B.
Control

 (1)  
Open the hatch from inside the airplane as follows:

 (a)  
Remove the acoustic pad that is attached to the hatch interior panel.

 NOTE: The acoustic pad is attached to the interior panel with
____
 velcro tape.

 (b)  
Turn the interior handle counterclockwise 180 degrees.

 (c)  
Move the hatch down and outboard.

 (2)  
Open the hatch from outside the airplane as follows:

 (a)  
Push the release trigger.

 (b)  
Turn the exterior handle clockwise 180 degrees.

 (c)  
Move the hatch down and outboard.

 (3)  
Close the hatch from inside the airplane as follows:

 (a)  
Remove the acoustic pad (if installed).

 (b)  
Move the hatch upward and inboard until the door keeper fittings touch the door jamb fittings.

 (c)  
Rotate the interior handle clockwise 180 degrees.

 (d)  
Align the velcro tape on the acoustic pad with the velcro tape on the hatch interior panel.

 (e)  
Attach the acoustic pad to the hatch interior panel.

 (f)  
Push edges of the acoustic pad into the opening in the ceiling panel.

 (4)  
Close the hatch from outside the airplane as follows:

 NOTE: You must install the acoustic pad from inside the airplane.
____
 (a)  
Move the hatch upward and inboard until the door keeper fittings touch the door jamb fittings.

 (b)  
Turn the exterior handle counterclockwise 180 degrees.

 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 52-21-00
 ALL  ú ú 01 Page 4 ú Jun 10/88
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL

 (c)  
If the acoustic pad was installed when the hatch was closed do these steps: 1) Make sure that the acoustic pad is correctly attached to

 the hatch interior panel. 2) Push the edges of the acoustic pad into the opening in the ceiling panel.

 (d)  
If the acoustic pad was not installed when the hatch was closed do these steps: 1) Align the velcro tape on the acoustic pad with the velcro

 tape on the hatch interior panel. 2) Attach the acoustic pad to the hatch interior panel. 3) Push the edges of the acoustic pad into the opening in the
 ceiling panel.
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

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 ALL  ú ú 01 Page 5 ú Jun 10/88
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
 CREW COMPARTMENT OVERHEAD HATCH - INSPECTION/CHECK
__________________________________________________
 1.  General_______
 A. This procedure contains three tasks:
 (1)  
An inspection of the drain system for the external handle mechanism on the overhead hatch in the crew compartment

 (2)  
An internal inspection of the latch mechanism for the overhead hatch in the crew compartment.

 (3)  
An operational check of the interior handle actuator, latch mechanism, release trigger, and exterior handle mechanism for the overhead hatch in the crew compartment.

 TASK 52-21-00-206-001
 2.  Drain System - Inspection (Fig. 601)_________________________
 A. References
 (1)  
IPC 52-21-01 Fig. 1

 B.
Access

 (1)  
Location Zone
 221 Control Cabin, LH

 (2)  
Access Panel
 839L Hatch - Control Cabin Overhead

 C.
Procedure

 S 016-002
 (1)  
Open the overhead hatch in the crew compartment.

 S 216-003

 (2)  
Examine the drain system.

 (a)  
Make sure that the hole in the external skin of the overhead hatch is clear.

 (b)  
Push the trigger on the external handle to extend the external handle.

 (c)  
　
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