### Commercial **Airplanes** 

# 747 Service Bulletin **ALERT Number: 747-25A3613**  Original Issue: June 22, 2012 ATA System: 2551 **SUBJECT:** EQUIPMENT/FURNISHINGS - Electrical/Electronic Equipment Centers - Aft Main Equipment Center (MEC) Drip Shield Gutter Repair Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15 CFR 300-774). An export license may be required before it is used for development, production or use by foreign persons from specific countries. The controller of this data has the individual responsibility to abide by all export laws. 9E991 ECCN: 

## BOEING PROPRIETARY, CONFIDENTIAL AND/OR TRADE SECRET Copyright © 2012 Boeing. Unpublished Work. All Rights Reserved. Treatment of this document and its content is governed by contract with Boeing. Rights to use this document are licensed on a per aircraft basis and such rights may not be transferable. For more information, contact The Boeing Company. Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, DreamlinerTM, 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 Boeing liveries are all trademarks owned by The Boeing Company; and no trademark license is granted in connection with this document unless provided in writing by Boeing. BOEING is a trademark of Boeing Management Company.

Original Issue: June 22, 2012 747-25A3613 1 of 39 2.0Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 2 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT**

BLANK PAGE**Table of Contents** Summary...................................................... 5 1. PLANNING INFORMATION ........................................ 9 A. Effectivity................................................ 9 1. Airplanes............................................. 9 2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 B. Concurrent Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 C. Reason. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 D. Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 I. Electrical Load Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 J. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2. Data Supplied with this Service Bulletin:. . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3. Installation Drawings Used in the Preparation of this Service Bulletin:. . . . . . . . . . . 15 K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 L. Interchangeability and Intermixability of Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . 15 M. Software Accomplishment Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2. MATERIAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 B. Industry Support Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 C. Parts Necessary for Each Airplane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 1. Kits/Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 2. Parts and Materials Supplied by the Operator. . . . . . . . . . . . . . . . . . . . . . . . 17 3. Parts Modified and Reidentified. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 4. Parts Removed and Not Replaced. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 18 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 A. GENERAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 FIGURE 1: CARGO LINER SUPPORT REMOVAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 FIGURE 2: AFT MEC DRIP SHIELD GUTTER CLEANING AND PREPARATION FOR GENERAL VISUAL INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 FIGURE 3: AFT MEC DRIP SHIELD GUTTER REPAIR. . . . . . . . . . . . . . . . . . . . . . . . . 29 FIGURE 4: AFT MEC DRIP SHIELD GUTTER REINFORCEMENT. . . . . . . . . . . . . . . . . . . 32 FIGURE 5: CARGO LINER SUPPORT INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 36

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 3 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 4 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 747 Service Bulletin **ALERT Summary**  **Number: 747-25A3613** Original Issue: June 22, 2012 ATA System: 2551 **SUBJECT:** EQUIPMENT/FURNISHINGS - Electrical/Electronic Equipment Centers - Aft Main Equipment Center (MEC) Drip Shield Gutter 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** This service bulletin will reduce the possibility of water penetration into the main equipment center (MEC). Disbonded aft MEC drip shield gutters have allowed water to drip past the MEC drip shield and into the Wire Integration Units (WIU). Water penetration into the WIUs could result in loss of flight critical systems. An operator experienced water leaking from main deck cargo into the WIU. It flowed from the drip shield through disbonded floor seams into the aft MEC drip shield gutter, then onto the WIU Liquids can leak through the MEC drip shield due to disbonded aft MEC drip shield gutters resulting in water intrusion into the WIU of the MEC. Disbonding can occur due to improper preparation of the drip shield/gutter material, aging of materials, and/or poor workmanship. This Service Bulletin does a general visual inspection of the aft MEC drip shield gutters for disbonded seams, and repairs them if necessary. A reinforcing layer of fiberglass is applied over the seam in the aft MEC drip shield gutter to ensure no future disbondments occur. Boeing Service Related Problem (SRP) 747-SRP-25-0304 is related to this service bulletin This table is provided to operators for planning purposes only. Refer to the applicable sections for more information.
**Reference Affected**  **Planning Data** Paragraph 1.A.2., Spares Affected No Spares Affected Paragraph 1.E., Compliance Yes AD Related Paragraph 1.H., Weight and Balance Changes Yes Weight and Balance Change

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 5 of 39**Reference Affected**  **Planning Data** Paragraph 1.I., Electrical Load Data No Electrical Load Changed Paragraph 1.K., Publications Affected No Publications Affected Paragraph 1.K., Publications Affected No Airplane Flight Operations Affected (Flight CrewOperations Manual and/or FAA Approved Airplane Flight Manual) Paragraph 2.C.1., Kits/Parts No Kits/Parts Required Paragraph 2.C.2., Parts and Materials Supplied by the Operator Yes Operator Supplied Material Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin No Special Tooling Required
**ACTION (PRR 85901-117RS)** - Do a general visual inspection of the aft MEC drip shield gutters for disbonded seam, and repair if necessary. - Add fiberglass reinforcement to aft MEC drip shield gutters. **EFFECTIVITY** 747-400, 747-400D, 747-400F Airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplane(s). **COMPLIANCE** The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. Boeing recommends that the inspection, change and/or repair given in this service bulletin be done within 24 months after the original issue date of this service bulletin. **INDUSTRY SUPPORT INFORMATION** Boeing warranty remedies are not available for the configuration changes, inspection, and/or repair procedures given in this service bulletin. **MANPOWER Elapsed Hours**  **Total Task Hours Airplanes**  6.15 10.65 Group 1 air- planes
**MATERIAL INFORMATION** Operator Supplied Parts/Materials. Refer to Paragraph 2.A., Material - Price and Availability.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 6 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 7 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 8 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 747 Service Bulletin **ALERT Number: 747-25A3613**  Original Issue: June 22, 2012 ATA System: 2551 **SUBJECT:** EQUIPMENT/FURNISHINGS - Electrical/Electronic Equipment Centers - Aft Main Equipment Center (MEC) Drip Shield Gutter 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 Refer to Service Bulletin Index D6-30300 Part 3 for Airplane Variable Number, Line Number, and Serial Number data. This service bulletin is for the airplane(s) shown below. Refer to PRR 85901-117RS for data about this change.

**DESCRIPTION CONFIGURATION**  **GROUP** 747-400 passenger and freighter airplanes that have a two piece aft MEC drip shield gutter - 1

Airplane Models: 747-400, 747-400D, 747-400F **Group Variable Number**  1 RF001 - RF006 1 RL401 - RL402 1 RL411 - RL418 1 RL651 - RL654 1 RM001 - RM007

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 9 of 39**Group Variable Number**  1 RM010 - RM013 1 RM021 - RM024 1 RM026 - RM030 1 RM036 - RM045 1 RM051 - RM053 1 RM071 1 RM081 - RM084 1 RM091 1 RM096 - RM097 1 RM116 - RM117 1 RM126 - RM127 1 RM129 - RM132 1 RM136 - RM147 1 RM156 - RM158 1 RM166 - RM177 1 RM191 - RM192 1 RM231 - RM233 1 RM241 - RM246 1 RM261 - RM264 1 RM316 - RM318 1 RM331 - RM333 1 RM341 1 RM351 - RM355 1 RM366 - RM367 1 RM401 - RM403 1 RM426 1 RM431 1 RM801 - RM803 1 RM811 - RM813 1 RM851 - RM858 1 RM861 1 RM871 - RM876 1 RM881 - RM886

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 10 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT Group**  **Variable Number** 1 RM891 - RM899 1 RM901 - RM903 1 RM911 1 RR701 1 RR721 - RR724 1 RR746 - RR748 1 RR851 - RR856 1 RR861 - RR862 1 RR951 - RR952 1 RT001 - RT014 1 RT034 - RT035 1 RT041 - RT047 1 RT073 - RT074 1 RT101 - RT103 1 RT121 1 RT131 - RT137 1 RT151 - RT152 1 RT162 - RT163 1 RT165 - RT168 1 RT401 - RT412 1 RT431 - RT447 1 RT452 - RT455 1 RT457 - RT460 1 RT462 - RT469 1 RT471 - RT499 1 RT502 - RT505 1 RT511 - RT512 1 RT514 - RT515 1 RT517 1 RT521 - RT523 1 RT525 1 RT527 1 RT529

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 11 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT Group**  **Variable Number** 1 RT531 - RT535 1 RT551 - RT568 1 RT571 1 RT580 - RT591 1 RT601 - RT614 1 RT616 - RT630 1 RT633 - RT634 1 RT636 - RT641 1 RT643 - RT654 1 RT672 - RT673 1 RT681 - RT682 1 RT691 - RT699 1 RT701 - RT704 1 RT711 - RT717 1 RT741 1 RT744 - RT750 1 RT753 - RT757 1 RT776 - RT777 1 RT783 - RT784 1 RT801 - RT803 1 RT811 - RT814 1 RT831 - RT835 1 RT861 - RT864 1 RT877 - RT880 1 RT931 - RT932 1 RT945 - RT949 1 RT951 - RT955 1 RT966 1 RU002 - RU006 1 RU016 - RU017 1 RU031 - RU032 1 RU051 - RU052 1 RU059 - RU062

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 12 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT Group**  **Variable Number** 1 RU081 - RU083 1 RU101 - RU102 1 RU121 - RU132 1 RU803 1 RU805 1 RU808 - RU809 1 RU831 1 RU833 - RU841 2. Spares Affected None. **B. Concurrent Requirements** None. **C. Reason** This service bulletin will reduce the possibility of water penetration into the main equipment center (MEC). Disbonded aft MEC drip shield gutters have allowed water to drip past the MEC drip shield and into the Wire Integration Units (WIU). Water penetration into the WIUs could result in loss of flight critical systems. An operator experienced water leaking from main deck cargo into the WIU. It flowed from the drip shield through disbonded floor seams into the aft MEC drip shield gutter, then onto the WIU Liquids can leak through the MEC drip shield due to disbonded aft MEC drip shield gutters resulting in water intrusion into the WIU of the MEC. Disbonding can occur due to improper preparation of the drip shield/gutter material, aging of materials, and/or poor workmanship. This Service Bulletin does a general visual inspection of the aft MEC drip shield gutters for disbonded seams, and repairs them if necessary. A reinforcing layer of fiberglass is applied over the seam in the aft MEC drip shield gutter to ensure no future disbondments occur. Boeing Service Related Problem (SRP) 747-SRP-25-0304 is related to this service bulletin **D. Description** - Do a general visual inspection of the aft MEC drip shield gutters for disbonded seam, and repair if necessary. - Add fiberglass reinforcement to aft MEC drip shield gutters. The work in this service bulletin is done in the maintenance zone(s) given below.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 13 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT Affected Maintenance Zones**  **Zone Model**  117, 118 747-400, 747-400D, 747-400F **E. Compliance** The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. Boeing recommends that the inspection, change and/or repair given in this service bulletin be done within 24 months after the original issue date of this service bulletin. **F. Approval** This service bulletin was examined by the Federal Aviation Administration (FAA). The changes specified in this service bulletin comply with the applicable regulations and are FAA approved, as well as European Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved airplanes listed in the service bulletin effectivity. This service bulletin and its approval were based on the airplane in its original Boeing delivery configuration or as modified by other approved Boeing changes. If an airplane has a non-Boeing modification or repair that affects a component or system also affected by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval before incorporating this service bulletin. **G. Manpower** The table below shows an estimate of the task hours necessary to do this 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: • Time to adjust to the workplace • Time to schedule the work • Time to inspect the work • Time to cure the materials • Time to make the parts • Time to find the tools. **Elapsed Hours Task Hours**  **Number of Persons Task**  0.25 0.25 1 Open Access 2.25 4.50 2 Figure 1 0.75 0.75 1 Figure 2 0.05 (a) 0.05 (a) 1 Figure 3 0.40 0.40 1 Figure 4 2.25 4.50 2 Figure 5

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 14 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT Elapsed Hours**  **Task Hours Number of Persons**  **Task** 0.25 0.25 1 Close Access 6.15 10.65 TOTAL FOR EACH AIRPLANE **H. Weight and Balance Changes** None. **I. Electrical Load Data** Not changed. **J. References** 1. Existing Data: a. Engineering Change Memo PRR 85901-117RS b. Boeing Service Related Problem (SRP) 747-SRP-25-0304 c. Service Bulletin Index D6-30300 d. Standard Overhaul Practices Manual (SOPM) 20-30-03, 20-50-12 e. 747-400 Structural Repair Manual (SRM) 51-70-06 2. Data Supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin: None. **K. Publications Affected** 1. Publications: None. 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 does not affect FCS, therefore DTIs are not necessary. **L. Interchangeability and Intermixability of Parts** Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 15 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT M. Software Accomplishment Summary**  Not affected.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 16 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT 2. MATERIAL INFORMATION**  **A. Material - Price and Availability** The operator can supply the parts and materials shown in Paragraph 2.C., Parts Necessary for Each Airplane. As an alternative, operators can purchase the parts from Boeing Spares. This service bulletin does not show the Boeing price and supply data. **B. Industry Support Information** Boeing warranty remedies are not available for the 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** (a) ADHESIVE 1 Qt BMS 5-92, Any Type (a) SEALANT 1 Qt BMS 5-95, Type I, Class B (a) FIBERGLASS CLOTH 1 Roll BMS 9-3, Type H, H-2, or H-3, Class 7 (a) EPOXY RESIN 1 Qt BMS 8-201, Type III or Type IV RIVET 48 NAS1398D5-5 (a) Refer to the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data.
3. Parts Modified and Reidentified None. 4. Parts Removed and Not Replaced None. **D. Parts Necessary to Change Spares** None.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 17 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT E. Special Tooling - Price and Availability**  None. **F. Special Tooling Necessary to do this Service Bulletin** No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 18 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT 3. ACCOMPLISHMENT INSTRUCTIONS**  **A. GENERAL INFORMATION CAUTION:**  KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL, METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR OTHER ELECTRICAL DAMAGE. **NOTE:** 1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 2. Obey all of the warnings and cautions given in the specified manual sections. 3. Unless shown differently, these dimensions and tolerances are used: – Linear dimensions are in inches – Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus or minus 0.03 inch – Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch – Hole dimensions for standard solid rivets and fasteners are in Structural Repair Manual (SRM) Chapter 51 – Torque limits to tighten nuts and bolts are in SRM Chapter 51 4. Use the approved fastener and process material substitutions in accordance with SRM Chapter 51. 5. If the length of any fastener specified in this service bulletin does not meet installation standards given in SRM Chapter 51, then a fastener of the same specification, or an approved substitute, with a length which meets the installation standards given in SRM Chapter 51 may be used. In addition, washers may be installed for fastener grip length in accordance with SRM Chapter 51. 6. A General Visual Inspection is defined as: A visual examination of an interior or exterior area, installation or assembly to detect obvious damage, failure or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight or drop-light and may require removal or opening of access panels or doors. Stands, ladders or platforms may be required to gain proximity to the area being checked. 7. These work instructions refer to procedures included in other Boeing documents. When the words "refer to" are used and the operator has an accepted alternative procedure, the accepted alternative procedure can be used. When the words "in accordance with" are included in the instruction, the procedure in the Boeing document must be used. 8. If it is necessary to remove more parts for access, you can remove those parts. If you can get access without removing identified parts, it is not necessary to remove all of the identified parts. Jacking and shoring limitations must be observed.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 19 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT**9. Where the work instructions include installation of a kept part, a new or serviceable part with the same part number can be installed as an alternative to the kept part. 10. Shaded areas in Figures are reference only. Shaded areas in Figures may look different than your airplane. **B. WORK INSTRUCTIONS** 1. Remove cargo liner support in accordance with Figure 1. 2. Clean the aft MEC drip shield gutter and do a general visual inspection for seam disbondment in accordance with Figure 2. a. If any seam disbondment is found, repair seam in accordance with Figure 3. b. If no seam disbondment is found, proceed to step 3. 3. Install aft MEC drip shield gutter reinforcement in accordance with Figure 4. 4. Install cargo liner support in accordance with Figure 5. 5. Put the airplane back to a serviceable condition.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 20 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT FIGURE 1: CARGO LINER SUPPORT REMOVAL**  **(SHEET 1 OF 4)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 21 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT FIGURE 1: CARGO LINER SUPPORT REMOVAL**  **(SHEET 2 OF 4)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 22 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for this figure.

**FIGURE 1: CARGO LINER SUPPORT REMOVAL (SHEET 3 OF 4)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 23 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT More Data**  **Qty Identification**  **Name Task**  **Step** 4
- FASTENERS Remove / Keep 1 1
- SPLICE PLATE Remove / Keep 2 4
- FASTENERS Remove / Keep 3 1
- SPLICE PLATE Remove / Keep 4 4
- FASTENERS Remove / Keep 5 1
- SPLICE PLATE Remove / Keep 6 15
- FASTENERS Remove / Keep 7 1
- LINER SUPPORT AS- SY Remove / Keep 8
15
- FASTENERS Remove / Keep 9 1
- LINER SUPPORT AS- SY Remove / Keep 10

4
- FASTENERS Remove / Keep 11 1
- SPLICE PLATE Remove / Keep 12 39
- FASTENERS Remove / Keep 13 1
- LINER SUPPORT AS- SY Remove / Keep 14
39
- FASTENERS Remove / Keep 15 1
- LINER SUPPORT AS- SY Remove / Keep 16

**FIGURE 1: CARGO LINER SUPPORT REMOVAL (SHEET 4 OF 4)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 24 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT FIGURE 2: AFT MEC DRIP SHIELD GUTTER CLEANING AND PREPARATION FOR GENERAL VISUAL**  **INSPECTION (SHEET 1 OF 4)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 25 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT FIGURE 2: AFT MEC DRIP SHIELD GUTTER CLEANING AND PREPARATION FOR GENERAL VISUAL**  **INSPECTION (SHEET 2 OF 4)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 26 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for this figure.
**More Data Qty**  **Identification Name**  **Task Step**  Solvent clean, refer to SOPM 20-30-03as an accepted procedure.(a) - - MEC DRIP SHIELD Clean 1

Carefully removeany loose old adhesive without causing further damage to MEC drip shield.(a) - BMS 5-92 ADHESIVE Remove 2

**FIGURE 2: AFT MEC DRIP SHIELD GUTTER CLEANING AND PREPARATION FOR GENERAL VISUAL INSPECTION**  **(SHEET 3 OF 4)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 27 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT More Data**  **Qty Identification**  **Name Task**  **Step** Solvent clean, refer to SOPM 20-30-03as an accepted procedure.(a) - - MEC DRIP SHIELD Clean 3

Abrasive clean, refer to SOPM 20-30-03as an accepted procedure.(a) - - MEC DRIP SHIELD Clean 4

Solvent clean, refer to SOPM 20-30-03as an accepted procedure.(a) - - MEC DRIP SHIELD Clean 5

Do a general visual inspection of the aftMEC drip shield gutters for disbonded seams. - - MEC DRIP SHIELD Inspect 6

(a) Cleaning and preparation of the aft MEC drip shield gutters should extend a minimum 2" on either side of the seams.

**FIGURE 2: AFT MEC DRIP SHIELD GUTTER CLEANING AND PREPARATION FOR GENERAL VISUAL INSPECTION**  **(SHEET 4 OF 4)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 28 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT FIGURE 3: AFT MEC DRIP SHIELD GUTTER REPAIR**  **(SHEET 1 OF 3)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 29 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for this figure.

**FIGURE 3: AFT MEC DRIP SHIELD GUTTER REPAIR (SHEET 2 OF 3)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 30 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT More Data**  **Qty Identification**  **Name Task**  **Step** Bond the aft MEC drip shield gutter seam using BMS 5- 92. Refer to SOPM 20-50-12, Type 70as an accepted procedure. - BMS 5-92 ADHESIVE Apply 1

**FIGURE 3: AFT MEC DRIP SHIELD GUTTER REPAIR (SHEET 3 OF 3)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 31 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT FIGURE 4: AFT MEC DRIP SHIELD GUTTER REINFORCEMENT**  **(SHEET 1 OF 4)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 32 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT FIGURE 4: AFT MEC DRIP SHIELD GUTTER REINFORCEMENT**  **(SHEET 2 OF 4)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 33 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for this figure.
**More Data Qty**  **Identification Name**  **Task Step**  (a)

- BMS 9-3, TYPE H, H-2, OR H-3, CLASS 7 FIBERGLASS CLOTH Cut 1 (b)

- BMS 8-201 EPOXY RESIN Prepare 2

**FIGURE 4: AFT MEC DRIP SHIELD GUTTER REINFORCEMENT (SHEET 3 OF 4)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 34 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT More Data**  **Qty Identification**  **Name Task**  **Step** (c)

- BMS 9-3, TYPE H, H-2, OR H-3, CLASS 7 FIBERGLASS CLOTH Install (New) 3 Bond using BMS 8- 201, Type III or Type IV. Refer to 747-400 SRM 51-70-06 as an accepted procedure. Vacuum bagging is not required. - BMS 8-201 EPOXY RESIN Apply

(a) Cut fiberglass cloth to overlay the aft MEC drip shield gutter seam in sections as required. Two plies will be required. All sections of fiberglass cloth shall overlap 2 inch minimum. (b) Prepare epoxy resin in sufficient quantity. Work in small batches consistent with working life of resin. Apply mixed epoxy resin and fiberglass cloth using squeegee or similar tool. (c) Install the prepared BMS 9-3 fiberglass impregnated fabric to the underside of the bonded seams. Place edge of impregnated fabric 0.40-0.60 inch forward from edge of re-bonded seam and extend upward and aft over seam gutter.

**FIGURE 4: AFT MEC DRIP SHIELD GUTTER REINFORCEMENT (SHEET 4 OF 4)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 35 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT FIGURE 5: CARGO LINER SUPPORT INSTALLATION**  **(SHEET 1 OF 4)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 36 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT FIGURE 5: CARGO LINER SUPPORT INSTALLATION**  **(SHEET 2 OF 4)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 37 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for this figure.

**FIGURE 5: CARGO LINER SUPPORT INSTALLATION (SHEET 3 OF 4)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 38 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT More Data**  **Qty Identification**  **Name Task**  **Step** 1
- LINER SUPPORT AS- SY Install (Kept) 1
15
- FASTENERS Install (Kept) 2 1
- LINER SUPPORT AS- SY Install (Kept) 3
15
- FASTENERS Install (Kept) 4 1
- SPLICE PLATE Install (Kept) 5 4
- FASTENERS Install (Kept) 6 1
- SPLICE PLATE Install (Kept) 7 4
- FASTENERS Install (Kept) 8 1
- SPLICE PLATE Install (Kept) 9 4
- FASTENERS Install (Kept) 10 1
- LINER SUPPORT AS- SY Install (Kept) 11
15
- FASTENERS Install (Kept) 12 1
- LINER SUPPORT AS- SY Install (Kept) 13
15
- FASTENERS Install (Kept) 14 24 NAS1398D5-5 RIVET Install (New) 15 24 NAS1398D5-5 RIVET Install (New) 16 1
- SPLICE PLATE Install (Kept) 17 4
- FASTENERS Install (Kept) 18

**FIGURE 5: CARGO LINER SUPPORT INSTALLATION (SHEET 4 OF 4)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 22, 2012 747-25A3613 39 of 39 **BOEING SERVICE BULLETIN 747-25A3613 ALERT**  **ALERT**