Commercial 

Airplanes 737

Service Bulletin

ALERT

Number: 737-57A1319

Original Issue: April 16, 2012

ATA System: 5752

SUBJECT: WINGS - Trailing Edge Flaps - Outboard Flap, Carriage Spindle - Inspection for

Corrosion

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.

ECCN: 9E991

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Unpublished Work.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.

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6.0
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BOEING SERVICE BULLETIN 737-57A1319

ALERT ALERT

BLANK PAGE
Table of Contents

Summary ...................................................... 5

1. PLANNING INFORMATION ........................................ 9

A. Effectivity ................................................ 9

1. Airplanes ............................................. 9

2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

E. Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

2. Data Supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

3. Installation Drawings Used in the Preparation of this Service Bulletin: . . . . . . . . . . . 24

K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

M. Software Accomplishment Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

C. Parts Necessary for Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

1. Kits/Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

2. Parts and Materials Supplied by the Operator . . . . . . . . . . . . . . . . . . . . . . . . 27

3. Parts Modified and Reidentified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

4. Parts Removed and Not Replaced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 27

3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

FIGURE 1: LOCATE SUB-ASSEMBLY PART NUMBER FOR CARRIAGES AT WBL 254 AND WBL 355

WITH HVOF THERMAL COATED SPINDLES . . . . . . . . . . . . . . . . . . . . . . . . 33

FIGURE 2: INSPECT SUSPECT CARRIAGE SPINDLES FOR CORROSION . . . . . . . . . . . . . 35

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BOEING SERVICE BULLETIN 737-57A1319

ALERT ALERT

BLANK PAGE
Commercial 

Airplanes 737

Service Bulletin

ALERT

Summary Number: 737-57A1319

Original Issue: April 16, 2012

ATA System: 5752

SUBJECT: WINGS - Trailing Edge Flaps - Outboard Flap, Carriage Spindle - Inspection for

Corrosion

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

Boeing has recently received reports of corrosion on outboard flap carriages from four operators, on carriage

spindles with less than 7,000 flight cycles. Each of these reports was on carriages with

Tungsten-Carbide-Cobalt-Chrome coating applied with High Velocity Oxygenated Fuel (HVOF) on the spindle

portion. None were reported to have any fractures. The coating had flaked off the lower surface of the spindle,

at the root. A crack in the coating can lead to moisture ingress which may begin corroding the alloy steel base

metal. If left unchecked, corrosion pits in this area may create a stress concentration where a crack can start in

the base metal resulting in the inability of the carriage to sustain limit load. One fractured carriage spindle can

be compensated for by the pilot with inputs to the aileron and or rudder. However fractures of both the inboard

and the outboard carriage spindles at the forward end of the spindle through the large diameter (the critical

section), on a given outboard flap may preclude continued safe flight and landing of the airplane.

This service bulletin provides instruction to inspect 737-100/-200/-200C/-300/400/500 carriage spindles with

High Velocity Oxy-Fuel (HVOF) thermal coating that are installed at WBL 254 and WBL 355 on the outboard

trailing edge flaps for corrosion and missing or flaked coating.

Boeing Service Related Problem (SRP) 737-SRP-57-0254 is related to this service bulletin.

ACTION

Review your records or do an inspection for the carriage part number to determine if you have any of the suspect

carriage sub-assemblies that have Tungsten-Carbide-Cobalt-Chrome coating applied with High Velocity

Oxygenated Fuel (HVOF) thermal coating on the spindle. If you determine that you do have suspect carriages

with the HVOF thermal coating on the spindle, inspect for missing or flaked coating and/or base metal corrosion

and presence of Corrosion Inhibiting Compound (CIC). Do a detailed inspection or a Borescope inspection on

the forward end of the spindle, that is forward of the flap front spar. Inspect the HVOF thermal coated spindles

in accordance with Paragraph 1.E., Compliance. Remove and replace the corroded carriages with a new or

serviceable carriage.

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The replacement of a carriage that has the suspect HVOF thermal coating on the spindle with one that does

not have this HVOF coating, will terminate the inspection in this service bulletin for that carriage only. As an

option, the suspect carriage may be reworked into a non-suspect condition. Contact Boeing for additional

information. If you determine that your airplane does not have any carriage with the HVOF thermal coating, then

there is no further action required.

EFFECTIVITY

737-100, -200, -200C, -300, -400, -500 Airplanes. Refer to Paragraph 1.A.1., Airplanes for the list of affected

airplanes.

COMPLIANCE

Refer to Paragraph 1.E., Compliance.

The Federal Aviation Administration (FAA) will possibly release another Airworthiness Directive related to this

service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service

bulletin mandatory.

INDUSTRY SUPPORT INFORMATION

Boeing warranty remedies are not available for the inspection, and/or repair procedures given in this service

bulletin.

MANPOWER

Refer to Paragraph 1.G., Manpower.

MATERIAL INFORMATION

None.

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BOEING SERVICE BULLETIN 737-57A1319

ALERT ALERT

BLANK PAGE
Commercial 

Airplanes 737

Service Bulletin

ALERT

Number: 737-57A1319

Original Issue: April 16, 2012

ATA System: 5752

SUBJECT: WINGS - Trailing Edge Flaps - Outboard Flap, Carriage Spindle - Inspection for

Corrosion

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

GROUP CONFIGURATION DESCRIPTION

1 - 737-100, -200, -200C, -300, -400, -500 airplanes.

Airplane Models:

737-100, 737-200, 737-200C, 737-300, 737-400, 737-500

Variable Number Group

PA001 - PA022 1

PA099 1

PA231 - PA232 1

PC001 - PC005 1

PG001 - PG075 1

PG199 1

PG201 - PG230 1

PG251 - PG255 1

PG271 - PG279 1

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Variable Number Group

PG301 - PG314 1

PG331 - PG332 1

PG351 - PG356 1

PG375 1

PG401 - PG403 1

PG431 - PG442 1

PG471 - PG475 1

PG501 - PG505 1

PG571 - PG586 1

PG621 - PG630 1

PG651 - PG652 1

PG701 - PG705 1

PH001 1

PH011 - PH013 1

PH021 - PH024 1

PH701 - PH715 1

PH731 - PH732 1

PH741 - PH743 1

PJ001 - PJ009 1

PJ031 - PJ032 1

PJ071 - PJ072 1

PJ101 - PJ119 1

PJ201 - PJ219 1

PJ301 - PJ302 1

PJ551 - PJ561 1

PJ601 - PJ615 1

PJ811 1

PJ816 - PJ817 1

PK026 - PK029 1

PK041 - PK053 1

PK061 - PK070 1

PK081 - PK082 1

PK091 - PK099 1

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BOEING SERVICE BULLETIN 737-57A1319

ALERT ALERT
Variable Number Group

PK101 - PK103 1

PK111 - PK120 1

PK141 - PK146 1

PK201 - PK204 1

PK211 - PK223 1

PK231 - PK241 1

PK251 - PK258 1

PK271 - PK274 1

PK281 - PK289 1

PK291 1

PK301 - PK318 1

PK341 1

PK351 - PK361 1

PK391 1

PK431 - PK433 1

PK451 - PK452 1

PK461 - PK469 1

PK495 1

PK501 - PK504 1

PK511 - PK515 1

PK519 1

PK521 - PK528 1

PK541 - PK565 1

PK581 1

PK591 - PK599 1

PK601 - PK617 1

PK621 - PK637 1

PK641 - PK642 1

PK661 - PK666 1

PK671 - PK681 1

PK691 - PK697 1

PK711 - PK716 1

PK731 - PK765 1

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ALERT ALERT
Variable Number Group

PK771 - PK779 1

PK801 - PK804 1

PK819 - PK827 1

PK830 1

PK861 - PK863 1

PK871 - PK874 1

PK881 - PK884 1

PK901 - PK938 1

PK971 - PK974 1

PL001 - PL028 1

PL061 1

PL081 1

PL101 - PL113 1

PL151 1

PL171 - PL172 1

PL201 - PL203 1

PL221 1

PL401 - PL417 1

PL421 1

PL441 1

PL451 - PL456 1

PL471 1

PL491 1

PL501 - PL506 1

PL551 - PL562 1

PL581 1

PL601 - PL603 1

PL611 1

PL621 - PL626 1

PL631 - PL632 1

PL711 - PL712 1

PL716 - PL747 1

PL756 1

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ALERT ALERT
Variable Number Group

PL758 1

PL761 - PL770 1

PL781 - PL788 1

PL793 1

PL801 - PL803 1

PM001 - PM006 1

PM016 - PM017 1

PM021 - PM023 1

PM051 - PM066 1

PM101 - PM119 1

PM141 - PM142 1

PM171 1

PM181 1

PM251 - PM255 1

PM281 - PM283 1

PM381 - PM399 1

PM401 - PM417 1

PM541 - PM564 1

PN001 - PN002 1

PN021 - PN043 1

PN081 - PN086 1

PN101 - PN117 1

PN131 - PN163 1

PN401 - PN420 1

PN431 - PN433 1

PN451 - PN456 1

PN471 - PN474 1

PN481 1

PN491 - PN493 1

PN501 - PN502 1

PN511 - PN512 1

PN521 1

PP001 - PP054 1

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ALERT ALERT
Variable Number Group

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 1

PQ026 - PQ041 1

PQ051 - PQ092 1

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BOEING SERVICE BULLETIN 737-57A1319

ALERT ALERT
Variable Number Group

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 1

PR077 - PR082 1

PR091 - PR092 1

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BOEING SERVICE BULLETIN 737-57A1319

ALERT ALERT
Variable Number Group

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 1

PT101 - PT105 1

PT121 - PT138 1

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ALERT ALERT
Variable Number Group

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 1

PV201 - PV209 1

PV226 - PV229 1

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ALERT ALERT
Variable Number Group

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 1

PW511 - PW522 1

PW524 - PW550 1

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ALERT ALERT
Variable Number Group

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 1

PX071 1

PX701 1

PY001 - PY008 1

PY021 - PY022 1

PY031 1

PY036 - PY037 1

PY046 - PY048 1

PY051 - PY053 1

PY056 - PY057 1

PY101 - PY103 1

PY111 - PY113 1

PY131 - PY135 1

PY141 - PY143 1

PY151 - PY154 1

PY156 - PY157 1

PY161 - PY162 1

PY166 1

PY191 1

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BOEING SERVICE BULLETIN 737-57A1319

ALERT ALERT
Variable Number Group

PY201 1

PY221 - PY222 1

PY231 1

PY241 - PY244 1

PY270 - PY275 1

PY281 1

PY286 1

PY301 - PY304 1

PY321 - PY323 1

PY341 - PY346 1

PY361 - PY362 1

PY381 1

PY401 1

PY409 - PY411 1

PY421 - PY422 1

PY441 1

PY451 1

PY461 - PY463 1

PY591 - PY595 1

PY611 - PY612 1

PY621 1

PY631 1

PY651 1

PY671 - PY672 1

PY721 1

PY741 1

2. Spares Affected

Examine your spares supply for the parts or components identified in this service bulletin. If any

parts or components are found, refer to Paragraph 3.B. Work Instruction for the required action

B. Concurrent Requirements

None.

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BOEING SERVICE BULLETIN 737-57A1319

ALERT ALERT
C. Reason

Boeing has recently received reports of corrosion on outboard flap carriages from four operators, on

carriage spindles with less than 7,000 flight cycles. Each of these reports was on carriages with

Tungsten-Carbide-Cobalt-Chrome coating applied with High Velocity Oxygenated Fuel (HVOF) on the

spindle portion. None were reported to have any fractures. The coating had flaked off the lower surface

of the spindle, at the root. A crack in the coating can lead to moisture ingress which may begin corroding

the alloy steel base metal. If left unchecked, corrosion pits in this area may create a stress concentration

where a crack can start in the base metal resulting in the inability of the carriage to sustain limit load.

One fractured carriage spindle can be compensated for by the pilot with inputs to the aileron and or

rudder. However fractures of both the inboard and the outboard carriage spindles at the forward end

of the spindle through the large diameter (the critical section), on a given outboard flap may preclude

continued safe flight and landing of the airplane

This service bulletin provides instruction to inspect 737-100/-200/-200C/-300/400/500 carriage spindles

with High Velocity Oxy-Fuel (HVOF) thermal coating that are installed at WBL 254 and WBL 355 on

the outboard trailing edge flaps for corrosion and missing or flaked coating.

Boeing Service Related Problem (SRP) 737-SRP-57-0254 is related to this service bulletin.

D. Description

Review your records or do an inspection for the carriage part number to determine if you have any of

the suspect carriage sub-assemblies that have Tungsten-Carbide-Cobalt-Chrome coating applied with

High Velocity Oxygenated Fuel (HVOF) thermal coating on the spindle. If you determine that you do

have suspect carriages with the HVOF thermal coating on the spindle, inspect for missing or flaked

coating and/or base metal corrosion and presence of Corrosion Inhibiting Compound (CIC). Do a

detailed inspection or a Borescope inspection on the forward end of the spindle, that is forward of the

flap front spar. Inspect the HVOF thermal coated spindles in accordance with Paragraph 1.E.,

Compliance. Remove and replace the corroded carriages with a new or serviceable carriage.

The replacement of a carriage that has the suspect HVOF thermal coating on the spindle with one that

does not have this HVOF coating, will terminate the inspection in this service bulletin for that carriage

only. As an option, the suspect carriage may be reworked into a non-suspect condition. Contact Boeing

for additional information. If you determine that your airplane does not have any carriage with the HVOF

thermal coating, then there is no further action required.

The work in this service bulletin is done in the maintenance zone(s) given below.

Group 1:

Affected Maintenance Zones

Model Zone

737-100, 737-200, 737-200C 3-7, 4-7

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Group 1:

Affected Maintenance Zones

Model Zone

737-300, 737-400, 737-500 307, 407

E. Compliance

The Federal Aviation Administration (FAA) will possibly release another Airworthiness Directive related

to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in

this service bulletin mandatory.

Table 1: Inspect HVOF thermal coated Outboard Flap, Carriage Spindles at WBL 254 and WBL

355 for missing or Flaked coating and Corrosion.

Repeat Interval

(Not to Exceed)

Condition Action Compliance Time

Within 90 days af- -

ter the original issue date of this

service bulletin

Determine if you have

any suspect carriage installed in accordance with

Work Instruction, Paragraph 3.B. Step 1.

All airplanes

Within 90 days af- 180 days (a)

ter the original issue date of this

service bulletin or

180 days from the

installation of a

suspect carriage,

whichever occurs

later. (a)

Inspect the lower surface

of the forward end of the

spindle at the root, in accordance with Work Instruction, Paragraph 3.B.

Step 6.

All airplanes with suspect

carriage part numbers

65C27409-29 or

65C27409-31 or 65-47821-

30 or unidentifiable part

numbers.

Before further (a)

flight.

Replace the carriage with

a serviceable carriage, in

accordance with Work Instruction, Paragraph 3.B.

Step 6.b.

Missing or flaked coating

or base metal corrosion is

found.

Before further -

flight.

Inspect the lower surface

of the forward end of the

spindle at the root for CIC

coverage in accordance

with Work Instruction,

Paragraph 3.B. Step 6.a.

No missing or flaked coating or base metal corrosion

is found.

Before further -

flight.

Apply CIC as necessary,

in accordance with Work

Instruction, Paragraph

3.B. Step 6.a.

CIC does not cover the inspection area.

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Table 1: Inspect HVOF thermal coated Outboard Flap, Carriage Spindles at WBL 254 and WBL

355 for missing or Flaked coating and Corrosion.

Repeat Interval

(Not to Exceed)

Condition Action Compliance Time

(a) Replacing a suspect carriage with a new or serviceable non-suspect carriage, in accordance

with Work Instruction, Paragraph 3.B. Step 7, terminates the inspections in this service bulletin

for that carriage only.

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

This estimate does not include the task hour data given in the service bulletins in Paragraph 1.B.,

Concurrent Requirements.

The table below shows an estimate of the task hours necessary to do this service bulletin for each

carriage spindle. 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.

Number of Per- Task Hours Elapsed Hours

sons

Task

Open Access 1 0.60 0.60

Inspect 1 0.80 0.80

Replace 4 17.00 4.25

Close Access 1 0.60 0.60

Test 2 1.50 0.75

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Number of Per- Task Hours Elapsed Hours

sons

Task

TOTAL FOR EACH AIRPLANE CAR- 20.50 7.00

RIAGE SPINDLE

H. Weight and Balance Changes

None.

I. Electrical Load Data

Not applicable.

J. References

1. Existing Data:

a. Service Related Problem (SRP) 737-SRP-57-0254

b. Boeing Parts Standards Document D-590

c. Boeing Drawing 65-88700

d. 737-300/400/500 Aircraft Maintenance Manual (AMM) 27-51-00, 27-51-34, 27-51-44

e. 737-100/200/200C Aircraft Maintenance Manual (AMM) 737-100/200 AMM 27-51-00,

737-100/200 AMM 27-51-72, 737-100/200 AMM 27-51-81

f. Standard Overhaul Practices Manual (SOPM) SOPM 20-50-10, SOPM 20-41-05

2. Data Supplied with this Service Bulletin:

None.

3. Installation Drawings Used in the Preparation of this Service Bulletin:

Drawing Number Title

65C16930 Trailing Edge Flap Installation and Rigging Procedures

65C27409 Carriage Sub Assy - Outboard Flap

65-46481 Carriage Assy, Outboard Flap, Wing

These drawings were used to prepare this service bulletin. These drawings are not necessary to

make the specified changes, and are not supplied with this service bulletin. These drawings may

not be applicable to all airplane configurations or operators.

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K. Publications Affected

Publication Chapter-Section

737 Illustrated Parts Catalog 27-51

Component Maintenance Manual 57-53

737 Aircraft Maintenance Manual 27-51

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. No new Damage Tolerance Inspections (DTIs) are required by this Service Bulletin.

L. Interchangeability and Intermixability of Parts

Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts.

M. Software Accomplishment Summary

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BLANK PAGE
2. MATERIAL INFORMATION

A. Material - Price and Availability

None.

B. Industry Support Information

Boeing warranty remedies are not available for the inspection, and/or repair procedures given in this

service bulletin.

C. Parts Necessary for Each Airplane

1. Kits/Parts

None.

2. Parts and Materials Supplied by the Operator

None.

3. Parts Modified and Reidentified

None.

4. Parts Removed and Not Replaced

None.

D. Parts Necessary to Change Spares

If you have outboard flap, carriage spindles 65C27409-29 / -31 or 65-47821-30 with the High Velocity

Oxygenated Fuel (HVOF) coating, refer to Paragraph 3.B., Work Instructions for the required action.

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.

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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. Unless shown differently, these dimensions and tolerances are used:

– Linear dimensions are in inches

– Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus

or minus 0.03 inch

– Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch

– Angular tolerance is plus or minus 2 degrees

– Hole dimensions for standard solid rivets are given in 737 SRM, Chapter 51

– Torque limits to tighten nuts and bolts are given in 737 SRM, Chapter 51

4. For approved fastener and process material substitutions, refer to 737 SRM, Chapter

51. Alternate fasteners are given in 737 SRM Chapter 51

5. If the length of any fastener specified in this service bulletin does not meet the

installation standards given in SRM Chapter 51, then a fastener of the same

specification, or an approved substitute, with a length which meets the installation

standards given in SRM Chapter 51 may be used.

6. A Detailed Inspection is defined as: An intensive examination of a specific item,

installation, or assembly to detect damage, failure, or irregularity. Available lighting

is normally supplemented with a direct source of good lighting at an intensity deemed

appropriate. Inspection aids such as mirrors, magnifying lenses, etc. may be

necessary. Surface cleaning and elaborate procedures may be required.

7. 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.

8. The instructions in Paragraph 3.B., Work Instructions and the figures can include

operation of tools or test equipment. Boeing Engineering Tool Drawings, the Illustrated

Tool and Equipment Manual, and the Special Tool and Ground Handling Drawing

Index contain data on versions of the tools or test equipment that you can use. It is

permitted to use replaced tools. It is not permitted to use superseded tools.

9. If it is necessary to remove more parts for access, you can remove those parts. If

you can get access without removing identified parts, it is not necessary to remove

all of the identified parts. Jacking and shoring limitations must be observed.

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10. Where the work instructions include installation of a kept part, a new or serviceable

part with the same part number can be installed as an alternative to the kept part.

11. 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.

12. Some Boeing parts are supplied in a temporary configuration. Those parts are

identified with a 'U', 'W', or 'Y' in place of the '-' (dash) in the part number. It is

permitted to install parts identified with a 'U', 'W', or 'Y' as an alternative to the '-'(dash)

part number. Boeing Drawing 005W0900 contains more data.

13. 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.

B. WORK INSTRUCTIONS

1. Use one of the two following methods to determine if you have any suspect carriages, i.e., carriages

with the High Velocity Oxygen Fuel (HVOF) coating, installed at WBL 254 or WBL 355. If you do

not have a carriage with HVOF coating, then there is no further action required. All 737-300, -400,

-500 carriage sub-assemblies have the base part number 65C27409-( ). The two suspect part

numbers are 65C27409-29 and 65C27409-31. All 737-100,-200, -200C carriage sub-assemblies

have the base part number 65-47821-( ). The 737-100, -200, -200C carriage sub-assembly suspect

part number is 65-47821-30. If you are unable to identify the sub-assembly part number in the

form of 65C27409-( ) or 65-47821-( ), you must assume you have a suspect carriage.

a. You may use your records, if your record review positively identifies the carriage sub-assembly

part number. If your records indicate a sub-assembly 65C27409 with a dash number other

than -29, and -31 for 737-300, -400, -500 or 65-47821-30 for 737-100, -200, -200C, then there

is no further action required.

If your records indicate that you have a sub-assembly part number 65C27409-29 or

65C27409-31 for 737-300, -400, -500 or 65-47821-30 for 737-100, -200, -200C, you have a

suspect carriage sub-assembly.

b. You can identify the carriage by the sub-assembly part number on the part. Gain access as

required to the carriages on the outboard flap at WBL 254 and WBL 355. Removal of the flap

fairing may be required to read the part mark information on the bottom side of the carriage.

Refer to FIGURE 1 for the location of the Boeing sub-assembly part number.

NOTE: Care must be taken, as an older assembly number does not preclude a newer

sub-assembly carriage with the HVOF coated spindle.

2. Gain access as required to the carriages on the outboard flap at WBL 254 and WBL 355.

3. Supply power to the hydraulic system. Refer to 737-100/200 AMM 27-51-00 and 737-300/400/500

AMM 27-51-00 as an accepted procedure.

4. Extend the flaps to 40 detent or as required, to expose the spindle area of the carriage.

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NOTE: For additional access you may manually deploy the flaps beyond the Flap 40 position,

down to the screwjack stops, by winding the torque tubes in the main wheel well.

5. Remove power from the hydraulic system. Refer to 737-100/200 AMM 27-51-00 and

737-300/400/500 AMM 27-51-00 as an accepted procedure.

6. For any suspect carriage, gain access through the front of the trailing edge flap for a detailed

inspection or an optional Borescope inspection of the carriage spindle forward section. Perform

the detailed inspection or the Borescope inspections of the indicated sections of the spindle, looking

for missing or flaked coating or base metal corrosion in accordance with FIGURE 2.

As an option, replacing a suspect carriage with a new or serviceable non-suspect carriage, in

accordance with Work Instruction, Paragraph 3.B Step 7, terminates the inspections in this service

bulletin for that carriage only.

a. If no indication of missing or flaked coating or base metal corrosion is found, the carriage does

not need to be disassembled or removed. Perform a detailed inspection for Corrosion Inhibiting

Compound (CIC) coverage in accordance with FIGURE 2. If CIC does not cover the inspection

area, apply BMS3-27 or BMS3-25 CIC to the indicated section, in accordance with FIGURE

2. Refer to SOPM 20-41-05 as an accepted procedure.

b. If missing or flaked coating or base metal corrosion is found, replace the carriage with a new

or serviceable carriage, in accordance with Step 7.

NOTE: For purposes of this service bulletin, a "serviceable" part can be either a "suspect"

part, i.e., a carriage with HVOF coating, or a "non-suspect" part, i.e., a carriage that

does not have HVOF coating. Boeing is currently developing service instructions to

rework suspect carriages into non-suspect carriages. Contact Boeing for further

information.

7. Use the following steps to remove or replace any carriage.

NOTE: Replacing a suspect carriage, with one that is not coated with HVOF will terminate the

inspections for that location.

a. Remove the outboard trailing edge flap. Refer to 737-100/200 AMM 27-51-72 or

737-300/400/500 AMM 27-51-34 as an accepted procedure.

b. Remove the midflap carriage from the outboard midflap. Refer to 737-100/200 AMM 27-51-81

or 737-300/400/500 AMM 27-51-44 as an accepted procedure.

c. Install the midflap carriage in the outboard midflap. Refer to 737-100/200 AMM 27-51-81 or

737-300/400/500 AMM 27-51-44 as an accepted procedure.

d. Install the outboard trailing edge flap. Refer to 737-100/200 AMM 27-51-72 or 737-300/400/500

AMM 27-51-34 as an accepted procedure.

8. Supply power to the hydraulic system. Refer to 737-100/200 AMM 27-51-00 or 737-300/400/500

AMM 27-51-00 as an accepted procedure

9. Retract the flaps fully to 0 detent position.

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10. Remove power from the hydraulic system. Refer to 737-100/200 AMM 27-51-00 or 737-300/400/500

AMM 27-51-00 as an accepted procedure.

11. Put the airplane back to a serviceable condition

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FIGURE 1: LOCATE SUB-ASSEMBLY PART NUMBER FOR CARRIAGES AT WBL 254 AND WBL 355 WITH

HVOF THERMAL COATED SPINDLES

(SHEET 1 OF 2)

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STEP TASK NAME IDENTIFICATION QTY MORE DATA

Carriage Sub-assem- 65C27409-29 - (a) (b) (d)

bly part number

1 Identify

65C27409-31 -

65-47821-30

Carriage Sub-assem- 65C27409-( ) - (b) (c) (d)

bly part number

2 Identify

65-47821-( )

(a) The carriage sub-assembly part number is etched at the bottom of the carriage.

(b) Care must be taken, as an older assembly number does not preclude a newer sub-assembly carriage with

the HVOF coated spindle

(c) This is the location of the part number on older carriage sub-assemblies.

Removal of the flap may be required to access this area.

(d) Accomplishment of step 2 is only required if no sub-assembly base part number is found in step 1.

FIGURE 1: LOCATE SUB-ASSEMBLY PART NUMBER FOR CARRIAGES AT WBL 254 AND WBL 355 WITH

HVOF THERMAL COATED SPINDLES

(SHEET 2 OF 2)

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FIGURE 2: INSPECT SUSPECT CARRIAGE SPINDLES FOR CORROSION

(SHEET 1 OF 2)

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STEP TASK NAME IDENTIFICATION QTY MORE DATA

Do a detailed inspection of

the forward end of the

spindle at the root for missing or flaked coating or

base metal corrosion. (a)

Suspect Carriage - -

Spindle

1 Inspect

Do a detailed inspect of the

lower surface of the spindle

portion of the root for CIC

coverage. If CIC does not

cover the inspection area,

apply or reapply CIC as

necessary. Refer to SOPM

20-41-05 as an accepted

procedure. Overspray of

CIC beyond the indicated

oval area is acceptable. (b)

(c)

Suspect Carriage - -

Spindle

2 Inspect

(a) As an option, use a zero degree Borescope and inspect the forward end of the spindle through the front of

the trailing edge flap for corrosion.

(b) If CIC is intact, no reapplication is necessary.

(c) It is not required to inspect for CIC coverage if missing or flaked coating or base metal corrosion was found.

FIGURE 2: INSPECT SUSPECT CARRIAGE SPINDLES FOR CORROSION

(SHEET 2 OF 2)

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