Definition
A Ground Communications Outlet (GCO) is an unstaffed, remotely controlled radio facility located on or near an airport that allows pilots on the ground to contact Air Traffic Control (ATC) or a Flight Service Station (FSS) by VHF radio, with the GCO automatically placing a telephone call to the appropriate facility. It is primarily used at airports without an operating control tower so pilots can pick up or close IFR flight plans, receive clearances, or obtain weather and other ATC services before departure or after landing.
Plain English
A radio on the airport that lets you reach ATC or Flight Service by phone when you can't talk to them directly from the ground. You key your microphone a set number of times and it dials the call for you.
Context Anchor
Seen in instrument procedures and airport information for airports without a control tower, especially when a pilot needs a clearance, release, cancellation, or weather help while on the ground.
Derivation
Ground communications outlet means exactly what the words suggest, but the key idea is outlet — a single point of access on the ground that connects (outlets) you into the wider ATC phone network through a radio link.
Why Pilots Care
It allows pilots to obtain clearances, cancel flight plans, or get weather information without driving to a phone.
Analogy
A GCO is like a call box for your aircraft radio: you tune the listed frequency and use it to reach someone who is not physically at the airport.
Intuition Check
Do not read “outlet” as an electrical outlet. In this term, an outlet is a radio access point for communication.
Example Sentence 1
After landing at the non-towered field, the pilot used the GCO to close her IFR flight plan with Flight Service.
Example Sentence 2
After landing, she used the GCO to close her VFR flight plan with Flight Service.