
FUEL DISTRIBUTION
GRAVITY FLOW
Fuel flows by gravity within the main tanks
through lightening holes in the ribs. One inner
rib in each main tank is equipped with flap-
per valves to prevent outward flow of fuel
(Figure 5-2 or 5-3).
Fuel flows from the inboard sections of the
main tanks to the collector tanks (Figure 5-2
or 5-3). Flapper valves at the collector tank
inlets prevent reverse flow of fuel into the
main tanks.
SCAVENGE EJECTORS
Gravity flow to the collector tanks is sup-
plemented by scavenge ejectors located at
the rear of the inboard section of each main
tank. The scavenge ejectors ensure that the
collector tanks are supplied with fuel re-
gardless of airplane attitude. Failure of a
scavenge ejector will cause illumination of
an amber caution light in the cockpit.
Motive flow for operation of a scavenge ejec-
tor comes from the high-pressure side of the
two-stage engine-driven fuel pump (Figure
5-2 or 5-3).
Ejectors have no moving parts. Each operates
on the venturi principle to convert small-
volume, high-pressure motive flow at the
throat of the ejector into large-volume, low-
pressure output at the ejector nozzle.
MAIN EJECTORS
Fuel is supplied from the collector tanks to the
low-pressure side of each engine-driven pump
by a main ejector located within the tank.
Motive flow for operation of the main ejectors
is supplied by the high-pressure side of each
engine-driven fuel pump.
Each main ejector provides continuous fuel
flow to its own engine through firewall shutoff
valves. Flow to the opposite engine is not pos-
sible because of one-way check valves in the
feed lines. Failure of a main ejector will cause
illumination of an amber caution light in the
cockpit, and will activate both standby elec-
tric pumps. (Figure 5-4 or 5-5).
TRANSFER EJECTORS
When main tank fuel quantity drops below
the 93% full level, float valves open, allow-
ing the transfer ejectors to draw fuel from the
auxiliary tank to the inboard sections of the
main tanks. Motive flow for the transfer ejec-
tors is provided by the output of the associated
main ejector. No cockpit indication of fuel
transfer or transfer ejector failure is provided.
A one-way check valve in each transfer ejec-
tor prevents fuel migration from the main
tanks to the auxiliary tank.
STANDBY ELECTRIC PUMPS
Electric standby pumps are provided for en-
gine starting and as a backup in the event that
a main ejector becomes inoperative (Figure
5-4 or 5-5). The two DC-powered pumps will
then operate simultaneously to draw fuel
from their respective collector tanks and feed
a common line capable of providing fuel to
either engine.
Once armed by cockpit switches, the standby
pumps operate automatically when the output
pressure of either main ejector falls below 10
psi. During the engine start sequence, both
pumps operate until the engine-driven pumps
generate enough motive flow to operate the
main ejectors.
The left electric pump is powered by the bat-
tery bus, while the right pump receives power
from DC bus No. 2.
FlightSafety Canada
L t é e
L t d .
CL-600-2B16 PILOT TRAINING MANUAL
CL 601-3A
5-3
FOR TRAINING PURPOSES ONLY