What happens to loads and bus power during a generator failure?

• A. All loads are shed.
• B. Nonessential loads continue to be powered.
• C. Automatic transfer logic disengages essential buses.
• D. Remaining sources must supply essential buses; automatic transfer logic keeps critical avionics powered while nonessential loads are shed.

Answer: (D)

When a generator fails, the electrical system redefines power distribution to protect the flight-critical systems. The remaining power sources (such as other generators or the battery) must carry the essential buses, and the automatic transfer logic prioritizes keeping critical avionics powered. To make this possible, nonessential loads are shed so the available power isn’t wasted on systems that aren’t needed for safe flight. This approach prevents a total power loss and preserves the instruments, avionic systems, and other essential functions.

The other scenarios aren’t correct because either all loads would be shed (essential systems would be lost), nonessential loads would continue ( risking essential power), or the transfer logic would disengage essential buses (which would defeat the purpose of automatic prioritization).