During ground operations, when is the GPU most likely used instead of the APU?

During ground operations, when is the GPU most likely used instead of the APU?

• A. During take-off in flight
• B. When the aircraft is on the ground
• C. During landing in flight
• D. While taxiing to gate with engines off

Answer: (B)

When the aircraft is on the ground and connected to external power, a ground power unit provides electricity to the aircraft’s systems without needing the on-board APU. This keeps the APU off, saving fuel, reducing noise, and cutting emissions while you’re parked at a gate or in maintenance. The APU is mainly used when external power isn’t available or when you need power to start the engines. In flight, power comes from engine-driven generators or the APU, not from the GPU. So the GPU is most likely used during ground operations because that’s when external power is available and preferable.

When the aircraft is on the ground and connected to external power, a ground power unit provides electricity to the aircraft’s systems without needing the on-board APU. This keeps the APU off, saving fuel, reducing noise, and cutting emissions while you’re parked at a gate or in maintenance. The APU is mainly used when external power isn’t available or when you need power to start the engines. In flight, power comes from engine-driven generators or the APU, not from the GPU. So the GPU is most likely used during ground operations because that’s when external power is available and preferable.