Why Aircraft Need Ground Power

Ground Power Units (GPUs) are important pieces of equipment in the aviation industry designed to provide power to aircraft on the ground.

These units are mobile or stationary power sources that are connected to the aircraft to provide electrical power for a variety of purposes, including cockpit operations, maintenance activities, and powering on-board systems.

GPUs are typically equipped with generators, converters, and distribution systems capable of delivering the required voltages and frequencies that are compatible with the aircraft’s electrical system.

They play a critical role during ground operations when the aircraft engines are shut down, ensuring a constant and stable supply of power to support essential functions without relying on the aircraft’s internal electrical system.

GPUs contribute to the efficiency of airport operations by facilitating pre-flight inspections, maintenance procedures and passenger services while the aircraft is on the  ground.

In flight, all of an aircraft’s power supply comes from the engines, which not only provide the thrust to keep the aircraft in flight, but also provide the electrical power to power all systems, including all control systems, flight instruments, communications and navigation equipment, electrically controlled mechanical devices, cabin and cockpit lighting systems, as well as the airliner’s meal systems and cabin entertainment systems.

After the airplane has landed, some pilots may choose to keep only one engine operating to provide the thrust needed before taxiing to the airplane’s position, and to keep all power systems on the airplane operating. If necessary, the pilot may also activate the auxiliary power unit APU.

Once the airplane is slid into position and stabilized, the engines are no longer needed to provide power, but power is always essential. For example, the cabin lights need to work during cabin cleaning, and the crew and flight attendants need a lot of power to do pre and post flight checks.

In order to ensure the safety of ground staff, the engine needs to be shut down, at this time the pilot will have to choose the APU or ground start power supply to power.

However, APUs initiate computational cycles, are fuel-intensive and noisy, and are very unfriendly, both in terms of economic cost and working environment.

Therefore, the use of APUs is generally discouraged, so ground power is indispensable.

Regardless of civil aviation or air traffic, the cost of ground start power is lower compared to aircraft onboard batteries, so operators choose ground start power to minimize the use of onboard components.