1.
In its natural state oxygen is?
Correct Answer
A. Tasteless, colorless, and odorless
Explanation
Oxygen in its natural state is tasteless, colorless, and odorless. This means that it does not have a distinct taste, it cannot be seen as it is transparent, and it does not have any smell.
2.
What gaseous oxygen (GOX) system valve type prevents a complete loss of oxygen?
Correct Answer
B. Check
Explanation
A check valve is a type of valve that allows the flow of fluid (in this case, gaseous oxygen) in only one direction. It prevents backflow, ensuring that oxygen does not flow back into the system and cause a complete loss. Therefore, a check valve is the correct valve type to prevent a complete loss of oxygen in a gaseous oxygen (GOX) system.
3.
The supply and distribution tubing for aircraft oxygen systems is identified by cellulose tape that is
Correct Answer
C. Green and white
Explanation
The supply and distribution tubing for aircraft oxygen systems is identified by cellulose tape that is green and white. This color combination is used to easily distinguish the oxygen tubing from other types of tubing in the aircraft. The green and white tape serves as a visual indicator for maintenance personnel and pilots to quickly identify and locate the oxygen supply and distribution system in case of emergency or routine checks.
4.
The disadvantage of a continuous-flow oxygen regulator is that it
Correct Answer
A. Wastes oxygen
Explanation
A continuous-flow oxygen regulator is disadvantageous because it wastes oxygen. This means that it does not efficiently utilize the oxygen supply, resulting in a higher consumption rate and potentially running out of oxygen sooner. This can be problematic, especially in situations where a limited oxygen supply is available, such as during high-altitude flights or in emergency medical settings.
5.
What does the molecular sieve oxygen generating system (MSOGS) concentrator supply to the OXYGEN regulator control panel?
Correct Answer
B. 93 percent oxygen-enriched gas.
Explanation
The molecular sieve oxygen generating system (MSOGS) concentrator supplies the OXYGEN regulator control panel with 93 percent oxygen-enriched gas. This means that the gas being supplied has a higher concentration of oxygen compared to the surrounding air, which is typically around 21 percent oxygen. The MSOGS concentrator uses a molecular sieve to selectively remove nitrogen and other gases from the air, resulting in a higher concentration of oxygen in the output gas. This oxygen-enriched gas can then be used for various applications, such as medical purposes or in aircraft systems.
6.
Liquid oxygen (LOX) converts to gaseous oxygen (GOX) at an expansion ratio of
Correct Answer
D. 860 to 1
Explanation
Liquid oxygen (LOX) converts to gaseous oxygen (GOX) at an expansion ratio of 860 to 1. This means that when liquid oxygen is converted into gaseous form, it expands in volume by a factor of 860. This expansion occurs due to the change in state from a liquid to a gas, where the molecules of the liquid oxygen gain energy and move more freely, occupying a larger space. This expansion ratio is important in various applications such as rocket propulsion, where the increase in volume allows for greater thrust and efficiency.
7.
Except during servicing, the liquid oxygen (LOX) system’s combination fill, buildup, and vent valve is always in the
Correct Answer
D. Buildup position
Explanation
The liquid oxygen (LOX) system's combination fill, buildup, and vent valve is always in the buildup position, except during servicing. This means that the valve is continuously allowing the buildup of liquid oxygen in the system. During servicing, the valve may be in a different position to facilitate maintenance or other procedures. However, during normal operation, the valve remains in the buildup position to ensure a constant supply of liquid oxygen in the system.
8.
On an aircraft liquid oxygen (LOX) system, the handle on a manually operated buildup and vent valve is designed to prevent
Correct Answer
D. The filler access door from closing in the vent position
Explanation
The handle on a manually operated buildup and vent valve is designed to prevent the filler access door from closing in the vent position. This means that when the valve is in the vent position, the handle ensures that the filler access door remains open, allowing for the rapid venting of system pressure. This is important to prevent any potential pressure buildup and ensure the safe operation of the liquid oxygen (LOX) system.
9.
Bleed air is usually taken from which part of the engine section?
Correct Answer
D. Compressor
Explanation
Bleed air is usually taken from the compressor section of the engine. The compressor is responsible for compressing the incoming air and supplying it to the combustion chamber. During this process, a small portion of the compressed air is bled off to perform various functions such as cabin pressurization, air conditioning, anti-icing, and starting other engines. Taking bleed air from the compressor ensures that it is at a high pressure and temperature, making it suitable for these applications.
10.
Aircraft engine temperature and pressure as it applies to the bleed air system is determined by the
Correct Answer
D. Engine throttle setting and ambient temperature.
Explanation
The temperature and pressure of the aircraft engine in relation to the bleed air system are influenced by the engine throttle setting and the ambient temperature. The engine throttle setting determines the amount of fuel and air mixture being supplied to the engine, which affects the temperature and pressure. Meanwhile, the ambient temperature refers to the temperature of the surrounding environment, which can also impact the engine temperature and pressure. Therefore, both factors play a role in determining the temperature and pressure of the aircraft engine in the bleed air system.
11.
What is the purpose of the engine bleed air (EBA) check valves?
Correct Answer
A. Prevent the loss of compressed bleed air.
Explanation
The purpose of the engine bleed air (EBA) check valves is to prevent the loss of compressed bleed air. These valves ensure that the air being bled from the engine for various purposes, such as cabin pressurization and air conditioning, remains within the system and does not escape. By preventing the loss of compressed bleed air, the check valves help maintain the efficiency and effectiveness of the aircraft's systems that rely on this air supply.
12.
What engine bleed air (EBA) component prevents loss of air through the engine when it is shutdown
Correct Answer
B. Shutoff valve.
Explanation
The shutoff valve is the component that prevents loss of air through the engine when it is shutdown. This valve is designed to close off the flow of bleed air, ensuring that it does not escape from the engine. By closing the shutoff valve, the bleed air is effectively contained within the engine, preventing any loss or leakage. This helps to maintain the integrity of the air system and ensures that the bleed air is available for use when the engine is started up again.
13.
The ducting for high-pressure/high-temperature air-conditioning is usually made of
Correct Answer
C. Stainless steel.
Explanation
The ducting for high-pressure/high-temperature air-conditioning is usually made of stainless steel because it has excellent corrosion resistance and can withstand high temperatures and pressures. Stainless steel is also durable and has a long lifespan, making it suitable for use in demanding environments. Additionally, stainless steel is easy to clean and maintain, making it a practical choice for air-conditioning systems.
14.
What tool do you use to ensure alignment and sealing when installing a V-band clamp on air-conditioning ducting
Correct Answer
C. Rawhide mallet.
Explanation
A rawhide mallet is used to ensure alignment and sealing when installing a V-band clamp on air-conditioning ducting. Rawhide mallets are made from rawhide, a material that is soft and non-damaging, making it ideal for use on delicate surfaces like ducting. When installing a V-band clamp, the rawhide mallet is used to tap the clamp into place, ensuring that it aligns correctly and creates a tight seal. The soft material of the mallet prevents any damage to the ducting while still providing enough force to secure the clamp in place.
15.
What type of high-pressure/high-temperature ducting does not require a gasket?
Correct Answer
D. Compressible flange
Explanation
A compressible flange is a type of high-pressure/high-temperature ducting that does not require a gasket. This type of flange uses a compressible material, such as rubber or elastomer, to create a seal between the two mating surfaces. When the flange is tightened, the compressible material is compressed, creating a tight and secure seal without the need for a gasket. This design is often used in applications where a gasket may not be suitable or where a more flexible seal is required.
16.
What lubricant can be used on a beaded channel clamp sleeve to ease installation?
Correct Answer
B. Water
Explanation
Water can be used as a lubricant on a beaded channel clamp sleeve to ease installation. Water acts as a temporary lubricant that reduces friction between the clamp sleeve and the surface it is being installed on. It allows the sleeve to slide more easily into place, making the installation process smoother and more efficient. Additionally, water is readily available and cost-effective, making it a convenient choice for this purpose.
17.
The crush-type gasket used in aircraft ducting is made of
Correct Answer
C. A soft aluminum, or fiber and metal mesh.
Explanation
The crush-type gasket used in aircraft ducting is made of a soft aluminum, or fiber and metal mesh. This type of gasket is designed to provide a tight seal in high-pressure environments. The soft aluminum allows for easy compression and deformation, ensuring a secure fit. The fiber and metal mesh provide additional strength and durability to the gasket, making it suitable for use in aircraft ducting where it may be subjected to vibrations and extreme temperatures.
18.
Expansion joints in bleed air systems are best used for
Correct Answer
C. A short run of ducting.
Explanation
Expansion joints in bleed air systems are best used for a short run of ducting. This is because expansion joints are designed to absorb thermal expansion and contraction in the ducting system. In a short run of ducting, there is less distance for the expansion and contraction to occur, so an expansion joint can effectively accommodate the movement without causing stress or damage to the system. In a long run of ducting, the expansion and contraction may be more significant, requiring additional expansion joints or alternative solutions. Therefore, a short run of ducting is the most appropriate application for expansion joints in bleed air systems.
19.
What prevents fiberglass fabric ducts from swelling when the aircraft climbs to high altitudes?
Correct Answer
D. Vent holes.
Explanation
Vent holes prevent fiberglass fabric ducts from swelling when the aircraft climbs to high altitudes. As the aircraft ascends, the air pressure decreases, causing a potential for the air trapped within the ducts to expand. However, the presence of vent holes allows the air to escape, preventing the ducts from swelling or becoming damaged. This ensures the proper functioning and integrity of the duct system during high altitude flights.
20.
What is defined as “a depression in the duct wall, where the surface of the material isn’t cut or removed but the depression has caused sharp bends or creases in the material?”
Correct Answer
B. Major dent.
Explanation
A major dent is defined as a depression in the duct wall where the surface of the material isn't cut or removed, but the depression has caused sharp bends or creases in the material. This means that the dent is significant and has caused noticeable damage to the material.
21.
“The simultaneous control of temperature, humidity, and air distribution within a space” is the definition of
Correct Answer
B. Air conditioning.
Explanation
Air conditioning is the correct answer because it refers to the simultaneous control of temperature, humidity, and air distribution within a space. Engine bleed air is the high-pressure air taken from the compressor section of a gas turbine engine, which is not related to temperature, humidity, and air distribution control. Pressurization refers to the process of increasing the air pressure within a space, but it does not necessarily involve controlling temperature and humidity. Air control is a general term that does not specifically refer to the simultaneous control of temperature, humidity, and air distribution.
22.
What aircraft air conditioning system component is a radiator that cold ram air passes through in order to cool the hot bleed air from the engine(s)?
Correct Answer
A. Primary heat exchanger.
Explanation
The primary heat exchanger is a component in the aircraft air conditioning system that cools the hot bleed air from the engine(s). It acts as a radiator, allowing cold ram air to pass through and cool the hot air. This process helps regulate the temperature inside the aircraft and ensures that the air conditioning system functions properly.
23.
What aircraft air conditioning system component controls the flow of ram air through the primary heat exchangers?
Correct Answer
C. Movable inlet and exit doors
Explanation
Movable inlet and exit doors control the flow of ram air through the primary heat exchangers in an aircraft air conditioning system. These doors can be adjusted to regulate the amount of air entering and exiting the heat exchangers, allowing for proper cooling or heating of the air before it is distributed throughout the aircraft. By controlling the flow of ram air, the movable inlet and exit doors help maintain the desired temperature and comfort level inside the aircraft cabin.
24.
The rapid cooling of bleed air causes
Correct Answer
B. Moisture to condense in the form of fog.
Explanation
When bleed air is rapidly cooled, the temperature of the air decreases, causing the moisture present in the air to condense. This condensation occurs in the form of fog, as the water vapor in the air turns into tiny water droplets suspended in the air. Therefore, the rapid cooling of bleed air causes moisture to condense in the form of fog.
25.
As bleed air enters the compressor of the air cycle machine, its pressure is increased. With the increase in pressure, there is also an increase in temperature. Which component removes most of this increased temperature?
Correct Answer
B. Secondary heat exchanger
Explanation
The secondary heat exchanger removes most of the increased temperature in the air cycle machine. As bleed air enters the compressor, its pressure is increased, leading to an increase in temperature. The secondary heat exchanger is responsible for transferring this excess heat to the surrounding environment, allowing the air cycle machine to maintain its efficiency and prevent overheating.
26.
The low atmospheric pressure found at extremely high altitudes can cause a person’s blood vessels to
Correct Answer
B. Rupture.
Explanation
At extremely high altitudes, the atmospheric pressure decreases significantly. This decrease in pressure can have adverse effects on the human body, including the potential for blood vessels to rupture. The low atmospheric pressure causes the blood vessels to expand, and if the pressure difference becomes too great, it can lead to the rupture of these vessels. This can be particularly dangerous as it can result in internal bleeding and other serious health complications.
27.
What controls the action of the outflow valve in a fixed-isobaric, single-differential pressurization system?
Correct Answer
D. Regulating control chamber pressure.
Explanation
In a fixed-isobaric, single-differential pressurization system, the action of the outflow valve is controlled by regulating control chamber pressure. This means that the pressure in the control chamber is adjusted to control the opening and closing of the outflow valve, which in turn regulates the cabin pressure. By adjusting the control chamber pressure, the system can maintain a constant cabin pressure regardless of changes in altitude or external conditions.
28.
What are the components of the differential section of the cabin pressure regulator?
Correct Answer
D. A diapHragm, spring, and metering valve.
Explanation
The components of the differential section of the cabin pressure regulator are a diaphragm, spring, and metering valve. The diaphragm is responsible for sensing the pressure difference and initiating the necessary adjustments. The spring provides the necessary force for the diaphragm to function properly. The metering valve controls the flow of air to maintain the desired cabin pressure. This combination of components allows for the regulation and control of the cabin pressure in an aircraft.
29.
What are the parts of the isobaric section of the cabin pressure regulator?What are the parts of the isobaric section of the cabin pressure regulator?
Correct Answer
C. An aneroid, spring, and metering valve.
30.
What maintains pressure if the dual-differential cabin pressure regulator fails during flight?
Correct Answer
A. The outflow valves.
Explanation
If the dual-differential cabin pressure regulator fails during flight, the outflow valves would maintain the pressure. These valves are responsible for regulating the airflow in and out of the cabin, ensuring that the pressure remains at a safe and comfortable level. By adjusting the position of the outflow valves, the cabin pressure can be controlled even if the regulator fails.
31.
What is the purpose of the pneumatic relay in a cabin pressurization system?
Correct Answer
C. Ensure that both outflow valves operate at the same time.
Explanation
The purpose of the pneumatic relay in a cabin pressurization system is to ensure that both outflow valves operate at the same time. This is important for maintaining the desired cabin pressure. If the outflow valves do not operate simultaneously, it can lead to an imbalance in cabin pressure, causing discomfort or potential safety issues for passengers and crew. The pneumatic relay helps to synchronize the operation of the outflow valves, ensuring that they open and close together to maintain the desired pressure in the cabin.
32.
N the variable isobaric pressurization system. the manual control valve is used as an alternate when the
Correct Answer
D. Cabin pressure controller fails.
Explanation
The correct answer is cabin pressure controller fails. In an isobaric pressurization system, the cabin pressure controller is responsible for maintaining a constant pressure inside the aircraft cabin. If the cabin pressure controller fails, it means that it is no longer able to regulate the cabin pressure. In such a scenario, the manual control valve can be used as an alternate to manually control the cabin pressure and ensure the safety of the passengers and crew onboard.
33.
The normal connection for thermal switches in a fire warning system is in series with
Correct Answer
D. The warning light and parallel with each other.
Explanation
In a fire warning system, the normal connection for thermal switches is in parallel with each other and with the warning light. This means that all the thermal switches are connected to each other in a parallel circuit, and this parallel circuit is also connected in parallel with the warning light. This configuration ensures that if any of the thermal switches detect a rise in temperature, the circuit will be completed and the warning light will be activated, indicating a fire hazard.
34.
The fire detector, frequently used in fire warning systems, that has a high-nickel steel rod located along the centerline of a stainless steel tube assembly is called
Correct Answer
B. An Iron Fireman switch.
Explanation
The correct answer is an Iron Fireman switch. The Iron Fireman switch is a type of fire detector commonly used in fire warning systems. It consists of a high-nickel steel rod located along the centerline of a stainless steel tube assembly. The purpose of this switch is to detect the presence of fire or heat and trigger the appropriate response, such as activating an alarm or sprinkler system.
35.
The direct current (DC) voltage supplied to the lights in a photoelectric circuit is pulsed at a rate of
Correct Answer
A. 10 Hz.
Explanation
The correct answer is 10 Hz because in a photoelectric circuit, the DC voltage supplied to the lights is pulsed at a frequency of 10 Hz. This means that the voltage is turned on and off 10 times per second. The frequency of the pulses determines the rate at which the lights flicker or flash. A higher frequency would result in a faster flickering, while a lower frequency would result in a slower flickering. Therefore, 10 Hz is the correct answer as it represents the rate at which the DC voltage is pulsed in the circuit.
36.
A liquid fire extinguishing agent douses a fire by
Correct Answer
B. Excluding oxygen from the area.
Explanation
A liquid fire extinguishing agent douses a fire by excluding oxygen from the area. Oxygen is necessary for combustion to occur, so by removing or reducing the oxygen supply, the fire is deprived of the fuel it needs to continue burning. This can be achieved through the use of foam, water mist, or other chemical agents that displace or suppress the oxygen in the surrounding environment. By excluding oxygen, the fire is effectively smothered and extinguished.
37.
A gaseous nitrogen charge is added to a liquid fire extinguishing agent in order to
Correct Answer
B. Expel the agent from the bottle.
Explanation
The gaseous nitrogen charge is added to the liquid fire extinguishing agent in order to expel the agent from the bottle. When the fire extinguisher is discharged, the pressure from the nitrogen gas forces the liquid agent out of the bottle, allowing it to reach the fire and extinguish it. The nitrogen charge creates the necessary pressure to propel the liquid agent effectively and efficiently.
38.
What liquid-agent fire extinguisher container component holds in both the liquid agent and the nitrogen charge?
Correct Answer
B. Frangible disc.
Explanation
The frangible disc is the component of a liquid-agent fire extinguisher container that holds both the liquid agent and the nitrogen charge. A frangible disc is a thin, breakable disk that is designed to rupture when the extinguisher is activated, allowing the agent and charge to be released. It acts as a barrier between the liquid agent and the nitrogen charge, ensuring that they are kept separate until needed.
39.
In a liquid-agent fire extinguisher container, why is the frangible disc undercut into pie-shaped sections?
Correct Answer
D. Prevent small pieces from passing through the strainer.
Explanation
The frangible disc is undercut into pie-shaped sections in a liquid-agent fire extinguisher container to prevent small pieces from passing through the strainer. By creating pie-shaped sections, the disc is more likely to break cleanly into small pieces, which can be easily filtered by the strainer. This ensures that only the desired fluid flows through the system, without any small fragments that could potentially clog or damage the strainer.
40.
What is usually located at the lowest point in a fuel tank?
Correct Answer
A. Sump and drain.
Explanation
The correct answer is sump and drain. In a fuel tank, the sump is typically located at the lowest point. The sump is designed to collect any sediment or water that may have accumulated in the tank. The drain is then used to remove this collected material from the tank. This helps to prevent any contaminants from being drawn into the fuel system, ensuring the fuel remains clean and free from any debris.
41.
A bladder-type tank conforms to the shape of the vacant cavity within the fuselage because it is made out of
Correct Answer
B. Rubber or nylon material.
Explanation
A bladder-type tank conforms to the shape of the vacant cavity within the fuselage because it is made out of rubber or nylon material. Rubber and nylon are both soft and malleable materials that can easily adapt to the shape of the cavity. This flexibility allows the bladder-type tank to fit snugly within the fuselage, maximizing the use of available space. Additionally, rubber and nylon are also durable materials that can withstand the pressure and stress associated with storing and transporting fluids, making them suitable for use in bladder-type tanks.
42.
Wing tanks are
Correct Answer
C. Sealed-off parts of the wing structure
Explanation
The correct answer is "sealed-off parts of the wing structure". Wing tanks are sealed-off compartments within the wing structure that are used to store fuel. They are not bladder-type tanks or lightweight aluminum tanks inserted into empty wing cavities. The term "soft, malleable plastic tanks" does not accurately describe wing tanks. Therefore, the correct answer is that wing tanks are sealed-off parts of the wing structure.
43.
A centrifugal-type aircraft fuel pump may be used
Correct Answer
A. For boost, transfer, or air refueling operations
Explanation
A centrifugal-type aircraft fuel pump may be used for boost, transfer, or air refueling operations because it is capable of delivering fuel at high pressure and flow rates, which are necessary for these operations. The centrifugal design of the pump allows it to generate the required pressure by using centrifugal force to push the fuel outward. Additionally, the absence of moving parts in the pump reduces the risk of mechanical failure, making it suitable for use in various operational scenarios.
44.
What type of fuel pump must have a fuel- and vapor-proof housing?
Correct Answer
D. Centrifugal pump with electrically driven, direct current (DC), series-wound motor.
Explanation
A centrifugal pump with an electrically driven, direct current (DC), series-wound motor must have a fuel- and vapor-proof housing because it is used to pump fuel. This type of pump is commonly used in automotive applications and needs to be able to handle fuel and prevent any leakage or vapor escape, which could be dangerous. A fuel- and vapor-proof housing ensures that the pump operates safely and efficiently without any risk of fuel leakage or vapor emissions.
45.
What kind of centrifugal pump is used when a fuel supply is required during periods of negative gravity conditions?
Correct Answer
C. Dual-impeller.
Explanation
A dual-impeller centrifugal pump is used when a fuel supply is required during periods of negative gravity conditions. This type of pump is designed with two impellers that work together to provide a continuous flow of fuel even in situations where gravity is working against the flow. The dual-impeller design allows for efficient pumping and ensures a reliable fuel supply in challenging conditions.
46.
In a dual-impeller fuel pump what prevents foreign objects from holding the bypass valve open?
Correct Answer
A. An inlet screen.
Explanation
An inlet screen prevents foreign objects from holding the bypass valve open in a dual-impeller fuel pump. This screen acts as a filter, allowing only fuel to pass through while blocking any debris or foreign objects that could potentially interfere with the bypass valve. By keeping the bypass valve free from obstruction, the inlet screen ensures proper functioning of the fuel pump and prevents any potential damage or malfunction caused by foreign objects.
47.
What air refueling pump components depend on fuel for lubrication?
Correct Answer
C. Bearings.
Explanation
Bearings in an air refueling pump depend on fuel for lubrication. Bearings are components that support the rotating parts of the pump, allowing them to move smoothly. In this case, the bearings rely on the fuel to provide lubrication, reducing friction and preventing damage to the pump's moving parts. The other components mentioned, such as rotors, stators, and impellers, may also be present in an air refueling pump, but they do not specifically require fuel for lubrication.
48.
What air refueling pump component removes fuel vapors caused by the centrifugal force of the impellers?
Correct Answer
A. Rotor.
Explanation
The rotor is the component in an air refueling pump that removes fuel vapors caused by the centrifugal force of the impellers. The impellers create the centrifugal force, which pushes the fuel towards the outer edges of the pump. The rotor then captures and removes any fuel vapors that are generated during this process. This helps to ensure that the fuel being transferred is free from any vapors, which could potentially cause issues during the refueling process.
49.
The arrow stamped on the body of a fuel system check valve indicates the
Correct Answer
A. Direction of free flow.
Explanation
The arrow stamped on the body of a fuel system check valve indicates the direction of free flow. This means that when fuel flows through the valve, it will follow the direction of the arrow. This is important for proper functioning of the fuel system, as it ensures that fuel is flowing in the correct direction and prevents any blockages or restrictions in the flow.
50.
A pressure-loaded fuel system check valve is used
Correct Answer
C. When gravity flow through the valve is undesirable.
Explanation
A pressure-loaded fuel system check valve is used when gravity flow through the valve is undesirable. This means that the valve is designed to prevent fuel from flowing back due to gravity when it is not desired. This could be the case when the fuel needs to be directed to a specific location or when the fuel flow needs to be regulated in a certain way. The valve ensures that the fuel only flows in the desired direction and prevents any backflow caused by gravity.