PNEUMATICS, AIR CONDITIONING, AND PRESSURIZATION (ASM)

Question 1

Where does the pneumatic system get air from

Answer 1

Engine compression stage
APU
Ground source

Question 2

When is the 14th stage used

Answer 2

Low thrust
Engine cross bleed start
Anti-Ice operations

Question 3

How many ECU are there

Answer 3

2 ECU

Question 4

What does the left ECU control

Answer 4

Cockpit

Question 5

What does the right ECU control

Answer 5

Cabin

Question 6

What distributes the air

Answer 6

The gasper system

Question 7

What happens if both ECU fail

Answer 7

Ram Air Inlets open

Question 8

Purpose of recirculation fans

Answer 8

2 electrical fans mix fresh air for passenger comfort

Question 9

Where does the ECU get air from

Answer 9

Bleed air from pneumatic system

Question 10

Where is pressure from the ECU regulated by

Answer 10

The pack valve

Question 11

After pack valve where does the airflow go

Answer 11

Divided into 2 lines, a cold air that goes through air cycle machine. Hot air bypasses air cycle machine.

Question 12

What happens to air in the Air Cycle Machine

Answer 12

Cooled in primary heat exchanger, then goes through secondary heat exchanger where is cooled again.

Question 13

What controls cabin temperature in AUTO MODE

Answer 13

Controlled by Digital Controller

Question 14

What controls cabin temperature in MANUAL MODE

Answer 14

Temperature control module

Question 15

Where does the pressurization system receive static pressure from

Answer 15

The static ports

Question 16

Purpose for pressurization pressure systems

Answer 16

For overpressure and negative pressure relief functions

Question 17

What controls the pressurization in automatic mode

Answer 17

The digital controller

Question 18

How do the outflow valves work in automatic mode

Answer 18

The pneumatic outflow valve is slaved to the electropneumatic outlfow valve

Question 19

How is Theoretical Cabin Altitude calculated

Answer 19

So that maximum cabin differential pressure (7.8PSI) is reached at lowest possible airplane altitude

Question 20

When does the automatic pressurization sequence on the ground occure

Answer 20

Plane on ground, engine 1 thrust lever set to THRUST SET

Question 21

When does automatic pressurization takeoff sequence begin

Answer 21

Initiated once airplane leaves ground

Question 22

When does automatic pressurization takeoff sequence end

Answer 22

Until theoretical cabin altitude is greater than actual cabin altitude or 15 minutes (whichever is first)

Question 23

When does automatic de-pressurization on ground occur

Answer 23

On ground, engine 1 thrust lever idle

Question 24

To avoid pressure bump during de-pressurization

Answer 24

Landing altitude -300 feet

Question 25

What is de-pressurization controlled at

Answer 25

Rate of 650 fpm

Question 26

What valve operates during manual mode

Answer 26

Only the pneumatic outflow valve (electropneumatic valve stays closed)

Question 27

When do the exhaust fans and shutoff valves open in the forward electronic bay

Answer 27

Once temperatures reach 75ºF

Question 28

When do the exhaust fans and shutoff valves close in the forward electronic bay

Answer 28

Once temperatures drop below 66ºF

Question 29

How is the rear electronic bay cooled

Answer 29

Door closed: Conditioned air from cabin
On ground: Gasper fans

Question 30

How is the baggage compartment ventilated

Answer 30

Recirculation fan