How many power sources are available to an aircraft parked at its gate?

How many power sources are available to an aircraft parked at its gate?

• A. Six total: two engine-driven generators, one APU generator, two batteries, and a GPU.
• B. Five total: two engine-driven generators, two batteries, and an APU.
• C. Four total: two engine-driven generators, one APU, and an external GPU.
• D. Seven total: three engine-driven generators, two batteries, one APU, and a GPU.

Answer: (A)

Power available to an aircraft on the ground comes from multiple sources so systems can stay powered without running the main engines. There are two engine-driven generators, each tied to an engine, that can provide electrical power when the engines are started. The APU generator offers an independent power source on the ground or in flight without needing the main engines running. The aircraft also carries batteries—typically a main and a standby battery—to supply essential DC power and to help start the engines. On the ramp, a ground power unit can supply external power directly to the aircraft. When you add these up, you have two engine-driven generators, one APU generator, two batteries, and a GPU, which makes six potential power sources. In practice, the GPU is often used at the gate to avoid running the APU, but all these sources exist as options for powering the aircraft while parked.

Power available to an aircraft on the ground comes from multiple sources so systems can stay powered without running the main engines. There are two engine-driven generators, each tied to an engine, that can provide electrical power when the engines are started. The APU generator offers an independent power source on the ground or in flight without needing the main engines running. The aircraft also carries batteries—typically a main and a standby battery—to supply essential DC power and to help start the engines. On the ramp, a ground power unit can supply external power directly to the aircraft. When you add these up, you have two engine-driven generators, one APU generator, two batteries, and a GPU, which makes six potential power sources. In practice, the GPU is often used at the gate to avoid running the APU, but all these sources exist as options for powering the aircraft while parked.