900 Air Conditioning And Pressurization

Question 1

In the event of dual pack failure what provides air

Answer 1

Ram air switchlight

Question 2

Using the ram air switch light the air enters which supply system

Answer 2

The left supply system

Question 3

How many avionic cooling fans are there and when will they operate?

Answer 3

Fan 1 - Operates during flight or on the ground as alternate

Fan 2 - Operates on the ground or in flight as alternate

Standby fan - Operates as backup

Question 4

When smoke is detected in the cargo bay

Answer 4

The heater power is removed and the shut off valves automatically close

Question 5

How many Galley heaters do we have

Answer 5

Two 500 W heaters to supply heat to the galley and Service door area

Question 6

Cabin pressure is maintained and controlled by

Answer 6

1 electro pneumatic outflow valve.

Question 7

If cabin altitude exceeds 14,000 feet

Answer 7

Passenger oxygen masks deploy

Question 8

The outflow valves are automatically controlled by

Answer 8

Either of two independent Cabin pressure controllers

Question 9

How many CPC’s

Answer 9

2

Question 10

The pressure controller automatically switches on the ground when

Answer 10

On the ground for three minutes

The active CPC is displayed on the ECS synoptic page

Question 11

EMER DEPRESS

Answer 11

Opens bothoutflow valves

14250 (plus or minus750)

Question 12

FASTEN SEATBELT SIGN

and

NO SMOKING SIGN

comes on automatically when

Answer 12

Cabin altitude is at or above 10,000 feet

Pax sign in auto

Question 13

What cools packs

Answer 13

Ram air

Question 14

Ram air also provides cooling airflow to

Answer 14

Cooling of number one and two hydraulic system fluids

Question 15

How many recirc fans are there

Answer 15

2

Question 16

What are the two avionics exhaust fans used for

Answer 16

To extract the heated air from behind the flight compartment displays and from the avionics equipment

On the ground the heated air is dumped overboard through the ground outflow valve

Inflight the heated air is ducted to the pressurization outflow valve and dumped overboard

Question 17

OVBD COOL FAIL status?

Answer 17

Overboard exhaust shutoff valve Has failed closed with the aircraft on the ground and the passenger door unlatched

Question 18

OVBD COOL caution

Answer 18

Over board exhaust shutoff valve is not closed with the passenger door and service door closed

Aircraft will not pressurize

Question 19

When will you see a CABIN ALT WARNING message?

Answer 19

When the cabin altitude is greater than 10,000 feet.

Question 20

When will you see a DIFF PRESS WARNING message?

Answer 20

When the cabin differential pressure greater than 8.6 PSI

Question 21

When will you see a CABIN ALT caution message?

Answer 21

When the cabin altitude is greater than 8500 feet but not greater than 10,000 feet

Question 22

Pressurization is controlled by

Answer 22

A single electric controlled outflow valve

Question 23

What happens if both CPC’s fail?

Answer 23

Outflow valves go to a barometric hold

Question 24

With the cargo fan switch in the Air position?

Answer 24

Recirc air keeps temp above freezing.

Question 25

With the cargo fan switch in the Cond air?

Answer 25

The heater is on.

Question 26

What happens to the packs when either engine start switch light is pressed in the 900?

Answer 26

The pack valves automatically close Controlled by a ACSC

Question 27

Are both forward and aft cargo compartments pressurized?

Answer 27

Yes

Question 28

Which cargo bay is ventilated by conditioned air?

Answer 28

Only the aft cargo bay

Question 29

Aft cargo switch should not be selected to conditioned air when?

Answer 29

Ambient temps are above 15°C

Question 30

How are all phases of pressurization controlled in the Auto mode?

Answer 30

Through two cabin pressure controllers Only one controller is active Switches three minutes after WOW

Question 31

How many outflow valves are there?

Answer 31

1, Located on aft pressure bulkhead

Question 32

How many pressure safety valves are there?

Answer 32

2, one for overpressure and one for negative pressure relief.

Question 33

How are the safety valves operated?

Answer 33

Pneumatically operated and spring loaded closed

Question 34

What is the purpose of the ground valve?

Answer 34

Ensures aircraft is depressurized on ground Also dumps CRT and avionics air overboard

Question 35

When do oxygen masks drop?

Answer 35

14,000 feet plus or -300

Question 36

With a failure of the CPC??

Answer 36

Auto oxygen mask deployments and illumination of fasten seatbelt and no smoking signs will not occur

Question 37

The Maximum negative differential pressure is?

Answer 37

-.5 psi

Question 38

Recirculation fan must be switched off when the cabin temperature is warmer than

Answer 38

30 degrees

Question 39

AFT CARGO SWITCH?

Answer 39

Do not select conditioned air until ambient temperatures are above 15°C

Question 40

PACK stands for

Answer 40

Pneumatic Air Conditioning Kit