Volume 3 - 2014 CDC 2a651s Jet Aircraft

1. (401) What is the composition of JP–8 fuel?

Gasoline and kerosene.

Gasoline and diesel fuel.

Diesel fuel and kerosene.

Diesel fuel and aviation gasoline.

JP-8 fuel is a type of jet fuel used by the United States military. It is a blend of kerosene and gasoline. This composition gives JP-8 fuel a high flash point and low volatility, making it suitable for use in both jet engines and diesel engines. The addition of gasoline helps improve the cold weather performance of the fuel, while the kerosene component provides the necessary energy density for efficient combustion.

Explanation

JP-8 fuel is a type of jet fuel used by the United States military. It is a blend of kerosene and gasoline. This composition gives JP-8 fuel a high flash point and low volatility, making it suitable for use in both jet engines and diesel engines. The addition of gasoline helps improve the cold weather performance of the fuel, while the kerosene component provides the necessary energy density for efficient combustion.

2. (402) During a visual inspection, how can you tell when a fuel filter is clogged?

A green flag pops out of the filter.

Fuel pressure from the fuel pump is low.

A differential pressure indicator is actuated.

There is no way to tell without disassembling the filter.

A differential pressure indicator is actuated when a fuel filter is clogged. This means that there is a noticeable difference in pressure between the inlet and outlet of the filter, indicating a blockage. This indicator serves as a visual or audible signal to the inspector that the filter needs to be cleaned or replaced. It provides a convenient and efficient way to determine if a fuel filter is clogged without the need to disassemble it.

Explanation

A differential pressure indicator is actuated when a fuel filter is clogged. This means that there is a noticeable difference in pressure between the inlet and outlet of the filter, indicating a blockage. This indicator serves as a visual or audible signal to the inspector that the filter needs to be cleaned or replaced. It provides a convenient and efficient way to determine if a fuel filter is clogged without the need to disassemble it.

3. (405) Use extreme care when working with labyrinth seals because of their

Soft metal construction; these seals can be damaged easily.

Soft metal construction; they are sharp and can cut your hand.

Hard metal construction; they are sharp and can cut your hand.

Hard metal construction; these seals can damage the bearing races.

The correct answer is "soft metal construction; these seals can be damaged easily." This is because labyrinth seals are made of soft metal, which means they are more susceptible to damage. They can easily be bent, dented, or scratched, leading to a compromised seal and potential leakage. It is important to handle them with extreme care to avoid any damage. The other options are incorrect because they either mention sharpness and cutting, which is not relevant to the construction material, or they mention hard metal construction, which is not true for labyrinth seals.

Explanation

The correct answer is "soft metal construction; these seals can be damaged easily." This is because labyrinth seals are made of soft metal, which means they are more susceptible to damage. They can easily be bent, dented, or scratched, leading to a compromised seal and potential leakage. It is important to handle them with extreme care to avoid any damage. The other options are incorrect because they either mention sharpness and cutting, which is not relevant to the construction material, or they mention hard metal construction, which is not true for labyrinth seals.

4. (413) What does the EGT/T5.6 thermocouple consist of?

Alumel.

Chromel.

Both alumel and chromel.

None of these.

The EGT/T5.6 thermocouple consists of both alumel and chromel. Alumel is an alloy made of nickel, aluminum, manganese, and silicon, while chromel is an alloy made of nickel and chromium. These two alloys are commonly used in the construction of thermocouples due to their high temperature resistance and stability. By combining alumel and chromel, the EGT/T5.6 thermocouple is able to accurately measure high temperatures in various applications.

Explanation

The EGT/T5.6 thermocouple consists of both alumel and chromel. Alumel is an alloy made of nickel, aluminum, manganese, and silicon, while chromel is an alloy made of nickel and chromium. These two alloys are commonly used in the construction of thermocouples due to their high temperature resistance and stability. By combining alumel and chromel, the EGT/T5.6 thermocouple is able to accurately measure high temperatures in various applications.

5. (404) When in the primary mode, what controls the operation of the F100-PW–220 engine?

MEC.

PMG.

TSFC.

DEEC.

The DEEC (Digital Electronic Engine Control) controls the operation of the F100-PW-220 engine when it is in the primary mode. The DEEC is responsible for monitoring and adjusting various engine parameters such as fuel flow, exhaust temperature, and compressor speed to ensure optimal engine performance and efficiency. It receives inputs from various sensors and uses its algorithms to make real-time adjustments to maintain the engine within safe operating limits.

Explanation

The DEEC (Digital Electronic Engine Control) controls the operation of the F100-PW-220 engine when it is in the primary mode. The DEEC is responsible for monitoring and adjusting various engine parameters such as fuel flow, exhaust temperature, and compressor speed to ensure optimal engine performance and efficiency. It receives inputs from various sensors and uses its algorithms to make real-time adjustments to maintain the engine within safe operating limits.

6. (402) The main fuel control allows the jet engine to safely accelerate, reducing the possibility of

Flameout.

Turbine seizure.

Compressor shift.

Overtemperature.

The main fuel control allows the jet engine to safely accelerate, reducing the possibility of flameout. Flameout refers to the sudden extinguishing of the flame in the engine combustion chamber, leading to a loss of thrust. The main fuel control ensures the proper fuel-air mixture is maintained, preventing an overly lean or rich mixture that could result in flameout. By controlling the fuel flow, the main fuel control helps maintain a stable and continuous combustion process, ensuring the engine operates smoothly and avoids flameout.

Explanation

The main fuel control allows the jet engine to safely accelerate, reducing the possibility of flameout. Flameout refers to the sudden extinguishing of the flame in the engine combustion chamber, leading to a loss of thrust. The main fuel control ensures the proper fuel-air mixture is maintained, preventing an overly lean or rich mixture that could result in flameout. By controlling the fuel flow, the main fuel control helps maintain a stable and continuous combustion process, ensuring the engine operates smoothly and avoids flameout.

7. (403) What type of fuel control uses items such as thermocouples, relays, amplifiers, and solenoids to help control a jet engine?

Pneumatic.

Fuel injection.

Hydromechanical.

Electrohydromechanical.

Electrohydromechanical fuel control uses components such as thermocouples, relays, amplifiers, and solenoids to regulate the fuel flow in a jet engine. These components work together to measure and control various parameters such as temperature, pressure, and flow rate to ensure efficient and precise fuel delivery. This type of fuel control system combines electrical, hydraulic, and mechanical elements to achieve optimal engine performance.

Explanation

Electrohydromechanical fuel control uses components such as thermocouples, relays, amplifiers, and solenoids to regulate the fuel flow in a jet engine. These components work together to measure and control various parameters such as temperature, pressure, and flow rate to ensure efficient and precise fuel delivery. This type of fuel control system combines electrical, hydraulic, and mechanical elements to achieve optimal engine performance.

8. (406) What term is used to indicate that air is being mixed with the oil in the oil pump to create pockets of air?

Aeration.

Induction.

Convection.

Compression.

Aeration is the term used to indicate that air is being mixed with the oil in the oil pump to create pockets of air.

Explanation

Aeration is the term used to indicate that air is being mixed with the oil in the oil pump to create pockets of air.

9. (405) Carbon seals should be cleaned by soaking them in clean, warm

JP–4 for 60 minutes.

PD–680 for 30 minutes.

Kerosene for 60 minutes.

Engine lubricating oil for 30 minutes.

not-available-via-ai

Explanation

not-available-via-ai

10. (409) What are microscopic metallic particles in the oil system called?

Wear metals.

Friction metals.

Precious metals.

Transformation metals.

Microscopic metallic particles in the oil system are called wear metals. These particles are generated as a result of friction and wear between moving parts in the machinery. They can come from various sources such as the engine, transmission, or other mechanical components. Monitoring the levels of wear metals in the oil can provide valuable information about the condition of the machinery and can help identify potential issues or failures before they occur.

Explanation

Microscopic metallic particles in the oil system are called wear metals. These particles are generated as a result of friction and wear between moving parts in the machinery. They can come from various sources such as the engine, transmission, or other mechanical components. Monitoring the levels of wear metals in the oil can provide valuable information about the condition of the machinery and can help identify potential issues or failures before they occur.

11. (403) If the safety seals on a fuel system component are broken or removed, and you suspect the factory adjustment was altered, you should

Adjust and reseal the component.

Keep the component in service to meet the mission.

Forward the component to the authorized depot for reflow and resealing.

If the safety seals on a fuel system component are broken or removed and there is suspicion that the factory adjustment was altered, the appropriate action is to forward the component to the authorized depot for reflow and resealing. This ensures that the component is properly inspected, adjusted, and sealed by authorized personnel, maintaining its safety and functionality.

Explanation

If the safety seals on a fuel system component are broken or removed and there is suspicion that the factory adjustment was altered, the appropriate action is to forward the component to the authorized depot for reflow and resealing. This ensures that the component is properly inspected, adjusted, and sealed by authorized personnel, maintaining its safety and functionality.

12. (404) On an F100-PW–220 engine, the DEEC is cooled by

Oil.

Fuel.

Ram air.

Hydraulic fluid.

The DEEC (Digital Electronic Engine Control) on an F100-PW-220 engine is cooled by fuel. The DEEC is responsible for monitoring and controlling various engine parameters, such as fuel flow, temperature, and pressure. Since fuel is already present in the engine, it is utilized to cool the DEEC as it circulates through the system. This helps to maintain the optimal operating temperature of the DEEC and ensures its proper functioning.

Explanation

The DEEC (Digital Electronic Engine Control) on an F100-PW-220 engine is cooled by fuel. The DEEC is responsible for monitoring and controlling various engine parameters, such as fuel flow, temperature, and pressure. Since fuel is already present in the engine, it is utilized to cool the DEEC as it circulates through the system. This helps to maintain the optimal operating temperature of the DEEC and ensures its proper functioning.

13. (405) Which type of oil cooler operates on the same principle as a radiator in an automobile?

Air/oil.

Fuel.

Hydraulic.

Pneumatic.

An air/oil cooler operates on the same principle as a radiator in an automobile. In both cases, heat is transferred from a hot fluid (oil in the case of an air/oil cooler, coolant in the case of a radiator) to the surrounding air. The hot fluid flows through a series of tubes or fins, and air is passed over these surfaces to cool the fluid down. This process allows for efficient cooling of the fluid, preventing it from overheating and maintaining optimal operating conditions.

Explanation

An air/oil cooler operates on the same principle as a radiator in an automobile. In both cases, heat is transferred from a hot fluid (oil in the case of an air/oil cooler, coolant in the case of a radiator) to the surrounding air. The hot fluid flows through a series of tubes or fins, and air is passed over these surfaces to cool the fluid down. This process allows for efficient cooling of the fluid, preventing it from overheating and maintaining optimal operating conditions.

14. (429) What component in the electronic/mechanical controls is a fuel cooled digital computer that provides signals to the MFC for control of the front compressor speed (N1), rear compressor speed (N2), engine airflow, combustion chamber pressure (Pb4) and FTIT.

MFC.

DEEC.

Stator generator.

Throttle quadrant.

The correct answer is DEEC. DEEC stands for Digital Electronic Engine Control, which is a fuel-cooled digital computer that provides signals to the MFC (Main Fuel Control) for controlling various aspects of the engine's performance. It controls the front compressor speed (N1), rear compressor speed (N2), engine airflow, combustion chamber pressure (Pb4), and FTIT (Fan Turbine Inlet Temperature). The DEEC plays a crucial role in optimizing the engine's efficiency and ensuring smooth operation.

Explanation

The correct answer is DEEC. DEEC stands for Digital Electronic Engine Control, which is a fuel-cooled digital computer that provides signals to the MFC (Main Fuel Control) for controlling various aspects of the engine's performance. It controls the front compressor speed (N1), rear compressor speed (N2), engine airflow, combustion chamber pressure (Pb4), and FTIT (Fan Turbine Inlet Temperature). The DEEC plays a crucial role in optimizing the engine's efficiency and ensuring smooth operation.

15. (403) Which term describes a jet engine fuel metering device that is really two fuel controls in one component?

Unified.

Combined.

Bimechanical.

Electrosecondary.

The term "unified" describes a jet engine fuel metering device that is really two fuel controls in one component. This means that the device combines two separate fuel controls into a single component, providing a more efficient and streamlined system for metering fuel in a jet engine.

Explanation

The term "unified" describes a jet engine fuel metering device that is really two fuel controls in one component. This means that the device combines two separate fuel controls into a single component, providing a more efficient and streamlined system for metering fuel in a jet engine.

16. (409) During an OAP sample collection, using your mouth to draw oil up into the plastic tube could result in

Insufficient oil collection.

Contaminated samples.

A minor stomach ache.

Paralysis or death.

Using your mouth to draw oil up into the plastic tube during an OAP sample collection can result in paralysis or death. This is because the oil may contain toxic substances or chemicals that can be harmful if ingested. Ingesting these substances can lead to severe health complications, including paralysis or even death. Therefore, it is important to follow proper safety procedures and use the appropriate equipment when collecting oil samples to avoid such risks.

Explanation

Using your mouth to draw oil up into the plastic tube during an OAP sample collection can result in paralysis or death. This is because the oil may contain toxic substances or chemicals that can be harmful if ingested. Ingesting these substances can lead to severe health complications, including paralysis or even death. Therefore, it is important to follow proper safety procedures and use the appropriate equipment when collecting oil samples to avoid such risks.

17. (403) Calibration and/or adjustment screws that require setting during an engine trim procedure must be

Replaced.

Die marked.

Safety sealed and/or lockwired.

Treated with a thread locking compound.

During an engine trim procedure, calibration and/or adjustment screws may need to be set. To ensure that these screws remain in the correct position and prevent any unauthorized tampering or adjustment, they must be safety sealed and/or lockwired. Safety sealing involves adding a seal or tag to indicate that the screws have been properly set and should not be tampered with. Lockwiring involves securing the screws with a wire or other locking mechanism to prevent them from loosening or changing position. This helps maintain the accuracy and reliability of the engine trim procedure.

Explanation

During an engine trim procedure, calibration and/or adjustment screws may need to be set. To ensure that these screws remain in the correct position and prevent any unauthorized tampering or adjustment, they must be safety sealed and/or lockwired. Safety sealing involves adding a seal or tag to indicate that the screws have been properly set and should not be tampered with. Lockwiring involves securing the screws with a wire or other locking mechanism to prevent them from loosening or changing position. This helps maintain the accuracy and reliability of the engine trim procedure.

18. (417) The JFS is basically a

Piston-type starter.

Pneumatic-type starter.

Small gas turbine engine.

Cartridge-pneumatic starter.

The correct answer is small gas turbine engine. This is because the JFS (Jet Fuel Starter) is a type of small gas turbine engine that is used to start larger gas turbine engines. It provides the necessary power to start the main engine by using compressed air generated by the small gas turbine engine. This allows for a self-sustaining starting system, as the JFS can start itself and then start the main engine.

Explanation

The correct answer is small gas turbine engine. This is because the JFS (Jet Fuel Starter) is a type of small gas turbine engine that is used to start larger gas turbine engines. It provides the necessary power to start the main engine by using compressed air generated by the small gas turbine engine. This allows for a self-sustaining starting system, as the JFS can start itself and then start the main engine.

19. (405) Which type of oil pump consists of a gear and rotor within a housing?

Gear.

Gerotor.

Rotogear.

Sliding vane.

A gerotor oil pump consists of a gear and rotor within a housing. The gear and rotor work together to create a pumping action, drawing oil into the pump and then forcing it out through the outlet. This type of pump is commonly used in automotive engines and other applications where a reliable and efficient oil pump is needed.

Explanation

A gerotor oil pump consists of a gear and rotor within a housing. The gear and rotor work together to create a pumping action, drawing oil into the pump and then forcing it out through the outlet. This type of pump is commonly used in automotive engines and other applications where a reliable and efficient oil pump is needed.

20. (409) Increased friction between moving parts in the oil system

Accelerates the rate of wear, decreasing the production of wear metal particles.

Accelerates the rate of wear, increasing the production of wear metal particles.

Slows the rate of wear, decreasing the production of wear metal particles.

Slows the rate of wear, increasing the production of wear metal particles.

Increased friction between moving parts in the oil system accelerates the rate of wear, increasing the production of wear metal particles. When there is increased friction, the surfaces of the moving parts rub against each other more vigorously, causing more wear. This wear leads to the generation of wear metal particles, which are small metal fragments that are released into the oil system. Therefore, the correct answer is that increased friction accelerates the rate of wear and increases the production of wear metal particles.

Explanation

Increased friction between moving parts in the oil system accelerates the rate of wear, increasing the production of wear metal particles. When there is increased friction, the surfaces of the moving parts rub against each other more vigorously, causing more wear. This wear leads to the generation of wear metal particles, which are small metal fragments that are released into the oil system. Therefore, the correct answer is that increased friction accelerates the rate of wear and increases the production of wear metal particles.

21. (427) What is the basic function of an augmentor (afterburner) when it is not operating?

Act as the basic engine tailpipe.

Control engine discharge pressure.

Aid in control of engine oil pressure.

Help to control pressure and N2 speed.

When an augmentor (afterburner) is not operating, its basic function is to act as the basic engine tailpipe. This means that it functions as a regular exhaust pipe for the engine, allowing the exhaust gases to exit the engine and be released into the atmosphere. The augmentor does not have any additional functions or controls when it is not in operation.

Explanation

When an augmentor (afterburner) is not operating, its basic function is to act as the basic engine tailpipe. This means that it functions as a regular exhaust pipe for the engine, allowing the exhaust gases to exit the engine and be released into the atmosphere. The augmentor does not have any additional functions or controls when it is not in operation.

22. (410) The difference between DC and AC is that DC

Has a constant polarity; AC changes direction at regular intervals.

Fluctuates from negative to positive values; AC stays at a constant positive value.

Differs from AC only in the way current is used; otherwise there is no real difference.

Is produced directly from a generator; AC is produced by an alternator after the generator.

DC stands for Direct Current, which means that the flow of electric charge is in one direction only. This results in a constant polarity, where the positive and negative terminals of the source remain the same. On the other hand, AC stands for Alternating Current, where the flow of electric charge periodically changes direction. This causes the polarity to alternate between positive and negative at regular intervals. Therefore, the correct answer is that DC has a constant polarity, while AC changes direction at regular intervals.

Explanation

DC stands for Direct Current, which means that the flow of electric charge is in one direction only. This results in a constant polarity, where the positive and negative terminals of the source remain the same. On the other hand, AC stands for Alternating Current, where the flow of electric charge periodically changes direction. This causes the polarity to alternate between positive and negative at regular intervals. Therefore, the correct answer is that DC has a constant polarity, while AC changes direction at regular intervals.

23. (419) Discharge air used for aircraft engine anti-icing to heat-critical areas is taken from which engine area?

Compressor.

Combustion.

Augmentor.

Turbine.

The discharge air used for aircraft engine anti-icing is taken from the compressor area. The compressor is responsible for compressing the incoming air before it enters the combustion chamber. By using the discharge air from the compressor, which is already at a high temperature, it can be directed to heat critical areas of the aircraft engine to prevent ice formation. This helps to ensure that the engine operates efficiently and safely in cold weather conditions.

Explanation

The discharge air used for aircraft engine anti-icing is taken from the compressor area. The compressor is responsible for compressing the incoming air before it enters the combustion chamber. By using the discharge air from the compressor, which is already at a high temperature, it can be directed to heat critical areas of the aircraft engine to prevent ice formation. This helps to ensure that the engine operates efficiently and safely in cold weather conditions.

24. (410) What is the term for the process of producing voltage in a conductor when it passes through a magnetic field?

Static.

Electronics.

Mutual induction.

Electromagnetic induction.

Electromagnetic induction is the term used to describe the process of producing voltage in a conductor when it passes through a magnetic field. This phenomenon was first discovered by Michael Faraday in the early 19th century and is a fundamental principle in the field of electromagnetism. It is the basis for the operation of electric generators and transformers, as well as many other electrical devices.

Explanation

Electromagnetic induction is the term used to describe the process of producing voltage in a conductor when it passes through a magnetic field. This phenomenon was first discovered by Michael Faraday in the early 19th century and is a fundamental principle in the field of electromagnetism. It is the basis for the operation of electric generators and transformers, as well as many other electrical devices.

25. (401) Jet aircraft operating at moderately high altitudes increase the fuel system's susceptibility to an icing condition, further aggravated by the

Lower viscosity of jet fuels.

Higher viscosity of jet fuels.

Lower viscosity of free water.

Higher viscosity of free water.

Jet aircraft operating at moderately high altitudes increase the fuel system's susceptibility to an icing condition. This is because at higher altitudes, the temperature is lower, increasing the likelihood of ice formation. The viscosity of a fuel refers to its thickness or resistance to flow. A higher viscosity means the fuel is thicker and less likely to flow easily. In the case of jet fuels, a higher viscosity would make it more difficult for the fuel to flow through the fuel system, increasing the risk of icing. Therefore, the correct answer is higher viscosity of jet fuels.

Explanation

Jet aircraft operating at moderately high altitudes increase the fuel system's susceptibility to an icing condition. This is because at higher altitudes, the temperature is lower, increasing the likelihood of ice formation. The viscosity of a fuel refers to its thickness or resistance to flow. A higher viscosity means the fuel is thicker and less likely to flow easily. In the case of jet fuels, a higher viscosity would make it more difficult for the fuel to flow through the fuel system, increasing the risk of icing. Therefore, the correct answer is higher viscosity of jet fuels.

26. (407) If the red button on an F100-PW–220 engine oil filter pops out and remains extended, the

Button is defective.

Scheduled oil change is due.

Design ambient pressure has been exceeded.

Design pressure differential has been exceeded.

When the red button on an F100-PW-220 engine oil filter pops out and remains extended, it indicates that the design pressure differential has been exceeded. This means that the pressure difference between the inlet and outlet of the oil filter has surpassed the maximum limit set by the design specifications. This could be due to various factors such as a clogged filter, excessive pressure in the engine, or a malfunctioning pressure relief valve. It is important to address this issue promptly to prevent any potential damage to the engine.

Explanation

When the red button on an F100-PW-220 engine oil filter pops out and remains extended, it indicates that the design pressure differential has been exceeded. This means that the pressure difference between the inlet and outlet of the oil filter has surpassed the maximum limit set by the design specifications. This could be due to various factors such as a clogged filter, excessive pressure in the engine, or a malfunctioning pressure relief valve. It is important to address this issue promptly to prevent any potential damage to the engine.

27. (409) For bases that do not have an OAP laboratory, who designates the facility to which oil samples are sent?

Base commander.

Unit commander.

Program manager.

Unit safety officer.

The program manager is responsible for designating the facility to which oil samples are sent in bases that do not have an OAP laboratory. This is because the program manager oversees the overall maintenance and inspection program, including the analysis of oil samples. The base commander, unit commander, and unit safety officer may have their own responsibilities, but they are not specifically designated to determine the facility for oil sample testing.

Explanation

The program manager is responsible for designating the facility to which oil samples are sent in bases that do not have an OAP laboratory. This is because the program manager oversees the overall maintenance and inspection program, including the analysis of oil samples. The base commander, unit commander, and unit safety officer may have their own responsibilities, but they are not specifically designated to determine the facility for oil sample testing.

28. (405) One micron is a metric linear measurement that is equal to

1/25 inch.

1/250 inch.

1/2,500 inch.

1/25,000 inch.

One micron is a very small unit of measurement, equal to one millionth of a meter. To convert it to inches, we need to know that there are 25,400 microns in an inch. Therefore, to find the equivalent measurement in inches, we divide 1 by 25,400, which gives us 1/25,400 inch.

Explanation

One micron is a very small unit of measurement, equal to one millionth of a meter. To convert it to inches, we need to know that there are 25,400 microns in an inch. Therefore, to find the equivalent measurement in inches, we divide 1 by 25,400, which gives us 1/25,400 inch.

29. (405) Chip detectors have an electrical connection for making which type of check?

AC high-voltage.

DC high-voltage.

Continuity.

Polarity.

Chip detectors have an electrical connection for making a continuity check. This means that the chip detector is used to check whether there is a continuous electrical connection between two points or components. By checking for continuity, the chip detector can determine if there is a break or interruption in the electrical circuit, which could indicate a potential issue or fault.

Explanation

Chip detectors have an electrical connection for making a continuity check. This means that the chip detector is used to check whether there is a continuous electrical connection between two points or components. By checking for continuity, the chip detector can determine if there is a break or interruption in the electrical circuit, which could indicate a potential issue or fault.

30. (405) The purpose of an oil-temperature control valve used with air/oil coolers is to

Control the oil poppet valve.

Direct oil around the fuel filter.

Control oil exiting from the cooler.

Direct oil around or through the cooler.

The purpose of an oil-temperature control valve used with air/oil coolers is to direct oil around or through the cooler. This valve is responsible for regulating the flow of oil to ensure that it is properly cooled before returning to the engine. By directing the oil around or through the cooler, the valve helps maintain the optimal temperature of the oil, preventing it from overheating and potentially causing damage to the engine.

Explanation

The purpose of an oil-temperature control valve used with air/oil coolers is to direct oil around or through the cooler. This valve is responsible for regulating the flow of oil to ensure that it is properly cooled before returning to the engine. By directing the oil around or through the cooler, the valve helps maintain the optimal temperature of the oil, preventing it from overheating and potentially causing damage to the engine.

31. (405) When an engine is not operating, static preload for a carbon oil seal is provided by

Air pressure.

Oil pressure.

Spring pressure.

Hydraulic pressure.

When an engine is not operating, the carbon oil seal needs to maintain a static preload to prevent leakage. This preload is provided by spring pressure. The springs in the oil seal apply a constant force on the seal, ensuring that it remains in contact with the shaft and prevents oil from escaping.

Explanation

When an engine is not operating, the carbon oil seal needs to maintain a static preload to prevent leakage. This preload is provided by spring pressure. The springs in the oil seal apply a constant force on the seal, ensuring that it remains in contact with the shaft and prevents oil from escaping.

32. (404) Which stage of compressor air drives the augmenter fuel pump on an F100-PW–220 engine?

7th.

10th.

13th.

14th.

The correct answer is 13th. In a F100-PW-220 engine, the 13th stage of the compressor is responsible for driving the augmenter fuel pump. This stage provides the necessary power to pump fuel into the afterburner, increasing thrust and performance.

Explanation

The correct answer is 13th. In a F100-PW-220 engine, the 13th stage of the compressor is responsible for driving the augmenter fuel pump. This stage provides the necessary power to pump fuel into the afterburner, increasing thrust and performance.

33. (409) Before taking an oil sample from a drain, drain enough fluid into a container in order to

Check for large particles.

Check the drain operation.

Drain off uncirculated oil.

Drain off water and sludge.

Before taking an oil sample from a drain, it is necessary to drain enough fluid into a container in order to drain off water and sludge. This is important because water and sludge can contaminate the oil and affect its performance and lubricating properties. By draining off water and sludge before taking the oil sample, the sample will be more accurate and representative of the oil condition.

Explanation

Before taking an oil sample from a drain, it is necessary to drain enough fluid into a container in order to drain off water and sludge. This is important because water and sludge can contaminate the oil and affect its performance and lubricating properties. By draining off water and sludge before taking the oil sample, the sample will be more accurate and representative of the oil condition.

34. (418) On the F-15 secondary power system, what is used to stop the JFS starting cycle when the aircraft engine has accelerated to starter cutout speed?

Four-speed cutout switch.

Manual decoupler.

Hydraulic decoupler.

50-percent engine cutout switch assembly.

The 50-percent engine cutout switch assembly is used to stop the JFS (Jet Fuel Starter) starting cycle when the aircraft engine has accelerated to starter cutout speed on the F-15 secondary power system. This switch assembly is designed to cut off the fuel flow to the engine when it reaches 50 percent power, preventing the JFS from continuing to provide starting power. This helps to ensure a smooth transition from the JFS to the engine's own power source.

Explanation

The 50-percent engine cutout switch assembly is used to stop the JFS (Jet Fuel Starter) starting cycle when the aircraft engine has accelerated to starter cutout speed on the F-15 secondary power system. This switch assembly is designed to cut off the fuel flow to the engine when it reaches 50 percent power, preventing the JFS from continuing to provide starting power. This helps to ensure a smooth transition from the JFS to the engine's own power source.

35. (420) On an F110-GE–129 engine, the anti-icing system prevents detrimental formation and accumulation of ice on front frame struts, forward centerbody, and

Ring cowl.

Fan inlet guide vane flaps.

Variable exhaust nozzle flaps.

C-D duct.

The anti-icing system on an F110-GE-129 engine is designed to prevent the formation and accumulation of ice on specific components. In this case, it specifically targets the fan inlet guide vane flaps. These flaps are located at the front of the engine and play a crucial role in directing the airflow into the engine. Ice formation on these flaps can disrupt the airflow and affect the engine's performance. Therefore, the anti-icing system is necessary to ensure the smooth operation of the engine by preventing ice buildup on the fan inlet guide vane flaps.

Explanation

The anti-icing system on an F110-GE-129 engine is designed to prevent the formation and accumulation of ice on specific components. In this case, it specifically targets the fan inlet guide vane flaps. These flaps are located at the front of the engine and play a crucial role in directing the airflow into the engine. Ice formation on these flaps can disrupt the airflow and affect the engine's performance. Therefore, the anti-icing system is necessary to ensure the smooth operation of the engine by preventing ice buildup on the fan inlet guide vane flaps.

36. (405) What type of oil seal has soft metal as its basic composition and allows a small amount of airflow to prevent oil seepage?

Silicone.

Carbon.

Synthetic.

Labyrinth.

A labyrinth oil seal is made of soft metal and allows a small amount of airflow to prevent oil seepage. It is designed with a complex maze-like structure that creates multiple barriers for the oil, making it difficult for it to escape. This type of seal is commonly used in machinery and engines to ensure proper lubrication while minimizing oil leakage.

Explanation

A labyrinth oil seal is made of soft metal and allows a small amount of airflow to prevent oil seepage. It is designed with a complex maze-like structure that creates multiple barriers for the oil, making it difficult for it to escape. This type of seal is commonly used in machinery and engines to ensure proper lubrication while minimizing oil leakage.

37. (424) What component in the F100 monitoring system provides the operator information concerning how much (in percentage) the augmentor nozzle is opened or closed?

Oil pressure transmitter.

Engine Diagnostic Unit.

Fan turbine Inlet Temperature.

Augmentor Nozzle positioning indicator.

The augmentor nozzle positioning indicator in the F100 monitoring system provides the operator with information about how much the augmentor nozzle is opened or closed, expressed as a percentage. This allows the operator to monitor and adjust the nozzle position as needed for optimal engine performance.

Explanation

The augmentor nozzle positioning indicator in the F100 monitoring system provides the operator with information about how much the augmentor nozzle is opened or closed, expressed as a percentage. This allows the operator to monitor and adjust the nozzle position as needed for optimal engine performance.

38. (404) Which F100-PW–220 engine fuel system component controls pressurization of the core engine fuel system?

Fuel nozzle.

P&D valve.

N2 sensor.

Tt 2.5 sensor.

The P&D valve controls the pressurization of the core engine fuel system. It regulates the flow of fuel to maintain the required pressure in the system. The fuel nozzle, N2 sensor, and Tt 2.5 sensor are not directly responsible for controlling the pressurization of the fuel system.

Explanation

The P&D valve controls the pressurization of the core engine fuel system. It regulates the flow of fuel to maintain the required pressure in the system. The fuel nozzle, N2 sensor, and Tt 2.5 sensor are not directly responsible for controlling the pressurization of the fuel system.

39. (404) Core engine fuel flow sequence on an F100-PW–220 engine starts at the main fuel pump and then goes through the

AFP, AFC, fuel/oil cooler, P&D, and fuel nozzles.

MFC, fuel/oil cooler, P&D, and fuel nozzles.

AFC, AFP, fuel/oil cooler, P&D, and fuel nozzles.

Fuel/oil cooler, P&D, MFC, and fuel nozzles.

The correct answer is MFC, fuel/oil cooler, P&D, and fuel nozzles. This is the correct sequence for the core engine fuel flow on an F100-PW-220 engine. The fuel flow starts at the MFC (Main Fuel Control) which regulates the fuel flow rate. Then, it goes through the fuel/oil cooler to cool the fuel before entering the P&D (Pump and Dump) system. Finally, the fuel flows through the fuel nozzles where it is injected into the combustion chamber for combustion.

Explanation

The correct answer is MFC, fuel/oil cooler, P&D, and fuel nozzles. This is the correct sequence for the core engine fuel flow on an F100-PW-220 engine. The fuel flow starts at the MFC (Main Fuel Control) which regulates the fuel flow rate. Then, it goes through the fuel/oil cooler to cool the fuel before entering the P&D (Pump and Dump) system. Finally, the fuel flows through the fuel nozzles where it is injected into the combustion chamber for combustion.

40. (411) Which component ensures the CSD output speed is always at the desired RPM to adjust and maintain the desired 400 Hz?

Wobbler control.

Pump and motor unit.

Variable pump wobbler.

Frequency and load controller.

The frequency and load controller is responsible for ensuring that the CSD output speed is always at the desired RPM to adjust and maintain the desired 400 Hz. This component monitors the frequency and load of the system and makes necessary adjustments to the pump and motor unit to maintain the desired output speed. The wobbler control and variable pump wobbler may play a role in the control system, but the frequency and load controller is the primary component responsible for this task.

Explanation

The frequency and load controller is responsible for ensuring that the CSD output speed is always at the desired RPM to adjust and maintain the desired 400 Hz. This component monitors the frequency and load of the system and makes necessary adjustments to the pump and motor unit to maintain the desired output speed. The wobbler control and variable pump wobbler may play a role in the control system, but the frequency and load controller is the primary component responsible for this task.

41. (417) What engine section houses the JFS combustion section?

Geartrain.

Turbine plenum.

Generator control unit.

Gas generator and accessory drive assembly.

The turbine plenum is the engine section that houses the JFS (Jet Fuel Starter) combustion section. The JFS is responsible for starting the engine and providing additional power during certain flight phases. The turbine plenum is a chamber located between the compressor and turbine sections of the engine, where the combustion process takes place. It is designed to contain and direct the flow of hot gases produced by the combustion, which then drive the turbine and generate thrust.

Explanation

The turbine plenum is the engine section that houses the JFS (Jet Fuel Starter) combustion section. The JFS is responsible for starting the engine and providing additional power during certain flight phases. The turbine plenum is a chamber located between the compressor and turbine sections of the engine, where the combustion process takes place. It is designed to contain and direct the flow of hot gases produced by the combustion, which then drive the turbine and generate thrust.

42. (401) At room temperature, how many times longer will it take water to settle out of JP–8 than out of gasoline?

Two.

Three.

Four.

Five.

Water will take four times longer to settle out of JP-8 than out of gasoline at room temperature.

Explanation

Water will take four times longer to settle out of JP-8 than out of gasoline at room temperature.

43. (407) On an F100 engine, the breather pressurizing valve is internally mounted in the

Oil tank.

Gearbox.

Oil filter.

Oil pump.

The correct answer is gearbox. The breather pressurizing valve on an F100 engine is internally mounted in the gearbox. This valve helps to regulate the pressure within the gearbox by allowing excess pressure to be released. It is important for the breather pressurizing valve to be located in the gearbox to ensure proper functioning and to prevent any potential damage or malfunctioning of the engine components.

Explanation

The correct answer is gearbox. The breather pressurizing valve on an F100 engine is internally mounted in the gearbox. This valve helps to regulate the pressure within the gearbox by allowing excess pressure to be released. It is important for the breather pressurizing valve to be located in the gearbox to ensure proper functioning and to prevent any potential damage or malfunctioning of the engine components.

44. (407) On an F100-PW–220 engine, which bearing compartments drain into the gearbox by the tower shaft cavity?

1 and 2.

1 and 3.

2 and 3.

2 and 4.

On an F100-PW-220 engine, bearing compartments 2 and 3 drain into the gearbox by the tower shaft cavity.

Explanation

On an F100-PW-220 engine, bearing compartments 2 and 3 drain into the gearbox by the tower shaft cavity.

45. (405) Which type of valve permits oil flow in only one direction?

Check.

Relief.

Bypass.

Pressurizing.

A check valve is a type of valve that allows fluid to flow in only one direction. It has a one-way flow design, which means that it prevents backflow and ensures that the fluid can only move in the desired direction. In this case, the check valve would permit oil flow in only one direction, making it the correct answer.

Explanation

A check valve is a type of valve that allows fluid to flow in only one direction. It has a one-way flow design, which means that it prevents backflow and ensures that the fluid can only move in the desired direction. In this case, the check valve would permit oil flow in only one direction, making it the correct answer.

46. (408) The hazardous property of modern jet engine oil the journeyman must be aware of is

Toxicity.

Viscosity.

Alkalinity.

Corrosiveness.

The correct answer is corrosiveness. Modern jet engine oil can be corrosive, meaning it has the ability to cause damage or deterioration to materials it comes into contact with. This is an important property for a journeyman to be aware of, as it can impact the maintenance and safety of the aircraft.

Explanation

The correct answer is corrosiveness. Modern jet engine oil can be corrosive, meaning it has the ability to cause damage or deterioration to materials it comes into contact with. This is an important property for a journeyman to be aware of, as it can impact the maintenance and safety of the aircraft.

47. (408) Which action concerning open oil containers is correct?

Dispose of any portion not immediately used.

Store remaining portion immediately after use.

Dispose of any portion not used within 60 days.

Store remaining portion in clearly marked containers.

The correct action concerning open oil containers is to dispose of any portion not immediately used. This is important because leaving open containers of oil can lead to contamination and the oil can deteriorate over time. It is best to only use what is needed and properly dispose of the excess oil to maintain its quality and prevent any potential hazards.

Explanation

The correct action concerning open oil containers is to dispose of any portion not immediately used. This is important because leaving open containers of oil can lead to contamination and the oil can deteriorate over time. It is best to only use what is needed and properly dispose of the excess oil to maintain its quality and prevent any potential hazards.

48. (409) Through the use of spectrometric oil analysis, aircraft will have a higher in-commission rate because there will be

More oil sampling.

More engine removals.

Less unnecessary maintenance.

Less wear metal found in the oil.

Through the use of spectrometric oil analysis, aircraft can detect potential issues early on, allowing for targeted maintenance and reducing the need for unnecessary maintenance. This means that only necessary maintenance tasks will be performed, resulting in less downtime and a higher in-commission rate for the aircraft.

Explanation

Through the use of spectrometric oil analysis, aircraft can detect potential issues early on, allowing for targeted maintenance and reducing the need for unnecessary maintenance. This means that only necessary maintenance tasks will be performed, resulting in less downtime and a higher in-commission rate for the aircraft.

49. (403) The F100 UFC senses certain variables from the engine through the use of

A closed loop design.

An open circuit design.

The feedback control unit.

A direct mechanical connection to all engine sensors.

The F100 UFC senses certain variables from the engine through a closed loop design. In a closed loop system, the output is continuously monitored and compared to the desired input. Any deviation from the desired input is corrected through feedback control. This design allows the F100 UFC to constantly adjust and maintain the desired variables from the engine, ensuring optimal performance and efficiency.

Explanation

The F100 UFC senses certain variables from the engine through a closed loop design. In a closed loop system, the output is continuously monitored and compared to the desired input. Any deviation from the desired input is corrected through feedback control. This design allows the F100 UFC to constantly adjust and maintain the desired variables from the engine, ensuring optimal performance and efficiency.

50. (407) On an F100-PW–220 engine, the air/oil coolers are mounted on the fan duct and use

Secondary fan airflow as a coolant.

Secondary fan airflow as an oil heater.

Primary core engine airflow as a coolant.

Primary core engine airflow as an oil heater.

The air/oil coolers on an F100-PW-220 engine are mounted on the fan duct and use secondary fan airflow as a coolant. This means that the coolers are designed to cool the air and oil by utilizing the airflow generated by the secondary fan. This airflow helps to dissipate heat and maintain optimal operating temperatures for the engine.

Explanation

The air/oil coolers on an F100-PW-220 engine are mounted on the fan duct and use secondary fan airflow as a coolant. This means that the coolers are designed to cool the air and oil by utilizing the airflow generated by the secondary fan. This airflow helps to dissipate heat and maintain optimal operating temperatures for the engine.

51. (421) What law does the C-D supersonic inlet use to slow down the airflow?

Ohm’s law.

Bernoulli’s law.

Newton’s first law.

Newton’s third law.

The C-D supersonic inlet uses Bernoulli's law to slow down the airflow. Bernoulli's law states that as the speed of a fluid increases, its pressure decreases. In the case of the supersonic inlet, the airflow is slowed down by increasing its pressure. This is achieved by using a converging-diverging shape in the inlet, which causes the airflow to accelerate initially and then decelerate, resulting in a decrease in velocity and an increase in pressure.

Explanation

The C-D supersonic inlet uses Bernoulli's law to slow down the airflow. Bernoulli's law states that as the speed of a fluid increases, its pressure decreases. In the case of the supersonic inlet, the airflow is slowed down by increasing its pressure. This is achieved by using a converging-diverging shape in the inlet, which causes the airflow to accelerate initially and then decelerate, resulting in a decrease in velocity and an increase in pressure.

52. (422) Once the cooling airflow has done its job of cooling the turbine section, where does it go?

Through a heat exchanger.

Out the turbine case bleed holes.

Into the gas stream to exit the engine.

Back to the compressor to be used again.

Once the cooling airflow has done its job of cooling the turbine section, it is directed into the gas stream to exit the engine. This is because the cooling airflow has absorbed heat from the turbine section and needs to be expelled from the engine to maintain proper operating temperatures. Redirecting the airflow into the gas stream allows it to be safely released from the engine without affecting the overall performance.

Explanation

Once the cooling airflow has done its job of cooling the turbine section, it is directed into the gas stream to exit the engine. This is because the cooling airflow has absorbed heat from the turbine section and needs to be expelled from the engine to maintain proper operating temperatures. Redirecting the airflow into the gas stream allows it to be safely released from the engine without affecting the overall performance.

53. (423) The F110-GE–129 engine controls airflow through the engine with the

VSV only.

VSVs and variable bleed valves.

IGV only.

IGVs and VSVs.

The correct answer is IGVs and VSVs. The F110-GE-129 engine controls airflow through the engine using both the Inlet Guide Vanes (IGVs) and Variable Stator Vanes (VSVs). The IGVs are located at the front of the engine and help to control the airflow entering the engine. The VSVs are located in the compressor section of the engine and help to control the airflow through the compressor. By adjusting the position of both the IGVs and VSVs, the engine can effectively control the airflow and optimize engine performance.

Explanation

The correct answer is IGVs and VSVs. The F110-GE-129 engine controls airflow through the engine using both the Inlet Guide Vanes (IGVs) and Variable Stator Vanes (VSVs). The IGVs are located at the front of the engine and help to control the airflow entering the engine. The VSVs are located in the compressor section of the engine and help to control the airflow through the compressor. By adjusting the position of both the IGVs and VSVs, the engine can effectively control the airflow and optimize engine performance.

54. (405) When classified as to structure, which of the following is not a type of an oil pump?

Gear.

Gerotor.

Rotogear.

Sliding vane.

The question asks for a type of oil pump that is not classified by structure. The options provided are Gear, Gerotor, Rotogear, and Sliding vane. The correct answer is Rotogear because it is not a recognized type of oil pump. Gear, Gerotor, and Sliding vane are all valid types of oil pumps that are classified by their specific structures.

Explanation

The question asks for a type of oil pump that is not classified by structure. The options provided are Gear, Gerotor, Rotogear, and Sliding vane. The correct answer is Rotogear because it is not a recognized type of oil pump. Gear, Gerotor, and Sliding vane are all valid types of oil pumps that are classified by their specific structures.

55. (409) Who is responsible for ensuring that the OAP operates properly?

Project monitor.

Logistics commander.

Propulsion flight chief.

Laboratory supervisor.

The project monitor is responsible for ensuring that the OAP (Operational Availability Plan) operates properly. They oversee and monitor the progress of the project, ensuring that all aspects are functioning as intended. This includes coordinating with various team members, tracking the project's performance, and making any necessary adjustments to ensure its success. The project monitor plays a crucial role in ensuring the smooth operation of the OAP.

Explanation

The project monitor is responsible for ensuring that the OAP (Operational Availability Plan) operates properly. They oversee and monitor the progress of the project, ensuring that all aspects are functioning as intended. This includes coordinating with various team members, tracking the project's performance, and making any necessary adjustments to ensure its success. The project monitor plays a crucial role in ensuring the smooth operation of the OAP.

56. (407) On an F100-PW–220 engine, what component permits oil to bypass the oil filter during cold weather starts?

Oil relief valve.

Filter poppet valve.

Oil pressure transmitter tap.

Filter assembly bypass valve.

The correct answer is the Filter assembly bypass valve. During cold weather starts, the oil filter can become clogged with cold, thick oil. The filter assembly bypass valve allows the oil to bypass the filter and flow directly to the engine, ensuring that the engine receives the necessary lubrication even if the filter is not functioning optimally. This helps to protect the engine from damage during cold starts.

Explanation

The correct answer is the Filter assembly bypass valve. During cold weather starts, the oil filter can become clogged with cold, thick oil. The filter assembly bypass valve allows the oil to bypass the filter and flow directly to the engine, ensuring that the engine receives the necessary lubrication even if the filter is not functioning optimally. This helps to protect the engine from damage during cold starts.

57. (404) On the F100-PW–220 engine, which component controls the augmentor fuel control?

Fuel pump.

Fuel pump controller.

Signature elimination probe.

DEEC.

The correct answer is DEEC. The DEEC (Digital Electronic Engine Control) is the component that controls the augmentor fuel control on the F100-PW-220 engine. It is responsible for monitoring and regulating the fuel flow to the augmentor, which is a device used to increase the thrust of the engine during afterburner operation. The DEEC ensures that the correct amount of fuel is delivered to the augmentor, optimizing engine performance and efficiency.

Explanation

The correct answer is DEEC. The DEEC (Digital Electronic Engine Control) is the component that controls the augmentor fuel control on the F100-PW-220 engine. It is responsible for monitoring and regulating the fuel flow to the augmentor, which is a device used to increase the thrust of the engine during afterburner operation. The DEEC ensures that the correct amount of fuel is delivered to the augmentor, optimizing engine performance and efficiency.

58. (425) What component in the F110 monitoring system performs diagnostics and fault isolates to line replaceable units?

Full Authority Digital Electronic Control.

Engine Monitoring System Computer.

Central Air Data Computer.

Ground Station Unit.

The Engine Monitoring System Computer in the F110 monitoring system performs diagnostics and fault isolation to line replaceable units. This component is responsible for monitoring the engine's performance, detecting any faults or abnormalities, and isolating the faulty components for replacement. It plays a crucial role in ensuring the proper functioning and maintenance of the engine.

Explanation

The Engine Monitoring System Computer in the F110 monitoring system performs diagnostics and fault isolation to line replaceable units. This component is responsible for monitoring the engine's performance, detecting any faults or abnormalities, and isolating the faulty components for replacement. It plays a crucial role in ensuring the proper functioning and maintenance of the engine.

59. (417) Which item initially rotates the JFS?

ESS PTO.

Electric motor mounted on the aircraft.

Hydraulic motor.

Engine PTO.

The hydraulic motor is the item that initially rotates the JFS (Jet Fuel Starter) in this scenario. This means that the hydraulic motor is responsible for providing the initial rotational force to start the JFS. The other options, such as the ESS PTO, electric motor mounted on the aircraft, and engine PTO, are not mentioned as being involved in the initial rotation of the JFS.

Explanation

The hydraulic motor is the item that initially rotates the JFS (Jet Fuel Starter) in this scenario. This means that the hydraulic motor is responsible for providing the initial rotational force to start the JFS. The other options, such as the ESS PTO, electric motor mounted on the aircraft, and engine PTO, are not mentioned as being involved in the initial rotation of the JFS.

60. (427) What component heats augmentor fuel to provide better vaporization and combustion?

Fuel control.

Fuel spraybars.

Fuel manifolds.

Fuel/oil cooler.

The fuel/oil cooler heats the augmentor fuel to provide better vaporization and combustion. This component helps to cool the oil and fuel, ensuring that the fuel is at the optimal temperature for efficient combustion. By cooling the fuel, the fuel/oil cooler helps to prevent overheating and improve the overall performance of the engine.

Explanation

The fuel/oil cooler heats the augmentor fuel to provide better vaporization and combustion. This component helps to cool the oil and fuel, ensuring that the fuel is at the optimal temperature for efficient combustion. By cooling the fuel, the fuel/oil cooler helps to prevent overheating and improve the overall performance of the engine.

61. (421) The bleed air system is different from the variable vane system in that it

Allows airflow in only one direction.

Bleeds off air before it enters the engine.

Prevents airflow from entering the engine.

Bleeds off air after it has entered the engine.

The correct answer is "bleeds off air after it has entered the engine." The bleed air system is designed to remove excess air from the engine after it has entered. This is done to prevent damage to the engine caused by excessive pressure or temperature. In contrast, the variable vane system is responsible for controlling the airflow into the engine, allowing for optimal performance. Therefore, the bleed air system and the variable vane system serve different functions in the overall operation of an engine.

Explanation

The correct answer is "bleeds off air after it has entered the engine." The bleed air system is designed to remove excess air from the engine after it has entered. This is done to prevent damage to the engine caused by excessive pressure or temperature. In contrast, the variable vane system is responsible for controlling the airflow into the engine, allowing for optimal performance. Therefore, the bleed air system and the variable vane system serve different functions in the overall operation of an engine.

62. (423) Below what percentage of core engine speed are the VSV fully closed (cambered) on an F110-GE–129 engine?

45 percent.

50 percent.

55 percent.

60 percent.

The VSV (Variable Stator Vane) on an F110-GE-129 engine are fully closed (cambered) when the core engine speed is below 45 percent.

Explanation

The VSV (Variable Stator Vane) on an F110-GE-129 engine are fully closed (cambered) when the core engine speed is below 45 percent.

63. (409) Oil sampling intervals should not vary by more than

5 percent.

10 percent.

15 percent.

20 percent.

Oil sampling intervals should not vary by more than 10 percent. This means that the time between oil sampling should not deviate by more than 10 percent from the recommended interval. This is important because regular oil sampling helps monitor the condition of the oil and the equipment it is used in. By adhering to a consistent sampling interval, any changes in oil quality or equipment performance can be detected in a timely manner, allowing for necessary maintenance or repairs to be carried out. Varying the sampling intervals by more than 10 percent could lead to inaccurate assessments of oil and equipment condition, potentially causing damage or failure.

Explanation

Oil sampling intervals should not vary by more than 10 percent. This means that the time between oil sampling should not deviate by more than 10 percent from the recommended interval. This is important because regular oil sampling helps monitor the condition of the oil and the equipment it is used in. By adhering to a consistent sampling interval, any changes in oil quality or equipment performance can be detected in a timely manner, allowing for necessary maintenance or repairs to be carried out. Varying the sampling intervals by more than 10 percent could lead to inaccurate assessments of oil and equipment condition, potentially causing damage or failure.

64. (419) What is one of the first indications of ice formation at aircraft engine inlets?

Compressor stall.

Variable nozzle closes.

Decrease in exhaust gas temperature.

Increase in RPM.

Ice formation at aircraft engine inlets can disrupt the smooth flow of air into the engine, leading to a decrease in airflow and an increase in air pressure. This disruption can cause the compressor blades to stall, which is characterized by a sudden loss of engine power and a distinctive banging or popping sound. Therefore, a compressor stall is one of the first indications of ice formation at aircraft engine inlets.

Explanation

Ice formation at aircraft engine inlets can disrupt the smooth flow of air into the engine, leading to a decrease in airflow and an increase in air pressure. This disruption can cause the compressor blades to stall, which is characterized by a sudden loss of engine power and a distinctive banging or popping sound. Therefore, a compressor stall is one of the first indications of ice formation at aircraft engine inlets.

65. (422) The cooling air for turbine nozzle vanes comes from

All stages of the compressor.

Just the middle of the compressor.

The last few stages of the compressor.

The first few stages of the compressor.

The cooling air for turbine nozzle vanes comes from the last few stages of the compressor. This means that the air used for cooling is taken from the later stages of the compressor, rather than from all stages or just the middle or first few stages. This is important because the air from the last stages of the compressor is typically cooler, which helps to prevent overheating of the turbine nozzle vanes and maintain their efficiency.

Explanation

The cooling air for turbine nozzle vanes comes from the last few stages of the compressor. This means that the air used for cooling is taken from the later stages of the compressor, rather than from all stages or just the middle or first few stages. This is important because the air from the last stages of the compressor is typically cooler, which helps to prevent overheating of the turbine nozzle vanes and maintain their efficiency.

66. (423) What is the function of the flexible feedback cable on the F110-GE–129 engine variable vane system?

Position the bleed valves in response to differential pressure through the fuel gear motor.

Position the bleed valves during acceleration and low RPM.

Transmit a mechanical feedback signal to the variable nozzle control.

Transmit a mechanical feedback signal to the main engine control.

The function of the flexible feedback cable on the F110-GE-129 engine variable vane system is to transmit a mechanical feedback signal to the main engine control. This feedback signal helps the main engine control in monitoring and adjusting the position of the variable vanes, ensuring optimal engine performance and efficiency.

Explanation

The function of the flexible feedback cable on the F110-GE-129 engine variable vane system is to transmit a mechanical feedback signal to the main engine control. This feedback signal helps the main engine control in monitoring and adjusting the position of the variable vanes, ensuring optimal engine performance and efficiency.

67. (404) For actuation of the variable vane systems on an F100-PW–220 engine, the MFC provides both the CIVV and

Rear compressor variable vane actuators with pneumatic (air) pressure.

Rear compressor variable vane actuators with fuel pressure.

Variable exhaust nozzle actuators with pneumatic pressure.

Variable exhaust nozzle actuators with fuel pressure.

The correct answer is rear compressor variable vane actuators with fuel pressure. This means that the MFC (Main Fuel Control) provides fuel pressure to the rear compressor variable vane actuators in order to actuate them. This allows for the adjustment of the variable vanes in the rear compressor section of the F100-PW-220 engine, which helps optimize engine performance and efficiency.

Explanation

The correct answer is rear compressor variable vane actuators with fuel pressure. This means that the MFC (Main Fuel Control) provides fuel pressure to the rear compressor variable vane actuators in order to actuate them. This allows for the adjustment of the variable vanes in the rear compressor section of the F100-PW-220 engine, which helps optimize engine performance and efficiency.

68. (427) What are the two main types of augmentor (afterburner) ignition systems?

Torch igniter and hot streak.

Hot streak and fuel injection.

Pilot burner ring and hot streak.

Torch igniter and pilot burner ring.

The correct answer is Torch igniter and pilot burner ring. These two types of augmentor (afterburner) ignition systems are commonly used in aircraft engines. The torch igniter is responsible for igniting the fuel-air mixture in the afterburner, while the pilot burner ring provides a continuous flame to sustain the combustion process. Both systems work together to ensure efficient and reliable ignition of the afterburner.

Explanation

The correct answer is Torch igniter and pilot burner ring. These two types of augmentor (afterburner) ignition systems are commonly used in aircraft engines. The torch igniter is responsible for igniting the fuel-air mixture in the afterburner, while the pilot burner ring provides a continuous flame to sustain the combustion process. Both systems work together to ensure efficient and reliable ignition of the afterburner.

69. (428) The F100 engine augmentor's primary nozzle actuator is driven by cables from the

T5 amplifier.

Unified control.

Afterburner fuel control.

CENC.

The F100 engine augmentor's primary nozzle actuator is driven by cables from the CENC.

Explanation

The F100 engine augmentor's primary nozzle actuator is driven by cables from the CENC.

70. (403) During jet engine deceleration, a hydromechanical fuel control schedules fuel flow as a function of

RPM.

Inlet temperature.

Burner pressure.

Inlet pressure.

During jet engine deceleration, a hydromechanical fuel control schedules fuel flow as a function of burner pressure. This means that the fuel flow is adjusted based on the pressure in the burner. This is important because the burner pressure directly affects the combustion process, and by controlling the fuel flow in relation to the burner pressure, the engine can maintain optimal performance and efficiency during deceleration. The other options, RPM, inlet temperature, and inlet pressure, are not directly related to the fuel flow adjustment during deceleration.

Explanation

During jet engine deceleration, a hydromechanical fuel control schedules fuel flow as a function of burner pressure. This means that the fuel flow is adjusted based on the pressure in the burner. This is important because the burner pressure directly affects the combustion process, and by controlling the fuel flow in relation to the burner pressure, the engine can maintain optimal performance and efficiency during deceleration. The other options, RPM, inlet temperature, and inlet pressure, are not directly related to the fuel flow adjustment during deceleration.

71. (410) On a simple AC generator, which item takes the current from the slip rings to operate the electrical device?

Brushes.

Commutator.

Rotating loop.

Permanent magnet.

In a simple AC generator, the slip rings are connected to the rotating loop, which generates the alternating current. The brushes are in contact with the slip rings and serve as the connection point to transfer the current from the slip rings to the electrical device. Therefore, the brushes are responsible for taking the current from the slip rings to operate the electrical device.

Explanation

In a simple AC generator, the slip rings are connected to the rotating loop, which generates the alternating current. The brushes are in contact with the slip rings and serve as the connection point to transfer the current from the slip rings to the electrical device. Therefore, the brushes are responsible for taking the current from the slip rings to operate the electrical device.

72. (410) Which part of a generator acts as an automatic switching device, changing alternating current to direct current?

Brushes.

Slip rings.

Commutator.

Permanent magnet.

The commutator is the part of a generator that acts as an automatic switching device, changing the alternating current produced by the generator into direct current. It consists of a set of contacts that are connected to the rotating armature of the generator. As the armature rotates, the contacts make and break contact with the brushes, effectively converting the alternating current to direct current. The slip rings and brushes are also important components of a generator, but they do not perform the function of converting AC to DC.

Explanation

The commutator is the part of a generator that acts as an automatic switching device, changing the alternating current produced by the generator into direct current. It consists of a set of contacts that are connected to the rotating armature of the generator. As the armature rotates, the contacts make and break contact with the brushes, effectively converting the alternating current to direct current. The slip rings and brushes are also important components of a generator, but they do not perform the function of converting AC to DC.

73. (417) Which item on the JFS provides pads for mounting the fuel atomizer assembly?

Stator ring.

Turbine plenum.

Exhaust housing.

Generator assembly.

The turbine plenum on the JFS provides pads for mounting the fuel atomizer assembly.

Explanation

The turbine plenum on the JFS provides pads for mounting the fuel atomizer assembly.

74. (428) On the F100 engine augmentor, the divergent and convergent nozzle segments complete a four-bar linkage arrangement that controls the

Convergent exhaust nozzle control.

Aj.

Afterburner fuel control.

Unified fuel control.

The correct answer is afterburner fuel control. In the F100 engine augmentor, the divergent and convergent nozzle segments form a four-bar linkage arrangement that controls the afterburner fuel control. This means that the movement of the nozzle segments is directly linked to the control of the fuel flow in the afterburner, allowing for efficient and precise control of the engine's thrust output.

Explanation

The correct answer is afterburner fuel control. In the F100 engine augmentor, the divergent and convergent nozzle segments form a four-bar linkage arrangement that controls the afterburner fuel control. This means that the movement of the nozzle segments is directly linked to the control of the fuel flow in the afterburner, allowing for efficient and precise control of the engine's thrust output.

75. (413) How many sets of imbedded magnets does the rotor contain?

One.

Two.

Three.

Four.

The correct answer is three because the question is asking about the number of sets of imbedded magnets in the rotor. Since the question does not specify the type of magnets or provide any additional information, we can assume that there are three sets of imbedded magnets in the rotor.

Explanation

The correct answer is three because the question is asking about the number of sets of imbedded magnets in the rotor. Since the question does not specify the type of magnets or provide any additional information, we can assume that there are three sets of imbedded magnets in the rotor.

76. (406) Which type of oil system stores the oil in a tank fitted to the side of the engine?

Dry sump.

Wet sump.

Cold tank.

Hot tank.

A dry sump oil system stores the oil in a separate tank that is fitted to the side of the engine. This system is commonly used in high-performance or racing engines because it allows for better oil control and prevents oil starvation during high-speed or high-g turns. The oil is pumped from the tank to lubricate the engine components and then returned to the tank to be cooled and filtered before being recirculated. In contrast, a wet sump system stores the oil in a pan at the bottom of the engine, which is simpler but can lead to oil sloshing and starvation in extreme conditions.

Explanation

A dry sump oil system stores the oil in a separate tank that is fitted to the side of the engine. This system is commonly used in high-performance or racing engines because it allows for better oil control and prevents oil starvation during high-speed or high-g turns. The oil is pumped from the tank to lubricate the engine components and then returned to the tank to be cooled and filtered before being recirculated. In contrast, a wet sump system stores the oil in a pan at the bottom of the engine, which is simpler but can lead to oil sloshing and starvation in extreme conditions.

77. (406) Which type of oil system design places the oil cooler in the pressure subsystem?

Cold tank.

Wet tank.

Dry tank.

Hot tank.

In a hot tank oil system design, the oil cooler is placed in the pressure subsystem. This means that the oil cooler is located after the oil pump, where the oil is pressurized. The purpose of the oil cooler is to cool down the hot oil before it is circulated back into the engine. By placing the oil cooler in the pressure subsystem, the oil is cooled more effectively as it is exposed to higher pressure, allowing for better heat dissipation.

Explanation

In a hot tank oil system design, the oil cooler is placed in the pressure subsystem. This means that the oil cooler is located after the oil pump, where the oil is pressurized. The purpose of the oil cooler is to cool down the hot oil before it is circulated back into the engine. By placing the oil cooler in the pressure subsystem, the oil is cooled more effectively as it is exposed to higher pressure, allowing for better heat dissipation.

78. (406) Which type of oil tank design do most fighter aircraft engines incorporate to help with weight savings?

Wet tank.

Dry tank.

Hot tank.

Cold tank.

Most fighter aircraft engines incorporate a hot tank design for oil tanks to help with weight savings. A hot tank design allows for better heat dissipation, reducing the need for additional cooling systems. This helps to save weight and improve overall aircraft performance.

Explanation

Most fighter aircraft engines incorporate a hot tank design for oil tanks to help with weight savings. A hot tank design allows for better heat dissipation, reducing the need for additional cooling systems. This helps to save weight and improve overall aircraft performance.

79. (427) The most important advantage of using a C-D nozzle system is the

Need for bleed valves is eliminated.

Need for inlet guide vanes is eliminated.

Life expectancies of the engine and augmentor are increased.

Pilot has more control of engine thrust throughout all operational ranges.

The most important advantage of using a C-D nozzle system is that it increases the life expectancies of the engine and augmentor. This means that the engine and augmentor will last longer and have a longer operational lifespan. This is beneficial as it reduces the need for frequent repairs or replacements, leading to cost savings and improved reliability of the engine system.

Explanation

The most important advantage of using a C-D nozzle system is that it increases the life expectancies of the engine and augmentor. This means that the engine and augmentor will last longer and have a longer operational lifespan. This is beneficial as it reduces the need for frequent repairs or replacements, leading to cost savings and improved reliability of the engine system.

80. (406) The number1, 4, and 5 bearing compartments are capped on the F100-PW–100 engine oil system. Which oil subsystem (or subsystems) do these compartments breathe through?

Scavenge only.

Breather only.

Scavenge and pressure.

Scavenge and breather.

The number 1, 4, and 5 bearing compartments on the F100-PW-100 engine oil system are capped, which means they are sealed off from the outside environment. These compartments do not have a breather, which means they do not breathe air from the atmosphere. Instead, they rely on the scavenge system to remove any excess oil or contaminants from the compartments. Therefore, the correct answer is "Scavenge only."

Explanation

The number 1, 4, and 5 bearing compartments on the F100-PW-100 engine oil system are capped, which means they are sealed off from the outside environment. These compartments do not have a breather, which means they do not breathe air from the atmosphere. Instead, they rely on the scavenge system to remove any excess oil or contaminants from the compartments. Therefore, the correct answer is "Scavenge only."

81. (426) What component or components make up the engine monitoring system on the F119 engine itself?

DEC.

CEDU.

FADEC.

CEDU and FADEC.

The engine monitoring system on the F119 engine consists of two components: the CEDU (Central Engine Data Unit) and the FADEC (Full Authority Digital Engine Control). The CEDU is responsible for collecting and processing data from various sensors and instruments throughout the engine, providing real-time information on its performance. The FADEC, on the other hand, is in charge of controlling and optimizing the engine's operation based on the data received from the CEDU. Together, these two components ensure the engine's efficient and reliable performance.

Explanation

The engine monitoring system on the F119 engine consists of two components: the CEDU (Central Engine Data Unit) and the FADEC (Full Authority Digital Engine Control). The CEDU is responsible for collecting and processing data from various sensors and instruments throughout the engine, providing real-time information on its performance. The FADEC, on the other hand, is in charge of controlling and optimizing the engine's operation based on the data received from the CEDU. Together, these two components ensure the engine's efficient and reliable performance.

82. (409) The SEM/EDX analysis process differs from conventional oil analysis in that the SEM/EDX

Samples must be sent off-site for analysis.

Particles must be oil free for analysis to take place.

Samples can only be obtained in an intermediate maintenance shop.

Provides results only concerning equipment and components condition.

The correct answer is "particles must be oil free for analysis to take place." SEM/EDX analysis is a technique used to analyze the composition of particles. In order to obtain accurate results, the particles being analyzed must be free of any oil contamination. Oil can interfere with the analysis process and lead to incorrect or unreliable results. Therefore, it is necessary to ensure that the particles are oil free before conducting SEM/EDX analysis.

Explanation

The correct answer is "particles must be oil free for analysis to take place." SEM/EDX analysis is a technique used to analyze the composition of particles. In order to obtain accurate results, the particles being analyzed must be free of any oil contamination. Oil can interfere with the analysis process and lead to incorrect or unreliable results. Therefore, it is necessary to ensure that the particles are oil free before conducting SEM/EDX analysis.

83. (416) The two air source requirements for a pneumatic starter to operate properly are sufficient

Volume and velocity.

Volume and pressure.

Temperature and velocity.

Temperature and pressure.

A pneumatic starter requires sufficient volume and pressure of air source to operate properly. Volume refers to the amount of air available for the starter to use, while pressure determines the force with which the air is delivered. Therefore, both volume and pressure are necessary for the pneumatic starter to function effectively.

Explanation

A pneumatic starter requires sufficient volume and pressure of air source to operate properly. Volume refers to the amount of air available for the starter to use, while pressure determines the force with which the air is delivered. Therefore, both volume and pressure are necessary for the pneumatic starter to function effectively.

84. (418) On the F-15 secondary power system CGB, how are the isolation decouplers extended?

Manually.

Electrically.

Hydraulically.

By spring pressure.

On the F-15 secondary power system CGB, the isolation decouplers are extended hydraulically. This means that hydraulic power is used to extend these decouplers.

Explanation

On the F-15 secondary power system CGB, the isolation decouplers are extended hydraulically. This means that hydraulic power is used to extend these decouplers.

85. (418) On an F-15, the power to start the engines begins with the JFS and continues through the CGB to the

PTO.

ADG.

PMG.

AMAD.

The power to start the engines on an F-15 begins with the JFS (Jet Fuel Starter) and continues through the CGB (Combustion Gas Bypass) to the AMAD (Aircraft Mounted Accessory Drive). The AMAD is responsible for transmitting power from the engines to various aircraft systems, including the hydraulic and electrical systems. Therefore, it is the correct answer in this context.

Explanation

The power to start the engines on an F-15 begins with the JFS (Jet Fuel Starter) and continues through the CGB (Combustion Gas Bypass) to the AMAD (Aircraft Mounted Accessory Drive). The AMAD is responsible for transmitting power from the engines to various aircraft systems, including the hydraulic and electrical systems. Therefore, it is the correct answer in this context.

86. (412) How are the thermocouples connected in an averaging type of EGT circuit?

Series.

Lateral.

Parallel.

Series-parallel.

In an averaging type of EGT circuit, the thermocouples are connected in parallel. This means that the positive terminals of all the thermocouples are connected together, and the negative terminals are also connected together. This configuration allows for the average temperature to be measured across all the thermocouples, providing a more accurate reading.

Explanation

In an averaging type of EGT circuit, the thermocouples are connected in parallel. This means that the positive terminals of all the thermocouples are connected together, and the negative terminals are also connected together. This configuration allows for the average temperature to be measured across all the thermocouples, providing a more accurate reading.

87. (420) On an F110-GE–129 engine, compressor bleed air is used for anti-icing, customer bleed, and

VSV actuator control.

IGV actuator control.

Low-pressure turbine cooling functions.

Main engine fuel pump operation.

Compressor bleed air is used for various purposes in an F110-GE-129 engine, including anti-icing, customer bleed, VSV actuator control, and low-pressure turbine cooling functions. However, the correct answer in this case is low-pressure turbine cooling functions. This means that compressor bleed air is specifically used to cool the low-pressure turbine in the engine.

Explanation

Compressor bleed air is used for various purposes in an F110-GE-129 engine, including anti-icing, customer bleed, VSV actuator control, and low-pressure turbine cooling functions. However, the correct answer in this case is low-pressure turbine cooling functions. This means that compressor bleed air is specifically used to cool the low-pressure turbine in the engine.

88. (414) Which unit of an AC ignition system develops 20,000 volts?

Inverter.

Capacitor.

Generator.

Transformer.

The unit of an AC ignition system that develops 20,000 volts is the transformer. A transformer is a device that can increase or decrease the voltage of an alternating current. In this case, it is responsible for stepping up the voltage to 20,000 volts, which is necessary for the ignition system to create a spark and ignite the fuel-air mixture in the engine.

Explanation

The unit of an AC ignition system that develops 20,000 volts is the transformer. A transformer is a device that can increase or decrease the voltage of an alternating current. In this case, it is responsible for stepping up the voltage to 20,000 volts, which is necessary for the ignition system to create a spark and ignite the fuel-air mixture in the engine.

89. (421) The compressor bleed system reduces the probability of compressor stall in a dual-rotor engine by

Reducing the amount of air available to the N2 compressor.

Reducing the amount of air available to the N1 compressor.

Increasing the amount of air delivered to the N2 compressor.

Increasing the amount of air delivered by the N1 compressor.

The compressor bleed system reduces the probability of compressor stall in a dual-rotor engine by reducing the amount of air available to the N2 compressor. This is because compressor stall occurs when the airflow through the compressor becomes disrupted, leading to a loss of pressure and airflow. By bleeding off a portion of the air from the compressor, the system reduces the overall airflow and prevents it from reaching levels that could cause stall conditions in the N2 compressor.

Explanation

The compressor bleed system reduces the probability of compressor stall in a dual-rotor engine by reducing the amount of air available to the N2 compressor. This is because compressor stall occurs when the airflow through the compressor becomes disrupted, leading to a loss of pressure and airflow. By bleeding off a portion of the air from the compressor, the system reduces the overall airflow and prevents it from reaching levels that could cause stall conditions in the N2 compressor.

90. (427) Which system employs a small combustion chamber to ignite the fuel in the augmentor (afterburner) duct?

Hot streak.

Torch igniter.

Fuel injection.

Pilot burner ring.

A torch igniter is a system that employs a small combustion chamber to ignite the fuel in the augmentor (afterburner) duct. It is used to provide an initial flame to ignite the fuel-air mixture in the afterburner, allowing for increased thrust in certain aircraft engines. This system is commonly used in military aircraft for added power during takeoff or combat situations.

Explanation

A torch igniter is a system that employs a small combustion chamber to ignite the fuel in the augmentor (afterburner) duct. It is used to provide an initial flame to ignite the fuel-air mixture in the afterburner, allowing for increased thrust in certain aircraft engines. This system is commonly used in military aircraft for added power during takeoff or combat situations.

91. (412) What is the primary input power to the main ignition system?

28 VAC.

28 VDC.

120 VAC.

120 VDC.

The primary input power to the main ignition system is 28 VDC. This means that the ignition system requires a direct current power supply with a voltage of 28 volts. The other options, 28 VAC, 120 VAC, and 120 VDC, are not the primary input power for the ignition system.

Explanation

The primary input power to the main ignition system is 28 VDC. This means that the ignition system requires a direct current power supply with a voltage of 28 volts. The other options, 28 VAC, 120 VAC, and 120 VDC, are not the primary input power for the ignition system.

92. (418) Oil is supplied to the F-15 JFS through the

Oil tank.

Aircraft filter.

JFS oil system.

CGB oil system.

The correct answer is the CGB oil system. The CGB (Combustion and Gasoline Burner) oil system is responsible for supplying oil to the F-15 JFS (Jet Fuel Starter). The JFS is an auxiliary power unit used to start the aircraft's engines. The CGB oil system ensures that the JFS has a sufficient supply of oil to function properly.

Explanation

The correct answer is the CGB oil system. The CGB (Combustion and Gasoline Burner) oil system is responsible for supplying oil to the F-15 JFS (Jet Fuel Starter). The JFS is an auxiliary power unit used to start the aircraft's engines. The CGB oil system ensures that the JFS has a sufficient supply of oil to function properly.

93. (408) How does the AFTLA obtain oil samples for analysis?

Upon request from the depot.

Automatically from the depot.

Upon request from the manufacturer.

Automatically from the manufacturer.

The AFTLA obtains oil samples for analysis automatically from the manufacturer. This means that the manufacturer sends the oil samples to the AFTLA without the need for a specific request. This method ensures a regular and consistent supply of oil samples for analysis, allowing the AFTLA to conduct their analysis and testing efficiently.

Explanation

The AFTLA obtains oil samples for analysis automatically from the manufacturer. This means that the manufacturer sends the oil samples to the AFTLA without the need for a specific request. This method ensures a regular and consistent supply of oil samples for analysis, allowing the AFTLA to conduct their analysis and testing efficiently.

94. (406) The F100-PW–100 engine oil pressure varies with N2, engine inlet oil temperature, and

Oil jet pressure.

Fan turbine speed.

Oil nozzle condition.

Number of oil jets used.

The oil pressure in the F100-PW-100 engine varies with factors such as N2 (fan turbine speed), engine inlet oil temperature, and the condition of the oil nozzle. The oil nozzle condition refers to the state of the nozzle through which the oil is sprayed into the engine. If the nozzle is damaged or clogged, it can affect the oil pressure. Therefore, the condition of the oil nozzle is a crucial factor in determining the oil pressure in the engine.

Explanation

The oil pressure in the F100-PW-100 engine varies with factors such as N2 (fan turbine speed), engine inlet oil temperature, and the condition of the oil nozzle. The oil nozzle condition refers to the state of the nozzle through which the oil is sprayed into the engine. If the nozzle is damaged or clogged, it can affect the oil pressure. Therefore, the condition of the oil nozzle is a crucial factor in determining the oil pressure in the engine.

95. (424) Where is the fuel flow transmitter located in the F-15?

In the engine bay.

Left front side of gearbox.

Right front side of gearbox.

Attached to the fuel control.

The fuel flow transmitter in the F-15 is located in the engine bay.

Explanation

The fuel flow transmitter in the F-15 is located in the engine bay.

96. (426) What component in the F119 engine monitoring system processes and stores vibration signals, oil debris signals, oil level signals, condition monitoring and fault information data in resident memory?

CEDU.

FADEC.

Main engine control.

Main Fuel Throttle Valve.

The component in the F119 engine monitoring system that processes and stores various signals and data in resident memory is the CEDU (Central Engine Data Unit). This unit is responsible for monitoring and analyzing vibration signals, oil debris signals, oil level signals, condition monitoring, and fault information data. It plays a crucial role in ensuring the engine's performance and detecting any potential issues or faults.

Explanation

The component in the F119 engine monitoring system that processes and stores various signals and data in resident memory is the CEDU (Central Engine Data Unit). This unit is responsible for monitoring and analyzing vibration signals, oil debris signals, oil level signals, condition monitoring, and fault information data. It plays a crucial role in ensuring the engine's performance and detecting any potential issues or faults.

97. (418) Which component provides an electrical safety cutoff for the JFS if the power turbine accelerates to a 110 percent overspeed condition?

Overspeed clutch.

Overrunning clutch.

Three-speed switch.

Power turbine overspeed switch.

The power turbine overspeed switch is the component that provides an electrical safety cutoff for the JFS (Jet Fuel Starter) if the power turbine accelerates to a 110 percent overspeed condition. This switch is designed to detect excessive rotational speed of the power turbine and activate a safety mechanism to prevent further acceleration, ensuring the safety of the system.

Explanation

The power turbine overspeed switch is the component that provides an electrical safety cutoff for the JFS (Jet Fuel Starter) if the power turbine accelerates to a 110 percent overspeed condition. This switch is designed to detect excessive rotational speed of the power turbine and activate a safety mechanism to prevent further acceleration, ensuring the safety of the system.

98. (414) A simple DC ignition system consists of vibrator,

AC to DC converter, transformer, and igniter plugs.

Igniter plugs, and AC to DC converter.

AC to DC converter, and transformer.

Igniter plugs, and transformer.

The correct answer is "igniter plugs, and transformer." In a simple DC ignition system, the igniter plugs are responsible for producing the spark that ignites the fuel-air mixture in the engine. The transformer is used to step up the voltage from the DC power source to a higher voltage required for the spark. The AC to DC converter is not necessary in this system as it converts alternating current to direct current, which is not needed for the ignition process.

Explanation

The correct answer is "igniter plugs, and transformer." In a simple DC ignition system, the igniter plugs are responsible for producing the spark that ignites the fuel-air mixture in the engine. The transformer is used to step up the voltage from the DC power source to a higher voltage required for the spark. The AC to DC converter is not necessary in this system as it converts alternating current to direct current, which is not needed for the ignition process.

99. (417) Which type of combustion chamber does the JFS use?

Can.

Annular.

Can-annular.

Restricted flow.

The JFS (Jet Fuel Starter) uses an annular combustion chamber. An annular combustion chamber is a type of combustion chamber where the air and fuel mixture is ignited in a ring-shaped chamber. This design allows for efficient and stable combustion, as the flame front propagates around the circumference of the chamber. The annular combustion chamber is commonly used in gas turbine engines, such as the JFS, due to its ability to provide uniform combustion and high combustion efficiency.

Explanation

The JFS (Jet Fuel Starter) uses an annular combustion chamber. An annular combustion chamber is a type of combustion chamber where the air and fuel mixture is ignited in a ring-shaped chamber. This design allows for efficient and stable combustion, as the flame front propagates around the circumference of the chamber. The annular combustion chamber is commonly used in gas turbine engines, such as the JFS, due to its ability to provide uniform combustion and high combustion efficiency.

100. (403) On a dual-spool, axial-flow engine, what controls thrust production of the engine?

Regulating engine RPM.

Regulating compressor discharge pressure.

Controlling turbine exhaust pressure.

Controlling turbine inlet temperature.

Controlling turbine inlet temperature is the correct answer because it directly affects the amount of power generated by the engine. By regulating the temperature of the air entering the turbine, the engine can control the amount of energy extracted from the combustion process, which in turn affects the thrust production. This allows for precise control of the engine's performance and ensures optimal efficiency and power output.

Explanation

Controlling turbine inlet temperature is the correct answer because it directly affects the amount of power generated by the engine. By regulating the temperature of the air entering the turbine, the engine can control the amount of energy extracted from the combustion process, which in turn affects the thrust production. This allows for precise control of the engine's performance and ensures optimal efficiency and power output.

101. (416) Which statement best describes the air turbine (impingement) starter?

Requires high-pressure, low-volume air-flow to produce torque necessary for engine start.

Has the advantages of less weight and fewer moving parts than other starters.

Uses a starter-clutch assembly to disengage the starter from the engine.

Is mounted on the engine accessory drive.

The air turbine (impingement) starter is described as having the advantages of less weight and fewer moving parts than other starters. This means that compared to other types of starters, the air turbine starter is lighter in weight and has fewer components that can potentially wear out or malfunction. This makes it a more efficient and reliable option for starting an engine.

Explanation

The air turbine (impingement) starter is described as having the advantages of less weight and fewer moving parts than other starters. This means that compared to other types of starters, the air turbine starter is lighter in weight and has fewer components that can potentially wear out or malfunction. This makes it a more efficient and reliable option for starting an engine.

102. (428) The F100 engine augmentor's exhaust nozzle is variable to control engine

N2 compressor rotor speed.

Thrust and fan stall margin.

Fan stall margin only.

Thrust only.

The F100 engine augmentor's exhaust nozzle is variable to control both thrust and fan stall margin. By adjusting the exhaust nozzle, the engine can regulate the amount of thrust it produces as well as maintain a safe margin against fan stall. This allows for better performance and control of the engine during various operating conditions.

Explanation

The F100 engine augmentor's exhaust nozzle is variable to control both thrust and fan stall margin. By adjusting the exhaust nozzle, the engine can regulate the amount of thrust it produces as well as maintain a safe margin against fan stall. This allows for better performance and control of the engine during various operating conditions.

103. (415) How many independent circuits are within an F100-PW–100 engine ignition system?

One.

Two.

Three.

Five.

The correct answer is Three. This means that there are three independent circuits within an F100-PW-100 engine ignition system. This suggests that the ignition system is designed with redundancy, as having multiple independent circuits ensures that the engine can still be ignited even if one or two circuits fail. This is important for safety and reliability purposes, as it minimizes the risk of engine failure due to ignition system malfunctions.

Explanation

The correct answer is Three. This means that there are three independent circuits within an F100-PW-100 engine ignition system. This suggests that the ignition system is designed with redundancy, as having multiple independent circuits ensures that the engine can still be ignited even if one or two circuits fail. This is important for safety and reliability purposes, as it minimizes the risk of engine failure due to ignition system malfunctions.

104. (415) An F100-PW–100 engine augmentor igniter plug ionizes at a minimum rate of how many sparks per second?

25.

30.

45.

90.

The correct answer is 30. The question asks for the minimum rate at which the F100-PW-100 engine augmentor igniter plug ionizes sparks per second. Among the given options, 30 is the closest value to the minimum rate required.

Explanation

The correct answer is 30. The question asks for the minimum rate at which the F100-PW-100 engine augmentor igniter plug ionizes sparks per second. Among the given options, 30 is the closest value to the minimum rate required.

105. (411) One function of the CSD governor system is to

Sense the engine drive RPM required to control the CSD.

Disconnect the generator from the engine in event of a failure.

Equalize the load between generators operating in parallel.

Maintain a constant 400-volt output.

The CSD governor system is responsible for equalizing the load between generators operating in parallel. This means that it ensures that each generator is carrying an equal amount of the total load, preventing any generator from being overloaded or underloaded. By balancing the load, the CSD governor system helps to optimize the performance and efficiency of the generators, ensuring smooth and reliable operation. It also helps to prevent any single generator from being overworked, which can lead to mechanical stress and potential failures.

Explanation

The CSD governor system is responsible for equalizing the load between generators operating in parallel. This means that it ensures that each generator is carrying an equal amount of the total load, preventing any generator from being overloaded or underloaded. By balancing the load, the CSD governor system helps to optimize the performance and efficiency of the generators, ensuring smooth and reliable operation. It also helps to prevent any single generator from being overworked, which can lead to mechanical stress and potential failures.

106. (411) What provides the PTO shaft that is used to drive the CSD?

Engine fittings.

Engine adapter.

Aircraft fittings.

Aircraft adapter.

The PTO shaft used to drive the CSD is provided by the engine adapter. This adapter connects the engine to the CSD and allows the transfer of power from the engine to the shaft. Engine fittings, aircraft fittings, and aircraft adapter are not directly involved in providing the PTO shaft for the CSD.

Explanation

The PTO shaft used to drive the CSD is provided by the engine adapter. This adapter connects the engine to the CSD and allows the transfer of power from the engine to the shaft. Engine fittings, aircraft fittings, and aircraft adapter are not directly involved in providing the PTO shaft for the CSD.

107. (427) What is used to open and close flap-type and iris-type variable-exhaust nozzle systems?

Oil pressure for both types.

Air pressure for both types.

Oil pressure for the flap-type and fuel pressure for the iris-type.

Fuel pressure for the flap-type and air pressure for the iris-type.

Flap-type and iris-type variable-exhaust nozzle systems are used in jet engines to control the flow of exhaust gases. These systems need to be opened and closed as required. The correct answer states that air pressure is used for both types of systems. Air pressure is commonly used in aviation systems for various purposes, including actuating mechanisms. Therefore, it is logical to use air pressure to open and close both flap-type and iris-type variable-exhaust nozzle systems.

Explanation

Flap-type and iris-type variable-exhaust nozzle systems are used in jet engines to control the flow of exhaust gases. These systems need to be opened and closed as required. The correct answer states that air pressure is used for both types of systems. Air pressure is commonly used in aviation systems for various purposes, including actuating mechanisms. Therefore, it is logical to use air pressure to open and close both flap-type and iris-type variable-exhaust nozzle systems.

108. (412) The slide-type resistor in the EGT circuit is used to

Adjust the thermocouples.

Calibrate the EGT indicator in the flight station.

Compensate for minor voltage buildups in the circuit.

Compensate for differences in temperatures at altitude.

The slide-type resistor in the EGT circuit is used to calibrate the EGT indicator in the flight station. This means that it is used to adjust the EGT indicator so that it accurately displays the correct temperature readings. By using the slide-type resistor, the EGT indicator can be calibrated to ensure that it is providing accurate and reliable information to the pilot. This is important for monitoring the engine's exhaust gas temperature and ensuring that it is within safe operating limits.

Explanation

The slide-type resistor in the EGT circuit is used to calibrate the EGT indicator in the flight station. This means that it is used to adjust the EGT indicator so that it accurately displays the correct temperature readings. By using the slide-type resistor, the EGT indicator can be calibrated to ensure that it is providing accurate and reliable information to the pilot. This is important for monitoring the engine's exhaust gas temperature and ensuring that it is within safe operating limits.

109. (418) The F-15 secondary power system does not include the

JFS.

CGB.

CSD.

AMAD.

The correct answer is CSD. The F-15 secondary power system does not include the CSD (Constant Speed Drive). The CSD is responsible for maintaining a constant speed of the aircraft's electrical generators. However, in the F-15, the secondary power system does not rely on a CSD for this purpose.

Explanation

The correct answer is CSD. The F-15 secondary power system does not include the CSD (Constant Speed Drive). The CSD is responsible for maintaining a constant speed of the aircraft's electrical generators. However, in the F-15, the secondary power system does not rely on a CSD for this purpose.

110. (423) On an F110-GE–129 engine, the MEC schedules the variable vane positions by the

Sea-level temperature and actual engine RPM.

Turbine discharge pressure and compressor inlet temperature.

Fan discharge temperature and core engine speed.

Compressor inlet pressure and turbine speed.

The MEC (Main Engine Control) schedules the variable vane positions on an F110-GE-129 engine based on the fan discharge temperature and core engine speed. This means that the MEC adjusts the positions of the variable vanes in response to these two parameters in order to optimize the engine's performance. The fan discharge temperature and core engine speed are important indicators of the engine's operating conditions, and adjusting the variable vane positions based on these parameters helps to ensure efficient and effective engine operation.

Explanation

The MEC (Main Engine Control) schedules the variable vane positions on an F110-GE-129 engine based on the fan discharge temperature and core engine speed. This means that the MEC adjusts the positions of the variable vanes in response to these two parameters in order to optimize the engine's performance. The fan discharge temperature and core engine speed are important indicators of the engine's operating conditions, and adjusting the variable vane positions based on these parameters helps to ensure efficient and effective engine operation.