section 7- fuel system Flashcards
what does the fuel system consist of?
2 independent systems which can be connected by crossfeed
what does each independent fuel system feed during normal operation?
the corresponding engine
what 4 components make up each fuel tank system?
- fuel tanks
- fuel booster pumps
- jet pumps
- fire cock
how many fuel tanks in each fuel tank system?
3 (outboard, inboard and feeder)
what is the total usable fuel?
2386 litres
what 5 components do the outboard and inboard tanks contain?
- jet pumps
- fuel quantity trnsmitters
- drain valves
- vent lines
- magna-stick level indicator
what 5 components do the feeder tanks contain?
- booster pumps
- fuel quantity transmitter
- drain valves
- fuel low level transmitter
- crossfeed shutoff valve (LH system only)
where is the defueling quick disconnect?
in the engine nacelles
what do the flapper valves allow?
fuel gravity flow int the feeder tank in case of boost pump failure or during refueling
what happens to accumulated air in the fuel tanks?
it is collected in the vent tank and vented overboard
where are the fuel drain valves located?
on the lower side of each wing
what is provided in the feeder tank for engine fuel supply and jet pump operation?
2 electrically driven boost pumps
how is fuel transferred into the feeder tank from the inboard and outboard tank?
2 boost pump operated jet pumps located in each tank
if the boost pumps become inoperative during flight, will all the fuel be able to be transferred into the feeder tank by gravity?
no
what energises the fuel boost pumps?
2 pump switches per engine on the LH overhead switch panel
what powers the fuel boost pumps?
28v DC
what protects the fuel pumps?
- LP PUMP LH1/BUS 1 (overhead breaker panel
- LP PUMP LH2/BUS 2 on ACDC breaker panel
- LP PUMP RH1/BUS 2 on ACDC breaker panel
- LP PUMP RH2/BUS 1 on the overhead breaker panel
what does the FIRECOCK switch on the LH overhead panel provide for?
firewall fuel shutoff in the low pressure fuel system
what is the FIRE COCK switch directly connected to?
the battery
what powers the firecosk switch?
28V DC
what protects the FIRE COCK switch?
- FIRE COCK LH OPEN/ BUS 1 on the overhead breaker panel
- FIRE COCK RH OPEN/BUS 2 on the AC/DC breaker panel
- COCK LH/HOT BUS 1 in the battery compartment
- COCK RH/HOT BUS 1 in the battery compartment
what does the fuel flow indicator show?
displays fuel flow to the engines in lb/hr
how is fuel flow meaured?
mechanically by a turbine and electrically transmitted to the instrument
what is the scale on the fuel flow indicator?
0-500lb per hour
what powers the fuel flow indicator?
28v DC
what protects the fuel flow indicators?
- FF LH/BUS 1 on the overhead breaker panel
- FF RH/BUS 2 on the AC/DC circuit breaker panel
what does the 4 digit FUEL COUNTER do?
informs of total fuel used
what does it mean for the FUEL COUNTER if the fuel flow indicator is inoperative?
it becomes unreliable
how does the fuel quantity indicator compensate for fuel density?
it is an automatic function of the electronic quantity indicating system
what scale does the fuel quantity indicator show?
0-24
what powers the fuel quantity indicators?
28v DC
what protects the fuel quantity indicators?
F-QTY LH/BUS 1 on the overhead breaker panel
F-QTY RH/BUS 2 on the AC/DC breaker panel
what are the 3 positions on the fuel tank quantity selector switch?
- TOTAL (X 100)
- OUTER (X100)
- FEEDER (X10)
HOW DO WE TAKE A READING USING THE MAGNA-stick fuel level indicator?
push up the slotted latch, rotate 90 degrees and allow the calibrated stick to extend until the magnet locks on
what is the magna-stick calibrated for?
Jet-A1 at 15 degrees
what must we do to the boost pumps in the low fuel level system before operating crossed feed?
switch them off
when must the cross feed section be switched off?
for takeoff and landing during normal operation
how do we refilll the feeder tank with a low fuel indication during cross feeding?
switch on the respective boost pump
what powers the crossfeed system?
28V DC
what controls the cross feed valve?
CROSSFEED SWTICH LOCATED ON THE LH overhead switch panel
