CRJ-200 Fuel System

Question 0

How does fuel flow within the main tanks?

Answer 0

It flows through one way check valves in balance pipes from the wingtips to the wing roots.

Question 1

How many tanks are in the fuel system?

Answer 1

5 - Two main tanks (4,760 lbs each), One center tank (4,998 lbs) for a total of (14,518 lbs) and two collector tanks which are intergral to the center tank.

Question 2

What is the minimum fuel in the main tanks when the center tank has over 500 lbs?

Answer 2

4,400 lbs

Question 3

What is the maximum fuel imbalance?

Answer 3

800 lbs

Question 4

What is the maximum fuel imbalance for takeoff?

Answer 4

800 lbs

Question 5

What is the minimum fuel required for a Go-Around in the main tanks per wing?

Answer 5

450 lbs (amber)

Question 6

What is the minimum fuel temperature for takeoffs?

Answer 6

As noted by a L/R FUEL TEMP Caution message the temperature must be +5C or greater.

Question 7

What crossflow techniques must be off and on for takeoffs?

Answer 7

The powered and gravity crossflows must be off and the system must be selected to manual crossflow.

Question 8

What is the purpose of the collector tanks?

Answer 8

Each collector tank recieves fuel from the respective main tank to supply a constant fuel supply to the respective engine regardless of aircraft attitude (6 gal.)

Question 9

What does the Fuel System Computer monitor?

Answer 9

Fuel Quantinty, Balance, Fuel Feed and Refuel/Defuel operations

Question 10

Where does the FSC recieve inputs?

Answer 10

Fuel tank probes, High level sensors, AHRS, PSEU

Question 11

What are the outputs of the FSC?

Answer 11

EICAS, Refuel/Defuel panel, Fuel Control Panel, and fuel balance control

Question 12

How is fuel quantity measured?

Answer 12

Through 15 DC capacity probes located in the three tanks that communicate with the FSC which compensates for pitch and roll. (6 in each main, 3 in center)

Question 13

When does the fuel quantity display as amber?

Answer 13

When there is an imbalance greater than 800 lbs or when the total fuel quantity is 900 lbs total fuel or less (450 lbs in a wing).

Question 14

When does fuel flow display amber dashes?

Answer 14

When the fuel flow is greater than 5000 lbs/hr, fuel flow data is invalid.

Question 15

What is the minimum bulk fuel temperature for takeoff?

Answer 15

For Jet A -30C

Question 16

What does an amber fuel filter indicate?

Answer 16

A pressure drop is detected through the fuel filter.

Question 17

What does a magenta fuel filter indicate?

Answer 17

It indicates invalid data from the fuel filter pressure sensor.

Question 18

What are the different types of ejectors and what do they operate?

Answer 18

Transfer ejectors move fuel from the center tanks to the main tank, Scavenge ejectors move fuel from the main tank to the collector tanks and Primary ejectors move fuel from the collector tanks to the coresonding engines.

Question 19

What provides the suction to move fuel through the ejectors?

Answer 19

Motive flow from the engine driven fuel pumps provides high pressure fuel that creates the suction required for the ejectors.

Question 20

What is the main source of moving fuel, what are the backups?

Answer 20

Ejector pumps are the primary method of moving fuel through the system. The Scavenge ejectors are backed up by gravity feed lines connecting the main tanks to the collector tanks. The Primary ejectors are backed up by the AC powered boost pumps. There is no backup for the transfer ejectors.

Question 21

When and how is fuel transfered from the center tank to the main tanks?

Answer 21

When the main tanks reach approx 94% capacity (4760 lbs) the transfer shutoff valves are opened automatically by the Fuel System Computer (FSC), no crew input is required.

Question 22

Which pump(s) activate if the L Ejector Pump fails?

Answer 22

So long as both are armed and AC power is avaialable they will both turn on backing up the failed ejector pump since they are both connected to one another.

Question 23

Which engine must be started first with DC power only and why?

Answer 23

The left engine must be started first with DC power only because the L AC Electric Fuel Pump is powered by the BATT DIR BUS.

Question 24

When does the FSC start autobalancing fuel and how does it operate?

Answer 24

When a fuel imbalance of 200 lbs exists the FSC will activate the XFLOW/APU pump. It will also open up the low tanks XFLOW SOV. Fuel is then taken from both tanks and placed into the low tank until it is ~50 lbs heavier.

Question 25

How does manual fuel balancing operate?

Answer 25

It operates using the same principles as the autoleveling except all steps must be performed by the crew utilizing the FCP.

Question 26

What is the purpose of the gravity crossflow option?

Answer 26

It provides a backup should the powered crossflow pump fail.

Question 27

What provides the primary fuel for the APU?

Answer 27

The APU is primarily supplied from both bank tanks via the XFLOW/APU pump.

Question 28

What is the backup fuel supply for the APU?

Answer 28

A negative-g relief line supplies fuel for the APU from the right ejector/ACFP in the event of a XFLOW/APU pump failure.

Question 29

How is fuel shutoff accomplished to the engines or the APU?

Answer 29

By pressing the corresponding Fire Push swithchlight the Fuel SOV closes isolating fuel from the engine.

Question 30

What supplies power to the Refuel/Defuel Panel?

Answer 30

The panel is hotwired to the BATT DIR BUS

Question 31

What provides the positive pressure on the fuel tanks?

Answer 31

NACA vents provide positive pressure on the fuel tanks, normal fuel venting is also provided by the NACA scoops.

Question 32

What is the purpose of having the AC Fuel Pumps interconnected?

Answer 32

By having a fuel line connecting the outputs of both pumps it allows one collector tank to provide fuel for both engines or one engine to be supplied from both collector tanks.