(a)  
The latches are operated by the blade of a standard 10 inch screwdriver inserted into the trigger slot. A force between 10 and 30 pounds applied outboard releases the latch trigger and releases the latch hook from the U-bolt.

 (b)  
With all six latches released and the detent cable at aft end of the right door detached from the stud on fuselage station 2742 bulkhead, the doors are rotated outboard and are propped open by door stay rods at each end of each door. The free end of the stay rods are released from the spring clips (stowed position), pivoted, and attached to the bulkheads.

 (c)  
To close the doors, the right door stay rods are released from the bulkheads and rotated to the stowed position. The detent cable on the aft edge of the door is hooked to the stud on station 2742 bulkhead. The left door stay rods are released and stowed. Then the doors are brought together and forward latch is closed. After checking that the guide pins are still aligned, the remaining latches are closed.

 (2)
Main (Forward) Electronic Bay External Access Door (Fig. 4)

 (a)  
Door opening from outside the airplane is initiated by pushing the trigger in the outer handle. This allows the handle to spring out from its flush position so that it may be easily grasped. Rotating the handle 180 degrees clockwise withdraws all four latch pins, closes the switch to energize the appropriate door warning light in the control cabin, and allows the door to be pushed up and to the right. Before sliding the door to the right, the external handle must be depressed to its retained, flush position. The door is pushed up, and then inboard until in the full open or stowed position, and retained there by stops on the lower track. The door is also opened from inside the airplane using the same procedures except that handle rotation appears counterclockwise.

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747-400
MAINTENANCE MANUAL

 (b)  
To close the door from outside the airplane, the door is drawn to the left on the tracks until the operating handle is within reach. The trigger is depressed to release the handle from its flush position and the operating handle is grasped continuing to draw door to the left. The door then drops into closed position. With door properly seated, a slight downward pull and a final counterclockwise rotation of the handle throws all four latch pins into engagement and opens the door warning switch. The handle is then returned to its recess in the exterior skin, being retained in the flush position by the trigger latch. The door may be closed from inside the airplane using the same procedures except that handle rotation appears clockwise.

 (3)  
Center Electronic Bay External Access Door (Fig. 5)

 (a)  
Door opening from outside the airplane is initated by pushing the trigger in the door handle. This allows the handle to spring out from its flush position so that it may be easily grasped. Rotating the handle clockwise withdraws the pin latch, energizes the door warning light in the control cabin, and allows the door to be hinged upward. As soon as the door is fully open, it may be locked in open position by rotating the handle counterclockwise. The handle may then be pushed back into its recess in the exterior of the door.

 (b)  
When the door is to be closed, the handle must be returned to its open position to release the door from the hold-open fitting. The door is then lowered to the closed position. It is latched by a final counterclockwise rotation of the handle, which positions the pin latch into the latch keeper and opens the door warning circuit. When the door is closed and latched, the handle is pushed back into its recess.

 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
 AIR CONDITIONING ACCESS DOORS - REMOVAL/INSTALLATION
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