### Commercial **Airplanes** 

# 737 Service Bulletin **SPECIAL ATTENTION Number: 737-28-1303**  Original Issue: April 26, 2012 ATA System: 2800 **SUBJECT:** FUEL - General - Left Environmental Control Systems Bay Wire Clamp - Inspection and 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 © 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 Unpublished Work.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Original Issue: April 26, 2012 737-28-1303 1 of 33 9.0Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 2 of 33 **BOEING SERVICE BULLETIN 737-28-1303**

BLANK PAGE**Table of Contents** Summary...................................................... 5 1. PLANNING INFORMATION ........................................ 9 A. Effectivity................................................ 9 1. Airplanes............................................. 9 2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 B. Concurrent Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 C. Reason. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 D. Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 I. Electrical Load Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 J. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 2. Data Supplied with this Service Bulletin:. . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3. Installation Drawings Used in the Preparation of this Service Bulletin:. . . . . . . . . . . 17 K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 L. Interchangeability and Intermixability of Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . 17 M. Software Accomplishment Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2. MATERIAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 C. Parts Necessary for Each Airplane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 1. Kits/Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2. Parts and Materials Supplied by the Operator. . . . . . . . . . . . . . . . . . . . . . . . 19 3. Parts Modified and Reidentified. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 4. Parts Removed and Not Replaced. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 20 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 A. GENERAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 FIGURE 1: LEFT SIDE - ENVIRONMENTAL CONTROL SYSTEMS (ECS) BAY - WIRE CLAMP - INSPECTION [Group 1]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 FIGURE 2: LEFT SIDE - ENVIRONMENTAL CONTROL SYSTEMS (ECS) BAY - WIRE CLAMP - INSPECTION [Group 2]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 FIGURE 3: LEFT SIDE - ENVIRONMENTAL CONTROL SYSTEMS (ECS) BAY - WIRE CLAMP - REPLACEMENT [Group 1] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 FIGURE 4: LEFT SIDE - ENVIRONMENTAL CONTROL SYSTEMS (ECS) BAY - WIRE CLAMP - REPLACEMENT [Group 2] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 3 of 33 **BOEING SERVICE BULLETIN 737-28-1303**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 4 of 33 **BOEING SERVICE BULLETIN 737-28-1303**

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### Commercial **Airplanes** 

# 737 Service Bulletin **SPECIAL ATTENTION Summary**  **Number: 737-28-1303** Original Issue: April 26, 2012 ATA System: 2800 **SUBJECT:** FUEL - General - Left Environmental Control Systems Bay Wire Clamp - Inspection and Replacement BOEING RECOMMENDS THAT EACH OPERATOR EXAMINE THIS SERVICE BULLETIN IMMEDIATELY. **CONCURRENT REQUIREMENTS** None. **BACKGROUND** This service bulletin gives instructions to inspect and replace incorrect wire bundle clamp(s) installed on a wire bundle in the left Environmental Control Systems (ECS) bay. A fully cushioned clamp should be installed to prevent potential conductor to clamp short circuits. If this service bulletin is not done, conductor to clamp short circuits could produce arcing from a hot short and introduce a potential ignition source in the center wing tank and a subsequent fire or explosion. During a drawing review, Boeing found that some callouts for the fully cushioned wire bundle clamp were accidentally left out from the production drawings in the left ECS bay. This could lead to the installation of an incorrect clamp. It was found that the incorrect clamp could be installed at two locations on 737-600 and -700 airplanes and one location on 737-800 and 900ER airplanes. The clamp(s) that should have been installed are fully cushioned and part of the Special Federal Aviation Regulation (SFAR) 88 requirement. The production drawings have now been corrected and airplane line number 3488 and subsequent have the correct clamp(s) installed. Boeing initiated this service bulletin to address this condition. Accomplishment of this service bulletin replaces incorrect wire bundle clamp(s) installed in the left ECS bay with fully cushioned clamp(s). Installation of fully cushioned clamp(s) will prevent an electrical fault current paths to the center wing tank caused by wiring hot shorts. Boeing Service Related Problem (SRP) 737-SRP-28-0136 is related to this service bulletin. Boeing Fleet Team Digest (FTD) 737NG-FTD-28-11001 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 No AD Related

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 5 of 33**Reference Affected**  **Planning Data** 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 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** Get access to the left side ECS bay by opening the ECS bay access door 192CL. Do a Detailed Inspection of the wire clamp installed at specified location(s). If TA0930034-10 clamp has not been installed, remove the clamp and install a TA0930034-10 fully cushioned wire clamp. Close left side ECS bay access door 192CL. **EFFECTIVITY** 737-600/-700/-800/-900ER Airplane(s). 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 and change given in this service bulletin be done within 60 months after the original issue date of this service bulletin. **INDUSTRY SUPPORT INFORMATION** Boeing warranty remedies are available for airplanes in warranty as of June 02, 2011. Please refer to Paragraph 2.B., Industry Support Information. **MANPOWER** Refer to Paragraph 1.G., Manpower. **MATERIAL INFORMATION** Operator Supplied Parts/Materials. Refer to Paragraph 2.A., Material - Price and Availability.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 6 of 33 **BOEING SERVICE BULLETIN 737-28-1303**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 7 of 33 **BOEING SERVICE BULLETIN 737-28-1303**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 8 of 33 **BOEING SERVICE BULLETIN 737-28-1303**

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### Commercial **Airplanes** 

# 737 Service Bulletin **SPECIAL ATTENTION Number: 737-28-1303**  Original Issue: April 26, 2012 ATA System: 2800 **SUBJECT:** FUEL - General - Left Environmental Control Systems Bay Wire Clamp - Inspection and Replacement BOEING RECOMMENDS THAT EACH OPERATOR EXAMINE THIS SERVICE BULLETIN IMMEDIATELY. **1. PLANNING INFORMATION A. Effectivity**  1. Airplanes This service bulletin is for the airplane(s) shown below. Refer to Service Bulletin Index D6-19567 Part 3 for Airplane Variable Number, Line Number, and Serial Number data.
**DESCRIPTION CONFIGURATION**  **GROUP** 737-600/-700 airplanes, line numbers 1820 thru 3487 that could have two incorrect wire bundle clamps installed. - 1
737-800/-900ER airplanes, line numbers 2007 thru 2040 and 2621 thru 3222 that could have one incorrect wire bundle clamp installed. - 2

Airplane Models: 737-600, 737-700, 737-800, 737-900ER **Group Variable Number**  1 YA977 - YA978 1 YB384 - YB392 1 YB575 1 YB578 - YB580 1 YB592 - YB598 1 YB633 - YB635

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 9 of 33**Group Variable Number**  1 YB671 - YB672 1 YB889 - YB893 1 YB964 - YB974 1 YB986 - YB996 2 YC095 2 YC743 2 YD415 - YD416 1 YE374 - YE383 2 YF001 - YF006 2 YF023 - YF039 2 YF046 2 YF052 - YF060 2 YF086 2 YF112 - YF114 2 YF116 - YF117 2 YF121 - YF122 2 YF191 - YF192 2 YF201 - YF241 2 YF401 - YF402 2 YF451 - YF454 2 YF501 - YF570 2 YF701 - YF705 2 YF801 2 YF831 - YF832 2 YF901 - YF902 1 YG094 - YG099 1 YG101 - YG103 1 YG111 - YG114 1 YG116 - YG128 1 YG203 - YG205 1 YG212 - YG214 1 YG221 - YG224 1 YG251 - YG252

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 10 of 33 **BOEING SERVICE BULLETIN 737-28-1303 Group**  **Variable Number** 2 YH011 - YH012 2 YH031 - YH047 2 YH054 - YH055 2 YH111 - YH130 2 YH207 2 YH301 - YH305 2 YH321 - YH322 2 YJ006 2 YJ010 2 YJ554 - YJ556 2 YJ565 - YJ575 2 YJ597 - YJ599 2 YJ874 - YJ880 2 YJ909 - YJ910 2 YK133 2 YK176 - YK177 2 YK186 2 YK191 2 YK196 2 YK201 - YK202 2 YK310 - YK312 2 YK333 2 YK338 - YK340 2 YK375 - YK378 2 YK437 - YK439 2 YK461 - YK465 2 YK471 2 YK486 - YK487 2 YK496 - YK497 2 YK521 - YK529 2 YK563 - YK565 2 YK567 - YK570 2 YK576

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 11 of 33 **BOEING SERVICE BULLETIN 737-28-1303 Group**  **Variable Number** 2 YK580 2 YK615 - YK616 2 YK626 - YK630 2 YK632 2 YK661 - YK664 2 YK671 - YK672 2 YK676 - YK677 2 YK681 - YK686 2 YK691 2 YK713 2 YK722 - YK723 2 YK759 - YK770 2 YK776 - YK778 2 YK885 - YK899 2 YK911 - YK912 2 YK919 2 YK952 - YK956 2 YK961 2 YK972 - YK980 2 YK985 - YK992 2 YL005 2 YL115 - YL130 2 YL208 - YL218 2 YL283 - YL284 2 YL320 - YL321 2 YL351 - YL353 2 YL374 2 YL401 2 YL427 - YL429 2 YL438 - YL444 2 YL473 - YL478 2 YL506 - YL509 2 YL534

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 12 of 33 **BOEING SERVICE BULLETIN 737-28-1303 Group**  **Variable Number** 2 YL541 - YL544 2 YL562 - YL568 2 YL592 2 YL611 - YL612 2 YL616 - YL617 2 YL621 2 YL626 2 YL631 - YL633 2 YL662 - YL664 2 YL676 - YL681 2 YL691 2 YL701 - YL702 2 YL731 2 YL751 - YL752 2 YL761 - YL769 2 YL801 - YL809 2 YL905 - YL910 2 YL921 - YL930 2 YL933 - YL936 2 YL951 - YL960 1 YM206 - YM242 1 YM273 - YM299 1 YM301 - YM397 1 YM506 - YM515 1 YM553 1 YM581 - YM582 1 YM591 - YM599 1 YM631 - YM634 1 YM641 - YM652 1 YM671 - YM674 1 YM691 - YM698 1 YM701 - YM710 1 YM761 - YM765

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 13 of 33 **BOEING SERVICE BULLETIN 737-28-1303 Group**  **Variable Number** 1 YN002 - YN016 1 YN021 - YN024 1 YN061 1 YN071 - YN082 1 YN091 - YN092 1 YN101 - YN112 1 YN121 1 YN201 - YN202 1 YN211 - YN219 1 YN231 - YN235 1 YN261 2 YQ001 - YQ003 2 YQ011 2. Spares Affected None. **B. Concurrent Requirements** None. **C. Reason** This service bulletin gives instructions to inspect and replace incorrect wire bundle clamp(s) installed on a wire bundle in the left Environmental Control Systems (ECS) bay. A fully cushioned clamp should be installed to prevent potential conductor to clamp short circuits. If this service bulletin is not done, conductor to clamp short circuits could produce arcing from a hot short and introduce a potential ignition source in the center wing tank and a subsequent fire or explosion. During a drawing review, Boeing found that some callouts for the fully cushioned wire bundle clamp were accidentally left out from the production drawings in the left ECS bay. This could lead to the installation of an incorrect clamp. It was found that the incorrect clamp could be installed at two locations on 737-600 and -700 airplanes and one location on 737-800 and 900ER airplanes. The clamp(s) that should have been installed are fully cushioned and part of the Special Federal Aviation Regulation (SFAR) 88 requirement. The production drawings have now been corrected and airplane line number 3488 and subsequent have the correct clamp(s) installed. Boeing initiated this service bulletin to address this condition. Accomplishment of this service bulletin replaces incorrect wire bundle clamp(s) installed in the left ECS bay with fully cushioned clamp(s). Installation of fully cushioned clamp(s) will prevent an electrical fault current paths to the center wing tank caused by wiring hot shorts. Boeing Service Related Problem (SRP) 737-SRP-28-0136 is related to this service bulletin.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 14 of 33 **BOEING SERVICE BULLETIN 737-28-1303**Boeing Fleet Team Digest (FTD) 737NG-FTD-28-11001 is related to this service bulletin. **D. Description** Get access to the left side ECS bay by opening the ECS bay access door 192CL. Do a Detailed Inspection of the wire clamp installed at specified location(s). If TA0930034-10 clamp has not been installed, remove the clamp and install a TA0930034-10 fully cushioned wire clamp. Close left side ECS bay access door 192CL. The work in this service bulletin is done in the maintenance zone(s) given below. **Group 1:**
**Affected Maintenance Zones Zone**  **Model** 192 737-600, 737-700 **Group 2:**
**Affected Maintenance Zones Zone**  **Model** 192 737-800, 737-900ER **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 and change given in this service bulletin be done within 60 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.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 15 of 33 **BOEING SERVICE BULLETIN 737-28-1303 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 inspect the work • Time to cure the materials • Time to make the parts • Time to find the tools. **Group 1: Elapsed Hours**  **Task Hours Number of Persons**  **Task** 0.50 0.50 1 Open Access 0.30 0.30 1 FIGURE 1 2.00 4.00 2 Left Side PrimaryHeat Exchanger Removal 0.40 0.40 1 FIGURE 3 (a) 2.00 4.00 2 Left Side PrimaryHeat Exchanger Installation 0.50 0.50 1 Close Access 5.30 9.30 TOTAL FOR EACH AIRPLANE (b) (a) Estimate does not include time for repair if damage to the wire bundle is found. (b) Estimate is based on correct installation of all wire clamps. **Group 2: Elapsed Hours**  **Task Hours Number of Persons**  **Task** 0.50 0.50 1 Open Access 0.15 0.15 1 FIGURE 2 0.40 0.40 1 FIGURE 4 (a) 0.50 0.50 1 Close Access 1.15 1.15 TOTAL FOR EACH AIRPLANE (b) (a) Estimate does not include time for repair if damage to the wire bundle is found. (b) Estimate is based on correct installation of all wire clamps.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 16 of 33 **BOEING SERVICE BULLETIN 737-28-1303 H. Weight and Balance Changes**  None. **I. Electrical Load Data** Not changed. **J. References** 1. Existing Data: a. Service Bulletin Index D6-19567 b. Standard Wiring Practices Manual (SWPM) 20-10-11, 20-10-12, 20-10-13, 20-10-19 c. 737-600/700/800/900 Aircraft Maintenance Manual (AMM) 06-41-00, 21-51-03 d. Service Related Problem (SRP) 737-SRP-28-0136 e. Fleet Team Digest (FTD) 737-FTD-28-11001 2. Data Supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin:
**Title Drawing Number**  Wire Bundle Instl - Left, A/C Pack Bay and Wing to Body Fairing 288A1139 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: 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: April 26, 2012 737-28-1303 17 of 33 **BOEING SERVICE BULLETIN 737-28-1303 M. Software Accomplishment Summary**  Not affected.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 18 of 33 **BOEING SERVICE BULLETIN 737-28-1303 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 737-600/700/800/900ER airplanes in warranty as of June 02, 2011. For inspection man hour reimbursement for airplanes in warranty as of that date, send a warranty claim to Boeing Commercial Airplanes Group - Warranties. If the condition described in this service bulletin is found during the inspection for airplanes in warranty as of that date and additional man hours and kits, parts, and/or special tools are required, send a warranty claim to Boeing Commercial Airplanes Group - Warranties. Please refer to this service bulletin number and reference the airplane variable number(s) in your purchase order. **C. Parts Necessary for Each Airplane** 1. Kits/Parts None 2. Parts and Materials Supplied by the Operator **Group 1:**
**Notes Name**  **QTY Part Number /**  **Specification** (a) (b) Saddle Clamp 2 TA0930034-10 (a) The Quantity shown is the maximum amount that may be necessary if the inspection shows incorrect clamp installation. (b) Can be procured from TA Aerospace, Kirkhill-TA Division of Esterline Technologies Corporation, (84971), 28065 Franklin Parkway, Valencia, California, 91380-9031. **Group 2:**
**Notes Name**  **QTY Part Number /**  **Specification** (a) (b) Saddle Clamp 1 TA0930034-10 (a) The Quantity shown is the maximum amount that may be necessary if the inspection shows incorrect clamp installation. (b) Can be procured from TA Aerospace, Kirkhill-TA Division of Esterline Technologies Corporation, (84971), 28065 Franklin Parkway, Valencia, California, 91380-9031.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 19 of 33 **BOEING SERVICE BULLETIN 737-28-1303**3. Parts Modified and Reidentified None 4. Parts Removed and Not Replaced None **D. Parts Necessary to Change Spares** None. **E. Special Tooling - Price and Availability** None. **F. Special Tooling Necessary to do this Service Bulletin** No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 20 of 33 **BOEING SERVICE BULLETIN 737-28-1303 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. Use the approved fastener and process material substitutions in accordance with SRM Chapter 51. 4. Refer to the SWPM 20-10-11 and SWPM 20-10-12 for the wire installation procedures, and SWPM 20-10-19 for the wire separation requirements, as accepted procedures. 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 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. 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. The instructions in Paragraph 3.B., Work Instructions and the figures can include operation of tools or test equipment. Boeing Engineering Tool Drawings, the Illustrated Tool and Equipment Manual, and the Special Tool and Ground Handling Drawing Index contain data on versions of the tools or test equipment that you can use. It is permitted to use replaced tools. It is not permitted to use superseded tools. 9. 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. 10. 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.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 21 of 33 **BOEING SERVICE BULLETIN 737-28-1303 B. WORK INSTRUCTIONS**  1. Get access to the left side ECS bay by opening ECS bay access door 192CL. Refer to 737-600/700/800/900 AMM 06-41-00 as an accepted procedure.
2. **Group 1:** Remove the primary heat exchanger to get access to the wire clamps. Refer to 737-600/700/800/900 AMM 21-51-03 as an accepted procedure. 3. Do a Detailed Inspection of the wire bundle to make sure that TA0930034-10 wire clamps are installed in accordance with FIGURE 1 or FIGURE 2:

a. **Group 1:** In accordance with FIGURE 1. (1) If the installed wire clamps are not TA0930034-10, replace wire clamp installation in accordance with FIGURE 3. (2) If the installed wire clamps are TA0930034-10, no more work is necessary. b. **Group 2:** In accordance with FIGURE 2. (1) If the installed wire clamp is not TA0930034-10, replace wire clamp installation in accordance with FIGURE 4. (2) If the installed wire clamp is TA0930034-10, no more work is necessary. 4. **Group 1:** Install the primary heat exchanger. Refer to 737-600/700/800/900 AMM 21-51-03 as an accepted procedure. 5. Close the left side ECS bay access door 192CL. Refer to 737-600/700/800/900 AMM 06-41-00 as an accepted procedure. 6. Put the airplane back in a serviceable condition.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 22 of 33 **BOEING SERVICE BULLETIN 737-28-1303 This Figure applies only to: Group 1.** 

**FIGURE 1: LEFT SIDE - ENVIRONMENTAL CONTROL SYSTEMS (ECS) BAY - WIRE CLAMP - INSPECTION (SHEET 1 OF 3)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 23 of 33 **BOEING SERVICE BULLETIN 737-28-1303 FIGURE 1: LEFT SIDE - ENVIRONMENTAL CONTROL SYSTEMS (ECS) BAY - WIRE CLAMP - INSPECTION**  **(SHEET 2 OF 3)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 24 of 33 **BOEING SERVICE BULLETIN 737-28-1303**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) 2
- Clamp Inspect 1 (a) Do a Detailed Inspection of the clamp to make sure that the flanged cushions completely surrounds the two metal strap sections of the clamp. Inspect to make sure that the P/N of the clamp installed is a TA0930034-10 clamp.

**FIGURE 1: LEFT SIDE - ENVIRONMENTAL CONTROL SYSTEMS (ECS) BAY - WIRE CLAMP - INSPECTION (SHEET 3 OF 3)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 25 of 33 **BOEING SERVICE BULLETIN 737-28-1303 This Figure applies only to: Group 2.** 

**FIGURE 2: LEFT SIDE - ENVIRONMENTAL CONTROL SYSTEMS (ECS) BAY - WIRE CLAMP - INSPECTION (SHEET 1 OF 3)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 26 of 33 **BOEING SERVICE BULLETIN 737-28-1303 FIGURE 2: LEFT SIDE - ENVIRONMENTAL CONTROL SYSTEMS (ECS) BAY - WIRE CLAMP - INSPECTION**  **(SHEET 2 OF 3)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 27 of 33 **BOEING SERVICE BULLETIN 737-28-1303**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for this figure.
**More Data Qty**  **Identification Name**  **Task Step**  (a) 1
- Clamp Inspect 1 (a) Do a Detailed Inspection of the clamp to make sure that the flanged cushions completely surrounds the two metal strap sections of the clamp. Inspect to make sure that the P/N of the clamp installed is a TA0930034-10 clamp.

**FIGURE 2: LEFT SIDE - ENVIRONMENTAL CONTROL SYSTEMS (ECS) BAY - WIRE CLAMP - INSPECTION (SHEET 3 OF 3)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 28 of 33 **BOEING SERVICE BULLETIN 737-28-1303 This Figure applies only to: Group 1.** 

**FIGURE 3: LEFT SIDE - ENVIRONMENTAL CONTROL SYSTEMS (ECS) BAY - WIRE CLAMP - REPLACEMENT**  **(SHEET 1 OF 3)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 29 of 33 **BOEING SERVICE BULLETIN 737-28-1303 FIGURE 3: LEFT SIDE - ENVIRONMENTAL CONTROL SYSTEMS (ECS) BAY - WIRE CLAMP -**  **REPLACEMENT (SHEET 2 OF 3)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 30 of 33 **BOEING SERVICE BULLETIN 737-28-1303**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) 4
- Fasteners Remove / Keep 1

- - Clamp Remove 2 (b) 1
- Wire Bundle Inspect 3 (c) (a) 2 TA0930034-10 Clamp Install (New) 4 (c) (a) 4
- Fastener Install (Kept) 5 (a) The Quantity shown is the maximum amount that is necessary if both clamps must be replaced. (b) Do a Detailed Inspection of the wire bundle for chaffing at the specified clamp locations. If damaged wiresare found, repair damaged wires. Refer to SWPM 20-10-13 as an accepted procedure for damage conditions and repair instructions. (c) Refer to SWPM 20-10-12 as an accepted procedure.

**FIGURE 3: LEFT SIDE - ENVIRONMENTAL CONTROL SYSTEMS (ECS) BAY - WIRE CLAMP - REPLACEMENT**  **(SHEET 3 OF 3)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 31 of 33 **BOEING SERVICE BULLETIN 737-28-1303 This Figure applies only to: Group 2.** 

**FIGURE 4: LEFT SIDE - ENVIRONMENTAL CONTROL SYSTEMS (ECS) BAY - WIRE CLAMP - REPLACEMENT**  **(SHEET 1 OF 2)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 32 of 33 **BOEING SERVICE BULLETIN 737-28-1303**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**  2
- Fastener Remove / Keep 1 1
- Clamp Remove 2 (a)

- - Wire Bundle Inspect 3 (b) 1 TA0930034-10 Clamp Install (New) 4 (b) 2
- Fastener Install (Kept) 5 (a) Do a Detailed Inspection of the wire bundle for chaffing at the specified clamp location. If damaged wiresare found, repair damaged wires. Refer to SWPM 20-10-13 as an accepted procedure for damage conditions and repair instructions. (b) Refer to SWPM 20-10-12 as an accepted procedure.

**FIGURE 4: LEFT SIDE - ENVIRONMENTAL CONTROL SYSTEMS (ECS) BAY - WIRE CLAMP - REPLACEMENT**  **(SHEET 2 OF 2)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 26, 2012 737-28-1303 33 of 33 **BOEING SERVICE BULLETIN 737-28-1303**