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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.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
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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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