2A553B Vol. 4 Pretest

Triangulation is the process of using fixed points and their bearings to isolate a position in space. It involves measuring the angles between the fixed points and the unknown position, and then using trigonometry to calculate the distance and direction of the unknown position. This method is commonly used in surveying and navigation to determine the location of objects or to create accurate maps. Pseudo fixing, decoding, and shading are not related to this process and therefore are incorrect answers.

The correct answer is Flap. Flaps are a type of flight control surface that are located on the trailing edge of the wings. They can be extended or retracted to change the shape and surface area of the wing, which helps to increase lift and decrease stall speed during takeoff and landing. The position of the flaps is indicated by a percentage, showing how much they are extended or retracted.

The global positioning system satellites and receivers need to be synchronized to the nanosecond in order to accurately determine positions on Earth. Atomic clocks are the most precise timekeeping devices available, as they measure time based on the vibrations of atoms. Therefore, atomic clocks are used to synchronize the satellites and receivers, ensuring accurate and reliable positioning information.

The process of neutralizing or weakening the permanent magnetic field that exists around an aircraft is known as degaussing. This is done to prevent the magnetic field from interfering with the aircraft's instruments and systems.

The global positioning system (GPS) is a worldwide radio-navigation system that relies on a constellation of satellites. These satellites orbit the Earth and provide signals that a GPS receiver can use to determine its location. The question asks how many satellites are in this constellation, and the correct answer is 24. This means that there are 24 satellites constantly transmitting signals that can be used by GPS receivers to calculate their position accurately.

The three attitude heading reference system (AHRS) heading modes of operation are DG (Directional Gyro), and compass. The DG mode provides heading information based on the rotation of a gyroscopic device, while the compass mode uses magnetic sensors to determine the heading. Both modes are commonly used in aviation to provide accurate and reliable heading information to pilots. The other options, Coriolis and azimuth, are not related to AHRS heading modes.

The most accurate inertial navigation system alignment is "pure inertial" because it relies solely on the internal sensors of the system to measure and track the aircraft's position and movement. This method does not require any external references or inputs, making it less prone to errors caused by external factors such as magnetic interference or GPS signal loss. Pure inertial alignment provides highly accurate and reliable navigation information, making it the preferred choice for precise aircraft navigation.

Global positioning system (GPS) receivers have almanacs programmed into their computers to continually determine the location of each satellite. An almanac is a set of data that includes information about the orbit and position of each satellite. By using this information, the receiver can calculate the precise location of each satellite and accurately determine its own position through triangulation. The almanac is updated periodically to ensure accuracy in satellite positioning.

The INS mode selector unit BAT light illuminates if the battery unit is not charged enough to sustain INS operation. This means that if the battery is not sufficiently charged, it will not be able to provide the necessary power for the INS system to function properly. Therefore, the BAT light serves as a warning indicator to alert the pilot that the battery needs to be charged or replaced in order to ensure the continued operation of the INS.

The correct answer is constant 60 RPM. This means that the fuel flow transmitter motor always drives the impeller at a fixed speed of 60 revolutions per minute.

The correct answer is Hi-Z. Hi-Z refers to high impedance, which means that the wire used as a signal lead has a high resistance to the flow of electrical current. Shielded wires are used to minimize interference and noise in signal transmission, and using a high impedance wire helps to maintain the integrity of the signal by reducing the amount of signal loss. Therefore, the shielded wire used as a signal lead is called Hi-Z.

The correct answer is PSD60-1AF. This fuel quantity tester is approved as safe for use with fuel in the tank.

To establish our lateral and longitudinal coordinates using the global position system (GPS), a minimum of three satellites is needed. This is because GPS works on a principle called trilateration, where the receiver determines its position by measuring the distance to at least three satellites. By intersecting the spheres created by these distances, the receiver can pinpoint its location. Therefore, having three satellites is necessary to accurately establish our lateral and longitudinal coordinates.

The term "Lo-Z" is commonly used to refer to low impedance, which means that the unshielded wire used as a power lead has a low electrical resistance. This type of wire is designed to minimize signal loss and interference, making it suitable for carrying power efficiently. "Hi-Z" refers to high impedance, which is not suitable for power leads. "Return" is a term used to describe the path for current flow in an electrical circuit. "Kapton" is a type of insulating material and not specifically related to power leads.

Near the equator, the lines of magnetic force are parallel to the Earth's surface. This is because the Earth's magnetic field is primarily generated by the motion of molten iron in its outer core. Near the equator, the magnetic field lines are relatively horizontal and parallel to the Earth's surface. As we move away from the equator towards the poles, the magnetic field lines become more inclined and eventually become perpendicular to the Earth's surface.

The magnetic azimuth detector measures the direction of the Earth's magnetic field. The input frequency of 400 Hz refers to the frequency of the alternating current supplied to the detector. The magnetic azimuth detector processes this input frequency and produces an output frequency that is double the input frequency, resulting in a frequency of 800 Hz.

The attitude heading reference system (AHRS) uses one vertical gyro and one directional gyro. The vertical gyro measures the aircraft's pitch and roll, providing information about its attitude. The directional gyro, also known as the heading gyro, measures the aircraft's yaw, indicating its heading. Together, these two gyros provide crucial information about the aircraft's orientation and movement in three dimensions, allowing for accurate navigation and control.

When the flight director system's HSI remote heading slew switch is in the DUAL position, both the pilot's and copilot's HSI heading markers move when the pilot's heading slew control is pressed. This means that both the pilot and copilot can control and adjust the heading marker simultaneously.

The vertical scale fuel flow indicator is read as pounds per hour x 1000. This means that each numbered increment on the scale represents the fuel flow rate in pounds per hour, and it is multiplied by 1000 for easier reading and accuracy. This unit of measurement is commonly used in aviation to monitor the fuel consumption rate of an aircraft.

Before calibrating the torquemeter indicating system, it is necessary to obtain the air temperature and barometric pressure. These two factors are important for accurate calibration as they can affect the performance and accuracy of the torquemeter. Air temperature can impact the density and viscosity of the fluid being measured, while barometric pressure can affect the overall pressure and performance of the system. Therefore, obtaining these measurements is crucial to ensure precise calibration of the torquemeter indicating system.

The correct answer is ALERT. During flight, the INS control display unit light illuminates approximately two minutes before reaching a waypoint to alert the pilot. This alert indicates that the aircraft is approaching a significant point in its flight plan and serves as a reminder for the pilot to prepare for any necessary actions or maneuvers.

A fully charged battery unit can sustain INS (Inertial Navigation System) operation for a maximum of 30 minutes. This means that the battery can power the INS system for half an hour before it needs to be recharged or replaced. It is important to keep track of the battery life and plan accordingly to ensure uninterrupted operation of the INS system.

The torquemeter assembly consists of two concentric shaft assemblies. This means that there are two shafts that are aligned and positioned one inside the other. These shafts are designed to measure the torque, or twisting force, applied to the assembly. The use of two concentric shafts allows for accurate torque measurement as any twisting force applied to the assembly will be transferred from one shaft to the other, enabling the measurement of torque.

The DC fuel quantity indicating system uses a compensation capacitor to correct for variations in fuel density. This is because the density of fuel can change due to factors such as temperature and the type of fuel being used. By using a compensation capacitor, the system can accurately measure the quantity of fuel regardless of these density variations. This ensures that the fuel level indication is reliable and accurate for the pilot and other aircraft systems.

The AHRS cuts off slaving of the AHRS to magnetic heading when a fore-aft acceleration of 0.055-g or a turn rate of 8 degrees per minute is exceeded. This means that if the aircraft experiences an acceleration greater than 0.055 times the force of gravity in the fore-aft direction, or if the turn rate exceeds 8 degrees per minute, the AHRS will no longer use the magnetic heading for its calculations.

The correct answer is TACAN, SKE, or manually. This means that the inertial navigation system can be updated through TACAN, which is a military navigational aid that provides range and bearing information, SKE (Selective Availability Anti-Spoofing Module Key Encryption), which is a device used to encrypt and secure GPS signals, or manually, indicating that the system can be updated by inputting the information directly.

To determine aircraft altitude using global positioning system (GPS), at least four satellites are needed. This is because GPS works on a trilateration principle, where the receiver calculates its position based on the distance from multiple satellites. By receiving signals from four satellites, the GPS receiver can accurately determine the altitude along with the latitude and longitude of the aircraft. Therefore, four GPS satellites are required to determine aircraft altitude.

The N1 and N2 RPM tapes indicate a percentage of RPM from 0 to 110.

The amount of current produced in the vertical scale exhaust gas temperature indicating system is dependent on the difference in temperature between the hot and cold junctions. The hot junction is the part of the system that is heated, while the cold junction is the reference point for temperature measurement. The difference in temperature between these two junctions affects the flow of current in the system.

After adjusting the torquemeter indicator, the switch on the back of the indicator must be returned to the "R" position. This suggests that the switch has multiple positions and "R" is the correct position to set it back to after making adjustments.

As the dielectric constant of the fuel increases, the capacitance of the fuel quantity probe increases. This is because the dielectric constant is a measure of how well a material can store electrical energy in an electric field, and a higher dielectric constant means that the fuel can store more charge. As the capacitance increases, the capacitive reactance decreases. Capacitive reactance is the opposition to the flow of alternating current in a capacitor, and it is inversely proportional to the capacitance. Therefore, as the capacitance increases, the capacitive reactance decreases. Finally, as the capacitive reactance decreases, the current flowing through the fuel quantity probe increases.

Deviation is the correct answer because it refers to the magnetic compass error that occurs due to magnetism within the aircraft. This error is caused by the presence of magnetic materials or electrical systems in the aircraft, which can create their own magnetic fields and interfere with the accuracy of the compass. Deviation is different from variation, which is the angular difference between true north and magnetic north, and is not affected by the aircraft's magnetism. Interference and vibration are not specific compass errors caused by magnetism within the aircraft.

The correct answer is WARN. The WARN light indicates an operator error or an out-of-tolerance condition in the INS computer. This light is designed to alert the operator to any potential issues or mistakes that may have occurred during the operation of the computer. It serves as a warning signal to prompt the operator to take corrective action or to investigate the error or condition further.

The tachometer generator used with a vertical scale revolutions per minute indicating system typically consists of a 2-pole permanent magnet rotor and a 3-phase stator. This configuration allows for accurate measurement of the rotor's speed by generating a three-phase AC voltage proportional to the rotor's rotational speed. The 2-pole rotor ensures a higher frequency output, while the 3-phase stator provides a more stable and accurate measurement.

The cold junction compensator in the vertical scale exhaust gas temperature indicating system is designed to compensate for changes in ambient temperature. This is because the accuracy of the temperature measurement can be affected by variations in the surrounding temperature. The compensator ensures that the readings are adjusted accordingly, allowing for more accurate and reliable measurements of the exhaust temperature.

The correct answer is NORM, and SET. The fuel center of gravity management system's panel allows the selection of three operational modes: NORM, which refers to the normal mode of operation, and SET, which allows the adjustment and setting of the fuel center of gravity. These modes are crucial in managing the distribution of fuel and maintaining the desired center of gravity for optimal aircraft performance and stability. The other options, such as FUEL, CG, MAC, and EMP, do not correspond to the operational modes on the fuel center of gravity management system's panel.

The attitude heading reference system (AHRS) DG pitch gimbal is aligned with and continuously follows the VG pitch gimbal. This means that the AHRS DG pitch gimbal adjusts its position to match the movements of the VG pitch gimbal, ensuring accurate and synchronized measurements of the aircraft's pitch attitude. The VG pitch gimbal is responsible for detecting and measuring changes in the aircraft's pitch, and the AHRS DG pitch gimbal is designed to mirror these movements for precise attitude reference.

The correct answer is 22-power and rotates 360 degrees. This means that the telescope on the magnetic field monitor has a magnification power of 22 and is able to rotate a full 360 degrees.

The control display unit serves as the communication link between the pilot and the INU digital computer. It is responsible for displaying the information from the INU and allows the pilot to input commands and make selections. The control display unit is an essential component in the communication and interaction between the pilot and the INU digital computer.

The torquemeter indicator displays torque value in inch-pounds from -4,000 to 28,000. This means that the indicator is capable of measuring torque in units of inch-pounds, and it can display values ranging from -4,000 inch-pounds to 28,000 inch-pounds.

The ATT switch position on the INS mode selector unit is used to select only attitude signals. This means that when the switch is set to ATT, the INS will only receive and use attitude information, such as pitch and roll, from the aircraft's sensors. It will not receive or use heading signals, present position information, or any other type of data.

The heading marker on the flight director system's horizontal situation indicator displays the manually selected heading. This means that the pilot can input a specific heading that they want the aircraft to follow, and the flight director system will provide guidance to help the pilot maintain that heading. The other options, such as actual ground track, desired ground track, and actual compass heading, are not displayed on the heading marker.

The correct answer is 45 degrees clockwise. The question states that the BIT (Built-In Test) is initiated by rotating a small screw on the front of the N1 revolutions per minute indicator. Since the question does not provide any specific instructions on the direction of rotation, we can assume that the default direction is clockwise. Therefore, rotating the screw 45 degrees clockwise would be the correct action to initiate the BIT.

The correct answer is rotor. The oil pressure indicator measures the pressure of the oil in an engine. The rotor is the only moving part in the indicator that is responsible for converting the pressure into a rotational motion, which in turn displays the oil pressure on the gauge. The other options, such as the calibrated hairspring, Bourdon tube, and limit gear, are not directly involved in the movement or measurement of the oil pressure and therefore are not the correct answer.

The navigation function is primarily accomplished through the sensing element and measurement of acceleration. Acceleration refers to the rate of change of velocity, and by measuring acceleration, navigation systems can determine the changes in speed and direction of movement. This information is crucial for determining position, velocity, and orientation in navigation. Sensing and measuring magnetic north, Earth rotation, or gravity alone cannot provide the necessary data for navigation purposes, making acceleration the correct answer.

The correct answer is CMPTR. The flight director system's attitude director indicator warning flag indicates faulty command bar information when the computer (CMPTR) is not providing accurate guidance commands to the pilot. This warning flag alerts the pilot to the potential issue with the computer's commands, allowing them to take appropriate action.

The two mechanical adjustments on the resistance liquid quantity indicating system are centering and range. Centering is the adjustment that ensures the indicator needle is at the correct position when the tank is empty or full. Range adjustment allows the system to accurately measure the liquid quantity within a specific range, ensuring that the indicator needle moves proportionally to the actual liquid level. This combination of centering and range adjustments allows for precise and reliable indication of the liquid quantity in the tank.

Attitude sensors are the components that eliminate the requirement to have numerous fuel probes in the fuel tanks. Attitude sensors are responsible for measuring the orientation or attitude of an aircraft in flight. By using these sensors, the fuel management system can accurately determine the fuel level in the tanks without the need for multiple probes. This reduces complexity and cost, as well as minimizing the risk of fuel measurement errors.

When both intermediate devices experience a signal conditioning processor test failure, it indicates that the signal is not being properly conditioned or processed. This can result in a decrease in the overall throughput or the amount of data that can be transmitted successfully. Therefore, the correct answer is throughput.

The correct answer is a fluid type sensor. A fluid type sensor is responsible for providing the erection signal for the VG pitch gimbal of the attitude heading reference system. This sensor measures the level or pressure of a fluid, which is then used to determine the orientation of the VG pitch gimbal.