systems: fuel

Question 1

fuel tanks & capacity

Answer 1

main fuel in each wing: 26 gal total, 1 gal unusable
auxiliary tank in each engine nacelle: 13.7 gal total, 0.5 unusable
total capacity: 79.4 gal, 76.4 usable
max imbalance between main tanks: 5 gal

Question 2

fuel system flow

Answer 2

high pressure fuel injected directly into the cylinders
common rail supplies nozzles with fuel
pressure inside the rail is generated by a high pressure pump
low pressure pump send fuel to high pressure pump
both pumps are engine-driven
ECU controls rail pressure via electric valve
rail pressure depends on power setting
fuel that is not injected is fed back into the appropriate wing tank
unusual fuel passes through fuel cooler, which pressurizes and cools fuel

Question 3

fuel selectots

Answer 3

options: ON, OFF, CROSSFEED
crossfeed RIGHT engine will take fuel from LEFT wing tank, unused fuel rerouted via RIGHT fuel cooler

Question 4

main fuel tanks

Answer 4

three aluminum chambers: inboard, middle, outboard
tank in filled and filtered in outboard chamber
fuel tank vents and pressure relief valves
drain sump + gascolator

Question 5

auxiliary fuel tanks

Answer 5

electrical transfer pump moves fuel from auxiliary tank to main tank (one for each tank)
activated via a toggle switch
deactivates automatically if aux is empty or main is full
cannot know fuel level of aux tank
recommended to use simultaneously

Question 6

in the event of a transfer pump failure…

Answer 6

use other aux tank & its transfer pump, plus crossfeed to maintain wing balance
always keep a mental note of aux tank level