-
Remove the flight crew oxygen mask/stowage box

 -
Remove power from the valve

 -
Remove the valve.

 C.  The steps that are necessary for installation of a windshield air shutoff valve are as follows:
 -
Install the valve in the duct

 -
Install the oxygen mask/stowage box

 -
Install the captain's and/or the first officer's seat

 -Do a test of the valve.
 TASK 21-22-01-004-001
 2.  Remove the Windshield Air Shutoff Valve (Fig. 401)_______________________________________
 A.  References
 (1)  
35-11-18/401, Mask/Regulator/Stowage Box

 (2)  
25-11-01/401, Pilots'Seats

 (3)  
AIPC 21-22-01 Fig. 1

 B.  Access
 (1)  Location Zone
 221 Control Cabin, LH
 222 Control Cabin, RH

 C.  Prepare For Removal
 S 864-012
 (1)  Open the circuit breaker 180H25 WSHLD AIR on the P180 DC power distribution panel.
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 21-22-01
 ALL  ú ú 01 Page 401 ú Oct 18/00
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A

747-400
MAINTENANCE MANUAL

SEEA
CLAMP
ELECTRICAL CONNECTOR
WINDSHIELD AIR SHUTOFF VALVE
FWD
INBD
WINDSHIELD AIR SHUTOFF VALVE
A

Windshield Air Shutoff Valve Installation Figure 401
H27635
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 21-22-01
 ALL  ú ú 03 Page 402 ú Jun 15/98
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
 S 014-014
 (2)  
Remove the captain's and/or first officer's seat (AMM 25-11-01/401).

 S 014-002

 (3)  
Remove the flight crew oxygen mask/stowage box.

 (a)  
Loosen the four fasteners which hold the stowage box to the structure.

 (b)  
Lift the stowage box out.

 WARNING:_______LOOSEN THE FITTING CONNECTIONS CAREFULLY. THE REMAINING OXYGEN CAN RELEASE WITH A LARGE FORCE. THIS CAN CAUSE INJURY TO PERSONS AND DAMAGE TO THE AIRPLANE AND EQUIPMENT.

 (c)  
Disconnect the electrical connector (captain - DB637, and first officer - DB641) from the stowage box.

 (d)  
Do not disconnect the oxygen line from the stowage box.

 D. Remove the Windshield Air Shutoff Valve
 S 024-003
 (1)  Remove the windshield air shutoff valve.
 (a)  
Remove the electrical connector from the valve (captain - DV464, first officer DV465).

 (b)  
Remove the clamps and ducts from each end of the valve.

 (c)  
Remove the valve.

 TASK 21-22-01-004-004
 3.  Install the Windshield Air Shutoff Valve________________________________________
 A. References
 (1)  
21-00-00/201, Air Conditioning

 (2)  
24-22-00/201, Manual Control

 (3)  
25-11-01/401, Pilots'Seats

 (4)  
35-11-18/401, Mask/Regulator/Stowage Box

 (5)  
AIPC 21-22-01 Fig. 1

 B. Access
 (1)  Location Zone
 221 Control Cabin, LH
 222 Control Cabin, RH

 C. Install the Windshield Air Shutoff Valve
 S 024-005
 (1)  Install the windshield air shutoff valve.
 (a)  
Install the ducts and the clamps on each end of the valve.

 (b)  
Install the electrical connector on the valve (captains - DV464, first officers - DV465).

 (c)  
Install the sidewall lining in the flight deck.

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