Commercial 

Airplanes 777

Service Bulletin

ALERT

Number: 777-27A0109

Original Issue: December 01, 2011

ATA System: 2711

SUBJECT: FLIGHT CONTROLS - Rudder and Tab - Rudder Power Control Units Reaction Link

Assembly Replacement or Repair

Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15

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3.0
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BLANK PAGE
Table of Contents

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

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

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

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

2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

E. Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

1. Existing Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2. Data supplied with this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3. Installation Drawings Used in the Preparation of this Service Bulletin . . . . . . . . . . . . 14

K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

C. Parts Necessary For Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

1. Kits/Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

2. Parts and Materials Supplied by the Operator . . . . . . . . . . . . . . . . . . . . . . . . 17

3. Parts Modified and Reidentified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

4. Parts Removed and Not Replaced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 18

3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

FIGURE 1: REACTION LINK ASSEMBLY, END CAP ASSEMBLY BUSHINGS REPLACEMENT . . . 21

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BLANK PAGE
Commercial 

Airplanes 777

Service Bulletin

ALERT

Summary Number: 777-27A0109

Original Issue: December 01, 2011

ATA System: 2711

SUBJECT: FLIGHT CONTROLS - Rudder and Tab - Rudder Power Control Units Reaction Link

Assembly Replacement or Repair

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

Accomplishment of this service bulletin will prevent vibration caused by the bushing liners of the rudder power

control unit (PCU) reaction link end cap assemblies coming out of the bushing bores. Loss of the bushing liners

in each of the three PCU reaction link assemblies can cause the rudder control surface to have excessive

freeplay which may cause rudder vibration and could result in structural damage severe enough to prevent

continued safe flight and landing.

Boeing received a report from a 777-300ER operator of abnormal airframe vibration in the aft fuselage during

flight. A subsequent inspection of the rudder PCU installations found that the bushing liners were missing from

all six end cap assemblies There have also been several reports from other 777-300ER operators of either

partial or complete loss of the bushing liners. An investigation revealed that the cause of the problem was a

failure of the bond between the liner and the bushing substrate because of the use of liquid nitrogen during

installation of the bushing into the reaction link end cap housing. All of these reports are associated with one

bushing supplier and limited to bushings manufactured before 2008, after which the installation procedure for

the bushings in the end cap assemblies was changed from liquid nitrogen to a dry ice alcohol bath. Because

777-200LR's use the same bushings, they are subject to the same condition.

This Service Bulletin gives instructions to install serviceable Rudder PCUs and related Reaction Link Assemblies

or PCU Reaction Link Assemblies which have been repaired on airplanes in which bushings have been installed

using liquid nitrogen. Installation of serviceable PCUs and their related reaction link assembly with bushings

installed using a dry ice ethyl alcohol or Dowanol DPM bath procedure will prevent the loss of rudder power

control unit (PCU) reaction link assembly bushing liners and subsequent rudder vibration.

Boeing Service Related Problem (SRP) 777-SRP-27-0212 is related to this service bulletin.

Boeing Fleet Team Digest (FTD) 777 FTD 27-07005 is related to this service bulletin.

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ACTION

For Each Rudder PCU, check maintenance records to identify if its related Reaction Link Assembly end cap

assembly bushings have been replaced in accordance with Part 1. Remove each affected Rudder PCU with its

related Reaction Link Assembly from the airplane and install a serviceable Rudder PCU and its related Reaction

Link Assembly in accordance with Part 2. As an alternative, a PCU Reaction Link Assembly which has been

repaired in accordance with Part 3 can be installed.

EFFECTIVITY

777-200LR/-300ER 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 available for airplanes in warranty as of October 28, 2010. Please refer to

Paragraph 2.B., Industry Support Information.

MANPOWER

Refer to Paragraph 1.G., Manpower.

MATERIAL INFORMATION

Boeing Supplied Parts.

Refer to Paragraph 2.A., Material - Price and Availability.

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BLANK PAGE
Commercial 

Airplanes 777

Service Bulletin

ALERT

Number: 777-27A0109

Original Issue: December 01, 2011

ATA System: 2711

SUBJECT: FLIGHT CONTROLS - Rudder and Tab - Rudder Power Control Units Reaction Link

Assembly Replacement or Repair

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 D624W001 Part 3 for Airplane Variable Number, Line Number, and

Serial Number data.

This service bulletin is for the airplanes shown below.

GROUP CONFIGURATION DESCRIPTION

777-200LR airplanes line numbers 504 through 679, and 777-300ER

airplanes line numbers 540 through 686

1 -

Airplane Models:

777-200LR, 777-300ER

Variable Number Group

WD001 - WD002 1

WD011 - WD014 1

WD031 - WD033 1

WD046 - WD048 1

WD505 - WD507 1

WD532 - WD537 1

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Variable Number Group

WD546 - WD552 1

WD564 - WD571 1

WD585 - WD594 1

WD606 - WD609 1

WD625 - WD632 1

WD653 - WD658 1

WD672 - WD675 1

WD691 - WD701 1

WD741 - WD745 1

WD761 - WD768 1

WD786 - WD787 1

WD796 - WD800 1

WD826 - WD828 1

WD846 1

WD871 - WD872 1

2. Spares Affected

Examine your spares records for any original rudder Power Control Units (PCUs) removed and

held as a spare and also, any Reaction Link Assemblies held as spare to identify assemblies where

the end cap bushing liners have not been installed using a dry-ice ethyl alcohol or Dowanol DPM

bath.

B. Concurrent Requirements

None.

C. Reason

Accomplishment of this service bulletin will prevent vibration caused by the bushing liners of the rudder

power control unit (PCU) reaction link end cap assemblies coming out of the bushing bores. Loss of

the bushing liners in each of the three PCU reaction link assemblies can cause the rudder control

surface to have excessive freeplay which may cause rudder vibration and could result in structural

damage severe enough to prevent continued safe flight and landing.

Boeing received a report from a 777-300ER operator of abnormal airframe vibration in the aft fuselage

during flight. A subsequent inspection of the rudder PCU installations found that the bushing liners

were missing from all six end cap assemblies There have also been several reports from other

777-300ER operators of either partial or complete loss of the bushing liners. An investigation revealed

that the cause of the problem was a failure of the bond between the liner and the bushing substrate

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BOEING SERVICE BULLETIN 777-27A0109

ALERT ALERT
because of the use of liquid nitrogen during installation of the bushing into the reaction link end cap

housing. All of these reports are associated with one bushing supplier and limited to bushings

manufactured before 2008, after which the installation procedure for the bushings in the end cap

assemblies was changed from liquid nitrogen to a dry ice alcohol bath. Because 777-200LR's use the

same bushings, they are subject to the same condition.

This Service Bulletin gives instructions to install serviceable Rudder PCUs and related Reaction Link

Assemblies or PCU Reaction Link Assemblies which have been repaired on airplanes in which bushings

have been installed using liquid nitrogen. Installation of serviceable PCUs and their related reaction

link assembly with bushings installed using a dry ice ethyl alcohol or Dowanol DPM bath procedure

will prevent the loss of rudder power control unit (PCU) reaction link assembly bushing liners and

subsequent rudder vibration.

Boeing Service Related Problem (SRP) 777-SRP-27-0212 is related to this service bulletin.

Boeing Fleet Team Digest (FTD) 777 FTD 27-07005 is related to this service bulletin.

D. Description

For Each Rudder Power Control Unit (PCU), check maintenance records to identify if its related Reaction

Link Assembly end cap assembly bushings have been replaced in accordance with Part 1. Remove

each affected Rudder PCU with its related Reaction Link Assembly from the airplane and install a

serviceable Rudder PCU and its related Reaction Link Assembly in accordance with Part 2. As an

alternative, a PCU Reaction Link Assembly which has been repaired in accordance with Part 3 can be

installed.

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

Affected Maintenance Zones

Model Zone

777-200LR, 777-300ER 323, 324, 325

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.

Accomplish the required action(s), based on the applicable condition(s), in Table 1 in accordance with

Paragraph 3. Accomplishment Instructions.

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Table 1

Repeat Interval

(Not to Exceed)

Condition Action Compliance Time

Within 48 months -

after the original issue date of this

service bulletin.

Check maintenance

records for each Rudder

PCU to identify the condition of its related Reaction Link Assembly End

Cap Bushings in accordance with PART 1.

All Airplanes

No further action is neces- - -

sary.

Condition 1:

The two End Cap Assembly Bushings have been

replaced on the Reaction

Link Assembly in accordance with CMM 27-21-77

dated March 01, 2011 or

later, or an equivalent procedure has been used

No further action is neces- - -

sary.

Condition 2:

The two End Cap Assembly Bushings have been

replaced on the Reaction

Link Assembly in accordance with CMM 27-21-77

dated before March 01,

2011, or an equivalent procedure was used, and it

can be confirmed that a dry

ice ethyl alcohol or

Dowanol DPM bath was

used to install the bushings

into the end caps.

No further action is neces- - -

sary.

Condition 3:

The Reaction Link Assembly was replaced with a unit

which was manufactured

before November 1, 2004

or after October 31, 2007.

Within 48 months -

after the original issue date of this

service bulletin.

Do the Rudder PCU Reaction Link Assembly replacement in accordance

with PART 2.

Condition 4:

The condition of the Reaction Link Assembly is not

in accordance with Conditions 1, 2 or 3.

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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 task 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.

Airplane Work

Task Number of Persons Task Hours Elapsed Hours

Open Access 1 1.00 1.00

PCU/Reaction Link 2 3.00 1.50

Assembly Removal

PCU/Reaction Link 2 4.00 2.00

Assembly Installation

and Test

Close Access 1 1.00 1.00

TOTAL FOR EACH PCU/REACTION LINK 9.00 5.50

(a)

(a) Open and close access only required once if multiple PCU/Reaction Link Assembly worked simultaneously.

Component Work

Number of Per- Task Hours Elapsed Hours

sons

Task

FIGURE 1 1 1.00 1.00

TOTAL FOR EACH COMPONENT (a) 1.00 1.00

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Component Work

Number of Per- Task Hours Elapsed Hours

sons

Task

(a) Total given is for the repair of one Reaction Link Assembly.

H. Weight and Balance Changes

None.

I. Electrical Load Data

Not changed.

J. References

1. Existing Data

a. Boeing Service Related Problem (SRP) 777-SRP-27-0212

b. Component Maintenance Manual (CMM) 27-21-77

c. Service Bulletin Index D624W001

d. Standard Overhaul Practices Manual (SOPM) 20-50-03, 20-50-10

e. 777 Aircraft Maintenance Manual (AMM) 27-21-11

f. 777 Fleet Team Digest (FTD) 27-07005

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:

Publication Chapter-Section

777 Illustrated Parts Catalog 27-21

2. Damage Tolerance Based Structural Inspections:

Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue

Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the

Maintenance Program. This service bulletin does not affect FCS, therefore DTIs are not necessary.

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L. Interchangeability and Intermixability of Parts

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

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BLANK PAGE
2. MATERIAL INFORMATION

A. Material - Price and Availability

Boeing can supply the parts shown in Paragraph 2.C., Parts Necessary for Each Airplane. Operators

are encouraged to share schedule requirements with Boeing for incorporation of the service bulletin.

The kits are subject to the terms and conditions of the Boeing standard purchase order acknowledgment.

Prices are in United States Dollars. Terms: Net 30 days.

Reference this service bulletin and submit your purchase order by one of these methods:

1. Order on-line via ATA Spec 2000 or The Boeing PART Page

2. Fax to (206) 662-7145

REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER

AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION

Unit Price as of

the original issue

date of this Service Bulletin (US

Dollars)

ROLT as of the

original issue

date of this Service Bulletin (Calendar Days)

Part Number Name

251W3135-5 BUSHING, END CAP 180 794.00

B. Industry Support Information

Boeing warranty remedies are available for 777 airplanes in warranty as of October 28, 2010. For task

hour reimbursement for airplanes in warranty as of that date, send a warranty claim to Boeing

Commercial Airplanes Group - Warranties. The parts for airplanes in warranty as of that date will be

supplied at no charge. Send a purchase order for the parts to Boeing Spares. Please refer to this

service bulletin number and reference the airplane variable numbers in your purchase order.

C. Parts Necessary For Each Airplane

1. Kits/Parts

To get the parts shown below, refer to Paragraph 2.A., Material - Price and Availability.

Part Number / QTY Name Notes

Specification

251W3135-5 2 BUSHING, END CAP (a)

(a) The quantity specified is sufficient to replace the end cap bushing assemblies of one

rudder PCU reaction link assembly. There are three rudder PCU reaction link assemblies

on each airplane.

2. Parts and Materials Supplied by the Operator

None.

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3. Parts Modified and Reidentified

The parts shown below are changed as shown in this service bulletin. The quantity (QTY) is the

number of parts changed on each rudder PCU reaction link assembly.

Existing Part QTY Name New Part Number Notes

Number

251W3131-5 2 End Cap Assembly 251W3131-5 (a) (b)

(a) Make the change in accordance with this service bulletin.

(b) Identify on the part that the change given in this service bulletin was made.

4. Parts Removed and Not Replaced

None.

D. Parts Necessary to Change Spares

It is recommended that operators check their records to see if they have any affected Reaction link

Assemblies or Power Control Units with affected Reaction Link Assemblies fitted held as spare. Once

this data is known, evaluate the condition and do the applicable action.

To get the parts shown below, refer to Paragraph 2.A., Material - Price and Availability. The QTY given

is for each rudder PCU reaction link assembly.

Part Number Name QTY

251W3135-5 BUSHING, END CAP 2 (a)

(a) The quantity specified is sufficient to replace

the end cap bushing assemblies of one rudder

PCU reaction link assembly.

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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BOEING SERVICE BULLETIN 777-27A0109

ALERT ALERT
3. ACCOMPLISHMENT INSTRUCTIONS

A. GENERAL INFORMATION

CAUTION: KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL

PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL,

METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE

DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR

OTHER ELECTRICAL DAMAGE.

NOTE: 1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for

definition of the acronyms.

2. Obey all of the warnings and cautions given in the specified manual sections.

3. 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.

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

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

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

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

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

5. 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.

6. 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.

B. WORK INSTRUCTIONS

PART 1 - RUDDER POWER CONTROL UNIT, REACTION LINK ASSEMBLY END CAP ASSEMBLY

- MAINTENANCE RECORD CHECK

1. For each Rudder Power Control Unit (PCU) check maintenance records to identify the condition

of its related reaction link assembly.

a. Condition 1: The two End Cap Assembly Bushings have been replaced in accordance with

CMM 27-21-77 dated March 01, 2011 or later, or an equivalent procedure has been used.

b. Condition 2: The two End Cap Assembly Bushings have been replaced in accordance with

versions of CMM 27-21-77 dated before March 01, 2011, or an equivalent procedure has

been used, and it can be confirmed that a dry ice ethyl alcohol or Dowanol DPM bath was

used to shrink fit the bushings into the end caps.

c. Condition 3: The Reaction Link Assembly was manufactured before November 1, 2004 or

after October 31, 2007.

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d. Condition 4: The condition of the reaction link assembly is not in accordance with Conditions

1, 2 or 3.

2. For each reaction link assembly found to have Conditions 1, 2 or 3, no further action is necessary.

3. For each reaction link assembly found to have Condition 4, do Part 2.

PART 2 - PCU REACTION LINK ASSEMBLY REPLACEMENT

1. Do these steps for each reaction link assembly found to have Condition 4:

a. Remove the applicable Rudder PCU and its related Reaction Link Assembly from the airplane.

Refer to 777 AMM 27-21-11 as an accepted procedure.

NOTE: It is not necessary to remove the Kick Link Assembly and the Damped Solenoid from

the Power Control Unit.

b. Install a serviceable Rudder PCU and its related Reaction Link Assembly. Refer to 777 AMM

27-21-11 as an accepted procedure. The PCU Reaction Link Assembly which is installed must

be in accordance with Condition 1, Condition 2 or Condition 3. As an alternative, the PCU

Reaction Link Assembly must have its bushings replaced in accordance with Part 3.

2. Put the airplane back to a serviceable condition.

PART 3 - PCU REACTION LINK ASSEMBLY END CAP ASSEMBLY BUSHING REPLACEMENT

1. Replace the Reaction Link Assembly End Cap Assembly Bushings in accordance with FIGURE

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 Reaction Link Assembly.

FIGURE 1: REACTION LINK ASSEMBLY, END CAP ASSEMBLY BUSHINGS REPLACEMENT

(SHEET 1 OF 2)

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Step Task Name Identification Qty More Data

1 Inspect Reaction Link Leg - 2 Serial Number. (a)

Inspect Bushing, End Cap 251W3135-5 2 Serial Number. (a)

Refer to SOPM 20-

50-03 as an accepted procedure.

2 Remove Bushing, End Cap 251W3135-5 2

Refer to CMM 27-

21-77 dated March

01, 2011 or later,

Repair 2-1 as an accepted procedure.

(b)

3 Install (New) Bushing, End Cap 251W3135-5 2

Service Bulletin Num- SB 777-27A0109 - (c)

ber

4 Apply

(a) To make sure that marking of matched set serial numbers are legible and visible, on the outside face, on

the Reaction Link Assembly link legs and their related End Cap Assemblies. If matched set markings are

not visible on all of the parts, then apply markings as follows: Each Reaction Link leg and mating End

Cap Assembly must be marked with the unique assembly serial number XXXX and serial dash number

"-001" or "-002" where XXXX represents the digits in a unique number. When marking is complete, one

Reaction Link leg and its mating/matched End Cap Assembly should be marked "S/N XXXX -001", and

the opposite Reaction Link leg and its mating/matched End Cap Assembly should be marked "S/N XXXX002". Refer to SOPM 20-50-10 code M as an accepted procedure to apply markings.

(b) CMM 27-21-77 dated March 01, 2011, or later, uses dry ice ethyl alcohol or Dowanol DPM bath to shrink

fit bushings into reaction link assembly end cap assemblies.

(c) Use rubber stamp method. Refer to SOPM 20-50-10 as an accepted procedure. Make sure that the

marking is on the outside face of each End Cap Assembly.

FIGURE 1: REACTION LINK ASSEMBLY, END CAP ASSEMBLY BUSHINGS REPLACEMENT

(SHEET 2 OF 2)

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