Cabin Atmosphere Control Systems

Question 1

How does a continuous flow oxygen system operate ?

Answer 1

Oxygen flows from a charged cylinder through a high pressure line to a reducing valve, then to mask outlets

Question 2

How does basic pressure demand oxygen system operate ?

Answer 2

Oxygen flows from a charged cylinder to a pressure demand regulator, on demand from each crew member

Question 3

What type of oxygen must be used in aircraft ?

Answer 3

Aviators Breathing Oxygen

Question 4

What must be accomplished if an oxygen system had been open to atmosphere for 2 hours or more ?

Answer 4

It must be purged to remove moisture

Question 5

What is used to purge oxygen lines or moisture ?

Answer 5

Dry air, Dry nitrogen, or Oxygen

Question 6

What safety precaution should be observed when servicing oxygen system ?

Answer 6

Clean, grease free tools, clothing, hands, no smoking or open flames within 50 feet, do not use adhesive tape of any kind

Question 7

What are the two groups of independent cabin compressors ?

Answer 7

Positive displacement and Centrifugal

Question 8

What is a Roots blower ?

Answer 8

An engine driven compressor, used on old reciprocating engines for cabin pressurization

Question 9

What method is used by some turbine powered aircraft for pressurization ?

Answer 9

Engine bleed air

Question 10

What pressurization control unit will regulate the position of an outflow valve ?

Answer 10

The cabin pressure controller

Question 11

What is the principal control of a pressurization system ?

Answer 11

An outflow valve

Question 12

What components are used in an air cycle cooling system ?

Answer 12

Expansion turbine, heat exchanger, various valves

Question 13

Describe the basic operating principles that allow an air cycle system to produce cool air ?

Answer 13

1 Engine bleed air is cooled primary heat exchanger
2 Compressed air cooled again secondary heat exchanger
3 Air goes to expansion turbine that extracts the energy and pressure of the air dropping the temperature

Question 14

What causes a temperature drop in an Air cycle cooling system ?

Answer 14

The compressed air turns a turbine, then it undergoes a pressure and temperature drop

Question 15

How does a water separator remove moisture from the air ?

Answer 15

The moist air passes through vanes that swirls the air water droplets which are collected and drained

Question 16

What is a vapor cycle cooling ?

Answer 16

A closed system in which freon is circulated through tubing and various components to remove heat from the aircraft

Question 17

In what significant way is a vapor cycle cooling system different from an air cycle cooling system ?

Answer 17

Vapor cycle uses freon

Question 18

What components are in a vapor cycle cooling ?

Answer 18

Receiver dryer, Evaporator, Compressor, Condenser, Expansion Valve

Question 19

Why is oil added to a vapor cycle freon system ?

Answer 19

To seal and lubricate the compressor

Question 20

What is the function of ventilating air in a combustion heater ?

Answer 20

It transports heat from the heater into the cabin and prevents combustion gases from entering the cabin if the combustion chamber develops a crack

Question 21

Name several methods used on reciprocating engine aircraft for providing heated cabin air ?

Answer 21

Exhaust shroud heat exchangers, combustion heaters and electric heaters

Question 22

What are sources of ventilating air in a combustion heater ?

Answer 22

A blower / fan, ram air or possilby a compressor if the airplane is pressuirzed