Systems Guide
A318/A319/A320/A321
Professional
SYSTEMS
Systems guide
Vol
4
04-03-48
11 July 2018
WEIGHT
2 X 6048 KG
2 X 13,140 LB
6437 KG
14,190 LB
18605 KG
41,010 LB
ENGINE FEED
The main fuel pumps feed fuel from the wing tanks to the engines using two fuel pumps in each wing
tank.
MAIN COMPONENTS
• Tank pumps, two in each wing tank, normally both activated.
• Cross feed valve, allows the left and right systems to be connected and to feed both engines
from one wing tank, normally closed.
• Engine low pressure valves, when closed (by using the engine master switch or the ENG FIRE
PUSH button) they cut the fuel flow to the engine, normally open.
• Suction valves, when open they allow the engines to be gravity-fed from the wing tanks.
Normally the fuel pump action will close these valves.
FUEL FEED SEQUENCE
• During engine start (and for 2 minutes after engine start) engines are fueled from the wing tanks.
• When slats are extended engines are fueled from the wing tanks.
• When wing tanks are full engines are fueled from the wing tanks (to allow fuel expansion) until
an ‘under level’ sensor is triggered. While engines are fueled from the wing tanks, fuel is
transferred from the center tank to the wing tanks. When the inner wing tank reaches 750 kg of
fuel, the outer wing tank fuel content will be transferred to the inner tanks.
CENTRE FUEL TANK TRANSFER
The Fuel Level Sensing Control Unit (FLSCU) controls the transfer of fuel from the center tank to the wing
tanks. When 500 KG of fuel has been used (from a wing tank) the FLSCU will start the transfer of fuel from
the center tank to the wing tank. When the FLSCU senses the wing tank is full the transfer is stopped. This
system ensures that the wing tanks are always as full as possible and that the wing tanks fuel levels are
always as equal as possible.
NOTE: to avoid an incorrect fuel load, always fill the wing tanks complete before
adding fuel to the center tank. If you see the MODE SEL button light up with an
amber FAULT, the most obvious cause is that the center contains too much fuel and
the wing tanks too little.