Fuel Flashcards by ashlan richardson

How many fuel tanks do we have and what are their approximate capacities?

7 fuel tanks (+ horizontal stab for pax airplanes)
1 and 4 mains = 13.2 kgs each
2 and 3 mains = 38.1 kgs each
center tank = 52.1 kgs.
2 and 3Reserves = 4.0.kgs. each
total capacity = 163, 042

Note:FCOM, VOL 2; 12.20.4

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What commands fuel valves to open or close and fuel pumps to turn on and off according to fuel management logic?

• Fuel system management cards (FSMCs)

Note:FCOM, VOL 2; 12.20.11

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Which crossfeed valves are affected by flap extension on the ground?

• 2 and 3. They are closed by the FSMCs when flaps extend to takeoff position on the ground.

Note:FCOM, VOL 2; 12.20.12

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Which fuel pumps are system logic pumps, in other words, commanded to turn on and off by system logic during normal operations?

• Override/jettison pumps 2 and 3. They are inhibited from operating when pressure is detected from both CWT override/jettison pumps.

Note:FCOM, VOL 2; 12.20.12

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Trace the flow of fuel to the engines when there are 7700 kgs or MORE fuel in the Center Wing Tank., from blockout.

Both CWT pump switches should be ON.
X-feed valves 2 and 3 close when flaps extended for takeoff
CWT pumps feed engines 1 and 4.
Main pumps 2 and 3 feed their related engine.

After Takeoff with Flaps not in 10 or 20
All x-feed valves are open
CWT pumps feed all engines

Note:FCOM, VOL 2; 12.20.12

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Trace the flow of fuel to the engines when there is LESS than 7700 kgs of fuel in the center wing tank, from blockout.

Both CWT tank pumps should be off.
X-feed valves 2 and 3 close when flaps extended for takeoff.
Override/jettison pumps 2 feed engine 1
Override/jettison pumps 3 feed engine 4.
Main pumps 2 and 3 feed their related engine.

After Takeoff with Flaps not in 10 or 20
All x-feed valves are open
• Override/jettison pumps 2 feed engine 1 and 2
• Override/jettison pumps 3 feed engine 3 and 4

Note:FCOM, VOL 2; 12.20.12

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When do the FSMCs open the reserve transfer valves?

When main tank 2 or 3 fuel quantity decreases to approximately 18,200 kgs.
Fuel transfers from reserve tanks 2 and 3 to the related main tank.

Note:FCOM, VOL 2; 12.20.11

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Under what conditions would fuel automatically transfer from main tanks 1 and 4 to their adjacent tanks 2 and 3?

• During fuel jettison, when either main tank 2 or 3 fuel quantity decreases to 9,072 kgs.

Note:FCOM, VOL 2; 12.20.11

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Can fuel be manually transferred from any tank to another tank?

Yes, there is a Main Tank 1 and 4 Transfer Switch on the overhead panel.
Fuel can transfer from the outboard to the inboard main tanks, to approximately 3,200 kgs remaining in each outboard main tank.

Note:FCOM, VOL 2; 12.20.11

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State what occurs when you select the Fuel Jettison Switch to A or B.

Arms the jettison system
Displays preselected fuel to remain on EICAS

Note:FCOM, VOL 2; 10.4

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Describe how the fuel quantity indication changes upon termination of fuel Jettison

The fuel to remain quantity indication changes from magenta to white.
The fuel to remain quantity flashes for 5 seconds.

Note:FCOM, VOL 2; 12.20.15

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What occurs when you push either fuel jettison nozzle valve to ON during the QRH fuel jettison procedure?

It activates all override/jettison pumps in the tanks containing fuel (pump switches must be on).
The required jettison nozzle valve also opens.

Note:FCOM, VOL 2; 12.20.14

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What is the source of fuel for the APU?

• Normally supplied from main tank 2.
• When ac power is available, fuel is supplied by main pump 2 aft.
• If AC power is not available, a dedicated DC pump in main tank 2
supplies fuel to the APU.
• Main pump 3 aft operates to prevent tank to tank transfer and provides
fuel if main pump 2 aft fails (with aircraft exceptions)

Note:FCOM, VOL 2; 12.20.11

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In general, how would you handle a fuel imbalance situation?

• By opening or closing crossfeed valves and turning off and on fuel pump switches (refer to QRH and Supplementary Procedures)

Note:FCOM, VOL 2; 12.20.3

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What is the impact on the aircraft of excessive fuel imbalance?

Adversely affects CG
Aerodynamic drag
Fuel economy

Note:FCOM, VOL 2; 12.20.3

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When is an engine on suction feed, and how would you correct a suction feed situation?

An engine is on suction feed when main tank fuel pressure is low.
Open the appropriate fuel crossfeed valve from a main tank with operating pumps.

Note:FCOM, VOL 2; 12.20.3

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Does the suction feed line go through the main tank fuel pumps?

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• No, the suction feed line bypasses the pumps

Note:FCOM, VOL 2; 12.20.3

A single main tank fuel pump can provide sufficient fuel to how many engines?

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One engine at takeoff thrust
Two engines at cruise thrust.

Note:FCOM, VOL 2; 12.20.2

A single main tank 2 or 3 override/jettison pump can provide sufficient fuel to how many engines?

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• Two engines at takeoff and cruise conditions

Note:FCOM, VOL 2; 12.20.2

Can the main tank 2 or 3 override/jettison pumps operate when the related Main tank is below 3,200 kgs (standpipe level)

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• No

Note:FCOM, VOL 2; 12.20.2

Fuel tank temperature is measured in which tank?

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• Main tank 1

Note:FCOM, VOL 2; 12.20.1

When does the fuel temperature display on primary EICAS display in amber?

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• - 37 C or below

Note:FCOM, VOL 2; 12.20.1

Which aircraft are the only ones with horizontal stabilizer tanks?

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• Passenger aircraft

Note:FCOM, VOL 2; 12.20.1

How is Center Wing Tank Fuel scavenged?

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CWT fuel is scavenged by 4 jet pumps, two pumping into each main tank 2 and 3.
Scavenge begins when main tank 2 or 3 fuel quantity decreases to approximately 27,200 kgs.

Note:FCOM, VOL 2; 12.20.2

What are the fuel imbalance differences that would generate an EICAS Advisory message?

* 1360 between tanks 1 and 4 * 2720 between tanks 2 and 3 * 2720 after reaching fuel tank/eng condition there is a longitudinal fuel Imbalance between inboard main tanks and outboard main tanks plus reserve. Note:FCOM, VOL 2; 12.30.1

When correcting a fuel imbalance condition, when would you expect the associated EICAS Advisory IMBAL message to no longer display?

• When the difference is less than 450 kgs Note:FCOM, VOL 2; 12.30.1

What does a Crossfeed Valve ON, with the bar visible, indication mean for Crossfeed Valve Switches 2 and 3?

• Crossfeed valve open when commanded by system logic Note:FCOM, VOL 2; 12.10.1

What does a Crossfeed Valve ON, with the bar visible, indication mean for Crossfeed Valve Switches 1 and 4?

• The crossfeed valve is open Note:FCOM, VOL 2; 12.10.1

What does it mean when the main tank 2 and 3 Override (OVRD) Fuel Pump Switches are ON? How about OFF, ON not visible?

* ON – fuel pump operates when commanded by system logic. * OFF (ON not visible) – fuel pump selected OFF. Note:FCOM, VOL 2; 12.10.2

How many FSMCs do we have?

Two (A&B)

How is the fuel system affected when the flaps are set to takeoff on the ground. .

Crossfeed valves 2 and 3 close when the flaps extend to takeoff position

With a full load in all tanks, what tanks feed the engines during takeoff?

Tanks 2&3 feed engines 2&3 respectively. The CWT feeds engines 1 & 4

What situation would cause a “shared flow” between the center wing tank and the outboard main?

A shared flow situation would develop at lower CWT fuel levels (approx.. 2,300 Kgs.) and high total fuel consumption rates (6,800Kgs per hour). Approximately 900Kgs of fuel are consumed from each outboard main tank prior to display of the EICAS message FUEL LOW CTR.

How is center tank fuel scavenged?

By 4 jet pumps, two pumping into each main tank 2 and 3

What is the source of fuel for the APU?

AC power available Main pumps 2 and 3 aft. DC only, a dedicated DC pump in main tank2 supplies fuel to APU

In-flight fuel tank temperature must be maintained at least ____ degrees above the fuel freeze point of the fuel being used.

3 degrees

Why should we wait until we get a fuel imbalance message before balancing fuel?

Because the first step in a fuel imbalance checklist is to determine if a fuel leak exists.

When would we ever select the FUEL TRANSFER 1 AND 4 SWITCH?

By checklist…example if during fuel jettison fuel transfer valves 1 & 4 fail to open, you can manually select for the valves to open, or if both main pumps in 1 or 4 are inop

Do not extend or retract flaps between positions ___ and ___ during fuel jettison

Flaps 1 and 5.

When will the Fuel Low CTR L, R EICAS illuminate

center wing tank quantity less than 7,700kg before start with pump switches on center wing tank quantity approximately 3,200kg in climb with pump switches on center wing tank quantity approximately 1,300kg in crusie with pump switches on

EICAS >Fuel Tank/Eng

Manually turn #2 and #3 OVRD pumps off Manually close crossfeeds #1 and #4 one of these occurs with crossfeed valve 1 or 4 open: Main tank 2 quantity is equal to or less than main tank 1 quantity OR Main tank 3 quantity is equal to or less than main tank 4 quantity On the ground after refueling, after initial electrical power established or after CMC ground test; Main tank 2 quantity less than or equal to main tank 1 plus 500kgs AND Main tank 3 quantity less than or equal to main tank 4 plus 500kgs

Fuel Flashcards

(41 cards)