曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
is available for EICAS.
Fuel Temperature
Fuel temperature is measured in main tank 1 and displays on primary EICAS. The
temperature normally displays in white. It displays in amber when the fuel
temperature is -37°C or below. During jettison, the TO REMAIN quantity replaces
the EICAS display fuel temperature indication.
Fuel Pumps
Each main tank contains two AC–powered fuel pumps. A single pump supplies
sufficient fuel to operate one engine at takeoff thrust conditions or two engines at
cruise thrust. Main tank 2 and main tank 3 also contain two AC-powered
override/jettison pumps which can operate to a standpipe level of approximately
3,200 kilograms remaining in the tank. Each override/jettison pump supplies
sufficient fuel to operate two engines during takeoff and cruise conditions.
The two center wing tank (CWT) fuel pumps are override/jettison pumps. These
pumps have a higher output pressure than the left and right main tank fuel pumps.
The CWT pumps override the main tank pumps so CWT fuel is used before wing
tank fuel. One CWT pump does not override 2 and 3 override/jettison pumps or
the outboard main pumps.
CWT fuel is scavenged by an electric pump activated by system logic when one
CWT override/jettison pump has low output pressure. The scavenged fuel is
pumped into main tank 2.
December 01, 1999
747 Operations Manual
Copyright © The Boeing Company. See title page for details.
12.20.2 D6-30151-425
Fuel -
System Description
The horizontal stabilizer tank contains two AC-powered transfer/jettison pumps.
Each pump can transfer all fuel in the horizontal stabilizer tank to the CWT.
Fuel Crossfeed
A common fuel manifold connects all main tanks and the CWT. There are four
crossfeed valves in the fuel manifold. In flight, the combination of active pumps
and automatically or manually controlled crossfeed valves direct the flow of fuel
from tanks to engines.
Fuel Imbalance
Excessive fuel imbalance adversely affects CG, aerodynamic drag, and fuel
economy.
Fuel balancing is accomplished by opening or closing crossfeed valves and
turning off and on fuel pump switches.
Fuel Tank Capacities
Tank Liters Kilograms *
1 and 4 Main 33,100 26,576
2 and 3 Main 94,984 76,263
Center 64,973 52,167
Reserves 10,009 8,036
Stabilizer 12,492 10,030
Total 215,558 173,072
* Usable fuel at level attitude, fuel density = 0.8029 kilograms per liter.
October 1, 2000
747 Operations Manual
Fuel -
System Description
Copyright © The Boeing Company. See title page for details.
D6-30151-425 12.20.3
Fuel Quantity Indication
173.0
13.3 13.3
CENTER
WING
TANK
STAB
TANK
CTR
MAIN 3
MAIN 1 MAIN 4
MAIN 2
RES 2
STAB
TOTAL FUEL
1
2 3
4
FMC
FUEL QUANTITY
PROCESSOR
RES 3
INIT
PREV
PAGE
DEP
RTE ARR
PROG
1
PAGE
NEXT
LEGS
EXEC
OFST
BRT
Z
MSG
FAIL
DSP
U V W
P Q R S
X
T
Y
F G
L
H
M
I
N
J
O
A B C D E
DEL / CLR
2 3
4 5 6
7 8 9
. 0 +/-
V NAV
FIX HOLD
MENU
NAV
RAD
L
K
REF
TOTAL
FUEL
52.2
38.1
4.0
10.0
4.0
38.1
ATC
COMM
FMC
December 01, 1999
747 Operations Manual
Copyright © The Boeing Company. See title page for details.
12.20.4 D6-30151-425
Fuel -
System Description
Fuel System Schematics
Main Tank Main Pump Schematic
JETTISON
W
F
D
F
A
T
VALVE
VALVES
CROSSFEED
TO APU
OVERRIDE/
JETTISON PUMP
P
P
P
P
P
P
MAIN 1 OVRD 2 MAIN
X FEED
FUEL
PRESS PRESS PRESS
PRESS PRESS PRESS
VALVE
ON
ON
ON
ON
ON
ON
1 2
VALVE
FUEL PANEL
MAIN PUMP
L_E_G_E_N_D_
December 01, 1999
747 Operations Manual
Fuel -
System Description
Copyright © The Boeing Company. See title page for details.
D6-30151-425 12.20.5
Main Tank Override/Jettison Pump and Fuel Crossfeed
Schematic
FUEL
MANAGEMENT
L_E_G_E_N_D_
MAIN PUMP
VALVE
1 2
ON
ON
VALVE
PRESS
PRESS
FUEL
X FEED
OVRD 2
FUEL PANEL
CROSSFEED
VALVE
OVERRIDE
PUMPS
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波音747-441操作手册2(113)
