Definition
A mobile or fixed external power source used to supply electrical power to an aircraft on the ground, allowing aircraft systems to operate without running the engines or relying on the aircraft battery or auxiliary power unit.
Plain English
A power supply on wheels (or built into the ramp) that plugs into the aircraft to run its electrical systems while it's parked.
Context Anchor
Seen during ramp operations, aircraft servicing, maintenance checks, and engine start procedures.
Why Pilots Care
It lets the crew power avionics, lights, and other systems for checks or passenger comfort without burning fuel or creating noise and exhaust on the ground.
Intuition Check
GPU does not mean a computer graphics processor here. In aviation maintenance and ramp use, it means an external power source for an aircraft on the ground.
Example Sentence 1
The mechanic connected a GPU to the aircraft so he could run the avionics during the inspection without draining the battery.
Example Sentence 2
With the GPU supplying power, the pilot could run the avionics and complete the flight planning without starting an engine.