FUEL

Question 1

Recall fuel tank layout and general tank capacities:

Answer 1

Fuel is stored in three integral wing tanks; a left main, center, and right
main.
 The left and right tanks each have a capacity of 9,266 lbs.The center tank
has a capacity of 6,077 lbs.
 Total fuel capacity is 24,609 lbs. and is displayed along with individual tank
quantities on the FUEL synoptic page. It is also displayed on the top left of
Secondary ENGINE page.
 FUEL LEVEL LO- Amber Alert indicates center tank is below 1000 lbs and
either the left or right main tank fuel quantity is below 2000 for 2 minutes.
 LAT FUEL UNBAL - Amber Alert appears when fuel quantities in the left
and right main tanks differ by more than 1400 pounds.

Question 2

Recall the function of the DC START PUMP:

Answer 2

A DC Start Pump, operated by the START PUMP switch on the overhead
panel, is installed in the right main tank and is used for APU or engine
starting when AC power is not available.

Question 3

Recall the Fuel Return to Tank (RTT) process

Answer 3

 Excess warmed fuel cycling through the engine fuel system is returned to
the main tank. This warms the fuel in the tank, which retards wing ice
formation due to cool soaked fuel.
 Fuel return to tank flow is inhibited by the EEC for many reasons, including
takeoff, landing, main tank fuel low or high fuel temperature.

Question 4

Recall the function of the FUEL switches on the pedestal:

Answer 4

ON - Commands EEC to energize ignition and open FMU high-pressure
shutoff valve when start requirements are satisfied.
 OFF - Shuts off fuel to respective engine, and then turns off ignition

Question 5

Explain how fuel is supplied to the engines with all pumps operating:

Answer 5

Each main tank has two AC boost pumps. The main tank boost pumps are
arranged in parallel. Normally, fuel from the left main tank feeds the left
engine and fuel from the right main tank feeds the right engine.
 The center tank pumps are located in the right main fuel tank and arranged
in series. If the center tank contains fuel, its higher-pressure output allows
the center to feed both engines before the main tanks feed the engines.
 Normally the Right main pumps supplies fuel to the APU

Question 6

Describe the use of the FUEL X-FEED lever:

Answer 6

OFF - Closes fuel crossfeed valve. Left main tank feeds left engine and
right main tank feeds right engine.
 ON - Opens fuel crossfeed valve. Either or both main tanks can feed both
engines and APU.

Question 7

Explain the function of the FUEL SYS TEST button:

Answer 7

Push - When pushed and held for 2 seconds, starts a fuel system test
display on the SD fuel page. System will remain in test for 45 seconds.
 FUEL SYS TEST on the fuel synoptic indicates that a fuel system test is in
progress.

Question 8

Recall the function of the FUEL QTY A/B button

Answer 8

Push - Selects the alternate channel of the Fuel Quantity Gauging System
 The currently active fuel quantity channel is displayed on the fuel SD

Question 9

Recall the meaning of fuel EAD Alerts including:

Answer 9

 FUEL OFF SCHEDULE–Either the left or the right main tanks have low fuel
while the center tank has usable fuel.
 SEL CTR PUMPS OFF - Center tank has low fuel and either center pump
has low pressure or, center tank quantity is slightly greater than the ballast
quantity with either pump on.

Question 10

Recall the 717 Fuel Venting system:

Answer 10

• Right and Left main tanks are vented to the center tank
.
• Center tank fuel is vented to the wingtip vent boxes.
• System permits overflow from main tanks to drain into the center tank during fuel return to tank operations with the main tanks full.
Recall the fuel usage for ground APU operations
Normal fuel usage during ground APU operations is 350 lbs/hr