B-737 Ng - Fuel System

Front 1

What switches control the ENGINE VALVE and SPAR VALVE's?

Back 1

Engine Start Lever AND Engine Fire Switch

Front 2

When ENG VALVE CLOSED light is illuminated in dim blue what does that indicate?

Back 2

The engine valve is closed

Front 3

When the ENG VALVE CLOSED light is extinguished what does that indicate?

Back 3

The Engine valve is open

Front 4

When ENG VALVE CLOSED light is illuminated in BRIGHT blue what does that indicate?

Back 4

The engine valve is either;

In transit

OR

The valve doesn't agree with the engine start Lever or engine fire switch position

Front 5

When the main tank LOW PRESSURE lights are illuminated what could be meant?

Back 5

Either;

The Main tank FWD/AFT fuel switches are OFF

OR

The switches are ON but there is low pump output pressure

Front 6

The center fuel tank pump LOW PRESSURE lights are illuminated, what does that mean?

Back 6

The pumps are ON, but output pressure is low

Front 7

If more than 10 seconds has elapsed since the center tank LOW PRESSURE lights have illuminated and you have not turned the center tank pumps off, what will happen?

Back 7

Master Caution light will illuminate and FUEL annunciator light

Front 8

When will the FILTER BYPASS lights illuminate?

Back 8

When fuel is bypassing the filter because it has been contaminated

Front 9

When an imbalance of more than 1000 lbs exists in the main tanks how will this be displayed?

Back 9

IMBAL in amber will be displayed on fuel display under the tank with the imbalance on the upper DU.

Front 10

If all fuel pumps fail can the engines still get fuel under pressure?

Back 10

Yes through suction feed from the MAIN TANKS ONLY

Center tank fuel is unusable

Front 11

How is remaining fuel from the center tank scavenged?

Back 11

If the No.1 tank FWD fuel pump switch is ON the fuel from the center tank will be automatically scavenged to tank 1 when the number 1 tank is ~1/2 empty

Front 12

What tank is the fuel temperature measured from?

Back 12

Number 1 tank

Front 13

How does the APU get its fuel?

Back 13

If AC pumps are not operating fuel is suction fed from main tank number 1. When pumps are operating fuel is drawn from the left manifold. (Left of crossfeed valve)

Some airplanes have a automatic DC pump which operates when AC pumps are off.

Front 14

Total fuel capacity in Lbs?

Back 14

46,000 LBS

Front 15

What tank burns gas first if all three are full and how is this done?

Back 15

Center tanks as the pumps pump at a higher pressure

Front 16

What is the maximum tank fuel tempreture?

Back 16

49C

Front 17

Can you run the center tank pumps with the flight deck unattended?

Back 17

No

Front 18

On the ground if atleast 1000 LBS of fuel is loaded in the center tank what fuel pump switch should be on if you want to run the APU and not cause an imbalance?

Back 18

Left center AC pump

Front 19

Will a single low pressure light in tank 1 cause a master caution?

Back 19

No, there need to be 2 pumps in each tank that are activated to cause a master caution

Front 20

What is the main and center tank capacity?

Back 20

Main tanks: 8,600 LBS each (17.2)

Center tank: 28,800 LBS

46,000 LBS Total

Front 21

What powers the Crossfeed valve?

Back 21

DC power

Front 22

What powers the fuel pumps?

Back 22

AC power

Front 23

Fuel freezing point in flight?

Back 23

The warmer of -43C or 3C above fuel freezing point