Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

REX - 737 Systems > Chapter 12 - Fuel > Flashcards

Chapter 12 - Fuel Flashcards

1
Q

Centre fuel tank fuel is used before main tank fuel because:

A

Centre tank fuel pumps produce higher pressure than main tank pumps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The fuel quantity indication system calculates:

A

Usable fuel quantity in each tank.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The capacity of the centre fuel tank is:

A

Greater than the capacity of the two main fuel tanks combined.

No 1 & 2: 4,876 / each
Centre: 16,273

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

There are CDS fuel alert indications for:

3x - two mains, one centre.. think Fuel L.I.C for the lights..

A
  1. Main tank - fuel quantity less than 2000 lbs. (907 kg.) “LOW”. Displayed until 1134kg in the tank
  2. Main tanks - greater than 1000 lbs. (453 kg.) fuel difference “IMBAL”. Displayed until less than 91kg difference
  3. Centre tank - greater than 1600 lbs. (726 kg.) and both switches turned off “CONFIG”. Displayed until 363kg in tank, engines off, one pump switch on.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

During cruise, both centre tank fuel pumps have failed and the centre tank fuel pump switches are OFF. You still have 700 lbs. (320 kg.) of fuel in the centre tank and both main tanks are full.

The Upper Display Unit will show:

A

a. LOW indication - 2000 lbs (907kg) in main tank but mains are full
b. a CONFIG indication - greater than 1600 lbs. (726 kg.) and both CTR fuel pump switches turned off but CTR has 320kg.
c. a pump LOW PRESSURE indication - only activates with pump switches on and they’re off
d. None of the answers are correct.

D - none

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

You have 5,500 lbs. (2500 kg.) of fuel in the No 1 main tank and 6750 lbs. (3060 kg.) of fuel in the No.2 main tank.

You will see:

A

An IMBAL indication below main tank No.1 with no Master Caution light and no system annunciation for fuel.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

In flight, below FL300, two fuel pump LOW PRESSURE lights for the No.1 tank illuminate.

What happens to the No.1 engine?

A

It will continue to operate. Mechanical engine-driven fuel pumps provide suction feed
in the event that normal electrical fuel pump operation is not available.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The centre tank scavenge jet pump operates when:

A

The No.1 main fuel tank is about 1/2 full and the main tank No.1 forward pump is operating.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

In which fuel tanks are bypass valves located?

A

Both main tanks.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the condition of the VALVE OPEN light when the cross feed selector is positioned OPEN and the cross feed valve is closed?

A

Illuminated bright blue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the source of electrical power for the engine fuel shutoff valves?

A

The Battery Bus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Ground transfer of fuel between the tanks:

A

is accomplished at the wing fuelling station.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

During fuel balancing operations, fuel pump pressure should be supplied at all times.

Without fuel pump pressure, thrust deterioration or engine flameout may occur above which altitude?

A

30,000 feet.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

If the fuel quantity indication system is inoperative:

A

Enter and periodically update manually calculated fuel weight on the FMC PERF INIT page.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What causes the ENG VALVE CLOSED lights to illuminate bright blue?

A

When the valve is in transit or valve position and engine start lever or engine fire warning switch disagree.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the power source for opening and closing the SPAR FUEL SHUTOFF VALVES?

A

DC power from the Hot Battery Bus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Where is the fuel temperature sensor located?

A

In Main Tank number 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the maximum tank fuel temperature?

A

49 degrees C.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the minimum in-flight tank fuel temperature?

A

-43 degrees C or 3 degrees C above freezing point of fuel being used. Whichever is
higher

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What causes the Crossfeed VALVE OPEN light to illuminate bright blue?

A

Crossfeed valve is in transit or valve position and crossfeed selector disagree

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When must the crossfeed valve be closed?

A

for takeoff and landing.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What powers the crossfeed valve?

A

DC power so with complete loss of AC power, fuel can be directed to both engines from any tank.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What causes the FILTER BYPASS light to illuminate?

A

Impending fuel filter bypass due to a contaminated filter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What causes the centre tank fuel pump LOW PRESSURE light to illuminate?

A

Fuel pump output pressure is low with the FUEL PUMP switch ON.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What causes the centre tank fuel pump LOW PRESSURE light to extinguish?

A

Centre tank FUEL PUMP switch OFF, or FUEL PUMP switch ON and output pressure is normal.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How is the centre tank fuel pump LOW PRESSURE light different from the main tank fuel pump LOW PRESSURE lights?

A

Main tank fuel pump LOW PRESSURE lights illuminate when output pressure is low, regardless of switch position.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

The centre wing tank fuel scavenge jet pump transfers fuel remaining in the centre wing into
which main tank?

A

Number 1 main tank

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

When AC fuel pumps are not operating, fuel for the APU is suction fed from which tank?

A

Number 1 main tank.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What does an illuminated main tank fuel pump LOW PRESSURE light indicate?

A

Fuel pump switch is OFF and /or the fuel pump output pressure is low.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What powers the centre wing and main tank fuel pumps?

A

AC powered. Therefore with a complete loss of AC power, the engines are being suction fed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the defueling valve used for?

A

The defueling valve, located outboard of the number 2 engine, is used for defueling and tank to tank transfer operation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Can tank-to-tank transfer of fuel be accomplished in flight?

A

No.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Which fuel tank pumps produce greater pressure?

A

Centre wing tanks produce greater pressure overriding the main tank pumps in the fuel manifold. Therefore the centre wing fuel will be used to pressure feed the engines before the main tank fuel is used.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Which fuel tank pumps produce greater pressure?

A

Centre wing tanks produce greater pressure overriding the main tank pumps in the fuel manifold. Therefore the centre wing fuel will be used to pressure feed the engines before the main tank fuel is used.

35
Q

At what fuel quantity would you see the amber LOW indication on the Upper Display Unit?

A

Either main tank less than 2,000 pounds (907 kg)

36
Q

When is the CONFIG indication inhibited?

A

When the centre tank quantity is less than 800 pounds (363 kg).

37
Q

Random fuel imbalances must not exceed ______

A

1,000 pounds (453kg)

38
Q

If the centre tank contains more than 1000 pounds (453 kg), what must be true of the main tank fuel quantity?

A

Main tanks must be full.

39
Q

The engine fuel shutoff valves:

A

and the spar fuel shutoff valves close whenever their respective engine fire-warning switch is pulled or engine start lever is placed to CUTOFF.

40
Q

On the ground with an 1100-pound fuel difference in the main tanks, would you see the IMBAL indication?

A

No. It is inhibited when the airplane is on the ground

41
Q

If you have an IMBAL and LOW situation simultaneously, which one will be displayed on
the Upper Display Unit?

A

LOW has priority

42
Q

The IMBAL indication shows until the main tanks are within _______ pounds/kilograms of each other.

A

200 pounds / 91 kg.

43
Q

At what fuel quantity would you see the amber IMBAL indication between main tank quantity displays on the upper display unit?

A

When main tanks differ by more than 1000 lbs. (453 kg)

44
Q

What is the allowable SCHEDULED fuel imbalance between main tanks 1 and 2?

A

Zero

45
Q

What causes the amber CONFIG indication at the CTR tank fuel indicator on the Upper Display Unit?

A

Both of the answers are correct

46
Q

How are the boost pumps powered under normal operations?

A

One by Transfer Bus 1 and one by Transfer Bus 2

47
Q

How are the boost pumps powered with the loss of AC power?

A

They aren’t, suction feed only using bypass valves.

(Centre tank can’t suction feed).

48
Q

What is the purpose of the NGS?

A

To reduce the increased flammability caused by the packs.

49
Q

NGS air supplied by:

A

Bleed air from the left side of the pneumatic manifold

50
Q

The NGS provides nitrogen enriched air to the:

A

Centre tank

51
Q

LOW PRESSURE lights, main tank:

A

Fuel pump output pressure is low, or FUEL PUMP switch is OFF.

52
Q

LOW PRESSURE lights, main tank pump switches ON:

A

Pump failure or no fuel.

53
Q

LOW PRESSURE lights, centre tank:

A

Fuel pump output pressure is low and FUEL PUMP switch is ON.

54
Q

Indications when two LOW PRESSURE main tank lights illuminate:

A
  1. FUEL annunciator
  2. MASTER CAUTION

If only one LOW PRESSURE light illuminates, the recall feature can be used to show the FUEL annunciator.

55
Q

Switch configuration for pump failure or empty fuel tank:

A

Main tank: Pump switches OFF

Centre tank: Pump switches ON

56
Q

When are the centre tank LOW PRESSURE lights inhibited?

A

When the respective pump switches are OFF.

57
Q

Indications when one LOW PRESSURE center tank light illuminates:

A
  • MASTER CAUTION

- FUEL annunciator

58
Q

Possible outcomes if both LOW PRESSURE main tank lights illuminate in-flight:

A
  • Engine flameout-

- Thrust deterioration.

59
Q

Three conditions for VALVE OPEN light:

A
  1. Extinguished – crossfeed valve is closed.
  2. Illuminated (blue) –
    • bright – crossfeed valve is in transit, or valve position and CROSSFEED selector disagree.
    • dim – crossfeed valve is open.
60
Q

The crossfeed valve is powered by:

A

The battery bus

61
Q

Maximum fuel imbalance:

A

1,000lbs

62
Q

FILTER BYPASS lights:

A

Extinguished – fuel filter operating normally.
Illuminated (amber) – impending fuel filter bypass due to a contaminated filter (remain illuminated until engine shutdown on the ground)

63
Q

The spar fuel shutoff valves are powered by:

A

The hot battery bus.

64
Q

The engine fuel shutoff valves are powered by:

A

The battery bus

65
Q

Both the engine shutoff valve and the spar shutoff valve close when:

A

The respective Start Lever is moved to cutoff or the Fire Switch is pulled.

66
Q

ENG VALVE CLOSED light dim:

A

Associated valve is closed.

67
Q

ENG VALVE CLOSED light bright:

A

In transit or disagreement between valve position and engine start lever or engine fire switch

68
Q

ENG VALVE CLOSED light bright:

A

In transit or disagreement between valve position and engine start lever or engine fire switch

69
Q

ENG VALVE CLOSED light extinguished:

A

Associated valve is open.

70
Q

When does the LOW message appear?

A
  • When fuel quantity is less than 907kg (2000lb).
  • Indication remains until 1134kg 2500lb during refuelling.
  • Message inhibited on the ground

Think 4000lb total, tie the 4 to 40 minutes fixed reserve

71
Q

When does the fuel CONFIG message appear?

A
  • either engine running
  • center fuel tank quantity greater than 726 kgs (1600 lb); and
  • both center fuel tank pump switches positioned OFF

The quantity digits on the center tank fuel quantity indicator turn amber.

So, CONFIG = CTR Tank ONLY.

72
Q

What conditions are required to clear the fuel CONFIG message?

A
  • both engines not running
  • center fuel tank quantity less than 363kg (800lb)
  • one center fuel tank pump switch ON

Divide the initial threshold (1600lb) by 2 = 800lb

CTR tank threshold quantities not whole numbers to the 1000.

73
Q

When does the fuel IMBAL message appear?

A
  • main tanks differ by more than 453kgs (1000lb)
  • displayed below main tank with lower fuel quantity
  • displayed when airplane is on the ground or in the air

Main tank related fuel messages both neat numbers… 2000, 1000.

74
Q

What conditions are required to clear the fuel IMBAL message?

A

• displayed until imbalance is reduced to 91kg (200lb)

75
Q

Which conditions inhibit the LOW fuel message?

A
  • inhibited by fuel LOW indication when both indications exist or
  • when aircraft is on the ground
76
Q

What happens if FUEL FLOW switch held in USED for more than 30 seconds?

A

Indication returns to FUEL FLOW and USED not available for the rest of the flight.

77
Q

The RESET function of the FUEL FLOW switch causes:

A

The USED fuel to decrease to zero

78
Q

What powers external indications and valves?

A

Hot Battery Bus

78
Q

What powers external indications and valves?

A

Hot Battery Bus

79
Q

What can deliver fuel to the Manual Defuel Valve when transferring from the right to the centre tank?

A

The right CTR Tank boost pump or either of the tank 2 pumps.

AC power therefore required

80
Q

How to transfer fuel from Tank 1 to Centre Tank:

A
  • Boost Pump ON
  • Crossfeed valve OPEN
  • Defueling valve OPEN
  • Centre tank fill valve OPEN

Close the pump and valves in same order to stop the process

81
Q

How to transfer fuel from Tank 2 to Tank 1?

A
  • Both Tank 2 AC Boost Pumps ON
  • Manual Defuel Valve OPEN
  • Tank 1 Fill Valve OPEN
82
Q

How to transfer fuel from Tank 1 to Tank 2?

A
  • Tank 1 Aft AC Boost Pump ON
  • Crossfeed OPEN
  • Manual Defuel Valve OPEN
  • Tank 2 Fill Valve OPEN
83
Q

When transferring fuel, when must the CROSSFEED valve be open?

A

Any time Tank 1 is being used to transfer FROM.

REX - 737 Systems (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions