King Air C90GTi, Pilot Training Manual

Page: 131 / 557

FUEL DRAINS
During each preflight, the fuel sumps on
t h e t a n k s , p u m p s a n d f i l t e r s o r s t r a i n e r s
s h o u l d b e d r a i n e d t o c h e c k f o r f u e l c o n -
tamination. There are four sump drains and
o n e f i l t e r d r a i n o r s t r a i n e r d r a i n i n e a c h
wing (Figures 5-13 and 5-14).
The leading edge tank sump has a drain on
the underside of the outboard wing just for-
ward of the main spar. The flush drain valve
for the f irewall fuel strainer drain is acces-
sible on the underside of the engine cowl-
ing. The boost pump sump drain is at the
bottom center of the nacelle, just forward
of the wheel well. The wheel well sump drain
is inside the wheel well on the g ravity feed
line. The drain for the transfer pump sump
is just outboard of the wing root, forward of
the flap.
When draining the flush-mounted drains,
d o n o t t u r n t h e d r a i n i n g t o o l . Tu r n i n g o r
twisting of the draining tool will unseat the
O-ring seal and cause a leak.
The flush valve attached to the base of the
fuel strainer can be opened or closed with a
coin, a screw driver, or a fuel drain tool mak-
ing it possible to drain fuel from the fuel
strainer for preflight check.
S i n c e j e t f u e l a n d w a t e r a r e o f s i m i l a r
densities, water does not settle out of jet
fuel as easily as from aviation gasoline. For
this reason, the air plane must sit perfectly
still, with no fuel being added, for approx-
i m a t e ly t h r e e h o u r s p r i o r t o d r a i n i n g t h e
sumps if water is to be removed. Although
turbine engines are not so critical as recip-
rocating engines regarding water ingestion,
water should still be removed periodically
to prevent for mations of fungus and con-
tamination induced inaccuracies in the fuel
gaging system.
KING AIR C90GTi/C90GTx PILOT TRAINING MANUAL
5-14
FOR TRAINING PURPOSES ONLY
5
FUEL
SY
STEM
FUEL DRAINS
Figure 5-13. Fuel Drains