Air Systems

Question 1

Dual bleed light

Answer 1

APU bleed air valve open and No. 1 engine air switch on

OR engine No. 2 bleed air swtich ON and APU bleed valve open and isolation valve open

Question 2

Isolation valve switch

Answer 2

CLOSE- closes isolation valve

AUTO-
-closes iso valve if both packs are AUTO OR HIGH and both ENG bleed air switches are ON
-

OPEN- isolation valve open

Question 3

wing body overheat (amber)

Answer 3

LEFT- overheat from bleed air duct leak in left engine strut, IB wing LE, left AC bay, keel beam or apu bleed air duct

Right- overheat from bleed air duct leak in right engine strut, IB wing le, right AC bay

Question 4

BLEED TRIP OFF light (amber)

Answer 4

excessive engine bleed air temperature or pressure

the related bleed air valve will close automatically

requires reset

Question 5

TRIP RESET switch

Answer 5

Resets BLEED TRIP OFF, PACK or ZONE TEMP lights

Related bleed air valve opens, pack valve opens, or trim air modulating valve opens

Question 6

ZONE TEMP lights (amber)

Answer 6

CONT CAB- indicates duct temp overheat or failure of flight deck primary and standby temp control

FWD CAB or AFT CAB- duct temp overheat

Question 7

ZONE TEMP lights (amber on recall)

Answer 7

CONT CAB- indicates failure of flight deck primary or standby temp control

FWD Or AFT CAB- failure of associated zone temp control

Question 8

AC Pack Switch

Answer 8

AUTO-
with both packs operating, each pack is at low flow
with one pack operating, operating pack goes to high flow with flaps up

HIGH- pack regulates to high flow
max flow rate on ground with APU bleed air switch on

Question 9

RAM DOOR FULL OPEN light (Blue)

Answer 9

Ram door is in full open position

Question 10

Trim air switch

Answer 10

on: trim air pressure regulating and shutoff valve signaled open
off: trim air pressure regulating and shutoff valve signaled closed

Question 11

PACK light (amber)

Answer 11

1. pack trip off or failure of both primary and standby pack controls
2. during recall, failure of either primary or standby pack control. extinguishes on master caution reset

Question 12

EQUIP cooling supply switch or exhaust switch

Answer 12

NORM: normal cooling fan activated or normal cooling exhaust fan activated

ALTN: alternate cooling fan activated or alternate cooling exhaust fan activated

Question 13

Equip Cooling supply OFF light (amber)

Answer 13

no airflow from selected cooling fan

Question 14

AUTO FAIL light (amber)

Answer 14

• indicates single controller failure when ALTN light is also illuminated
• indicates dual controller failure if illuminated alone

Question 15

OFF SCHED DESCENT light (amber)

Answer 15

• airplane descended before reaching planned cruise altitude set

Question 16

pressurization MANUAL light (green)

Answer 16

pressurization in manual mode

Question 17

pressurization ALTN light (green)

Answer 17

• illumination of both ALTN and AUTO FAIL lights indicate single controller failure and auto transfer to ALTN mode
• pressurization mode selector in ALTN position

Question 18

which stages of the compressor is engine bleed air obtained from?

Answer 18

5th and 9th stage of compressor

Question 19

Engine bleed air valves act as pressure regulator and shutoff valve. how is the valve activated?

Answer 19

DC activated and pressure operated

Question 20

How is the isolation valve operated?

Answer 20

AC power

Question 21

The APU bleed air valve will close automatically on shutdown. What powers that valve?

Answer 21

DC controlled and pressure operated

Question 22

The ram air system provides cooling air for the heat exchangers. The ram air inlet doors are controlled by the packs for cooling. When are they opened/closed?

Answer 22

On the ground or in slow flight with flaps not fully retracted, the doors move to full open.

in cruise they will modulate between open and close

Question 23

What is the purpose of the deflector doors that are forward of the ram air inlet doors?

Answer 23

they prevent slush ingestion prior to liftoff and after touchdown. They extend on the ground

Question 24

The equipment cooling system consists of what?

Answer 24

a supply duct and exhaust duct with each having a normal and alternate fan. The supply duct supplies cool air to the flight deck displays and electronic equipment in E and E bay. Exhaust duct collects and discards warm air from that equipment and vents it.

Question 25

Pressurization is controlled by the cabin pressure control system. It includes how many automatic controllers ?

Answer 25

2– AUTO and ALTN and a manual pilot controlled mode

Question 26

There are two positive pressure relief valves. They limit max differential pressure to:

Answer 26

9.1 PSI

Question 27

The negative pressure relief valve prevents what?

Answer 27

prevents external atmospheric pressure from exceeding internal pressure

Question 28

When is the overboard exhaust valve open?

Answer 28

when the a/c is on the ground and in flight with low differential pressure, the overboard exhaust valve is open and warm air from the E and E bay is discharged overboard.

In flight, the overboard exhaust valve is normally
closed and exhaust air is diffused to the lining of the forward cargo compartment

the overboard exhaust valve is driven open if either pack switch is in
high. This allows increased ventiliation in the smoke removal configuration

Question 29

When is the overboard exhaust valve closed?

Answer 29

In flight and at higher cabin differential pressures, the overboard exhaust valve is closed and exhaust air goes to the lining of the forward cargo compartment