Air Supply Flashcards
Name the 3 bleed air sources for the air conditioning system?
- Engines
- APU
- Ground Pneumatic sources
What can supply the Aircraft Cabin with its air supply?
- Air Cond System
- Mobile Ground Cond Unit
- Emerg Ram Air System
When should air conditioning packs and air conditioning sources supply an aircraft simultaneously?
Never, to prevent excessive airflow and possible air conditioning duct damage
What type of connector is used to supply the aircraft with conditioned air?
Bayonet Type with a diameter of 8 inches
For what reason are aircraft fitted with an emergency ram air supply system?
To ventilate the cockpit and the cabin if all packs fail or for smoke removal
What type of connector is used to connect Bleed Air sources to the aircraft?
Quick release connectors with a diameter of 3 inches
When operating the ram air button, cabin pressure must be?
A differential pressure of below 1 PSI
What type of air is the input to the Air Conditioning system?
Bleed Air
What should be preferred for longer ground cooling of an aircraft?
External air conditioning sources, they are more economical and ecological.
What is another name for the complete cabin atmosphere control system?
Cabin Environmental Control System
What conditions must be in normal range to create a comfortable feeling in the cabin?
Pressure, Temperature, Humidity and Air Movement.
What temperature should she can be maintained at?
21 - 27 Degrees
How does an aircraft supply the cabin with enough oxygen for humans to function?
By pressurizing the cabin
Name 3 methods of heat transfer?
Conduction, Convection and Radiation
What is one calorie?
The amount of heat energy needed to raise the temp of 1 gram of pure water to 1 Degree Cent
What is one BTU (British Thermal Unit)?
The amount of heat energy needed to raise the temp of 1 pound of pure water to 1 Degree Farenheight
A pan of water is put on a stove and heated, its temp will increase but the water will remain a liquid, this is an example of?
Sensible heat
What is the function of the thermal expansion valve in the vapour cooling system?
regulates the amount of liquid refrigerant flowing into the evaporator.
What are the two types of compressors used in refrigeration systems?
Piston (small A/C) Radial (Bigger A/C)
What should be done in an vapour cycle cooling system to protect the compressor?
All refrigerant should be vaporized
What is another name for an air cycle machine?
Air Conditioning Pack
An Air cycle machine consists of a ……………. which drives a …………. via a common shaft?
Turbine, compressor and a cooling fan
In an air conditioned pack the air from the pneumatic system is cooled to a usable temp of?
Between 2 and 60 Degrees
Which unit in the Air Cycle Machine is used to remove moisture from the air?
Water Separator
Why is there a cooling fan driven by the shaft of an Air Cycle Machine?
To provide assistance to the airflow. If ram airflow is higher than the cooling fan delivers the Fan Bypass Check Valve is opened.
When routing ducts what must be taken into consideration?
Expansion and Contraction through heating
There are 2 main types of flow control valves, these are?
Flow control Valves to regulate constant airflow and flow control valves to regulate variable airflow.
Why is a cabin pressure reference signal used to control a flow control valve?
Airflow measuring devices are mass flow meters, therefore it needs a reference signal (cabin pressure) to regulate a specific volumetric airflow.
What is the pack outlet temp and why?
0 -64 Degrees C to prevent icing or overheating of the Air Cycle Machine
What valve will automatically close if in a zone supply duct an overheat condition is detected?
Trim Air Pressure Regulator Valve
Why is zone supply temp limited to a maximum value?
To 74 Degrees C to prevent damages of the zone supply ducts and a possible bad smell in the cabin
What is cabin Climb rate and Decent rate limited to?
500ft/min and 300ft/min
At what cabin altitude will a intermittent warning sound be heard in the flight deck?
10000 Feet
If a cabin climbs >3100ft/min or descends >2000ft/min this is?
Excessive cabin rate
Why must air conditioning packs be supplied with hot air only?
Otherwise freezing and damage of turbine may occur
