What is load shedding and when is it typically activated?

• A. Automatic reduction of nonessential loads to preserve power for essential systems when generation is insufficient
• B. Manual shutdown of all avionics during engine start
• C. Increase of nonessential loads to balance the electrical load
• D. Automatic disconnection of the battery from all buses during fault

Answer: (A)

Load shedding means automatically reducing electrical demand by disconnecting or turning off nonessential systems so that essential power remains available when the power source can’t meet the total load. This is triggered when generation is insufficient or a fault reduces a generator’s output, causing bus voltages to drop. The goal is to keep critical systems—like flight controls, primary flight instruments, and other essential avionics—powered so the aircraft can continue safe operation. In practice, the shedding of nonessential loads is usually automatic to react quickly; some designs may allow crew command under specific conditions, but the core idea is to prioritize essential equipment. The other options don’t describe this behavior: shutting down all avionics during engine start isn’t load shedding; increasing nonessential loads worsens the shortage; and disconnecting the battery from all buses during a fault is a fault-isolation action, not the typical load-shedding concept.