1.
(601) All of these aircraft systems use engine bleed air except
Correct Answer
B. Fire extinguishing.
Explanation
Engine bleed air is used in aircraft systems for various purposes such as anti-gravity (anti-G), rain removal, and anti-icing. It is used to pressurize and de-ice the aircraft, as well as to power various systems. However, engine bleed air is not used for fire extinguishing. Fire extinguishing systems in aircraft typically use specialized agents such as foam or halon to suppress and extinguish fires.
2.
(601) Bleed air is usually taken from this aircraft engine section.
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 to increase its pressure and deliver it to the combustion chamber. During this process, a small amount of compressed air is bled off for various purposes such as cabin pressurization, anti-icing, and pneumatic systems. Therefore, the correct answer is the compressor.
3.
(601) What is the approximate pressure and maximum temperature of engine bleed air as it is tapped from the engine compression section?
Correct Answer
C. 200 psi and 900°F.
Explanation
The engine bleed air is tapped from the engine compression section at an approximate pressure of 200 pounds per square inch (psi) and a maximum temperature of 900 degrees Fahrenheit (°F).
4.
(601) Which component determines the amount of bleed air bled from a gas turbine compressor (GTC)?
Correct Answer
C. Load control valve.
Explanation
The load control valve is the component that determines the amount of bleed air bled from a gas turbine compressor (GTC). This valve regulates the flow of bleed air based on the load requirements of the turbine. By adjusting the position of the load control valve, the amount of bleed air can be controlled, ensuring that the turbine operates efficiently and effectively. The other options, such as the thermocouple, fuel control valve, and bleed air control governor, do not have a direct role in determining the amount of bleed air bled from the compressor.
5.
(601) Engine bleed air check valves are installed to
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 high-pressure bleed air does not escape from the system when it is not needed. By preventing the loss of compressed bleed air, the valves help maintain the efficiency and effectiveness of the aircraft's bleed air system. This is important because bleed air is used for various purposes such as cabin pressurization, air conditioning, and anti-icing.
6.
(601) What engine bleed air valve prevents air from being lost through the engine when it is shutdown?
Correct Answer
B. Shutoff.
Explanation
The engine bleed air valve that prevents air from being lost through the engine when it is shutdown is the shutoff valve. This valve is designed to close off the flow of bleed air, effectively shutting down the engine and preventing any air from escaping. The shutoff valve is an important component in maintaining the integrity of the engine system during shutdown and ensuring that no air is wasted.
7.
Pressure limiter.
Correct Answer
D. System shutoff valve.
Explanation
The correct answer is System shutoff valve. A system shutoff valve is responsible for completely stopping the flow of fluid or gas in a system. It is typically used to isolate a system or equipment for maintenance or emergency purposes. In this context, a system shutoff valve would be the most appropriate choice as it would allow for the complete shutdown of the system, ensuring safety and preventing any further flow of air or fluid.
8.
(602) If electrical power is interrupted to the solenoid of an electrically controlled, pneumatically operated air-conditioning system shutoff valve with a fail-safe feature, the valve
Correct Answer
D. Opens or closes depending on system design requirements.
Explanation
The correct answer is "opens or closes depending on system design requirements." This is because the valve has a fail-safe feature, which means that in the event of an interruption in electrical power to the solenoid, the valve will either open or close based on the specific design of the system. The system may be designed to open the valve to allow for the flow of air or close the valve to stop the flow, depending on the requirements of the system.
9.
(602) What pressure and flow control device restricts airflow and protects aircraft engines against air starvation?
Correct Answer
A. Orifice.
Explanation
An orifice is a pressure and flow control device that restricts airflow. It is commonly used to protect aircraft engines against air starvation by maintaining a consistent and controlled flow of air. By limiting the amount of air that can pass through, the orifice ensures that the engine receives enough air for proper combustion while also preventing excessive airflow that could cause damage or inefficiency. Therefore, the orifice is the correct answer as it effectively restricts airflow and protects aircraft engines from air starvation.
10.
(602) Due to a loss of energy, the outlet air pressure of an orifice is
Correct Answer
A. Lower than the inlet.
Explanation
When air flows 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.
11.
(602) What is the bleed air system component that controls the airflow by protecting downstream components from excessive pressure?
Correct Answer
B. Pressure limiter.
Explanation
A pressure limiter is a component in the bleed air system that controls the airflow by protecting downstream components from excessive pressure. It ensures that the pressure does not exceed a certain limit, preventing any damage or malfunctioning of the system. This is important as excessive pressure can cause harm to the components and compromise the overall performance of the system. Therefore, a pressure limiter is necessary to maintain the proper functioning and safety of the bleed air system.
12.
(602) The amount of airflow through a pressure limiter is affected by each of these except
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 have any impact on the airflow through the pressure limiter.
13.
(602) The butterfly valve of the air-conditioning pressure limiter is open when
Correct Answer
B. There is not enough pressure applied to the system.
Explanation
The correct answer is "there is not enough pressure applied to the system." This means that the butterfly valve of the air-conditioning pressure limiter is open when there is insufficient pressure in the system. In other words, when the pressure is below the required level, the valve opens to allow more air or fluid to flow into the system in order to increase the pressure.
14.
(604) You perform an aircraft bleed air system leakage check using the pressure decay method with an aircraft engine; the time for the pressure to drop 30 pounds per square inch (psi) took 11 seconds. This indicates that the system leakage test
Correct Answer
D. Results are not dangerously excessive.
Explanation
The given information states that the time for the pressure to drop 30 psi took 11 seconds. This indicates that the system leakage is not dangerously excessive because if there was a significant leak, the pressure would have dropped much faster. Therefore, the results are not dangerously excessive.
15.
(602) Which bleed air system component is installed upstream of the flow control valve to control the valve’s inlet pressure?
Correct Answer
D. Air pressure regulator and shutoff valve.
Explanation
The air pressure regulator and shutoff 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 enters the flow control valve, ensuring that the valve receives the appropriate pressure for its operation. Additionally, the shutoff valve allows for the complete closure of the bleed air system when needed.
16.
(602) If the source pressure drops below the bleed air pressure regulator setting,
Correct Answer
C. All available air pressure is supplied to the flow control valve.
Explanation
When the source pressure drops below the bleed air pressure regulator setting, the flow control valve closes. This means that all available air pressure is then supplied to the flow control valve.
17.
(602) Which bleed air system component modulates to maintain a constant downstream air pressure?
Correct Answer
B. Airflow regulator.
Explanation
The correct answer is Airflow regulator. The airflow regulator is a component of the bleed air system that modulates to maintain a constant downstream air pressure. It regulates the flow of air to ensure that the pressure remains consistent, preventing any fluctuations or deviations. This is important for the proper functioning of the system and to ensure that the downstream equipment receives the required air pressure.
18.
(602) The flow control valve control in the bleed air air-conditioning system controls flow by maintaining a constant differential pressure between the
Correct Answer
A. Inlet and throat of the venturi.
Explanation
The flow control valve in the bleed air air-conditioning system maintains a constant differential pressure between the inlet and throat of the venturi. This means that the valve regulates the flow of air by ensuring that there is a consistent pressure difference between the two points. By doing so, it controls the flow rate and ensures that the air-conditioning system operates effectively.
19.
(602) After replacing a bleed air system air-conditioning airflow regulator fusible plug, you must also reset the
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 fusible plug is designed to melt at a specific temperature to prevent excessive pressure build-up in the system. When the fusible plug melts, it triggers the pneumatic switch to shut off the airflow. Therefore, after replacing the fusible plug, the pneumatic switch needs to be reset to restore the airflow and ensure proper functioning of the air-conditioning system.
20.
(602) The downstream air temperature of the bleed air air-conditioning system has exceeded the predetermined temperature and has caused the butterfly to close. What flow control and shutoff switch now opens?
Correct Answer
B. Thermal.
Explanation
The correct answer is "Thermal." In this scenario, the downstream air temperature of the bleed air air-conditioning system has exceeded the predetermined temperature, causing the butterfly to close. To address this issue, a flow control and shutoff switch that is specifically designed to respond to temperature changes is needed. A thermal switch is capable of opening when the temperature reaches a certain threshold, allowing for proper flow control and shutoff in this situation.
21.
(603) Aircraft high-pressure/high-temperature air-conditioning ducting is usually made of this type material.
Correct Answer
C. Stainless steel.
Explanation
Aircraft high-pressure/high-temperature air-conditioning ducting is usually made of stainless steel because it is a strong and corrosion-resistant material that can withstand the high pressures and temperatures involved in aircraft operations. Titanium is also a strong material, but it is more commonly used in applications where weight reduction is a priority. Aluminum is lightweight but not as strong as stainless steel, making it less suitable for high-pressure/high-temperature environments. Aluminum/nickel alloy is not commonly used for air-conditioning ducting in aircraft.
22.
603) What tool do you use to install a high-pressure/high-temperature V-band clamp to ensure it is aligned and sealed properly?
Correct Answer
C. Rawhide mallet.
Explanation
A rawhide mallet is the correct tool to use when installing a high-pressure/high-temperature V-band clamp to ensure it is aligned and sealed properly. Rawhide mallets are made of rawhide material, which is soft and non-damaging to the clamp or other surfaces. It provides a controlled and gentle force to align and seal the clamp without causing any damage. Using a screwdriver, center punch, or ball peen hammer could potentially damage the clamp or create an improper seal, making the rawhide mallet the best tool for the job.
23.
603) While installing a bleed air system bolted flanged duct end, use a metal or fiber gasket, align the flange, and insert the bottom bolts first to form a cradle. Then, you install the remaining bolts and tighten all the nuts. After the installation is complete, you perform an operational check that reveals a leak. From the above information, what important procedure was overlooked?
Correct Answer
B. Flange bolts were not torqued in the proper sequence.
Explanation
The important procedure that was overlooked is that the flange bolts were not torqued in the proper sequence. Torquing the bolts in the correct sequence ensures that they are tightened evenly and prevents leaks in the system. Failing to follow the proper torquing sequence can result in uneven pressure distribution and cause a leak to occur during the operational check.
24.
(603) A crush-type gasket used in the bolted flange aircraft-ducting end is made of
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 crush-type gasket is commonly used in bolted flange aircraft-ducting ends. It is made of a combination of soft aluminum and either fiber or metal mesh. The soft aluminum provides a flexible and malleable component, while the fiber or metal mesh adds strength and durability to the gasket. This combination allows the gasket to effectively seal the flange and prevent leaks in the aircraft ducting system.
25.
(603) What important fact must you remember, that can be overlooked, when replacing gaskets used in aircraft ducting?
Correct Answer
B. Always install a 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 result in leaks or other issues. Installing a new gasket ensures a proper seal and helps maintain the integrity of the aircraft ducting system.
26.
(603) What type of high-pressure/high-temperature flange ducting does not require a gasket?
Correct Answer
D. Compressible.
Explanation
A compressible high-pressure/high-temperature flange ducting does not require a gasket because it is designed to create a tight seal by compressing the flange material itself. This type of ducting is able to withstand high pressures and temperatures without the need for an additional gasket, making it a more efficient and cost-effective option. The compressible nature of the flange allows it to conform to the mating surface, ensuring a secure and leak-free connection.
27.
(603) What corrective action should you take when a high-pressure/high-temperature compressible flange duct end becomes distorted?
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 to take 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 distorted ends should be carefully reshaped to restore their original form. This is the most efficient and cost-effective solution to ensure proper sealing and functionality of the duct.
28.
(603) Which lubricant can you only use on a medium-pressure/medium-temperature beaded channel clamp sleeve to ease installation?
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 lubricants for this specific application.
29.
(603) Expansion joints in aircraft bleed air systems are best used on this type of ducting.
Correct Answer
C. Short runs.
Explanation
Expansion joints in aircraft bleed air systems are best used on short runs of ducting. This is because short runs of ducting are more prone to thermal expansion and contraction, which can cause stress and damage to the ducting if not properly accommodated. Expansion joints are designed to allow for this movement, absorbing the expansion and contraction without causing harm to the ducting. In contrast, long runs of ducting are less susceptible to these thermal effects and may not require expansion joints. Therefore, short runs of ducting are the most appropriate application for expansion joints in aircraft bleed air systems.
30.
(604) To perform a leakage test on an entire bleed air distribution system you
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, you can listen for the sound of leaking high-pressure air and also feel for any air escaping through leaks. This method allows you to detect any potential leaks in the system by using your senses of hearing and touch. Using an ultrasonic leak detector is not mentioned as a method for this specific test, and feeling for hot leaking air is not specified as a step in the process.
31.
(604) If a bleed air system leak is found in a high pressure/high temperature area, your next step is to
Correct Answer
B. Inspect for heat damage.
Explanation
If a bleed air system leak is found in a high pressure/high temperature area, the next logical step would be to inspect for heat damage. This is because the high pressure and temperature can cause damage to the surrounding components, such as blistered paint, insulation peeling back, or deterioration. Therefore, inspecting for heat damage would help identify any potential issues and ensure the safety and functionality of the system.
32.
(604) The hand survey air-leakage test method is performed on the aircraft bleed air distribution system after
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 replacing couplings or valves can potentially introduce air leaks into the system. The hand survey air-leakage test is conducted to ensure that there are no leaks in the system that could affect its performance and safety. By performing the test after replacing couplings or valves, any potential leaks can be identified and addressed before the system is put back into operation.
33.
(605) You are troubleshooting an aircraft’s bleed air system and find a leak. What could have caused the leak?
Correct Answer
B. An improperly installed clamp.
Explanation
The leak in the aircraft's bleed air system could have been caused by an improperly installed clamp. This means that the clamp was not secured properly or was not tightened enough, leading to a gap or space where air can escape.
34.
(605) While troubleshooting an aircraft’s bleed air system you find the system air pressure exceeds the pressure relief valve setting, so the next step you must take is to
Correct Answer
C. Replace the pressure relief valve.
Explanation
When troubleshooting an aircraft's bleed air system and finding that the system air pressure exceeds the pressure relief valve setting, the next step is to replace the pressure relief valve. This is because the pressure relief valve is designed to open and release excess pressure when it reaches a certain level. If the valve is not functioning properly or is damaged, it may not be able to relieve the excess pressure, leading to potential system malfunctions or damage. Therefore, replacing the pressure relief valve is necessary to ensure the proper functioning and safety of the bleed air system.
35.
(605) You are leak checking an aircraft bleed air system and need to know if the engine bleed air (EBA) shutoff valve is working, so you
Correct Answer
B. Check the small drill hole for escaping air.
Explanation
The correct answer is to check the small drill hole for escaping air. This is because a small drill hole is intentionally made in the outlet side of the engine bleed air (EBA) shutoff valve. If there is escaping air from this hole, it indicates that the valve is working properly. This method helps in leak checking the aircraft bleed air system and ensuring the functionality of the EBA shutoff valve.
36.
(606) An aircraft’s bleed air cooling system’s pre-cooler is sometimes known as the
Correct Answer
C. Primary heat exchanger.
Explanation
The correct answer is "primary heat exchanger." The pre-cooler in an aircraft's bleed air cooling system is responsible for cooling the hot bleed air before it enters the air cycle machine. This is achieved by transferring heat from the hot air to a cooler medium, which is typically ambient air or engine coolant. The pre-cooler acts as the primary heat exchanger in this process, as it is the first component that cools the air.
37.
(606) What components aid the aircraft’s bleed air pre-cooler assembly in maintaining a constant outlet temperature?
Correct Answer
C. Sensor, temperature control circuit, and modulating valve.
Explanation
The components that aid the aircraft's bleed air pre-cooler assembly in maintaining a constant outlet temperature are a sensor, a temperature control circuit, and a modulating valve. The sensor measures the outlet temperature, which is then fed into the temperature control circuit. The temperature control circuit processes this information and sends signals to the modulating valve, which adjusts the flow of bleed air to maintain a constant outlet temperature.
38.
(606) Close-assault attack aircraft may develop insufficient cooling in the air conditioning system (ACS) due to
Correct Answer
D. Low amounts of ram air associated with slower speeds.
Explanation
Close-assault attack aircraft often fly at slower speeds, which results in lower amounts of ram air entering the air conditioning system (ACS). Ram air is the air that is forced into the system by the aircraft's forward motion. At slower speeds, there is less air entering the ACS, leading to insufficient cooling. This is the most likely explanation for the development of insufficient cooling in the ACS of close-assault attack aircraft.
39.
(606) 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
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. The water aspirator is designed to draw in air and mix it with water, creating a fine mist or spray that can effectively cool the incoming air. This process helps to enhance the cooling capabilities of the system and maintain optimal operating temperatures.
40.
(606) One purpose of the fan in the aircraft bleed air system cooling turbine and fan assembly is to prevent
Correct Answer
C. Turbine over speeding.
Explanation
The purpose of the fan in the aircraft bleed air system cooling turbine and fan assembly is to prevent turbine over speeding. The fan helps regulate the airflow and prevents the turbine from spinning too fast, which could lead to damage or malfunction. By controlling the speed of the turbine, the fan ensures the safe and efficient operation of the aircraft's bleed air system.
41.
(606) 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?
Correct Answer
A. Depot.
Explanation
Cooling turbines in a depot level of maintenance often have a pair of unused wires that are cut-off close to the turbine housing. This indicates that the depot level of maintenance uses these wires.
42.
(606) The maximum temperature that a full ceramic bearing can operate is
Correct Answer
B. 1800°F.
Explanation
A full ceramic bearing is designed to withstand high temperatures, and the maximum temperature it can operate at is 1800°F. This means that the bearing is capable of functioning effectively and without damage in environments where the temperature does not exceed this limit.
43.
(607) 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?
Correct Answer
A. Rapid expansion.
Explanation
The moisture in the conditioned air is removed by the aircraft bleed air system water separators through rapid expansion. When the air expands rapidly, its temperature drops, causing the moisture to condense and separate from the air. This process allows the system to remove 70 to 85 percent of the accumulated moisture and provide dry air for the aircraft's systems.
44.
(607) The aircraft bleed air system water separator anti-icing system prevents the condenser bag from icing by keeping the turbine
Correct Answer
C. Outlet temperature above 32°.
Explanation
The aircraft bleed air system water separator anti-icing system prevents the condenser bag from icing by keeping the outlet temperature above 32°. This means that the system is designed to ensure that the temperature of the air leaving the system is above freezing point, which prevents the formation of ice on the condenser bag.
45.
(607) This bleed air system component causes the aircraft’s cooling turbine to slow down when an icing condition occurs.
Correct Answer
B. Ice control screen.
Explanation
The ice control screen is the correct answer because it is a component of the bleed air system that helps to prevent ice formation. When an icing condition occurs, the ice control screen works by filtering out ice particles from the air before it enters the cooling turbine. This prevents the turbine from becoming clogged or damaged, allowing it to continue operating at the correct speed. Therefore, the ice control screen plays a crucial role in maintaining the efficiency and safety of the aircraft's cooling system during icing conditions.
46.
(607) What type air source ventilates the aircraft cockpit when smoke or fumes are discharged from the air-conditioning system?
Correct Answer
D. AtmospHeric.
Explanation
When smoke or fumes are discharged from the aircraft's air-conditioning system, the cockpit is ventilated by the atmospheric air source. This means that the air in the cockpit is refreshed and replaced with outside air from the atmosphere. This is important to ensure the safety and well-being of the crew members in the cockpit, as it helps to remove any potential harmful substances or odors caused by the smoke or fumes.
47.
(608) 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.
Correct Answer
A. Turbine over speed switch.
Explanation
The warning light in the cockpit is activated by the turbine over speed switch if duct pressure on a fighter aircraft's air-conditioning system becomes excessive.
48.
(608) The position of this valve depends on the temperature of conditioned air going to the crew compartment.
Correct Answer
D. Cabin dual-temperature mixing.
Explanation
The correct answer is Cabin dual-temperature mixing. The position of this valve depends on the temperature of conditioned air going to the crew compartment. This suggests that the valve is responsible for mixing air of different temperatures to achieve the desired temperature in the cabin. The other options, such as cabin air inlet, ground cooling ejector, and water separator bypass, do not directly relate to the temperature control in the crew compartment.
49.
(608) Before the conditioned air enters the crew area of a fighter aircraft, it goes through a final cooling stage in the
Correct Answer
A. Expansion turbine.
Explanation
The conditioned air in a fighter aircraft goes through a final cooling stage in the expansion turbine. This turbine helps to further cool the air before it enters the crew area. This is important to ensure that the air is at a comfortable temperature for the crew members. The expansion turbine works by expanding the air, which causes it to cool down. This cooling process helps to remove any excess heat from the air, making it suitable for the crew area.
50.
(608) This component removes excessive moisture from conditioned air, preventing it from reaching the cockpit of a fighter aircraft.
Correct Answer
B. Anti-ice valve.
Explanation
The correct answer is the Anti-ice valve. This component is responsible for removing excessive moisture from conditioned air in order to prevent it from reaching the cockpit of a fighter aircraft. This is important because excessive moisture can cause fogging on the aircraft's windshield, obstructing the pilot's view and potentially compromising safety. The Anti-ice valve helps to maintain clear visibility by preventing moisture from reaching the cockpit.