Fuel Flashcards
The Fuel Low Level Caution turns what color and at what lbs remaining in respective tank?
Gauge indications turn yellow and turns yellow at 1320 lbs remaining
The Fuel Low Level Warning turns what color and at what lbs remaining in respective tank?
Gauge indications turns red and turns red at 660 lbs remaining
Is fuel temp taken from both tanks?
No, only from tank 1. Sensor is near fuel x-feed valve in Main LT LG Bay
What is the primary fuel source to the engine?
EDP provides motive flow to the primary ejector pumps then back to EDP to complete circuit
How do the engine driven pumps help power the fuel system?
provides motive flow to both the 3 scavenge pumps (to keep collector full) and primary ejector pump (constant flow to ENG)
Where are the ejector pumps located and what method is used to move the fuel?
The primary ejector pump is located in the collector box and uses motive flow provided from the EDP
What is the primary job of the scavenge pumps?
Keep the collector box full of fuel to keep the pumps submerged
When is the ACMP on?
- Primary ejector pump fails
- Used for engine start
- X-Feed operations
- AC Pump 2 provides fuel to APU when EDP2 is not running
Where is the DCFMP located and what is its purpose?
Located in the right collector box and is used for APU start when AC power or ACMP2 is not available
What is the fuel imbalance EICAS Indication and when does the message go away?
FUEL IMBAL (yellow) and goes away when fuel quantity is within 100 lbs between both tanks
Max fuel imbalance is what?
794 lbs (EICAS message appears around 800 lbs)
Tank 1 fuel is low, what is the process?
LOW 1 is selected on Fuel Panel, which commands ACMP2 ON and opens X-Feed Valve to provide fuel to both engines
What is the surge/vent tank?
- Collects fuel during wing-down maneuvers and returns it to the main tanks once the wings are level
- Equalizes tank pressure with atmosphere in flight and during refueling
What is the purpose of the collector box?
- Keeps fuel pumps submerged
- Ensures constant fuel flow to the respective engine
Can fuel be transferred from tank-to-tank or be dumped overhead?
Official answer is no, but yes fuel transfer is possible (a mx on ground function only); no fuel scuttling;
What is the only way to close the fuel SOV?
Pull the associated engine fire extinguisher handle
Where is refueling done on the aircraft and what powers it?
- Single point or over wing with refueling panel on right wing
- Powered by Hot Battery Bus 2
Where are the surge tanks located?
Outboard section of the wing tanks
How many water fuel drains?
4 drains and is usually done by MX
How many Magnetic Level Indicators are there?
3 per wing (6 total)
What happens to fuel flow if the scavenge pumps fails?
Fuel will begin equalizing with the integral tank until they are the same level (may get erroneous FUEL LO indications)
Where is the fuel level sensor located?
Middle of both inboard walls of the collector boxes
Where is the x-feed valve located?
Main LT LG Bay, near AFT aileron torque tubes
How many baffle oval check valves are in each wing tank?
4
How many flap valves are in each wing tank?
18
Are the x-feed valves and shutoff valves DC or AC powered?
DC powered
Where is the APU fuel SOV located?
It is located next to fuel X-feed and 2 pressure switches in Main LT LG Bay
What is the job of the FCU or Fuel Conditioning Unit? and where is it located?
It gathers info on fuel temp and fuel level and processes that then sends it to the MAUs to be displayed on MFDs. It is located in the Middle Avionics Bay
