### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Number: 737-28A1307**  Original Issue: May 14, 2012 ATA System: 2822 **SUBJECT:** FUEL - Engine Fuel Feed System - Engine Fuel Suction Feed Operational Test 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 Unpublished Work.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Original Issue: May 14, 2012 737-28A1307 1 of 31 4.0Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 2 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT**

BLANK PAGE**Table of Contents** Summary...................................................... 5 1. PLANNING INFORMATION........................................ 7 A. Effectivity................................................ 7 1. Airplanes............................................. 7 2. Spares Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 B. Concurrent Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 C. Reason. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 D. Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 F. Approval. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 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:. . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3. Installation Drawings Used in the Preparation of this Service Bulletin:. . . . . . . . . . . 18 K. Publications Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 L. Interchangeability and Intermixability of Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . 18 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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 4. Parts Removed and Not Replaced. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 19 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 A. GENERAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 3 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 4 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT**

BLANK PAGE

### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Summary**  **Number: 737-28A1307** Original Issue: May 14, 2012 ATA System: 2822 **SUBJECT:** FUEL - Engine Fuel Feed System - Engine Fuel Suction Feed Operational Test 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 operators to perform an Engine Fuel Suction Feed Operational Test on each engine individually. This test is required in order to protect against engine flameout during suction feed operations. The instructions given in this service bulletin are provided to detect and correct failure of the engines fuel suction feed of the fuel system, which could result in dual engine flameout and inability to restart the engines, and consequent forced landing of the airplane. Accomplishing the fuel system suction feed test and continuing to repeat the testing within the specified compliance times will reduce the possibility of an engine flameout resulting from air ingestion into the engine fuel feed system during low fuel level conditions with inoperative boost pumps . An Operator reported a 737-400 Engine No. 1 flameout during cruise. The Engine No. 2 continued to operate normally. The flight crew conducted two restart attempts within the start envelope with no success then diverted uneventfully. Another Operator reported a 737-300 Engine No. 2 flameout during taxi to the gate when the start lever was placed in the idle position. Maintenance performed a vacuum test of the fuel feed system and found a crack in the fuel feed tube. The fuel feed tube was replaced, and a vacuum test of the fuel feed system was performed and passed successfully. This table is provided to operators for planning purposes only. Refer to the applicable sections for more information.
**Reference Affected**  **Planning Data** Paragraph 1.E., Compliance Yes AD Related

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 5 of 31**ACTION ENGINE NO. 1, FUEL SUCTION FEED - OPERATIONAL TEST**  1. Do the Engine No. 1 Fuel Suction Feed - Operational Test. 2. If the Fuel Suction Feed Operational Test fails isolate the cause, repair, and repeat the Engine No. 1 Fuel Suction Feed - Operational Test. **ENGINE NO. 2, FUEL SUCTION FEED - OPERATIONAL TEST** 1. Do the Engine No. 2 Fuel Suction Feed - Operational Test. 2. If the Fuel Suction Feed Operational Test fails isolate the cause, repair, and repeat the Engine No. 2 Fuel Suction Feed - Operational Test. **EFFECTIVITY** 737-300/400/500 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. Federal Aviation Administration (FAA) Notice of Proposed Rule Making NPRM 2007-NM-351-AD, is related to this service bulletin. Refer to Paragraph 1.E., Compliance. **INDUSTRY SUPPORT INFORMATION** Boeing warranty remedies are not available for the test and/or repair procedures given in this service bulletin. **MANPOWER** Refer to Paragraph 1.G., Manpower. **MATERIAL INFORMATION** None.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 6 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT**

### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Number: 737-28A1307**  Original Issue: May 14, 2012 ATA System: 2822 **SUBJECT:** FUEL - Engine Fuel Feed System - Engine Fuel Suction Feed Operational Test 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. Refer to Service Bulletin Index D6-19567 Part 3 for Airplane Variable Number, Line Number, and Serial Number data.
**DESCRIPTION CONFIGURATION**  **GROUP** 737-300/400/500 airplanes

- 1

Airplane Models: 737-300, 737-400, 737-500 **Group Variable Number**  1 PJ301 - PJ302 1 PJ551 - PJ561 1 PJ601 - PJ615 1 PJ811 1 PJ816 - PJ817 1 PM381 - PM399 1 PM401 - PM417

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 7 of 31**Group Variable Number**  1 PM541 - PM564 1 PP001 - PP054 1 PP101 - PP169 1 PP181 - PP199 1 PP201 - PP205 1 PP221 1 PP231 - PP243 1 PP281 - PP286 1 PP301 - PP305 1 PP351 - PP353 1 PP376 - PP384 1 PP391 - PP393 1 PP401 - PP440 1 PP471 - PP475 1 PP501 - PP522 1 PP631 - PP634 1 PP651 - PP652 1 PP671 - PP699 1 PP701 - PP733 1 PP771 - PP779 1 PP801 - PP808 1 PP821 - PP827 1 PP831 - PP848 1 PP851 - PP852 1 PP861 - PP877 1 PP891 - PP899 1 PP901 - PP936 1 PP946 - PP948 1 PP951 - PP952 1 PP961 - PP967 1 PP981 - PP991 1 PP993 1 PQ001 - PQ016

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 8 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT Group**  **Variable Number** 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 1 PR041 - PR045 1 PR061 - PR072

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 9 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT Group**  **Variable Number** 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 1 PT021 - PT031 1 PT041 - PT064

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 10 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT Group**  **Variable Number** 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 1 PU311 - PU313 1 PV001 - PV055

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 11 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT Group**  **Variable Number** 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 1 PW461 - PW467 1 PW501 - PW504

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 12 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT Group**  **Variable Number** 1 PW511 - PW522 1 PW524 - PW550 1 PW556 - PW557 1 PW561 - PW564 1 PW571 - PW576 1 PW591 - PW596 1 PW611 - PW622 1 PW631 - PW637 1 PW661 - PW662 1 PW681 - PW683 1 PW701 - PW702 1 PW711 - PW717 1 PW741 - PW742 1 PW761 1 PW771 1 PW831 1 PW851 - PW856 2. Spares Affected None. **B. Concurrent Requirements** None. **C. Reason** This service bulletin provides instructions to operators to perform an Engine Fuel Suction Feed Operational Test on each engine individually. This test is required in order to protect against engine flameout during suction feed operations. The instructions given in this service bulletin are provided to detect and correct failure of the engines fuel suction feed of the fuel system, which could result in dual engine flameout and inability to restart the engines, and consequent forced landing of the airplane. Accomplishing the fuel system suction feed test and continuing to repeat the testing within the specified compliance times will reduce the possibility of an engine flameout resulting from air ingestion into the engine fuel feed system during low fuel level conditions with inoperative boost pumps .

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 13 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT**An Operator reported a 737-400 Engine No. 1 flameout during cruise. The Engine No. 2 continued to operate normally. The flight crew conducted two restart attempts within the start envelope with no success then diverted uneventfully. Another Operator reported a 737-300 Engine No. 2 flameout during taxi to the gate when the start lever was placed in the idle position. Maintenance performed a vacuum test of the fuel feed system and found a crack in the fuel feed tube. The fuel feed tube was replaced, and a vacuum test of the fuel feed system was performed and passed successfully **D. Description ENGINE NO. 1, FUEL SUCTION FEED - OPERATIONAL TEST**  1. Do the Engine No. 1 Fuel Suction Feed - Operational Test. 2. If the Fuel Suction Feed Operational Test fails, isolate the cause, repair, and repeat the Engine No. 1 Fuel Suction Feed - Operational Test. **ENGINE NO. 2, FUEL SUCTION FEED - OPERATIONAL TEST** 1. Do the Engine No. 2 Fuel Suction Feed - Operational Test. 2. If the Fuel Suction Feed Operational Test fails, isolate the cause, repair, and repeat the Engine No. 2 Fuel Suction Feed - Operational Test. The work in this service bulletin is done in the maintenance zone(s) given below.
**Affected Maintenance Zones Zone**  **Model** 101, 102, 305, 405 737-300, 737-400, 737-500 **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. Federal Aviation Administration (FAA) Notice of Proposed Rule Making NPRM 2007-NM-351-AD, is related to this service bulletin.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 14 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT Table 1: ENGINE NO. 1, FUEL SUCTION FEED - OPERATIONAL TEST** **Repeat Interval (Whichever Oc**  **curs First) Compliance Time** **(Whichever Oc curs First)**  **Action Condition** 

7,500 Flight Hours or 24 Months Within 7,500 Flight Hours or 24 Months after the original issue dateof this service bulletin Do the Engine No. 1 FuelSuction Feed - Operational Test in accordancewith Accomplishment Instructions, paragraph 3.B., Work Instructions, CONFIGURATION 1, WORKPACKAGE 1 orAccomplishment Instructions paragraph 3.B., CONFIGURATION 2, WORKPACKAGE 3. Group 1

- Before Further Flight Isolate the cause, repair, and repeat the Engine No. 1 Fuel Suction Feed- Operation Test in accordance with Accomplishment Instructions, paragraph 3.B., Work Instructions, CONFIGURATION 1, WORKPACKAGE 1 orAccomplishment Instructions paragraph 3.B., CONFIGURATION 2, WORKPACKAGE 3. If the Engine No. 1 Fuel Suction Feed Operation Test fails

**Table 2: ENGINE NO. 2, FUEL SUCTION FEED - OPERATIONAL TEST Repeat Interval** **(Whichever Oc curs First)**  **Compliance Time (Whichever Oc**  **curs First) Action**  **Condition**

7,500 Flight Hours or 24 Months Within 7,500 Flight Hours or 24 Months after the original issue dateof this service bulletin Do the Engine No. 2 FuelSuction Feed - Operational Test in accordancewith Accomplishment Instructions, paragraph 3.B., Work Instructions, CONFIGURATION 1, WORKPACKAGE 2 orAccomplishment Instructions, paragraph 3.B., CONFIGURATION 2, WORKPACKAGE 4. Group 1

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 15 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT Table 2: ENGINE NO. 2, FUEL SUCTION FEED - OPERATIONAL TEST** **Repeat Interval (Whichever Oc**  **curs First) Compliance Time** **(Whichever Oc curs First)**  **Action Condition** 

- Before Further Flight Isolate the cause, repair, and repeat the Engine No. 2 Fuel Suction Feed- Operation Test in accordance with Accomplishment Instructions, paragraph 3.B., Work Instructions, CONFIGURATION 1, WORKPACKAGE 2 orAccomplishment Instructions, paragraph 3.B., CONFIGURATION 2, WORKPACKAGE 4. If the Engine No. 2 Fuel Suction Feed Operation Test fails

**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 TABLE 1 - ENGINE NO. 1, FUEL SUCTION FEED - OPERATIONAL TEST**  **Elapsed Hours Task Hours**  **Number of Persons Task**  1.00 3.00 3 Test, AccomplishmentInstructions, paragraph 3.B., Work Instructions, CONFIGURATION 1, WORKPACKAGE 1 (a) 2.00 6.00 3 Test, AccomplishmentInstructions, paragraph 3.B., Work Instructions, CONFIGURATION 2, WORKPACKAGE 3 (b)

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 16 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT TABLE 1 - ENGINE NO. 1, FUEL SUCTION FEED - OPERATIONAL TEST**  **Elapsed Hours Task Hours**  **Number of Persons Task** 

- - TOTAL FOR ENGINE NO.1 (c) (a) The Fuel Suction Feed Operational Test provided in Configuration 1, Workpackage 1 requires only one engine run. (b) The Fuel Suction Feed Operational Test provided in Configuration 2, Workpackage 3 requires two engine runs and may not require fuel to be removed from the aircraft. (c) Use the Task Hours for the test you accomplished to obtain Total Task hours. **TABLE 2 - ENGINE NO. 2, FUEL SUCTION FEED - OPERATIONAL TEST Elapsed Hours**  **Task Hours Number of Persons**  **Task** 1.00 3.00 3 Test, AccomplishmentInstructions, paragraph 3.B., Work Instructions, CONFIGURATION 1, WORKPACKAGE 2 (a) 2.00 6.00 3 Test, AccomplishmentInstructions, paragraph 3.B., Work Instructions, CONFIGURATION 2, WORKPACKAGE 4 (b)

- - TOTAL FOR ENGINE NO.2 (c) (a) The Fuel Suction Feed Operational Test provided in Configuration 1, Workpackage 2 requires only one engine run. (b) The Fuel Suction Feed Operational Test provided in Configuration 2, Workpackage 4 requires two engine runs and may not require fuel to be removed from the aircraft. (c) Use the Task Hours for the test you accomplished to obtain Total Task hours. **H. Weight and Balance Changes** None. **I. Electrical Load Data** Not changed. **J. References** 1. Existing Data: a. Boeing Service Letter 737-SL-51-042

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 17 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT**b. Federal Aviation Administration (FAA) Notice of Proposed Rule Making (NPRM) 2007-NM-351-AD c. Service Bulletin Index D6-19567 d. 737-300/400/500 Aircraft Maintenance Manual (AMM) 28-22-00, 71-00-00 a. Boeing Service Letter 737-SL-51-042 b. Federal Aviation Administration (FAA) Notice of Proposed Rule Making (NPRM) 2007-NM-351-AD c. Service Bulletin Index D6-19567 d. 737-300/400/500 Aircraft Maintenance Manual (AMM) 12-11-02, 28-22-00, 28-23-00, 71-00-00 2. Data Supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin: None. **K. Publications Affected** 1. Publications: **Chapter-Section Publication**  28-22 737 Aircraft Maintenance Manual 2. Damage Tolerance Based Structural Inspections: Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the Maintenance Program. This service bulletin 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: May 14, 2012 737-28A1307 18 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT 2. MATERIAL INFORMATION**  **A. Material - Price and Availability** None. **B. Industry Support Information** Boeing warranty remedies are not available for the test and/or repair procedures given in this service bulletin. **C. Parts Necessary for Each Airplane** 1. Kits/Parts None. 2. Parts and Materials Supplied by the Operator None. 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: May 14, 2012 737-28A1307 19 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 20 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT**

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. The work instructions are divided into work packages. Task Hours and Elapsed Hours for each package are given in Paragraph 1.G., Manpower. You can do each work package independently. 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. Boeing Service Letter 737-SL-51-042, Damage Reporting and Repair Plan/Design Guidelines, is an acceptable procedure to request information from Boeing for additional structural repair instructions. The Service Letter describes what information must be provided to Boeing before a structural repair can be provided. 6. 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. 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. **B. WORK INSTRUCTIONS** 1. ENGINE FUEL SUCTION FEED OPERATIONAL TEST - CONFIGURATION 1 PROCEDURE **NOTE:** If the fuel quantities exceed the limits shown in Configuration 1, remove fuel to meet the fuel quantities provided, or do the Engine Fuel Suction Feed tests in accordance with Configuration 2. **NOTE:** The Fuel Suction Feed Operational Tests provided in Configuration 1, Workpackage 1 and Workpackage 2 require only one engine run for each engine.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 21 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT WORK PACKAGE 1 - ENGINE NO. 1, FUEL SUCTION FEED - OPERATIONAL TEST**  **WARNING:** DO NOT OPERATE A FUEL PUMP IF THE LOW PRESSURE LIGHT COMES ON AND STAYS ON. THIS CONDITION CAN CAUSE THE IGNITION OF THE FUEL FUMES IN THE FUEL TANK. A FIRE OR AN EXPLOSION CAN CAUSE INJURIES TO PERSONNEL AND DAMAGE TO EQUIPMENT. **WARNING:** OBSERVE PROPER SAFETY PRECAUTIONS AROUND RUNNING ENGINE. WEAR EAR PROTECTORS AND STAY CLEAR OF ENGINE HAZARD AREAS. SEE "ENGINE GROUND SAFETY PRECAUTIONS" FOR ENGINE HAZARD DESCRIPTION. a. Do the "Engine Fuel Suction Feed - Operational Test". Refer to 737-300/400/500 AMM 28-22-00 as an accepted procedure. During the Test you must meet the following requirements: (1) Make sure that these quantities of fuel are in the fuel tanks:
**FUEL QUANTITY TANK**  0 Lb - 2000 Lb (0 Kg- 907 Kg) CENTER TANK 1500 Lb -1700 Lb (680 Kg - 771 Kg) MAIN TANK 1 (Left) 0 Lb - 200 Lb (0 Kg - 91 Kg) AUXILIARY TANK (If Installed)
**NOTE:** The fuel quantity values given above are at or below the fuel level needed to cover the hydraulic heat exchangers. You must set the hydraulic system pumps "Off" when you operate the engines for this test. **NOTE:** If there is more fuel in the Center Tank and/or Main Tank 1 (Left) than recommended in the tables above, transfer the excess fuel as necessary or remove fuel from the fuel tanks. If defueling is not an option, the Engine No.1 Fuel Suction Feed Operational Test can be done twice in accordance with "Engine Fuel Suction Feed Operational Test - Configuration 2". To remove fuel refer to 737-300/400/500 AMM 28-23-00 - "Fuel Tank Defueling" as an accepted procedure. To transfer fuel refer to 737-300/400/500 AMM 28-23-00 - "Fuel Transfer from One Tank to a Different Tank" as an accepted procedure. To add fuel refer to 737-300/400/500 AMM 12-11-02 - "Pressure Refuel Procedure" as an accepted procedure. (2) All fuel boost pump switches on P5 Overhead Panel are in the OFF position before the test. **NOTE:** For Airplanes with Auxiliary Tank the FWD and AFT Auxiliary Tank Fuel Boost Pumps switches on the P5 overhead panel should also be in the OFF position. (3) The CROSSFEED valve switch, on the P5 Overhead Panel, is set to the CLOSED position. (4) The APU switch on the overhead panel, P5, is in the OFF position. (5) With at least one Main Tank 1 fuel boost pump ON, operate Engine No. 1 at idle power for a minimum of two (2.0) minutes. Make a record of the engine parameters (N1, N2, and Fuel Flow).

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 22 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT**(6) With the fuel boost pumps OFF, make sure that the Engine No. 1 continues to operate for a minimum of five (5.0) minutes and the engine parameters (N1, N2, and Fuel Flow) do not decrease. b. If the engine does not operate for the full five (5.0) minutes or there is a decrease in N1, N2, or Fuel Flow, then do the following: (1) Set the two Main Tank 1 (Left) fuel boost pumps switches on the P5 Overhead Panel to the ON position. (2) Shut down the Engine No. 1. Refer to 737-300/400/500 AMM 71-00-00 as an acceptable procedure. (3) If the Engine Fuel Suction Feed Operational Test fails, Isolate the cause, repair, and repeat the "Engine Fuel Suction Feed - Operational Test". To troubleshoot refer to 737-300/400/500 AMM 28-22-00, "Engine Fuel Feed Lines/Coupling Vacuum Test". c. If the engine operates for the full five (5) minutes with no decrease in N1, N2, or Fuel Flow, then do the following: (1) Set the two Main Tank 1 (Left) fuel boost pumps switches on the P5 Overhead Panel to the ON position. (2) Shut down the Engine No. 1. Refer to 737-300/400/500 AMM 71-00-00 as an accepted procedure. (3) Put the airplane back to serviceable condition. **WORK PACKAGE 2 - ENGINE NO. 2, FUEL SUCTION FEED - OPERATIONAL TEST WARNING:**  DO NOT OPERATE A FUEL PUMP IF THE LOW PRESSURE LIGHT COMES ON AND STAYS ON. THIS CONDITION CAN CAUSE THE IGNITION OF THE FUEL FUMES IN THE FUEL TANK. A FIRE OR AN EXPLOSION CAN CAUSE INJURIES TO PERSONNEL AND DAMAGE TO EQUIPMENT. **WARNING:** OBSERVE PROPER SAFETY PRECAUTIONS AROUND RUNNING ENGINE. WEAR EAR PROTECTORS AND STAY CLEAR OF ENGINE HAZARD AREAS. SEE "ENGINE GROUND SAFETY PRECAUTIONS" FOR ENGINE HAZARD DESCRIPTION. a. Do the "Engine Fuel Suction Feed - Operational Test". Refer to 737-300/400/500 AMM 28-22-00 as an accepted procedure. During the Test you must meet the following requirements: (1) Make sure that these quantities of fuel are in the fuel tanks:
**FUEL QUANTITY TANK**  0 Lb - 2000 Lb (0 Kg- 907 Kg) CENTER TANK 1500 Lb -1700 Lb (680 Kg - 771 Kg) MAIN TANK 2 (Right) 0 Lb - 200 Lb (0 Kg - 91 Kg) AUXILIARY TANK (If Installed)

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 23 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT NOTE:**  The fuel quantity values given above are at or below the fuel level needed to cover the hydraulic heat exchangers. You must set the hydraulic system pumps "Off" when you operate the engines for this test. **NOTE:** If there is more fuel in the Center Tank and/or Main Tank 2 (Right) than recommended in the tables above, transfer the excess fuel as necessary or remove fuel from the fuel tanks. If defueling is not an option, the Engine No.2 Fuel Suction Feed Operational Test can be done twice in accordance with "Engine Fuel Suction Feed Operational Test - Configuration 2". To remove fuel refer to 737-300/400/500 AMM 28-23-00 - "Fuel Tank Defueling" as an accepted procedure. To transfer fuel refer to 737-300/400/500 AMM 28-23-00 - "Fuel Transfer from One Tank to a Different Tank" as an accepted procedure. To add fuel refer to 737-300/400/500 AMM 12-11-02 - "Pressure Refuel Procedure" as an accepted procedure. (2) All fuel boost pump switches on P5 Overhead Panel are in the OFF position before the test. **NOTE:** For Airplanes with Auxiliary Tank the FWD and AFT Auxiliary Tank Fuel Boost Pumps switches on the P5 overhead panel should also be in the OFF position. (3) The CROSSFEED valve switch, on the P5 Overhead Panel, is set to the CLOSED position. (4) The APU switch on the overhead panel, P5, is in the OFF position. (5) With at least one Main Tank 2 fuel boost pump ON, operate Engine No. 2 at idle power, with the boost pumps on for a minimum of two (2.0) minutes. Make a record of the engine parameters (N1, N2, and Fuel Flow). (6) With the fuel boost pumps OFF, make sure that the Engine No. 2 continues to operate for a minimum of five (5.0) minutes and the engine parameters (N1, N2, and Fuel Flow) do not decrease. b. If the engine does not operate for the full five (5.0) minutes or there is a decrease in N1, N2, or Fuel Flow, then do the following: (1) Set the two Main Tank 2 (Right) fuel boost pumps switches on the P5 Overhead Panel to the ON position. (2) Shut down the Engine No. 2. Refer to 737-300/400/500 AMM 71-00-00 as an acceptable procedure. (3) If the Engine Fuel Suction Feed Operational Test fails, Isolate the cause, repair, and repeat the "Engine Fuel Suction Feed - Operational Test". To troubleshoot refer to 737-300/400/500 AMM 28-22-00, "Engine Fuel Feed Lines/Coupling Vacuum Test". c. If the engine operates for the full five (5.0) minutes with no decrease in N1, N2, or Fuel Flow, then do the following: (1) Set the two Main Tank 2 (Right) fuel boost pumps switches on the P5 Overhead Panel to the ON position.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 24 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT**(2) Shut down the Engine No. 2. Refer to 737-300/400/500 AMM 71-00-00 as an acceptable procedure. (3) Put the airplane back to serviceable condition.

2. ENGINE FUEL SUCTION FEED OPERATIONAL TEST - CONFIGURATION 2 PROCEDURE **NOTE:** The Fuel Suction Feed Operational Test provided in Configuration 2, Workpackage 3 and Workpackage 4 require two engine runs for each engine and may not require fuel to be removed from the aircraft. **NOTE:** If the fuel quantities exceed the limits shown in Configuration 1 and defueling is not an option, Engine Fuel Suction Feed Operational Test must be accomplished twice on each engine. The first test must meet the requirements of CONFIGURATION 2, ENGINE RUN 1 which will test the center tank fuel feed plumbing, and the second test must meet the requirements of CONFIGURATION 2, ENGINE RUN 2 which will test the Main Tank fuel feed plumbing. a. WORKPACKAGE 3 **ENGINE NO. 1, FUEL SUCTION FEED - OPERATIONAL TEST, ENGINE RUN 1 WARNING:**  DO NOT OPERATE A FUEL PUMP IF THE LOW PRESSURE LIGHT COMES ON AND STAYS ON. THIS CONDITION CAN CAUSE THE IGNITION OF THE FUEL FUMES IN THE FUEL TANK. A FIRE OR AN EXPLOSION CAN CAUSE INJURIES TO PERSONNEL AND DAMAGE TO EQUIPMENT. **WARNING:** OBSERVE PROPER SAFETY PRECAUTIONS AROUND RUNNING ENGINE. WEAR EAR PROTECTORS AND STAY CLEAR OF ENGINE HAZARD AREAS. SEE "ENGINE GROUND SAFETY PRECAUTIONS" FOR ENGINE HAZARD DESCRIPTION. (1) Do the "Engine Fuel Suction Feed - Operational Test". Refer to 737-300/400/500 AMM 28-22-00 as an accepted procedure. During the Test you must meet the following requirements: (a) Make sure that these quantities of fuel are in the fuel tanks:
**FUEL QUANTITY TANK**  0 Lb - 2000 Lb (0 Kg- 907 Kg) CENTER TANK Any quantity above 1700 Lb (771 Kg) and within 1000 Lb (454 Kg) of Main Tank 2 MAIN TANK 1 (Left) 0 Lb - 200 Lb (0 Kg - 91 Kg) AUXILIARY TANK (If Installed)
**NOTE:** The fuel quantity values given above are at or below the fuel level needed to cover the hydraulic heat exchangers. You must set the hydraulic system pumps "Off" when you operate the engines for this test.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 25 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT NOTE:**  If there is more fuel in the Center Tank and/or Main Tank 1 (Left) than recommended in the tables above, transfer the excess fuel as necessary or remove fuel from the fuel tanks. To remove fuel refer to 737-300/400/500 AMM 28-23-00 - "Fuel Tank Defueling" as an accepted procedure. To transfer fuel refer to 737-300/400/500 AMM 28-23-00 - "Fuel Transfer from One Tank to a Different Tank" as an accepted procedure. To add fuel refer to 737-300/400/500 AMM 12-11-02 - "Pressure Refuel Procedure" as an accepted procedure. (b) All fuel boost pump switches on P5 Overhead Panel are in the OFF position before the test. **NOTE:** For Airplanes with Auxiliary Tank the FWD and AFT Auxiliary Tank Fuel Boost Pumps switches on the P5 overhead panel should also be in the OFF position. (c) The CROSSFEED valve switch, on the P5 Overhead Panel, is set to the CLOSED position. (d) The APU switch on the overhead panel, P5, is in the OFF position. (e) With at least one Main Tank 1 fuel boost pump ON, operate Engine No. 1 at idle power, with the boost pumps on for a minimum of two (2.0) minutes. Make a record of the engine parameters (N1, N2, and Fuel Flow). (f) With the fuel boost pumps OFF, make sure that the Engine No. 1 continues to operate for a minimum of five (5.0) minutes and the engine parameters (N1, N2, and Fuel Flow) do not decrease. (2) If the engine does not operate for the full five (5.0) minutes or there is a decrease in N1, N2, or Fuel Flow, then do the following: (a) Set the two Main Tank 1 (Left) fuel boost pumps switches on the P5 Overhead Panel to the ON position. (b) Shut down the Engine No. 1. Refer to 737-300/400/500 AMM 71-00-00 as an acceptable procedure. (c) If the Engine Fuel Suction Feed Operational Test fails, Isolate the cause, repair, and repeat the "Engine Fuel Suction Feed - Operational Test". To troubleshoot refer to 737-300/400/500 AMM 28-22-00, "Engine Fuel Feed Lines/Coupling Vacuum Test". (3) If the engine operates for the full five (5) minutes with no decrease in N1, N2, or Fuel Flow, then do the following: (a) Set the two Main Tank 1 (Left) fuel boost pumps switches on the P5 Overhead Panel to the ON position. (b) Shut down the Engine No. 1. Refer to 737-300/400/500 AMM 71-00-00 as an acceptable procedure.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 26 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT ENGINE NO. 1, FUEL SUCTION FEED - OPERATIONAL TEST, ENGINE RUN 2**  **WARNING:** DO NOT OPERATE A FUEL PUMP IF THE LOW PRESSURE LIGHT COMES ON AND STAYS ON. THIS CONDITION CAN CAUSE THE IGNITION OF THE FUEL FUMES IN THE FUEL TANK. A FIRE OR AN EXPLOSION CAN CAUSE INJURIES TO PERSONNEL AND DAMAGE TO EQUIPMENT. **WARNING:** OBSERVE PROPER SAFETY PRECAUTIONS AROUND RUNNING ENGINE. WEAR EAR PROTECTORS AND STAY CLEAR OF ENGINE HAZARD AREAS. SEE "ENGINE GROUND SAFETY PRECAUTIONS" FOR ENGINE HAZARD DESCRIPTION. (1) Do the "Engine Fuel Suction Feed - Operational Test". Refer to 737-300/400/500 AMM 28-22-00 as an accepted procedure. During the Test you must meet the following requirements: (a) Make sure that these quantities of fuel are in the fuel tanks:
**FUEL QUANTITY TANK**  Any quantity above 200 Lb (91 Kg) CENTER TANK 1500 Lb -1700 Lb (680 Kg - 771 Kg) MAIN TANK 1 (Left) Any quantity above 200 Lb (91 Kg) AUXILIARY TANK (If Installed)
**NOTE:** The fuel quantity values given above are at or below the fuel level needed to cover the hydraulic heat exchangers. You must set the hydraulic system pumps "Off" when you operate the engines for this test. **NOTE:** If there is more fuel in the Center Tank and/or Main Tank 1 (Left) than recommended in the tables above, transfer the excess fuel as necessary or remove fuel from the fuel tanks. To remove fuel refer to 737-300/400/500 AMM 28-23-00 - "Fuel Tank Defueling" as an accepted procedure. To transfer fuel refer to 737-300/400/500 AMM 28-23-00 - "Fuel Transfer from One Tank to a Different Tank" as an accepted procedure. To add fuel refer to 737-300/400/500 AMM 12-11-02 - "Pressure Refuel Procedure" as an accepted procedure. (b) All fuel switches on P5 Overhead Panel are in the OFF position before the test. **NOTE:** For Airplanes with Auxiliary Tank the FWD and AFT Auxiliary Tank Fuel Boost Pumps switches on the P5 overhead panel should also be in the OFF position. (c) The CROSSFEED valve switch, on the P5 Overhead Panel, is set to the CLOSED position. (d) The APU switch on the overhead panel, P5, is in the OFF position. (e) With at least one Main Tank 1 fuel boost pump ON, operate Engine No. 1 at idle power, with the boost pumps on for a minimum of two (2.0) minutes. Make a record of the engine parameters (N1, N2, and Fuel Flow).

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 27 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT**(f) With the fuel boost pumps OFF, make sure that the Engine No. 1 continues to operate for a minimum of five (5.0) minutes and the engine parameters (N1, N2, and Fuel Flow) do not decrease. (2) If the engine does not operate for the full five (5.0) minutes or there is a decrease in N1, N2, or Fuel Flow, then do the following: (a) Set the two Main Tank 1 (Left) fuel boost pumps switches on the P5 Overhead Panel to the ON position. (b) Shut down the Engine No. 1. Refer to 737-300/400/500 AMM 71-00-00 as an acceptable procedure. (c) If the Engine Fuel Suction Feed Operational Test fails, Isolate the cause, repair, and repeat the "Engine Fuel Suction Feed - Operational Test". To troubleshoot refer to 737-300/400/500 AMM 28-22-00, "Engine Fuel Feed Lines/Coupling Vacuum Test". (3) If the engine operates for the full five (5) minutes with no decrease in N1, N2, or Fuel Flow, then do the following: (a) Set the two Main Tank 1 (Left) fuel boost pumps switches on the P5 Overhead Panel to the ON position. (b) Shut down the Engine No. 1. Refer to 737-300/400/500 AMM 71-00-00 as an acceptable procedure. (c) Put the airplane back to serviceable condition. b. WORKPACKAGE 4 **ENGINE NO. 2, FUEL SUCTION FEED - OPERATIONAL TEST, ENGINE RUN 1 WARNING:**  DO NOT OPERATE A FUEL PUMP IF THE LOW PRESSURE LIGHT COMES ON AND STAYS ON. THIS CONDITION CAN CAUSE THE IGNITION OF THE FUEL FUMES IN THE FUEL TANK. A FIRE OR AN EXPLOSION CAN CAUSE INJURIES TO PERSONNEL AND DAMAGE TO EQUIPMENT. **WARNING:** OBSERVE PROPER SAFETY PRECAUTIONS AROUND RUNNING ENGINE. WEAR EAR PROTECTORS AND STAY CLEAR OF ENGINE HAZARD AREAS. SEE "ENGINE GROUND SAFETY PRECAUTIONS" FOR ENGINE HAZARD DESCRIPTION. (1) Do the "Engine Fuel Suction Feed - Operational Test". Refer to 737-300/400/500 AMM 28-22-00 as an accepted procedure. During the Test you must meet the following requirements: (a) Make sure that these quantities of fuel are in the fuel tanks:
**FUEL QUANTITY TANK**  0 Lb - 2000 Lb (0 Kg- 907 Kg) CENTER TANK

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 28 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT FUEL QUANTITY**  **TANK** Any quantity above 1700 Lb (771 Kg) and within 1,000 Lb (454 Kg) of the Main Tank 1 MAIN TANK 2 (Right) 0 Lb - 200 Lb (0 Kg - 91 Kg) AUXILIARY TANK (If Installed)
**NOTE:** The fuel quantity values given above are at or below the fuel level needed to cover the hydraulic heat exchangers. You must set the hydraulic system pumps "Off" when you operate the engines for this test. **NOTE:** If there is more fuel in the Center Tank and/or Main Tank 2 (Right) than recommended in the tables above, transfer the excess fuel as necessary or remove fuel from the fuel tanks. To remove fuel refer to 737-300/400/500 AMM 28-23-00 - "Fuel Tank Defueling" as an accepted procedure. To transfer fuel refer to 737-300/400/500 AMM 28-23-00 - "Fuel Transfer from One Tank to a Different Tank" as an accepted procedure. To add fuel refer to 737-300/400/500 AMM 12-11-02 - "Pressure Refuel Procedure" as an accepted procedure. (b) All fuel boost pump switches on P5 Overhead Panel are in the OFF position before the test. **NOTE:** For Airplanes with Auxiliary Tank the FWD and AFT Auxiliary Tank Fuel Boost Pumps switches on the P5 overhead panel should also be in the OFF position. (c) The CROSSFEED valve switch, on the P5 Overhead Panel, is set to the CLOSED position. (d) The APU switch on the overhead panel, P5, is in the OFF position. (e) With at least one Main Tank 2 fuel boost pump ON, operate Engine No. 2 at idle power, with the boost pumps on for a minimum of two (2.0) minutes. Make a record of the engine parameters (N1, N2, and Fuel Flow). (f) With the fuel boost pumps OFF, make sure that the Engine No. 2 continues to operate for a minimum of five (5.0) minutes and the engine parameters (N1, N2, and Fuel Flow) do not decrease. (2) If the engine does not operate for the full five (5.0) minutes or there is a decrease in N1, N2, or Fuel Flow, then do the following: (a) Set the two Main Tank 2 (Right) fuel boost pumps switches on the P5 Overhead Panel to the ON position. (b) Shut down the engine No. 2. Refer to 737-300/400/500 AMM 71-00-00 as an acceptable procedure. (c) If the Engine Fuel Suction Feed Operational Test fails, Isolate the cause, repair, and repeat the "Engine Fuel Suction Feed - Operational Test". To troubleshoot refer to 737-300/400/500 AMM 28-22-00, "Engine Fuel Feed Lines/Coupling Vacuum Test".

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 29 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT**(3) If the engine operates for the full five (5.0) minutes with no decrease in N1, N2, or Fuel Flow, then do the following: (a) Set the two Main Tank 2 (Right) fuel boost pumps switches on the P5 Overhead Panel to the ON position. (b) Shut down the Engine No. 2. Refer to 737-300/400/500 AMM 71-00-00 as an acceptable procedure. **ENGINE NO. 2, FUEL SUCTION FEED - OPERATIONAL TEST, ENGINE RUN 2 WARNING:**  DO NOT OPERATE A FUEL PUMP IF THE LOW PRESSURE LIGHT COMES ON AND STAYS ON. THIS CONDITION CAN CAUSE THE IGNITION OF THE FUEL FUMES IN THE FUEL TANK. A FIRE OR AN EXPLOSION CAN CAUSE INJURIES TO PERSONNEL AND DAMAGE TO EQUIPMENT. **WARNING:** OBSERVE PROPER SAFETY PRECAUTIONS AROUND RUNNING ENGINE. WEAR EAR PROTECTORS AND STAY CLEAR OF ENGINE HAZARD AREAS. SEE "ENGINE GROUND SAFETY PRECAUTIONS" FOR ENGINE HAZARD DESCRIPTION. (1) Do the "Engine Fuel Suction Feed - Operational Test". Refer to 737-300/400/500 AMM 28-22-00 as an accepted procedure. During the Test you must meet the following requirements: (a) Make sure that these quantities of fuel are in the fuel tanks:
**FUEL QUANTITY TANK**  Any quantity above 200 Lb (91 Kg) CENTER TANK 1500 Lb -1700 Lb (680 Kg - 771 Kg) MAIN TANK 2 (Right) Any quantity above 200 Lb (91 Kg) AUXILIARY TANK (If Installed)
**NOTE:** The fuel quantity values given above are at or below the fuel level needed to cover the hydraulic heat exchangers. You must set the hydraulic system pumps "Off" when you operate the engines for this test. **NOTE:** If there is more fuel in the Center Tank and/or Main Tank 2 (Right) than recommended in the tables above, transfer the excess fuel as necessary or remove fuel from the fuel tanks. To remove fuel refer to 737-300/400/500 AMM 28-23-00 - "Fuel Tank Defueling" as an accepted procedure. To transfer fuel refer to 737-300/400/500 AMM 28-23-00 - "Fuel Transfer from One Tank to a Different Tank" as an accepted procedure. To add fuel refer to 737-300/400/500 AMM 12-11-02 - "Pressure Refuel Procedure" as an accepted procedure. (b) All fuel boost pump switches on P5 Overhead Panel are in the OFF position before the test.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 30 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT NOTE:**  For Airplanes with Auxiliary Tank the FWD and AFT Auxiliary Tank Fuel Boost Pumps switches on the P5 overhead panel should also be in the OFF position. (c) The CROSSFEED valve switch, on the P5 Overhead Panel, is set to the CLOSED position. (d) The APU switch on the overhead panel, P5, is in the OFF position. (e) With at least one Main Tank 2 fuel boost pump ON, operate Engine No. 2 at idle power, with the boost pumps on for a minimum of two (2.0) minutes. Make a record of the engine parameters (N1, N2, and Fuel Flow). (f) With the fuel boost pumps OFF, make sure that the Engine No. 2 continues to operate for a minimum of five (5.0) minutes and the engine parameters (N1, N2, and Fuel Flow) do not decrease. (2) If the engine does not operate for the full five (5.0) minutes or there is a decrease in N1, N2, or Fuel Flow, then do the following: (a) Set the two Main Tank 2 (Right) fuel boost pumps switches on the P5 Overhead Panel to the ON position. (b) Shut down the Engine No.2. Refer to 737-300/400/500 AMM 71-00-00 as an acceptable procedure. (c) If the Engine Fuel Suction Feed Operational Test fails, Isolate the cause, repair, and repeat the "Engine Fuel Suction Feed - Operational Test". To troubleshoot refer to 737-300/400/500 AMM 28-22-00, "Engine Fuel Feed Lines/Coupling Vacuum Test". (3) If the engine operates for the full five (5.0) minutes with no decrease in N1, N2, or Fuel Flow, then do the following: (a) Set the two Main Tank 2 (Right) fuel boost pumps switches on the P5 Overhead Panel to the ON position. (b) Shut down the Engine No. 2. Refer to 737-300/400/500 AMM 71-00-00 as an acceptable procedure. (c) Put the airplane back to serviceable condition.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 14, 2012 737-28A1307 31 of 31 **BOEING SERVICE BULLETIN 737-28A1307 ALERT**  **ALERT**