757 Systems - Air Systems

Question 1

What temp do the PACKs output?

Answer 1

The coldest of the selected zones. Trim air then fine tuned them others.

Question 2

What powers the three different pressurization controllers?

Answer 2

AUTO 1 and 2 are AC power. MANUAL is DC powered by the DC Stby Bus.

Question 3

What do the L or R ENG BLEED VAL and engine BLEED caution lights indicate? And what automatically happens?

Answer 3

Engine bleed air temp is excessive. The engine bleed cable auto closes.

Question 4

What do the L or R ENG HI STAGE and engine HI STAGE caution lights indicate? And what automatically happens?

Answer 4

The engine bleed system pressure is excessive. The high pressure bleed air valve is auto locked and closed?

Question 5

What does PACK OFF light indicate?

Answer 5

The PACK valve closed due to

1. Loss of system pressure or
2. System shutdown

Question 6

What are the 2 possible things

a PACK TEMP EICAS message with an INOP light indicate?

Answer 6

1. PACK controller fault or

2. High PACK outlet temp

Question 7

If a PACK controller fails, what temp will it output?

Answer 7

Last commander temp

Question 8

If the TRIM AIR is selected OFF, what temps do the PACKs output?

Answer 8

78° on both sides

Question 9

What does a single cabin temp EICAS message with an associated INOP light indicate?

Answer 9

1. INOP zone controller or

2. Over temp in zone

Question 10

Red CABIN ALTITUDE with siren illuminated

Answer 10

Cabin altitude is 10,000 (cancels when cabin alt is below 8,500)

Question 11

What happens automatically when Cabin Alt is above 11,000 in the auto mode?

Answer 11

Outflow valve is moved full closed. (Goes back to normal below 9,500)