Airframe Systems and Components (Cabin Atmosphere) Flashcards
What is the principal control element in a cabin pressurization system?
Cabin outflow valve.
what is the purpose of the negative pressure relief in the pressurization system?
Prevents accidentally obtaining a cabin altitude which is higher than the altitude of the aircraft.
What control changes the position of the outflow valve?
The pressurization controller.
What are the two groups of independent cabin compressors?
Positive displacement, and centrifugal compressors.
What method is used by turbine powered aircraft for pressurization?
Bleed air from the compressor.
What limits the degree of cabin pressurization?
By structural design of the fuselage, and by capacity of the superchargers to maintain a constant volume of air flow to the fuselage.
Where does the warm air for cabin heating come from in most small reciprocating engine aircraft?
From the shroud around the muffler.
what are three methods of supplying here to the conditioned air when the heat of compression is not sufficient for this purpose?
Combustion heaters, electric heaters, and exhaust gas air-to-air heat exchangers.
What is the function of ventilating air in a combustion heater?
carries the heat to where it needs to go
where does the fuel used in aircraft combustion heater come from?
Aircraft fuel tanks.
What controls the temperature in aircraft cabin that is heated with a combustion heater?
a thermostat
what are sources for ventilation air?
On the ground the blower is used. In-flight ram air inlets or cabin compressors on pressurized aircraft.
What are the components of an air cycle cooling system?
Expansion turbine, air to air heat exchanger, and various valves to control airflow through the system.
What causes a temperature drop in an air cycle cooling system?
As the compressed air passes through expansion turbine, they performed the work of turning the turbine and undergoes a pressure and temperature drop.
What are the components in a vapor cycle cooling system?
The compressor, condenser, receiver/dryer, expansion valve, and evaporator.
how do you determine the liquid level in vapor cycle cooling system?
Operate the system for about five minutes to reach stabilize condition, and then observe the flow of Freon through the site glass. A steady flow indicates sufficient charge. If Freon is low, bubbles will appear inside glass.
How is the vapor cycle cooling system compressor lubricated ?
Specialized refrigerant oil
What are the components of a continuous flow oxygen system?
Oxygen will flow continuously from a high-pressure cylinder, through a high-pressure line to the pressure regulation reducing valve. The oxygen will then flow through a calibrated orifice in the outlet, controlling the amount of oxygen delivered to the rebreathing mask.
What must be done if an oxygen system has been depleted and not recharge within two hours?
It must be purged with dry nitrogen or dry air and oxygen.
What safety considerations must be observed when filling oxygen cylinders?
Cylinder should be filled in an oil free environment. The mechanical fills a cylinder should should not have any petroleum products on their close hands or in their hair.
what is the main chemical agent inside of an oxygen generator?
Sodium chlorate
how are high and low pressure oxygen cylinders identified?
High pressure is Green (18000-1850 PSI)
Low pressure is yellow (400-425 PSI)
Both have “AVIATORS BREATHING OXYGEN” in 1 inch letters
what are the three ways supplemental oxygen can be carried in an aircraft ?
as a liquid, high pressure gas, or oxygen candle
what is an acceptable lubricant for installing oxygen system fittings?
Teflon or water based lubricant
