Chapter 11: Air System Flashcards

1
Q

functions of air system

A

1) internal engine & accessory unit cooling
2) bearing chamber sealing
3) control of bearing axial load
4) control turbine blade tip clearance
5) engine anti-icing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

function of INTERNAL air system

A

1) cooling of turbine blades/discs
2) cooling of NGV
3) cooling of combustor thru combustion liner
4) sealing of main bearing compartments in labryinth seal
5) thrust bearing load relief

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

function of EXTERNAL air system

A

1) customer bleed
2) nacelle ventilation
3) accessory cooling
4) TCC
5) engine anti-icing (using hot air)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is customer bleed?

A

pressurised air taken out for airframe usage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is bleed air used for?

A

aircon, pressurisation of aircraft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

why is nacelle ventilation needed?

A

avoid accumulation of fluid vapour which can self ignite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

which air is used for nacelle ventilation?

A

fan air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

accessories cooled by external air

A

1) IDG
2) EEC
3) igniter lead & box

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how many volts does the high tension lead / igniter lead carry?

A

22 kV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how is TCC controlled by?

A

EEC, which uses fuel pressure regulated by actuator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how does engine anti-icing system work?

A

hot air from compressor is delivered to IGV and inlet strut to prevent ice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how does variable guide vane changes its angle?

A

EEC signals to HMU > HMU provides fuel to linear variable differential transformer to adjust angle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

which portion of the engine is air being tapped to cool down the ingiter?

A

low pressure compressor stage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly