Commercial 

Airplanes 747

Service Bulletin

ALERT

Number: 747-27A2497

Original Issue: September 30, 2010

ATA System: 2722

SUBJECT: FLIGHT CONTROLS - Rudder and Rudder Trim Control System - Rudder Power

Control Module Change

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ECCN: 9E991

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This document includes proprietary information owned by The Boeing Company and/or one or more third parties.

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2.0
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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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

1. Existing Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2. Data supplied with this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

3. Installation Drawings Used in the Preparation of this Service Bulletin . . . . . . . . . . . . 13

K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

C. Parts Necessary For Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

1. Kits/Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

2. Parts and Materials Supplied by the Operator . . . . . . . . . . . . . . . . . . . . . . . . 15

3. Parts Modified and Reidentified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

4. Parts Removed and Not Replaced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 16

3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

FIGURE 1: UPPER RUDDER POWER CONTROL MODULE - REPLACEMENT . . . . . . . . . . . . 21

FIGURE 2: LOWER RUDDER POWER CONTROL MODULE - REPLACEMENT . . . . . . . . . . . 23

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BLANK PAGE
Commercial 

Airplanes 747

Service Bulletin

ALERT

Summary Number: 747-27A2497

Original Issue: September 30, 2010

ATA System: 2722

SUBJECT: FLIGHT CONTROLS - Rudder and Rudder Trim Control System - Rudder Power

Control Module 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

Accomplishment of this service bulletin ensures that the upper or lower rudder Power Control Modules (PCM)

do not create a hard-over condition in the event of a manifold cracking and separation. This will be accomplished

by replacing the rudder PCM manifold access cap with a two-piece cap that includes a retention feature for the

yaw damper modulating piston assembly in the rudder PCM. The secondary retention engages an existing

window in the sleeve of the yaw damper modulating piston assembly. This restricts the yaw damper modulating

piston assembly from significantly shifting and causing considerable uncommanded input to the Rudder PCM

main control valve in an event where the primary retention endcap is detached or compromised. Uncommanded

input to the Rudder PCM main control valve may create a hard-over condition. A hard-over condition can result

in a high speed runway excursion after touchdown in a landing.

A lower rudder hard-over left event was reported by an operator of a 747-400 series airplane. The hard-over

was caused by the lower rudder PCM manifold cracking in the area of the yaw damper cavity end-cap. This

allowed the yaw damper sleeve to shift, giving the system a lower rudder left input. Three additional rudder PCM

manifold cracking events have been reported by other operators. These events did not result in a hard-over,

but created the need for a retention feature solution. Upon investigation, it was determined that the 747-SP fleet

could be susceptible to the same failure because they use the same manifold sub-assembly as the 747-400

aircraft.

Boeing Service Related Problem (SRP) 747-SRP-27-0193 is related to this service bulletin.

ACTION (PRR 85656-R)

Open access to the upper and the lower rudder PCM. Replace each rudder PCM. As an alternative, you can

make the change to each PCM as given in Parker service bulletin 241700-27-333. Do the operational tests.

Close access. Put the airplane back to a serviceable condition.

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EFFECTIVITY

All 747SP 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.

Boeing recommends that the change given in this service bulletin be done within 24 months or 8,400 flight hours

after the original issue date on this service bulletin, whichever occurs first.

INDUSTRY SUPPORT INFORMATION

Boeing warranty remedies are not available for the configuration changes given in this service bulletin.

MANPOWER

Work Package 1, Option 1: Replace the Upper Rudder PCM:

Airplanes Total Task Hours Elapsed Hours

Group 1 11.00 5.50

Work Package 1, Option 2: Change the Upper Rudder PCM:

Airplanes Total Task Hours Elapsed Hours

Group 1 2.75 1.75

Work Package 2, Option 1: Replace the Lower Rudder PCM:

Airplanes Total Task Hours Elapsed Hours

Group 1 11.00 5.50

Work Package 2, Option 2: Change the Lower Rudder PCM:

Airplanes Total Task Hours Elapsed Hours

Group 1 2.75 1.75

MATERIAL INFORMATION

Operator Supplied Parts/Materials.

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

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ALERT ALERT

BLANK PAGE
Commercial 

Airplanes 747

Service Bulletin

ALERT

Number: 747-27A2497

Original Issue: September 30, 2010

ATA System: 2722

SUBJECT: FLIGHT CONTROLS - Rudder and Rudder Trim Control System - Rudder Power

Control Module 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

This service bulletin is for the airplanes shown below. An equivalent change is on subsequent

production airplanes. Refer to PRR 85656-R for data about this change.

Refer to Service Bulletin Index Document D6-30300 Part 3 for Airplane Variable Number, Line

Number, and Serial Number data.

GROUP CONFIGURATION DESCRIPTION

1 - All 747SP airplanes.

Airplane Models:

747SP

Variable Number Group

RG001 - RG009 1

RG091 1

RG095 1

RG101 - RG104 1

RG121 - RG126 1

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Variable Number Group

RG141 - RG142 1

RG161 - RG164 1

RG171 - RG174 1

RG191 - RG193 1

RG211 - RG213 1

RG221 - RG222 1

RH101 - RH102 1

RH111 - RH112 1

RH121 - RH122 1

2. Spares Affected

Examine your spares supply for the parts or components identified in Paragraph 2.C., Parts

Necessary for Each Airplane. If any parts or components are found, refer to Paragraph 2.C. for

the recommended use.

B. Concurrent Requirements

None.

C. Reason

Accomplishment of this service bulletin ensures that the upper or lower rudder Power Control Modules

(PCM) do not create a hard-over condition in the event of a manifold cracking and separation. This will

be accomplished by replacing the rudder PCM manifold access cap with a two-piece cap that includes

a retention feature for the yaw damper modulating piston assembly in the rudder PCM. The secondary

retention engages an existing window in the sleeve of the yaw damper modulating piston assembly.

This restricts the yaw damper modulating piston assembly from significantly shifting and causing

considerable uncommanded input to the Rudder PCM main control valve in an event where the primary

retention endcap is detached or compromised. Uncommanded input to the Rudder PCM main control

valve may create a hard-over condition. A hard-over condition can result in a high speed runway

excursion after touchdown in a landing.

A lower rudder hard-over left event was reported by an operator of a 747-400 series airplane. The

hard-over was caused by the lower rudder PCM manifold cracking in the area of the yaw damper cavity

end-cap. This allowed the yaw damper sleeve to shift, giving the system a lower rudder left input. Three

additional rudder PCM manifold cracking events have been reported by other operators. These events

did not result in a hard-over, but created the need for a retention feature solution. Upon investigation,

it was determined that the 747-SP fleet could be susceptible to the same failure because they use the

same manifold sub-assembly as the 747-400 aircraft.

Boeing Service Related Problem (SRP) 747-SRP-27-0193 is related to this service bulletin.

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BOEING SERVICE BULLETIN 747-27A2497

ALERT ALERT
D. Description

Open access to the upper and the lower rudder PCM. Replace each rudder PCM. As an alternative,

you can make the change to each PCM as given in Parker service bulletin 241700-27-333. Do the

operational tests. Close access. Put the airplane back to a serviceable condition.

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

Affected Maintenance Zones

Model Zone

747SP 325, 326

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.

Boeing recommends that the change given in this service bulletin be done within 24 months or 8,400

flight hours after the original issue date on this service bulletin, whichever occurs first.

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

Work Package 1, Option 1: Replace the Upper Rudder Power Control Module (PCM)

Number of Per- Task-Hours Elapsed Hours

sons

Task

Open Access 2 3.00 1.50

Figure 1 2 4.00 2.00

Test 2 1.00 0.50

Close Access 2 3.00 1.50

Total per airplane 11.00 5.50

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BOEING SERVICE BULLETIN 747-27A2497

ALERT ALERT
Work Package 1, Option 2: Change the Upper Rudder Power Control Module (PCM)

Number of Per- Task-Hours Elapsed Hours

sons

Task

Open Access 2 1.00 0.50

Test 1 0.75 0.75

Close Access 2 1.00 0.50

Total per airplane 2.75 1.75

Work Package 2, Option 1: Replace the Lower Rudder Power Control Module (PCM)

Number of Per- Task-Hours Elapsed Hours

sons

Task

Open Access 2 3.00 1.50

Figure 2 2 4.00 2.00

Test 2 1.00 0.50

Close Access 2 3.00 1.50

Total per airplane 11.00 5.50

Work Package 2, Option 2: Change the Lower Rudder Power Control Module (PCM)

Number of Per- Task-Hours Elapsed Hours

sons

Task

Open Access 2 1.00 0.50

Test 1 0.75 0.75

Close Access 2 1.00 0.50

Total per airplane 2.75 1.75

Work Package Number 1 can be done at the same time as Work Package Number 2.

H. Weight and Balance Changes

None.

I. Electrical Load Data

Not changed.

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BOEING SERVICE BULLETIN 747-27A2497

ALERT ALERT
J. References

1. Existing Data

a. Engineering Change Memo PRR 85656-R

b. 747-100/200/300 Aircraft Maintenance Manual (AMM) 12-09-07, 22-16-00, 24-22-00, 27-22-15,

27-22-16, 29-11-00

c. Parker Service Bulletin 241700-27-333

NOTE: The supplier was told to send copies of the service bulletin to each operator.

d. Service Related Problem (SRP) 747-SRP-27-0193

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

747 Maintenance Manual 27-22

747 Illustrated Parts Catalog 27-22

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.

L. Interchangeability and Intermixability of Parts

Refer to Paragraph 2.C., Parts Necessary for Each Airplane, for interchangeability and intermixability

information.

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BOEING SERVICE BULLETIN 747-27A2497

ALERT ALERT

BLANK PAGE
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

Correspond- Notes

ing Existing

Parker Part

Number

Existing Boeing Part NumberCorrespond- QTY Name

ing New Parker Part Number / Specification

New Boeing

Part Number

/ Specification

60B80093-104 241700-9007 2 Rudder PCM 60B80093-3 241700-1005 (a) (b) (c)

60B80093-4 241700-1007 (a) (b) (c)

(a) You cannot use the existing part to replace the new or changed part.

(b) Parker service bulletin 241700-27-333 gives instructions to change the existing part to the new part.

(c) The Upper and Lower PCMs in the 747SP are exactly the same and have the same part numbers. There

is one Upper and one Lower PCM per airplane.

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.

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ALERT ALERT
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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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. The instructions identified in Paragraph 3.B., Work Instructions and 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. The work instructions are divided into work packages. Task Hours and Elapsed Hours

for each package are given in Paragraph 1.G., Manpower. You can do each work

package independently.

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.

B. WORK INSTRUCTIONS

WORK PACKAGE 1, Option 1: Replace the Upper Rudder Power Control Module (PCM)

1. Replace the Upper Rudder PCM in accordance with Figure 1.

2. Put the airplane back to a serviceable condition.

NOTE: It is recommended to make sure that the rudder actuators for the upper rudder are correctly

adjusted. Refer to 747-100/200/300 AMM 27-22-16 "Test Rudder Actuator" as an accepted

procedure.

WORK PACKAGE 1, Option 2: Change the Upper Rudder Power Control Module (PCM) while

installed on the airplane

1. Supply electrical power. Refer to 747-100/200/300 AMM 24-22-00 as an accepted procedure.

2. Remove power from hydraulic systems 1 and 3. Refer to 747-100/200/300 AMM 29-11-00 as an

accepted procedure.

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BOEING SERVICE BULLETIN 747-27A2497

ALERT ALERT
NOTE: Make sure to depressurize hydraulic systems 1 and 3 when you remove power from these

systems.

3. Set ELEVATOR/RUDDER FLT CONTROLS HYD POWER system switches No. 1 and 3 on pilot's

overhead panel P5 to OFF.

4. Open ELEVATOR/RUDDER FLT CONTROLS circuit breakers for systems No. 1 and 3 on panel

P12.

5. Open the yaw damper circuit breakers on P7.

6. Remove the access panels 324HR and 324HL for access to the Upper Rudder PCM. Refer to

747-100/200/300 AMM 12-09-07 as an accepted procedure.

WARNING: RELEASE HYDRAULIC SYSTEM PRESSURE BEFORE YOU OPEN THE HYDRAULIC

SYSTEM. HYDRAULIC FLUID THAT HAS PRESSURE CAN CAUSE INJURIES TO

PERSONNEL.

WARNING: DO NOT LET THE HYDRAULIC FLUID STAY ON YOUR SKIN. YOU CAN ABSORB

POISONOUS MATERIALS FROM THE FLUID THROUGH YOUR SKIN.

CAUTION: IMMEDIATLY CLEAN ALL THE HYDRAULIC FLUID THAT FALLS ON THE AIRPLANE

PARTS. THE FLUID CAN CAUSE DAMAGE TO THE PAINT AND CORROSION TO

SOME PARTS.

7. Change the Upper Rudder PCM in accordance with Parker service bulletin 241700-27-333.

8. Close the yaw damper circuit breakers on P7.

9. Close ELEVATOR/RUDDER FLT CONTROLS circuit breakers for systems No. 1 and 3 on panel

P12.

10. Set ELEVATOR/RUDDER FLT CONTROLS HYD POWER system switches No. 1 and 3 on pilot's

overhead panel P5 to NORM.

11. Supply power to hydraulic systems 1 and 3. Refer to 747-100/200/300 AMM 29-11-00 as an

accepted procedure.

12. Do an operational test of the rudder control system. Refer to 747-100/200/300 AMM 27-22-15

"Test Rudder Control Module" as an accepted procedure.

13. Do an operational test of the yaw damper system. Refer to 747-100/200/300 AMM 22-16-00

"Operational Test - Yaw Damper System" as an accepted procedure.

14. Make sure that the Upper Rudder PCM does not have hydraulic leaks.

15. Install the access panels 324HR and 324HL. Refer to 747-100/200/300 AMM 12-09-07 as an

accepted procedure.

16. Put the airplane back to a serviceable condition.

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ALERT ALERT
WORK PACKAGE 2, Option 1: Replace the Lower Rudder Power Control Module (PCM)

1. Replace the Lower Rudder PCM in accordance with Figure 2.

2. Put the airplane back to a serviceable condition.

NOTE: It is recommended to make sure that the rudder actuators for the lower rudder are correctly

adjusted. Refer to 747-100/200/300 AMM 27-22-16 "Test Rudder Actuator" as an accepted

procedure.

WORK PACKAGE 2, Option 2: Change the Lower Rudder Power Control Module (PCM) while

installed on the airplane

1. Supply electrical power. Refer to 747-100/200/300 AMM 24-22-00 as an accepted procedure.

2. Remove power from the hydraulic systems 2 and 4. Refer to 747-100/200/300 AMM 29-11-00 as

an accepted procedure.

NOTE: Make sure to depressurize the hydraulic systems 2 and 4 when you remove power from

these systems.

3. Set ELEVATOR/RUDDER FLT CONTROLS HYD POWER system switches No. 2 and 4 on pilot's

overhead panel P5 to OFF.

4. Open ELEVATOR/RUDDER FLT CONTROLS circuit breakers for systems No. 2 and 4 on panel

P12.

5. Open the yaw damper circuit breakers on P7.

6. Remove the access panels 324DR and 324DL for access to the Lower Rudder PCM. Refer to

747-100/200/300 AMM 12-09-07 as an accepted procedure.

WARNING: RELEASE HYDRAULIC SYSTEM PRESSURE BEFORE YOU OPEN THE HYDRAULIC

SYSTEM. HYDRAULIC FLUID THAT HAS PRESSURE CAN CAUSE INJURIES TO

PERSONNEL.

WARNING: DO NOT LET THE HYDRAULIC FLUID STAY ON YOUR SKIN. YOU CAN ABSORB

POISONOUS MATERIALS FROM THE FLUID THROUGH YOUR SKIN.

CAUTION: IMMEDIATLY CLEAN ALL THE HYDRAULIC FLUID THAT FALLS ON THE AIRPLANE

PARTS. THE FLUID CAN CAUSE DAMAGE TO THE PAINT AND CORROSION TO

SOME PARTS.

7. Change the Lower Rudder PCM in accordance with Parker service bulletin 241700-27-333.

8. Close the yaw damper circuit breakers on P7.

9. Close ELEVATOR/RUDDER FLT CONTROLS circuit breakers for systems No. 2 and 4 on panel

P12.

10. Set ELEVATOR/RUDDER FLT CONTROLS HYD POWER system switches No. 2 and 4 on pilot's

overhead panel P5 to NORM.

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ALERT ALERT
11. Supply power to the hydraulic systems 2 and 4. Refer to 747-100/200/300 AMM 29-11-00 as an

accepted procedure.

12. Do an operational test of the rudder control system. Refer to 747-100/200/300 AMM 27-22-15

"Test Rudder Control Module" as an accepted procedure.

13. Do an operational test of the yaw damper system. Refer to 747-100/200/300 AMM 22-16-00

"Operational Test - Yaw Damper System" as an accepted procedure.

14. Make sure that the Lower Rudder PCM does not have hydraulic leaks.

15. Install the access panels 324DR and 324DL. Refer to 747-100/200/300 AMM 12-09-07 as an

accepted procedure.

16. Put the airplane back to a serviceable condition.

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Original Issue: September 30, 2010

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BOEING SERVICE BULLETIN 747-27A2497

ALERT ALERT
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 this figure.

FIGURE 1: UPPER RUDDER POWER CONTROL MODULE - REPLACEMENT

(SHEET 1 OF 2)

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Original Issue: September 30, 2010

747-27A2497

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BOEING SERVICE BULLETIN 747-27A2497

ALERT ALERT
STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Remove Rudder PCM 60B80093-( ) 1 (a) (b) (d)

2 Install (New) Rudder PCM 60B80093-104 1 (c) (e)

(a) Refer to Paragraph 2.C.2 for existing Rudder PCM part number.

(b) Refer to 747-100/200/300 AMM 27-22-15 "Remove Rudder Control Module" as an accepted procedure.

(c) Refer to 747-100/200/300 AMM 27-22-15 "Install Rudder Control Module" as an accepted procedure.

(d) Corresponding Parker part number 241700-100( ).

(e) Corresponding Parker part number 241700-9007.

FIGURE 1: UPPER RUDDER POWER CONTROL MODULE - REPLACEMENT

(SHEET 2 OF 2)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: September 30, 2010

747-27A2497

22 of 24

BOEING SERVICE BULLETIN 747-27A2497

ALERT ALERT
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 this figure.

FIGURE 2: LOWER RUDDER POWER CONTROL MODULE - REPLACEMENT

(SHEET 1 OF 2)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: September 30, 2010

747-27A2497

23 of 24

BOEING SERVICE BULLETIN 747-27A2497

ALERT ALERT
STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Remove Rudder PCM 60B80093-( ) 1 (a) (b) (d)

2 Install (New) Rudder PCM 60B80093-104 1 (c) (e)

(a) Refer to Paragraph 2.C.2 for existing Rudder PCM part number.

(b) Refer to 747-100/200/300 AMM 27-22-15 "Remove Rudder Control Module" as an accepted procedure.

(c) Refer to 747-100/200/300 AMM 27-22-15 "Install Rudder Control Module" as an accepted procedure.

(d) Corresponding Parker part number 241700-100( ).

(e) Corresponding Parker part number 241700-9007.

FIGURE 2: LOWER RUDDER POWER CONTROL MODULE - REPLACEMENT

(SHEET 2 OF 2)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: September 30, 2010

747-27A2497

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BOEING SERVICE BULLETIN 747-27A2497

ALERT ALERT