King Air C90GTi, Pilot Training Manual

Page: 121 / 557

BOOST PUMPS
Each system has a submerged boost pump in
the nacelle tank. This pump supplies a pres-
sure of about 30 psi to the engine-driven fuel
pump. The boost pumps are submerged, ro-
tary, vane-type impeller pumps, and are elec-
trically-driven. A 10-amp circuit breaker for
each boost pump is located on the fuel panel.
Two red FUEL PRESS annunciators are as-
sociated with the boost pumps. When illu-
minated, there is low fuel pressure on the
side indicated. Check the boost pumps prior
to flight.
With crossfeed in AUTO, a boost pump fail-
ure will be denoted by the momentary illu-
mination of the FUEL PRESS annunciator
and fault war ning flasher, then the illumi-
nation of the FUEL CROSSFEED annuncia-
tor. To identify the failed boost pump, mo-
mentarily place the crossfeed in the CLOSED
position. The FUEL PRESS annunciator on
the side of the failed boost pump will illu-
minate. Place the crossfeed switch in the
OPEN position. The FUEL PRESS annunci-
ator will then extinguish.
In the event of a boost pump failure during
any phase of flight, the system will begin to
crossfeed automatically. If the boost pump
fails , the cross-feed switch may be closed
and the flight continued, relying on the en-
gine-driven high pressure pump. In some in-
stances the pilot may elect to continue the
f l i g h t w i t h t h e r e m a i n i n g p u m p a n d t h e
crossfeed system in operation.
KING AIR C90GTi/C90GTx PILOT TRAINING MANUAL
5-4
FOR TRAINING PURPOSES ONLY
5
FUEL
SY
STEM
L
QUANTITY
LBS. 100
0
2
4
6
8
10
12
14
TO ENGINE FUEL
OUTLET NOZZLES
QUANTITY
INDICATOR
NOTE:
TOTAL USABLE FUEL—384 U.S. GALLONS.
Figure 5-2. Fuel Tank System