Pneumatic, AC, Pressurization

Question 1

With the destination altitude below 7850’ when does the CABIN ALTITUDE CAS illuminate?

Answer 1

Caution at 8500’

Warning at 9400’

Question 2

Flying into Telluride(KTEX) the CABIN ALTITUDE WARNING HIGH (A) CAS illuminates. How does this affect the CABIN ALTITUDE (C) and (W)?

Answer 2

Increases caution to Field elevation +650’/ Increases warning to Field Elevation +1550’.

Question 3

What is the IASC and how many are there?

Answer 3

Integrated Air System Controller –
controls all pneumatics

(Environmental, Anti-ice, and Leak monitoring)

(2 controllers each with 2 channels)

Question 4

How many outflow valves are there?

Answer 4

1

Question 5

Where is the outflow valve located.

Answer 5

Below the right wing leading edge, Behind right landing light.

Question 6

How is the outflow valve opened and closed?

Answer 6

Electrically by servo motors.

Question 7

How many safety valves are installed and where are they located?

Answer 7

Two on the aft pressure bulkhead

Question 8

What is the function of the safety valves?

Answer 8

To provide overpressure and negative pressure relief

Question 9

Do the safety valves require electrical power to operate?

Answer 9

No, they are pneumatically operated and spring loaded closed.

Question 10

Does the environmental system use IP air or HP air?

Answer 10

IP (Intermediate Pressure) …regulated to ~ 50 psi

Question 11

Most valves in the bleed and air conditioning system are controlled and actuated by?

Answer 11

Electrically controlled

Pneumatically actuated

Question 12

What two valves are electrically actuated?

Answer 12

Outflow valve and avionics cooling valve

Question 13

What does the Ozone Converter do?

Answer 13

Converts the Ozone from the IP bleed air into O2 to combat fatigue and dehydration

Question 14

When the START switch is selected, what happens to the Flow Control Valves?

Answer 14

They automatically close to shut down the air conditioning system allocating all bleed air to the Starter(ATS)

Question 15

When does the ditching switch become active?

Answer 15

Below 15000’ the outflow valve opens on a depressurizing schedule.

When pressurization delta P is 0, then the outflow valve
closes to prevent water from entering.

Question 16

What does Ram air do?

Answer 16

Provides cooling air to the air heat exchangers and for cabin ventilation at low altitudes(unpressurized <10000)

(if the pack and trim air fail or unpressurized flight is required.)

Question 17

Is the pack cold or hot air?
Trim air?
Hot air.

Answer 17

Pack air -Cold air.

Trim air-Hot air.

Question 18

Pressing the Emer. Depress switch does what?
(MAN/AUTO)

Answer 18

Cabin depressurizes at:

2500fpm to 14000 in MAN mode,

3000fpm to 14500 in AUTO mode or aircraft altitude which ever is lower.

Question 19

How is temp controlled in “Auto”?

Answer 19

Ventilated temp sensors in the cockpit and cabin input to the IASC’s to regulate set temperature.

Question 20

How is temp controlled in “Manual”?

Answer 20

Direct control through the IASC’s to regulate the temperature.

Question 21

The temperature “Pull up/Pull down works under what conditions?

Answer 21

APU or Pneumatic cart, Air source = Normal, Temp mode = AUTO, main cabin door not closed, and more
than 10* difference between selected and indicated temperature.

Question 22

How many modes of pressurization operation are there?

Answer 22

3 Total modes

2 in “Auto” through the IASC’s
1 in “Manual” direct control of outflow valve via rate knob (max. 3000 fpm)

Question 23

Where do you find “X-Bleed”/ “External Air Cart” start procedures?

Answer 23

QRH Volume 1 – Supplemental Section

Question 24

How do you set landing altitude manually while in Auto Press mode?

Answer 24

Landing alt outer knob to manual and inner knob to select alt in 20 ft increments (cyan indicator)

Question 25

Explain the takeoff and return to base sequence for pressurization.

Answer 25

When the aircraft leaves the ground, the takeoff sequence is initiated. The system will maintain the
pre−pressurization cabin altitude of 300 ft below field elevation until the aircraft reaches:

6,000 ft mean sea level (MSL) or differential from takeoff,

or

10 minutes has elapsed.

If a descent is initiated, the cabin altitude will descend to the takeoff altitude and the landing field elevation does not have to
be reset.