Pressurisation

Question 1

How can the outflow valve be controlled?

Answer 1

2 Normal AC AUTO controllers
1 Manual DC Manual controller

Question 2

What is our target cabin differential pressure?

Answer 2

8.6Psi

Question 3

What does a cabin pressurisation above 8.6psi indicate?

Answer 3

Non normal. Cabin failing to maintain optimum

Question 4

If the FO is managing the pressurisation controller, how would the system be configured?

Answer 4

AUTO 2

Question 5

In Auto what are the standard rates of climb and descent for the cabin?

Answer 5

500fpm climb
300fpm descent

Question 6

How does Boeing logic climb or descend the cabin?

Answer 6

Approximately relative to the rate of climb or descent of the cabin

Question 7

On take off, what is the max cabin differential pressure?

Answer 7

0.125psi (approx 200 feet)

Question 8

What happens to the outflow valve as the Thrust levers are advanced?

Answer 8

Starts to close, cabin begins descent to max of 0.125

Question 9

Where does the cabin start to maintain 8.6psi?

Answer 9

FL350

Question 10

At less than FL350 where would you expect to see the cabin PSI?

Answer 10

Less than 8.6

Question 11

Above FL350 what cabin altitude would you expect to see?

Answer 11

8.6psi maintained relative to the aircraft altitude

Question 12

Where does the pressurisation controller get inputs from?

Answer 12

Thrust levers
ADC
Landing Field Elevation
Captains Altimeter
Air/Ground Logic Main wheels

Question 13

For a flight originating from a high altitude airport (>approx 4000’) what altitude would you see for the cabin altitude?

Answer 13

Take off airport altitude?

Question 14

What are the 3 phases of flight that the cabin pressurisation recognises?

Answer 14

Climb
Cruise
Dsecent

Question 15

How does the cabin transition from climb to cruise phase?

Answer 15

Level off for more than 1 minute

Question 16

How does the cabin transition from cruise to climb?

Answer 16

Change of altitude >1000 feet

Question 17

What does the cabin pressurisation consider upon entering cruise?

Answer 17

Cabin altitude and final landing altitude comparison
Selects higher of the 2

Question 18

How does the cabin enter descent phase from cruise?

Answer 18

Descent of more than 1000 feet
Maintains 8.6 psi until FL350 then descends at Boeing logic

Question 19

With an RTO what happens to the outflow valve?

Answer 19

Automatically opens fully

Question 20

If the cabin reaches 11,000 feet what happens to the outflow valve?

Answer 20

Boeing logic uses the DC power to close the outflow valve
Uses different system to sense cabin altitude in this situation
Called Cabin Rate limiting

Question 21

What happens at 14,000 feet?

Answer 21

Deploys the oxygen masks automatically

Question 22

How long does the oxygen generation system last?

Answer 22

12 minutes

Question 23

When does the cabin altitude warning system message display on the EICAS?

Answer 23

10,000
‘Resets at 8,500

Question 24

On standby power, who controls the pressurisation?

Answer 24

Manual control

Question 25

When does the pressurisation auto INOP light come on?

Answer 25

AUTO 1 and 2 fail Select manual, in flight, with all systems powered

Question 26

With failure of AUTO 2 what happens with Boeing logic?

Answer 26

Automatically swaps between AUTO 2 and 1, but with no indication or light

Question 27

When both auto controllers fail, where does the outflow valve go?

Answer 27

Freezes in the the position it was in when the failure occurred. Stays in that position until manual control is established

Question 28

Placing the mode selector in Manual what happens?

Answer 28

Power removed from both AUTO controllers

Question 29

Where are the pressure relief valves located?

Answer 29

FWD of the left wing root, just above wing

Question 30

When do the Positive pressure relief valves open?

Answer 30

>9.1psi

Question 31

The positive pressure relief valve doors open in flight, what happens to the doors?

Answer 31

They remain open. Reset by maintenance

Question 32

When do the negative pressure relief doors open?

Answer 32

Px greater inside the aircraft than outside

Question 33

How many negative pressure relief doors do we have?

Answer 33

5 2 Rear cargo doors have 2 negative pressure relief doors

Question 34

Discreet cabin altitude light comes on when?

Answer 34

>10,000 cabin altitude Master Warning light and aural Extinguishes when cabin descends below 8500

Question 35

With a failure of AC power, what happens to the outflow valve?

Answer 35

Freezes in position until Manual power is established

Question 36

What has to happen for the AUTO INOP light to turn on inflight?

Answer 36

Manual Mode Select