A/c and Oxygen

What is the condition of the refrigerant as it enters the condenser of a vapor-cycle

cooling system?

• High-pressure liquid.

• Low-pressure liquid.

• High-pressure vapor.

What is the condition of the refrigerant as it leaves the condenser of a vapor-cycle

cooling system?

• Low-pressure liquid.

• High-pressure liquid.

• High-pressure vapor.

In a freon vapor-cycle cooling system, where is cooling air obtained for the

condenser?

• Turbine engine compressor.

• Ambient air.

• Pressurized cabin air.

Which section of a turbine engine provides high pressure bleed air to an air cycle

machine for pressurization and air conditioning?

• Low or high pressure compressor.

• Compressor inlet.

• C-D inlet compressor duct.

The purpose of a subcooler in a vapor-cycle cooling system is to

• augment the cooling capacity during periods of peak demand.

• aid in quick cooling a hot aircraft interior.

• cool the freon to prevent premature vaporization.

The operation of an aircraft combustion heater is usually controlled by a thermostat

circuit which

• alternately turns the fuel on and off, a process known as cycling.

• meters the amount of fuel continuously entering the heater and therefore regulates the

  heater's BTU output

• regulates the voltage applied to the heater's ignition transformer.

How is the cabin pressure of an aircraft maintained in flight?

• By controlling the rate of the air flowing into the cabin

• By inflating the door seals and recirculating the conditioned cabin air

• By controlling the rate of the air flowing out of the cabin.

When an aircraft's oxygen system has developed a leak, the lines and fittings should

be

• removed and replaced

• inspected using a special oxygen system dye penetrant

• bubble tested with a special soap solution manufactured specifically for this purpose.

After cleaning or replacing the filtering element in a combustion heater fuel system,

the system should be pressurized and

• all connections checked for leaks

• the fuel filter bypass valve reset to the filter position

• a sample of fuel taken downstream from the filter to ensure proper operation of the

  new filtering element

The air-cycle cooling system produces cold air by

• extracting heat energy across a compressor.

• passing air through cooling coils that contain a refrigerant.

• extracting heat energy across an expansion turbine.