FUEL Flashcards
How many fuel takes does the aircraft have and what are their approximate capacities?
Seven tanks.
4.0 / 13.3 / 38.1 / 52.2
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 (FSMC’s)
Which crossfeed valves are affected by flap extension on the ground?
2 and 3
Which fuel pumps are system logic pumps? In other words, which fuel pumps are commanded to turn on and off by system logic during normal operations?
Override/jettison pumps 2 &3
Trace the flow of fuel to the engines when there are 7700 kgs or more fuel in the Center Wing Tank from blockout.
Flaps t/o range; crossfeed valves 2&3 close. CWT override/jettison pumps prove fuel to Engines 1 and 4. Main pumps 2 and 3 supply their related engines.
Trace the flow of fuel to the engines when there is less than 7700 kgs of fuel in the Center Wing Tank from blockout
Flaps in t/o position crossfeed valves 2&3 close. Override/jettison pump 2 supplies engine 1, override/jettison pump 3 supplies engine 4. Main pumps 2 &3 supply their respective engines.
When do the FSMCs open the reserve transfer valves?
When main tank 2 or 3 fuel quantity decreases to 18,200kg.
Under what conditions would fuel automatically transfer from Main Tanks 1 and 4 to their adjacent Tanks 2 and 3?
Fuel jettison when main tanks 2 or 3 reach 9,072kg remaining.
Can fuel be manually transferred from any tank to another tank?
What occurs when Fuel Jettison Switch is selected to either A or B?
Fuel temp on EICAS replaced with fuel to remaining quantity indication. The jettison manifold and jettison time display on the fuel synoptic.
Describe how the fuel quantity indication changes upon termination of fuel jettison.
Fuel to remain quantity indicator changes from magenta to white and flashes for five seconds.
What occurs when you push either fuel jettison nozzle valve to ON during the QRH fuel jettison procedure?
Activates all override/jettison pumps in the tanks containing fuel (pump switches must be on) and opens the required jettison valves. The related jettison nozzle valve also opens.The jettison time is displayed- programmed rates initially then updated by actual rate of change.
What is the source of fuel for the APU?
Main tank 2.
In general, how are fuel imbalance situations handled?
Opening or closing crossfeed valves and turning on or off fuel pimp switches.
What is the impact on the aircraft of excessive fuel imbalance?
Affects C of G
Aerodynamic drag
Fuel economy.
When is an engine on suction feed, and how are suction feed situations corrected?
Fuel pressure can be provided from a main tank with operating pumps to another engine by opening the appropriate fuel crossfeed valves.
Does the suction feed line go through the main tank fuel pumps?
No the suction feed line bypasses the pumps.
A single Main Tank Fuel Pump can provide sufficient fuel to how many engines?
One at takeoff thrust, two at cruise thrust.
A single Main Tank 2 or 3 Override/Jettison Pump can provide sufficient fuel to how many engines?
Sufficient fuel to operate two engines at take off and cruise condititons.
Can the Main Tank 2 or 3 Override/Jettison Pump operate when the related Main Tank is below 3200 kgs (standpipe level)?
No.
Fuel tank temperature is measured in which tank?
One
When does the fuel temperature display on Primary EICAS in amber?
At or below -37
How is the Center Wing Tank fuel scavenged?
CWT fuel is scavenged by four jet pumps, two pumping into each main tank 2 and 3. Scavenging begins when main tank 2 or 3 fuel quantity decreases to approx 27,200kg.
What three different conditions will generate a fuel imbalance message on the EICAS?
FUEL IMBAL 1-4 1360 KG
FUEL IMBAL 2-3 2720KG,
FUEL IMBALANCE 2720KG longitudinally. (after FUEL TANK/ENG displayed)
When does the fuel imbalance message no longer display on the EICAS?
When difference is less than 450KG.
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
What does a Crossfeed Valve On with the bar visible indication mean for Crossfeed Valve Switches 1 and 4?
Crossfeed valves open.
When are Override/Jettison Pumps 2 and 3 displayed in Cyan on the Fuel System Synoptic?
Armed for system Logic operation.
