Fuel System Flashcards
How many wing tanks?
4 wing tanks
Capacity of all 4 wing tanks (non-ER)
180, 664 lbs JP-8
how is fuel transferred within the inboard wing tanks (non-ER)?
automatically transferred from aft compartment to forward feed box by jet pump energized by boost pumps or transfer pump
SCHED light comes on if it occurs as scheduled
how is fuel transferred within the outboard wing tanks (non-ER)?
fuel is transferred internally from inboard to outboard and then to the engine
Capacity of all 4 wing tanks (w/ ER) plus 4 center wing box compartments?
245, 208 lbs JP-8
how is fuel transferred within the ER tanks?
pumped to the inboard wing tanks then to the forward feed boxes until ER tanks are empty
How is fuel transferred within the inboard and out board tanks for a w/ ER aircraft?
same as non-ER aircraft
What does the fuel management system keep the outboard tanks full at?
~38,000 lbs until the inboard tanks reach the same level and then they burn down evenly
fuel management flow of fuel
flows fuel outboard from tank #2 to #1 and tank #3 to #4 to maintain balance
what is fuel scheduling?
the internal process within the tanks to move the fuel outboard (outboard tanks) or forward (inboard tanks) within the respective tanks
What does the SCHD light on the fuel mgt button mean?
automatic management of fuel to maintain the outboard tanks full at 38,000 lbs has failed
or the inboard to outboard transfer fails to stop and outboard tanks quantity exceeds inboard tank quantity
don’t confuse it with an “inboard” tank SCHD light
What does an inboard tank SCHD light mean?
fuel isn’t transferring from the aft inboards for the forward inboards
inboard tank capacities?
~52K (84K with ER) JP-8
outboard tank capacities?
~38K JP-8
total fuel capacity?
~180K/245K with ER
fuel capacity memory aids
T-38 (outboard w/o ER)
B-52 (inboard)
F-84 (total w/o ER)
What happens when fuel drops to 16K lbs?
“LOW” light on Total Fuel Indicator and LOW FUEL appears on the WAP
LOW appears on the Total Fuel panel
What happens if a tank reaches 4K lbs?
Fuel QTY X message appears on the WAP
At what quantity to inboard tank XFER pumps become uncovered at?
28K/12K (inboards/outboards)
At what quantity should fuel dumping automatically stop at?
20,000 lbs
Dumping at altitudes above ___ could cause a flameout
20,000 ft
How does the fuel feed between tanks?
“FAA”
Forward ER to forward inboard
Aft ER to forward inboard
Aft inboard to forward inboard
FUEL QUANTITY X
appears on the WAP when fuel level is below 4000 lbs in the respective tank
LOW fuel light on the Total Fuel Indicator (TFI)
total fuel quantity is less than 16,000 lbs
L/R FUEL HEAVY
fuel difference between wings exceeds 8000 lbs and may require manual fuel transfer to solve the imbalance
SCHD light (respective inboard tank)
fuel in the fwd compartment of inboard tank decreases to 25,000 lbs but there is still 1000 lbs in the aft compartment
Fuel Management SCHD light
outboard tanks is less than 37,700 lbs and the adjacent inboard tank is more than 40,400 lbs
or
outboard tank is full and the adjacent inboard tank is less than 36,900 lbs
