Learjet 60 - Aircraft Fuel System; Fuselage Tank; Wing Tanks

Pilot's
Manual

Learjet 60
AIRCRAFT
FUEL SYSTEM
The aircraft
fuel system consists of
two wing tanks, a fuselage fuel
tank, a fuel
supply system, a fuel
quantity indicating system, a fuel
transfer
system and a fuel
vent system . Fuel fillers are located out-
board near each
wing tip . A single-point
pressure refuel (SPPR) sys-
tem is also installed
.
WING TANKS
The wing
is divided by a
center bulkhead into two
separate fuel-tight
compartments
which serve
as fuel tanks . Each tank
extends from the
center
bulkhead outboard to
the wing tip rib, thus
providing a separ-
ate fuel
supply for each
engine . A tank crossflow
valve is installed to
permit
fuel transfer
between wing tanks . Center
bulkhead relief
valves
prevent wing tank
overpressurization
during fuel crossflow
operations
. Flapper-type
check valves,
located in the various
wing
ribs,
allow free fuel flow
inboard but restrict
outboard fuel flow . A
jet
pump and an electric
standby pump
are mounted in each wing tank
near the center
bulkhead to supply
fuel under pressure to the
respec-
tive engine fuel
system . An electric
scavenge pump, located
in the for-
ward
inboard section of each
wing tank, is used to
transfer fuel to the
section
containing the main
fuel pumps and is operated
by the low-
fuel
float switch . Three
jet-type transfer pumps,
located along the aft
portion of each wing
tank, transfer fuel to the section
containing the
main fuel pumps . A filler
cap, located in the
outer section of the wing
tank, is used for fuel
servicing .
FUSELAGE TANK
The fuselage tank,
installed in the aft
fuselage, consists of two inter-
connected bladder-type
cells . The fuselage
tank is provided with two
transfer pumps,
a float switch, a fuel
quantity probe, and single-point
pressure
refuel provisions . The fuselage
tank can be refueled
by
pumping wing fuel
with the wing tank standby
pumps through both
transfer lines or by
using the single-point pressure
refuel system . Fuel
can be transferred to the
wing tanks by normal fuel
transfer, auxiliary
fuel transfer, rapid fuel
transfer or gravity transfer .
During the nor-
mal fuel transfer, the
left fuselage tank transfer
pump will pump fuel
into both wing tanks .
During the auxiliary fuel transfer, the right fuse-
lage
tank transfer pump will pump fuel
into both wing tanks . During
rapid fuel
transfer, both the normal and auxiliary
fuel transfer modes
are energized .
During gravity transfer, fuel will
flow to both wing
tanks
through both transfer lines .
2-26B
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PM-123
Change 3