Aircraft Systems, Part 1 Trivia Questions

The three states of matter are liquids, gases, and solids. Liquids have a definite volume but not a definite shape, gases have neither a definite volume nor a definite shape, and solids have both a definite volume and a definite shape. Minerals and organic substances are not states of matter, but rather types of substances that can exist in different states of matter.

Aircraft trim systems are designed to adjust the aircraft's control surfaces in order to maintain a desired flight attitude. These systems help to correct any minor deviations in the aircraft's pitch, roll, or yaw, ensuring that the aircraft stays in a stable and controlled state of flight. By making these adjustments, the trim systems help pilots to maintain a balanced and efficient flight, without the need for constant manual control inputs.

The correct answer is "occupies space" because matter refers to anything that takes up space and has mass. This means that matter has a physical presence and can be measured in terms of volume. Therefore, the statement "occupies space" accurately describes one of the fundamental characteristics of matter.

Atoms are the basic building blocks of matter, and they are composed of three main subatomic particles: protons, neutrons, and electrons. Protons have a positive charge, neutrons have no charge, and electrons have a negative charge. These particles are held together in the nucleus of an atom, with protons and neutrons making up the nucleus and electrons orbiting around it. Therefore, the correct answer is that atoms are made up of protons, neutrons, and electrons.

The purpose of the arrow on a check valve is to show the direction of free flow through the valve. This arrow indicates the direction in which the fluid or gas can flow through the valve, allowing for proper installation and operation of the check valve.

The landing gear warning horn is designed to sound when the gear is not safe. This means that if the landing gear is not properly extended or locked in place, the warning horn will alert the pilot to the potential danger. It serves as a crucial safety feature, ensuring that the pilot is aware of any issues with the landing gear before landing or taking off.

The correct answer is the ability to conform to the shape of its container. Unlike solids, liquids do not have a fixed shape and can take the shape of the container they are placed in. This is due to the weak intermolecular forces between liquid particles, allowing them to flow and move freely. Liquids are not rigid, as they can be poured or transferred from one container to another. They also cannot be compressed within their container, as their particles are already close together.

Using a wire brush to clean aircraft wheels can cause damage to the surface of the wheels. Wire bristles can be too abrasive and may scratch or scrape the wheels, potentially leading to corrosion or other issues. It is important to use non-abrasive materials, such as fiber brushes, clean rags, or fiber pads, to safely and effectively clean aircraft wheels without causing any damage.

The resulting force can be calculated by multiplying the cylinder pressure (50 PSI) by the piston head area (5 square inches). This gives us a force of 250 pounds.

The term that describes current that reverses its direction at regularly recurring intervals is "alternating." This type of current is commonly used in electrical power systems, where the flow of electricity changes direction periodically. Unlike direct current, which flows in only one direction, alternating current alternates between positive and negative directions, allowing for efficient transmission of electricity over long distances.

Multiple disc brakes have a major disadvantage of warping when overheated. This means that when the brakes get too hot, they can become distorted and lose their shape, causing them to be less effective in stopping the vehicle. This can lead to decreased braking performance and potentially unsafe driving conditions.

The force that acts upward at a right angle to the direction of the relative wind is called lift. Lift is the force that allows an object, such as an airplane, to overcome gravity and stay in the air. It is generated by the shape of the object's wings or airfoils and the flow of air over them. This upward force counters the weight of the object, allowing it to stay aloft.

When 24 volts are applied to a total resistance of 6 ohms in a series circuit, the amperage can be calculated using Ohm's Law, which states that current (amperage) is equal to voltage divided by resistance. In this case, the current can be calculated as 24 volts divided by 6 ohms, which equals 4 amperes.

The volume of liquid displaced can be calculated by multiplying the area of the piston (8 square inches) by the distance it moves (5 inches). This gives us a volume of 40 cubic inches.

A semi-monocoque design is a type of fuselage construction that combines longerons, stringers, bulkheads, and frames. In this design, the skin of the fuselage carries a significant portion of the structural load, while the internal framework provides additional support and strength. This design is commonly used in modern aircraft as it offers a good balance between strength and weight.

Electromotive force is the correct answer because it refers to the electrical pressure that causes electrons to flow through a conductor. It is the driving force that pushes the electrons in a circuit, enabling the flow of electrical current. The other options, such as chemical swap, crossfeed field, and transferring magnetic field, do not accurately describe the electrical pressure that causes electron flow.

In a pneudraulic system, flow is typically produced by the piston pushing the fluid. The piston creates pressure within the system, which then forces the fluid to flow through the system. This flow is essential for the proper functioning of the pneudraulic system, as it allows for the transfer of power and the operation of various components. The relief valve, scrupper, and selector valve may play important roles in controlling the flow or regulating the pressure, but they do not directly produce the flow in the system.

Boyle was among the first to study the compressibility of gases. His work in the 17th century led to Boyle's Law, which states that the volume of a gas is inversely proportional to its pressure, when temperature is held constant. Boyle conducted experiments using a J-shaped tube filled with mercury and observed the relationship between the volume and pressure of gases. His contributions laid the foundation for the understanding of gas behavior and the development of the field of thermodynamics.

A venturi is a tube with a gradually decreasing cross-sectional area, which results in an increase in fluid velocity. This phenomenon is known as the venturi effect. The reduction in diameter creates a pressure difference between the wider and narrower sections of the tube. This principle is utilized in various applications such as fluid flow measurement and creating suction in devices like vacuum cleaners. A torus is a doughnut-shaped object, a pipette is a laboratory tool used for transferring small amounts of liquid, and a vortex refers to the swirling motion of fluids.

The antiskid system is designed to prevent wheel skid by releasing pressure from the skidding wheel. When a wheel begins to skid, the antiskid system detects this and reduces the pressure on that wheel, allowing it to regain traction and prevent further skidding. By releasing pressure, the system helps to maintain control and stability of the vehicle, reducing the risk of accidents. Increasing friction between the wheel and tire would actually contribute to skidding, so it is not the purpose of the antiskid system.

A universal motor is able to operate on both alternating current (AC) and direct current (DC). This type of motor is designed with a special configuration that allows it to work efficiently with either type of current. It is commonly used in household appliances, power tools, and other applications where flexibility in power supply is required. The other options, such as shunt, circuit, and compound motors, are not capable of operating on both AC and DC.

The most common type of material used for fuselage construction is aluminum alloy. This is because aluminum alloys offer a good balance of strength and weight, making them ideal for aircraft structures. They have high strength-to-weight ratio, corrosion resistance, and can withstand the stresses and pressures experienced during flight. Additionally, aluminum alloys are relatively easy to work with and can be formed into complex shapes, making them suitable for the curved and streamlined design of fuselages. Steel, titanium, and magnesium are also used in aircraft construction, but aluminum alloy is the most commonly used material for fuselages.

The correct answer is in the aircraft cabin. This is because the aircraft cabin is the central location where the majority of the aircraft's electrical systems and components are housed. Placing the circuit protection devices in the cabin allows for easy access and maintenance. Additionally, locating them in the cabin ensures that they are protected from external elements and potential damage.

Atmospheric pressure at sea level is commonly measured as 14.7 pounds per square inch (psi). This value represents the average pressure exerted by the Earth's atmosphere at sea level. It is important to note that atmospheric pressure can vary slightly depending on factors such as weather conditions and altitude. However, 14.7 psi is considered the standard value used for reference in various scientific and engineering applications.

A barometer is a device used to measure atmospheric pressure. The most common unit for measuring pressure using a barometer is inches of mercury (inHg). This unit is derived from the height of a column of mercury that is supported by the atmospheric pressure. As the pressure changes, the height of the mercury column also changes, allowing for the measurement of pressure in inches of mercury. This unit is widely used in meteorology and aviation.

The nickel-cadmium battery can be fully charged only by a constant current. This is because a constant current ensures a steady flow of electrons into the battery, allowing for a controlled and efficient charging process. Pulsating current, varying current, and eddy current would not provide a consistent and stable flow of electrons, which could result in incomplete or inefficient charging of the battery.

Electrons can be released from their outer orbit by various forces such as heat, chemical action, and changing magnetic fields. However, cold temperatures do not have enough energy to overcome the binding forces holding electrons in their orbits. Therefore, cold is the only force mentioned that cannot release electrons from their outer orbit.

In aircraft circuits, the current flow is controlled by switches. Switches are used to open or close the circuit, allowing or stopping the flow of electric current. They act as control devices that enable the pilot or operator to activate or deactivate various electrical components or systems in the aircraft. Fuses protect the circuit from excessive current, batteries provide the power source, and signals are used for communication or indicating purposes. However, neither fuses, batteries, nor signals directly control the current flow in aircraft circuits.

The reference locations in the vertical direction measured from a reference datum that is usually well below the aircraft are called waterlines. Waterlines are horizontal reference lines that are used to determine the position of various components of an aircraft, such as the wings, fuselage, and tail, in relation to the waterline. These reference locations help in ensuring proper balance and stability of the aircraft during flight and are crucial for design, maintenance, and performance purposes.

Movement about the vertical axis is called "yaw." Yaw refers to the rotation of an object or body around its vertical axis, which is an imaginary line passing through the center of gravity and extending vertically from the object. This movement causes the object to turn left or right, similar to the motion of a ship or an airplane changing its direction horizontally. Roll refers to the rotation around the longitudinal axis, pitch refers to the rotation around the lateral axis, and crab refers to a sideways movement caused by crosswinds.

When the wear on a tire reaches the bottom of any tread groove for a continuous length of 12 inches, the tire must be removed. This means that if there is a section of the tire where the tread is worn down to the bottom of the groove for a distance of 12 inches or more, it is no longer safe to use the tire and it should be replaced.

An O-ring seal is used to maintain an airtight seal between split wheel halves. O-rings are made of rubber or other elastomer materials and are designed to fit into a groove between two mating surfaces. When compressed, the O-ring creates a tight seal, preventing any air or fluid from leaking between the split wheel halves. This type of seal is commonly used in various applications where a reliable and leak-proof connection is required.

The accessory gearbox supplies rotary power to the input gear of the constant speed drive (CSD). This means that the accessory gearbox is responsible for providing the necessary power to the CSD, allowing it to function properly. The other options, such as the transmission shaft, torque converter, and hydraulic gear, are not directly involved in supplying power to the CSD.

Installed bearing races should be free of scratches, dents, dye marks, and paint marks as these can indicate damage or contamination. However, overheating marks are particularly important to avoid as they can indicate excessive heat and potential damage to the bearing race. Overheating can lead to premature wear and failure of the bearing, so it is crucial to ensure that there are no signs of overheating marks on the installed bearing races.

A hydraulic motor is designed to utilize hydraulic pressure to generate rotary mechanical motion. It is commonly used in various applications such as construction equipment, manufacturing machinery, and vehicles. By harnessing the power of hydraulic fluid, the motor can convert the pressure into rotational force, allowing it to drive different types of machinery and perform tasks such as rotating a shaft or powering a hydraulic pump. This enables the hydraulic system to efficiently transmit power and control the movement of various mechanical components.

When soft iron is brought close to a permanent magnet, it becomes magnetized. Soft iron is a ferromagnetic material, which means it can be easily magnetized and demagnetized. When it is brought close to a permanent magnet, the magnetic field of the permanent magnet induces a magnetic field in the soft iron, aligning its domains and making it temporarily magnetic. This magnetization disappears when the soft iron is no longer in the presence of the permanent magnet. Therefore, the correct answer is magnetized.

The main difference between inspection plates and panels is their size. Inspection plates are typically smaller in size and are used for accessing specific areas or components for inspection or maintenance purposes. On the other hand, panels are larger and are used to cover larger areas or enclosures. The size difference allows for easier access and maintenance of different parts or systems in a given structure or equipment.

The strength of an electromagnet is directly proportional to the current flow through it. As the current increases, the magnetic field produced by the electromagnet becomes stronger. This is because the magnetic field is created by the alignment of the magnetic domains within the core material, and a higher current flow leads to a greater alignment of these domains, resulting in a stronger magnetic field. Therefore, the greater the current flow through an electromagnet, the greater its strength.

Crazing refers to the formation of a network of fine cracks on or under the surface of transparent plastics. This phenomenon typically occurs due to the stress or strain applied to the material, causing it to develop small fractures that resemble a spider web pattern. Casting, fretting, and pitting are unrelated terms and do not describe the specific cracking behavior observed in crazing.

Shear stress refers to the stress that resists the force that tries to cause one layer of material to slide over an adjacent layer. It occurs parallel to the plane of contact between the layers and acts in opposite directions on each layer. Bending stress is related to the deformation of a material due to bending, tension stress is caused by the pulling force applied to a material, and torsion stress is the stress caused by twisting or rotating forces. However, shear stress specifically addresses the resistance to sliding between layers, making it the correct answer in this case.

When a solid is subjected to a force that causes it to change permanently, it means that the solid has exceeded its elastic limit. The elastic limit is the maximum stress or force that a material can withstand without undergoing permanent deformation. Once the elastic limit is surpassed, the solid loses its ability to return to its original shape and size after the force is removed. Therefore, the correct answer is that the solid has passed the elastic limit.

Stringers are structural members that are used to give shape to the aircraft and provide a means for attaching the skin to the structure. They are long, thin strips of material that run longitudinally along the fuselage or wing. Stringers help to distribute the loads and stresses evenly throughout the structure, providing strength and rigidity. They also help to maintain the shape of the aircraft and prevent deformation. Therefore, stringers are the correct answer in this case.

Before emergency extension of the landing gear, the landing gear control handle must be in the DN (Down) position. This allows for the emergency extension process to be initiated, causing the landing gear to be lowered manually. The UP position is for normal retraction of the landing gear, AUX is for auxiliary operations, and EMERG is for emergency operations after the gear has been manually extended.

The correct answer is reduced weight. An electricity controlled solenoid valve is advantageous because it has a reduced weight compared to other types of valves. This reduced weight makes it easier to install and transport, and also reduces the strain on the system where it is being used. Additionally, the reduced weight allows for more flexibility in design and placement, making it a preferred choice in many applications.

Engine mounts are typically made of corrosion-resistant steel that is able to withstand forces of 180,000 to 200,000 pounds per square inch (psi). This range of psi ensures that the engine mounts can endure the high levels of stress and pressure generated by the engine during operation.

A restrictor check valve is designed to allow the normal operating speed of a hydraulic actuator in one direction while limiting the speed in the other direction. This valve contains a check valve that allows flow in one direction and a restrictor that limits the flow rate in the opposite direction. This setup ensures that the actuator can move quickly in the desired direction while controlling the speed and preventing excessive movement in the opposite direction.

The elevator is attached to the trailing edge of a horizontal stabilizer. It is a movable control surface that is used to control the pitch of an aircraft. By changing the angle of the elevator, the pilot can control the aircraft's nose-up or nose-down attitude, allowing for changes in altitude. Flaps are attached to the wings and are used to increase lift during takeoff and landing. Spoilers are also attached to the wings and are used to decrease lift and increase drag. The rudder is attached to the vertical stabilizer and is used to control the yaw of the aircraft.

The purpose of the torsion links on a main landing gear is to prevent the inner cylinder from rotating within the outer cylinder. Torsion links are designed to provide stability and prevent unwanted rotation between the inner and outer cylinders of the landing gear. This is important during landing and takeoff to ensure that the landing gear remains in the correct position and does not rotate or twist, which could lead to instability and potential damage to the aircraft. By preventing rotation, the torsion links help maintain the structural integrity and stability of the landing gear system.

Aircraft wheels are typically made of magnesium and/or aluminum alloys. These materials are chosen for their lightweight properties, which help to reduce the overall weight of the aircraft and improve fuel efficiency. Additionally, magnesium and aluminum alloys offer good strength and durability, allowing the wheels to withstand the high loads and stresses experienced during takeoff, landing, and taxiing.

The purpose of a hydraulic reservoir is to replenish fluid, allow for thermal expansion, and provide a means of bleeding air from the system. Replenishing fluid is important to ensure that the hydraulic system always has an adequate amount of fluid to operate effectively. Allowing for thermal expansion is necessary because as the fluid heats up during operation, it expands and needs space to accommodate this expansion. Lastly, providing a means of bleeding air from the system is crucial as air in the hydraulic system can cause inefficiencies and potential damage.