Cabin atmosphere control systems

Question 1

What is the principal control element in a cabin pressurization system

Answer 1

The cabin out flow valve

Question 2

What is the purpose of the negative pressure relief valve in a pressurization system

Answer 2

Prevent accidentally obtaining a cabin altitude which is higher than the altitude of the aircraft

Question 3

What control changes the position of the outflow valve

Answer 3

The pressurization controller

Located in the cockpit is used to set the cabin air pressure to a desired altitude, normally between six and 8000 feet

Question 4

What are two groups of independent cabin Compressors

Answer 4

Positive displacement and centrifugal compressors

Question 5

What method is used by turban powered aircraft for pressurization

Answer 5

Bleed air from the engine compressor is used for pressurization

Question 6

What limits the degree of Cabin pressurization

Answer 6

The structural design feature of a fuselage, and by capacity of the supperchargers to maintain a constant volume of air flow to the fuselage

Question 7

Where does the warm air for cabin heating come from in most small reciprocating engines

Answer 7

The shroud around the engine muffler

Question 8

What are three methods of supplying heat to the conditioned air when the heat of the compressor is not sufficient for this purpose

Answer 8

Fuel burning combustion heaters, electric heaters, and exhaust gas air to air heat exchangers

Question 9

What is the function of ventilating air in a combustion heater

Answer 9

Ventilation airs to be used to carry heat to the place where it is needed

Question 10

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

Answer 10

The aircraft fuel tanks

Question 11

What controls the temperature in an aircraft cabin that is heated with the combustion heater

Answer 11

The thermostat

Question 12

What are the sources for ventilation air

Answer 12

For air circulation and heater operation on the ground a blower is used. In-flight, ram air inlet, or cabin compressors on pressurized Aircraft

Question 13

What are the components of an air cycle cooling system

Answer 13

And expansion turbine, and air to air heat exchanger, and various valves which control airflow through the system

Question 14

What causes a temperature drop in an air cycled cooling system

Answer 14

As a compressed air passes through the expansion Turbine, it performs the work of turning the turbine and undergoes a pressure and temperature drop

Question 15

What are the components in a vapor cycle cooling system

Answer 15

The compressor, condenser, receiver dryer, expansion valve, and evaporator

Question 16

How do you determine the liquid level in a vapor Cycle cooling system

Answer 16

Operates a system for about five minutes to reach a stabilized condition, then observes the flow of Freon through the site glass. A steady flow indicates significant charge. If the Freon is low, bubbles will appear in sight glass

Question 17

How is the vapor cycle cooling system compressor lubricated

Answer 17

Specialized refrigerant oil

Question 18

What are the components of a continuous flow oxygen system

Answer 18

Oxygen will flow continuously from the high-pressure cylinder, through the high pressure Line to the pressure regulator reducing valve. The oxygen will then flow through a calibrated office in the outlet, controlling the amount of oxygen delivered to the breathing mask

Question 19

What must be done if an oxygen system has been depleted and not recharge within two hours

Answer 19

It must be purged with dry nitrogen or dry air and oxygen

Question 20

What safety considerations must be observed when filling oxygen cylinders

Answer 20

Oxygen cylinders should be filled in an oil free environment. The mechanic who fills the cylinder should not have any petroleum products on their clothes, Hans, or in their hair

Question 21

What is the main chemical agent inside and oxygen generator

Answer 21

Sodium chlorate Is used In the main chemical agent use an aviation oxygen generators

The chemical is ignited by a spark admitting cap, and when it burns, O2 is generated. These systems are lighter and less complex than oxygen storage-based systems. The main drawback of the oxygen generators is that once the burning of the sodium chloride begins, it cannot be stopped into the chemical is Consumed

Question 22

How are high and low pressure oxygen cylinders identified

Answer 22

High pressure oxygen cylinders are green in color and have the words aviators breathing oxygen stenciled lengthwise and white 1 inch letters. Low pressure cylinders are painted light yellow

Question 23

What are the three ways supplemental oxygen can be carried into the aircraft

Answer 23

As liquid oxygen, a high-pressure gas, or a chemical candle

Question 24

What is the acceptable lubricant for installing oxygen system fittings

Answer 24

Teflon, or water-based lubricant