Pressurisation

Question 1

Max pressure differential for a jet transport

Answer 1

9 psi

Question 2

Max cabin alt (normal)

Answer 2

8,000ft

Question 3

At what height does the cabin alt warning system activate

Answer 3

10,000ft

Question 4

Cabin o2 automatically drops at

Answer 4

14,000ft

Question 5

Max cabin alt in an emerg

Answer 5

15,000ft

Question 6

Pax comfort roc and rod of the cabin

Answer 6

Roc = 500fpm

Rod = 300fpm

Question 7

Max roc and rod for the cabin

Answer 7

1800fpm

Question 8

Max negative differential pressure

Answer 8

1/2 psi

Question 9

Pressurised areas of the a/c

Answer 9

F/d
Fwd and aft cabins
Fwd and aft cargo holds

Question 10

Unpressurised areas of the a/c

Answer 10

Radome 
Nose u/c bay
Centre section torque box 
Main u/c bay
Tail cone

Question 11

Discharge/ outflow valves purpose and are controlled by - pressurisation

Answer 11

Controls pressurisation to allow for a varying rate of air being discharged to the atmosphere

Controlled by the pressure controller when in automatic or manual by the flight crew

Question 12

Safety valve - pressurisation

Answer 12

Outwards pressure relief valve for when the max diff has been exceeded

Valve will open at 0.25 psi above the max diff

Normally occurs when the pressure controller is unserviceable

Question 13

Inwards relief valve

Answer 13

Fitted to prevent excessive negative differential pressure - open if the pressure outside the a/c exceeds that of inside by 0.5

Question 14

Dump valve

Answer 14

Allows the crew to dump all cabin pressure - operated manually

Question 15

Pressure controller

Answer 15

As the cabin altitude changes, the controller automatically sends a signal to the outflow valves - regulate the release of air - maintain the a/c at the preselected levels

Question 16

What happens when ditching - pressurisation

Answer 16

Slated ditching control will close the outflow valves in the event of l/d on water

Question 17

Min system instrumentation for pressurisation

Answer 17

Cabin altimeter - reads cabin pressure

Cabin VSI

Cabin diff pressure - diff between the cabin and atmospheric pressure

Question 18

What are the aural/visual warnings when the cabin alt exceeds 10,000

Answer 18

Horn and a red light on the centralised panel - visual and aural CABIN ALT warning
Or
Warning caption on the EICAS or ECAM

Question 19

At what height does the AUTO FAIL light on the pressure controller panel illuminate

Answer 19

13,850ft

Question 20

When is the pressurisation system ground tested and checked

Answer 20

Initial proof testing
When specified in the manual
After actual or suspected malfunction
After repairs and modifications to the hull

Question 21

Ground testing and system checking of the pressurisation system include testing

Answer 21

Pressure controllers and temp control 
Max diff control 
Safety valve check 
Leak rate check 
General functioning

Question 22

Rate/proportional control is maintained during (pressurisation)

Answer 22

Climb and descent

Cabin climbs and descends proportionally

Question 23

Why do we put a bit of pressure in while taxing

Answer 23

Makes for a smooth transition and stops crap getting in

Set to about 0.1psi - doors can’t open until this has been dumped