Enviromentals Misc > Enviromentals Handout > Flashcards

Enviromentals Handout Flashcards

(47 cards)

Study These Flashcards
1
Q

What is air density

A

The amount of molecules squeezed into one space

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

As altitude increase, air density…

A

Decreases

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

What’s is the pressure of earth atmosphere at sea level

A

14.7 psi

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

What is hypoxia

A

Impairment due to lack of oxygen

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

What is air made up of

A

Nitrogen
Oxygen
Carbon dioxide

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

What is the purpose of air conditioning

A

Provide comfortable cabin pressures regardless of outside temperatures

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

What is a shut off valve in a aircon system

A

A simple butterfly operated valve

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

The shut off bleed air (butterfly valve) is then fed into…

A

A primary heat exchanger

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

What is a primary head exchanger

A

A radiator which cold air passes through. It is used to cool hot bleed air from the engine

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

What is a compressor do in a aircyle machine (turbo looking thing)

A

Raises both the pressure and temperature

Warm air is directed through a second heat exchanger to cool it before it enters the turbine section of the air cycle machine

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

What does the turbine do in the air cycle machine

A

The turbine is connected to the compressor via a single shaft.

As air passes over the turbine heat is further extracted cooling it close to the freezing point

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

What are the two purposes of a temperature control valve

A

Control the amount of by passed air depending on what temperature the crew have selected

Direct warm air to the water separator to prevent the freezing of water droplets

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

What is air cycle machine by pass used for

A

When cooling requirements are low hot bleed air is directed into the cabin for air conditioning by by passing the air cycle machine

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

What is a water separator

A

Controls the humidity of the conditioned air by imparting a swirling motion on the air. Water droplets in the air are centrifugally slung out to the sides of the container where they collect and then are dispersed via a drain valve

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

What is ducting

A

Stainless steel pipes that carry bleed air to the various systems

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

What are the types of ducting insulation

A

Fibreglass stainless steel blankets

Integral wrappings consisting of white fibreglass microfibres covered in two layers of black fibreglass tape

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

what is ducting made of

A

stainless steel and ancones materials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how is ducting connected

A

V bands

Ring and coupling

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

How is air-conditioning distributed

Study These Flashcards
A

Managed by a system of ducts and components throughout the cabin.

Air is released via punkah louvres distribution nozzles and ceiling vents

20
Q

What is cabin altitude

Study These Flashcards
A

The maintained pressure held within the cabin

21
Q

What is cabin differential pressure

Study These Flashcards
A

The difference between the air pressure inside the cabin and the air pressure outside the cabin

22
Q

What is cabin rate of climb

Study These Flashcards
A

The rate of change of air pressure inside the cabin, expressed in feet per minute of cabin altitude change

23
Q

What are the two modes of pressurisation operation

Study These Flashcards
A

Isobaric (constant pressure despite changing altitude)

Constant differential (The pressure controller maintains a a set differential between the inside and outside pressure. This mode protects the airframe from structural damage)

24
Q

cabin pressurisation is accomplished by regulating the amount of air that flows out of the cabin, how is this achieved

Study These Flashcards
A

outflow valve

25
How is the outflow valve controlled
Opens and closed electronically or pneumatically by the pressure regulator which is situated on the flight deck
26
What is the Aux vent valve
Opens the aircraft to atmosphere once the aircraft has landed (weight on wheels)
27
Describe operation of safety valve and negative relief valve
A safety valve is a failsafe to prevent catastrophic failure of the aircraft structure due to the outside air pressure being higher than the internal air pressure When this happens the Negative Relief Valve operates opening up to allow internal / external pressures to stabilise.
28
Name three cabin pressurisation indicators
Cabin Altimeter Cabin Rate of climb Cabin differential indicators
29
Why is overheating a concern in regards to pressurisation
Overheating could lead to a fire hazard Fire loop detection systems are run alongside bleed air ducting
30
What are some safety and warning devices
Fire detection system with run alongside the bleed air ducting. Smoke detection Audible warnings Thermal cut off switches Cabin altitude must be maintained within the range of human survival Oxygen masks
31
What is the point of sealing aircraft
To ensure that the integrity of the aircraft is maintained. structural areas such as doors, windows, loading ramps, undercarriage bays and cable runs and control tubes need to be sealed.
32
What is AC ground pressure testing
A maintenance task performed on pressurised aircraft. The aircrafts engines or a ground test rig provide the means for pressurisation
33
When is pressure testing required
Required when any component that affects the sealing characteristics of the aircraft is replaced (including doors. windows and transparencies) When functional checks are required to fault find aircraft air conditioning and pressurisation defects.
34
What are the mandatory 6 RNZAF safety precautions
Post a safety man outside the aircraft. There must be audio/visual contact between the cabin crew and the external safety man. The aircraft is to be fully depressurised before personnel attempt open doors, windows, hatches etc. Personnel carrying out external leak checks are to exercise great care around windows, doors, hatches and transparencies, due to the high risk of explosive rupture Personnel suffering from cold or sinus symptoms are not to be within a pressurised cabin. Due to decompression sickness personnel are to wait 12 hrs between the completion of a pressure test and flying / diving.
35
How does ice formation affect the aircraft
Ice increases weight Increases drag Affects shape of wing and boundary layer Decreases lift Can brake off and damage lift devices and engine components.
36
Where are areas that we need to protect from ice
``` Wing leading edges Horizontal and vertical stabilizer leading edges Engine cowl leading edges Propellers Propeller spinner Air data probes Flight deck windows Water and waste system drain lines Antenna ```
37
How is ice detected
Visually Ice detection sensors Optical ice detectors An unnunciator light comes on to alert the flight crew when ice is detected.
38
How do ice detectors work
resonates at a set frequency, Ice changes the frequency a slight lowering of the frequency causes an integral electric probe heater to come ON and sends a message to the flight deck. The heater quickly melts the ice in 5-7 seconds and shuts OFF
39
What is anti ice vs de ice
Anti ice prevent the formation of ice De ice removes ice that has already formed
40
Name 4 methods of preventing/removing ice
Electrical Chemical Hot air rubber boots Heating the surface with hot air Heating via electrical elements Breaking ice with inflatable boots Application of chemicals to prevent the adhesion of ice
41
Describe thermal anti ice system
Heated air directed along heater ducts along the leading edge of wings to prevent ice formation Engine compressor bleed air used
42
Describe electrical anti ice
Windows, pitot tubes and other elements are electrically heated Can only be operated in flight with cold air passing over them
43
Describe chemical anti ice
Aircraft surface coated in isopropyl alcohol or equivalent product. The chemicals lower the freezing point of water
44
Describe thermal de ice boots
Inflatable leading edges used to break ice
45
Describe thermal de icing
Used in propellers for prop aircraft. Rubber boots with heater wires are bonded to the leading edges of propeller blades. An electrical current is passed through the wires to heat the rubber and melt away ice
46
How does rain affect the aircraft
Obscures visibility
47
How is rain repelled
Chemical rain repellent to prevent water from touching the glass screen Pneumatic rain removal via high pressure compressed air ducted from the engine. The blasted air prevent rain from rebadging the windscreen Windscreen wipers
Enviromentals Misc
flashcards
Decks in class (2)
# Cards
Brainscape helps you reach your goals faster, through stronger study habits.
© 2026 Bold Learning Solutions. Terms and Conditions