# Boeing Alert Service Bulletin 757-27A0145: Revision 1

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- Document: [Boeing Alert Service Bulletin 757-27A0145](https://openairdocs.org/service-documents/boeing/757-27a0145.md)
- Title as filed: U.S. DOT/FAA - Service Bulletin (1)
- Pages: 27
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- Page: https://openairdocs.org/service-documents/boeing/757-27a0145/file/fa7715433e8e

## Text

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### Page 1

Commercial 
Airplanes
757
Service Bulletin
ALERT
Number: 757-27A0145
Original Issue: August 07, 2003
Revision 1: January 20, 2010
ATA System: 2741
SUBJECT: FLIGHT CONTROLS - Horizontal Stabilizer - Horizontal Stabilizer Trim Actuator -
Ballscrew Freeplay Inspection Addition and Lubrication Interval Change
Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15
CFR 730-774). 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 © 2003 The Boeing Company
Unpublished Work - All Rights Reserved
Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable
subject matter. Boeing also claims copyright in this document as a compilation and/or collective work.
This document includes proprietary information owned by The Boeing Company and/or one or more third parties.
Treatment of the document and the information it contains is governed by contract with Boeing. For more
information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124.
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, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8A, Poseidon and the
Boeing livery 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.
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2.0

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Table of Contents
Revision Transmittal Sheet ............................................ 5
Summary ...................................................... 7
1. PLANNING INFORMATION ........................................ 1 1
A. Effectivity ............................................... 1 1
1. Airplanes ............................................ 1 1
2. Spares Affected ........................................ 1 2
B. Concurrent Requirements ...................................... 1 2
C. Reason ................................................ 1 2
D. Description .............................................. 1 3
E. Compliance .............................................. 1 4
F. Approval ............................................... 1 8
G. Manpower .............................................. 1 8
H. Weight and Balance Changes .................................... 1 8
I. Electrical Load Data ......................................... 1 8
J. References .............................................. 1 9
1. Existing Data: ......................................... 1 9
2. Data supplied with this Service Bulletin: ........................... 1 9
3. Installation Drawings Used in the Preparation of this Service Bulletin: ........... 1 9
K. Publications Affected ........................................ 1 9
L. Interchangeability and Intermixability of Parts ........................... 1 9
2. MATERIAL INFORMATION ........................................ 2 1
A. Material - Price and Availability ................................... 2 1
B. Industry Support Information .................................... 2 1
C. Parts Necessary For Each Airplane ................................. 2 1
1. Kits/Parts: ........................................... 2 1
2. Parts and Materials Supplied by the Operator: ........................ 2 1
3. Parts Modified and Reidentified: ............................... 2 1
4. Parts Removed and Not Replaced: .............................. 2 1
D. Parts Necessary to Change Spares ................................. 2 1
E. Special Tooling - Price and Availability ............................... 2 1
F. Special Tooling Necessary to do this Service Bulletin ....................... 2 1
3. ACCOMPLISHMENT INSTRUCTIONS .................................. 2 3
A. GENERAL INFORMATION ..................................... 2 3
B. WORK INSTRUCTIONS ....................................... 2 3
FIGURE 1: INSPECTION OF HORIZONTAL STABILIZER BALLSCREW LOAD PATH ........ 2 5
FIGURE 2: HORIZONTAL STABILIZER BALLSCREW AND BALLNUT FREEPLAY CHECK ..... 2 6
FIGURE 3: HORIZONTAL STABILIZER TRIM BALLSCREW ACTUATOR REPLACEMENT ..... 2 7
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ALERTALERT
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### Page 5

Commercial 
Airplanes
757
Service Bulletin
ALERT
Revision Transmittal SheetNumber: 757-27A0145Original Issue: August 07, 2003
Revision 1: January 20, 2010
ATA System: 2741
SUBJECT: FLIGHT CONTROLS - Horizontal Stabilizer - Horizontal Stabilizer Trim Actuator -
Ballscrew Freeplay Inspection Addition and Lubrication Interval Change
This Revision includes all pages of the service bulletin.
COMPLIANCE INFORMATION RELATED TO THIS REVISION
No more work is necessary on airplanes changed as shown in the original issue of this service bulletin. However,
operators must continue with the repeat inspections, lubrication and freeplay checks in accordance with Paragraph
1.E., Compliance.
REASON FOR REVISION
This revision is sent to change the compliance times of the detailed inspection, lubrication and ballnut-to-ballscrew
freeplay check. Instructions on how to accomplish the detailed inspection are replaced by an instruction to do
the detailed inspection in accordance with the Aircraft Maintenance Manual (AMM) and Part 3 is added to the
work instructions to give lubrication instructions. This revision also adds an Airworthiness Directive (AD) statement
and removes all figures as the procedures are now accomplished by the AMM.
These sections are changed:
1. Summary:
– Background: A interim notification of a revision to the Maintenance Planning Document (MPD) statement
is removed.
– Action: The statement is updated to agree with the updated work instructions.
– Compliance: An Airworthiness Directive (AD) statement is added.
– Manpower: The manpower table is removed.
– Illustration: The summary illustration paragraph is updated.
2. Planning Information:
– Paragraph 1.A., Effectivity: A group configuration table is added which splits the effectivity into 3
configurations.
– Paragraph 1.C., Reason: A interim notification of a revision to the Maintenance Planning Document
(MPD) statement is removed.
– Paragraph 1.D., Description: The statement is updated to agree with the updated work instructions and
maintenance zones are added.
– Paragraph 1.E., Compliance: An Airworthiness Directive (AD) statement is added.
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### Page 6

– Paragraph 1.E., Compliance: The compliance times and the repeat intervals for the detailed inspection,
lubrication and freeplay check in Tables 1 and 2 are changed. The corrective action for damaged parts
is added, footnotes (a) and (b) are changed and footnote (c) is deleted.
– Paragraph 1.E., Compliance: The compliance times and the repeat intervals for the detailed inspection,
lubrication and freeplay check in Table 3 are changed. The corrective action for damaged parts is
added, footnotes (a) and (b) are changed and footnotes (c) and (d) are deleted.
– Paragraph 1.G., Manpower: The manpower table is updated.
3. Accomplishment Instructions:
– Paragraph 3.B., Work Instructions: A note is removed from Part 1, Step 1 and the access, cleaning,
lubrication and detailed inspection instructions are replaced by one instruction to do a detailed inspection
in accordance with the AMM.
– Paragraph 3.B., Work Instructions: The access instruction is removed from Part 2 and an AMM task
is added to the instruction to do the stabilizer ballscrew to ballnut freeplay check.
– Paragraph 3.B., Work Instructions: Part 3 is added to give lubrication instructions.
– Figure 1: This Figure is deleted.
– Figure 2: This Figure is deleted.
– Figure 3: This Figure is deleted.
Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity, to show the location
of important changes.
Pages with no vertical lines have no important changes.
REVISION HISTORY
August 07, 2003Original Issue:
January 20, 2010Revision 1:
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BOEING SERVICE BULLETIN 757-27A0145
ALERTALERT

### Page 7

Commercial 
Airplanes
757
Service Bulletin
ALERT
SummaryNumber: 757-27A0145Original Issue: August 07, 2003
Revision 1: January 20, 2010
ATA System: 2741
SUBJECT: FLIGHT CONTROLS - Horizontal Stabilizer - Horizontal Stabilizer Trim Actuator -
Ballscrew Freeplay Inspection Addition and Lubrication Interval Change
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 is being issued to provide a new stabilizer ballscrew lubrication interval and detailed inspection
interval. Also, a new stabilizer ballscrew to ballnut freeplay check is included with a recommended check interval.
The inspections/check are an added level of protection which reduces the potential of unlikely failure modes of
the stabilizer ballscrew assembly used on the stabilizer actuator. The inspections/check can be run in-situ on
the airplane.
After an MD-80 horizontal stabilizer jackscrew incident, a design review was initiated of the Boeing heritage
horizontal stabilizer ballscrews. During this review, an operator reported a 757 horizontal stabilizer ballscrew
with extensive corrosion. An investigation was initiated. This investigation identified that a maintenance procedure
to check the stabilizer ballscrew primary load path was required. Loss of the horizontal stabilizer ballscrew
primary and secondary load paths, although extremely improbable, could potentially result in the loss of control
of the airplane.
Boeing Service Related Problem (SRP) 757-SRP-27-0153 is related to this service bulletin.
NOTE: Service Bulletin 757-27-0138 served as an interim maintenance action related to 757-SRP-27-0153.
Service Bulletin 757-27A0145 is the final maintenance recommendation related to 757-SRP-27-0153.
Upon release of Service Bulletin 757-27A0145, operators should perform the maintenance actions in
that bulletin rather than those in Service Bulletin 757-27-0138. However, it should be noted that Service
Bulletin 757-27-0138 includes one maintenance action that is not included in Service Bulletin
757-27A0145: lubrication of the stabilizer pivot hinges. Lubrication of the stabilizer pivot hinges was
included in Service Bulletin 757-27-0138 as a convenience; it is unrelated to the safety issue addressed
in safety 757-SRP-27-0153. Boeing recommends that operators continue to perform the stabilizer hinge
lubrication task per 757 MPD Volume 1 Section 5, and 757 AMM 12-21-05.
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### Page 8

ACTION
Get access to the horizontal stabilizer trim ballscrew actuator and do the procedures that follow below at the
intervals shown in Paragraph 1.E., Compliance:
– Do a detailed inspection of the stabilizer ballscrew assembly.
– Lubricate the horizontal stabilizer trim control system.
– Do a stabilizer ballscrew to ballnut freeplay check.
– Replace damaged and/or cracked and/or worn stabilizer trim ballscrew actuators.
EFFECTIVITY
All 757-300 Airplanes. Refer to Paragraph 1.A.1., Airplanes for the list of affected airplanes.
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 tasks given in this service bulletin.
MANPOWER
Refer to Paragraph 1.G., Manpower.
MATERIAL INFORMATION
Operator Supplied Parts/Materials.
Refer to Paragraph 2.A., Material - Price and Availability.
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BOEING SERVICE BULLETIN 757-27A0145
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### Page 9 (OCR)

BOEING SERVICE BULLETIN 757-27A0145
ALERT  ALERT
STA
1768
\0
DO A DETAILED INSPECTION OF THE
STABILIZER BALLSCREW ASSEMBLY.
LUBRICATE THE HORIZONTAL
STABILIZER TRIM CONTROL SYSTEM
AND DO A STABILIZER BALLSCREW TO
BALLNUT FREEPLAY CHECK.
SERVICE ACCESS
DOOR (311AL)
W17811
Original Issue: August 07, 2003
Revision 1: January 20, 2010  757-27A0145
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ALERTALERT
BLANK PAGE

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Commercial 
Airplanes
757
Service Bulletin
ALERT
Number: 757-27A0145
Original Issue: August 07, 2003
Revision 1: January 20, 2010
ATA System: 2741
SUBJECT: FLIGHT CONTROLS - Horizontal Stabilizer - Horizontal Stabilizer Trim Actuator -
Ballscrew Freeplay Inspection Addition and Lubrication Interval Change
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
Refer to Service Bulletin Index Document D624N001 Part 3 for Airplane Variable Number, Line
Number, and Serial Number data.
This service bulletin is for the airplanes shown below.
DESCRIPTIONCONFIGURATIONGROUP
All 757-300 airplanes.-1
Airplanes that have not done an overhaul of the stabilizer trim actuator
in accordance with Service Bulletin 757-27A0143 and have less than
or equal to 15,000 total flight hours.
1
Airplanes that have not done an overhaul of the stabilizer trim actuator
in accordance with Service Bulletin 757-27A0143 and have more
than 15,000 total flight hours.
2
Airplanes that have done an overhaul of the stabilizer trim actuator
in accordance with Service Bulletin 757-27A0143.
3
Airplane Models:
757-300
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### Page 12

GroupVariable Number
1NL001 - NL002
1NL006 - NL017
1NL101 - NL109
1NL141
1NL601 - NL616
1NU701 - NU705
1NU721 - NU728
1NU731 - NU732
2. Spares Affected
None.
B. Concurrent Requirements
None.
C. Reason
This service bulletin is being issued to provide a new stabilizer ballscrew lubrication interval and detailed
inspection interval. Also, a new stabilizer ballscrew to ballnut freeplay check is included with a
recommended check interval. The inspections/check are an added level of protection which reduces
the potential of unlikely failure modes of the stabilizer ballscrew assembly used on the stabilizer actuator.
The inspections/check can be run in-situ on the airplane.
After an MD-80 horizontal stabilizer jackscrew incident, a design review was initiated of the Boeing
heritage horizontal stabilizer ballscrews. During this review, an operator reported a 757 horizontal
stabilizer ballscrew with extensive corrosion. An investigation was initiated. This investigation identified
that a maintenance procedure to check the stabilizer ballscrew primary load path was required. Loss
of the horizontal stabilizer ballscrew primary and secondary load paths, although extremely improbable,
could potentially result in the loss of control of the airplane.
Boeing Service Related Problem (SRP) 757-SRP-27-0153 is related to this service bulletin.
NOTE: Service Bulletin 757-27-0138 served as an interim maintenance action related to
757-SRP-27-0153. Service Bulletin 757-27A0145 is the final maintenance recommendation
related to 757-SRP-27-0153. Upon release of Service Bulletin 757-27A0145, operators should
perform the maintenance actions in that bulletin rather than those in Service Bulletin
757-27-0138. However, it should be noted that Service Bulletin 757-27-0138 includes one
maintenance action that is not included in Service Bulletin 757-27A0145: lubrication of the
stabilizer pivot hinges. Lubrication of the stabilizer pivot hinges was included in Service Bulletin
757-27-0138 as a convenience; it is unrelated to the safety issue addressed in safety
757-SRP-27-0153. Boeing recommends that operators continue to perform the stabilizer hinge
lubrication task per 757 MPD Volume 1 Section 5, and 757 AMM 12-21-05.
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757-27A0145Revision 1: January 20, 2010
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BOEING SERVICE BULLETIN 757-27A0145
ALERTALERT

### Page 13

Revision 1 is sent to change the compliance times of the detailed inspection, lubrication and
ballnut-to-ballscrew freeplay check. Instructions on how to accomplish the detailed inspection are
replaced by an instruction to do the detailed inspection in accordance with the Aircraft Maintenance
Manual (AMM) and Part 3 is added to the work instructions to give lubrication instructions. Revision 1
also adds an Airworthiness Directive (AD) statement and removes all figures as the procedures are
now accomplished by the AMM.
These sections were changed:
1. Summary:
– Background: A interim notification of a revision to the Maintenance Planning Document (MPD)
statement is removed.
– Action: The statement is updated to agree with the updated work instructions.
– Compliance: An Airworthiness Directive (AD) statement is added.
– Manpower: The manpower table is removed.
– Illustration: The summary illustration paragraph is updated.
2. Planning Information:
– Paragraph 1.A., Effectivity: A group configuration table is added which splits the effectivity
into 3 configurations.
– Paragraph 1.C., Reason: A interim notification of a revision to the Maintenance Planning
Document (MPD) statement is removed.
– Paragraph 1.D., Description: The statement is updated to agree with the updated work
instructions and maintenance zones are added.
– Paragraph 1.E., Compliance: An Airworthiness Directive (AD) statement is added.
– Paragraph 1.E., Compliance: The compliance times and the repeat intervals for the detailed
inspection, lubrication and freeplay check in Tables 1 and 2 are changed. The corrective action
for damaged parts is added, footnotes (a) and (b) are changed and footnote (c) is deleted.
– Paragraph 1.E., Compliance: The compliance times and the repeat intervals for the detailed
inspection, lubrication and freeplay check in Table 3 are changed. The corrective action for
damaged parts is added, footnotes (a) and (b) are changed and footnotes (c) and (d) are
deleted.
– Paragraph 1.G., Manpower: The manpower table is updated.
3. Accomplishment Instructions:
– Paragraph 3.B., Work Instructions: A note is removed from Part 1, Step 1 and the access,
cleaning, lubrication and detailed inspection instructions are replaced by one instruction to do
a detailed inspection in accordance with the AMM.
– Paragraph 3.B., Work Instructions: The access instruction is removed from Part 2 and an
AMM task is added to the instruction to do the stabilizer ballscrew to ballnut freeplay check.
– Paragraph 3.B., Work Instructions: Part 3 is added to give lubrication instructions.
– Figure 1: This Figure is deleted.
– Figure 2: This Figure is deleted.
– Figure 3: This Figure is deleted.
D. Description
Get access to the horizontal stabilizer trim ballscrew actuator and do the procedures that follow below
at the intervals shown in Paragraph 1.E., Compliance:
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BOEING SERVICE BULLETIN 757-27A0145
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### Page 14

– Do a detailed inspection of the stabilizer ballscrew assembly.
– Lubricate the horizontal stabilizer trim control system.
– Do a stabilizer ballscrew to ballnut freeplay check.
– Replace damaged and/or cracked and/or worn stabilizer trim ballscrew actuators.
Revision 1 - No more work is necessary on airplanes changed in accordance with the original issue of
this service bulletin. However, operators must continue with the repeat inspections, lubrication and
freeplay checks in accordance with Paragraph 1.E., Compliance.
The work in this service bulletin is done in the maintenance zone(s) given below.
Affected Maintenance Zones
ZoneModel
311, 312757-300
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.
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### Page 15

Group 1, Configuration 1:
Table 1 : All airplanes that have not done the overhaul of the stabilizer trim actuator in accordance with
Service Bulletin 757-27A0143 and have completed less than or equal to 15,000 flight hours.
Repeat Interval (Not to Ex-
ceed, Whichever Occurs
First)
Compliance Time (Whichev-
er Occurs First)
ActionCondition
2 years.3,500 flight
hours.
Within 2 years
from the last
detailed in-
spection.
Within 3,500
flight hours
from the last
detailed in-
spection.
Detailed inspection of
the stabilizer ballscrew
assembly in accor-
dance with Paragraph
3.B., Work Instructions,
Part 1.
All airplanes that have
not done the overhaul
of the stabilizer trim ac-
tuator in accordance
with Service Bulletin
757-27A0143 and have
completed less than or
equal to 15,000 flight
hours.
1 year.2,000 flight
hours.
Within 1 year
from the last
lubrication.
Within 2,000
flight hours
from the last
lubrication.
Lubricate the horizontal
stabilizer trim control
system in accordance
with Paragraph 3.B.,
Work Instructions, Part
3. (a)
5 years.18,000 flight
hours.
If the Airplane will complete
15,000 total flight hours within
18 months from the date on
Revision 1 of this service bul-
letin, do the freeplay check
within 18 months.
Stabilizer ballscrew to
ballnut freeplay check
in accordance with
Paragraph 3.B., Work
Instructions, Part 2. (b)
If the Airplane completes less
than 15,000 total flight hours
within 18 months from the date
on Revision 1 of this service
bulletin, do the freeplay check
within 15,000 total flight hours
or 5 years, whichever occurs
first.
-Before further flight.Replace the stabilizer
trim ballscrew actuator.
Damage and/or cracks
and/or excessive wear
found on the stabilizer
trim ballscrew actuator.
(a) Lubrication is accomplished as a part of either the detailed inspection or the freeplay check.
(b) If the detailed inspection and the freeplay check are to be accomplished at the same time, do the detailed
inspection before the freeplay check.
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### Page 16

Group 1, Configuration 2:
Table 2 : All airplanes that have not done the overhaul of the stabilizer trim actuator in accordance with
Service Bulletin 757-27A0143 and have completed more than 15,000 flight hours.
Repeat Interval (Not to Ex-
ceed, Whichever Occurs
First)
Compliance Time (Whichev-
er Occurs First)
ActionCondition
2 years.3,500 flight
hours.
Within 18
months from
the last de-
tailed inspec-
tion.
Within 3,500
flight hours
from the last
detailed in-
spection.
Detailed inspection of
the stabilizer ballscrew
assembly in accor-
dance with Paragraph
3.B., Work Instructions,
Part 1.
All airplanes that have
not done the overhaul
of the stabilizer trim ac-
tuator in accordance
with Service Bulletin
757-27A0143 and have
completed more than
15,000 flight hours. 1 year.2,000 flighthours.Within 1 yearfrom the last
lubrication.
Within 2,000
flight hours
from the last
lubrication.
Lubricate the stabilizer
trim control system in
accordance with Para-
graph 3.B., Work In-
structions, Part 3. (a)
5 years.18,000 flight
hours.
Within 18
months after
the date on
Revision 1 of
this service
bulletin.
-Stabilizer ballscrew to
ballnut freeplay check
in accordance with
Paragraph 3.B., Work
Instructions, Part 2. (b)
-Before further flight.Replace the stabilizer
trim ballscrew actuator.
Damage and/or cracks
and/or excessive wear
found on the stabilizer
trim ballscrew actuator.
(a) Lubrication is accomplished as a part of either the detailed inspection or the freeplay check.
(b) If the detailed inspection and the freeplay check are to be accomplished at the same time, do the detailed
inspection before the freeplay check.
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### Page 17

Group 1, Configuration 3:
Table 3: All airplanes that have done the overhaul of the stabilizer trim actuator in accordance with
Service Bulletin 757-27A0143.
Repeat Interval (Not to Ex-
ceed, Whichever Occurs
First)
Compliance Time (Whichev-
er Occurs First)
ActionCondition
2 years.3,500 flight
hours.
Within 2 years
from the last
detailed in-
spection.
Within 3,500
flight hours
from the last
detailed in-
spection.
Detailed inspection of
the stabilizer ballscrew
assembly in accor-
dance with Paragraph
3.B., Work Instructions,
Part 1.
All airplanes that have
done the overhaul of
the stabilizer trim actua-
tor in accordance with
Service Bulletin 757-
27A0143.
1 year.2,000 flight
hours.
Within 1 year
from the last
lubrication.
Within 2,000
flight hours
from the last
lubrication.
Lubricate the horizontal
stabilizer trim control
system in accordance
with Paragraph 3.B.,
Work Instructions, Part
3. (a)
5 years.18,000 flight
hours.
If the Airplane will complete
15,000 total flight hours since
overhaul within 18 months from
the date on Revision 1 of this
service bulletin, do the freeplay
check within 18 months.
Stabilizer ballscrew to
ballnut freeplay check
in accordance with
Paragraph 3.B., Work
Instructions, Part 2. (b)
If the Airplane completes less
than 15,000 total flight hours
since overhaul within 18
months from the date on Revi-
sion 1 of this service bulletin,
do the freeplay check within
15,000 toal flight hours or 5
years, whichever occurs first.
-Before further flight.Replace the stabilizer
trim ballscrew actuator.
Damage and/or cracks
and/or excessive wear
found on the stabilizer
trim ballscrew actuator.
(a) Lubrication is accomplished as a part of either the detailed inspection or the freeplay check.
(b) If the detailed inspection and the freeplay check are to be accomplished at the same time, do the detailed
inspection before the freeplay check.
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757-27A0145Revision 1: January 20, 2010
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### Page 18

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 the detailed inspection, lubrication
and freeplay check 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 examine the work
— Time to cure the materials
— Time to make the parts
— Time to find the tools.
Elapsed HoursTask-HoursNumber of Per-
sons
Task
2.004.002Part 1 - Detailed Inspec-
tion
3.006.002Part 2 - Freeplay Check
1.503.002Part 3 - Lubrication
(a)(a)TOTAL FOR EACH AIRPLANE
(a) The total task-hours and elapsed hours are not given as the Parts accomplished
at the same time are variable.
H. Weight and Balance Changes
None.
I. Electrical Load Data
Not changed.
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### Page 19

J. References
1. Existing Data:
a. Boeing Service Bulletin 757-27-0138, 757-27A0143
b. Boeing Service Related Problem (SRP) 757-SRP-27-0153
c. 757 Aircraft Maintenance Manual (AMM) 12-21-05, 27-41-10
d. 757 Maintenance Planning Data (MPD) 757 MPD Volume 1 Section 5
2. Data supplied with this Service Bulletin:
None.
3. Installation Drawings Used in the Preparation of this Service Bulletin:
None.
K. Publications Affected
Chapter-SectionPublication
27-41757 Aircraft Maintenance Manual
L. Interchangeability and Intermixability of Parts
Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts.
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### Page 20

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### Page 21

2.    MATERIAL INFORMATION
A. Material - Price and Availability
None.
B. Industry Support Information
Boeing warranty remedies are not available for the inspections/check 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.
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### Page 22

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### Page 23

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. The instructions identified in Paragraph 3.B., Work Instructions and the Figure(s)
give the recommended sequence of steps. The sequence of steps to do this service
bulletin can be changed.
2. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for
definition of the acronyms.
3. Obey all of the warnings and cautions given in the specified manual sections.
4. 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
5. 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.
6. 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
PART 1 : Stabilizer Ballscrew Assembly Detailed Inspection:
1. Do a detailed inspection of the stabilizer ballscrew assembly in accordance with 757 AMM 27-41-10.
2. Put the airplane back to a serviceable condition.
PART 2 : Stabilizer Ballscrew to Ballnut Freeplay Check:
1. Do a stabilizer ballscrew to ballnut freeplay check in accordance with 757 AMM 27-41-10.
2. Put the airplane back to a serviceable condition.
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### Page 24

Part 3: Horizontal Stabilizer Trim Control System Lubrication:
1. Lubricate the horizontal stabilizer trim control system in accordance with 757 AMM 12-21-05.
2. Put the airplane back to a serviceable condition.
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### Page 25 (OCR)

BOEING SERVICE BULLETIN 757-27A0145
ALERT  ALERT
THIS FIGURE IS DELETED.
D38438
FIGURE 1: INSPECTION OF HORIZONTAL STABILIZER BALLSCREW LOAD PATH
(SHEET 1 OF 1)
Devision Jai: any 20, 201003  BOEING PROPRIETARY -  757-27A0145
Copyright © Unpublished Work - See page 1 for details.  25 of 27

### Page 26 (OCR)

BOEING SERVICE BULLETIN 757-27A0145
ALERT  ALERT
THIS FIGURE IS DELETED.
FIGURE 2: HORIZONTAL STABILIZER BALLSCREW AND BALLNUT FREEPLAY CHECK
(SHEET 1 OF 1)
riginal issue: August , 200
evision 1 January 20, 201(  757-27A0145
BOEING PROPRIETARY -
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### Page 27 (OCR)

BOEING SERVICE BULLETIN 757-27A0145
ALERT  ALERT
THIS FIGURE IS DELETED.
D38438
FIGURE 3: HORIZONTAL STABILIZER TRIM BALLSCREW ACTUATOR REPLACEMENT
(SHEET 1 OF 1)
Devision Jai any 20, 201003  OEING PROPRIETARY  757-27A0145
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