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 and to mask outlets.

Question 2

How does a basic pressure-demand oxygen system operate?

Answer 2

Oxygen flows from a charged cylinder to a pressure-demand regulator, adjustable by each crewmember.

Question 3

What type of oxygen must be used in aircraft?

Answer 3

Aviator´s Breathing Oxygen.

Question 4

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

Answer 4

It must be purged to remove the moisture.

Question 5

What is used to purge oxygen lines of moisture?

Answer 5

Dry air, Dry nitrogen or oxygen.

Question 6

What safety precautions should be observed when servicing oxygen systems?

Answer 6

Clean, grease free tools, clothing, hands, no smoking or open flames withing 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 IN 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 regulates 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

outflow valve

Question 12

What components are used in an air-cycle cooling system?

Answer 12

An expansion turbine, heat exchanger and various valves.

Question 13

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

Answer 13

(1)Engine air bleed is cooled in the primary heat exchanger, (2)compressed cooled again in the second heat exchanger
(3)then goes to a turbine that extracts the energy and pressure of the air droping the air temperature.

Question 14

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

Answer 14

The compressed air performs the work of turning a turbine, and 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 swril the air and the droplets
are collected and drained.

Question 16

What is a vapor-cycle cooling?

Answer 16

A closed system in which a refrigerant freon is circulated through tubing and variety of components to remove heat from the aircraft.

Question 17

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

Answer 17

Vapor-Cycle uses Freon.

Question 18

What components are in a vapor-cycle cooling?

Answer 18

A Receiver Dryer, Evaporator, Compressor, Condenser and 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 the 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 or ram air or possibily a compressor if the airplane is pressurized.