What supplies power for aircraft avionics?

The correct answer is that both the generator and battery buses supply power for aircraft avionics. This dual power source system ensures a reliable supply of electrical power essential for avionics operation.

The generator bus is connected to the aircraft's generators, which produce electrical power when the engines are running. This power is critical during flight, as it supports not only avionics but also other electrical systems, ensuring that all essential instruments and control systems function properly.

The battery bus comes into play primarily when the aircraft is not running, such as during pre-flight checks or emergencies. It provides a backup power source that ensures avionics can operate even if the generator systems fail or the aircraft is on the ground without engine power.

Having both the generator and battery buses enables redundancy and reliability in the aircraft’s electrical system, which is crucial for safety and operational integrity. The auxiliary battery only serves specific backup functions, and a generator bus on its own would not guarantee power under all conditions, thereby making the combination of both buses the most effective solution for powering avionics.