27-41-00
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A
747-400
MAINTENANCE MANUAL

BALLSCREW 
STOP 
BALLNUT 
STOP 
SEE  A 
STABILIZER
TRIM 
JACKSCREW 
HYDRAULIC 
BRAKES 
HYDRAULIC 
MOTORS  STABILIZER TRIM 
HYDRAULIC  JACKSCREW GEARBOX 
BRAKE 
A  SEE  B 
JACKSCREW 
GEARBOX 
DUST 
COVER 

ADAPTER MOTOR HYDRAULIC  WRENCH 
B 
Stabilizer Trim Drive Mechanism Figure 201 

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747-400 MAINTENANCE MANUAL
 S 022-006
 (5)  
Do this task to remove one hydraulic brake: "Stabilizer Trim Hydraulic Brake Removal" (AMM 27-41-05/401).

 S 492-007

 (6)
Install the air motor tool, the dust cover and the adapter.

 S 862-008
 WARNING: MAKE SURE THAT PERSONS AND EQUIPMENT ARE CLEAR OF THE
_______ HORIZONTAL STABILIZER CONTROL SURFACES BEFORE YOU MOVE THE STABILIZER. A MOVEMENT OF THE STABILIZER CAN CAUSE INJURY TO PERSONS OR DAMAGE TO EQUIPMENT.
 CAUTION: USE THE AIR MOTOR TOOL WITH THE FREE SPEED LESS THAN 1200 RPM.
_______ IF THE SPEED IS TOO HIGH, THE AIR MOTOR TOOL CAN CAUSE DAMAGE TO THE AIRPLANE COMPONENTS.
 (7)  
Use the power wrench of the air motor tool to move the stabilizer jackscrew through the adapter.

 S 862-009

 (8)  
Move the stabilizer to the necessary position.

 S 092-010

 (9)
Remove the air motor tool, the dust cover and the adapter.

 S 422-011

 (10)
 Do this task:  "Stabilizer Trim Hydraulic Motor Installation" (AMM 27-41-10/401).

 S 422-012

 (11)
 Do this task:  "Stabilizer Trim Hydraulic Brake Installation" (AMM 27-41-05/401).

 TASK 27-41-00-822-026
 3. Horizontal Stabilizer Neutral Rig Position (Fig. 202)
__________________________________________
 A. General
 (1)  This task is used to set the horizontal stabilizer to the neutral rig position. It can also be used to set the stabilizer to other positions.
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747-400
MAINTENANCE MANUAL

STABILIZER 
SEE  A  TRIM LIMIT SWITCHES 
STABILIZER 
JACKSCREW 
STABILIZER TRIM 
CONTROL MODULE 
BALLSCREW 
STOP 
MANUAL ELECTRICAL 
STABILIZER TRIM 
SWITCHES 
B" 
BALLNUT 
STOP 
UPPER GIMBAL 

A
Horizontal Stabilizer Neutral Setting Figure 202
STABILIZER TRIM POSITION INDICATORS
ALTERNATE ELECTRICSTABILIZER TRIM SWITCHES
STABILIZER TRIM CUTOUT SWITCHES
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MAINTENANCE MANUAL

 (2)  
The horizontal stabilizer is at the neutral rig position when the "B" dimension is at 7.42 |0.05 inches (188.5 |1.3 millimeters) and the stabilizer position indicator is at 3 units of trim (Fig. 202).

 (3)  
The "B" dimension is the distance along the ballscrew between the surfaces of the ballnut stop and the ballscrew stop.