Under normal engine running conditions, Gen 1 powers which of the following?

• A. Essential Bus, Avionics 1 Bus, and Gen 1 Bus
• B. Main Bus, Avionics 2 Bus, and Gen 2 Bus
• C. Non-Essential Bus, Cabin Bus, and Gen 2 Bus
• D. Landing gear, RH windshield de-ice, and Vapor Cycle cooling

Answer: (A)

Understanding the two-generator electrical layout is key. When both engines are running, Gen 1 provides power to the essential systems that must stay alive for safe flight, plus its own generator feed. So Gen 1 powers the Essential Bus, Avionics 1 Bus, and the Gen 1 Bus. This arrangement ensures that the most critical flight instruments and primary avionics stay energized even if Gen 2 isn’t supplying power.

Gen 2 takes care of the remaining loads, typically the Main Bus, Avionics 2 Bus, and its own Gen 2 Bus, giving redundancy for non-critical systems. The other options involve buses that aren’t normally fed by Gen 1 under normal running, such as loads assigned to the Main or Avionics 2 buses, or systems like landing gear or de-ice/Vapor Cycle cooling, which aren’t the direct Gen 1 feeds.