28-11-00
 ALL  ú ú 05 Page 631 ú Feb 18/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A

747-400 MAINTENANCE MANUAL
A
VENT SCOOP PLUG
A
TEST BOLT (4 LOCATIONS)
VENT SCOOP
B

VENT SCOOP
VENT SCOOP PLUG
A-A
Wing Fuel Tanks - Air Pressure Leak Check Figure 609 (Sheet 2)
A77938
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 28-11-00
 ALL  ú ú 04 Page 632 ú Feb 18/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL

PRESSURE TEST DOOR
(VIEW IN THE UP DIRECTION)

NOTE:REMOVE SURGE TANK ACCESS DOOR AND INSTALL PRESSURE TEST DOOR (2 LOCATIONS).
Wing Fuel Tanks - Air Pressure Leak Check
Figure 609 (Sheet 3)

EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 28-11-00
 ALL  ú ú 04 Page 633 ú Feb 18/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
L50888
A
747-400
MAINTENANCE MANUAL

SURGE TANK BLOCKER PLATE
(VIEW IN THE UP DIRECTION)

NOTE:REMOVE SURGE TANK ACCESS DOOR SCREWS (4 LOCATIONS) AND INSTALL BLOCKER PLATE (2 LOCATIONS).
Wing Fuel Tanks - Air Pressure Leak Check
Figure 609 (Sheet 4)

EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 28-11-00
 ALL  ú ú 04 Page 634 ú Feb 18/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
L83865
A
747-400
MAINTENANCE MANUAL

 (5)  
G28019-17, Wing System Test Equipment

 (6)  
Markers - non-lead, Berol filmograph to mark in the tank (or equivalent)

 D.
Consumable Materials

 (1)  
G00034 Cloth, Process Cleaning Absorbent Wiper (cheesecloth, gauze) BMS15-5

 (2)  
G00091 - Compound, Oxygen System Leak Detection - Snoop Leak Detector (MIL-PRF-25567)

 E.
Access

 (1)  
Location Zones
 130 Center Wing Tank
 500 Wing Tanks, Left
 600 Wing Tanks, Right

 (2)  
Access Panels
 555AB Surge Tank Access Door
 555BB Surge Tank Access Door
 655AB Surge Tank Access Door
 655BB Surge Tank Access Door

 F.
Prepare the Airplane for the Pressure Check

 S 656-216
 (1)  Do this task: Fuel Tank Defueling (AMM 28-26-00/201).
 S 656-217
 WARNING: CAREFULLY DO ALL OF THE SAFETY PROCEDURES IN THE PURGING AND
_______ ENTRY PROCEDURE FOR THE FUEL TANK. INJURY TO PERSONS AND DAMAGE TO EQUIPMENT CAN OCCUR.
 (2)
Do this task: Purging and Fuel Tank Entry (AMM 28-11-00/201).

 G.
Install the Pressure Test Equipment

 S 486-190
 (1)  
At the left and right wingtip vent scoop do these steps
 (Fig. 609, View B):

 (a)  
Remove four bolts from the wingtip vent scoop.

 (b)  
Install the vent scoop plug G28011, into the vent scoop.

 (c)  
Fasten the plug assembly with the four supplied bolts.

 (d)  
Turn the plug handles to tighten the plug assembly.

 S 486-220
 (2)  
Do these steps to install the pressure test door B28019-20 (left and right wing) (Fig. 609, View C):

 (a)  
Remove one surge tank access door from the left and the right wing (AMM 28-11-03/401).

 (b)  
Install the pressure test door into the surge tank door opening (two locations).