FUEL QUANTITY
INDICATING SYSTEM
GENERAL
The aircraft is equipped with a fuel quantity
signal conditioner (FQSC) located in the tail-
cone equipment bay. This unit is a two chan-
nel fuel quantity computer microprocessor
based component responsible for interfacing
with fuel quantity probes, fuel density com-
pensator probes and the single-point refuel
control panel. The left channel provides
TOTAL and LEFT WING fuel quantity to the
EICAS and the right channel provides FUSE-
LAGE and RIGHT WING quantity to the
EICAS. If either channel fails, the corre-
sponding wing quantity indication and total
fuel quantity indication will show invalid
(amber dashes).
One channel of the fuel quantity computer is
provided with DC electrical power through
the L QTY circuit breaker in the left FUEL
group of circuit breakers and the other chan-
nel through the R QTY circuit breaker in the
right FUEL group of circuit breakers.
L E A R J E T 4 5
P I L O T T R A I N I N G M A N U A L
FlightSafety
international
5-5
FOR TRAINING PURPOSES ONLY
LEFT
CHANNEL
RIGHT
CHANNEL
28 VDC
L ESS BUS
28 VDC
R ESS BUS
SPPR CONTROL PANEL
FMS
FMS
L R FUEL QTY LOW
EICAS/MFD (LEFT WING/TOTAL)
EICAS/MFD (FUSE TANK/RIGHT WING)
LEFT WING
TANK
RIGHT WING
TANK
FUSELAGE
TANK
PROBE OUTPUTS
PROBE OUTPUTS
POWER
INPUTS
POWER
INPUTS
FUEL DENSITY
COMPENSATOR
PROBES
L QTY
R QTY
AHRS #1
AHRS #1
FUEL QUANITY
COMPUTER
FLAP POSITION
FLAP POSITION
RMU
RMU
FUEL IMBALANCE
L R FUEL QTY FAULT
Figure 5-3. Fuel Quantity Indicating System