Which power source can be used on the ground to supply electrical power to ATR systems?

Which power source can be used on the ground to supply electrical power to ATR systems?

• A. Engine-driven generators
• B. APU
• C. Battery
• D. External power

Answer: (D)

On the ground, supplying electrical power to ATR systems is done through external power. A ground power unit connects to the aircraft’s power receptacles and provides full electrical power without starting the aircraft’s engines or its APU. This keeps engines and the APU off, reduces fuel use and noise, and ensures all systems—avionics, lighting, climate control, and charging—are available for boarding, maintenance, and preflight checks. Engine-driven generators require the engines to be running, which isn’t practical for ground operations. The APU can supply power on the ground but uses fuel and adds noise, so external power is preferred when available. A battery alone cannot sustain the entire electrical load for an extended ground period.

On the ground, supplying electrical power to ATR systems is done through external power. A ground power unit connects to the aircraft’s power receptacles and provides full electrical power without starting the aircraft’s engines or its APU. This keeps engines and the APU off, reduces fuel use and noise, and ensures all systems—avionics, lighting, climate control, and charging—are available for boarding, maintenance, and preflight checks.

Engine-driven generators require the engines to be running, which isn’t practical for ground operations. The APU can supply power on the ground but uses fuel and adds noise, so external power is preferred when available. A battery alone cannot sustain the entire electrical load for an extended ground period.