Fuel Flashcards
What is the AFM limitation for the fuel XFEED SOV?
Must be closed for takeoff and landing
When does fuel transfer from the center tank to the wing tanks?
Wing tank quantity below 93% and continues until wing reaches full (3% of volume maintained for fuel expansion)
Under which condition is a lateral fuel imbalance automatically corrected?
A wing imbalance of 400 lb (181 kg) and DC AUX pumps are not already running
Which fuel tanks cannot be gravity refueled?
Forward or aft auxiliary tanks (XRS / 6000)
Where is the fuel SOV located and how is the valve closed?
Located behind the aft pressure bulkhead. It is closed via the associated fire discharge handle.
What is the fuel quantity at which fuel transfers automatically from the AFT auxiliary tank to the wing tanks?
When either of the wing tank quantities reduces to 5500 lb
What does the COMPARE FUEL QUANTITY
indication in the FMS mean?
FMQGC and FMS fuel quantity differ by more than 2% BOW
After an engine failure, why is the XFEED SOV opened?
To ensure balanced fuel use from both tanks avoiding any significant lateral fuel imbalance
Is it permissible to takeoff and land with the XFEED SOV switch/light indicating OPEN?
No
Which fuel pumps have no pilot control?
Center tank transfer pumps
Why must manual operation of the wing transfer system be monitored?
Because no automatic shutdown or overfill protection is provided
What is the purpose of the XFEED SOV?
Single engine feed from both wing tanks or both engines to be fed from a single tank
What are two limitations associated with the fuel recirculation system?
Fuel recirculation is prohibited when using wide cut fuels, asymmetric operation is prohibited
If use of the center / aft tank is planned, what is the minimum required tank load?
500 lb (230 kg) to ensure transfer pump reprime
How is fuel automatically transferred to the center tank from the forward auxiliary tank? (XRS/6000)
Transfer ejector or gravity flow
What is the power source for the refuel/defuel panel?
APU battery direct bus (to prevent APU battery drain, ensure the panel is selected OFF after use)
What will happen if one or both AC boost pumps fail?
Onside DC AUX pump automatically operates, providing engine fuel feed pressure
How is positive fuel tank pressure maintained during flight?
NACA scoops provide ram air
Below which fuel temperature is takeoff prohibited?
Below +5°C is prohibited
What is the maximum useable fuel load for the aft fuel tank on the XRS and 6000?
2300 lb (1025 kg)
Under which combination of conditions does the fuel recirculation system automatically activate?
Above 34,000 ft and a single fuel temperature sensor below -20°C, or above 34,000 ft and an average of
all temperature sensors below -9°C
What is minimum go-around fuel?
600 lb (266 kg) per wing with wings level and maximum climb attitude of 10° nose up
Which wing tank normally provides fuel for the APU?
Right wing tank
What is the maximum permissible fuel imbalance during flight?
1100 lb (488 kg)
During the refuel SOV test, what does the SOV FAIL message indicate?
Fuel flow will not stop when the tank is full
When should the operation of the pressure relief valves not be tested?
When associated wing tank is above 11,800 lb and center tank above 8,000 lb
When do the two AC boost pumps in each wing tank operate?
Onside ENG RUN switch ON
What is the maximum useable fuel load for the wing tanks when pressure refueling?
15,050 lb (6825 kg) per wing tank
What is the maximum permissible fuel imbalance on ground and during takeoff and landing if the aircraft fuel
weighs less than 19,450 lb (8823 kg)?
1100 lb (488 kg)
What is the maximum permissible fuel imbalance on ground and during takeoff and landing if the aircraft fuel weighs >20,250 lb (9186 kg)?
600 lb (266 kg)
According to the AFM, which combination of two conditions
makes the aft tank fuel unusable?
Each wing does NOT contain at least 5500 lb (2495 kg) fuel at departure and planned cruise altitude is less than 30,000ft
According to the AFM, which combination of two conditions
makes the center tank fuel unusable?
Each wing is NOT full at departure and planned cruise altitude is less than 30,000ft
Under which three conditions would both DC AUX pumps
automatically operate?
Flap position greater than 0, in flight with landing gear down and locked, less than 600b in either wing
Which four conditions inhibit an automatic wing fuel transfer?
Flap position greater than 0, in flight with landing gear
down and locked, low fuel condition less than 600lb wing, DC aux pump supplying fuel feed to eng(AC pump fail)
