Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ATR > Air Con & Pressurisation > Flashcards

Air Con & Pressurisation Flashcards

1
Q

Where are the air conditioning packs located?

A

In the main landing gear fairings

Work independently of each other

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

What pack supplies the flight deck/cabin?

A

Left pack - flight deck
Right pack - cabin

In the event of a failure one pack can supply both compartments

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

What is the Air Cycle Machine?

A

One on each side of the aircraft

Adjusts the air to the proper temperature for the cabin and flight deck

Air then flows to a mixing chamber located under the floor and is mixed with ambient cabin air

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

How is air distributed to the cabin?

A

From the mixing chamber through overhead ducts which route the air to eyeball vents

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

How is air evacuated from the cabin?

A

Through guides along the floor of the left cabin side

Part of the air is recirculated through the cabin via fans

The remainder is exhausted overboard through outflow valves located on underside of the fuselage

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

How is the loo ventilated?

A

Through a vent line

Airflow is generated by cabin differential pressure

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

How is cabin pressurisation maintained?

A

By constricting the amount of air that is exhausted overboard

Outflow valves are located on the bottom side of the aft fuselage

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

What is the normal flow mode?

A

Constant 22 psi of pressure delivered to the packs

When pb is pushed out

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

What is the high flow mode?

A

When pb is pushed in

Delivers 30 psi

HIGH caption illuminated in blue on the pb

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

What is the primary heat exchanger?

A

Located in a ram air duct in the landing gear fairing

Exhaust located on the bottom of the landing gear fairing, just forward of the landing gear

If there is insufficient airflow, a ground turbo fan will draw air from the ground inlet

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

When will the turbofan shut off valve automatically open?

A

when speed is less than or equal to 150 kt and landing gear extended or retracted for less than 10 minutes

Closed anytime the airspeed is greater than 150 kts as this produces sufficient airflow over heat exchanger

If an engine is experiencing low oil pressure, the turbo fan valve on the opposite side will automatically open

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

What does the compressor section do after the primary heat exchanger?

A

Increases the pressure and temperature of the partially cool bleed air

Then flows through a secondary heat exchanger for additional heat extraction

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

How is temperature control achieved?

A

Bleed air is mixed with the air produced by the expansion turbine

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

What does the temperature selector use to control the temperature when pb selected in?

A
  • the temp selected on the selector
  • the temp in the pack supply duct
  • the aircraft skin temp
  • associated compartment ambient temp
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the temperature limit in manual mode?

A

88 degrees

If this is reached or exceeded, a limiter will gradually close the temp control valve to allow more air into the duct

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

When will you get an OVHT warning?

A

When the duct temp exceeds 92 degrees

Single chime
Master caution
AIR on CAP

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

When will the pack valve automatically close?

A

If the temp exceeds 204 degrees

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

When will the pack valve automatically close?

A

If the temp exceeds 204 degrees

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

What happens in the mixing chamber?

A

Mixes the air produced by the air conditioning pack with air drawn from the cabin

One mixing chamber per pack

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

What do the recirculation fans do?

A

Located in the under floor area just ahead of the wheel wells

Draw air through the floor vents and circulate air through the cabin while keeping the floor temp comfortable

Powered by the DC utility bus

Fan rotation speed depends on position of associated temp control valve - varies between 1500 and 2200 RPM

Will automatically run at full speed if temp is less than 18 degrees

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

When will you get a recirculation fan FAULT?

A
  • fan speed less than 900 RPM
  • associated electrical motor overheats
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Where is ventilated using ambient air?

A
  • flight deck
  • forward cargo compartment
  • electric and electronic equipment racks

Direction of air is controlled by two valves - under floor valve and overboard valve

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

How are the flight instruments cooled?

A

Air is drawn forward through the flight deck into ducting by an extract fan

Used to cool flight instruments, floor mounted batteries and electronics racks

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

When will the ventilation extract fan operate at high/low speeds?

A

Low speed - if temp is below 20 degrees

Full speed - if temp is above 52 degrees

Fan speed will vary with temp if it is between these two values

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the purpose of the extract air flow lever?

A

Located on the right maintenance panel

Closes the extract air flow valve in order to stop air from flowing forward through the flight deck in case smoke is detected in the forward cargo compartment

26
Q

What happens to the extract fan during engine start?

A

Will stop for 120 seconds to avoid pressure shocks

FAULT light on exhaust mode pb will illuminate

27
Q

What does the overboard valve do?

A

Allows air to be discharged overboard

Controls the operation of the under floor valve

Overboard valve switch should be in the auto position to allow proper operation of the under floor valve

28
Q

What happens if the exhaust mode pb is pushed in

A

Aicraf on ground and engine 1 has low oil pressure or is not running - overboard valve will be fully open and under floor valve fully closed and extract fan will run continuously

29
Q

What happens if the aircraft is on the ground with number 1 engine running

A

Extract fan will run continuously, overboard valve fully closed and under floor valve fully open

30
Q

How is pressurisation achieved?

A
  • controlling the amount of air that is exhausted overboard
  • cabin and flight deck pressurised through both the left and right packs
31
Q

What are the outflow valves?

A
  • control cabin pressurisation and cabin rate of change
  • one electro-pneumatic valve and one pneumatic valve
  • bottom aft portion of fuselage just forward of the aft entry door
32
Q

What is the automatic mode?

A

The pneumatic valve slaved to the electro pneumatic valve by interconnected vacuum tube, which allows both valves to operate simultaneously

33
Q

What pressure will the outflow valve open?

A

If cabin pressure differential exceeds 6.35 psi

If differential pressure exceeds 0.5 psi, a non-return line will open the outflow valve to relieve the negative pressure differential

34
Q

What does the pressurisation controller use to calculate cabin elevation?

A
  • departure field elevation
  • destination field elevation
  • existing cabin altitude
  • aircraft flight altitude

Uses info from ADC 1 + captains altimeter

35
Q

What happens if ADC 1 fails?

A

Pressurisation controller will use ADC 2 and a baro setting of 29.92

Crew will need to input the landing airport pressure altitude into the landing elevation window of the controller

36
Q

What powers the electro-pneumatic valve?

A

Requires electrical power in order to operate

Loss of power or loss of signal from the pressurisation controller will cause the valve to close automatically

Powered by DC emer bus

37
Q

How can you place the system in automatic mode?

A

When the MODE SEL button on the CAB PRESS panel is pressed in

MAN RATE knob must be in the NORM position

38
Q

How is manual mode selected and indicated?

A

Releasing out the MODE pb

MAN caption illuminates in the pb

Digits in the landing elevation window will extinguish and the electro-pneumatic outflow valve close

39
Q

What is manual mode?

A

MAN RATE knob is used to directly control the pneumatic outflow valve

Can select a rate of change from -1500 to +2500 FPM

MAN RATE knob should be set to 9 to 10 position to avoid a pressure bump when transitioning from auto to manual

40
Q

What range of landing elevation can be set?

A

-1500 to +9900 feet in 100 foot increments

41
Q

What is the maximum cabin rate of climb?

A

550 feet per minute

42
Q

What is the maximum cabin differential pressure?

A

6 psi

43
Q

What will be the cabin altitude if the aircraft is at FL250?

A

6740 ft

44
Q

What is the max cabin rate of descent?

A

400 fpm

45
Q

What does the pressurisation controller target in a descent?

A

Landing field elevation that was set during the pre flight, minus 300 ft

46
Q

What is the max cabin rate of climb after touchdown?

A

550 fpm

47
Q

What is the automatic return feature?

A

If you need to return to the departure airport after take off, pressurisation controller will use the departure airfield elevation minus 300 ft as target altitude for landing

Available until the aircraft climbs 3500 ft above departure airfield elevation

48
Q

How can you change the maximum rate of descent?

A

By pressing the DESCENT RATE pb on the AUTO PRESS control panel

49
Q

What will happen to the right pack valve after the pb is pressed?

A

It will open after a 6 sec delay for passenger comfort

50
Q

When will the FAULT caption on the pack valve pb illuminate?

A
  • associated pack valve position disagrees with the commanded position
  • overheat downstream of the pack compressor (pack valve will be latched closed)
51
Q

When should you not open the overboard valve?

A

If the differential pressure exceeds 1 psi

Opening the valve in flight could result in a depressurisation of the cabin and a possible collapse of the overboard duct

52
Q

What is the position of the overboard/underfloor valves in flight?

A

Overboard valve will be partially open to allow differential pressure to provide necessary suction to provide cooling airflow in the compartments

Underfloor valve will be closed

Extract fan will be off

53
Q

When will the exhaust mode pb FAULT light illuminate

A
  • failure of extract fan
  • fan overheat (more than 90 degrees)
54
Q

When will the FAULT light illuminate on the avionics panel?

A

When the overboard valve is not in the commanded position

Will not illuminate if the overboard valve switch is in the FULL close position

  • in ground with low oil pressure on eng 1 - if not full open
  • on ground with eng 1 running/inflight - if the valve is fully open
55
Q

When will the MODE SEL FAULT light illuminate?

A

In the event of a failure of the digital pressurisation controller

56
Q

What does the DITCH position do?

A

Closes both outflow valves - two electric motors maintain them closed, powered by DC emer bus

Prevents water from entering the fuselage

57
Q

What is the guarded dump pb used for?

A

To dump cabin pressure

When pressed, the digital pressurisation controller is disabled and electrical signal will fully open the electro-pneumatic valve and in turn the pneumatic valve

Only available in automatic mode

58
Q

What is the indication of a successful test?

A
  • alternating 18800 and -8800 in the landing elevation window
  • FAULT on pressurisation mode pb
  • test function inhibited in flight
59
Q

What warning will you get if the cabin alt exceeds 10,000 ft?

A
  • master warning
  • CRC
  • EXCESS ALT on CAP
60
Q

What is the max differential pressure for landing?

A

0.35 psi

61
Q

What is the max operating altitude with one bleed system operative?

A

20,000 ft

ATR (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions