5 Level Volume 3

The fuel/oil cooler heats the augmentor fuel to provide better vaporization and combustion. This component helps to cool the fuel and oil, which in turn increases the efficiency of the combustion process by ensuring that the fuel is properly vaporized before being ignited. This helps to improve the overall performance of the system and optimize the combustion process.

At room temperature, water will take four times longer to settle out of JP-8 than out of gasoline.

A torch igniter is a system that employs a small combustion chamber to ignite the fuel in the augmentor (afterburner) duct. It is specifically designed to provide a reliable and efficient ignition source for the afterburner. The torch igniter creates a high-energy spark or flame that ignites the fuel-air mixture, allowing for increased thrust and performance in the engine. This system is commonly used in jet engines to enhance their power output during certain flight conditions.

A unified fuel metering device refers to a jet engine component that combines two separate fuel controls into a single unit. This means that instead of having two separate controls for fuel metering, the unified device integrates both controls into one component. This simplifies the fuel metering system and improves efficiency by reducing the number of components required.

A check valve is a type of valve that allows fluid (in this case, oil) to flow in only one direction. It prevents backflow, ensuring that the oil can only move in the desired direction. This is achieved through a mechanism that automatically closes the valve when the flow reverses, preventing any backward movement of the oil. Therefore, a check valve is the correct answer for a valve that permits oil flow in only one direction.

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. This switch assembly is designed to cut off the fuel flow to the JFS at 50% engine RPM, preventing it from continuing to supply fuel and start the engine once it has reached the desired speed. This helps to ensure a smooth and controlled start-up process for the aircraft engine.

CEDU stands for Central Engine Data Unit. It is a component in the F119 engine monitoring system that processes and stores various types of data including vibration signals, oil debris signals, oil level signals, condition monitoring, and fault information data. This data is stored in the resident memory of the CEDU, allowing for real-time monitoring and analysis of the engine's performance and health.

In an F100-PW-220 engine, the stage of the compressor air that drives the augmenter fuel pump is the 13th stage.

The cooling air for turbine nozzle vanes comes from the last few stages of the compressor. This is because the air in the last few stages of the compressor is at a higher pressure and temperature, which makes it ideal for cooling the turbine nozzle vanes. The high-pressure air is directed towards the nozzle vanes to prevent them from overheating and to maintain their efficiency.

The F110-GE-129 engine controls airflow through the engine using both IGVs (Inlet Guide Vanes) and VSVs (Variable Stator Vanes). IGVs are located at the front of the engine and help to direct the incoming air into the engine. VSVs, on the other hand, are located in the compressor section of the engine and help to control the airflow by adjusting the angle of the stator vanes. By using both IGVs and VSVs, the engine can effectively control and optimize the airflow for better performance and efficiency.

The F100 UFC senses certain variables from the engine through a closed loop design. In a closed loop design, the system continuously monitors and adjusts its output based on feedback from sensors. This allows for precise control and optimization of engine performance. An open circuit design would not provide the necessary feedback for accurate adjustments. The feedback control unit may be involved in the closed loop design, but it is not the design itself. A direct mechanical connection to all engine sensors would not allow for real-time adjustments based on feedback.

Most fighter aircraft engines incorporate a hot tank design for weight savings. A hot tank design allows the engine to use the fuel as a heat sink, dissipating the heat generated by the engine. This eliminates the need for additional cooling systems, reducing the overall weight of the aircraft. By utilizing the fuel as a heat sink, the hot tank design improves the efficiency and performance of the engine while also saving on weight, which is crucial in fighter aircraft where every pound matters.

A labyrinth oil seal is made of soft metal and allows a small amount of airflow to prevent oil seepage. The design of a labyrinth seal consists of multiple interlocking grooves or channels that create a tortuous path for the oil to flow through. This design helps to minimize oil leakage and prevent contaminants from entering the system. Silicone, carbon, and synthetic oil seals do not have the same characteristics as a labyrinth seal and are not specifically designed to allow airflow while preventing oil seepage.

In a simple AC generator, the current is taken from the slip rings to operate the electrical device by the brushes. Brushes are made of conductive material and are in constant contact with the slip rings, allowing them to transfer the current from the rotating loop to the external circuit. The brushes act as a bridge between the stationary part of the generator and the rotating part, ensuring a continuous flow of current to the electrical device. The commutator is typically found in DC generators, not AC generators.

The correct answer is three because the question asks about the number of sets of embedded magnets in the rotor. Since the answer choices are given in numerical form, we can conclude that the rotor contains three sets of embedded magnets.

The correct answer is 10 percent. Oil sampling intervals should not vary by more than 10 percent. This means that the time between oil sampling should not differ by more than 10 percent from the recommended interval. This is important because regular oil sampling helps to monitor the condition of the oil and detect any potential issues or contaminants. By adhering to a consistent sampling interval, the data collected will be more accurate and reliable for analysis and decision-making. Varying the intervals by more than 10 percent could lead to inconsistent and unreliable data.

SEM/EDX analysis is a process that involves scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). This technique is used to analyze the composition and structure of particles. In order to obtain accurate results, the particles being analyzed must be free of oil. This is because oil can interfere with the analysis and affect the accuracy of the results. Therefore, the correct answer is that particles must be oil free for analysis to take place.

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 to various aircraft systems, including the engine. Therefore, it is the correct answer in this context.

The VSV (Variable Stator Vane) is a component in the F110-GE-129 engine that controls the airflow and improves engine performance. The question is asking at what percentage of the core engine speed the VSV is fully closed. The correct answer is 45 percent, meaning that when the engine is operating below 45 percent of its maximum speed, the VSV is completely closed or cambered. This information is important for understanding the behavior and functioning of the engine at different speeds.

The number 1, 4, and 5 bearing compartments on the F100-PW-100 engine oil system are capped, meaning they are closed off from the outside environment. Therefore, these compartments do not have a breather, which allows air to flow in and out. Instead, they only breathe through the scavenge system, which removes excess oil and gases from the compartments.

The turbine plenum is the engine section that houses the JFS (Jet Fuel Starter) combustion section. The JFS is responsible for starting the engine by providing compressed air and fuel for combustion. The turbine plenum is located between the JFS and the main engine and acts as a transition section, allowing the hot gases from the JFS to flow into the main engine's turbine.

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

Jet aircraft operating at moderately high altitudes increase the fuel system's susceptibility to an icing condition. This is further aggravated by the higher viscosity of jet fuels. Higher viscosity means that the fuel is thicker and more resistant to flow. In cold temperatures, this can lead to the fuel becoming even thicker and potentially forming ice crystals, which can clog fuel lines and cause engine failure. Therefore, the higher viscosity of jet fuels makes the fuel system more prone to icing conditions at high altitudes.

The Engine Monitoring System Computer in the F110 monitoring system is responsible for performing diagnostics and fault isolation to line replaceable units. This component is specifically designed to monitor the engine's performance and detect any faults or malfunctions in the system. It analyzes data from various sensors and systems to identify potential issues and isolate them to specific line replaceable units, allowing for efficient troubleshooting and maintenance.

The AFTLA obtains oil samples for analysis automatically from the manufacturer. This means that the manufacturer has a system in place to regularly collect and send oil samples to the AFTLA for analysis without the need for a specific request. This automated process ensures that the AFTLA receives oil samples consistently and can conduct analysis on them as needed.

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 high-speed 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 decelerate and increase in pressure. Therefore, Bernoulli's law is the correct explanation for how the C-D supersonic inlet slows down the airflow.

The correct answer is corrosiveness. Modern jet engine oil can be corrosive, meaning it has the potential to cause damage to the surfaces it comes into contact with. This is an important hazard that a journeyman must be aware of when working with jet engines, as it can lead to deterioration and failure of engine components if not properly handled and maintained.

A simple DC ignition system requires igniter plugs to create a spark for ignition, and a transformer to step up the voltage from the DC power source. The AC to DC converter is not necessary in this system as it converts AC power to DC power, which is already provided by the DC power source. Therefore, the correct answer is igniter plugs and transformer.

A pneumatic starter requires two air source requirements to operate properly: sufficient volume and pressure. Volume refers to the amount of air available, while pressure is the force exerted by the air. Both volume and pressure are crucial for the starter to function effectively.

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 monitor the speed of the power turbine and activate a safety cutoff mechanism if it exceeds the specified limit. It ensures that the power turbine does not operate at dangerous speeds, preventing potential damage or failure of the JFS system.

The given options are Gear, Gerotor, Rotogear, and Sliding vane. The question asks for the type of oil pump that is not classified based on structure. Gear, Gerotor, and Sliding vane are all types of oil pumps classified based on their structure. However, Rotogear is not a recognized type of oil pump based on structure. Therefore, the correct answer is Rotogear.

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

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 share of the load, preventing any one generator from becoming overloaded. By maintaining a balanced load distribution, the CSD governor system helps to optimize the performance and efficiency of the generators in a parallel operation.

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

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 the EGT circuit to calculate the average temperature by measuring the combined voltage output of all the thermocouples. Connecting the thermocouples in parallel ensures that each thermocouple contributes equally to the overall temperature measurement, resulting in a more accurate and reliable reading.

The air turbine (impingement) starter is described as having the advantages of less weight and fewer moving parts than other starters. This means that it is a lightweight and simple starter compared to other types, making it more efficient and easier to maintain. It does not require high-pressure, low-volume air-flow to produce torque, use a starter-clutch assembly to disengage, or be mounted on the engine accessory drive.

The correct answer is "afterburner fuel control." The four-bar linkage arrangement on the F100 engine augmentor controls the convergent exhaust nozzle, but it is specifically used for controlling the afterburner fuel flow.

A gerotor oil pump consists of a gear and rotor within a housing. The gear and rotor rotate together, creating chambers between them that trap and move the oil. This design allows for efficient and reliable oil pumping, making it a commonly used type of oil pump in various applications.

If 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 exceeded the maximum limit set by the design specifications. This could be due to a blockage or restriction in the oil filter, causing a buildup of pressure. It is important to address this issue promptly to prevent any potential damage to the engine.

The F100-PW-100 engine augmentor igniter plug ionizes at a minimum rate of 45 sparks per second. This means that the plug produces 45 sparks every second, ensuring proper ignition and combustion in the engine.

The JFS (Jet Fuel Starter) uses an annular combustion chamber. An annular combustion chamber is a type of combustion chamber where the fuel and air mixture is ignited in a ring-shaped chamber surrounding the turbine. This design allows for more efficient combustion and better mixing of fuel and air, resulting in improved performance and reduced emissions.

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 generators, which provide electrical power. However, the F-15 utilizes a different power system that does not require the use of a CSD.

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. This fuel pressure is used to actuate the variable vane systems on the F100-PW-220 engine.

The correct answer is the Filter assembly bypass valve. During cold weather starts, the oil filter can become clogged or restricted due to the thickening of the oil. The filter assembly bypass valve allows the oil to bypass the filter and continue flowing to the engine, ensuring that the engine receives the necessary lubrication even if the filter is not functioning properly.

The F100 engine augmentor's exhaust nozzle is variable in order to control both the engine thrust and the fan stall margin. By adjusting the exhaust nozzle, the engine can regulate the amount of thrust it produces and also maintain a safe margin against fan stall, which is a condition where the airflow over the fan blades becomes disrupted and can lead to engine performance issues.

The correct answer is the CGB oil system. The CGB (Constantly Geared Drive) oil system is responsible for supplying oil to the F-15 JFS (Jet Fuel Starter) for its operation. The JFS is a small turbine engine used to start the main engines of the aircraft. The CGB oil system ensures that the JFS has a constant supply of oil for lubrication and cooling purposes, allowing it to function properly during engine start-up.

Air pressure is used to open and close both flap-type and iris-type variable-exhaust nozzle systems. This means that air pressure is responsible for controlling the movement of the nozzles in both types of systems.

The commutator is the part of a generator that acts as an automatic switching device, changing alternating current to direct current. It consists of a set of copper segments that are connected to the armature windings. As the armature rotates, the commutator reverses the direction of the current flow in the windings, ensuring that the output of the generator is direct current. This allows the generator to convert the alternating current produced by the armature into the direct current needed for many electrical devices.

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 under pressure. The purpose of placing the oil cooler in the pressure subsystem is to ensure that the oil is cooled down before it is circulated back into the engine or other components. This helps in maintaining the optimal temperature of the oil and prevents overheating of the system.

The primary input power to the main ignition system is 28 VDC. This means that the main ignition system requires a direct current power supply of 28 volts.

A dry sump oil system stores the oil in a separate tank that is typically mounted to the side of the engine. This design allows for a larger oil capacity and better oil control compared to a wet sump system, where the oil is stored in a pan underneath the engine. The dry sump system is commonly used in high-performance and racing engines to prevent oil starvation during high-speed cornering or acceleration.

The breather pressurizing valve on an F100 engine is internally mounted in the gearbox. This valve is responsible for regulating the pressure inside the gearbox by allowing excess air or oil vapor to escape. By being internally mounted in the gearbox, the valve can effectively control the pressure within the system and prevent any potential damage or malfunction.

The correct answer is oil nozzle condition. The F100-PW-100 engine oil pressure is affected by various factors such as N2, engine inlet oil temperature, and oil jet pressure. However, the condition of the oil nozzle has a direct impact on the oil pressure. If the oil nozzle is damaged or clogged, it can restrict the flow of oil, leading to a decrease in oil pressure. Therefore, maintaining the proper condition of the oil nozzle is crucial for ensuring optimal oil pressure in the engine.

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 stalls can occur when there is too much air pressure in the compressor, causing a disruption in the airflow and a loss of engine performance. By reducing the amount of air available to the N2 compressor, the compressor bleed system helps maintain a stable airflow and prevents compressor stalls.

The PTO shaft used to drive the CSD (Constant Speed Drive) is provided by the engine adapter. The engine adapter is a component that connects the engine to the CSD, allowing the transfer of power from the engine to the CSD via the PTO shaft. This connection ensures that the CSD receives the necessary power to operate efficiently.

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 signal is important for the engine control system to accurately adjust and regulate the engine's performance based on the feedback received from the variable vane system.

A transformer is a unit of an AC ignition system that develops 20,000 volts. Transformers are used to increase or decrease the voltage in a circuit. In this case, the transformer is responsible for stepping up the voltage to the required 20,000 volts for the ignition system.

The slide-type resistor in the EGT circuit is used to compensate for differences in temperatures at altitude. As an aircraft ascends to higher altitudes, the temperature decreases. The slide-type resistor allows the pilot to adjust the resistance in the circuit, which in turn adjusts the temperature indication on the EGT (Exhaust Gas Temperature) indicator. This compensation is necessary because the EGT readings can be affected by the changes in temperature at different altitudes, ensuring accurate temperature measurements for the engine's performance monitoring.

The correct answer is controlling turbine inlet temperature. In a dual-spool, axial-flow engine, the thrust production is controlled by regulating the temperature of the air entering the turbine. By controlling the turbine inlet temperature, the engine can effectively manage the energy output and optimize thrust production. This is achieved by adjusting the fuel flow rate and maintaining the desired temperature level for efficient engine operation.

During jet engine deceleration, the fuel flow needs to be adjusted to ensure the engine operates smoothly. A hydromechanical fuel control system is responsible for regulating the fuel flow. In this case, it schedules the fuel flow based on the burner pressure. Burner pressure is a crucial factor as it directly affects the combustion process and the engine's performance. By adjusting the fuel flow according to the burner pressure, the hydromechanical fuel control system ensures that the engine decelerates safely and efficiently.

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 position of the variable vanes in the engine based on these two parameters. The fan discharge temperature represents the temperature of the air leaving the fan section of the engine, while the core engine speed refers to the rotational speed of the engine's core components. By considering these two factors, the MEC can optimize the performance and efficiency of the engine.