Cabin Atmosphere Control Systems Flashcards
How does a continuous flow oxygen system operate ?
Oxygen flows from a charged cylinder through a high pressure line to a reducing valve, then to mask outlets
How does basic pressure demand oxygen system operate ?
Oxygen flows from a charged cylinder to a pressure demand regulator, on demand from each crew member
What type of oxygen must be used in aircraft ?
Aviators Breathing Oxygen
What must be accomplished if an oxygen system had been open to atmosphere for 2 hours or more ?
It must be purged to remove moisture
What is used to purge oxygen lines or moisture ?
Dry air, Dry nitrogen, or Oxygen
What safety precaution should be observed when servicing oxygen system ?
Clean, grease free tools, clothing, hands, no smoking or open flames within 50 feet, do not use adhesive tape of any kind
What are the two groups of independent cabin compressors ?
Positive displacement and Centrifugal
What is a Roots blower ?
An engine driven compressor, used on old reciprocating engines for cabin pressurization
What method is used by some turbine powered aircraft for pressurization ?
Engine bleed air
What pressurization control unit will regulate the position of an outflow valve ?
The cabin pressure controller
What is the principal control of a pressurization system ?
An outflow valve
What components are used in an air cycle cooling system ?
Expansion turbine, heat exchanger, various valves
Describe the basic operating principles that allow an air cycle system to produce cool air ?
1 Engine bleed air is cooled primary heat exchanger
2 Compressed air cooled again secondary heat exchanger
3 Air goes to expansion turbine that extracts the energy and pressure of the air dropping the temperature
What causes a temperature drop in an Air cycle cooling system ?
The compressed air turns a turbine, then it undergoes a pressure and temperature drop
How does a water separator remove moisture from the air ?
The moist air passes through vanes that swirls the air water droplets which are collected and drained
What is a vapor cycle cooling ?
A closed system in which freon is circulated through tubing and various components to remove heat from the aircraft
In what significant way is a vapor cycle cooling system different from an air cycle cooling system ?
Vapor cycle uses freon
What components are in a vapor cycle cooling ?
Receiver dryer, Evaporator, Compressor, Condenser, Expansion Valve
Why is oil added to a vapor cycle freon system ?
To seal and lubricate the compressor
What is the function of ventilating air in a combustion heater ?
It transports heat from the heater into the cabin and prevents combustion gases from entering the cabin if the combustion chamber develops a crack
Name several methods used on reciprocating engine aircraft for providing heated cabin air ?
Exhaust shroud heat exchangers, combustion heaters and electric heaters
What are sources of ventilating air in a combustion heater ?
A blower / fan, ram air or possilby a compressor if the airplane is pressuirzed
