*
Catch release

*
Handle

*
Spring (internal)

*
Connection to the lock mechanism.

The handle is spring loaded to the open position. The catch holds it closed.
Functional Description
A pull outboard on the catch or a pull inboard on the internal catch release, releases the lock handle. The spring moves the handle. The connections to the lock mechanism transmits the movement to the lock pawls.
EFFECTIVITY BEJ ALL  52-34-00 
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D633W101-BEJ  Sep 05/2002 

FORWARD LARGE CARGO DOOR SYSTEM -LOCK HANDLE MECHANISM

EFFECTIVITY BEJ ALL  52-34-00 
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D633W101-BEJ  Jan 05/2002 

FORWARD LARGE CARGO DOOR SYSTEM -LOCK MECHANISM

Purpose
The lock mechanism holds the large cargo door main latch cams in the latched position and the vent door closed.
Physical Description
The lock mechanism has these components:
*
Bellcranks

*
Torque tubes

*
Push rods

*
Vent door interlock

*
Torque tubes

*
Lock pawls.

Functional Description
The lock mechanism does two things when you move the lock handle to the lock position.
The mechanism transmits the movement of the lock handle to the lock pawls. The lock pawls move to a position that will not let the main latch cams turn.
The mechanism also transmits the movement of the lock handle to the vent door interlock. The vent door interlock keeps the vent door closed if the airplane is ditched in water.
EFFECTIVITY BEJ ALL  52-34-00 
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D633W101-BEJ  Sep 05/2002 

FORWARD LARGE CARGO DOOR SYSTEM -LOCK MECHANISM

EFFECTIVITY BEJ ALL  52-34-00 
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D633W101-BEJ  Jan 05/2002 

FORWARD LARGE CARGO DOOR SYSTEM -VENT DOOR AND VENT DOOR MECHANISM

Purpose
The vent door and vent door mechanism prevent damage from pressurization when you open the cargo door.
Physical Description
The door has stops and connections to the torque shaft. The mechanism has these components:
*
A spring that pulls the vent door open

*
A torque shaft

*
Linkage that connects the vent door to the lock mechanism.

Functional Description
The door and vent door mechanism have two functions.
One function is to release air pressure from inside the airplane before you open the cargo door. When the lock mechanism moves to the unlock position, it causes the vent door mechanism to pull the vent door open. This releases any air pressure that remains.
The second function is to keep the cargo door locked if there is too much pressure to let you open the cargo door safely. Pressure on the vent door prevents movement of the vent door mechanism. This stops movement of the lock mechanism. You cannot unlock and open the cargo door.
EFFECTIVITY BEJ ALL  52-34-00 
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D633W101-BEJ  Sep 05/2002 

FORWARD LARGE CARGO DOOR SYSTEM -VENT DOOR AND VENT DOOR MECHANISM

EFFECTIVITY BEJ ALL  52-34-00 
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D633W101-BEJ  Jan 05/2002 

FORWARD LARGE CARGO DOOR SYSTEM -CONTROL SWITCHES

Purpose
Control switches let you operate the door electrically.
Physical Description
The internal and external toggle type door control switches are spring-loaded.
Functional Description
The switches let you operate the door electrically, after the door is unlocked. You can use either switch. The internal switch has priority over the external switch.
EFFECTIVITY BEJ ALL  52-34-00 
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