Aircrew Fundamentals Block 3 Test 2026 – 400 Free Practice Questions to Pass the Exam

The primary function of the Main DC Buses in an aircraft is to supply 28 volt DC power, which is vital for the operation of various electrical components, including relays. These relays are essential for controlling electrical systems within the aircraft, allowing for efficient operation and management of power distribution.

In many aircraft systems, the 28 volt DC output ensures that both critical and non-critical systems receive the appropriate voltage necessary for normal operation, which is crucial for maintaining aircraft functionality. Understanding this role highlights how electrical systems are organized and managed in aviation, emphasizing the importance of reliable power supply for safety and operational efficiency.