*
Elevator feel units

*
Elevator feel actuators

*
Column position transducers

*
Column breakout mechanism

*
Backdrive actuators

*
Stick shaker actuators

*
Travel stops.

Control Columns

The two control columns are conventional in design and serve as the interface between the pilots and the flight controls. Forward and aft movement of the control columns command the movement of the elevators through flight control system electronics.
Each control column connects to a torque tube.
Column Torque Tubes

Each column torque tube moves when the control column moves. These are the components on the torque tube:
EFFECTIVITY
BEJ ALL

*
Force transducer

*
Compliance spring

*
Column damper

*
Column balance weight

*
Column stick shaker.

The torque tubes connect to the elevator feel and centering mechanisms with a control rod.
Elevator Feel Units
The two elevator feel units supply feel forces to the pilots and column position data to the ACEs. Each feel unit has a feel and centering mechanism.
The elevator feel actuators on each elevator feel unit change the feel force on the control column.
Each elevator feel unit connects to the column breakout mechanism with a control rod.
Column Position Transducers
Three column position transducers are on each feel unit.
Column Breakout Mechanism
The column breakout mechanism connects the two control column systems together. The mechanism also makes it possible to move one control column should the other jam.
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ELEVATOR CONTROL -FORWARD CONTROLS

Backdrive Actuators

Two backdrive actuators connect to cranks on the left and right sides of the column breakout mechanism. The backdrive actuators are part of the autopilot system.
See the autopilot flight director system section for more information on the backdrive actuators (SECTION 22-11).
Stick Shaker Actuator
One stick shaker actuator is on each column torque tube.

See the warning electronic system section for more information on the stick shaker actuators and stall warning function (SECTION 31-51).
Travel Stops

Travel stops are on the column torque tubes. They limit control column travel to 9.6 degrees forward and 10.5 degrees aft.
EFFECTIVITY BEJ ALL  27-30-00 
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777 AIRCRAFT MAINTENANCE MANUAL

ELEVATOR CONTROL -FORWARD CONTROLS

EFFECTIVITY BEJ ALL  27-30-00 
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D633W101-BEJ  Jan 05/2002 

ELEVATOR CONTROL -CONTROL COLUMNS

Purpose
Each pilot has a control column to command pitch control.
Physical Description

The control column is a one piece aluminum casting. It is approximately 36 inches (.9 m) long.
The control column extends down through the flight deck floor and attaches to the torque tube with four bolts.
Location
The two control columns are on the flight deck.
Functional Description

Fore and aft movement of the control column operates the pitch control mechanisms below the flight deck.
EFFECTIVITY BEJ ALL  27-30-00 
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777 AIRCRAFT MAINTENANCE MANUAL

ELEVATOR CONTROL -CONTROL COLUMNS

EFFECTIVITY BEJ ALL  27-30-00 
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D633W101-BEJ  Jan 05/2002 

ELEVATOR CONTROL -COLUMN TORQUE TUBES

Purpose

Each control column attaches to a column torque tube below the flight deck floor. The torque tube also connects to the elevator feel unit with a control rod.
Each column torque tube has these components:
*
Stick shaker actuator

*
Compliance spring

*
Column force transducer

*
Lost motion device

*
Column balance weight

*
Crank for column damper.

Compliance Spring

The compliance spring connects the column torque tube and the column force transducer. The flexibility of the compliance spring simulates the feel of a mechanical system to the pilots.
Lost Motion Device
The lost motion device permits movement in the force transducers. The elevator feel unit supplies resistance to fore and aft movement of the control column. The lost motion device allows some movement of the force transducers as control column force increases. If the column force transducer fails or disconnects, the lost motion device allows control column force to be transmitted to the elevator feel unit. Additionally, the lost motion device permits the force transducer to compress and expand. Lost motion is approximately two degrees at the control column.
　
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