C-130h Hercules APU Run Test: Quiz!

The APU (Auxiliary Power Unit) is a small engine located at the rear of an aircraft that provides power for various functions when the main engines are not running. It can be quite noisy when running. Therefore, to protect their hearing, it is necessary for everyone in the vicinity of the airplane to wear hearing protection when the APU is running.

Clearing the props before applying bleed air pressure to the manifold is necessary to ensure the safety and efficiency of the system. Clearing the props involves ensuring that the propellers are in a position where they will not cause any damage or interference when the bleed air pressure is applied. This step is important to prevent any potential accidents or damage to the aircraft. Therefore, the statement is true.

Prior to starting the APU, it is necessary to have the NLG ground pin in place, which ensures the aircraft is properly grounded. Additionally, the airplane must be statically grounded to prevent any electrical discharge. Lastly, the wheels should be chocked to prevent any movement of the aircraft during the APU start. Therefore, all of the given options are required prior to starting the APU.

The correct answer is "PULL FIRE CONTROL HANDLE." In the event of an APU emergency shutdown, the first step is to pull the fire control handle. This action helps to cut off the fuel supply and electrical power to the APU, preventing any further damage or potential fire hazards. It is a crucial initial step in ensuring the safety of the aircraft and its occupants.

If the AGENT DISCHARGE switch is held for more than the recommended time, it can cause the fire extinguisher circuit breaker to trip and the system to become inoperable. This means that the fire extinguisher system will not be able to function properly, potentially leading to a dangerous situation if there is a fire. It is important to follow the recommended procedures and guidelines to ensure the safe and effective operation of the fire extinguisher system.

Prior to starting the APU, all 5 fire handles should be positioned in the "pushed in" position. This means that the APU fire handle should be pushed in, and all the other fire handles should also be pushed in. This is the correct position to ensure that the fire suppression system is not activated and that there are no false alarms or accidental discharges of the fire extinguishing agent.

Operating the APU with a malfunctioning APU fuel shutoff valve is not recommended. The APU fuel shutoff valve is responsible for controlling the flow of fuel to the APU. If it is not operating properly, it could result in fuel leakage or other safety hazards. Therefore, it is important to ensure that the APU fuel shutoff valve is functioning correctly before operating the APU.

If the APU fire warning system is not operating properly, it is not safe to run the APU. The fire warning system is designed to detect and alert the crew in case of a fire in the APU. Without a functioning fire warning system, there is a risk of not being able to detect a potential fire, which could lead to a dangerous situation. Therefore, the correct course of action would be to not run the APU until the fire warning system is fixed.

If the APU fire warning system is not operating properly, it is not safe to run the APU. The fire warning system is designed to detect any potential fire in the APU and alert the pilot. Without a functioning fire warning system, the pilot would not be aware of any fire hazard, increasing the risk of an APU fire going undetected and potentially causing a catastrophic event. Therefore, it is important to ensure that the APU fire warning system is working properly before running the APU.

If the APU (Auxiliary Power Unit) has been used recently, it is likely that its components and the oil inside it are still hot. This means that if someone were to come into contact with these hot components or oil, they could potentially get burned. Therefore, the statement "If the APU has been operated on recently, APU components and oil in APU may be hot enough to cause burns" is true.

The question asks for the number of people required to run APU. The correct answer is 2, which implies that APU requires two people to operate it efficiently.

The APU (Auxiliary Power Unit) gets its fuel from the aircraft's main fuel tanks. These tanks contain the fuel that is used by the engines during flight. The APU is a small turbine engine located at the rear of the aircraft, and it provides power for various functions such as starting the main engines, operating electrical systems, and providing air conditioning when the main engines are not running. Since the APU is an integral part of the aircraft, it relies on the same fuel source as the main engines, which is the main fuel tanks.

The statement is asking if it is necessary to monitor the UHF radio set to ground control frequency for emergency communications. The correct answer is "True" because monitoring the UHF radio set to ground control frequency is essential in order to receive emergency communications and respond accordingly.

If there is frost on the intake screen but no ice, it means that the temperature is low enough to cause frost to form, but not low enough for the frost to turn into ice. The presence of frost indicates that there is moisture in the air, which can potentially damage the APU. However, since there is no ice, it suggests that the APU can still be operated safely without the risk of ice causing any issues. Therefore, the statement "If you have frost but no ice on the intake screen you can still run the APU" is true.

The minimum fuel level required in the fuel tank prior to APU operation is 2000 lbs. This is because the APU (Auxiliary Power Unit) requires a certain amount of fuel to operate effectively. Having a minimum fuel level of 2000 lbs ensures that there is enough fuel to power the APU and perform its functions without any issues.

When applying bleed air and not using air conditioning, A/C plugs are still required to be removed. This is because bleed air is used for other purposes such as pressurization and anti-icing, and not removing the A/C plugs can cause damage or malfunction to the system.

In the event of a fire in the APU compartment, the proper position for the AGENT DISCHARGE switch is to place it to #1 and release. If the fire persists, the switch should then be placed to #2 and released. This suggests that there are two different levels or options for discharging the agent, and if the first option does not extinguish the fire, the second option should be tried.

The frequency meter should indicate a reading between 380-420 Hz for a proper reading. This range of frequencies is the correct range that the meter should measure in order to provide accurate results. Frequencies outside of this range may not be properly detected or measured by the meter.

If there is a rapid drop in bleed air pressure or evidence of excessive duct leakage, it is necessary to shut the APU (Auxiliary Power Unit) down immediately and correct the problem. This is because a rapid drop in bleed air pressure or excessive duct leakage can indicate a serious issue with the APU, which could potentially lead to further damage or safety hazards. By shutting the APU down and addressing the problem, any potential risks can be mitigated and the aircraft can be safely operated.

To verify the APU fire warning system is operating properly, the correct procedure is to place the fire test switch to test and ensure that all fire indicator warning lights come on. This test is necessary to ensure that the system is functioning correctly and that all warning lights are operational. By performing this test, any issues or malfunctions in the APU fire warning system can be identified and addressed promptly.

If the pressure drop exceeds the time allotted, it is important to shut down the system and correct the fault before proceeding. Continuing to run the system with a significant pressure drop can lead to further damage or malfunction. It is necessary to identify and address the cause of the pressure drop to ensure the system operates safely and efficiently. Following emergency shutdown procedures may also be necessary depending on the severity of the situation.

Once you clear the APU door area and place the APU control switch to run, both the APU door open light should illuminate and the APU door should open. This means that when the APU control switch is set to run, it activates the mechanism to open the APU door and simultaneously illuminates the APU door open light to indicate that the door is indeed opening.

To check the fuel strainer, you should place a container under it, depress the drain valve, and ensure that fuel flow stops. This process allows you to collect any fuel that may be draining from the strainer and verify that it is functioning properly. By ensuring that the fuel flow stops, you can confirm that the strainer is effectively filtering out any debris or contaminants from the fuel system.

The correct answer is "As soon as practical to provide electrical power." When the battery is used to start the APU (Auxiliary Power Unit), it is important to turn on the APU generator as soon as possible to ensure a continuous supply of electrical power. This will help prevent any interruption or loss of power during the operation of the aircraft.

If the isolated DC power is interrupted while the APU is operating, the control circuit will be opened, causing the APU to stop. This means that the APU will no longer continue to run.

The correct answer is "No more than 2 sec." This means that you should hold the AGENT DISCHARGE SWITCH for a maximum of 2 seconds. Holding it for longer than that may have negative consequences or be unnecessary.

The correct answer is 95%. This means that when the speed reaches 95% of the maximum revolutions per minute (rpm), the light comes on and stays on. This suggests that the light is a warning or indicator for when the engine is running at a very high speed, close to its maximum capacity.

A DC voltmeter should indicate a minimum of 21 volts. This means that if the voltage being measured is lower than 21 volts, the voltmeter will not provide an accurate reading. Therefore, any voltage below 21 volts will not be detected by the voltmeter.

The start light must go out within 1 minute.

In case of an emergency on an airplane, it is important to prioritize the safety of the passengers and crew. By calling the fire department before notifying everyone to evacuate, you ensure that professional help is on the way to handle any potential fires or other emergencies. This allows for a more organized and efficient evacuation process, reducing the risk of injuries and increasing the chances of a successful rescue operation.

If there is a failure in the APU inlet door actuator during ground operations, you may gain access to the actuator and reposition it. Additionally, you can also install an actuator simulator. Both options A and C are correct.

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Prior to starting the APU, the aft cargo door and ramp controls should be placed in specific positions. The ramp control should be set to either 6N or 3N, the pump should be turned off, and the cargo door manual control handle should be in the neutral position. All of these actions are necessary to ensure the proper functioning and safety of the cargo door and ramp controls before starting the APU.

The correct answer is 1 min on, 4 min off. This means that the starter is active for 1 minute and then inactive for 4 minutes before being active again. This duty cycle allows for the starter to rest and cool down for a longer period of time compared to the other options, which can help prevent overheating and prolong the lifespan of the starter.

The correct answer is "Headed into the wind, if practical." This is because parking the plane into the wind allows for better control during takeoff and landing. When the plane is facing into the wind, it experiences increased airflow over the wings, which generates more lift and reduces the groundspeed needed for takeoff. It also allows for better control during landing by reducing the groundspeed and providing a shorter landing distance. However, the practicality of parking into the wind depends on factors such as the wind direction and the available parking space.

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Prior to starting the APU, the condition levers should be in the "Ground stop" position. This is because the ground stop position ensures that the APU remains off and prevents it from starting unintentionally. It is a safety precaution to ensure that the APU is not running when it is not required, such as during ground operations or maintenance.

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The correct answer is 680 C because EGT (Exhaust Gas Temperature) is a critical parameter in a cycle. If the EGT exceeds a certain limit, it can cause damage to the engine components. Therefore, it is important to ensure that the EGT does not exceed a safe threshold. Out of the given options, 680 C is the highest temperature mentioned, indicating that there is a limit and the EGT must not exceed this value.

The tachometer indicator on ACFT AF95-1001 and up requires 115 VAC and 400 Hz to provide RPM indicators.

If the pressure drop exceeds the time allotted when checking bleed air pressure ducts, it indicates that there is a fault in the bleed air system. This means that there is a problem with the system that is responsible for supplying air to different parts of the aircraft, such as the cabin and the engines. The pressure drop exceeding the allotted time suggests that there is a leak or some other issue in the system that is causing the air pressure to drop more quickly than it should.

The correct answer is 30/15 psi. When checking bleed air pressure ducts, the start/stop timing should be done when the pressure has dropped to 30/15 psi. This indicates that the pressure has reached a safe level for inspection and maintenance purposes.

When the outside temperature is below freezing point (0 deg C, 32 deg F), it is necessary to wait for a certain period of time before applying a load to the APU (Auxiliary Power Unit). This is because at such low temperatures, the APU needs time to warm up and reach its optimal operating temperature. Waiting for 4 minutes allows the APU to warm up sufficiently before applying a load, ensuring proper functioning and preventing potential damage.

When starting an APU, you have a total of 10 seconds to place the APU control switch to START after it has been moved from STOP. This time frame is crucial to ensure that the APU starts up properly and efficiently. If the switch is not moved to START within 10 seconds, it may cause delays or issues with the APU's functionality.

The APU door serves the purpose of fire containment within a fireproof area. This means that in case of a fire in the APU (Auxiliary Power Unit), the door helps to prevent the fire from spreading to other areas of the aircraft by containing it within the designated fireproof area. This is crucial for the safety of the aircraft and its passengers, as it helps to minimize the risk of a fire causing further damage or endangering the flight.

The failure of the APU inlet door to open could be the result of two possible reasons. Firstly, it could be due to the APU being low on oil, which can prevent the door from opening properly. Secondly, it could be because the APU door actuator has failed, which means it is unable to open the door. Therefore, both options A and C are correct explanations for the failure of the APU inlet door to open.

The correct answer is 16 sec. This means that when checking bleed air pressure ducts for ACFT AF86-0486 and up, the timing should be stopped when the pressure drops to 15 psi within 16 seconds.

The correct answer is 102 +/- 1%. This means that the normal rpm after the starting cycle is complete can range from 101 to 103, with 102 being the most accurate value. The "+/- 1%" indicates that the rpm can deviate by 1% from the central value of 102. This range allows for slight variations in the rpm while still maintaining the expected normal level.

When the battery is used for a normal shutdown, the DC BUS TIE switch should be placed in the "Untied" position after the door closes. This means that the switch should be set to disconnect or separate the two DC bus systems. By untieing the DC bus systems, the battery power is isolated and not connected to the other systems, ensuring a safe shutdown process.

The start light goes out at 50% because it indicates that the device or system has successfully started or powered on. Once it reaches 50% of the startup process, the light turns off to indicate that the startup is complete and the device is ready for use.