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A
747-400
MAINTENANCE MANUAL

 S 203-071
 (2)  Open the doors on the main deck to let the air flow freely.
 S 203-072
 (3)  Remove all the main deck seats and floor panels to get access to the
 ice.
 S 203-073
 (4)  Remove the insulation blankets from the sidewall and below the floor
 in the forward and aft lower lobe cargo compartments where it is
 possible.
 NOTE:____ This will let the water flow freely to the structural drains
 and will make sure the blankets do not get wet.

 S 203-074
 (5)  Remove the insulation blankets in the nose wheel well area (forward of the EE bay).
 S 203-075
 WARNING:_______DO NOT PUT HOT AIR DIRECTLY ON HALON OR OXYGEN BOTTLES. IF YOU PUT HOT AIR ON THE HALON OR OXYGEN BOTTLES, THE BOTTLES CAN EXPLODE.
 CAUTION: THE TEMPERATURE OF THE HOT AIR MUST NOT BE ABOVE 150°F (70°C).
_______ HOT AIR CAN CAUSE DAMAGE TO AIRPLANE SYSTEMS.
 (6)  
Use a conditioned ground cart to blow hot air on the open airplane structure in the lower lobes and main deck (if it is applicable) to melt the ice that has collected.

 S 203-076

 (7)  
Make sure the airplane's structural drains in the bilge are open to let the water drain.

 S 203-077

 (8)  
Use (Fig. 301) to find the time needed to melt the ice.

 NOTE: You can use a conditioned ground cart to heat the inside of
____ the airplane. This will shorten the time needed to melt the ice.
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747-400 MAINTENANCE MANUAL
 S 203-078
 (9)  
After the water drains, put the airplane back to its usual condition.

 S 203-079

 (10)
 You must remove or dry all wet insulation blankets before you install them again.

 S 203-080

 (11)
 After the water drains, put the airplane back to its usual condition.

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747-400 MAINTENANCE MANUAL
200

DURATION OF TIME (HOURS)

180
160
140
120
100
80
60
40
20
0

5 10 15 20 25 30 35 40`C
AIR TEMPERATURE OUTSIDE AIRPLANE
Time Required to Melt Interior Ice Figure 301
L07975
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