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747-400 MAINTENANCE MANUAL 
ACTUATOR CONTROL POWER  MODULE CONTROL POWER 

LOWER RUDDER POWER
CONTROL ACTUATORRUDDER
RATIO CHANGER SEE E
LOWER POWER CONTROL PACKAGE
SERVO 
BONDING  UNIT  D
JUMPER 
ELEVATOR AUTOPILOT 
SERVO MODULES 

ACTUATOR
OUTPUT
INPUT CRANK
CRANK ELEVATOR AFT QUADRANT
INPUT ROD FOR THE INPUT ROD FOR THEPOWER RUDDER RATIOCONTROL CHANGER (EXAMPLE)PACKAGE RIG PIN E-2
RUDDER RATIO CHANGER (EXAMPLE) RIG PIN E-2 E
F
Rudder Ratio Changer Adjustment Figure 501 (Sheet 2)
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747-400
MAINTENANCE MANUAL

Rudder Ratio Changer Adjustment
Figure 501 (Sheet 3)

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747-400 MAINTENANCE MANUAL
 S 495-054
 WARNING:_______ MAKE SURE THE NOSE LANDING GEAR IS POINTED FORWARD.  IF THE
 TIRES ARE NOT PARALLEL WITH THE AIRPLANE , THEY CAN TURN
 QUICKLY WHEN YOU REMOVE THE TOW PIN.  THIS CAN CAUSE INJURY TO

 PERSONS AND DAMAGE TO EQUIPMENT.
 (1)  Install the TOW PIN at the steering metering valve for the nose landing gear (Ref 09-11-00/201).
 NOTE: This is to make sure the nose landing gear does not turn.
____
 S 865-068
 (2)  
Supply electrical power (Ref 24-22-00/201).

 S 865-003

 (3)  
Set the rudder trim to zero.

 S 015-004

 (4)  
Remove access panel 324UL for access to the upper rudder ratio changer or access panel 324DL for access to the lower rudder ratio changer.

 S 015-066

 (5)  
Open access panel 324FL for access to the feel, centering, and trim mechanism (Ref 06-09-07/201).

 S 015-005

 (6)  
Open access door 315A for access to the elevator aft quadrant (Ref 06-09-05/201).

 S 495-006

 (7)  
Install rig pin R-4 in the feel, centering, and trim mechanism.

 (8)  
Install rig pin E-2 at the bottom of the elevator aft quadrant.

 S 495-044
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747-400 MAINTENANCE MANUAL
 S 865-049
 (9)  
Find the switches for the FLT CONTROL HYD POWER on the pilot's overhead maintenance panel, P461:

 (a)  
Put the No. 1 and No. 3 tail switches in the SHUTOFF position.

 S 865-039
 (10)
 Open these circuit breakers and attach DO-NOT-CLOSE tags:

 (a)  
P180, DC Power Distribution Panel
 1) 180H8 ELEV/RUD VLV SYS 1
 2) 180H23 ELEV/RUD VLV SYS 3

 F.  
Lower Rudder Ratio Changer Adjustment

 S 865-013
 WARNING: MAKE SURE THAT PERSONS AND EQUIPMENT ARE CLEAR OF ALL CONTROL
_______ SURFACES BEFORE YOU SUPPLY HYDRAULIC POWER. THE AILERONS, RUDDERS, ELEVATORS, FLAPS, SPOILERS, LANDING GEAR, AND THRUST REVERSERS CAN MOVE QUICKLY WHEN YOU SUPPLY HYDRAULIC POWER. THIS CAN CAUSE INJURY TO PERSONS AND DAMAGE TO EQUIPMENT.
 (1)  
Supply hydraulic power to hydraulic systems No. 2 and No. 4
 (Ref 29-11-00/201).

 S 845-064

 (2)  
Do one of the two subsequent procedures to extend the servo units for the two rudder ratio changers.
　
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