Fuel System Flashcards
How many fuel tanks?
2 (1 each wing)
What is the purpose of the collector tank?
Keeps fuel pumps submerged to ensure constant fuel flow to respective engine
Max fuel quantity?
20,935 lbs.
Fuel low level warning?
660 lbs. in each tank
Fuel temperature taken from which tank?
Left wing tank
Minimum fuel temp?
-40 C
How many fuel pumps?
13 total
- 2 engine driven
- 2 ejector
- 6 scavenge
- 2 AC electric
- 1 DC electric
Engine driven pump
Primary fuel source to engine
- Provides motive flow to primary ejector pump
- Provides the pressure for motive flow to scavenge pumps
Where are the ejector pumps located?
Collector tanks
Purpose of scavenge pumps?
Maintain adequate fuel level in collector tank
Purpose of AC fuel pumps?
Backup for ejector pumps
Used during cross feed operations
AC pump 2 provides fuel to APU when engine driven pump (EDP 2) is not running
What provides fuel to APU when EDP 2 is not running?
AC Pump 2
Where is the DC fuel pump installed?
The right wing
What is the purpose of the DC fuel pump?
Provides pressurized fuel for normal APU start when AC power or the AC fuel pump 2 is not available
Fuel cross feed
Allows fuel to both engines from one tank & used to correct fuel imbalance
Max fuel imbalance?
794 lbs
EICAS message appears at 800 lbs.
When does the EICAS fuel imbalance message disappear?
Fuel is within 100 lbs balanced
XFEED Knob
-LOW 1
Right wing tank electric pump turns ON and X-FEED valve opens
XFEED Knob
-LOW 2
Left wing tank electric pump turns ON and X-FEED valve opens
What closes the engine fuel shutoff valves?
Fire handles
Refueling
Pressure refueling or over wing gravity refueling
Powered by BATT 2 or DC BUSSES
Where is the fuel temperature taken?
Left tank
Fuel pumps in each wing?
- Primary ejector pump
- ACMP
- DCMP (right tank)
- 3 scavenge ejector pumps
Pupose of ACMP?
- Back-up in case of primary ejector pump failure
- Engine start
- Cross Feed operations
Purpose of DCMP?
Used for APU or engine start if AC power or the ACMP not available
Purpose of scavenge pumps?
Maintains fuel level in collector box
What pumps are used once the engine is started?
Associated primary ejector pump
Purpose of the collector box?
Keeps the fuel pumps submerged and ensures constant fuel flow to respective engine
What is the surge/vent tank?
Collects fuel during wing down maneuvers and returns it to the main tank. Also equalizes tank pressure with atmosphere in flight and during refueling
Can fuel be transferred from tank to tank or dumped overboard?
No
What happens when the cross feed switch is selected to LOW 1?
Cross feed valve is opened, commands the ACMP 2 pump ON to provide fuel from right tank to both engines
When will the FUEL 1(2) LO LEVEL EICAS be presented?
660 lbs of fuel remaining in the associated tank
