SP SRM 51-30-05. If the holes are already within SRM limits for transition fit holes, do not further oversize.

**(SHEET 4 OF 5) FIGURE 14: OVERSIZED HOLE REPAIR - Group 3**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 153 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

(f) A minimum 1.5D edge margin (center of hole to edge of part) and 2.5D spacing (center of hole to center of hole) should be maintained if edge margin and spacing cannot be maintained, contact Boeing for repair instructions. (g) At open hole locations common to the Steel Plates, install fasteners in close ream holes in accordance with 747-SP SRM 51-30-05. Install fasteners wet with BMS 3-27 or BMS 3-38. Refer to SOPM 20-50-19 wet fastener installation method 2. If BACB30NX hex-drive bolts are installed with BMS 3-38, they must be installed with the following torque values applied to the nut: 3/16 inch bolt = 20 to 25 pound-inches. 1/4 inch bolt = 50 to 75 pound-inches. 5/16 inch bolt = 90 to 125 pound-inches. (h) At open hole locations not common to the Steel Plates, install fasteners in transition fit holes in accordance with 747-SP SRM 51-30-05. (i) If necessary, it is acceptable to substitute fasteners in accordance with 747-SP SRM 51-30-03. However, if fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. (j) To allow for easier removal during repeat inspections, it is optional to install BACB30MR( )K( ) bolts and BACW10BP( )CD washers, with BACN11Z( )CD nuts and BACW10BP( )DP washers at fastener locations common to the steel plates. However, availability of BACB30MR( )K( ) bolts is limited. Also, if fasteners are substituted, the same type of fastener should be used throughout each joint, as shown in Appendix C, Figure F. **STEP TASK NAME PART NUMBER NOTES**

**(SHEET 5 OF 5) FIGURE 15: INSPECTION - Group 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 154 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 15: INSPECTION - Group 4** 

760 STA 940 STA

760 STA

940 STA FRAME (TYPICAL)

ONLY AT STA 760 TENSION TIE BUILT-UP

(2 LOCATIONS) HORIZONTAL SHEAR WEB (2 LOCATIONS) SLOPING SHEAR WEB (TYPICAL) TENSION TIE

780 STA

FWD B OR SEE A OR SEE E SEE

D SEE C SEE 10 10D37017

**(SHEET 1 OF 9) FIGURE 15: INSPECTION - Group 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 155 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

REMOVED STEEL PLATE (KEEP)

SURFACE HFEC OPEN HOLE HFEC EXISTING FASTENERS (REF) SKIN

BL26 STRINGERS

FRAME ALL LOCATIONS) (NOT PRESENT AT VERTICAL POST

CHORD FAILSAFE

VIEW LOOKING AFT (TYPICAL) SHEAR TIES

CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION, ACTUAL FASTENER PATTERN AND TO VERTICAL POST FITTING COMMON

A A 8

6 1 4 UP

INBD 2



### A 5

9
13 14 11

7D37018

**(SHEET 2 OF 9) FIGURE 15: INSPECTION - Group 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 156 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

REMOVED STEEL PLATE (KEEP)

OPEN HOLE HFEC SURFACE HFEC EXISTING FASTENERS FITTING COMMON TO VERTICAL POST

SHEAR TIES SKIN

NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN AND CONFIGURATION VARIES DEPENDING ON LOCATION. BL26 STRINGERS

FAILSAFE CHORD VERTICAL POST (NOT PRESENT AT ALL LOCATIONS)

VIEW LOOKING AFT FRAME C C

D D

E B B E

2



### B UP
OUTBD 8

6 1 4 5

9

13 14 11

7D37019

**(SHEET 3 OF 9) FIGURE 15: INSPECTION - Group 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 157 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

A-A BL26 STRINGERS FRAME VERTICAL POST (ACTUAL LOCATION MAY VARY)

FAILSAFE CHORD SHEAR TIES (TYPICAL)

NOTE: TYPICAL CONFIGURATION, ACTUAL FASTENER PATTERN AND CONFIGURATION VARIES DEPENDING ON LOCATION. ALUMINUM REPAIR STRAP STEEL PLATE

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL REMOVED STEEL PLATE (KEEP)

EXISTING FASTENERS (REF) OPEN HOLE HFEC SURFACE HFEC SKIN REMOVED ALUMINUM REPAIR STRAP (KEEP)

VIEW LOOKING AFT (TYPICAL WITH REPAIR PER SERVICE BULLETIN 747-53-2371 FIGURE 3) (AIRPLANES LINE 1-203 ONLY) G G
A A E E 8

6

1 4 UP

INBD 2



### C

2 5

9

9 13 14 11

7 3 12

3 12D38635

**(SHEET 4 OF 9) FIGURE 15: INSPECTION - Group 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 158 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

TENSION TIE FORWARD CHANNEL TENSION TIE AFT CHANNEL REMOVED STEEL PLATE (KEEP)

EXISTING FASTENERS (REF) OPEN HOLE HFEC SURFACE HFEC SKIN REMOVED ALUMINUM REPAIR STRAP (KEEP)

BL26 STRINGERS

FRAME VERTICAL POST (ACTUAL LOCATION MAY VARY)

FAILSAFE CHORD SHEAR TIES (TYPICAL)

NOTE: TYPICAL CONFIGURATION, ACTUAL FASTENER PATTERN AND CONFIGURATION VARIES DEPENDING ON LOCATION.

ALUMINUM REPAIR STRAP STEEL PLATE



### B-B FRAME

VIEW LOOKING AFT (TYPICAL WITH REPAIR PER SERVICE BULLETIN 747-53-2371 FIGURE 3) (AIRPLANES LINE 1-203 ONLY) G G
B B
E E 8

6
1 4 UP

INBD 2



### D

2 5

9

9 13 14 11

7 3

3 12 12D38638

**(SHEET 5 OF 9) FIGURE 15: INSPECTION - Group 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 159 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

H H

H-H E

9 9

9 9 9 BL 81 BL 81

WEB UPPER CHORD STA 760 ONLY

LOWER CHORDD37020

**(SHEET 6 OF 9) FIGURE 15: INSPECTION - Group 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 160 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

FRAME

ALUMINUM CHANNEL

HORIZONTAL SHEAR WEB TENSION TIE AFT CHANNEL (TYPICAL)

STEEL PLATE

TENSION TIE FWD CHANNEL (TYPICAL) 

### C-C

E-E (STA 940 ONLY)

(AT LOCATIONS WITH A SHEAR WEB) (AT ALL OTHER

LOCATIONS) 

### D-D

D-D D-D

G-G 2 1

2 1 2 1 2 1

2 1 3 12 9 9

9 9 9

9 9

9 9 10D37021

**(SHEET 7 OF 9) FIGURE 15: INSPECTION - Group 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 161 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** This Figure applies to Group 4: The step numbers shown below agree with the numbers shown in the circle symbols in the Figure. **CAUTION:** UNLESS THE AIRPLANE IS SUPPORTED IN THE JIGGED POSITION, DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. **STEP TASK NAME Part Number NOTES** 1 Remove Fasteners - (a) 2 Remove/Keep Steel Plates 65B09631-( ) - 3 Remove/Keep Aluminum Repair Strap - (n) 4 Inspect Fastener Holes in the Frame and Frame doubler (if installed) - (b) Tension Tie channels, and all aluminum parts in the stackup. 65B09631-( ) (b) 5 Inspect Steel Plates 65B09631-( ) (c) 6 Inspect Tension Tie forward and aft channels 65B09631-( ) (d) 7 Inspect Frame Structure - (e) 8 Inspect Skin - (f) 9 Inspect Tension Tie 65B09631-( ) (g) 10 Inspect Tension Ties, Shear Webs, Aluminum Channel 65B09631-( ) 65B09661 (g) 11 Install (Kept) Steel Plates 65B09631-( ) (h) 12 Install (Kept) Aluminum Repair Strap - (n) 13 **CAUTION:** If fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations common to Steel Plates. Install washers under nuts. (i) (j) (l) (m) (o) Washers BACW10BP( )DP Nuts BACN10YT( )CD 14 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations NOT common to Steel Plates. Install washers under nuts. (i) (k) (l) (m) (p) Washers BACW10BP( )DP Nuts BACN10YT( )CD (a) Remove all fasteners common to steel plates, plus six fasteners inboard of the steel plate at each end of the tension tie. (b) Open-hole HFEC inspect all holes in aluminum parts, in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. (c) One Steel Plate on each side of the Airplane at each Tension Tie location. Open-hole HFEC inspect all holes in the steel plates in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 19.

**(SHEET 8 OF 9) FIGURE 15: INSPECTION - Group 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 162 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

(d) Surface HFEC inspect the Tension Tie forward and aft channel vertical webs adjacent to and around all fastener heads and bucked tails between BL 26 and the outboard to three fastener rows inboard of the steel plates. Include all remaining fastener locations where fasteners have not been removed for inspection per step 4. Exclude areas around fasteners in the fittings common to the vertical posts at BL 39. Do inspections in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 4. (e) Do a detailed inspection for cracks in the Frames and associated parts from minimum (2) stringers above to a minimum (2) stringers below the Tension Ties. Pay special attention to the corners of the stringer cut outs. On built-up frames, also pay special attention to the fail-safe chords and shear ties. (f) Do this step only if cracks were found in the shear tie. If cracks were found on the shear tie, remove fasteners in the fuselage skin common to the affected shear tie and open-hole HFEC inspect the skin in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. (g) Do a detailed inspection of the Tension Tie forward and aft channels from end to end. At STA 940, do a detailed inspection of the Aluminum Channel. Pay special attention at locations where shear webs and other structure attach to the Tension Tie channels. Also, do a detailed inspection of the shear webs where they attach to the tension tie. At STA 760, do a detailed inspection of the upper chord, lower chord, and web of the built up tension tie. (h) Only reinstall the Steel Plates if step 4 inspections reveal no crack indications. If the Steel Plate is found cracked, before further flight, replace with new or contact Boeing for repair instructions. (i) Oversize undamaged holes up to 0.0312 inch over original as required to make holes round and to be within diameter limits for the specified hole size and fastener fit. If the holes need additional oversizing, do the OVERSIZE HOLE REPAIR steps as specified in the Work Instructions. (j) At open hole locations common to the Steel Plates, install fasteners in close ream holes in accordance with 747-100/200/300 SRM 51-30-05. Install fasteners wet with BMS 3-27 or BMS 3- 38. Refer to SOPM 20-50-19 wet fastener installation method 2. If BACB30NX hex-drive bolts are installed with BMS 3-38, they must be installed with the following torque values applied to the nut: 3/16 inch bolt = 20 to 25 pound-inches. 1/4 inch bolt = 50 to 75 pound-inches. 5/16 inch bolt = 90 to 125 pound-inches. (k) At open hole locations not common to the Steel Plates, install fasteners in transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. (l) It is acceptable to substitute fasteners in accordance with 747-100/200/300 SRM 51-30-03. However, if fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. (m) New fasteners are to be supplied by the operator. (n) This part is only installed on Tension Ties that have been modified in accordance with Service Bulletin 747-53-2371, Figure 3. It is not necessary to re-install this part if the affected end of the Tension Tie aft channel is being replaced (either complete replacement of the channel, or a new segment spliced in). (o) To allow for easier removal during repeat inspections, it is optional to install BACB30MR( )K( ) bolts and BACW10BP( )CD washers, with BACN11Z( )CD nuts and BACW10BP( )DP washers at fastener locations common to the steel plates. However, availability of BACB30MR( )K( ) bolts is limited. Also, if fasteners are substituted, the same type of fastener should be used throughout each joint, as shown in Appendix C, Figure F.(p) If an aluminum repair strap was installed by Service Bulletin 747-53-2371, Figure 3, and is being reinstalled, install BACB30NX( )K( ) bolts inboard of the steel plate, common to the aluminum repair strap plus three fastener rows inboard of the aluminum repair strap. **STEP TASK NAME Part Number NOTES**

**(SHEET 9 OF 9) FIGURE 16: OVERSIZED HOLE REPAIR - Group 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 163 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 16: OVERSIZED HOLE REPAIR - Group 4** 

760 STA 940 STA

780 STA

940 STA FRAME (TYPICAL) (TYPICAL) TENSION TIE (2 LOCATIONS) HORIZONTAL SHEAR WEB

(2 LOCATIONS) SLOPING SHEAR WEB

FWD B OR SEE A OR SEE
D SEE C SEE386171

**(SHEET 1 OF 7) FIGURE 16: OVERSIZED HOLE REPAIR - Group 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 164 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BL26 STRINGER CHORD FAILSAFE

FRAME

VIEW LOOKING AFT STEEL PLATE

AND CONFIGURATION VARIES DEPENDING ON LOCATION NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN SHEAR TIE A A 1 2 3 4

UP

INBD



### A 5 6385928

**(SHEET 2 OF 7) FIGURE 16: OVERSIZED HOLE REPAIR - Group 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 165 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

STEEL PLATE SHEAR TIE

AND CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN BL26 STRINGER CHORD FAILSAFE

FRAME

VIEW LOOKING AFT B B 1 2 3 4



### B UP
OUTBD 5 6385929

**(SHEET 3 OF 7) FIGURE 16: OVERSIZED HOLE REPAIR - Group 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 166 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

STRINGER CHORD FAILSAFE

(AIRPLANES LINE 1-203 ONLY) 747-53-2371 FIGURE 3) (TYPICAL WITH REPAIR PER SERVICE BULLETIN VIEW LOOKING AFT

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL SHEAR TIE

AND CONFIGURATION VARIES DEPENDING ON LOCATION NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN FRAME



### A-A (ACTUAL LOCATION MAY VARY) ALUMINUM REPAIR STRAP

(ACTUAL LOCATION MAY VARY) TRIM LINE IN AFT TENSION CHANNEL PLATE STEEL
BL26

A A 1 2 3 4

UP

INBD 5 6



### CD38641

**(SHEET 4 OF 7) FIGURE 16: OVERSIZED HOLE REPAIR - Group 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 167 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BL26 STRINGER CHORD FAILSAFE

FRAME (ACTUAL LOCATION MAY VARY) ALUMINUM REPAIR STRAP
(ACTUAL LOCATION MAY VARY) TRIM LINE IN AFT TENSION CHANNEL

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL SHEAR TIE PLATE STEEL

AND CONFIGURATION VARIES DEPENDING ON LOCATION NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN 

### B-B (AIRPLANES LINE 1-203 ONLY) 747-53-2371 FIGURE 3) (TYPICAL WITH REPAIR PER SERVICE BULLETIN VIEW LOOKING AFT B B 1 2 3 4

UP

INBD



### D 5 6D38642

**(SHEET 5 OF 7) FIGURE 16: OVERSIZED HOLE REPAIR - Group 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 168 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** This Figure applies to Group 4: The step numbers shown below agree with the numbers shown in the circle symbols in the Figure. **NOTE:** The oversize hole repair per this Figure does not apply to built-up Tension Tie located at STA 760 on Group 4 and Group 6 Airplanes. **NOTE:** Only do these steps at locations where crack indications are present in the Frame and/or Tension Tie and can be cleaned up by oversizing the hole to a maximum hole size of 0.313 inch. If the crack is larger, contact Boeing for repair instructions. **CAUTION:** UNLESS THE AIRPLANE IS SUPPORTED IN THE JIGGED POSITION, DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. **STEP TASK NAME PART NUMBER NOTES** 1 Oversize Holes in Tension Tie Channels, Frame, Steel Plate, associated parts in the stackup. - (a)

2 Inspect Holes in Tension Tie Channels, Frame, and associated aluminum parts in the stack up. - (b) (c)

3 Oversize Holes Tension Tie Channels, Frame, Steel Plate, and associated parts in the stackup. - (d) (e)

**NOTE:** Holes can only be oversized to a maximum 0.313 inch diameter. 4 Measure Edge Margin and Spacing - (f) 5 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations common to the Steel Plates. Install washers under nuts. (g) (i) (j) Washers BACW10BP( )DP Nuts BACN10YT( )CD 6 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations NOT common to the Steel Plates. Install washers under nuts. (h) (i) Washers BACW10BP( )DP Nuts BACN10YT( )CD (a) Oversize the minimum amount required to remove the cracks, in 0.0156 inches increments, up to a maximum hole size of 0.313 inch. (b) Open-hole HFEC inspect holes in the aluminum parts in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. (c) Repeat steps 1 to 2 if crack indications are still present, until there are no more crack indications. Once there are no more crack indications, go to step 3. (d) Make the final hole diameters in the entire stackup common to the steel plates within limits for close ream holes in accordance with 747-100/200/300 SRM 51-30-05. If holes are already within SRM limits for close ream holes, do not further oversize.

**(SHEET 6 OF 7) FIGURE 16: OVERSIZED HOLE REPAIR - Group 4**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 169 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

(e) Make the final hole diameters in the stackup NOT common to the steel plates within limits for transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. If the holes are already within SRM limits for transition fit holes, do not further oversize. (f) A minimum 1.5D edge margin (center of hole to edge of part) and 2.5D spacing (center of hole to center of hole) should be maintained. If edge margin or spacing cannot be maintained, contact Boeing for repair instructions. (g) At open hole locations common to the Steel Plates, install fasteners in close ream holes in accordance with 747-100/200/300 SRM 51-30-05. Install fasteners wet with BMS 3-27 or BMS 3- 38. Refer to SOPM 20-50-19 wet fastener installation method 2. If BACB30NX hex-drive bolts are installed with BMS 3-38, they must be installed with the following torque values applied to the nut: 3/16 inch bolt = 20 to 25 pound-inches. 1/4 inch bolt = 50 to 75 pound-inches. 5/16 inch bolt = 90 to 125 pound-inches. (h) At open hole locations not common to the Steel Plates, install fasteners in transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. (i) If necessary, it is acceptable to substitute fasteners in accordance with 747-100/200/300 SRM 51-30-03. However, if fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. (j) To allow for easier removal during repeat inspections, it is optional to install BACB30MR( )K( ) bolts and BACW10BP( )CD washers, with BACN11Z( )CD nuts and BACW10BP( )DP washers at fastener locations common to the steel plates. However, availability of BACB30MR( )K( ) bolts is limited. Also, if fasteners are substituted, the same type of fastener should be used throughout each joint, as shown in Appendix C, Figure F. **STEP TASK NAME PART NUMBER NOTES**

**(SHEET 7 OF 7) FIGURE 17: INSPECTION - Group 5**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 170 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 17: INSPECTION - Group 5** 

760 STA 940 STA

760 STA

940 STA FRAME (TYPICAL)

ONLY AT STA 760 TENSION TIE BUILT-UP

(2 LOCATIONS) HORIZONTAL SHEAR WEB (2 LOCATIONS) SLOPING SHEAR WEB (TYPICAL) TENSION TIE

FWD B SEE A SEE 9 9 E SEE

D SEE C SEE380697

**(SHEET 1 OF 9) FIGURE 17: INSPECTION - Group 5**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 171 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BL26 STRINGERS

FRAME ALL LOCATIONS) (NOT PRESENT AT VERTICAL POST

CHORD FAILSAFE

VIEW LOOKING AFT (TYPICAL) SHEAR TIES

CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION, ACTUAL FASTENER PATTERN AND TO VERTICAL POST FITTING COMMON REMOVED STEEL PLATE (KEEP)

SURFACE HFEC OPEN HOLE HFEC EXISTING FASTENERS (REF) SKIN

A A 7

5 1 3

UP

INBD 2



### A 4

8 11 12 10

6380698

**(SHEET 2 OF 9) FIGURE 17: INSPECTION - Group 5**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 172 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BL26 STRINGERS

FAILSAFE CHORD FRAME VERTICAL POST (NOT PRESENT AT ALL LOCATIONS)

VIEW LOOKING AFT REMOVED STEEL PLATE (KEEP)

OPEN HOLE HFEC SURFACE HFEC EXISTING FASTENERS FITTING COMMON TO VERTICAL POST

SHEAR TIES SKIN

NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN AND CONFIGURATION VARIES DEPENDING ON LOCATION. C C

D D

E E
B B 6

1 3 2 5



### B UP
OUTBD 4

8

12 11 10

7381633

**(SHEET 3 OF 9) FIGURE 17: INSPECTION - Group 5**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 173 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

SURFACE HFEC OPEN HOLE HFEC EXISTING FASTENERS (REF)

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL BL26 ALL LOCATIONS) (NOT PRESENT AT VERTICAL POST

(STA 780 ONLY) VIEW LOOKING AFT REMOVED STEEL PLATE (KEEP)

VERTICAL POST FITTING COMMON TO STRINGERS



### A-A BL37.8

C C

D D

E E
A A

2 6 7

1 11 3 12 5 8 10 4



### C 2D37034

**(SHEET 4 OF 9) FIGURE 17: INSPECTION - Group 5**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 174 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

SURFACE HFEC OPEN HOLE HFEC EXISTING FASTENERS (REF) STRINGERS

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL BL37.8 BL26

(STA 780 ONLY) VIEW LOOKING AFT REMOVED STEEL PLATE (KEEP)

ALL LOCATIONS) (NOT PRESENT AT VERTICAL POST

VERTICAL POST FITTING COMMON TO



### B-B C C

D D

E E B B

2 6 7

1 11 3 12 5 2 8 10 4



### DD37035

**(SHEET 5 OF 9) FIGURE 17: INSPECTION - Group 5**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 175 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

F F

F-F 8 

### E

8 8

8 8 BL 81 BL 81

WEB UPPER CHORD STA 760 ONLY

LOWER CHORDD30807

**(SHEET 6 OF 9) FIGURE 17: INSPECTION - Group 5**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 176 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

This Figure applies to Group 5: The step numbers shown below agree with the numbers shown in the circle symbols in the Figure. **CAUTION:** UNLESS THE AIRPLANE IS SUPPORTED IN THE JIGGED POSITION, DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. **STEP TASK NAME Part Number NOTES** 1 Remove Fasteners - (a) 2 Remove/Keep Steel Plates 65B09631-( ) - FRAME HORIZONTAL SHEAR WEBS

TENSION TIE AFT CHANNEL (TYPICAL)

STEEL PLATE

TENSION TIE FWD CHANNEL (TYPICAL) ALUMINUM CHANNEL 

### C-C

E-E (STA 940 ONLY) (AT LOCATIONS WITH A SHEAR WEB)

(AT ALL OTHER

LOCATIONS) 

### D-D D-D

D-D 2 1

2 1 2 1 2 1

8

8 8 8

8 8

8

8 9380700

**(SHEET 7 OF 9) FIGURE 17: INSPECTION - Group 5**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 177 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

3 Inspect Fastener Holes in the Frame and Frame doubler (if installed) - (b) Tension Tie channels, and all aluminum parts in the stackup. 65B09631-( ) (b) 4 Inspect Steel Plates 65B09631-( ) (c) 5 Inspect Tension Tie forward and aft channels 65B09631-( ) (d) 6 Inspect Frame Structure - (e) 7 Inspect Skin - (f) 8 Inspect Tension Tie 65B09631-( ) (g) 9 Inspect Tension Ties, Shear Webs, Aluminum Channel 65B09631-( ) 98B09661-( ) (g) 10 Install (Kept) Steel Plates 65B09631-( ) (h) 11 **CAUTION:** If fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations common to the Steel Plates. Install washers under nuts. (i) (j) (l) (m) (n) Washers BACW10BP( )DP Nuts BACN10YT( )CD 12 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations NOT common to the Steel Plates. Install washers under nuts. (i) (k) (l) (m) Washers BACW10BP( )DP Nuts BACN10YT( )CD (a) Remove all fasteners common to steel plates, plus six fasteners inboard of the steel plate at each end of the tension tie. (b) Open-hole HFEC inspect all holes in aluminum parts, in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. (c) One Steel Plate on each side of the Airplane at each Tension Tie location. Open-hole HFEC inspect all holes in the steel plates in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 19. (d) Surface HFEC inspect the Tension Tie forward and aft channel vertical webs adjacent to and around all fastener heads and bucked tails between BL 26 and the outboard to three fastener rows inboard of the steel plates. Include all remaining fastener locations where fasteners have not been removed for inspection per step 3. Exclude areas around fasteners in the fittings common to the vertical posts at BL 39. Do inspections in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 4. (e) Do a detailed inspection for cracks in the Frames and associated parts from minimum (2) stringers above to a minimum (2) stringers below the Tension Ties. Pay special attention to the corners of the stringer cut outs. On built-up frames, also pay special attention to the fail-safe chords and shear ties. (f) Do this step only if cracks were found in the shear tie. If cracks were found on the shear tie, remove fasteners in the fuselage skin common to the affected shear tie and open-hole HFEC inspect the skin in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. **STEP TASK NAME Part Number NOTES**

**(SHEET 8 OF 9) FIGURE 17: INSPECTION - Group 5**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 178 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

(g) Do a detailed inspection of the Tension Tie forward and aft channels from end to end. At STA 940, do a detailed inspection of the Aluminum Channel. Pay special attention at locations where shear webs and other structure attach to the Tension Tie channels. Also, do a detailed inspection of the shear webs where they attach to the tension tie. At STA 760, do a detailed inspection of the upper chord, lower chord, and web of the built up tension tie. (h) Only reinstall the Steel Plates if step 4 inspections reveal no crack indications. If the Steel Plate is found cracked, before further flight, replace with new or contact Boeing for repair instructions. (i) Oversize undamaged holes up to 0.0312 inch over original as required to make holes round and to be within diameter limits for the specified hole size and fastener fit. If the holes need additional oversizing, do the OVERSIZE HOLE REPAIR steps as specified in the Work Instructions. (j) At open hole locations common to the Steel Plates, install fasteners in close ream holes in accordance with 747-100/200/300 SRM 51-30-05. Install fasteners wet with BMS 3-27 or BMS 3- 38. Refer to SOPM 20-50-19 wet fastener installation method 2. If BACB30NX hex-drive bolts are installed with BMS 3-38, they must be installed with the following torque values applied to the nut: 3/16 inch bolt = 20 to 25 pound-inches. 1/4 inch bolt = 50 to 75 pound-inches. 5/16 inch bolt = 90 to 125 pound-inches. (k) At open hole locations not common to the Steel Plates, install fasteners in transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. (l) If necessary, it is acceptable to substitute fasteners in accordance with 747-100/200/300 SRM 51-30-03. However, if fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. (m) New fasteners are to be supplied by the operator. (n) To allow for easier removal during repeat inspections, it is optional to install BACB30MR( )K( ) bolts and BACW10BP( )CD washers, with BACN11Z( )CD nuts and BACW10BP( )DP washers at fastener locations common to the steel plates. However, availability of BACB30MR( )K( ) bolts is limited. Also, if fasteners are substituted, the same type of fastener should be used throughout each joint, as shown in Appendix C, Figure F. **STEP TASK NAME Part Number NOTES**

**(SHEET 9 OF 9) FIGURE 18: OVERSIZE HOLE REPAIR - Group 5**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 179 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 18: OVERSIZE HOLE REPAIR - Group 5** 

760 STA 940 STA

780 STA

940 STA FRAME (TYPICAL) (TYPICAL) TENSION TIE (2 LOCATIONS) HORIZONTAL SHEAR WEB

(2 LOCATIONS) SLOPING SHEAR WEB

FWD B SEE SEE D SEE C SEE

AD38651

**(SHEET 1 OF 7) FIGURE 18: OVERSIZE**  **HOLE REPAIR - Group 5** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 180 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

VIEW LOOKING AFT SHEAR TIE

STEEL PLATE

AND CONFIGURATION VARIES DEPENDING ON LOCATION NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN BL26 STRINGER CHORD FAILSAFE

FRAME A A 1 2 3 4

UP

INBD



### A 5 6D38652

**(SHEET 2 OF 7) FIGURE 18: OVERSIZE HOLE REPAIR - Group 5**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 181 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BL26

FRAME

VIEW LOOKING AFT STEEL PLATE SHEAR TIE

AND CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN STRINGER CHORD FAILSAFE

B B 1 2 3 4



### B UP
OUTBD 5 6D38654

**(SHEET 3 OF 7) FIGURE 18: OVERSIZE**  **HOLE REPAIR - Group 5** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 182 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL BL26 VERTICAL POST

(STA 780 ONLY) VIEW LOOKING AFT FAILSAFE CHORD

SHEAR TIES

FRAME STEEL PLATE

AND CONFIGURATION VARIES DEPENDING ON LOCATION NOTE: TYPICAL CONFIGURATION. ACTUAL FSTENER PATTERN STRINGERS



### A-A A A

UP
INBD 1 2



### C 3 4 5 6D37045

**(SHEET 4 OF 7) FIGURE 18: OVERSIZE HOLE REPAIR - Group 5**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 183 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

FRAME TENSION TIE AFT CHANNEL BL26 VERTICAL POST

(STA 780 ONLY) VIEW LOOKING AFT SHEAR TIES

FRAME STEEL PLATE FAILSAFE CHORD

STRINGERS

TENSION TIE FORWARD CHANNEL 

### B-B B B 1 2



### D 3 4 5 6

AND CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN UP
INBDD37049

**(SHEET 5 OF 7) FIGURE 18: OVERSIZE**  **HOLE REPAIR - Group 5** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 184 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** This Figure applies to Group 5: The step numbers shown below agree with the numbers shown in the circle symbols in the Figure. **NOTE:** The oversize hole repair per this Figure does not apply to built-up Tension Tie located at STA 760 on Group 4 and Group 6 Airplanes. **NOTE:** Only do these steps at locations where crack indications are present in the Frame and/or Tension Tie and can be cleaned up by oversizing the hole to a maximum hole size of 0.313 inch. If the crack is larger, contact Boeing for repair instructions. **CAUTION:** UNLESS THE AIRPLANE IS SUPPORTED IN THE JIGGED POSITION, DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. **STEP TASK NAME PART NUMBER NOTES** 1 Oversize Holes in Tension Tie Channels, Frame, Steel Plate, associated parts in the stackup. - (a)

2 Inspect Holes in Tension Tie Channels, Frame, and associated aluminum parts in the stack up. - (b) (c)

3 Oversize Holes Tension Tie Channels, Frame, Steel Plate, and associated parts in the stackup. - (d) (e)

**NOTE:** Holes can only be oversized to a maximum 0.313 inch diameter. 4 Measure Edge Margin and Spacing - (f) 5 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations common to the Steel Plates. Install washers under nuts. (g) (i) (j) Washers BACW10BP( )DP Nuts BACN10YT( )CD 6 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations NOT common to the Steel Plates. Install washers under nuts. (h) (i) Washers BACW10BP( )DP Nuts BACN10YT( )CD (a) Oversize the minimum amount required to remove the cracks, in 0.0156 inches increments, up to a maximum hole size of 0.313 inch. (b) Open-hole HFEC inspect holes in the aluminum parts in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. (c) Repeat steps 1 to 2 if crack indications are still present, until there are no more crack indications. Once there are no more crack indications, go to step 3. (d) Make the final hole diameters in the entire stackup common to the steel plates within limits for close ream holes in accordance with 747-100/200/300 SRM 51-30-05. If holes are already within SRM limits for close ream holes, do not further oversize.

**(SHEET 6 OF 7) FIGURE 18: OVERSIZE HOLE REPAIR - Group 5**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 185 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

(e) Make the final hole diameters in the stackup NOT common to the steel plates within limits for transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. If the holes are already within SRM limits for transition fit holes, do not further oversize. (f) A minimum 1.5D edge margin (center of hole to edge of part) and 2.5D spacing (center of hole to center of hole) should be maintained. If edge margin or spacing cannot be maintained, contact Boeing for repair instructions. (g) At open hole locations common to the Steel Plates, install fasteners in close ream holes in accordance with 747-100/200/300 SRM 51-30-05. Install fasteners wet with BMS 3-27 or BMS 3- 38. Refer to BSOPM 20-50-19 wet fastener installation method 2. If BACB30NX hex-drive bolts are installed with BMS 3-38, they must be installed with the following torque values applied to the nut: 3/16 inch bolt = 20 to 25 pound-inches. 1/4 inch bolt = 50 to 75 pound-inches. 5/16 inch bolt = 90 to 125 pound-inches. (h) At open hole locations not common to the Steel Plates, install fasteners in transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. (i) If necessary, it is acceptable to substitute fasteners in accordance with 747-100/200/300 SRM 51-30-03. However, if fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. (j) To allow for easier removal during repeat inspections, it is optional to install BACB30MR( )K( ) bolts and BACW10BP( )CD washers, with BACN11Z( )CD nuts and BACW10BP( )DP washers at fastener locations common to the steel plates. However, availability of BACB30MR( )K( ) bolts is limited. Also, if fasteners are substituted, the same type of fastener should be used throughout each joint, as shown in Appendix C, Figure F. **STEP TASK NAME PART NUMBER NOTES**

**(SHEET 7 OF 7) FIGURE 19: INSPECTION - Group 6**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 186 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 19: INSPECTION - Group 6** 

940 STA

800 STA

800 STA

940 STA FRAME (TYPICAL)

(TYPICAL) TENSION TIE

(2 LOCATIONS) HORIZONTAL SHEAR WEB (2 LOCATIONS) SLOPING SHEAR WEB

920 STA FWD 9 8 9

B SEE A SEE

B SEE D

SEE

SEE C SEE

AD36986

**(SHEET 1 OF 8) FIGURE 19: INSPECTION - Group 6**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 187 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BL26 STRINGERS

FRAME ALL LOCATIONS) (NOT PRESENT AT VERTICAL POST

CHORD FAILSAFE

VIEW LOOKING AFT (TYPICAL) SHEAR TIES

AND CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION, ACTUAL FASTENER PATTERN TO VERTICAL POST FITTING COMMON

SURFACE HFEC OPEN HOLE HFEC EXISTING FASTENERS (REF) SKIN

A A 7

5 1 3 UP

INBD



### A 4 REMOVED STEEL PLATE (KEEP)

8

11 12 10
6

2D36988

**(SHEET 2 OF 8) FIGURE 19: INSPECTION - Group 6**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 188 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BL26 STRINGERS

FAILSAFE CHORD FRAME VERTICAL POST (NOT PRESENT AT ALL LOCATIONS)

VIEW LOOKING AFT REMOVED STEEL PLATE (KEEP)

OPEN HOLE HFEC SURFACE HFEC EXISTING FASTENERS FITTING COMMON TO VERTICAL POST

SHEAR TIES SKIN

NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN AND CONFIGURATION VARIES DEPENDING ON LOCATION. C C

D D

E E
B B 6

1 3

2 5



### B UP
OUTBD 4

8 12 11 10

7D36989

**(SHEET 3 OF 8) FIGURE 19: INSPECTION - Group 6**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 189 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

SURFACE HFEC OPEN HOLE HFEC EXISTING FASTENERS (REF)

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL BL26 ALL LOCATIONS) (NOT PRESENT AT VERTICAL POST

(STA 920 ONLY) VIEW LOOKING AFT REMOVED STEEL PLATE (KEEP)

VERTICAL POST FITTING COMMON TO STRINGERS



### A-A BL37.8

C C

D D

E E
A A

2 6 7

1 11 3 12 5 8 10 4



### C 2D37211

**(SHEET 4 OF 8) FIGURE 19: INSPECTION - Group 6**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 190 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

EXISTING FASTENERS (REF) OPEN HOLE HFEC SURFACE HFEC STRINGERS

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL BL37.8 BL26

VIEW LOOKING AFT (STA 920 ONLY) REMOVED STEEL PLATE (KEEP)

VERTICAL POST (NOT PRESENT AT ALL LOCATIONS)

FITTING COMMON TO VERTICAL POST



### B-B C C

D D

E E B B

2 6 7

1 11 3 12 5 2 8 10 4



### DD37212

**(SHEET 5 OF 8) FIGURE 19: INSPECTION - Group 6**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 191 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

This Figure applies to Group 6: The step numbers shown below agree with the numbers shown in the circle symbols in the Figure. **CAUTION:** UNLESS THE AIRPLANE IS SUPPORTED IN THE JIGGED POSITION, DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. **STEP TASK NAME Part Number NOTES** 1 Remove Fasteners - (a) 2 Remove/Keep Steel Plates 65B09631-( ) - FRAME HORIZONTAL SHEAR WEB

TENSION TIE AFT CHANNEL (TYPICAL)

STEEL PLATE

TENSION TIE FWD CHANNEL (TYPICAL) ALUMINUM CHANNEL 

### C-C

E-E (STA 940 ONLY) (AT LOCATIONS WITH A SHEAR WEB)

(AT ALL OTHER

LOCATIONS) 

### D-D D-D

D-D 2 1

2 1 2 1 2 1

8

8 8 8

8 8

8

8 9D36991

**(SHEET 6 OF 8) FIGURE 19: INSPECTION - Group 6**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 192 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

3 Inspect Fastener Holes in the Frame and Frame doubler (if installed) - (b) Tension Tie channels, and all aluminum parts in the stackup. 65B09631-( ) (b) 4 Inspect Steel Plates 65B09631-( ) (c) 5 Inspect Tension Tie forward and aft channels 65B09631-( ) (d) 6 Inspect Frame Structure - (e) 7 Inspect Skin - (f) 8 Inspect Tension Tie forward and aft channels and associated parts attached to the Tension Tie channels 65B09631-( ) (g)

9 Inspect Tension Ties, Shear Webs, Aluminum Channel 65B09631-( ) 65B09661-( ) (g) 10 Install (Kept) Steel Plates 65B09631-( ) (h) 11 **CAUTION:** If fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. Install (New) Hex Drive Bolts BACB30NX( )K( ) at locations common to the Steel Plates. Install washers under nuts. (i) (j) (l) (m) (n) Washers BACW10BP( )DP Nuts BACN10YT( )CD 12 Install (New) Hex Drive Bolts BACB30NX( )K( ) at locations NOT common to the Steel Plates. Install washers under nuts. (i) (k) (l) (m) Washers BACW10BP( )DP Nuts BACN10YT( )CD (a) Remove all fasteners common to steel plates, plus six fasteners inboard of the steel plate at each end of the tension tie. (b) Open-hole HFEC inspect all holes in aluminum parts, in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. (c) One Steel Plate on each side of the Airplane at each Tension Tie location. Open-hole HFEC inspect all holes in the steel plates in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 19. (d) Surface HFEC inspect the Tension Tie forward and aft channel vertical webs adjacent to and around all fastener heads and bucked tails between BL 26 and the outboard to three fastener rows inboard of the steel plates. Include all remaining fastener locations where fasteners have not been removed for inspection per step 3. Exclude areas around fasteners in the fittings common to the vertical posts at BL 39. Do inspections in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 4. (e) Do a detailed inspection for cracks in the Frames and associated parts from minimum (2) stringers above to a minimum (2) stringers below the Tension Ties. Pay special attention to the corners of the stringer cut outs. On built-up frames, also pay special attention to the fail-safe chords and shear ties. (f) Do this step only if cracks were found in the shear tie. If cracks were found on the shear tie, remove fasteners in the fuselage skin common to the affected shear tie and open-hole HFEC inspect the skin in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. **STEP TASK NAME Part Number NOTES**

**(SHEET 7 OF 8) FIGURE 19: INSPECTION - Group 6**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 193 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

(g) Do a detailed inspection of the Tension Tie forward and aft channels from end to end. At STA 940, do a detailed inspection of the Aluminum Channel. Pay special attention to where shear webs and other structure attach to the Tension Tie channels. Also, do a detailed inspection of the shear webs where they attach to the tension tie. (h) Only reinstall the Steel Plates if step 4 inspections reveal no crack indications. If the Steel Plate is found cracked, before further flight, replace with new or contact Boeing for repair instructions. (i) Oversize undamaged holes up to 0.0312 inch over original as required to make holes round and to be within diameter limits for the specified hole size and fastener fit. If the holes need additional oversizing, do the OVERSIZE HOLE REPAIR steps as specified in the Work Instructions. (j) At open hole locations common to the Steel Plates, install fasteners in close ream holes in accordance with 747-100/200/300 SRM 51-30-05. Install fasteners wet with BMS 3-27 or BMS 3- 38. Refer to SOPM 20-50-19 wet fastener installation method 2. If BACB30NX hex-drive bolts are installed with BMS 3-38, they must be installed with the following torque values applied to the nut: 3/ 16 inch bolt = 20 to 25 pound-inches. 1/4 inch bolt = 50 to 75 pound-inches. 5/16 inch bolt = 90 to 125 pound-inches. (k) At open hole locations not common to the Steel Plates, install fasteners in transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. (l) If necessary, it is acceptable to substitute fasteners in accordance with 747-100/200/300 SRM 51-30-03. However, if fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. (m) New fasteners are to be supplied by the operator. (n) To allow for easier removal during repeat inspections, it is optional to install BACB30MR( )K( ) bolts and BACW10BP( )CD washers, with BACN11Z( )CD nuts and BACW10BP( )DP washers at fastener locations common to the steel plates. However, availability of BACB30MR( )K( ) bolts is limited. Also, if fasteners are substituted, the same type of fastener should be used throughout each joint, as shown in Appendix C, Figure F. **STEP TASK NAME Part Number NOTES**

**(SHEET 8 OF 8) FIGURE 20: OVERSIZE**  **HOLE REPAIR - Group 6** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 194 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 20: OVERSIZE HOLE REPAIR - Group 6** 

940 STA

800 STA

FRAME (TYPICAL)

(TYPICAL) TENSION TIE (2 LOCATIONS) HORIZONTAL SHEAR WEB

(2 LOCATIONS) SLOPING SHEAR WEB

920 STA 800 STA

940 STA D SEE C SEE

D SEE B

SEE

C SEE A SEE

FWDD36994

**(SHEET 1 OF 7) FIGURE 20: OVERSIZE HOLE REPAIR - Group 6**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 195 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

STRINGERS BL26 VERTICAL POST

(STA 920 ONLY) VIEW LOOKING AFT SHEAR TIES

FRAME STEEL PLATE

AND CONFIGURATION VARIES DEPENDING ON LOCATION NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN FAILSAFE CHORD

A A

UP
INBD 1 2



### A 3 4 5 6D36996

**(SHEET 2 OF 7) FIGURE 20: OVERSIZE**  **HOLE REPAIR - Group 6** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 196 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BL26 VERTICAL POST

(STA 920 ONLY) VIEW LOOKING AFT SHEAR TIES

FRAME FAILSAFE CHORD

AND CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN STRINGERS

STEEL PLATE B B 1 2



### B 3 4 5 6

UP
INBDD37934

**(SHEET 3 OF 7) FIGURE 20: OVERSIZE HOLE REPAIR - Group 6**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 197 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

BL26 STRINGER CHORD FAILSAFE

VIEW LOOKING AFT

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL SHEAR TIE

STEEL PLATE

AND CONFIGURATION VARIES DEPENDING ON LOCATION NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN FRAME



### A-A A A 1 2 3 4

UP

INBD



### C 5 6D37002

**(SHEET 4 OF 7) FIGURE 20: OVERSIZE**  **HOLE REPAIR - Group 6** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 198 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

TENSION TIE FORWARD CHANNEL FRAME TENSION TIE AFT CHANNEL

STEEL PLATE SHEAR TIE

AND CONFIGURATION VARIES DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN BL26 STRINGER CHORD FAILSAFE

FRAME

VIEW LOOKING AFT



### B-B B B 1 2 3 4



### D UP
OUTBD 5 6D37004

**(SHEET 5 OF 7) FIGURE 20: OVERSIZE HOLE REPAIR - Group 6**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 199 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** This Figure applies to Group 6: The step numbers shown below agree with the numbers shown in the circle symbols in the Figure. **NOTE:** Only do these steps at locations where crack indications are present in the Frame and/or Tension Tie and can be cleaned up by oversizing the hole to a maximum hole size of 0.313 inch. If the crack is larger, contact Boeing for repair instructions. **CAUTION:** UNLESS THE AIRPLANE IS SUPPORTED IN THE JIGGED POSITION, DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. **STEP TASK NAME PART NUMBER NOTES** 1 Oversize Holes in Tension Tie Channels, Frame, Steel Plate, associated parts in the stackup. - (a)

2 Inspect Holes in Tension Tie Channels, Frame, and associated aluminum parts in the stack up. - (b) (c)

3 Oversize Holes Tension Tie Channels, Frame, Steel Plate, and associated parts in the stackup. - (d) (e)

**NOTE:** Holes can only be oversized to a maximum 0.313 inch diameter. 4 Measure Edge Margin and Spacing - (f) 5 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations common to the Steel Plates. Install washers under nuts. (g) (i) (j) Washers BACW10BP( )DP Nuts BACN10YT( )CD 6 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations NOT common to the Steel Plates. Install washers under nuts. (h) (i) Washers BACW10BP( )DP Nuts BACN10YT( )CD (a) Oversize the minimum amount required to remove the cracks, in 0.0156 inches increments, up to a maximum hole size of 0.313 inch. (b) Open-hole HFEC inspect holes in the aluminum parts in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. (c) Repeat steps 1 to 2 if crack indications are still present, until there are no more crack indications. Once there are no more crack indications, go to step 3. (d) Make the final hole diameters in the entire stackup common to the steel plates within limits for close ream holes in accordance with 747-100/200/300 SRM 51-30-05. If holes are already within SRM limits for close ream holes, do not further oversize. (e) Make the final hole diameters in the stackup NOT common to the steel plates within limits for transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. If the holes are already within SRM limits for transition fit holes, do not further oversize.

**(SHEET 6 OF 7) FIGURE 20: OVERSIZE**  **HOLE REPAIR - Group 6** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 200 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

(f) A minimum 1.5D edge margin (center of hole to edge of part) and 2.5D spacing (center of hole to center of hole) should be maintained. If edge margin and spacing cannot be maintained, contact Boeing for repair instructions. (g) At open hole locations common to the Steel Plates, install fasteners in close ream holes in accordance with 747-100/200/300 SRM 51-30-05. Install fasteners wet with BMS 3-27 or BMS 3- 38. Refer to SOPM 20-50-19 wet fastener installation method 2. If BACB30NX hex-drive bolts are installed with BMS 3-38, they must be installed with the following torque values applied to the nut: 3/16 inch bolt = 20 to 25 pound-inches. 1/4 inch bolt = 50 to 75 pound-inches. 5/16 inch bolt = 90 to 125 pound-inches. (h) At open hole locations not common to the Steel Plates, install fasteners in transition fit holes in accordance with 747-100/200/300 SRM 51-30-05. (i) If required, it is acceptable to substitute fasteners in accordance with 747-100/200/300 SRM 51-30-03. However, if fasteners are substituted the same type fasteners should be used throughout each joint, as shown in Appendix C, Figure F. (j) To allow for easier removal during repeat inspections, it is optional to install BACB30MR( )K( ) bolts and BACW10BP( )CD washers, with BACN11Z( )CD nuts and BACW10BP( )DP washers at fastener locations common to the steel plates. However, availability of BACB30MR( )K( ) bolts is limited. Also, if fasteners are substituted, the same type of fastener should be used throughout each joint, as shown in Appendix C, Figure F. **STEP TASK NAME PART NUMBER NOTES**

**(SHEET 7 OF 7) FIGURE 21: HFEC INSPECTION OF HOLES FOR INSULATION BLANKET STUDS**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 201 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 21: HFEC INSPECTION OF**  **HOLES FOR INSULATION BLANKET STUDS**

FRAME (TYPICAL)

TENSION TIE (TYPICAL)

(2 LOCATIONS) HORIZONTAL SHEAR WEB (2 LOCATIONS) SLOPING SHEAR WEB

B SEE A SEE

FWDD72679

**(SHEET 1 OF 3) FIGURE 21: HFEC INSPECTION OF HOLES FOR INSULATION BLANKET STUDS**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 202 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

STRINGERS

TRIPLER DOUBLER, AND FRAME WEB,

CHORD FAILSAFE



### VIEW LOOKING AFT STRINGERS CHORD INNER

CHORD INNER TIE TENSION

TIE TENSION ATTACH STUD INSULATION BLANKET

CHORD FAILSAFE



### VIEW LOOKING AFT TRIPLER DOUBLER, AND FRAME WEB,

PATTERN AND FRAME CONFIGURATION MAY VARY DEPENDING ON LOCATION. NOTE: TYPICAL CONFIGURATION. ACTUAL INSULATION BLANKET STUD

(TYPICAL) INSULATION BLANKET STUD UP

INBD



### A

UP

INBD



### B SEE C

3 1 2



### C 3 1D72703

**(SHEET 2 OF 3) FIGURE 21: HFEC INSPECTION OF HOLES FOR INSULATION BLANKET STUDS**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 203 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** The step numbers shown below agree with the numbers shown in the circle symbols in the figure. **STEP TASK NAME IDENTIFICATION QTY MORE DATA**

1 Remove / Keep Insulation Blanket Stud - 1 Only remove studs that are installed through the Frame Web in the inspection area. Studs that are bonded on to the Frame Web do not need to be removed.

2 Inspect Hole - 1 Do an open hole HFEC inspection of the hole in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 1, 11, or 16. **NOTE:** If there is a crack indication during the HFEC inspection, contact Boeing for repair and/or re-installation instructions. 3 Install (Kept) Insulation Blanket Stud - 1-

**(SHEET 3 OF 3) FIGURE 22: ONE-TIME INSPECTION FOR CORRECT CONFIGURATION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 204 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 22: ONE-TIME INSPECTION**  **FOR CORRECT CONFIGURATION - Group 2**

STA 720 FRAME (TYPICAL)

TENSION TIE (TYPICAL) STA 720 STA 940

STA 720

STA 740 STA 760 STA 780

STA 800 STA 820 STA 840

STA 860 STA 880

STA 900 STA 920 STA 940 A
B C D
E F G H I J K L FWD1926501

**(SHEET 1 OF 14) FIGURE 22: ONE-TIME INSPECTION FOR CORRECT CONFIGURATION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 205 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

SKIN FRAME

TENSION TIE

STA 720 LEFT SIDE SHOWN RIGHT SIDE OPPOSITE FWD

INBD STA 720



### A

**A**

LEFT SIDE SHOWN RIGHT SIDE OPPOSITE 1



### A-A A1931561

**(SHEET 2 OF 14) FIGURE 22: ONE-TIME INSPECTION FOR CORRECT CONFIGURATION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 206 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

SKIN FRAME

TENSION TIE

STA 740 LEFT SIDE SHOWN RIGHT SIDE OPPOSITE FWD

INBD STA 740 

### B

**B**

LEFT SIDE SHOWN RIGHT SIDE OPPOSITE 2



### B-B B1931550

**(SHEET 3 OF 14) FIGURE 22: ONE-TIME INSPECTION FOR CORRECT CONFIGURATION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 207 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

SKIN FRAME

TENSION TIE

STA 760 LEFT SIDE SHOWN RIGHT SIDE OPPOSITE FWD

INBD STA 760


### C

C

LEFT SIDE SHOWN RIGHT SIDE OPPOSITE 3



### C-C C1931403

**(SHEET 4 OF 14) FIGURE 22: ONE-TIME INSPECTION FOR CORRECT CONFIGURATION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 208 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**



### D

**D**

SKIN FRAME

TENSION TIE STA 780 LEFT SIDE SHOWN RIGHT SIDE OPPOSITE FWD

INBD STA 780

LEFT SIDE SHOWN RIGHT SIDE OPPOSITE 4



### D-D D1930915

**(SHEET 5 OF 14) FIGURE 22: ONE-TIME INSPECTION FOR CORRECT CONFIGURATION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 209 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

SKIN FRAME

TENSION TIE
STA 800 LEFT SIDE SHOWN RIGHT SIDE OPPOSITE FWD

INBD STA 800


### E

**E**

LEFT SIDE SHOWN RIGHT SIDE OPPOSITE 5



### E-E E1930851

**(SHEET 6 OF 14) FIGURE 22: ONE-TIME INSPECTION FOR CORRECT CONFIGURATION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 210 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

SKIN FRAME

TENSION TIE

STA 820 LEFT SIDE SHOWN RIGHT SIDE OPPOSITE FWD

INBD STA 820 

### F

**F**

LEFT SIDE SHOWN RIGHT SIDE OPPOSITE 6



### F-F F1930627

**(SHEET 7 OF 14) FIGURE 22: ONE-TIME INSPECTION FOR CORRECT CONFIGURATION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 211 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

SKIN FRAME

TENSION TIE

STA 840 LEFT SIDE SHOWN RIGHT SIDE OPPOSITE FWD

INBD STA 840 

### G

**G**

LEFT SIDE SHOWN RIGHT SIDE OPPOSITE 7



### G-G G1930622

**(SHEET 8 OF 14) FIGURE 22: ONE-TIME INSPECTION FOR CORRECT CONFIGURATION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 212 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

SKIN FRAME

TENSION TIE

STA 860 LEFT SIDE SHOWN RIGHT SIDE OPPOSITE FWD

INBD STA 860 

### H

**H**

LEFT SIDE SHOWN RIGHT SIDE OPPOSITE 8



### H-H H1930466

**(SHEET 9 OF 14) FIGURE 22: ONE-TIME INSPECTION FOR CORRECT CONFIGURATION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 213 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

SKIN FRAME

TENSION TIE

STA 880 LEFT SIDE SHOWN RIGHT SIDE OPPOSITE FWD

INBD STA 880 

### I

**I**

LEFT SIDE SHOWN RIGHT SIDE OPPOSITE 9



### I-I I1930364

**(SHEET 10 OF 14) FIGURE 22: ONE-TIME INSPECTION FOR CORRECT CONFIGURATION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 214 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

SKIN FRAME

TENSION TIE

STA 900 LEFT SIDE SHOWN RIGHT SIDE OPPOSITE FWD

INBD STA 900 

### J

**J**

10

LEFT SIDE SHOWN RIGHT SIDE OPPOSITE 

### J-J J1930279

**(SHEET 11 OF 14) FIGURE 22: ONE-TIME INSPECTION FOR CORRECT CONFIGURATION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 215 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

SKIN FRAME

TENSION TIE

STA 920 LEFT SIDE SHOWN RIGHT SIDE OPPOSITE FWD

INBD STA 920 

### K

**K**

LEFT SIDE SHOWN RIGHT SIDE OPPOSITE 11



### K-K K1929844

**(SHEET 12 OF 14) FIGURE 22: ONE-TIME INSPECTION FOR CORRECT CONFIGURATION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 216 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

SKIN FRAME

TENSION TIE

STA 940 LEFT SIDE SHOWN RIGHT SIDE OPPOSITE FWD

INBD STA 940

LEFT SIDE SHOWN RIGHT SIDE OPPOSITE 

### L-L L

12 

### L

**L**1929718

**(SHEET 13 OF 14) FIGURE 22: ONE-TIME INSPECTION FOR CORRECT CONFIGURATION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 217 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT** This Figure applies to Group 2: 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 side of the airplane. **STEP TASK NAME IDENTIFICATION QTY MORE DATA** 1 Inspect STA 720 Tension Tie - - (a) (b)

2 Inspect STA 740 Tension Tie - - (a) (b)

3 Inspect STA 760 Tension Tie - - (a) (b)

4 Inspect STA 780 Tension Tie - - (a) (b)

5 Inspect STA 800 Tension Tie - - (a) (b)

6 Inspect STA 820 Tension Tie - - (a) (b)

7 Inspect STA 840 Tension Tie - - (a) (b)

8 Inspect STA 860 Tension Tie - - (a) (b)

9 Inspect STA 880 Tension Tie - - (a) (b)

10 Inspect STA 900 Tension Tie - - (a) (b)

11 Inspect STA 920 Tension Tie - - (a) (b)

12 Inspect STA 940 Tension Tie - - (a) (b) (a) Do a general visual inspection to ensure the configuration on the airplane matches the configuration shown in the illustration. (b) Make sure that the number of fasteners on the airplane is the same as the number of fasteners shown. Do the inspection at both ends of the tension tie.

**(SHEET 14 OF 14) FIGURE 23: ADDITIONAL INSPECTION**  **OF INCORRECT CONFIGURATION - Group 2** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 218 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT FIGURE 23: ADDITIONAL INSPECTION OF**  **INCORRECT CONFIGURATION - Group 2**

STA 720

STA 940 FRAME (TYPICAL)

TENSION TIE (TYPICAL)

HORIZONTAL SHEAR WEB (2 LOCATIONS) SLOPING SHEAR WEB (2 LOCATIONS) STA 720 STA 940

B SEE A SEE

FWD1963631

**(SHEET 1 OF 5) FIGURE 23: ADDITIONAL INSPECTION OF INCORRECT CONFIGURATION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 219 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

REMOVED STEEL PLATE (KEEP)

EXISTING FASTENERS (REF) OPEN HOLE HFEC SKIN

STRINGERS

FRAME VERTICAL POST (NOT PRESENT AT ALL LOCATIONS)



### VIEW LOOKING AFT

NOTE: TYPICAL CONFIGURATION, ACTUAL FASTENER PATTERN AND CONFIGURATION VARIES DEPENDING ON LOCATION. FITTING COMMON TO VERTICAL POST

A A

B B

1 3 UP

INBD 2



### A 4 5

7 8 6 51963637

**(SHEET 2 OF 5) FIGURE 23: ADDITIONAL INSPECTION**  **OF INCORRECT CONFIGURATION - Group 2** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 220 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

REMOVED STEEL PLATE (KEEP)

OPEN HOLE HFEC EXISTING FASTENERS FITTING COMMON TO VERTICAL POST SKIN

NOTE: TYPICAL CONFIGURATION. ACTUAL FASTENER PATTERN AND CONFIGURATION VARIES DEPENDING ON LOCATION. STRINGERS

FRAME VERTICAL POST (NOT PRESENT AT ALL LOCATIONS)



### VIEW LOOKING AFT A A

B B B

1 3 6



### B UP

OUTBD 4

7 8 2 5

51963646

**(SHEET 3 OF 5) FIGURE 23: ADDITIONAL INSPECTION OF INCORRECT CONFIGURATION - Group 2**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 221 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

This Figure applies to Group 2: The step numbers shown below agree with the numbers shown in the circle symbols in the Figure. **CAUTION:** UNLESS THE AIRPLANE IS SUPPORTED IN THE JIGGED POSITION, DO NOT REMOVE THE FASTENERS FROM ADJACENT TENSION TIE TO FRAME JOINTS AT THE SAME TIME. IF FASTENERS ARE REMOVED FROM ADJACENT TENSION TIES, DAMAGE TO THE AIRPLANE STRUCTURE MAY OCCUR. REFER TO APPENDIX B FOR ALLOWABLE METHODS TO DISCONNECT THE TENSION TIES. **STEP TASK NAME Part Number NOTES** 1 Remove Fasteners - (a) 2 Remove/Keep Steel Plates - - 3 Inspect Fastener holes in aluminum parts. - (b) 

### A-A

(STA 940 ONLY) (AT ALL OTHER LOCATIONS) 

### B-B B-B FRAME

TENSION TIE AFT CHANNEL (TYPICAL)

STEEL PLATE

TENSION TIE FWD CHANNEL (TYPICAL) ALUMINUM CHANNEL 2 1

2 1 2 11963649

**(SHEET 4 OF 5) FIGURE 23: ADDITIONAL INSPECTION**  **OF INCORRECT CONFIGURATION - Group 2** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 222 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

4 Inspect Steel plates - (c) 5 Inspect Frame, tension tie, and steel plates. - (d) 6 Install (Kept) Steel plates - (e) 7 **CAUTION:** If fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations common to Steel Plates. Install washers under nuts. (f) (g) (i) (j) (k) Washers BACW10BP( )DP Nuts BACN10YT( )CD 8 Install (New) Hex Drive Bolts BACB30NX( )K( ) at hole locations NOT common to Steel Plates. Install washers under nuts. (f) (h) (i) (j) Washers BACW10BP( )DP Nuts BACN10YT( )CD (a) At both ends of the tension tie, remove all fasteners common to steel plates, plus six fasteners inboard of the steel plates. (b) At both ends of the tension tie, do open-hole high frequency eddy current (HFEC) inspection for cracks in the aluminum parts where fasteners were removed. Do the HFEC inspections in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 16. (c) At both ends of the tension tie, do open-hole HFEC inspection for cracks in the steel plate at all fastener holes. Do the HFEC inspections in accordance with 747 NDT, Part 6, Subject 51-00-00, Figure 19. (d) Do a detailed inspection for cracks in the tension tie and frame structure in the area shown. Also, do a detailed inspection for cracks in the steel plate. (e) Only reinstall the kept steel plates if they are crack free. If they are cracked, install a new or serviceable plate with the same part number as the plate that was removed. (f) Oversize undamaged holes up to 0.0312 inch over original as required to make holes round and to be within diameter limits for the specified hole size and fastener fit. If the holes need additional oversizing, do the OVERSIZE HOLE REPAIR steps as specified in the Work Instructions. (g) At open hole locations common to the Steel Plates, install fasteners in close ream holes in accordance with 747-400F SRM 51-40-05. Install fasteners wet with BMS 3-27 or BMS 3-38. Refer to SOPM 20-50-19 wet fastener installation method 2. If BACB30NX hex-drive bolts are installed with BMS 3-38, they must be installed with the following torque values applied to the nut: 3/16 inch bolt = 20 to 25 pound-inches. 1/4 inch bolt = 50 to 75 pound-inches. 5/16 inch bolt = 90 to 125 pound-inches. (h) At open hole locations not common to the Steel Plates, install fasteners in transition fit holes in accordance with 747-400F SRM 51-40-05. (i) It is acceptable to substitute fasteners in accordance with 747-400F SRM 51-40-03. However, if fasteners are substituted, the same type of fastener should be used throughout each joint as shown in Appendix C, Figure F. (j) New fasteners are to be supplied by the operator. (k) To allow for easier removal during repeat inspections, it is optional to install BACB30MR( )K( ) bolts and BACW10BP( )CD washers, with BACN11Z( )CD nuts and BACW10BP( )DP washers at fastener locations common to the steel plates. However, availability of BACB30MR( )K( ) bolts is limited. Also, if fasteners are substituted, the same type of fastener should be used throughout each joint, as shown in Appendix C, Figure F. **STEP TASK NAME Part Number NOTES**

**(SHEET 5 OF 5) APPENDIX A: DELETED**  Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 223 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT APPENDIX A: DELETED** 

THIS APPENDIX IS DELETED.1551112**APPENDIX B: TENSION TIE DISCONNECTION METHODS** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 224 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT APPENDIX B: TENSION TIE DISCONNECTION METHODS** 

SYMMETRICAL ABOUT 1

C L

1

OF AIRPLANE 

### VIEW LOOKING DOWN C L WEB SHEAR

WEB SHEAR



### TENSION TIE AT BOTH ENDS. METHOD 1: DISCONNECT EVERY OTHER487858**APPENDIX B: TENSION TIE DISCONNECTION METHODS** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 225 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

**METHOD TASK NOTES** 1 With the airplane on its gear, disconnect every other Tension Tie from the Frame at both ends, as shown in the view for Method 1. 2 Deleted. (b) 3 not shown With the airplane on its gear, remove all but four fasteners at each end of each Tension Tie. Do the necessary Work Instructions specified in this service bulletin, and re-install fasteners. Remove the remaining four fasteners at each end of each Tension Tie and do the necessary Work Instructions at those locations. 4 not shown Deleted. (b)

(a) This note has been deleted. (b) Method 2 and Method 4 have been deleted.**APPENDIX C: GENERAL ILLUSTRATIONS** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 226 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT APPENDIX C: GENERAL ILLUSTRATIONS** 

1000 STA

WITH OR WITHOUT EXTENDED UPPER DECK 747-100, -200, -400F

NON-SUD AIRPLANES

1283 STA

747-200 SUD MOD, 747-300, -400 PASSENGER STRETCHED UPPER DECK (SUD) AIRPLANES CONTOUR ENDS AT UPPER DECK



### FIGURE A CONTOUR ENDS AT UPPER DECKD37011**APPENDIX C: GENERAL ILLUSTRATIONS** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 227 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

(REF) CHANNELS ALUMINUM

(REF) THE TENSION TIES OUTBOARD ENDS OF INSTALLED AT THE STEEL PLATES ARE

COVERED BY THIS SERVICE BULLETIN. THIS IS THE CONFIGURATION THAT IS ACTUAL CONFIGURATION MAY VARY. TWO BACK-TO-BACK CHANNELS. TYPICAL TENSION TIE CONFIGURATION: (REF) CHORD UPPER

WEB (REF)

(REF) CHORD LOWER

DO NOT). ATTACHED TO THEM, THE TENSION TIES (NOTE: FLOOR BEAMS HAVE FLOOR PANELS BEAMS ARE NOT. COVERED BY THIS BULLENTIN, BUT FLOOR THAT LOOK LIKE FLOOR BEAMS ARE BS 760 TENSION TIES ARE SIMILAR. AND 747 SPECIAL FREIGHTER AIRPLANES WEB. STA 760 TENSION TIE ON 747-200F UPPER CHORD, LOWER CHORD, AND SHEAR TYPICAL FLOOR BEAM CONFIGURATION:



### FIGURE BD37037**APPENDIX C: GENERAL ILLUSTRATIONS** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 228 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

FRAME

FRAME STRINGER

LONG STEEL PLATE CHORD FAILSAFE

STRINGER CHORD FAILSAFE

PLATE SHORT STEEL

CONFIGURATION AT STA 920. GROUP 6 AIRPLANES HAVE THIS CONFIGURATION AT STA 780. GROUP 5 AIRPLANES HAVE THIS MODIFICATION). DUE TO EXTENDED UPPER DECK BEEN REPLACED WITH A FLOOR BEAM WHERE STA 760 TENSION TIE HAS CONFIGURATION AT STA 760 (EXCEPT 203 AND ON WILL HAVE THIS GROUP 1 AIRPLANES, LINE NUMBERS MODIFICATION). TO EXTENDED UPPER DECK REPLACED WITH A FLOOR BEAM DUE 760 TENSION TIE HAS BEEN 747-53-2088 (EXCEPT WHERE STA MODIFIED PER SERVICE BULLETIN CONFIGURATION AT STA 760 IF 1 THRU 203 WILL HAVE THIS GROUP 1 AIRPLANES, LINE NUMBERS LONG STEEL PLATE CONFIGURATION

EXCEPT WHERE LONG STEEL PLATE IS INSTALLED. SHORT STEEL PLATE CONFIGURATION - TYPICAL



### FIGURE CD37085**APPENDIX C: GENERAL ILLUSTRATIONS** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 229 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

OF TENSION TIE RUNS FULL-LENGTH ALUMINUM DOUBLER 0.025" 2024-T42 940 STA

OF TENSION TIE RUNS FULL-LENGTH ALUMINUM CHANNEL 0.051" 2024-T42

STA 780 ON GROUP 5 AIRPLANES 6 AIRPLANES. STA 760 ON GROUP 1 AND GROUP

STA 1140 ON GROUP 3 AIRPLANES AIRPLANES. GROUP 4, GROUP 5 AND GROUP 6 STA 940 ON GROUP 1, GROUP 2,



### FIGURE DD37129

FRAME STRINGER

(REF) STEEL PLATE END OF ORIGINAL CHORD FAILSAFE

HAS BEEN REPLACED WITH A LONGER STEEL PLATE. BULLETIN 747-53-2088. THE ORIGINAL STEEL PLATE STA 780 (DEPENDING ON THE AIRPLANE) PER SERVICE MODIFIED CONFIGURATION AT STA 760 OR



### FIGURE ED37141**APPENDIX C: GENERAL ILLUSTRATIONS** Original Issue: April 21, 2005 Revision 1: June 17, 2010 747-53A2502 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 230 of 230 

### BOEING SERVICE BULLETIN 747-53A2502 **ALERT ALERT**

PLATE STEEL

FRAME STRINGER CHORD FAILSAFE

AREA SHOULD BE THE SAME TYPE. THIS AREA, ALL FASTENERS IN THIS IF FASTENERS ARE SUBSTITUTED IN

STEEL PLATE SHOULD BE THE SAME TYPE. STEEL PLATE, ALL FASTENERS COMMON TO THE IF FASTENERS ARE SUBSTITUTED COMMON TO THE



### FIGURE FD37193