ASA sistemas II

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.

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.

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

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.

Turbine engine air used for air-conditioning and pressurization is generally called. compressed air. ram air. bleed 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.

The cabin pressure of an aircraft in flight is maintained at the selected altitude by. controlling the air inflow rate. inflating door seals and recirculating conditioned cabin air. controlling the rate at which air leaves the cabin.

What controls the operation of the cabin pressure regulator?. Cabin altitude. Bleed air pressure. Compression air pressure.

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.

The purpose of the dump valve in a pressurized aircraft is to relieve. all positive pressure from the cabin. a negative pressure differential. pressure in excess of the maximum differential.

What component might possibly be damaged if liquid refrigerant is introduced into the low side of a vapor-cycle cooling system when the pressure is too high or the outside air temperature is too low?. Compressor. Condenser. Evaporator.

How can it be determined that a vapor-cycle cooling system is charged with the proper amount of freon?. Air bubbles in the sight glass disappear. The compressor loads up and RPM decreases. Air bubbles appear in the sight glass.

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.

What component in a vapor-cycle cooling system would most likely be at fault if a system would not take a freon charge?. Expansion valve. Condenser. Receiver-dryer.

Frost or ice buildup on a vapor-cycle cooling system evaporator would most likely be caused by. the mixing valve sticking closed. moisture in the evaporator. inadequate airflow through the evaporator.

What test is used to determine the serviceability of an oxygen cylinder?. Pressure test with manometer. Pressure test with nitrogen. Pressure test with water.

How often should standard weight high-pressure oxygen cylinders be hydrostatically tested?. Every 5 years. Every 4 years. Every 3 years.

To be eligible for recharging, a DOT 3HT oxygen cylinder must have been hydrostatically tested every three years and be retired from service after. 24 years or 4,380 filling cycles. 15 years or 10,000 filling cycles. 10 years or 5,000 filling cycles.

What type of oxygen system uses the rebreather bag-type mask?. Diluter demand. Continuous flow. Demand.

The altitude controller maintains cabin altitude by modulation of the. safety and outflow valves. safety valve. outflow valve.

Hot compressor bleed air operates the conditioned air system on some turbine aircraft, cold air supplied by the. hot air mixing valve. sonic airflow control unit. ram air cycle cooling unit.

For use in pressurized aircraft, which is generally the least complicated and requires the least maintenance?. Chemical oxygen generator systems. High-pressure oxygen systems. Low-pressure oxygen systems.

The main cause of contamination in gaseous oxygen systems is. moisture. dust and other airborne particulates. other atmospheric gases.

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

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

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.

Which is considered a good practice concerning the inspection of heating and exhaust systems of aircraft utilizing a jacket around the engine exhaust as a heat source?. Supplement physical inspections with periodic operational carbon monoxide detection tests. All exhaust system components should be removed periodically, and their condition determined by the magnetic-particle inspection method. All exhaust system components should be removed and replaced at each 100-hour inspection period.

On some cabin pressurization systems, pressurization on the ground is restricted by the. main landing gear operated switch. cabin pressure regulator. negative pressure-relief valve.

The cabin pressure control setting has a direct influence upon the. outflow valve opening. pneumatic system pressure. inflow valve opening.

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.

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.

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.

If the liquid level gauge in a vapor-cycle cooling system indicates a low freon charge, the system should. be operated and a pressure check performed. be operated for a period of time to reach a stable condition and then the freon level rechecked. not be operated until freon and oil have been added.

If the cabin rate of climb is too great, the control should be adjusted to cause the. outflow valve to close slower. outflow valve to close faster. cabin compressor speed to decrease.

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.

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.

The function of an expansion valve in a freon cooling system is to act as a metering device and to. reduce the pressure of the gaseous freon. increase the pressure of the liquid freon. reduce the pressure of the liquid freon.

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.

When servicing an air-conditioning system that has lost all of its freon, it is necessary to. check oil and add as necessary, evacuate the system, relieve vacuum, and add freon. check oil and add as necessary, evacuate the system, and add freon. check oil and add as necessary, and add freon.

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.

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.

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 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.

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.

(Refer to Figure 13.) Determine what unit is located immediately downstream of the expansion valve in a freon refrigeration system. Condenser. Compressor. Evaporator coils.

When checking a freon system, a steady stream of bubbles in the sight gauge indicates the charge is. high. correct. low.

An aircraft pressurization cycle is normally considered to be. one complete series of events or operations that recur regularly. one take off and one landing. when the fuselage reaches its maximum pressure differential one time.

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.

Composite oxygen bottles that conform to DOT-E-8162 have a service life of. 5 years or 5,000 filling cycles whichever occurs first. 10 years or 5,000 filling cycles whichever occurs first. 15 years or 10,000 filling cycles whichever occurs first.

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

(1) Usually bleed air from a gas-turbine engine compressor can be safely used for cabin pressurization. (2) Independent cabin condition air machines (air cycle machine) can be powered by bleed air from an aircraft turbine engine compressor. Regarding the above statements,. only No. 1 is true. only No. 2 is true. both No. 1 and No. 2 are true.

A pressurization controller uses. bleed air pressure, outside air temperature, and cabin rate of climb. barometric pressure, cabin altitude, and cabin rate of change. cabin rate of climb, bleed air volume, and cabin pressure.

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

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 enters the evaporator of a vapor-cycle cooling system?. High-pressure liquid. Low-pressure liquid. High-pressure vapor.

The evacuation of a vapor-cycle cooling system removes any water that may be present by. drawing out the liquid. raising the boiling point of the water and drawing out the vapor. lowering the boiling point of the water and drawing out the vapor.

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.

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 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.

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.

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.

In an operating vapor-cycle cooling system, if the two lines connected to the expansion valve are essentially the same temperature, what does this indicate?. The system is functioning normally. The expansion valve is not metering freon properly. The compressor is pumping too much refrigerant.

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.

(1) A small amount of water in a vapor-cycle cooling system can freeze in the receiver-dryer and stop the entire system operation. (2) Water in a vapor-cycle cooling system will react with refrigerant to form hydrochloric acid which is highly corrosive to the metal in the system. Regarding the above statements,. only No. 1 is true. only No. 2 is true. both No. 1 and No. 2 are true.

When Refrigerant-12 is passed over an open flame, it. changes to methane gas. is broken down into its basic chemical elements. changes to phosgene gas.

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 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.

If oxygen bottle pressure is allowed to drop below a specified minimum, it may cause. the pressure reducer to fail. the automatic altitude control valve to open. moisture to collect in the bottle.

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

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 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.

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.

In a high-pressure oxygen system, if the pressure reducer fails, what prevents high-pressure oxygen from entering the system downstream?. Check valve. Pressure relief valve. Manifold control valve.

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.

(Refer to Figure 14.) One hour after an oxygen system was charged for a leakage check, the oxygen pressure gauge read 460 PSI at 63°F; 6 hours later the temperature was 51°F. (A 5 PSI change is the maximum allowable in a 6-hour period.) What pressure gauge readings would be acceptable to remain within the allowable limits?. 445 to 450 PSI. 446 to 450 PSI. 455 to 460 PSI.

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.

In a gaseous oxygen system, which of the following are vented to blow out plugs in the fuselage skin?. Pressure relief valves. Filler shutoff valves. Pressure reducer valves.

79- The purpose of pressurizing aircraft cabins is to (1) create the proper environment for prevention of hypoxia. (2) permit operation at high altitudes. Regarding the above statements,. only No. 1 is true. only No. 2 is true. both No. 1 and No. 2 are true.

(1) Oxygen used in aircraft systems is at least 99.5 percent pure and is practically water free. (2) Oxygen used in aircraft systems is 99.5 percent pure and is hospital quality. Regarding the above statements,. only No. 1 is true. both No. 1 and No. 2 are true. neither No. 1 nor No. 2 is true.

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

The purpose of the airflow metering aneroid assembly found in oxygen diluter demand regulators is to. regulate airflow in relation to oxygen flow when operating in emergency or diluter demand positions. regulate airflow in relation to cabin altitude when in diluter demand position. automatically put the regulator in emergency position if the demand valve diaphragm ruptures.

If a high-pressure oxygen cylinder is to be installed in an airplane, it must meet the specifications of the. aircraft manufacturer or the cylinder manufacturer. Department of Transportation. National Transportation Safety Board or the Standards of Compressed Gas Cylinders.

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.

A contaminated oxygen system is normally purged with. oxygen. compressed air. nitrogen.

How should you 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.

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

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.

Which of the following are characteristic of a chemical or solid state oxygen system? 1. An adjustable oxygen release rate. 2. A volume storage capacity about three times that of compressed oxygen. 3. The system generators are inert below 400°F even under severe impact. 4. A distribution and regulating system similar to gaseous oxygen systems. 2 & 3. 3 & 4. 1 & 2.

Prior to installation of a pneumatic surface-bonded type deicer boots, on the leading edge of the wing, you should. remove all paint from the area to be covered by the deicer boot. apply adhesive to the back of the deicer boot and leading edge of the wing. apply a silastic compound between the boot and the wing skin.

Which of the following are found in a laminated integral electrically heated windshield system? 1. Autotransformer. 2. Heat control relay. 3. Heat control toggle switch. 4. 24V dc power supply. 5. Indicating light. 1, 2, 4, 5. 2, 3, 4, 5. 1, 2, 3, 5.

What is one check for proper operation of a pitot/static tube heater after replacement?. Ammeter reading. Voltmeter reading. Continuity check of system.

What controls the inflation sequence in a pneumatic deicer boot system?. Shuttle valve. Vacuum pump. Distributor valve.

What is the source of pressure for inflating deicer boots on reciprocating engine aircraft?. Vane-type pump. Gear-type pump. Piston-type pump.

Which of the following regulates the vacuum of the air pump to hold the deicing boots deflated when the pneumatic deicing system is off?. Distributor valve. Pressure regulator. Suction relief valve.

What may be used to clean deicer boots?. Unleaded gasoline or Jet A fuel. Naphtha. Soap and water.

Some aircraft are protected against airframe icing by heating the leading edges of the airfoils and intake ducts. When is this type of anti-ice system usually operated during flight?. Continuously while the aircraft is in flight. In symmetric cycles during icing conditions to remove ice as it accumulates. Whenever icing conditions are first encountered or expected to occur.

Which of the following indications occur during a normal operational check of a pneumatic deicer system?. Relatively steady readings on the pressure gauge and fluctuating readings on the vacuum gauge. Fluctuating readings on the pressure gauge and relatively steady readings on the vacuum gauge. Pressure and vacuum gauges will fluctuate as the deicer boots inflate and deflate.

What method is usually employed to control the temperature of an anti-icing system using surface combustion heaters?. Thermo-cycling switches. Thermostats in the cockpit. Heater fuel shutoff valves.

What is the purpose of the distributor valve in a deicing system utilizing deicer boots?. To equalize the air pressure to the left and right wings. To sequence the deicer boots inflations symmetrically. To distribute anti-icing fluid to the deicer boots.

What is the purpose of the oil separator in the pneumatic deicing system?. To protect the deicer boots from oil deterioration. To remove oil from air exhausted from the deicer boots. To prevent an accumulation of oil in the vacuum system.

Where are the heat sensors located on most aircraft with electrically heated windshields?. Imbedded in the glass. Attached to the glass. Around the glass.

Two possible sources of heat for the operation of a wing thermal anti-icing system are. first stage of the aircycle turbine and turbo compressor. compressor bleed air and aircraft electrical system. combustion heater and exhaust gases.

What maintains normal windshield temperature control in an electrically heated windshield system?. Thermal overheat switches. Thermistors. Electronic amplifiers.

Arcing in an electrically heated windshield panel usually indicates a breakdown in the. temperature-sensing elements. autotransformers. conductive coating.

Which of the following connects vacuum to the deicer boots when the system is not in operation, to hold the boots tightly against the leading edges in flight?. Vacuum relief valve. Ejector. Distributor valve.

How do deicer boots help remove ice accumulations?. By preventing the formation of ice. By breaking up ice formations. By allowing only a thin layer of ice to build up.

Why are the tubes in deicer boots alternately inflated?. Alternate inflation of deicer boot tubes keeps disturbance of the airflow to a minimum. Alternate inflation of deicer boot tubes does not disturb airflow. Alternate inflation of deicer boot tubes relieves the load on the air pump.

Carburetor icing may be eliminated by which of the following methods?. Alcohol spray and heated induction air. Ethylene glycol spray and heated induction air. Electrically heating air intake, ethylene glycol spray, or alcohol spray.

Why should a chemical rain repellant not be used on a dry windshield?. It will etch the glass. It will restrict visibility. It will cause glass crazing.

What is the principle characteristic of a windshield pneumatic rain removal system?. An air blast spreads a liquid rain repellant evenly over the windshield that prevents raindrops from clinging to the glass surface. An air blast forms a barrier that prevents raindrops from striking the windshield surface. A pneumatic rain removal system is simply a mechanical windshield wiper system that is powered by pneumatic system pressure.

What mixture may be used as a deicing fluid to remove frost from an aircraft surface?. Ethylene glycol and isopropyl alcohol. Methyl ethyl ketone and ethylene glycol. Naphtha and isopropyl alcohol.

Which of the following is the best means to use when removing wet snow from an aircraft?. A brush or a squeegee. Hot air. Warm water.

What are three methods of anti-icing aircraft windshields? 1. Blanket-type heating system. 2. An electric heating element in the windshield. 3. Heated air circulating system. 4. Hot water system. 5. Windshield wipers and anti-icing fluid. 6. Ribbon-type heating system. 2, 3, 5. 1, 2, 6. 2, 3, 4.

What icing condition may occur when there is no visible moisture present?. Injector ice. Inlet ice. Carburetor ice.

What should be used to melt the ice in a turbine engine if the compressor is immobile because of ice?. Deicing fluid. Anti-icing fluid. Hot air.

What is used as a temperature-sensing element in an electrically heated windshield?. Thermocouple. Thermistor. Thermometer.