### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Number: 737-54A1044**  Original Issue: December 10, 2007 Revision 2: January 20, 2010 ATA System: 5410 **SUBJECT:** NACELLES/PYLONS - Nacelle Strut - Midspar Fuse Pin - Inspection, Repair and Replacement Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15 CFR 730-774). An export license may be required before it is used for development, production or use by foreign persons from specific countries. The controller of this data has the individual responsibility to abide by all export laws. 9E991 ECCN: 

## BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2007 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter. Boeing also claims copyright in this document as a compilation and/or collective work. This document includes proprietary information owned by The Boeing Company and/or one or more third parties. Treatment of the document and the information it contains is governed by contract with Boeing. For more information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124. Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner, BBJ, DC-8, DC-9, DC-10, KC-10, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8A, Poseidon and the Boeing livery are all trademarks owned by The Boeing Company; and no trademark license is granted in connection with this document unless provided in writing by Boeing.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 1 of 57 6.0BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 2 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT**

BLANK PAGE**Table of Contents** Revision Transmittal Sheet............................................ 5 Summary...................................................... 7 1. PLANNING INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 A. Effectivity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 1. Airplanes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2. Spares Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 B. Concurrent Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 C. Reason. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 D. Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 F. Approval. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 G. Manpower. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 I. Electrical Load Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 J. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 1. Existing Data:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 2. Data supplied with this Service Bulletin:. . . . . . . . . . . . . . . . . . . . . . . . . . . 29 3. Installation Drawings Used in the Preparation of this Service Bulletin:. . . . . . . . . . . 29 K. Publications Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 L. Interchangeability and Intermixability of Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . 29 2. MATERIAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 B. Industry Support Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 C. Parts Necessary For Each Airplane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 1. Kits/Parts:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 2. Parts and Materials Supplied by the Operator:. . . . . . . . . . . . . . . . . . . . . . . . 31 3. Parts Modified and Reidentified:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 4. Parts Removed and Not Replaced:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 32 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 A. GENERAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 FIGURE 1: LEFT SIDE ENGINE STRUT - INBOARD AND OUTBOARD - MIDSPAR FUSE PIN - INSPECTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 FIGURE 2: RIGHT SIDE ENGINE STRUT - INBOARD AND OUTBOARD - MIDSPAR FUSE PIN - INSPECTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 FIGURE 3: MIDSPAR FUSE PIN - REPAIR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 FIGURE 4: LEFT SIDE ENGINE STRUT - INBOARD - MIDSPAR FUSE PIN - INSTALLATION OF NEW MATERIAL FUSE PIN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 FIGURE 5: LEFT SIDE ENGINE STRUT - OUTBOARD - MIDSPAR FUSE PIN - INSTALLATION OF NEW MATERIAL FUSE PIN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 FIGURE 6: RIGHT SIDE ENGINE STRUT - INBOARD - MIDSPAR FUSE PIN - INSTALLATION OF NEW MATERIAL FUSE PIN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 3 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT**FIGURE 7: RIGHT SIDE ENGINE STRUT - OUTBOARD - MIDSPAR FUSE PIN - INSTALLATION OF NEW MATERIAL FUSE PIN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 4 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT**

### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Revision Transmittal Sheet**  **Number: 737-54A1044** Original Issue: December 10, 2007 Revision 2: January 20, 2010 ATA System: 5410 **SUBJECT:** NACELLES/PYLONS - Nacelle Strut - Midspar Fuse Pin - Inspection, Repair and Replacement This revision includes all pages of the service bulletin. **COMPLIANCE INFORMATION RELATED TO THIS REVISION** Federal Aviation Administration (FAA) Airworthiness Directive AD 2008-21-03, is related to this service bulletin. No more work is necessary on airplanes changed as shown in Revision 1 of this service bulletin.

**REASON FOR REVISION** This revision is sent to change the compliance table number referenced in the second paragraph in Section F. Approval, from Table 7 to Table 1. These sections were changed: 1. Paragraph 1.E., Compliance: added that AD 2008-21-03 is related to this service bulletin. 2. Paragraph 1.F., Approval: revised Table 7 to Table 1 and added "or revision 2", in the AMOC paragraph. 3. Paragraph 1.K., Publications Affected: added the damage tolerance statement that was at the bottom of the compliance table. Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity, to show the location of important changes. Pages with no vertical lines have no important changes. **REVISION HISTORY** December 10, 2007 Original Issue: November 26, 2008 Revision 1: January 20, 2010 Revision 2:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 5 of 57BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 6 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Summary**  **Number: 737-54A1044** Original Issue: December 10, 2007 Revision 2: January 20, 2010 ATA System: 5410 **SUBJECT:** NACELLES/PYLONS - Nacelle Strut - Midspar Fuse Pin - Inspection, Repair and Replacement THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH 1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OWNER. **CONCURRENT REQUIREMENTS** None. **BACKGROUND** This service bulletin gives instructions to replace or to inspect the left and right side engine strut, inboard and outboard midspar fuse pins for any cracking, pitting, corrosion and chrome plate damage. If the work given in this service bulletin is not accomplished, damage to the midspar fuse pins may go undetected. Undetected damage could result in the loss of structural integrity of the midspar fuse pins and cause an engine breakaway from the airplane. One operator found one 737-300 airplane with all four engine strut midspar fuse pins with corrosion damage. One of the midspar fuse pins had corrosion common to the chrome run out on the head side. Also, a large portion of the chrome plate was missing from the corroded area of the shank. The airplane had a total of 28,621 flight cycles. Boeing Service Related Problem (SRP) 737-SRP-54-0115 is related to this service bulletin. **ACTION (PRR 35005-273RS)** Identify the part numbers of the left and right side engine strut, inboard and outboard midspar fuse pins. Remove 311A1092-2 midspar fuse pins and install 311A1092-3 midspar fuse pins. Alternatively, for a limited time, do a detailed inspection of 311A1092-2 midspar fuse pins for any cracking, pitting, corrosion or chrome plate damage. If damage is found, discard or repair the damaged midspar fuse pins. Install new or serviceable midspar fuse pins and do the repeat inspection at the specified interval. **EFFECTIVITY** All 737-300, -400, -500 Airplanes. Refer to Paragraph 1.A.1., Airplanes for the list of affected airplanes.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 7 of 57**COMPLIANCE** Refer to Paragraph 1.E., Compliance. Federal Aviation Administration (FAA) Airworthiness Directive AD 2008-21-03 is related to this service bulletin. **INDUSTRY SUPPORT INFORMATION** Boeing warranty remedies are not available for the inspection given in this service bulletin. **MANPOWER** Refer to Paragraph 1.G., Manpower. **MATERIAL INFORMATION** Operator Supplied Parts/Materials. Refer to Paragraph 2.A., Material - Price and Availability.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 8 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 9 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 10 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT**

BLANK PAGE

### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Number: 737-54A1044**  Original Issue: December 10, 2007 Revision 2: January 20, 2010 ATA System: 5410 **SUBJECT:** NACELLES/PYLONS - Nacelle Strut - Midspar Fuse Pin - Inspection, Repair and Replacement THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH 1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OWNER. **1. PLANNING INFORMATION A. Effectivity**  1. Airplanes This service bulletin is for the airplanes shown below. Refer to PRR 35005-273RS for data about this change. Refer to Service Bulletin Index Document D6-19567 Part 3 for Airplane Variable Number, Line Number, and Serial Number data.
**DESCRIPTION CONFIGURATION**  **GROUP** All 737-300, -400, -500 airplanes.

- 1

Airplane Models: 737-300, 737-400, 737-500 **Group Variable Number**  1 PJ301 - PJ302 1 PJ551 - PJ561 1 PJ601 - PJ615 1 PJ811 1 PJ816 - PJ817

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 11 of 57**Group Variable Number**  1 PM381 - PM399 1 PM401 - PM417 1 PM541 - PM564 1 PP001 - PP054 1 PP101 - PP169 1 PP181 - PP199 1 PP201 - PP205 1 PP221 1 PP231 - PP243 1 PP281 - PP286 1 PP301 - PP305 1 PP351 - PP353 1 PP376 - PP384 1 PP391 - PP393 1 PP401 - PP440 1 PP471 - PP475 1 PP501 - PP522 1 PP631 - PP634 1 PP651 - PP652 1 PP671 - PP699 1 PP701 - PP733 1 PP771 - PP779 1 PP801 - PP808 1 PP821 - PP827 1 PP831 - PP848 1 PP851 - PP852 1 PP861 - PP877 1 PP891 - PP899 1 PP901 - PP936 1 PP946 - PP948 1 PP951 - PP952 1 PP961 - PP967 1 PP981 - PP991

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 12 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT Group**  **Variable Number** 1 PP993 1 PQ001 - PQ016 1 PQ026 - PQ041 1 PQ051 - PQ092 1 PQ101 - PQ199 1 PQ201 - PQ202 1 PQ221 - PQ237 1 PQ241 - PQ243 1 PQ251 - PQ267 1 PQ281 - PQ299 1 PQ301 - PQ307 1 PQ331 - PQ332 1 PQ341 - PQ348 1 PQ361 - PQ373 1 PQ391 - PQ395 1 PQ401 - PQ418 1 PQ421 1 PQ431 - PQ438 1 PQ447 - PQ448 1 PQ451 1 PQ454 1 PQ471 - PQ475 1 PQ479 - PQ481 1 PQ486 - PQ487 1 PQ491 - PQ493 1 PQ771 - PQ772 1 PQ791 - PQ793 1 PQ801 - PQ805 1 PQ931 - PQ935 1 PQ951 1 PQ971 - PQ997 1 PR001 - PR017 1 PR021 - PR034

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 13 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT Group**  **Variable Number** 1 PR041 - PR045 1 PR061 - PR072 1 PR077 - PR082 1 PR091 - PR092 1 PR096 1 PR101 1 PR121 - PR122 1 PR131 - PR132 1 PR141 - PR143 1 PR161 - PR172 1 PR181 1 PS601 - PS631 1 PS636 - PS638 1 PS641 - PS644 1 PS651 - PS657 1 PS666 - PS669 1 PS691 - PS692 1 PS701 - PS706 1 PS751 - PS799 1 PS811 1 PS836 - PS837 1 PS841 - PS846 1 PS851 - PS852 1 PS856 1 PS861 - PS863 1 PS866 - PS868 1 PS871 - PS874 1 PS896 - PS897 1 PS901 - PS941 1 PS956 - PS957 1 PS961 - PS963 1 PS971 - PS978 1 PT001 - PT015

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 14 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT Group**  **Variable Number** 1 PT021 - PT031 1 PT041 - PT064 1 PT101 - PT105 1 PT121 - PT138 1 PT146 - PT148 1 PT161 - PT170 1 PT181 - PT188 1 PT211 - PT220 1 PT295 1 PT301 - PT309 1 PT331 - PT360 1 PT381 - PT399 1 PT401 - PT438 1 PT501 - PT517 1 PT561 - PT565 1 PT581 - PT586 1 PT611 - PT621 1 PT641 - PT644 1 PT651 - PT656 1 PT671 - PT672 1 PT681 - PT685 1 PT701 - PT703 1 PT716 - PT717 1 PT721 - PT725 1 PT801 - PT834 1 PT851 - PT854 1 PT871 - PT886 1 PT901 - PT930 1 PT971 - PT973 1 PT981 - PT985 1 PT996 1 PU001 - PU025 1 PU301

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 15 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT Group**  **Variable Number** 1 PU311 - PU313 1 PV001 - PV055 1 PV201 - PV209 1 PV226 - PV229 1 PV231 - PV237 1 PV271 - PV272 1 PV281 - PV287 1 PV296 1 PV301 - PV302 1 PV351 1 PV356 - PV357 1 PW001 - PW054 1 PW061 - PW068 1 PW072 1 PW086 - PW088 1 PW091 - PW094 1 PW101 - PW102 1 PW106 1 PW111 - PW120 1 PW156 - PW157 1 PW161 - PW171 1 PW201 - PW252 1 PW261 - PW268 1 PW271 - PW276 1 PW278 1 PW281 - PW293 1 PW296 1 PW301 - PW327 1 PW401 - PW408 1 PW411 - PW418 1 PW421 - PW424 1 PW431 - PW435 1 PW441 - PW450

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 16 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT Group**  **Variable Number** 1 PW461 - PW467 1 PW501 - PW504 1 PW511 - PW522 1 PW524 - PW550 1 PW556 - PW557 1 PW561 - PW564 1 PW571 - PW576 1 PW591 - PW596 1 PW611 - PW622 1 PW631 - PW637 1 PW661 - PW662 1 PW681 - PW683 1 PW701 - PW702 1 PW711 - PW717 1 PW741 - PW742 1 PW761 1 PW771 1 PW831 1 PW851 - PW856 2. Spares Affected None. **B. Concurrent Requirements** None. **C. Reason** This service bulletin gives instructions to replace or to inspect the left and right side engine strut, inboard and outboard midspar fuse pins for any cracking, pitting, corrosion and chrome plate damage. If the work given in this service bulletin is not accomplished, damage to the midspar fuse pins may go undetected. Undetected damage could result in the loss of structural integrity of the midspar fuse pins and cause an engine breakaway from the airplane. One operator found one 737-300 airplane with all four engine strut midspar fuse pins with corrosion damage. One of the midspar fuse pins had corrosion common to the chrome run out on the head side. Also, a large portion of the chrome plate was missing from the corroded area of the shank. The airplane had a total of 28,621 flight cycles.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 17 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT**Boeing Service Related Problem (SRP) 737-SRP-54-0115 is related to this service bulletin. Revision 1 is sent to add new replacement midspar fuse pins. The 311A1092-3 midspar fuse pins are manufactured from 15-5PH CRES material and do not require repeat inspections. Refer to Paragraph 1.E., Compliance. These sections were changed: 1. Paragraph 1.C., Reason: Information is added for the installation of the new material midspar fuse pins. 2. Paragraph 1.D., Description: Information is added for the installation of the new material midspar fuse pins. 3. Paragraph 1.E., Compliance: Information is added for the installation of the new material midspar fuse pins and the termination of repeat inspections. 4. Paragraph 1.J., References: Boeing CMM 54-50-01 and 737-300/400/500 SRM Chapter 51 are added to Existing Data. 5. Paragraph 2.K., Publications Affected: Boeing CMM 54-50-01 is added. 6. Paragraph 2.C., Parts Necessary for Each Airplane: A new replacement midspar fuse pin is added to Parts and Materials Supplied by the Operator. 7. Paragraph 3.B., Work Instructions: Instructions are added for the installation of the new material midspar fuse pins. 8. Figures 4 to 7: These figures are added to install the new material midspar fuse pins. Revision 2 is sent to change the compliance table number referenced in the second paragraph in Section F. Approval, from Table 7 to Table 1. These sections were changed: 1. Paragraph 1.E., Compliance: added that AD 2008-21-03 is related to this service bulletin. 2. Paragraph 1.F., Approval: revised Table 7 to Table 1 and added "or revision 2", in the AMOC paragraph. 3. Paragraph 1.K., Publications Affected: added the damage tolerance statement that was at the bottom of the compliance table. **D. Description** Identify the part numbers of the left and right side engine strut, inboard and outboard midspar fuse pins. Remove 311A1092-2 midspar fuse pins and install 311A1092-3 midspar fuse pins.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 18 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT**Alternatively, for a limited time, do a detailed inspection of 311A1092-2 midspar fuse pins for any cracking, pitting, corrosion or chrome plate damage. If damage is found, discard or repair the damaged midspar fuse pins. Install new or serviceable midspar fuse pins and do the repeat inspection at the specified interval. Revision 1 - More work is necessary on airplanes changed as shown in the original issue of this service bulletin. Installation of 311A1092-3 midspar fuse pins is required after the specified time. Revision 2 - No more work is necessary on airplanes changed in accordance with Revision 1 of this service bulletin. The work in this service bulletin is done in the maintenance zone(s) given below.
**Affected Maintenance Zones Zone**  **Model** 507, 607 737-300, 737-400, 737-500 **E. Compliance** Federal Aviation Administration (FAA) Airworthiness Directive AD 2008-21-03 is related to this service bulletin. **Table 1: Engine strut midspar fuse pins replacement and detailed inspection Repeat In**  **terval (Not to Ex**  **ceed) Compliance Time (Whichever Occurs**  **Later) Action**  **Condition**

- - - - No action is required. Airplaneswith all engine strut midspar fuse pins with part number 311A1092-3.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 19 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT Table 1: Engine strut midspar fuse pins replacement and detailed inspection**  **Repeat In terval (Not** **to Ex ceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- - - Within 120 months after the date on Revision 1 of this service bulletin. On the left side engine strut: Install anew inboard midspar fuse pin in accordance with the Accomplishment Instructions paragraphs 3.B.1.a.(2)(a) See note (a) Airplanes with engine strut midspar fuse pins with part number 311A1092-2. On the left side engine strut: Install anew outboard midspar fuse pin in accordance with the Accomplishment Instructions paragraphs 3.B.2.a.(2)(a) See note (a) On the right side engine strut: Install anew inboard midspar fuse pin in accordance with the Accomplishment Instructions paragraphs 3.B.3.a.(2)(a) See note (a) On the right side engine strut: Install anew outboard midspar fuse pin in accordance with the Accomplishment Instructions paragraphs 3.B.4.a.(2)(a) See note (a)

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 20 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT Table 1: Engine strut midspar fuse pins replacement and detailed inspection**  **Repeat In terval (Not** **to Ex ceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

60 months. See note (b) Within 24 months after the date on this service bulletin. Within 180 months fromdate of previous pin replacement. Within 180 months fromthe date of issuance oforiginal standard certificateof airworthiness or original export certificate of airworthiness.On the left side engine strut: Do a detailed inspection of the inboard midsparfuse pin in accordance with the Accomplishment Instructions paragraph 3.B.1.a.(2)(b)2) See notes (a) (b) Airplanes with engine strut midspar fuse pins with part number 311A1092-2. On the left side engine strut: Do a detailed inspection of the outboard midspar fuse pin in accordance withthe Accomplishment Instructions paragraph 3.B.2.a.(2)(b)2) See notes (a) (b) On the right side engine strut: Do a detailed inspection of the inboard midspar fuse pin in accordance withthe Accomplishment Instructions paragraph 3.B.3.a.(2)(b)2) See notes (a) (b) On the right side engine strut: Do a detailed inspection of the outboard midspar fuse pin in accordance withthe Accomplishment Instructions paragraph 3.B.4.a.(2)(b)2) See notes (a) (b)

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 21 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT Table 1: Engine strut midspar fuse pins replacement and detailed inspection**  **Repeat In terval (Not** **to Ex ceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- - - Before further flight. On the left side engine strut inboard midspar fuse pin: If the pin is damaged install a new or serviceable midsparfuse pin in accordance with the Accomplishment Instructions paragraph 3.B.1.a.(2)(b)3) See note (b) If any crack is found.

On the left side engine strut outboard midspar fuse pin: If the pin is damaged install a new or serviceable midsparfuse pin in accordance with the Accomplishment Instructions paragraph 3.B.2.a.(2)(b)3) See note (b) On the right side engine strut inboard midspar fuse pin: If the pin is damaged install a new or serviceable midsparfuse pin in accordance with the Accomplishment Instructions paragraph 3.B.3.a.(2)(b)3) See note (b) On the right side engine strut outboard midspar fuse pin: If the pin is damaged install a new or serviceable midsparfuse pin in accordance with the Accomplishment Instructions paragraph 3.B.4.a.(2)(b)3) See note (b)

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 22 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT Table 1: Engine strut midspar fuse pins replacement and detailed inspection**  **Repeat In terval (Not** **to Ex ceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- - - Before further flight On the left side engine strut inboard midspar fuse pin: If the pin is damaged install a new or serviceable midsparfuse pin in accordance with the Accomplishment Instructions paragraph 3.B.1.a.(2)(b)3) See note (b) If any pitting or corrosion damage is found in the inner bore, threads, or under the chromed area. On the left side engine strut outboard midspar fuse pin: If the pin is damaged install a new or serviceable midsparfuse pin in accordance with the Accomplishment Instructions paragraph 3.B.2.a.(2)(b)3) See note (b) On the right side engine strut inboard midspar fuse pin: If the pin is damaged install a new or serviceable midsparfuse pin in accordance with the Accomplishment Instructions paragraph 3.B.3.a.(2)(b)3) See note (b) On the right side engine strut outboard midspar fuse pin: If the pin is damaged install a new or serviceable midsparfuse pin in accordance with the Accomplishment Instructions paragraph 3.B.4.a.(2)(b)3) See note (b)

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 23 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT Table 1: Engine strut midspar fuse pins replacement and detailed inspection**  **Repeat In terval (Not** **to Ex ceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- - - Before further flight. On the left side engine strut inboard midspar fuse pin: If the pin is damaged install a new or serviceable midsparfuse pin in accordance with the Accomplishment Instructions paragraph 3.B.1.a.(2)(b)3) See note (b) If any pitting or corrosion damage is found not common to the inner bore, threads, or under the chromedarea and requires a blend depth more than 0.010 inch. On the left side engine strut outboard midspar fuse pin: If the pin is damaged install a new or serviceable midsparfuse pin in accordance with the Accomplishment Instructions paragraph 3.B.2.a.(2)(b)3) See note (b) On the right side engine strut inboard midspar fuse pin: If the pin is damaged install a new or serviceable midsparfuse pin in accordance with the Accomplishment Instructions paragraph 3.B.3.a.(2)(b)3) See note (b) On the right side engine strut outboard midspar fuse pin: If the pin is damaged install a new or serviceable midsparfuse pin in accordance with the Accomplishment Instructions paragraph 3.B.4.a.(2)(b)3) See note (b)

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 24 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT Table 1: Engine strut midspar fuse pins replacement and detailed inspection**  **Repeat In terval (Not** **to Ex ceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- - - Before further flight. On the left side engine strut inboard midspar fuse pin: If any pitting or corrosion damage is found not common to the inner bore, threads, or under the chromedarea and requires a blend depth less than or equal to 0.010 inch. If the fuse pin is damaged, repair inaccordance with Accomplishment Instructions paragraph 3.B.1.a.(2)(b)2)d){1} and install theserviceable midspar fuse pin in accordance with the Accomplishment Instructions paragraph 3.B.1.a.(2)(b)3) Or If the pin is damaged install a new orserviceable midspar fuse pin in accordance with the Accomplishment Instructions paragraph 3.B.1.a.(2)(b)3) See note (b) On the left side engine strut outboard midspar fuse pin: If the fuse pin is damaged, repair inaccordance with Accomplishment Instructions paragraph 3.B.2.a.(2)(b)2)d){1} and install theserviceable midspar fuse pin in accordance with the Accomplishment Instructions paragraph 3.B.2.a.(2)(b)3) Or If the pin is damaged install a new orserviceable midspar fuse pin in accordance with the Accomplishment Instructions paragraph 3.B.2.a.(2)(b)3) See note (b) On the right side engine strut inboard midspar fuse pin: If the fuse pin is damaged, repair inaccordance with Accomplishment Instructions paragraph 3.B.3.a.(2)(b)2)d){1} and install theserviceable midspar fuse pin in accordance with the Accomplishment Instructions paragraph 3.B.3.a.(2)(b)3) Or

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 25 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT Table 1: Engine strut midspar fuse pins replacement and detailed inspection**  **Repeat In terval (Not** **to Ex ceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

If the pin is damaged install a new orserviceable midspar fuse pin in accordance with the Accomplishment Instructions paragraph 3.B.3.a.(2)(b)3) See note (b) On the right side engine strut outboard midspar fuse pin: If the fuse pin is damaged, repair inaccordance with Accomplishment Instructions paragraph 3.B.4.a.(2)(b)2)d){1} and install theserviceable midspar fuse pin in accordance with the Accomplishment Instructions paragraph 3.B.4.a.(2)(b)3) Or If the pin is damaged install a new orserviceable midspar fuse pin in accordance with the Accomplishment Instructions paragraph 3.B.4.a.(2)(b)3) See note (b)

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 26 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT Table 1: Engine strut midspar fuse pins replacement and detailed inspection**  **Repeat In terval (Not** **to Ex ceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- - - Before further flight. On the left side engine strut inboardmidspar fuse pin: Install a new or serviceable midspar fuse pin in accordance with the Accomplishment Instructions paragraph 3.B.1.a.(2)(b)3) See note (b)If no cracking, pitting, corrosion or chrome plate damage is found. On the left side engine strut outboardmidspar fuse pin: Install a new or serviceable midspar fuse pin in accordance with the Accomplishment Instructions paragraph 3.B.2.a.(2)(b)3) See note (b) On the right side engine strut inboardmidspar fuse pin: Install a new or serviceable midspar fuse pin in accordance with the Accomplishment Instructions paragraph 3.B.3.a.(2)(b)3) See note (b) On the right side engine strut outboardmidspar fuse pin: Install a new or serviceable midspar fuse pin in accordance with the Accomplishment Instructions paragraph 3.B.4.a.(2)(b)3) See note (b) (a) No action is required if a midspar fuse pin with part number 311A1092-3 is already installed at this location. (b) For each midspar fuse pin location, the installation of a new midspar fuse pin with part number 311A1092- 3 terminates the requirement for inspections at that location. **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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 27 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT**In addition, the Manager of the Seattle Aircraft Certification Office approves the accomplishment of the inspections, repairs, and modifications specified in Section 1.E., Compliance, of SB 737-54-1044, Revision 1 or SB 737-54A1044, Revision 2 as an AMOC to the applicable inspections and repairs required by paragraph (f) of AD 2008-21-03. All provisions of AD 2008-21-03 that are not specifically referenced in the preceding sentence remain fully applicable and must be complied with. Replacement of the existing midspar fuse pin with the new dash number fuse pin per Section 1.E, Table 1, Note (b) of Service Bulletin 737-54-1044, Revision 1, or 737-54A1044, Revision 2 terminates the inspections required by paragraph (f) of AD 2008-21-03. If an airplane has a non-Boeing modification or repair that affects a component or system also affected by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval before incorporating this service bulletin. **G. Manpower** The table below shows an estimate of the task-hours necessary to do this inspection for each airplane. This estimate is for direct labor only, done by an experienced crew. Adjust the estimate with operator task-hour data if necessary. The estimate does not include lost time. These are some examples of lost time: — Time to adjust to the workplace — Time to schedule the work — Time to examine the work — Time to cure the materials — Time to make the parts — Time to find the tools. **Midspar Fuse Pin - Inspection and replacement Elapsed Hours**  **Task-Hours Number of Per-**  **sons Task** 

3.25 6.50 2 Open Access (a) 1.50 1.50 1 Figure 1 1.50 1.50 1 Figure 2 3.25 6.50 2 Close Access (b) 9.50 16.00 TOTAL FOR EACH AIRPLANE (a) This includes time for the removal of the midspar fuse pins. (b) This includes time for the installation of the midspar fuse pins. **H. Weight and Balance Changes** None. **I. Electrical Load Data** Not changed.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 28 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT J. References**  1. Existing Data: a. Engineering Change Memo PRR 35005-273RS. b. 737-300/400/500 Aircraft Maintenance Manual (AMM) 54-10-00, 54-10-01. c. Boeing Drawing 65-88700. d. Service Related Problem (SRP) 737-SRP-54-0115. e. Standard Overhaul Practices Manual (SOPM) 20-30-03, 20-41-02, 20-42-10. f. Boeing Component Maintenance Manual (CMM) 54-50-01 g. 737-300/400/500 Structural Repair Manual (SRM) Chapter 51 h. Federal Aviation Administration (FAA) Airworthiness Directive AD 2008-21-03 2. Data supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin:
**Title Drawing Number**  STRUT MOUNT INSTALLATION - CFM56-3 ENGINE 310A1030 This drawing was used to prepare this service bulletin. This drawing is not necessary to make the specified changes, and is not supplied with this service bulletin. This drawing may not be applicable to all airplane configurations or operators. **K. Publications Affected** 1. Publications: **Chapter-Section Publication**  54-42 737 Illustrated Parts Catalog 54-50-01 Component Maintenance Manual 2. Damage Tolerance Based Structural Inspections: Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the Maintenance Program. This service bulletin affects FCS but no new DTIs are necessary. **L. Interchangeability and Intermixability of Parts** Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 29 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 30 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT**

BLANK PAGE**2. MATERIAL INFORMATION A. Material - Price and Availability**  None. **B. Industry Support Information** Boeing warranty remedies are not available for the configuration changes inspection, and/or repair procedures given in this service bulletin. **C. Parts Necessary For Each Airplane** 1. Kits/Parts: None. 2. Parts and Materials Supplied by the Operator:
**Notes Name**  **QTY Part Number /**  **Specification** (b)(f) Fuse Pin 1 311A1092-3 (b)(f) Fuse Pin 1 311A1092-2 (a)(c) Primer 4 Ounces BMS10-11, Type I (c)(d) Low Hydrogen Embrittlement Stylus Cadmium Plate 4 Ounces SPS-5070 (e) Methyl Ethyl Ketone (MEK) Solvent 8 Ounces ASTM D 740(a) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data. (b) This part is only necessary if the midspar fuse pin is replaced. The quantity shown is for one midspar fuse pin replacement. There are four midspar fuse pins on an airplane. (c) This part is only necessary if the midspar fuse pin is repaired. The quantity shown is an estimate for one midspar fuse pin. There are four midspar fuse pins on an airplane. (d) Refer to SOPM 20-42-10 for supplier details. (e) Refer to SOPM 20-30-03 for supplier details. (f) Part 311A1092-2 is optional to 311A1092-3 for a limited time, however the requirement for repeat inspections is not terminated if 311A1092-2 is used. Refer to Paragraph 1.E., Compliance.
3. Parts Modified and Reidentified: None.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 31 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT**4. Parts Removed and Not Replaced:
**Notes QTY**  **Name Existing Part**  **Number** 4 WASHER 311A1097-1 **D. Parts Necessary to Change Spares** None. **E. Special Tooling - Price and Availability** None. **F. Special Tooling Necessary to do this Service Bulletin** No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 32 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT 3. ACCOMPLISHMENT INSTRUCTIONS**  **A. GENERAL INFORMATION CAUTION:**  KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL, METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR OTHER ELECTRICAL DAMAGE. **NOTE:** 1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 2. Obey all of the warnings and cautions given in the specified manual sections. 3. Unless shown differently, these dimensions and tolerances are used: — Linear dimensions are in inches — Torque limits to tighten nuts and bolts are given in 737 Structural Repair Manual, Chapter 51. 4. For approved fastener and process material substitutions, refer to 737 Structural Repair Manual, Chapter 51, Alternate fasteners are given in 737 Structural Repair Manual Chapter 51 and Boeing Drawing 65-88700. 5. If the length of fasteners specified in this service bulletin do not meet the installation standards, fasteners of the same specification, or an approved substitute, one grip length longer or shorter may be used. 6. A Detailed Inspection is defined as: An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirrors magnifying lenses, etc. may be necessary. Surface cleaning and elaborate procedures may be required. 7. A General Visual Inspection is defined as: A visual examination of an interior or exterior area, installation or assembly to detect obvious damage, failure or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to 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. 8. 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. **B. WORK INSTRUCTIONS** 1. PART 1 - LEFT SIDE ENGINE STRUT - INBOARD - MIDSPAR FUSE PIN

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 33 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT**a. Do a General Visual Inspection to identify the part number of the left side engine strut inboard midspar fuse pin. **NOTE:** The part number can be found on the head of the fuse pin. (1) If the midspar fuse pin has part number 311A1092-3, no action is required. (2) If the midspar fuse pin has part number 311A1092-2 or the part number cannot be found, do one of the following: (a) Install a midspar fuse pin with part number 311A1092-3: **NOTE:** Installation of new midspar fuse pin with part number 311A1092-3 terminates the requirement to do the repeat inspections of the left side engine strut inboard midspar fuse pin. Refer to Paragraph 1.E., Compliance. **WARNING:** REMOVE ONLY ONE MIDSPAR FUSE PIN AT A TIME. INJURY TO PERSONS OR DAMAGE TO EQUIPMENT CAN OCCUR. 1) Remove the left side engine strut inboard midspar fuse pin. Refer to 737-300/400/500 AMM 54-10-01 as an accepted procedure. **NOTE:** As an option, remove the left side nacelle strut from the wing. Refer to 737-300/400/500 AMM 54-10-00 as an accepted procedure. 2) Install the left side engine strut inboard midspar fuse pin in accordance with Figure 4. (b) Inspect the midspar fuse pin that is currently installed: **WARNING:** REMOVE ONLY ONE MIDSPAR FUSE PIN AT A TIME. INJURY TO PERSONS OR DAMAGE TO EQUIPMENT CAN OCCUR. 1) Remove the left side engine strut inboard midspar fuse pin. Refer to 737-300/400/500 AMM 54-10-01 as an accepted procedure. **NOTE:** As an option, remove the left side nacelle strut from the wing. Refer to 737-300/400/500 AMM 54-10-00 as an accepted procedure. 2) Do a detailed inspection of the left side inboard midspar fuse pin for any cracking, pitting, corrosion or chrome plate damage in accordance with Figure 1.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 34 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT**a) If any cracking is found, then discard the midspar fuse pin. b) If any pitting, corrosion or chrome plate damage is found in the inner bore, threads, or under the chromed area, then discard the midspar fuse pin. c) If any pitting or corrosion damage is found not common to the inner bore, threads, or under the chromed area and requires a blend depth more than 0.010 inch, then discard the midspar fuse pin. d) If any pitting or corrosion damage is found not common to the inner bore, threads, or under the chromed area and requires a blend depth less than or equal to 0.010 inch, then do one of the steps that follow: {1} Repair the midspar fuse pin in accordance with Figure 3. {2} Discard the midspar fuse pin. e) If no cracking, pitting, corrosion or chrome plate damage is found, then the midspar fuse pin is serviceable and can be kept for re-installation. 3) Do one of the following: a) Install the left side engine strut inboard midspar fuse pin with new part number 311A1092-3 in accordance with Figure 4. **NOTE:** Installation of new midspar fuse pin with part number 311A1092-3 terminates the requirement to do the repeat inspections of the left side engine strut inboard midspar fuse pin. Refer to Paragraph 1.E., Compliance. b) Install the left side engine strut inboard midspar fuse pin with new part number 311A1092-2 or serviceable midspar fuse pin. Do not install part number 311A1097-1 special washer under the head of the midspar fuse pin. Refer to 737-300/400/500 AMM 54-10-01 as an accepted procedure. 4) Do the repeat detailed inspection at the interval specified in Paragraph 1.E., Compliance. 2. PART 2 - LEFT SIDE ENGINE STRUT - OUTBOARD - MIDSPAR FUSE PIN a. Do a General Visual Inspection to identify the part number of the left side engine strut outboard midspar fuse pin. **NOTE:** The part number can be found on the head of the fuse pin. (1) If the midspar fuse pin has part number 311A1092-3, no action is required. (2) If the midspar fuse pin has part number 311A1092-2 or the part number cannot be found, do one of the following: (a) Install a midspar fuse pin with part number 311A1092-3:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 35 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT NOTE:**  Installation of new midspar fuse pin with part number 311A1092-3 terminates the requirement to do the repeat inspections of the left side engine strut outboard midspar fuse pin. Refer to Paragraph 1.E., Compliance. **WARNING:** REMOVE ONLY ONE MIDSPAR FUSE PIN AT A TIME. INJURY TO PERSONS OR DAMAGE TO EQUIPMENT CAN OCCUR. 1) Remove the left side engine strut outboard midspar fuse pin. Refer to 737-300/400/500 AMM 54-10-01 as an accepted procedure. **NOTE:** As an option, remove the left side nacelle strut from the wing. Refer to 737-300/400/500 AMM 54-10-00 as an accepted procedure. 2) Install the left side engine strut outboard midspar fuse pin in accordance with Figure 5. (b) Inspect the midspar fuse pin that is currently installed: **WARNING:** REMOVE ONLY ONE MIDSPAR FUSE PIN AT A TIME. INJURY TO PERSONS OR DAMAGE TO EQUIPMENT CAN OCCUR. 1) Remove the left side engine strut outboard midspar fuse pin. Refer to 737-300/400/500 AMM 54-10-01 as an accepted procedure. **NOTE:** As an option, remove the left side nacelle strut from the wing. Refer to 737-300/400/500 AMM 54-10-00 as an accepted procedure. 2) Do a detailed inspection of the left side outboard midspar fuse pin for any cracking, pitting, corrosion or chrome plate damage in accordance with Figure 1. a) If any cracking is found, then discard the midspar fuse pin. b) If any pitting, corrosion or chrome plate damage is found in the inner bore, threads, or under the chromed area, then discard the midspar fuse pin. c) If any pitting or corrosion damage is found not common to the inner bore, threads, or under the chromed area and requires a blend depth more than 0.010 inch, then discard the midspar fuse pin. d) If any pitting or corrosion damage is found not common to the inner bore, threads, or under the chromed area and requires a blend depth less than or equal to 0.010 inch, then do one of the steps that follow: {1} Repair the midspar fuse pin in accordance with Figure 3. {2} Discard the midspar fuse pin. e) If no cracking, pitting, corrosion or chrome plate damage is found, then the midspar fuse pin is serviceable and can be kept for re-installation. 3) Do one of the following:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 36 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT**a) Install the left side engine strut outboard midspar fuse pin with new part number 311A1092-3 in accordance with Figure 5. **NOTE:** Installation of new midspar fuse pin with part number 311A1092-3 terminates the requirement to do the repeat inspections of the left side engine strut outboard midspar fuse pin. Refer to Paragraph 1.E., Compliance. b) Install the left side engine strut outboard midspar fuse pin with new part number 311A1092-2 or serviceable midspar fuse pin. Do not install part number 311A1097-1 special washer under the head of the midspar fuse pin. Refer to 737-300/400/500 AMM 54-10-01 as an accepted procedure. 4) Do the repeat detailed inspection at the interval specified in Paragraph 1.E., Compliance. 3. PART 3 - RIGHT SIDE ENGINE STRUT - INBOARD - MIDSPAR FUSE PIN a. Do a General Visual Inspection to identify the part number of the right side engine strut inboard midspar fuse pin. **NOTE:** The part number can be found on the head of the fuse pin. (1) If the midspar fuse pin has part number 311A1092-3, no action is required. (2) If the midspar fuse pin has part number 311A1092-2 or the part number cannot be found, do one of the following: (a) Install a midspar fuse pin with part number 311A1092-3: **NOTE:** Installation of new midspar fuse pin with part number 311A1092-3 terminates the requirement to do the repeat inspections of the right side engine strut inboard midspar fuse pin. Refer to Paragraph 1.E., Compliance. **WARNING:** REMOVE ONLY ONE MIDSPAR FUSE PIN AT A TIME. INJURY TO PERSONS OR DAMAGE TO EQUIPMENT CAN OCCUR. 1) Remove the right side engine strut inboard midspar fuse pin. Refer to 737-300/400/500 AMM 54-10-01 as an accepted procedure. **NOTE:** As an option, remove the right side nacelle strut from the wing. Refer to 737-300/400/500 AMM 54-10-00 as an accepted procedure. 2) Install the right side engine strut inboard midspar fuse pin in accordance with Figure 6. (b) Inspect the midspar fuse pin that is currently installed: **WARNING:** REMOVE ONLY ONE MIDSPAR FUSE PIN AT A TIME. INJURY TO PERSONS OR DAMAGE TO EQUIPMENT CAN OCCUR. 1) Remove the right side engine strut inboard midspar fuse pin. Refer to 737-300/400/500 AMM 54-10-01 as an accepted procedure.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 37 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT NOTE:**  As an option, remove the right side nacelle strut from the wing. Refer to 737-300/400/500 AMM 54-10-00 as an accepted procedure. 2) Do a detailed inspection of the right side inboard midspar fuse pin for any cracking, pitting, corrosion or chrome plate damage in accordance with Figure 2. a) If any cracking is found, then discard the midspar fuse pin. b) If any pitting, corrosion or chrome plate damage is found in the inner bore, threads, or under the chromed area, then discard the midspar fuse pin. c) If any pitting or corrosion damage is found not common to the inner bore, threads, or under the chromed area and requires a blend depth more than 0.010 inch, then discard the midspar fuse pin. d) If any pitting or corrosion damage is found not common to the inner bore, threads, or under the chromed area and requires a blend depth less than or equal to 0.010 inch, then do one of the steps that follow: {1} Repair the midspar fuse pin in accordance with Figure 3. {2} Discard the midspar fuse pin. e) If no cracking, pitting, corrosion or chrome plate damage is found, then the midspar fuse pin is serviceable and can be kept for re-installation. 3) Do one of the following: a) Install the right side engine strut inboard midspar fuse pin with new part number 311A1092-3 in accordance with Figure 6. **NOTE:** Installation of new midspar fuse pin with part number 311A1092-3 terminates the requirement to do the repeat inspections of the right side engine strut inboard midspar fuse pin. Refer to Paragraph 1.E., Compliance. b) Install the right side engine strut inboard midspar fuse pin with new part number 311A1092-2 or serviceable midspar fuse pin. Do not install part number 311A1097-1 special washer under the head of the midspar fuse pin. Refer to 737-300/400/500 AMM 54-10-01 as an accepted procedure. 4) Do the repeat detailed inspection at the interval specified in Paragraph 1.E., Compliance. 4. PART 4 - RIGHT SIDE ENGINE STRUT - OUTBOARD - MIDSPAR FUSE PIN a. Do a General Visual Inspection to identify the part number of the right side engine strut outboard midspar fuse pin. **NOTE:** The part number can be found on the head of the fuse pin.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 38 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT**(1) If the midspar fuse pin has part number 311A1092-3, no action is required. (2) If the midspar fuse pin has part number 311A1092-2 or the part number cannot be found, do one of the following: (a) Install a midspar fuse pin with part number 311A1092-3: **NOTE:** Installation of new midspar fuse pin with part number 311A1092-3 terminates the requirement to do the repeat inspections of the right side engine strut outboard midspar fuse pin. Refer to Paragraph 1.E., Compliance. **WARNING:** REMOVE ONLY ONE MIDSPAR FUSE PIN AT A TIME. INJURY TO PERSONS OR DAMAGE TO EQUIPMENT CAN OCCUR. 1) Remove the right side engine strut outboard midspar fuse pin. Refer to 737-300/400/500 AMM 54-10-01 as an accepted procedure. **NOTE:** As an option, remove the right side nacelle strut from the wing. Refer to 737-300/400/500 AMM 54-10-00 as an accepted procedure. 2) Install the right side engine strut outboard midspar fuse pin in accordance with Figure 7. (b) Inspect the midspar fuse pin that is currently installed: **WARNING:** REMOVE ONLY ONE MIDSPAR FUSE PIN AT A TIME. INJURY TO PERSONS OR DAMAGE TO EQUIPMENT CAN OCCUR. 1) Remove the right side engine strut outboard midspar fuse pin. Refer to 737-300/400/500 AMM 54-10-01 as an accepted procedure. **NOTE:** As an option, remove the right side nacelle strut from the wing. Refer to 737-300/400/500 AMM 54-10-00 as an accepted procedure. 2) Do a detailed inspection of the right side outboard midspar fuse pin for any cracking, pitting, corrosion or chrome plate damage in accordance with Figure 2. a) If any cracking is found, then discard the midspar fuse pin. b) If any pitting, corrosion or chrome plate damage is found in the inner bore, threads, or under the chromed area, then discard the midspar fuse pin. c) If any pitting or corrosion damage is found not common to the inner bore, threads, or under the chromed area and requires a blend depth more than 0.010 inch, then discard the midspar fuse pin. d) If any pitting or corrosion damage is found not common to the inner bore, threads, or under the chromed area and requires a blend depth less than or equal to 0.010 inch, then do one of the steps that follow:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 39 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT**{1} Repair the midspar fuse pin in accordance with Figure 3. {2} Discard the midspar fuse pin. e) If no cracking, pitting, corrosion or chrome plate damage is found, then the midspar fuse pin is serviceable and can be kept for re-installation. 3) Do one of the following: a) Install the right side engine strut outboard midspar fuse pin with new part number 311A1092-3 in accordance with Figure 7. **NOTE:** Installation of new midspar fuse pin with part number 311A1092-3 terminates the requirement to do the repeat inspections of the right side engine strut outboard midspar fuse pin. Refer to Paragraph 1.E., Compliance. b) Install the right side engine strut outboard midspar fuse pin with new part number 311A1092-2 or serviceable midspar fuse pin. Do not install part number 311A1097-1 special washer under the head of the midspar fuse pin. Refer to 737-300/400/500 AMM 54-10-01 as an accepted procedure. 4) Do the repeat detailed inspection at the interval specified in Paragraph 1.E., Compliance. b. Put the airplane back to a serviceable condition.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2: January 20, 2010 40 of 57 **BOEING SERVICE BULLETIN 737-54A1044 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 to inspect.

**FIGURE 1: LEFT SIDE ENGINE STRUT - INBOARD AND OUTBOARD - MIDSPAR FUSE PIN - INSPECTION (SHEET 1 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2 January 20, 2010 41 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** (a) 2 311A1092-2 Midspar Fuse Pin Clean 1 (b) 2 311A1092-2 Midspar Fuse Pin Inner Bore Inspect 2 (b) 2 311A1092-2 Midspar Fuse Pin Thread Inspect 3 (c) 2 311A1092-2 Midspar Fuse Pin Shank Inspect 4 (b) 2 311A1092-2 Midspar Fuse Pin Head Inspect 5 (a) Use methyl ethyl ketone to remove all dirt and grease. Refer to SOPM 20-30-03 as an accepted procedure. (b) Do a detailed inspection for any cracking, pitting or corrosion damage. (c) Do a detailed inspection for any cracking, pitting, corrosion or chrome plate damage.

**FIGURE 1: LEFT SIDE ENGINE STRUT - INBOARD AND OUTBOARD - MIDSPAR FUSE PIN - INSPECTION (SHEET 2 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2 January 20, 2010 42 of 57 **BOEING SERVICE BULLETIN 737-54A1044 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 to inspect.

**FIGURE 2: RIGHT SIDE ENGINE STRUT - INBOARD AND OUTBOARD - MIDSPAR FUSE PIN - INSPECTION (SHEET 1 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2 January 20, 2010 43 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** (a) 2 311A1092-2 Midspar Fuse Pin Clean 1 (b) 2 311A1092-2 Midspar Fuse Pin Inner Bore Inspect 2 (b) 2 311A1092-2 Midspar Fuse Pin Thread Inspect 3 (c) 2 311A1092-2 Midspar Fuse Pin Shank Inspect 4 (b) 2 311A1092-2 Midspar Fuse Pin Head Inspect 5 (a) Use methyl ethyl ketone to remove all dirt and grease. Refer to SOPM 20-30-03 as an accepted procedure. (b) Do a detailed inspection for any cracking, pitting or corrosion damage. (c) Do a detailed inspection for any cracking, pitting, corrosion or chrome plate damage.

**FIGURE 2: RIGHT SIDE ENGINE STRUT - INBOARD AND OUTBOARD - MIDSPAR FUSE PIN - INSPECTION (SHEET 2 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2 January 20, 2010 44 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  (a)(b)(c)

- - Pitting or Corrosion Damage Remove 1 (d)

- - Blended Areas Inspect 2 (e)

- - Low HydrogenEmbrittlement Stylus Cadmium Plate Apply 3

(f)(g)

- - BMS 10-11, Type I Primer Apply 4 (a) Blend out the pitting or corrosion damage from the midspar fuse pin. Make sure the blend depth is less than or equal to 0.010 inch. (b) Taper out the damage area with a 10:1 inch taper. (c) Surface finish to a 63 microinch RA smoothness or better. (d) Do a detailed inspection of the blended areas to make sure all corrosion damage has been removed. Use a 10X magnifying lens to aid the inspection. (e) To the damaged area. Refer to SOPM 20-42-10 as an accepted procedure. (f) Apply two coats of primer to the blended areas and any other areas showing primer loss. Refer to SOPM 20-41-02 as an accepted procedure. (g) Do not apply primer to the threads or chrome areas of the midspar fuse pin.

**FIGURE 3: MIDSPAR FUSE PIN - REPAIR (SHEET 1 OF 1)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2 January 20, 2010 45 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT FIGURE 4: LEFT SIDE ENGINE STRUT - INBOARD - MIDSPAR FUSE PIN - INSTALLATION OF NEW**  **MATERIAL FUSE PIN (SHEET 1 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2 January 20, 2010 46 of 57 **BOEING SERVICE BULLETIN 737-54A1044 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 new parts necessary for this location.

**FIGURE 4: LEFT SIDE ENGINE STRUT - INBOARD - MIDSPAR FUSE PIN - INSTALLATION OF NEW MATERIAL FUSE PIN**  **(SHEET 2 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2 January 20, 2010 47 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** (a) (b) 1 311A1092-3 Fuse Pin Install (New) 1 (a) Do not install part number 311A1097-1 special washer under the head of the fuse pin. (b) Refer to737-300/400/500 AMM 54-10-01as an accepted procedure.

**FIGURE 4: LEFT SIDE ENGINE STRUT - INBOARD - MIDSPAR FUSE PIN - INSTALLATION OF NEW MATERIAL FUSE PIN**  **(SHEET 3 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2 January 20, 2010 48 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT FIGURE 5: LEFT SIDE ENGINE STRUT - OUTBOARD - MIDSPAR FUSE PIN - INSTALLATION OF NEW**  **MATERIAL FUSE PIN (SHEET 1 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2 January 20, 2010 49 of 57 **BOEING SERVICE BULLETIN 737-54A1044 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 new parts necessary for this location.

**FIGURE 5: LEFT SIDE ENGINE STRUT - OUTBOARD - MIDSPAR FUSE PIN - INSTALLATION OF NEW MATERIAL FUSE PIN**  **(SHEET 2 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2 January 20, 2010 50 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** (a) (b) 1 311A1092-3 Fuse Pin Install (New) 1 (a) Do not install part number 311A1097-1 special washer under the head of the fuse pin. (b) Refer to 737-300/400/500 AMM 54-10-01 as an accepted procedure.

**FIGURE 5: LEFT SIDE ENGINE STRUT - OUTBOARD - MIDSPAR FUSE PIN - INSTALLATION OF NEW MATERIAL FUSE PIN**  **(SHEET 3 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2 January 20, 2010 51 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT FIGURE 6: RIGHT SIDE ENGINE STRUT - INBOARD - MIDSPAR FUSE PIN - INSTALLATION OF NEW**  **MATERIAL FUSE PIN (SHEET 1 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2 January 20, 2010 52 of 57 **BOEING SERVICE BULLETIN 737-54A1044 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 new parts necessary for this location.

**FIGURE 6: RIGHT SIDE ENGINE STRUT - INBOARD - MIDSPAR FUSE PIN - INSTALLATION OF NEW MATERIAL FUSE PIN**  **(SHEET 2 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2 January 20, 2010 53 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** (a) (b) 1 311A1092-3 Fuse Pin Install (New) 1 (a) Do not install part number 311A1097-1 special washer under the head of the fuse pin. (b) Refer to 737-300/400/500 AMM 54-10-01 as an accepted procedure.

**FIGURE 6: RIGHT SIDE ENGINE STRUT - INBOARD - MIDSPAR FUSE PIN - INSTALLATION OF NEW MATERIAL FUSE PIN**  **(SHEET 3 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2 January 20, 2010 54 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT FIGURE 7: RIGHT SIDE ENGINE STRUT - OUTBOARD - MIDSPAR FUSE PIN - INSTALLATION OF NEW**  **MATERIAL FUSE PIN (SHEET 1 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2 January 20, 2010 55 of 57 **BOEING SERVICE BULLETIN 737-54A1044 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 new parts necessary for this location.

**FIGURE 7: RIGHT SIDE ENGINE STRUT - OUTBOARD - MIDSPAR FUSE PIN - INSTALLATION OF NEW MATERIAL FUSE PIN**  **(SHEET 2 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2 January 20, 2010 56 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** (a) (b) 1 311A1092-3 Fuse Pin Install (New) 1 (a) Do not install part number 311A1097-1 special washer under the head of the fuse pin. (b) Refer to 737-300/400/500 AMM 54-10-01 as an accepted procedure.

**FIGURE 7: RIGHT SIDE ENGINE STRUT - OUTBOARD - MIDSPAR FUSE PIN - INSTALLATION OF NEW MATERIAL FUSE PIN**  **(SHEET 3 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 10, 2007 737-54A1044 Revision 2 January 20, 2010 57 of 57 **BOEING SERVICE BULLETIN 737-54A1044 ALERT**  **ALERT**