Aerospace Propulsion CDC Quiz

The section of a jet engine that introduces and burns fuel is called the combustion section. In this section, fuel is injected into the engine and mixed with compressed air. The mixture is then ignited, creating a high-temperature and high-pressure gas that expands and drives the turbine. The combustion section is crucial for generating the necessary thrust to propel the aircraft forward.

When metal is attacked by chemical corrosion, it will start on the surface of the metal. This is because corrosion is a surface phenomenon that occurs when the metal reacts with its surroundings, such as air or moisture. The outer layer of the metal is exposed to these corrosive agents, leading to the formation of corrosion products. As the corrosion progresses, it may penetrate deeper into the metal, but it initially begins on the surface where the metal is in direct contact with the corrosive environment.

The stationary vanes positioned between rotor discs in a compressor are used to direct air and increase pressure. These vanes act as guide vanes, redirecting the airflow and increasing its velocity before it reaches the rotor blades. By directing the air in a specific path, the vanes help to optimize the compressor's efficiency and increase the pressure of the air being compressed. This is essential in various applications where high-pressure air is required, such as in gas turbines, jet engines, and industrial compressors.

The three major sections of all jet engines are the compressor, combustion, and turbine. The compressor section is responsible for compressing incoming air, while the combustion section mixes fuel with the compressed air and ignites it to produce hot gases. These hot gases then flow through the turbine section, where the energy from the gases is used to drive the turbine blades. The turbine section is crucial as it converts the energy from the hot gases into mechanical energy to drive the compressor and other engine components.

The given answer, "reaction-impulse," suggests that there are two types of turbine and vane assemblies used in jet engines, which combine both reaction and impulse principles. This means that these turbine and vane assemblies utilize both the action of the gas flow and the change in momentum to generate power. However, the explanation is not clear about the specific characteristics or applications of these reaction-impulse turbine and vane assemblies.

To prepare the engine fuel system for service after depreservation, it is necessary to flush the system with fuel. This is because fuel is the appropriate substance to clean and remove any contaminants or debris that may have accumulated during the depreservation process. Flushing the system with fuel ensures that the engine's fuel system is clean and ready for use, allowing for optimal performance and efficiency.

The most common type of fuel nozzle system is the pressure-atomizing system. In this system, fuel is forced through a small nozzle at a high pressure, causing it to atomize into a fine spray. This allows for efficient combustion and better fuel-air mixing, resulting in improved fuel efficiency and reduced emissions. Pressure-atomizing systems are widely used in various industries, including automotive, aviation, and industrial applications.

The correct answer is small gas turbine engine. This is because the JFS (Jet Fuel Starter) is a small gas turbine engine used to start larger engines on aircraft. It provides the necessary power to initiate the rotation of the main engines, allowing them to start and operate efficiently. It is commonly used in military aircraft and some commercial aircraft as well.

The parts on a can-annular combustion section must be removed in a specific order because of the combustion chamber crossover tubes. These tubes connect the individual combustion chambers within the can-annular section, allowing for the flow of fuel and air mixture. Removing the crossover tubes first ensures that the fuel and air flow is properly interrupted, preventing any potential hazards or accidents during the maintenance process.

When blending fourth stage compressor blades on an F100-PW-220 engine, a maximum of two blends are allowed on any single edge. This means that if a blade is damaged or worn, it can only be blended twice before it needs to be replaced. This limitation ensures the integrity and performance of the engine by preventing excessive blending, which could compromise the blade's strength and efficiency.

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 ends of the armature coil. As the armature rotates, the brushes make contact with different segments of the commutator, allowing the current to flow in the same direction. This process ensures that the output of the generator is direct current rather than alternating current.

Kerosene is a type of fuel commonly used for heating and lighting. The heat content per pound refers to the amount of heat energy that can be produced by burning one pound of kerosene. In this case, the correct answer is 18,500 Btu's, which means that burning one pound of kerosene can produce 18,500 British Thermal Units of heat energy.

The correct answer is "ground start." Ground start is the switch that energizes the starter control valve to the OPEN position on the T56 engine. This means that when the ground start switch is activated, it allows the starter control valve to open, enabling the engine to start.

To release the internal air pressure in a shipping container/module, you must remove the filler valve on the front of the container. This valve is specifically designed to allow the release of air pressure. Removing the parting surface nuts or bolts would not have any effect on the internal air pressure.

The T700 power turbine drive shaft assembly is composed of two components: the drive shaft and the torque sensor tube. The drive shaft is responsible for transmitting power from the engine to the power turbine, while the torque sensor tube measures the torque being applied to the shaft. These two components work together to ensure the efficient and accurate transfer of power within the turbine system.

A dry sump oil system is the type of oil system that stores the oil in a tank fitted to the side of the engine. In this system, the oil is pumped from the engine into the external tank, where it is stored and cooled before being recirculated back into the engine. This design allows for better oil control, as it prevents oil from pooling in the bottom of the engine (wet sump), ensuring a constant supply of oil to all the engine components.

When an engine is not operating, the carbon seal requires a static preload to maintain its sealing capability. This preload is provided by spring pressure. Springs are used to apply a constant force on the carbon seal, ensuring that it remains in contact with the mating surface and prevents any leakage. The spring pressure acts as a mechanical force that keeps the seal compressed and maintains its effectiveness even when the engine is not running.

Directing air around the plug helps prevent igniter plug fouling by ensuring that the plug remains cool and free from deposits. When air is directed around the plug, it helps to dissipate heat and prevent the build-up of carbon deposits, which can cause fouling. This design feature helps to maintain the efficiency and performance of the engine by ensuring that the igniter plug functions properly without any obstructions or fouling.

The correct answer is that the impeller is forged as a single unit. This means that the impeller is manufactured as one solid piece, rather than being assembled from multiple parts. This constructional feature ensures that the impeller is sturdy and durable, as there are no weak points or potential areas for leakage or failure. It also allows for better balance and efficiency in the compressor's operation.

The T56 engine uses a gear oil pump. This type of oil pump uses gears to create suction and pressure, which allows it to effectively circulate oil throughout the engine. Gear oil pumps are commonly used in engines because they are reliable, durable, and can handle high-pressure applications. They are designed to efficiently pump oil to lubricate engine components and ensure proper functioning.

The correct answer is 2J-1-19. This TO (Technical Order) covers the disposition of engines that have been removed from aircraft involved in mishaps. It provides guidance on how to handle and document these engines to ensure proper accountability and prevent their reuse in potentially unsafe conditions.

When the rectangular teeth on the exciter wheels are aligned at zero torque, it means that no torque is being transmitted. This alignment indicates that there is no power being transmitted from the power unit and no negative or positive torque being transmitted to the torque indicator. Therefore, this alignment signifies that the torquemeter is at a neutral position with no torque being measured or transmitted.

The correct answer is 21. The F119 engine contains 21 hollow struts/inlet guide vanes in its inlet fan case. These components play a crucial role in directing and guiding the airflow into the engine, ensuring efficient combustion and optimal performance. The specific number of 21 has been determined based on the engine design and requirements.

The term "propeller brake" refers to a mechanism used to stop or slow down the rotation of a propeller. In this context, the propeller brake can be in different positions or states. "Engaged" means that the propeller brake is activated or in use, which contradicts the question's statement that asks for a position that is NOT a propeller brake position. Therefore, "Engaged" is not a propeller brake position.

The correct answer is actuator. The core reverser lock proximity sensors are mounted on the actuator. This suggests that the actuator plays a crucial role in the functioning of the core reverser lock system. It is likely that the actuator is responsible for controlling the movement or position of the core reverser lock, and the proximity sensors are used to detect its position.

The T56 engine anti-icing solenoid valve is normally open, meaning that it is in an open position by default. In this state, the valve allows the flow of fluid or air to pass through. It only closes or restricts the flow when it is energized or activated by an external power source. This configuration ensures that the anti-icing system remains operational and allows for the continuous flow of fluids to prevent ice formation.

The external flanges on the F100 engine are referred to by letter designations. This means that each flange is assigned a specific letter to identify it. This method of designation allows for easy communication and reference when discussing or working with the engine. Number designations, directional references, and accessories references are not used to identify the external flanges on the F100 engine.

When the null orifice on the T56 engine TD valve is set at zero, it means that it is completely closed. In this position, the valve will bypass 20% of the fuel. This means that 20% of the fuel will not go through the TD valve and will instead bypass it.

The T56 component that allows 14th stage air to close the bleed air valve is the speed-sensitive valve. This valve is designed to respond to changes in engine speed and adjust the flow of air accordingly. When the engine speed reaches a certain level, the speed-sensitive valve closes, preventing the bleed air from escaping and allowing it to be directed to other systems as needed.