In the event of a generator failure, which action is taken to preserve essential aircraft systems?

• A. External power automatically re-engages all systems
• B. Essential buses are prioritized (often via the battery/standby power), nonessential systems may shed load to preserve critical avionics and controls
• C. Avionics remain powered by the failed generator
• D. The flight crew must manually power each system individually

Answer: (B)

When a generator fails, the aircraft’s electrical system automatically reconfigures to protect flight-critical equipment. Essential buses are given priority and are supported by standby power and the battery if needed, while nonessential loads can be shed to conserve power. This ensures vital avionics and flight controls remain powered for safe operation or a controlled diversion.

That automatic prioritization and load-shedding is why the correct choice fits best: it describes preserving essential systems by prioritizing essential buses and using standby power to keep critical avionics and controls powered. The other options would imply powering all systems with external power, keeping power to the failed generator, or requiring manual power-up of each system, which isn’t how the electrical system operates in a generator failure.