2A656 Aircraft Electrical And Environmental Systems Journeyman Volume 4

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Quizzes Created: 2 | Total Attempts: 259

Questions: 86 | Attempts: 121 | Updated: Mar 20, 2023

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2A656 Aircraft Electrical And Environmental Systems Journeyman Volume 4 - Quiz

Questions and Answers

1.

All of these aircraft systems use engine bleed air except
- A.
  
  Anti-gravity (anti-G)
- B.
  
  Fire extinguishing
- C.
  
  Rain removal
- D.
  
  Anti-icing
Correct Answer
B. Fire extinguishing

Explanation
Engine bleed air is used in aircraft systems for various purposes such as anti-icing, rain removal, and anti-G (anti-gravity) systems. However, fire extinguishing systems do not rely on engine bleed air. Instead, they typically use dedicated fire suppression agents or extinguishing agents to control or extinguish fires on board the aircraft.

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2.

Bleed air is usually taken from this aircraft engine section.
- A.
  
  Intake
- B.
  
  Turbine
- C.
  
  Exhaust
- D.
  
  Compressor
Correct Answer
D. Compressor

Explanation
Bleed air is usually taken from the compressor section of an aircraft engine. The compressor is responsible for compressing the incoming air before it enters the combustion chamber. Bleed air is extracted from this section to provide various functions such as cabin pressurization, anti-icing, and air conditioning. Taking bleed air from the compressor ensures that it is at a high pressure and temperature, making it suitable for these purposes. Therefore, the compressor is the correct answer.

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3.

What is the approximate pressure and maximum temperature of engine bleed air as it is tapped from the engine compressor section
- A.
  
  100 psi and 700 degrees F
- B.
  
  150 psi and 750 degrees F
- C.
  
  200 psi and 900 degrees F
- D.
  
  250 psi and 950 degrees F
Correct Answer
C. 200 psi and 900 degrees F

Explanation
The approximate pressure and maximum temperature of engine bleed air as it is tapped from the engine compressor section is 200 psi and 900 degrees F.

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4.

Which component determines the amount of bleed air bled from the a gas turbine compressor (GTC)
- A.
  
  Thermocouples
- B.
  
  Fuel control valve
- C.
  
  Load control valve
- D.
  
  Bleed air control governor
Correct Answer
C. Load control valve

Explanation
The load control valve determines the amount of bleed air bled from the gas turbine compressor. This valve is responsible for regulating the flow of bleed air, which is used for various purposes such as aircraft engine anti-icing, cabin pressurization, and pneumatic systems. By adjusting the load control valve, the operator can control the amount of bleed air needed for different operations, ensuring efficient and optimal performance of the gas turbine compressor.

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5.

Engine bleed air check valves are installed to
- A.
  
  Reduce bleed air pressure when the pressure is too high
- B.
  
  Maintain a balanced airflow from each engine
- C.
  
  Prevent the loss of compressed bleed air
- D.
  
  Provide a primary source for bleed air
Correct Answer
C. Prevent the loss of compressed bleed air

Explanation
Engine bleed air check valves are installed to prevent the loss of compressed bleed air. These valves ensure that the compressed bleed air from the engine does not escape or leak out. By preventing the loss of this air, the check valves help maintain the efficiency and effectiveness of the aircraft's systems that rely on bleed air, such as air conditioning, pressurization, and anti-icing. This ensures that the aircraft operates smoothly and safely during flight.

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6.

What engine bleed air valve prevents air from being lost through he engine when it is shutdown?
- A.
  
  Check
- B.
  
  Shut off
- C.
  
  Isolation
- D.
  
  Crossover
Correct Answer
B. Shut off

Explanation
The engine bleed air valve that prevents air from being lost through the engine when it is shutdown is the "shut off" valve. This valve closes off the flow of bleed air, ensuring that no air escapes from the engine when it is not in use.

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7.

This component stops the flow of air to the air-conditioning system
- A.
  
  Pressure limiter
- B.
  
  Flow control valve
- C.
  
  Air regulator valve
- D.
  
  System shut off valve
Correct Answer
D. System shut off valve

Explanation
The system shut off valve is the correct answer because it stops the flow of air to the air-conditioning system. This valve is responsible for cutting off the supply of air, effectively shutting down the system. It is designed to control the flow of air and prevent it from reaching the air-conditioning system when necessary.

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8.

If electrical power is interrupted to the solenoid of an electrically controlled, pneumatically operated air-conditioning system shut off valve with a fail safe feature, the valve
- A.
  
  Opens
- B.
  
  Closes
- C.
  
  Opens, if closed; closes if opened
- D.
  
  Opens or closes depending on system design requirments
Correct Answer
D. Opens or closes depending on system design requirments

Explanation
If the electrical power is interrupted to the solenoid of an electrically controlled, pneumatically operated air-conditioning system shut off valve with a fail-safe feature, the valve can either open or close depending on the system design requirements. The fail-safe feature ensures that the valve will take a specific action (either open or close) in the event of a power failure, based on the predetermined design specifications. Therefore, the valve's response in this situation is not fixed and can vary depending on the system's design.

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9.

What pressure and flow control device restricts airflow and protects aircraft engines against air starvation
- A.
  
  Orifice
- B.
  
  Air regulator
- C.
  
  Pressure limiter
- D.
  
  Pressure regulator
Correct Answer
A. Orifice

Explanation
An orifice is a pressure and flow control device that restricts airflow and protects aircraft engines against air starvation. It acts as a small opening or hole in a pipe or valve, which reduces the flow rate of air passing through it. By restricting the airflow, the orifice helps maintain proper pressure levels and prevents excessive air from entering the engine, which could lead to damage or inefficiency. Therefore, an orifice is an essential component in ensuring the safe and efficient operation of aircraft engines.

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10.

Due to loss of energy, the outlet air pressure of an orifice is
- A.
  
  Lower than the inlet
- B.
  
  Higher than the inlet
- C.
  
  Lower than the throat
- D.
  
  The same as the throat
Correct Answer
A. Lower than the inlet

Explanation
When a fluid passes through an orifice, there is a loss of energy due to factors such as friction and turbulence. This loss of energy causes a decrease in pressure. Therefore, the outlet air pressure of an orifice is lower than the inlet pressure.

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11.

What is the bleed air system component that controls the air flow by protecting downstream components from excessive pressure?
- A.
  
  Orifice
- B.
  
  Pressure limiter
- C.
  
  Pressure regulator
- D.
  
  Flow control valve
Correct Answer
B. Pressure limiter

Explanation
A pressure limiter is a component in the bleed air system that controls the air flow by protecting downstream components from excessive pressure. It ensures that the pressure does not exceed a certain limit, preventing damage to the system and ensuring safe operation.

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12.

The amount of airflow through a pressure limiter is affected by these except
- A.
  
  Inlet pressure
- B.
  
  Outlet pressure
- C.
  
  Inlet temperature
- D.
  
  Differential pressure
Correct Answer
B. Outlet pressure

Explanation
The amount of airflow through a pressure limiter is affected by the inlet pressure, inlet temperature, and differential pressure. However, the outlet pressure does not affect the airflow. The pressure limiter is designed to regulate the pressure on the outlet side, ensuring that it remains constant regardless of changes in the inlet pressure, temperature, or differential pressure. Therefore, the outlet pressure is not a factor in determining the amount of airflow through the pressure limiter.

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13.

The butterfly valve of the air-conditioning pressure limiter is open when
- A.
  
  The upper limiter is compressed
- B.
  
  There is not enough pressure applied to the system
- C.
  
  A force is applied downward on the actuating diaphram
- D.
  
  The down stream pressure port receives 70 pounds per min airflow
Correct Answer
B. There is not enough pressure applied to the system

Explanation
When there is not enough pressure applied to the system, the butterfly valve of the air-conditioning pressure limiter is open. This suggests that the valve is designed to open when the system does not have sufficient pressure, allowing airflow to continue and preventing any potential damage or malfunction.

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14.

The flow control valve control in the bleed air air-conditioning system controls flow by maintaining a constant differential pressure between
- A.
  
  Inlet and throat of venturi
- B.
  
  Outlet and inlet of venturi
- C.
  
  Outlet and throat of venturi
- D.
  
  Inlet, outlet, and throat of venturi
Correct Answer
A. Inlet and throat of venturi

Explanation
The flow control valve in the bleed air air-conditioning system controls flow by maintaining a constant differential pressure between the inlet and throat of the venturi. This means that the valve adjusts the flow of air in order to keep the pressure difference between the inlet and throat of the venturi constant. By doing so, the valve ensures that the air flows smoothly and at the desired rate through the system.

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15.

Which bleed air system component is installed upstream of the flow control valve to control the valve's inlet pressure?
- A.
  
  Metering valve
- B.
  
  Pressure limiter
- C.
  
  System shut off valve
- D.
  
  Air pressure regulator and shut off valve
Correct Answer
D. Air pressure regulator and shut off valve

Explanation
The air pressure regulator and shut off valve is installed upstream of the flow control valve to control the valve's inlet pressure. This component regulates the pressure of the bleed air before it reaches the flow control valve, ensuring that the valve receives the appropriate pressure for optimal operation. Additionally, the shut off valve allows for the complete closure of the bleed air system when necessary.

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16.

If the source pressure drops below the bleed air pressure regulator setting,
- A.
  
  The flow control valve closes
- B.
  
  The pressure regulator closes
- C.
  
  All available pressure is supplied to the flow control valve
- D.
  
  The air-conditioning system goes into a low-flow mode of operation
Correct Answer
C. All available pressure is supplied to the flow control valve

Explanation
If the source pressure drops below the bleed air pressure regulator setting, all available pressure is supplied to the flow control valve. This means that the flow control valve will receive the maximum amount of pressure possible in order to maintain the desired flow rate. This ensures that the air-conditioning system continues to operate effectively even when the source pressure is lower than the regulator setting.

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17.

Which bleed air system component modulates to maintain a constant downstream air pressure?
- A.
  
  Pressure limiter
- B.
  
  Air flow regulator
- C.
  
  Pressure regulator
- D.
  
  Flow control valve
Correct Answer
B. Air flow regulator

Explanation
The air flow regulator is responsible for modulating the bleed air system to maintain a constant downstream air pressure. It adjusts the flow of air to ensure that the pressure remains consistent, preventing any fluctuations or deviations. This component plays a crucial role in maintaining the overall stability and efficiency of the bleed air system.

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18.

After replacing a bleed air system air-conditioning airflow regulator fusible plug, you must also reset
- A.
  
  Lockout butterfly
- B.
  
  Pneumatic switch
- C.
  
  Pneumatic thermostat
- D.
  
  Break away plug assembly
Correct Answer
B. Pneumatic switch

Explanation
After replacing a bleed air system air-conditioning airflow regulator fusible plug, you must also reset the pneumatic switch. This is because the pneumatic switch controls the flow of air in the system. When the fusible plug is replaced, it may cause a disruption in the airflow, and resetting the pneumatic switch ensures that the system is functioning properly again.

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19.

The downstream air temperature of the bleed air air-conditioning system has exceeded the predetermined temperature and has cause the butterfly valve to close. what flow control and shutoff switch now opens?
- A.
  
  Fusible
- B.
  
  Thermal
- C.
  
  Pnuematic
- D.
  
  Breakaway
Correct Answer
B. Thermal

Explanation
The correct answer is thermal. When the downstream air temperature of the bleed air air-conditioning system exceeds the predetermined temperature, it triggers the thermal flow control and shutoff switch to open. This switch is designed to respond to temperature changes and activate the necessary actions to regulate the flow of air and maintain the desired temperature.

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20.

Aircraft high-pressure/high-temperature air-conditioning ducting is usually made of this type of material.
- A.
  
  Titanium
- B.
  
  Aluminum
- C.
  
  Stainless steel
- D.
  
  Aluminum/ nickel alloy
Correct Answer
C. Stainless steel

Explanation
Aircraft high-pressure/high-temperature air-conditioning ducting is usually made of stainless steel because it has excellent corrosion resistance, high strength, and can withstand high temperatures. Stainless steel is also lightweight, which is important for aircraft applications. Additionally, stainless steel has good ductility, allowing it to be easily formed into complex shapes for ducting systems.

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21.

What tool do you use to install high pressure/ high temperature v band clap to ensure it is aligned and sealed properly?
- A.
  
  Screwdriver
- B.
  
  Center punch
- C.
  
  Rawhide mallet
- D.
  
  Ball peen hammer
Correct Answer
C. Rawhide mallet

Explanation
A rawhide mallet is used to install a high pressure/high temperature V band clamp to ensure it is aligned and sealed properly. The rawhide mallet is a soft-faced hammer that won't damage or deform the clamp or the surrounding components while providing enough force to properly align and seal the clamp. It is a preferred tool for this task because it minimizes the risk of damaging the clamp or causing leaks in the high pressure/high temperature system.

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22.

While installing a bleed air system bolted flanged duct end, use a metal or fiber gasket, align the flange, and insert the bottom bolt first to form a cradle. then you install the remaining bolt and tightened all the nuts. after the installation is complete, you preform an op check that reveals a leak. what important procedure was overlooked?
- A.
  
  Sealant compound was not used with the gasket
- B.
  
  Flange bolts were not torqued in the proper sequence
- C.
  
  Flange was not tapped with rawhide mallet while torquing
- D.
  
  Gasket should have been installed before cradle bolts were installed
Correct Answer
B. Flange bolts were not torqued in the proper sequence

Explanation
The important procedure that was overlooked in the installation process was torquing the flange bolts in the proper sequence. Torquing the bolts in a specific sequence ensures that they are evenly tightened and prevents any leaks from occurring. By not following the correct sequence, it is possible that some of the bolts were not tightened enough, resulting in a leak in the system.

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23.

A crush-type gasket used in the bolted flange aircraft-ducting end is made of
- A.
  
  Fiber and fiberglass
- B.
  
  Fiberglass and neoprene or rubber
- C.
  
  Soft aluminum or fiber and metal mesh
- D.
  
  Soft aluminum and fiber reinforced rubber or plastic
Correct Answer
C. Soft aluminum or fiber and metal mesh

Explanation
The correct answer is soft aluminum or fiber and metal mesh. This type of gasket is commonly used in bolted flange aircraft-ducting ends because it provides a strong and durable seal. The soft aluminum helps to create a tight fit between the flanges, while the fiber and metal mesh provide additional reinforcement and prevent leakage. This combination of materials ensures that the gasket can withstand the high pressure and temperature conditions typically found in aircraft ducting systems.

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24.

What important fact must you remember, that can be over looked, when replacing gaskets used in aircraft ducting?
- A.
  
  Only replace gaskets if they are distorted
- B.
  
  Always install new gasket each time a joint is reconnected
- C.
  
  Only replace gaskets in high pressure/ high temperature ducting
- D.
  
  Always reuse a gasket because it is already shaped to fit the duct
Correct Answer
B. Always install new gasket each time a joint is reconnected

Explanation
When replacing gaskets used in aircraft ducting, it is important to remember to always install a new gasket each time a joint is reconnected. This is because gaskets can become worn or damaged over time, and reusing them may lead to leaks or other issues. Installing a new gasket ensures a proper seal and helps maintain the integrity of the ducting system.

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25.

What type of high pressure/high temperature flange ducting does not require a gasket?
- A.
  
  Clamp
- B.
  
  Bolted
- C.
  
  Beaded
- D.
  
  Compressible
Correct Answer
D. Compressible

Explanation
A compressible high pressure/high temperature flange ducting does not require a gasket because it is designed to deform and create a tight seal under pressure. The compressible material allows for flexibility and adaptability, ensuring a secure connection without the need for a separate gasket. This type of ducting is commonly used in applications where frequent disassembly and reassembly is required, as it can easily be compressed and resealed without the need for additional components.

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26.

What corrective action should you take when a high pressure/ high temperature compressible flange duct end becomes distorted?
- A.
  
  Replace the duct flange ends
- B.
  
  Use a gasket with the duct end
- C.
  
  Reposition the duct for better sealing
- D.
  
  Reshape the duct flange ends to its original shape
Correct Answer
D. Reshape the duct flange ends to its original shape

Explanation
When a high pressure/high temperature compressible flange duct end becomes distorted, the correct corrective action is to reshape the duct flange ends to its original shape. This means that instead of replacing the entire duct flange ends or using a gasket, the best course of action is to manipulate the distorted ends back to their original form. This ensures that the duct maintains its proper sealing and functionality without the need for replacement or additional materials.

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27.

Which lubricant can you only use on a medium pressure/ medium temperature beaded channel clamp sleeve to ease installation?
- A.
  
  Soap
- B.
  
  Water
- C.
  
  Grease
- D.
  
  Silicone
Correct Answer
B. Water

Explanation
Water is the correct answer because it is the only lubricant that can be used on a medium pressure/medium temperature beaded channel clamp sleeve to ease installation. Soap, grease, and silicone are not suitable for this purpose.

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28.

Expansion joints in aircraft bleed air systems are best used on this type of ducting
- A.
  
  Low pressure
- B.
  
  Long runs
- C.
  
  Short runs
- D.
  
  Ram air
Correct Answer
C. Short runs

Explanation
Expansion joints in aircraft bleed air systems are best used on short runs of ducting. This is because expansion joints are designed to accommodate thermal expansion and contraction of the ducting. Short runs of ducting experience less thermal expansion and contraction compared to long runs. Therefore, using expansion joints on short runs helps to prevent damage to the ducting and maintain the integrity of the system.

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29.

To preform a leakage test on an entire bleed air distribution system you
- A.
  
  Listen for leaking high pressure air
- B.
  
  Use an ultrasonic leak detector
- C.
  
  Listen and feel for leaks
- D.
  
  Feel for hot leaking air
Correct Answer
C. Listen and feel for leaks

Explanation
The correct answer is to listen and feel for leaks. When performing a leakage test on an entire bleed air distribution system, it is important to use multiple senses to detect leaks. By listening carefully, one can identify any unusual sounds that may indicate air leakage. Additionally, feeling for leaks can involve running one's hand along the system to detect any air currents or temperature changes that may suggest a leak. This combination of listening and feeling allows for a more comprehensive detection of leaks in the system.

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30.

If a bleed air system leak is found in a high pressure/ high temperature area, your next step is to
- A.
  
  Look around for blistered paint
- B.
  
  Inspect for heat damage
- C.
  
  Peel back the insulation
- D.
  
  Look for deterioration
Correct Answer
B. Inspect for heat damage

Explanation
In this scenario, the correct next step would be to inspect for heat damage. Since the leak is found in a high pressure/high temperature area, it is important to check for any signs of damage caused by the heat. This could include discoloration, warping, or melting of nearby components. By inspecting for heat damage, you can assess the extent of the issue and determine the appropriate course of action to address the leak.

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31.

The hand survey air-leakage test method is preformed on the aircraft bleed air distribution system after
- A.
  
  Resetting the lock out butterfly
- B.
  
  Replacing any couplings or valves
- C.
  
  Troubleshooting the system malfunctions
- D.
  
  Inspecting the bleed air system and operational check.
Correct Answer
B. Replacing any couplings or valves

Explanation
The hand survey air-leakage test method is performed on the aircraft bleed air distribution system after replacing any couplings or valves. This is because when couplings or valves are replaced, there is a possibility of air leakage in the system. The hand survey air-leakage test is conducted to ensure that there are no leaks in the system after the replacement, as leaks can affect the performance and efficiency of the bleed air system.

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32.

You preform and aircraft bleed air system leakage check using pressure decay method with aircraft engine: the time for the pressure to drop 30 psi took 11 seconds.this indicates that the system leakage test
- A.
  
  Needs to be repeated
- B.
  
  Results are dangerouly excessive
- C.
  
  Results are below allowable limits
- D.
  
  Results are not dangerously excessive
Correct Answer
D. Results are not dangerously excessive

Explanation
Based on the given information, the time it took for the pressure to drop 30 psi was 11 seconds. Since the question states that the pressure decay method was used for the leakage check, a longer time for the pressure to drop would indicate a higher level of leakage. However, in this case, the time of 11 seconds suggests that the leakage is not dangerously excessive. Therefore, the correct answer is that the results are not dangerously excessive.

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33.

You are troubleshooting an aircraft bleed air system and find a leak, what could have cause the leak?
- A.
  
  An orifice that is defective
- B.
  
  An improperly installed clamp
- C.
  
  A precooler air ejector valve that is defective
- D.
  
  A pressure regulator that is installed backwards
Correct Answer
B. An improperly installed clamp

Explanation
The leak in the aircraft bleed air system could have been caused by an improperly installed clamp. If the clamp is not securely fastened or positioned correctly, it can result in a gap or opening through which the air can escape. This can lead to a loss of pressure and affect the overall functioning of the system. Therefore, ensuring that clamps are installed properly is crucial in preventing leaks in the bleed air system.

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34.

While troubleshooting and aircraft bleed air system you find the system air pressure exceeds the pressure relieve valve settings, the next step to take is to
- A.
  
  Look for additional leaks
- B.
  
  Adjust the pressure regulator
- C.
  
  Replace the pressure relief valve
- D.
  
  Replaced the cracked heat exchanger
Correct Answer
C. Replace the pressure relief valve

Explanation
If the system air pressure exceeds the pressure relieve valve settings while troubleshooting an aircraft bleed air system, the next step is to replace the pressure relief valve. This is because the pressure relief valve is responsible for regulating and maintaining the desired pressure within the system. If it is not functioning properly, it can lead to excessive pressure. Therefore, replacing the pressure relief valve would be the appropriate course of action to address the issue.

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35.

You are leak checking and aircraft bleed air system and need to know if the engine bleed air (EBA) shut off valve is working, so you
- A.
  
  Connect a pressure gage to the outlet side
- B.
  
  Check the small drill hole for escaping air
- C.
  
  Preform a pressure decay leak check
- D.
  
  Secure the valve insulation
Correct Answer
B. Check the small drill hole for escaping air

Explanation
To determine if the engine bleed air (EBA) shut off valve is working, you should check the small drill hole for escaping air. This is because the small drill hole is designed to release air when the valve is closed. If there is no escaping air, it indicates that the valve is working properly and effectively shutting off the bleed air system.

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36.

An aircraft bleed air cooling system's pre-cooler is sometimes known as the
- A.
  
  Air cycle machine
- B.
  
  Contaminated air
- C.
  
  Primary heat exchanger
- D.
  
  Regenerative temperature changer
Correct Answer
C. Primary heat exchanger

Explanation
The pre-cooler in an aircraft bleed air cooling system is referred to as the primary heat exchanger. This component is responsible for cooling the hot bleed air from the engine before it is used for various purposes such as cabin air conditioning and pressurization. The primary heat exchanger plays a crucial role in maintaining the temperature and comfort inside the aircraft by efficiently transferring heat from the bleed air to the surrounding environment.

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37.

What components aid the aircraft's bleed air pre-cooler assembly in maintaining a constant outlet temperature?
- A.
  
  Sensor, modulating valve, and jet pump
- B.
  
  Sensor, temperature control circuit, and jet pump
- C.
  
  Sensor, temperature control circuit, and modulating valve
- D.
  
  Temperature control circuit, modulating valve, and jet pump
Correct Answer
C. Sensor, temperature control circuit, and modulating valve

Explanation
The sensor is responsible for measuring the temperature of the bleed air. The temperature control circuit receives the temperature measurement from the sensor and adjusts the modulating valve accordingly. The modulating valve regulates the flow of bleed air to maintain a constant outlet temperature.

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38.

Close-assault attack aircraft may develop insufficient cooling in the air conditioning system (ACS) due to
- A.
  
  The higher altitudes flown
- B.
  
  High speeds associated with this type aircraft
- C.
  
  Icing associated with flying at higher altitudes
- D.
  
  Low amounts of ram air associated with slower speeds
Correct Answer
D. Low amounts of ram air associated with slower speeds

Explanation
Close-assault attack aircraft may develop insufficient cooling in the air conditioning system (ACS) due to low amounts of ram air associated with slower speeds. Ram air is the air that is forced into the ACS by the forward motion of the aircraft. At slower speeds, there is less air being forced into the system, leading to reduced cooling. This can result in inadequate cooling for the aircraft, especially in hot environments or during prolonged operations.

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39.

To create a greater cooling effect, atomized water is sprayed across the inlet of the aircraft bleed air system's secondary heat exchanger by the
- A.
  
  Jet pump
- B.
  
  Jet sprayer
- C.
  
  Water aspirator
- D.
  
  Water separater
Correct Answer
C. Water aspirator

Explanation
A water aspirator is used to create a greater cooling effect by spraying atomized water across the inlet of the aircraft bleed air system's secondary heat exchanger. This device works by using the high velocity of the air flow to draw in and mix the water, creating a fine mist that can effectively cool the incoming air. The water aspirator is specifically designed for this purpose and is the most suitable option among the given choices.

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40.

One purpose of the fan in the aircraft bleed air system cooling turbine and fan assembly is to prevent
- A.
  
  Excessive airflow
- B.
  
  Low system pressure
- C.
  
  Turbine over speeding
- D.
  
  Moisture in the cold air
Correct Answer
C. Turbine over speeding

Explanation
The fan in the aircraft bleed air system cooling turbine and fan assembly helps prevent turbine over speeding. When the turbine spins too fast, it can cause mechanical stress and damage to the engine. The fan helps regulate the airflow and maintain a safe operating speed for the turbine, ensuring the engine's efficiency and longevity.

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41.

Some cooling turbines have a pair of unused wires that are cut-off close to the turbine housing. what level of maintenance uses these wires?
- A.
  
  Depot
- B.
  
  Squadron
- C.
  
  Intermediate
- D.
  
  Organizational
Correct Answer
A. Depot

Explanation
Some cooling turbines have a pair of unused wires that are cut-off close to the turbine housing. These wires are used for maintenance purposes at the depot level. The depot level maintenance involves more extensive repairs and overhauls of equipment, and these wires may be used for diagnostic or testing purposes during the maintenance process.

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42.

The maximum temperature that a full ceramic bearing can operate is
- A.
  
  1900 degrees fahrenheit
- B.
  
  1800 degrees F
- C.
  
  1700 degrees F
- D.
  
  1600 degrees F
Correct Answer
B. 1800 degrees F

Explanation
The maximum temperature that a full ceramic bearing can operate is 1800 degrees F. This means that the bearing can withstand temperatures up to 1800 degrees Fahrenheit without experiencing any significant damage or failure. Operating at higher temperatures can potentially cause the bearing to degrade or fail, making 1800 degrees F the maximum limit for safe operation.

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43.

Aircraft bleed air system water separators remove 70 to 85 percent of the moisture that accumulates in the conditioned air. what causes this to happen?
- A.
  
  Rapid expansion
- B.
  
  Regulated air flow
- C.
  
  Internal compression
- D.
  
  Regulated air pressure
Correct Answer
A. Rapid expansion

Explanation
The rapid expansion of air causes the moisture to condense and separate from the conditioned air. When the air expands rapidly, its temperature drops, leading to the condensation of moisture. This condensed moisture is then removed by the water separators, which can remove 70 to 85 percent of the accumulated moisture in the conditioned air.

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44.

The aircraft bleed air system water separator anti icing system prevents the condenser bag from icing by keeping the turbine
- A.
  
  Inlet temperature above 32 degrees
- B.
  
  Inlet temperature below 32 degrees
- C.
  
  Outlet temperature above 32 degrees
- D.
  
  Outlet temperature below 32 degrees
Correct Answer
C. Outlet temperature above 32 degrees

Explanation
The correct answer is "outlet temperature above 32 degrees". The aircraft bleed air system water separator anti-icing system prevents the condenser bag from icing by maintaining the outlet temperature above 32 degrees. This ensures that any water or moisture in the system does not freeze and cause ice buildup, which could potentially disrupt the operation of the aircraft's systems.

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45.

This bleed are system component causes the aircraft's cooling turbine to slow down when an icing condition occurs.
- A.
  
  Anti-icing valve
- B.
  
  Ice control screen
- C.
  
  Anti-icing controller
- D.
  
  Turbine bypass valve
Correct Answer
B. Ice control screen

Explanation
The ice control screen is the correct answer because it is a system component that is designed to prevent ice from forming on the aircraft's cooling turbine. When an icing condition occurs, the ice control screen will effectively block the ice from accumulating on the turbine, allowing it to continue operating at its normal speed. This helps to maintain the proper functioning of the aircraft's cooling system and prevents any potential issues or damage that could occur if the turbine were to slow down due to ice buildup.

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46.

What type air source ventilates the aircraft cockpit when smoke or fumes are discharged from the air-conditioning system?
- A.
  
  Liquid
- B.
  
  Compressed
- C.
  
  Conditioned
- D.
  
  Atmosheric
Correct Answer
D. Atmosheric

Explanation
When smoke or fumes are discharged from the aircraft's air-conditioning system, the cockpit is ventilated using atmospheric air. This means that outside air is brought into the cockpit to replace the contaminated air. Atmospheric air is the most common and readily available source of air for ventilation purposes in aircraft.

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47.

The warning light in the cockpit is activated by this component if duct pressure on a fighter aircraft's air-conditioning system (ACS) becomes excessive/
- A.
  
  Turbine over speed switch
- B.
  
  Cabin temperature limiter
- C.
  
  Manual temperature limiter
- D.
  
  Pneumatic-thermal overheat switch
Correct Answer
A. Turbine over speed switch

Explanation
The turbine over speed switch is responsible for activating the warning light in the cockpit if the duct pressure on a fighter aircraft's air-conditioning system becomes excessive. This switch is designed to detect when the turbine speed exceeds a safe limit, indicating a potential problem with the system. When this happens, the switch triggers the warning light to alert the pilot of the issue.

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48.

The position of this valve depends on temperature of conditioned air going to the crew compartment.
- A.
  
  Cabin air inlet
- B.
  
  Ground cooling ejector
- C.
  
  Water separator bypass
- D.
  
  Cabin dual-temperature mixing
Correct Answer
D. Cabin dual-temperature mixing

Explanation
The cabin dual-temperature mixing valve is responsible for regulating the temperature of the conditioned air that is supplied to the crew compartment. It adjusts the position of the valve based on the temperature of the air, ensuring that the air entering the cabin is at the desired temperature. This valve is crucial in maintaining a comfortable and controlled environment for the crew members.

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49.

Before the conditioned air enters the crew area of a fight aircraft, it goes through a final cooling stage in the
- A.
  
  Expansion turbine
- B.
  
  Compressor turbine
- C.
  
  Primary heat exchanger
- D.
  
  Secondary heat exchanger
Correct Answer
A. Expansion turbine

Explanation
The conditioned air in a flight aircraft goes through a final cooling stage in the expansion turbine. This turbine helps to reduce the temperature of the air before it enters the crew area. The expansion turbine works by expanding the air, which causes it to cool down. This cooling stage is important to ensure that the air entering the crew area is at a comfortable temperature for the crew members. The expansion turbine is therefore the correct answer in this case.

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50.

This component removes excessive moister from conditioned air, preventing it from reaching the cockpit of a fighter aircraft
- A.
  
  Defog valve
- B.
  
  Anti-icing valve
- C.
  
  Water separator
- D.
  
  Cabin dual-temperature mixing valve
Correct Answer
C. Water separator

Explanation
A water separator is a component that removes excessive moisture from conditioned air. In the context of a fighter aircraft, this is important to prevent the moisture from reaching the cockpit. Excessive moisture can cause fogging on the cockpit windshield, which can obstruct the pilot's vision and compromise safety. Therefore, a water separator is necessary to ensure clear visibility for the pilot and maintain optimal conditions inside the cockpit.

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Current Version
Mar 20, 2023

Quiz Edited by
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Jun 02, 2015

Quiz Created by
Mirand Rudd

2A656 Aircraft Electrical And Environmental Systems Journeyman Volume 4

All of these aircraft systems use engine bleed air except

Bleed air is usually taken from this aircraft engine section.

What is the approximate pressure and maximum temperature of engine bleed air as it is tapped from the engine compressor section

Which component determines the amount of bleed air bled from the a gas turbine compressor (GTC)

Engine bleed air check valves are installed to

What engine bleed air valve prevents air from being lost through he engine when it is shutdown?

This component stops the flow of air to the air-conditioning system

If electrical power is interrupted to the solenoid of an electrically controlled, pneumatically operated air-conditioning system shut off valve with a fail safe feature, the valve

What pressure and flow control device restricts airflow and protects aircraft engines against air starvation

Due to loss of energy, the outlet air pressure of an orifice is

What is the bleed air system component that controls the air flow by protecting downstream components from excessive pressure?

The amount of airflow through a pressure limiter is affected by these except

The butterfly valve of the air-conditioning pressure limiter is open when

The flow control valve control in the bleed air air-conditioning system controls flow by maintaining a constant differential pressure between

Which bleed air system component is installed upstream of the flow control valve to control the valve's inlet pressure?

If the source pressure drops below the bleed air pressure regulator setting,

Which bleed air system component modulates to maintain a constant downstream air pressure?

After replacing a bleed air system air-conditioning airflow regulator fusible plug, you must also reset

The downstream air temperature of the bleed air air-conditioning system has exceeded the predetermined temperature and has cause the butterfly valve to close. what flow control and shutoff switch now opens?

Aircraft high-pressure/high-temperature air-conditioning ducting is usually made of this type of material.

What tool do you use to install high pressure/ high temperature v band clap to ensure it is aligned and sealed properly?

A crush-type gasket used in the bolted flange aircraft-ducting end is made of

What important fact must you remember, that can be over looked, when replacing gaskets used in aircraft ducting?

What type of high pressure/high temperature flange ducting does not require a gasket?

What corrective action should you take when a high pressure/ high temperature compressible flange duct end becomes distorted?

Which lubricant can you only use on a medium pressure/ medium temperature beaded channel clamp sleeve to ease installation?

Expansion joints in aircraft bleed air systems are best used on this type of ducting

To preform a leakage test on an entire bleed air distribution system you

If a bleed air system leak is found in a high pressure/ high temperature area, your next step is to

The hand survey air-leakage test method is preformed on the aircraft bleed air distribution system after

You preform and aircraft bleed air system leakage check using pressure decay method with aircraft engine: the time for the pressure to drop 30 psi took 11 seconds.this indicates that the system leakage test

You are troubleshooting an aircraft bleed air system and find a leak, what could have cause the leak?

While troubleshooting and aircraft bleed air system you find the system air pressure exceeds the pressure relieve valve settings, the next step to take is to

You are leak checking and aircraft bleed air system and need to know if the engine bleed air (EBA) shut off valve is working, so you

An aircraft bleed air cooling system's pre-cooler is sometimes known as the

What components aid the aircraft's bleed air pre-cooler assembly in maintaining a constant outlet temperature?

Close-assault attack aircraft may develop insufficient cooling in the air conditioning system (ACS) due to

To create a greater cooling effect, atomized water is sprayed across the inlet of the aircraft bleed air system's secondary heat exchanger by the

One purpose of the fan in the aircraft bleed air system cooling turbine and fan assembly is to prevent

Some cooling turbines have a pair of unused wires that are cut-off close to the turbine housing. what level of maintenance uses these wires?

The maximum temperature that a full ceramic bearing can operate is

Aircraft bleed air system water separators remove 70 to 85 percent of the moisture that accumulates in the conditioned air. what causes this to happen?

The aircraft bleed air system water separator anti icing system prevents the condenser bag from icing by keeping the turbine

This bleed are system component causes the aircraft's cooling turbine to slow down when an icing condition occurs.

What type air source ventilates the aircraft cockpit when smoke or fumes are discharged from the air-conditioning system?

The warning light in the cockpit is activated by this component if duct pressure on a fighter aircraft's air-conditioning system (ACS) becomes excessive/

The position of this valve depends on temperature of conditioned air going to the crew compartment.

Before the conditioned air enters the crew area of a fight aircraft, it goes through a final cooling stage in the

This component removes excessive moister from conditioned air, preventing it from reaching the cockpit of a fighter aircraft