Aeronautics Knowledge Test: The 54h60-117, Dowty R391 Propeller Systems and Gtcp 165 Engine

The barrel is the correct answer because it is a component of the propeller subassembly that is responsible for transmitting engine torque to the propeller blades. The barrel is designed to house and support the propeller blades, allowing them to rotate and generate thrust. It plays a crucial role in converting the rotational motion of the engine into forward propulsion.

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 not at a high enough pressure to properly inflate the tires. Inflating aircraft tires requires a high-pressure air source, such as an air compressor, to ensure that the tires are properly inflated to the required pressure for safe operation. Therefore, the air bled from the small gas turbine engine is not suitable for this purpose.

During normal propeller operation, the output of the main pressure and main scavenge pumps is used. These pumps are responsible for maintaining the necessary pressure and scavenging functions in the propeller system. The main pressure pump ensures that there is sufficient oil pressure for proper lubrication and operation of the propeller, while the main scavenge pump removes any excess oil and debris from the system. Therefore, the combination of main pressure and main scavenge pumps is crucial for the efficient and reliable functioning of the propeller.

Synchrophasing refers to the process of keeping the propellers of an aircraft rotating at the same speed. This is important because it helps maintain the optimum blade phase angle relationship between all propellers. By keeping the propellers at the same speed, the aircraft can achieve better efficiency and reduce vibrations. It also helps in reducing noise levels and improving overall performance.

The barrel of the 54h60-117 propeller subassembly carries high centrifugal loads created by the propeller blades. This means that the barrel is designed to withstand and distribute the forces exerted by the rotating blades, ensuring stability and efficiency of the propeller system. The dome, control, and front spinner may have other functions in the propeller assembly, but they do not specifically carry the high centrifugal loads created by the propeller blades.

The correct answer is a four-wheel trailer. When used for ground operation, the sgt engine can be installed on a four-wheel trailer. This means that the engine can be easily transported and moved around on a trailer with four wheels. This option provides stability and maneuverability for the engine during ground operations.

When attempting to unfeather the 54h60-117 propeller in flight, the throttle must be positioned above flt idle. This means that the throttle should be set to any position higher than the flight idle position.

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

The deicer contact ring holder is responsible for providing electrical circuits between the brush block assembly and the deicing elements of the blade assemblies. It acts as a connector or interface between these two components, allowing the electrical current to flow and power the deicing elements.

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 spinning too fast, which could lead to an engine overspeed.

The correct answer is no.2 and no.3. This means that the master synchrophaser board located in the synchrophaser unit contains a master channel and a slave channel.

The fuel shutoff solenoid is the valve that closes to ensure fuel flow is terminated when the gtcp 165 engine shuts down. This solenoid is responsible for stopping the fuel supply to the engine, preventing any further fuel from entering the system. By closing this valve, the fuel flow is effectively cut off, ensuring the engine is no longer receiving fuel and can safely shut down.

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 all three components are attached to the same shaft, allowing them to rotate together and transfer power from the impeller wheel to the turbine wheels. Couplings provide a secure and efficient connection, ensuring smooth operation of the engine.

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

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.

During the manufacture of the 54h60-117 propeller, the beveled thrust washer is installed on the blade before the blade butt is formed. This component helps to provide stability and support to the blade, ensuring smooth and efficient operation of the propeller. It is designed with beveled edges to distribute the thrust load evenly, reducing friction and wear on the propeller system.

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 in the opposite direction to the decrease in pitch, keeping the blades in position.

On a GTCP 165 engine oil system, air that leaks past various oil seals exits through the vent system. The vent system is designed to release any excess pressure or air that may accumulate in the oil system. This helps to prevent any potential damage or malfunction caused by excessive pressure build-up.

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 will cause an increase in blade angle.

The beta range indication display on the coordination for the 54h60-117 propeller is 0 to 34 degrees. This means that the propeller can be adjusted to a minimum of 0 degrees and a maximum of 34 degrees of beta range. The beta range refers to the angle of the propeller blades in relation to the plane of rotation. By adjusting the beta range, the pilot can control the thrust and drag produced by the propeller, allowing for better maneuverability and performance of the aircraft.

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

The movable wedge is responsible for forcing the stop levers on the low pitch stop to move outward on the 54H60-117 propeller.

The compensating network in the synchrophaser unit allows the speed bias motor to correct a change in rpm by 2%. This means that if there is a deviation in the speed of the system, the compensating network will adjust the speed bias motor to correct it by 2% of the current rpm value.

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.

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 backplate is the correct answer because it provides an aerodynamic fairing over the aft section of the hub. The backplate is a component of the R391 Dowty propeller assembly and is designed to improve the overall aerodynamic efficiency of the propeller system by reducing drag and improving airflow. It is located at the back of the hub and helps to streamline the propeller assembly, ultimately enhancing its performance.

The beta tube routes engine oil to and from the cylinder and piston.

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. The synchrophase master switch controls the synchronization of propellers on multi-engine aircraft, and in this case, it needs to be turned off for the propeller to operate normally. The other options, such as below FLT IDLE or with the synchrophase master switch in the ENG 2 or ENG 3 position, do not meet the requirements for normal operation.

The pitchlock control cam is the component that mechanically holds the stationary and rotating pitchlock ratchets apart during reversing and unfeathering operations. This allows for the proper functioning of the propeller during these operations.

If the main filter becomes clogged on the 54h60-117 propeller, the bypass valve opens to assure continued flow. The bypass valve allows the fluid to bypass the clogged filter, ensuring that there is still a flow of fluid to the system. This prevents any potential damage or loss of function that could occur if the flow was completely blocked.

The feather actuating valve assists the feather solenoid valve with the hydraulic positioning of the feather and pilot valves. This means that it helps control the movement and positioning of these valves, ensuring that they function properly in the feathering process. The high pressure relief valve, standby valve, and backup valve do not have a direct role in assisting the feather solenoid valve with hydraulic positioning.

During a normal start on a GTCP 165 engine, the igniter plug continues firing until the engine rotation in RPM reaches 95%. This is because the igniter plug is responsible for igniting the fuel-air mixture in the engine's combustion chamber. By continuing to fire until 95% of the engine's rotation speed is reached, it ensures that the fuel is properly ignited and the engine can start running smoothly. Once the engine reaches this RPM, the igniter plug is no longer needed as the combustion process is self-sustaining.

The minimum psi required to release the feather latches and allow the piston to move forward on the 54h60-117 propeller is 200.

During a normal GTCP 165 engine shutdown, the 110% circuit trips to stop the engine. This circuit is designed to monitor the engine's speed and if it exceeds 110% of the normal operating speed, it triggers a shutdown to prevent any potential damage or unsafe conditions. By tripping the 110% circuit, the engine is safely stopped and brought to a halt.

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 stays within a certain range of pitch angles when the throttle is in a specific position, preventing the propeller from entering a range that could potentially cause issues or malfunctions.

When the throttle is positioned from flt idle to take off, it allows the engine to increase its power output gradually, which results in the aircraft accelerating smoothly and reaching a constant speed. This is because flt idle is the minimum throttle position required to keep the engine running, and as the throttle is advanced towards take off, more fuel is supplied to the engine, increasing its power and propelling the aircraft forward. Therefore, constant speed can only be achieved when the throttle is positioned from flt idle to take off.

The PCBS (Propeller Control Backup System) is a switch located in the valve housing that is opened by a cam when the propeller blade angle is between 81 to 85 degrees. The PCBS is responsible for controlling the propeller pitch and ensuring proper functioning of the propeller system.

When feathering the 54h60-117 propeller, the mechanical linkage is acted upon by the manual feather cam to open the feather actuating valve.

The oil pressure switch is responsible for shutting down the engine if the oil pressure drops below the safe minimum operating limit. This switch is designed to monitor the oil pressure and send a signal to the engine control system when the pressure falls below the threshold. This is a crucial safety feature as low oil pressure can lead to engine damage or failure. By shutting down the engine, the oil pressure switch helps prevent further damage and ensures the safe operation of the engine.

If the R391 Dowty propeller loses hydraulic pressure, the counterweights installed at the root of each propeller blade would drive the propeller blades towards the feather position. Feathering the propeller means adjusting the blade angle to minimize drag and allow the aircraft to glide more efficiently in the event of an engine failure. This helps to maintain control and maximize the chances of a safe landing.

During the propeller feathering operation, the feather valve is positioned to meter hydraulic fluid to the forward end of the dome piston. This is because the forward end of the dome piston is responsible for controlling the pitch of the propeller blades. By metering hydraulic fluid to this end, the propeller pitch can be adjusted to the desired angle for feathering.

If the slave propeller blades are in the correct phase angle position during the synchrophasing governing mode, the resultant phase error voltage is 0. This means that there is no phase error between the slave propeller blades and the governing mode, indicating that they are in perfect synchronization.

The correct answer is turbine plenum. In a GTCP 165 engine, the air for the load control system is extracted from the turbine plenum. The turbine plenum is a chamber located between the turbine and the compressor. It collects and distributes air to various systems within the engine, including the load control system. This system helps regulate the load on the engine by controlling the amount of fuel being burned. Extracting air from the turbine plenum ensures that the load control system receives the necessary air supply to function properly.

The throttle is responsible for coordinating the propeller blade pitch and engine fuel flow in the controllable pitch range. By adjusting the throttle, the pilot can control both the pitch of the propeller blades and the amount of fuel being supplied to the engine. This coordination allows for precise control over the aircraft's speed and power output.

The auxiliary pressure pump is used to feather or unfeather the propeller during static propeller operation.

The 54H60-117 propeller governor speeder spring tension positions the pilot valve to maintain a specific percentage of RPM in the beta range. The correct answer is 109 to 113%.

Normal and synchrophasing modes add more functionality to basic mechanical governing mode. Normal mode allows the propeller to operate at a constant speed, while synchrophasing mode allows for synchronization of multiple propellers on a multi-engine aircraft. This allows for smoother operation and reduces vibrations.

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.

Ball bearings allow the rotating cam to turn while the stationary cam remains fixed. Ball bearings are designed to reduce friction and allow smooth rotation between two surfaces. In this case, the ball bearings enable the rotating cam to spin freely while the stationary cam remains in a fixed position, ensuring proper functioning of the propeller.

In the mechanical governing mode, the pilot valve is moved and sets the propeller speed by the speeder spring or flyweights. These components work together to regulate the flow of oil to the propeller, adjusting the pitch and controlling the speed. The speeder spring provides tension to counteract the centrifugal force of the flyweights, allowing for precise control over the propeller speed.