Plain English Meaning

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.

Full 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 a set number of times to place a phone-patch call: typically four clicks for ATC and six clicks for FSS. GCOs are primarily for picking up , opening or closing , and obtaining at airports without an or FSS on the .