Definition
A Ground Communication Outlet (GCO) is an unstaffed, remotely controlled ground-to-ground communications facility located at an airport, allowing pilots on the ground to contact the nearest Air Traffic Control (ATC) facility or Flight Service Station (FSS) by VHF radio. The pilot keys the microphone a set number of times to place a phone-patch call: typically four clicks for ATC and six clicks for FSS. GCOs are intended primarily for picking up IFR clearances, opening or closing flight plans, and obtaining weather briefings at airports without an operating control tower or FSS on the field.
Plain English
A radio-to-phone link at smaller airports. By clicking the mic a few times on the published GCO frequency, the pilot connects through the radio to a controller or briefer over the phone, even though no tower or briefer is at that airport.
Context Anchor
Seen in airport information and flight planning when a pilot needs a way to contact Flight Service before departure or after landing.
Derivation
Ground refers to use on the airport surface; communication outlet describes the device as an access point to the ATC/FSS communication system. The name reflects its function: a remote outlet through which ground-bound pilots reach controllers or briefers.
Why Pilots Care
Gives pilots access to FSS services like weather updates and flight plan filing at airports that lack a control tower or on-site specialist.
Intuition Check
Do not read “outlet” as an electrical plug. Here, an outlet means a radio access point on the ground.
Example Sentence 1
After landing at the non-towered field, the pilot tuned the GCO frequency, clicked the mic six times, and closed the IFR flight plan with Flight Service.
Example Sentence 2
Before engine start she used the GCO to obtain an updated weather briefing for the route.