Enviromental system part 1

What is ventilating air used for on a combustion heater?. Provides combustion air for ground blower. Carries heat to the places where needed. Provides air required to support the flame.

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.

What unit in a vapor-cycle cooling system serves as a reservoir for the refrigerant?. Receiver-dryer. Evaporator. Condenser.

The function of the evaporator in a freon cooling system is to. liquefy freon in the line between the compressor and the condenser. lower the temperature of the cabin air. transfer heat from the freon gas to ambient air.

In a freon vapor-cycle cooling system, where is cooling air obtained for the condenser?. Turbine engine compressor. Ambient air. Pressurized cabin air.

In the combustion heater, combustion air system, what prevents too much air from entering the heaters as air pressure increases?. Either a combustion air relief valve or a differential pressure regulator. Only a differential pressure regulator can be used. Only a combustion air relief valve can be used.

How should the aviation mechanic determine the amount of oxygen in a portable, high-pressure cylinder?. Weigh the cylinder and its contents. Read the pressure gauge mounted on the cylinder. Measure the pressure at the mask.

In what position should the bottle be placed when adding liquid freon to a vapor-cycle cooling system?. Vertical with the outlet at the top. Horizontal with the outlet to the side. Vertical with the outlet at the bottom.

What may be used as a lubricant on oxygen system tapered pipe thread connections?. Silicone dielectric compound. Glycerine. Teflon tape.

The basic air-cycle cooling system consists of. a source of compressed air, heat exchangers, and a turbine. heaters, coolers, and compressors. ram air source, compressors, and engine bleeds.

An aircraft oxygen bottle may be considered airworthy if it has been hydrostatically tested and identified. with the test date, DOT number, and serial number stamped on the cylinder near the neck. with the DOT number, serial number, and manufacturer stamped on the cylinder near the neck. with the DOT number and manufacturer stamped on the cylinder near the neck.

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.

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.

When charging a vapor-cycle cooling system after evacuation, the low-pressure gauge fails to come out of a vacuum. What is indicated?. Blockage in the system. The expansion valve failed to close. The compressor is not engaging.

The function of the condenser in a freon cooling system is to. transfer heat from the freon gas to ambient air. change liquid freon into a gas before it enters the compressor. transfer heat from the cabin air to the liquid freon.

Which of the following are characteristics of a chemical or solid-state oxygen system?. A volume storage capacity about three times that of compressed oxygen and system generators that are inert below 400°F, even under severe impact. An adjustable oxygen release rate and a volume storage capacity about three times that of compressed oxygen. System generators are inert below 400°F, even under severe impact, and a distribution and regulating system similar to gaseous oxygen systems.

Where does the last stage of cooling in an air-cycle air conditioning system occur?. Refrigeration unit compressor. Secondary heat exchanger. Expansion turbine.

What component of a pressurization system prevents the cabin altitude from becoming higher than airplane altitude?. Cabin rate-of-descent control. Negative pressure relief valve. Positive pressure relief valve.

What type of oil is suitable for use in vapor-cycle cooling system?. Low viscosity engine oil with the inability to absorb water. Special high grade refrigeration oil. Highly refined synthetic oil, free from impurities with special water absorbing additives.

When a vapor-cycle cooling system is not in operation, what is an indication that the system is leaking freon?. Oil seepage. Bubbles in the sight glass. An ozone-like odor in the immediate area.

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.

The primary difference between aviation breathing oxygen and other types of commercially available compressed oxygen is that. the other types are usually somewhat less than 99.5 percent pure oxygen. aviation breathing oxygen has had all the water vapor removed. aviation breathing oxygen has a higher percentage of water vapor to help prevent drying of a person's breathing passages and possible dehydration.

The primary function of the cabin pressurization system outflow valve is to. provide protection against overpressurization. maintain the desired cabin pressure. maintain the same cabin air pressure at all altitudes.

Before a high-pressure oxygen cylinder is serviced, it must be the correct type and have been. hydrostatically tested within the proper time interval. approved by the National Transportation Safety Board. inspected by a certificated airframe mechanic.

On transport category aircraft what might be an indication of an over pressure event of the aircraft oxygen system?. The green thermal expansion disk missing. The green thermal expansion disk in the cockpit missing. The green thermal expansion disk on the oxygen regulator missing.

What is the condition of the refrigerant as it leaves the evaporator of a vapor-cycle cooling system?. Low-pressure liquid. Low-pressure vapor. High-pressure vapor.

In the diluter demand oxygen regulator, when does the demand valve operate?. When the diluter control is set at normal. When the user demands 100 percent oxygen. When the user breathes.

The point at which freon flowing through a vapor-cycle cooling system absorbs heat and changes from a liquid to a gas is the. condenser. evaporator. expansion valve.

How is the cabin pressure of a pressurized aircraft usually controlled?. By a pressure-sensitive switch that causes the pressurization pump to turn on or off as required. By an automatic outflow valve that dumps all the pressure in excess of the amount for which it is set. By a pressure-sensitive valve that controls the output pressure of the pressurization pump.

Oxygen systems in unpressurized aircraft are generally of the. continuous-flow and pressure-demand types. pressure-demand type only. portable-bottle type only.

The position of the thermostatic expansion valve in a vapor-cycle cooling system is determined by temperature and pressure of the. freon entering the evaporator. air in the outlet of the condenser. freon in the outlet of the evaporator.

Which prevents a sudden loss of pressurization in the event that there is a loss of the pressurization source?. Firewall shutoff valve. Cabin pressure outflow valve. Delivery air duct check valve.

One purpose of a jet pump in a pressurization and air conditioning system is to. produce a high pressure for operation of the out-flow valve. provide for augmentation of airflow in some areas of the aircraft. assist in the circulation of freon.

Which best describes cabin differential pressure?. Difference between cabin flight altitude pressure and mean sea level pressure. Difference between the ambient and internal air pressure. Difference between cabin pressure controller setting and actual cabin pressure.

What does a steady stream of bubbles indicate when servicing a vapor cycle air conditioning system?. The system is over charged. The system is properly charged. The system is under charged.

At which component in an air-cycle cooling system does air undergo a pressure and temperature drop?. Expansion turbine. Primary heat exchanger. Refrigeration bypass valve.

What controls the amount of oxygen delivered to a mask in a continuous-flow oxygen system?. Calibrated orifice. Pressure reducing valve. Pilot's regulator.

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.

What is the purpose of a mixing valve in a compressor bleed air air conditioning system?. Control the supply of hot, cool, and cold air. Distribute conditioned air evenly to all parts of the cabin. Combine ram air with conditioned air.

The cabin pressurization modes of operation are. isobaric, differential, and maximum differential. differential, unpressurized, and isobaric. ambient, unpressurized, and isobaric.

What is used in some oxygen systems to change high cylinder pressure to low system pressure?. Pressure reducer valve. Calibrated fixed orifice. Diluter demand regulator.

High-pressure cylinders containing oxygen for aviation use can be identified by their. green color and the words BREATHING OXYGEN stenciled in 1-inch white letters. yellow color and the words AVIATOR'S BREATHING OXYGEN stenciled in 1-inch white letters. green color and the words AVIATOR'S BREATHING OXYGEN stenciled in 1-inch white letters.

What is the purpose of pressurizing the aircraft cabin?. To permit the aircraft to operate in thunderstorms. To allow aircraft systems to operate properly. To make human flight possible in the hostile environment of the upper atmosphere.

When purging a freon air conditioning system, it is important to release the charge at a slow rate. What is the reason for the slow-rate discharge?. Prevent the large amount of freon from contaminating the surrounding atmosphere. Prevent excessive loss of refrigerant oil. Prevent condensation from forming and contaminating the system.