Ch. 14 Cabin Atmosphere Control Systems

Front 1

Is there any special requirement as to the type of oxygen used in an aircraft system, and if so, what is it?

Back 1

Only aviators breathing oxygen should be used

Front 2

Describe the operating principle of a continuous flow oxygen system

Back 2

high-pressure oxygen flows from the storage cylinder to a pressure regulator where it's pressure is reduced and then to the mask outlets whenever the system is turned on

Front 3

Describe the operating principle of a pressure demand oxygen system

Back 3

demand systems allow oxygen to flow from the cylinder to the regulator and then to the mask only when the user inhales. Pressure demand systems provide oxygen to the mask at higher than atmospheric pressure when used at extremely high altitudes, forcing oxygen into the users lungs

Front 4

What should be used to purge an oxygen system of moisture?

Back 4

Oxygen, dry air, or dry nitrogen

Front 5

What action must be taken when an oxygen system has been open to the atmosphere?

Back 5

The system must be purged of any moisture

Front 6

Describe the safety precautions that should be observed when servicing oxygen systems

Back 6

Avoid all contact with petroleum-based oil or grease, don't smoke, keep everything clean, service systems outdoors if at all possible, and keep the caps on the bottles to preserve the valves

Front 7

What is a Roots blower?

Back 7

A type of engine driven compressor

Front 8

Name two different types of independent cabin air compressors

Back 8

Positive displacement and centrifugal

Front 9

What is the source of pressurization air in most jet aircraft?

Back 9

Engine bleed air

Front 10

What device provides the principal means of controlling cabin pressure?

Back 10

The outflow valve

Front 11

What unit regulates the position of an outflow valve?

Back 11

The cabin pressure controller

Front 12

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

Back 12

Exhaust shroud heat exchangers, combustion heaters, and electric heaters

Front 13

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

Back 13

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

Front 14

What are the sources of ventilating air in a combustion heater?

Back 14

Ram Air in-flight, a blower on the ground, or possibly a compressor if the airplane is pressurized

Front 15

Name the basic components of an air cycle cooling system

Back 15

The compressor and expansion turbine, heat exchangers, and various valves

Front 16

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

Back 16

hot engine bleed air is cooled in the primary heat exchanger, compressed, then cooled again in the secondary heat exchanger. The air is expanded across the turbine where energy is extracted in the pressure is reduced. This produces a large temperature drop

Front 17

Describe the basic operating principles of a water separator

Back 17

Cool, moist air is world so that water droplets are separated by centrifugal force, captured by a sock, and drained

Front 18

Name of the principal components of a vapor cycle system

Back 18

A compressor, condenser, expansion valve, and an evaporator

Front 19

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

Back 19

Vapor cycle systems use a refrigerant liquid, usually freon

Front 20

Why is oil added to the refrigerant in a vapor cycle air conditioning system?

Back 20

To lubricate the compressor