How is redundancy achieved for critical avionics power?

• A. Multiple generators, an essential/standby bus, bus ties, and sometimes a dedicated standby power source.
• B. A single generator with no backups.
• C. Solar arrays.
• D. Only battery power.

Answer: (A)

Redundancy for critical avionics power relies on keeping power available to essential systems even if one source fails. This is built with multiple generators feeding an essential or standby bus dedicated to critical loads, plus bus ties that allow cross-feeding between power paths. In many aircraft, a dedicated standby power source—such as an emergency generator or battery—can keep the essential bus powered if the main generators or normal buses are lost. This arrangement ensures that vital avionics stay powered during faults or outages, providing time to maintain safe flight and complete the approach or landing.

The other options don’t fit because a single generator with no backups offers no redundancy, solar arrays are not a standard means for avionics power redundancy in conventional aircraft, and relying on only battery power generally cannot sustain all essential avionics for the required duration.