Pressurization - Question Bank

Question 1

How many cabin altitude controllers are provided?

Answer 1

-Two controllers, A & B. Each controller controls both outflow valves.

Question 2

Can either outflow valve maintain cabin altitude and full ventilation?

Answer 2

• Yes
• One pack is selected off to ensure cabin doors may be opened regardless of the position of the outflow valves if an emergency evacuation is required immediately after landing

Question 3

What are the three modes controlled by the cabin altitude controllers?

Answer 3

• Climb
• Cruise
• Descent

Question 4

How do the cabin altitude controllers calculate a cabin pressurization schedule?

Answer 4

• They use ambient pressure and

- Flight plan data from the FMC

Question 5

Does cabin altitude continue to increase, or level-off, if there is a planned level segment during the climb phase?

Answer 5

Continues to increase during the level segment.

Question 6

What is maximum cabin altitude in cruise mode?

Answer 6

8,000 feet

Question 7

When do the cabin altitude controllers enter descent mode?

Answer 7

-T/D
or
-An initial descent of approx 1,000 feet from cruise altitude, regardless of T/D

Question 8

When is descent mode, do the cabin altitude controllers program a positive or negative pressurization at touchdown?

Answer 8

-Small positive pressurization at touchdown

Question 9

When does the cabin rate limiter close both outflow valves?

Answer 9

When cabin altitude exceeds 11,000 feet

Question 10

How can you gain manual control of the landing altitude, if the airport for takeoff or landing is not in the data base?

Answer 10

• By pushing the Landing Altitude (LDG ALT) switch on the overhead panel
• MAN (amber) displays on primary EICAS

Question 11

What altitude is assumed by the cabin altitude controllers if landing altitude is not available from the FMC, and MAN is not selected?

Answer 11

2,000 feet

Question 12

Describe the NORM position of the Cabin Altitude Selector

Answer 12

Cabin altitude controller A or B selected automatically on alternate flights

Question 13

What happens if the primary controller selected by the cabin altitude selector switch fails?

Answer 13

The secondary controller is automatically selected.

Question 14

What action would allow you to gain manual operation of the pressurization system?

Answer 14

• Turn both Outflow Manual switches to ON

- All automatic cabin altitude control functions are bypassed