Air Conditioning And Pressurization

Question 1

What is normally operating max differential pressure as applied by the controller

Answer 1

7.46 psi

Question 2

At that differential pressure what is the cabin altitude at 35000 ft

Answer 2

8000ft

Question 3

What is the diff pressure limited by the outflow valves

Answer 3

7.65

Cabin Alt limiting at 12500ft +/- 1500ft

Question 4

What is the altitude limiter set to

Answer 4

12000ft +/- 1500ft

Question 5

What warning is there of excessive cabin altitude

Answer 5

An excessive cabin Altitude warning is presented when the cabin Altitude reaches 10000ft

Question 6

How is the fuselage protected against negative pressure

Answer 6

The cabin is automatically depressurised upon landing, two inward pressure relief valves prevent negative cabin pressure

Question 7

How do you set the panel for automatic operation

Answer 7

Set the landing elevation and rate control knob in the datum.

Question 8

What happens if the active Channel fails

Answer 8

The standby channel takes over, level 1 alert

Question 9

How do you manually change channels on the controller

Answer 9

Pressing the PRESS CONTROL p/b twice in succession

Question 10

What happens if both channels fail? What do you do

Answer 10

Manual mode is automatically activated and an alert is generated level 2 alert CAB PRESSURE CONTROL

Question 11

How do you control pressurisation in manual

Answer 11

Bu selecting PRESS CONTROL p/b and the up and down toggle and decrease or increase the rate with the rate knob

Question 12

What pressurisation alerts are there and at what level

Answer 12

CABIN PRESSURISATION CONTROLLER CHANEL FAULT- level 1
CABIN PRESSURISATION CONTROLLER FAULT—level 2
EXCESSIVE CABIN ALTITUDE— level 3

Question 13

how many air conditioning packs are installed

Answer 13

Two, Pack 1 and Pack 2

Question 14

Is a single pack enough to satisfy the requirements

Answer 14

Yes single pack can meet all requirements

Question 15

Which pack supplies what area

Answer 15

Pack 1 serves Flightdeck

Pack 2 serves cabin

Question 16

What conditions must be met for a pack valve to open

Answer 16

when pressure is >10 psi and system is on

Question 17

When will auto shutoff of both packs occur

Answer 17

Auto Shut-off​ of​ both packs occurs:​ ​- ​On the ground​ during engine starting or​ ​when both thrust​ reversers are unlocked.​ ​- ​If​ an engine failure is detected during​ ​take-​off​ or​ in flight​ at​ altitudes below​ ​ ​13 500 ft​ and a thrust​ lever​ setting above​ ​MIN​ TO is​ selected.​

Question 18

How is pack operation restored after an auto shutoff due to engine failure

Answer 18

In case of an auto shut-off​ due to engine fail-​ure,​ pack operation is restored by​ operating​ ​the​ AIRCOND AUTO SH​UT​ p/b located​ at​ ​ ​the ram​ air​ panel​ or by​ selecting a lower​ ​thrust​ lever​ setting. Pack​ operation​ will​ be​ ​automatically​ restored when climbing above​ ​13 500 ft

Question 19

How are normal and economy flows selected

Answer 19

There are three modes​ of​ flow​ control:​ nor-​ ​mal,​ economy and​ augmented.​ ​Normal​ and​ ​economy flows​ can​ be selected​ manually.​ ​Economy​ flow is​ obtained when both pack ​valves are open and the automatically​ con-​trolled cabin temperature is​ ​within a preset​ ​range​ from​ the​ selected​ temperature.​ Econ-​ ​omy​ flow​ is automatically​ selected:

Question 20

What is augmented flow

Answer 20

High output flow of 140%

Question 21

If you are in economy mode and a pack fails, what happens

Question 22

How do you select a cabin or Flightdeck temperature

Answer 22

The temperature may​ be controlled automat-​ically​ or manually​ via the temperature selec-​tors.​ The air​ temperature​ of​ cabin,​ cabin ​ ​supply, and flight​ deck supply​ can be dis-​played

Question 23

Where is air temperature displayed

Answer 23

The air​ temperature​ of​ cabin,​ cabin ​ ​supply, and flight​ deck supply​ can be dis-​played on the overhead panel

Question 24

How is the flight deck and cabin air distributed

Answer 24

Conditioned air from​ the manifold is distrib-​ ​uted to the flight deck​ and cabin via​ indepen-​dent​ ducts

Question 25

How many recirculating fans are there, what do they do and how are they controlled

Answer 25

4 fansCabin​ air​ is distributed​ overhead along​ each​ ​cabin wall.​ The cabin air​ can be recirculated​ ​ ​by​ four​ recirculation fans which are mounted​ ​ ​in the cabin ceiling. The fans are controlled​ ​ ​by​ the RECIRC​ FANS p/b’s

Question 26

How and when would you introduce Ram air into the aircraft

Answer 26

During unpressurized flight ram air may be introduced to the​ manifold via a valve. Control is by ​the RAM AIR p/b located at the ram air panel

Question 27

What happens to the air conditioning system if an engine failure occurs above 13500ft? And below 13500ft

Answer 27

On the ground​ during engine starting or​ ​when both thrust​ reversers are unlocked.​ ​- ​If​ an engine failure is detected during​ ​take-​off​ or​ in flight​ at​ altitudes below​ ​ ​13 500 ft​ and a thrust​ lever​ setting above​ ​MIN​ TO is​ selected.​ ​In case of an auto shut-off​ due to engine fail-​ure,​ pack operation is restored by​ operating​ ​the​ AIRCOND AUTO SH​UT​ p/b located​ at​ ​ ​the ram​ air​ panel​ or by​ selecting a lower​ ​thrust​ lever​ setting. Pack​ operation​ will​ be​ ​automatically​ restored when climbing above​ ​13 500 ft.

Question 28

Is there anytime the automatic switch to economy flow will not work

Answer 28

Economy​ flow​ is inhibited when both temper-​ature control​ p/b’s are in manual​ mode and 1 pack is off

Question 29

If an external air conditioning unit is supplying ventilated air, what precautions must you take and why

Answer 29

Open avionics hatch or cockpit windows before connecting the unit

Question 30

What would you do to reduce cabin air temperature during ground ops and initial flight

Answer 30

Low pressure conditioned air can be supplied to the manifold for distribution throughout the ​aircraft via​ a​ ground connection provided at the forward right section of the aircraft.