Electrical Systems & Avionics Flashcards
7 cards from real ACS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Electrical Systems & Avionics flashcards as text
What is the purpose of shielding on aircraft wiring, and where must the shield be grounded?
Answer: Shielding reduces electromagnetic interference; grounded at one end only to prevent ground loop currents
Coaxial cable and shielded wire shields are grounded at one end only to prevent ground loops that would introduce noise into the shielded circuit.
An aircraft GPS receiver shows a valid position fix but the CDI needle of the integrated course deviation indicator remains deflected. What is the most likely cause?
Answer: An incorrectly entered flight plan or destination waypoint in the GPS
If the GPS has a valid fix but the CDI is deflected, the most common cause is an incorrect or incomplete flight plan entry causing the unit to navigate to an unintended waypoint.
When replacing an aircraft battery, what information must be recorded in the aircraft maintenance records?
Answer: Date, battery part number, serial number, battery type, and a description of the work performed
Per 14 CFR Part 43.9, maintenance records must describe the work, include a reference to data used, date, and the certificate number of the person performing the work, including battery traceability data.
What is the purpose of an aircraft's essential (emergency) bus?
Answer: To provide power to critical flight instruments and navigation equipment when the main bus fails
The essential bus maintains power to flight-critical instruments and navigation equipment even if the main electrical bus fails.
A landing gear warning horn sounds in flight with the gear retracted and the throttle not reduced. What should the technician investigate?
Answer: A faulty throttle position switch sending a false low-power signal
The landing gear warning system activates when a throttle position switch signals low power; a faulty switch can trigger this warning even with full power applied.
What is a major advantage of a CANBUS (Controller Area Network) data bus system in modern aircraft avionics?
Answer: It allows multiple electronic modules to communicate over two wires, reducing wiring weight and complexity
CAN bus allows many avionics components and sensors to share a common two-wire data link, dramatically reducing the number of individual wire runs in the aircraft.
After replacing a magnetic compass on an aircraft, what procedure must be performed before returning the aircraft to service?
Answer: A compass swing to determine and record deviation errors on a new compass correction card
After compass installation, a compass swing must be performed to check for and compensate deviation errors, with results recorded on a new deviation card placed at the compass.