### Commercial **Airplanes** 

# 737 Service Bulletin **Number: 737-21-1186** Original Issue: April 17, 2012 ATA System: 2100 **SUBJECT:** AIR CONDITIONING - Control Cabin Conditioned Air Distribution System - Inspection of the Metal Clamp Installed on Hoses to the Air Conditioning Temperature Sensor, Gasper Air Outlet and Diffuser 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 Unpublished Work.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Original Issue: April 17, 2012 737-21-1186 1 of 40 2.0Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 2 of 40 **BOEING SERVICE BULLETIN 737-21-1186**

BLANK PAGE**Table of Contents** Summary...................................................... 5 1. PLANNING INFORMATION........................................ 9 A. Effectivity................................................ 9 1. Airplanes............................................. 9 2. Spares Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 B. Concurrent Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 C. Reason. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 D. Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 F. Approval. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 G. Manpower. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 I. Electrical Load Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 J. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 1. Existing Data:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 2. Data Supplied with this Service Bulletin:. . . . . . . . . . . . . . . . . . . . . . . . . . . 29 3. Installation Drawings Used in the Preparation of this Service Bulletin:. . . . . . . . . . . 29 K. Publications Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 L. Interchangeability and Intermixability of Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . 30 M. Software Accomplishment Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 2. MATERIAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 B. Industry Support Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 C. Parts Necessary for Each Airplane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 1. Kits/Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 2. Parts and Materials Supplied by the Operator. . . . . . . . . . . . . . . . . . . . . . . . 31 3. Parts Modified and Reidentified. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 4. Parts Removed and Not Replaced. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 31 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 A. GENERAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 FIGURE 1: INSPECT OF THE METAL CLAMP INSTALLATION [Group 1]. . . . . . . . . . . . . . . 35 FIGURE 2: INSPECT OF THE METAL CLAMP INSTALLATION [Group 2]. . . . . . . . . . . . . . . 38

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 3 of 40 **BOEING SERVICE BULLETIN 737-21-1186**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 4 of 40 **BOEING SERVICE BULLETIN 737-21-1186**

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### Commercial **Airplanes** 

# 737 Service Bulletin **Summary Number: 737-21-1186**  Original Issue: April 17, 2012 ATA System: 2100 **SUBJECT:** AIR CONDITIONING - Control Cabin Conditioned Air Distribution System - Inspection of the Metal Clamp Installed on Hoses to the Air Conditioning Temperature Sensor, Gasper Air Outlet and Diffuser **CONCURRENT REQUIREMENTS** None. **BACKGROUND** This service bulletin gives instructions to do a General Visual inspection of the installation of metal clamps installed on the hoses of the Air Conditioning Temperature Sensor, Gasper Air Outlet and the Diffuser on the left side of the Control Cabin at STA 259.5. If the metal clamps are not the correct part number or not correctly positioned on the hose, the adjacent wire bundles can become damaged. Also, if the metal clamps are not the correct part number or not installed in the correct position, do a General Visual inspection of the wire bundles and repair if necessary. If this inspection is not done, any damaged wires could cause an electrical short circuit that can cause a fire or smoke in the Control Cabin. Operators have informed Boeing of chafed wire bundles caused by metal clamps installed on hoses to the Air Conditioning Temperature Sensor, Gasper Air Outlet and the Diffuser on the left side of the Control Cabin at STA 259.5. A metal clamp can cause chafed wire bundles if it is the incorrect part number or incorrectly installed. Accomplishment of this service bulletin will check the part number and position of the metal clamps and adjacent wire bundles for chafing. Boeing Service Related Problem (SRP) 737-SRP-21-0186 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 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)

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 5 of 40**Reference Affected**  **Planning Data** 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 Group 1-2:**  Get access to the hoses of the Air Conditioning Temperature Sensor, Gasper Air Outlets and the Diffuser at STA 259.5. Do a General Visual Inspection of the metal clamp installation. – If the metal clamp is not the correct part number, install the correct part number metal clamp or as an option install a plastic tie strap. Do a General Visual Inspection of the adjacent wire bundles and repair if necessary. – If the metal clamp is the correct part number but not in the correct position, rotate the clamp to the correct position. Do a General Visual Inspection of the adjacent wire bundles and repair if necessary. – If the metal clamp part number and position is correct, no more work is necessary. As an option the metal clamp can be replaced with a plastic tie strap. **Group 3:** Contact Boeing to get instructions for the change for this service bulletin, 737-21-1186 original issue, and do the work instructed by Boeing. **EFFECTIVITY** 737-100/-200/-200C/-300/-400/-500 Airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplane(s). **COMPLIANCE** No compliance time is given. Boeing recommends this service bulletin be done to prevent possible operational disruptions. On Group 3 airplanes, contact Boeing to get instructions for the change for this service bulletin, 737-21-1186 original issue, and do the work instructed by Boeing **INDUSTRY SUPPORT INFORMATION** Boeing warranty remedies are not available for the inspection and repair procedure given in this service bulletin. **MANPOWER Elapsed Hours**  **Total Task Hours Airplanes**  1.25 1.25 Group 1 1.25 1.25 Group 2

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 6 of 40 **BOEING SERVICE BULLETIN 737-21-1186 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 17, 2012 737-21-1186 7 of 40 **BOEING SERVICE BULLETIN 737-21-1186**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 8 of 40 **BOEING SERVICE BULLETIN 737-21-1186**

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### Commercial **Airplanes** 

# 737 Service Bulletin **Number: 737-21-1186** Original Issue: April 17, 2012 ATA System: 2100 **SUBJECT:** AIR CONDITIONING - Control Cabin Conditioned Air Distribution System - Inspection of the Metal Clamp Installed on Hoses to the Air Conditioning Temperature Sensor, Gasper Air Outlet and Diffuser **1. PLANNING INFORMATION A. Effectivity**  1. Airplanes Refer to Service Bulletin Index D6-19567 Part 3 for Airplane Variable Number, Line Number, and Serial Number data. This service bulletin is for the airplane(s) shown below.
**DESCRIPTION CONFIGURATION**  **GROUP** 737 Airplanes with an Air Conditioning Temperature Sensor, 1 Gasper Air Outlet and Diffuser. - 1
737 Airplanes with an Air Conditioning Temperature Sensor, 2 Gasper Air Outlets and a Diffuser. - 2

737 Airplanes line numbers 1 - 291

- 3

Airplane Models: 737-100, 737-200, 737-200C, 737-300, 737-400, 737-500 **Group Variable Number** 3 PA001 - PA022 3 PA099 3 PA231 - PA232 3 PC001 - PC005 3 PG001 - PG075 3 PG199 3 PG201 - PG230

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 9 of 40**Group Variable Number** 3 PG251 - PG255 3 PG271 - PG279 3 PG301 - PG314 3 PG331 - PG332 3 PG351 - PG356 3 PG375 3 PG401 - PG403 3 PG431 - PG442 3 PG471 - PG475 3 PG501 - PG505 3 PG571 - PG583 1 PG584 - PG585 2 PG586 3 PG621 - PG630 3 PG651 - PG652 3 PG701 - PG705 2 PH001 2 PH011 1 PH012 2 PH013 2 PH021 1 PH022 - PH023 2 PH024 3 PH701 - PH715 3 PH731 - PH732 3 PH741 - PH742 2 PH743 3 PJ001 - PJ002 1 PJ003 - PJ006 2 PJ007 - PJ009 3 PJ031 - PJ032 3 PJ071 - PJ072 3 PJ101 - PJ104

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 10 of 40 **BOEING SERVICE BULLETIN 737-21-1186 Group**  **Variable Number**1 PJ105 - PJ112 2 PJ113 - PJ114 1 PJ115 - PJ118 2 PJ119 2 PJ201 1 PJ202 - PJ218 2 PJ219 1 PJ301 - PJ302 1 PJ551 - PJ561 1 PJ601 - PJ615 1 PJ811 1 PJ816 - PJ817 2 PK026 1 PK027 - PK028 2 PK029 2 PK041 1 PK042 - PK052 2 PK053 2 PK061 1 PK062 - PK069 2 PK070 2 PK081 - PK082 2 PK091 1 PK092 - PK098 2 PK099 2 PK101 1 PK102 2 PK103 2 PK111 1 PK112 - PK119 2 PK120 2 PK141 1 PK142 - PK145

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 11 of 40 **BOEING SERVICE BULLETIN 737-21-1186 Group**  **Variable Number**2 PK146 2 PK201 1 PK202 2 PK203 - PK204 2 PK211 1 PK212 2 PK213 - PK214 1 PK215 - PK219 2 PK220 - PK223 2 PK231 1 PK232 - PK234 2 PK235 - PK236 1 PK237 - PK239 2 PK240 - PK241 2 PK251 1 PK252 - PK257 2 PK258 2 PK271 1 PK272 2 PK273 - PK274 2 PK281 - PK285 1 PK286 2 PK287 - PK289 2 PK291 2 PK301 1 PK302 - PK305 2 PK306 - PK307 1 PK308 - PK309 2 PK310 - PK311 1 PK312 - PK316 2 PK317 - PK318 2 PK341 2 PK351

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 12 of 40 **BOEING SERVICE BULLETIN 737-21-1186 Group**  **Variable Number**1 PK352 - PK354 2 PK355 - PK356 1 PK357 - PK360 2 PK361 2 PK391 2 PK431 - PK433 2 PK451 - PK452 2 PK461 1 PK462 - PK468 2 PK469 2 PK495 2 PK501 - PK502 1 PK503 2 PK504 2 PK511 - PK512 1 PK513 - PK514 2 PK515 2 PK519 2 PK521 - PK523 1 PK524 - PK527 2 PK528 2 PK541 1 PK542 - PK545 2 PK546 - PK547 1 PK548 - PK559 2 PK560 - PK563 1 PK564 2 PK565 2 PK581 2 PK591 1 PK592 2 PK593 - PK594 1 PK595 - PK598

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 13 of 40 **BOEING SERVICE BULLETIN 737-21-1186 Group**  **Variable Number**2 PK599 2 PK601 1 PK602 - PK609 2 PK610 - PK611 1 PK612 2 PK613 - PK614 1 PK615 - PK616 2 PK617 2 PK621 1 PK622 - PK636 2 PK637 2 PK641 - PK642 2 PK661 - PK662 1 PK663 - PK665 2 PK666 2 PK671 1 PK672 - PK680 2 PK681 2 PK691 - PK693 1 PK694 - PK696 2 PK697 2 PK711 1 PK712 - PK714 2 PK715 - PK716 2 PK731 1 PK732 - PK764 2 PK765 2 PK771 1 PK772 - PK778 2 PK779 2 PK801 1 PK802 - PK803 2 PK804

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 14 of 40 **BOEING SERVICE BULLETIN 737-21-1186 Group**  **Variable Number**2 PK819 1 PK820 - PK826 2 PK827 2 PK830 2 PK861 1 PK862 2 PK863 2 PK871 1 PK872 - PK873 2 PK874 2 PK881 1 PK882 - PK883 2 PK884 2 PK901 1 PK902 - PK937 2 PK938 2 PK971 1 PK972 - PK973 2 PK974 2 PL001 1 PL002 - PL013 2 PL014 - PL015 1 PL016 - PL027 2 PL028 2 PL061 2 PL081 2 PL101 1 PL102 - PL112 2 PL113 2 PL151 2 PL171 - PL172 2 PL201 1 PL202

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 15 of 40 **BOEING SERVICE BULLETIN 737-21-1186 Group**  **Variable Number**2 PL203 2 PL221 2 PL401 1 PL402 2 PL403 - PL404 1 PL405 - PL416 2 PL417 2 PL421 2 PL441 2 PL451 1 PL452 - PL455 2 PL456 2 PL471 2 PL491 2 PL501 1 PL502 - PL505 2 PL506 2 PL551 1 PL552 - PL561 2 PL562 2 PL581 2 PL601 1 PL602 2 PL603 2 PL611 2 PL621 1 PL622 - PL625 2 PL626 2 PL631 - PL632 3 PL711 - PL712 3 PL716 1 PL717 - PL743 2 PL744 - PL745

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 16 of 40 **BOEING SERVICE BULLETIN 737-21-1186 Group**  **Variable Number**1 PL746 2 PL747 2 PL756 2 PL758 2 PL761 1 PL762 - PL768 2 PL769 - PL770 2 PL781 - PL783 1 PL784 - PL787 2 PL788 2 PL793 3 PL801 - PL803 2 PM001 1 PM002 - PM005 2 PM006 2 PM016 - PM017 2 PM021 1 PM022 2 PM023 2 PM051 1 PM052 - PM065 2 PM066 2 PM101 1 PM102 - PM118 2 PM119 2 PM141 - PM142 2 PM171 2 PM181 2 PM251 1 PM252 - PM254 2 PM255 2 PM281 1 PM282

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 17 of 40 **BOEING SERVICE BULLETIN 737-21-1186 Group**  **Variable Number**2 PM283 1 PM381 - PM399 1 PM401 - PM417 1 PM541 - PM564 2 PN001 - PN002 2 PN021 1 PN022 - PN042 2 PN043 2 PN081 1 PN082 - PN085 2 PN086 2 PN101 1 PN102 - PN116 2 PN117 2 PN131 1 PN132 - PN162 2 PN163 2 PN401 1 PN402 - PN419 2 PN420 2 PN431 1 PN432 2 PN433 2 PN451 1 PN452 - PN455 2 PN456 2 PN471 1 PN472 - PN473 2 PN474 2 PN481 2 PN491 1 PN492 2 PN493

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 18 of 40 **BOEING SERVICE BULLETIN 737-21-1186 Group**  **Variable Number**2 PN501 - PN502 2 PN511 - PN512 2 PN521 1 PP001 - PP054 1 PP101 - PP169 1 PP181 - PP199 1 PP201 - PP205 1 PP221 1 PP231 - PP243 1 PP281 - PP286 1 PP301 - PP305 1 PP351 - PP353 1 PP376 - PP384 1 PP391 - PP393 1 PP401 - PP440 1 PP471 - PP475 1 PP501 - PP522 1 PP631 - PP634 1 PP651 - PP652 1 PP671 - PP699 1 PP701 - PP733 1 PP771 - PP779 1 PP801 - PP808 1 PP821 - PP827 1 PP831 - PP848 1 PP851 - PP852 1 PP861 - PP877 1 PP891 - PP899 1 PP901 - PP936 1 PP946 - PP948 1 PP951 - PP952 1 PP961 - PP967 1 PP981 - PP991

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 19 of 40 **BOEING SERVICE BULLETIN 737-21-1186 Group**  **Variable Number**1 PP993 1 PQ001 - PQ016 1 PQ026 - PQ041 1 PQ051 - PQ092 1 PQ101 - PQ199 1 PQ201 - PQ202 1 PQ221 - PQ237 1 PQ241 - PQ243 1 PQ251 - PQ267 1 PQ281 - PQ299 1 PQ301 - PQ307 1 PQ331 - PQ332 1 PQ341 - PQ348 1 PQ361 - PQ373 1 PQ391 - PQ395 1 PQ401 - PQ418 1 PQ421 1 PQ431 - PQ438 1 PQ447 - PQ448 1 PQ451 1 PQ454 1 PQ471 - PQ475 1 PQ479 - PQ481 1 PQ486 - PQ487 1 PQ491 - PQ493 1 PQ771 - PQ772 1 PQ791 - PQ793 1 PQ801 - PQ805 1 PQ931 - PQ935 1 PQ951 1 PQ971 - PQ997 1 PR001 - PR017 1 PR021 - PR034

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 20 of 40 **BOEING SERVICE BULLETIN 737-21-1186 Group**  **Variable Number**1 PR041 - PR045 1 PR061 - PR072 1 PR077 - PR082 1 PR091 - PR092 1 PR096 1 PR101 1 PR121 - PR122 1 PR131 - PR132 1 PR141 - PR143 1 PR161 - PR172 1 PR181 1 PS601 - PS631 1 PS636 - PS638 1 PS641 - PS644 1 PS651 - PS657 1 PS666 - PS669 1 PS691 - PS692 1 PS701 - PS706 1 PS751 - PS799 1 PS811 1 PS836 - PS837 1 PS841 - PS846 1 PS851 - PS852 1 PS856 1 PS861 - PS863 1 PS866 - PS868 1 PS871 - PS874 1 PS896 - PS897 1 PS901 - PS941 1 PS956 - PS957 1 PS961 - PS963 1 PS971 - PS978 1 PT001 - PT015

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 21 of 40 **BOEING SERVICE BULLETIN 737-21-1186 Group**  **Variable Number**1 PT021 - PT031 1 PT041 - PT064 1 PT101 - PT105 1 PT121 - PT138 1 PT146 - PT148 1 PT161 - PT170 1 PT181 - PT188 1 PT211 - PT220 1 PT295 1 PT301 - PT309 1 PT331 - PT360 1 PT381 - PT399 1 PT401 - PT438 1 PT501 - PT517 1 PT561 - PT565 1 PT581 - PT586 1 PT611 - PT621 1 PT641 - PT644 1 PT651 - PT656 1 PT671 - PT672 1 PT681 - PT685 1 PT701 - PT703 1 PT716 - PT717 1 PT721 - PT725 1 PT801 - PT834 1 PT851 - PT854 1 PT871 - PT886 1 PT901 - PT930 1 PT971 - PT973 1 PT981 - PT985 1 PT996 1 PU001 - PU025 1 PU301

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 22 of 40 **BOEING SERVICE BULLETIN 737-21-1186 Group**  **Variable Number**1 PU311 - PU313 1 PV001 - PV055 1 PV201 - PV209 1 PV226 - PV229 1 PV231 - PV237 1 PV271 - PV272 1 PV281 - PV287 1 PV296 1 PV301 - PV302 1 PV351 1 PV356 - PV357 1 PW001 - PW054 1 PW061 - PW068 1 PW072 1 PW086 - PW088 1 PW091 - PW094 1 PW101 - PW102 1 PW106 1 PW111 - PW120 1 PW156 - PW157 1 PW161 - PW171 1 PW201 - PW252 1 PW261 - PW268 1 PW271 - PW276 1 PW278 1 PW281 - PW293 1 PW296 1 PW301 - PW327 1 PW401 - PW408 1 PW411 - PW418 1 PW421 - PW424 1 PW431 - PW435 1 PW441 - PW450

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 23 of 40 **BOEING SERVICE BULLETIN 737-21-1186 Group**  **Variable Number**1 PW461 - PW467 1 PW501 - PW504 1 PW511 - PW522 1 PW524 - PW550 1 PW556 - PW557 1 PW561 - PW564 1 PW571 - PW576 1 PW591 - PW596 1 PW611 - PW622 1 PW631 - PW637 1 PW661 - PW662 1 PW681 - PW683 1 PW701 - PW702 1 PW711 - PW717 1 PW741 - PW742 1 PW761 1 PW771 1 PW831 1 PW851 - PW856 3 PX071 3 PX701 3 PY001 - PY008 3 PY021 2 PY022 3 PY031 2 PY036 - PY037 2 PY046 1 PY047 2 PY048 2 PY051 1 PY052 2 PY053 2 PY056 - PY057

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 24 of 40 **BOEING SERVICE BULLETIN 737-21-1186 Group**  **Variable Number**2 PY101 1 PY102 2 PY103 2 PY111 1 PY112 2 PY113 2 PY131 1 PY132 2 PY133 - PY135 2 PY141 1 PY142 2 PY143 2 PY151 - PY154 2 PY156 - PY157 2 PY161 - PY162 2 PY166 2 PY191 2 PY201 2 PY221 - PY222 2 PY231 2 PY241 1 PY242 - PY243 2 PY244 2 PY270 - PY271 1 PY272 - PY274 2 PY275 2 PY281 2 PY286 3 PY301 - PY304 3 PY321 - PY323 3 PY341 - PY346 3 PY361 - PY362 3 PY381

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 25 of 40 **BOEING SERVICE BULLETIN 737-21-1186 Group**  **Variable Number**2 PY401 2 PY409 - PY411 2 PY421 - PY422 2 PY441 2 PY451 2 PY461 1 PY462 2 PY463 2 PY591 1 PY592 - PY594 2 PY595 2 PY611 - PY612 2 PY621 2 PY631 2 PY651 2 PY671 - PY672 2 PY721 2 PY741 2. Spares Affected None. **B. Concurrent Requirements** None. **C. Reason** This service bulletin gives instructions to do a General Visual inspection of the installation of metal clamps installed on the hoses of the Air Conditioning Temperature Sensor, Gasper Air Outlet and the Diffuser on the left side of the Control Cabin at STA 259.5. If the metal clamps are not the correct part number or not correctly positioned on the hose, the adjacent wire bundles can become damaged. Also, if the metal clamps are not the correct part number or not installed in the correct position, do a General Visual inspection of the wire bundles and repair if necessary. If this inspection is not done, any damaged wires could cause an electrical short circuit that can cause a fire or smoke in the Control Cabin.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 26 of 40 **BOEING SERVICE BULLETIN 737-21-1186**Operators have informed Boeing of chafed wire bundles caused by metal clamps installed on hoses to the Air Conditioning Temperature Sensor, Gasper Air Outlet and the Diffuser on the left side of the Control Cabin at STA 259.5. A metal clamp can cause chafed wire bundles if it is the incorrect part number or incorrectly installed. Accomplishment of this service bulletin will check the part number and position of the metal clamps and adjacent wire bundles for chafing. Boeing Service Related Problem (SRP) 737-SRP-21-0186 is related to this service bulletin. **D. Description Group 1-2:**  Get access to the hoses of the Air Conditioning Temperature Sensor, Gasper Air Outlets and the Diffuser at STA 259.5. Do a General Visual Inspection of the metal clamp installation. – If the metal clamp is not the correct part number, install the correct part number metal clamp or as an option install a plastic tie strap. Do a General Visual Inspection of the adjacent wire bundles and repair if necessary. – If the metal clamp is the correct part number but not in the correct position, rotate the clamp to the correct position. Do a General Visual Inspection of the adjacent wire bundles and repair if necessary. – If the metal clamp part number and position is correct, no more work is necessary. As an option the metal clamp can be replaced with a plastic tie strap. **Group 3:** Contact Boeing to get instructions for the change for this service bulletin, 737-21-1186 original issue, and do the work instructed by Boeing. The work in this service bulletin is done in the maintenance zone(s) given below. **Group 1:**
**Affected Maintenance Zones Zone**  **Model** 101 737-300, 737-400, 737-500 **Group 1-2:**
**Affected Maintenance Zones Zone**  **Model** 1-11 737-200, 737-200C **Group 3:**
**Affected Maintenance Zones Zone**  **Model** 1-11 737-100, 737-200, 737-200C

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 27 of 40 **BOEING SERVICE BULLETIN 737-21-1186 E. Compliance**  No compliance time is given. Boeing recommends this service bulletin be done to prevent possible operational disruptions. **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 inspection and 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. **Group 1: Elapsed Hours**  **Task Hours Number of Persons**  **Task** 0.50 0.50 1 Open Access 0.25 0.25 1 FIGURE 1 0.50 0.50 1 Close Access 1.25 1.25 TOTAL FOR EACH AIRPLANE **Group 2: Elapsed Hours**  **Task Hours Number of Persons**  **Task** 0.50 0.50 1 Open Access 0.25 0.25 1 FIGURE 2 0.50 0.50 1 Close Access

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 28 of 40 **BOEING SERVICE BULLETIN 737-21-1186 Group 2:**  **Elapsed Hours Task Hours**  **Number of Persons Task**  1.25 1.25 TOTAL FOR EACH AIRPLANE **H. Weight and Balance Changes** None. **I. Electrical Load Data** Not changed. **J. References** 1. Existing Data: a. Boeing Service Related Problem (SRP) 737-SRP-21-0186 b. Service Bulletin Index D6-19567 c. Standard Wiring Practices Manual (SWPM) 20-10-11, 20-10-12, 20-10-13, 20-10-19 d. 737-100/200 Aircraft Maintenance Manual (AMM) 21-22-09, 25-11-21 e. 737-300/400/500 Aircraft Maintenance Manual (AMM) 21-22-09, 25-11-21 2. Data Supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin:
**Title Drawing Number**  TEMP SENSOR INSTL - CONTROL CABIN, AIR CONDITIONING 65-52958 TEMP SENSOR INSTL - CONTROL CABIN, AIR CONDITIONING 65-55402 DIFFUSER INSTL - OVERHEAD DISTRIB, CONTROL CABIN 65-54415 DUCT INSTL - INDIVIDUAL AIR CONTROL CABIN 69-42753 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:

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 29 of 40 **BOEING SERVICE BULLETIN 737-21-1186 Chapter-Section**  **Publication** 21-00, 21-20, 21-60 737 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** Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts. **M. Software Accomplishment Summary** Not affected.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 30 of 40 **BOEING SERVICE BULLETIN 737-21-1186 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 inspection and repair procedure given in this service bulletin. **C. Parts Necessary for Each Airplane** 1. Kits/Parts None. 2. Parts and Materials Supplied by the Operator
**Notes Existing Part Number**  **Name QTY**  **Part Number / Specification**  (a)

- STRAP, PLASTIC, ADJUSTABLE, SELF-LOCKING 1 BACS38K7 (a) Quantity required for each metal clamp replaced.
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 17, 2012 737-21-1186 31 of 40 **BOEING SERVICE BULLETIN 737-21-1186**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 32 of 40 **BOEING SERVICE BULLETIN 737-21-1186**

BLANK PAGE**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. 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. 4. 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. 5. 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. 6. 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. **B. WORK INSTRUCTIONS**
1.**Group 1-2:** At the left side of the Control Cabin, get access to the hoses that attach to the Air Conditioning Temperature Sensor, Gasper Air Outlet and Diffuser at STA 259.5. Refer to 737-100/200 AMM 25-11-21 or 737-300/400/500 AMM 25-11-21 as an accepted procedure.
2.**Group 1:** Do a General Visual Inspection of the metal clamp installation in accordance with FIGURE 1. a. If metal clamp is the incorrect part number, install the correct part number metal clamp or as an option install a plastic tie strap. Refer to the Illustrated Parts Catalog for the correct metal clamp part number. Do a General Visual Inspection of the adjacent wire bundles. If any wire bundles are damaged, repair the wire bundle. Refer to SWPM 20-10-13 as an accepted procedure.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 33 of 40 **BOEING SERVICE BULLETIN 737-21-1186 NOTE:** If an optional plastic tie strap is installed, install so that the head of the plastic tie strap is next to the panel. Use plastic tie strap tool to tighten the strap. Use a tension setting of 1 or a tension between 18-22 inch-lbs. Refer to SWPM 20-10-11 as an accepted procedure. b. If the metal clamp is the correct part number but is not in the correct position, rotate the metal clamp to the correct position so that the head of the clamp is next to the panel. Refer to 737-100/200 AMM 21-22-09 or 737-300/400/500 AMM 21-22-09 as an accepted procedure. Do a General Visual Inspection of the adjacent wire bundles. If any wire bundles are damaged, repair the wire bundle. Refer to SWPM 20-10-13 as an accepted procedure. c. If the metal clamp is the correct part number and in the correct position, no more work is necessary. As an option a plastic tie strap can be installed. **NOTE:**If an optional plastic tie strap is installed, install so that the head of the plastic tie strap is next to the panel. Use plastic tie strap tool to tighten the strap. Use a tension setting of 1 or a tension between 18-22 inch-lbs. Refer to SWPM 20-10-11 as an accepted procedure. 3.**Group 2:** Do a General Visual Inspection of the metal clamp installation in accordance with FIGURE 2. a. If metal clamp is the incorrect part number, install the correct part number metal clamp or as an option install a plastic tie strap. Refer to the Illustrated Parts Catalog for the correct metal clamp part number. Do a General Visual Inspection of the adjacent wire bundles. If any wire bundles are damaged, repair the wire bundle. Refer to SWPM 20-10-13 as an accepted procedure. **NOTE:**If an optional plastic tie strap is installed, install so that the head of the plastic tie strap is next to the panel. Use plastic tie strap tool to tighten the strap. Use a tension setting of 1 or a tension between 18-22 inch-lbs. Refer to SWPM 20-10-11 as an accepted procedure. b. If the metal clamp is the correct part number but is not in the correct position, rotate the metal clamp to the correct position so that the head of the clamp is next to the panel. Refer to 737-100/200 AMM 21-22-09 or 737-300/400/500 AMM 21-22-09 as an accepted procedure. Do a General Visual Inspection of the adjacent wire bundles. If any wire bundles are damaged, repair the wire bundle. Refer to SWPM 20-10-13 as an accepted procedure. c. If the metal clamp is the correct part number and in the correct position, no more work is necessary. As an option a plastic tie strap can be installed. **NOTE:**If an optional plastic tie strap is installed, install so that the head of the plastic tie strap is next to the panel. Use plastic tie strap tool to tighten the strap. Use a tension setting of 1 or a tension between 18-22 inch-lbs. Refer to SWPM 20-10-11 as an accepted procedure. 4.**Group 1-2:** Put the airplane back to a serviceable condition. 5.**Group 3:** Contact Boeing to get instructions for the change for this service bulletin, 737-21-1186 original issue, and do the work instructed by Boeing.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 34 of 40 **BOEING SERVICE BULLETIN 737-21-1186 This Figure applies only to: Group 1.** 

**FIGURE 1: INSPECT OF THE METAL CLAMP INSTALLATION (SHEET 1 OF 3)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 35 of 40 **BOEING SERVICE BULLETIN 737-21-1186 FIGURE 1: INSPECT OF THE METAL CLAMP INSTALLATION**  **(SHEET 2 OF 3)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 36 of 40 **BOEING SERVICE BULLETIN 737-21-1186**The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
**More Data Qty**  **Identification Name**  **Task Step**  (a)

- - Clamp Inspect 1 (a) Do a General Visual Inspection for metal clamp part number and position.

**FIGURE 1: INSPECT OF THE METAL CLAMP INSTALLATION (SHEET 3 OF 3)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 37 of 40 **BOEING SERVICE BULLETIN 737-21-1186 This Figure applies only to: Group 2.** 

**FIGURE 2: INSPECT OF THE METAL CLAMP INSTALLATION (SHEET 1 OF 3)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 38 of 40 **BOEING SERVICE BULLETIN 737-21-1186 FIGURE 2: INSPECT OF THE METAL CLAMP INSTALLATION**  **(SHEET 2 OF 3)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 39 of 40 **BOEING SERVICE BULLETIN 737-21-1186**The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
**More Data Qty**  **Identification Name**  **Task Step**  (a)

- - Clamp Inspect 1 (a) Do a General Visual Inspection for metal clamp part number and position.

**FIGURE 2: INSPECT OF THE METAL CLAMP INSTALLATION (SHEET 3 OF 3)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 17, 2012 737-21-1186 40 of 40 **BOEING SERVICE BULLETIN 737-21-1186**