Pneumatics

Question 1

When can ECS high flow be selected?

Answer 1

Only during ground ops with APU as bleed air source.

Question 2

The APU can be used for engine start up to what altitude?

Answer 2

15,000 ft

Question 3

The APU can be used for AC and pressurization up to what altitude?

Answer 3

20,000 ft

Question 4

What are the sources of bleed air?

Answer 4

Ground air, Engine bleed, APU bleed.

Question 5

In flight with both engines and APU running, if APU bleed has been selected on what would you expect to see happen?

Answer 5

The isolation valve will open, engine bleeds will remain on, and you will get an amber CAS message.

Question 6

During a bleeds off takeoff, at what altitude will the engine bleed automatically come on if selected? What CAS message will this cause?

Answer 6

1500ft bleeds come on.

If APU is not deselected before 1500 ft the open isolation valve will cause BLEED CONFIG message.

Question 7

When may the WAI be operated in AUTO?

Answer 7

Never. WAI in auto is prohibited?

Question 8

What is the function of the Manifold Pressure Regulator Shutoff Valves? (MPRSOV)

Answer 8

They maintain the desired pressure in the main manifold and also shutoff bleed air extraction from the engine.

Question 9

How are the MPRSOV controlled?

Answer 9

Overhead panel the L-R bleed off will command the MPRSOV open or closed. The logic for how much the valve opens is a function of the AMSC (air management system controller).