Fuel Flashcards
Briefly explain the centre tank logic?
The usual order of fuel feeding is from the centre tank first, however If the inner and outer tanks are completely full, then 500kg will be burned from the inners first in order to accomodate the IDG return. Slat logic ensures the centre tank pumps are stopped until slat retraction.
How is the IDG cooled and where does the return fuel get fed to?
Fuel is tapped off to cool the IDG through heat exchange. The warm fuel is then returned to the outer and inner tanks. Hence why you see a slightly higher fuel temperature.
On a CEO/NEO when do the transfer valves open?
Once the fuel quantity in each inner tank <750kg
When would you see the low level fuel ECAM?
When the tank sensors become dry
What is a jet pump and why might they have an advantage over the conventional centre tank pump configuration?
Jet pumps use the centrifugal pressure generated by the inner pumps to suck fuel out of the centre tank and feed to the inners.
It’s a more simple system and more cost effective, ie replaces the need for more expensive and weighty fuel pumps.
What indications in the flight deck might help you identify a fuel leak from an engine or pylon?
Excessive fuel flow, low N1
When operating in colder climates, what might you consider to help increase the temperature of the fuel back into normal range?
Descend to a lower FL below the tropopause as temperature constant above it. Increase speed/mach no.
In which order is the fuel burned from each tank, why?
Centre, inners, then when fuel <750kg in each inner tank the outer TXFR valves will latch open (reset at next refuelling) and fuel continues to be burned from the inners. For wing loading purposes.