Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

M11 R > M11.4 > Flashcards

M11.4 Flashcards

1
Q

What type of gas is used in pneumatics?

A

Air

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

Other than the engines what also supplies pneumatic systems?

A

The APU

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

What are the two types of pressure that have been bled from the compressor?

A

Intermediate pressure and high pressure

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

What is used to regulate bleed air temperature from the engine?

A

A built in pre-cooler

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

How does the engine pre-cooler lower the bleed air temperature?

A

By using fan air

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

How is the amount of pressurisation calculated?

A

By using pressure differential

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

What is meant by pressure differential?

A

The difference in pressure between the aircraft air pressure and ambient air pressure

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

What is classified as high pressure differential?

A

8-10psi

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

What is classified as low differential pressure?

A

3.5-5 psi

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

What fuselage areas are not pressurised?

A
  • radome
  • landing gear bays
  • tail cone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the acceptable amount of fresh air that needs to be supplied to the cabin?

A

0.283 cubic metres per minute per person

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

What temperature range do aircraft need to be able to supply?

A

18-30 Celsius

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

What is pressurisation a compromise between?

A

Passenger comfort and structural design

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The regulations state that what is a reasonable cabin altitude?

A

8,000 feet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the hot air from upstream of the packs know as?

A

Trim air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Where are the conditioning packs, valves, mixing unit located?

A

Centre wing box area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the three types of cooling devices on an aircraft?

A
  • heat exchanger
  • vapour-cycle machine
  • air-cycle machine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How does a heat exchanger work?

A

It allows one substance to flow through a pipe which is surrounded by another substance so they exchange heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

When are vapour cycle machines used?

A

When engine bleed is not available

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How does a vapour cycle machine work?

A

It uses a cold liquid to cool something but whilst it gets hot it evaporates but then gets collected and cooled again by ambient air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How does an air cycle machine work?

A

It takes warm bleed air and puts it into a compressor where temperature and pressure increase. Then passes through ambient air which cools but pressure remains then it enters a turbine where pressure lowers along with temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What catalyst is used inside an ozone converter?

A

Palladium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the job of a pack valve?

A

It determines the amount of air going to the cabin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How do you find volumetric flow?

A

By dividing mass flow by density

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What does the air conditioning airflow depend on?
The amount of passengers onboard
26
What turns everything in the air cycle machine?
The expanded air in the turbine?
27
If the air cycle machine has air available what s it said to be?
Self sustaining
28
What is the air cycle machine also known as?
Boot-strap air cycle machine
29
What are the two heat exchangers called?
- primary heat exchange (before compressor) | - secondary / main heat exchanger (before turbine)
30
Why is a bypass valve install in the air conditioning system?
To allow hot air to meet the new cold air at the end
31
What happens to the turbine after using the bypass valve?
It slows down due to loss of pressure
32
When would the bypass valve open and close?
It would open when the temperature is too low and close when its too high
33
What does changing the amount of ram air flow do to the air conditioning system?
It alters it’s efficiency
34
What is the ram air outlet called?
Ram air exit R.A.E
35
What does the pack outlet temperature depend on?
Ram inlet, ram outlet and bypass valve
36
What type of duct is the ram air inlet?
NACA
37
What type of door is the ram air outlet?
Flap or Louvre
38
Why is a fan located in the ram air duct?
Because there is no ram air whilst on the ground
39
Why is water removed from the air conditioning system?
Because temperature can reach -50 Celsius
40
What can carry more water, hot or cold air?
Hot air
41
What are the two places water can be separated in the cooling pack?
The high or low pressure loop
42
Where is separated water sent in the air conditions system?
To the ram air to increase cooling efficiency
43
How does a water separator work?
It spins the air to for the water o the sides
44
Why is a coalescer used in the water separator?
To increase water droplet size
45
What are used in the water extractor to spin the air and water?
Swirl vanes
46
What is meant by dew point?
The point at which the dry conditioned air mixes with the warm unconditioned bypass air
47
What is the average temperature of the dew point?
10 Celsius
48
What does the pack controller assume when there is a pressure increase?
There is ice
49
What does each air conditioning pack have?
It’s own pack controller and a back up controller
50
In flight what must happen for maximum cooling from the air conditioning system?
Ram air doors open and bypass valve closed
51
In flight what must happen for maximum heating from the air conditioning system?
Ram air doors nearly closed and bypass valve open
52
During take off and landing what position is the ram air inlet?
Fully closed to prevent FOD
53
What would happen if the air conditioning by-pass valve failed open?
It will start to overheat
54
What will happen if the air conditioning by-pass valve fails in the closed position?
It will start to freeze
55
After the the packs have made cold air where does it go?
Into mixing chamber then into the cabin
56
What does the cabin mixing unit mix together?
New pack air and old cabin air
57
What is meant by gasper system?
It’s when the passengers get there own air supply from the hat racks
58
What is it called when the mixing unit re-uses old cabin air?
Recirculating system
59
What is the trim air system?
It is a set of valves that help control individual cabin zone temperatures
60
What is the computer called that controls the cabin zonal temperature?
Zone controller
61
Why must the air going to the mixing unit be colder than the set temperature?
Because it will be mixed with recirculated warm air
62
What do protection circuits do?
Prevent the system from duct overheat in the event of a component failure
63
Why must there be a window or door open when starting you air conditioning system?
To prevent pressure build up
64
What temperature does the cargo heating automatically come on at?
7 Celsius
65
What are the two ways the cargo bays are heated?
Hot bleed air or electrical heaters
66
What is the name of the computer that controlled the cargo temperature?
Zone temperature controller
67
What happens if the whole cargo ventilation system fails?
Two blowers kick in and use cabin air
68
What is the equipment cooling system separate to?
Air conditioning system
69
What is a skin heat exchanger?
Warm air flows through a duct onto the cold aircraft skin to exchange temperature
70
What are the two modes the equipment cooling system can be in?
Inboard (exhaust air stays in) or outboard (exhaust air goes out)
71
What is used if the ambient air is too cold for cooling?
Cabin air
72
Atmospheric pressure decrease with?
An increase in altitude
73
What is atmospheric pressure measured in?
Hectopascals
74
What is the abbreviation of differential pressure?
Delta p
75
What is differential pressure measured in?
Psi
76
What is 14.5 psi equal to in newtons?
10 newtons per cm2
77
What is meant by positive rate of climb/ vertical speed?
The altitude climbed in the time it took
78
What happens to cabin pressure during decent?
The pressure increases
79
What is the maximum positive cabin rate?
500ft/min
80
What is the maximum negative cabin rate?
300ft/min
81
What must you do if cabin altitude starts to increase?
Reduce the amount of air that leaves the cabin
82
What happens when cabin altitude increases above normal values at 10,000ft?
Flight crew get a warning
83
What happens when cabin altitude increases above normal values at 14,000ft?
Oxygen masks deploy
84
What happens when cabin altitude increases above normal values at 15,000ft?
Outflow valves close automatically
85
What increase when differential pressure increases?
Aircraft structure stress
86
What is in place to reduce the risk of structural damage due to pressure?
Positive pressure relief valves
87
What psi do the positive pressure relief valves open?
8.5 psi
88
Why is having a negative differential pressure bad?
Because the pressure inside is larger than outside
89
What is in place to prevent negative differential pressure?
Negative pressure relief valves
90
What is the ditching mode used for?
To isolate the cabin from water entering
91
What happens in the pre-pressurisation mode?
The aircraft sets the cabin pressure higher than the ambient pressure to check for leaks
92
What is the difference between internal and external climb/descent modes?
- internal changes cabin altitude in proportion to ambient altitude - external is a preset that increases/decreases over time not altitude
93
When would the external climb mode stop?
When the aircraft starts to make an unplanned descent
94
When the external climb mode is interrupted, what is the cabin altitude set to?
The altitude of the take off airport
95
What follows the climb phase?
The cruise phase
96
When does the controller start the descent mode?
When the aircraft starts to descend
97
When does the controller switch to ground mode?
When the air ground logic senses weight on wheels
98
What happens to the controllers if the aircraft has two of them?
They switch after every flight
99
How much difference in psi is there for a cabin pressure leakage test?
4psi

M11 R (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions