PTM Ch. 12 Pressurization

Question 1

How is the airplane pressurized?

Answer 1

Controlling the amount of conditioned air that is allowed to exit the aircraft through the outflow valve

Question 2

Normal Max cabin differential pressure

Answer 2

7 psi

Question 3

This allows for sea level cabin altitude below:

Answer 3

16,800’

Question 4

What is the only part of the aircraft that isn’t pressurized?

Answer 4

Nose compartment

Question 5

When must the cabin be depressurized?

Answer 5

During takeoff and landing

Question 6

The motive force for OPERATION of pressurization comes from:

Answer 6

Engine bleed air

Question 7

How is the outflow valve opened?

Answer 7

Vacuum

Question 8

How is the outflow valve closed?

Answer 8

Spring pressure

Question 9

If the pressure exceeds what, the outflow valve will fully open.

Answer 9

7.25 psi

Question 10

How else will the outflow valve open?

Answer 10

If negative pressure condition is present

Question 11

What was installed to speed up outflow valve reaction time?

Answer 11

Pneumatic relay

Question 12

What do you set the pressurization altitude to for take off and landing?

Answer 12

500’ AGL

Question 13

What do you set the pressurization altitude to during cruise?

Answer 13

1000’ above cruise altitude

Question 14

What is the cabin rate of climb?

Answer 14

A VSI for the cabin altitude in fpm.

Question 15

On the cabin altitude what is the outer scale used for?

Answer 15

Cabin altitude

Question 16

What is the inner scale on the cabin altitude for?

Answer 16

Differential pressure

Question 17

Where is the dump valve located?

Answer 17

Left side of the forward pressure bulkhead

Question 18

How is the dump valve opened?

Answer 18

Vacuum

Question 19

How is the dump valve closed?

Answer 19

Spring pressure

Question 20

If the outflow valve fails closed, the dump valve will open at what PSI?

Answer 20

7.3 +/- 0.1 psi

Question 21

Upon landing what does the squat switch do to the dump valve?

Answer 21

Open it.

Question 22

How else can the dump valve be opened?

Answer 22

Electrically with the CABIN PRESS switch

Question 23

What is the CABIN PRESS switch that electrically opens the dump valve powered by?

Answer 23

Left essential bus transferable to the right

Question 24

What does the DUMP switch do?

Answer 24

Bypasses the squat switch and applies vacuum to the dump valve, fully opening it.

Question 25

When would the CABIN ALTITUDE annunciator illuminate?

Answer 25

When cabin altitude exceeds 10,000’

Question 26

What does the emergency release handle located under the FO’s seat do when rotated 90 degrees CCW?

Answer 26

Releases the up-lock on the gear and allows pressure holding gear up to be released.

Question 27

What squat switch controls the pressurization dump valve?

Answer 27

Right landing gear squat switch (page 12-5 PTM, figure 12-5)

Question 28

What differential pressure will the outflow valve open at according to the PTM?

Answer 28

7.15 psi (PTM 12-6)