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B757 SYSTEMS > AIR SUPPLY > Flashcards

Flashcards in AIR SUPPLY Deck (18):
1

When does the pack goes automatically to high flow? (3)

1 pack INOP
1 recirc fan INOP (same side)
Ground Operation (APU or GND source)

2

When is High flow inhibited? (4)

wing anti ice ON and 1 eng supplying bleed
Engine INOP
Flaps NOT UP
AFT cargo switch ARMED (reduce flow in case of acrgo fire)

3

L/R ENG HI STAGE means? (3)

Eng bleed air is excessive pressure
High press bleed air valve automatically locks closed
maintenance action required

4

L/R ENG BLEED VAL means? (4)

eng bleed air temp is excessive
eng bleed air valve automatically closed
HP bleed valve closed
system can be reset

5

L/R BLD DUCT LEAK means? (3)

high temp bleed air leak is detected
leak must be isolated
bleed source turned OFF to prevent structural damage

6

PACK OFF means?

illuminated whenever the pack valve is closed

7

When is the pack valve closes? (3)

pack control selector is OFF
pack trip has occured
with associated eng bleed air OFF light: loss of air to the pack

8

Where does the barometric pressure correction for the pressurization system comes from?

from the Captain altimeter

9

How many pressurization controller do we have for the outvlow valves?

3, 2 automatic and 1 manual

10

What are the indication of an uncontrollable cabin pressurisation?

Pax cabin altitude increase
cabin rate increase
differential pressure decrease
outflow valve fully closed

11

What happen to the APU valve with the isolation valve closed?

APU valve will close automatically if the left engine bleed air valve opens
APU bleed valve senses the positions of the engine bleed valves and isolation valve and closes automatically when an engine bleed air valve opens, but if the isolation valve is closed then the APU valve looks at the left engine bleed valve only

12

In automatic control, an aneroid switch closes the outflow valve when?

Cabin altitude exceeds 11000ft
when aircraft descent below 9500ft the aneroid switches open and outflow circuits are restored

13

Outflow valve opens when the pressure differential is?

Less than 2.5psi

14

Prior to start with eng BLEED switches ON, eng bleed air OFF lights?

Are extinguished because they are dependant on switch position

15

When is an air condioning pack is automatically set to maximum cooling?

When there is an overheat in the air as it leaves the pack
After cooling, the pack can be reset for automatic or standby operation by pushing the PACK RESET switch

16

If one of the equipment cooling supply fans fails?

The alternate fan must be manually selected

17

If a fault occurs in the automatic pack control, What happen to the pack temperature control valves?

it freeze in the last position
pack cannot be reset and must be operated in standby

18

Supplemental heating of cargo compartment air is provided in which compartment?

the AFT compartment only by an electric heater.
FWD compartment does not require a supplemental heater