In the case of a dual generator failure, how is electrical load shedding accomplished?

In the case of a dual generator failure, how is electrical load shedding accomplished?

• A. Interior bus two on the left and right electrical systems are shed. Five minutes later interior bus one is shed on each side
• B. Interior bus one on the left and right electrical systems are shed first
• C. Exterior buses shed first
• D. All buses shed simultaneously

Answer: (A)

When both generators have failed, the electrical system uses a staged load-shedding approach to keep essential systems powered while reducing overall demand in a controlled way. The first step is to shed interior bus two on both sides. This targets noncritical cabin and auxiliary loads, lightening the system without cutting power to the crucial flight-deck avionics and controls. After about five minutes, if power margins are still tight, the next step is to shed interior bus one on both sides, further reducing load while continuing to preserve the essential systems needed for safe flight. This symmetric, time-delayed sequence helps maintain balance between the left and right sides and avoids a sudden, drastic loss of power. Choosing to shed exterior buses first or shedding all buses at once would either risk losing essential cabin services too early or create abrupt power loss, which isn’t the intended method for managing a dual-generator failure.

When both generators have failed, the electrical system uses a staged load-shedding approach to keep essential systems powered while reducing overall demand in a controlled way. The first step is to shed interior bus two on both sides. This targets noncritical cabin and auxiliary loads, lightening the system without cutting power to the crucial flight-deck avionics and controls. After about five minutes, if power margins are still tight, the next step is to shed interior bus one on both sides, further reducing load while continuing to preserve the essential systems needed for safe flight. This symmetric, time-delayed sequence helps maintain balance between the left and right sides and avoids a sudden, drastic loss of power.

Choosing to shed exterior buses first or shedding all buses at once would either risk losing essential cabin services too early or create abrupt power loss, which isn’t the intended method for managing a dual-generator failure.