Pneumatics 747-400 Flashcards Preview

CAL Cargo Airlines > Pneumatics 747-400 > Flashcards

Flashcards in Pneumatics 747-400 Deck (16)
Loading flashcards...
1
Q

What are the required thrust power settings for anti-ice operation with the bleed air switch in off ?

A

Works only at high power settings.

2
Q

What does BLEED 4 on the primary EICAS mean?

A

Either:

1) HP bleed valve failed open
2) PRV failed open
3) Engine bleed over pressure

  • Combination can be critical
3
Q

If BLEED 4 appears on primary EICAS, will Nacelle anti ice and Thrust reverser work, one of them or none of them?

A

Only thrust reverser would work.

4
Q

What does BLD 4 PRV on the primary EICAS mean?

A

Bleed overheat or PRV failed closed, or both.

5
Q

What is a typical reason for a Bleed air overheat?

A

Faulty fan air modulating valve leading to insufficient bleed air pre cooling.

6
Q

What does BLEED HP ENG 4 on primary EICAS mean?

A

HP bleed valve failed closed.

  • For Anti-ice add more power
  • Reverser will deploy slower during touchdown.
7
Q

With the BLEED HP ENG 4 on primary EICAS, and thrust is at idle power, what is the position of the PRSOV?

A

Closed.

With intermediate pressure only, the engine produces only little pressure when idle. PRSOV closes due to reverse flow protection.

8
Q

What does the BLD DUCT LEAK L on the primary EICAS mean?

A

A bleed leak has occurred.

9
Q

What could cause a BLD DUCT LEAK C on the primary EICAS while on the ground?

A

If air conditioning bay doors are closed while in hot weather.

10
Q

What does BLEED ISLN R on primary EICAS mean?

A

The isolation valve is not in commanded position.

11
Q

If all packs are turned off for takeoff, will you still have TR and NAI, and what is the reason you will either loose or have them?

A

Have both as the NAI and TR valves are before the PRSOV.

12
Q

If APU is off, does the APU bleed valve switch need to be OFF?

A

No. When the APU bleed valve switch in the ON position, the bleed valve operates automatically.

13
Q

What pressure stage supplies the engine pressure duct at low thrust settings?

A

The 14th Stage (HP)

14
Q

What do you loose when the BLD 4 OVHT / PRV message is displayed?

A

No NAI, or TR.

15
Q

If the right main duct is isolated, what do you expect to loose?

A

Wing Anti-ice for right wing, and right leading edge flaps will work in secondary mode.

16
Q

When does NAI not work?

A

1) When PRV is failed closed, or overheat is detected.
BLD OVHT / PRV.
2) When HP bleed valve failed open and engine bleed air switch in OFF.