When would external power be used on the ground?

When would external power be used on the ground?

• A. For preflight checks, electrical system tests, and engine start when ground power is available or preferred.
• B. For parking.
• C. For takeoff.
• D. For in flight.

Answer: (A)

On the ground, external power is used to provide electrical power to the aircraft so you can perform preflight checks, electrical system tests, and even engine start without running the aircraft’s own generators or APU. When a ground power unit is available or preferred, plugging in keeps the ship’s systems alive for verification and start-up while conserving fuel and reducing wear on the APU. The other scenarios—parking alone, takeoff, or in flight—don’t involve using external ground power, since parking can be done with power off or on but not tied to the testing/start sequence, and takeoff or flight rely on the aircraft’s own power sources.

On the ground, external power is used to provide electrical power to the aircraft so you can perform preflight checks, electrical system tests, and even engine start without running the aircraft’s own generators or APU. When a ground power unit is available or preferred, plugging in keeps the ship’s systems alive for verification and start-up while conserving fuel and reducing wear on the APU. The other scenarios—parking alone, takeoff, or in flight—don’t involve using external ground power, since parking can be done with power off or on but not tied to the testing/start sequence, and takeoff or flight rely on the aircraft’s own power sources.