AET Aircraft Power Systems Flashcards
6 cards from real AET practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 AET Aircraft Power Systems flashcards as text
What is the function of a current transformer (CT) in an aircraft AC power system?
Answer: Provides a proportional low-current signal for metering and protection circuits without direct connection
Current transformers produce a scaled-down current proportional to the high line current, allowing ammeters and protective relays to measure and monitor generator load safely.
What is the role of a voltage regulator in an aircraft alternator/generator system?
Answer: To maintain constant output voltage despite varying loads and engine speeds
The voltage regulator senses alternator output voltage and adjusts field current to maintain a constant, preset output voltage regardless of changes in engine speed or electrical load.
When troubleshooting an aircraft electrical system and the ammeter shows a discharge indication with the engine running, what is the most likely cause?
Answer: The alternator is not producing output or is off-line
A discharge reading on the ammeter with the engine running indicates the battery is supplying the electrical load, which means the alternator has failed or been disconnected.
Thermal runaway in a NiCd aircraft battery is dangerous because it can result in:
Answer: A self-sustaining charging reaction that generates heat, gas, and potential fire
Thermal runaway occurs when heat from charging increases the battery's ability to accept charge, generating more heat in a feedback loop that can lead to fire, explosion, and toxic gas release.
What is the purpose of an overvoltage protection relay in an aircraft electrical system?
Answer: To disconnect the alternator from the bus if output voltage rises above a safe threshold
The overvoltage protection relay monitors alternator output and automatically disconnects the alternator from the bus if voltage rises above approximately 31–32V (28V system) to protect sensitive avionics from damage.
In aircraft wiring, what is the minimum voltage drop allowed across a wire under full load current according to MIL-W-5088 / FAA AC 43.13-1B guidelines?
Answer: The voltage drop should be as low as possible, typically not to exceed 1 volt for essential circuits
FAA AC 43.13-1B guidance recommends limiting voltage drop to no more than 1 volt for essential avionics circuits to ensure proper equipment operation.