# Boeing Alert Service Bulletin 757-34A0611: Revision 1

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- Document: [Boeing Alert Service Bulletin 757-34A0611](https://openairdocs.org/service-documents/boeing/757-34a0611.md)
- Title as filed: SB-757-34A0611-01 03-22-1019
- Pages: 29
- PDF: https://openairdocs.org/files/sha256/cc/2a/cc2a782cd738b92e6953c2741026ce9cb7d8f8debf917a28a49fc6a7cc02d6b0
- Page: https://openairdocs.org/service-documents/boeing/757-34a0611/file/cc2a782cd738

## Text

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### Page 1

Commercial 
Airplanes
757
Service Bulletin
ALERT
Number: 757-34A0611
Original Issue: November 06, 2018
Revision 1: March 22, 2019
ATA System: 3412
SUBJECT: NAVIGATION - Air Data Computing System - Angle Of Attack Sensor Inspection and
Replacement
Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15
CFR 300-774). An export license may be required before it is used for development, production or use by foreign
persons from specific countries. The controller of this data has the individual responsibility to abide by all export
laws.
9E991ECCN:
BOEING PROPRIETARY, CONFIDENTIAL AND/OR TRADE SECRET
Copyright © 2018 Boeing.
Unpublished Work. All Rights Reserved.
Treatment of this document and its content is governed by contract with Boeing. Rights to use this document
are licensed on a per aircraft basis and such rights may not be transferable. For more information, contact The
Boeing Company.
Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner,
BBJ, DC-8, DC-9, DC-10, KC-10, KC-46, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8, Poseidon and
Boeing liveries are all trademarks owned by The Boeing Company; and no trademark license is granted in
connection with this document unless provided in writing by Boeing.
Original Issue: November 06, 2018
757-34A0611Revision 1: March 22, 2019
1 of 29
2.0

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Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: November 06, 2018
757-34A0611Revision 1: March 22, 2019
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ALERTALERT
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### Page 3

Table of Contents
Revision Transmittal Sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1. PLANNING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
A. Effectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1. Airplanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
E. Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2. Data Supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3. Installation Drawings Used in the Preparation of this Service Bulletin: . . . . . . . . . . . 19
K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
M. Software Accomplishment Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
C. Parts Necessary for Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
1. Kits/Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2. Parts and Materials Supplied by the Operator . . . . . . . . . . . . . . . . . . . . . . . . 21
3. Parts Modified and Reidentified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
4. Parts Removed and Not Replaced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 22
3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
FIGURE 1: AREA OUTBOARD AND ABOVE NOSE LANDING GEAR WHEEL WELL - INSPECT LEFT
ANGLE OF ATTACK SENSOR - SLINGER . . . . . . . . . . . . . . . . . . . . . . . . . . 26
FIGURE 2: AREA OUTBOARD AND ABOVE NOSE LANDING GEAR WHEEL WELL - INSPECT RIGHT
ANGLE OF ATTACK SENSOR - SLINGER . . . . . . . . . . . . . . . . . . . . . . . . . . 27
FIGURE 3: AREA OUTBOARD AND ABOVE NOSE LANDING GEAR WHEEL WELL - INSPECT LEFT
ANGLE OF ATTACK SENSOR - PART NUMBER . . . . . . . . . . . . . . . . . . . . . . 28
FIGURE 4: AREA OUTBOARD AND ABOVE NOSE LANDING GEAR WHEEL WELL - INSPECT RIGHT
ANGLE OF ATTACK SENSOR - PART NUMBER . . . . . . . . . . . . . . . . . . . . . . 29
Export Controlled ECCN: 9E991 - BOEING
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757-34A0611Revision 1: March 22, 2019
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BOEING SERVICE BULLETIN 757-34A0611
ALERTALERT

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Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
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Original Issue: November 06, 2018
757-34A0611Revision 1: March 22, 2019
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BOEING SERVICE BULLETIN 757-34A0611
ALERTALERT
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Commercial 
Airplanes
757
Service Bulletin
ALERT
Revision Transmittal SheetNumber: 757-34A0611Original Issue: November 06, 2018
Revision 1: March 22, 2019
ATA System: 3412
SUBJECT: NAVIGATION - Air Data Computing System - Angle Of Attack Sensor Inspection and
Replacement
This revision includes all pages of the service bulletin.
COMPLIANCE INFORMATION RELATED TO THIS REVISION
The Federal Aviation Administration (FAA) will possibly release an additional Airworthiness Directive related to
this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service
bulletin mandatory.
Effects of this Revision on airplanes on which Original Issue was previously done:
None.
REASON FOR REVISION
This revision is sent to correct the part number of the gasket in the Parts and Materials Supplied by the Operator
table.
These sections were changed:
1. In Paragraph 1.C., Reason, added revision and Information Notice statements.
2. In Paragraph 1.D., Description, added revision statement.
3. In Paragraph 1.K.1., Publications, added publication reference.
4. In Paragraph 2.C.2., Parts and Materials Supplied by the Operator, changed the gasket part number.
The data given in Information Notice 757-34A0611 IN 01 is included in this revision.
Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity and format changes,
to show the location of all content changes.
Pages with no vertical lines have no changes.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: November 06, 2018
757-34A0611Revision 1: March 22, 2019
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### Page 6

REVISION HISTORY
November 06, 2018Original Issue:
March 22, 2019Revision 1:
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: November 06, 2018
757-34A0611Revision 1: March 22, 2019
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BOEING SERVICE BULLETIN 757-34A0611
ALERTALERT

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Commercial 
Airplanes
757
Service Bulletin
ALERT
SummaryNumber: 757-34A0611Original Issue: November 06, 2018
Revision 1: March 22, 2019
ATA System: 3412
SUBJECT: NAVIGATION - Air Data Computing System - Angle Of Attack Sensor Inspection and
Replacement
THIS DOCUMENT 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 DOCUMENT
TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS DOCUMENT TO THE
NEW OWNER.
CONCURRENT REQUIREMENTS
None.
BACKGROUND
Boeing has received reports from operators of nuisance stick shaker activation while the airplane is accelerating
to cruise speed at the top of a climb. A review of recorded flight data and weather reports indicated that the
cause of the nuisance stick shakers was that the Angle of Attack (AOA) sensor vanes were frozen and had
become immobilized because the heaters in the AOA sensor were not sufficient to prevent ice build-up in the
faceplate and vane. This can be caused during heavy moisture conditions leading to water entering the AOA
vane pivot and freezing during takeoff. If this service bulletin is not done AOA sensors can freeze and become
immobilized, which can lead to an unrecoverable Stall at Low Altitude, which can result in unsafe flight conditions.
This service bulletin gives instructions to inspect the left and right AOA sensor part numbers. Also, instructions
are given to replace existing AOA sensors that have heaters that are not sufficient to prevent ice build-up in the
faceplate and vane. Installation of new or serviceable AOA sensor(s) prevents immobilization of the AOA sensor
vane because of ice build-up.
Boeing Service Related Problem (SRP) 757-SRP-34-0141 is related to this service bulletin.
Boeing Fleet Team Digest (FTD) 757 FTD 34-15001 is related to this service bulletin.
Boeing Service Letter (SL) 757-SL-34-126-D is related to this service bulletin.
This table is provided to operators for planning purposes only. Refer to the applicable sections for more
information.
ReferenceAffectedPlanning Data
Paragraph 1.A.2., Spares AffectedNoSpares Affected
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ReferenceAffectedPlanning Data
Paragraph 1.E., ComplianceYesAD Related
Paragraph 1.H., Weight and Balance ChangesNoWeight and Balance Change
Paragraph 1.I., Electrical Load DataNoElectrical Load Changed
Paragraph 1.K., Publications AffectedYesPublications Affected
Paragraph 1.K., Publications AffectedNoAirplane Flight Operations Affected (Flight Crew
Operations Manual and/or FAA Approved Air-
plane Flight Manual)
Paragraph 2.C.1., Kits/PartsNoKits/Parts Required
Paragraph 2.C.2., Parts and Materials Supplied
by the Operator
YesOperator Supplied Parts/Material
Paragraph 2.F., Special Tooling Necessary to
do this Service Bulletin
NoSpecial Tooling Required
ACTION
At the area outboard and above the nose landing gear wheel well, do the following:
1. Inspect the left and right AOA sensor.
2. If an AOA sensor has an incorrect part number, replace it with a new or serviceable AOA sensor.
3. If an AOA sensor has a correct part number, no AOA sensor replacement is required.
EFFECTIVITY
757-200, 757-200CB, 757-200PF and 757-300 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.
Refer to Paragraph 1.E., Compliance.
INDUSTRY SUPPORT INFORMATION
Boeing warranty remedies are not available for the configuration changes given in this service bulletin.
MANPOWER
Refer to Paragraph 1.G., Manpower.
MATERIAL INFORMATION
Operator Supplied Parts/Materials.
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ALERTALERT

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BOEING SERVICE BULLETIN 757-34A0611
ALERT  ALERT
Refer to Paragraph 2.A., Material - Price and Availability.
00
AT THE AREA OUTBOARD AND ABOVE NOSE LANDING GEAR WHEEL WELL:
- INSPECT THE LEFT AND RIGHT ANGLE OF ATTACK SENSORS
- REPLACE THE ANGLE OF ATTACK SENSORS IF IT IS AN INCORRECT PART NUMBER
(LEFT SIDE SHOWN, RIGHT SIDE OPPOSITE)  2830394
ANGLE OF ATTACK SENSOR
Original Issue: November 06, 2018
Revision 1: March 22, 2019  PROPRIETARY - Copyright © Unpublished  Export Controlled ECCN: 9E991 - BOEING  757-34A0611
Work - See page 1 for details.  9 of 29

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Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: November 06, 2018
757-34A0611Revision 1: March 22, 2019
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ALERTALERT
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Commercial 
Airplanes
757
Service Bulletin
ALERT
Number: 757-34A0611
Original Issue: November 06, 2018
Revision 1: March 22, 2019
ATA System: 3412
SUBJECT: NAVIGATION - Air Data Computing System - Angle Of Attack Sensor Inspection and
Replacement
THIS DOCUMENT 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 DOCUMENT
TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS DOCUMENT TO THE
NEW OWNER.
1.    PLANNING INFORMATION
A. Effectivity
1. Airplanes
Refer to Service Bulletin Index D624N001 Part 3 for Airplane Variable Number, Line Number, and
Serial Number data.
This bulletin is applicable to 757-200, 757-200CB, 757-200PF, 757-300 Airplane(s), line number(s)
1-965 in 1 Group(s).
The Variable Numbers and Group Information for the applicable airplanes is given below.
DESCRIPTIONCONFIGURATIONGROUP
Airplanes that require inspection of the left and right Angle of Attack
(AOA) sensors and replacement of the AOA sensors as necessary.
-1
Airplane Models:
757-200, 757-200CB, 757-200PF, 757-300
GroupVariable Number
1NA001 - NA028
1NA191 - NA199
1NA201 - NA239
1NA301 - NA305
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GroupVariable Number
1NA341 - NA352
1NA391 - NA399
1NA401 - NA408
1NA441 - NA447
1NA501 - NA586
1NB001 - NB004
1NB021 - NB023
1NB036 - NB041
1NB051 - NB053
1NB061 - NB073
1NB079
1NB131 - NB148
1NB161 - NB162
1NB166 - NB168
1NB201 - NB204
1NB221 - NB228
1NB230
1NB236
1NB239
1NB261 - NB267
1NB291 - NB299
1NB301 - NB302
1NB311 - NB312
1NB321 - NB331
1NB421 - NB438
1NB446
1NB451 - NB454
1NB501 - NB523
1NB561
1NB571
1NB581 - NB583
1NC001 - NC033
1NC041 - NC042
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GroupVariable Number
1NC051 - NC052
1NC056 - NC062
1NC066 - NC084
1NC091 - NC094
1NC151
1NC161
1NC901 - NC951
1NC971 - NC974
1ND001 - ND007
1ND011 - ND059
1ND111 - ND113
1ND161 - ND199
1ND201 - ND203
1ND221 - ND225
1ND241 - ND248
1ND301 - ND322
1ND401
1ND891
1ND895
1NE001 - NE008
1NE011 - NE088
1NE091 - NE094
1NE141 - NE150
1NE161 - NE177
1NE201 - NE204
1NE301 - NE302
1NE311 - NE325
1NL001 - NL002
1NN001 - NN002
1NP901 - NP904
1NS601 - NS616
1NT001 - NT009
1NT201 - NT202
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GroupVariable Number
1NT231 - NT234
1NT237 - NT240
1NT242
1NT245 - NT246
1NT281 - NT289
1NT341 - NT345
1NT351 - NT360
1NT371 - NT373
1NT375 - NT379
1NT381 - NT384
1NT401 - NT409
1NT411 - NT412
1NT426 - NT427
1NT431 - NT432
1NT436 - NT438
1NT441 - NT442
1NT446
1NT701 - NT745
1NT751 - NT769
1NT791 - NT796
1NT861 - NT862
1NT881 - NT885
1NT901 - NT916
1NU701 - NU705
1NU721 - NU728
1NU731 - NU732
2. Spares Affected
None.
B. Concurrent Requirements
None.
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C. Reason
Boeing has received reports from operators of nuisance stick shaker activation while the airplane is
accelerating to cruise speed at the top of a climb. A review of recorded flight data and weather reports
indicated that the cause of the nuisance stick shakers was that the Angle of Attack (AOA) sensor vanes
were frozen and had become immobilized because the heaters in the AOA sensor were not sufficient
to prevent ice build-up in the faceplate and vane. This can be caused during heavy moisture conditions
leading to water entering the AOA vane pivot and freezing during takeoff. If this service bulletin is not
done AOA sensors can freeze and become immobilized, which can lead to an unrecoverable Stall at
Low Altitude, which can result in unsafe flight conditions.
This service bulletin gives instructions to inspect the left and right AOA sensor part numbers. Also,
instructions are given to replace existing AOA sensors that have heaters that are not sufficient to prevent
ice build-up in the faceplate and vane. Installation of new or serviceable AOA sensor(s) prevents
immobilization of the AOA sensor vane because of ice build-up.
Boeing Service Related Problem (SRP) 757-SRP-34-0141 is related to this service bulletin.
Boeing Fleet Team Digest (FTD) 757 FTD 34-15001 is related to this service bulletin.
Boeing Service Letter (SL) 757-SL-34-126-D is related to this service bulletin.
Revision 1: sent to correct the part number of the gasket in the Parts and Materials Supplied by the
Operator table.
The data given in Information Notice 757-34A0611 IN 01 is included in this revision.
D. Description
At the area outboard and above the nose landing gear wheel well, do the following:
1. Inspect the left and right AOA sensor.
2. If an AOA sensor has an incorrect part number, replace it with a new or serviceable AOA sensor.
3. If an AOA sensor has a correct part number, no AOA sensor replacement is required.
The changes in this service bulletin will not change the Engine Indication and Crew Alerting System
(EICAS).
Effects of this Revision on airplanes on which Original Issue was previously done:
None.
The work in this service bulletin is done in the maintenance zone(s) given below.
Affected Maintenance Zones
ZoneModel
117, 118757-200, 757-200CB, 757-
200PF, 757-300
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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.
When more than one OPTION is given for a CONDITION, do only one of the OPTION numbers. When
more than one ACTION is given for a CONDITION or an OPTION, do all of the ACTION numbers for
that CONDITION or OPTION.
Accomplish the required action(s), based on the applicable condition(s) in Table(s) 1, in accordance
with Paragraph 3. Accomplishment Instructions.
Table 1: ANGLE OF ATTACK SENSOR INSPECTION
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Within 9,960 flight
hours after the
original issue date
of this service bul-
letin.
OPTION 1: Do a General
Visual Inspection of the
Angle of Attack sensor on
the airplane.
All Airplanes
OPTION 2: Inspection for
the Angle of Attack sen-
sor not on airplane.
-Before further
flight.
Replace the affected An-
gle of Attack sensor.
CONDITION 1: OPTION 1:
ANY ANGLE OF ATTACK
SENSOR WITH THE
GRADUAL SLOPE OF
SLINGER FOUND
--No further action is re-
quired.
CONDITION 2: OPTION 1:
ANY ANGLE OF ATTACK
SENSOR WITHOUT THE
GRADUAL SLOPE OF
SLINGER FOUND
-Before further
flight.
Replace the affected An-
gle of Attack sensor.
CONDITION 3: OPTION 2:
ANY ANGLE OF ATTACK
SENSOR WITH PART
NUMBER 0861CAB (BOE-
ING PART NUMBER
S233T913-1) FOUND
--No further action is re-
quired.
CONDITION 4:OPTION 2:
NO ANGLE OF ATTACK
SENSOR WITH PART
NUMBER 0861CAB (BOE-
ING PART NUMBER
S233T913-1) FOUND
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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 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
OPTION 1: GENERAL VISUAL INSPECTION (GVI) OF THE ANGLE OF ATTACK SENSOR ON
AIRPLANE
Elapsed HoursTask HoursNumber of PersonsTask
0.100.101Open Access
0.050.051FIGURE 1
0.050.051FIGURE 2
1.001.001Remove (a)
1.001.001Install (a)
0.250.251Test (a)
0.100.101Close Access
2.552.55TOTAL FOR EACH AIRPLANE (a)
(a) Removal, installation and test are dependent on inspection results. This estimate in-
cludes the hours necessary for the removal, installation and test of both left and right
AOA sensors.
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OPTION 2: INSPECTION WITH THE ANGLE OF ATTACK SENSOR NOT ON AIRPLANE
Elapsed HoursTask HoursNumber of PersonsTask
0.100.101Open Access
1.001.001Remove
0.050.051FIGURE 3
0.050.051FIGURE 4
1.001.001Install
0.250.251Test
0.100.101Close Access
2.552.55TOTAL FOR EACH AIRPLANE
H. Weight and Balance Changes
OPTION 1, CONDITION 1; OPTION 2, CONDITION 3
Change in Moment
(Pound-Inches)
Change in Weight
(Pounds)Airplane
-230-0.9757-200, 757-
200CB, 757-200PF
(a)
-115.0-0.5757-200, 757-
200CB, 757-200PF
(b)
(a) Airplanes that have 2 AOA sensors replaced.
(b) Airplanes that have 1 AOA sensor replaced.
OPTION 1, CONDITION 1; OPTION 2, CONDITION 3
Change in Moment
(Pound-Inches)
Change in Weight
(Pounds)Airplane
-82.8-0.9757-300 (a)
-41.4-0.5757-300 (b)
(a) Airplanes that have 2 AOA sensors replaced.
(b) Airplanes that have 1 AOA sensor replaced.
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OPTION 1, CONDITION 2; OPTION 2, CONDITION 4
Change in Moment
(Pound-Inches)
Change in Weight
(Pounds)Airplane
00757-200, 757-
200CB, 757-200PF,
757-300
I. Electrical Load Data
Not changed.
J. References
1. Existing Data:
a. Boeing Service Letter 757-SL-34-126-D
b. Boeing Service Related Problem (SRP) 757-SRP-34-0141
c. Service Bulletin Index D624N001
d. 757 Aircraft Maintenance Manual (AMM) 34-12-03
e. 757 Fleet Team Digest (FTD) 34-15001
f. Rosemount Aerospace Incorporated Service Bulletin 0861FL-27A-01
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-SectionPublication
05-00757 Aircraft Maintenance Manual
34-12757 Illustrated Parts Catalog
2. Damage Tolerance Based Structural Inspections:
Boeing has evaluated the repairs 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.
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L. Interchangeability and Intermixability of Parts
Refer to Paragraph 2.C., Parts Necessary for Each Airplane, for interchangeability and intermixability
information.
M. Software Accomplishment Summary
Not affected.
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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 configuration changes given in this service bulletin.
C. Parts Necessary for Each Airplane
1. Kits/Parts
None.
2. Parts and Materials Supplied by the Operator
The following parts or materials are necessary to do the change in this service bulletin. Parts and
materials in the manuals given in Paragraph 1.J., References, can also be necessary. Examine
operator part and material supply to make sure all necessary parts and materials are available.
NotesExisting Boe-
ing Part Num-
ber
Existing Sup-
plier Part
Number
NameQTYNew Boeing
Part Number
New Supplier
Part Number
(a)(b)(c)(d)S233T913-10861CAB (f)SENSOR, ANGLE OF
ATTACK
2S233T913-40861FL
(a)(b)(c)S233T913-10861CAB (f)SENSOR, ANGLE OF
ATTACK
2S233T913-50861FL1
(e)233T9131-1-GASKET2233T9131-1-
(a) The quantity shown is the maximum quantity of AOA sensors installed on one airplane. Inspection results
will determine quantity needed.
(b) You cannot use the existing part to replace the new part.
(c) Supplier Information:
Primary: Supplier Cage Code: 59885, UTC Aerospace Systems, 14300 Judicial Road,Burnsville,
MN55306-4898, U.S.A.
(d) Part number 0861FL is usable under the constraints of Rosemount Aerospace Incorporated Service
Bulletin 0861FL-27A-01.
(e) The quantity shown is the maximum quantity required. A new gasket is required every time the AOA
sensor gets removed and installed.
(f) This part can be written as 861CAB or 861CABMOD(x).
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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.
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3.    ACCOMPLISHMENT INSTRUCTIONS
A. GENERAL INFORMATION
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.
CAUTION
NOTE: 1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for
definition of the acronyms.
2. Obey all of the warnings and cautions given in the specified manual sections.
3. Unless shown differently, these dimensions and tolerances are used:
– Linear dimensions are in inches
– Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus
or minus 0.03 inch
– Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch
– Angular tolerance is plus or minus 2 degrees
– Hole dimensions for standard solid rivets and fasteners are in Structural Repair
Manual (SRM) Chapter 51
– Torque Values:
— Values for structural fasteners are given in 757 Structural Repair Manual,
Chapter 51.
— Values for airframe maintenance tasks are included in Chapter 20 of 757
Aircraft Maintenance Manual (AMM).
— Values for electrical maintenance tasks are included in Chapter 20 of
Standard Wiring Practices Manual (SWPM).
— Values for engine maintenance tasks are included in Chapter 70 of 757
Aircraft Maintenance Manual (AMM).
— Non-standard torque values for maintenance tasks are included in the
applicable installation step.
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.
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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.
7. 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.
8. 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.
9. Use of colors in Figures is based on guidance from the ATA e-Business Program
(ATA) iSpec 2200.
10. When more than one OPTION is given for a CONDITION, do only one of the OPTION
numbers. When more than one ACTION is given for a CONDITION number or an
OPTION number, do all of the ACTION numbers for that CONDITION number or
OPTION number.
11. The compliance times for the actions in Paragraph 3.B., WORK INSTRUCTIONS
are in Paragraph 1.E., Compliance.
12. Some steps in the Work Instructions are labeled as Required for Compliance (RC).
If this service bulletin is mandated by an Airworthiness Directive (AD), then the steps
labeled as RC, including sub-steps under an RC step and any figures identified in
an RC step, must be done to comply with the AD. If a step or sub-step is labeled
"RC Exempt," then the RC requirement is removed from that step or sub-step. An
Alternative Method of Compliance (AMOC) is required for any deviations to RC steps,
including sub-steps and identified figures. Steps not labeled as RC may be deviated
from using accepted methods in accordance with the operator's maintenance or
inspection program without obtaining approval of an AMOC. This is provided that
the RC steps, including sub-steps and identified figures, can still be done as specified,
and the airplane can be put back in an airworthy condition.
B. WORK INSTRUCTIONS
1. Get access to the left and right Angle of Attack (AOA) sensors in the area outboard and above the
nose landing gear wheel well.
2. RC - Do one of the options that follow:
a. OPTION 1: GENERAL VISUAL INSPECTION (GVI) OF THE ANGLE OF ATTACK SENSOR
ON AIRPLANE
(1) Do a GVI of the left and right AOA sensors in accordance with FIGURE 1 and FIGURE
2.
(a) CONDITION 1: ANY AOA SENSOR WITH THE GRADUAL SLOPE OF SLINGER
FOUND
1) Remove the affected AOA sensor. Refer to 757 AMM 34-12-03 as an accepted
procedure.
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2) Install new or serviceable AOA sensor part number 0861FL (Boeing part number
S233T913-4) or 0861FL1 (Boeing part number S233T913-5). Refer to 757 AMM
34-12-03 as an accepted procedure.
3) RC Exempt - Do the functional test. If the test fails, accomplish corrective actions
and repeat the test and applicable corrective actions until the test is passed.
Refer to 757 AMM 34-12-03 as an accepted procedure.
(b) CONDITION 2: ANY AOA SENSOR WITHOUT THE GRADUAL SLOPE OF SLINGER
FOUND
1) No further action is required.
b. OPTION 2: INSPECTION WITH THE ANGLE OF ATTACK SENSOR NOT ON AIRPLANE
(1) Remove the left and right AOA sensors. Refer to 757 AMM 34-12-03 as an accepted
procedure.
(2) Do a GVI of the left and right AOA sensors for the part number in accordance with FIGURE
3 and FIGURE 4.
(a) CONDITION 3: ANY AOA SENSOR WITH PART NUMBER 0861CAB (BOEING
PART NUMBER S233T913-1) FOUND
1) Install new or serviceable AOA sensor part number 0861FL (Boeing part number
S233T913-4) or 0861FL1 (Boeing part number S233T913-5). Refer to 757 AMM
34-12-03 as an accepted procedure.
2) RC Exempt - Do the functional test. If the test fails, accomplish corrective actions
and repeat the test and applicable corrective actions until the test is passed.
Refer to 757 AMM 34-12-03 as an accepted procedure.
(b) CONDITION 4: NO AOA SENSOR WITH PART NUMBER 0861CAB (BOEING PART
NUMBER S233T913-1) FOUND
1) Install the existing part back on the airplane. Refer to 757 AMM 34-12-03 as an
accepted procedure.
2) RC Exempt - Do the functional test. If the test fails, accomplish corrective actions
and repeat the test and applicable corrective actions until the test is passed.
Refer to 757 AMM 34-12-03 as an accepted procedure.
3. Put the airplane back to a serviceable condition.
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The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for each airplane.
More DataQtyIdentificationNameTaskStep
(a)1-SENSOR, ANGLE OF
ATTACK
Inspect1
(a) Do a general visual inspection of the AOA sensor's slinger to determine if the slinger has a gradual slope.
FIGURE 1: AREA OUTBOARD AND ABOVE NOSE LANDING GEAR WHEEL WELL - INSPECT LEFT ANGLE
OF ATTACK SENSOR - SLINGER
(SHEET 1 OF 1)
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The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for each airplane.
More DataQtyIdentificationNameTaskStep
(a)1-SENSOR, ANGLE OF
ATTACK
Inspect1
(a) Do a general visual inspection of the AOA sensor's slinger to determine if the slinger has a gradual slope.
FIGURE 2: AREA OUTBOARD AND ABOVE NOSE LANDING GEAR WHEEL WELL - INSPECT RIGHT
ANGLE OF ATTACK SENSOR - SLINGER
(SHEET 1 OF 1)
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### Page 28 (OCR)

BOEING SERVICE BULLETIN 757-34A0611
ALERT  ALERT
• 0
ANGLE OF ATTACK SENSOR
The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for each airplane.
Step  Task  Name  Identification  Qty  More Data
1  Inspect  SENSOR, ANGLE OF  1  Inspect for part
ATTACK  number.
FIGURE 3: AREA OUTBOARD AND ABOVE NOSE LANDING GEAR WHEEL WELL - INSPECT LEFT ANGLE
OF ATTACK SENSOR - PART NUMBER
(SHEET 1 OF 1)
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### Page 29 (OCR)

BOEING SERVICE BULLETIN 757-34A0611
ALERT  ALERT
ANGLE OF ATTACK SENSOR
The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for each airplane.
Step  Task  Name  Identification  Qty  More Data
Inspect  SENSOR, ANGLE OF  1  Inspect for part
ATTACK  number.
FIGURE 4: AREA OUTBOARD AND ABOVE NOSE LANDING GEAR WHEEL WELL - INSPECT RIGHT
ANGLE OF ATTACK SENSOR - PART NUMBER
(SHEET 1 OF 1)
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