1.
(601) The heater control unit (HCU) on the New Generation Heater (NGH) starts the main air fan for output air when
Correct Answer
D. The inside temperature reaches 140 degrees Fahrenheit (°F).
Explanation
The correct answer is "the inside temperature reaches 140 degrees Fahrenheit (°F)". This is because the heater control unit (HCU) on the New Generation Heater (NGH) starts the main air fan for output air when the inside temperature reaches 140 degrees Fahrenheit. This indicates that the HCU is programmed to activate the fan once the temperature reaches a certain level to ensure proper heating.
2.
(602) When should starting aids be used to start the New Generation Heater (NGH)?
Correct Answer
B. Never, as it will result in serious engine damage.
Explanation
Starting aids should never be used to start the New Generation Heater (NGH) as it will result in serious engine damage. This means that using starting aids, such as jump-starting or using additional equipment to assist in starting the NGH, can cause harm to the engine. It is important to avoid using starting aids to prevent any potential damage to the engine.
3.
(602) When operating the New Generation Heater (NGH), turn the heat control switch to the desired position after
Correct Answer
C. System voltage indicates 120 volts alternating current (VAC).
Explanation
The correct answer is "system voltage indicates 120 volts alternating current (VAC)." This answer is correct because the question is asking about when to turn the heat control switch to the desired position when operating the New Generation Heater (NGH). According to the given information, the heat control switch should be turned to the desired position when the system voltage indicates 120 volts alternating current (VAC).
4.
(603) Repair of ground heater equipment should never be attempted
Correct Answer
C. Unless accurate technical data is available.
Explanation
Repairing ground heater equipment without accurate technical data can be dangerous and may result in further damage or injury. It is important to have the necessary information and instructions before attempting any repairs to ensure the proper procedures are followed. Consulting the operator or supervisor may provide some guidance, but without accurate technical data, the repair should not be attempted.
5.
(604) Heat that can be felt and added or subtracted to a substance without changing its state is called
Correct Answer
D. Sensible heat.
Explanation
Sensible heat refers to the heat that can be felt and added or subtracted to a substance without changing its state. It is the heat that causes a change in temperature of a substance, without causing it to change from a solid to a liquid or from a liquid to a gas. This type of heat is easily detectable and can be measured using a thermometer. Super heat refers to the heat added to a substance above its boiling point, latent heat refers to the heat absorbed or released during a phase change, and specific heat refers to the amount of heat required to raise the temperature of a substance by a certain amount.
6.
(604) Heat added to a gas is
Correct Answer
C. Super heat.
Explanation
When heat is added to a gas and its temperature increases above its boiling point, it is referred to as superheat. Superheating occurs when a substance is heated beyond its boiling point without changing its state from a gas to a liquid. This additional heat energy increases the kinetic energy of the gas molecules, causing them to move faster and increase in temperature. Sensible heat refers to the heat added or removed from a substance resulting in a change in temperature, specific heat is the amount of heat required to raise the temperature of a substance by a certain amount, and latent heat refers to the heat added or removed during a phase change, such as from a liquid to a gas.
7.
(605) A good refrigerant will
Correct Answer
B. Operate in low to moderate pressure.
Explanation
A good refrigerant will operate in low to moderate pressure because high pressure can put stress on the system and increase the risk of leaks or damage. Additionally, low to moderate pressure allows for more efficient heat transfer and better performance of the refrigeration system.
8.
(606) Which MA–3D air conditioner control switch allows the operator to control the overall volume of air leaving the unit?
Correct Answer
B. Airflow.
Explanation
The MA-3D air conditioner control switch that allows the operator to control the overall volume of air leaving the unit is the Airflow switch. This switch enables the operator to adjust the speed or intensity of the blower, thus controlling the amount of air being circulated by the air conditioner. The Evaporator and Temperature switches are not specifically designed for controlling the overall volume of air, while the Blower switch is related to the operation of the airflow but does not directly control the overall volume.
9.
(606) Refrigerant leaving the evaporator coil, in the MA–3D air conditioner, is a
Correct Answer
A. Low-pressure gas.
Explanation
In the MA-3D air conditioner, the refrigerant leaving the evaporator coil is in a low-pressure gas state. This is because the evaporator coil is responsible for absorbing heat from the surrounding air, causing the refrigerant to evaporate and turn into a gas. As a gas, the refrigerant has low pressure, which allows it to flow easily through the system and continue the cooling process.
10.
(606) When starting the MA–3D air conditioner, hold the safety override switch until
Correct Answer
A. 30 pounds of oil pressure is reached on the engine oil pressure gauge.
Explanation
When starting the MA-3D air conditioner, it is necessary to hold the safety override switch until 30 pounds of oil pressure is reached on the engine oil pressure gauge. This is important because the air conditioner relies on the engine oil pressure to function properly. Once the oil pressure reaches the required level, it indicates that the engine is running smoothly and can provide the necessary power for the air conditioner to operate effectively. Releasing the start switch or waiting for the engine to warm up or start are not relevant to ensuring the proper functioning of the air conditioner.
11.
(606) On the MA–3D air conditioner, which component shuts off the compressor when suction pressure drops below 5 pounds of pressure?
Correct Answer
B. Temperature controller.
Explanation
The temperature controller is the component that shuts off the compressor when the suction pressure drops below 5 pounds of pressure on the MA-3D air conditioner. It is responsible for monitoring the temperature and pressure levels in the system and triggering the compressor to turn off when necessary to prevent damage or malfunction. The low pressure cutout, pressure control cutout, and compressor pump down overload are not specifically designed to shut off the compressor based on suction pressure, making them incorrect choices.
12.
(607) Which type of refrigeration system leak occurs when the pressure within the system is less than atmospheric pressure?
Correct Answer
A. Inward.
Explanation
When the pressure within the refrigeration system is less than atmospheric pressure, it creates a vacuum effect. This causes the refrigerant to leak inwards, towards the lower pressure area. Therefore, the correct answer is "Inward."
13.
(607) A refrigerant reclaimer is used to
Correct Answer
D. Remove and store refrigerant and separate oil and acids from the refrigerant.
Explanation
A refrigerant reclaimer is a device used to safely remove and store refrigerant from a system. Additionally, it is designed to separate oil and acids from the refrigerant, ensuring that it is clean and ready for reuse. This process helps to protect the environment by preventing the release of harmful substances and also allows for the efficient and responsible management of refrigerant resources.
14.
(607) Refrigerant is always removed through the
Correct Answer
C. Receiver outlet valve.
Explanation
The correct answer is "receiver outlet valve." The receiver is a storage tank in a refrigeration system where the refrigerant is stored. The receiver outlet valve is responsible for controlling the flow of refrigerant out of the receiver. When the system needs to remove refrigerant, it is done through the receiver outlet valve. This valve allows the refrigerant to be directed to the appropriate location in the system, such as the condenser or other components.
15.
(608) An A/M32C–10D air conditioner air cycle machine consists of
Correct Answer
D. An expansion turbine and a compressor fan.
Explanation
The correct answer is an expansion turbine and a compressor fan. This means that the A/M32C-10D air conditioner air cycle machine includes both an expansion turbine and a compressor fan. These two components are essential for the functioning of the machine. The expansion turbine is responsible for expanding the compressed air, which cools it down and reduces its pressure. On the other hand, the compressor fan is used to compress the air and increase its pressure. Both of these components work together to regulate the temperature and pressure of the air in the machine.
16.
(608) Which A/M32C–10D air conditioner component extracts energy from bleed air on the air cycle machine?
Correct Answer
C. Expansion turbine.
Explanation
The expansion turbine is the component of the A/M32C-10D air conditioner that extracts energy from bleed air on the air cycle machine. This turbine is responsible for expanding the high-pressure air from the compressor and converting its energy into mechanical work. This work is then used to drive the air cycle machine and provide cooling to the aircraft. The expansion turbine plays a crucial role in the overall functioning of the air conditioner system by extracting energy from the bleed air and using it to cool the aircraft's cabin.
17.
(609) The ACE 802S air conditioner compressor switch must be held in the HOLD position when engaging the compressor in order to
Correct Answer
B. Allow compressor oil and discharge pressures to stabilize.
Explanation
When engaging the compressor of the ACE 802S air conditioner, it is necessary to hold the compressor switch in the HOLD position. This is done to allow the compressor oil and discharge pressures to stabilize. Stabilizing the oil and pressure ensures that the compressor operates efficiently and effectively. It also helps to prevent any damage or issues that may arise from sudden changes in oil flow or pressure. Holding the switch in the HOLD position gives the system time to stabilize before the compressor fully engages.
18.
(609) Which is the compressor displacement when the ACE 802S air conditioner compressor is in the HOLD position?
Correct Answer
C. Constant.
Explanation
The correct answer is "Constant." When the ACE 802S air conditioner compressor is in the HOLD position, it maintains a constant level of compressor displacement. This means that the compressor is not changing its displacement or output, and it remains at a steady level.
19.
(609) Which medium does the ACE 802S air conditioner heat boost system use to trim output air temperature?
Correct Answer
D. Engine coolant.
Explanation
The ACE 802S air conditioner heat boost system uses engine coolant to trim the output air temperature. Engine coolant is a liquid that circulates through the engine to regulate its temperature, and in this case, it is used to adjust the temperature of the air being produced by the air conditioner. This coolant absorbs heat from the engine and transfers it to the air, allowing for precise temperature control.
20.
(609) Which action occurs in the ACE 802S air conditioner evaporator?
Correct Answer
B. Boiling refrigerant absorbs heat from the air stream.
Explanation
In the ACE 802S air conditioner evaporator, the action that occurs is that the boiling refrigerant absorbs heat from the air stream. This means that as the refrigerant boils, it takes in heat from the surrounding air, cooling it down. This process allows the air conditioner to remove heat from the air and lower the temperature in the room or space being cooled.
21.
(610) Which valve must be opened prior to starting the ACE 802S air conditioner engine?
Correct Answer
A. Air shutoff.
Explanation
Prior to starting the ACE 802S air conditioner engine, the air shutoff valve must be opened. This valve controls the airflow to the engine and needs to be opened to allow air to enter the engine for combustion. Without the air shutoff valve being open, the engine will not be able to start and run properly. Therefore, it is important to ensure that the air shutoff valve is opened before starting the engine.
22.
(610) Which must be accomplished to avoid damage prior to operating the ACE 802S air conditioner in the HEATING mode after COOLING mode operation?
Correct Answer
A. Permit refrigerant pressure to equalize.
Explanation
To avoid damage prior to operating the ACE 802S air conditioner in the HEATING mode after COOLING mode operation, it is necessary to permit refrigerant pressure to equalize. This is important because the refrigerant pressure needs to stabilize and equalize before switching between modes to prevent any sudden changes in pressure that could potentially damage the system.
23.
(611) In troubleshooting, which is the first step that must be completed when a unit comes in with a write-up?
Correct Answer
D. Recognize the write-up as a malfunction.
Explanation
When a unit comes in with a write-up, the first step that must be completed in troubleshooting is to recognize the write-up as a malfunction. This means acknowledging and understanding the reported issue or problem that has been documented. This step is crucial as it sets the foundation for further investigation and troubleshooting processes to identify the root cause of the malfunction. By recognizing the write-up as a malfunction, the technician can proceed with the necessary steps to isolate and resolve the problem effectively.
24.
(611) How can a restriction in a refrigerant system be identified?
Correct Answer
B. Frosting at the outlet of a component.
Explanation
Frosting at the outlet of a component can be an indication of a restriction in a refrigerant system. When there is a restriction, the flow of refrigerant is hindered, causing a decrease in pressure and temperature. This can lead to the formation of frost on the component's outlet as the refrigerant expands and cools rapidly. Therefore, observing frosting at the outlet of a component can help identify a restriction in the refrigerant system.
25.
(612) On a basic rotary compressor, which prevents air from leaving the discharge port while the intake port is taking air in?
Correct Answer
A. Sliding barrier.
Explanation
A basic rotary compressor uses a sliding barrier to prevent air from leaving the discharge port while the intake port is taking air in. The sliding barrier acts as a seal between the two ports, ensuring that the compressed air flows in the desired direction and does not escape prematurely. This mechanism helps maintain the efficiency and effectiveness of the compressor by controlling the air flow and preventing any loss of pressure.
26.
(612) Oil in a rotary vane compressor
Correct Answer
C. Forms a seal between the vanes and the stator.
Explanation
The correct answer is "forms a seal between the vanes and the stator." In a rotary vane compressor, oil is used to create a seal between the vanes and the stator. This seal is necessary to prevent leakage of compressed air and to ensure efficient operation of the compressor. The oil fills the gaps between the vanes and the stator, creating a barrier that allows the vanes to move smoothly and maintain a tight seal. Without this oil, the compressor would not be able to generate the necessary pressure and efficiency would be compromised.
27.
(612) Which provides pressurized oil to the rotor blades of the MC–2A rotary sliding vane compressor?
Correct Answer
C. Hollow rotor shaft.
Explanation
The correct answer is hollow rotor shaft. In a rotary sliding vane compressor like the MC-2A, pressurized oil is provided to the rotor blades through a hollow rotor shaft. This design allows for the oil to flow through the shaft and reach the blades, lubricating them and reducing friction. The hollow rotor shaft ensures efficient oil distribution to the rotor blades, enabling smooth operation of the compressor.
28.
(612) On the MC–2A rotary sliding vane compressor, the minimum pressure valve does all of the following except
Correct Answer
B. Ensure minimum pressure to the condensate drain.
Explanation
The minimum pressure valve on the MC-2A rotary sliding vane compressor serves multiple functions, including ensuring minimum pressure within the oil chamber, preventing receiver air from flowing back to the compressor by working as a check valve, and increasing the efficiency of the felt pads by ensuring they receive a constant minimum air pressure. However, it does not play a role in ensuring minimum pressure to the condensate drain.
29.
(613) The MC–20 air compressor provides which kind of air for pneumatic tools and tire inflation?
Correct Answer
B. Low pressure.
Explanation
The MC-20 air compressor provides low pressure air for pneumatic tools and tire inflation. This means that it produces air at a lower pressure level, which is suitable for tasks that require less force and precision. Low pressure air is commonly used for inflating tires, as well as operating various pneumatic tools such as nail guns and paint sprayers.
30.
(613) Every how many years is the hydrostatic test due on the receiver tank on a MC–20 air compressor?
Correct Answer
C. 5.
Explanation
The correct answer is 5 because the hydrostatic test is due on the receiver tank of a MC-20 air compressor every 5 years.
31.
(613) Which is the proper compressor oil level when checking the sight glass on a MC–20 air compressor?
Correct Answer
C. Any oil level present in the sight glass.
Explanation
The correct answer is "Any oil level present in the sight glass." This means that as long as there is some oil visible in the sight glass, the compressor oil level is considered proper. The specific level between the bottom and top of the sight glass is not specified, indicating that any amount of oil is acceptable.
32.
(614) Which position should the vent valve be in when liquid oxygen (LOX) carts are being transported?
Correct Answer
B. Closed.
Explanation
The vent valve should be in the closed position when liquid oxygen (LOX) carts are being transported. This is because liquid oxygen is highly volatile and can easily evaporate into a gas. Keeping the vent valve closed prevents any leakage or loss of oxygen during transportation, ensuring the safety and integrity of the LOX carts.
33.
(615) How is the air compressor in the self generating nitrogen servicing cart (SGNSC) categorized?
Correct Answer
A. High-pressure.
Explanation
The air compressor in the self-generating nitrogen servicing cart (SGNSC) is categorized as high-pressure. This means that it is capable of producing air at a high pressure level, which is necessary for certain applications such as filling high-pressure nitrogen cylinders or servicing aircraft systems that require high-pressure air.
34.
(616) To start the self generating nitrogen servicing cart (SGNSC), the operator places the ignition switch in the start position for no more than how many seconds?
Correct Answer
B. 10.
Explanation
To start the self-generating nitrogen servicing cart (SGNSC), the operator should place the ignition switch in the start position for no more than 10 seconds. This time limit ensures that the cart's engine is given enough time to start without causing any damage or unnecessary wear. Placing the ignition switch in the start position for a longer duration may result in issues such as overheating or draining the battery. Therefore, it is important for the operator to adhere to the recommended time limit of 10 seconds.
35.
(616) At which storage cylinder pressure, in pounds per square inch gauge (psig), should the self generating nitrogen servicing cart (SGNSC) nitrogen booster compressor stop?
Correct Answer
C. 4,400.
Explanation
The self-generating nitrogen servicing cart (SGNSC) nitrogen booster compressor should stop at a storage cylinder pressure of 4,400 pounds per square inch gauge (psig).
36.
(617) Which is the proper level in the self generating nitrogen servicing cart (SGNSC) hydraulic reservoir?
Correct Answer
D. 1/2 inch below the top of the glass.
Explanation
The proper level in the self-generating nitrogen servicing cart (SGNSC) hydraulic reservoir is 1/2 inch below the top of the glass. This means that the hydraulic fluid should be filled up to this level, ensuring that there is enough fluid for proper operation without overfilling the reservoir.
37.
(618) During an operational check of a self-generating nitrogen servicing cart (SGNSC) the engine is running at 3,000 revolutions per minute (rpm), but the nitrogen purity does not reach 95.5 percent within 30 minutes. Which is a probable cause of this malfunction?
Correct Answer
A. Warming door is not lowered for cold weather operating conditions.
Explanation
The warming door is responsible for maintaining the temperature inside the self-generating nitrogen servicing cart (SGNSC) during cold weather operating conditions. If the warming door is not lowered, it can result in lower temperatures inside the cart, which can affect the nitrogen purity. This is because colder temperatures can cause condensation and freezing of moisture, which can contaminate the nitrogen and lower its purity. Therefore, the probable cause of the malfunction is the warming door not being lowered for cold weather operating conditions.
38.
(618) Which is important to keep in mind when performing maintenance on the self generating nitrogen servicing cart (SGNSC)?
Correct Answer
D. Safety.
Explanation
When performing maintenance on the self-generating nitrogen servicing cart (SGNSC), it is important to keep safety in mind. This means following proper procedures, using the correct tools and equipment, and taking necessary precautions to prevent accidents or injuries. Weather conditions, wind direction, and ventilation may be important factors in other situations, but when it comes to maintenance on the SGNSC, safety should always be the top priority.
39.
(619) The purpose of the MJ–2A–1 hydraulic test stand fill-and-bleed system is to fill the hydraulic system with fluid and
Correct Answer
B. Purge entrapped air before operation.
Explanation
The purpose of the MJ-2A-1 hydraulic test stand fill-and-bleed system is to purge entrapped air before operation. This system is designed to remove any air that may be trapped in the hydraulic system, ensuring proper functioning and preventing any potential issues that may arise from air bubbles. By purging the entrapped air, the system can operate efficiently and effectively.
40.
(619) Which position must the reservoir selector valve be in when filling and bleeding the MJ–2A–1 hydraulic test stand hydraulic system?
Correct Answer
C. AIRCRAFT.
Explanation
The reservoir selector valve must be in the AIRCRAFT position when filling and bleeding the hydraulic system of the MJ-2A-1 hydraulic test stand. This position allows the hydraulic fluid to be drawn from the aircraft's hydraulic system, ensuring that the test stand is properly filled and bled.
41.
(619) Which valve protects the MJ–2A–1 hydraulic test stand from over pressurization when the unit is not operating?
Correct Answer
B. Thermal relief.
Explanation
The thermal relief valve is responsible for protecting the MJ-2A-1 hydraulic test stand from over pressurization when the unit is not operating. This valve is designed to release excess pressure caused by thermal expansion of the fluid inside the system. It prevents damage to the test stand by ensuring that pressure does not build up to dangerous levels when the unit is not in use.
42.
(619) The purpose of the low pressure pump on the MJ–2A–1 is to ensure a constant flow of fluid to the
Correct Answer
D. High pressure pump.
Explanation
The purpose of the low pressure pump on the MJ-2A-1 is to ensure a constant flow of fluid to the high pressure pump. The high pressure pump requires a continuous supply of fluid to operate effectively and efficiently. The low pressure pump helps to maintain a consistent flow of fluid to the high pressure pump, ensuring that it can deliver the necessary pressure for various aircraft systems. This helps to maintain the overall performance and functionality of the high pressure pump and the aircraft systems it supports.
43.
(619) The output volume (gallons per minute) of the MJ–2A–1 hydraulic test stand high pressure pump is controlled by the
Correct Answer
A. Volume control.
Explanation
The correct answer is volume control. The output volume of the hydraulic test stand high pressure pump is controlled by the volume control. This means that the volume of fluid being pumped per minute can be adjusted using this control. The flow control valve, compensator control, and flowmeter assembly may have different functions in the system, but they do not directly control the output volume of the pump.
44.
(620) Which MJ–2A–1 hydraulic test stand engine system safety device sounds the warning horn in the event of an engine system malfunction?
Correct Answer
B. Oil pressure switch.
Explanation
The oil pressure switch is the correct answer because it is a safety device in the MJ-2A-1 hydraulic test stand engine system that sounds the warning horn when there is a malfunction in the engine system. This switch monitors the oil pressure and triggers the horn to alert the operator if the pressure drops below a certain level, indicating a potential problem with the engine. The other options, such as the water level switch, fuel level indicator, and fuel pressure switch, are not directly related to monitoring engine system malfunctions or sounding warning horns.
45.
(620) Which MJ–2A–1 hydraulic test stand switch provides an alternate means of energizing the fill pump when either of the micro switches are defective?
Correct Answer
A. Fill switch, LS4.
Explanation
The correct answer is Fill switch, LS4. This switch provides an alternate means of energizing the fill pump when either of the micro switches are defective. It serves as a backup switch to ensure that the fill pump can still be activated even if the micro switches fail.
46.
(621) Which valve must be opened when setting up the MJ–2A–1 hydraulic test stand controls for operation?
Correct Answer
A. Return system bypass.
Explanation
When setting up the MJ-2A-1 hydraulic test stand controls for operation, the valve that must be opened is the return system bypass. This valve allows the hydraulic fluid to bypass the system and return directly to the reservoir. By opening this valve, any excess pressure in the system can be relieved, ensuring safe and efficient operation of the test stand controls.
47.
(621) Which is the setting of the MJ–2A–1 hydraulic test stand system relief valve?
Correct Answer
B. 300 psi above required test pressure.
Explanation
The setting of the MJ-2A-1 hydraulic test stand system relief valve is 300 psi above the required test pressure. This means that the relief valve will open and release excess pressure when the pressure in the system exceeds the required test pressure by 300 psi.
48.
(622) Which type of wrench should be used on brass or aluminum fittings?
Correct Answer
C. Tubing.
Explanation
The correct answer is "Tubing." When working with brass or aluminum fittings, it is important to use a tubing wrench. This type of wrench is specifically designed to provide a secure grip on cylindrical objects, such as tubing or pipes. Using a tubing wrench ensures that the fittings are tightened or loosened without causing damage to the softer brass or aluminum materials.
49.
(622) The hydraulic test stand high pressure pump is difficult to repair because of its
Correct Answer
A. Precision tolerances.
Explanation
The correct answer is precision tolerances. The hydraulic test stand high pressure pump is difficult to repair because it requires precise adjustments and measurements. The pump operates under high pressure, and any deviation from the specified tolerances can result in malfunctioning or failure. Therefore, it is crucial to have a deep understanding of the pump's intricate parts and the ability to work with precision to ensure proper repair and functionality.
50.
(623) Which type of pump is used on the MJ–1B bomblift truck hydrostatic system?
Correct Answer
A. Variable displacement.
Explanation
The correct answer is variable displacement. This type of pump is used on the MJ-1B bomblift truck hydrostatic system. Variable displacement pumps are designed to vary the flow rate of hydraulic fluid, allowing for more precise control of the system. This is particularly important in applications where varying loads or speeds are required, such as in a bomblift truck where different amounts of hydraulic power may be needed to lift and transport different bomb loads.