Which statements correctly describe the primary power sources available to the 787 during normal operations?

Which statements correctly describe the primary power sources available to the 787 during normal operations?

• A. Engine-integrated generators on each engine and a generator from the APU only.
• B. Engine-integrated generators on each engine, a generator from the APU, and on-ground power if connected.
• C. APU generator and on-ground power only, no engine generators.
• D. External ground power only.

Answer: (B)

Electrical power for the 787 comes from multiple sources so the aircraft can stay powered in different phases of flight and on the ground. The primary sources are the engine-integrated generators on each engine, the APU generator, and external ground power when the aircraft is connected to a GPU. When the engines are running, the engine generators provide the needed electrical power. If the engines aren’t running or extra power is required, the APU generator steps in to supply power. When the aircraft is parked and connected to ground power, the GPU can power all systems without starting the engines or the APU. This combination—engine generators, the APU generator, and ground power when connected—covers normal operations across flight and ground scenarios.

Electrical power for the 787 comes from multiple sources so the aircraft can stay powered in different phases of flight and on the ground. The primary sources are the engine-integrated generators on each engine, the APU generator, and external ground power when the aircraft is connected to a GPU. When the engines are running, the engine generators provide the needed electrical power. If the engines aren’t running or extra power is required, the APU generator steps in to supply power. When the aircraft is parked and connected to ground power, the GPU can power all systems without starting the engines or the APU. This combination—engine generators, the APU generator, and ground power when connected—covers normal operations across flight and ground scenarios.