Pressurization & Oxygen

Question 1

If cabin pressurization is lost, the aircraft will enter the emergency descent mode (EDM) if:

Answer 1

Autopilot ON
Red CABIN PRESS LOW CAS
Aircraft above 40,000 ft

Question 2

If the airplane enters the emergency descent mode it will automatically level off at 15,000 ft. If this altitude is too low, what must be done to change the level-off altitude?

Answer 2

Disengage the autopilot and select the appropriate altitude in the flight guidance panel

Question 3

On the ground, when does the FLIGHT / LANDING switch automatically switch to FLIGHT?

Answer 3

At taxi speeds above 9 kts, PLA > 15 degrees, or manually selected by crew

Question 4

On the ground with the FLIGHT / LANDING switch selected to FLIGHT, how will the cabin pressurize?

Answer 4

Cabin will descend to 500’ below field elevation

Question 5

How do you select between the 2 cabin pressure controller channels?

Answer 5

They automatically swap every flight (by opening & closing the main cabin door after landing), or by selecting the AUTO/MANUAL switch to MANUAL, then back to AUTO

Question 6

What are the outflow valve motor power sources?

Answer 6

2 AC - ESS AC & R MAIN AC - Auto Mode
1 DC - L ESS DC - Manual Mode

Question 7

When will the CABIN PRESS LOW CAS illuminate?

Answer 7

LFE < 7,500’ - 8,000 ft
LFE 7,500-9,500’ - 10,000 ft
LFE > 9,500’ - 14,500 ft
Manual Mode - 10,000 ft

Question 8

What is the power source of the AUTO/SEMI pressure selection switch?

Answer 8

Channel 1 - ESS AC
Channel 2 - R MAIN AC

Question 9

When does the dual channel pressurization controller switch channels?

Answer 9

By selecting then deselecting MANUAL on the pressurization controller, or by cycling the main door open and closed after landing

Question 10

Is there a way to determine which channel of the pressurization controller is active?

Answer 10

By viewing the ECS / PRESS synoptic page - lower right corner, or SUMMARY page

Question 11

Where does the pressurization system obtain altitude information?

Answer 11

Captain’s side selected ADM (Air Data Module)

Question 12

Where does the pressurization system obtain its landing field elevation information?

Answer 12

The FMS or pressurization selector panel

Question 13

When does the FLIGHT / LANDING switch change to landing?

Answer 13

During descent, change of altitude of more than 1000 ft, or selecting LANDING on the cabin pressure control panel

Question 14

What happens to the FLIGHT / LANDING mode if the aircraft levels off after descent begins?

Answer 14

The pressurization system will continue to pressurize the aircraft to a normal pressure for that altitude. However, the FLIGHT / LANDING switch will still indicate LANDING (for 3 minutes >FL250, then switches back to FLIGHT)

Question 15

What is the maximum cabin altitude in the AUTO operation?

Answer 15

8,000 ft

Question 16

How do you control aircraft pressurization in the SEMI mode?

Answer 16

By pre-setting all the information in the CABIN PRESSURE SELECTOR PANEL located on the center console

Question 17

How long does it take to open the PRV after landing in the SEMI / AUTO mode of operation?

Answer 17

1 minute after the outflow valve has fully opened

Question 18

How is aircraft pressurization controlled in the MANUAL mode?

Answer 18

By manipulating the manual hold rate knob that controls the DC motor to open and close the TROV

Question 19

If you are planning a flight from a low altitude airport to a high altitude airport (such as above 8000 MSL), how will the cabin pressurization system function?

Answer 19

The cabin pressurization (in AUTO) will climb the cabin to the correct cruise altitude differential until a descent is begun, at which time the cabin will climb to the landing field elevation.

Question 20

What are the cabin differential pressure limits?

Answer 20

9.94 psi max differential
0.3 psi for taxi takeoff and landing

Question 21

When will the pressure relief valve open?

Answer 21

If the TROV has failed, the PRV will begin to open at 9.74 PSID or -0.25PSID. However during normal operations, the PRV will open 1 minute after the TROV has fully opened on the ground after landing

Question 22

How many power sources are there for the TROV?

Answer 22

3 Total: 2 AC, 1 DC
Channel 1 - ESS AC
Channel 2 - R MAIN AC
Manual - L ESS DC

Question 23

At what cabin altitude will the passenger oxygen masks deploy, if in AUTO?

Answer 23

Either 13,000’ or 14,500’ depending on serial number an/or ASC installation

Question 24

At what pressure and/or temperature will the oxygen blow-out disc discharge?

Answer 24

1. Regulator oxygen pressure exceeding 90psi
2. Oxygen cylinder pressure exceeding 2600psi
3. Oxygen temperature exceeding 225F

Question 25

If the small knob on the front of the oxygen mask is rotated to emergency, what will happen?

Answer 25

The recipient will be provided with oxygen under positive pressure

Question 26

What will the normal position on the flight crew oxygen mask provide?

Answer 26

Diluted oxygen in a decreasing ratio up to approximately 35,000 feet