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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
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757 MAINTENANCE MANUAL
 CARGO LOADER SYSTEM - DESCRIPTION & OPERATION
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 1.  General (Fig. 1)_______
 A.  A telescoping cargo loading system is installed in the forward and aft cargo compartments. The telescoping module extend and retract to load and unload baggage. An electric drive system moves the modules. The modules have rollers which roll in the tracks on the compartment sidewalls and floor.
 B.  In the forward compartment, the cargo loader has three telescoping modules aft of the forward (No. 1) cargo door.
 C.  In the aft compartment, the cargo loader has two telescoping modules forward of the aft (No. 2) cargo door.
 2.  Telescoping Modules (Fig. 1)___________________
 A.  The telescoping modules are assigned numbers (Fig. 1). These numbers make it easy for you to refer to a module.
UPPER GUIDE ROLLERS (EXAMPLE)

Cargo Loader
Figure 1

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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
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757
MAINTENANCE MANUAL

 B.  The telescoping modules are made from aluminum honeycomb sandwich panels. The panels are made with the contour of the cargo compartments.
 C.  There are hook plates attached to each end of each module. The hook plates lock the modules together when the modules move (loading). The hook plates also hold the modules in the fully extended (fully loaded) position.
 D.  The modules have spring-loaded plungers on the top and bottom surfaces. Some plungers are spring-loaded downward and hold the modules together while the modules retract (unloading). Other plungers are spring-loaded upward and hold the modules together while the modules extend (loading).
 3.  Rollers (Fig. 1)
_______
 A.  There are rollers on the side and bottom of each telescoping module that move in the sidewall and floor tracks. On module 2 and module 3 in the forward compartment, the rear rollers on the module move in the floor tracks. The front and center rollers move in the upper surface of the next module forward.
 4.  Tracks (Fig. 1)
______
 A.  There are tracks in the cargo compartments. Rollers move in the tracks to hold the modules and to keep the movement straight. There are four tracks on the floor of each compartment. There are two tracks on the left sidewall, and two tracks on the right sidewall of each compartment.
 5.  Drive Motor (Rotary Actuator) (Fig. 2)
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 A.  The drive motor for the cargo loader is aft of module 3 in forward compartment, and forward of module 2 in aft compartment. Access to the motor is through a door on the module bulkhead.
 B.  The drive motor operates on a 3-phase, 400-Hz, 115V ac power. The motor is reversible. It is connected directly to the jackscrew. The motor has an overheat switch to prevent damage to the motor.
 6.  Jackscrew (Fig. 2)
_________
 A.  The jackscrew is connected directly to the drive motor. The ball nut connects the jackscrew to telescoping module. There are beariang blocks at each end of the jackscrew. The jackscrew is below the floor, between the two middle floor tracks.
 7.  Cargo Loader Control Switch (Fig. 2)
___________________________
 A.  The CARGO LOADER CONTROL SWITCH is in the ceiling of the compartment, on the left side of the airplane, in the doorway area.
 (1)  
The switch has three positions: LOAD, OFF, and UNLOAD.

 (2)  
The switch is spring-loaded to the OFF (center) position.

 8.  Operation (Fig. 2 and 3)
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 A.  Functional Description (Fig. 3)
 (1)  When you load baggage on the modules, operate (extend) the modules as follows:
 NOTE: When you start, the modules are in position 1.
　
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