Cabin Atmosphere Control Ststems Flashcards
- What is the principal control element in a cabin pressurization system?
Cabin outflow valve
- What is the purpose of the negative pressure relief valve in the pressurization system?
Prevents obtaining cabin altitude which is higher than the aircrafts altitude
- What control changes the position of the outflow valve?
Pressurization controler
- What are the two groups of independent cabin compressors?
Positive displacement & centrifugal
- What method is used by turbine powered aircraft for pressurization?
Bleed air from engine compressor
- What limits the degree of cabin pressurization?
Structural design of fuselage & capacity of superchargers
- Where does the warm air for cabin heating come from in most small reciprocating engine aircraft?
Shroud around engine muffler
- What are three methods of supplying heat to the conditioned air when the “heat of compression” is not sufficient for this purpose?
Fuel burning combustion heaters
Electric heaters
Exhaust gas air to air heat exchangers
- What is the function of ventilating air in a combustion heater?
Ventilation air carries heat to the places where it is needed
- Where does the fuel used in an aircraft combustion heater come from?
Aircraft fuel tanks
- What controls the temperature in an aircraft cabin that is heated with a combustion heater?
Thermostat
- What are the sources for ventilation air in a combustion heater?
On ground - blower is used for air circulation & heat
In flight - ram air inlets or cabin compressors
- What are the components of an air cycle cooling system?
Expansion turbine
Air to air heat exchanger
Various valves control airflow
- What causes a temperature drop in an air cycle cooling system?
Compressed air passes through expansion turbine, turns turbine & undergoes pressure & temperature drop
- What are the components in a vapor cycle (Freon) cooling system?
Compressor
Condenser
Receiver/dryer
Expansion valve
Evaporator
- How do you determine the liquid level in a vapor cycle cooling system?
Operate system for 5 min
If bubbles show in sight glass system is low
- How is the vapor cycle cooling system compressor lubricated?
Specialized refrigerant oil
- What are the components of a continuous flow oxygen system?
High pressure cylinder
Pressure regulation reducing valve
Calibrated orifice
Breathing mask
- What must be done if an oxygen system has been depleted and not recharged within two hours?
Purged with dry nitrogen or dry air & oxygen
- What safety considerations must be observed when filling oxygen cylinders?
Filled in oil free environment
Petroleum free clothes, hands, or 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 (1800-1850psi) - green cylinders marked “Aviator’s Breathing Oxygen” stenciled lengthwise in white 1” letters
Low pressure (400-425psi) - light yellow cylinders
- What are the three ways supplemental oxygen can be carried in an aircraft?
Liquid oxygen
High pressure gas
Chemical candle
- What is an acceptable lubricant for installing oxygen system fittings?
Teflon or water based lubricants
- What type or grade of oxygen must be used in aircraft?
Aviator’s grade breathing oxygen
- What is a roots blower?
Engine driven compressor
- What is a British Thermal Unit?
Unit of heat (BTU)
