1.
(801) A gaseous nitrogen (N2) 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 to expel the agent from the bottle. When the extinguisher is discharged, the pressure from the nitrogen gas forces the liquid agent out of the bottle and onto the fire. This helps to effectively extinguish the fire by rapidly dispersing the agent onto the flames.
2.
(801) In a liquid-agent fire extinguisher container, why is the frangible disc undercut into pie shaped sections?
Correct Answer
B. To break cleanly into large pieces.
Explanation
The frangible disc in a liquid-agent fire extinguisher container is undercut into pie-shaped sections to break cleanly into large pieces. This design allows for easy and effective dispersal of the liquid agent when the disc is broken. Breaking cleanly into large pieces ensures that the liquid agent is released in a controlled manner, without any small fragments that could potentially clog the strainer or impede the flow of the agent.
3.
(802) The purpose of a time delay relay that is used on some liquid-agent fire extinguishing systems is to
Correct Answer
A. Position the valves.
Explanation
The purpose of a time delay relay used on liquid-agent fire extinguishing systems is to position the valves. This means that the relay is responsible for controlling the opening and closing of the valves at the appropriate time, allowing the liquid agent to be released and extinguish the fire effectively. The time delay ensures that the valves are activated at the right moment, providing a controlled and timed response to the fire emergency.
4.
(802) BANK no. 2 in a two-shot liquid-agent fire extinguishing system failed to discharge, while BANK no. 1 discharged normally. The most probable cause of this malfunction is what type of faulty switch?
Correct Answer
D. Discharge selector.
Explanation
The most probable cause of the malfunction is a faulty discharge selector switch. This switch controls the discharge of the liquid agent in the fire extinguishing system. Since BANK no. 2 failed to discharge while BANK no. 1 discharged normally, it suggests that there is an issue with the switch specifically for BANK no. 2. This could be due to a faulty connection or a malfunctioning switch mechanism.
5.
(802) A flashing red light on the fire emergency control T-handle indicates
Correct Answer
C. An overheat condition.
Explanation
A flashing red light on the fire emergency control T-handle indicates an overheat condition. This means that there is excessive heat in the system, which could potentially lead to a fire. It is important to address this situation immediately to prevent any further damage or danger.
6.
(802) When depressed, which switch on a T-handle fire extinguishing system completes the circuit to the squib?
Correct Answer
D. Bottle selector switch.
Explanation
The bottle selector switch is the switch on a T-handle fire extinguishing system that completes the circuit to the squib when depressed. This switch is responsible for activating the extinguishing agent and initiating the fire suppression process. The other options mentioned - time delay relay switch, agent discharge switch, and engine selector switch - are not directly involved in completing the circuit to the squib. Therefore, the correct answer is the bottle selector switch.
7.
7. (802) In the T-handle fire extinguishing system, the two-way check valve is pushed into position by the
Correct Answer
A. Liquid agent.
Explanation
In the T-handle fire extinguishing system, the two-way check valve is pushed into position by the liquid agent. This means that when the liquid agent is released from the system, it exerts pressure on the check valve, causing it to move into the correct position. The liquid agent plays a crucial role in ensuring that the check valve functions properly and allows for the effective discharge of the extinguishing agent.
8.
(803) How does a liquid coolant system keep electronic components cool?
Correct Answer
A. Cycles coolant through the electronic component.
Explanation
A liquid coolant system keeps electronic components cool by cycling coolant through the electronic component. This means that the coolant is continuously flowing through the component, absorbing heat and carrying it away. This process helps to maintain a stable temperature and prevent the electronic component from overheating.
9.
(803) What characteristic of the fluid used in a liquid coolant system makes it suitable as a coolant for electronic components?
Correct Answer
D. Nonconductance.
Explanation
The characteristic of nonconductance in the fluid used in a liquid coolant system makes it suitable as a coolant for electronic components. This means that the fluid does not conduct electricity, which is important in preventing any electrical short circuits or damage to the electronic components.
10.
(803) During initial start of a liquid coolant system, the controller timer energizes the solenoid shutoff valve closed for three minutes. The purpose of this action is to
Correct Answer
C. Allow for system stabilization.
Explanation
During the initial start of a liquid coolant system, the controller timer energizes the solenoid shutoff valve closed for three minutes. This action allows for system stabilization. By closing the valve, it restricts the flow of coolant, allowing the system to reach a steady state and stabilize before full operation. This helps to prevent pressure surges and ensures that the system is functioning properly before normal operation begins.
11.
(803) What component of a liquid coolant system is positioned by the temperature of the coolant?
Correct Answer
A. Thermal pilot valve.
Explanation
The component of a liquid coolant system that is positioned by the temperature of the coolant is the thermal pilot valve. This valve is designed to open or close based on the temperature of the coolant, allowing for proper regulation of the coolant flow and temperature within the system.
12.
(803) In a liquid coolant system, what tells you that the liquid coolant filter is dirty?
Correct Answer
D. A mechanical pop-up indicator is activated.
Explanation
When the liquid coolant filter in a liquid coolant system becomes dirty, a mechanical pop-up indicator is activated. This indicator serves as a visual signal to the operator that the filter needs to be cleaned or replaced. The activation of the pop-up indicator allows for timely maintenance and prevents any potential damage or malfunction in the system.
13.
(803) What components control the temperature of the coolant in a liquid coolant system?
Correct Answer
D. Thermal modulating valve and thermal pilot valve.
Explanation
The components that control the temperature of the coolant in a liquid coolant system are the thermal modulating valve and the thermal pilot valve. These valves work together to regulate the flow of coolant and adjust its temperature accordingly. The thermal modulating valve controls the flow of coolant, while the thermal pilot valve senses the temperature and signals the modulating valve to adjust accordingly. This ensures that the coolant temperature remains within the desired range.
14.
(804) When maintaining a liquid coolant system, over-torquing clamps may cause what to happen?
Correct Answer
C. Damage or failure of the component.
Explanation
Over-torquing clamps in a liquid coolant system can cause damage or failure of the component. This is because excessive torque can lead to the deformation or cracking of the component, compromising its integrity and functionality. It is important to apply the correct amount of torque when tightening clamps to prevent such damage and ensure the proper functioning of the coolant system.
15.
(804) In a liquid coolant system, what is the purpose of purging the servicing unit supply hose?
Correct Answer
C. Prevent air from entering the system.
Explanation
Purging the servicing unit supply hose is done to prevent air from entering the system. Air can cause problems such as cavitation and air locks, which can reduce the efficiency of the coolant system and potentially damage components. By removing air from the hose, the system can operate more effectively and efficiently.
16.
(805) Why are multiplace liferaft cylinders wire-wound and dip-soldered?
Correct Answer
B. Adds strength to the cylinder.
Explanation
Multiplace liferaft cylinders are wire-wound and dip-soldered to add strength to the cylinder. This process helps to reinforce the cylinder and make it more durable. By wire-winding and dip-soldering, the cylinder becomes stronger and less susceptible to damage or failure. This is important for liferafts as they need to withstand rough conditions and maintain their integrity to ensure the safety of the occupants.
17.
(805) To ensure that a multiplace liferaft will inflate in extremely low temperatures, the inflation cylinder has a charge of
Correct Answer
B. Nitrogen.
Explanation
The correct answer is nitrogen. Nitrogen is used to inflate the inflation cylinder of a multiplace liferaft in extremely low temperatures because it remains a gas at low temperatures and does not freeze or become solid like other gases such as air, hydrogen, or carbon dioxide. This ensures that the liferaft will inflate properly and be ready for use in emergency situations, even in extremely cold environments.
18.
(805) What component of a liferaft inflation cylinder assembly keeps carbon dioxide (CO2) within the cylinder and permits an unrestricted flow of CO2 to the liferaft?
Correct Answer
D. Discharge valve.
Explanation
The discharge valve is the component of a liferaft inflation cylinder assembly that keeps carbon dioxide (CO2) within the cylinder and permits an unrestricted flow of CO2 to the liferaft. It allows the CO2 to be released from the cylinder and inflate the liferaft when activated. The other options, such as the diffuser plug, seating sleeve, and cartridge filter, do not have the same function of controlling the flow of CO2 and maintaining it within the cylinder.
19.
(805) Releasing carbon dioxide (CO2) from a liferaft cylinder into a liferaft is normally done by activating the
Correct Answer
A. Cam.
Explanation
Releasing carbon dioxide (CO2) from a liferaft cylinder into a liferaft is typically done by activating the cam. The cam is a mechanical device that controls the movement of other parts in the liferaft system. By activating the cam, it triggers the release of CO2 from the cylinder, allowing it to fill the liferaft and provide buoyancy. The other options, rupture disc, locking sleeve, and check valve seat, are not directly involved in the process of releasing CO2 from the cylinder.
20.
(806) How many pounds of carbon dioxide (CO2) does a fully charged shipping/storage cylinder contain?
Correct Answer
B. 50
Explanation
A fully charged shipping/storage cylinder contains 50 pounds of carbon dioxide (CO2).
21.
(806) Liferaft inflation cylinders having an outside diameter of less than 2 inches and a length of less than 2 feet do not require
Correct Answer
C. Hydrostatic testing.
Explanation
Liferaft inflation cylinders with small dimensions do not need to undergo hydrostatic testing. Hydrostatic testing is a process that checks the integrity of pressure vessels by subjecting them to high-pressure water to ensure they can withstand the specified pressure. Since the inflation cylinders in question are small and have specific dimensions, they are exempt from this testing requirement.
22.
(807) After recharging a liferaft inflation cylinder—but before returning it to serviceable status—
Correct Answer
C. Test for leaks, then reweigh after 24 hours.
Explanation
After recharging a liferaft inflation cylinder, it is necessary to test for leaks before returning it to serviceable status. This ensures that the cylinder is functioning properly and does not have any leaks that could compromise its ability to inflate the liferaft. After the leak test, the cylinder should be reweighed after 24 hours to ensure that it is holding the correct amount of gas and is ready for use.
23.
(807) What is added to multiplace liferaft inflation cylinders to ensure proper discharge of the carbon dioxide (CO2)?
Correct Answer
B. Dry nitrogen.
Explanation
Dry nitrogen is added to multiplace liferaft inflation cylinders to ensure proper discharge of the carbon dioxide (CO2). This is because dry nitrogen is an inert gas that does not react with other substances, making it suitable for maintaining the pressure and integrity of the CO2 system in the liferaft.
24.
(808) Oxygen in its natural state is
Correct Answer
A. Colorless, tasteless, and odorless.
Explanation
Oxygen in its natural state is colorless, tasteless, and odorless. This means that it does not have any color, it does not have any taste, and it does not have any odor.
25.
(808) Which part of the body usually suffers first from the effects of hypoxia?
Correct Answer
B. Eyes
Explanation
The eyes usually suffer first from the effects of hypoxia because they have a high oxygen demand and are very sensitive to changes in oxygen levels. Hypoxia can cause blurry vision, difficulty focusing, and even vision loss in severe cases. The lack of oxygen can damage the delicate tissues of the eyes, leading to various eye problems.
26.
(808) Supply and distribution tubing for aircraft oxygen systems is identified by cellulose tape in what colors?
Correct Answer
C. Green and white.
Explanation
Supply and distribution tubing for aircraft oxygen systems is identified by cellulose tape in green and white colors.
27.
(808) What valve decreases system pressure in a high-pressure oxygen system?
Correct Answer
D. Reducer valve.
Explanation
The correct answer is "Reducer valve." A reducer valve is used to decrease or regulate the pressure in a high-pressure oxygen system. It is designed to lower the pressure to a safe and manageable level for the system. A relief valve, on the other hand, is used to release excess pressure in a system to prevent damage or failure. Closing valve and control valve are not specifically designed to decrease system pressure.
28.
(808) In a high-pressure oxygen system, the tubing between the filler valve and the pressure reducer valve is made of
Correct Answer
C. Copper alloy.
Explanation
The correct answer is copper alloy. Copper is commonly used in high-pressure oxygen systems because it is resistant to corrosion and does not react with oxygen. It also has good thermal conductivity, which helps to dissipate heat generated by the high-pressure oxygen flow. Copper alloy tubing is strong and durable, making it suitable for withstanding the high pressures involved in these systems.
29.
(808) What does the molecular sieve oxygen generating system (MSOGS) concentrator supply to the OXYGEN regulator control panel?
Correct Answer
C. 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.
30.
(809) Liquid oxygen converts to gaseous oxygen at an expansion ratio of
Correct Answer
D. 860 to 1.
Explanation
Liquid oxygen converts to gaseous oxygen at an expansion ratio of 860 to 1. This means that when liquid oxygen expands, its volume increases 860 times. This expansion ratio is a measure of how much the substance expands when changing from a liquid to a gas state. It indicates the significant increase in volume that occurs during this phase change.
31.
(809) If a leak develops in the inner shell of a liquid oxygen container, it will be protected from excessive pressure by the
Correct Answer
C. Blowout disc.
Explanation
If a leak develops in the inner shell of a liquid oxygen container, it will be protected from excessive pressure by the blowout disc. A blowout disc is a safety device designed to rupture and release pressure when it exceeds a certain limit. In this case, if there is a leak in the inner shell, the blowout disc will rupture and allow the excess pressure to escape, preventing the container from becoming overpressurized and potentially causing a catastrophic failure.
32.
(809) In a liquid oxygen (LOX) system, what component has the ability to draw gaseous oxygen from the top of the converter for breathing purposes?
Correct Answer
D. Pressure opening valve.
Explanation
The pressure opening valve in a liquid oxygen (LOX) system has the ability to draw gaseous oxygen from the top of the converter for breathing purposes. This valve is designed to open when the pressure inside the system reaches a certain level, allowing the gaseous oxygen to be released and used for breathing.
33.
(809) Which one of these is a disadvantage of a continuous-flow oxygen regulator?
Correct Answer
A. It wastes oxygen.
Explanation
A continuous-flow oxygen regulator wastes oxygen because it delivers a constant flow of oxygen regardless of whether the user is inhaling or exhaling. This means that oxygen is being constantly supplied even when it is not needed, resulting in wastage of oxygen.
34.
(809) When the cabin altitude of an aircraft reaches 30,000 feet, what component in the pressure demand oxygen regulator causes 100 percent oxygen to be delivered to the user?
Correct Answer
C. Diluter aneroid.
Explanation
When the cabin altitude of an aircraft reaches 30,000 feet, the diluter aneroid in the pressure demand oxygen regulator causes 100 percent oxygen to be delivered to the user. The diluter aneroid is a component that senses the altitude and adjusts the oxygen flow accordingly. At higher altitudes, the diluter aneroid closes off the diluter ports, allowing only pure oxygen to be delivered to the user. This ensures that the user receives the necessary oxygen concentration to maintain proper oxygenation at high altitudes.
35.
(809) When the PBG/ON/OFF toggle of an oxygen system is placed in the PBG position, what causes the availability of oxygen and pressure breathing?
Correct Answer
D. Positive signal from the anti-g valve.
Explanation
When the PBG/ON/OFF toggle of an oxygen system is placed in the PBG position, the availability of oxygen and pressure breathing is caused by a positive signal from the anti-g valve. This means that the anti-g valve is responsible for allowing the oxygen to flow and maintaining the required pressure for pressure breathing.
36.
(809) Which oxygen system allows oxygen to flow automatically to the distribution system when cabin altitude reaches 12,500 feet?
Correct Answer
B. Troop system.
37.
37. (810) What happens when extended demand on a liquid oxygen (LOX) system causes converter head pressure to drop below 70 pounds per square inch (psi)?
Correct Answer
B. The pressure closing valve will open.
Explanation
When extended demand on a liquid oxygen (LOX) system causes converter head pressure to drop below 70 pounds per square inch (psi), the pressure closing valve will open.
38.
(810) A liquid oxygen (LOX) system’s pressure fails to stabilize at 110 pounds per square inch(psi). This could be caused by a failure of the
Correct Answer
B. Converter relief valve.
Explanation
A liquid oxygen (LOX) system's pressure failing to stabilize at 110 psi could be caused by a failure of the converter relief valve. The converter relief valve is responsible for regulating the pressure in the LOX system by releasing excess pressure. If this valve fails, it could lead to an inability to stabilize the pressure at the desired level.
39.
39. (810) A liquid oxygen (LOX) system is continuously venting gaseous oxygen overboard. The most probable malfunction is a faulty
Correct Answer
C. Pressure closing valve.
Explanation
The most probable malfunction in a continuously venting liquid oxygen (LOX) system is a faulty pressure closing valve. This valve is responsible for closing off the flow of oxygen when the system reaches a certain pressure. If the valve is faulty, it may not close properly, leading to continuous venting of gaseous oxygen overboard.
40.
(811) You should replace an oxygen mask-to-regulator connector if the no-go portion of the gono-go gage passes through the
Correct Answer
D. Smallest internal port.
Explanation
The correct answer is "smallest internal port." When replacing an oxygen mask-to-regulator connector, the no-go portion of the gono-go gauge should not pass through the smallest internal port. This is because the smallest internal port is a critical component that ensures proper oxygen flow and prevents leaks. If the gauge passes through this port, it indicates that the connector is worn or damaged and needs to be replaced to ensure the safety and effectiveness of the oxygen system.
41.
(811) The minimum required clearance between oxygen system tubing and aircraft control cables is
Correct Answer
B. 2 inches.
Explanation
The minimum required clearance between oxygen system tubing and aircraft control cables is 2 inches. This clearance is necessary to ensure that there is no interference or contact between the tubing and the control cables, which could potentially lead to damage or malfunction of the aircraft's systems. A clearance of 2 inches provides an adequate buffer to prevent any potential issues and allows for safe operation of the aircraft.
42.
(811) What is the minimum required clearance between oxygen system tubing and electrical wiring with electrical insulation and clamps installed?
Correct Answer
A. 1/4 inch.
Explanation
The minimum required clearance between oxygen system tubing and electrical wiring with electrical insulation and clamps installed is 1/4 inch. This clearance is necessary to prevent any potential contact or interference between the oxygen system tubing and the electrical wiring, which could lead to safety hazards or malfunctions.
43.
(812) To reduce vibration and prevent chafing of oxygen system tubing, you should secure long runs of oxygen tubing at least every
Correct Answer
D. 15 inches
Explanation
To reduce vibration and prevent chafing of oxygen system tubing, it is necessary to secure long runs of tubing at regular intervals. The correct answer is 15 inches because securing the tubing at this distance will effectively minimize vibration and prevent chafing. This ensures the safety and proper functioning of the oxygen system.
44.
(812) How do you loosen a B-nut from a fitting on the tubing of an oxygen regulator?
Correct Answer
A. Hold the fitting with a wrench to prevent twisting of the tubing.
Explanation
When loosening a B-nut from a fitting on the tubing of an oxygen regulator, it is important to hold the fitting with a wrench to prevent twisting of the tubing. This is necessary because if the tubing twists, it can cause damage or leaks, which can be dangerous when working with oxygen. By holding the fitting with a wrench, it ensures that only the B-nut is being loosened, while the tubing remains stable and secure.
45.
(812) Which statement best describes the proper use of anti-seize tape in an oxygen system?
Correct Answer
D. Apply a small amount on the first three threads of a pipe thread fitting.
Explanation
Anti-seize tape should be applied on the first three threads of a pipe thread fitting in an oxygen system. This helps to prevent galling and seizing of the threads, ensuring a proper seal and easy disassembly in the future. It is not necessary to use anti-seize tape on flared fittings, all fittings through which liquid oxygen flows, or only when a leak is suspected.
46.
(813) An aircraft gaseous oxygen system must be purged only with
Correct Answer
C. Gaseous oxygen.
Explanation
An aircraft gaseous oxygen system must be purged only with gaseous oxygen because it is the same type of gas that is used in the system. Purging with any other gas, such as nitrogen, liquid oxygen, or compressed dry air, could introduce contaminants or cause damage to the system. Therefore, gaseous oxygen is the correct choice for purging the system to ensure its proper functioning and safety.
47.
(813) On a gaseous oxygen servicing trailer, what does the purifier assembly remove from gaseous oxygen?
Correct Answer
C. Moisture.
Explanation
The purifier assembly on a gaseous oxygen servicing trailer removes moisture from the gaseous oxygen.
48.
(813) The gaseous oxygen (GOX) cart pressure gauge must be replaced if it varies from the aircraft gauge by more than what amount?
Correct Answer
D. ±10 psig.
Explanation
The correct answer is ±10 psig. This means that if the pressure gauge on the gaseous oxygen (GOX) cart varies from the aircraft gauge by more than 10 pounds per square inch (psig), it must be replaced. This is important because a significant difference in pressure readings could indicate a malfunction or potential danger in the oxygen system.
49.
(813) What is the maximum pressure of compressed air used for cleaning?
Correct Answer
B. 30 psi.
Explanation
The maximum pressure of compressed air used for cleaning is 30 psi. This pressure is sufficient to effectively clean surfaces without causing damage or injury. Higher pressures can be dangerous and may cause harm to the user or the equipment being cleaned. Lower pressures may not provide enough force to remove dirt and debris effectively. Therefore, 30 psi is the recommended maximum pressure for compressed air cleaning.
50.
(814) What is the service test pressure for a low-pressure gaseous oxygen system leak test?
Correct Answer
C. 425 to 450 psi.
Explanation
The correct answer is 425 to 450 psi. This is the service test pressure for a low-pressure gaseous oxygen system leak test. This pressure range is necessary to ensure that the system is able to withstand the pressure it will experience during normal operation without any leaks. It is important to test the system at this pressure to ensure its safety and reliability.