Fuel Flashcards
How much can fuel expand by in any tank without spilling?
2% (20ºc rise in temp)
What are the individual and total tank capacities in kg?
A321 Inner tank?
What is total capacity in litres?
Outer: 680 kg
Inner: 5567 kg (A321 5 396 kg)
Centre: 6474 kg
Total 18 968 kg (A321 18 623 kg)
Total 24 166 litre
What are the two functions of the Crossfeed valve? How many motors?
Double motor
Allows both engines to be fed by one tank
OR
One engine to be fed by both tanks
Which two buttons close the LP valve?
Engine Master
ENG FIRE pb
What is a suction valve and how is it closed?
Do the centre tanks have them?
Allows gravity feed if the inner pumps fail
Closed by pump pressure in normal operations
No suction valves on centre pumps, fuel unusable.
??jet pumps
What does the FLSCU control?
What should we be careful to do if MODE SEL is in MAN?
- Controls the centre tank transfer valves
- Shuts them when inner tanks full
- Reopens them when underfull sensors reached (i.e. 500kg burnt)
Turn CTR TK XFR off until 500kg burnt to avoid outer tank overflow. Turn off also when empty
How many transfer valves are there in the outer tank?
When do they open?
When are they latched til?
Two each
Open when Inner tank LO LVL
750kg, based on level flight, no acceleration.
Unlatch at refuel.
What is the APU pump for?
Which AC busses is it on?
Feeding APU if low fuel pressure, i.e. the tank pumps or AC supply are off
AC ESS SHED, if shed can also be powered by AC STAT INV BUS
Which line feeds the IDG cooler? Where does it go afterwards?
What controls circulation?
When is IDG fuel cooling most needed?
HP line, goes back to the outer tank, can spill into the inner.
Fed back to outer via Fuel Return Valve, controlled by FADEC
Most needed at low engine power or high oil temperature
not inhibited on ground, may overflow into spill tanks
What order do the fuel tanks refuel?
Which order should we manually refuel?
Centre and outer (ACT if fitted) fill simultaneously.
Outer spills into the inner.
Valves close when tanks reach full or the desired quantity
Battery power must be avail for refueling.
Manual refuel
Fill wings, then centre (then ACT)
Why might auto refuelling be interrupted? How to resume?
How long does refuelling take?
Wing tanks only, 12 T?
All tanks, 18.9 T?
Electrical transients, e.g APU start
Re-enter the figure on the fuel panel
Wing tanks 17 min
All tanks 20 min
What is the fuel transfer valve for (centre of gallery).
Allows defueling or inter-tank transfer
What two things does FQI do, and how many channels does it have?
What three sensors does it have?
Does it run the refuel panel?
Where does FQI get attitude information?
- Controls auto refuelling
- Transmits fuel mass/quantity/temp to ECAM
- Capacitance probes in each tank
- 1 densitometer / cadensicon per inner tank
- 1 capacitance index compensator as backup per inner tank
Yes
Attitude from ADIRS
FLSCU gets level and temperature information for what three purposes?
What sensors does it have?
- Refuel / defuel
- IDG recirculation
- Centre to inner transfer
- High/low/overflow sensor
- Temperature sensor
- controls IDG recirc*
Where does the FUEL: LO LVL warning come from?
FLSCU low level sensor (≈750 kg)
Independent of numerical FQI calculation
Which tanks have fuel inerting and why?
What two systems is the fuel inerting process made of?
When is it active?
Centre tanks only, these have more high flammability exposure.
Conditioned Service Air System CSAS
conditions air to right temp / press
Inert Gas Generation System IGGS
taps nitrogen molecules in air
produces air with less than 12% oxygen
Active whenever engines running
Overhead fuel panel
Why would the L(R) PUMP pb have an amber FAULT light?
Low pressure
Overhead fuel panel
Centre tank MODE SEL pb: what happens when in AUTO for centre pumps and jet pumps?
What does a FAULT lt mean?
Centre Pumps
* Open when inner tank not full
* Close 5 minutes after LO LVL
Jet Pumps
* Runs for 2 mins at engine start
* Run when slats retracted
* Stops 5 mins after LO LVL
FAULT:
* Centre over 250kg
* Inner under 5 T
Fuel Panel
What does the END light mean when solid or flashing green?
BAT PWR sw: when ON
What supplies FQI?
How long test cycle?
When does it switch off?
Steady: auto refuel complete
Flashing: aborted
- HOT BUS 1 supplies FQI
- 40 sec test cycle before avail
- 10 mins of inactivity or Refuel complete
ECAM
LP Valve indication is amber crosslined when closed, why would it be amber but inline?
Why would the crossfeed line be amber?
LP open but MASTER OFF
Crossfeed: Opposite position to switch
ECAM
Outer transfer valve symbols- what do the following mean?
- Hollow green
- Hollow amber
- Solid amber
- XX
- Disappeared
- Hollow green - transferring
- Hollow amber - in transit
- Solid amber - open but should be closed
- XX - position unknown
- Disappeared - closed
ECAM
APU valve symbols: what do the following mean?
- White APU / Green triangle
- White APU / White triangle
- Amber APU / Amber triangle
- Amber APU
- White APU / Green triangle
APU valve OPEN - White APU / White triangle
APU valve CLOSED - Amber APU / Amber triangle
APU valve OPEN but FIRE OUT or Master OFF - Amber APU
APU valve CLOSED, FIRE OUT or Master OFF
ECAM
Fuel temperature is shown when the sensor is wet, why would it appear amber?
When above 45ºC (inner) or 55ºC (outer)
When below -40ºC
ECAM
Why would fuel quantity indications be between lines?
Why would fuel quantity indications be in amber boxes?
Why would the FOB be in a half amber box?
What happens to the inner tank number in an overflow?
When does the Fuel Used reset?
Why would it be amber?
Between lines: FQI inaccurate
(±110/130kg inner/centre)
Amber boxes:
Outer: transfer valves fail to open
Centre: both pumps failed or OFF
FOB half amber box:
Centre tanks failed or OFF
No outer transfer when inner LO
Inner tank quantity amber in overflow
Resets on engine start, amber when less than idle.
Limitations
Minimum fuel temp for JET A1 / JET A?
Maximum fuel temp?
Can fuels be mixed?
-43ºC (JET A1)
-36ºC (JET A)
54ºC
(55ºC neo)
Yes, in all proportions, but temperature guides no longer apply
Limitations
Max inner tank imbalance (TO)?
Max inner tank imbalance (FLT/LDG)?
Max outer tank imbalance (TO, FLT/LDG)?
Heavier tank / max imbalance
Full / 500kg
3T / 1050kg
1450kg / 1450kg
Full / 1500kg
4.3T / 1600kg
2250kg / 2250 kg
linear variation
Outer tank
370kg (TO) 690kg (FLT/LDG)
690 allowed if wings are balanced overall, or for the full outer tank, its inner must be lighter than the opposite inner)
In exceptional conditions, you can ignore all of this and the plane will still be fine
Limitations
Minimum fuel for TO?
1.5T
No ECAM FUEL alerts allowed before takeoff
