CDC Volume 4 Edit Code 2

The correct answer is "Barrel." In a 54H60-117 propeller subassembly, the barrel is responsible for transmitting the engine torque to the propeller blades. The barrel is a crucial component that connects the engine to the propeller and ensures that the power generated by the engine is effectively transferred to the blades, allowing them to rotate and generate thrust.

The barrel carries high centrifugal loads created by the propeller blades.

The beta range indication display on the coordinator for the 54H60-117 propeller is 0° to 34°.

The low pitch stop assembly on the 54H60-117 propeller is responsible for preventing the propeller from going into the beta range when the throttle is positioned in the alpha range. This means that it ensures the propeller remains in the appropriate pitch range based on the throttle position, preventing any unintended movements or adjustments that could affect the propeller's performance.

Synchrophasing is a technique used to maintain the optimum blade phase angle relationship between all propellers in an aircraft. This means that all the propellers are rotating at the same speed. By keeping the propellers rotating at the same speed, it helps to reduce noise and vibration, improve efficiency, and enhance the overall performance of the aircraft.

The auxiliary pressure pump is used to feather or unfeather the propeller during static propeller operation on the 54H60-117 propeller.

If the main filter becomes clogged on the 54H60–117 propeller, the bypass valve opens to assure continued flow. This means that the bypass valve allows the fluid to bypass the clogged filter and continue flowing through the system.

During propeller static operation, the auxiliary pressure pump and the auxiliary scavenge pump are used. These pumps are responsible for providing the necessary pressure and scavenging functions to ensure proper operation of the propeller system. The main pressure and main scavenge pumps are not used during propeller static operation.

The pneumatic air bled from the small gas turbine engine cannot be used to inflate aircraft tires because the air bled from the engine is typically at a high temperature and pressure, which is not suitable for inflating tires. Tires require a specific pressure and temperature range for proper inflation, which cannot be achieved with the air bled from the engine.

The correct answer is 109 to 113%. The 54H60-117 propeller governor speeder spring tension is responsible for positioning the pilot valve to maintain a specific percentage of RPM in the beta range. In this case, the tension is set to maintain a range of 109 to 113% RPM. This ensures that the propeller operates within the desired speed range during beta operations.

When the pressure between 240 and 280 psi on the 54H60-117 propeller is reached, the servo valve is unseated. This unseating of the servo valve allows the stop levers to retract.

If the slave propeller blades are in the correct phase angle position during the synchrophasing governing mode, it means that they are perfectly synchronized with the master propeller. In this case, there is no phase error between the two propellers, resulting in a phase error voltage of 0.

When attempting to unfeather the 54H60-117 propeller in flight, the throttle can be positioned at any throttle position. However, the correct answer is above FLT IDLE, indicating that the throttle should be set higher than the flight idle position. This is because unfeathering the propeller requires a higher power setting to provide the necessary oil pressure to move the feathering mechanism and restore the propeller to the normal operating position.

During feather operation on the 54H60-117 propeller, the pressure cutout switch contacts open within the range of 600 to 800 pounds per square inch (psi) of fluid pressure.

The compensating network in the synchrophaser unit allows the speed bias motor to correct a change in rpm of 2%. This means that the synchrophaser unit can adjust the speed bias motor to compensate for a small variation in rpm, ensuring that the system maintains synchronization and operates smoothly.

During an overspeed condition in the alpha range on the 54H60-117 propeller, the flyweights move the governor pilot valve to meter hydraulic fluid. This action is taken to counteract the excessive speed and prevent further acceleration of the propeller. By metering hydraulic fluid, the flyweights increase the blade angle, which results in a higher pitch and reduces the propeller's rotational speed. Therefore, the correct answer is to increase the blade angle.

During normal propeller operation on the 54H60-117 propeller, the output of both the main pressure pump and the main scavenge pump is used. These pumps are responsible for maintaining the necessary pressure and lubrication in the propeller system. The main pressure pump supplies oil to the propeller for hydraulic control, while the main scavenge pump removes excess oil and debris from the propeller system. Using the output of both pumps ensures proper functioning and efficiency of the propeller during operation.

The deicer contact ring holder's purpose is to provide electrical circuits between the brush block assembly and the deicing elements of the blade assemblies. This component ensures that the electrical current is properly transmitted to the deicing elements, allowing them to effectively remove ice from the blades. The other options listed, such as the control assembly, front spinner section, and hub mounting bulkhead, do not have this specific function of providing electrical circuits for deicing.

Constant speed can only occur when the throttle is positioned from FLT IDLE to TAKE OFF. This is because FLT IDLE is the lowest throttle position where the engine is running and producing enough power to maintain a constant speed. Moving the throttle from FLT IDLE to TAKE OFF increases the power output of the engine, allowing it to maintain a constant speed. The other options, RVS to FLT IDLE, RVS to GND IDLE, and GND IDLE to FLT IDLE, do not involve increasing the power output of the engine and therefore cannot result in a constant speed.

The SGT engine, when used for ground operation, can be installed on a four-wheel trailer. This suggests that the engine is designed to be mobile and can be easily transported using a trailer with four wheels. This configuration allows for flexibility and ease of movement, making it convenient for ground operations.

The beveled thrust washer is installed on the blade before the blade butt is formed during manufacture. This component helps to provide stability and support to the blade, ensuring smooth operation and reducing friction during rotation. Slip rings, microadjusting ring, and roller thrust bearing are not relevant to the installation process of the blade butt.

The "C" in the engine number GTCP 165 indicates that the engine provides compressed air.

The correct answer is the movable wedge. The stop levers on the low pitch stop are forced to move outward by the movable wedge.

The purpose of the 54H60–117 propeller pitchlock assembly is to prevent engine overspeed due to a loss of hydraulic pressure. This means that if there is a loss of hydraulic pressure, the pitchlock assembly will engage and prevent the propeller from rotating freely, thus preventing the engine from overspeeding. This is an important safety feature to ensure the engine operates within safe limits even in the event of a hydraulic system failure.

The minimum psi required to release the feather latches and allow the piston to move forward on the 54H60-117 propeller is 200.

When the backup valve is opened on the 54H60-117 propeller, the hydraulic pressure routed to the governor pilot valve is used for the operation of reversing the propeller.

The PCBS (Propeller Control Blade Switch) is the switch located in the valve housing that is opened by a cam from 81° to 85° propeller blade angle on the 54H60–117 propeller. The PCBS is responsible for controlling the pitch of the propeller blades and adjusting them based on the desired blade angle.

The correct answer is Beta set. The question is asking which cam schedules a desired blade angle in the beta range on the 54H60-117 propeller. The term "beta range" refers to the range of blade angles that can be achieved by adjusting the propeller blades. The cam that is responsible for setting the desired blade angle in the beta range is the Beta set cam. This cam is specifically designed to control the blade angle and ensure that it is set correctly within the desired range.

The pitchlock control cam is the component that mechanically holds the stationary and rotating pitchlock ratchets apart during reversing and unfeathering operations on the 54H60-117 propeller. This cam ensures that the pitchlock mechanism functions properly and allows for the desired pitch adjustments during these operations. The other options, such as the pitchlock ratchet piston, externally threaded ring, and externally splined spacer ring, do not perform this specific function.

The fuel shutoff solenoid closes to ensure that fuel flow is terminated during a GTCP 165 engine shutdown. This solenoid is responsible for controlling the fuel supply to the engine and shutting it off when necessary. By closing the fuel shutoff solenoid, the flow of fuel is stopped, preventing any further fuel from entering the engine and effectively shutting it down.

During the 54H60-117 propeller feathering operation, the feather valve is positioned to meter hydraulic fluid to the forward end of the dome piston. This means that the hydraulic fluid is being directed to the front of the dome piston, which is responsible for controlling the pitch of the propeller blades. By metering the fluid to the forward end of the dome piston, the propeller pitch is decreased, allowing for feathering of the propeller.

The stop ring is the component in the dome assembly that limits cam travel and prevents the propeller from exceeding feather and reverse blade angles. It acts as a physical barrier, restricting the movement of the propeller blades beyond certain angles. This ensures that the propeller functions within its intended operating range and prevents any potential damage or malfunction.

The centrifugal twisting moment is the force that prevents the blades of the 54H60-117 propeller from decreasing pitch during pitchlock. This force is generated due to the rotation of the propeller and acts to counteract any external forces that would cause the blades to change their pitch. It is an important factor in maintaining the desired pitch of the propeller blades during operation.

The correct answer is "Check." In this context, a "check" valve is a type of valve that allows fluid to flow in one direction only. In this case, the check valve opens to allow the output of the standby pump to combine with the output of the main pump. This ensures that the fluid flows in the desired direction and prevents backflow or mixing of the fluids.

The feather actuating valve assists the feather solenoid valve with hydraulic positioning of the feather and pilot valves on the 54H60-117 propeller. This valve helps control the movement and positioning of the feather and pilot valves, ensuring proper operation of the propeller system.

The beta feedback shaft delivers the actual propeller blade angle from the blade to the control assembly.

The backplate is the correct answer because it provides an aerodynamic faring over the aft section of the hub. The backplate is a component of the R391 Dowty propeller assembly and is designed to streamline the airflow and reduce drag at the rear of the hub. It helps to improve the overall performance and efficiency of the propeller system. The rear spinner, front spinner, and afterbody assemblies are not specifically mentioned as providing an aerodynamic faring over the aft section of the hub, making them incorrect choices.

If the R391 Dowty propeller loses hydraulic pressure, the counterweights installed at the root of each propeller blade would drive the propeller blades toward the feather position. Feathering refers to the process of aligning the propeller blades with the airflow to minimize drag and prevent windmilling. By feathering the propeller blades, the aircraft can reduce the resistance caused by a non-functioning propeller and maintain better control during an emergency situation.

The impeller wheel and two turbine wheels in the turbine section of the GTCP 165 engine are connected by couplings on a common shaft. This means that the impeller wheel and the two turbine wheels are attached to the same shaft, allowing them to rotate together. Couplings are mechanical devices used to connect two shafts together, transmitting power and torque between them. In this case, the couplings on a common shaft ensure that the impeller wheel and the turbine wheels are synchronized and work in tandem to generate power in the engine.

When feathering the 54H60-117 propeller, the mechanical linkage is acted upon by the manual feather cam to open the feather actuating valve.

When the overspeed condition of the 54H60-117 propeller is corrected and the pilot valve is returned to the center position, the result is that the system is back on-speed. This means that the propeller is operating at the desired speed and is functioning properly.

The correct answer is Speeder spring or flyweights. In the mechanical governing mode, the pilot valve is moved and sets the propeller speed by the action of the speeder spring or flyweights. These components work together to regulate the flow of oil to the propeller, thereby controlling its speed. The speeder spring provides the initial force to move the pilot valve, while the flyweights adjust the tension on the spring based on the rotational speed of the propeller. This allows for precise control of the propeller speed in the mechanical governing mode.

Normal and synchrophasing governing modes add more functionality to the basic mechanical governing mode. Normal governing mode adjusts the propeller blade angle to maintain a constant engine speed, while synchrophasing mode synchronizes the propeller speeds on multi-engine aircraft, reducing noise and vibration. This combination of modes enhances the control and performance of the propeller system beyond the basic mechanical governing mode.

In order for the 54H60-117 propeller to operate in the normal governing mode, the throttle must be at or above FLT IDLE and the synchrophase master switch must be in the OFF position. This means that the throttle needs to be set to a certain level and the synchrophase master switch should not be engaged. These conditions are necessary for the propeller governor control switch to function properly and regulate the propeller's operation.

The correct answer is "Speed set." During alpha range operation on the 54H60-117 propeller, the speed set cam changes the tension of the speeder spring. This adjustment allows the governor pilot valve to maintain 100 percent engine speed.

When an increase in rpm occurs during engine speed stabilization, an overspeed condition is prevented by decreasing speeder spring tension. This reduces the force exerted by the speeder spring on the flyweights, causing them to move inward and increase the blade angle. By positioning the pilot valve to increase the blade angle, the airflow through the engine is restricted, which helps to decrease the engine speed and prevent an overspeed condition.

The correct answer is one because the question asks about the number of slave channels on the master synchrophaser board. This implies that there is only one slave channel on the board.

The pressure cutout switch is the primary electrical ground for energizing the feather override holding coil. This means that when the pressure cutout switch is activated, it provides the necessary electrical connection for the feather override holding coil to be energized. This allows the propeller to be feathered in emergency situations. The other options, such as the feather relay, feather solenoid, and pressure cutout backup switch, do not serve as the primary electrical ground for energizing the feather override holding coil.

When the standby pump output is not required on the 54H60-117 propeller, it is routed to the pressurized sump.

The rotating cam and stationary cam need to move independently of each other in order for the propeller to function properly. Ball bearings are designed to allow smooth rotation of one part while keeping another part fixed, making them the most suitable option for this purpose. Roller shaft, track slopes, and roller bearings do not provide the same level of flexibility and independence required in this scenario.