### Commercial **Airplanes** 

# 747 Service Bulletin **ALERT Number: 747-27A2506**  Original Issue: February 03, 2014 ATA System: 2709 **SUBJECT:** FLIGHT CONTROLS - Flight Controls Electronics - Lateral Control Electronic Module Replacement 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 © 2014 Boeing. Unpublished Work. All Rights Reserved. Treatment of this document and its content is governed by contract with Boeing. Rights to use this document are licensed on a per aircraft basis and such rights may not be transferable. For more information, contact The Boeing Company. Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner, BBJ, DC-8, DC-9, DC-10, KC-10, KC-46, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8, Poseidon and Boeing liveries are all trademarks owned by The Boeing Company; and no trademark license is granted in connection with this document unless provided in writing by Boeing.

Original Issue: February 03, 2014 747-27A2506 1 of 18 3.0Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 03, 2014 747-27A2506 2 of 18 **BOEING SERVICE BULLETIN 747-27A2506 ALERT**  **ALERT**

BLANK PAGE**Table of Contents** Summary...................................................... 5 1. PLANNING INFORMATION ........................................ 9 A. Effectivity................................................ 9 1. Airplanes ............................................. 9 2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2. Data Supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3. Installation Drawings Used in the Preparation of this Service Bulletin:. . . . . . . . . . . 13 K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 M. Software Accomplishment Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 C. Parts Necessary for Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 1. Kits/Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2. Parts and Materials Supplied by the Operator . . . . . . . . . . . . . . . . . . . . . . . . 15 3. Parts Modified and Reidentified. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 4. Parts Removed and Not Replaced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 16 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 03, 2014 747-27A2506 3 of 18 **BOEING SERVICE BULLETIN 747-27A2506 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 03, 2014 747-27A2506 4 of 18 **BOEING SERVICE BULLETIN 747-27A2506 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 747 Service Bulletin **ALERT Summary**  **Number: 747-27A2506** Original Issue: February 03, 2014 ATA System: 2709 **SUBJECT:** FLIGHT CONTROLS - Flight Controls Electronics - Lateral Control Electronic Module 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 provides instructions to replace the existing Lateral Control Electronic (LCE) modules with new LCE modules with revised software. There are two (2) LCE modules that each operate six (6) spoiler Power Control Units (PCUs) and two (2) outboard aileron PCUs. If the existing LCE modules are not replaced, there is a possibility for divergent flutter or unacceptable vibration for certain parts of the flight envelope. Divergent flutter could result in loss of controllability of the airplane. Boeing observed an airplane had experienced a large 2.3 Hertz (Hz) vibration during a steady turn at 1.8 g-force (g) load factor during developmental flight testing. Boeing determined that the solution to this problem should be extended to all 747-8 and 747-8F airplanes. No operators have reported any divergent flutter or unacceptable vibration in service. The existing LCE modules have a control system architecture that allows symmetric outboard spoiler (positions 1 or 2 and 11 or 12) deflections more than six (6) degrees. Deflections above six (6) degrees can adversely affect the airplane flutter stability during high g maneuvers in certain parts of the flight envelope. The new LCE modules have a control system architecture that will limit the symmetric outboard spoiler deflections to six (6) degrees. Additional changes were made to increase the LCE module's capabilities and decrease nuisance messages during electrical power transitions. Boeing Service Related Problem (SRP) 747-8-SRP-27-0234 is related to this service bulletin. Boeing Fleet Team Digest (FTD) 747 FTD 27-13008 is related to this service bulletin. This table is provided to operators for planning purposes only. Refer to the applicable sections for more information.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 03, 2014 747-27A2506 5 of 18**Reference Affected**  **Planning Data** Paragraph 1.A.2., Spares Affected Yes Spares Affected Paragraph 1.E., Compliance and Paragraph 1.F., Approval Yes AD Related Paragraph 1.H., Weight and Balance Changes No Weight and Balance Change Paragraph 1.I., Electrical Load Data No Electrical Load Changed Paragraph 1.K., Publications Affected Yes Publications Affected Paragraph 1.K., Publications Affected No Airplane Flight Operations Affected (Flight CrewOperations Manual and/or FAA Approved Airplane Flight Manual) Paragraph 2.C.1., Kits/Parts No Kits/Parts Required Paragraph 2.C.2., Parts and Materials Supplied by the Operator Yes Operator Supplied Parts/Material Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin No Special Tooling Required

**ACTION (PRR 86601-2)** 1. Open access to the Main Equipment Center (MEC). 2. Remove the two (2) LCE modules. 3. Adjust the polarization post of the electrical connectors on the E1-2 and E2-2 shelves. 4. Change the part number on each changed electrical connector. 5. Install the new LCE modules, part number CA49253-003. 6. Do the LCE module operational test. 7. Close access to the MEC. 8. Put the airplane back to a serviceable condition. **EFFECTIVITY** 747-8 and 747-8F Airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes. **COMPLIANCE** The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. Boeing recommends that the change given in this service bulletin be done within 12 months after the original issue date of this service bulletin.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 03, 2014 747-27A2506 6 of 18 **BOEING SERVICE BULLETIN 747-27A2506 ALERT**  **ALERT INDUSTRY SUPPORT INFORMATION**  Boeing warranty remedies are available for airplanes in warranty as of July 11, 2011. Please refer to Paragraph 2.B., Industry Support Information. The warranty remedies will expire eight years from the original issue date of this service bulletin. **MANPOWER** Refer to Paragraph 1.G., Manpower. **MATERIAL INFORMATION** Boeing Supplied Kits/Parts. 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: February 03, 2014 747-27A2506 7 of 18 **BOEING SERVICE BULLETIN 747-27A2506 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 03, 2014 747-27A2506 8 of 18 **BOEING SERVICE BULLETIN 747-27A2506 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 747 Service Bulletin **ALERT Number: 747-27A2506**  Original Issue: February 03, 2014 ATA System: 2709 **SUBJECT:** FLIGHT CONTROLS - Flight Controls Electronics - Lateral Control Electronic Module 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 airplane(s) shown below. An equivalent change is on subsequent production airplanes. Refer to PRR 86601-2 for data about this change. Refer to Service Bulletin Index D6-30300 Part 3 for Airplane Variable Number, Line Number, and Serial Number data. **NOTE:** Variable numbers for airplanes scheduled to be delivered more than a year after the Original Issue date of this service bulletin are not listed in the table below. MyBoeingFleet (MBF) will show current listing of the affected airplanes. **NOTE:** This service bulletin is for the airplanes shown in the effectivity list below. The effectivity list includes all affected airplanes scheduled to be delivered before DEC 02, 2014. In addition, at least one airplane scheduled to be delivered after DEC 02, 2014 is affected by this service bulletin and is in Group(s) 1 as described in the Group Configuration table. Affected airplanes will be added to the service bulletin's MyBoeingFleet.com (MBF) "get effectivity" result when they are added to the MBF Fleet Profile Page.
**DESCRIPTION CONFIGURATION**  **GROUP** 747-8 and 747-8F airplanes, lines numbers 1420 through 1434, and 1436 through 1491 - 1

Airplane Models: 747-8, 747-8F

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 03, 2014 747-27A2506 9 of 18**Group Variable Number**  1 RC001 - RC008 1 RC022 - RC030 1 RC501 - RC511 1 RC521 - RC528 1 RC541 1 RC546 - RC549 1 RC551 - RC563 1 RC571 - RC572 1 RC574 - RC582 1 RC601 - RC605 2. Spares Affected Examine your spares supply for the parts or components identified below. If any parts or components are found, refer to Paragraph 2.C.2., Parts and Materials Supplied by the Operator, for the recommended action.
**Part Number** CA49253-001 CA49253-002 **B. Concurrent Requirements** None. **C. Reason** This service bulletin provides instructions to replace the existing Lateral Control Electronic (LCE) modules with new LCE modules with revised software. There are two (2) LCE modules that each operate six (6) spoiler Power Control Units (PCUs) and two (2) outboard aileron PCUs. If the existing LCE modules are not replaced, there is a possibility for divergent flutter or unacceptable vibration for certain parts of the flight envelope. Divergent flutter could result in loss of controllability of the airplane. Boeing observed an airplane had experienced a large 2.3 Hertz (Hz) vibration during a steady turn at 1.8 g-force (g) load factor during developmental flight testing. Boeing determined that the solution to this problem should be extended to all 747-8 and 747-8F airplanes. No operators have reported any divergent flutter or unacceptable vibration in service. The existing LCE modules have a control system architecture that allows symmetric outboard spoiler (positions 1 or 2 and 11 or 12) deflections more than six (6) degrees. Deflections above six (6) degrees can adversely affect the airplane flutter stability during high g maneuvers in certain parts of the flight envelope.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 03, 2014 747-27A2506 10 of 18 **BOEING SERVICE BULLETIN 747-27A2506 ALERT**  **ALERT**The new LCE modules have a control system architecture that will limit the symmetric outboard spoiler deflections to six (6) degrees. Additional changes were made to increase the LCE module's capabilities and decrease nuisance messages during electrical power transitions. Boeing Service Related Problem (SRP) 747-8-SRP-27-0234 is related to this service bulletin. Boeing Fleet Team Digest (FTD) 747 FTD 27-13008 is related to this service bulletin. **D. Description** 1. Open access to the Main Equipment Center (MEC). 2. Remove the two (2) LCE modules. 3. Adjust the polarization post of the electrical connectors on the E1-2 and E2-2 shelves. 4. Change the part number on each changed electrical connector. 5. Install the new LCE modules, part number CA49253-003. 6. Do the LCE module operational test. 7. Close access to the MEC. 8. Put the airplane back to a serviceable condition. The work in this service bulletin is done in the maintenance zone(s) given below.
**Affected Maintenance Zones Zone**  **Model** 117, 118 747-8, 747-8F **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 replacement given in this service bulletin be done within 12 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.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 03, 2014 747-27A2506 11 of 18 **BOEING SERVICE BULLETIN 747-27A2506 ALERT**  **ALERT**If an airplane has a non-Boeing modification or repair that affects a component or system also affected by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval before incorporating this service bulletin. **G. Manpower** The table below shows an estimate of the task hours necessary to do 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**  1.00 1.00 1 Open Access 0.50 0.50 1 Install 1.00 1.00 1 Close Access 1.25 1.25 1 Test 3.75 3.75 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 86601-2 b. Boeing Service Related Problem (SRP) 747-8-SRP-27-0234 c. Service Bulletin Index D6-30300 d. Standard Wiring Practices Manual (SWPM) 20-71-14 e. 747 Fleet Team Digest (FTD) 27-13008 f. 747-8 Aircraft Maintenance Manual (AMM) 27-09-01

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 03, 2014 747-27A2506 12 of 18 **BOEING SERVICE BULLETIN 747-27A2506 ALERT**  **ALERT**g. Moog Service Bulletin CA49253-27-02 2. Data Supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin:
**Title Drawing Number**  EQUIPMENT INSTL - E1/E2 RACK, ELEX EQUIP CTR 284U1800 The table above lists applicable drawings used to prepare this service bulletin. The drawings are not necessary to make the specified changes, and are not supplied with this service bulletin. The drawings may not be applicable to all airplane configurations or operators. **K. Publications Affected** 1. Publications: **Chapter-Section Publication**  27-09 747 Illustrated Parts Catalog 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** Refer to Paragraph 2.C., Parts Necessary for Each Airplane, for interchangeability and intermixability information. **M. Software Accomplishment Summary** Not affected.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 03, 2014 747-27A2506 13 of 18 **BOEING SERVICE BULLETIN 747-27A2506 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 03, 2014 747-27A2506 14 of 18 **BOEING SERVICE BULLETIN 747-27A2506 ALERT**  **ALERT**

BLANK PAGE**2. MATERIAL INFORMATION A. Material - Price and Availability**  The operator can supply the parts and materials shown in Paragraph 2.C., Parts Necessary for Each Airplane. As an alternative, operators can purchase the parts from Boeing Spares. This service bulletin does not show the Boeing price and supply data. **B. Industry Support Information** Boeing warranty remedies are available for 747 airplanes in warranty as of July 11, 2011. For task hour and material reimbursement for airplanes in warranty as of that date, send a warranty claim to Boeing Warranty & Product Assurance Contracts. The warranty remedies will expire eight years from the original issue date of this service bulletin. **C. Parts Necessary for Each Airplane** 1. Kits/Parts None. 2. Parts and Materials Supplied by the Operator The following parts or materials are necessary to do the change in this service bulletin. Parts and materials in the manuals given in Paragraph 1.J., References, can also be necessary. Examine operator part and material supply to make sure all necessary parts and materials are available.
**Notes Existing Part Number**  **Name QTY**  **Part Number / Specification**  (a) (b) (c) (d) CA49253-002 or CA49253-001 Lateral Control Electronic (LCE) Module 2 CA49253-003 (a) Moog SB CA49253-27-02 provides instructions to change the existing LCE module to the new LCE module. (b) This part is used in production. (c) You cannot use the existing part to replace the new or changed part. (d) Moog Aircraft Group (CAGE Code 0ZWK8), Seneca & Jamison Roads, Plant 24, East Aurora NY 14052 USA
3. Parts Modified and Reidentified
**Notes New Part Number**  **Name QTY**  **Existing Part Number** (a) (b) (c) BACC66H33F42AA01 Electrical Connector 2 BACC66H33F38AA01 (a) Make the change in accordance with this service bulletin. (b) This is the part number after the change is done in accordance with this service bulletin. (c) This part is used in production.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 03, 2014 747-27A2506 15 of 18 **BOEING SERVICE BULLETIN 747-27A2506 ALERT**  **ALERT**4. Parts Removed and Not Replaced None. **D. Parts Necessary to Change Spares** None. **E. Special Tooling - Price and Availability** None. **F. Special Tooling Necessary to do this Service Bulletin** No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 03, 2014 747-27A2506 16 of 18 **BOEING SERVICE BULLETIN 747-27A2506 ALERT**  **ALERT 3. ACCOMPLISHMENT INSTRUCTIONS**  **A. GENERAL INFORMATION NOTE:**  1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 2. Obey all of the warnings and cautions given in the specified manual sections. 3. Unless shown differently, these dimensions and tolerances are used: – Linear dimensions are in inches – Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus or minus 0.03 inch – Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch – Angular tolerance is plus or minus 2 degrees – Hole dimensions for standard solid rivets and fasteners are in Structural Repair Manual (SRM) Chapter 51 – Torque Values: — Values for structural fasteners are given in 747 Structural Repair Manual, Chapter 51. — Values for airframe maintenance tasks are included in Chapter 20 of 747 Airplane Maintenance Manual (AMM). — Values for electrical maintenance tasks are included in Chapter 20 of Standard Wiring Practices Manual (SWPM). — Values for engine maintenance tasks are included in Chapter 70 of 747 Airplane Maintenance Manual (AMM). — Non-standard torque values for maintenance tasks are included in the applicable installation step.
4. 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. 5. 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. 6. 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. 7. This service bulletin includes functional test procedures for the systems changed by this service bulletin. More functional tests can possibly be necessary in accordance with standard maintenance practices because of interruption to other airplane systems. 8. If shading is used, shaded areas in Figures are to separate the non-critical and non-authoritative information from the critical and authoritative information. 9. The compliance times for the actions in Paragraph 3.B., WORK INSTRUCTIONS are in Paragraph 1.E., Compliance.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 03, 2014 747-27A2506 17 of 18 **BOEING SERVICE BULLETIN 747-27A2506 ALERT**  **ALERT**10. Some steps in the Work Instructions are identified as Required for Compliance (RC). If this service bulletin is mandated by an Airworthiness Directive (AD), then the steps identified as RC must be done to comply with the AD. Alternative procedures for steps not identified with RC can be used if the RC steps can still be done as specified, and the airplane can be put back in a serviceable condition. An Alternative Method of Compliance (AMOC) is not necessary for deviations to steps that are not identified as RC. **B. WORK INSTRUCTIONS** 1. Open access to the E1-2 and E2-2 shelves in the Main Equipment Center (MEC). 2. RC - Remove the two (2) Lateral Control Electronic (LCE) modules from the E1-2 and E2-2 shelves in the MEC. Refer to 747-8 AMM 27-09-01 as an accepted procedure. **NOTE:** The equipment number locations on the shelves are M14704 (E1-2) located on the left side and M14703 (E2-2) located on the right side. 3. RC - On the E1-2 and E2-2 shelves, adjust the polarization post on the electrical connectors to Polarization Code 42. Refer to SWPM 20-71-14 as an accepted procedure. **NOTE:** Once this step is completed, only LCE module part number CA49253-003 can be installed on the E1-2 and E2-2 shelves. 4. Change the part number of each electrical connector to BACC66H33F42AA01. Refer to SWPM 20-71-14 as an accepted procedure. 5. RC - Install two (2) new LCE modules, part number CA49253-003, on the E1-2 and E2-2 shelves in the MEC. Refer to 747-8 AMM 27-09-01 as an accepted procedure. 6. RC - Do an operational test of the LCE modules. Refer to 747-8 AMM 27-09-01 as an accepted procedure. 7. Close access to the E1-2 and E2-2 shelves in the MEC. 8. Put the airplane back to a serviceable condition.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 03, 2014 747-27A2506 18 of 18 **BOEING SERVICE BULLETIN 747-27A2506 ALERT**  **ALERT**