# Boeing Alert Service Bulletin 767-78A0081: Revision 2

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- Document: [Boeing Alert Service Bulletin 767-78A0081](https://openairdocs.org/service-documents/boeing/767-78a0081.md)
- Title as filed: U.S. DOT/FAA - SB-767-78A0081-02
- Pages: 19
- PDF: https://openairdocs.org/files/sha256/0b/c9/0bc99cbe27d1d689486477459ae63036667b210b2a4f90c6547ae223c280bdc3
- Page: https://openairdocs.org/service-documents/boeing/767-78a0081/file/0bc99cbe27d1

## Text

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### Page 1

Commercial
Airplane
Group
767
Service Bulletin
ALERT
Number: 767-78A0081 Revision Transmittal SheetDate: July 24, 1997
Revision 2: April 19, 2001
ATA System: 7830
SUBJECT: EXHAUST (CF6-80C2 Engines) - Thrust Reverser - Thrust Reverser Control System - Center
Drive Unit (CDU) Cone Brake Integrity Test
This revision includes all pages of the service bulletin.
COMPLIANCE INFORMATION RELATED TO THIS REVISION
Federal Aviation Administration (FAA) Airworthiness Directive (AD) 2000-09-04, Amendment 39-11712, is
related to this service bulletin.
More work is necessary on airplanes changed as shown in the Revision 1 of this service bulletin.
Airplanes were added to Group 2 of the service bulletin effectivity.
REASON FOR REVISION
This revision adds the inspection interval of the Electro-Mechanical brake and CDU cone brake for airplanes
equipped with thrust reversers that have been modified in accordance with Boeing Service Bulletin
767-78-0063 or after the equivalent modification (Production Revision Record B11481-90) incorporating in
production. Revise the service bulletin effectivity to add Group 2 airplanes which is included all 767-200,
-300 and -300F airplanes (including future 767-200, -300 and -300F airplanes) with CF6-80C2 engines from
production control line 475. Also, the Industry Support Information statement has been changed.
Paragraph 1.A., Effectivity, shows changes of airplane operators. Each operator should examine the
Effectivity paragraph for changes.
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
Initial Release: July 24, 1997
Revision 1: October 9, 1997
Revision 2: April 19, 2001
767-78A0081
Revision Transmittal Page 1 of 1

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### Page 3

Commercial
Airplane
Group
767
Service Bulletin
ALERT
Number: 767-78A0081 SummaryDate: July 24, 1997
Revision 2: April 19, 2001
ATA System: 7830
SUBJECT: EXHAUST (CF6-80C2 Engines) - Thrust Reverser - Thrust Reverser Control System - Center
Drive Unit (CDU) Cone Brake Integrity Test
CONCURRENT REQUIREMENTS
None
BACKGROUND
This inspection will make sure that the center drive
unit (CDU) cone brake and the Thrust Reverser
Actuation System (TRAS) brake have the holding
torque required to prevent any uncommanded thrust
reverser sleeve movement.
The CDU cone brake and the TRAS brake are
primary safety devices required to prevent
inadvertent thrust reverser sleeve movement. To
meet the system reliability requirements, periodic
torque checks are required to ensure the integrity of
these locking devices. A failure of either of these
locks is not detected during normal operation. The
torque check intervals have been determined
through industry-wide accepted probability and
reliability methods.
The TRAS lock is a solenoid activated disk brake
this is connected to the upper angle gearbox by a
flexible drive shaft. The brake is released when 28
VDC is applied from the control circuit and is locked
at all other times. Low torque can be the result of a
brake or flexible shaft failure.
The CDU cone brake is a spring load, unidirectional
device that prevent rotation of the air motor in the
deploy direction. The cone brake always allows the
air motor to rotate in the stow direction. The brake
is disengaged when the directional control valve
actuator piston is commanded to the deploy position
from the control circuit.
Boeing Service Related Problem (SRP)
767-SRP-78-0036 is related to this service bulletin.
ACTION
For Group 1 airplanes that have not incorporated
Boeing Service Bulletin 767-78-0063, on each thrust
reverser half, do a functional test on the CDU cone
brake to verify the holding torque.
For Group 1 airplanes that have incorporated
Boeing Service Bulletin 767-78-0063 and Group 2
airplanes, on each thrust reverser half, do a
functional test of the Electro-Mechanical brake and
CDU cone brake to verify the holding torque.
EFFECTIVITY
All 767-200, -300 and -300F airplanes powered by
CF6-80C2 engines.
COMPLIANCE
Boeing recommends the operators do this service
bulletin within 650 flight hours after receipt of this
service bulletin.
For Group 1 airplanes that have not incorporated
Boeing Service Bulletin 767-78-0063, Boeing
recommends the operators repeat CDU cone brake
test every 650 flight hours.
For Group 1 airplanes on which Boeing Service
Bulletin 767-78-0063 has been incorporated and on
Group 2 airplanes, Boeing recommends the
operators repeat the Electro-Mechanical brake and
CDU cone brake tests every 1,000 flight hours.
Federal Aviation Administration (FAA) Airworthiness
Directive (AD) 2000-09-04, Amendment 39-11712,
is related to this service bulletin.
767-78A0081
Summary Page 1 of 2

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ALERT BOEING SERVICE BULLETIN 767-78A0081 ALERT
INDUSTRY SUPPORT INFORMATION
Boeing warranty remedies are not available for the
inspection given in this service bulletin.
MANPOWER
Total Man-hours - 6 for each airplane
Elapsed Time - 3 Hours
MATERIAL INFORMATION
None
ELECTRO−MECHANICAL BRAKE
DO A FUNCTIONAL TEST ON THE
FOR EACH THRUST REVERSER HALF:
DO A FUNCTIONAL TEST ON THE
FOR EACH THRUST REVERSER HALF:
CENTER DRIVE UNIT (CDU) CONE BRAKE
RIGHT SIDE OPPOSITE
LEFT SIDE SHOWN,
S13036
July 24, 1997 767-78A0081
Revision 2: April 19, 2001 Summary Page 2 of 2

### Page 5

Commercial
Airplane
Group
767
Service Bulletin
ALERT
Number: 767-78A0081
Date: July 24, 1997
Revision 2: April 19, 2001
ATA System: 7830
SUBJECT: EXHAUST (CF6-80C2 Engines) - Thrust Reverser - Thrust Reverser Control System - Center
Drive Unit (CDU) Cone Brake Integrity Test
1. PLANNING INFORMATION
A. Effectivity
NOTE:* THIS EFFECTIVITY INCLUDES ALL FUTURE 767-200, -300 AND -300F AIRPLANES
WITH CF6-80C2 ENGINES FROM PRODUCTION LINE NUMBER 475, EVEN IF THEY
ARE NOT LISTED IN THIS SECTION.
1. Airplanes
Refer to Service Bulletin Index Document D624T001, Part 3 for Airplane Variable Number, Line
Number, and Serial Number data.
Airplane Models:
767-200 767-300 767-300F
IDENTIFICATION BY CUSTOMER, CUSTOMER CODE, GROUP AND VARIABLE NUMBER
AEROFLOT (ARO)
2 VS321-VS324
AIR ALGERIE (ALG)
1 VK131-VK133
AIR CANADA (ACN)
1 VN052 VN054 VN057 VN731
2 VS546-VS548
AIR DO (HIA)
2 VS176
AIR EUROPA (ARE)
2 VS291-VS292
AIR EUROPE ITALY (EIY)
1 VN811-VN812
AIR FRANCE (AFA)
2 VN634-VN635
July 24, 1997 767-78A0081
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ALERT BOEING SERVICE BULLETIN 767-78A0081 ALERT
AIR MADAGASCAR (MAD)
2 VS316
AIR MAURITIUS (MAU)
1 VF001-VF002
AIR NEW ZEALAND (ANZ)
1 VN651-VN652
2 VN653-VN658 VS112-VS113
AIR PACIFIC (APC)
2 VN676
AIR SEYCHELLES (ASY)
1 VF051
2 VL941 VS526
AIR 2000 (ATZ)
2 VN921-VN922 VS216-VS217
AIRTOURS INT'L AIRWAYS (GUE)
2 VN951-VN953
ALITALIA (ALI)
2 VL701-VL702 VN422-VN427 VS366-VS367 VS401
ALL NIPPON AIRWAYS (ANA)
1 VK081-VK102 VN191-VN195
2 VK103-VK113 VN196-VN198 VR401
AMERICAN AIRLINES (AAL)
1 VN001-VN028
2 VN029-VN041 VS196-VS203
AMIRI FLIGHT (ABD)
2 VS391
ANSETT AUSTRALIA (ANS)
2 VL755
ASIANA AIRLINES (AAR)
1 VK141-VK142 VN753
2 VK143-VK148 VL703 VR426 VS231 VW851
BOEING (TBC)
2 VY999
BRITANNIA AIRWAYS (BRI)
1 VB331-VB332
2 VL911-VL913 VS051-VS056
BRITANNIA AIRWAYS AB (TNS)
2 VL914
CANADIAN AIRLINES (CDI)
1 VN051 VN053 VN058-VN062 VN751-VN752 VN813
2 VN732 VS381-VS382
July 24, 1997 767-78A0081
Revision 2: April 19, 2001 2

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ALERT BOEING SERVICE BULLETIN 767-78A0081 ALERT
CHINA UNITED AIRLINES (CUL)
2 VS274
CITY BIRD (CBD)
2 VN436 VS177
CONTINENTAL AIRLINES (CAL)
2 VR051-VR058
DELTA AIR LINES (DAL)
1 VN301-VN306
2 VL753 VS073-VS078 VS266-VS273 VS466-VS471
EUROFLY (EUY)
2 VS392
EVA AIR (EVA)
1 VN471-VN472 VN791-VN792
2 VB441-VB444
GULF AIR (GUL)
1 VL004-VL006 VN307-VN308
2 VN309-VN310 VN313-VN314
H.M.S.F. AND AMEDEO CORP. (BWN)
2 VF180
IBERIA AIRLINES (IBE)
2 VN546-VN547
ITOCHU CORPORATION (CIT)
2 VF181-VF184
JAPAN AIRLINES (JAL)
2 VK012-VK016 VK181 VK186 VR441 VR461
K.B.A. FOUNDATION (KBA)
2 VN312
KALAIR USA CORP (KLA)
2 VN311
KENYA AIRWAYS (KEN)
2 VS331
KLM - ROYAL DUTCH AIRLINES (KLM)
2 VL891-VL900 VS136-VS137
LANCHILE AIRLINES (LAN)
1 VN063-VN064
2 VN968-VN970 VR251 VR256-VR257 VS131-VS133
LAPA ARGENTINA (LAZ)
2 VS111
LOT POLISH AIRLINES (LOT)
1 VF041-VF042 VN291
2 VN292-VN293
July 24, 1997 767-78A0081
Revision 2: April 19, 2001 3

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ALERT BOEING SERVICE BULLETIN 767-78A0081 ALERT
MALEV HUNGARIAN AIRLINES (HGA)
1 VL003
2 VF171-VF172
MID EAST JET (SKL)
2 VF251
QANTAS (QAN)
1 VN081-VN093
2 VN094-VN099 VS186-VS187 VS486
ROYAL BRUNEI AIRLINES (RBA)
2 VN637-VN638
SKYMARK AIRLINES (SKM)
2 VS261-VS262
SOBELAIR (SBL)
2 VN421 VN636
TRANSBRASIL (TBL)
1 VL001-VL002
UPS (UPS)
2 VR201-VR209 VW701-VW721
US AIRWAYS (USA)
1 VE141-VE151
2 VE152
VARIG AIRLINES (VAR)
1 VE121-VE126 VN055-VN056 VN231-VN234
VIETNAM AIRLINES (VIE)
2 VL751-VL752 VL754
IDENTIFICATION BY VARIABLE NUMBER
GROUP 1
VB331-VB332 VE121-VE126 VE141-VE151 VF001-VF002 VF041-VF042 VF051
VK081-VK102 VK131-VK133 VK141-VK142 VL001-VL006 VN001-VN028
VN051-VN064 VN081-VN093 VN191-VN195 VN231-VN234 VN291 VN301-VN308
VN471-VN472 VN651-VN652 VN731 VN751-VN753 VN791-VN792 VN811-VN813
GROUP 2 *
VB441-VB444 VE152 VF171_VF172 VF180-VF184 VF251 VK012-VK016
VK103-VK113 VK143-VK148 VK181 VK186 VL701-VL703 VL751-VL755
VL891-VL900 VL911-VL914 VL941 VN029-VN041 VN094-VN099 VN196-VN198
VN292-VN293 VN309-VN314 VN421-VN427 VN436 VN546-VN547 VN634-VN638
VN653-VN658 VN676 VN732 VN921-VN922 VN951-VN953 VN968-VN970
VR051-VR058 VR201-VR209 VR251 VR256-VR257 VR401 VR426
VR441 VR461 VS051-VS056 VS073-VS078 VS111-VS113 VS131-VS133
VS136-VS137 VS176-VS177 VS186-VS187 VS196-VS203 VS216-VS217 VS231
VS261-VS262 VS266-VS274 VS291-VS292 VS316 VS321-VS324 VS331
VS366-VS367 VS381-VS382 VS391-VS392 VS401 VS466-VS471 VS486
VS526 VS546-VS548 VW701-VW721 VW851 VY999
July 24, 1997 767-78A0081
Revision 2: April 19, 2001 4

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ALERT BOEING SERVICE BULLETIN 767-78A0081 ALERT
2. Spares
None
July 24, 1997 767-78A0081
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ALERT BOEING SERVICE BULLETIN 767-78A0081 ALERT
B. Concurrent Requirements
None
C. Reason
This inspection will make sure that the center drive unit (CDU) cone brake and the Thrust Reverser
Actuation System (TRAS) brake have the holding torque required to prevent any uncommanded
thrust reverser sleeve movement.
The CDU cone brake and the TRAS brake are primary safety devices required to prevent inadvertent
thrust reverser sleeve movement. To meet the system reliability requirements, periodic torque
checks are required to ensure the integrity of these locking devices. A failure of either of these locks
is not detected during normal operation. The torque check intervals have been determined through
industry-wide accepted probability and reliability methods.
The TRAS lock is a solenoid activated disk brake this is connected to the upper angle gearbox by a
flexible drive shaft. The brake is released when 28 VDC is applied from the control circuit and is
locked at all other times. Low torque can be the result of a brake or flexible shaft failure.
The CDU cone brake is a spring load, unidirectional device that prevent rotation of the air motor in the
deploy direction. The cone brake always allows the air motor to rotate in the stow direction. The
brake is disengaged when the directional control valve actuator piston is commanded to the deploy
position from the control circuit.
Boeing Service Related Problem (SRP) 767-SRP-78-0036 is related to this service bulletin.
Revision 1 is sent to change the inspection interval for the CDU cone brake test from 600 to 650 flight
hours to coincide with operators maintenance schedule.
Revision 2 adds the inspection interval of the Electro-Mechanical brake and CDU cone brake for
airplanes equipped with thrust reversers that have been modified in accordance with Boeing Service
Bulletin 767-78-0063 or after the equivalent modification (Production Revision Record B11481-90)
incorporating in production. Revise the service bulletin effectivity to add Group 2 airplanes which is
included all 767-200, -300 and -300F airplanes (including future 767-200, -300 and -300F airplanes)
with CF6-80C2 engines from production control line 475. Also, the Industry Support Information
statement has been changed.
D. Description
For Group 1 airplanes that have not incorporated Boeing Service Bulletin 767-78-0063, on each
thrust reverser half, do a functional test on the CDU cone brake to verify the holding torque.
For Group 1 airplanes that have incorporated Boeing Service Bulletin 767-78-0063 and Group 2
airplanes, on each thrust reverser half, do a functional test of the Electro-Mechanical brake and CDU
cone brake to verify the holding torque.
Revision 1 - No more work is necessary on airplanes changed as shown in the initial release of this
service bulletin.
Revision 2 - More work is necessary on airplanes changed as shown in the Revision 1 of this service
bulletin.
An evaluation form is attached to this service bulletin. Please use this form to tell us what you think
of the quality of this service bulletin.
July 24, 1997 767-78A0081
Revision 2: April 19, 2001 6

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ALERT BOEING SERVICE BULLETIN 767-78A0081 ALERT
E. Compliance
Boeing recommends the operators do this service bulletin within 650 flight hours after receipt of this
service bulletin.
For Group 1 airplanes that have not incorporated Boeing Service Bulletin 767-78-0063, Boeing
recommends the operators repeat CDU cone brake test every 650 flight hours.
For Group 1 airplanes on which Boeing Service Bulletin 767-78-0063 has been incorporated and on
Group 2 airplanes, Boeing recommends the operators repeat the Electro-Mechanical brake and CDU
cone brake tests every 1,000 flight hours.
Federal Aviation Administration (FAA) Airworthiness Directive (AD) 2000-09-04, Amendment
39-11712, is related to this service bulletin.
F. Approval
This service bulletin was examined by the Federal Aviation Administration (FAA). The changes
specified in this service bulletin comply with the applicable Federal Aviation Regulations (FAR) and
are FAA approved. This service bulletin and the FAA approval were based on the airplane in its
original Boeing delivery configuration or as modified by other FAA 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.
This service bulletin has been approved by the FAA. In addition, the Manager of the FAA Seattle
Aircraft Certification Office approves the inspection and tests defined in this service bulletin as an
alternative method of compliance to the requirements of paragraphs (d)(2), (f) and (g) of AD
2000-09-04. All provisions of AD 2000-09-04 that are not specifically referenced in the above
sentence remain fully applicable and must be complied with.
G. Manpower
Approximately 6 man-hours and 2 persons are necessary to do this test for each airplane.
Time does not include CDU replacement.
This estimate is for direct labor only, done by an experienced crew. Adjust the estimate with operator
man-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.
H. Weight and Balance Changes
None
I. Electrical Load Data
Not changed
July 24, 1997 767-78A0081
Revision 2: April 19, 2001 7

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ALERT BOEING SERVICE BULLETIN 767-78A0081 ALERT
J. References
1. Existing Data:
a. Service Related Problem (SRP) 767-SRP-78-0036
b. 767 Maintenance Manual (AMM) Subject 71-11-04, 78-31-21
c. Boeing Service Bulletin 767-78-0047, "Thrust Reverser (CF6-80C2 Engines) - Thrust Reverser
Control System - Operational Test"
d. Boeing Service Bulletin 767-78-0063, "Exhaust (GE CF6-80C2 Engines) - Thrust Reverser -
Lock Installation"
2. Data supplied with this service bulletin:
None
3. Installation Drawings:
None
K. Publications Changed
None
L. Interchangeability and Intermixability of Parts
Refer to Paragraph 2.E., Existing Parts Accountability, for interchangeability and intermixability
information.
July 24, 1997 767-78A0081
Revision 2: April 19, 2001 8

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ALERT BOEING SERVICE BULLETIN 767-78A0081 ALERT
2. MATERIAL INFORMATION
A. Material - Price and Availability
None
B. Industry Support Information
Boeing warranty remedies are not available for the inspection given in this service bulletin.
C. Parts Necessary For Each Airplane
Parts and Materials Supplied by the Operator:
NOTE: Part quantity dependent on test result.
Quantity Part Number Name
4 126784-() Center Drive Unit (a)
(a) Replace this part when the holding torque is less than 15 pound inches.
D. Parts Necessary to Change Spares
None
E. Existing Parts Accountability
None
F. Special Tooling - Price and Availability
None
G. 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.
July 24, 1997 767-78A0081
Revision 2: April 19, 2001 9

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ALERT BOEING SERVICE BULLETIN 767-78A0081 ALERT
3. ACCOMPLISHMENT INSTRUCTIONS
GENERAL NOTES
1. The lettered paragraphs contain the test to be accomplished at the specifies interval.
2. Obey all of the warnings and cautions given in the specified manual sections.
3. For Group 1 airplanes that have not incorporated Boeing Service Bulletin 767-78-0063, repeat
CDU cone brake test every 650 flight hours.
For Group 1 airplanes on which Boeing Service Bulletin 767-78-0063 has been incorporated and
on Group 2 airplanes, repeat the Electro-Mechanical brake and CDU cone brake tests every 1,000
flight hours.
4. Refer to Compliance Paragraph for recommendation and repeat inspection requirements.
WORK INSTRUCTIONS
A. Do the functional test on both thrust reverser for the Electro-Mechanical brakes of both engines as
follows:
1. Open the engine fan cowl panels as shown in 767 Maintenance Manual Subject 71-11-04 or
your own equivalent procedure.
2. Do a check of the running torque of the thrust reverser system:
a. Manually extend the thrust reverser six inches and measure the running torque. Make sure
the torque is less than 10 pound-inches.
3. Do a check of the electro-mechanical brake holding torque:
a. Make sure the thrust reverser translating cowl is extended at least one inch.
b. Make sure the CDU lock handle is released.
c. Pull down on the manual release handle on the electro-mechanical brake until the handle
fully engages the retaining clip.
NOTE: This will lock the electro-mechanical brake.
d. With the manual drive lockout cover removed from the CDU, install a 1/4-inch extension tool
and dial -type torque wrench into the drive pad.
NOTE: You will need a 24-inch extension to provide adequate clearance for the torque
wrench.
e. Apply 90 pound-inches of torque to the system.
1) The electro-mechanical brake system is working correctly if the torque is reached before
you turn the wrench 450 degrees (1-1/4 turns).
2) If the flexshaft turns more than 450 degrees (1-1/4 turns) before you reach the specified
torque, you must replace the long flexshaft between the CDU and the upper angle
gearbox.
July 24, 1997 767-78A0081
Revision 2: April 19, 2001 10

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ALERT BOEING SERVICE BULLETIN 767-78A0081 ALERT
3) If you do not get 90 pound-inches of torque, inspect the short flexshaft between the
upper angle gearbox and the electro-mechanical brake. If the flexshaft is twisted, broken
or otherwise damaged, replace the flexshaft and repead (e). If you still do not get 90
pound-inches of torque, you must replace the electro-mechanical brake.
f. Release the torque by turning the wrench in the position direction until you read zero
pound-inches.
1) If the wrench does not turn to within 30 degrees of initial starting point, you must replace
the long flexshaft between the CDU and upper angle gearbox.
4. Fully retract the thrust reverser.
5. Repeat this procedure on other reverser half and on the remaining engines.
6. End the Electro-Mechanical brake check.
B. For Group 1 airplanes on which Boeing Service Bulletin 767-78-0063 has been incorporated and
on Group 2 airplanes, repeat the Electro-Mechanical brake test at 1,000 flight hours intervals
C. Do the functional test on both thrust reverser for the Center Drive Unit (CDU) cone brakes of both
engines as follows:
1. Pull up on the manual release handle to unlock the electro-mechanical brake (if so equipped).
2. Pull the manual brake release lever on the CDU to release the cone brake. Refer to Figure 1
for location.
NOTE: This will release the pre-load tension that may occur during a stow cycle.
3. Return the manual brake release lever to the locked position to engage the cone brake. Refer
to Figure 1 for location.
4. Remove the two bolts that hold the lockout plate to the CDU and remove the lockout plate.
Refer to Figure 1 for location.
5. Install a 1/4-inch drive and a dial-type torque wrench into the CDU drive pad.
WARNING: Do not use more than 100 pound-inches of torque when carrying out this check.
Excessive torque will damage the CDU.
6. Turn the torque wrench to try to manually extend the translating cowl until you get at least 15
pound-inches of torque.
NOTE: The cone brake prevents movement in the extend direction only. If you try to measure
the torque in the retract direction, you will get a false reading.
7. If the sleeve translates to deploy with a torque less than 15 pound inches you must replace the
CDU. Refer to 767 Maintenance Manual Subject 78-31-21.
8. Reinstall the lockout plate.
9. Fully retract the thrust reverser.
10. Pull down on the manual release handle on the electro-mechanical brake until the handle fully
engages the retaining clip (if so equipped).
NOTE: This will lock the electro-mechanical brake.
July 24, 1997 767-78A0081
Revision 2: April 19, 2001 11

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ALERT BOEING SERVICE BULLETIN 767-78A0081 ALERT
11. Repeat this procedure on other reverser half and on the remaining engines.
12. Close the engine fan cowl panels as shown in 767 Maintenance Manual Subject 71-11-04 or
your own equivalent procedure.
13. End the CDU cone brake check.
D. For Group 1 airplanes that have not incorporated Boeing Service Bulletin 767-78-0063, repeat
CDU cone brake test every 650 flight hours.
E. For Group 1 airplanes on which Boeing Service Bulletin 767-78-0063 has been incorporated and
on Group 2 airplanes, repeat CDU cone brake tests every 1,000 flight hours.
July 24, 1997 767-78A0081
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ALERT BOEING SERVICE BULLETIN 767-78A0081 ALERT
FIGURE TABLE OF CONTENTS
Title Page
FIGURE 1. ELECTRO-MECHANICAL BRAKE, CDU MANUAL BRAKE RELEASE
LEVER, LOCKOUT PLATE AND DRIVE PAD LOCATIONS . . ........... 1 4
July 24, 1997 767-78A0081
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ALERT BOEING SERVICE BULLETIN 767-78A0081 ALERT
UPPER ANGLE GEARBOX
ELECTRO−MECHANICAL BRAKE
(LEFT SIDE SHOWN,
RIGHT SIDE TURNED 180 DEGREES)
CENTER
(CDU)
DRIVE UNIT
DRIVE PAD
PLATE AND
LOCKOUT
BRAKE RELEASE
CDU MANUAL
LEVER
CENTER DRIVE UNIT
S13037
FIGURE 1. ELECTRO-MECHANICAL BRAKE, CDU MANUAL BRAKE RELEASE LEVER, LOCKOUT
PLATE AND DRIVE PAD LOCATIONS
July 24, 1997 SHEET 1 OF 1 767-78A0081
Revision 2: April 19, 2001 14

### Page 19

Commercial
Airplane
Group
767
Service Bulletin
Number: 767-78A0081 Evaluation FormDate: July 24, 1997
Revision 2: April 19, 2001
ATA System: 7830
Prepared By: Phuoc Tran
SUBJECT: EXHAUST (CF6-80C2 Engines) - Thrust Reverser - Thrust Reverser Control System - Center
Drive Unit (CDU) Cone Brake Integrity Test
Use this evaluation form to tell us what you think of the quality of this service bulletin. We will use the data
that you give us to improve the quality of our service bulletins.
NOTE: Please do not use this evaluation form to tell us to make changes to your manuals. To make these
changes, please use a Publication Change Request (PCR) form.
Please give us this data:
(If necessary, please use the other side. Thank you for the time you used to give us your comments.)
OPERATOR: TODAY'S DATE:
PREPARED BY: TITLE:
ORGANIZATION: TELEX CODE:
TELEPHONE NUMBER: BASE:
Please rate the quality of this service bulletin: (good) 4321 (poor)
Please rate the quality of the illustrations: (good) 4321 (poor)
Will you do the change given by this service bulletin? Yes No If not, please explain:
Is this service bulletin easy to understand? Yes No If not, please explain:
Is this service bulletin easy to use? Yes No If not, please explain:
Are the Planning Information, Material Information, and
Accomplishment Instructions accurate? Yes No If not, please explain:
Is the Manpower estimate accurate? Yes No If not, please explain:
Give the completed evaluation form to your Boeing Field Service Representative or send the evaluation form
directly to this address:
Manager
Service Bulletin Engineering
Boeing Commercial Airplane Group
P.O. Box 3707, Mail Stop 2H-37
Seattle, WA 98124-2207

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