Fuel Flashcards
what order does the fuel feed
1) center tank
2) respective main tanks
to what fuel tank does the NGS supply nitrogen
center tank
when does the NGS operate
from takeoff until a short period after landing (during taxi in)
when will the NGS auto shutdown
- A/C on the ground and not in test mode
- either engine is not running in-flight
- fire/smoke detection in cargo or main deck areas
- left pack overheat
- CTR TK refuel valve OPEN
what is the only indication of for the NGS and where is it located
operability indicator located on the main wheel well
how many fuel pumps are there
6:
- 2 center tank pumps
- 2 main tank pumps no.1 (FWD & AFT)
- 2 main tank pumps no.2 (FWD & AFT)
which pumps have a higher output pressure
center tank pumps
when will the center tank pumps automatically shutoff
a short delay after “low pressure” lights illuminate
how long can the center tank “low pressure” lights flicker for before the alert is triggered
up to 5 minutes
what other methods are there for drawing fuel from the main tanks apart from the main tank pumps (e.g. low output pressure)
each engine can draw fuel from its corresponding main tank through a suction feed line that bypasses the tank pumps
what is a limitation with regards to the suction fuel feed line
during climb, dissolved air in the fuel may be sucked into the suction feed line which may restrict fuel flow (eventually depletes in the cruise)
what causes the spar fuel shutoff and engine fuel shutoff valves to close
- engine fire switch - pulled; or
- engine start lever - cutoff
what switch controls the center tank fuel scavenge jet pump
main tank fuel pump no.1 forward switch
how does the center tank fuel scavenge jet pump operate
- transfers the remaining ‘center tank’ fuel to main tank no.1
- transfer begins when main tank no.1 qty = half
- operates for the remainder of the flight
what tank is the fuel temperature indicator’s sensor in
main tank no.1