Pneumatics

Question 1

Overview 1

Answer 1

The Soverign aircraft has a pneumatic control system to regulate the pressure of engine bleed air.
All pneumatic systems except engine inlet and stator vane anti-ice use this controlled bleed air.
As air passes through the engine pylon, a precooler reduces the temperature before entering the fuselage.

Question 2

Three onboard bleed-air sources are used on the ground or in flight, what are they?

Answer 2

Three onboard bleed-air sources are used on the ground or in flight:

1. Low pressure engine compressor air.
2. High pressure engine compressor air.
3. APU air.

Question 3

Can the high pressure and low pressure air be used simultaneously?

Answer 3

High pressure and low pressure air cannot be used simultaneously.

Question 4

Where does the Service Air System get its air from?

Answer 4

From either operating engine and or the APU when it’s operating.

Question 5

What does the bleed air travel through?

Answer 5

The bleed air travel through pressure regulators that control downstream pressure.

Question 6

What is service bleed air used for? (4)

Answer 6

1. Rudder bias actuator hear.
2. Air-cycle machine (ACM) water separator aspiration.
3. Outflow valve vacuum ejector.
4. Acoustic door seal.

Question 7

What does the Bleed Air Leak Detection System do?

Answer 7

The bleed air leak detection systems monitor over temperature conditions in ACM areas, wing area, stabilizer, and engine pylons.

Question 8

If an over temperature condition due to bleed air leak exists, how is the crew alerted?

Answer 8

By a CAS message.

Question 9

How many zones does the CAS monitor?

Answer 9

Six.

1. Left and right wing anti-ice zones.
2. Left and right supply bleed leak zones.
3. Stabilizer anti-ice bleed leak zone.
4. ACM bleed leak zone.

Question 10

Where is the engine bleed air cooled?

Answer 10

In the heat exchanger with N1 bypass air.

Question 11

How is the bleed air temperature regulated, prior to entering the fuselage?

Answer 11

An electrically controlled actuator controls the amount of bypass air to regulate the bleed air temperature prior to entering the fuselage.

Question 12

What is the function of mass flow valves?

Answer 12

Mass flow valves control bleed air flow from each engine to the ACM supply duct.

Question 13

How are the mass flow valves controlled?

Answer 13

By the PRESS SOURCE selector.

Question 14

What does the ACM do?

Answer 14

The ACM conditions the bleed air for environmental temperature control In the cockpit and cabin.

Question 15

What does the ACM water separator aspirator do?

Answer 15

The ACM water separator aspirator removes and disposes of water collected by the water separator.

Question 16

How does the ACM water separator aspirator remove water?

Answer 16

Service air passes through an ejector, creating a vacuum to remove water from the water separator and sprays it into the ram air upstream of the ACM heat exchangers.

Question 17

Where is the baggage heat shutoff valve located?

Answer 17

The baggage heat shutoff valve is downstream of the left mass flow valve and is controlled by the baggage heat button in the cockpit.
The valve is energized open in flight with main DC electrical power and when the minimum temperature value is reached.

Question 18

What parameters are used to decide whether HP or LP is used?

Answer 18

High pressure bleed air logic automatically selects the type of air used based on the following inputs:

1. Weight on wheels.
2. Throttle lever angle (TLA).
3. Aircraft altitude.
4. Anti ice systems on or off.