Fuel Flashcards
Describe the fuel tank venting system.
There are NACA vents and climb vents. The tanks are positively pressurized.
Describe the fuel quantity guaging system.
A DC type capacitance system indicates usable fuel.
Is the capacitance system calibrated for ground or flight conditions?
Both. In flight the computer compensates for aircraft attitude.
Aside from digital readouts, is there any other way to detirmine fuel quantity?
Yes. There are five Magnetic Level Indicators than can manually be checked on the exterior of the aircraft, two under each wing and one under the fuselage.
Can raw data from the Magnetic Level Indicators be used to detirmine the fuel level?
No. A conversion chart from the AFM must be used.
Is dispatch authorized with the Fuel Quantity Gauging Computer inoperative?
No.
What are the tank capacities with pressure refueling vs gravity?
Pressurized: 7,492 in each wing, and 4,610 int he center totalling 19.594.
Unpressurized: 7,290 in each wing totalling 14,580. The center tank cannot be gravity refueled.
Where is the bulk temperature sensor?
In the right wing tank.
Explain the automatic fuel crossflow system.
The FQGC initiates a crossflow by activating the bi-directional crossflow pump when it detects a fuel imbalance of 200 pounds between the wings. The crossflow will continue to operate until the low wing has 50 pounds more fuel that the wing with the previous higher quanitity.
How is fuel manually transfered?
First, press the MAX XFLOW AUTO OVERRIDE switchlight. Then press the L or R XFLOW switchlight on the low side (remember: “press the light on the light side”) to activate the bi-directional crossflow pump. The GRAVITY XFLOW switchlight could also be pressed allowing fuel to freely move from one tank to another. By banking the aircraft or entering a gentle slip, gravity will move the fuel.
Where does the APU get fuel from?
A dedicated boost pump in the left collector tank.
If the APU boost pump fails will the APU keep running?
Yes, but it will not start unless the pump is operating.
Will the main engines start without their respective boost pumps running?
Yes.
After turning on the boost pumps, what do the switchlights looks like?
The upper section of the switchlights illuminate “on,” because low pressure is detected in the fuel lines and the pumps begin running.
AFter starting both engines, what do the fuel switchlights look like?
The lights extinguish because the pumps enter the standby mode. Motive flow supplies the fuel to the engines.
Will both boost pumps turn on if only one of the boost pump switchlights is pressed?
Yes.
At what fuel quanitity does the digital fuel readout turn amber?
Less than 1,200 lbs total or less than 600 lbs per wing.
What is the maximum fuel imbalance for takeoff and flight?
300 for takeoff, 800 for flight.
What is the minimum fuel for execution of a go-around?
600 lbs per wing assuming a maximum of 10º nose up.
What is the center fuel tank limitation?
Each wing tank must have a minimum of 4,400 lbs to takeoff with more than 500 lbs in the center tank.
What is the bulk fuel freezing temperature for Jet A?
-40º C
What is the minimum bulk fuel temperature of Jet A for takeoff?
-30º C
What fuel temp is required for takeoff at the engine?
5º C
How is the fuel warmed to reach 5º C or greater?
The fuel/oil heat exchanger.
