Pnumatics

Question 1

Where do you find pressure reg valve

Answer 1

(Engine bleed valve) upstream of pre cooler

Question 2

Where does bleed air come from

Answer 2

Engine compressor

Question 3

What is the pneumatic bleed air used for

Answer 3

Air con , engine start , and resivouirs

Question 4

Purpose of pneumatic controllers

Answer 4

Monitor pressure temp , register leaks , monitor operation of pneumatic controllers

Question 5

How many pneumatic controllers for each engine bleed system

Answer 5

1 per engine

Question 6

How is pnuematic vaccine pressured on ground

Answer 6

Via high pressure ground connectors

Question 7

What’s the pressure in most systems

Answer 7

45psi

Question 8

What type of valve is the bleed

Answer 8

Butterfly type valve , spring loaded

Question 9

What does check valve do

Answer 9

Prevent back flow

Question 10

What the purpose of pre cooler

Answer 10

Cool engine bleed air temperature

Question 11

What does the fan air valve do

Answer 11

Allow more or less fan air to pass through pre cooler

Question 12

If the mass of air is constant what effect does it have on cooling effect

Answer 12

It is constant as well

Question 13

What does the pre cooler cooling effect depend on

Answer 13

Mass and temp

Question 14

How are pneumatic ducts monitored

Answer 14

Leak detection system

Question 15

How is control of pnuemanic system achieved manually

Answer 15

Control panel in cockpit

Question 16

How is control of pnuematic system achieved automatically

Answer 16

Pnuematic controller

Question 17

Where is bleed valve operated manually

Answer 17

Switch in cockpit

Question 18

What measures temp in bleed valve

Answer 18

Thermostat

Question 19

Where is thermostat located

Answer 19

Downstream of pre cooler

Question 20

What does bleed valve do

Answer 20

Main part which regulates bleed air from engine

Question 21

When is reverse flow through bleed valve allowed

Answer 21

Only during engine start

Question 22

When is over pressure valve closed

Answer 22

85psi

Question 23

What monitors temp reg pre cooler

Answer 23

Temperature sensor

Question 24

What happens when there’s a malfunction on the temperature regulator pre cooler

Answer 24

System fault which is illuminated on bleed panel in cockpit

Question 25

Where is air taken while operating at low speed

Answer 25

High stage of engine compressor

Question 26

When does the hp valve open

Answer 26

When pressure from ip stage not sufficient to meet requirements of pneumatic system

Question 27

When does hp valve close

Answer 27

Pressure of hp reaches pre determined value

Question 28

What are the alternate air sources

Answer 28

Apu air supply and hp ground supply

Question 29

How is ground supply connected

Answer 29

3 inch ground connectors

Question 30

What the purpose of cross bleed valve

Answer 30

Connect or isolate two parts of bleed air system

Question 31

How is cross bleed valve operated

Answer 31

Motor operated as it’s commanded to open and close

Question 32

Cross bleed valve position

Answer 32

Usually closed

Question 33

What’s the result of a leak in air duct

Answer 33

Overheat

Question 34

What happens after a leak in air duct is detected

Answer 34

Engine bleed air system is shut off automatically via pneumatic controller or manually