Pneumatics

Question 1

Where does the bleed air for anti ice cone from?

Answer 1

A tapping pre the HSV from the 14th stage of the HP compressor.

Question 2

Where is the HSV? What does it do?

Answer 2

On 14th stage of the compressor. Automatically opens during xbleed start and low thrust settings to supply pneumatic power.

Question 3

What does the EBV (engine bleed valve) do?

Answer 3

Automatically closes pack 1 below 24,600ft when icing is encountered.

Question 4

Which systems supply the horizontal stabilizer and LE ice protection?

Answer 4

Left pneumatic for T tail. Relevant side for wing LE

Question 5

How many air cycle machines and ecu’s,

Answer 5

2 and 2

Question 6

Under what conditions does FADEC deactivate the ECS?

Answer 6

AEI - up to 1700ft if temp >19°

OEI - up to 9700 if temp >19°

Question 7

To what temperature does the pre cooler limit the bleed air?

Answer 7

299°

Question 8

What side of the system does the APU bleed air go to?

Answer 8

Left

Question 9

When will the APU bleed valve open?

Answer 9

​ APU Bleed Button is pressed to open the valve;​− ​ Essential DC Bus 1 is energized;​− ​ Engine 1 bleed valve is closed (no pressure from the left side);​− ​ Engine 2 bleed valve or cross-bleed valve is closed (no pressure​from the right side);​− ​ APU rpm above 95% after 7 seconds; and​− ​ There is no massive leakage on the APU line.

Question 10

When does cross bleed valve CBV open?

Answer 10

​ Essential DC Bus 2 is energized;​− ​ There is no massive bleed leakage downstream of the pre-cooler or​in the Rear Electronic Compartment; and​− ​ Cross Bleed Knob is set to OPEN; or​− ​ Cross Bleed Knob is set to AUTO and one of the following​conditions occurs:​− ​ Engine 2 is starting; or​− ​ Engine 1 is starting assisted by engine 2 or external pneumatic​source (with APU Bleed Valve manually commanded to the​close position); or​− ​ The Horizontal Stabilizer Anti-Icing System is operating​(airplanes Pre-Mod. SB 145-36-0028).

Question 11

What happens when the ECUs are shut off in flight?

Answer 11

Emergency RAM air is supplied to the cabin

Question 12

Where will you find bleed temp indications? What are the green amber and red temp ranges?

Answer 12

MFD
Amber pointer below ​ 260C .​
Green ​ from ​ 260 ​ to ​ 305C
Red ​ above ​ 305C ​ (581F) ​ to ​ indicate ​ an ​ overtemperature​ ​condition. ​​ ​
In ​ case ​ of ​ an ​ outlet ​ temperature ​ sensor ​ failure, ​ the ​respective ​ pointer ​ is ​ removed