Pneumatics And Pressurization

Question 1

Pneumatics provides compressor air for what systems?

Answer 1

ECS
Pressurization
Wing anti ice

Question 2

At what stages does compressor air get used for pneumatics?

Answer 2

P2.5
P3

Question 3

What is P2.5 air used for?

Answer 3

ECS and pressurization

Question 4

What is P3 air used for?

Answer 4

Wing anti ice

Question 5

When would P3 air be used for ECS instead of P2.5 air?

Answer 5

Idle power or less than 36 psi on P2.5

Question 6

At what Ng and psi does the P2.5 line carry the ECS load?

Answer 6

62% Ng or 43 psi

Question 7

At what pressure is bleed air supplied to the wing anti ice system?

Answer 7

14 psi

Question 8

When must ECS be shutoff?

Answer 8

Engine fire suspected

Question 9

When would ECS automatically shut down?

Answer 9

Pressure greater than 40 psi (high pressure)
290 C upstream of shutoff valve (high temp)
105 C downstream of water separator (high temp)
Firewall SOV closed

Question 10

What component provides air for the ECS system?

Answer 10

Air cycle machine

Question 11

What will happen in the cabin if the ECS firewall shutoff is pulled?

Answer 11

Pressurization cannot be maintained

Question 12

CPCS components

Answer 12

Outflow valve
Safety valve
Manual control valve
Auxiliary volume tank
Check valve
Ejector valve
Solenoid valve

Question 13

Where is the outflow valve located?

Answer 13

Bottom right firewall

Question 14

How can you depressurize the aircraft after an aborted takeoff?

Answer 14

Dump switch

Question 15

Where is the safety valve located?

Answer 15

Bottom left firewall

Question 16

What is the function of the safety valve and when does it open?

Answer 16

Opens automatically between 6.15 and 6.35 psi

Question 17

What does the check valve do?

Answer 17

Prevent high pressure air from entering the control unit when a system blockage occurs

Question 18

What is the function of the ejector valve?

Answer 18

Operates the outflow valve

Question 19

What is the function of the solenoid valve?

Answer 19

Depressurizes aircraft from the squat switch or the condition lever

Question 20

Cabin rate of climb can be adjusted within what range?

Answer 20

100 fpm and 2000 fpm

Question 21

Pulling the ECS emergency shutoff handle does what?

Answer 21

Closes the outflow valve
Opens the ram air scoop

Question 22

When would you get a cabin pressure warning on the CAWS panel?

Answer 22

Cabin altitude 10,500 (+/- 200)
>5.75 psi differential

Question 23

Set cabin altitude is maintained unless…

Answer 23

AC descends below selected altitude
AC climbs and max pressure differential is reached
Pilot changes the setting

Question 24

What cabin altitude would be reached at 30,000’?

Answer 24

10,000

Question 25

Where should the controller be set for landing?

Answer 25

500’ above field elevation

Question 26

Cabin rate of descent should be set how?

Answer 26

To achieve LFE set prior to getting to that altitude (descend the cabin faster than you get there)

Question 27

What ensures no pressure bump when landing?

Answer 27

Cabin pressure will maintain 150’ (+/- 100) below field elevation on landing

Question 28

What should you do if the cabin controller fails?

Answer 28

Use manual control

Question 29

Where should you check pressurization during flight?

Answer 29

After takeoff and at 10,000’