Brainscape's Knowledge GenomeTM

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


See full index

Ground School Systems 2 > PC-21 Environmental Control System (ECS) > Flashcards

PC-21 Environmental Control System (ECS) Flashcards

1
Q

What is the purpose of the ECS?

A

1) Cockpit air temp
2) Humidity
3) pressure
4) Provide conditioned are to the avionics bay
5) Provides bleed air to OBOGS
6) Bleed air to Anti-g system

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

What are the 7 subsystems of the ECS?

A

1) Engine bleed air distribution
2) Air Cycle System (ACS)
3) Vapor Cycle System (VCS)
4) Cockpit air distribution
5) Cabin Pressurization Control System (CPCS)
6) Ram air system

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

What is the purpose of the engine bleed air distribution?

A

Supplies hot compressed bleed air that is tapped off two high pressure or low pressure ports, depending on engine power setting.

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

What two distinct routes does engine bleed air supply take?

A

1) To the Air Cycle System (ACS) which supplies air for heating, cooling and pressurization
2) To the Oxygen and Anti-g systems

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

What is pressure for ACS decreased to? How is this controlled?

A
  • 20 +- 3 psi

- Controlled by overpressure and over-temperature switches

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

Which pressure bleed air line is the Oxygen and Anti-g supplied from?

A

High pressure section

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

What is the function of the ACS?

A

Control the temperature of the bleed air passing through it to a value determined by the IECS controller

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

How is airflow from ACS separated?

A
  • Part is cooled in the refrigeration pack

- Other part bypasses refrigeration pack and it mixed with the cooled air before entering water separator

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

How is air cooled in the refrigeration pack?

A
  • In a heat exchanger by flow of ram air

- By expansion by flowing through a turbine

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

What controls the mixture ratio of hot and cooled air?

A
  • IECS controller

- This is controlled by the temperature selector on the front cockpit ECS panel.

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

What occurs once hot and cooled air has been mixed?

A

Dried in the water separator and then enters the cockpit air distribution through the firewall shut off valve.

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

What does the VCS do?

A

Augments the ACS in hot weather conditions by passing cockpit air through an evaporator and heat exchanger that is cooled by refrigerant gas

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

What prevents ice formation on the cockpit and avionics bay evaporators?

A

Hot gas bypass valves

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

What is the function of the cockpit air distribution?

A

To allow the pilot to control the quantity and direction of conditioned air coming from the ACS and VCS.

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

What does the Y separator valve do? How is it controlled in the cockpit?

A
  • Directs flow to demisting transparencies
  • Pilots feet
  • Controlled by Y-separator valve by means of the AIR SUPPLY lever on the centre pedestal in each cockpit.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How can cooled air from the VCS be controlled?

A

By the air vents in the centre pedestal in each cockpit.

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

What must the pilot do for max defogging?

A

Close the air vents on the centre pedestal, so that the VCS evaporator fan can augment the ACS defog.

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

What is the function of the Cabin Pressure Control System (CPCS)?

A

Automatically control the pressure in the cockpit by adjusting the outflow of the air from the cabin through the cabin pressure control valve.
- Fully automatic

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

What does the cabin pressure control valve do?

A
  • Interfaces with the no.2 static pressure port and operates automatically to release conditioned air to the avionics bay at a rate that maintains cabin pressure at correct altitude.
20
Q

What is max pressure differential? What altitude is this achieved at? What cabin altitude does it give?

A
  • 3.76 psi
  • Achieved at 25,000 ft
  • Gives cabin altitude of 13,000 ft
21
Q

What is provided as a safety feature for cockpit pressurisation?

A

Safety inward relief valve

22
Q

What is the purpose of the ram air system?

A
  • Provides a means to equalize the cabin pressure with ambient pressure and to ventilate the cockpit with fresh air.
  • Normally held closed by the pressure of servo air drawn from ACS air supply.
23
Q

How can pilot control the RAM air system?

A

Using cabin pressure selector on the front cockpit ECS panel.

24
Q

What does the IECS do?

A

Automatically regulates the cockpit temperature by adjusting the delivery temperatures of the ACS and the VCS to maintain the temperature set by the temperature selector on the front cockpit ECS panel

25
Q

What components does the IECS receive input signals from?

A
  • Over pressure and over temp switches
  • Temperature sensors
  • Micro switches at the front AIR SUPPLU lever
26
Q

What does the IECS send output drive signals to?

A
  • High pressure shut-off valve (HPSOV)
  • Pressure Reducing Shut off Valve (PRSOV)
  • Temperature COntrol Valve (TCV)
  • Evaporator and condenser fans
  • Ram air inlet control valves
  • VCS compressor clutch
  • Engine power management unit for engine speed control when VCS compressor is engaged.
27
Q

What supplies electrical power for ECS?

A

GEN 2 through GEN 2 BUS

28
Q

What directly supplies VCS condenser fan?

A

Generator 2

29
Q

What MFD pages is ECS related info shown on?

A
  • MFD ECS

- MFD SYS

30
Q

What info does MFD ECS page show?

A
  • Bleed Air Flow lines to VCS, ACS and OXY
  • Avionics Bay Temperature
  • Cabin differential pressure
  • Cabin altitude
  • OAT temp
31
Q

What do the amber and red caution marks on cabin differential pressure scale show?

A
  • Amber = 3.9 psi

- Red = 4.5 psi

32
Q

What do the amber lines on cabin altitude scale show?

A

Acceptable limits for the cabin altitude relative to the current aircraft altitude.

33
Q

What are the amber cautions marks on the avionics bay temperature gauge?

A

-20 and 55 deg

34
Q

What does the FAN SPEED selector in either cockpit control? What controls the evaporator fan in the avionics bay?

A
  • Controls the speed of the respective cockpit evaporator fan.
  • Evaporator fan in avionics bay is controlled automatically by the IECS controller
35
Q

What does the CABIN PRESS selector control? What do the NORM, PRESS DUMP and RAM positions mean?

A
  • The ram air valves
  • NORM means it operates automatically
  • PRESS DUMP means pressure is equalized to ambient pressure, cockpit is still air conditioned.
  • RAM means pressure is equalized to ambient pressure and to ventilate the cockpit with RAM air, no airflow from engine to cockpit.
36
Q

What does the VCS pushbutton in the front cockpit do?

A
  • Turns it on and off

- Off by pushing it in

37
Q

What does the AIR SUPPLY lever on the pedestal do at the HEAT detent position?

A
  • Controls the air temperature at the foot well diffusers to 30 degrees above the cockpit temp.
  • Enables pilot to warm the feet but cool the body
38
Q

What does the AIR SUPPLY lever on the pedestal do at the DEFOG MAX position?

A

Temperature of the conditioned air at the defog diffusers is held at 75 C

39
Q

What does the ACS SHUT OFF valve do?

A
  • Controls the firewall shut off valve
  • When off, conditioned air doesn’t flow into cockpit
  • Oxygen System, anti-g system, cockpit pressurization, air conditioning through ACS are not available
  • Only cockpit cooling from VCS remains available.
40
Q

What does red CAB HI PRESS and red OVPR caption on DWP caption mean?

A
  • Cabin differential pressure > 4.5 psi

- Cabin absolute pressure exceeds 16 psi

41
Q

What does the amber CAB HI PRESS caution mean?

A
  • Cabin differential pressure is > 3.9 psi

- Cabin differential pressure on the ground > 0.5 psi for > 15 seconds

42
Q

What does a red CAB ALTITUDE on MFD mean?

A

Cabin altitude > 25,000 ft

43
Q

What does an amber CAB ALTITUDE mean?

A

Cabin altitude > 15,000 ft

44
Q

When is the amber ECS caution displayed?

A

If there is a malfunction in any of the following components:

1) Engine bleed air distribution
2) Air Cycle System
3) Cockpit air distribution
4) Vapor cycle system
5) IECS controller

45
Q

When does amber AVI HOT caution displayed on MFD?

A

Avionics bay temp > 55 C

46
Q

When is amber AFCT ALT caution displayed on MFD?

A

IF aircraft altitude > 26,000 ft

47
Q

What the the safety functions that the CPCS provides?

A
  • Equalizes the cabin pressure with ambient pressure, PRESS DUMP
  • Maintains cabin pressure and supplies cooled air to the avionics bay, NORM

Ground School Systems 2 (19 decks)

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