2a676 Vol 1 General Mx and Troubleshooting

The correct answer is 1-1a-14. This AF T.O. outlines repair procedures for aircraft electric and electronic wiring.

The given correct answer is "continuously." This means that the BIT system consistently monitors both external and internal performance information during normal operation. It does not wait for a specific request or intermittently check the performance, but rather does it continuously.

The correct answer is AC X TIE. This switch in the ESCP commands the ACXTR (AC Transfer Bus) which is responsible for transferring electrical power between the two AC buses. The AC X TIE position connects the two AC buses together, allowing power to flow between them. This is important in case one AC bus fails, as it ensures that power is still available to critical systems by transferring it from the functioning AC bus to the failed one.

The TRPT input is rated at 115/200 VAC, 3-phase, 400hz. This means that the TRPT input can accept a voltage range of 115/200 VAC and it operates on a 3-phase power system with a frequency of 400hz.

The compressed air/nitrogen type of heating tool is acceptable for use around fueled aircraft when using shrinkable insulation sleeves to cover a soldered contact connection. This type of heating tool does not introduce any potential fire hazards or contaminants, making it a safe option for use in aircraft maintenance.

When soldering heat-sensitive parts, using a heat shunt is recommended. A heat shunt is a device that helps to divert and dissipate excess heat away from the sensitive components, preventing damage or overheating. By using a heat shunt, the heat is evenly distributed and controlled, ensuring that the temperature does not rise to a level that could harm the sensitive parts. This precautionary measure helps to maintain the integrity and functionality of the heat-sensitive components during the soldering process.

Fault isolation is typically the most challenging step in troubleshooting because it involves identifying the specific component or system that is causing the problem. It requires a systematic approach of eliminating potential causes and narrowing down the issue to a single point of failure. This step often requires in-depth technical knowledge, critical thinking, and problem-solving skills to accurately identify and resolve the problem.

The control power for all the GCU is 28VDC.

The BPCU (Battery Power Control Unit) is the component in the AC power system that provides the BIT (Built-In Test) circuitry used in troubleshooting. The BPCU is responsible for monitoring and controlling the power supply from the battery, and it includes diagnostic features that can help identify and troubleshoot any issues with the power system.

The GCU (Generator Control Unit) is responsible for both controlling and protecting the AC power system. It monitors and regulates the generator's output, ensuring it operates within safe limits. Additionally, it detects any abnormalities or faults in the system and initiates protective measures, such as shutting down the generator or activating backup systems. The GCU plays a crucial role in maintaining the stability and reliability of the AC power system.

If all troubleshooting procedures have been exhausted and the defective LRU still cannot be located, a slaving procedure should be tried. Slaving involves connecting a known good LRU in place of the suspected defective one and observing if the problem persists. If the problem disappears, it indicates that the original LRU is indeed defective. This procedure helps in isolating the faulty component and narrowing down the troubleshooting process.

The TRPT output is rated at 200amp, 28VDC. This means that the maximum current that can be delivered by the TRPT is 200 amps, and the voltage at which it operates is 28 volts DC.

The battery's charger has an input rating of 3-phase, 400hz. This means that the charger is designed to be powered by a 3-phase electrical system, which is commonly used in industrial and commercial settings. The 400hz frequency indicates that the charger is designed to operate at a higher frequency than the standard 50 or 60hz used in residential systems. This higher frequency is often used in aerospace and military applications, where it allows for more compact and lightweight electrical systems.

In the Emergency generator system, emergency generator voltage sensing is a function of the EGCU. The EGCU stands for Emergency Generator Control Unit, which is responsible for monitoring and controlling the voltage output of the emergency generator. It ensures that the voltage remains within the desired range and provides feedback to the system to make any necessary adjustments. Without the EGCU, the emergency generator may not be able to effectively sense and regulate its voltage output, leading to potential issues or failures in the system.

The most probable cause of the malfunction is the Cabin temp control MOD valve. This valve is responsible for controlling the temperature in the cabin, so if it is not functioning properly, it would explain why there is no temp control in the cabin. The other options, such as the regenerative heat exchanger MOD valve, turbine inlet overtemp sensor, and duct anticipator, are not directly related to cabin temperature control and therefore less likely to be the cause of the malfunction.

The systems that utilize a BIT system for troubleshooting are AC, DC, and External. This means that all three types of systems, AC, DC, and External, have the capability to use a Built-In Test (BIT) system for troubleshooting purposes.

In isolated mode, all four IDG ACGs operate as separate systems. This means that each IDG ACG functions independently and is not connected or dependent on the other IDG ACGs. In this mode, if one IDG ACG fails or malfunctions, it will not affect the operation of the other IDG ACGs. This provides redundancy and ensures that the electrical power supply remains stable even if one IDG ACG fails.

Load lights can be effective for locating problems with high resistance because high resistance in a circuit can cause a voltage drop. Load lights are designed to illuminate when voltage is present, and if there is a high resistance in the circuit, the voltage drop across that resistance will cause the load light to dim or not illuminate at all. This can help identify the specific area or component in the circuit where the high resistance is occurring, allowing for troubleshooting and repair.

The APU/EPCU BPCU (Auxiliary Power Unit/Engine and Propulsion Control Unit Battery Power Control Unit) provides control and protection for the APU ACG (Auxiliary Power Unit Alternating Current Generator). It is responsible for managing the power supply and ensuring the proper functioning of the APU ACG.

The correct answer is EXT PWR. The switch on the ESCP (Engine Start Control Panel) that commands the EPR (Engine Pressure Ratio) closed when placed to on is marked EXT PWR. This means that when the switch is turned on, the engine will receive power from an external power source.

The battery chargers will terminate their high-rate charge only after a full charge is sustained for 1 hour. This means that the chargers are designed to continue charging the battery at a high rate until it reaches a full charge and maintains that level for a duration of 1 hour. Once the battery has sustained a full charge for this amount of time, the chargers will automatically stop the high-rate charge.

An open outflow valve would cause the cabin to pressurize but fail to reach the selected altitude. When the outflow valve is open, it allows air to escape from the cabin, preventing the cabin from reaching the desired pressure level. This would result in the malfunction described in the question.

When soldering a contact to a twisted shield wire, the lead that will be visible in the forward inspection window is the signal lead. The signal lead carries the electrical signal and is typically the most important lead in a circuit.

Based on the given information, the most probable cause for the malfunction is an open ground. This is indicated by the voltage check at pin B of the crossover valve reading 28 VDC, while the ohm check from pin C to ground shows infinite ohms. An open ground would prevent the proper flow of electrical current, causing the crossover valve to malfunction.

The correct answer is ACXTR. Tying the left and right AC buses is accomplished by energizing the ACXTR.

Based on the given information, the most probable cause for the malfunction is the ENG B/A SOV (Engine Bleed Air Shutoff Valve). The voltage check at pin 5 of the SOV shows 28 VDC, indicating that power is reaching the valve. Additionally, the ohm check from pin 3 of the SOV to ground shows 0 ohms, suggesting a short circuit. This indicates a fault within the SOV itself, rather than the topping control rheostat, B/A control switch, or ENG Fire Switch.

The most probable cause of the malfunction is aircraft wiring. This is because the voltage check at pin 18 of the light tests relay panel showed no voltage, indicating a potential issue with the wiring. The other options, such as the lights test relay panel or the right jury link gear down limit switch, may also be potential causes, but the lack of voltage suggests that the issue lies with the aircraft wiring.

The correct answer is 24,000 RPM. This suggests that the CSD (Constant Speed Drive) is regulated to operate at a speed of 24,000 RPM. The CSD is a device used in aircraft to maintain a constant rotational speed of the generator or hydraulic pump. This speed regulation is important for the proper functioning of the aircraft's systems.

To prevent overheating of the component and circuit board when desoldering the joints on a multilead component, it is recommended to desolder using a random pattern. This means that instead of focusing on one specific lead at a time, you should move the soldering iron tip around and desolder different leads in a non-sequential order. This helps distribute the heat evenly and prevents excessive heat buildup in one area, reducing the risk of overheating the component and circuit board.

BIT fault info is stored in nonvolatile memory. Nonvolatile memory refers to a type of computer memory that retains its stored data even when the power is turned off or lost. This is in contrast to volatile memory, which requires continuous power to retain data. Storing BIT fault info in nonvolatile memory ensures that the information is not lost in case of power failure or system shutdown, allowing for the retrieval and analysis of fault data even after a power interruption.

Before connecting any connectors to equipment containing ESDS devices, it is necessary to equalize electrostatic potentials. This ensures that there is no difference in electrical charge between the equipment and the connector, which helps prevent the occurrence of electrostatic discharge (ESD). ESD can cause damage to sensitive electronic components, so equalizing the electrostatic potentials is crucial to protect the equipment from potential harm.

To place the DC power system in isolated mode, both the L DCT RPC and R DCT RPC must be commanded open. This means that both the left and right DCT RPCs need to be opened in order to isolate the system.

Permeability is not a physical characteristic used for the identification of coatings on printed circuit boards. Hardness, solubility, and thickness are commonly used physical characteristics to identify coatings, as they can be measured and quantified. Permeability, on the other hand, refers to the ability of a material to allow the passage of substances through it, such as liquids or gases. While permeability may be relevant in other contexts, it is not typically used as a characteristic for identifying coatings on printed circuit boards.

The correct answer is 50 because when repairing a shielded wire harness, it is recommended to have a 50% overlap of copper foil tape around the damaged area of the shield. This overlap helps ensure proper shielding and protection against electromagnetic interference.

To visually inspect a solder connection, it is recommended to clean and magnify the connection up to 7x. This level of magnification allows for a closer examination of the solder joint, making it easier to identify any potential defects or issues. Magnifying the connection at this level ensures a thorough inspection and helps to ensure the quality and reliability of the solder connection.

The correct answer is "exciter". In an electrical generator, the exciter is responsible for providing the rectified DC exciting current for the main generator field. The exciter is a separate component that is connected to the main generator and its main function is to supply the necessary electrical energy to the field winding, which in turn creates the magnetic field required for generating electricity. Without the exciter, the main generator would not be able to produce power efficiently.

A braided shield is commonly used to protect electrical circuits from electromagnetic interference. The higher the coverage range of the braided shield, the better the protection it provides. Therefore, a cover range of 85% to 95% would satisfy most applications as it offers a high level of protection against interference.

Insulators generate high levels of electrostatic voltage because the voltage is not distributed over the entire surface of the substance. Unlike conductors, which allow the flow of electricity, insulators have high resistance and do not easily allow the movement of electrons. This causes the voltage to concentrate in specific areas, resulting in a high level of electrostatic voltage. Semiconductors, on the other hand, have properties between conductors and insulators, while resistors are components designed to limit the flow of current in a circuit.

The storage battery's rated capacity in ampere hours is 40. This means that the battery is designed to deliver a current of 40 amperes for one hour. It indicates the amount of charge that the battery can hold and deliver over a specific period of time. A higher rated capacity means that the battery can provide power for a longer duration before needing to be recharged.

To prevent a loss of power on any GEN BUS, the engines that must be started first are 1 and 2. This means that in order to maintain power on the generator bus, both engines 1 and 2 need to be started before the other engines. Starting engines 1 and 2 first ensures that there is a continuous power supply to the generator bus, preventing any potential power loss.

During a Ground Readiness Test (GRT), the fault signals sent to the GCU (Ground Control Unit) and SIP (System Interface Panel) are simulated. This means that the signals are artificially generated to mimic the behavior of actual faults that may occur during flight. Simulated fault signals allow for testing and troubleshooting without the need for real-time or in-flight faults, ensuring the safety and effectiveness of the system.

The most probable cause for the red light in the LDG control panel remaining on with the gear down is the lights test relay panel. This is indicated by the continuity check from pin 55 and ground on the lights test relay panel reading infinity, suggesting that there is no connection or continuity in the circuit. Therefore, the lights test relay panel is likely malfunctioning and causing the red light to remain on.

The most probable cause for the malfunction is the right MLG up limit switch. This is indicated by the fact that there is no voltage at pin 30 of the LDG Test receptacle, which suggests that the switch is not functioning properly. Additionally, the voltage check at pin 1 of the LDG Test receptacle shows 28 VDC, indicating that the power supply is functioning correctly. Therefore, the right MLG up limit switch is the likely culprit for the door not closing when the gear is retracted.

The most probable cause of the malfunction is a defective pressure regulator and shutoff valve. This is because the pressure regulator and shutoff valve are responsible for controlling the airflow in the cabin. If they are defective, they may not be allowing any airflow, resulting in the lack of airflow in the cabin. The other options, such as the cabin temp control MOD valve, left flow control shutoff valve, and low limit MOD valve, are not directly related to controlling the airflow in the cabin, so they are less likely to be the cause of the malfunction.

Energizing the EPR (Electro-Pneumatic Relay) provides a current path from AEEPR (Auxiliary Electric Equipment Panel Relay) to the right AC tie bus. The EPR is responsible for controlling the flow of current in the circuit and ensures that the current is directed towards the correct destination. By energizing the EPR, it allows the current to flow from AEEPR to the right AC tie bus, establishing the desired current path.

To parallel TRPT 1 and 2, the component that must be energized is the L DCT RPC.

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The correct answer is the indicator isolation relay. This is because the question states that the nose gear down position light does not illuminate with the gear down and locked. The indicator isolation relay is responsible for providing power to the nose gear down position light, so if it is malfunctioning, it could explain why the light is not illuminating. The fact that the ohms check from pin 81 to ground reads infinity suggests that there is an issue with the indicator isolation relay.

Automatically initiated Built-In Test (BIT) checks occur on the first engine shutdown. This means that when the engine is shut down for the first time, the system will automatically perform self-diagnostic tests to check for any faults or malfunctions. These tests are important to ensure the system's functionality and identify any potential issues that may need to be addressed before the next use.

The most probable cause for the malfunction is the LDG Control Panel. This is because the question states that the NLG does not extend when 28VDC is not present at certain pins, indicating an electrical issue. The LDG Control Panel is responsible for controlling the landing gear system, so if there is a problem with it, it could prevent the NLG from extending properly.