Cabin Atmosphere

Question 1

Describe the operating principle of a continuous flow oxygen system

Answer 1

High pressure oxygen flows from the

cylinder to the regulator where pressure is reduced and then to the mask outlets whenever the system is turned on

Question 2

Describe the operating principle of a pressure demand oxygen system

Answer 2

oxygen flows from the cylinder to the regulator and then to the mask when the user inhales.

Question 3

What should be used to purge an oxygen system of moisture

Answer 3

Oxygen, dry air, or dry nitrogen

Question 4

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

Answer 4

Purge of any moisture

Question 5

Name two different types of independent cabin air compressor

Answer 5

Positive displacement and centrifugal compressor

Question 6

What is the source of pressurization air in most jet aircraft

Answer 6

Engine bleed air

Question 7

What device provides the principle means of a controlling element in a cabin pressurized system

Answer 7

Outflow valve

Question 8

What unit regulates the position of an outflow valve

Answer 8

Cabin pressure controller

Question 9

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

Answer 9

Exhaust shroud heat exchangers, combustion heaters and electric heaters

Question 10

What are the sources of ventilating air in a combustion heater

Answer 10

Ram air, cooling fans on the ground, or a compressor if the airplane is pressurized

Question 11

Name the basic components of an air-cycle cooling system

Answer 11

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

Question 12

Describe the basic operating principle that allows an air-cycle system to produce cool air

Answer 12

Hot engine bleed air is cooled in the primary heat exchanger and compressed and cooled again in the secondary heat exchanger. Then the air is expanded across the turbine where energy is extracted and pressure is reduced and produces a rapid temperature drop

Question 13

Name the principle components of a vapor cycle system

Answer 13

A compressor, condenser, expansion valve and an evaporator

Question 14

Describe the basic operating principles of a water separator

Answer 14

Cool, moist air is swirled so that water droplets are separated by centrifugal force

Question 15

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

Answer 15

Vapor cycle system uses Freon

Question 16

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

Answer 16

Lubricate the compressor

Question 17

What method is used by turbine powered aircraft for pressurization

Answer 17

Bleed air and engine compressor

Question 18

What is the function of ventilating air in a combustion heater

Answer 18

Used to carry the heat to the places where it is needed

Question 19

How are high and low pressure oxygen cylinder identified

Answer 19

High pressure oxygen cylinders are green and have AVIATORS BREATHING OXYGEN wrote on the cylinder and All low pressure oxygen cylinders are painted light yellow

Question 20

How can you tell that there is carbon monoxide on the aircraft cabin

Answer 20

Crystals in the detector will change color

Question 21

Where does the fuel used in an aircraft combustion heater come from

Answer 21

Aircraft fuel tanks

Question 22

What maintenance is required for a combustion heater

Answer 22

Clean the fuel filters and check for fuel leaks

Question 23

What are two types of air conditioning systems that may be installed on an aircraft

Answer 23

Air-cycle and Vapor-cycle

Question 24

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

Answer 24

Only aviators breathing oxygen

Question 25

Oxygen cylinders should have what on them

Answer 25

A DOT or ICC rating stamped on the bottle neck, the word AVIATION BREATHING OXYGEN and the last hydrostatic test must be stamped in the filler neck