Pressurisation

Question 1

How many Automatic Cabin Pressure Controllers are there?

Answer 1

2

Question 2

How many motors can drive the Outflow Valve?

Answer 2

• 3 (2 auto AC, a manual DC)

- Slow on DC for manual to slow OFV.

Question 3

What causes a safety valve to operate?

Answer 3

> 8.6 PSI or < 1 PSI

Question 4

What is the OFV position with the AC on the ground?

Answer 4

Before takeoff and 55secs after landing, the outflow valve fully opens to ensure that there is no residual cabin pressure. At touch down, any remaining cabin pressure is released at a cabin v/s of 500’/min.

Question 5

During climb, cabin ROC is a function of what?

Answer 5

The cabin attitude varies according to a fixed pre-programmed law that takes into account the aircraft’s actual ROC.

Question 6

What is the (approx.) Max ROD of the cabin in AUTO?

Answer 6

750’/min

Question 7

What happens to the OFV after touchdown?

Answer 7

• At touch down, any remaining cabin pressure is released at a cabin v/s of 500’/min.
• 55sec after landing, valve fully opens.

Question 8

If the MAN V/S CTL is moved UP, what happens to the Press Diff, Cabin V/S, Cabin Alt, and OFV?

Answer 8

• Pressure Difference: decreases
• Cabin Vertical Speed: increases
• Cabin Altitude: increases
• OFV: selecting UP moves the valve towards the open position.

Question 9

What does the Ditching switch do?

Answer 9

Close the OFV (only if its in auto position, not in manual position), emergency ram air valve. Inlet, avionics ventilation inlet and extract valves, pack flow control valves.

Question 10

When is cabin v/s displayed on the doors SD?

Answer 10

Phase 5-7 (lift off til touchdown)