King Air C90GTi, Pilot Training Manual

Page: 123 / 557

The fuel transfer system may be monitored
by periodically checking the nacelle tank
quantity against the total tank quantity.
If the NO FUEL XFR does not illuminate
a n d t h e t r a n s f e r t e s t i n d i c a t e s a wo r k i n g
pump, the flow switches may be suspect.
Using the transfer test will begin the f ill-
up cycle, however, fuel quantity in the na-
c e l l e w i l l d r o p b e l o w t h e l o w e r l e v e l
w i t h o u t a c t i v a t i n g t h e t r a n s f e r p u m p .
Proceed by moving the transfer pump switch
( Fi g u r e 5 - 3 ) t o t h e OV E R R I D E p o s i t i o n .
I n t h i s m o d e , t h e t r a n s f e r p u m p w i l l r u n
continuously until the transfer pump switch
is retur ned to the OFF position. When the
nacelle tank becomes full, excess fuel will
be retur ned to the center section wing tank
through the vent line.
Illumination of the NO FUEL XFR annun-
ciator may indicate a nor mal or abnor mal
situation. During nor mal operation, when
the fuel in the wing tanks is exhausted, the
NO FUEL XFR annunciator indicates that
the wing tanks are empty.
If the transfer pump fails to operate during
flight, g ravity feed will perfor m the trans-
fer. When the nacelle tank level drops to ap-
proximately 150 pounds, or approximately
22 gallons, the g ravity por t in the nacelle
tank opens and g ravity flow from the wing
tank star ts. All wing fuel, except 28 gallons
from the center section tank, will transfer
during g ravity feed.
FUEL CAPACITY
The fuel quantity system is a capacitance
gaging system with one quantity indicator
per wing (Figure 5-4). A toggle switch se-
lector allows the pilot to check total system
or just the nacelle tank quantity. The system
has a total capacity of 387 gallons, and a max-
imum usable fuel quantity of 384 gallons.
The fuel quantity gages and the engine fuel
flow indicators read in pounds times 100. At
6.7 pounds per gallon, 2572.8 pounds of us-
able fuel are available in the system, 1286.4
pounds per side.
On the C90GTi, there is no str uctural limi-
t a t i o n f o r w h i c h a M a x i m u m Z e r o F u e l
KING AIR C90GTi/C90GTx PILOT TRAINING MANUAL
5-6
FOR TRAINING PURPOSES ONLY
5
FUEL
SY
STEM
Figure 5-3. Fuel Transfer Pump Switch
Figure 5-4. Fuel Control Panel